125 Results Found

With the advent of soft X-ray imaging enabling global magnetopause detection, it is critical to use reconstruction techniques to derive the 3-dimensional magnetopause location from 2-dimensional X-ray images. One of the important assumptions adopted...

We have studied the variation of the time profile of X-ray emission of solar flares that occurred during the second half of solar cycle 23 (SC 23) and for about the full solar cycle 24 (SC 24) (2002–2018). We define a new index, called the &ldq...

We study the Quasi-Periodic Pulsations (QPPs) of an M4.4 class solar flare, which occurred in active region NOAA 11165 on 8 March 2011. With the Fast Fourier Transform (FFT) method, we decompose the flare light curve into fast- and slowly-varying com...

The fabrication of high-efficiency GaAsP-based solar cells on GaAs wafers requires addressing structural issues arising from the materials lattice mismatch. We report on tensile strain relaxation and composition control of MOVPE-grown As-rich GaAs1&m...

The spectra and global distributions of the X-ray emissions generated by the solar wind charge-exchange (SWCX) process in the terrestrial magnetosheath are investigated based on a global hybrid model and a global geocoronal hydrogen model. Solar wind...

We have studied the quasi-periodic pulsations (QPPs) of the M2.3 flare that occurred in the active region NOAA 12172 on 23 September 2014. Through the fast Fourier transform (FFT) method, we decompose the flare light curves into fast- and slowly-vary...

X-ray and EUV solar flare emission cause increases in the Earth’s dayside ionospheric electron density. While the response of the lower ionosphere to X-rays is well studied, the delay between EUV flare emission and the response of the ionospher...

Around 50 years ago, the famous bet between Stephen Hawking and Kip Thorne on whether Cyg X-1 hosts a stellar-mass black hole became a well-known story in the history of black hole science. Today, Cyg X-1 is widely recognised as hosting a stellar-mas...

Microquasars are Galactic black hole systems in which matter is transferred from a donor star and accretes onto a black hole of, typically, 10–20 solar masses. The presence of an accretion disk and a relativistic jet made them a scaled down analogue...

Centaurus A, powered by a 55 million solar mass supermassive black hole, has been intensively monitored in all accessible wavelength ranges of the electromagnetic spectrum. However, its very-high energy gamma ( γ ) ray flux (TeV photons), o...

This paper reports on the successful preparation of a low absorption–emission thermal control coating on the surface of LAZ933 magnesium–lithium alloy using the micro-arc oxidation method. This study analyzed the microstructure, phase com...

Two-dimensional (2D) tungsten diselenide (WSe2) has attracted considerable attention in the field of photovoltaic devices owing to its excellent structure and photoelectric properties, such as ordered 2D network structure, high electrical conductivit...

Accreting stellar-mass black holes represent unique laboratories for studying matter and radiation under the influence of extreme gravity. They are highly variable sources going through different accretion states, showing various components in their...

Discrepancies exist between theoretical and experimental opacity data for iron, at temperatures 180–195 eV and electron densities near 3 × 1022/cm3, relevant to the solar radiative-convective boundary. Another discrepancy, between theory...

This study introduces an innovative method for synthesizing Cadmium Oxide /Cadmium Sulfide/Zinc Oxide heterostructures (CdO/CdS/ZnO), emphasizing their potential application in solar energy. Utilizing a combination of electrochemical deposition and o...

In this study, a TiO2-CNT-Ag ternary composite film was successfully synthesized using the plasma-enhanced chemical vapor deposition method by simultaneously feeding a carbon nanotube (CNT)/Ag suspension and titanium tetraisopropoxide gas. The prepar...

Alternative photo-sintering techniques for thermal annealing processes are used to improve the morphology, layer properties, and enhance solar cell performance. The fast, nontoxic, low cost, and environmentally friendly characteristics of Cu2ZnSnS4 h...

A hydrothermal method was successfully employed to synthesize kesterite Cu2ZnSnS4 (CZTS) nanoparticles. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), energy-...

Our Sun is the closest X-ray astrophysical source to Earth. As such, it makes for a strong case study to better understand astrophysical processes. Solar flares are particularly interesting as they are linked to coronal mass ejections as well as magn...

The disposal of end-of-life (EOL) photovoltaic solar panels has become a relevant environmental issue as they are considered to be a hazardous electronic waste. On the other hand, enormous benefits are achieved from recovering valuable metals and mat...

TiO2 nanowire networks were prepared, using the corrosion of Ti foils in alkaline (potassium hydroxide, KOH) solution at different temperatures, and then a further ion-exchange process. The prepared nanostructures were characterized by field emission...

Quasi-solid-state electrolytes in dye-sensitized solar cells (DSSCs) prevent solvent leakage or evaporation and stability issues that conventional electrolytes cannot; however, there are no known reports that use such an electrolyte based on fly ash...

The present contribution aims to enhance solar cells’ performance via the development of advanced luminescent down-shifting based on encapsulated nanostructured perovskite materials. Here, thin films of inorganic lead halide (CsPbBr3) perovskit...

A series of Bi4O5Br2 photocatalysts were prepared via an innovation method of synthesis with ionic liquids (ILs). The crystal structures were investigated by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The Field Emiss...

Photocatalysis is an effective advanced oxidation process to mineralize recalcitrant contaminants in aqueous media. TiO2 is the most used photocatalyst in this type of process. To improve the deficiencies of this material, one of the most used strate...

