MIST International Journal of Science and Technology (MIJST)
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Item The Influence of Silt Layer Orientation on Slope Stability in Shale Formations(Research and Development Wing, MIST, 2025-06) Alam, AKM Badrul; Fujii, Yoshiaki; Li, Zhixue; Hasan Dipu, Nahid; Tajib–Ul–Islam, Md.; Ahmed Razo, ShakilShale rock masses often include silt layers, impacting slope stability in construction and mining. Analyzing their interaction is crucial for long-term stability. This study used an elasto-plastic model, incorporating the stress transfer method and Coulomb's criterion. It computed stress distribution, assessed failure potential, and identified vulnerable regions. A shale rock mass ranging from 14.75 to 16.75 meter thick, with silt layers varying from 0.36 to 0.5 meter thick was considered in the model. It examined four silt layer conditions: horizontal (SilHL), vertical (SilVL), in-facing (SilIN), and out-facing slope (SilOUT). Mechanical parameters like Uniaxial Compressive Strength (UCS), Tensile Strength (TS),andYoung’s modulus (E) were adjusted for varied scenarios: UCS (0.5 to 5 MPa), and E(6 to 60 MPa), keeping UCS/TS = 5 for all the conditions. In the elasto-plastic analysis, overall reductions of 20%, 40%, 60%, 80%, and 90% in E, UCS and TS were evaluated, taking into consideration the temporal degradation. The findings for SilHL indicate that: (i) when the E, UCS, and TS of the silt layer and shale were equivalent, significant structural failure occurred at 60% reduction, with pronounced collapse at 80% and complete failure at 90%; (ii) a lower Ein the silt layer with equivalent strength to shale showed no significant differences; (iii) reductions in both Eand UCS for the silt layer also revealed no notable differences. For SilVL, the results were similar, with (i) consistent effects as SilHL; (ii) slippage occurring with a lower Efor the silt layer; and (iii) bitension failure and toppling observed when the silt layer's strength was one-tenth that of shale. In SilIN, similar patterns emerged, with slippage and tension failures noted under reduced Eand UCS conditions. For SilOUT, results mirrored SilHL, with tension failures and divergence in failure patterns under reduced Eand UCS. The results of this study indicate that slope failure scenarios involving shale with a silt layer can be effectively simulated using the elasto-plastic method, particularly by incorporating reductions in strength and Young’s modulus. Furthermore, these findings highlight the critical need for additional research on specific slope configurations to refine design methodologies and enhance stability assessments within the context of the elasto-plastic model.Item Aerodynamic Characteristics and Flow Patterns of Square Cylinders with Rounded Facets(Research and Development Wing, MIST, 2025-06) Biswas, NripendranathThis study experimentally investigates the effect of facet widthon the static pressure distribution around a single square cylinder with rounded facets. Experiments are conducted in an open-circuit wind tunnel at a Reynolds number of 5.4 × 10⁴, based on the side dimension of the cylinder subjected to a uniform flow velocity of 13.6 m/s. Five different dimensionless facet widthsare systematically introduced to assess their influence on pressure distribution at varyinganglesof attack. Static pressure measurements are collected around the perimeter of the cylinder, and the resulting data are processed through numerical integration to determine the corresponding drag coefficients. The results demonstrate that incorporating facets significantly modifies the aerodynamic characteristics of the cylinder by reducing the drag coefficient comparedto that of a sharp-edged configuration. The drag reduction is primarily attributed to delayed flow separation and a decreasein the size of the wake region. However, beyond a critical facet width, further increases produce only marginal improvements, indicating the presence of an optimal range for facet dimensions. This research demonstrates that facet modification is an effective and practical approach for controlling aerodynamic drag in bluff bodies. The findings offer valuable insights for optimizing structural designs subjected to wind loads, highlighting potential applications in civil engineering fields such as building design, bridge construction, and tower development. By deepening the understanding of how minor geometric alterations can impact flow behaviour, this work contributes to the development of safer, more efficient, and aerodynamically stable structures exposed to atmospheric winds.Item Correlation Analysis of Rate of TEC Index and Spread F over North American Ionosondes(Research and Development Wing, MIST, 2025-06) Rafi, Mehdi Hasan; Mostafa, Md GolamThis study investigates the diurnal, seasonal, and latitudinal variations of Spread F and theRate of TEC Index (ROTI) over North America during the high solar activity period of 2014. Using GNSS-based ROTI measurements and Digisonde ionograms from multiple stations, we systematically analyze the relationship between Spread F occurrences and ROTI enhancements. The analysis incorporated Diurnal and seasonal variations to determine dominant trends and potential drivingmechanisms, such as medium-scale traveling ionospheric disturbances (MSTIDs) and polarization electric fields. Seasonal and latitudinal variations of Spread F occurrences and ROTI fluctuations are found to be strongly linked to MSTIDs and geomagnetic activity. A clear seasonal dependence was observedat the stations situated under the transitional and mid-latitude regions