SciEn Conference Series: Engineering (SCS: Engineering) is an international, multidisciplinary, open access, and peer-reviewed journal that publishes conference proceedings in various fields of engineering. The journal is published by SciEn Publishing Group (SciEnPG), a registered publishing company based in Bangladesh. SciEnPG is responsible for all activities related to the journal. SCS: Engineering aims to publish high-quality conference proceedings comprising the latest advancements in the field of Engineering. The journal would serve as an extraordinary platform for the latest multidisciplinary research outcomes for the scientific community, engineers, students, and academicians from various backgrounds.
All the articles published by this journal are licensed under a Creative Commons Attribution 4.0 International License
Computational Modeling of Metal Toe Caps to Reinforce Safety Footwear: A Finite Element Approach
Toe caps in safety footwear improve protection against workplace injuries, and the commonly used toe cap materials are metal, plastic, and composite. Metal is used to strengthen the toe cap; however, increased thickness proportionally adds weight to the shoe. Adding flutings can strengthen the toe cap rather than increase the thickness, and a study is required to evaluate the impact of fluting height and direction on the strength of the toe cap. The objectives of this study were to optimize the strength of the toe caps by applying flutings along different directions with various fluting heights and toe cap materials. Toe caps with no flutings, longitudinal flutings, and transverse flutings were the three types of samples used to evaluate deformation. For both longitudinal and transverse directions, the heights of 2 mm, 3 mm, and 4 mm flutings were added to the toe cap surface, and those models of the toe caps were developed by SolidWorks software. Ansys software performed finite element analyses of all the toe cap models for different materials (steel, aluminum, titanium). The strength of the toe cap was determined through deformation analysis by applying a load to the surface. Compared to longitudinally fluted toe caps, transversely fluted toe caps displayed a lower deformation in this test. Furthermore, the 4 mm steel transverse fluted toe cap showed less deformation than the 2 mm and 3 mm steel transverse fluted toe caps. Moreover, steel has the lowest rate of deformation among the three materials. Therefore, the toe cap with 4 mm transverse flutings was considered the strongest among the analyzed toe cap models. This study may be helpful for footwear manufacturers to produce stronger toe caps for safety footwear for workers who need to carry heavy-weight objects in their workplace.
Copyright (c) 2025 Md. Imrul Kayes Limon, Hanjala Tahmid, Tatini Goswami, Md Istiaq Mahmud Tanvir, Shihab Ahemed (Author) https://creativecommons.org/licenses/by/4.0
Water Supply Network in Rajshahi City Corporation: Water Quality, Regeneration Effect and Pump Performance
Urban water supply systems are currently facing considerable challenges posed by rapid population growth and the constraints of limited resources. Across many urban areas, pumping stations are tasked with providing drinking water; however, the quality of this water often falls short of the rigorous standards set by Bangladesh’s Drinking Water Standards (BDS) and the World Health Organization (WHO). This situation is alarming, as water quality can have dire implications for public health. The efficiency of numerous pumping facilities is significantly lower than the optimal benchmarks established in laboratory tests. As a result, city residents frequently face inadequate access to safe drinking water, a critical resource for daily living. The present study focuses on the performance evaluation of pumping sites within the Rajshahi City Corporation (RCC). This study aims to uncover specific issues that hinder the effective operation of these pumping stations and to propose viable solutions. The analysis investigates essential parameters, including static water levels, the conditions of aquifers, and the impacts of drawdown—each factor playing a pivotal role in the overall performance of water supply systems. The investigation reveals that many pumps fall short of established laboratory standards, with significant seasonal fluctuations in groundwater levels and the effects of drawdown being prominent factors contributing to this inefficiency. By addressing these critical issues, the study seeks to pave the way for sustainable water management practices that ensure equitable access to safe drinking water for all residents, ultimately improving the quality of life in resource constrained urban areas.
Copyright (c) 2025 Md. Sanowar Hossain, Asma-Ul-Husna, Mohammad Rofiqul Islam, Md. Shazu Ahamed Anik, Fardin-Al-Rafin (Author) https://creativecommons.org/licenses/by/4.0
Today, the quality of work lives, occupational safety, and health are issues that both management and employees care about. Information and communication technology, specialized jobs that need repeated tasks, and other new advancements all contribute to the need for human factors engineering. Through the analysis, design, testing, and evaluation of the workplace and human interactions, human factors engineers are able to establish safe, effective, and fulfilling work environments. In order to create systems, organizations, jobs, machines, equipment, and consumer goods that are safe, effective, and comfortable for individuals to use, ergonomics incorporates knowledge of human capabilities and limitations. The basic philosophy of ergonomics is to design workstations that are comfortable, convenient, and productive to work at. According to its definition, ergonomics is the "science of fitting the job to the works". Hence, being an engineer is frequently advantageous when it comes to properly incorporating ergonomics into manufacturing design and planning. Ergonomics is highly related to safety due to its inherent linkage with human-environment interactions. The purpose of ergonomics is to employ design and training to improve comfort, safety, and productivity. Through the implementation of ergonomics an industrial engineer can improve productivity, high employ morale and the quality of products, which will smoothen the operation of an industry. The paper includes (i) the importance of ergonomics in industrial design (ii) ergonomics within industry and manufacturing (iii) ergonomics relation with industrial engineering and (iv) applicability of ergonomics in chair and table design have been cited in this paper.
