This study evaluates the effect of Calcium carbonate (CaCO₃) on the mechanical properties and structure of SEBS-compatible PA6/ABS composites. Composites consisting of 50/50 PA6/ABS, 5% SEBS, and 0–20% by weight CaCO₃ were fabricated by injection molding. Tensile and flexural strengths were determined according to ISO 527-2:2012 and ISO 178:2019, respectively. The tensile strength increased with filler content, peaking at 15 wt% CaCO₃ (24.72 MPa), while flexural strength reached a maximum at 10 wt% (32.51 N/mm2). FESEM revealed a uniform dispersion of CaCO₃ particles and strong interfacial adhesion at optimal filler contents, whereas agglomeration and microvoids occurred at higher loadings. The results demonstrate that moderate CaCO₃ addition enhances stiffness and strength through effective stress transfer, while excessive loading induces brittleness due to poor interfacial bonding. This study contributes to the optimization of hybrid polymer composites for structural, automotive and precision engineering

Proton exchange membrane fuel cells (PEMFCs) have attracted significant attention due to their high efficiency and low emission characteristics. However, the cell performance is strongly influenced by operating conditions and membrane properties, which are difficult to investigate comprehensively by experimental approaches alone. This study develops a complete electrochemical model of a single PEM fuel cell in the MATLAB – Simulink environment based on the voltage loss mechanisms including the Nernst potential, activation overpotential, ohmic losses, and concentration losses. The model is employed to quantitatively investigate the effects of operating temperature, hydrogen partial pressure, oxygen partial pressure, and membrane thickness on the polarization characteristics (I – V curves) of the PEMFC. Simulation results indicate that increasing temperature significantly enhances activation kinetics and improves cell voltage, while elevated oxygen partial pressure yields the most pronounced performance improvement among gas parameters. Conversely, increasing membrane thickness leads to higher ohmic losses and voltage degradation, especially in the high –current – density regime. The proposed model provides an effective numerical tool for teaching, system analysis, and preliminary optimization of PEMFC operating conditions.

In recent years, water hyacinth (Eichhornia crassipes) has been widely recognized as an invasive aquatic plant that proliferates rapidly on rivers, canals, ponds, and lakes, obstructing waterway transportation, impeding water flow, and contributing to environmental degradation. Despite its abundance in large river systems such as the Bach Dang River in Thu Dau Mot City, Binh Duong Province, this biomass resource remains largely underutilized, leading to significant waste of natural materials and ongoing ecological challenges. This study proposes an eco-friendly alternative by transforming water hyacinth into handmade paper sheets with natural coloration, rustic aesthetic, and complete absence of harmful chemicals. The resulting products exhibit acceptable strength and surface quality, making them suitable for practical and decorative applications including coasters, shoe insoles, greeting cards, notebooks, biodegradable packaging, paper bags, and eco-handicraft items. Raw materials were collected directly from the Bach Dang River by a student research group. The research employed a combination of primary and secondary data collection methods, along with experimental, analytical, and synthesis approaches to develop and evaluate the manual paper-making process. The developed chemical-free production method successfully yielded durable paper sheets that are environmentally safe and biodegradable. The findings demonstrate the feasibility of converting an invasive plant into value-added sustainable products, thereby contributing to waste reduction, biomass reuse, and the promotion of green production practices. Although the study is preliminary and limited by manual processing, lack of mechanization, and absence of standardized quantitative testing (e.g., tensile strength, water absorption, and biodegradability under controlled conditions), it provides a promising foundation for further optimization and scale-up. Future research should focus on improving uniformity, enhancing mechanical properties through natural additives, and conducting comprehensive performance and life-cycle assessments to support practical commercialization and broader environmental impact

This study explores the fabrication and performance analysis of ultra-thin III-V solar cells using indium phosphide (InP) epitaxial wafers through two approaches: substrate thinning via lapping and thermocompression bonding. The thinning method reduced the substrate thickness to 160 μm, while the bonding process achieved a final thickness of 0.9 μm. Photoluminescence (PL), internal quantum efficiency (IQE), and external quantum efficiency (EQE) measurements were conducted to evaluate the devices. Results showed that the thinned solar cells exhibited poor photovoltaic characteristics due to suboptimal n-type metal contacts and excessive electron-hole recombination, with no observable light-induced current at zero bias. Backside solar cells fabricated through bonding showed better performance, with improved IQE and EQE due to enhanced light penetration and reduced reflectance from an anti-reflection coating. PL analysis revealed a distinct 1280 nm peak for the backside structure, indicating better light interaction with the active region. Despite these advances, both methods demonstrated low open-circuit current and power efficiency, underscoring the need for further optimization to achieve commercially viable III-V solar cells.

