bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment adherence of Covid-19 in students from central Mexico: Contrast of a structural equation model
Authors: García-Lirios Cruz
Published: September 2024

Treatment adherence is a central axis in the health agenda. In the framework of the SARS CoV-2 pandemic, it is necessary to predict this phenomenon. The objective of the present work was to contrast a model of structural equations. A confirmatory, psychometric and cross-sectional work was carried out with a selection of 100 students, considering their participation in the social service and professional practices in public hospitals in central Mexico. A factorial structure was found that explained 62% of the total variance, suggesting the contrast of the model in other scenarios.
Effect of Diethyl Ether on Performance and Exhaust Gas Emissions of Heavy-Duty Diesel Engines Fueled with Biodiesel-Diesel Blend (B35)
Authors: Hardiyanto Catur , Prawoto Prawoto
Published: September 2024

To accelerate the energy transition, starting February 1, 2023, the Indonesian government has made it mandatory to use biodiesel (B35). Biodiesel has different characteristics from diesel oil, especially its greater viscosity and density, lower heating value, and high NOx emission. Therefore, this research has been carried out by adding the additive diethyl ether (DEE) to B35 to reduce the viscosity and density, increase the cetane number, and reduce emissions. The effects of diethyl ether on engine performances have been evaluated, including parameters of torque, power, brake thermal efficiency, brake-specific fuel consumption, exhaust emissions, and lubricants. The fuels used are B35 (35% FAME palm oil + 65% diesel oil), and B35 + DEE, with a DEE volume percentage of 3% to 6%. Diesel fuel (B0) was used as a comparison. Tests were carried out in the engine performance test laboratory using the heavy-duty diesel engine Komatsu SAA12V140E-3 at various engine speeds. The test results showed that adding diethyl ether slightly increases the average maximum power, increases brake thermal efficiency, and reduces brake-specific fuel consumption and emissions compared to B35. Very significant effects were seen in NOx and SO2 exhaust emissions. At maximum load, the mixture with 4% diethyl ether gave the greatest brake thermal efficiency, the lowest brake-specific fuel consumption, and the greatest reduction in NOx and SO2 emissions, respectively 7.69%, 6.30%, 53.48%, and 40.89% compared to B35, and 2.24%, (-0.90%), 48.88% and 71.17% compared to B0, respectively. Evaluation of lubricating oil during the performance test did not show a significant difference for all types of fuel used.
Crédito y crecimiento económico. El papel estratégico de las instituciones públicas en el Ecuador
Authors: Villarreal Satama Freddy Lenin
Published: September 2024

Introducción: Este estudio hace rederencia al análisis del desarrollo económico por medio del crédito público y variables de impacto como inflación, riesgo país, desempleo e inversión extranjera. Metodología: Se realiza un estudio cuantitativo mediante el método MCO-Anova y regresión lineal múltiple tomando en cuenta diferentes pruebas de multicolinealidad, normalidad y residuales para generar un modelo final del período 2000-2023. Resultados: Indican que las variables planteadas son significativas en especial el crédito público que ayuda en la generación de fuentes de trabajo mediante los emprendiemintos. Discusión: Respecto al Crédito de la Banca Pública, el coeficiente para el 0.00000032261, lo que indica una relación positiva del PIB es decir que por cada unidad de incremento en Crédito Banca Pública, log(PIB) se incrementa en 0.00000032261 unidades. Conclusiones: El desarrollo económico sostenible requiere un equilibrio controlado entre el acceso al crédito bancario público, la creación de empleo, inflación y la gestión efectiva del riesgo país. Políticas públicas coherentes y transparentes, acompañadas de una supervisión regulatoria sólida, son fundamentales para garantizar que estos elementos se alineen de manera que promuevan un crecimiento inclusivo y sostenible.
Оподаткування доходів фізичних осіб в Україні
Authors: Novytskyi Andryi N. , Orłowski Janusz
Published: September 2024

Celem opracowania jest przedstawienie podstawowych założeń podatku dochodowego od osób fizycznych w Ukrainie. Uwagę skupiono na ukształtowaniu źródeł przychodów (dochodów w terminologii ukraińskiej), określeniu podstawy opodatkowania, ulg i zwolnień oraz stawek podatku. Punktem wyjścia do analizy był opis dynamicznej ewolucji unormowań tego podatku od 1991 r., gdy zmianom podlegała zwłaszcza podstawa opodatkowania oraz skala podatkowa – od progresywnej do liniowej, po podatek zryczałtowany. Wskazano też główne czynniki wpływające na jego współczesne ukształtowanie oraz znaczenie fiskalne i społeczno-gospodarcze.
Rozważania przeprowadzono z wykorzystaniem formalno-dogmatycznej metody badania prawa oraz wybranych danych statystycznych dotyczących dochodów budżetowych Ukrainy w ostatnich latach. Ustalenia poczynione w opracowaniu pozwalają na stwierdzenie, iż aktualne unormowania podatku dochodowego od osób fizycznych w Ukrainie są co do zasady oparte na cedularnym modelu opodatkowania dochodów. Do dochodów z poszczególnych grup źródeł przychodów przyporządkowane są odpowiednie stawki podatku. W Kodeksie Podatkowym z 2010 r. brak definicji dochodu podlegającego opodatkowaniu, niemniej składają się na niego wszystkie dochody osoby fizycznej osiągnięte w roku podatkowym, oprócz wyłączonych spod opodatkowania. Na uwagę zasługuje zerowa stawka podatku, dotycząca nieperiodycznych dochodów (np. ze zbycia składników majątku), które podlegają jedynie wykazaniu w zeznaniu podatkowym. Wyróżnianie grup źródeł przychodów pozwala odpowiednio uwzględniać koszty ich uzyskania.
Jedną z głównych wad konstrukcji analizowanego podatku dostrzega się w niekonsekwentnych regułach partycypacji jednostek samorządu terytorialnego we wpływach budżetowych z tego tytułu. Z kolei w związku zaś z gospodarczymi następstwami konfliktu zbrojnego od 2022 r. wprowadzono nowe ulgi i zwolnienia podatkowe, choć ich system już był bardzo rozbudowany. W polityce fiskalnej władz Ukrainy zakłada się zwiększanie w najbliższych latach wpływów budżetowych z podatku dochodowego od osób fizycznych.
PRODUÇÃO DE MUDAS DE BURITI EM FUNÇÃO DO TEOR DE ÁGUA E ARMAZENAMENTO DAS SEMENTES
Authors: Martins de Santana Douglas , Borges de Sousa Diego , Chaves Fialho Sharle , Oliveira Diniz Fábio
Published: September 2024