Copyright (c) 2025 Mohammad Iqbal, Syed Misbah Uddin, Farjin Anyar Rahman, Syed Sabbir Hasan, Md. Mushtaq Tahmid, Achia Khatun (Author) https://creativecommons.org/licenses/by/4.0
Kinematic Analysis and Comparison of Mechanical Walkers Using Theo Jansen’s Mechanism
A comprehensive kinematic analysis and modeling of four, six, as well as eight-legged mechanical models based on the Theo Jansen mechanism has been conducted in this paper. This locomotion assisted structures are ideal for replacing wheeled robots, which in most cases have a challenge on rough surfaces. Three models were designed and analyzed for motion using Solid Works with specific parameters such as angular velocity and motor torque analyzed. This study shows that walking with an eight-legged configuration is much smoother than that of the four and six-legged configurations. Nonetheless, this benefit is counteracted by the large amounts of materials needed as well as a larger body weight. It provides an effective understanding of the performance of walking, its associated mechanical system, and the material required for the system. The results indicated that more walking legged robots would be more adaptable to the environment and would be a better option than wheeled robots, since the ingenious machines in legs provided more movement in difficult terrain. Such research helps to foster interest in bio-inspired robotics and helps develop better walking mechanisms for non-flat surfaces.
Copyright (c) 2025 Kazi S M Jaman Fahim, Asha Rani Shorma, Tauseef Ahmad, Md. Ashraful Islam (Author) https://creativecommons.org/licenses/by/4.0
Chloride Removal from Tannery Soaking Wastewater by Adsorption onto Activated Alumina
Tannery soaking waste water is characterized by very high chloride content that is responsible for severe environmental problems such as damage to human health, microbial population and aquatic lives. This study was aimed by the preparation and characterization of activated alumina along with its application for chloride adsorption from tannery soaking waste liquor. Activated alumina was prepared through sol-gel technique using aluminum nitrate as precursor with the pHpzc of 8.1. The XRD analysis revealed the both crystalline and fine amorphous nature of the alumina with average particle size of 5.04nm. Chlorides adsorption experiments onto activated alumina was conducted by both batch and column adsorption method to explore the optimal adsorption condition and to investigate the practical usability of the adsorbent. The batch study revealed that pH of 6 and temperature of 40 ⁰C was the optimal operational conditions for chloride adsorption onto activated alumina. In the column study, higher chloride removal was observed at lower flow rates, with a reduction in efficiency from 93.27% to 86.94% as the flow rate increased from 2 to 4 mL/min. Breakthrough curve analysis at different flow rates revealed that a comparatively higher break point of 270 minutes and 240 minutes was observed for lower flow rates, 2 and 4 mL/min, respectively, whereas at higher flow rates, 8 mL/min breakpoint was noticed at 150 minutes. Breakthrough curve modeling demonstrated that the column adsorption process followed the Thomas model of adsorption kinetics. Better regeneration of the alumina up to two wash cycles was achieved for alkali wash. The adsorption efficacy of activated alumina for chlorides, BOD and COD as 93.24%, 69.18%, 75.68% from raw soaking liquor and 43.19%, 32.23% and 38.69% from diluted soaking wastewater signifies its potentiality to adsorb not only chlorides but also organic pollutants from tannery effluent.
Copyright (c) 2025 Rajan Kumar Raha, Atri deb, Md. Marufur Rahman Maruf, Nowshin Nawal, Faria Jerin (Author) https://creativecommons.org/licenses/by/4.0
Effect of Corrugation on the Stall Angle Characteristics of NACA 0012 Airfoil: A Numerical Approach
The aim of the study is to numerically examine the effect of corrugation on the stall angle characteristics including the coefficient of lift and drag NACA 0012 airfoil. The FLUENT module of ANSYS version 2020 R1 software was employed for performing the simulations to compute the lift coefficient and drag coefficient at various incidence angle (α) and a Reynolds number (Re) of definite value 2.5×105. A sinusoidal corrugation profile was inserted at the apt 1/3rd of the chord on the upper surface. The numerical results indicate that the corrugation delays the flow separation improving the stall characteristics whereas some penalty on other aerodynamic characteristics was also noticeable such as lower value of lift coefficient at low angle of attack, higher drag coefficient compared to smooth airfoil. The stall angle is delayed by 3° and the maximum lift coefficient value significantly increased. Hence corrugation can be implemented to enhance some particular characteristics while sacrificing one or more other aerodynamic performances. The optimization of the profile is required to achieve the desired improvement and minimize the adverse effects.
Copyright (c) 2025 Fahim Al Galib, Adnan Roshid Shawon, Mohammad Ilias Inam (Author) https://creativecommons.org/licenses/by/4.0
Stature Estimation from Foot Measurements in Primary Students: A Case Study in Bangladesh
This study investigates the relationship between foot anthropometric measurements and human stature among primary school students in Bangladesh, aiming to establish reliable anthropometric models for forensic and ergonomic applications. Employing data from 360 children (180 males and 180 females), the study utilizes linear and multiple regression models to establish predictive equations for stature estimation. Foot measurements, including foot length and width for both feet, were recorded with high precision. Results reveal strong correlations between foot dimensions and stature, with foot lengths showing higher predictive accuracy for males, and foot widths being more effective for females. Multiple regression analysis enhances predictive precision, with gender-specific models significantly improving accuracy. The female-specific multiple regression model demonstrated an almost perfect prediction correlation (R = 0.9997), compared to the male model (R = 0.9524). The findings underscore the necessity of using gender-specific equations due to variations in growth patterns and body proportions. This research fills a critical gap in anthropometric studies focused on children and presents practical applications for forensic science and ergonomic design in resource-limited settings. Additionally, it contributes to the standardization of foot dimensions based stature estimation techniques, enhancing their applicability for diverse demographic groups.
