bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of healthcare workers’ personalities on health service quality: A case study of hospitals on the Malaysia-Indonesia border
Authors: Komari Nurul , Djafar Fariastuti
Published: January 2023

The personality of healthcare workers, including doctors, nurses, and any employee who directly provide supportive services to a patient, is vital in health service quality, contributing to the hospital’s brand image. Malaysia has successfully built that brand image attracting many Indonesians to have health treatment in this country. This study aims to examine the effect of healthcare workers’ personalities on health service quality at Malaysian hospitals. The study adopted the Big Five Traits and SERVQUAL models to measure healthcare workers’ personalities and health service quality. One hundred respondents from the families in West Kalimantan, Indonesia, who had health treatment in Malaysia, were selected to respond to the statements based on a Likert scale. The regression model was employed in data analysis in which the healthcare worker’s personality was an independent variable, and health service quality was a dependent variable. The regression test results show that agreeableness and emotional stability positively and significantly influenced health service quality at the 5% level, with each coefficient of 0.332 and 0.701. Due to less varied responses, conscientiousness, extraversion, and openness to experience did not significantly influence health service quality. That was supported by the high average index of health workers’ personalities (4.14) and hospital services (4.27), indicating that the respondents agreed with healthcare workers’ excellent personalities and health service quality in Malaysia. Each indicator in healthcare workers’ personalities also significantly correlated with each indicator in health service quality.
Acknowledgment The authors thank the Faculty of Economics and Business, Tanjungpura University, for funding this study.
Development of Electrolyte and Nonelectrolyte E-Modules Integrated Demonstration Video and Science Literacy
Authors: Aulia Annisa , Hardeli Hardeli
Published: January 2023

The type of research used is Educational Design Research with the Plomp development model. The Plomp development model consists of 3 stages, namely; the preliminary research, the prototype phase, and the assessment phase. The research instruments used are; student observation sheets, teacher interview sheets, validity questionnaire sheets, practicality questionnaire sheets, and student learning outcomes tests. The e-module was validated by 5 validators. The results of the e-module validity test were analyzed using the Aiken's V formula, while the practicality test results were analyzed using a Likert scale. The results of the validity of the e-module obtained an average Aiken's V of 0.85 with a valid category and has a CVR value of 1  with a valid category. The results of the practicality of the e-module by teachers and students obtained an average practicality value of 98% and 84% with a very practical practicality category. The results of the e-module effectiveness test obtained an average N-Gain value for the experimental class of 0.63 with a medium category. Based on the research results, it can be concluded that the problem-based learning e-module electrolyte and nonelectrolyte solution integrated demonstration video and scientific literacy that has been developed is valid, practical, and effective.
MULTIMODALITY OF A PRECEDENT TEXT IN THE RESEARCH OF THE CULTURAL SPACE OF A LITERARY TEXT
Authors:   Kuban State University, Oleynik Marina A. , Gorbatovsky Alexandr S. ,   Kuban State University
Published: January 2023

The article aims to describe the phenomenon of “precedence” in its multimodal specificity, which is realized in the process of recreating cultural space in a literary text. The authors rely on the achievements of modern linguocultural studies of the relationship between language and culture, which focus on the consideration of paradigmatic and syntagmatic relations of linguistic units, modelling the cultural space in the texts. At the same time, the possibility of realization by language units of their semiotic nature is taken into account, the peculiarities of its manifestation are determined by this or that context in the structure of precedent texts. The novelty of the research lies in the application of the theory of multimodality to the study of the precedent text as an element of cultural space in a literary text. One of the main questions is which units of a precedent text create prerequisites for its multimodality and how these units are interconnected with each other. Taking into account the denotative meaning of lexical units that verbalize the “channel” of information transmission and the recipient’s perception of this information, we can identify in the empirical material explicit and implicit ways of implementing the multimodality of precedent texts. The results of the analysis of the key lexemes of precedent texts served as the basis for characterizing multimodality, they are descriptive and were obtained with the help of comparative method, as well as the method of semantic, contextual and linguocultural analysis. The article suggests the multimodality of the precedent text not only contributes to the transmission of additional culturally significant information, due to which the cultural space in the literary text is modelled, but also allows the literary text itself to reveal its multimodal character. The material for the study is the novels “Der Weltensammler” by I.Trojanow, “1913: Der Sommer des Jahrhunderts” by F.Illias, and “Tyll” by D.Kehlmann, whose plots are set against the background of culturally significant historical events.
RISK AND FEAR COMMUNICATION IN THE CORONA PANDEMIC: MULTIMODAL COMMUNICATION AND ITS PERSUASIVE FUNCTION
Authors:   University of Greifswald, Institute for German Philology, Gansel Christina
Published: January 2023