A principal forma de propagação do buriti é via seminal, porém este método apresenta germinação baixa e desuniforme, sendo influenciada pelo teor de água das sementes, uma vez que são classificadas como recalcitrantes. Deste modo, objetivou-se avaliar o efeito do teor de água e dos períodos de armazenamento de sementes em condição ambiente e refrigerada, na formação de mudas de buriti. Os frutos foram coletados e separados em dois lotes. O primeiro foi constituído por sementes com teor de água inferior a 40%, enquanto o segundo, por sementes contendo teor de água superior a 40%. As sementes foram subdivididas para a realização dos estudos: no ensaio I, o armazenamento foi realizado em condição ambiente (laboratório), e o ensaio II, em condição refrigerada (geladeira). Empregou-se o delineamento inteiramente casualizado, em esquema fatorial 2 x 4, com 4 repetições de 25 sementes. Os tratamentos foram dois teores de água (< 40% e > 40%) e quatro tempos de armazenamento (0, 30, 60 e 90 dias). As sementes foram semeadas em vasos contendo areia de textura média. Aos 130 dias após a semeadura, foram avaliadas a percentagem de emergência, altura, diâmetro de colo, matéria seca da parte aérea e das raízes e o índice de qualidade de Dickson. Sementes com teor de água menor que 40% e armazenadas por 90 dias (ambiente) e por até 60 dias (sob refrigeração) mantém alta emergência (72% e 82%, respectivamente). Não é recomendado o armazenamento de sementes de buriti com teor de água superior a 40%. As sementes de buriti com teor de água < 40% originam mudas com maior qualidade.
AVALIAÇÃO DE DIFERENTES TIPOS DE INÓCULOS DE KOMBUCHA COMO STARTER PARA FERMENTAÇÃO DE LEITE BOVINO E CAPRINO
Authors: Rabêlo Elisandra , Pereira dos Anjos Débora Ciriaco , Pedroza da Silva Suzana , Souza Porto Tatiana , Lira de Oliveira Rodrigo
Published: September 2024

Kombucha é uma bebida levemente doce e acidificada produzida através da fermentação de uma infusão de folhas ou chás, por uma cultura simbiótica de leveduras e bactérias. Alguns micro-organismos presentes nesta cultura também são capazes de fermentar lactose, o que torna possível a utilização da kombucha com starter na formulação de produtos lácteos fermentados como iogurte e bebidas lácteas, que se apresentam como produtos probióticos, que auxiliam no melhoramento da saúde humana. A maioria dos estudos que reportam a capacidade de fermentar lactose por culturas de kombucha são realizados utilizando leite bovino. Entretanto, o leite caprino também apresenta características nutricionais elevadas e menor alergenicidade, contudo devido aos ácidos graxos apresenta um sabor forte e característico, assim é necessário o desenvolvimento de novas formulações para este produto. Desse modo, o objetivo do trabalho foi produzir e avaliar bebidas lácteas fermentadas por kombucha a partir de leites bovino (LB) e caprino (LC). Para isto, na fermentação utilizou-se amostras leites pasteurizados (bovino e caprino) com a adição de 20% de inóculo de kombucha preparados a partir de chás verde e preto. Posteriormente, as bebidas obtidas foram avaliadas em termos de parâmetros físico-químicos, teor de fenólicos totais e atividade antioxidante frente os radicais ABTS e DPPH. Foi observado que para ambos os tipos de leite, as bebidas preparadas com inóculos a base chá verde (LB: 1,45 g de ácido lático/100 g; LC: 1,25 g de ácido lático/100 g) apresentaram valores de acidez superiores aos obtidos para as obtidas por inóculos de chá preto (LB: 0,74 g de ácido lático/100 g; LC: 0,91 g de ácido lático/100 g). Por outro lado, uma tendencia contrária foi observada para os parâmetros proteína e cinzas, sendo o maior teor de proteína observado para a amostra de leite bovino fermentada com inóculo a base chá preto (3,67%). Com relação à atividade antioxidante, verificou-se que para o radical ABTS, não houve diferenças estatísticas entre as amostras. Entretanto, a maior capacidade sequestrante do radical DPPH (0,507 mM Trolox/mL) foi observada na amostra de leite caprino fermentada com inóculo a base chá verde, que também foi a que apresentou o maior teor de compostos fenólicos (73,69 mg EAG/100 mL). Os resultados obtidos, especialmente relacionados à atividade antioxidante são um indicativo do potencial de utilização de culturas de kombucha como starter para fermentação de leite, sobretudo no desenvolvimento de novos produtos com leite caprino.
ELABORAÇÃO DE BISCOITO FUNCIONAL DO TIPO COOKIES ADICIONADO COM O RESÍDUO DA POLPA DE CAJU
Authors: XAVIER SORAYA , COSTA ANA PAULA
Published: September 2024