Copyright (c) 2025 Md. Asadujjaman, Wardatul Akmam, Abdullah Al Mahmud, Md. Ariful Haque (Author) https://creativecommons.org/licenses/by/4.0
Micoremediation of Leather Dyes by Novel Fungal Strains Isolated From Tannery Sludge
The complex nature of leather dyes makes them resistant to conventional biological treatment processes. Fungi have proven to be a promising alternative due to their resilience in harsh environments and ability to remove dyes through bio-sorption, biodegradation, and bioaccumulation mechanism. This study explored the potential of unique fungal strains, Brown fungus (F1) and Green Fungus (F3) isolated from tannery solid waste to remediate leather dye biologically. A synthetic dye solution of acid brown was tested in the micoremediation process. Factors influencing dye removal by micoremediation were investigated using batch culture technique. Maximum dye removal achieved for the initial dye concentration of 50 mg/L and culture incubation time of 7 days for both the fungi. Optimal pH of dye removal was found to be 4 for F1 and 5 for F3. At the optimal experimental conditions fungus F3 remediated more dye in comparison with fungus F1 with the removal percentages of 92.32% and 88.24% respectively. Various carbon media to support fungal growth for dye removal were also tested where Potato Dextrose Broth (PDB) achieved the highest removal. The fungal species F1 and F3 demonstrated dye removal efficiencies of 52.03% and 55.13% respectively at a dilution factor of 10, for real wastewater from leather dyeing operation showcasing its practical applicability in industrial wastewater treatment. Alcohol wash was identified as the best decolorizing solution for fungus reusability where dry fungal biomass of F1 was better reusable than F3. The SEM studies provided insights into the structure of fungi involved in the micoremediation process. This study reveals that, the novel fungal isolates have a potential for micoremediation of leather dyes at its optimal growth conditions for both synthetic dye solution and tannery dyeing waste liquor.
Copyright (c) 2025 Rajan Kumar Raha, Nishat Salsabil, Fahad Bin Siddique, Nowshin Nawal (Author) https://creativecommons.org/licenses/by/4.0
Impact of Particle Size Distribution on Fly Ash-Based Geopolymer Composites
This study investigates the properties of fly ash-based composites using particles of varying sizes, sourced from the hopper located immediately before the electrostatic precipitator (ESP) and the final field hopper of the ESP. The research focuses on the development of geopolymer mortars, using sodium silicate and sodium hydroxide as alkali activators (AA). After curing and drying, the samples were analyzed for compressive strength, flexural strength and porosity to assess their physical characteristics. All tests were conducted to evaluate the mechanical performance of different fly ash and activator compositions. The microstructure of the geopolymer samples was examined using scanning electron microscopy, providing insights into the morphological changes associated with the activation process. This investigation highlights the potential of fly ash as a sustainable material for advanced geopolymer applications.
Copyright (c) 2025 Jasim Ahmed Chowdhury, Md. Shahidul Islam, Md. Ashraful Islam (Author) https://creativecommons.org/licenses/by/4.0
Numerical Investigation on the Effect of Converging Channel in Crossflow Heat Exchanger
The objective of this numerical study is to investigate the effect of converging channel in crossflow heat exchanger using Rectangular Winglet Pair (RWP) in different arrangement from the tube center. For a defined converging angle, the placement of RWPs affects the heat exchanger performance. The FLUENT module of ANSYS version 2020 R1 was used to simulate the flow in a single strip of a crossflow heat exchanger to calculate the heat transfer coefficient and pressure drop. It was performed in low Reynolds number ranges from 550 to 960. Using those RWPs, heat transfer coefficient increases significantly as the converging channel accelerates the local flow around the tube and increases local Reynolds number that also affects in pressure drop also. Forward and backward arrangement provides better performance more specifically the RWPs placed behind the tube provide better performance.
Copyright (c) 2025 Adnan Roshid Shawon, Fahim Al Galib, Mohammad Ilias Inam (Author) https://creativecommons.org/licenses/by/4.0
Numerical Analysis of Flow Separation Control of an Airfoil by Plasma Actuator
Plasma actuators operating under atmospheric conditions show great promise for flow control due to their unique physical characteristics, such as the body force generated by a strong electric field. This study numerically examines the effect of low-powered plasma actuation on the aerodynamic performance of a NACA 2412 airfoil. Utilizing the Shyy plasma actuation model, the study simulates its effects through defined functions. The analysis investigates the lift and drag coefficients at various angles of attack, with a freestream velocity of 14.5 m/s. Without plasma actuation, the airfoil experiences common aerodynamic challenges, such as flow separation near the trailing edge, which reduces efficiency. However, plasma actuation accelerates the airflow over the upper surface, delaying flow separation and decreasing drag. This results in smoother airflow and increased lift, particularly at higher angles of attack. The use of plasma actuation achieved approximately a 21% increase in the lift coefficient. Overall, plasma actuators enhance airflow control, reduce drag, and boost lift, improving the airfoil’s aerodynamic performance. This improvement is supported by pressure contour analysis, which demonstrates a more favorable pressure distribution with plasma actuation.
