Solar-Terrestrial Physics最新文献

{"title":"Advances on Sb2Se3 Solar Cells Fabricated by Physical Vapor Deposition Techniques","authors":"Roberto Jakomin, Stefano Rampino, Giulia Spaggiari, Francesco Pattini","doi":"10.3390/solar3040031","DOIUrl":"https://doi.org/10.3390/solar3040031","url":null,"abstract":"Sb2Se3, as an earth-abundant and low-toxic material, has emerged as one of the most interesting absorbers for clean renewable power generation technologies. Due to its optical properties, especially bandgap and absorption coefficient, the number of papers on Sb2Se3-based solar cells has been constantly increasing in the last ten years, and its power conversion efficiency has raised from 1% in 2014 to 10.57% in 2022. In this review, different Sb2Se3 solar cells’ fabrication technologies based on physical vapor deposition are described and correlated to the texture coefficient (ribbon orientation). Moreover, recent research works of the most promising solar cell configurations with different electron-transporting layers and hole-transporting layers are analyzed with a special emphasis on photovoltaic performances. Furthermore, different Sb2Se3 doping techniques are discussed. All these aspects are considered as new strategies to overcome the Sb2Se3 solar cell’s actual limitations.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136013678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Modeling and Experimental Validation of Heat Transfer Characteristics in Small PTCs with Nonevacuated Receivers","authors":"Amedeo Ebolese, Domenico Marano, Carlo Copeta, Agatino Bruno, Vincenzo Sabatelli","doi":"10.3390/solar3040030","DOIUrl":"https://doi.org/10.3390/solar3040030","url":null,"abstract":"The development of small-sized parabolic trough collectors (PTCs) for processing heat production at medium temperatures (100–250 °C) represents an interesting approach to increase the utilization of solar thermal technologies in industrial applications. Thus, the development of simplified models to analyze and predict their performance under different operative and climatic conditions is crucial for evaluating the application potential of this low-cost technology. In this paper, we present a numerical method that by combining three-dimensional finite element simulations (implemented with COMSOL Multiphysics software version 6.1) with a one-dimensional analysis (based on a MATLAB script) allows for the theoretical determination of the power output of a small-PTC with a nonevacuated tubular receiver operating at a medium temperature. The finite element model considers both the nonuniformity of the concentrated solar flux on the receiver tube (evaluated using Monte Carlo ray-tracing analysis) and the establishment of natural convection in the air gap between the glass envelope and absorber tube. The model calculates, for several values of direct normal irradiance (DNI) and inlet temperatures, the thermal power transferred to the heat transfer fluid (HTF) per unit length. The data are fitted using the multiple linear regression method, obtaining a function that is then used in a one-dimensional multi-nodal model to estimate the temperatures and the heat gains along the receiver tube. The outputs of the model are the outlet temperature and the total thermal power transferred to the HTF. In order to validate the developed methodology for the assessment of the heat transfer characteristics in the small-PTC with a nonevacuated receiver, an experiment at the ENEA Trisaia—Solar Thermal Collector Testing Laboratory was carried out. This work compares the theoretical data with those acquired through experimentation, obtaining a good agreement, with maximum differences of 0.2% and 3.6% for the outlet temperatures and the power outputs, respectively.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135968363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retrospective analysis of long-term regional features of the dynamic regime of the ionosphere over the south of Eastern Siberia","authors":"Denis Khabituev, Marina Chernigovskaya","doi":"10.12737/stp-93202309","DOIUrl":"https://doi.org/10.12737/stp-93202309","url":null,"abstract":"We have carried out a statistical analysis of a huge array of archival experimental data on the dynamic regime of the ionosphere over Irkutsk, obtained by a radiophysical spaced-receiver method with a small base of a radio signal reflected from the ionosphere during vertical ground-based radio sounding near Irkutsk in 1958–1982. Statistical long-term characteristics of drifts of ionization irregularities over the region of the south of Eastern Siberia were obtained. We confirmed clear differences in the nature of the dynamic regime of the lower and upper ionosphere. The motion of ionization in the zonal direction is shown to be more regular than the meridional drift. We determined the characteristic seasonal features of variations in magnitudes and directions of horizontal drift motions at heights of E and F ionospheric regions. The lower ionosphere is characterized by high variability and seasonal variations in motion velocities. In winter, the zonal component of the horizontal ionization drift velocity is directed to the west; in summer, to the east. At the heights of the upper ionosphere, the dynamic regime is more regular. The prevailing zonal direction of the motion of ionization irregularities to the west is observed for all seasons (heights above 230 km). The meridional component of the horizontal drift velocity mainly has a southerly direction. Thus, the horizontal drift of plasma irregularities at the heights of the upper ionosphere is, on the whole, directed to the southwest with the zonal direction predominating.