bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of the physical mechanism of a solar flare using MHD modeling over an active region: the onset of an extended surface of magnetic lines passing through a chain of current density maxima
Authors: Podgorny A. , Podgorny I.
Published: December 2024

The primary release of solar flare energy in the corona at altitudes of 15,000 — 70,000 km is explained by the physical mechanism of S.I. Syrovatsky, based on the rapid release of energy accumulated in the magnetic field of the current layer. The observed manifestations of the solar flare are explained by its electrodynamic model proposed by I.M. Podgorny.
The model uses analogies with the electrodynamic model of a substorm, previously developed by its author.
Since it is impossible to obtain the magnetic field configuration in the corona from observations, it is necessary to conduct MHD modeling. When setting the problem, no assumptions were made about the mechanism of the solar flare. For the numerical solution, an upwind absolutely implicit finite-difference scheme, conservative with respect to magnetic flux, was developed. The scheme is realized in the PERESVET computer program.
A detailed study of the pre-flare state over the active region AR 10365 was conducted. The study revealed the emergence of an extended current sheet 50,000 km wide, which is a surface of magnetic lines passing through a chain of closely spaced current density maxima. The magnetic lines of the surface are in the form of arches located in the bright region of the flare emission. At the center of such a current sheet, a 3D maximum of current density does not necessarily have to be achieved. An appearance of a flare in such an arcade is explained by the fact that the main part of the surface of the magnetic arcs has properties that contribute to the development of flare instability.
Recognition of solar flares in the microwave range of observations using machine learning
Authors: Shamsutdinova J. , Kashapova L.
Published: December 2024

We present the results of testing machine learning methods for the recognition of solar flares observed in the microwave range. The catalogue of observations by the Nobeyama spectropolarimeters (NoRP) was used for both training and analysis of method effectiveness. The input data are one-dimensional temporal profiles with a frequency of 9.4 GHz, which are mostly associated with the emission of an optically thin source and the non-thermal emission from accelerated electrons. The input dataset consisted of 100 events and included temporal profiles with simple and complex structures. The aim of recognition is to distinguish between the temporal profiles of ``classical'' or simple-looking shapes, and ``complex'' ones. We compared the classification results provided by the correlation coefficient application with the results obtained using the Support Vector Machine (SVM) method with different parameters. True Positive (TP) and True Negative (TN) are values describing the number of events which the model correctly recognized, in our case, ``classical'' and ``complex'' profiles. False Postive (FP) and False Negative (FN) indicate incorrect model predictions of ``classical'' or ``complex'' profiles. The number of correctly recognized events using the correlation coefficient method was 75, compared to 90 events obtained using the SVM method. The number of false predicted events resulting from the application of the correlation coefficient was 25, versus 10 by SVM application. These results indicate the advantage of the SVM technique over the correlation coefficient approach. The SVM method allows us to process datasets using different functions as kernels - linear, polynomial and Radial Basis Function (RBF). In our study, we found that the most accurate result was provided by the RBF kernel with a gamma hyperparameter of 1.
Photospheric disturbances and acoustic sources of the helioseismic ``circular'' X1.5 flare of May 10, 2022
Authors: Sharykin I. , Zimovets I.
Published: December 2024

This paper is devoted to the analysis of the energy release of the X1.5-class solar flare that occurred on May 10, 2022, during which the powerful helioseismic response (``sunquake'') was observed. An additional feature is the fact that this powerful sunquake was generated in the NOAA active region 13006 of Hale class $\beta\delta$, whereas earlier it was shown that the strongest helioseismic disturbances are generated in the sunspot groups with the most complex Hale class of $\beta\gamma\delta$. We analyze magnetic fields and photospheric perturbations basing on the Helioseismic and Magnetic Imager (HMI) data. Analysis of the distribution of acoustic sources and photospheric perturbations reveals a ring geometry in the form of a chain of sources roughly corresponding to the geometry of flare ribbons. The photospheric perturbations developed in two regions near the magnetic field polarity inversion line (PIL) and corresponded to two series of hard X-ray bursts seen in the KONUS/WIND data. We extrapolated the coronal magnetic field from the HMI vector magnetograms within the framework of the nonlinear force-free field (NLFFF) approximation. The geometry of the ``dome with a spine'' type was revealed. The regions of the photospheric perturbations approximately corresponded to the base of the dome. In this work we also briefly discuss penumbral decay and the flare dynamics of the observed $\delta$-spot. The data obtained vividly show the local features of the magnetic fields in a relatively morphologically simple active region, where the conditions for the powerful helioseismic response during the solar flare arose. The paper also discusses the morphological properties of the active region with similar properties of the most helioseismically active regions of the 24th cycle.
The features of the north-south asymmetry of the magnetic flux in active regions with different magnetic morphology in solar cycles 23 and 24
Authors: Zhukova A. , Abramenko V.
Published: December 2024