Copyright (c) 2025 Jishan Ahmed , Aditya Das, Mushfiqur Rahman Shihab, Mohammad Ilias Inam (Author) https://creativecommons.org/licenses/by/4.0
Effect of Injection Timing on a Diesel Engine Fueled with Biomass to Liquid Diesel and Spirulina Microalgae Biodiesel Blends
Due to fossil diesel's limited supply and environmental worries, scientific research on alternative fuels is gaining traction in a promising way. The significant lipid content of third generation microalgae oil makes it preferable over regular biodiesel sources. Currently, biomass to liquid (BTL) diesel, a sustainable fuel, is regarded as a novel fuel for diesel engines due to their drop in characteristics and enhanced engine performance compared to biodiesel. Hence, the authors aim to conduct a numerical investigation to trace the impact of neat BTL diesel and the blends of Spirulina microalgae biodiesel and BTL diesel on a diesel engine using Diesel-RK software. The performance, combustion, and emission attributes of the engine are explored for neat BTL diesel and for three separate blends produced by including 20, 40, and 60 vol% (BD80MB20, BD60MB40, and BD40MB60, respectively) of microalgae biodiesel into BTL diesel, and then the results are compared to those of conventional diesel. The parameters are measured for three different injection timings (ITs) of -1⁰, 4⁰, and 7⁰ bTDC, keeping the swirl ratio constant at 1. BTL diesel is figured out to have a lower brake specific fuel consumption (BSFC) than neat diesel. However, the addition of microalgae biodiesel into BTL diesel raised the BSFC compared to pure BTL diesel. For all ITs, the brake thermal efficiency is higher for BTL diesel and other blends than conventional diesel. Reductions in ignition delay period, combustion duration, and peak heat release rate in premixed combustion are noticed for BTL diesel and remaining biofuel blends compared to neat diesel, leading to favorable combustion attributes. Additionally, the quantity of CO2, smoke, and particulate matter in engine exhaust is decreased, although the emission of oxides of nitrogen rose while using BTL fuel and biodiesel/BTL fuel blends compared to regular diesel.
Copyright (c) 2025 Minhaz Ahmed, Md. Mizanur Rahman, Tafsirul Hassan, Md. Arafat Rahman (Author) https://creativecommons.org/licenses/by/4.0
Numerical Analysis of Supersonic Flow and Shockwave Behavior Over a Convex Wedge
The present study describes the flow behavior around the leading edge of a convex wedge having a specific dimension under varying upstream Mach numbers ranging from 1.4 to 2. The interaction between the free stream flow and the wedge significantly affects flow parameters such as static pressure, density, static temperature, downstream Mach number, and shock standoff distance (SSD), which are crucial for efficient aerodynamic design. Previously, various researchers have considered the convex wedge flow configuration specifically for inviscid flow but limited attention has been given to the detailed behavior of flow parameters at the leading edge of a convex wedge under varying upstream Mach numbers. The results indicate that, static pressure increased almost 80% at upstream Mach number 2 at the leading edge of the convex wedge. Density, static temperature, downstream Mach number all of them increased by 40%, 28%, and 40% respectively. The downstream Mach number, at first increases slowly but change takes place rather rapidly when the upstream Mach number crosses the value of 1.6. Again, the SSD showed an abrupt change (almost 95% decrease of its initial value at upstream Mach number 2). The leading edge was chosen for this study since it’s considered to be the critical design point which experiences the highest thermal and aerodynamic loads due to the shockwave. Evaluating flow behavior at this point is crucial in managing shockwave-induced loads.
Copyright (c) 2025 Nobin Dhar , Mohammad Ilias Inam, Azizul Hakim Aakash (Author) https://creativecommons.org/licenses/by/4.0
Glass & Jute Fiber Composites Pressure Vessel Design and Optimization Using Finite Element Analysis
This study focuses on maintaining the structural strength of composite pressure vessels (CPVs) used to store highly pressurized liquids and gases. CPVs are employed across multiple industries to store or transport substances under pressure. They find applications in sectors such as oil & gas, chemicals, and petrochemicals. CPVs offer a significant advantage over traditional metal vessels due to their lighter weight. However, their design, manufacturing, and testing processes require more specialized techniques. This research utilizes finite element analysis (FEA) software, specifically ABAQUS, to perform a design optimization of a CPV. The optimization of the CPV involved considering lamina sequences, thickness variations, and fiber winding angles to determine their impact on the vessel's maximum burst pressure capacity. The CPVs under investigation are constructed from glass fiber and jute fiber, with a specific lay-up configuration of six plies oriented at 0, 45, 60, -45, -60, and 90 degrees. The study investigates several key aspects. Firstly, it examines variations in different types of stresses—such as circumferential, axial, and radial—due to different meshing techniques. Secondly, it analyzes the maximum burst pressure under specific internal pressures. Finally, it applies failure criteria including Maximum stress (MSTRS), Tsai-Wu (TSAIW), and Tsai Hill (TSAIH) to predict the burst strength of the composite pressure vessel. Overall, this work aims to enhance the performance and reliability of CPVs through advanced numerical simulations and testing methodologies, ensuring their suitability for critical applications in demanding environments.
Copyright (c) 2025 Zabir Al Nahian , Chaitee Das, Md Mafidul Islam (Author) https://creativecommons.org/licenses/by/4.0
Effect of Grout Thermal Conductivity and Leg-spacing on the Borehole Length of U-tube Ground Heat Exchanger
This study explores the effects of grout thermal conductivity and leg spacing between a single U tube pipe on the borehole length of a ground-coupled heat exchanger, which is required to dissipate heat from a 1-ton air conditioner to the ground under the climatic conditions of Bangladesh. The result obtained from the zeroth-order multipole approach has been compared with first-order multipole, and Liao et al. methods to predict borehole length. Additionally, the impact of flow rate and inner pipe diameter on the pressure drop of U tube pipe has been evaluated here. Python-based simulations have been conducted to analyze them. The results demonstrate that increasing grout thermal conductivity significantly reduces borehole length—up to 31%—by minimizing grout thermal resistance. However, at higher conductivities, borehole length approaches an asymptotic behavior as other factors, such as ground thermal conductivity, dominate. Comparisons revealed that zeroth-order and first-order methods yield almost identical results, while minor deviations (<6%) occur with the Liao et al. method in the low-conductivity regime due to differing heat transfer assumptions. It has been investigated that larger leg spacings were shown to reduce thermal interference between U-tube legs, thereby shortening borehole lengths. The study also highlights that smaller pipe diameters lead to higher pressure drops, necessitating lower flow rates to minimize frictional resistance and higher pumping costs. However, ensuring sufficient flow rates to maintain turbulent flow is recommended for effective heat transfer. These findings underscore the importance of optimizing grout conductivity, leg spacing, and flow conditions to enhance borehole heat exchanger efficiency. The results provide a robust foundation for further research and practical applications in sustainable Ground Heat Exchanger (GHE) technologies over conventional air-cooling systems.
