List of Accepted Papers
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Abstract
With the Artemis program, The United States plans to return to the Moon and create a permanent human presence in the lunar south pole before the next decade. Lunar poles and cislunar space offer a great option to expand human settlement beyond the planet earth. Scientific and economic opportunities of such human settlement are enormous. However, a paradigm of new technologies: In-Situ Resource Utilization, Sustainable Power, Dust Mitigations, Precision Landing, Surface Excavation and Construction, Cryogenic Fluid Management, Extreme Access/Extreme Environment, and Communication and Navigation Systems need to be deployed to support a long-term lunar habitat. The development and testing of large-scale industrial systems that can autonomously operate in extreme thermal and dust environment to extract and utilize lunar resources for human habitation are critically needed. This presentation provides an overview of the key technical challenges of human settlement on the Moon.
International partnerships will be critical in ensuring a sustainable and robust human settlement on the Moon. The United States has established the Artemis Accords to develop a global coalition for peaceful exploration of the Moon. Lunar exploration can create global harmony and prosperous relationships among nations. Artemis Accords focuses on, among others, Peaceful Exploration, Transparency, Interoperability, Space Resources, and Release of Scientific Data. To date, Australia, Canada, Italy, Japan, Luxembourg, United Arab Emirates, the United Kingdom, and the United States of America have joined the effort. Bangladesh should aspire and actively engage in getting an opportunity to join this global coalition.
The name Artemis is derived from the Greek goddess of the Moon and twin sister to Apollo. The world will need an Artemis generation of young engineers, scientists, and explorers from every corner of the globe to meet humanity’s ambition to become a multi-planet species. A global engagement and investment for talent development and innovation will be essential for sustainable human presence beyond the lower earth orbit.
Research and Development of Next Generation Refrigerants and Refrigeration Systems
Abstract
After the innovative development of machine refrigeration in the nineteenth century, refrigerants used as working fluid in the refrigeration machine have changed in response to safety and environmental issues. And the refrigeration systems have also been designed to adapt the refrigerants. Currently used refrigerants called the third generation are facing regulations of production amount and usage methods because of global warming. In the Kigali amendment of the Montreal Protocol, the reduction of Hydrofluorocarbons which are the most widely used refrigerants is severely scheduled for developed countries, developing countries of groups 1 and 2, respectively. To satisfy the reduction schedule of the Kigali amendment is not so easy because there is very limited number of refrigerants that have low global warming potential (GWP) and safe properties such as no flammability and lower toxicity. And, each heat pump and refrigeration system demands suitable thermophysical properties for their operating conditions. Because the numerous number of operating conditions which are temperature, capacity and others exist, newly proposed pure refrigerants cannot cover all the systems. To fit the suitable thermophysical properties with acceptable GWP and safety properties, a lot of refrigerant mixtures with two to six components have been proposed and further searches are continuously carried out. Accurate estimation of thermophysical properties of new pure and mixture refrigerants is needed for the design and simulation of refrigeration systems. Therefore, measurements of the thermophysical properties are intensively being conducted. Drop-in tests of the new refrigerants are also being conducted. In this paper, the recent situation of next generation refrigerants and refrigeration systems are briefly reported.
Tires, Tires, Tires Everywhere-What Shall We Do? An Entrepreneurial Thinking and Innovation Model
Abstract
The challenge of engaging students in the learning process has been a topic of educators around the globe. The opportunity to engage students through student-based and active and collaborative learning continues to offer great promise in meeting this challenge. The creation of an exercise that engages the student demonstrates that Problem Based Learning outcomes can be an effective approach to delivering meaningful engineering education content. This presentation will focus on the utilization of Problem Based Learning as a vehicle that fosters student- based learning as a key ingredient to engage the learner. Students learn differently! The implementation of Problem Based Learning in the engineering discipline has proven to be a viable approach to harnessing the student’s curiosity and desire to explore. The Tires, Tires, Tires Everywhere exercise relies on the collaboration of student groups to address a systemic societal environmental problem. It further enables the student to express the solution in economic terms while applying business model thinking. The level of learning that occurs in utilizing the project based interactive exercises with global and societal issues is worth examining as a viable tool in engineering education. Problem Based Learning exercises that apply to solving real-world problems appeal to engineering students.
Abstract
Magnetic suspension maintains an object (floator) in space with no visible means by magnetic force. No mechanical friction is expected in operation even without lubrication. This advantage has already given rise to a lot of industrial applications such as Maglev system, and active magnetic bearing for complete contact-free suspension of rotating object.
Researches and developments on magnetic suspension have been actively pursued for several decades and some people may consider this technology to be rather mature now. However, to fully utilize this unique technology and to increase industrial applications, technical advances are still important.
This report presents several recent innovations and advances in magnetic suspension technology. An overview of technological fundamentals is presented first, which is followed by reports on the recent and ongoing works conducted in the author's laboratory.
Bioinspired Electrospun Nanocomposites: An Emerging Technology of Atmospheric Fog Water Generator
Abstract
Nature-inspired fog harvesting is a promising technology aimed at acquiring freshwater from the atmosphere. However, the design of nature-inspired surfaces with unique characteristics for the specific application provides a paradigm shift in the development of the new engineering surfaces. An efficient fog collecting nanofibers was designed inspired by the fog harvesting capability of Stenocara beetles in the Namib Desert. Several available polymers such as polyacrylonitrile (PAN), poly (methyl methacrylate) (PMMA), recycled expanded polystyrene (EPS) foam with various proportions of titanium dioxide (TiO2) nanoparticles and aluminum (Al) microparticles were spun into superhydrophobic-hydrophilic nanocomposites fibers using the facile electrospinning technique. The fiber morphology, wetting characteristics, and fog-harvesting capacity of the nanocomposite was investigated. The as-prepared PAN/PMMA and EPS nanocomposites having 10% inclusion of combined micro- and nanoparticles exhibit superhydrophobic characteristics i.e. a water contact angle of 154.8° and 152.03° respectively. The experimental tests of PAN/PMMA and EPS nanocomposites reveal the daily freshwater productivity of more than 1.49 liter/m2 and 1.35 liter/m2 of nanocomposites. The materials cost of making such nanocomposites to supply minimum daily water consumption for a household with 2 members (i.e., 6 liters) is only US$2.67 (EPS nanocomposite) and US$4.97 (PAN/PMMA nanocomposite). These nanocomposites harvest fog water without any additional energy input and large infrastructure thus, it’s cheap and affordable. This technology offers a novel tool for the mass production of fresh water in arid areas.
Energy Security through Nuclear Power Plant and Human Resource Development
Abstract
Access to reliable electric power supply is paramount for poverty alleviation, economic and industrial development. The quest for clean energy in power generation necessitates to look for nuclear energy for power generation to reduce our absolute dependency on fossil fuel. Currently over 50 countries from Asia, Africa and South America are considering nuclear energy for power generation due to its numerous advantages compared to fossil fuels and renewables. Globally, 48 nuclear reactors powered power plants are under construction most of which are located at developing nations. Industry needs uninterrupted power supply round the clock. The power supply from nuclear power plants is ideal for such needs. Apart from finance, the major hinderance in nuclear power plant expansion in developing nations is the severe shortage of nuclear skilled human resources. The lack of nuclear experience, knowledge, educational infrastructures, and resources is another constraint for developing nuclear skilled human resources in all emerging countries. This paper reviews the current trend of nuclear power plant development in developing countries and nuclear skilled human resources development models required for safe and cost-effective nuclear power plant design, construction, operation, maintenance, repair and fuel management. The paper also highlights the nuclear engineering education programs in South Asia.
Acoustic Emission Technique, a Nondestructive Monitoring Tool for Damage Detection and Evaluation
Abstract
Acoustic emission (AE) signals that are generated due to the sudden rearrangements of stresses inside a material as elastic waves, are widely used in non-destructive testing (NDT) of material cracking especially in health monitoring of structures for damage detection as well as in plant maintenance etc. When a body is subjected to an external stimulus (in the form of changing pressure, load, or temperature), any micro fracture inside the body releases energy in the form of AE wave which is received by AE sensor, later on, is converted to electrical signals termed as AE signals for internal inspection. This evaluation technique is termed as acoustic emission technique. In early stage, major importance was given on studying the AE characteristics during the deformation and fracture on various materials (by J. Kaiser in Germany in 1950, by B. H. Schofield in the U. S. in 1954). However, as the time passed, lots of researches have been conducted in different fields about behavioral formulation, theoretical explanation as well as experimental validation of this technique in AE signal generation, propagation and inspection with various kinds of deformations as an important health monitoring tool for NDT. In the present topic, features outlook of AE based nondestructive monitoring technique perspective to the damage detection and evaluation are planned to be elaborated. Basic theories, experiments related to the material cracking behavior are included to the presentation. Source localization of internal damage that has become an important characteristic feature in AE technique based NDT is also planned to be elaborated to this presentation. Furthermore, AE technique perspective to the advanced applications are also summarized in the present topic. Several practical research results are planned to discuss in the proposed presentation as well.
Industry 4.0 and Digital Twin and Global Competition-Challenges and Opportunity
Abstract
According to the World Economic Forum, 65% of children entering primary school today will ultimately end up working in completely new job types that currently do not exist. Industry 4.0 transformation is shaping our talent pipeline in the manufacturing industry. Disruptive technologies are forcing the development of new business models. Uber Technologies has nearly eliminated long standing taxi industries. Nowadays the biggest question is who will win the game of smart industrialized revolutions? Lack of skilled qualified workforce with this smart integration is forcing academic community to embrace new smart curriculum. This talk will showcase the challenges and opportunities of disruptive technologies in industrial sectors. Industrial engineering tools and techniques can prepare the next generation workforce for the upcoming challenges. Digital twin and MSV (Modeling, Simulation and Visualization) from the Automation Alley Industry 4.0 will presented. Readiness of engineering graduates on smart technologies and continuous improvement around the global are various. Focues should be given to reduce the gaps globally. It will add global competitiveness. Automotive supply chain and logistics optimization will be presentation with smart integration.
Development of Smart Materials for Invasive Medical Applications using Shape Memory Polymers
Abstract
Shape memory polymers (SMPs) represent an intelligent polymeric material which can fix deformed temporary shape and recover their permanent shapes upon an external stimulus such that temperature, light, electricity, water, pH, magnetism and specific ions. This property is called shape memory effect (SME). The SME has underpinned its usefulness of SMPs in delicate minimally invasive surgeries (MIS’s) such as vascular stents, clot removals etc. The invasive biodegradable SMP devices can avoid second surgery and have a great potential over any conventional metallic biomedical device. The ability to change triggering temperature to use in a broader range of temperatures while keeping SME is another superior capability of SMPs. Additionally, SMPs have shown a good prospective due to their special characteristics such as biocompatibility, biodegradability, low rejection by host and low density. However, intrinsic low stiffness, strength and recovery stress possess a significant limitation in the applications of SMPs. In-depth literature survey has revealed that, existing many concepts were terminated without further continuation. This may be mainly due to strict, lengthier Vitro and Vivo certification process. Therefore, to date, a limited number of invasive products have been realized and commercially available. This paper provides a brief overview of current SMP based invasive medical applications, status and limitations. This review will be more beneficial to identify current research gaps, for those who are emerging into SMP based invasive biomedical applications.
How Resilient is Our Supply Chain in the Context of COVID-19? – An Emerging Research Area in Supply Chain
Abstract
Resilience has received a growing importance since its introduction to supply chain literature nearly two decades earlier. Supply chain resilience is the adaptive capability of a supply chain to prepare for and/or respond to disruptions, to make a timely and cost effective recovery, and therefore progress to a post-disruption state of operations – ideally, a better state than prior to the disruption. Ample studies (e.g. empirical, mathematical or theoretical studies) have been conducted to understand the how firms and its supply chain can build resilience in the context of unexpected event (e.g. Tsunami, earthquake, fire, hurricane, etc.). For example – collaboration, redundancy, flexibility, agility, social capital, etc. are well-known antecedents of building supply chain resilience. One of the common trends of supply chain resilience research is that it always focuses on unexpected event that affects either buyer or supplier. As unexpected event is concentrated on a particular geographical location, its negative effect has always been felt on part of supply chain i.e. either on demand side or on supply side. Supply chain researchers never ever discuss how firms and its supply chain partners can built its resilience capability in the context of an event that impact both demand and supply side of a supply chain simultaneously. Such a rare event is COVID-19. COID-19 is a pandemic that negatively influences all the firms and its supply chain globally. As a result, it becomes an important research question for academics and practitioners to investigate to what extent our existing practice of building supply chain resilience is valid in the context of an event that affects the entire supply chain. In this keynote presentation, I will focus on this research question.
Abstract
Functional impairments of the Upper and/or Lower Extremities (ULE) are common not only among the elderly, but also can occur after a stroke. The World Health Organization reports that stroke affects each year more than 15 million people worldwide. In the US alone, more than 795,000 US people suffer a stroke each year that results in significant deficits in ULE functions and the performance of everyday tasks for those affected. The problem is further compounded by the constantly growing number of such cases. It is estimated that about two-thirds of the stroke survivors incur acute arm impairment. Therefore, one of the challenging aspects of stroke rehabilitation is upper extremity intervention. There is mounting evidence that functional recovery can occur well into the chronic stages of stroke. Late improvements may be attributable to sensorimotor learning and adaptive plasticity in the remaining cortical and subcortical brain tissue. On the other hand, the literature review reveals that the aged population also significantly loses arm and hand function. Thus, there is a pressing need to develop better treatment/therapeutic approaches to decrease the effects of disability due to stroke/geriatric disorders.
The current standard for treatment of upper extremity dysfunctions resulting from a stroke/geriatric disorders is personalized therapy with an OT (involves a large time commitment on the part of the OT, and the treatment duration is very long). Unfortunately, there is a consistent shortage of qualified therapists/clinicians both in developing and developed countries. Therefore, an alternative to conventional treatments/interventions is essential. Past research has shown that intensive movement therapy of the affected extremity, incorporating functional tasks where feedback is provided may lead to improved functions. These key elements of motor learning need to be integrated in rehabilitation paradigms and this can be accomplished through rehabilitation robotics.
To rehabilitate individuals with upper-limb dysfunctions, we have developed end-effector type and exoskeleton type therapeutic robots. The exoskeleton type robot, named Smart Robotic Exoskeleton (SREx) is comprised of a shoulder motion support part, an elbow and forearm motion support part, and a wrist motion support part. It is designed to be worn on the lateral side of the upper limb in order to provide naturalistic movements of the shoulder (i.e., vertical and horizontal flexion/extension, and internal/external rotation), elbow (i.e., flexion/extension), forearm (i.e., pronation/supination), and wrist joint (i.e., radial/ulnar deviation, and flexion/extension). Our end-effector type robot, named Intelligent Therapeutic Robot (iTRob, V.1), composed of 2DoF specially designed for the individuals who are not able to use exoskeleton robot.
The SREx was modeled based on the upper-limb biomechanics; it has a relatively low weight, an excellent power/weight ratio, can be easily fitted or removed, and is able to effectively compensate for gravity. The exoskeleton was designed for use by typical adults, whereas the iTRob was designed for use by children, adults, and/or elderly individuals. The kinematic models of the robots were developed based on modified Denavit-Hartenberg notations, and Newton-Euler formulation was used in dynamic modeling. The control architecture was implemented on a field-programmable gate array (FPGA) in conjunction with a real-time PC. Nonlinear control techniques (model-based and adaptive controller) were used to maneuver the robots to provide active and passive arm movement therapy.
In experiments, typical rehabilitation exercises for single and multi-joint movements (e.g., reaching) were performed. Experimental results show that the developed therapeutic robots can effectively perform passive and active rehabilitation exercises for shoulder, elbow, and wrist joint movements.
Identifying Barriers of Implementing IoT in Manufacturing Industry using Analytical Hierarchy Process (AHP): A Bangladeshi Perspective
Abstract
Internet of Things (IoT) is considered as the core of the fourth industrial revolution commonly known as, Industry 4.0. This area has acquired a significant amount of attention in the last few years. IoT represents an image of the future internet and considered as an ecosystem of interconnected devices while holding the ability to transfer data. It creates a network without requiring any kind of human interventions. IoT is proven to be profitable in the areas where rapid development and product quality are the important factors for ensuring financial feasibility in the long run. Manufacturing industry can be considered as a vital implementing field, and the Industrial Internet of Things (IIoT) has converted it digitally with concepts like big data, artificial intelligence (AI), and machine learning. However, IoT implementation is still considered as a challenge due to the presence of many difficulties. Therefore, this paper worked with an objective to identify and investigate the barriers in the implementation of IoT systems in the manufacturing industry from a Bangladeshi perspective. Thirteen (13) challenges and barriers for successful IoT implementation in the manufacturing industry of Bangladesh were identified from the literature review and professionals’ opinions. Consequently, the Analytical Hierarchy Process (AHP) approaches were applied to analyze the challenges in IoT implementation in the manufacturing industry of Bangladesh. Key barriers of successful IoT implementation were identified and ranked according to their significance. The result of this study may help professionals and policymakers in removing the barriers for successful IoT implementation in the manufacturing industry. Finally, comparative analysis, conclusions and future research directions are presented.
The Effect of Externally Applied Ultrasonic Sound Wave on the Cutting Tool during Dry Turning Operation Mild Steel
Abstract
The present paper investigates the effect of externally applied ultrasonic sound waves on the flank wear of the cutting tool and chip morphology during the dry turning operation of a mild steel bar. Ultrasound was applied by using two ultrasonic transducers from both sides of the tool post of the lathe machine during the turning process in an attempt to reduce tool wear and surface roughness. Two high-speed steel (HSS) cutting tools had been used and Cutting parameters were kept constant for both ultrasound and conventional machining operation. The result indicated the application of ultrasound significantly reduced the flank wear of the tool and noteworthy improvement was also eminent in chip behavior after the implementation of ultrasound.
A Numerical Study on the Drag Reduction of Sedan Car using Vortex Generator
Abstract
Petroleum fuel reserve has been decreasing at a very high rate. Almost all the automobiles rely upon IC engine which is run by petroleum fuels. As the number of automobiles is increasing in this modern world, it is necessary to reduce the fuel consumption. One of the ways to do this is to reduce the drag of the car. Among a numerous process of reducing drag, using Vortex Generators is one. Delta shaped vortex generators are used at the rear trunk of the sedan type car where the flow separates. K-epsilon turbulent model in ANSYS-Fluent 16.2 (student version) software is used to simulate the airflows. The drag and lift coefficients depends upon the velocity, frontal area, number of vortex generators used and force exerted on the body. In this work, number and spacing between successive vortex generators were investigated based on the comparison of drag coefficient values with each other. The contours of static pressure and velocity magnitude were also investigated for each models. Velocity vectors were scrutinized to detect the flow separation regions. Vortex generators were attached just before the beginning of flow separation. When the vortex generators were attached, the pressure coefficients at the rear trunk began to increase, that also confirmed the increment in back pressure. Hence, the increase of back pressure indicates the reduction in drag coefficient. It has been found that a combination of 8 vortex generators is the optimum solution. After that, the effectiveness of the vortex generators has been measured at different velocities. The devices work better at higher velocity than the lower velocity without creating any effect in the car stability.
