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. Each published paper is assigned a unique DOI (prefix 10.38032). 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
Numerical Analysis of Bubble Dynamics in Bifurcation Vessels with Stenosis and Varying Bifurcation Angle
In this study, a numerical investigation was conducted into the transport and splitting behavior of perfluorocarbon (PFC) bubbles within bifurcating arterial networks, with a focus on gas embolotherapy, a potential cancer treatment. A two-dimensional arterial model was used to examine how blood flow affects bubble dynamics. The volume of fluid (VOF) method in computational fluid dynamics (CFD) simulations was employed to model the interaction between capsular-shaped bubbles and blood flow. Multiple bifurcation angles, 60° and 90°, were analyzed, both with and without stenosis, to assess their impact on bubble movement and splitting phenomena. The results demonstrated that both bifurcation angle and stenosis significantly affected bubble behavior. In the 60° and 90° bifurcation vessels without stenosis, the bubble split homogeneously and traveled through the entire vessel path. However, in the 60° bifurcation vessel with stenosis, the bubble did not split homogeneously and passed through only one daughter artery. In contrast, the bubble split homogeneously in the 90° bifurcation vessel with stenosis. These findings provide valuable insights into how vessel geometry impacts bubble movement and splitting in blood and contribute to optimizing gas embolotherapy treatments.
Copyright (c) 2025 Ratul Das, Md. Mamunur Roshid (Author) https://creativecommons.org/licenses/by/4.0
Comparative Environmental Impact Analysis for Natural and Synthetic Fiber Reinforced Composites from a Life Cycle Assessment Context
Nowadays composites have become an interest for research due to their exceptional characteristics in various engineering fields. There are so many options available to be used as reinforcement in the composites. This results into combination of various desired properties for the suitable purposes. Despite these advantages, their production processes pose significant environmental concerns, warranting a thorough environmental impact assessment. Life Cycle Assessment (LCA) is an effective tool for evaluating the environmental implications of composite materials across their entire lifecycle, from "cradle to grave." this study, three distinct epoxy-based composite systems were analyzed: (1) glass fiber-reinforced, (2) jute fiber-reinforced, and (3) a hybrid composite combining natural and synthetic fibers. The assessment considered key environmental impact categories, including global warming potential, ozone depletion potential and non-carcinogenic human toxicity potential. To find out which composite is environmentally friendly the composites product system was compared using Openlca. Contribution analysis done for the composite containing both glass and jute fiber. Results reveal that jute fiber-reinforced composites, composed entirely of natural fibers, exhibited the lowest environmental impact due to their renewable and biodegradable nature. JFRPMC shows a GWP value of 1.933 kg CO2-eq, ODP value of 1.12x10-6 kg CFC-11-eq & HTP value of 2.2069 kg 1,4-DCB-eq. In contrast, the hybrid composite, incorporating both synthetic and natural fibers, demonstrated the highest impact in every evaluated category, attributed to the energy-intensive production of synthetic fibers and challenges in recycling mixed materials. Comparative analysis highlights the advantages of using natural fiber reinforcements for sustainable composite development, aligning with global efforts to minimize environmental footprints. This research underscores the importance of material selection and lifecycle optimization in reducing the ecological impact of composite production. The findings contribute valuable insights for industries aiming to balance performance and sustainability in composite manufacturing.
Copyright (c) 2025 Md. Sidratul Montaha Hossain, Abdullah Al Mahmood (Author) https://creativecommons.org/licenses/by/4.0
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
Assessment of Nickel and Iron levels in soil of Khulna City, Bangladesh
Nickel and iron are fundamental elements of soil composition. Due to urbanization, industrialization, and human activities, the accumulation of these metals is increasing in the soil, crossing the permissible limit, and threatening the ecosystem, humankind, and animals. This study's objective was to evaluate the amount of Ni and Fe in the soil of Khulna, a city in Bangladesh. 26 Samples were collected from several locations, including living and non-living area, industrial, roadway, riverbank, and dumping sites. The soil sample was processed, and then heavy metal contents of the soil sample was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The WHO specifies an acceptable level for Fe is 50,000 ppm and for Ni is 35 ppm. After analyzing the soil by ICP-MS, the quantity of Ni ranged between 22.6 ppm-137 ppm, and for Fe, it was 11100 ppm-59000 ppm. The amount of Ni in the sample region is relatively high; all the samples except sample-5 exceed the permissible limit. Conversely, only sample-10 of Fe crosses the permissible limit. These results provide information on the concerning buildup of nickel in Khulna’s soil, whereas the level of iron is quite tolerable. This study offers useful data for research investigations and decisions the concerned authority will need to make addressing Ni and Fe concentration.