Copyright (c) 2025 Takia Tashbih, Mohammad Ariful Islam (Author) https://creativecommons.org/licenses/by/4.0
Development of a Robotic Exoskeleton Model Operated via Arduino for Mechanical Actuation
In this paper, we present the design, development, and initial testing of a prototype exoskeleton model created for augmenting human strength and mobility, specifically for upper-body weightlifting applications. This model, crafted to fit a small articulated doll (approximately 11.9% the size of an average human), using a PLA-constructed frame, an Arduino control system, and a rope-pulley mechanism for movement, this design represents a practical approach to wearable assistive robotics. While primarily a proof-of-concept, the project aims to explore foundational principles of wearable robotics and mechanical augmentation in a simplified manner. The proposed exoskeleton can be served as a robotic tool in demonstrating the interaction between mechanical design and control systems. The exoskeleton design also contributes to the field of wearable robotics by addressing the specific needs of weightlifters, offering a practical and functional solution to enhance strength, reduce fatigue, and minimize the risk of musculoskeletal injuries during weightlifting exercises. Preliminary results discuss feasibility and working efficiency of this model while providing insights into potential applications and improvements in larger-scale wearable robotics. The exoskeleton’s performance was assessed for vertical holding and lifting tasks, identifying challenges in torque, friction, and material choice, which inform future improvements in exoskeleton technology.
Copyright (c) 2025 Azizul Hakim Aakash, Mohammad Ariful Islam (Author) https://creativecommons.org/licenses/by/4.0
Effect of Nano Clay on the Mechanical Properties of Sandwich Structure
Sandwich composite materials are widely used in numerous engineering fields and applications due to their excellent mechanical properties and lightweight. The mechanical and physical properties, cost-effectiveness, and sustainability of composite materials can be improved by adding various organic and inorganic filler materials. In this study, nano clay was used as filler in epoxy resin to examine the mechanical properties of the composite material by conducting tension, bending, cyclic bending, and short beam shear tests. PVC foam, widely known as a load-bearing component was used as the core, and Aluminum sheet was used as the upper and lower facing of the sandwich structure. Epoxy resin of 10:1 ratio was chosen for the intermediate interface with a variation of nano clay containing 0.5%, and 1% of the total mixture by mass. While manufacturing the sandwich structure, pressure was applied by creating a vacuum chamber using thick polythene and a vacuum pump and sucking the air out of the chamber. The study reveals that incorporating nano-clay affects material properties variably. Bending strength, specific energy absorption (SEA), and short beam shear strength increase to 0.5% but decline or stabilize beyond that. Modulus of elasticity (MOE) and tensile strength decrease initially, then rise. Cyclic bending deformation increases with nano-clay content, peaking at 1%. No delamination occurs, though wrinkling is observed. The overall finding was negative and it was observed that the effect of nano clay was not significant due to the low strength of the soft PVC core.
Copyright (c) 2025 Devashis Bagchi, Bickrom Saha, Md. Roknuzzaman, Md Arifuzzaman, Md Shariful Islam (Author) https://creativecommons.org/licenses/by/4.0
Enhancing the Flexural Strength of Perlite/Gypsum Composite Panels and Their Sandwich Structures using Gypsum Layer
In gypsum/perlite composite panels, due to incorporation of lightweight expanded perlite particles, the flexural properties are affected negatively. To address this issue, the flexural strength of gypsum/perlite composite panels and their sandwich structures with a gypsum surface layer was investigated in this work. The perlite contents of the composite were varied (40 g, 60 g and 80 g for each 390 g of gypsum) to manufacture the composites. A single gypsum layer was given on one side of the gypsum/perlite composite panels to improve the flexural strength. The sandwich structures with and without gypsum layer were fabricated by attaching formica sheet skins on both sides of the panels. Results show that the density reduced with more perlite content, making the panels lightweight and slightly increased due to addition of gypsum layer. Flexural testing revealed that pure gypsum panels had the maximum flexural strength while, with the increase of perlite in the matrix, the flexural strength decreased. Introducing the gypsum layer improved the flexural strength for these panels. Introducing formica sheet skins to the panels improved their flexural strength significantly. However, the best result was obtained for the sandwich panels using the gypsum layer in the gypsum/perlite composite core. The findings of this work show the method of improving the flexural strength of gypsum/perlite composite panels without losing the lightweight properties significantly.
Copyright (c) 2025 Md. Sabbir Raihan, Md. Mohaimenul Islam, Md Arifuzzaman, Md Shariful Islam (Author) https://creativecommons.org/licenses/by/4.0
Advances in Solid-State Hole Transport Materials for Next-Generation Dye-Sensitized Solar Cells
Dye-sensitized solar cells (DSSCs) offer a promising alternative to conventional photovoltaic technologies due to their low cost, simple fabrication process, and potential for high efficiency. This review focuses on recent advancements in solid-state hole transport materials (HTMs) for next-generation DSSCs. Traditionally, DSSCs rely on dye molecules adsorbed on a semiconductor surface to harvest light and inject excited electrons into the conduction band. A critical challenge has been developing efficient HTMs to regenerate the dye molecules after electron injection. While liquid electrolyte-based DSSCs suffer from issues such as solvent evaporation, leakage, and stability concerns, solid-state HTMs have emerged to address these problems while maintaining high power conversion efficiencies. This review examines the evolution of solid-state HTMs, exploring materials such as organic small molecules, polymers, inorganic materials, and coordination metal complexes. Key breakthroughs in HTM design are highlighted, including improvements in conductivity, pore infiltration, and interface engineering, which have helped overcome challenges like poor pore filling and high recombination rates. Additionally, the review addresses the growing focus on low-cost, environmentally friendly HTMs and scalable fabrication techniques. Despite these advances, critical challenges remain, such as better understanding interfacial dynamics and developing HTMs with enhanced conductivity and stability. The review concludes with a discussion of future research directions, providing valuable insights for advancing the commercialization of efficient solid-state DSSCs.