We use the CrAO catalog of the magneto-morphological classes (MMC) of active regions (ARs) to study the hemispheric distribution of the number and magnetic fluxes of ARs that appeared on the disk from May 1996 to December 2021. 3047 ARs were distributed between classes of the regular (bipolar groups that obey empiric rules for sunspots) and irregular (all the rest, except for unipolar sunspots) ARs. The analysis of the results showed that all the trends are more pronounced in the flux data. For the irregular ARs, the strongest peaks in time profiles are observed in the second maximum of the cycle in the S-hemisphere. ARs of both MMC types demonstrate noticeable N-S asymmetry. The most abrupt changes are shown by the irregular ARs fluxes. For the compiled quadrupolar-like component of the flux, the evidence of oscillations with a period of about 15 years is found for all studied ARs and for the irregular groups. For the regular ARs, cross-correlation of ARs fluxes in different hemispheres in adjacent cycles showed no features. For the irregular groups, a high correspondence in flux dynamics in the N-hemisphere of cycle 23 and in the S-hemisphere of cycle 24 is found.
Multipoint multiwavelength observations of a near-the-limb eruptive solar flare with quasi-periodic pulsations
Authors: Zimovets I. , Sharykin I.
Published: December 2024

We present results of the analysis of multiwavelength observations of the M3.4 eruptive flare that occurred near the western limb of the Sun on September 2, 2023 (SOL2023-09-02T06:33). We use observations from the near-Earth spacecraft ASO-S/HXI, SDO/AIA, HMI, GOES/XRS, and Fermi/GBM. X-ray observations by the STIX telescope-spectrometer on board the Solar Orbiter from the opposite side of the Sun are also used. The flare was associated with a two-stage inclined ( $\approx 40-50^{\circ}$ to the radial direction) eruption, the second stage of which was accompanied by the impulsive flare phase and quasi-periodic pulsations (QPPs) of hard X-rays with a characteristic time scale $P\approx1.56$ min. HXI observed hard X-ray sources located above the apex of a coronal Y-shaped structure, visible in the ``hot'' 94 and 131 Å EUV channels, behind a drop-shaped erupting plasmoid/prominence. Hard X-ray sources near the foot of the flare loops and flare ribbons were also observed, mainly after the peak of the impulsive phase. The HXI and STIX observations from different locations in the heliosphere are consistent with each other. Temporal dynamics of the spectral index of nonthermal electron flux had a ``soft-hard-soft'' behavior during QPPs. The observational results do not contradict the ``standard'' model of eruptive two-ribbon flares, where populations of electrons are accelerated episodically due to magnetic reconnection in a current sheet in the corona behind an erupting structure. However, understanding the quasi-periodicity of electron acceleration/injection requires further studies.
On the parameters of encounters of NEOs with the Earth
Authors: Zolotarev R. , Shustov B.
Published: December 2024

The paper presents the results of statistical modeling of the entry of near-Earth objects (NEOs) into the near-Earth space - a sphere with a radius of 0.01 AU around the Earth. The distributions of asteroids in the direction and velocity of approach to the Earth are constructed. The NEO population was modeled using the NEOMOD package and integrated for 110 years using the REBOUND package. The main results are: 1) the number of asteroids larger than 10 m in size entering to near-Earth space is approximately 1000 per year; 2) up to half of the asteroids can enter the near-Earth space from the side of the day-time-hemisphere; 3) there is anisotropy in the flux density of incoming asteroids. Typical velocity of approach to the Earth at the entrance to the near-Earth space is approximately 7.5 km/s (maximum speed can reach up to 30 km/s). These distributions can be useful in the design of a System of Observation of Day-time Asteroids (SODA).
Doppler confirmation of TESS planet candidate TOI-1408.01: updated analysis and fitting
Authors: Baluev R. , Galazutdinov G. , Valyavin G. , Aitov V. , Gadelshin D. , Valeev A. , Sendzikas E. , Sokov E. , Mitiani G. , Burlakova T. , Yakunin I. , Antonyuk K. , Vlasyuk V. , Romanyuk I. , Rzaev A. , Yushkin M. , Ivanova A. , Tavrov A. , Korablev O.
Published: December 2024

Based on the Doppler observations from the FFOREST spectrograph of the 6-meter telescope (BTA) and on the photometric observations from the TESS spacecraft, we provide an updated analysis for TOI-1408, an F-type main sequence star, located 140 pc away, that hosts exoplanet TOI-1408.01. We confirm the qualitative conclusions from our initial paper: (1) a grazing transit geometry such that the planet obscures its host star by only a portion of the visible disc,(2) unreliably fitted planet radius, (3) which nonetheless has a lower bound constraint of $\sim\!1~R_{\rm Jup}$, (4) unexpectedly large planet mass of $\simeq\!1.7~M_{\rm Jup}$, and (5) significant evidence in favor of a moderately eccentric orbit with $e\simeq0.27$. This solution may suggest that the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding or may indicate the possible presence of other unseen companions in the system, yet to be detected.
Investigation of the infrared profiles of exoplanet HD 209458 b secondary eclipses
Authors: Fedotov A. , Baluev R.
Published: December 2024