O Brasil é um dos maiores produtores de caju, e sua produção está concentrada na região Nordeste. O pedúnculo de caju é um fruto rico em vitaminas, fibras e minerais, e apenas cerca de 20% é aproveitado. Seu beneficiamento gera uma grande quantidade de resíduos referentes a fração fibrosa e película, que são geralmente utilizados para ração animal, ou descartados como lixo industrial, gerando problemas ambientais. Esse resíduo pode ser facilmente inserido na alimentação humana através do seu aproveitamento para a elaboração de subprodutos, principalmente na produção de biscoitos, que geralmente utiliza a casca do trigo ou aveia como fonte de fibras. Diante disso, este trabalho objetivou apresentar uma alternativa de aproveitamento e agregação de valor para o resíduo do pedúnculo de caju, com a elaboração de biscoitos tipo cookies adicionados de resíduos obtidos da produção da polpa de fruta. Para a obtenção de um projeto de fabricação em escala fabril, foi realizado um estudo das etapas do fluxograma de produção, com equipamentos necessários, cálculos para balanço de massa, tabela nutricional, análise econômica para o cálculo dos possíveis custos, determinação do preço final unitário, e sugestão de rotulagem para o produto. Foi considerado o custo zero na obtenção do resíduo do pedúnculo de caju, ao considerar um acordo feito com empresas produtoras de polpa de fruta para a retirada desse resíduo, já que seu destino seria o descarte.  Os resultados demonstram uma análise satisfatória para a produção do produto sugerido, entregando ao mercado uma alternativa de biscoito tipo cookie saudável, com formulação única, composta por ingredientes com relevante teor de fibras, consciência ambiental, e preço competitivo.
Twin Deficit Assumptions: A Case Study of Pakistan (Cab from 2000 to 2023) and (FD from 2008 to 2024)
Authors: Rahpoto Muhammad Saleem , Shah Syed Iftikhar Ali , Nabi Haque
Published: September 2024

The aim of this article is to investigate the link between fiscal deficit and current account deficit which is the high rate of fiscal deficit budget and commonly known as twin deficit or deficits assumptions in the Pakistani economy (Khalil Mudassar, Amjad Fakher, Sajid Ali & Fozia Sarwar 2013); present economy below growing stress in the fiscal and foreign fronts as a output of huge fiscal deficit & current account balance deficit. The error rectification specification is used to find evidence of long-running connection from fiscal deficit to current account deficit. The analysis results suggest that the current account balance deficit can be determined but the fiscal deficit budget balance is very challenging and from deficit to growth rate but through strong policies of the government for imposing direct and indirect taxes which will be strong can reduce the fiscal deficit and growing towards the growth rate of the economy.
Combining of Heterogeneous Destructive Impact on the Information System and Countering Attacks (on Example by Insider Activity and DDoS-Attack)
Authors: Buinevich Mikhail , Moiseenko Grigory
Published: September 2024

Problem statement. By now, information security specialists have developed a sufficiently broad pool of mechanisms and means of countering cyberattacks for virtually all classes of destructive effects on information systems. Therefore, in order to break the relative parity "attack vs defense", attackers intensify their onslaught on information security systems by combining heterogeneous destructive influences, thus hampering the ability to counteract them. Despite a significant number of publications devoted to such information confrontation, there are no scientific studies devoted to analyzing this relatively new phenomenon in terms of identifying the limits of combinations, as well as the ability to counteract possible combinations in the public domain. The aim of the work is to study the phenomenon of combining heterogeneous destructive influences on the information system and counteracting such attacks. Methods used. The possibility of combining qualitatively heterogeneous attacks on the information system of the organization is studied. In order to classify and distinguish such attacks, categorical division apparatus is applied using the following pairs: Human vs Automaton, Inside vs Outside, Single vs Multiple. Result. The application of categorical division allowed to distinguish 8 classes of attacks from the position of their realization mechanism; the interpretation of each of the classes is given and an example is given. Novelty. The combination of two seemingly unrelated destructive influences – insider activity and DDoS-attack – is considered for the first time; their generalized scheme, stages of their implementation, as well as the complexity of counteraction to them are given.
The theory of synchrotron radiation limited beams diffraction in single crystal in the Laue case
Authors: Kohn V. G. , Smirnova I. A.
Published: September 2024

The features of the Bragg diffraction of coherent synchrotron radiation on the atomic lattice of a single crystal in the Laue geometry are studied theoretically, provided that the radiation beam is limited by a relatively large slit placed in front of the crystal. The method of numerical simulation is used and dependences of the intensity distribution are obtained for various thicknesses of the crystal. It is shown that the slit edges introduce inhomogeneous intensity distortions inside the Bormann triangles with an angle of 2θB, where θB is the Bragg angle. In the area where the triangles intersect, the intensity distribution is similar to that for diffraction by a slit in air at a certain (large) distance. An equation for the correspondence between the distance and the thickness of the crystal is obtained, which describes well the results of numerical calculations.
Effect of a traveling magnetic field on the parameters of doped tellurium gallium arsenide single crystals grown by the chokhralsky method
Authors: Yugova T. G. , Chuprakov V. A. , Sanzharovsky N. A. , Yugov A. A. , Martynov I. D. , Knyazev S. N.
Published: September 2024