In this study, remote plasma sputtering deposition of niobium-doped SnO2 transparent conductive oxides on glass substrates was carried out at ambient temperature with no post-deposition annealing. The microstructure, optical, electrical, and surface...

Silver (Ag) nanoparticles (NPs) have been synthesized through an easy, inexpensive, and ecofriendly method. Petroselinum crispum, parsley, leaf extract was utilized as a reducing, capping, and stabilizing agent, without using any hazardous chemical m...

Models of particle acceleration in solar eruptive events suggest that roughly equal energy may go into accelerating electrons and ions. However, while previous solar X-ray spectroscopic imagers have transformed our understanding of electron accelerat...

The efficient reduction of CO2 into valuable products such as methanol, over metal-organic frameworks (MOFs) based catalyst, has received much attention. The photocatalytic reduction is considered the most economical method due to the utilization of...

CH3NH3PbI3-xClx species were fabricated as light-absorbing layers for perovskite solar cells (PSCs), by employing NH4I, NH4Br, and NH4Cl as additives via annealing at 100 °C for different times. Solutions containing CH3NH3I, PbI2, and PbCl2 (4:1:...

Here, we reconsider the historical data, assuming a gamma-ray burst (GRB) as its source. A Supernova correlated with the GRB explains well the fading time observed by the ancient Chinese astronomers in the daytime and the nighttime, while the GRB pow...

Photo-hydrogenation of carbon dioxide (CO2) is a green and promising technology and has received much attention recently. This technique could convert solar energy under ambient temperature and pressure into desirable and sustainable solar fuels, suc...

This study focuses on the problem of identifying and extracting the magnetopause boundary of the Earth’s magnetosphere using the Soft X-ray Imager (SXI) onboard the Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE) mission. The SXI empl...

The Pt-Bi (Bi2O3)/GNs (PVP) composite was synthesized using aqueous solution synthesis and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma-atomic emi...

Nowadays, several opacity codes are able to provide data for stellar structure models, but the computed opacities may show significant differences. In this work, we present state-of-the-art precise spectral opacity calculations, illustrated by stella...

Luminescent down-shifting (LDS) spectral conversion is a feasible approach to enhancing the short-wavelength response of single junction solar cells. This paper presents the optical and electrical characteristics of LDS spectral conversion layers con...

Reduced graphene oxide has certain unique qualities that make them versatile for a myriad of applications. Unlike graphene oxide, reduced graphene oxide is a conductive material and well suited for use in electrically conductive materials, such as so...

A comprehensive statistical analysis on the properties and accompanied phenomena of all M-class solar flares (as measured in soft X-rays) in the last two solar cycles (1996–2019) is presented here with a focus on their space weather potential....

In this study, the optical properties of a TiO2 photocatalyst were enhanced with various impregnations of Er3+ and Ni2+ separately, using the impregnation method as photocatalysts for the direct solar photolysis degradation of chloroxylenol. The synt...

Tertiary diethylpyridylphosphine was synthesized by the reaction of pyridylphosphine with bromoethane in a suberbasic medium. The reaction of phosphine with the copper(I) iodide led to the formation of a copper(I) coordination polymer, which, accordi...

In this work, WO3 nanostructures were synthesized with different complexing agents (0.05 M H2O2 and 0.1 M citric acid) and annealing conditions (400 °C, 500 °C and 600 °C) to obtain optimal WO3 nanostructures to use them as a photoanode i...

High-stability, high-efficiency, and low-cost solar photoelectrochemical (PEC) water splitting has great potential for hydrogen-energy applications. Here, we report on gold/titanium dioxide (Au/TiO2) nanofiber structures grown directly on a conductiv...

Titanium dioxide (TiO2) has been widely used as a catalyst material in different applications such as photocatalysis, solar cells, supercapacitor, and hydrogen production, due to its better chemical stability, high redox potential, wide band gap, and...

In this study, polyethylene glycol-modified titanium dioxide (PEG-modified TiO2) nanopowders were prepared using a fast solvothermal method under microwave irradiation, and without any further calcination processes. These nanopowders were further imp...

In this study, aligned zinc oxide (ZnO) nanorods (NRs) with various lengths (1.5–5 µm) were deposited on ZnO:Al (AZO)-coated glass substrates by using a solution phase deposition method; these NRs were prepared for application as working electrodes t...

Manifestations of two solar flares of March 2022 were studied over Mexico. The flare effects in the lower ionosphere had a ~3 min delay from the X1.3-flare onset and ~5 min from the M9.6-flare onset. The maximal impact on the HF signal amplitude was...

The accurate long-term forecasting of solar activity is crucial in the current era of space explorations and in the study of planetary climate evolution. With timescales of about 11 years, these forecasts deal with the prediction of the very general...

Antimicrobial resistance poses a significant threat to global health, amplified by factors such as water scarcity and suboptimal hygienic practices. Addressing AMR effectively necessitates a comprehensive strategy encompassing enhanced access to pota...

Spinel ferrite MFe2O4 (M = Cu, Ca, Mg, Ni, etc.) nanoparticles and their composites are a new promising materialbecause they have shown great interest in the field of sensing, optoelectronics, catalysis, and solar cells due to their unique physical a...

New 3D micro-nanostructured composite materials have been synthesised. These materials comprise SiO2/CaCO3/Corg/NdVO4NPs and SiO2/CaO/Corg/NdVO4NPs, exhibiting strong upconversion luminescence. The synthesis was accomplished by metabolically doping d...