In this work we process infrared light curves for 13 secondary eclipses of the exoplanet HD 209458 b, obtained with the Spitzer Space Telescope. The objective of the study was to identify any discrepancies that might be attributed to the inhomogeneity of the planet's surface brightness or a difference of the planet's shape from a sphere. Firstly, an attempt was made to ascertain whether the observed midpoint of the secondary eclipse exhibited a shift from the ephemeris moment. This could indicate the presence of a hot spot on the planet's surface that is shifted from the central meridian. The analysis allowed for the correlated noise that remained in the IRAC detector data after aperture photometry by approximating the noise with a Gaussian random process. As a result, we detected two components of red noise with different time scales: $\sim\!10$ s and $\sim\!5$ min. In addition, we constructed a unified model of the effect of inhomogeneous pixel sensitivity as a periodic function of the brightness centroid coordinates, which works well for all the analyzed eclipses. According to the results, the main parameters of the HD 209458 b eclipse coincided with those obtained by other authors: a depth of $0.125 \pm 0.004$% and a shift of the observed midpoint of $-0.53 \pm 0.61$ min.
ExoClock: up-to-date ephemerides for the ARIEL mission
Authors: Garmash A.
Published: December 2024

Atmospheres of about 1000 exoplanets are going to be spectroscopically observed with ESA's future ARIEL mission. For the mission to be as efficient as possible, good preliminary knowledge of planet ephemerides is required before its launch, scheduled for 2029. To achieve this goal, the ExoClock project dedicated to continuous monitoring and updating the ephemerides of ARIEL candidates has been created. The project has been developed in a manner to make the best use of all available resources: observations reported in the literature, observations from space instruments, and, mainly, observations from ground-based telescopes, including both professional and amateur observatories. In this report we present our observations of exoplanet transits performed within the ExoClock project in 2022–2024.
Interpretation of the Balmer-alpha line absorption in the exoplanet WASP-69 b
Authors: Miroshnichenko I. , Sharipov S. , Rumenskikh M. , Shaikhislamov I.
Published: December 2024

In this work, the absorption in the H$\alpha$ line of the exoplanet Wasp-69 b was simulated. A three-dimensional self-consistent multifluid magnetohydrodynamic (MHD) model of the atmosphere was used to calculate the characteristic distributions of density, velocity, and temperature of various components in the atmosphere of WASP-69 b. To obtain the profile of hydrogen atoms excited to the second energy level H($2\ell$), a Monte Carlo model of Ly$\alpha$ photon transport in the atmosphere, obtained by MHD simulation, was used. Three main sources were taken into account as the ``pumping'' of the atmosphere with Ly$\alpha$ photons in the model: the photons incident from the star, photons generated in the process of collisions of hydrogen atoms with electrons, and photons arising in the process of recombination of electrons and protons in the atmosphere of the planet. Modeling of the resonant scattering of Ly$\alpha$ photons on hydrogen atoms was performed in the approximation of partially coherent isotropic scattering. The calculations have shown that the population of the hydrogen excited to the second energy level due to the pumping by intra-atmospheric Ly$\alpha$ photons is insignificant and does not lead to absorption in the H$\alpha$ line, but such absorption can appear due to the pumping by stellar photons. Nevertheless, judging by the observed data obtained and their analysis, the absorption in this line was not detected, which may indicate a low intensity of the Ly$\alpha$ line radiation from the parent star.
Transit absorption in the oxygen lines for constraining the atmosphere temperature of hot exoplanets
Authors: Shepelin A. , Golubovsky M. , Shaikhislamov I.
Published: December 2024

Atomic oxygen, due to its unique chemical properties, is widely used in astrophysics to study chemical composition, nucleosynthesis conditions, and the processes of formation and evolution. The recent detection of the O I 1304 Å and 7774 Å lines in the upper atmospheres of exoplanets using space and ground-based telescopes opens the possibility to evaluate its abundance in these objects and constrain important atmospheric parameters. However, the simple approximation of thermodynamic equilibrium is often inaccurate in describing the formation and absorption for many spectral lines in stars and hot exoplanets. The development of a kinetic model that takes into account detailed radiative and collisional processes in advanced atomic models is required to interpret the observations. In this work we for the first time analyze the advantages of transit absorption measurement of two oxygen lines simultaneously.
Exchange of meteorites between the terrestrial planets and the Moon
Authors: Ipatov S.
Published: December 2024

The evolution of the orbits of bodies ejected from the Earth, Moon, Mercury and Mars was studied. The probabilities of collisions of ejected bodies with planets depended on ejection velocities, ejection angles and points of ejection. At a velocity of ejection close to the parabolic velocity, most of bodies fell onto the planet from which they had been ejected. Below results are presented not for such small ejection velocities. At ejection velocities about 12-14 km/s, the fraction of bodies ejected from the Earth that fall back onto the Earth was about 0.15-0.25. The total number of bodies ejected from the Earth and delivered to the Earth and Venus probably did not differ much. The probability of collisions of bodies ejected from the Earth with the Moon moving in its present orbit was of the order of 0.01. Probabilities of collisions of bodies ejected from the Earth with Mercury were about 0.02-0.08 at ejection velocities greater than 11.3 km/s. The probabilities of collisions of bodies ejected from the Earth with Mars did not exceed 0.025. For the ejection of bodies from the present orbit of the Moon, probabilities of collisions of ejected bodies with planets were similar to those ejected from the Earth if we consider smaller ejection velocities from the Moon than from the Earth. The probability of a collision of a body ejected from Mars with Mars usually did not exceed 0.04 at an ejection velocity greater than 5.3 km/s. The fraction of bodies ejected from Mars and collided with Mercury was typically less than 0.08. Probabilities of collisions of bodies ejected from Mars with the Earth and Venus were about 0.1-0.2 (each) at an ejection velocity between 5.05 and 10 km/s. Most of bodies ejected from Mercury fall back onto Mercury. Probabilities of collisions of bodies ejected from Mercury with the Earth typically did not exceed 0.02 and 0.1 at an ejection velocity less than 8 km/s and 15 km/s, respectively. The fraction of bodies ejected from Mercury and collided with Venus was greater than that with the Earth typically by an order of magnitude. Probabilities of collisions of bodies with Venus were about 0.1-0.3 at a velocity of ejection from Mercury between 4.3 and 10 km/s.
The effect of encounters with interstellar objects
Authors: Mikryukov D. , Shevchenko I.
Published: December 2024