The effect of a traveling magnetic field on the parameters of Te-doped GaAs single crystals in the carrier density range of 5 × 1017–2 × 1018 cm–3 has been studied. A traveling magnetic field was induced in a melt by a graphite inductor located in the setup chamber around the main heater. It is shown that a high-frequency magnetic field slightly reduces the dislocation density in the crystals without changing the shape of the dislocation distribution over their cross sections. The magnetic field affects the impurity distribution along the crystal axis, almost doubling the distance between the striation bands from 9 µm in the absence of magnetic field to 17 µm in a field with a frequency of 300 Hz.
Defect structure of tin-doped inas single crystals grown by the Czochralski method
Authors: Sanjarovskii N. A. , Parfenteva I. B. , Yugova T. G. , Knyazev S. N.
Published: September 2024

Indium arsenide (InAs) single crystals heavily doped with Sn are found to have various violations of structural perfection, which depend on the Sn concentration in different regions of crystal. At low charge-carrier (electron) concentrations (~1.5 × 1018 cm–3) an unusual annular distribution of dislocations in the cross section is observed for the initial parts of crystal. The dislocation density lies in the range of (0.1–1.0) × 104 cm–2. At a carrier concentration above 4.0 × 1018 cm–3 indium inclusions and “vicinal growth hillocks” are observed in the final parts of crystals. The dislocation density in the final cross sections of crystals, in which the aforementioned defects are not observed, is in the range of (0.4–2.1) × 104 cm–2.
Electron diffraction structure analysis of the amorphous polytetrafluoroethylene film
Authors: Kulygin A. K. , Sadovskaya N. V. , Avilov A. S. , Vasin O. I.
Published: September 2024

A thin amorphous film of fluoroplast (polytetrafluoroethylene) was obtained and studied by the electron diffraction structure analysis methods. The previously developed method of constructing the radial distribution function of atoms by the electron diffraction patterns from amorphous structures is applied, based on the determination of the normalization coefficient by varying the thermal parameter. The possibility of applying and necessary adaptations of this technique for the studied polytetrafluoroethylene samples are shown, taking into account its not quite usual amorphous structure due to the rigid spiral conformation of polymer chains …–CF2–…, which does not allow us to speak about the complete absence of the long-range order of the arrangement of atoms along the direction of the spiral axis. The measurements were carried out using the developed registration system on the electron diffraction camera EMR-102.
Two-dimensional ferroelectric crystals
Authors: Fridkin V. M.
Published: September 2024

Within the framework of the Landau–Ginzburg theory, the kinetics of polarization switching of ferroelectric crystals and the transition from domain switching to homogeneous switching in nanoscale monocrystalline films are considered. It is shown that, within the framework of the chosen theory, homogeneous (domain-free) switching can be described only for two-dimensional ferroelectrics. Experimental results for two-dimensional films of ferroelectric polymer and barium titanate are presented. For ultrathin polymer films, these results are also confirmed by calculations based on first principles.
Upper limit of mobility and concentration of charge carriers in fluoride superionic conductors with fluorite and tysonite structures
Authors: Sorokin N. I.
Published: September 2024

Within the framework of a crystal-physical model, the maximum values of mobility and concentration of charge carriers in fluoride superionic conductors belonging to the structural types of fluorite (CaF2, SrF2, BaF2, PbF2) and tysonite (LaF3) were calculated. It has been shown that the upper limit of ionic conductivity, mobility and charge carrier concentration in the crystalline state of fluoride superionics is 4 ± 1 S/cm, (5 ± 1) × 10–3 cm2/(сВ) и (5 ± 2) × 1021 cm–3 (10 ± 4% of the total fluoride ions), respectively.
Polycrystalline methylammonium-lead bromide perovskite films for photonic metasurfaces
Authors: Yurasik G. A. , Kasyanova I. V. , Artemov V. V. , Ezhov A. A. , Pavlov I. S. , Antonov A. A. , Long Guankui , Gorkunov M. V.
Published: September 2024

Polycrystalline films of organo-inorganic perovskite semiconductors are promising as a foundation for creating functional optical metasurfaces. The requirements for film structural perfection, thickness uniformity, and defect-free characteristics are much more stringent compared to perovskite films for photovoltaics. This work presents the results of searching for optimal conditions for one-step synthesis of lead methylammonium bromide films using centrifugation, and describes the successful fabrication of subwavelength optical gratings from these films through focused ion beam processing. The measured spectra of light transmission through the gratings demonstrated their excellent optical quality and confirmed the possibility of creating semiconductor photon metasurfaces with submicrometer periodicity and high-Q dielectric resonances.
Selecting a target for obtaining films of higher manganese silicide using magnetron sputtering
Authors: Lukasov M. S. , Arkharova N. A. , Orekhov A. S. , Kamilov T. S. , Klechkovskaya V. V.
Published: September 2024

A film of manganese silicides on mica was obtained using a magnetron sputter from three types of targets. Microstructure and elemental composition of targets and films studied by scanning electron microscopy and electron reflection diffraction methods. The phase composition and texture of films by thickness (cross sections) were controlled by scanning and transmission electron microscopy. It has been shown that when depositing films from a poly- and single-crystalline target of higher manganese silicide, in contrast to a target of sintered Mn and Si powders, after successive annealing at a temperature of 800 K and a temperature of 10–3 Pa for 1 hour, polycrystalline films of higher silicide can be obtained. manganese composition Mn4Si7.
Determination of the structure of weakly ordered films according to x-ray diffraction data
Authors: Astaf’ev S. B. , Yanusova L. G.
Published: September 2024