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical analysis of microflares as observed by the 4–8 GHz spectropolarimeter","authors":"Dmitriy Zhdanov, Alexander Altyntsev, Nataliya Meshalkina, Sergey Anfinogentov","doi":"10.12737/stp-93202312","DOIUrl":"https://doi.org/10.12737/stp-93202312","url":null,"abstract":"Radio observations of weak events are one of the promising methods for studying energy release and non-thermal processes in the solar corona. The development of instrumental capabilities allows for radio observations of weak transient coronal events, such as quasi-stationary brightenings and weak flares of X-ray class B and below, which were previously inaccessible for analysis. We have measured the spectral parameters of microwave radiation for thirty weak solar flares with X-ray classes ranging from A to C1.5, using observations from the Badary Broadband Microwave Spectropolarimeter (BBMS). The spectra indicate that plasma heating is caused by the appearance of non-thermal electron fluxes, which can be detected by bursts of microwave radiation, predominantly with an amplitude ~5–6 solar flux units (SFU) at 4–5 GHz frequencies. One solar flux unit (SFU) of radio emission is equal to 10–22 W/(m•Hz). The range of low-frequency spectrum growth indices fα varies widely from α=0.3 to 15. The distribution of high-frequency decay indices is similar to the distributions of regular flares. One of the explanations for the appearance of large fα values is the Razin effect, which can influence the shape of the gyrosynchrotron spectrum during the generation of bursts in dense plasma under relatively weak magnetic fields. We have detected two events in which the appearance of non-thermal electrons led to the generation of narrowband bursts at frequencies near the double plasma frequency. SRH test trials have shown the potential for measuring the structure of flare sources with fluxes of the order of 1 SFU, indicating the high diagnostic potential of the radioheliograph for detecting acceleration processes in weak flare events and their localization in active regions.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of strong solar proton events on propagation of radio signals in the VLF range in a high-latitude region","authors":"Oleg Akhmetov, Igor Mingalev, Oleg Mingalev, Vladimir Belahovskiy, Evgeniy Maurchev, Aleksey Larchenko, Zoya Suvorova, Yuriy Balabin","doi":"10.12737/stp-93202305","DOIUrl":"https://doi.org/10.12737/stp-93202305","url":null,"abstract":"In this paper, we examine the features of RSDN-20 signal propagation in a high-latitude Earth–ionosphere waveguide during solar proton events, using computational experiment methods. We have analyzed two proton ground-level enhancement (GLE) events of December 13, 2006 (GLE70) and September 10, 2017 (GLE72). Electron density profiles were constructed using the Global Dynamic Model of Ionosphere (GDMI) and the RUSCOSMICS model, developed at PGI. We present estimated phase and amplitude changes in RSDN-20 signals during precipitation of high-energy protons in the high-latitude region of the Earth–ionosphere waveguide. From the results of computational experiments and the analysis of the electromagnetic signal attenuation based on analytical Maxwell’s equation system solution in magnetized ionospheric plasma, we have found a pattern in the signal attenuation frequency dependence associated simultaneously with the signal reflection height, electron density profiles, and the collision frequency of electrons with neutral particles and ions. We discuss limitations of the computational experiment method and compare simulation results with data from Lovozero and Tuloma observatories.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136280323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral analysis of IAR oscillations to determine the value and variability of the peak electron density NmF2","authors":"Alexander Potapov, Tatyana Polyushkina, Anatol Guglielmi, Konstantin Ratovsky, Ilya Moskalev","doi":"10.12737/stp-93202306","DOIUrl":"https://doi.org/10.12737/stp-93202306","url":null,"abstract":"This methodical paper explores the possibility of estimating the peak electron density of the F2-region of the ionosphere (NmF2) under different conditions, using data on the frequency of spectral bands (harmonics) of the ionospheric Alfvén resonator (IAR) oscillation. We describe a simple technique for tracking the frequency of spectral bands during the day by measuring their position on the plot of the IAR daily dynamic spectrum. Through calculations within the framework of the global ionospheric model IRI-2016, we verify the correctness of the comparison of the frequencies of resonant bands, measured at one point, with data from radio sounding, performed at other points remote from IAR frequency measurement sites at a distance. We propose an algorithm for comparing NmF2, measured by a radiosonde, with frequencies of spectral lines by precalculating the evaluation factor. It is formed on the basis of a nonlinear combination of the frequencies of the three observed harmonics. Then the time series of this factor is compared with the results of radio sounding, and correlation and regression coefficients, as well as estimation errors are calculated. Using the material on rare cases of round-the-clock observation of IAR oscillations in the winter months of 2011–2012, we trace the dependence of the average error in determining the peak electron density on local time. We present the data on the most favorable local time intervals for determining NmF2 from IAR harmonic frequencies depending on season. Some additional factors are discussed which affect the accuracy of estimates and determine the frequency range of IAR oscillations.