EDP Sciences

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    Design of Heater Control Equipment in Interface Mill Product Part Separator Process

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    The interface mill product's indication of the supporting components reveals a surplus of flaws, leading to the waste of plastic and iron materials. Black spots and holes are the two main forms of defect criterion finds, and both require correct handling to prevent long-term material and financial consequences. The equipment in this study is being designed with the intention of separating the supporting components of the plastic material from the iron substance so that both materials can be recycled. The strategy used to accomplish the goals of this study is the creation of a heater control system. The findings indicated that for the separation process for iron material portions to be carried out optimally, the temperature needed to melt plastic material was between 177 and 276 oC. Conclusion: This tool's design makes it easier for workers to separate parts with a 93% efficiency, lowering material prices by about Rp. 39,280,000 and handling time with tools by 164,976 seconds. Additionally, the iron material that is separated may be recycled

    and its determination of planting dates based on seed germination in different ecological environments of Uzbekistan

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    In this article, the main research conducted on the Raphanus sativus plant, in particular, which countries and scientific organizations of the world are the leaders for learning about this plant, based on the results obtained, the information on the publication of articles in various journals in the Scopus database is analyzed. According to the analysis, China and the United States are the leaders in conducting research with the Raphanus sativus L. and the University of Western Australia conducts the most research among scientific organizations. There are more than 520 articles based on Raphanus sativus L. plant research in various journals in Scopus, and among them, Agricultural and Biological Sciences journal is the leader in the number of articles, among the researchers, Li. Y has the highest result in publishing many articles is shown to record. Also, temperature dependence of daikon seed germination was studied in field and laboratory conditions, and according to the results of the study, 20-30 0C is the most favorable temperature for germination, daikon plant can be grown in 4 ecological zones of Uzbekistan. It has been shown that the average daily temperature for seed germination should not be higher than 30 0C when planted as a second crop in the summer season

    Spatially resolving the AGB star V3 in the metal-poor globular cluster 47 Tuc with VLTI/GRAVITY

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    Context. Mass loss at the asymptotic giant branch (AGB) plays an important role not only in the final fates of stars, but also in the chemical evolution of galaxies. Nevertheless, the metallicity effects on AGB mass loss are not yet fully understood. Aims. We present spatially resolved observations of an AGB star, V3, in the metal-poor globular cluster 47 Tuc (NGC 104). Methods. The AGB star 47 Tuc V3 was observed using the GRAVITY instrument at ESO’s Very Large Telescope Interferometer (VLTI) at 2–2.45 μm, with a projected baseline length of up to 96 m. Results. The object 47 Tuc V3 has been spatially resolved and stands as the first to attempt to spatially resolve an individual star in a globular cluster. The uniform-disk fit to the observed data results in an angular diameter of ∼0.7 mas. Our modeling of the spectral energy distribution and near-infrared interferometric GRAVITY data suggests that the observed data can be explained by an optically thin dust shell with a 0.55 μm optical depth of 0.05–0.25, consisting of metallic iron grains, likely together with effects of the extended atmosphere of the central star. The dust temperature at the inner shell boundary is 500–800 K (corresponding to 23–90 stellar radii), significantly lower than observed in nearby oxygen-rich AGB stars. Radiation pressure on small (< 0.05 μm) iron grains is not sufficient to drive stellar winds. Therefore, iron grains may grow to larger sizes, even in the metal-poor environment. Alternatively, it is possible that the observed iron grain formation is a result of the mass outflow initiated by some other mechanism(s). Conclusions. The sensitivity and angular resolution of VLTI provides a new window onto spatially resolving individual stars in metal-poor globular clusters. This allows us to improve subsequent studies of the metallicity dependence of dust formation and mass loss