Copyright (c) 2025 Nasrin Ferdous Talukder, Zunaid Hasan Tajim, Anika Abdullah (Author) https://creativecommons.org/licenses/by/4.0
Numerical Investigation on Heat Transfer Characteristics of a Mist Cooled Ribbed Channel with Different Rib Angle
The present work focuses on numerical analysis of a mist cooled rib channel with baffle in an internal cooling of a turbine blade. In this paper, flow and heat transfer characteristics are presented for rib channel with baffle at different angle of ribs that is used as internal cooling passage of turbine blades. ANSYS Workbench software is employed to measure surface heat transfer characteristics and friction factor over the ribbed surfaces in the designed ribbed channel with baffle. Using different boundary conditions, a mist cooled rib channel with baffle is validated for better Heat Transfer Characteristics, Friction factor and pressure profiles. The fundamental goal is to describe the heat transfer performance at different values of Reynolds Number, Prandtl Number with variation of rib angle. Besides this to calculate the friction factors at different values of Reynolds Number, Prandtl Number and rib angle. Increase of Reynolds Number increases the Nusselt Number. Increase of Rib angle increases Nusselt Number. But this is not satisfactory at angle 60°. At angle 60° Nusselt Number is comparatively lower. Because at rib angle 60° the formation of vortex is distributed near all row of rib. Compared with continuous baffle, the low heat transfer behind the rib is enhanced by the designed mist cooled ribbed channel with a slightly reduction of pressure drops. Variation of heat transfer as well as friction factors are respectively 5.6% and 5.4 % compared with continuous baffle. As Rib with baffle can enhance the overall hear transfer performance and create more uniform heat transfer fields, it is used in internal cooling of gas turbine blades.
Copyright (c) 2025 Sadhan Mondal, Khandkar Aftab Hossain (Author) https://creativecommons.org/licenses/by/4.0
Influence of Surface Temperature on The Hydrodynamic Characteristics for Flow over Rotational Cylinder
Turbulent flow over a rotational cylinder produces lift due to pressure differences on the upper and lower surfaces. The present numerical analysis focuses on the effect of the rotating cylinder's surface temperature. Simulations are carried out at the Reynolds number of 5000 for a series of velocity ratios ( 0 to 5). The surface temperature varied from 300 K to 500 K. A temperature-variable viscous model is used for the simulations as fluid viscosity depends on temperature. Results from the simulation show that the increased surface temperature of the cylinder for the velocity ratio below 3 slightly improves the lift coefficient. However, for higher velocity ratios (4 to 5), a significant improvement in the lift coefficient is found. In the case of the drag coefficient, however, values increase infinitesimally. The flow streamlines are around the cylinder, and the stagnation point is attached to the cylinder surface for 3. On the other hand, the streamlines fold around the cylinder, creating an Envelope Vortex at .
Copyright (c) 2025 Sayedul Islam, Abdullah Al-Faruk (Author) https://creativecommons.org/licenses/by/4.0
Effect of Rayleigh number on Heat Transfer Characteristics of Finned Heat sink
In the present work, the performance of a vertical rectangular fin array based on a horizontal heat sink is analyzed for various Rayleigh number with increasing heating power by numerical analysis of steady state natural convection heat transfer. The continuity, momentum, and energy equations are solved using three-dimensional numerical simulations with FLUENT software to forecast the flow and temperature field with air as working medium. Governing equations are discretized and evaluated throughout the solid heat sink and fluid air computational domain. Fins made of aluminum with a high thermal conductivity were chosen for better heat dissipation. The enhancement of temperature differentials between the fluid domain and heat sink causes the Rayleigh number to rise with increased heating power. Using fixed fin base length, the declining character of thermal resistance, enhancement of heat transfer coefficients and Nusselt numbers were analyzed for Rayleigh numbers ranging from 4×106 to 20×106. The temperature increases across the heat sink array, reaches to maximum in the middle, and then progressively releases the heat through the fins bodies into the surrounding air. Fluid flow and thermal structure between the transverse and longitudinal fin channels as well as along the entire fin array were depicted. Two different kinds of flow patterns were identified in the fin arrays channel, and the temperature flow had a parabolic structure.
Copyright (c) 2025 Oishi Kanta, Md Abdullah Al Mohotadi, Khandkar Aftab Hossain (Author) https://creativecommons.org/licenses/by/4.0
Comparative Analysis of Forecasting Methods and Integration with Inventory Models for Efficient Demand Management in the Electronics Sector
Demand fluctuates over time, so forecasting future needs based on the previous data is crucial for proper inventory management. This study aims to showcase the proper way of choosing the perfect forecasting technique for a system and utilize it in the inventory model. In this study, the forecasted demands have been determined based on the sales data obtained from an electrical appliance retailer company using three forecasting techniques: Simple Moving Average, Simple Exponential Smoothing method, and Linear Regression. The forecasting results from these three methods are then examined by several error detection techniques: Mean Absolute Deviation (MAD), Mean Squared Error (MSE), Mean Forecast Error (MFE), and Mean Absolute Percentage Error (MAPE). The Linear regression has fewer errors among the forecasting techniques than the other two. The linear regression has 207.37 for MAD, 74679.50 for MSE, 0 for MAPE, and 25.13% for MAPE. Hence, the data obtained from linear regression was used to build an inventory model. The retailer sells electronic appliances, which are finished goods, and there is no evidence of extreme fluctuation or shortage, so the purchase model with instantaneous replenishment without shortage has been chosen as the inventory model. Sensitivity analysis on this inventory model has been conducted based on different carrying costs and ordering costs, which suggested that small changes in the ordering cost or the carrying cost result in remarkable changes in the total cost, and it indicates that the sensitivity of each type of cost on this inventory model is very high. This sensitivity can be mitigated by keeping the ordering and carrying costs within a fixed range. The findings of the study focuses on the importance of robust demand forecasting for effective inventory management.