We explore the immediate and long-term consequences of close passages of interstellar planet-mass and substellar-mass objects for the Solar system dynamics. Two approach orbits of such objects are considered, namely, the hyperbolic orbits of two real interstellar objects, 1I/'Oumuamua and 2I/Borisov. For each orbit, a series of massive numerical experiments is performed, in which the mass of the interstellar object is varied in small steps over a broad range. It is shown that even if the interloper does not experience any close encounter with a planet of the Solar system, and has a mass typical for a free-floating planet, a disruption of the Solar system may occur on time scales of several million years.
Estimation of short-period disturbances in the motion of NEAs in the presence of an inverse-square perturbing acceleration
Authors: Sannikova T.
Published: December 2024

Let a point of zero mass move under the influence of attraction to the central body and a small perturbing acceleration $P' = P/r^2$, where $r$ is the distance to the attracting center, the components of the $P$ vector are assumed to be constant in the reference system with axes directed along the radius vector, transversal and angular momentum vector. For this problem, the equations of motion in the mean elements and formulas for the conversion from osculating elements to the mean ones in the first order of smallness were previously found. The analytical solution to the averaged equations and the Euclidean (root-mean-square over the mean anomaly) displacement norm $\varrho^2=||dr||^2$ were also obtained earlier, where $dr$ represents the difference between the position vectors in the osculating and mean orbits. Using these relations, it is possible to estimate the $\varrho$ magnitude of short-period orbital disturbances arising due to the presence of a small perturbing acceleration $P'$, as well as the $d$ displacement of the position of the asteroid in the mean perturbed orbit from its unperturbed position after one orbital period. For 412 near-Earth asteroids (NEAs), the $\varrho$ displacement and the $d$ distance were calculated. An analysis of the calculation results showed that in most cases the deviation of the osculating orbit from the mean one due to periodic perturbations is small, however, cases with the $\varrho$ displacement of the order of several tens and hundreds of kilometers have been identified. This indicates the need to take into account short-period disturbances when short-term forecasting the movement of these objects, e.g. when planning space missions.
Large-format photodetecting system pCam6060 with a GSENSE6060BSI CMOS detector, developed at SAO RAS and optimized for photometric methods
Authors: Afanasieva I. , Murzin V. , Ardilanov V. , Ivaschenko N. , Pritychenko M.
Published: December 2024

The pCam6060 photodetecting system has been developed at SAO RAS based on the GSENSE6060BSI photodetector manufactured by GPixel (China) with a frame format of $6144 \times 6144$ active pixels and a pixel size of 10 micrometers. The readout speed reaches 11 fps. The back-illuminated detector has a wide spectral range of 200–1040 nm with a minimum quantum efficiency (QE) of 10% and a maximum sensitivity of 95% at 580 nm. The quantum efficiency in the near-infrared range is 58% at 850 nm. The pCam6060 system controller implements a mode of simultaneous image readout via two 12-bit video channels with different gain and their subsequent combination in the controller into a single frame with an extended 16-bit dynamic range. This method achieves simultaneously a low readout noise level (about 3 e$^{-}$) in the high-gain channel and a large dynamic range (full well capacity of about 100000 e$^{-}$) in the low-gain channel. Back-illuminated CMOS detectors, unlike front-illuminated devices, are not susceptible to the long-term preservation of the residual charge from previous exposures, which makes them suitable for recording faint objects in photometric long-exposure observing methods. Communication between the host computer and the camera is carried out via a fiber optic line at distances of up to 50 m. Video data are recorded on the computer hard drive in real-time. The pCam6060 photodetecting system is designed for astronomical applications and has a moisture-proof design.
Liquid scintillation detector based on an acrylic sphere and silicon photomultiplier matrices
Authors: Dzaparova I. , Yanin A. , Gorbacheva E. , Kurenya A. , Petkov V.
Published: December 2024