The subject of this article is the fear-related communication in German journalistic media indexed by the COVID pandemic since 2020. Fear communication is considered in the article as a resonance amplifier that can be processed by all functional systems of society, but can only be processed by an individual as an emotion in consciousness. The article does not examine the evocation of fear in an individual, but seeks to grasp theoretically how fear is communicated. The symbolically generalized medium of journalistic media and the coding of communication related to it play a special role. Fear-related communication is based on information selection and the constant differentiation between information and non-information in the journalistic media. It is used purposefully to form opinions and to help legitimize political decisions. Findings on linguistic strategies of fear-related communication are elaborated and substantiated with examples. The strategies include the use of neologisms in certain meanings, degradations of meaning, the choice of photos in text-image interaction as well as metaphors
Modeling of dynamic phenomena in aqueous foams (review)
Authors:   Mavlyutov Institute of Mechanics, UFRC RAS, Ufa, Russia, Bolotnova R.Kh. , Gainullina E.F.
Published: January 2023

Analytical review of investigations aimed at studying the aqueous foam behavior under the shock-wave impact is given. The main approaches and theoretical approximations used in the development of aqueous foams models are analyzed. The two-phase gas-drop model of aqueous foam is considered, based on the laws of conservation of mass, momentum, and energy in accordance with one-pressure, two-velocity, two-temperature approximations. The model describes foam dynamics under a high - intensity impact, which destroys the foam structure into microdroplets, and takes into account interfacial heat transfer, interfacial drag and virtual mass forces and the phenomenon of foam syneresis (deposition). The numerical implementation of the model was carried out using new solvers in the OpenFOAM software. The analysis of the numerical solution of the spherical explosion in aqueous foam is given for the conditions of the literature experimental data. The syneresis influence on the intensity and velocity of shock wave propagation is shown. The two-phase model of aqueous foam is considered, which takes into account its elastic- viscous-plastic properties for conditions of weak impact that does not destroy foam structure. The model takes into account the elastic properties of aqueous foam at small deformations and describes it as a non-Newtonian fluid when the foam changes its state from the elastic to viscoplastic. The weak shock wave propagation dynamics in the layer of aqueous foam with the formation of a two-wave structure, consisting of the main wave and the elastic precursor ahead of it, is analyzed. The process of local aqueous foam compaction zone formation, followed by a gaseous region, behind the shock wave front is shown. The reliability of the obtained results of numerical studies is confirmed by their agreement with the literature experimental data.
gestão democrática da escola pública brasileira
Authors: Fernandes José Munhoz , Miceli Kerbauy Maria Teresa
Published: January 2023

A legislação brasileira que regulamenta a educação considera a gestão democrática escolar um direito garantido, cabendo às instituições subnacionais a sua operacionalização. Este estudo, de abordagem qualitativa, faz uma breve análise das escolas vencedoras do Prêmio Gestão Escolar, organizado pelo Conselho Nacional de Secretários de Educação, no período de 2013 a 2020, à luz de elementos da gestão democrática da escola brasileira, discutidos por autores que tratam do tema. Os resultados das análises indicam que as ações empreendidas pelos gestores escolares e os demais atores dessas escolas resultaram na melhoria da qualidade do ensino, traduzida, por exemplo, pela melhora no Índice de Desenvolvimento da Educação Básica (IDEB) e na redução da evasão escolar, que em uma das escolas foi zero. Considera-se, portanto, que a gestão democrática e a gestão participativa são elementos fundamentais para um ensino público de qualidade e parecem estar presentes nas escolas vencedoras do Prêmio Gestão Escolar no Brasil, no período estudado.
Ressignificações de práticas docentes no ensino superior com base nos princípios da educação online
Authors: Carvalho Felipe , Pimentel Mariano
Published: January 2023