Copyright (c) 2025 Samia Rahman, Maherjabin Elma, Ananya Barma, Shemanto Karmokar (Author) https://creativecommons.org/licenses/by/4.0
Verification and Validation of the Added Resistance of a Container Ship in Head Waves using Computational Fluid Dynamics Technique
Prediction of resistance in a seaway is always a challenging task for a naval architect. It is necessary to evaluate the performance of sea-going vessels in the earlier stage of design for both sea-keeping and economic perspectives of views. Traditionally required power is predicted based on calm water simulation with a predetermined allowance of (15-30%) of sea margin. This type of practice is totally reliant on experience and never represents the actual sea state. The present study evaluates the added resistance of a ship in a seaway at various wavelengths using RaNS based open-source Computational Fluid Dynamics solver OpenFOAM. The ship model was developed by the Korean Research Institute of Ship and Ocean Engineering and named as KRISO container ship of 3600 TEU. The experimental results of the hull are provided by NMRI (National Maritime Research Institute) in Tokyo CFD Workshop 2015. The current study begins with the validation of numerical results against experimental results. A systematic verification study based on grid size is further performed to evaluate the uncertainty present in numerical results. Finally, the added resistance coefficient is predicted for four different wavelengths at Froude number 0.26. It is seen from the computational results that the total resistance in the seaway increases with wave length and maximum resistance is found which is close to twice of calm water resistance in a situation where wave length is greater than ship length.
Copyright (c) 2025 Md. Golam Kibria, Md. Mashiur Rahaman (Author) https://creativecommons.org/licenses/by/4.0
Comparative Study on Hydrodynamic Performance of Planing Hull based on Empirical and Numerical Methods
Predicting the resistance of a planing hull is a challenging task due to its complex hydrodynamic behavior. The present study evaluates the hydrodynamic performance of a high speed patrol boat using Savitsky’s empirical method and an open-source RANS-based CFD (Computational Fluid Dynamics) solver, OpenFOAM 11. The key performance parameters include resistance, trim, and sinkage. The study begins with the validation of results obtained from CFD and empirical method against the experimental result of a deep V-type planing hull, known as the GPPH (Generic Prismatic Planing Hull), towed in calm water. The numerical results are also compared with the well-known Savitsky's 1964 method. The validation reveals that the CFD model, with an error of 0.95%, is more reliable than the empirical method, which has an error of 2.79%, as the CFD approach captures the dynamic behavior of the planing hull more effectively. A systematic verification study is performed to assess the numerical uncertainty based on grid size. Following the validation study, the same CFD model and empirical method were applied to a similar deep V-type patrol boat sailing in the waterways of Bangladesh. At higher speeds, a lower deviation between the empirical and numerical methods is observed. The dynamic pressure distribution on the hull and wave pattern were less affected due to a reduction in wave making resistance at a higher Froude number. Finally, the study extrapolates the resistance to the full scale, and the power requirements at five different speeds are obtained using both empirical and numerical methods. Savitsky's method and CFD method provide reliable resistance and power prediction for planing hull, with a deviation of 5% at higher Froude numbers.
Copyright (c) 2025 Sayed Sadik Siddique, Tausif Razzak, Md. Mashiur Rahaman, Laboni Afroz (Author) https://creativecommons.org/licenses/by/4.0
Predicting Gas Well Performance with Decline Curve Analysis: A Case Study on Semutang Gas Field
Decline-curve analysis (DCA) is a widely utilized method for production forecasting and estimating remaining reserves in gas reservoir. Based on the assumptions that past production trend can be mathematically characterized and used to predict future performance. It relies on historical production data and assumes that production methods remain unchanged throughout the analysis. This method is particularly valuable due to its accuracy in forecasting and its broad acceptance within the industry. Wells in the same geographical area and producing from similar geological formations often exhibit similar decline curve parameters. This study applies DCA to forecast the future production performance and estimate the ultimate recovery for the Semutang gas field's well 5 in Bangladesh. Using historical production data, decline curves were generated based on exponential, hyperbolic, and harmonic model equations. The cumulative production estimations were 11,139.34 MMSCF for the exponential model, 11,620.26 MMSCF for the hyperbolic model, and 14,021.92 MMSCF for the harmonic model. In terms of the well's productive life, the estimates were 335.13 days, 1,152 days, and 22,611 days, respectively. Among these models, the hyperbolic decline provided the most realistic forecast, closely aligning with observed production trend. The study highlights the importance of selecting an appropriate decline model for accurate production forecasting and reserve estimation, which is essential for effective reservoir management and resource optimization.