of the ionosphere. The maximum irregularity occurred in April for transitional region stations and in Novemberfor mid-latitudinal stations. Additionally, Spread F and ROTI exhibit similar diurnal and seasonal trends, with maximum irregularity occurrences during nighttime (20:00–02:00 LT). A distinct seasonal dependence is observed, with transitional region stations peaking in winter and mid-latitude stations in summer. Notably, spread Fwas consistently associated with notable ROTI values (>0.15 TECU/min), suggesting gravity waves and polarization electric fields as driving mechanisms. Through detailed case studies, we demonstrated that MSTIDs, likely driven by gravity wave dynamics, play a crucial role in generating plasma irregularities, which in turn enhance ROTI values and contribute to Spread F formation. Under quiet geomagnetic conditions, these irregularities exhibit a strong daytime preference. Conversely, during disturbed geomagnetic conditions (e.g., the geomagnetic storm), the spatial extent of ionospheric irregularities increased significantly, affecting both transitionaland mid-latitude stations for both daytime and nighttime.By demonstrating a persistent relationship between Spread F and ROTI, this study advances ionospheric modelling efforts and supports the development of improved space weather forecasting techniques, crucial for GNSS-based navigation and communication systems.Item System Usability and Design Evaluation of AI Chatbots: A Comparative Analysis of ChatGPT, Google Bard, and Bing Chat(Research and Development Wing, MIST, 2025-06) Mustafina, Sumaiya Nuha; Khan, Nusrat Kaniz; Islam, Muhammad Nazrul; Siddiqua Nusrat, Fatema; Akhtaruzzaman, M.Artificial intelligence (AI) has brought significant advancements in technology while the chatbots like ChatGPT, Google Bard, and Bing Chat are some of its remarkable innovations. These chatbots are helping users with diverse backgrounds by generating ideas, providing resources, and overall knowledge management. We acknowledge that these chatbots are still in their experimental stages of use. Evaluating the usability and user experience of chatbots becomes crucial to make them more usable, accessible, and intuitive to end users around the globe. Thus, the objectives of this research are to make a comparative usability analysis of AI-generated chatbots: Google Bard, ChatGPT, and BingChat. To achieve these goals, firstly, the System Usability Score (SUS) through questionnaire surveys and secondly, Heuristic Evaluation (HE) through expert observation were used. Through HE, we investigated characteristics of design, user engagement, and some other specific usability lacking along with a severity score that suggests both urgent and gradual usability improvement action. As an outcome, this study found that the SUS evaluation provided a comprehensive view of user satisfaction. Google Bard and Bing Chat received lower SUSscores, while ChatGPT demonstrated comparatively better usability, with a SUS score above 70. Again, a comparative usability analysis of AI-generated chatbots (ChatGPT, Google Bardand Bing Chat) reveals that, while all these applications suffer from a notable number of usability problems, ChatGPT demonstrates better usability performance compared to Google Bard and BingChat.Item Predicting Economic Resilience in Nigeria Using Machine Learning: A Framework for Policy Intervention(Research and Development Wing, MIST, 2025-06) Omololu, Akinrotimi Akinyemi; Ajibade, Oyekunle Rafiat; Abolore, Mabayoje ModinatEconomic resilience is important in sustaining the state of the Nigerian economy from different distortions. Therefore, the current study implemented a machine learning method for estimating and forecasting Nigeria's economic resilience by using the following principal macroeconomic indicators: GDP growth, inflation, exchange rate, unemployment, debt-GDP ratio, and foreign reserves through Decision Trees (DT) and Random Forest (RF) algorithms. Amongst these, the prediction accuracy was approximately 86% by Random Forest in terms of predicting an economic downturn when compared to Decision Tree. Thus, GDP growth, inflation, and exchange rate variability were singled out as the key predictors of economic resilience. This implies that the policy ramifications of the machine learning model results are geared toward controlling inflation, stabilizing the exchange rate, creating jobs, and promoting economic diversification. The results provide data-informed policy-making to support the resilience features of the Nigerian economy.Item Structural and Thermal Analysis of Fuel Rod of VVER-1200 Nuclear Reactor Using ANSYS Software(Research and Development Wing, MIST, 2025-06) Nusrat Jahan Shanta, Shah; Mollah, Abdus SattarThis study focuses on analyzing the thermo-mechanical behavior of fuel rods in VVER-1200 nuclear reactors to ensure their safe and efficient operation. Bangladesh plans to operate two VVER-1200 reactors at Rooppur by 2025/2026, aligning with global effortsto shift toward low-carbon energy sources. The analysis, performed using ANSYS software, evaluates key parameters such as deformation, stress, strain, temperature distribution, and heat flux. A detailed geometric model of the UO₂ fuel rod with zirconium alloy cladding and helium gas in the gaphas been developed. Thermal distribution simulations under steady-state conditions reveal critical temperature gradients, while structural analysis identifies high-stress regions due to thermal expansion and operational loads.Item A Preliminary Assessment of Power Savings by Flettner Rotors Installed on a Cargo Ship(Research and Development Wing, MIST, 