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Ozone (O3), a major air pollutant, can negatively impact plant growth and yield. While O3 impacts have been widely documented in crops such as wheat and soybean, few studies have looked at the effects of O3 on sorghum, a C4 plant and the fifth most important cereal crop worldwide. We exposed grain sorghum (Sorghum bicolor cv. HAT150843) to a range of O3 concentrations (daytime mean O3 concentrations ranged between 20 and 97 ppb) in open-top chambers, and examined how whole plant and leaf morphological traits varied in response to O3 exposure. Results showed no significant impact of realistic O3 exposure on whole plant biomass and its partitioning in sorghum. These findings suggest that sorghum is generally resistant to O3 and should be considered as a favourable crop in O3 polluted regions, while acknowledging further research is needed to understand the mechanistic basis of O3 tolerance in sorghum.

Hybrid renewable energy systems, well-known for their ability to use multiple renewable sources parallelly to supply power, generate significant energy excess to demand. This study optimizes a standalone hybrid renewable energy system (HRES) for Rangabali Upazila, Bangladesh, integrating PV, wind turbines, a diesel generator, and either pumped-hydro storage (PHS) or batteries. The system addresses electricity demand and freshwater production using excess energy. Simulations in HOMER Pro indicate that PHS outperforms battery storage in both economic and environmental aspects. Systems with PHS achieve a net present cost (NPC) of $28.33M and a cost of energy (COE) of $0.175/kWh in both load-following and cycle-charging strategies, compared to $33.57M NPC and $0.207/kWh COE for the systems with battery. Additionally, PHS systems achieve zero emission as they do not require diesel generator operation, while battery systems consume up to 415 L of fuel and emit 1098 kg of CO₂ annually. The results demonstrate that the proposed systems ensure reliable power and freshwater supply, contributing to sustainable development in remote regions. Note: This paper was accepted at ICMIME 2024, organized by Faculty of Mechanical Engineering, RUET. The proceedings were not formally published or assigned a DOI. This version is uploaded as a preprint to ensure open access and proper citation.

In this study, a simplified computational model of the blanket mock-up is created using the SERPENT Monte Carlo Code. The nuclear data is obtained from the enriched ENDF/B.VII.1 data library to conduct this study. The model is validated, as the error percentage for 63Cu(n,2n)62Cu and 65Cu(n,2n)64Cu reactions is less than 10% when compared to experimental results. The computational model is used to calculate the tritium production rate in different lithium zones with various neutron multipliers (U, Pb) and without any multipliers. The results show that the tritium production rate with a uranium multiplier is 86% higher than with a lead multiplier and 238% higher than with no multiplier. The neutron energy spectrum shows a peak in the 0.1 MeV to 10 MeV energy range for every case. This study also examines the effects of fusion neutrons on different isotopes, providing valuable data on how materials behave under high-speed neutron exposure.

The microgrid (MG) faces significant security issues due to the two-way power and information flow. Integrating an Energy Management System (EMS) to balance energy supply and demand in Malaysian microgrids, this study designs a Fuzzy Logic Controller (FLC) that considers intermittent renewable sources and fluctuating demand patterns. FLC offers a flexible solution to energy scheduling effectively assessed by MATLAB/Simulink simulations. The microgrid consists of PV, battery, grid, and load. A Maximum Power Point Tracking (MPPT) controller helps to extract the maximum PV output and manages the power storage by providing or absorbing excess power. System analysis is performed by observing the State of Charge (SoC)of the battery and output power for each source. The grid supplies additional power if the battery and PV fail to meet the load demand. Total Harmonic Distortion (THD) analysis compares the performance of the Proportional-Integral Controller (PIC) and FLC. The results show that the PI controller design reduces the THD in the current signal, while FLC does not reduce the THD of the grid current when used in the EMS. However, FLC offers better control over the battery's SOC, effectively preventing overcharging and over-discharging. While PI reduces THD, FLC provides superior SOC control in a system comprising PV, battery, grid, and load. The findings demonstrate that the output current is zero when the SOC is higher than 80% or lower than 20%, signifying that no charging or discharging takes place to avoid overcharging and over-discharging. The third goal was accomplished by comparing and confirming that the grid current's THD for the EMS designed with both the PI Controller and the FLC is maintained below 5%, following the IEEE 519 harmonic standard, using the THD block in MATLAB Simulink. This analysis highlights FLC's potential to address demand-supply mismatches and renewable energy variability, which is crucial for optimizing microgrid performance.