    Discovery of the first olivine-dominated A-type asteroid family

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    The classical theory of differentiation states that due to the heat generated by the decay of radioactive elements, some asteroids form an iron core, an olivine-rich mantle, and a crust. The collisional breakup of these differentiated bodies is expected to lead to exposed mantle fragments, creating families of newly-formed asteroids. Among these new objects, some are expected to show an olivine-rich composition in spectroscopic observations. However, several years of spectrophotometric surveys have led to the conclusion that olivine-rich asteroids are rare in the asteroid main belt, and no significant concentration of olivine-rich bodies in any asteroid family has been detected to date. Using ESA’s Gaia DR3 reflectance spectra, we show that the family (36256) 1999 XT17 presents a prominence of objects that are likely to present an olivine-rich composition (A-type spectroscopic class). If S-complex asteroids as the second most prominent spectroscopic class in the family are real family members, then arguably the 1999 XT17 family has originated from the break-up of a partially differentiated parent body. Alternatively, if the S-complex asteroids are interlopers, then the 1999 XT17 family could have originated from the breakup of an olivine-rich body. This body could have been part of the mantle of a differentiated planetesimal, which may have broken up in a different region of the Solar System, and one of its fragments (i.e. the parent body of the 1999 XT17 family) could have been dynamically implanted in the main belt

    Spatial resolution effects on the solar open flux estimates

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    Context. Spectropolarimetric observations used to infer the solar magnetic fields are obtained with a limited spatial resolution. The effects of this limited resolution on the inference of the open flux over the observed region have not been extensively studied. Aims. We aim to characterize the biases that arise in the inference of the mean flux density by performing an end-to-end study that involves the generation of synthetic data, its interpretation (inversion), and a comparison of the results with the original model. Methods. We synthesized polarized spectra of the two magnetically sensitive lines of neutral iron around 630 nm from a state-of-the-art numerical simulation of the solar photosphere. We then performed data degradation to simulate the effect of the telescope with a limited angular resolution and interpreted (inverted) the data using a Milne-Eddington spectropolarimetric inversion code. We then studied the dependence of the inferred parameters on the telescope resolution. Results. The results show a significant decrease in the mean magnetic flux density – related to the open flux observed at the disk center – with decreasing telescope resolution. The original net magnetic field flux is fully resolved by a 1m telescope, but a 20 cm aperture telescope yields a 30% smaller value. Even in the fully resolved case, the result is still biased due to the corrugation of the photospheric surface. Conclusions. Even the spatially averaged quantities, such as the open magnetic flux in the observed region, are underestimated when the magnetic structures are unresolved. The reason for this is the presence of nonlinearities in the magnetic field inference process. This effect might have implications for the modeling of large-scale solar magnetic fields; for example, those corresponding to the coronal holes, or the polar magnetic fields, which are relevant to our understanding of the solar cycle

    Discovery of an old supernova remnant candidate through carbon monoxide line emission

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    Most old supernova remnants (SNRs) in the Milky Way have not yet been identified. Considering their high potential number and the sufficient momentum-energy transfer to the interstellar medium (ISM), they are a key part of our understanding of the overall role of SNRs in the ISM. Here, we report our discovery of an expanding molecular shell identified by CO line observations, namely G16.11–0.51. It covers a known SNR, specifically G16.0–0.5, and is larger in size (i.e., 0.56° over 0.20°). Based on its spatial and kinematic structures, weak nonthermal radio-continuum emission, and derived physical properties, we suggest that it is an old SNR. At a systemic velocity of +41.3 km s−1, the best estimated kinematic distance of G16.11–0.51 is ~3.2 kpc, implying its radius of about 15.6 pc. The age of G16.11–0.51 is estimated to be greater than ~105 yr, and, in a dense molecular environment, it has formed dense and thin shell layers. The kinetic energy of the expanding molecular gas of G16.11–0.51 is about 6.4 × 1049 erg, accounting for approximately 6% of the initial SN explosion energy. Although old SNRs have essentially become cold and hard to detect, our discovery suggests that they can be found by searching for CO line emissions

    Spectroscopic observations of progenitor activity 100 days before a Type Ibn supernova