Copyright (c) 2025 Md. Ashaduzzaman, Shakil Ahmed Khan, Nahiyan Ishmam Nawar, Atif Abrar Biswas, Md. Limonur Rahman Lingkon, Md. Sanowar Hossain (Author) https://creativecommons.org/licenses/by/4.0
Influence of Tube Geometry and Spacing on Thermal Performance in Automobile Radiators
This study investigates the influence of tube geometry and spacing on the heat transfer performance of automobile radiators using MATLAB and Simulink simulations. Despite innovations in heat exchanger designs, the impact of practical geometries like circular and rectangular tubes on radiator efficiency remains underexplored. The study examines heat exchanger performance by comparing outlet temperatures for circular and rectangular tubes at inlet temperatures of 310 K to 360 K, and analyzing the effectiveness-NTU relationship, highlighting geometric and operational impacts on efficiency. The NTU method was used to predict fluid outlet temperatures and also validated the simulations. In the case of tube shaping, the rectangular tubes achieve outlet temperatures of 307–347 K, compared to 308–351 K for circular tubes. For tube spacing, circular tubes stabilize at 334 K (2–15 tubes), while rectangular tubes drop to 323 K (up to 140 tubes) but rise to 340 K at 198 tubes due to flow limitations. The effectiveness of rectangular tubes rises sharply to 0.75 at NTU of 1, approaching 1 with minimal gains beyond NTU of 5. The NTU method predicts outlet temperatures of 309 to 359K, closely matching circular tubes but overestimating rectangular performance. This research identifies optimal tube configurations, contributing to improved thermal management. The findings have applications in automotive cooling systems, with future studies recommended for transient behavior analysis.
Copyright (c) 2025 Jyotirmoy Mondal, Dipayan Mondal, Mohammad Sultan Mahmud (Author) https://creativecommons.org/licenses/by/4.0
Flexural Properties of Fly Ash Reinforced Perlite/Sodium Silicate Composite and Their Sandwich Structures
The current investigation is focused on improving the flexural properties of perlite/sodium silicate composites using fly ash as reinforcement. Perlite/sodium silicate composites are reinforced with varying amount of fly ash (15 %, 30 %, and 45 %). Formica sheet was used as skins of the sandwich structures with fly ash reinforced perlite/sodium silicate composite as core. To attach the formica sheet skins with core pure epoxy and fly ash reinforced epoxy was used. The flexural strength and modulus of perlite/sodium silicate composite, fly ash reinforced perlite/sodium silicate composite, and two types of sandwiches are determined by three point bending test according to the standard. Results showed that the flexural strength of fly ash reinforced perlite/sodium silicate composite for 30 % fly ash content was maximum and 147.62 % greater than perlite/sodium silicate composite without reinforcement. The flexural modulus increased with increasing fly ash content up to 40 % fly ash content. The maximum enhancement in flexural strength and modulus of fly ash reinforced core-based sandwiches were also found at a fly ash content of 30 %. Utilization of fly ash reinforced epoxy as adhesive layer in the interface between the core and the skin improved the flexural modulus of the sandwiches significantly but the flexural strength slightly decreased. The study suggests that fly ash is an excellent reinforcing agent for the improvement of the flexural properties of perlite/sodium silicate composites and their sandwich structures.
Copyright (c) 2025 Bickrom Saha, Devashis Bagchi, Md. Roknuzzaman, Alamin Islam, Md. Shariful Islam, Md. Arifuzzaman (Author) https://creativecommons.org/licenses/by/4.0
Cooling Load Analysis of a Household Refrigeration System: Evaluating the Impact of Compressor Efficiency
This research explores the cooling load and compressor performance in a R600a-based household refrigeration system, focusing on energy efficiency and thermal optimization. A refrigerator with two compartments was studied, which combines the thermodynamic model and experimental evaluation to assess the cooling demand and compressor work. The total cooling load, including transmission, product, and infiltration loads, accounted for 70.087W. Freezer and refrigerator temperatures were recorded at -19.84°C and 4.06°C while energy consumed was 56–58W compared to the specified 100W with suction and discharge temperatures of 32 and 54°C. However, the 130W compressor was rated at 66 ⁓70W with suction and discharge temperatures of 38℃ and 63℃ respectively with marked inefficiencies. The selection of materials was of particular importance for the performance. High R-value polyurethane foam insulation was able to cut thermal conductivity by 50%, thus saving energy by lowering cooling loads. The overall thermal management was further improved by the use of cold-rolled steel panels and polystyrene liners, the latter ensuring high strength and excellent insulation. The calculations for product and infiltration loads showed how the cooling efficiency might be affected by the ambient conditions and the thermal characteristics of the stored items. The findings confirm that a 100 W compressor is the most optimal choice for domestic refrigerators for this model since it performs well with a duty cycle of 70%, providing cooling in an energy-efficient way. This study brings out the role of advanced insulation materials and compressor technologies that are efficient in reducing energy consumption. Future developments will revolve around the use of variable-speed compressors and energy recovery systems to better cope with fluctuating operational requirements, thus contributing to international energy conservation standards and the furtherance of sustainable refrigeration technologies.