A method for searching for parameters of structural models of weakly ordered thin films based on X-ray diffraction data containing a small number of reflexes is proposed. The developed method makes it possible to narrow down the number of possible structural models, despite the small number of interference maxima, determine the parameters of possible elementary cells and index the corresponding peaks on diffractograms. It is shown how the use of a priori data makes it possible to obtain physically adequate solutions. The method of determining structural parameters is demonstrated by analyzing an experimental curve containing only 3 diffraction peaks (maxima).
The corresponding search algorithms are implemented within the framework of the analytical software package BARD (Basic Analisys of xRay Diffraction).
Characterization and photocatalytic properties of zno tetrapods synthesized by high-temperature pyrolysis
Authors: Krasnova V. V. , Muslimov A. E. , Lavrikov A. S. , Zadorozhnaya L. A. , Orudzhev F. F. , Gulakhmedov R. R. , Kanevsky V. M.
Published: September 2024

The presented work presents the structural and morphological characterization and the results of studies of luminescent, photocatalytic properties of ZnO tetrapods synthesized by the method of high-temperature pyrolysis. It has been shown that the morphology and structural parameters of ZnO tetrapods are determined by the location in the synthesis zone (correlated with the distance from the air inflow window). All samples were characterized by pseudo-three-dimensional morphology of tetrapods. A correlation was found between luminescent properties and photocatalytic activity of tetrapods. The highest photodegradation rates of methylene blue under ultraviolet radiation were demonstrated by ZnO tetrapods grown in the zones closest and farthest from the window (rate constants 54 × 10–3 min–1 and 50 × 10–3 min–1, respectively).
Computer simulation of the effect of focusing X rays by means of refractive-diffractive lens
Authors: Kohn V. G.
Published: September 2024

The features of focusing X rays using a refractive-diffractive lens (RDL), which is a system of two asymmetrically reflecting crystals with asymmetry factors, the product of which is equal to unity, and a refractive lens with a large focal length, are theoretically studied. Crystals make it possible to shorten the focal length of the lens by b2 times, where b is the asymmetry factor of the second crystal. A detailed numerical simulation of the effect of radiation focusing using the RDL has been performed. The universal computer program XRWP was used which is created to calculate the effects of coherent X-ray optics. Analytical formulas are obtained for the optimal aperture and radius of curvature of the lens, as well as for the width of the radiation spectrum that can be focused.
Novel ternary intermetallic compounds of R4Ru2Ga3 (R = Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er)
Authors: Grekhov I. А. , Kurenbaeva Zh. М. , Murashova Е. V.
Published: September 2024

A number of new isostructural ternary intermetallides of the composition R4Ru2Ga3 (R = Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) have been discovered in R–Ru–Ga ternary systems. X-ray examination of the Nd4Ru2Ga3 single crystal showed that this compound crystallizes in the monoclinic system and is a representative of a new structural type: a = 10.899(3), b = 4.0533(11), c = 9.720(3) Å, β = 111.080(7)°, C2, Z = 2, R1 = 0.043, wR2 = 0.077 for 1518 reflections. A feature of the structure is the presence of distorted fragments of RuNd6 (type AlB2) and GaNd8 (type CsCl) in it. The minimum Nd–Ru distance in a polyhedron is 2.8463(16) Å, which is significantly shorter than the sum of their atomic radii. The parameters and volumes of the elementary cells in the R4Ru2Ga3 series (R = Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) decrease in accordance with lanthanide compression, and the melting temperatures increase.
Diversity of fundamental building blocks [M(IO3)6] in iodate families and new trigonal polymorph of Cs2HIn(IO3)6
Authors: Reutova O. V. , Belokoneva E. L. , Volkov A. S. , Dimitrova О. V.
Published: September 2024

Crystals of new structural high-symmetry modification of Cs2HIn(IO3)6, which crystallyzes in sp. gr. R3 with parameters of unit cell a = 11.8999(4), c = 11.6513(5) Å were obtained in hydrothermal conditions. Crystal chemical comparison with triclinic modification the investigated earlier was carried out. Both structures are composed of isolated blocks [In(IO3)6]3–. The new modification belongs to the family of trigonal iodates isostructural to K2Ge(IO3)6 compound. Local symmetry of separated blocks [M(IO3)6] (M = Ge, Ti, Sn, Ga, In and other metals) are analyzed. Structural systematic of iodate families is suggested on the base of comparative crystal chemical analysis. The influence of cation composition and synthesis conditions on symmetry and topology of crystal structures as well as local symmetry of blocks on physical properties of compounds are discussed.
Induction of ductile modes of ice fracture and drastic enhancement of its fracture energy by means of introduction of nanoscale additives
Authors: Golovin Yu. I. , Vasyukov V. М. , Rodaev V. V. , Samodurov A. А. , Golovin D. Yu. , Tyurin A. I. , Razlivalova S. S. , Buznik V. M.
Published: September 2024

Ice brittleness and low strength limits its usage as a construction material in cold climate regions on Earth (Arctics, Antarctic, high mountain regions on other continents) as well as in construction of habitable colonies at Moon and Mars planned by several countries despite attractiveness of its other properties. The paper presents experimental study of enhancement of ice carrying capacity and fracture energy by introduction of SiO2 nanoparticles and polyvinyl alcohol into it. Concentration dependences of these properties enhancement are found. Quantitative characteristics of transition from brittle fracture mode in pure ice to ductile one in ice composite caused by growing content of additives are revealed. This transition results in 2–3 orders of magnitude increase in ice fracture energy.
Synthesis of nano-sized solid electrolyte Pr1–ySryF3–y and the effect of heat treatment on the ionic conductivity of fluoride nanoceramics
Authors: Sorokin N. I. , Arkharova N. A. , Karimov D. N.
Published: September 2024

