To address the difficulty of predicting plate heat exchanger performance under variable-flow and fouling-prone coastal conditions, this study developed a novel combined framework for a BR50 plate heat exchanger by integrating a steady-state heat transfer model with a transfer-function-based dynamic wall-temperature model. The main innovation is that the framework simultaneously captures steady thermal performance and transient wall-temperature response, while explicitly quantifying the coupled effects of flow velocity and kinematic viscosity. The model was evaluated for sewage-side velocities of 0.8–1.5 m/s and viscosities up to ten times that of clean water. Results show that wall temperature increases slightly with velocity and can be described by a fourth-order polynomial. Its transient response follows first-order inertia, and the time constant decreases as velocity increases, indicating faster thermal response at higher flow rates. Both the sewage-side heat transfer coefficient and the overall heat transfer coefficient increase with velocity but decrease with viscosity; increasing velocity from 0.8 to 1.5 m/s raises the sewage-side coefficient by 49.2%. Sensitivity analysis identifies kinematic viscosity as the dominant factor affecting thermal performance, followed by flow velocity and wall temperature. The framework provides a practical basis for seawater-source heat pumps and coastal heat recovery systems under fouling-influenced conditions.
Mixotrophic culture can improve the growth of Haematococcus lacustris, an alga that can produce the high-value carotenoid astaxanthin. However, these conditions make the culture susceptible to bacterial contamination. Ozone gas was therefore investigated for its ability to inhibit the growth of heterotrophic bacteria during the mixotrophic cultivation of H. lacustris. The concentration and flow rate of ozone were then optimized. While the flow rate had no significant effect, an ozone concentration of 0.4 mg/L allowed algal growth but inhibited bacterial growth. Additionally, different wavelengths of light exposure were used to enhance algal growth and biomass production, and red light showed the highest increase, followed by blue light. The addition of 0.08 mg/L ozone to light exposure improved growth for both red and blue light. In mixotrophic culture using sodium acetate as a carbon source, the same concentration of ozone improved growth compared to untreated mixotrophic culture or to pure autotrophic culture.
This study uses a qualitative, descriptive, and phenomenological approach to understand the adaptation of flood-prone village communities in Southeast Sulawesi through social, economic, and environmental capacity analysis based on the Building Village Index. The results of the study show that socio-ecological resilience is formed through solidarity synergy, social capital bonding-bridging-linking, and adaptive local institutional mechanisms. Mechanical solidarity, mutual cooperation, and reconstruction of ecological norms encourage the formation of collective actions that strengthen responses to recurrent floods. Main Findings: Community resilience in flood-prone villages emerges through solidarity, social capital, and adaptive institutions reinforcing collective ecological action. The C-BS-ERCM confirms that resilience develops iteratively through risk identification, coordination, learning, and sustainable village governance. Theoretically, this study enriches the study of resilience by combining the perspectives of Durkheim, Putnam, and Scott–North institutional theories into the Community-Based Social-Ecological Resilience Cycle Model (C-BS-ERCM), which is a community-based resilience cycle. In practical terms, these findings provide a direction for strengthening village adaptive governance through institutional collaboration, social capacity building, and integration of local values in sustainable flood mitigation and adaptation strategies.
The present study pioneers the investigation of mechanochemical synthesis based on polyphenylsilsesquioxane and β-diketonate complexes of scandium, yttrium, and lanthanum. It has been demonstrated that the degree of metal incorporation into the polymer chain increases with the growth of the ionic radius and with the decrease in the stability of the initial acetylacetonate complex. The resulting polymers exhibit high thermal stability, comparable to that of the parent organosilicon polymer. Moreover, owing to their developed surface area and light-transforming properties, the synthesized compounds hold promise for applications in catalysis, production of electronic materials, and fabrication of nanoelectronic components.
As the world faces the dual challenges of climate change and rising energy demands, renewable energy sources have become a necessity. The global energy mix is projected to have renewables contribute 63% of the total primary energy supply by 2050, a significant increase from 14% in 2015 This transition relies on advancements in energy storage technologies, which are a key solution to solve one of the main issues of renewable sources, which is intermittency. This study aims to develop and optimize hybrid energy storage systems in Malaysia, combining hybrid renewable energy resources with energy storage technologies. The methodology includes a comprehensive analysis of five scenarios, followed by sensitivity analysis on the optimal configuration. The optimal system consists of a grid-connected solar PV and hydropower system with SunPower E20-327 panels and a zinc bromide flow battery as the energy storage system. This system achieved a renewable fraction of 82.8%, a levelized cost of energy (LCOE) of 0.057 USD/kWh, and a return on investment (ROI) of 4.4%. The optimal system also demonstrated a 12.1-year payback period. The SunPower PV-only case achieved a CO2 reduction of 5918 kg/year. When the zinc bromide battery was included, the optimized PV-battery case achieved reductions of 6797 kg/year CO2, 29.5 kg/year SO2, and 14.4 kg/year NOx. These findings support the feasibility of hybrid systems in contributing to Malaysia’s Energy Target 2050 and provide a framework for future energy storage solutions.