Copyright (c) 2025 Md. Sohan Hossain, Dipayan Mondal, Md. Shamim Ahammed (Author) https://creativecommons.org/licenses/by/4.0
Numerical Analysis of Bicycle Frame Using FEM
Bicycles are popular mode of transportation around the world. The frame is an important part of a bicycle, which comprises various parts including the top tube, bottom tube, seat tube, chain stay, seat stay, and head tube. The commonly used bicycle frame is diamond shaped. Extensive research has been conducted on the overall frame of different shaped sports bicycle using different materials. However, there are opportunities to conduct detailed research on individual frame tubes under a variety of load conditions. Such investigations could provide deeper insights into the stress distribution, deformation characteristics, and failure mechanisms of each tube. Using finite element analysis, this paper investigates the comparative behavior of each tube of a diamond-shaped bicycle frame using three different materials: Steel, Aluminum 6061-T6 and Titanium alloy. Three load conditions - static start up, horizontal load and vertical load are considered for the analysis. This analysis examines the stresses, that occur within the bicycle frame tubes and indicate that, steel tubes show superior performance in handling both stress and deformation comparing to aluminum and titanium tubes. The analysis reveals that, steel tubes exhibit approximately 65% less deformation compared to aluminum tubes and 51% less deformation compared to titanium tubes. Among the frame components, the seat stay, seat tube, and top tube experience the highest levels of deformation for all load cases. Also, the results show that, strain energy is highest in steel tubes, while aluminum tubes exhibit the lowest strain energy.
Copyright (c) 2025 Md. Shaiful Islam, Md. Shahidul Islam (Author) https://creativecommons.org/licenses/by/4.0
Enhancement of Solar Panel Efficiency using Integrating Mirror-Based Solar Concentration and Passive Cooling Strategy
Solar photovoltaic systems are a pragmatic, scalable approach to capturing clean energy, providing a sustainable substitute for fossil fuel-derived electricity, and leading to a crucial element in the global shift to renewable energy. Significant emphasis is placed on improving the efficiency of solar panels. In this study, a mirror-augmented solar photovoltaic system was developed to absorb maximum solar radiation from the sun, and to lower the solar panel's temperature, a passive cooling mechanism was implemented. The modified system was incorporated with two mirrors aligned at an angle of 60° (approximately) relative to the PV panel surface on either side of the panel construction for solar radiation concentration. Fins made of aluminum were also embedded in the backside of the modified system to prevent solar panel damage due to excessive heat generation. A comparative investigation was conducted between a conventional solar photovoltaic system and a modified photovoltaic system. The typical conventional photovoltaic module produced a maximum current, voltage, and power of 1.24 A, 20.90 V, and 13.21 W, respectively, at a solar radiation level of 655.50 W/m². Under identical solar radiation, the newly designed solar panel produced a maximum current and voltage of 1.47 A and 21.5 V and a power output of 16.75 W. The modified system exhibits a 27% improvement in output power compared to the reference one.
Copyright (c) 2025 Mahmudul Hassan, Nibir Mondol, Reni Hossain, Md. Tanjir Rahman Mitul (Author) https://creativecommons.org/licenses/by/4.0
Study of Two Temperatures on Lab-scale Synthesis and Characterization of Hexagonal Boron Nitride
Hexagonal boron nitride (h-BN) is a potential 2D material due to its advantageous characteristics such as low specific density, resilience to high temperatures, increased interlayer shear force, broad bandgap, and resistance to oxidation. This study aimed to explore a cost-effective and lab-scale synthesis method of h-BN by optimizing two temperatures. For the synthesis of h-BN, sol-gel synthesis method has been used. The synthesized h-BN was characterized by FTIR, XRD, and Zeta potential. FTIR confirmed the formation of BN at 600°C for 4 M boric acid-based precursor solution. XRD analysis showed the crystal size 27.74 nm for h-BN. Zeta potential was measured -26.8 mV for h-BN. This study will help the scientific community to easily synthesize and further tune the properties of h-BN which will ultimately open a new door in many fields such as medicine, drug delivery, environmental remediation.
Copyright (c) 2025 Sifat Kawsar, Abrar Rafid Siddique, Abdullah-Al- Noman, Sayem Kawsar, Sumaiya Khan, Iftheker Ahmed Khan (Author) https://creativecommons.org/licenses/by/4.0
Experimental Analysis of Mechanical Properties of Carbon Fiber Composite with Nanoparticle Integration
This thesis investigates the mechanical properties of composite materials with varying fiber orientations and nanoparticle compositions. Tensile tests reveal distinct mechanical properties: the unidirectional (0-degree) composite demonstrates the highest strength (657.41 MPa), stiffness (32.39 GPa), and ductility (5.437% strain), while the 90-degree composite exhibits lower strength (437.95 MPa) and stiffness (19.25 GPa) but higher ductility (4.847% strain). The 45-degree composite falls between the other two in terms of mechanical properties. Three-point flexural tests show similar trends, with the unidirectional (0-degree) composite displaying the highest strength (589.09 MPa) and stiffness. Charpy impact tests confirm the superior impact strength of the 0-degree composite, with an average impact strength of 13.51 J/cm2 and a maximum of 14.1287 J/cm2 for the 0-degree-1 sample, while the 90-degree composite exhibits the lowest average impact strength of 7.27 J/cm2. Overall, this study provides valuable insights into composite material properties for specific applications.
Copyright (c) 2025 Amlan Biswas, Sobahan Mia, Md. Sabbir Hossain (Author) https://creativecommons.org/licenses/by/4.0