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This study presents a comprehensive numerical investigation into the thermal performance of solar collectors integrated with encapsulated phase change materials (PCMs) using a transient three-dimensional (3D) approach. The performance of two distinct PCMs—paraffin wax and RT60—was evaluated under varying operational conditions, including seasonal variations, inlet pipe velocities, and inlet temperatures. The results indicate that paraffin wax exhibits a higher peak temperature, reaching approximately 360 K, compared to RT60's peak of 345 K, making paraffin wax more effective for consistent thermal energy storage. Paraffin wax also maintained higher fluid fractions, with a maximum of 0.9 in summer, indicating superior heat absorption and retention capabilities. In contrast, RT60 demonstrated a quicker phase transition, fully liquefying at a lower fluid fraction, which is advantageous for rapid heat release. Seasonal variations significantly impacted system efficiency, with the highest efficiency observed in June at 365 K and the lowest in December at 340 K. The study also found that lower inlet velocities (e.g., 0.25 L/s) significantly improved heat retention, resulting in higher outlet temperatures, while increasing the inlet temperature from 290 K to 310 K led to a marked increase in outlet temperatures throughout the day. These findings underscore the importance of optimizing PCM selection, inlet velocity, and temperature in enhancing the performance of solar thermal systems, offering quantitative insights that contribute to the development of more efficient and reliable renewable energy solutions. [ABSTRACT FROM AUTHOR]

Li-ion batteries are crucial for sustainable energy, powering electric vehicles, and supporting renewable energy storage systems for solar and wind power integration. Keeping these batteries at temperatures between 285 K and 310 K is crucial for optimal performance. This requires efficient battery thermal management systems (BTMS). Many studies, both numerical and experimental, have focused on improving BTMS efficiency. This paper presents a comprehensive review of the latest BTMS designs developed in 2023 and 2024, with a focus on recent advancements and innovations. The primary objective is to evaluate these new designs to identify key improvements and trends. This review categorizes BTMS designs into four cooling methods: air-cooling, liquid-cooling, phase change material (PCM)-cooling, and thermoelectric cooling. It provides a detailed analysis of each method. It also offers a unique examination of hybrid cooling BTMSs, classifying them based on their impact on the cooling process. A hybrid-cooling BTMS refers to a method that combines at least two of the four types of BTMS (air-cooling, liquid-cooling, PCM-cooling, and thermoelectric-cooling) to enhance thermal management efficiency. Unlike previous reviews, this study emphasizes the novelty of recent designs and the substantial results they achieve, offering significant insights and recommendations for future research and development in BTMS. By highlighting the latest innovations and providing an in-depth analysis, this paper serves as a valuable resource for researchers and engineers aiming to enhance battery performance and sustainability through advanced thermal management solutions. [ABSTRACT FROM AUTHOR]

Background: Blood transfusion is essential in severely ill patients whose hemoglobin (Hb) levels are low, but there are some factors that inhibit optimal increase in Hb. The aim of this study was to evaluate the amount of increase in Hb levels after packed red blood cell (PRBC) transfusions in the Intensive Care Unit (ICU) patients and its related factors. Materials and Methods: This cross-sectional study included 124 patients admitted to the ICU, and needed PRBC transfusion. Demographic information, Hb on the 1st day of admission, blood volume transfusions during the 7 days, and the 7th day of admission Hb level were extracted from patients' records. Results: The average initial Hb level of patients was reported as 6.17 ± 1.43 g/dl, and after administrating PRBC (4.23 ± 1.87 units during 7 days), the Hb level was 8.09 ± 1.66 g/dl after 7 days (mean difference was 1.91 ± 1.93, t = 11.06, P < 0.001). No significant differences were found between change in Hb level in the terms of age, gender, underlying illness, body mass index, hospitalization history, fever, and duration of hospitalization (P > 0.05). However, the mean increased Hb level in hospitalized patients with internal disorders was the lowest (0.25 g/dl, P = 0.002). Conclusion: The results of our study showed that the increased Hb level based on one unit of received PRBC was low, especially in patients with internal. Therefore, based on high frequency of anemia in ICU patients and relative complications, physicians should pay attention to factors affecting Hb levels after PRBC transfusion such as medical history. [ABSTRACT FROM AUTHOR]