Solid electrolyte nanoceramics Pr1–ySryF3–y (y = 0.03, sp. gr. P3c1) were obtained by high-energy grinding of melt-grown crystals followed by cold pressing. The phase composition, microstructure, morphology, and electrical properties of nanoceramics were studied using X-ray diffraction analysis, electron microscopy and impedance spectroscopy. The room temperature conductivity of the synthesized Pr0.97Sr0.03F2.97 nanoceramics (σcer = 1.7 × 10–7 S/cm) is significantly lower than the conductivity of the original single crystal (σcrys = 4.0 × 10–4 S/cm), which is due to its low (about ~74% of the theoretical value) density. Heat treatment of nanoceramics at 823 K in vacuum leads to a 3-fold increase in the value of σcer, and annealing at 1273 K in a fluorinating atmosphere results in further increase in conductivity (σcer = 4.3 × 10–5 S/cm) due to the process of collective recrystallization and significant increase the density of ceramics up to 90%. The mechanical grinding technique and subsequent heat treatment of Pr1–ySryF3–y nanopowder makes it possible to processing single-phase highly conductive ceramics. The proposed method for the synthesis of ceramic fluoride nanomaterials as a technological form of solid electrolytes is a promising direction for further developments in the field of creating fluorine-ion current sources and fluorine gas sensors.
Study of the features of concentration inhomogeneities during the on ground-based processing of the space experiment of the Ge(Ga) crystals growth
Authors: Korobeynikova E. N. , Strelov V. I. , Supel’nyak S. I. , Vlasov V. N.
Published: September 2024

The article presents the results of the preparation and ground testing of the space experiment for growing Ge (Ga) crystals, planned on board the multifunctional laboratory module as part of the ISS RS. Under the conditions simulating microgravity, the features of the formation of concentration inhomogeneity in the form of growth bands when growing crystals under various thermal conditions (in the presence or absence of a free melt surface (Marangoni convection)), as well as when changing technological parameters (variations in growth rate) were investigated. Based on the obtained results of metallographic and electrophysical studies, conclusions were made about the peculiarities of the influence of the technological parameters of the crystallization process on the structural perfection of the grown crystals under microgravity conditions
Transitions between equilibrium and nonequilibrium phenomena in the description of crystal growth
Authors: Rakin V. I.
Published: September 2024

The close intertwining of equilibrium and nonequilibrium thermodynamic representations and transitions between the two limiting principles of thermodynamics: the second beginning and the principle of least coercion (minimum entropy production in the stationary regime) constitute the main content of phenomenological theories of crystal growth. The difference of basic postulates of two sections of thermodynamics forces to discuss problems of reversibility and irreversibility of time, scales of observed phenomena and rules of conjugation of thermodynamic forces and flows in theories of crystal growth. A variant of the solution of some conjugation problems is shown on the example of the fluctuation model of dislocation crystal growth, which is based on the stationary isothermal process of thermodynamic free energy fluctuations. In the case of the limiting mode of adsorption of impurities on the crystal face according to the Langmuir model, the free energy fluctuations possessing the absence of the memory effect allow us to identify three chemical potentials of building particles that determine the corresponding values of solution supersaturations realized at different scale levels at the growing crystal face containing a helical dislocation. The supersaturations control quasi-equilibrium and nonequilibrium thermodynamic processes that constitute a single dislocation mechanism of crystal growth.
On the mechanism of growth of lactose crystals from supersaturated solutions
Authors: Fialkova E. А. , Shevchuk V. B. , Gnezdilova A. I. , Vinogradova Y. V. , Baronov V. I.
Published: September 2024

The substantiation of the existence of cavitation zones on the edges of a growing lactose crystal and its driving role in the crystal growth process is presented. It is shown that the most favorable conditions for the conversion of dissolved lactose into its crystalline form are created around the edges of the crystal in the phase transition zones. The size of the phase transition zone of the crystallizing substance is calculated and compared with the available data on the size of crystalline nuclei. The values of the radius of cavitation zones were obtained, which amounted to: nanometers (for a crystal with a size of 60.5 microns, at a temperature of 30°C and supersaturation of 0.55) and nanometers (for a crystal with a size of 84 microns, at a temperature of 50°C and supersaturation of 1.88). A mathematical model of the growth rate of lactose crystals in a supersaturated solution is proposed. The possibility of studying the mechanisms of crystallization and determining the growth rate of lactose crystals is substantiated, based on the theory of dynamic interaction of bodies and liquids by A. Y. Milovich.
Light-emitting AlGaAs/GaAs diodes based on ingaas strain-compensated quantum wells with minimized internal losses OF 940 nm radiation absorption
Authors: Salii R. А. , Malevskaya A. V. , Malevskii D. А. , Mintairov S. А. , Nadtochiy A. M. , Kalyuzhnyy N. A.
Published: September 2024

IR light-emitting diodes based on InGaAs/AlGaAs multiple quantum wells and AlxGa1–xAsyP1–y-layers that compensate stresses in the active region have been developed. The optical losses caused by absorption of radiation generated by the active region (λ = 940 nm) were studied at different doping levels of n-GaAs substrates. It has been shown that reducing the donor doping level from 4 × 1018 to 5 × × 1017 cm–3 gives an increase in the quantum efficiency of LEDs by ~ 30%. A technology that eliminates optical losses caused by absorption during radiation output has been developed. By removing the growth substrate and transferring the device structure to a carrier substrate with the formation of a rear metal reflector, LEDs were created that demonstrate a twofold increase in external quantum efficiency and efficiency (~ 40%) compared to the technology of outputting radiation through an n-GaAs substrate.
Observations of Tsunami Waves on the Pacific Coast of Russia Originating from the Hunga Tonga-Hunga Ha'apai Volcanic Eruption on January 15, 2022
Authors: Medvedev I. P. , Ivelskaya T. N. , Rabinovich A. B. , Tsukanova E. S. , Medvedeva A. Yu.
Published: September 2024