Analysis of Performance of Cooling Towers with Different Fill Characteristics at Different Weather Conditions in Bangladesh
Abstract
The design and operation of cooling towers are needed to be studied and optimized before the installation because of their tremendous importance, especially in industrial applications. As both heat and mass transfer takes place in a functional cooling tower it becomes quite complex to derive the design calculation for a specific requirement and to do performance analysis of existing ones. The present study focuses on the critical performance analysis of different types of cooling towers found in the industries of Bangladesh. . A full and step-by-step procedure of characteristic curve for specific type of cooling tower has been discussed. From the collected data, the tower characteristics curve for different types of cooling tower is generated. Tower characteristic equation from the linear relation of KaV/L vs L⁄G on log log demand curve has been deduced for a cooling tower to understand the fill characteristics of a specific type. In order to assess the performance of the cooling towers, Merkel’s theory has been adopted. Merkel’s theory is based on the enthalpy analysis of the surrounding air under tower operating conditions. Volumetric heat and mass transfer coefficient for the modern cooling towers are investigated. The proper fill volume can be easily determined from the deduced volumetric heat and mass transfer co efficient prior to the design. The effect of wet bulb temperature, considering the monthly local variation throughout the year, on NTU and L/G of cooling towers is examined. In addition, the effect of the fill type is analyzed based on the cooling capacity and flow rate. The methodology and analysis presented in this work will aid in proper designing and predicting the performance of a cooling tower for a given condition in the industries of the region.
Evaluation of the Electrochemical Capacitor Performance of MnO2-NiO Nanoparticles Prepared by the Simple Gel Formation Method
Abstract
The unique features like fast charge-discharging, high power density, and extensive cycle life of energy materials are highly desirable for developing high-performance electrochemical supercapacitors. In this study, a binary transition metal oxide of manganese and nickel (MnO2-NiO) was prepared via a facile gel formation method. A mixed metal oxide gel was synthesized by the reduction of potassium permanganate using glycerol as a reducing agent in the presence of pre-prepared nickel hydroxide. The MnO2-NiO was obtained by heat-treatment at 650 °C temperature. The electrochemical capacitance performance was evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) in a single compartment three-electrode system with 0.5 M Na2SO4 aqueous electrolyte solution. The heat-treated MnO2-NiO demonstrated deviated pseudo capacitance behavior. The GCD has deviated from the symmetrical shape which allies with CV curves. However, the CV and GCD results indicated the fast-electrochemical response, good conductivity, and redox reversibility of the material. The MnO2-NiO nanocomposite exhibited a specific capacitance of 450 Fg−1 at 0.5 Ag-1 current density. Interestingly, this electrode material showed higher specific capacitance as compared to neat MnO2, which is related to the synergistic effects of mixed oxide and porous structure of the material. Here the hybrid structure of the material offers a better solid electrolyte interface (SEI), and more active sites with more surface area for electrolyte charge intercalation and deintercalation. The binary oxide electrode material reported here exhibited an excellent choice for high-performance supercapacitor devices of large-scale applications.
Investigation of Mechanical Properties of Jute, Cotton and Glass Fiber Reinforced Hybrid Composites
Abstract
Natural fiber concentrates on controlling the nature impact, diminish item weight, and lessen the expense of items. The improvement of composite materials and their parts are expanding quickly. The natural fiber incorporated with synthetic fiber provides a material with better strength. Synthetic fiber is mostly not eco-friendly, and they are not recyclable, so it is harmful to nature. The natural fiber is renewable and biodegradable. In this work, hybridization was done using jute, cotton, and glass fiber combination. For the fabrication of the hybrid composite material, the hand lay-up process was followed. The work objectives were to investigate the jute, cotton, and glass fiber reinforced epoxy hybrid composites' mechanical properties and compare them with jute fiber and glass fiber composite. The properties of that hybrid composite were dictated by testing tensile, flexural, and impact strength experimentally, as indicated by ASTM standards. The analysis's after-effects through various tests show that the hybrid composite of jute, cotton, and glass fiber indicated better mechanical properties over jute fiber composite and glass fiber composite except for the tensile strength. However, this hybrid composite's tensile strength is 42.09 MPa, enough for real-life applications in automobile industries. From all results, it can say that the hybrid composite can replace the glass fiber composite.
A Numerical Study on Interaction of A0-mode Lamb Wave with Cylindrical Hole in CFRP Composite Laminates
Abstract
This study represents the interaction of A0-mode Lamb wave at a cylindrical hole in composite laminates focusing on its scattering characteristics. A 3-dimensional Finite Element Modeling (FEM) is used to discuss the effect of the stacking sequence in the wave propagation. An excitation signal of 30 kHz, modulated by Hanning window is allowed to propagate with plane strain condition in a defected squared shape laminate. Propagations of Lamb wave in 8-layered composite laminates with an identical defect are considered. It is found that the reflecting and transmitting characteristics of the incident wave dominated by the outermost layer and the pattern varied with different stacking sequences. The outcomes of this computational study help to the use of the A0-mode Lamb wave for damage characterization and detection in composite laminates.
Process Parameter Optimization of Cryogenic Turning of Ni-Cr Steel using Taguchi Grey Relational Analysis
Abstract
In the present research work, turning of Ni-Cr steel was done under both dry and cryogenic cooling and an attempt was taken to optimize the responses using integrated Taguchi method and Grey Relational Analysis (GRA). The experiments were conducted based on Taguchi L18 orthogonal array and then responses were optimized concurrently using Grey Relational Analysis (GRA). Two numerical factors cutting velocity and feed rate and one categorical factor (cutting condition) were selected as input variables. The effects of those input factors were investigated on surface roughness (Ra), coefficient of friction (µ) and chip tool interface temperature (θ) using two different geometry shaped cutting inserts. After optimization cryogenic cooling was found significant in reducing the selected responses. In case of multi-response optimization, Taguchi-GRA (supported by ANOVA) concluded that cutting condition exerts the domain influence on changing responses followed by feed and cutting speed. For multi-response optimization grey Taguchi results revealed that the optimal settings of input parameters are Vc1f1CC2 and Vc3f1CC2 by using SNMM 120408 and SNMG 120408 cutting inserts, respectively. At 95% confidence interval ANOVA results reveal that all parameters are statistically significant. Validation test results also coincide with statistically optimized results.
Investigation of Jute Stick Carbonization for the Optimum Production of Charcoal
Abstract
Bangladesh is one of the largest jute producing countries next to India. After, extracting fiber from jute, jute sticks remain unused. These sticks are generally used as household fuel in the rural area. Jute stick has a hollow structure with composition almost similar to other woody substances. One of the alternative use of these sticks could be converting them into charcoal. However, the current industrial process in Bangladesh is not efficient and has a yield about seventeen percent only. Therefore, an investigation had been done in this research project to compare the yield and quality of charcoal produced at different temperature ranges on a laboratory scale. A proximate analysis had been carried out to determine the percentage of moisture, volatile matter, ash, and fixed carbon in charcoal by ASTM standard (D1762 – 84). From the output result, an ideal temperature range 300-350 degree Celsius had been deduced that could allow a substantial yield and fixed carbon of charcoal production in industrial cases.
Corrosion Behavior of Work Hardened Commercial Copper Alloys in the Bay of Bengal Water Environment
Abstract
Corrosion behaviors of metals and alloys have been studied by different researchers for different oceans and seas to have comprehensive design variables for optimum operations and maintenance of ships, offshore structures and marine machineries as well as systems. Unfortunately, the Bay of Bengal has not become very efficacious to draw required attention in relation to corrosion study especially for those metallic materials which are generally considered as corrosion resistant. Therefore, present paper is an attempt to investigate the corrosion behavior of three copper based materials, i.e., pure copper, brass and bronze which are being used in contact of the bay water. Here, the results of gravimetric analysis, conductivity tests, optical electronic microscope (OEM) images, scanning electron microscopy (SEM) images and energy dispersive X-ray analyzer (EDX) investigations have been presented. Gravimetric analysis has established that the total corrosion of all copper based materials have been increased gradually but nonlinearly with the increase of exposure periods in sea water. After the immersion period of 27 days, pure copper is found to be the most corrosion resistant amongst three sample materials and brass is the least one, where bronze is found to be in between the rest two. The corrosion rate profiles have shown an initial steep rise, but with the increase of submersion period the rates are reduced with subsequent steady values for prolong exposure in sea water. Microstructures observed through OEM and SEM images have clearly indicated a general uniform surface corrosion with little crystallographic pitting spots after exposure in sea water.
Compatibility of Different Fusible Interlinings with Goat Nappa Leather
Abstract
Suitability of fusible interlinings with leathers is very essential for comfort and fit of garments. Fusing reinforcement is a sort of material which sandwiched an upper leather of a particular product and base lining materials. Fusing interlining is the sheet of fabric between the upper leather and the lining materials. It's more often than not included to allow article of clothing extra warmth. At present, apparel manufacturing cannot be imagined without fusing process. In these endeavor, there are three different fusible interlinings like Tetoron Cotton (TC) pasting, Cotton pasting and Polyester pasting which are used with goat nappa leather and the performance has been measured in respect of bond strength, tensile strength, ball bursting strength, single edge tear load and double hole stitch tear load. The main feature of TC pasting is non-woven which is polyester/cotton blended. Cotton pasting is non-woven and polyester pasting is woven in nature. Latex adhesive has been used to join fused upper and fusible interlinings. After examining the overall performance, it is clear that polyester fusible interlinings performed nicely in the areas of tensile strength, bond strength, double hole stitch tear strength and bursting strength whereas cotton fusible interlinings exhibits higher performance in case of single edge tear strength. Finally, we can say that the overall performance is better for polyester interlinings. The outcomes not only emphasize the basic perception of the fusing attitude of fusing materials with nappa calf skin but also are helpful for leather product shape and design.
Generation of Electricity from Biogas Source: An Alternative Way to Fulfill the Electricity Demand in Remote Area of Bangladesh
Abstract
Due to increased population, escalation of GDP and to have universal access of electricity to all with the middle income country by 2021, more generation of electricity is required as per the target. For generation of electricity, Bangladesh greatly relays on domestic natural gas, coal and imported fuel. Natural gas is still leading in generating the power by 48% in Bangladesh. At present, gas production is 889.29 bcf which are expected to be reduced to 63.69 bcf in 2041-42. Again, the domestic coal is likely to finish by next decade. Further, as per Power System Master Plan 2016, Bangladesh has targeted to produce 50% electricity from domestic and imported coal by 2030. As fossil fuel is diminishing day by day, policymakers are questing for alternative fuel to produce electricity. Further, as per the geographical location, Bangladesh has bestowed with enormous renewable energy sources which can be utilized to mitigate the increasing energy demand of the country. As per the policy, Bangladesh has aspired to achieve 10% renewable energy by 2020. So utilization of renewable energy not only helps in curbing environmental degradation but also assist in achieving the energy security and saves from exhaustion of the fossil fuels. The objective of this paper is to explore the feasibility of generation of electricity from a renewable source, biogas in an island. This paper highlighted the design of digester and hydraulic chamber for the produced biogas and calculates the total cost of the system and also accounts the payback period. The cost of energy is only 4.79 taka per kWh which is less than the present cost.
A Study on Generation of Electricity Plan by 2041 for Sustainable Development in Bangladesh
Abstract
Bangladesh having 147,570 km2 with a population of approximately 166 million has manifested extraordinary success in attainment of average gross domestic product in recent years. The demand of electricity has increased in several manifolds due to the thriving economic progress, quick urbanization and increasing industrialization. For socio economic emancipation and poverty alleviation, energy is considered a key ingredient. As such the vision of the GoB is to generate 24,000 MW for universal access to electricity by 2021, 40,000 MW for affordable, reliable, sustainable and modern energy for all according to SDG 7 by 2030 and 60,000 MW to be for developed nation by 2041. To fulfill those visions, the GoB is relentlessly working and given due importance to generate electricity through non-renewable and renewable energy resources and also forecasted short, medium and long-term power production plans. Further, the GoB has given additional attention to produce electricity from renewable sources especially in the remote areas of the country. Therefore, Bangladesh is at par to develop huge infrastructure of power plant as per the master plan PSMP 2016. For this reason it is required to know the future plans for power generation, transmission and distribution by 2041.
Net Energy Metering-An Optimistic Endeavour for Augmenting Renewable Power Generation in Bangladesh
Abstract
The vision of the government of Bangladesh is to produce 24,000 MW electricity for all by 2021, 40,000 MW for affordable, reliable, sustainable and modern energy for all according to SDG 7 by 2030 and 60,000 MW to be for developed nation by 2041. To get clean energy, renewable energy option is the first requirement to replace the fossil fuels as it causes greenhouse effect and environment pollution. Though around 55 million of solar home system is installed in the recent past, but very tiny amount of electricity is added to the grid. Net metering is a proper energy meter capable of recording both import and export of electricity from solar for self-consumption and excess amount is exported to the grid which results the reduction of electricity bills. This paper highlighted the requirement as well the benefits along with schematic diagram of net energy metering system in Bangladesh. Two pilot projects are being briefly narrated. Finally, a successful story of net metering system has been presented to encourage the investors and the customers that will curb the greenhouse Gas emission.
Development of a New Material Balance Equation for Naturally Fractured Reservoir
Abstract
Reservoir engineers are no more fascinated to use the simplified Material Balance Equation (MBE) for naturally fractured reservoir. Because of the complexity of naturally fractured reservoir, reservoir engineers are trending to a modified version of the material balance equation for a good estimation of hydrocarbon. This study presents a new material balance equation for naturally fractured reservoir considering laminar fluid flow. The proposed model will be a reliable tool to estimate the initial hydrocarbon in place for fracture and matrix. A general material balance equation has been derived for the naturally fractured reservoir. By using the fundamentals of fluid flow, a velocity term has been incorporated to derived model. This velocity term defines the condition of flow such as laminar and turbulent. Velocity for the laminar flow has been used to validate the model. By using field data, fracture compressibility versus original oil in place plot has been generated. The plot shows some deviation with one established model where no velocity was considered. A big number of hydrocarbons is left because of a significant pressure drop in later stage of production. By using the material balance equation for low velocity fluid flow reservoir, the estimation of reserve can be optimized.
Finite Element Simulation of Flow Stress and Its Implications for Machining Process Optimization
Abstract
In metallic ultra-precision machining, the flow stress model has a significant influence in determining the ploughing effect from the manifestation of chip separation. The distinction of material deformation (in ploughing) and lamella formation (in chip separation) is realized by the relative tool sharpness (RTS), which is obtained by dividing the thickness of undeformed chip with cutter edge radius. The study discussed here demonstrates the ‘flow stress phenomenon’ with the help of finite element (FE) simulation in metal cutting operation using Simulia Abaqus Computer-Aided Engineering (CAE) software. The model is developed in orthogonal turning process of aluminum alloy workpiece for the occurrence of continuous and discontinuous chips. The Johnson-Cook damage model was used for workpiece deformation and input boundary conditions (BC) in Abaqus CAE were provided for creating a simulation intended to compare the FE data with experimented results. The simulated results showed consistency with experimental results in certain criteria which have been explained with proper justifications. The implications of this study lie in the flow stress model verified through simulation and further opportunity for optimization and improvement.
Experimental Analysis on the Physical Manners of Thermally Affected Bell Metal
Abstract
The effect of thermal annealing on copper based alloy bell metal has been conducted. The metal is prepared through conventional melting and casting process. Bell metal samples are isochronally annealed for 60 minutes at different temperatures up to 500ºC and isothermally annealed at various temperatures up to 350ºC for different period of time ranging from 15 to 240 minutes. Hardness values as well as sound intensity of differently heat treated alloy samples have been measured to study its after-effect. It is found that the bell metal shows continuous softening up to 300ºC due to stress relieving, recovery and recrystallization behavior of the experimental alloy. After that its hardness is seemed to be augmented because of the grain growth. The variation of sound intensity with temperature almost followed the similar pattern of hardness curve as a very hard, homogenous and extremely durable combination produces inferior sound. The sound intensity is seemed to be attenuating for a short period but hereafter it starts to increase to a maximum dB value due to the grain growth with the formation of new set of defect free grains. The optical response study is done using UV-VIS-NIR reflectance spectroscopy and it reveals that the spectral reflectance of the alloy increases initially due to chemical changes such as formation of copper oxides and decreases with temperature due to intermetallic formation, precipitation coarsening and recrystallization of the alloy. As cast state there are islands of α phase and needle-like matrix of β phase along the grain boundaries are observed into the microstructure. The study also reveals that the alloy attained almost fully recrystallized state after annealing at 300oC for 60 minutes.
Abstract
Nano-fluids are liquid colloidal suspensions of nanoparticles or nanotubes or Nano fibers of metals or nonmetals, metallic oxides or ceramics having Nano scale dimension 1~100nm in a base fluid such as low viscous water and refrigerant or high viscous oils or ethylene glycol or a mixture of various fluids. In recent decades researchers are highly motivated to use Nano-fluids as a novel cutting fluids due to its some attractive properties such as high thermal conductivity, better wetting and spreading ability, suitable rheological properties with changing nanoparticles size, shape and mixing contribution. It has already been reported by many researchers that the main challenge of applying Minimum quantity lubrication (MQL) in machining processes is its lower cooling effect which has already been reduced remarkably by using nanoparticles as additives in base oils and this paper is an effort of authors to represent the successful implications of Nano-fluids assisted MQL in different machining processes in terms of cutting temperature, surface roughness, tool wear, cutting forces, power consumption and productivity. It is tried to point out the benefits of Nano-fluids assisted MQL in various machining processes such as turning, milling, drilling and grinding in a systematic organized way. Moreover recent challenges of using Nano-fluids are also pointed out with specific research gaps as a direction of future researchers.