2025-06) Hasan Moon, Mahin; Ariyan Zaman, Sikder; Hussain, Md. Daluar; Uddin, Md. MezbahIn response to increasingly stringent environmental regulations by the International Maritime Organization (IMO), this study presents a preliminary assessment of Flettner rotors as a viable wind-assisted propulsion system for cargo ships. Using RANS-based Computational Fluid Dynamics (CFD), the aerodynamic performance of various rotor configurations is evaluated under different wind speeds, spin ratios, and angles of attack. Initially, an isolated 2D and 3D rotor at model scale are simulated for various operating conditions. A grid convergence study is conducted as part of the CFD results verification process. A cargo ship fitted with Flettner rotors is simulated to compute resistance and to evaluate rotor to rotor interaction. The obtained results and analyses demonstrate that, under optimal conditions, Flettner rotors have the potential to reduce fuel consumption and emissions by around 20%, significantly enhancing propulsive efficiency.Item The Impact of Modern Research and Innovation on Society and Individuals(Research and Development Wing, MIST, 2025-06) Rahman, Fazlar; Rabbi, Fazle; Bhuiyan, Md. Shahnewaz; Harun-or-Rashid, MohammadLife quality and socio-economic conditions have improved dramatically over the last century due to the rapid advancement and innovation of modern technologies, which have evolved from the fruitful research of scientists. It will continue to grow throughout the twenty-first century and beyond and reach every corner of the globe without ambiguities. Scientists research and innovate ideas, technology, and tools for enhancing life quality, productivity,economy, and environment. However, inappropriate implementation, strategy, and design could drive society and individuals backwards. Recently, humans have encountered severe and periodic natural catastrophes, such as intense hot and cold climates, deluges, tsunamis, typhoons, landslides, droughts, wildfires, pandemics, etc., as well as nation-and society-driven riots, wars, espionage, and social phobia, where modern tools and innovations employed. It severely affects the mental health and socio-economic conditions of individuals and society due to the damage to infrastructure, shelter, agricultural land, deaths of humans, animals, and livestock, and environmental pollution. Besides, detrimental events are caused by environmental pollution and global warming and are triggered by human activities and abusing of modern innovations and science. This study qualitatively explores the most influential impacts of contemporary research and innovation in different fields on society and individuals by investigating the recent relevant research and events. It is revealed that modern innovations and technology have severe detrimental impacts on society and individuals if they are abused and executed recklessly. This study will aid in reducing and understanding the harmful effects of research and innovation on society, ultimately enhancing social health and progress.Item Investigation of the Mechanical Properties of Repurposed-Net-Bag Reinforced Plastic(Research and Development Wing, MIST, 2025-06) A. Saqafi, Ahmed; Sadia, Afnan; R. Tarek, Al-Amin; A. Alim, Ahad; Y. Tuly, Farzana; Rahman, Md. A.This study investigates the potential of recycling grocery net bags for reinforcing epoxy matrix composites, leveraging their favorable strength-to-weight ratio and offering a costreduction and non-biodegradable waste reduction method. A composite material was made by combining 90 layers of fiber mesh with Lapox Metalam System B epoxy and hardener. The primary objective was to explore major mechanical properties, including ultimatetensile strength, yield strength, flexural strength, and impact strength. The ASTM-specified standards were maintained for the fabrication and testing of the specimen, utilizing a universal testing machine (UTM) and a pendulum impact tester. Test results show that elastic modulus of the composite ranges from 0.72 to 0.88 GPa and shear modulus ranges from 1.73 to 2.26 GPa. Also, the impact tests show an average impact strength of 66.27 kJ/m2.Item A Review on Assessment and Management of Occupational and Health Risks in the Shipbuilding Sector of Bangladesh(Research and Development Wing, MIST, 2025-06) Islam, A H M Rafiqul; Tasnim Sarah, Umme; Zakaria, N. M. Golam; Begum, ShahidaBangladesh’s shipbuilding sector makesa significant contributionto the country’s economy. However, it is also associated with occupational risks for its workforce. This paper aims to review and explore existing literature on assessing and managing these risks within the context of Bangladesh shipbuilding industry. The review delved into different types of hazards encountered by shipyard workers, including physical, chemical, and biological dangers, by analyzing incident reports, safety audits, and exposure data elaborated in the literature. Furthermore, the review also examines established methods applied to the international and local shipbuilding industry for risk assessment and management and makes a comparison to find the gap in the literature. The study reveals a significant amount of literature covering various focus areas within the global shipbuilding sector. However, only a limited number of these works are relevant to Bangladesh shipbuilding industry, and among them, only very few papers deal with the Occupational Health and Safety assessment technique. This highlights a huge gap in the literature and suggests a need for more studies regarding Occupational Health and Safety management in Bangladesh shipbuilding.