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relation between the area of polar coronal holes and the solar wind speed at a minimum between solar cycles 22 and 23","authors":"Aleksey Borisenko, Sergey Bogachev","doi":"10.12737/stp-93202313","DOIUrl":"https://doi.org/10.12737/stp-93202313","url":null,"abstract":"We have used data from the space telescope SOHO/EIT and the spectrometer VEIS on the Wind spacecraft to compare the solar wind (SW) speed near Earth's orbit with changes in the area of polar coronal holes (CHs) on the Sun during the 1996 solar activity minimum. We have found that in March 1996 the SW speed correlated with the southern CH area by a factor of 0.64. In September and October 1996, a correlation was revealed between the SW speed and the area of the northern CH (the coefficients are 0.64 and 0.85 respectively). We believe that this confirms the assumption that the solar wind from polar CHs can penetrate into the ecliptic plane at solar minimum. The SW speed was 460–500 km/s, which is lower than that from equatorial CHs (600–700 km/s).","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of magnetospheric parameters based on cosmic ray effects in August","authors":"Ivan Kovalev, Sergey Olemskoy, Valeriy Sdobnov","doi":"10.12737/stp-93202303","DOIUrl":"https://doi.org/10.12737/stp-93202303","url":null,"abstract":"Using data (uncorrected for the temperature effect) from the global network of neutron monitors (GNNM), along with data from the Yakutsk muon telescope complex and the muon hodoscope URAGAN (Moscow), we have applied a modified spectrographic global survey (SGS) method to the 2018 August event in order to split cosmic ray variations into components of primary, magnetospheric, and atmospheric origin. We obtained time variations in the 4 GV-rigidity primary particle isotropic flux and pitch-angle anisotropy, as well as in the interplanetary magnetic field (IMF) orientation. We also showed variations in the geomagnetic cutoff rigidity (GCR) in Irkutsk.
 Using the obtained data on the changes in the planetary system of GCR within a simple model of a bounded magnetosphere, we have calculated some parameters of magnetospheric current systems, namely, the ring current radius, the magnetopause current radius, and the Dst index.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solar activity cycle 25: the first three years","authors":"Sergey Yazev, Elena Isaeva, Battulga Hos-Erdene","doi":"10.12737/stp-93202301","DOIUrl":"https://doi.org/10.12737/stp-93202301","url":null,"abstract":"We analyze features of current solar activity cycle 25 for the first three years of its development (2020–2022). Compared to cycle 24, the current cycle is shown to exceed the previous one in the number of sunspot groups (1.5 times), the number of flares (1.8 times), and the total flare index (1.5 times). We have found that distributions of sunspot groups during cycles 24 and 25 differ in maximum area. Solar cycle 25, unlike cycle 24, exhibits the most significant increase in the number of sunspot groups with areas up to 30 pmh and in the interval from 570 to 1000 pmh. In contrast to cycle 24, the degree of north-south asymmetry in cycle 25 is significantly reduced. This allows us to predict an increased height of cycle 25, as compared to cycle 24 (by 20–50 %), in accordance with the Gnevyshev—Ol rule, as well as the possible unimodal nature of the cycle.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hysteresis effect between geomagnetic activity indices (Ap, Dst) and interplanetary medium","authors":"Nadezhda Kurazhkovskaya, Alexander Kurazhkovskii","doi":"10.12737/stp-93202308","DOIUrl":"https://doi.org/10.12737/stp-93202308","url":null,"abstract":"We have studied the relationship of geomagnetic activity indices (Ap, Dst) on time intervals, equal to solar cycles (∼11 years), with solar activity indicators and heliospheric parameters. It is shown that the plots of the Ap and Dst indices versus solar activity indicators, as well as versus heliospheric parameters, i.e. solar wind and IMF parameters in the ascending and descending phases of solar activity cycles 21–24 do not coincide, which is indicative of the hysteresis phenomenon. The Ap and Dst indices form hysteresis loops with all parameters we analyze during cycles 21–24. The shape and area of the hysteresis loops, as well as the direction of rotation, clockwise or counterclockwise, depend significantly on indicators of solar activity, heliospheric parameters and change from cycle to cycle. We have found a tendency for the extension and area of the hysteresis loops to decrease from cycle 21 to cycle 24. Analysis of the variability in the shape and size of the hysteresis loops formed by the Ap and Dst indices with solar indicators and heliospheric parameters gives reason to believe that the obtained loops reflect the long-term evolution of the solar wind energy flux, which determines global geomagnetic activity and the magnetospheric ring current intensity in the ascending and descending phases of solar activity cycles 21‒24.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}