Rice is the staple food of the people of Bangladesh. Burning and landfilling of carbon-rich rice straw (RS) causes greenhouse gas emissions. On the other hand, cow dung (CD) and poultry droppings (PD) produced from the livestock sector in Bangladesh could be a potential threat to the environment if the wastes are not properly managed. However, anaerobic co-digestion of RS with CD and PD could be an effective means of biogas generation. Therefore, co-digestion of CD and PD with carbon-rich RS was conducted in batch assay at seven different mixing ratios (100:0, 90:10, 70:30, 50:50, 30:70, 10:90, 0:100) separately. Mesophilic condition (35 °C) was maintained for 92 days of digestion time to investigate biogas production potential and find out optimal mixing ratios of both co-digestion sets. Co-digestion of CD and RS at 70:30 ratio significantly showed maximum biogas yield (441.7 ± 54.1 ml/gVS). Additionally, an increase in biogas yield in this ratio was 212.11 % and 38.10 % compared to mono-digestion of CD and RS, respectively. Another co-digestion set of PD with RS showed highest biogas yield (344.8 ± 22.3 ml/gVS) at 90:10 ratio. The 90:10 ratio of PD and RS improved biogas yield by 173.16 % and 7.8 % as compared to mono-digestion of PD and RS, respectively. Co-digestion of RS with CD and PD had a statistically significant effect (P ≤ 0.05) on biogas production. Furthermore, kinetic modelling outcomes suggested the modified Gompertz model as ideal for forecasting biomethane production over time in both cases. The findings of this study will help in the implementation of ACoD at the field level.

Concrete, the most widely utilized material in construction worldwide, contributes significantly to the consumption of natural resources and energy. The construction sector is a major source of waste and greenhouse gas (GHG) emissions, making it essential to improve the environmental impact of concrete to address climate change and pollution concerns. Evaluating the environmental footprint of concrete is crucial for advancing sustainable building practices. Cement, a key binder in concrete, is particularly responsible for GHG emissions due to its energy-intensive production process. This study applies the Life Cycle Assessment (LCA) methodology, using SimaPro software and the Ecoinvent database, to assess the environmental impact of concrete. A modified concrete mix was developed by replacing Portland Composite Cement with Eggshell Powder (ESP) (60% by weight) and Sawdust Ash (SDA) (40% by weight) at varying replacement rates of 10%, 20%, 30%, and 40%. The results showed up to 20% for replacement cement with ESP and SDA improved compressive strength in a 28-56 day period, with the highest strength growth rate of 29.58% observed for the mixes with replacement. However, higher replacement levels of 30% and 40% showed limited strength improvement during the same period. The enhanced compressive Strength and higher strength growth (compared to tra- ditional concrete) are observed withare0-20 % replacement of cement s. This suggests that this blend of materials could be used in projects with significant budget constraints, directly decreasing carbon emissions associated with concrete production. This aligns with global sustainability goals and can be used in projects aiming for green certifications like LEED (Leadership in Energy and Environmental Design). The study indicates that substituting cement with ESP and SDA reduces costs. This can sig- nificantly benefit low-budget housing projects or areas with high cement prices, providing a direct economic advantage. The environmental performance of the modified concrete was analyzed through LCA following the ISO 14040:2006 framework, focusing on the cradle-to-grave impacts, including raw material extraction, energy consumption, and water usage. One cubic meter of concrete was chosen as the functional unit. The analysis revealed significant reductions in the endpoint impact categories, including a 59% reduction in ecosystem impacts, 60% in human health, 61% in resource depletion, 59.79% in ozone depletion, and 54.32% in fossil fuel depletion. These results highlight the potential of ESP and SDA as sustainable alternatives for improving concrete's mechanical properties and environ- mental performance, supporting the development of more sustainable construction practices.

