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Over the past few years, the combination of solar power with refrigeration technology has matured, providing a promising solution for sustainable cooling. However, a key challenge remains, namely the inherent intermittency of solar energy. Due to its uneven temporal distribution, it is difficult to ensure continuous 24 h operation when relying solely on solar energy. To address this issue, thermal energy storage technology has emerged as a viable solution. This paper presents a comprehensive systematic review of phase-change material (PCM) applications in solar refrigeration systems. It systematically categorizes solar energy conversion methodologies and refrigeration system configurations while elucidating the fundamental operational principles of each solar refrigeration system. A detailed examination of system components is provided, encompassing photovoltaic panels, condensers, evaporators, solar collectors, absorbers, and generators. The analysis further investigates PCM integration strategies with these components, evaluating integration effectiveness and criteria for PCM selection. The critical physical parameters of PCMs are comparatively analyzed, including phase transition temperature, latent heat capacity, specific heat, density, and thermal conductivity. Through conducting a critical analysis of existing studies, this review comprehensively evaluates current research progress within PCM integration techniques, methodological classification frameworks, performance enhancement approaches, and system-level implementation within solar refrigeration systems. The investigation concludes by presenting strategic recommendations for future research priorities based on a comprehensive systematic evaluation of technological challenges and knowledge gaps within the domain.

During solar cell operation, most light energy converts to heat, raising the battery temperature and reducing photoelectric conversion efficiency. Thus, lowering the temperature of solar cells is essential. Nanofluids, with their superior heat transfer capabilities, present a potential solution to this issue. This study investigates the mechanism of enhanced heat transfer by nanofluids in two-dimensional rectangular microchannels using the two-phase lattice Boltzmann method. The results indicate a 3.53% to 22.40% increase in nanofluid heat transfer, with 0.67% to 6.24% attributed to nanoparticle–fluid interactions. As volume fraction (φ) increases and particle radius (R) decreases, the heat transfer capability of the nanofluid improves, while the frictional resistance is almost unaffected. Therefore, the performance evaluation criterion (PEC) of the nanofluid increases, reaching a maximum value of 1.225 at φ = 3% and R = 10 nm. This paper quantitatively analyzes the interaction forces and thermal physical parameters of nanofluids, providing insights into their heat transfer mechanisms. Additionally, the economic feasibility of nanofluids is examined, facilitating their practical application, particularly in solar cell cooling.

Due to the complexity of extrusion 3D printing objects and lack of universal parameters, there are few classified statistics or quantitative description for the “extrudability” of material with shear thinning properties. In order to systematically study the rheological properties of extrudable materials and establish a unified criterion or quality evaluation standard from the basic process theory, a Nishihara rheological constitutive model based on visco-elastic and visco-plastic characteristics of materials is explored to predict and investigate the extrusion performance of four typical dispersed-continuous phase binary mixture. The creep model result shows that, expect for the gelatin network-water system with almost complete elastic behavior, the material with shear thinning property based on Nishihara model is in good agreement with the experimental results. In the extrusion process, the shear stress is related to the advancing speed, material viscosity, and nozzle size. The effects of advancing speed and nozzle size on shear stress show antagonistic characteristics in a certain range; that is, the velocity gradient is the dominant factor at lower extrusion speed, and the dynamic viscosity is the dominant factor at higher extrusion speed. In terms of extrusion properties, the material system with smaller yield strain/stress has the least obvious extrusion delay characteristics, and is easier to extrude under the condition of the same material strength.

Fluid elastic excitation in shell side of heat exchanger was deduced theoretically in this paper. Model foundation was completed by using Pro / Engineer software. The finite element model was constructed and imported into the FLUENT module. The flow field simulation adopted the dynamic mesh model, RNG k-ε model and no-slip boundary conditions. Analysing different positions vibration of tube bundles by selecting three regions in shell side of heat exchanger. The results show that heat exchanger tube bundles at the inlet of the shell side are more likely to be failure due to fluid induced vibration.

Background The center of sustainable development of grassland husbandry is the balance between forage intake and growth characteristics of animals, and one of the keys to restricting the conversion efficiency of forage intake is the digestibility of forage produced by rumen microorganisms. Thus, the interaction between grass intake and rumen microbial fermentation is a key driver of both ruminant productivity and grassland ecosystem health. However, interactions between grass species, supplementary feeding, rumen microbiome, and rumen epithelium function, remain poorly understood. Results We employed metagenomic and metatranscriptomic analyses, coupled with single-cell RNA sequencing (scRNA-seq) of rumen wall and serum metabolomics, to investigate how the rumen microbiome regulates grass intake and host metabolism. In a two-factor (grazing intensity and concentrate supplementation) experiment with 72 lambs, supplementary feeding under moderate grazing increased dry matter intake but decreased grass consumption of Artemisia tanacetifolia . These shifts correlated with contrasting trends between metagenomic and metatranscriptomic profiles of Lachnospiraceae . scRNA-seq revealed an increased abundance of basal cells (BCs), terminally differentiated keratinocytes (TDKs), and differentiated keratinocytes (DKs) in the supplemented group, with solute carrier genes (e.g., SLC16A1 ) involved in short chain fatty acids (SCFAs) transport enriched in basal cells. We also identified interactions between the rumen microbiome and host epithelial cells, influencing gene expression and localization, which in turn mediated the animal serum nutrient metabolism, particularly in B vitamin, bile acids, and amino acids. Conclusions Our study identified key microbiome and epithelial cell subtypes involved in grass digestion and SCFAs metabolism in the rumen. This novel link between ruminal microbial function, epithelial cell cluster-based genes, and host metabolism provides critical insights into mechanisms underlying the interaction between grass intake and supplementary feeding for optimizing ruminant management strategies in sustainable grazing systems. Dz6droppdVqVC6bzHwnNxf Video Abstract