Climate change is an important environmental issue that is causing global temperatures to rise. The primary environmental targets are to reduce carbon emissions and mitigate the impacts of climate change. The refrigeration system is a major emitter of greenhouse gases because it uses refrigerants with a high global warming potential. Due to its excellent thermophysical properties, the R134a is the most commonly used refrigerant in refrigeration systems; however, its high GWP will need to be disposed of earlier. To achieve global environmental objectives, conventional refrigerants need to be replaced with environmentally friendly and energy-efficient refrigerants. In the present work, a mathematical simulation has been carried out to check the performance of low-GWP refrigerant mixtures as environmentally friendly alternatives for R134a in a low-temperature system. In this study, a 190-L domestic refrigerator has been considered a low-temperature system. This simulation was performed using the MATLAB software, and the REFPROP database was used to obtain thermophysical properties of the refrigerants. The results showed that the COP of HFO mixtures decreased by 4-20% compared to R134a. The exergy efficiency of the R1234ze/R134a mixture improves by 4 to 16% as compared to the other mixtures and its performance is very similar to the R134a. Due to the environmentally friendly properties and flammability aspects, R1234ze/R134a (90/10) could be a good substitute for R134a in lower temperature applications and to satisfy the Montreal and Kyoto Protocol expectations.
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http://dx.doi.org/10.1007/s11356-021-15875-2 | DOI Listing |
ACS Nano
January 2025
Department of Urology, Peking University First Hospital, Beijing 100034, China.
Although considered an "eco-friendly" biodegradable plastic, polylactic acid (PLA) microplastic (PLA-MP) poses a growing concern for human health, yet its effects on male reproductive function remain underexplored. This study investigated the reproductive toxicity of PLA in male mice and its potential mechanisms. To this end, our in vivo and in vitro experiments demonstrated that after degradation in the digestive system, a significant number of PLA-MP-derived nanoparticles could penetrate the blood-testis barrier (BTB) and localize within the spermatogenic microenvironment.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
The aging population necessitates a critical need for medical devices, where polymers-based surface lubrication coating is essential for optimal functionality. In fact, lubrication and mechanical requirements vary depending on the service environment of different medical devices. Until now, key mean is still blank for general preparation of hydrophilic polymers-based lubrication coatings with on-demand mechanics and lubricity.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Experimental Center of Advanced Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.
In this study, employing a simple anion exchange strategy and straightforward three-step synthetic route, a pair of promising nitrogen-rich heterocyclic cation and oxygen-rich anion were assembled together to generate two novel dinitramide energetic salts, both of which exhibit prominent detonation performance comparable to benchmark explosive RDX while possessing significantly lower mechanical sensitivity than RDX, thereby highlighting them as promising candidates for advanced secondary explosives. This work has directly led to a practical protocol for the design of chloride-free environmentally friendly IEMs, and accelerates the development of organic explosives with high-energy and low-sensitivity.
View Article and Find Full Text PDFBiol Aujourdhui
January 2025
Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin for Plant Sciences (IJPB), 78000 Versailles, France.
Today, weed control in agricultural systems is largely based on the use of synthetic pesticides. However, the use of these compounds is increasingly controversial among farmers and consumers, who point to their harmful properties for human health and the environment. In this context, the development of eco-friendly agricultural approaches and practices is becoming essential, and allelopathy represents a promising solution.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
College of Chemistry, Baicheng Normal University, Baicheng 137018, P. R. China.
Herein, the construction of potential donor-acceptor (D-A) structures was guided using density-functional theory (DFT) calculations. The photocatalytic nitrogen fixation performance of TAPT-CHF was then experimentally determined to be 327.58 μmol g h, which was attributed to its efficient photo-induced charge separation and migration ability.
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