A Cyber-Physical System (CPS) for Automating Additive Manufacturing Process with Industry 4.0
Abstract
This paper focuses on the development of a cloud-based cyber-physical system (CPS), where various types of optimization models, approaches, and monitoring systems will be carried out. The CPS, an enabler for Industry 4.0, automated the manufacturing process by bringing all the optimization processes and various steps into a cloud framework. This CPS created an autonomous network where all the details went directly to the web platform. Thus, appropriate process parameters, based on the performance value evaluation form the previously generated algorithm, will go directly to the additive manufacturing machine (3D printer). Microsoft Azure was used as cloud platform. Raspberry pi will be used to connect the 3D printer to the Azure IoT hub and access the Azure machine learning studio, where the generated algorithm will automatically evaluate and determines the most suitable value. In this study, Fused Deposition Modeling (FDM), one of the most used methods of 3D printing was used. The property (tensile strength) of a 3D printed gear was considered as the output parameter for optimization. The methodology of the CPS starts with receiving customer demand (input data) directly at Azure IoT hub. Then the system will transmit suitable output data automatically through the raspberry pi module to the 3D printer. Subsequently, the printing process will be completed as per the instruction from the system. The benefit of this project lies in the successful implementation of an automated system, thereby minimizing human monitoring for additive manufacturing process via cloud platform in Industry 4.0 perspective.
An Experimental Investigation of High-Speed End Milling of Ti-6Al-4V Alloy
Abstract
Cutting of titanium alloys has been a subject of high interest for research projects worldwide, especially due to the widespread application of those materials within the aerospace industry. Titanium alloys are recognized as extremely difficult to cut materials for a number of their innate characteristics, like their high-temperature strength and low thermal conductivity. Poor machinability of those materials is said to the generation of high temperatures at the chip-tool interface and formation of serrated chips, which end in low chip-tool contact length and high fluctuation of cutting force working on the tip of the tool. Such dynamic loading behavior leads to instant failure of the tooltip and consequently poor surface finish in machining. Many researchers have actively administered innovative research to enhance tool life, MRR, improvement of surface finish, and elimination of chip serration to reduce chatter and vibration during machining. However, less success has been achieved in improving surface finish and tool life. This study aims to optimize the cutting parameters to achieve the finest possible surface finish in conjunction with a reasonable tool performance in high-speed end milling of Ti-6Al-4V using uncoated tungsten carbide tools. The experiment design was supported by the response surface methodology (RSM). Empirical Mathematical models were developed for output response – Surface Roughness in terms of the machining parameters. Based on the developed model, optimization was conducted using RSM. The influence of input parameters, namely, cutting speed, axial depth of cut, and feed, were analyzed, and their optimum combinations for minimum surface roughness, were identified. It is observed that with the rise in spindle speed (from 16000 to 22000 rpm) and the lowering of feed rates (from 26 to 38 mm/min), the possibility of finding the best surface roughness from the contour graph increases. A Scanning Electron Microscope (SEM) was applied to study the cutting-edge wear behavior, chip morphology, and texture of the machined surface.
Optimum Design of a Grid Connected PV/Battery Hybrid System for Commercial Load in Bangladesh: Effects of PV, Battery, and Dispatch Strategies
Abstract
This study investigates the potentiality of a grid connected PV/Battery system for a daily 900 kWh commercial load in northern region of Bangladesh. The effects of two PV modules (monocrystalline and polycrystalline) on the cost of energy (COE) and net present cost (NPC) using different dispatch strategies is carried out in the study. Five battery technologies namely (lead acid (LA), Li-ion, zinc flow, vanadium flow, and nickel-iron) are selected to determine the cost effective hybrid system using HOMER (Hybrid Optimization Model for Electric Renewable) software. The results indicate that grid connected polycrystalline/LA system in Load following (LF) strategy has the optimized COE ($0.05/kWh) and NPC ($307,657). The study also shows the effects of sell-back price on the COE. Moreover, the article discusses the social, economic and environmental benefits of executing the hybrid system.
Abstract
Rising automation usage in the supply chain and logistics sectors has made the system more convenient, efficient, and useful. Vehicle routing is an essential segment of logistics. Nowadays, Super shops are suffering from faulty scheduling and improper planning of vehicle routing. In this paper, vehicle routing and scheduling have been investigated for the Super shop Swapno of Dhaka, Bangladesh. This research aims to make vehicle routing more effective and automotive by making it intelligent. It used the demands of different outlets, combined those demands, and clustered these by territory. The scheduling and routing plans were developed by using those clustered territories. The Application is based on artificial intelligence to respond to the real-time data of traffic that makes the vehicle routing intelligent. As a result, the scheme changed its prior direction to find the shortest available path based on the instant location. Firstly, we used the demand at different outlets for scheduling by using the solver toolbox of the google sheets-vehicle routing feature. After scheduling, the Shortest Path First algorithm (SPF algorithm) was used to identify the best route to reach the next outlet based on the instant location. HTML and Javascript languages were used to develop the Application. This research aims to make the vehicle routing of the Super Shop more optimized and intelligent by responding in a real-time scenario.
Investigation of Mechanical Properties of Bagasse Fiber and Human Hair Reinforced Hybrid Composite
Abstract
Now-a-days various types of mechanical applications require composite of better quality and performance having lower weight to strength ratio. Sometimes natural fibers are treated with different chemicals or combined with other materials to achieve better performance. This work represents the fabrication and evaluation of different mechanical properties of hybrid composite made from alkali-treated (10% NaOH solution) bagasse fiber and human hair reinforced with epoxy resin and compared the properties with the composite that made from untreated natural bagasse fiber and human hair. Hand lay-up technique is used for fabrication process. In both cases, six total layers have been used, four human hair stitched layers in between two bagasse fiber stitched layers. Mechanical tests such as tensile, flexural and impact tests are performed for both hybrid composites and then comparisons are deliberated. The result of this work indicates the hybrid composite made from treated bagasse fiber shows slightly better properties than the composite with untreated bagasse fiber.
Effect of Dynamic Stall on the Flow Characteristics of a Darrieus Wind Turbine Blade at Low Wind Speed: A Numerical Approach
Abstract
Increased concern for the environment has led us in search of eco-friendlier energy sources. Wind energy can be an invigorating option in this regard. Vertical axis wind turbines offer a reliable and auspicious solution for the remote areas that are away from the integrated grid systems. These turbines show a very unpredictable nature especially due to the effect of dynamics stall. In this paper, the influence of dynamic stall and blade vortex interaction is investigated on the flow properties around a vertical axis Darrieus wind turbine blade. The blade is constructed of NACA 0015 airfoil profile and operates under a low tip speed ratio at the wind velocity 1 m/s. A two-dimensional CFD analysis is executed in ANSYS Fluent 16.2 using the realizable k-epsilon turbulence model and enhanced wall treatment. Graphical representations of the pressure coefficient, turbulent kinetic energy, skin friction coefficient are discussed for the different azimuthal positions of the turbine blade. The tangential and normal force around the blade is also calculated and variation of the forces for different blade positions is discussed. Moreover, the coefficient of power at different wind velocities is calculated and analyzed. It is observed that the dynamic stall and blade vortex interaction significantly affect the flow properties and forces around the blade, which results in the fluctuation of power generation.
Condition Monitoring of An Automobile IC Engine and Gearbox Through Used Oil Analysis
Abstract
It is becoming very essential to regularly monitor different machinery to detect failure initiation and to prevent the failure by taking timely remedial action. The aim of this work is to present a systematic analysis of lubricant degradation of an IC engine and gearbox of an automobile. The automobile has been monitored over a period of five months through the oil analysis of lubricating oil. Two efficient techniques FTIR oil analysis using Fluid scan and viscosity testing using Viscotester have been performed to monitor oil condition. Later on, based on the oil condition, the probable condition of the engine and gear box is identified and the remedial actions which need to be taken are explained. Lastly, the significance of this method as a reliable condition monitoring tool in order to prevent the catastrophic failure of the machinery and expensive component replacement is illustrated.
Comparative Analysis of Additive and Subtractive Manufacturing Processes through the Fabrication of a Spur Gear
Abstract
The newest technology in the world of industrial production methods is additive manufacturing, commonly regarded as the 3D printing technique. In comparison to subtractive manufacturing methodologies, it is characterized as the process of joining materials to create structures from 3D model data, typically layer upon layer. In this research work, a comparative analysis was done to see how 3D printing fares against the common subtractive manufacturing processes. A sample product (Spur gear) was made of ABS (Acrylonitrile butadiene styrene) material using four manufacturing processes of Milling, Hobbing, CNC Machining and 3D printing. The comparative study between the processes was based on different parameters like surface roughness, dimensional accuracy, teeth profile formation. From the analysis, it was found that Additive manufacturing (3D printing) responded better than other three manufacturing processes due to the inherent process characteristics of layer by layer material addition. This has resulted in high precision process in fully automated manufacturing environment of a 3D spur gear.
Investigation on the Performance Test on Liquid Cooling System for CPU of Desktop Computer Cost Effective Enhancement
Abstract
The growth of rapid computing in modern era over past few years give personal computer microprocessor high computing ability with billions of transistors planted on it. This increasing transistor also increase total heat dissipation of CPU with higher voltage and frequency. Conventional aluminum extrudes heat sink used in desktop has several limitations to remove high heat flux generated from microprocessor, this paper main focus was to investigate how to improve cooling performance method with modification of the conventional heat sink. Conventional heat sink was shifted with Copper-Aluminum joint composite system for material modification and liquid cooling system introduced in lieu of conventional air-cooling system method. Both experimental and numerical investigation are carried out for no load and full load condition. ANSYS-FLUENT finite volume software was used to carried out the numerical simulation. CPU performance, processor temperature, thermal power, thermal resistance and different properties effect with varying material, method are demonstrated in this paper. Comparisons of the system with feasibility also checked out. This study lead guideline to design and modification a common Aluminum extrude heat sink with better heat transfer performance for microprocessor.
Characterization and Environmental Impacts on Mechanical Properties of Woven Jute/Carbon Fiber Reinforced Epoxy Composites
Abstract
As natural fiber is environment friendly and low cost as well as lightweight material, the development of natural fiber composites and its application are increasing day by day. Many researchers are doing research on jute fiber composites using twill type jute fiber mat. However, in this study, unidirectional jute fiber mat using jute yarn was used. The mat was fabricated by specially designed manual handloom and the composites and hybrid were fabricated by hand layout with cold press process. Unidirectional carbon/carbon fiber mat was incorporated to fabricate the hybrid composites. A series of composites and hybrids were introduced for the characterization of the composites and hybrid. Environmental impacts on mechanical properties were also investigated. Improved mechanical properties were found where jute fiber mats were placed separately in the case of hybrid composites.
Numerical Study of the Effects of Exhaust Gas Recirculation on Combustion Performance of a Homogeneous Charge Compression Ignition Engine
Abstract
Homogeneous Charge Compression Ignition (HCCI) engine offers several advantages like, high thermal efficiency, lower emission, fuel flexibility etc.; however successful implementation of this new engine technology is mainly challenged by difficulties in controlling start of autoignition, engine knock, emission of hydrocarbon (HC) and carbon monoxide (CO). Though, Exhaust gas recirculation (EGR) is mainly employed in conventional engine for NOx emission reduction, however, in HCCI engine EGR could be an effective method for controlling combustion timing, and reducing knock at high load while maintaining lower level of NOx emission. In this study, effects of EGR on the combustion and emission performance of a single cylinder four-stroke HCCI engine is investigated by using ANSYS Forte software. A sector with periodic boundary conditions is considered as the computational domain instead of using the whole geometry of a single-cylinder HCCI engine. Simulations are carried out at different EGR percentage varying from 0% to 30% by mass. Results show that, combustion duration become much shorter while apparent heat release rate (ROHR) is getting higher with increasing the EGR percentage. Compared to HCCI engine combustion without using EGR (i.e. 0% EGR), emission of NOx is reduced to 97.2% for addition of 10% EGR, 98.5% for 20% EGR and 90.4% for 30% EGR. It is found that, combustion timing can be controlled by adjusting the mass percentage of exhaust gas recirculation while maintaining very low level of NOx emissions with a slight increase in emission of CO.
A Study on the Effect of Nanocellulose Coating for Effective Deposition of Metallic Nanopartilces on Textile Substrate
Abstract
Cellulose is one of the most abundant and important substances among natural and synthetic polymeric materials. Fibrous cellulosic materials are capillary porous disperse systems with high specific surface areas. The degraded low molecular weight product, micro and nano-cellulose is highly renewable. Nanocrystalline cellulose (NCC) has gained a great attention of the researchers because of their inherent sustainability, renewability and unique physical and chemical properties. NCC has been extracted using sulfuric acid hydrolysis process of sugarcane bagasse and ultrasonic treatment. This process effectively removes the amorphous part of cellulose, which yields low molecular weight nanoparticles and form stable cellulose nanocrystal suspension. NCC has showed potential as versatile support for metallic nanoparticles. In this study, a novel method to produce uniform NCC layer on textile substrate using spin coater has been presented and the effect of NCC coating for effective deposition of silver nanoparticles (AgNPs) on regular textile surface has been investigated. The amount of AgNPs deposited on the nanocellulose precoated textile has been found 27 per cent of the original weight of the substrate whereas the regular substrate without NCC coating showed only 5.5 per cent of AgNPs deposition on surface which is significantly lower. The study effectively demonstrates that the NCC coating significantly improve the capability of metallic nanoparticle deposition on textile surface, which may potentially enhance the functional properties of textile materials.
Bullwhip Effect Minimization Strategy Formulation: Keys to Enhancing Competitiveness and Performance
Abstract
Bullwhip effect (BWE) is the lack of Supply Chain (SC) coordination and distortion of information. Variations in orders increase BWE as they move up from the downstream stage to the upstream stage of the SC. To be successful in competition and rapidly changing marketplace, industries must generate plans to provide proper information throughout the SC. This study makes a dual contribution. On the one hand, it finds out the main causes that create bullwhip causes and aggregate all other causes under two main causes’ operational causes and behavioral causes which have low to high impact on BWE. On the other hand, it develops relationships among these causes and finds out a significant analysis of Bullwhip causes on SC fitness by using Linear Structural Relations (LISREL) analysis. This analysis found statistically significant & positive relationship of operational causes & behavioral causes with BWE. Decreasing number of echelons, incentives, price, discount and policies variation, and increasing trust issues among participators of the SC can eliminate BWE in a significant manner.
A Systematic Approach to Solve Unsteady Thermodynamic Problems Using Python and Its Open-source Packages
Abstract
Although thermodynamics is used for steady state design and performance evaluation of thermal systems, unsteady problems are important from system dynamics and control point of view. From dynamics perspective it is desirable to predict the system’s pressure, temperature, and mass as a function of time. However, the governing conservation equations give rise to system of nonlinear coupled ordinary differential equations involving mass and energy, and solution of this system requires numerical methods. There exists a lack of textbooks that deals with unsteady thermodynamic problems except some that use proprietary software packages. Furthermore, in academia and industry state-of-the-art thermodynamic simulation are carried out using Engineering Equation Solver (EES), REFPROP, FLUID-PROP, Cycle-Tempo, Aspen HYSYS, MATLAB or similar software. However, the programming language Python and it open-source packages offer an excellent ecosystem that can be readily adopted to address thermodynamic simulation problems that is comparable to proprietary software. The challenge being though there exits little literature that discusses systematic solution strategy using Python. This paper presents a systematic solution approach to unsteady thermodynamic problems using Python and its open-source packages.
Numerical Investigation of Natural Convection Heat Transfer Characteristics on Partially Heated Square Enclosure at Different Rayleigh Numbers
Abstract
The paper presents a numerical analysis of natural convection inside a square cavity in which left and right wall were considered heated partially. A series of Direct Numerical Simulation (DNS) was conducted by using Ansys FLUENT to observe the effect of partially heated section on the heat transfer characteristics at different Rayleigh Number (Ra) which was considered to 104 and 105. During these simulations, it was assumed that vertical walls (left one and right one) heated by 20%,40%,60%,80% and 100% with constant temperature. The obtained numerical results were illustrated and discussed with temperature contour, heat transfer co-efficient, local and average Nusselt Number, stream function in tabular or graphical form. These DNS results demonstrate that Nusselt Number (Nu) and average heat transfer coefficient, both, decrease along with increasing the percentage of heated portion, whereas increase with Ra.
Vibration Analysis of Rolling Element Bearing using Micro Electro-Mechanical System (MEMS) Based Accelerometer
Abstract
Rolling element bearing is a common machine element which often leads to unexpected machine breakdown in case of its failure. Vibration analysis has long been studied for early bearing fault detection to prevent this type of costly damage. However, these studies often used expensive sensors and data acquisition systems. In the present study, a cost-efficient method was developed to extract and analyze vibration signals from a bearing and detect the bearing fault. To extract the signal, an experimental setup was built with one new healthy bearing and one randomly damaged bearing by mounting them on a shaft. The vibration signal was obtained using a tri-axial Micro-Electro-Mechanical System (MEMS) based accelerometer. An Arduino based microcontroller platform was used to acquire sensor data and send it to the computer via serial communication for further processing. For signal processing, High-Frequency Resonance Technique (HFRT) was applied. The envelope spectrum of the raw vibration signal was calculated to find the characteristic frequency of the system. Distinctive fault characteristic frequencies were obtained from the damaged bearing. This result shows that bearing condition can be effectively monitored by analyzing vibration data captured from a MEMS accelerometer.
Effects of the Fiber Orientation on Mechanical Properties of Jute Fiber Reinforced Epoxy Composites
Abstract
Among all the natural fiber epoxy composites jute turns to be a leading one reinforcement because of it’s strong bonding with matrix and also the easiest one to fabricate. Three types of jute fiber woven mat was prepared using a manual handloom to fabricate the composites by land layout with cold press process. It was discussed that mechanical properties of the composites depend on the volume and orientation of reinforcement in a certain amount of matrix and SEM and XRD were carried out to comprehend more precisely that the fiber quantity and orientation into the matrix is a key factor. In addition, the effects of the moisture on physical properties were also investigated. Higher mechanical properties were found where unidirectional mat using yarn was used to fabricate the composites. In this study, the orientation of the fiber reinforcement was varied to investigate the mechanical properties of the composites.
Numerical Investigation on the Thermal Performance of a Hospital Ward Roof Incorporating Phase Change Material (PCM)
Abstract
Overheating is a common phenomenon in a tropical country like Bangladesh. So, ensuring the thermal comfort of hospital patients is necessary for proper health treatment. But in Bangladesh, the thermal comfort of the patient is compromised as installation of the air conditioning system in every general ward of the hospital is impossible due to economic constraints. So, a cheap but effective solution is badly needed to cope with this situation. In that case, PCM (phase change materials) can be an alternative to improve the thermal condition and reduce temperature fluctuation in hospitals in Bangladesh. Phase changing ability at a constant temperature and latent heat storage property of PCM have been proved very effective for the improvement of building thermal condition over the years. In this study, the improvement of thermal condition of the general ward of Patuakhali Medical College (PkMC) is analyzed using PCM as a retrofitting option. A numerical simulation work is performed to analyze and compare the effect of three different PCMs on the enhancement of thermal comfort hours. Finally, based on the result, the best PCM is chosen for optimum thermal management.