This paper presents the results of applying the matrices of silicon photomultipliers (SiPMs) as multichannel photodetectors for the scintillation detectors based on a liquid scintillator. We consider the possibility of using the SiPM matrices with an appropriate optical collector to obtain an image of the luminous tracks of charged particles passing through a scintillator. Such a method allows one to obtain an image of an event inside the scintillator volume, the analysis of which makes it possible to separate different classes of events. It is expected that the proposed particle detection technique may be useful in the creation of new large detectors for neutrino astrophysics and geophysics. The detector is an acrylic sphere with a diameter of 500 mm, filled in with a liquid scintillator. The scintillator is viewed through an optical collector based on two Fresnel lenses with two matrices of 64 SiPMs. The paper describes the data collection system and the detector design, we also demonstrate a three-dimensional image of a recorded event.
Measurements of the flux densities and variability of the standard flux scale ``Artificial Moon'' sources on time scales of 1–8.5 years
Authors: Ivanov V. , Ipatov A. , Rakhimov I. , Andreeva T.
Published: December 2024

We present flux density measurements for the standard radio sources of the ``Artificial Moon'' (AM) absolute flux scale during the time interval of 2017.5–2024.0 at wavelengths $\lambda=3.5$ and $6.2$ cm. The standard sources are weakly variable, and maintaining the accuracy of the scale requires regularly recurring calibrations. Currently, the RT-32 radio telescope at the Svetloe Observatory of the Institute of Applied Astronomy of the Russian Academy of Sciences (IAA RAS) monitors the AM flux scale standard sources to study their variability and maintain the accuracy of the scale. We determined the flux densities of the AM flux scale calibrators at two wavelengths during the time interval of 2017.5–2024.0. The measurement errors for both wavelengths did not exceed $\pm2$%, the measurement data were averaged over time intervals of 1 year at the average epochs 2019.0, 2022.0, and 2023.0. A comparison of the standard source flux densities $S$ for the epochs 2019.0, 2022.0, and 2023.0 with each other as well as with the flux densities $S_0$ at the epoch 2015.5 has shown that at time intervals of more than 1 year, there exists variation in the standard source flux densities that exceeds the standard deviations $\sigma$ and the established flux scale error limits of $\pm3$%. We conclude that it is necessary to recalibrate the standard sources at least every 2 years to maintain the accuracy of the flux scale.
Obtaining the Chandrayaan-3 lander coordinates on the lunar surface by the Doppler measurements of the transmitted signal with an Earth-based receiving system
Authors: Kazantseva E. , Bondarenko Yu. , Marshalov D. , Medvedev Yu.
Published: December 2024

We determine the selenographic coordinates of the Chandrayaan-3 lander by Doppler measurements of its signal. The Chandrayaan-3 successfully landed in the south polar region of the Moon near the craters Manzinus and Simpelius on 23 August 2023 and had been transmitting scientific information and telemetry to Earth in the S and X-bands during 14 days. The accuracy of the obtained Doppler measurements do not allow unambiguous determination of the lander location on the lunar surface because the transmitter was degrading during the entire observing interval. For this reason, in our work we have evaluated the influence of the Doppler measurement characteristics on the accuracy of the transmitter location determination. It has been shown that for a signal with a relative frequency instability of the order of $10^{-13}$, the achievable accuracy of coordinate determination is about 34 meters.
Implementation of the $\alpha$ UMi monitoring system at SAO RAS
Authors: Shaldyrvan I. , Komarov V. , Komarova V. , Fokin M.
Published: December 2024

A new $\alpha$ UMi monitoring system based on an IP camera with a CMOS photodetector has been developed and installed at the Upper Scientific Site of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). The main aim of the development is to measure the astronomical seeing and monitor its variation. Here we briefly describe the method of differential image motion monitoring (DIMM) used as the device operational principle and give some details on the characteristics and operation of the monitoring system developed.
Continuum spectrum receiving complexes on the RATAN-600 radio telescope
Authors: Tsybulev P. , Nizhelskij N. , Borisov A. , Kratov D. , Udovitskiy R.
Published: December 2024

The results of many years of work on the creation and modernization of the continuum spectrum receiving complexes on the RATAN-600 radio telescope are presented. These complexes are located in the cabins of four secondary mirrors of the radio telescope, three of which can simultaneously conduct observations for three independent programs using separate sectors of the radio telescope primary mirror. To date, a total of 23 radiometers (35 frequency channels) operate on the radio telescope around the clock and all year round. The receiving complexes operate according to technical and scientific programs such as observation of individual objects or round-the-clock sky surveys. The main attention is payed to increasing the sensitivity and long-term stability of the radiometers. With a large number of receivers, the operational characteristics are also important (ease of maintenance, mean time to failure, dimensions, power consumption). One of the tasks being solved is the problem of noise protection in the operating frequency ranges as well as active noise reduction in the decimeter wavelength ranges. The groundwork and prospects in this direction are presented. The immediate plans for the commissioning of new radiometers are also introduced.
Teaching the basics of data science on astronomical data and catalogs
Authors: Arkhipova N. , Luzhnov A. , Fedorov N.
Published: December 2024

Today it is difficult to imagine research in the field of astronomy and astrophysics without qualitative and quantitative analysis of data obtained using modern astronomical instruments, the quantity and quality of which has grown significantly over the past quarter century. However, until now, this topic has not been studied in school astronomical education and pre-university training, which significantly hinders the inclusion of applicants and elementary students in scientific and research work. Therefore, our report will describe the methods of teaching astronomical data analysis and working with astronomical catalogs of famous space projects. The results of testing these techniques when working with students of the HSE (Higher School of Economics) Lyceum and the Center for Pedagogical Excellence will also be discussed.
Comparison of educational results in Astronomy for high school students in St. Petersburg
Authors: Grigoriev V.
Published: December 2024

