Current Issue : April-June Volume : 2024 Issue Number : 2 Articles : 5 Articles
In this paper, a new solar activity index based on a novel disturbance extraction method, the spectral whitening method (SWM), is introduced to process the solar EUV data on the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. Our research suggests that the spatial information derived by SWM can well reflect the location of disturbance extraction, which is consistent with the location of the solar active region. It indicates that the disturbance extraction is effective. From AIA 094 Å to AIA 335 Å, SWM results are strongly correlated with solar radio flux F107 and the sunspot number (SSN), especially at AIA 211 Å, where the correlation coefficient reaches the maximum, while at AIA 1600 Å and AIA 1700 Å there are no detectable correlations. The proposed new solar activity index, JP (AIA), has the following characteristics: (1) the new index can reflect the main variations of F107 and SSN, indicating that the index is valid; (2) the new index has higher temporal resolution, which is more conducive to the more detailed study of solar activities on short timescales; (3) the new index reveals that the solar atmosphere still has significant variability during solar minimum characterized by low F107 and SSN; (4) the new index can be used in conjunction with the new magnetospheric and ionospheric indices, which are also derived by SWM to deepen the understanding of the causal chain of space weather and promote the improvement of forecasting capabilities....
The impact of heat-generating facilities on the environmental condition of adjacent territories is assessed. The possibility of using solar energy to reduce the anthropogenic impact on the environment is substantiated. It is proposed to create cascade solar installations to provide hot water supply to residential buildings and industrial facilities. A scheme of a solar power station with a seasonal solar energy accumulator based on depleted quarries to ensure year-round supply of hot water is proposed. A mathematical model is proposed for calculating the efficiency of solar collectors with transparent and rear insulation, which make up the third stage of a three-stage solar DHW system. The relative error of mathematical models in comparison with test data is presented. The average monthly efficiency of the third cascade of calculated mathematical models for climatic conditions of the Crimean peninsula is given. A refined algorithm for calculating the efficiency of solar collectors of the third stage has been developed....
A mixed-mode forced-convection solar dryer (MMFCSD) is a device that utilizes both direct and indirect solar energy. The solar collector, which stores thermal energy for indirect solar uses, is an essential component of the dryer. Unfortunately, the thermal efficiency of this device is generally low. In this study, a technique was employed to improve the heat transfer of the solar collector in a MMFCSD. The technique involved adjusting the air flow pattern into a swirling flow to disturb the thermal boundary layer on the absorber plate under forced convection by using stainless wire mesh. The experiment was conducted under actual conditions and bananas were used as the drying sample. The experimental results of the thermal efficiency of the solar collector (ƞ solar) and the drying efficiency (ƞ drying) are presented. The results indicated that the air outlet temperature and ƞ solar of the solar collector with stainless wire mesh were higher than the case without stainless wire mesh, reaching a maximum temperature of 46.22°C and 37.97°C, and average ƞ solar of 0.26 ± 0.02 and 0.14 ± 0.01, respectively. The MMFCSD with stainless wire mesh had a higher ƞ drying than the case without stainless wire mesh, with values of 0.048 ± 0.004 and 0.039 ± 0.003, respectively, resulting in an ~23.07% increase. This was attributed to the air swirling flow through the stainless wire mesh and the heat accumulation in the drying chamber, which led to an increase in the drying chamber temperature from 54.03°C to 63.60°C, an increase in the effective moisture diffusivity from 7.28 × 10–7 to 1.19 × 10–6 m2/s and a decrease in the drying time of 5 h 30 min. However, further research is needed to investigate the quality of the dried samples and their economic value....
Perovskite solar cells have garnered significant attention as the next-generation photovoltaic devices. After more than a decade of dedicated research, commercializing these cells is now on the horizon. One of the primary focuses for developers aiming at large-scale industrial production is cost reduction. To achieve cost savings in perovskite solar cell manufacturing, researchers have successfully devised cost-effective room-temperature perovskite solar cells for fabricating perovskite films at room-temperature. Additionally, they have developed full room-temperature perovskite solar cells, where the entire solar cell is fabricated at room temperature. These cells excel in terms of their straightforward processing, low energy consumption, and continuous production capability, rendering them highly suitable for industrial applications. This article is intended to provide an overview of the latest advancements in room-temperature perovskite solar cell research. It will summarize commonly utilized methods for their fabrication, delve into the significant implications of full room-temperature perovskite solar cells for the commercialization of perovskite solar technology, and conclude by outlining various production techniques for room-temperature perovskite films. Furthermore, this article will offer insights into the future development directions of room-temperature perovskite solar cells and full room-temperature perovskite solar cells....
The increasing demand for energy and electricity and the depletion of fossil fuels are global problems. In recent years, dye-sensitized solar cell (DSSC) technologies have gained notoriety for their application in solar energy. DSSCs are considered a promising alternative renewable energy source to both inorganic and organic photovoltaic (PV) cells. Many types of dyes are being investigated to enhance the light-harvesting properties of DSSCs, but the actual realization of these absorbers in cell structure requires optimum parameters. The main aim of this study was to simulate proposed zinc phthalocyanine (ZnPC)-based structures to validate their design, assess their performance for commercial implementation, and optimize the cell parameters for optimum efficiency. To that end, Scaps-1D was employed to evaluate the performance of DSSCs to determine their optimum parameters. We found that ZnPC and isopropoxy ZnPC molecules outperform others molecules because of better optoelectronic properties. Several other parametric effects, such as photoactive layer thicknesses, doping densities, trap densities, and charge carrier mobilities, were also evaluated to observe their impact on device performance. The results show that moderate thickness, low defect density, moderate doping, and charge carrier mobility are favorable for better device performance due to low recombination losses, electrical losses, and better transport of charge carriers. The utmost power conversion efficiency values found for ZnPC- and ZnPC: PC70BM-based DSSCs after optimization were 9.50% and 9.81%. This paper also suggests a practical method for efficiently using DSSC cells by modifying factors that are significantly reliant on DSSC performance and output....
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