Assessing the Impact of Fading Effect by Potassium Permanganate Spray on Cotton-Jute Blended (Jutton) Denim Fabric Panel with Varying Parameters
Abstract
Fashion trend over the world is changing gradually but till here and now washed garments have been reigning with consistency throughout the fashion-sensible wearer. Although the demand for washed denim is always to the fullest but mostly cotton wins the position regarding the raw material of denim. To achieve a variety of raw materials for the huge market of washed denim at the same time to attain the best utility of Jute, this investigation was initiated. Keeping this in mind our main motive was to investigate the usability of Jute-Cotton blended (JUTTON) denim by comparing it with conventional cotton denim after Potassium Permanganate (PP) wash of varying concentration 1%, 2%, 3%. The physical and mechanical properties of Jutton were thoroughly studied by stiffness test, abrasion and pilling test, rubbing and color fastness test, absorbency test as per ISO, AATCC, and British standard. A comparative study is also made with cotton denim panels. The matter of success lies that most of the results are similar in the case of Jutton and Cotton at the same time in a few cases results are outstandingly better for Jutton. From our current experimental works, it can be said that Jute-cotton blended (Jutton) denim can be one of the best alternatives to cotton denim and can open a whole new frontier for fashion seekers.
Experimental Investigation on Mechanical Characterization of Jute-Kevlar Hybrid Composites
Abstract
The use of composite materials is increasing day by day. The main objective of this study was to characterize the mechanical properties of Jute-Kevlar reinforced epoxy hybrid composites, and investigate the environmental impacts on the physical and mechanical properties of the hybrid composites. Unidirectional jute mat which is made of jute yarn was used, and the mat was prepared by special type of manual hand loom. Hand layout with cold press technique was used to fabricate the composites and hybrid. The internal bonding between the matrix and fiber reinforcement were examined in a scanning electron microscope (SEM) and analyzed. Tensile test was done in a universal testing machine. The result shows that Kevlar has an impacts on the mechanical properties of fabricated hybrid composites. Also, it has an influence of heat on change in length of fabricated composites and hybrid.
Comparison of Thermal Battery Management of a Formula Electric Car using Passive Cooling with and without a Phase Change Material
Abstract
As charging and discharging state of a battery pack causes electrochemical reaction which give rise to excessive heat resulting in thermal runaway. The performance of an electric vehicle on a great extends depends on the temperature of the battery pack and a nominal temperature reduces the chance of accident and increases the efficiency of the car. In this paper a modelling and simulation of a cylindrical Lithium-ion battery pack, PCM, passive cooling is performed. The objective of the study is to control the temperature of the battery pack by forced convection and phase change material, and a comparison study of both methods. The battery pack is simulated using simulation software and the different temperature of the pack while charging and discharging was presented. The method used for the cell model is lumped battery interface and the thermal model used is modeled using electrochemical heating multiphysics coupling mode the software used is Comsol Multiphysics. Computational fluid dynamics analysis was carried out to investigate the performance of passive cooling with and without PCM. The temperature of the battery pack for both case is within the limit. The passive cooling without PCM method is more efficient. On the other hand, the passive cooling is cheap and it also gives a favorable result. The result was computed using numerical computation method but in the real life experiment there might be a slight change in the parameters but the result is satisfactory.
Improvement of Overall Equipment Effectiveness through Total Productive Maintenance: A Case Study
Abstract
In this competitive world, manufacturing industries are suffering from several problems such as breakdown of machine, production adjustments, poor working of defective equipment, poor maintenance and management and this lead to low productivity and major losses in the company’s growth. Total Productive Maintenance (TPM) approaches can be promising solution to overcome these problems. Therefore, this study attempts to apply the TPM strategy in a jute bag manufacturing company in Bangladesh to enhance their overall equipment effectiveness (OEE). A consecutive three month data is taken and identified the cause root of major losses. TPM strategy is applied based on these losses. As a results company achieved 50.33 % OEE which is still very low compare the benchmark world class manufacturing OEE (85%). By calculating the OEE Company can know where they are and where the weakness point is and how to it can be improved.
Abstract
A very large number of computational models have already been proposed to evaluate thermal conductivity for high-porosity foams. Each approach considered different cellular morphologies and used different solution methods and all they have significant differences. Porous foams are generally used as insulators. So, the effective thermal conductivity of high porous materials, like polyvinyl chloride, expanded polystyrene, asbestos and fiberglass for various meshes are measured to determine the best porous foam that gives the best insulation. Then the results are compared between them and with the results of the previous investigations. It had been found out that effective thermal conductivity is inextricably related to porosity. Effective thermal conductivity decreases with the increasing of porosity such as for polyvinyl chloride, the value decreases from 0.56 to 0.43 for increasing the porosity from 0.75 to 0.95. Similar results are observed for other materials too.
Abstract
A suspension system is one of the major analytical systems in a vehicle like Human Exploration Rover, a human-powered rover manufactured for human exploration outside the earth. This paper will introduce a perfect geometry, modeling and proper analysis of a double-wishbone suspension system which is manufactured for a human-powered rover. An ideal design of a suspension system includes good stiffness, low weight and low manufacture cost. To minimize the cost and for availability, Stainless steel (SS) material is selected for the designing procedure. In finding the suspension points, the wheelbase and track width are considered at first as the rover should not exceed the limit of 5×5ft tolerance. The modeling and analysis include all the components used in a suspension system with their calculations. Besides, this paper will assist in finding the perfect position of a roll center and minimizing the stability of sprung mass. The study will assist the participants in manufacturing a perfect suspension system for the human manipulated rover in the upcoming Human Exploration Rover Challenge competitions.
Investigation on Thermal Hydraulic Parameters of a Nuclear Reactor (VVER-1200) due to Loss of Coolant Accident with Station Blackout and Failure of Emergency Core Cooling System
Abstract
This paper present computational analysis of severe accident in VVER-1200 where the plant is subjected to confront loss of coolant accident (LOCA) with station blackout (SBO) condition also with arbitrary failure of Emergency Core Cooling System (ECCS). The LOCA break appears in hot leg of the primary coolant circuit after 5 seconds of full cent percent power running condition. Thermal hydraulic parameters of generation 3+ VVER-1200 reactor core for different arbitrary break of LOCA has been investigated to find the impact of accidents in detail. Pressure, temperature, power fall down significantly after the accident happened due to SBO and LOCA for reactor trip occurrence. After 65 seconds, core level water rapidly decreases to 4m height when the Hydro-Accumulator automatically started to prevent core damage. Thermal power of reactor core, Turbine load, Nuclear flux power fall down after 18 seconds of the accident initiation. LOCA with SBO only is generally mitigated by ECCS in times but failure or unavailability of ECCS turns the core uncover, fuel melt, radioactive material release and finally core collapse by molten core concrete interaction. Initially after the accident, all system acts protective to mitigate the accident. But when all the core water vaporizes and ECCS water inconvenient to reach reactor core then fuel peak temperature along with clad temperature rise to design basis accident prescribed value after 750 to 900 seconds. For different size of LOCA, the results can show different behaviors in SBO situation.
Numerical Investigation of Heat Transfer Characteristics of Nano-fluid flowing through a Circular Pipe Surrounded by Porous Medium
Abstract
Porous medium and nano-fluid have become very eminent area of interest in heat transfer analysis nowadays because of its enhanced heat transfer capacity than normal fluid flow in solid pipe. With expanding technological advancement, porous medium have drawn attention of the researchers. The main advantage of using porous medium in recent years which have been accomplished from numerous research works is the enhancement of heat transfer rate than solid pipe. Porous medium and nano-fluids have gigantic impact in engineering sectors such as automobile cooling system, nuclear reactors, industrial applications, and biomedical applications. The objective of this study is to numerically investigate the convective heat transfer of water-based Al2O3 nano-fluids flowing through a circular pipe surrounded by porous medium at constant heat flux of 6000 W/m2 under laminar flow conditions. The effects of nano-particle concentration, Reynolds number, Darcy Number and porosity on the heat transfer characteristics of Al2O3-water nano-fluids are investigated. Convective heat transfer co-efficient, Nusselt number and pressure drop have been estimated for porosity 0.1 to 0.5, Darcy number 10-2 to 10-6, volume fraction 0.01 to 0.05 and Reynolds number 100 to 500. Effective thermal conductivity is also observed for different volume fraction of nano-particle .The simulation was performed with ANSYS Fluent 16.2 .The investigated result concluded that convective heat transfer co-efficient and Nusselt number increase with Darcy number, Reynolds number and volume fraction of particle but decrease with porosity of porous medium. Effective thermal conductivity is increased with volume fraction of nano-particle. Pressure drop is decreased with Darcy number but increased with Reynolds number.
Numerical Analysis of Free Convection in a Lid-driven Cavity having a Heated Circular Hollow Cylinder
Abstract
Free convection heat transfer induced by the combined effect of mechanically driven lid and buoyancy force in a circular hollow cylinder. In the enclosure, the horizontal walls are maintained a uniform temperature at any point. The main focus will be the changes in pressure and velocity of our model with the changes in diameter and Ra & Gr no. The present study simulates a realistic system such as heat transfer in heated boiler cell. The governing equations for the problem are firstly transformed into non-dimensional form. The computation carried out with Grashof and Rayleigh number. The analysis is transmitted with the variation of streamlines and isothermals for different Rayleigh number ranging from 103 to 107 where Prandtl number kept 0.71 constant. Moreover, the results of this investigation are shown by the variation of fluid temperature in the enclosure with the different parameter (velocity, Pressure).
Performance Study of Vapor Compression Refrigeration System using Different Refrigerant Mixtures: Numerical Analysis
Abstract
Binary refrigerant mixture, a mixture of two refrigerants, is used rather than a single refrigerant in a refrigeration system to increase the performance and energy efficiency. In the present study, in pursuit of finding a better alternative refrigerant, numerical analysis of five types of mixtures, namely R600a-R134a, R152a-R600a, R290-R600a, R600a-R717 and R134a-R152a in a vapor compression refrigeration system (VCRS) has been done. The selection was based on the potential risk to the environment caused by the binary mixture. Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) were the key factors of consideration in terms of environmental risk. The analysis tool used for the computations in the VCRS was Aspen HYSYS. For each case, a particular composition of a single refrigerant mixture was considered in this refrigeration system. The refrigeration effect (RE), compressor work (Win), coefficient of performance (COP), dew point (Tdew), bubble point (Tbubble) and temperature glide (ΔTglide) were calculated with respect to the molar fraction and mass fraction of a single refrigerant. The calculations were performed with the help of few predefined parameters: composition of the mixture, condenser temperature, mass flow rate of the refrigerant mixture, pressure rise in compressor and pressure drop in expansion valve. Based on the results of the investigation, it can be declared that among these five mixtures, R600a-R290 mixture gave the best COP. But maximum COP was obtained for pure R600a. On the basis of temperature glide, it was found that except for the R152a-R134a mixture, all of the remaining four mixtures behaved as zeotropic mixtures.
Experimental Investigation of Mechanical Properties of Silk Reinforced Modified Polymer Matrix Composites
Abstract
Composite material has been an important contributor to modern industrial revolution. But with the emphasis given on environmentally sustainable technologies, importance of development of composites with natural materials is more than ever. As silk fiber is natural and can be obtained from it is renewable resources in abundance, it should be a good substitute with economic and environmental impact. In this work, we studied the performance and characteristics of composite made of Silk fiber and modified polyester matrix. The research covers silk and unsaturated polyester with matrix modification for a different range of wood crumble scientifically named as Tectona Grandis. A simple hand layup technique was used to make composites. We fabricated composites of three different volume fraction of silk fiber, polyester and wood crumble (silk v/v%: wood crumble v/v%: polyester v/v% =2.94: 0:97.06, 3.01: 6.23: 90.76 and 3.17: 31.78: 65.05. Tensile and flexural strength and thermal conductivity of the different compositions have been measured. Wood crumble free composition having silk v/v%: wood crumble v/v%: polyester v/v% =2.94%: 0%: 97.06% is found to have the highest flexural strength among the samples studied. The results showed an increase in strength with added wood crumble of the ratio silk: wood crumble: polyester= 3.01%: 6.23%: 90.76%. Although the thermal conductivity increases with the quantity of more wood added, young modulus of the composite decreases.
Fabrication and Mechanical Property Evaluation of Hemp and Glass Fiber Composite
Abstract
The hemp fiber and glass fiber epoxy hybrid composite were fabricated in this work through this project. Four types of samples were produced by varying different layers of glass fiber and hemp fiber. The composite samples were GHHG, HGGH, GHGH, HHGG. Then other mechanical properties such as Flexural strength test, Impact strength test, Hardness number test, and a water absorption test was done. In Flexural Test, GHHG combination composite material shows the best flexural strength, 54.24 MPa. The GHHG combination of composite shows best Impact Strength 54.05 J/cm2. In Tensile Strength test, the HGGH combination of composite gives the best tensile strength, which is 74.533 MPa. The best hardness number HRB was given by GHHG combination of composite that is 80.33. The least water absorption rate is given by GHGH combination of composite which is 11.88%. Results are calculated and plotted on Microsoft Excel to compare the data. The GHHG combination layer of composite material gives the best flexural strength. It also gives the best Impact strength. The best tensile property was given by HGGH combination of composite. The hardness number of the GHHG combination layer of composite is also higher. In the water absorption test, the GHGH combination layer of composite gives the least value. It can be concluded that the mechanical and physical property of hemp and glass fiber hybrid composite material varies with the change of layers. The composite materials can be used in aerospace industries, automobile industries. It can also be used to make car body parts.
Mechanical Characterization of Drumstick Fiber Reinforced Epoxy Composite
Abstract
The focus of this paper is using drumstick fiber and epoxy resin to manufacture a composite material offering high strength to weight ratio as compared to most conventional materials. As drumstick is very available in winter in our country, it can be a new source of fiber to replace the expensive and non-renewable synthetic fibers, so products can be produced cost effectively. The research is mainly focused on the manufacturing of the drumstick fiber reinforced epoxy composite and investigates the mechanical properties such as the tensile, flexural and impact strength of the manufactured composite. The tensile and flexural strength of the manufactured composite are on average 11.77 MPa and 41.032 MPa respectively. The tensile strength is quite close to the tensile strength of plastic. However, the flexural strength is much lower. Thus, it can be used as a replacement of plastic where flexural stress can be ignored. Also the fibers can be chemically modified to enhance the properties.
Tribological Investigation of Bio-lubricants Derived from Vegetable Oil Sources
Abstract
The utilization of petroleum based lubricating oils is expanding day by day and individuals are getting reliant on petroleum based oils to run them. Large use of crude oils may result shortage with future demand as the natural fields are gradually being empty. Petroleum based lubricants also have harmful effects on human life. Tremendous utilization of petroleum based oils additionally made many negative impacts on environment. So considering all the facts petroleum based lubricants should be replaced by some suitable oils. Among them Vegetable oils are mostly like to replace this place. Because vegetable oil is environment friendly, non-toxic, biodegradable, cheap and it can be cultivated according to the demand.
In this paper, five different bio-lubricants derived from vegetable oil sources have been investigated to study and analyze its lubricating properties. Furthermore, an experimental comparison of viscosity and viscosity index has also been shown after mixing an additive with base oils. PMA (poly methyl acrylate) is a conventional commercially available viscosity modifier that enhances the tribological performance of lubricating oils. In order to ascertain the efficiency of PMA as additive, the tribological performance of PMA blended base oils have been compared with mineral based oils used in different industrial application. The comparative study of experimental result demonstrated that some vegetable oils have good lubricating properties like viscosity to be replaced with petroleum based oils and viscosity index of base oils were increased by adding additive in different concentration. So vegetable oils can be a better future recommendation for replacing a large portion of petroleum based lubricants in near future.
Effect of Cant Angles on the Aerodynamic Performances of an Airplane Wing with Blended Type Winglet: Numerical Analysis
Abstract
This study examined the potential of attaching winglets on wings in an airplane aiming to reduce the induced drag coefficient and increase the coefficient of lift while keeping the wing span the same. The aerodynamic characteristics of a wing having winglets have been studied numerically with the help of simulation software ANSYS-Fluent. The drag and lift coefficients have been studied for winglets having different values of cant angle, on an aircraft wing. For the work, subsonic flow of air is considered over the wing in the simulation. NACA 0012 symmetric airfoil is considered for the study. By reducing the induced drag that causes tip vortices, an enhanced winglet design with a certain cant angle can produce an aircraft's better performance significantly. Reduced fuel consumption would benefit from the overall improved aerodynamic performance. Blended winglets will increase the lift coefficient about approximately 42% to 49% and reduce the drag coefficients. These winglet designs are capable of reducing the induced drag and converting wingtip vortices to increase thrust, saving costs by reducing fuel consumption, reducing noise levels and enhancing aircraft engine performance.
Numerical Analysis on Heat Transfer with Nanofluid in an Automotive Radiator
Abstract
The present numerical analysis simulated heat transfer with nanofluid (Al2O3) passing through a two-dimensional radiator of turbulent flow using computational fluid dynamics (CFD) for single phase approaches. To validate the numerical results, the procedure involved to investigate the efficiency of water based Al2O3 nanofluids as coolant in a radiator of Tata Indica/Indigo. Particle concentration levels ranging between 1 vol% to 5 vol.% have been used as working fluids for investigating the current study. The advantages over using water were evaluated. Variations of outlet temperature with different mass flow and various nano-particle concentration level were obtained. Better heat transfer enhancement was found for higher nano-particle concentration levels. Nusselt number and pressure drop at various particle concentration levels of nanofluid in the radiator were compared. Local temperature and pressure with respect to distance from the radiator inlet have also been observed. Results have shown that temperature, pressure and Nusselt number decreases with the radiator length from the inlet. However, local pressure, temperature and Nusselt number also decreases with increasing of nano-particle concentration level. The current numerical investigation was validated through comparing of simulations with those mentioned in the literatures.
Abstract
The complete energy scenario can be facilitated if the exploitable source of energy could be harvested using sustainable technology. This paper describes the prospects of renewable energy in Bandarban by utilizing natural resources. As Bandarban is a hilly area so it has numerous waterfalls, canals which can be used through the construction of a small hydro plant for small energy generation which will be a promising solution to suppress the problem of electricity crisis in Ruma. In several areas of Bandarban, electricity is a name only. To suppress this problem, it will be the auspicious solution to make a step of installing the hydro plant. This paper also includes some information about waterfalls & canals in Ruma, Bandarban that are a vast source of hydropower generation. To do so, a reconnaissance survey has been taken place with the assistance of Chief Executive Engineer of Bandarban Hill District Council in several spots of Ruma. Data of some sites were taken using the conventional method of measuring head & flow rate. Also, an observation includes the utilization of forebay is required or not. Using the data's a mathematical procedure also followed for the approximation of total power generation & also the turbine selection method was carried out which was done by RETscreen. From the survey, it was seen that some of the flow remains dead at the time of summer & winter so this should be in concern before designing a small hydro plant. Also, the risk factor is high due to the severe slippery condition of some sites.
