Experimental thermal performance of deionized water and iron oxide nanofluid for cold thermal storage.

Phase change materials enhance the thermal comfort of buildings by utilizing stored thermal energy. In large air-conditioning systems, ice storage plays a crucial role in managing peak power loads. This experimental study explores the freezing characteristics of deionized water containing suspended iron oxide nanoparticles in spherical containers for cold storage. The synthesized nanofluid phase change material (NFPCM) was investigated for its freezing behavior under surrounding fluid temperatures of - 2 °C and - 6 °C. The uniformity in charging of NFPCM is the unique feature prevalent in the first quarter of the charging, with 50% mass frozen observed. An increased surface heat flux of 200% was achieved using NFPCM at Tsurr = -6 °C. The chiller operational time is optimally reduced by 75% by considering twice the container design's phase change materials. Adding iron oxide nanoparticles and partial charging is suitable for uniform heat transfer for the shorter freezing duration in cooling applications. The novelty of the present study is that the proposed NFPCM nearly nullifies the subcooling effects of deionized water without using nucleating agents. This NFPCM appreciably enhances power competence, yielding large-scale air-conditioning systems' desired economic impact and sustainability. The reported results align with Sustainable Development Goals (7-Affordable and Clean Energy and 13-Climate Action).

Experimental performance of a finned spherical container in cold thermal storage for tropical buildings.

The heating and cooling of buildings consume almost 40% of global energy consumption. Cooling building spaces require more input energy compared to heating in tropical buildings. The power tariff varies according to the base and peak demands. This research mainly minimizes peak electricity demand by operating cold thermal storage using deionized water as a phase change material (PCM). The experimental work investigates the partial charging of deionized water in an internally finned stainless steel spherical container immersed in a constant temperature bath. Encapsulated PCM is tested with constant bath temperatures of - 6 ℃, - 9 ℃, and - 12 ℃. Radial copper fins with a diameter of 3 mm are attached inside the container. The selected fin lengths are 7.5 mm, 13.5 mm, and 19.5 mm. The fin length of 13.5 mm is significantly reducing the freezing period. An effective reduction in the charging duration of 52% is observed at - 6 ℃ bath temperature. Partial charging is recommended by incorporating twice the amount of PCM in the design stage and utilizing 50% freezing during operation to achieve up to 52% energy savings. Therefore, the current findings help design effective cold storage for large-scale air-conditioning in buildings.

Attenuation of lipid metabolic abnormalities, proinflammatory cytokines, and matrix metalloproteinase expression by biochanin-A in isoproterenol-induced myocardial infarction in rats.

In the present study, we assessed the therapeutic potential of Biochanin-A (BCA) (10 mg/kg BW/day) pretreatment for 30 days on lipid metabolic abnormalities, proinflammatory cytokines and matrix metalloproteinase expression in isoproterenol (ISO)-induced myocardial infarction (MI) in rats. We measured the potential role of BCA on tissue and circulatory lipid profiles as well as on lipid metabolic enzymes: serum inflammatory cytokines (TNF-α, IL-1α, IL-1ß, IL-6 and MCP1) and serum Matrix Metalloproteinases (particularly, MMP-2 and MMP-9) together with mRNA expressions of TNF-α, IL-6, MMP-2 and MMP-9 by RT-PCR analysis. Administration of ISO to rats significantly distorted their lipid metabolism and augmented inflammatory process, MMP expression and proteolytic activity. In addition, pretreatment with BCA of ISO-induced MI rats significantly reestablished the altered lipid metabolism and concealed the inflammation of cytokines. BCA suppressed the expressions of proinflammatory cytokines and MMPs in ISO-induced MI in rats when compared to normal untreated MI rats. Hence, these results established that BCA could improve the pathological processes of myocardial remodeling which was confirmed by histopathology of heart in MI rats and might be an effective beneficial ingredient for the management of heart failure disorders.