The textile industry is growing due to economic development and a rising global population, raising environmental concerns such as high energy and water use, water emissions, and chemical consumption. This master thesis reviews emerging textile production technologies that claim to be environmentally friendly and establishes criteria for assessing them. Specifically, it evaluates the environmental performance of supercritical CO2 (SC-CO2) dyeing compared to conventional dyeing. SC-CO2 dyeing technology & Seven criteria are developed for evaluating these technologies: environmental potential, technical quality, flexibility, technology readiness level (TRL), cost, resource availability, and interest. SC-CO2 dyeing is chosen for detailed evaluation. A Life Cycle Assessment (LCA) was conducted comparing SC-CO2 dyeing with conventional dyeing across four scenarios, using two electricity mixes and optimizing CO2 losses. Results show that SC-CO2 dyeing can be environmentally beneficial if optimized for CO2 emissions and energy use, and if greener electricity is used. However, electricity production remains a major impact factor. This thesis provides an initial assessment of SC-CO2 dyeing’s environmental performance and suggests that further research is needed to confirm its benefits for the textile industry.

While climate change impacts the entire world, the people of Bangladesh bear a disproportionately heavy burden. Situated at the forefront of extreme climatic events such as cyclone, flood, saltwater intrusion, drought, and heavy rainfall, they face severe vulnerabilities. Coastal communities have been facing climate change impacts and livelihood threats for some time now. Hatiya – a coastal Upazila (sub-district) of the Noakhali District in Bangladesh faced extreme climatic and socio-economic challenges in the recent past. To understand the climate change-induced risks and vulnerabilities of Hatiya Upazila, it is vital to understand the socioeconomic and livelihood vulnerability index of this area. In this study, the Livelihood Vulnerability Index (LVI), Socioeconomic Vulnerability Index (SeVI) and Livelihood Vulnerability Index-Inter-Governmental Panel on Climate Change ​(LVI-IPCC) vulnerability index have been analyzed to evaluate the impacts of climate change on the livelihood and socioeconomic profile of the affected communities of Hatiya. A total of 150 household surveys and 11 Focus Group Discussions have been conducted in Hatiya Upazila for this purpose following purposive random sampling. The collected data included livelihood strategies, social network & communications, food, health, water, social, economic, physical, and climatic disaster & variability. All these vulnerability indicators were divided into 7 sub-components of LVI, and 5 subcomponents of SeVI, forming indicators to measure the desired vulnerability index. The index was formed by three IPCC endorsed climate change vulnerability indicators i.e., exposure, sensitivity, and adaptive capacity. The LVI value of Hatiya Upazila was found to be 0.495, which indicated that Hatiya has a medium vulnerability in terms of livelihood. Based on the weighted average scores, Hatiya was found to be the most vulnerable due to natural hazards (0.729), while indicators within this domain revealed that the highest percentage (64.6%) of households lost their property and other resources during natural hazards. In addition, Hatiya possessed a high level of socio-economic vulnerability (0.704). Livelihood Strategies become less diversified with the increased deterioration rate of natural resources such as fishing, agriculture, forest resources, etc. Most of the households were found to have weak Social Network & Communications as they did not go to the local government or others for any kind of help, so the score for these components (0.722) was in the highly vulnerable range of LVI. However, the LVI-IPCC value of the study area was 0.027, indicating medium vulnerability. The SeVI index value for Hatiya Upazila was 0.704 which indicated high vulnerability and social, and economic vulnerability mostly influenced by natural hazards. The average indexed values of the three LVI-IPCC climate change contributing factors such as adaptive capacity, exposure, and sensitivity of Hatiya Upazila were 0.631, 0.573, and 0.465 respectively. This study can be a baseline for vulnerability assessment of climate change-affected communities in coastal Bangladesh and the government can take proper initiatives to facilitate adaptive capacity to reduce the climate change vulnerability of the local communities.