Simulation and Risk Analysis of the Accidental Release of Toxic Gas from an Industrial Complex
Abstract
Toxic gas is capable of causing serious damage to human health and surrounding living things if it is ingested, inhaled, or absorbed. The amounts required to cause the damaging effects vary with the nature of the substance and duration of exposure. In this study, two common but toxic industrial gases, Chlorine and Ammonia were selected for modeling the accidental release cases and analyze the subsequent risks and impacts. For each case, a hypothetical toxic release scenario was developed and simulated with the help of risk assessment software ALOHA (Areal Location of Hazardous Atmospheres). An industrial complex in Khulna was assumed to process the gases and selected as the geographical area for the analysis. The surrounding affected areas at different levels of concern (LOCs) were detected. The study also analyzed various parameters that affect the release rate and duration, such as wind speed, air temperature, relative humidity, etc. This study simulated probable scenarios of toxic industrial gas dispersion and its effect on surrounding areas, which can be used as a model to tackle actual incidents in the future.
Construction and Performance Test of a Batch Pyrolyser for Plastic Waste
Abstract
In our daily life, plastic plays an important role and its use is increasing day by day resulting to a huge amount of wastes. Due to their non-biodegradable nature, they are posing a major problem to the environment. Recycling of waste plastics is a means of reducing it, but recently pyrolysis becomes a good option to manage these wastes. Moreover, pyrolysis is a relatively clean and less toxic method compared to incineration. Plastics are petroleum-based material, so it is possible to convert them into fuels by breaking their long molecular chain into small chains. This fuel could be used as alternative fuel to reduce the fossil fuel crisis in future. During pyrolysis, plastics are heated inside a reactor in absence of air and the final product of pyrolysis depends on the temperature, heating rate, etc. Most of the researchers, working on pyrolysis of plastic waste, are using electricity as the means of heating. But we know, electricity is the finished form of energy, so using electricity for pyrolysis is not a wise decision from an energy point of view. In this study, a batch type pyrolysis reactor was developed to extract liquid oil from plastic waste. Heating was done by using low-grade biomass fuel. The performance of the reactor was tested for different types of plastics like polythene, saline bottle, saline bag, etc. Properties such as density, calorific value, flash point, and boiling point were measured for the liquid oil obtained and they were within the range of 603-704 kg/m3, 36-44 MJ/kg, 62-78℃, 234-276℃ respectively which identifies its characteristics as alternative fuel.
Performance Comparison of Parabolic Solar Cooker using Different Reflecting Materials
Abstract
Solar energy is used for various purposes like water heating, cooking, drying, distillation, electricity generation and many more. Solar cookers that uses solar energy for cooking foods can be of various types. But whatever be the type, it is the cleanest, simplest and most convenient way of cooking food without using any fuel. Earlier a parabolic dish type solar cooker, with an aperture diameter of 106 cm and focal length 54 cm using plane glass as reflecting material, was developed and tested in 2014. The maximum temperature inside the cooking pot was found as high as 97°C in April at a radiation level of 329-389 W/m2. As plane mirror is difficult to give the shape of a sphere, pieces of plane mirror were used to construct the reflector. In the present study, different reflecting materials (glass, aluminum foil and stainless steel (SS) sheet) were used to compare the performances of the same cooker. The objective was to choose the proper reflecting material for efficiency and convenience. With the same cooker, only the reflecting materials were changed during the study and for that one set of experiments were conducted for all possible changes and then the reflecting material was changed for other sets. So, it was not possible to conduct all experiments under the same radiation level. The performance of the cooker was found quite satisfactory with all three reflecting materials. The maximum temperature inside the cooking pot with glass as reflecting material was found as 92°C in September at a radiation level of 331 W/m2. The same values with other reflecting materials are: with aluminum foil 90°C in October at a radiation level of 303 W/m2 and with SS sheet 95°C in March at a radiation level of 387 W/m2. Due to different time of the year the radiation level varied and different times were required for completion of cooking for a particular reflecting material. Comparing the results it can concluded that glass is the best as reflective material for parabolic dish solar cooker.
Construction and Performance Test of an Automatic GSM Based Fire Alarm System with Water Sprinkler
Abstract
Generally fire accidents occur more in areas like houses, factories, shopping malls, hospitals and so forth, which cause more misfortune to human life and properties. To reduce this overwhelming misfortune, automatic fire alarm system is very effective. An automatic fire alarm system detects the fire, convey message to fire control department and also will buzz alarm to the attendants. Sometimes, it may include water spraying system to extinguish the fire. In the present work, a low cost, portable, microcontroller based automatic fire alarm system has been developed for cautioning the fire occurrences in household or industrial premises. The aim of this system is to alert the remote property-owner and fire control department by sending a short message (SMS) via GSM network. This automatic fire alarm system will respond in time, when the presence of fire is detected and will also save goods or lives by sprinkling water on the fire. The system is included with a buzzer that could alert the guards or residents when fire incident is detected. The primary target of this project was to develop a fire alert system with minimal cost. The system has three fundamental components that are the detection system, the monitoring system and the controlling framework. This system would also diminish the correspondence time with the fire control department. A model fire alarm system was designed, constructed and tested. While testing it detects the fire, send SMS to two mobile numbers and sprays water to extinguish the fire. Thus, it performed satisfactorily. In order to prevent malfunction of the system a regular or periodical checking of the system by skilled operator should be necessary.
An Application of Industrial Engineering Tools to Enhance Productivity at a Knit Composite Industry
Abstract
Process improvement is of great concern to any manufacturing company. Due to the ever-growing competition in the market, companies must be proactive if they want to sustain and grow in the long run. But this is an intricate task which requires detailed research and adequate resources, resulting in a high initial investment which many companies are reluctant to do so. Nevertheless, companies always strive for optimization when it comes to production. This paper shows the application of industrial engineering tools in a knit composite industry. After analyzing the overall production flow some areas were identified for the implications of industrial engineering tools. A modification of cutting floor layout was done using Load-Distance (L-D) score calculation and a modified layout was proposed. This modification reduced the L-D score to 48 from 52 along with reduced worker movement which is more convenient and less time-consuming. In the sewing section, line balancing was used to reduce the Standard Minute Value (SMV) by 0.42 minute as well as increasing the efficiency of the sewing line by 1.89%. Sewing defects were identified and Pareto analysis was implemented to figure out the major defects that consisted the 80% of the total defects. Material handling is an important process in many industries because it not only contributes greatly to the profit margin but also allows industries to maintain a competitive edge in the market. Some improvement ideas were suggested which could be really useful for improving the material handling system.
Analysis of Overall Equipment Effectiveness in the Sewing Section of Garments Factory: A Case-Study
Abstract
Bangladesh is a fast-growing economy powered by the readymade garments (RMG) industry that shares the major part of country’s export earnings. However, competition is increasing day by day and this sector requires proper attention in performance improvement to strive with upcoming challenges. In this regard, continuous availability with reliable performance of resources and precise product production is indispensable. Considering this, present study aims to quantify the operational performance whereas overall equipment effectiveness (OEE) is taken as the metric of measurement. The sewing section of RMG factory is focused to conduct this study. Necessary data collection was carried out at five RMG factory based on the floor observation and the existing scenario of OEE was build up with its factors – availability, performance and quality. It was found that the average OEE along with its individual factors are far from the world standard. A regression model was developed to find the most influential factor for the resulted OEE. It has been found that, performance is the most dominating element for OEE, followed by availability and quality. Finally, root-cause analysis was carried out for performance loss to find the responsible causes that create hindrance in achieving the standard OEE. Accordingly, some recommendations were provided to improve the existing OEE condition.
Surface Modification of Synthetic Fabric by Polyurethane Coating to Reduce Harmful Formaldehyde Content and Produce Water Repellent Fabric
Abstract
Synthetic fabrics such as 100 percent polyester and viscose are inherently durable press because these are treated with chemicals i.e. formaldehyde during manufacturing. Formaldehyde, a carcinogen, is a substance capable of causing cancer in living tissue. This paper aims to describe how to reduce the formaldehyde content from polyester and viscose fabric and develop sustainable water repellent properties in synthetic fabrics. In this study, the formaldehyde has been reduced by applying Polyurethane (PU) coating on the fabric surface. After applying coating, formaldehyde content in the fabric, water repellency and wash fastness have been evaluated. The result shows that the water repellent property of the fabric has been improved after coating. The different layer of coatings such as single layer and the double layer has been applied on the fabric surface and a comparison has been made between the improved properties of the fabric. It has been found that the polyurethane coatings have good water repellent property and used for reducing the formaldehyde in the fabric. The result shows that the number of increasing layer of PU coating on fabric surface has inverse relation to the amount of formaldehyde content of fabric and direct relation to the water repellent property of the same fabric. As a consequence of increasing layer of coating, the amount of formaldehyde reduce in the both type of fabric composition. But the water repellent property increases with the increasing number of PU coating in the fabric surface. Moreover, wash fastness of the coating on the polyester fabric surface is excellent but the coating on the viscose fabric has poor wash fastness. The paper has provided a better solution to develop water repellent property in the fabric and to reduce the carcinogenic formaldehyde that could be implemented in sustainable water repellent applications.
Design and Optimization of Hybrid Energy System for an Off Grid Area of Bangladesh by using HOMER and Validation by RETScreen
Abstract
Bangladesh being the populated country and aspires to be a developed nation by 2041, Bangladesh is in race to generate electricity for economic emancipation. To get clean energy, renewable energy option is the first requirement to replace the environment degradation fossil fuels. This paper highlights the generation of electricity by renewable sources. However, precise energy prediction is important in total power demand especially for the energy mix. Moreover, any data measured or simulated should be validated for its reliability as well as prediction of future active loads properly. The main advantage is that RETScreen links between input and output parameters and concludes with a precise numeric value. About the initial cost, initial capital is obtained by HOMER is 40,451.200 taka for scenario A and 58,251.600 taka for scenario B whereas from RETScreen, the cost of scenario A and B are 91396.26 taka and 114000.56 taka respectively. Electricity Production by REScreen for Scenario A and B are 1037,390 kWh and 950,009 kWh respectively and by HOMER for both scenarios are 714,287 kWh and 704,706 kWh.
Metal Extraction from Recycled E-waste and its Future Prospects in Bangladesh: A Survey
Abstract
Around the world, 50 million tons of electronic waste (e-waste) is produced per year, with a 500% increasing rate in the years to come. Asia has a vast growing global economy and the total amount of e-waste is expected to rise to about 57.4 million tons by 2021. And that is more than 40% of the globally generated waste. Regarding environmental impact and increasing demand for raw materials and a gradual reduction in non-renewable sources, recycling can be a better secondary source of metals. In this paper, a survey is performed on all the existing processes of metal extraction from electronic-waste in Asia. The traditional metal separation techniques, pyrometallurgy, hydrometallurgy, electro-metallurgy, bioleaching, and mechanical processing are critically compared in this article. The introduction and future possibilities of several methods such as bio-hydrometallurgy, pyro-hydro hybrid metallurgical process, mechano-chemical technology, electro-chemical extraction are discussed. A comparison between different procedures leads to a decision on suggesting an efficient method applicable to Bangladesh. From the context of the recycling of e-waste in Bangladesh, an efficient e-waste management route is identified with defining the suitable metal extraction process.
Numerical Investigation of Ratcheting on a Rectangular Beam under Bending-Bending Loading Conditions
Abstract
This paper deals with the numerical investigation of ratcheting on a rectangular beam and develops a ratchet diagram for bending- bending loading conditions. A dynamic nonlinear elastic-plastic finite element analysis was used to evaluate the occurrence of ratcheting. Two kinds of loads were applied on the beam -primary loading and cyclic secondary loading. Distributed load on the upper part of the cantilever beam acts as a primary load and cyclic displacement load at the free end of the beam act as cyclic secondary loading on the beam. To find the ratcheting effect on the beam, Abaqus FEA software was used. In this paper, the numerical analysis results are verified by the analytical results of Yamashita et al.’s bending-bending ratcheting. The effect of frequency on the occurrence of ratcheting was also investigated. Finally, a ratcheting diagram for bending-bending loading has been proposed.
Numerical Analysis of Wall Characteristics for Turbulent Swirling Jets Impinged on a Concave Surface
Abstract
Impingement jets systems provide an effective method for achieving particularly high heat transfer coefficient. Whilst a significant amount of studies are available for flat surfaces, the flow and thermal performance for curved surface is limited in the literature. As such, a numerical study using finite volume method is conducted to investigate the wall behaviors, such as pressure, friction and heat transfer characteristics along the concave surface. In this regard, both non-swirling and swirling jets are considered in the range (S = 0 – 0.72) for a Reynolds number equals to 11,000 at various dimensionless nozzle-to-impingement surface distances (4.5 ≤ H/D ≤ 7.5). The Reynolds-averaged momentum and energy equations are solved together, with turbulence described by a two-equation turbulence model, such as the k-ϵ model. The simulation data is first compared with the literature for non-swirling jets on curved surface and the data agrees with convincing accuracy. The results of this study show the effects of the surface characteristics of non-swirling and swirling jets significantly depend on both the swirl effect and the impingement distance.
Damage Detection by Applying Three-Dimensional Source Location of Acoustic Emission Technique
Abstract
Damage evaluation has become the recent event of research in conducting mechanical maintenance evaluation of engineering structures. Acoustic emission (AE) technique is regarded an invaluable nondestructive technique (NDT) tool in structural health assessment, especially in a dynamic mode. Source location routines are practicable in AE monitoring to recognize the existence of damage as well as damage mechanisms. Hsu-Nielsen (H-N) method has been used as a simulated source for AE source location applications. Time of arrival (TOA) is the basic phenomenon for the damage evaluation in the present technique. This paper presents an experimental validation of three-dimensional (3D) AE source location using time difference of arrival (TDOA) measurements from multiple sensor locations. At least four sensors are necessary for a 3D source location. However, in the present experiment, six sensors have been used to get a robust source location. Six piezoelectric sensors (model R15α with a frequency range 50-200 kHz), six preamplifiers (model 2/4/6), and an eight-channel AE acquisition board featured with AEwin software of Physical Acoustics Corporation have been used for data collection. 3D source location method has been applied to an iron specimen, and the evaluation output of proposed investigation has clarified in the present document.
Leaching Behavior of Chromium from Tannery Sludge under Aerobic Condition
Abstract
Tannery solid waste management has become a great challenge for the survival of the leather industry in Bangladesh. The solid waste ‘Tannery sludge’ is the result of the physicochemical and biological treatment of the discharged liquid wastes through the effluent treatment plant (ETP). The tannery sludge contains heavy metals especially a huge amount of chromium. A trace level of trivalent chromium is essential for certain metabolic functions in the human body. The high concentration of chromium is toxic to human health. In this study, the leaching behavior of chromium was investigated from the tannery sludge using different extractants: rainwater, agricultural fertilizers, and ethylenediamine tetraacetic acid (EDTA) under aerobic conditions. The chromium in the selected tannery sludge was 99.8 mg/kg. About 4 (four) g dried tannery sludge was mixed with 50 mL extractant and the air was purged through an air pump. After a preselected time interval, the suspension was filtered through the filter paper and chromium in the leachate was quantified by the atomic absorption spectroscopy (AAS). Results indicate that rainwater was extracted more chromium than distilled water. The agricultural fertilizers have no significant effect on leach chromium from the tannery sludge. The EDTA could extract more chromium from the tannery sludge among the used extractants. Before dumping the tannery sludge more suitable technique e.g., phytoremediation could be an alternative option to recover the chromium.
Effect of Iron (III) Oxide Nanoparticles without Sonication on Properties of High Viscous Bentonite Water Base Mud
Abstract
Fluid invasion into the near-wellbore formation for bentonite treated spud mud is a common obstacle during the drilling operation, which increases non-productive time (NPT) and cost. To address this impediment, researchers recently introduced nanoparticles (NPs) base fluid, since these particles prove their advantage in different stages of petroleum exploration and recovery. Most of the researchers claimed that nanoparticles require a sonication before the inclusion of it into the mud system. However, the sonication of NPs at the field level is not so easy to implement. In this article, in-house prepared iron (III) oxide (Fe2O3) NPs without sonication is used in high viscous bentonite (HVB) water-base mud (WBM) to assess the effect of nanoparticles on the characteristics of drilling fluid. The experimental analysis shows that NPs reduces the fluid loss compared to bentonite base mud at all concentrations. At NPs concentration of 0.5 weight (wt)% a 10.72% reduction in the API low pressure low temperature (LPLT) filter volume is obtained. While at 3.0 wt% the plastic viscosity (PV), 10s, and 10min gel strength are enhanced by 43.75%, 37.50%, and 33.33%, respectively. The yield point (YP) is also enhanced by 20% at an optimal concentration of 0.5 wt%, that reflects a better cutting transport capacity of drilling mud.
CFD Analysis of Natural Convection in a Triangular Cavity Filled with Nanofluid Having a Rectangular Heat Source at the Bottom
Abstract
This CFD analysis explores the consequences of heat transfer by the process of free convection heat transfer inside a triangular cavity, which has an oblong heat source at the bottom. The entire cavity has been filled with nanofluid. The surfaces adjacent to the heat source have been assumed as an adiabatic wall. The two other faces of the triangle are treated as cold faces while maintaining the constant room temperature. In this investigation, two different types of nanofluid, Al2O3-water, and Cu-water have been used. This computational study has been carried out for Rayleigh numbers within the range of 103 ≤ Ra ≤ 107 and fraction of solid nanoparticle that ranges within 0.0 ≤ φ ≤0.1. The impact of parameters such as volume fraction of Al2O3 and Cu nanoparticles in the water, heat source temperature & variation of Rayleigh number has been studied. Results exhibit that the average heat transfer rises with the increment of Rayleigh number. Besides, the effects of Rayleigh number in terms of avg. Nusselt number, isotherm lines, and stream function lines have been studied. The consequences show that the average heat transfer rate rises simultaneously with the volume fraction of particles. On the other hand, the average Nusselt number decreases instead. Differences between heat transfer rates among these two nanofluids have also been concluded.