High penetration of photovoltaic (PV) sources causes volatility in distribution networks, challenging conventional operational strategies. This study introduces a multi-objective optimization framework using a Stabilized Genetic Algorithm (SGA) that co-optimizes daily energy losses and switching asset depreciation over typical and extreme loading scenarios. Contradicting common assumptions, results show that zero switching operations, i.e., maintaining a robust static configuration - yield optimal economic outcomes for the IEEE 33-bus test system, regardless of switching cost magnitude. The work formalizes an economic viability threshold for DDNR, providing network operators with a quantitative tool to assess when dynamic reconfiguration is truly justified. Results reveal that for the IEEE 33-bus system with PV integration, a robust static configuration remains economically optimal regardless of switching cost magnitude. The primary contribution is the formalization of an "Economic Viability Threshold" framework, providing DNOs a quantitative tool to determine when DDNR is truly justified. This framework provides a crucial, data-driven tool for network operators to prevent unnecessary investment in complex control schemes, ensuring that grid modernization efforts are both technically sound and economically viable

Enzyme immobilization offers an innovative approach for reuse, preservation, and optimization of production efficiency and costs in the food and biofuel industries. In this study, amylase enzymes immobilized in Ca-alginate membranes were utilized in the fermentation of traditional sticky rice wine. The morphology and activity of immobilized amylase beads were maintained effectively at a 2% concentration of both carrier material and enzyme solution. After seven days of fermentation, fermentation efficiency reached an ethanol concentration of 55% v/v. The activity of immobilized amylase retained 60% of its activity after four consecutive fermentation cycles. These results suggest that immobilized amylase beads have promising applications in sticky rice wine production, replacing free amylase, which is difficult to recover and reuse.

In this topic, we applied the Fmincon function to the optimum question when choosing the structure of a 7-bar bearing steel bearing, divided into groups of the same size, including group 1 (1, 2 bars), group 2 (3, 4, and 5 bars), and group 3 (6, and 7 bars) with three fixed head points and two bearing points. Using the Matlab software code, we have identified the structures of each group of steel bars corresponding to the radius of 1.564 cm, 3.509 cm, and 4.724 cm, respectively. Through this, we can identify the 1, 2, and 3 bars that are resistant to traction; the 3, 5, 6, and 7 bars that are subject to compression; and the 4 bars alone that are not subject to the action of the force. The results show that using the optimal method, we choose the different sizes, thicknesses, and volumes of the pipe so that it best suits the technical requirements of the paper, to avoid waste of raw materials, affecting the economic cost.

Cordyceps has long been considered as a valuable medicinal herb known to possess numerous biological activities, including anti-microbial, anti-cancer, anti-metastasis and immunomodulatory effects. With its benefits, many studies on optimizing the cultivation and production of C. militaris have been carried out. In addition, extraction methods have also been improved to intense efficiency extract the medicinal substances contained in this rare fungi. In this study, the aim was to optimize the process of C. militaris extraction from fruiting bodies based on 17 experimental data using water extraction method. The factors that affects to the extraction productivity such as: extraction temperature, extraction time and water/fungi ratio were investigated within a certain range. The experiments were arranged according to the Box-Behnken design, and then the results was optimized by Design expert software (version 13). In the optimal condition, the maximum productivity can be up to 32.23% with the extraction temperature is at 98oC, the water/fungi ratio is 18:1 and the extraction time is 4 hours.

This study deals with the stiffness design of geometrically nonlinear structures using topology optimization. Bi-directional Evolutionary Structures Optimization (BESO) is employed to implement the design process. The geometrically nonlinear behavior of the structures are modeled using a total Lagrangian finite element formulation and the equilibrium is found using a Newton-Raphson iterative scheme. The topology optimization of linear and nonlinear modeling are implemented. The sensitivity of the objective function is found with the adjoint method and the optimization problem is solved using BESO’s update method. Objective function of complementary work is evaluated. A special technique called the continuation method is applied to solve the instability of nonlinear structure optimization. ANSYS APDL is also used to do FEA of optimal topology to verify the effectiveness of geometrically nonlinear modelling. The results show that differences in stiffness of structures optimized using linear and nonlinear modelling is generally small but it can be large in some cases, especially structure highly involving buckling behaviour.

High power losses are a great concern in operating electric distribution system. Reconfiguration is one of the most economic approaches for reducing power losses of the system. This study suggests a technique for dealing with the distribution system reconfiguration problem based on a water cycle algorithm for minimizing active power loss. The water cycle algorithm is a recently developed metaheuristic algorithm that inspired the process of water circulation for solving optimization problems. The effectiveness and performance of the water cycle algorithm were tested on the 33-node and 69-node systems. The water cycle algorithm was applied to determine the best configuration of the distribution system for active power loss minimization. The results yielded by the water cycle algorithm were compared with other optimization algorithms in the literature and the comparisons showed that the water cycle algorithm obtained good quality of solution for the problem. Therefore, the water cycle algorithm is the potential method for the distribution system reconfiguration problem.

Environmental issues such as the wastewater have influenced each aspect of our lives. For human and environmental health protection, it is necessary to remove excess zinc in industrial wastewaters before discharging them to environment. Modified diatomite displayed larger surface area and pore volumes in comparison with untreated natural diatomite, which favored heavy metals sorption behavior. In this study, the removal of Zn(II) ions from aqueous solution was studied using Fe/Mn modified diatomite sample at different adsorption parameters such as contact initial metal ions concentration, dosage of Fe/Mn-Diatomite and ionic strength Na2CO3 on ionic Zn2+ adsorption capacity of diatomite modified. The residual zinc concentration in the solution was determined using flame atomic absorption spectroscopy. The results showed that: the gravitational increase increases with increasing time and then becomes almost stable, with 120 minutes timeliness; absorption increases when Fe/Mn-Ditomite is increased, absorption reaches 89.48% at a dose of 1.5 g/l; additional different concentrations Na2CO3 ranged from 0 ppm to 80 ppm the results showed that performance treatment Zn2+ of correspond 94,85%. This study could lay an essential foundation to develop modified diatomite for heavy metal removal from wastewater.