The Hunga Tonga-Hunga Ha´apai volcanic eruption on January 15, 2022 generated a tsunami that affected the entire Pacific Ocean. Tsunami from the event have been generated both by incoming waves from the source area, with a long-wave speed in the ocean of ~ 200–220 m/s, and by an atmospheric wave propagating at a sound speed ~315 m/s. Such a dual source mechanism created a serious problem and was a real challenge for the Pacific tsunami warning services. The work of the Russian Tsunami Warning Service (Yuzhno-Sakhalinsk) during this event is considered in detail. The tsunami was clearly recorded on the coasts of the Northwest Pacific and in the adjacent marginal seas, including the Sea of Japan, the Sea of Okhotsk and the Bering Sea. We examined high-resolution records (1-min sampling) of 20 tide gauges and 8 air pressure stations in this region for the period of January 14–17, 2022. On the Russian coast, the highest waves, with a trough-to-crest wave height of 1.3 m, were recorded at Malokurilskoe (Shikotan Island) and Vodopadnaya (the southeastern coast of Kamchatka). Using numerical simulation and data analysis methods, we were able to separate the oceanic “gravity” tsunami waves from propagating atmospheric pressure waves. In general, we found that on the outer (oceanic) coasts and the southern coast of the Sea of Okhotsk, oceanic tsunami waves prevailed, while on the coast of the Sea of Japan, oceanic and atmospheric tsunami waves had similar heights.
Geochemical Markers of Organic Matter Transformation in the Eastern Part of the Laptev Sea
Authors: Shulga N. A. , Streltsova E. A. , Vylegzhanina N. V. , Fedulov V. Yu. , Polyakova A. V. , Romankevich E. A.
Published: September 2024

The sources of supply and transformation of organic matter (OM) during the transition from the dissolved form to suspension, fluffy and bottom sediments on the meridional transect from the Lena River delta to the continental slope were described (depths from 10 to 2390 m, cruise 63 of the R/V Akademik Mstislav Keldysh, September 2015). The results of the study of OM molecular markers showed that dissolved and suspended OM of marine and terrigenous origin biodegrades in the water column and practically does not accumulate in bottom sediments. Thus, OM of the Lena river runoff does not contribute to the formation of OM in the bottom sediments in the summer period. On the outer shelf, an area of influence of ice bloom on the sedimentation process was revealed.
Relationship between Respiration Rate and Body Weight in Arctic Copepods at Subzero Temperature
Authors: Arashkevich E. G. , Drits A. V. , Pasternak A. F. , Frenkel S. E. , Karmanov V. A.
Published: September 2024

Dependence of the respiration rate (R) on the animal’s weight (W) is described by the equation R = a Wb, where the exponential coefficient b is usually taken equal to ¾. However, several authors indicate that the value of the coefficient b may vary with temperature changes as well as during ontogeny. In the Arctic seas, copepods spend most of their lives at temperature below or close to zero. Meanwhile, there are very few measurements of respiration rate at temperatures ≤ 0°C, which does not allow us to estimate the overall R(W) dependence at these temperatures. The work was carried out in three cruises of the R/V “Akademik Mstislav Keldysh” in the Siberian Arctic seas in 2018–2020. Copepods caught from the sea were adapted to experimental temperature and placed in tightly capped vials filled with filtered sea water for 24 h. The oxygen concentration was measured with a fiber-optic oxygen probe. The results of 120 measurements of respiration rate and 111 measurements of body carbon in five species of copepods at a temperature of -1.5°C are presented. The obtained relationship between body carbon content (W) and the prosome length (L) was described by the equation W = 6.982 L3.221, and the dependence of respiration on body weight was described by the equation R = 0.077 W0.753. No effect of a subzero temperature on the coefficient b was found. The regression parameters of R(W) did not change with the ontogenetic development of Calanus glacialis.
Assessment of the Abiotic Factors Influence on the Distribution of Zostera in the Internal Bays of Posyet Gulf Based on the Results of Numerical Simulation
Authors: Katrasov S. V. , Bugaets A. N. , Zharikov V. V. , Krasnopeev S. M. , Lebedev A. M. , Mainulov V. A.
Published: September 2024

In order to explain the spatial nature of the distribution of eelgrass in the inner bays of Posyet Bay, numerical experiments were performed to simulate hydrodynamics and morphodynamic processes. The hydrodynamics was modeled using the Delft3D Flow model. The spectral wave model SWAN (Simulating WAves Near shore) was used to calculate the wind wave parameters (propagation direction, wave length and height, near-bottom orbital velocities). Alteration of coastal zone profile under the impact waves and the hydrodynamic of tidal and wind currents was performed using the Delft3-MOR morphodynamics module included in the Delft3D software package. The results of numerical experiments have shown that the dynamics of the coastal bottom topography is determined by sediment transport forced by combined action of waves and currents. Comparison of the modeling results with information on the distribution of Zostera of previous studies and field surveys data showed a high agreement with model data on the spatial distribution of erosion and accumulation zones in the coastal zone.
Grain Size Distribution, Organic Carbon and Geochemical Markers in the Surface Layer of Bottom Sediments in the Northeastern Part of the Kara Sea
Authors: Streltsova E. A. , Belyaev N. A. , Fedulov V. Yu. , Pushkareva E. M.
Published: September 2024