Municipal Solid Waste Management: Scopes, Challenges of Sustainability and Treatments in Rajshahi City, Bangladesh
Abstract
The world is facing an enormous waste management problem nowadays. Municipal solid waste is one kind of a severe environmental threat and amiable concern globally. Adverse environmental outcomes from undeserving waste management can be frequently noticed in developing countries like Bangladesh. Turning MSW (Municipal Solid Waste) into energy would save more valuable fuels and enhance the environment by altering the quantity of waste to be disposed of and preserve energy and natural resources. The paper focuses on the waste to electricity production from the municipal solid wastes in the Rajshahi city of Bangladesh. A vast amount of solid waste is discarded in Rajshahi city, affecting habitat contamination and health endanger. The report suggests that MSW incineration can be a possible WTE (Waste to Energy) green power generation plan in RCC (Rajshahi City Corporation). Incineration is a useful technique for reducing the quantity and weight of solid waste, though it's a greenhouse gas supply. In modern incineration plants, the waste is burned within an adequately designed chamber below terribly rigorously controlled conditions. To prevent the release of organic compounds, air/fuel blending and temperature must be carefully regulated and "quench" areas in the oven avoided. This paper proposes incineration heat generated at a combined heat and power station and ash for construction and deposit. The pretreated MSW for fuel is expected to have a typical heating value of 1450 kcal/kg during a WTE plant.
Abstract
Piezoelectric materials have great influence on the development of smart structures because of its high functionality. Piezoelectric materials are widely used to make sensors and transducers as a result of their inherent straight and opposite piezoelectric effects developed between mechanical and electric deformation. In this paper the singular stress field and electric displacement distribution near the vertex along interface edge of piezoelectirc bonded joints is analyzed. Abaqus FEA software is used for stress singularity field analysis of piezoelectric dissimilar material joints. From the numerical result, it is obtained that displacement, electric potential, stress and electric displacement development near the vertex and interface edge is the maximum for model slant 75° and the minimum for model slant 45°.
Abstract
Worldwide the renewable energy demand has risen sharply over the past decades due to its environmental benefits compared to conventional fossil fuel power generation. The ocean is a vast source of renewable energy i.e. tidal energy, wave energy, wind, and ocean thermal energy. In this research, a model for extracting ocean wave energy using a piezo-electric device is considered. Piezoelectric materials when pressed, the atomic structure inside the materials change which cause a formation of dipole moment. This formation produces change in voltage differences across the piezoelectric materials. These piezo materials hold many potentials for renewable energy generation by reducing the consumption of oil and gas energy because of having the capability to generate electricity from renewable sources. The objective of this research is to explore relationships between the ocean wave and piezo material; for example, the relationship between significant wave height and amount of energy generated by the piezoelectric device. A model has been developed to study the relationships and prospects. Some interesting results have been produced which indicate the future potential of using this procedure in Bangladesh and around the world as well. Further developments are also recommended as a guide for future research.
Design, Construction and Performance Test of an Autonomous Low-Cost Pick and Place Robot Based on Color Detection
Abstract
Pick and place robots are regularly utilized in assembling but at the same time are utilized in applications like packaging, receptacle picking, and inspection. The essential advantages of pick and place robots are speed and consistency. In this work, a low-cost pick and place robot based on color detection is designed and constructed which is small in size and lightweight, making them perfect for use in applications where space is restricted. This pick and place robot assists with increasing output, helping with the picking and packaging processes in warehouse settings based on color detection of the object. The robot aims to detect products or goods of different colors, pick those items of products and place them in different predefined places according to the color. The robot will follow a line to pick and place the products which makes the robot more efficient. TCS 3200 color sensor is used for detecting the color of the object and TCRT 5000 IR sensor Array8 is used for detecting lines. Micro metal gear DC motor and L298N motor driver is used for driving the main motors. For constructing the gripper to pick, hold and place the object MG 995 servo motor is used. Arduino Mega 2560 microcontroller is used for controlling the whole system. The robot is tested in the Heat Engine Laboratory, KUET and it performed satisfactorily. The robot picks the item utilizing its gripper and afterward puts it at a specified location based on color following the line. In this paper, the pick and place system based on color detection is depicted in detail while featuring the design principles for the warehouse settings, including the structure rule for the gripper and other electrical and mechanical parts. Also, various experiments to evaluate the performance of the robot are presented and shown that the robot is competent enough to accomplish the specific tasks in warehouse settings, for example, picking an objective thing from a location, grasping the objects, and performing pick and place tasks following the line. The limitation of this robot is that it is only capable of handling only cubic shape products of a limited weight and size range because of a very simple gripping mechanism.
Conjugate Heat Transfer Analysis of Different CPU Cooling Processes using Computational Fluid Dynamics
Abstract
In the last few decades, a significant amount of technological advancements had occurred in computer systems. Such advancements primarily focused on performance increases and capabilities of the CPUs, which results in development of high heat fluxes and temperature. High temperature can damage the electrical components; therefore, cooling systems are necessary to design to optimize performance. Modern CPUs use air-cooling systems to regulate the temperature. However, the air-cooling system is not the most efficient heat dissipation system available and it also faces some problems due to space limitations. Nowadays high-performance liquid cooling systems imperative of modern technologies are widely being used in the CPU cooling process. In this regard, a comparative investigation is performed using finite volume based numerical simulation for conjugate heat transfer analysis of the CPU cooling system using both air and liquid cooling processes. For liquid cooling, water and nanofluids are used. Nanofluids are currently being a solution for more efficient heat transfer. In this study, CuO-Water nanofluid and Al2O3-Water nanofluid both with volume fraction of 0.5% and 2.0% are used as coolants. Results show that for the maximum flow rate, the maximum temperature difference was around 0.22K between water and 2% CuO-Water nanofluid. For the same mass flow rate, water has the heat transfer coefficient 1758.936 W/m2K and 2% Al2O3-water nanofluid has 1804.039 W/m2K. Heat transfer coefficient for 2% CuO-Water nanofluid is 1818.093 W/m2K for a certain Reynolds number. The thermal resistance of 0.5% CuO-Water is 1.54%, 0.5% Al2O3-water nanofluid is 0.7% and 2% Al2O3-water nanofluid is 2.75% less than water. Therefore, the results show that, nanofluid coolant performed better than the conventional air cooling in terms of improving the heat conductivity. It was also found that increasing the volume concentration resulted in better heat transfer characteristics. The numerical results are found to be encouraging and provide a future scope for designing a better nanofluid based cooling system for CPUs.
Abstract
Despite the advances in robotics and its wide-spreading applications, interior wall painting or mechanical parts painting with the irregular surface has shared little in scientific research. However, it has a lot of applications in the automotive, construction, shipbuilding, and production industries. Therefore, this research presents the development and implementation of a spray-painting robot to print or coat on regular flat surfaces and irregular curved surfaces within a short time and at a low cost. A three-dimensional (3 DOF) cartesian robot is designed to solve the purpose accordingly. A sonar sensor is installed in the end effector of the robot to track the shape of the surface and keep a constant distance between the nozzle and the job surface. Three gear motors are used to control the 3 DOF cartesian robot that is controlled by Arduino. The spray nozzle can move in the workspace of the x-y-z cartesian coordinate space. Two chain-sprocket systems are used for the movement of the spray nozzle along the x and y axes; and a rack and pinion mechanism guides the motion of the nozzle on the z-axis. To maintain the user-defined certain distance between the nozzle and work surface, it can adjust up to 3 cm irregularity along the z-axis concerning the x-y plane. The experimental results demonstrate that the robot can move in the x and y directions smoothly and it can follow the surface track accordingly. Besides, it may offer the chance of minimizing or eliminating human exposure to difficult to reach the surface and unsafe and unhygienic environments.
CFD Analysis of Flow Characteristics over Air-Propellers Used in a VTOL AquaUAV
Abstract
The amphibious (aquatic-aerial) vertical take-off and landing (VTOL) unmanned aerial vehicle simply known as (AquaUAV), a type of aircraft that can travel both in the air and in the underwater, has been seen as a new development to expand UAV's application scenario. It has wide application in the civil and military field, so many institutions have focused on the development of such a vehicle. Achieving a fully operational vehicle capable of aerial and underwater movement is a major challenge due to air-water travel and its stability. As compared to other Amphibious Vehicle designs, a single set of aerial rotors and propellers are used in both air and underwater which will reduce cost, weight and complexity for air to water travel. The aim of the present work is to model a single-layer VTOL AquaUAV and to investigate the fluid flow characteristics for the flow over the air-propellers used in the AquaUAV in air and water domain and to determine the efficient operating RPM for the AquaUAV. In this regard, a comparative investigation is performed using finite volume based CFD simulation to analyze the flow characteristics both in air and water domain. A propeller of 254 mm diameter with five different pitch configurations were tested both in air and water. Thrust forces along with pressure, velocity distributions were determined numerically and plotted to show the feasibility of using the air-propeller in a single-layer AquaUAV model. Numerical results show that the AquaUAV performs efficiently in air near the 4000 RPM range and underwater the efficient RPM is near 300. These results explore a new cross-domain modeling perspective and further improvement in the performance of aquatic-aerial vehicles.
Removal of Dye from Tannery Effluent using Date Palm (Phoenix dactylifera L.) Leaf as Bio-adsorbent
Abstract
In this study, the Date palm leaf (DPL) was explored as a low-cost bio-adsorbent for the treatment of dye loaded tannery effluent. The adsorption parameters viz. pH, adsorbent dosage, contact time and initial dye concentration were examined by batch experiment to determine the optimum adsorption condition. Standard NaOH solution was used for the surface modification of raw DPL. The morphological and chemical nature of the prepared adsorbent was studied by microscopic and spectral analysis respectively. The physicochemical parameters of the collected and treated dye effluent samples were investigated to evaluate the adsorption efficiency. Adsorption kinetics and mechanisms were illustrated with respect to various chemical reaction and isotherm models. The test results proved that the operating parameters, like pH (2), adsorbent dosage (3g/L), contact time (6h) and initial dye concentration (350ppm) were found optimum for maximum dye removal (63.23%) at ambient temperature. The value of regression coefficient (R2) was 0.997 and 0.999 for Langmuir and Freundlich isotherm model respectively, denoted the adsorption process. The Freundlich isotherm model best fitted the adsorption mechanism. The sorption kinetics was interpreted by pseudo-second-order reaction, which was thermodynamically exothermic and spontaneous at any temperature. Significant changes were observed in the physicochemical parameters of the dye effluent after treatment and the values were reduced closely to the permissible limit set by Department of Environment (DoE), except the pH. It was concluded that the application of Date palm leaf could be a cost-effective and efficient bio-adsorbent for the removal of dye and other pollutants from hazardous tannery effluents.
A Review Based Proposal on the Use of 4D Printing Smart Materials for Automobile Light Cover through Process Structure Performance Linkage with A Sustainable High Throughput Material Development Technique
Abstract
A lucrative light on the front or tail of a car is the first design feature that catches the potential customer's eye. Despite taking several measures, a cloudy or foggy light cover is quite familiar with the lights' present elements, whether it is a headlight, foglight, rear light, or tail light. This article proposes the high throughput material development of automobile light cover with 4D printing smart materials. After using conventional 3D printing technology such as fused deposition modelling (FDM), stereolithography (SLA), or selective laser sintering (SLS), these self-programmable smart material can change their shape autonomously. Multi-material 4D printing (time as the fourth dimension) utilizes additive manufacturing techniques to fabricate stimulus-responsive ingredients that can actively adjust their properties when subjected to appropriate stimuli like stress, humidity, temperature or solvents, as well as sunlight or pH. This paper illustrates that these 4D printable materials can be a better substitute for traditionally used light cover material polycarbonate, with various mechanical properties like superior transmitivity, opacity, impact resistance with the potential to extend design space beyond integrated geometries. This work discusses the required property combination with Ashby map and delivers some candidate 4D printable multi-material for the automobile light cover. The validation of the material selection is given through Process Structure-Property Combination linkage (PSP linkage) with a high throughput materials development technique of sustainable engineering. Finally, new promenades for the advancement of multi-material 4D printed light covers are proposed, reflecting current paucities and future opportunities for addition by additive manufacturing in the automobile industry.
Performance Improvement of Solar Photovoltaic Panel using Smart Water Cooling Technology
Abstract
Solar PV panel generates electricity by receiving irradiance from the sun. The amount of electricity generated by a solar panel mainly depends on the intensity of the sunlight and the materials of solar panel. The higher intensity of sunlight, the higher amount of electricity is generated. But with the increasing amount of intensity of sunlight, the surface temperature of the PV panel is also increased. Along with the duration and intensity of sunlight, temperature has also great effect on the efficiency of PV panel. The output of the photovoltaic panel is significantly reduced by the increased amount of temperature above optimal temperature of solar panel. This problem can be solved by using microcontroller based smart water cooling system which decreases the temperature of the PV panel. This decrease in temperature enhances the overall output of the PV panel. By observing the experimental results obtained from solar panel with smart water cooling system and without cooling system, significant improvement in efficiency has been found. The main motive of this work is to maintain the optimum temperature of the PV panel as it gives the best output power at optimum temperature and design a microcontroller base smart controlling system.
Abstract
The focus of this paper is on the design and fabrication of a dynamic testing machine capable of generating and testing the fatigue loading created on a steel-based specimen. The primary aim of this work is to adopt a simple design procedure followed by the fabrication with locally available cost-effective materials to enhance the lab facility. A mechanism based on ‘four-points-bending’ and simple torque balance was suggested out of which both static and dynamic fatigue loading were possible to generate. As a dynamic load generating device, a constant frequency drive motor was employed and then transferred to the specimen held by four rollers under compression. Though it was designed and fabricated based on steel specimens only, it is compatible with other materials also. The machine is also capable of testing the fatigue life cycle of different materials. Finally, a fast design and fabrication process has resulted in a dynamic fatigue testing machine at a lower cost of about 14000 BDT. As a future study, the machine is subjected to frequent testing and capability enhancement.
Abstract
The main objective of this research is to develop a conceptual model for transportation network considering the supply chain constraints. Theory of Constraints (TOC) is a decision-making paradigm that enables focused improvement of a system by thoroughly examining the process to identify the system constraints. These constraints pave the way of finding the focal point of development. The research is focused on the supply chain of a renowned company named Abdul Monem Carbonated Beverage Ltd. in Bangladesh for validating the developed model. At first phase of the study Eli's Five Focusing Steps and Evaporating Cloud Diagram are employed to identify the constraints. Upon developing the constraints for the supply chain being studied, Thinking Process tool has been adopted to propose the conceptual model. This research revealed the main constraint of the studied supply chain is transportation cost. It has also significant impact on supply chain logistics. Finally, a significant constraint mitigation methodology has been proposed which optimized supply chain transportation cost between manufacturer and distributor. The existing transportation network and modes are modified to get rid of unnecessary material handling and storage. The suggested model can reduce the material handling by 20% which in term can significantly alter the current transportation costs.
Design and Implementation of Smart Home Energy Management System Based on IoT
Abstract
An excellent amount of energy is wasted because of the dearth of smart management systems in home and office. Researchers are attempting to reduce the energy waste in many ways. The main target is added to avoid these varieties loss using a IoT base smart controlling system in home and office which has controlled light, fan, air-conditioner, and other electronic devices. So that introducing a new smart controller. This proposed project will be given priority in controlling during this stage to control electric device in home or office by daily companion of smartphone by android application at the identical time. The proposed system is to possible see the important time data of energy consumption for each device which can mentally force us to prevent wasting in a fun way. This controlling network is the global network once outside home so we'll be able to control the device from anywhere within the world but after receiving the communication network is that the local hotspot network. So don’t need the internet. Next, include an automation algorithm to the system (where light and fan will off or on with strength, temperature & humidity) which is able to make a decision whether a tool will on or off by using different quiet sensors. This may make it a lot easier to cut back the waste and smart control of electric device. Finally, going to develop a synthetic intelligence algorithm in the system where every data of energy consumption will be stored in an excel sheet. End of the month we will see a summary of energy usage information that may not only help us to automate home but also give us the prediction of energy usages.
Numerical Analysis of Recoverable Negative Stiffness Smart Structures for Energy Absorption in Shock Isolation
Abstract
The recently developed Negative Stiffness Honeycomb (NSH) structures have drawn tremendous interest in the field of energy absorption and shock isolation. The smart NSH structures have the advantage of being reused multiple times, where the conventional energy absorption techniques involve permanent deformation of the material via linear or nonlinear buckling or failure mode to absorb energy. In this study, the force-displacement characteristics of NSH structure with different materials has been investigated using Finite Element Method Based Software. A comprehensive investigation was undertaken to analyze the performance of the structure as energy absorbers in displacement-controlled loading condition. From the obtained results it was observed that the NSH structure shows good energy absorption without crushing. The energy absorption characteristics were analyzed for different flexible materials commonly used in additive manufacturing. Since the structure is recoverable after each unloading, with required specific energy absorption, these structures can be used for shock isolation in sensitive structures such as small containers, packaging, small shock absorbers etc.
Investigation on the Performance of Self-Cleaning Activity for TiO2 Treated Textile Fabrics and Laundry Effect on Their Durability
Abstract
In this study TiO2 was used as a coating compound to impart self-cleaning capability of textile fabrics and analyzed its absorbency and water vapor comfort ability of treated fabrics at several times washing . TiO2 solution of 1gm/100ml and 2gm/100ml were prepared with the binder and mixture was stirred at the sonicator for 30 min and applied by ossila spin coater on the single jersey knitted (cotton, Polyester-Cotton blend(65/35) and 5% grey Mélange) and woven ( 100% cotton and polyester)fabrics .The self cleaning ability of different fabrics were visually assessed after exposing under sunlight about 20hrs and also analyzed these samples appearance after sunlight exposure by value index of CIE L*A*B* color space in reflectance spectrophotometer The sample were prepared in consideration with different wash. The absorbency and water vapor permeability of treated samples were determined with respect to different wash. We have found that the self-cleaning ability of the fabric was convenient at the concentration 1gm/100 ml and it was appropriate for 100% cotton fabric only. With the increase of TiO2 concentration the absorbency i.e spray rating grade decreased except for the fact Polyester woven fabric. The breathability is remarkably well even in the increased of concentration of TiO2 and under different times of wash.
CFD Study on Aerodynamic Characteristics of a NACA 0012 Airfoil With and Without Flap
Abstract
This paper concerns on the aerodynamic characteristic study of a 2D NACA 0012 airfoil with and without flap. Here in this research a NACA 0012 airfoil geometry without flap is generated with ANSYS DesignModeler Geometry using airfoil tool. The solver setup and solution is validated for 0ᴼ, 10ᴼ, 15ᴼ angles of attack comparing with 2D NACA 0012 Airfoil Validation Case of NASA Langley Research Center’s Turbulence Modeling Resource. Then an airfoil is generated with plain flaps with various flap angles (4ᴼ, 8ᴼ, 12ᴼ, 16ᴼ, 20ᴼ). Different angles of attack are considered to compare the cases of flapped and no flapped airfoils. The aerodynamic behavior of both cases are compared in this paper. For this paper, Spalart-Allmaras turbulence model and an airfoil with chord length of 1m is used.