During five academic years from 2018 to 2024, students in grades 10 and 11 of three different High Schools in St. Petersburg studied the subject of Astronomy as part of the school curriculum under the guidance of the author of this study. Teaching was conducted in 15 classes, each of which had at least 20 students. During this time, several approaches to educational process were used, but the methodology of academic achievements in this subject was carried out in the most identical way. This paper describes the approaches to educational process during the specified time, describes the methodology for measuring academic achievements. Based on this methodology, measurable educational results were obtained in the subject of Astronomy among students, an analysis of these results was carried out, features were identified, and a justification for differences in academic achievements was proposed.
ОСОБЕННОСТИ СОЦИАЛЬНОЙ АДАПТАЦИИ ДЕТЕЙ-ИНВАЛИДОВ
Authors: Савина А.М. , Данковцев О.А.
Published: December 2024

В статье рассмотрена проблема социальной адаптации детей-инвалидов. Анализируется международный и российский опыт помощи инвалидам. Раскрыты особенности процесса адаптации, а так же подходы к исследованию данного вопроса. Приведены примеры поддержки инвалидов со стороны государства.
ПРИОРИТЕТНЫЕ НАПРАВЛЕНИЯ ПОДГОТОВКИ МОЛОДЕЖИ К СЕМЕЙНОЙ ЖИЗНИ
Authors: Пайзиева М.Н.
Published: December 2024

В статье рассматриваются аспекты семейных отношений, семейной психологии в идеальной реализации приоритетов общества в важной государственной политике личного воспитания, а также актуальные вопросы формирования единого культурного мировоззрения в семье, воспитания детей, этикетной деятельности. был проанализирован.
Plasticizer blending improved regenerated cellulose films as an alternative to plastics
Authors: Ahokas Pauliina , Kunnari Vesa , Majoinen Johanna , Harlin Ali , Mäkelä Mikko
Published: December 2024

Plasticizers are widely used to improve the elasticity of regenerated cellulose films, but academic research has thus far ignored the possibility of plasticizer blending. We studied the effects of glycerol, sorbitol, and maltitol on film properties based on a systematic design for mixture experiments and determined regression models to correlate blend composition with film properties. Our results showed that plasticizer blending enabled us to control film tensile strength and water vapour and oxygen permeabilities, which are key indicators to evaluate film efficacy in barrier packaging applications. Our films showed lower water vapor and oxygen permeabilities than commercial uncoated cellophane film and could potentially provide a renewable alternative to conventional polyolefin films with further improvements. These results are important and they indicate that plasticizer blending provides a novel and simple methodology to improve regenerated cellulose films to meet the increasing demand for alternatives to conventional plastics in packaging and other applications.
Practical synthesis of Csp3 Chlorinated Compounds from Cyclopropanes, Olefins and C-H Bonds via photolysis of Willgerodt-type reagents
Authors: Nguyen Tin V. T. , Tran Trinh T. H. , Nguyen Thanh V. Q. , Waser Jerome
Published: December 2024

Csp3-Cl bonds are essential as diversification handles in organic synthesis and are found in many natural products and bioactive molecules. In this work, we introduce a general protocol for the selective chlorination of aryl cyclopropanes, olefins, and activated C-H bonds using the direct photoexcitation of Willgerodt-type reagents to generate chlorine radicals. Preliminary results on an iodine(I/III) catalytic process starting from abundant chloride salts are also presented. Furthermore, a one-pot protocol has been developed for the telescoped functionalization of benzylic chlorides with C, N, O, and S nucleophiles. Especially, this approach provides a platform to access 1,1-diaryl motifs, which are important building blocks for the synthesis of pharmacophores.
Data-Driven Parametrization of All-atom force fields for Organic Semiconductors
Authors: Zhao Guojiang , Hu Taiping , Wang Hongshuai , Wu Lirong , Lu Shuqi , Yang FengTianCi , Chen Shangqian , Gao Zhifeng , Wang Xinyan , Cheng Zheng
Published: December 2024

Organic semiconductors (OSCs) composed of π conjugated molecules have gained significant interest in the study of bulk properties such as molecular arrangement and electron mobility. However, the types of torsion in the traditional force field (FF) are limited, fail to cover the chemical space of π conjugated molecules, and thus, hinder further molecular dynamics (MD) simulation to deduce these bulk properties through statistical mechanics. In this study, we introduce OSCFF, which supports various types of torsion for conjugated molecules and enables the generation of RESP charges with high accuracy through the neural network (NN). To develop the OSCFF, we construct two expansive and highly diverse molecular datasets: one consists of around 56,000 fragment geometries with torsion profiles, and another consists of around 472,000 optimized molecule geometries with RESP charges. The OSCFF demonstrates high accuracy in predicting torsional energy profiles, RESP charges, and the radial distribution function (RDF) for conjugated molecule systems. Furthermore, our OSCFF is compatible with the GAFF2 and a pipeline is provided for automatically generating the Gromacs supported topology file. We expect OSCFF will reduce the manual effort required for MD simulations of OSCs and serve as a valuable tool for multiple stages of OSCs design.
Improved Direct Bioelectrochemical Fructose Oxidation with Surfactant-Free Heterotrimeric Fructose Dehydrogenase Variant Truncating Heme 1c and C-Terminal Hydrophobic Regions
Authors: Adachi Taiki , Ichikawa Konatsu , Miyata Tomoko , Makino Fumiaki , Tanaka Hideaki , Namba Keiichi , Sowa Keisei
Published: December 2024

