Vladimir Ivanovich Velkin’s research while affiliated with Ural Federal University and other places

Because of environmental concerns, HFCs that were once widely used in air-conditioning and refrigeration systems may soon be phased out. The main reason for the phase-out of HFCs is that of their high potential for global warming (GWP). Consequently, there is now a greater need for appropriate, greener alternatives. In the recent years, significant initiatives are taken toward hydrocarbon (HC) refrigerants or other eco-friendly refrigerants to ensure the sustainability of the environment. In this research work, an experimental examination has been made using green hydrocarbon refrigerants, i.e., a mixture of R600a and R290 in a ratio 55:45, as a substitute to R134a in a 150 L domestic refrigerator. Continuous running experiments have been conducted at various ambient temperatures (24, 29, 34, 39, and 43 degrees Celsius), whereas cycling running (ON/OFF) experiments were piloted solely at 29 degrees Celsius. The results revealed that hydrocarbon combination has lowered the energy consumption by 13.8% with 2.85–4.6% increase in COP. Compared to R134a discharge temperature, the exit temperature of green mixture hydrocarbons is found to be 6–14 K lower. Overall, the aforementioned hydrocarbon refrigerant mixture has proven to be the greatest long-term solution for phasing out R134a.

Solar thermal collectors, such as evacuated tube collectors (ETCs), are essential for harnessing renewable energy, yet their efficiency is often hindered by thermal losses and limited heat transfer. This study focuses on enhancing ETC performance for seawater desalination by using nanofluids as heat transfer fluids. These modifications aim to improve heat transfer rates, reduce thermal losses, increase the maximum temperature attainable, and minimize the collector area required. An experimental setup has been developed at Parul University in Vadodara, Gujarat, India. Key parameters such as air mass flow rate, inclination angle, water mass flow rate, nanofluid volume percentage, and screw conveyor speed were optimized to achieve ideal temperature levels. Results indicate that the optimal configuration for steam generation includes a high air mass flow rate and a 40° inclination angle for the ETC. Additionally, a water mass flow rate of 10 LPH and a screw conveyor speed of 30 rpm are crucial for optimal performance. Data collected showed the highest solar energy levels between 12 PM and 1 PM, which significant decreases post this peak period. These findings highlight the potential of nanomaterial‐based enhancements in improving the efficiency and cost‐effectiveness of solar thermal systems for renewable energy applications.

Chemical reaction balancing is a fundamental aspect of chemistry, ensuring the conservation of mass and atoms in reactions. This article introduces a specialized Python functions designed for automating the balancing of chemical reactions. Leveraging the versatility and simplicity of Python, the module employs advanced algorithms to provide an efficient and user-friendly solution for scientists, educators, and industry professionals. This article delves into the design, implementation, features, applications, and future developments of the Python functions for automated chemical reaction balancing. The functions thus developed were tested on some typical chemical reactions and the results are the same as that in the literature. This is an open access article under the CC BY-SA license.

The use of aluminum alloys in automobiles is expanding, and the potential for additional increases is significant. Further growth will be determined by improvements in material qualities for existing applications or the discovery of new applications. Alloy A-356 (LM25) is commonly employed for high-quality alloy wheel rims in various motor vehicles, constituting 40% of global car usage. This study introduces 0.2% Cu into the Al–Si–Mg alloy system to enhance the mechanical properties. The alloy blend is cast into a metal mold, subjected to a 4-h cure at 540 °C, quenched with water, and precipitation hardened for 12 h at 1800 °C. Optical and scanning electron microscopes are utilized to analyze the alkali microstructure. The mechanical properties of alloyed and unalloyed castings, including hardness and tensile test results, are examined in untreated and heat-treated states. Fracture surfaces of tensile specimens are scrutinized. Intermetallic compounds formed during solidification are studied using scanning electron microscopy and x-ray diffraction analysis. The tensile strength under unalloyed (LM25) and alloyed (LM25 + 0.2 wt. % Cu) conditions before and after heat treatment [(72, 165.4 and 88.3, 237.1) and (78, 179.6 and 98, 252.9, respectively)] shows a significant increase.