The upper layer of bottom sediments in the northeastern part of the Kara Sea is studied. It is shown that the composition of sediments is dominated by silt, the proportion of sand increases towards the shore. The content of organic carbon (average value — 1.1% wt.) is close to the average content in sediments of the Kara Sea, increasing at deep-sea stations. The revealed linear relationship between the content of organic carbon and the surface area of sediment shows that sorption on the particles surface is the predominant accumulation form of organic matter (OM) in sediments. The average n-alkanes concentration in the analysed samples is 1.1 μg/g of sediment, the distribution spectrum is dominated by terrigenous origin odd high-molecular homologues.
Fine and rough structure of the frequency spectrum of high-power laser diodes during slow degradation
Authors: Bliznyuk V. V. , Parshin V. A. , Rzhanov A. G. , Semenova O. I. , Tarasov A. E.
Published: September 2024

It is shown that a fine and rough structure can be distinguished in the radiation spectrum of a powerful laser diode. The relationship between the spectrum characteristics and the internal parameters of the laser structure was established and experimentally verified, which was observed during the degradation of the device. The effect of losses in the resonator and coherence of laser radiation on both the fine and rough structure of its radiation spectrum is shown.
PT-symmetry and radiation structure of high-power laser diodes
Authors: Rzhanov A. G.
Published: September 2024

Possible conditions for the application of the quantum formalism of PT-symmetry in solving the wave equation in systems with pseudo-Hermitian Hamiltonian for determining the structure of the optical field and radiation spectra of modern high-power laser diodes are considered. The physical mechanisms affecting the spatial and spectral separation of radiation into separate generation channels are discussed.
Frequency up-conversion of an even coherent state
Authors: Belinsky A. V. , Singh R.
Published: September 2024

The problem of transferring the state of even coherent states from a low frequency to a high frequency is theoretically considered using a periodically-poled nonlinear crystal. With the help of the Wigner quasi-probability distribution function, a parallel implementation of two nonlinear processes is studied: parametric and sum frequency generation.
Accounting for the energy dispersion of free carriers induced by powerful femtosecond laser radiation in dielectrics
Authors: Lvov K. V. , Stremoukhov S. Yu.
Published: September 2024

Dynamics of free carriers in the conduction band of dielectrics induced by femtosecond near infrared laser radiation is analyzed. It is stressed the importance of accounting for the energy dispersion term in the Fokker-Planck equation describing such dynamics.
Simulation of electron-optical system for 300 GHz relativistic gyrotron
Authors: Danilov Yu. Yu. , Leontyev A. N. , Malkin A. M. , Plankin O. P. , Rozental R. M. , Semenov E. S.
Published: September 2024

Calculations were made for a three-electrode magnetron-injector gun with a thermionic cathode for a relativistic gyrotron in the 300 GHz range, which provides the formation of a helical beam with an energy of 250 keV, a current of 100—300 A, and a pitch factor of 1.1. The possibility of generating radiation with a power of more than 8 MW in a gyrotron with a longitudinally slotted cavity has been shown within the framework of three-dimensional PIC-simulations.
Phase transitions in rare-earth ferrimagnets with surface anisotropy near the magnetization compensation point
Authors: Yurlov V. V. , Zvezdin K. A. , Zvezdin A. K.
Published: September 2024

Theoretical model is proposed for calculating the phase H-T diagrams of a rare-earth ferrimagnet, considering the effects of each of the magnetic sublattices and surface anisotropy. Magnetic phase diagrams are numerically calculated. The presence of surface anisotropy leads to blurring of the second-order phase transition lines between the collinear and angular phases, displacement of the tricritical point, as well as the possibility of the formation of new phase transition lines.
Estimation of gas saturated sediments parameters in shallow water using vector receiver
Authors: Ivanov M. A. , Mukhanov P. Yu. , Shurup А. S.
Published: September 2024

A scheme for estimating parameters of gas-saturated sediments in shallow waters based on signals from moving noise source is proposed and tested on experimental data. Advantages of joint use of information about pressure and vertical component of particle velocity in solving the considered problem are discussed.
Impact of treatment trajectory on the thermal ablation rate and biological tissue volumetric lesion during irradiation by shock-wave focusing ultrasonic beam
Authors: Pestova P. A. , Yuldashev P. V. , Khokhlova V. A. , Karzova M. M.
Published: September 2024

Thermal ablation rates and the shapes of volumetric biological tissue lesion are compared in a numerical experiment, in which biological tissue is exposed to pulsed periodic shock-wave high intensity focused ultrasound. The comparison is performed across three different irradiation sequences of discrete foci placed uniformly within the target area.
Use of geometric properties of three invariants in wave problems of hydrodynamics and electrodynamics
Authors: Ovsyannikov V. M.
Published: September 2024

The theory of deformations is common to the theory of elasticity, hydrodynamics and electrodynamics. The conservation law for the deformation of the control figure contains linear, quadratic and cubic invariants. Passing to the limit of the derivation of the continuity equation destroys the quadratic and cubic invariants in the formula for the volume expansion coefficient. This simplification can lead to the loss of some fluid motion modes. This simplification can lead to the loss of some modes of behavior of electromagnetic fields. A method for taking into account three invariants in the solutions of the equations of hydrodynamics and electrodynamics is presented. For this, wave differential equations of the second and third order in time are used.