Direct electron transfer (DET)-type bioelectrocatalysis is a coupled redox reaction between enzymatic and electrode reactions. Such mediatorless reactions are an environmentally safe approach that can be applied to various bioelectrochemical devices. We focused on fructose dehydrogenase (FDH), a membrane-bound heterotrimeric enzyme that catalyzes DET-type D-fructose oxidation. Although the overall structure was recently elucidated, its membrane-bound region has not been completely identified. Therefore, this study assumed that the heme 1c region and C-terminal hydrophobic region (CHR) were bound to the membrane. A constructed double variant (Δ1cΔCHR_FDH) was soluble without any surfactants; additionally, cryo-electron microscopy confirmed that this variant was downsized. Δ1cΔCHR_FDH exhibited a 14-fold higher catalytic current density (11 ± 1 mA cm–2) than that of the wild-type recombinant FDH (rFDH) at multi-walled carbon nanotube electrodes. Kinetic analysis of the voltammograms suggested that downsizing of the enzyme and the removal of surfactants increased the surface concentration of enzymes at the electrode. This study elucidates the membrane-binding mechanism of proteins and efficient bioelectrocatalysis overcoming the interference of surfactants.
LASSO for CALPHAD model selection enables data-efficient thermodynamic modeling: an application in thermochemical hydrogen production materials
Authors: Guan Pinwen , Debusschere Bert , Bishop Sean R. , Witman Matthew , McDaniel Anthony H.
Published: December 2024

Phenomenological CALPHAD (CALculation of PHAse Diagrams) models, widely used for multicomponent materials, often contain a considerable number of parameters and require fitting using data from a relatively small number of experimental measurements or theoretical calculations. Sometimes these parameters are introduced for the purpose of improving model fits but without clear physical justification, which leads to over-parameterized models with poor generalization performance. Automated approaches for optimal model selection based on the available data therefore become critical. In this work, a least absolute shrinkage and selection operator (LASSO)-based approach is developed for model selection by leveraging the linearity of the CALPHAD model with respect to its parameters to convert the model selection and fitting to a LASSO minimization problem. We demonstrate its utility for thermodynamic modeling of thermochemical hydrogen (TCH) production materials, using lanthanum strontium manganite (LSM) as an example. Various TCH relevant properties, including oxygen stoichiometry as function of oxygen partial pressure, enthalpy of reduction, and entropy of reduction, are successfully predicted with reasonable accuracy using a minimal set of model parameters. Importantly, the model selection and fitting involve minimal human decision; it can therefore be applied to high-throughput DFT defect calculations and yield efficient workflows for TCH materials modeling and optimization.
Cytosolic Protein Delivery via Protein-Bound Microparticles Based on Anionic Boron Clusters and Cationic Polymers
Authors: Hirai Yuya , Makita Yoshimasa , Nakagawa Makoto , Kakehashi Rie , Fujiwara Shin-ichi
Published: December 2024

Direct protein delivery to the cytosol facilitates immediate functional expression of proteins without the risks associated with gene introduction. However, the technology for delivering various proteins to the cytosol is still in its infancy. Herein, the formation of microparticles comprising anionic boron clusters and the cationic polymer hexadimethrine bromide (HDB) was demonstrated. In particular, the microparticles formed from dodecabromododecaborate clusters and HDB were confirmed to be bound with proteins. The protein-bound boron cluster/polymer-based microparticles (protein-bound BPMs) were internalized into cells via endocytosis. Upon internalization, the protein-bound BPMs released the proteins with different isoelectric points and sizes into the cytosol. Furthermore, an enzyme was delivered by protein-bound BPMs into the cytosol of various cell types while maintaining its functional activity. This method shows considerable promise for delivering diverse proteins to a variety of cell types, potentially advancing the field of protein-based therapeutics. Our findings open new avenues for utilizing boron clusters in cytosolic delivery systems.
Localized Surface Plasmon Resonance in CuGaS2 Nanoparticles Dictated by Crystal Phase
Authors: Sakamoto Masanori , Sano Keito , Packwood Daniel
Published: December 2024