Abstract
This paper presents the design, simulation, and workspace analysis of a 5 DOF multi-purpose robotic manipulator. This manipulator is specially developed for a Mars Rover and the tasks to be executed by using this manipulator are screw tightening, pressing a key on the keyboard, weight carrying, etc. To solve the kinematics of this manipulator, Denavit Hartenberg (DH) method is used; and to obtain the desired position and orientation of end-effector, inverse kinematics model is used. After solving the equations generated from the Forward Kinematics model, the Inverse Kinematics model is implemented, which provides the rotation and orientation of each link of the manipulator. The physical structure of the manipulator is constructed with steel and aluminum plates of different thicknesses. The position and orientation of the end effector is controlled by using a microcontroller based on the parameters computed from the kinematic models. Motion of the links is operated by using DC gear motors and linear actuators. The microcontroller can be controlled remotely by the user, thus the manipulator. The kinematic models are simulated by Python programming language, which simulates the position and orientation of the end effector in the 3D coordinate system. From the simulation results, the workspace volume, minimum and maximum distance of the end effector from the base point are calculated. All the kinematics model and simulation process presented in this work is also applicable for a similar type of manipulator having different types of variables.
Moisture Dependent Rheological Properties Measurement of Porous Materials during Drying
Abstract
Drying is the most common food preservation method and it is practiced in both industry and household level applications. It increases the shelf life of plant-based food materials by removing water from high-moisture food. Significant changes takes place on the quality and nutrition of plant-based food materials due to the structural modification during the course of drying. Material properties including rheological properties and drying conditions are the main factors are responsible in microstructural changes of porous materials during drying; which eventually affect the dried food quality. However, limited study has been conducted to investigate the change of rheological properties of plant-based material during drying and its relationship with the change of moisture content. In this study, cylindrical shape potato samples having diameter and height of 25 mm and 12 mm respectively have been taken for the targeted observation. Convective dryer has been used to remove the moisture content from the sample. A mechanical testing machine has been used in order to compress the sample and a real time load measuring and data logging system was used to measure the developed stress for unit deformation. From this study, moisture content significantly affect rheological properties of porous plant-based food materials. At the early stage of drying, modulus of elasticity decrease from 0.3 MPa to 0.2 MPa with the decrease of moisture content from 85% to 81% wet basis. This result would help to design, and manufacturing of sustainable drying system for high-quality dried foods.
Comparison of Vibration Analysis among NACA Airfoil Wings Based on Natural Frequencies
Abstract
In modern aircraft, wings are considered one of the main sources of vibration and noise during the flight. To mitigate this problem, aircraft wing design becomes crucial which largely depends on the selection of airfoil profile and material. Among different airfoil profiles, the NACA series is widely used recently. In this paper, vibration analysis of different NACA series airfoil is performed theoretically using the Euler-Bernoulli beam theory considering the model as a cantilever beam and numerically to determine the natural frequencies and mode shapes of them and finally make a comparison among them based on those determining parameters for NACA 4412, NACA 16-015, and NACA 633-418. Numerical analysis has been performed by ANSYS to determine mode shapes and natural frequencies. The first six mode shapes were extracted. The comparison of natural frequencies among the different NACA series has been shown in this paper.
A Method of Style Convertible Footwear Construction by Replaceable Upper
Abstract
The traditional footwear uses stitch or adhesive bond to fix the upper with the bottom part. But permanently fixation makes several problems in shoe maintenance. The objectives of this study were to develop a shoe construction method where style and aesthetic look of shoe can be easily changed and to provide better cleaning facilities inside of the shoe. In this study, one pair of derby and another pair of oxford shoe with removable upper were designed and developed. In this construction, strips of Velcro and snap buttons were used along the feather edge of the shoe to attach the upper and bottom firmly. The replacement of the upper was possible through this construction. Several tests like strength analysis, wear trial and material consumption were carried out to ensure good functionality, comfort and efficient material consumption of the developed footwear. The average breaking load of the join along the lasting edge of the shoe was found to be 106 N by ASTM D 1683 method that was higher than the value of the control sample. Material consumption of derby shoe upper was compared by 00 of Russ and Small method (RSM) where the developed construction method consumed almost 125cm2 more leather compared to the conventional cemented method. But the material consumption reduces comparatively by using more replaceable uppers on the same bottom. 14 days with each day 30 minutes wear trial was also carried out and the wearer rate 1.67 in pain rating scale (1 to 10) which indicates that the wearer felt comfort by wearing these shoes. So, this construction method may be a solution for particular people who want to change their shoe style frequently and it may also solve several difficulties related to shoe maintenance.
Abstract
Copper (Cu) materials are widely used and with the rapid technological advancement the use of Cu is getting continuous rising demands. As such, old Cu is popular to reuse in many components, but sometimes tin (Sn) is doped in to Cu, which may alter its mechanical properties including friction and wear. In this context, the present paper is reporting the sliding wear behavior of Sn-doped Cu under dry, fresh water (FW) and sea water (SW) environments. Here, friction and wear tests are conducted using a pin-on-disk type of tribometer. The normal load of 20N is applied for varied period up to 90 minutes to cover up the sliding distance of 2772 m at a speed of 0.513 ms-1. The present investigation shows that inclusion of little amount of Sn in Cu has significant role to play on micro-hardness and wear behavior. As such, micro-hardness, wear rate and coefficient of friction have been found to be improved. ‘The harder the wear resistant’ has been matched with the present results. The results also illustrate the effect of environmental conditions during sliding operations causing the wear rate and frictional coefficient to be varied to a significant level. The wear properties especially in FW and SW environments are related to the formation of patina oxidation film and its onward breaking up. Moreover, wear rates have also been observed to be affected by the lubricating effect of FW and SW. The surfaces observed before and after sliding wear have demonstrated the combined outcome of adhesive as well as abrasive wear. The intense grooves are observed parallel to the sliding direction on the dry sliding worn surface whereas wear tracks are found relatively smooth for sliding in FW and SW environments.
Time Befitting Supply Chain for the Future of Bangladesh Apparel Industry by Aligning Industry 4.0
Abstract
The ready-made garment is the largest industry in Bangladesh, where the economy is growing depending on it. However, the supply chain structure of this industry is volatile in many cases. The traditional supply chain strategies may fall concerning the competitors and are facing alarming challenges. High lead time, low responsiveness, the ambiguity of information, high cost, uncertain demand forecasting, and lack of a proper industrial ecosystem are the barriers to Bangladesh's RMG supply chain structure. These problems are impeding the continuous growth of the industry. However, the fourth industrial revolution or Industry 4.0 is the latest modern industries' transformation with smart technologies. Integration of Industry 4.0 in traditional supply chain management provides additional benefits like high responsiveness, real-time data monitoring, forecasting, cost-effectiveness, reduction of the bullwhip effect, and making a good ecosystem worldwide. Nevertheless, the digitalized supply chain and Industry 4.0 can collaborate all the players and stakeholders in one platform to increase responsiveness with optimum cost. In this study, we considered three approaches to collaborate Industry 4.0 with the traditional supply chain of Bangladesh's ready-made garments industry to increase the responsiveness to cost efficiency. The strategies were based on the leagile supply chain, aggregate demand forecasting, and industrial ecosystem.
Fabrication and Performance Test of a Cold Model of Fire Tube with Fixed Heating Pyrolysis System
Abstract
Among various methods of thermochemical conversion of organic solid wastes into bio-crude, a fixed bed pyrolysis system has attained much attention. In this study, one cylindrical cold model fixed bed reactor has been constructed from a Plexi glass pipe. A gas distributor of Plexiglass sheet with 218 holes has been fabricated. In this study, the required air pressure and flow were measured to escape the pyrolytic char from the cylindrical reactor. The actual pyrolytic char makes the Plexiglass reactor and the laboratory dirty. Thus, a pulls husk of size range 3-5mm have been used as bed material. The working fluid was supplied from an air compressor. The airflow rate and char ejection pressure for the beds of different heights were measured. From the experimental results, a mathematical model has been developed. The results obtained by the cylindrical model are compared with those from the mathematical model.
An Experimental Study on Wheel Alignment and Shock Absorber Conditions for Fuel Performance Analysis of a Light Vehicle
Abstract
In this study, an EHCO PLUS- 2ZZ-GE-02 model light vehicle was used to analyze the fuel performance with the consideration of the effect of wheel alignment and shock absorber conditions. In the experimental setup, a computerized machine vision-based wheel alignment measuring system was used to detect the misalignment of the wheels and the fuel performance of the vehicle measured before and after wheel alignment. The analysis results reveal that fuel consumption depends on wheel alignment. Also, the wheel alignment has been greatly affected by shock absorber conditions. Through the experimental process, it is found that wheel misalignment under inflation pressure in the tire and improper shock absorber condition resulted in increasing the fuel consumption rate. However, the fuel consumption rate of the vehicle has significantly improved by adjusting the alignment of wheels.
A Water Level and Temperature Surveillance System Contingent on Automated PLC Controller
Abstract
Today, in numerous industrial and residential applications, an efficient water level and temperature surveillance system is a very essential requirement. Previously it was done under human supervision which was both unsafe and expensive. Many unpleasing occurrences happened because of the absence of sufficient regulation. The paper centers around the presentation of a PLC controlled system that is commensurately reliable and cost-effective. To supervise the entire system, an available assistant tool-type device, Siemens LOGO! PLC is utilized. Sensors of two distinct types are imposed; Float Switch (Bilge Sensor) and Resistance Temperature Detector (RTD). The float switches are used to track the water to the desired level. The RTD sensor of the PT-100 model is utilized for monitoring the temperature of the water to a required value. As output devices of the PLC, a regular water heater of 1000 watts and solenoid valves are used. To program this operation, a Ladder Diagram (LAD) network of LOGO! Soft software is used. With the help of the program, the PLC will operate thus controlling the input and output devices. This automatic system can impart proficiency in detecting water levels with temperature easily and securely. This sort of delicate operations controlled by PLC is very useful within the industries as well as in domestic territories.
Vibration-Based Fault Diagnosis of Spur Gear Operating under Constant Speed using Time Synchronous Averaging Method
Abstract
This paper presents a vibration-based fault diagnosis method for spur gear operating under constant speed. Vibration is the most usable signal obtained from any rotary machine, just using a simple accelerometer. As gear is one of the machines' most critical components, it is crucial to identify the problem early in damage propagation. But it is quite difficult to distinguish between a healthy signal and a faulty signal at an early stage in the time domain and even in the frequency domain. Time Synchronous Averaging Method (TSAM) can be the right solution for this problem. In this paper, a simulation-based approach has been proposed to gear fault identification purposes using the MATLAB platform. Alongside TSAM, a quantitative comparison of both healthy and faulty gear's statistical features has been presented in this paper. Due to rapid industrial growth, the early fault detection and reduction of production downtime have become a prime concern for maintenance engineers. The proposed method can be handy for them.
Design and Fabrication of Self-Weighted Material Handling (SWMH) Equipment
Abstract
In this study, a Self-Weighted Material Handling (SWMH) equipment is designed, constructed and evaluated its performance. Most of the material handling system using in industry is requires external energy or manpower to operate it. In this work, a spring operated SWMH system is developed and this system does not need external energy or manpower to operate which reduce the material handling cost as well as production cost. At first design of various mechanical parts, a details drawing is done using SOLIDWORKS software. All designed elements are fabricated and assembled for final SWMH system. After constructed the system, a performance test is performed in various loading condition. The performance test results show that maximum 75.5 kg weight is covered the about 4 m distance. The calculated and experimental results show the 1.92% error due to ignore the frictional loses during calculation.
Remaining Useful Life Prediction of a Motor Gear Test Rig using Autoencoder and Gated Recurrent Unit
Abstract
In this era of the smart world, it is of utmost importance to predict an upcoming scenario, particularly the failure of a system part in predictive maintenance. A significant term in condition monitoring is the Remaining Useful Life (RUL) of an element, which provides an indication of the time after which the element does not serve. It will result in a more effective way to minimize maintenance costs by forecasting the RUL of a system part with satisfactory accuracy. For forecasting the RUL of a motor gear test rig, this paper proposes a data-driven model. A dataset from the sensors detecting the vibration of the system's bearing in different health stages is fed to a Deep Neural Network (DNN) model, a combination of Autoencoder and Gated Recurrent Unit (GRU). For predicting RUL, the proposed model is faster because GRU consists of only two gates and requires less memory, whereas standard algorithms such as Long Short Term Memory (LSTM) consist of three gates and take more memory to operate on a more significant chain. The Autoencoder combination has made it unique and more effective as it compresses the input data to produce a smaller representation and can be rebuilt to the desired standard level. The model can also be handy for maintenance engineering as it demonstrates promising efficiency relative to conventional time series algorithms.
Computational Analysis of Multiple Non-Swirling and Swirling Impinging Air Jets
Abstract
The flow and heat transfer characteristics of multiple non-swirling and swirling impinging arrays of air jets have been numerically investigated. The air jets discharged from round orifices and perpendicularly impinge on a heated surface. On this array, total 25 nozzles are organized in inline arrangement, having nozzle to nozzle centerline spacing of 2D and nozzle orifice to heated impinging plate distance is fixed at H=2D (where D is the nozzle orifice diameter). Only a quarter portion of the model is constructed for computational analysis in order to save computational costing as the whole model is symmetric. That research is investigated for Reynolds number, Re = 11600 and swirl number, S = 0.74. Grid independence test is performed and a fine mesh consisting 890k nodes is found to be appropriate for this calculation. Calculations have been carried out by the applications of the SST k-ω turbulence models and performed on ANSYS v16.2. The jet flows are in downward direction and gravity is not considered during performing the simulation. Finally, comparisons are made between numerical results for different swirl number and conclusions drawn. This document also shows comparisons between numerical predictions with previously published literature about non-swirling jets. The results demonstrate that, the effects of higher swirl number ensure better industrial performances than non-swirl flows.
Numerical Analysis of Scale Effect on Performance of DU84-132 Airfoil for Small Wind Turbine Blade
Abstract
This paper presents a concise numerical investigation on DU84-132 airfoil based on a range of Reynolds numbers consistent with small wind turbines and low wind speed zones. It aims to find out the aerodynamic behavior of this airfoil under various wind speeds and angles of attack to ascertain the extent to which it is suitable for a small wind turbine blade. With the help of Qblade software, Panel code based numerical analysis shows that maximum glide ratio and stall point smoothly increases with the increase of Reynolds numbers. On the other hand, the design point and maximum lift coefficient decrease with the decrease of Reynolds numbers. Again, sensitivity to surface roughness on the performance of airfoil has been explored by forcing the boundary layer transition at 10% of the chord, which shows that it can be possible to avoid roughness effects by increasing the Reynolds number within the laminar limit. Finally, a comparative study with S2091 airfoil concludes that DU84-132 airfoil is suitable for a small wind turbine from the perspective of both blade performance ensured by maximum glide ratio and stability of energy production ensured by the smooth change of angle of attack. Still, there are a few limitations which can be eradicated by modification and redesign of the airfoil.
Abstract
Swarm robotics, as a segment of multi-robot systems, has the capability of coordinating multiple robots together to complete a complex task. The inspiration is predominated by the social instincts of insects which promote the cooperativeness of swarm robotics. In recent years, swarm robotics has advanced to its next level due to the advancements of artificial intelligence in this field. Several learning-based algorithms have been implemented on swarm robotics to address real-life problems in disaster management, transportation system, etc. These algorithms have shown promising performance towards solving various existing modeling and control problems in multi-robot systems. This paper delivers a preview of multiple researches that recently took place on learning-based swarm robotics. We provide a brief review and categorization of the existing works and their outcomes and identify some key future directions of this domain.
Thermal Stability Enhancement of Nylon-Jute Composite by Additions of Nanoparticles Made from Natural Sources
Abstract
Composites are wonderful materials in the sense of good combination of very useful engineering properties. In this regard, polymer composites have gained much more attention because of their light weight, low cost, ease of fabrication, corrosion resistance, good wear property, etc. For the development of polymer based green composites, the role of natural fibres is growing at an increasing rate in the field of engineering and technology. In this regard, jute fibre is a pioneer source of natural fibres. It is well known that thermal resistance of polymeric materials is very poor and that addition of jute fibre in nylon further degrades this property, which is a serious concern for the natural fibre reinforced polymer composites. This article reports the experimental results on the effect of locally produced river based nano silica sand and clay particles to enhance the thermal degradation temperature of the nylon-jute composite. At first, 90% nylon and 10% untreated chopped jute fibre reinforced composite was developed. In the next stage, 1% locally produced natural inorganic nano particles (either silica or clay) were added separately in the nylon-jute composite to make nano structured composites. All composites were then characterized by thermo-gravimetric analysis (TGA). Experimental results revealed that nano silica sand or clay particles could be a very good source for low cost reinforcement material to increase the thermal stability of polymeric materials.
Experimental Performance Investigation of a Solar Photovoltaic Thermal (PVT) Collector
Abstract
Photovoltaic Thermal (PVT) collector is a hybrid technology that produces both thermal and electrical energy simultaneously combining a photovoltaic (PV) cell and solar thermal collector. In this work, the performance of a PVT collector was investigated experimentally. A PVT collector was constructed by incorporating a heat exchanger in a PV cell. Electrical energy from the PVT collector was monitored by flowing cooling water in the heat exchanger. A small portion of solar radiation was transformed into electricity, but the unsettled portion was lost as heat that affected the PV cell's efficiency. Solar radiation intensity, inlet and outlet temperature of cooling water, surface temperature, voltage, and current of PV cell, was measured. The performance of the PVT collector was compared with a PV cell of the same configuration. Experimental results revealed that the output power of the PVT system is greater than that of the PV system and the average output power is approximately 15% higher compared to the PV system. Results also indicated that the surface temperature of the PVT system is 4-5°C lower than that of the PV system.
Computational Analysis of Horizontal Axis Wind Turbine Blade Profiles at Low Wind Speed
Abstract
To ensure the maximum energy efficiency and find the optimum operating conditions of a wind turbine, an analysis of the blade profile of a horizontal axis wind turbine was carried out. In this study, a wind turbine blade’s root and tip profiles were simulated to find the aerodynamic characteristics such as coefficient of lift (CL), coefficient of drag (CD), and sliding ratio (CL/CD) at different angle of attacks and wind speeds. A computational analysis of NREL’s S822 and S823 airfoils were performed to find the range of suitable operating angle of attack at low wind speed. The analysis showed that when the two-airfoil profiles were used in the same wind turbine blade, the operating angle of attack is preferable to lie between 6° to 8° for a wind velocity of 3, 4 and 5 m/s, respectively. S823 airfoil showed good aerodynamic characteristics compared to S822 airfoil. NREL’s S823 (Root) and S822 (Tip) airfoils can be used in a wind turbine having a blade length of 1 to 5 m to extract energy from wind.