Copyright (c) 2025 Md. Shakil Rahaman, Ahmed Sakib, Ataharuse Samad, Md. Ashraful Islam (Author) https://creativecommons.org/licenses/by/4.0
Multivariate Jute Forecasting Using Ensemble Learning for Supply Chain Optimization
Reliable forecasts of crop production and yield are critical to improving food security and optimizing agricultural supply chains. Through utilizing machine learning (ML) techniques, this study seeks to optimize Bangladesh's jute supply chain through multivariate forecasting. It focuses on evaluating six ensemble learning models in order to forecast jute yield and production. Algorithms including Random Forest (RF), Gradient Boosting (GB), Category Boosting (CatBoost), Adaptive Boosting (AdaBoost), Light Gradient Boosting (LightGBM), and Extreme Gradient Boosting (XGBoost) were employed and their performance was thoroughly assessed to forecast yield rate and production on the basis of historical data. Performance was evaluated utilizing mean squared error (MSE) and R2 scores to determine the best model. With the lowest MSE of 0.0820 and the highest R² of 0.9199, LightGBM was found to be the best-performing model, showcasing its superior accuracy in identifying intricate patterns and complex dependencies in the dataset. The findings demonstrate how LightGBM may lessen inefficiencies and lessen supply chain instability in the jute industry, which has historically been plagued by erratic weather patterns and shifting consumer demand. This study applies ensemble learning techniques specifically to jute forecasting and is one of the first to combine yield rate and production in a single multivariate framework. It is anticipated that the improved predictive capability of the model will help stakeholders such as farmers, traders, and policymakers to enhance decision-making, reduce waste, and promote better resource allocation across the supply chain. Moreover, the study's established ensemble learning framework's scalable nature provides a means of extending its use to other agricultural sectors in Bangladesh. This study also advances data-driven approaches to crop management and supply chain optimization, which boost sustainability and profitability in the jute sector and beyond.
Copyright (c) 2025 Mohammad Morshed, Faiyaz Bin Mahmud, Md Jawad Bin Rouf, Mohammad Mynul Islam Mahin (Author) https://creativecommons.org/licenses/by/4.0
Fabrication of Printed Luminescent Finished Leather using Cu-doped ZnS: A Versatile and Luxurious Innovation
This study introduces "Printed Luminescent Finished Leather," a novel finishing effect that enhances leather with a glowing feature. Copper-doped zinc sulfide (Cu-doped ZnS) luminescent pigment was synthesized via mixing and calcination at 600 °C, characterized by photoluminescent spectra (PL), X-ray diffraction (XRD), Fourier-transform infrared spectrometer (FT-IR), and Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) analysis. The analysis confirmed that Cu-successfully doped on ZnS nanostructure and exhibited Luminescent behaviour. Six leather samples, prepared with varying pigment quantities (3-7 gm/sq. ft), types (liquid and powder), and application methods (spraying, masking, stenciling, drop staining), and were evaluated through standard performance tests. These tests assessed color rub fastness, wash fastness, heat and perspiration resistance, with all samples scoring between 3 and 5 on the grey scale for finish film appearance and glow intensity under the both daylight and UV light. The adhesion strength of the finish film exceeded 200 gm/cm. The study found that a total luminescent pigment quantity of 7 gm/sq. ft yielded optimal results, with sample 5 exhibiting the best combination of glow intensity, adhesion, and persistence. The addition of luminescent pigments transforms ordinary leather into a visually appealing material, offering diverse applications such as fashion items, accessories, luxury upholstery, and interior design. This innovation holds significant economic potential for the leather sector, positioning it as a high-value product that can drive exports and satisfy consumer demands in global markets.
Copyright (c) 2025 Md Abdulla-Al-Mamun, Masrafe Bin Imran (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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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