Localized surface plasmon resonance (LSPR) is widely applied in photo-functional technologies such as photocatalysis and solar cells. Research into LSPR materials has recently extended to semiconductor nanoparticles (NPs) because their composition and structure flexibility allow for tuning of optical properties. However, many of the crystallographic factors governing the LSPR of semiconductor NPs are not understood due to the difficulty of controlling the crystal structure of NPs. Here we report for the first time on the crystal structure and size-controlled synthesis of CuGaS2 (CGS) NPs which are typical I-III-VI semiconductors. Moreover, we investigate their LSPR properties to reveal the crystal structure dependence of LSPR extinction. Chalcopyrite and wurtzite CGS (c-CGS and w-CGS, respectively) dictate LSPR in the NIR region. The extinction coefficient of c-CGS was approximately 3 times larger than that of w-CGS because of the larger polarizability of c-CGS. Semiconductors with larger polarizability are better candidates as NIR light-harvesting materials for plasmon-based photocatalysis and solar cells. These results should significantly deepen our understanding of semiconductor plasmonics and serve as a foundation for developing highly efficient energy conversion systems.
Perspectivas para la educación en IA: importancia de la inclusión de habilidades y competencias técnicas de IA en los planes de estudio
Authors: Bustillos Ortega Olda , Murillo Gamboa Jorge , Núñez Peralta Olman , Rodríguez Sibaja Fabián
Published: December 2024

La inteligencia artificial (IA) es el invento más importante de la humanidad. Lo tenemos presente en la sociedad y la economía, pero también ahora impacta en la academia, en la que los docentes y los estudiantes hacen uso de modelos lingüísticos y de interacción como el ChatGPT y otros más. En este estudio se hace referencia a encuestas e investigaciones sobre el uso y las aplicaciones de la IA. Se muestran resultados de una encuesta sobre temas de formación en IA, la cual fue aplicada a docentes y estudiantes universitarios en Costa Rica. Se hace un análisis comparativo de los resultados y se presentan cuadros de ambos grupos encuestados. Adicionalmente, se proveen lineamientos base para formular contenidos y temarios de IA dentro de la currícula de una carrera de tecnología. Finalmente, se brindan recomendaciones sobre las habilidades y competencias técnicas a desarrollar.
Lattice-Based Cryptography: Development and Analysis of a New Variant of the Crystals-Kyber Algorithm
Authors: Cisneros Laule Mauricio Sebastian , Olazabal Silva Javier Enrique , Nina Hanco Hernan
Published: December 2024

The imminent arrival of quantum computing has accelerated the need for cryptographic systems resistant to quantum attacks. Such attacks exploit the vulnerability in private and public key encryption systems, where the public key is derived from the private key, which could be refactored from the public key. To address this issue, the National Institute of Standards and Technology (NIST) launched a global competition in 2016 to create quantum-resistant algorithms. CRYSTALS-Kyber, a lattice-based algorithm focused on the learning with errors (LWE) problem, was selected for standardization. This work introduces RKyber, a variant that instead targets the learning with rounding (LWR) problem, simplifying computations by using deterministic errors rather than random noise. Both algorithms were executed 1000 times, showing that RKyber offers improved speed at the cost of some security.
Análisis de características en proyectos de big data: revisión sistemática de literatura
Authors: Ojeda Mariel Liliana , Vegega Cinthia , Pollo Cattaneo María F.
Published: December 2024

En el desarrollo de proyectos de big data se identifican diversas problemáticas que pueden deberse a distintos factores, como la baja calidad de los datos utilizados con anomalías que pueden afectar la precisión de los resultados o la falta de claridad en los objetivos comerciales. Esta situación puede provocar errores en el proceso de toma de decisiones, retrasos en las entregas y hasta la cancelación del proyecto. En este contexto, el presente trabajo surge de la necesidad de recopilar investigaciones previas con el fin de conocer la importancia de la aplicación de una metodología de trabajo en proyectos de big data. Se realiza con el objetivo de identificar los enfoques de las metodologías más utilizadas y analizar las características propias de cada una, así como las características comunes o transversales, que permiten la combinación, o adaptación, de distintas metodologías en un mismo proyecto. La generación de grandes volúmenes de datos provenientes de diferentes fuentes y formatos aumenta el desafío de verificar la calidad, ya que pueden presentar anomalías que afecten así la precisión de los resultados obtenidos.
Formulation and evaluation of luliconazole liposomal gel
Authors: Rajasekhar M , Rajyalakshmi A V , Audinarayana N , Jothieswari D
Published: December 2024

This investigation presents an innovative formulation and evaluation of luliconazole liposomal gel, designed to effectively bypass first-pass metabolism, improve bioavailability, and enhance the drug release mechanism for targeted drug delivery. Utilizing the physical dispersion method with varying lipid concentrations in chloroform, we successfully developed liposomes that were converted into a gel, creating a superior transdermal drug delivery system. We generated eight distinct liposomal gel formulations, each undergoing comprehensive evaluation studies, including identification, drug-polymer compatibility, solubility, morphological characteristics, particle size, drug content, zeta potential, entrapment efficacy, spreadability, and pH assessments. The results demonstrated that our liposomes were uniformly spherical and free of incompatibility. The zeta potential measurements ranged from -42.5 mV to -32 mV, and the entrapment efficacy was impressive, ranging from 65.49% to 84.02%. Furthermore, the particle sizes varied between 262.58 nm and 654.06 nm. With a pH below 5.5 and a viscosity ranging from 42510 to 63768 cps, our liposomal gel showcased excellent spreadability. Notably, these formulations exhibited zero-order kinetics with non-Fickian diffusion, establishing a reliable and sustained drug release profile that underscores the potential of this innovative delivery system.