Abstract
This paper presents the development of a pick and place articulated robot manipulator prototype. In some cases, human is liable to make error under stress or repetitive work; whereas the robot manipulator can provide precise and efficient performance if there is not much decision-making issue appears. This manipulator is designed and constructed to sort object based on their length. The design of the manipulator is done considering the stress on each link. The control system is embedded with microcontroller and manipulator mechanics. The microcontroller is used to render the activity when the sensor detects any presence of object in the work envelope of the manipulator. MATLAB had been used to simulate the work envelope of the manipulator and the trajectories it follows. The horizontal reach of the manipulator is 84 mm from the base up to which it can pick the object and place it. The manipulator can pick the sensed object through sensor and by following the joint angles, it places the object in the destination. It can place objects up to 15 cm length in one side and larger size in another side. The developed prototype of the manipulator can handle a little amount of weight (15g) but proper scaling to higher dimension may increase its lifting capacity.
Analysis of Thermal Hydraulics Behavior of Coolant through a Sub Channel in Fuel Assembly of a Pressurized Water Reactor (PWR)
Abstract
Nuclear power is the most promising energy resource to meet the future energy demand. Bangladesh has been reached to the new era of nuclear power generation by building Rooppor Nuclear Power Plant (RNPP). Computational fluid dynamics (CFD) is the most essential technique to measure different parameters for thermal hydraulics analysis inside the reactor. CFD methodology can be applied in investigating the detailed thermal–hydraulic characteristics of coolant through a sub channel within a fuel assembly. This paper represents the simulation of heat transfer and fluid flow in sub-channel of fuel assembly used in pressurized water reactors (PWR). Using a multiphysics software a model of sub-channel of PWR fuel assembly has been developed and different parameters such as temperature profile, velocity profile, isothermal contours and variation of Reynolds number have been analyzed as well. These CFD methodology is considered on steady-state condition inside a PWR fuel assembly.
Assessing Critical Factors Affecting the Mass Adoption of IoT in Bangladesh
Abstract
Internet of Things (IoT) is a system in which objects can exchange data among themselves by being interconnected with the help of the internet over a wireless connection without human intervention. IoT is a buzz word in the modern era. A developing country like Bangladesh may face different problems while trying to adopt IoT due to the lack of technological knowledge, underdeveloped infrastructure and deficiency of relevant resources. But to stay apace with the fast-growing world, Bangladesh should also cast aside existing systems and accept IoT with open arms. This research aims to find out the most important factors which might be responsible for IoT adoption in Bangladesh keeping in mind about its socio-economic conditions. Some hypotheses were formed to create a questionnaire for the survey. Indicator variables found from the survey were grouped into 5 (five) factors using Exploratory Factor Analysis (EFA). A measurement model was created based on the hypotheses formed previously. Structural Equation Modelling (SEM) technique was used to find out the estimates of different factors associated with IoT adoption. From the structural model, it was found that Affordability and Ability had the highest regression weight. This suggests that in developing countries like Bangladesh people give priority to products being affordable rather than thinking about its usefulness or the positive changes it would bring to society. Besides a huge portion of people are not highly educated because of which they have expressed concerns over their ability to use IoT devices efficiently and safely. So all these factors were incorporated in this study which explains its significance and relevance.
Comparison of Epithermal and Instrumental Neutron Activation Analysis for the Determination of Uranium and Other Elements in Soil Samples using BAEC TRIGA Reactor
Abstract
In this research, epithermal neutron activation analysis (ENAA) was implemented for the first time at 3 MW TRIGA research reactor of Bangladesh Atomic Energy Commission (BAEC) to determine Arsenic (As), Antimony (Sb), Samarium (Sm) and Uranium (U) in soil/sand samples and characteristically compared with instrumental neutron activation analysis (INAA) to find out advantageous features of ENAA over INAA. The ENAA detection limits (DL) were determined for the studied four elements (As, Sb, Sm and U) using standard reference materials (IAEA-Soil-7 and IAEA-SL-1) and compared with those of INAA. It is observed that DLs of As, Sb, Sm and U obtained by ENAA for SL-1 and Soil-7 are 17%, 42%, 28%, 25% and 29%, 25%, 31%, 35%, respectively lower than those obtained by INAA. The analytical sensitivities of those elements for SL-1 and Soil-7 are 31%, 9.0%, 75%, 28% and 25%, 11%, 15%, 48%, respectively higher than those obtained by INAA. Moreover, ENAA is the most effective if the Q0 values of the interested nuclides are greater than 10. The calculated Q0 values of As, Sb, Sm and U are 13.7, 20.3, 15.2 and 102, respectively. The findings from this research indicate that ENAA technique is better than INAA for the determination of trace amounts of As, Sb, Sm and U in soil samples using BAEC TRIGA Mark II research reactor. ENAA technique will be used for the determination of these elements, especially, U in soil/sand samples to find out potential U-mining areas in Bangladesh.
Design, Construction and Performance Testing of Passive Cooling System of a Building
Abstract
The rate of energy consumption is high in the current world. Day by day, energy consumption is increasing. On the other hand, the number of resources such as oil, coal, gas is decreasing. A large part of energy consumption occurs because of cooling and ventilation and it is because to provide thermal comfort. Nowadays, the building has a low ventilation system. Fans, air conditions are used to cool the building. By using the passive cooling system, the energy consumption of the buildings will be reduced. The thermal load will reduce. The thermal comfort will be increased. It not only improves the natural ventilation but also increases the insulation. The passive cooling system can be solar-powered. A solar chimney can be used to absorb heat from the sun. The solar chimney is black. As a result, it can act as a black body and it is a concentric shape. The metal sheet can be used to make the solar chimney. A passive evaporative cooler can be used to cool the air. The inlet air becomes cool when passes through it and the copper pipe will act as a heat exchanger. A layer of cork sheet can be used to provide more insulation to the building. As a result, the natural ventilation and insulation will increase. The passive model building temperature is compared with the ambient temperature and the ordinary room temperature. The passive model building gave 2°C to 3°C and 3°C to 4°C lower temperature from the ordinary reference model building and the ambient temperature. Keywords: Passive Cooling, Solar Chimney, Evaporative Cooler, Ventilation.
Abstract
A 3D printable design and it’s analysis for a myoelectric prosthetic arm was explored in this paper. The arm is electronically actuated and controlled by a user flexing and relaxing his/her biceps muscles. The bionic arm presented has the scope of being used by a person with no limbs or not having it from below the elbow. The main objective of this work was to make a cost effective prosthetic which was also sophisticated enough Normally such devices are mechanically actuated and therefore not as noticeably complicated as myoelectric devices are. The technology of 3D Printing is something that caused a new era of hope for physically challenged 3D printing does have its limitations but growth and development in the field will only lead to improvements over time. Low cost moderate strength materials for the body and parts available almost everywhere was used for the construction of it’s body to make it as affordable as possible. The electronics used were less, hence not so complicated to troubleshoot. The developed design showed promise as it could do many basic things having 5 DOFs.This study topic covers a broad range of engineering disciplines. The root of the system is an innovative mechanical design for a 3D printed prosthetic arm. Modern day electronic actuators, that is servo motors and circuitry using sensors animate the device and allow for sophisticated control schemes. It is hoped that this work will be of value to the future prosthetic manufacturing engineers of this subcontinent. The main objective of the research was fulfilled but due to the problems and shortcomings of availability and support community for the technologies used , seen in relatively underdeveloped countries some features of the arm were not achieved as expected but the project is nonetheless promising.
Investigation of Plastomer Effect on the Properties of Multilayer Cast Polypropylene for Food Packaging Film
Abstract
Cast polypropylene (CPP) multilayer films, manufactured by co-extrusion of polypropylene raw material were used in packaging of various products such as food, cloth, cosmetics and pharmaceutical. The nature of low crystallinity in PP structure during processing, the film brittleness results poor impact strength especially at lower temperature (below 0° C). Among CPP films, cast films can be plasticized to improve the impact resistance. This study aims to evaluate the effect of the addition of plastomer on physical and mechanical properties of multilayer CPP films with different thicknesses. Present work also includes characterization of CPP films by Scanning Electron Microscopy, X-ray Diffraction and Fourier Transform Infrared Spectroscopy. The impact strength of the film was determined through free-falling dart method. The tensile strength of CPP films has increased about 11.6 %~31.7 % with the presence of plastomer. In addition, the impact strength was improved by approximately 110 %, 90 % and 37 % for film thickness of 60 μm, 70 μm and 80 μm respectively. Along with a significant increase in the mechanical properties, a considerable improvement in the haze of CPP films with plastomer also been observed. Thus, CPP film that contains plastomer may have potential to replace certain applications of PE film in flexible packaging.
Numerical Investigation of Plate-fin Heat Exchanger with Wavy Channel and Wavy Vortex-generator Channel
Abstract
This paper aims to enhance the efficiency of the plate-fin heat exchanger with wavy plate fins (WPFs) and a passive heat transfer improvement technique, namely transverse vortex-generator. With the aim of enhancing efficiency in heat transfer, a new model of a wavy plate-fin channel, transversely mounted rectangular winged vortex-generator channel, is introduced and investigated by computational fluid dynamics (CFD) simulations. Comparative studies have been carried out among wavy plate-fin, wavy plate-fin with rectangular transversely mounted vortex-generator, and plain plate-fin, Reynolds number ranging from 285 to 1800 at laminar flow regime. The effect of different key parameters, including Colburn factor (j), pressure drop, and friction factor (f) along with Area goodness factor is investigated thoroughly with respect to the array length and Reynold number. The outcomes depict that values of f and j factor rise with the increment of pressure drop led by the peaks at WPFs and wings. Due to the effective blending of the streaming working fluid through the winglets, it is determined that the overall heat transfer efficiency of the winged WPFs is greater than that of the plain plate-fin and WPFs; on the other hand, Winged WPFs has a very high friction factor. At lower Reynold number, the results also depict, winged WPFs have a larger j factor value and larger area goodness factor value.
A Comprehensive Analysis of Bucket Wheel Conveyor for Lifting and Conveying Granular Materials
Abstract
In the modern world, it is of great importance to transfer materials from one place to another without the help of the workers and reduce the life threats. The objective of this research work is to construct a machine that can lift and convey granular materials without the help of manpower. Over and above, this machine is not only confined in transferring coals but also can be used in glass manufacturing industries, construction sites, foundry shops which will increase the company's profit. This was designed based on some assigned themes and also according to the steps of product design like Market Analysis by surveying, Quality Function Deployment(QFD), Functional Decomposition, Specification and Design Analysis, Material Selection Process, Manufacturing Process Selection, Cost Analysis. In Market Analysis a survey was performed to know the customer requirements. Ensuring the customer requirements and technical requirements a relation was made between these two requirements by QFD. Then the design of the machine was specified. In addition, the material and manufacturing processes were selected. Moreover, a cost analysis was done based on break-even analysis. Ensuring these factors, this analysis was able to reduce production time. A prototype of the machine was made to taste the overall production time based on the budget. From the cost analysis, it was found that the per-unit cost of the machine will be 21,146 BDT and the estimated profit will be 26,97,500 BDT if the sell is 600 units. As it is a prototype, it can convey materials 2.3 tons/hour. But with some modification & further development the capacity of this machine can be increased more. Also when the full scale industrial model is produced a whole new array of functions can be added to the machine. For bigger machine the capacity will increase 5 times more than 2.3 tons/hour as the power of motor will also increase.
Design and Implementation of Addressable Fire Detection and Alarm System in Ready-made Garments Sector of Bangladesh
Abstract
Fire accidents in the ready-made garments sector of Bangladesh have become an alarming issue in the recent era, hampering the safety of the garments workers. The source of the fire originates from electrical short circuits, storage of flammable materials, transformer explosion, etc. The dilatoriness in the fire detection system results in catastrophic mishaps. The conventional fire alarm detection process of our country cannot locate the exact fire origin on time causing fire hazards. The addressable fire alarm system resolves the problem by assigning a unique address to each detector to locate the exact position of the fire for further protection system. In this paper, an addressable fire alarm system is designed in ‘AutoCAD’ by following the NFPA (The National Fire Protection Association) rules for a garments factory of Bangladesh constituting of multi-detectors (heat/smoke), heat detectors, smoke detectors, sounder strobes, and manual call points, etc. The designed addressable fire alarm system sends the signal of the particularly addressed detector to the control panel for pinpointing the origin of the fire. This concept has not been implemented in ample garments factories of Bangladesh; thus, holding a major contribution indeed to ensure fire safety.
Nanoparticle Concentration and Ultrasonic Treatment Effects on Surface Tension of ZnO-water Nanofluids
Abstract
Applications of nanomaterials require thorough consideration of surface phenomena to understand in which ways nanomaterials differ from their conventional counterparts. Nanofluids attracted attention for potentially improved heating and cooling performance due to their enhanced thermal conductivity. Surface tension (ST) is another property that is highly worthy of research, as it reflects in bubble formation during phase change heat transfer, as well as in a variety of droplet-based applications. In this work, ST of ZnO-water (φ= 0.05–0.4 vol.%) nanofluids prepared via two-step method was investigated experimentally, dependent on direct ultrasonication amplitude (40% and 100%) and ultrasonication period (0.5-4 minutes). Results showed that ST of ZnO-water nanofluids depend on nanoparticle fraction and ultrasonication parameters in a non-monotonous fashion, such that optimum ultrasonication parameters were present maximizing or minimizing ST as the application necessitates. It is necessary to consider the effect of temperature of the liquid when interpreting ST of nanofluids after ultrasonication.
Investigation of Shoe Size and Toe Box Shape Variation Effect on Skeletal Alignment of Adult Foot
Abstract
Improper footwear has been attributed to poor fitting with discomfort, and resulting the ultimate major foot defects. Previous studies on footwear have investigated the effect of material composition, sole stiffness and thickness, heel height, motion etc. and minute amount is known regarding the effects of toe profile variation on forefoot. In consequence, the aim of this study is to investigate the impact of different toe shapes with different shoe sizes on foot bone alignment. An adult male as convenience subject with unknown foot difficulties was recruited for the study. After assessment of foot size and other associated demographic information, anteroposterior view of the participant’s foot was captured for each of the nine different footwear as well as barefoot condition. Data like hallux valgus angle (HVA), intermetatarsal angle (IMA), and hallux valgus interphalangeal angle (HVIPA) were collected from the radiographs and analyzed as well. Shoes with plain toe and smaller size provided the worst result with maximum deflection of HVA 157%, IMA 40%, and HVIPA 160% compared with barefoot condition. On the other hand, pointed toe with one size larger imparted the best result with minimum deflection of HVA 100%, IMA 13%, and HVIPA 20%. So, these results clearly indicated the significance of correct toe box room with the proper shoe size as well as fitting. Thus, footwear technologists should emphasize on ergonomic shoe design via using anthropometric measurements of human foot to enhance the comfort of product.
Abstract
Analysis of drag is a major concern in automotive sector based on the issues of fuel economy as well as CO2 discharge. Drag rate, which is mainly expressed by drag coefficient depends on several parameters. The parameters involved with diminishing drag are critical to designers of moving vehicles, aircrafts, ships and other structures. As the aerodynamic properties of a vehicle rely chiefly upon its shape, so the exterior shape of vehicle gets huge attention in planning a vehicle. So, the variation of drag with the adjustment in exterior shape of bus has got the priority in this work. Buses with their diverse mathematical measurements give distinctive stream qualities over the front and rear end of models. A total of six models have been designed to perform the numerical analysis. The width and height of the models are kept same, but the exterior shape in the rear and front end of the bus has been varied in each of the models. For different highway speed regulations, computational investigations have been carried out on the models using ANSYS Fluent 19.2 (Student Version). The results of the simulation are acquired in terms of coefficient of drag for different speeds of the bus. Then, the value of drag coefficient for different shaped models has been analyzed, which gives the outcome of the investigation as per improvement in shape.
Abstract
One of the significant challenges that manufacturing companies face today’s world is to sustain their production level for meeting their customer demand along with minimization of cost and ensuring quality to survive in the competitive market. This is particularly significant in Bangladesh, where many manufacturing companies are operating significantly below their potential capacity, or experiencing a high level of late-deliveries, due to problems with their current production scheduling and production management systems. This study attempts to apply the TPM strategy in a jute industry in Bangladesh to enhance their overall equipment effectiveness (OEE). Results show that OEE has improved from 64.97% to 69.50%, which is still very low compares the benchmark world class manufacturing OEE (85%). The company needs to work hard to improve their system machines and reduce the waste time.
Bending Behavior of Sandwich Structure Made of Aluminum Honeycomb Core and Steel Facing
Abstract
In this work the effect of face sheet thickness on the bending behavior of the aluminum honeycomb core sandwich structure was presented. The sandwich composites were fabricated using aluminum honeycomb core of cell size 10 mm with various steel facing thicknesses i.e. 0.2 mm, 0.64 mm and 0.71 mm. Three-point bend test was conducted to evaluate and analyze different bending properties such as peak load, bending strength, specific bending strength, shear stress, energy absorbed and specific energy absorption. Results show that all bending properties increased with increasing face sheet thickness except the specific properties. The specific bending strength and energy absorption were found to be the highest in the specimen with the thin face sheets. The failure initiation mechanism was found to be the debonding between the core and the face sheet. The thick face sheet showed more catastrophic debonding failure compared with the thin face sheet. The performance of the sandwich can be enhanced by improvement of the bonding between the core and the facings.
Novel Expanded Perlite Based Composite using Recycled Expanded Polystyrene for Building Material Applications
Abstract
The present investigation aims to develop a novel composite material using expanded perlite particles as filler and recycled Styrofoam as binder to attain properties like lightweight, sound and thermal insulation to be used for building interior walls and ceilings. The developed material is expected to not only serve as a cost effective solution for building insulation or energy saving but also to mitigate the environmental pollution due to the waste Styrofoam plastics. Composites with various densities are produced for the purpose of comparison with the available building materials currently being used all over the world for building energy saving. Manufactured composites are characterized for compressive properties to assess the usability in the intended purpose. The composites are manufactured for various densities (0.50 to 0.72 g/cm3) by varying the perlite content, Styrofoam content and the degree of compaction. The test results and the comparison with literature show that the compressive strength (1.32 MPa - 4.46 MPa) and specific compressive strength (3.03 MPa/(g/cm3) to 6.43 MPa/(g/cm3)) of the developed material are viable with the existing materials currently being utilized for the similar purpose. Additionally the stress – strain behavior and the failure mechanism during compression test has also been discussed which would be beneficial for the purpose of further development of this material.