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    Obtaining spectroscopic observations of the progenitors of core-collapse supernovae is often unfeasible, due to an inherent lack of knowledge as to what stars experience supernovae and when they will explode. In this Letter we present photometric and spectroscopic observations of the progenitor activity of SN 2023fyq before the He-rich progenitor explodes as a Type Ibn supernova. The progenitor of SN 2023fyq shows an exponential rise in flux prior to core collapse. Complex He 

    Deciphering driven phase transitions: a study on the dielectric and electrical properties of Ca

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    This study aims to contribute to the investigation of the electrical and dielectric behavior of the well-known brownmillerites Ca2Fe2O5 compound. The compound was produced using a solid-state reaction process and examined using X-ray powder diffraction and Rietveld refinement to confirm its orthorhombic crystal structure, as well as its cell characteristics. A thorough dielectric and electrical examination was carried out across a wide range of temperature and frequency, from 30 to 400 °C and 10 Hz to 1 MHz. Remarkably, at a relatively temperature of approximately 170 °C, the dielectric measurements revealed a complex behavior, indicative of diffuse phase transition. Similar distinctive changes were also observed in impedance spectroscopy and conductivity studies, suggesting a temperature like phase transition phenomenon. This observation was further substantiated through a differential scanning calorimetry analysis, which identified an endothermic dip at around 170 °C, signifying a structural disturbance at these temperatures. These findings contribute significantly to our comprehensive understanding of the material’s behavior across a wide temperature range, providing valuable insights into the polarization mechanisms, relaxation dynamics, and electrical conduction properties

    Optimization analysis of cold extrusion process parameters for valve screws

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    This study focuses on valve screws and establishes a cold extrusion simulation model using DEFORM-3D software to analyze the deformation characteristics and influencing factors during the extrusion process. Supported by the theory of rigid-plastic finite element, an orthogonal experimental design is conducted to establish a four-factor three-level simulation scheme with general fillet radius, die clearance, extrusion speed, and friction coefficient as the simulation variables, and maximum equivalent stress on the convex die, forming damage of the blank, and maximum wear depth on the concave die as the objective values. The prediction model based on BP neural network algorithm and orthogonal experimental data shows high accuracy. The optimization problem is simplified into a dimensionless numerical analysis problem using GC grey correlation analysis, and the optimal solutions within each variable range are determined using range analysis. The simulation results after optimization show a 20 5% reduction in maximum equivalent stress on the convex die compared to the original scheme, a 4.9% reduction in forming damage of the extruded part, and a 24.24% reduction in maximum wear depth on the concave die compared to before optimization. The actual verification confirms the good forming effect of valve screw extrusion, with well-formed contours and a uniform surface without wrinkles or defects. Finite element simulation provides valuable guidance for practical production

    Application of nowcasting to reduce the impact of irradiance ramps on PV power plants

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    Short-term fluctuations in photovoltaic power plants, known as ramps and caused by clouds, challenge grid stability and efficient energy use. These issues are traditionally managed with battery energy storage systems, which, while effective, are expensive. We propose an alternative solution: the use of short-term irradiance forecasts, or nowcasts. Using a photovoltaic power plant in Germany and its simulated model, we demonstrated that nowcasts could cut ramp rate violations by 81%. This led to a reduction in required battery capacity by 71% and the required maximum battery power provided by 48%, at the cost of a 13% curtailment loss, i.e. loss through reduction of power. Our data set of 18 chosen days from 2020 with high variability conditions was scaled up to a year for the economic analysis. From an economic standpoint, nowcasts could lower the Levelized Cost of Electricity by 5.5% from 4.74 to 4.48 EUR cents, and even by 35% to 3.09 EUR cents with ideal forecasting, showing its potential. While nowcasts cannot completely replace batteries, they substantially reduce the need for such storage solutions. This results in cost savings and adherence to grid stability requirements, making nowcasts a complement or partial alternative to battery systems for mitigating power fluctuations in photovoltaic power plants

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