Neste artigo, relatamos uma experiência em um curso voltado para desenvolver a competência de professoras/es universitárias/os em desenhar uma aula com base nos Princípios da Educação Online. Buscamos compreender como as/os docentes ressignificam suas práticas educativas em tempos de educação mediada por tecnologias. Movimentamo-nos pela epistemologia da prática e da pesquisa com a experiência docente para refletir sobre as narrativas que emergiram no curso, principalmente as relacionadas às aulas que as/os docentes dão, como as repensaram, atualizaram e lhes atribuíram novos/outros sentidos. Compreendemos que as ressignificações são constituídas por múltiplos processos de estranhamentos, por práticas reflexivas de si, pela desconstrução de algumas certezas, reconstrução dos pressupostos teórico-epistêmico-metodológicos e pela construção de novos/outros saberes docentes. Concluímos que a discussão sobre educação online e seus princípios têm potencial para a ressignificação das práticas das/os formadores no ensino superior.
Escola Confessional INSA, Salinas/MG
Authors: Santos Lílian Gleisia Alves dos , Honorato Tony , Marta Felipe Eduardo Ferreira
Published: January 2023

A proposição consiste em interpretar as memórias de formação e de relações civilizatórias das meninas estudantes no Instituto “Nossa Senhora Aparecida” (INSA) Salinas-MG (1951-1972). O INSA foi criado em 1951, sua organização contou com a ação das freiras Clarrisas Franciscanas. O estudo está situado nos campos da memória (HALBWACHS, 2006), história oral (PORTELLI, 2016) e das teorias dos processos civilizadores (ELIAS, 1993, 1994). Trata-se de uma abordagem qualitativa em que foram entrevistadas ex-estudantes do Instituto, e as suas evocações nos fizeram compreender que a figuração educacional apresentava características de um processo civilizador de meninas que se constituiu por meio de modelagem de hábitos e comportamentos através de práticas tradicionais e políticas-culturais. Consideramos que as memórias revelam a formação no INSA conectada a um modelo de organização social e civilizatória: as alunas eram educadas para demonstrar sutileza, delicadeza, obediência e disciplina em contextos de desigualdades de gênero e de orientação católica.
Evaluation of the Effectiveness of Dantrolene Sodium against Digoxininduced
Cardiotoxicity in Adult Rats
Authors: Zardast Mahmoud , Behmanesh Kosar , Farkhondeh Tahereh , Roshanravan Babak , Aramjoo Hamed , Aschner Michael , Samarghandian Saeed , Kiani Zahra
Published: January 2023

Background:

Digoxin poisoning commonly occurs in people treated with digoxin. It
has been suggested that treatment with dantrolene may be a suitable strategy for digoxin-induced
cardiotoxicity.

Objective:

The aim of this study was to evaluate the protective effect of dantrolene on digoxininduced
cardiotoxicity in male rats.

Methods:

This study was approved by the ethics committee of Birjand University of Medical
Sciences (Ethical number: IR.BUMS.REC.1400.067). Forty-two Wistar rats weighing between
300- 350 gr were randomly allocated to 7 groups (n = 6) as follows: Normal Saline (NS) group,
Normal Saline + Ethanol (NS + ETOH) group), Normal Saline + dantrolene 10 mg/kg (NS + Dan
10) group, Digoxin (Dig) group), Digoxin + dantrolene 5 mg/kg (Dig + Dan 5) group), Digoxin +
dantrolene 10 mg/kg (Dig + Dan 10) group), Digoxin + dantrolene 20 mg/kg (Dig + Dan 20)
group), Dig was injected intravenously at 12 mL / h (0.25 mg / mL). Dan (5, 10 and 20 mg/kg)
was injected intravenously at 5-8 min/mL. After 1 hour, blood samples were obtained from
the animals' cavernous sinus and each animal's heartremoved. The blood sample was rapidly
centrifuged at 2,500 rpm for 10 minutes and the serum was separated for measurement of creatine
phosphokinase (CPK), potassium (K), sodium (Na), calcium (Ca), and magnesium (Mg). The
samples were stored at -20oC. The heart samples were fixed in formalin 10% for histopathological
evaluation.

Results:

K levels slightly increased in the dig group versus the NS group. A significant increase in
the K levels was observed in the Dig + Dan 20 group versus the NS group (p < 0.001). Dig slightly
decreased Ca levels in the treated group versus the NS group. The levels of Ca significantly increased
in the Dig + Dan 10 group versus the Dig group (p < 0.05). Histological examination of
the heart tissue in the dig group showed cardiomyocyte degeneration, increased edematous intramuscular
space associated with hemorrhage, and congestion. Focal inflammatory cell accumulation
in the heart tissue was also seen. Cardiomyocytes were clear and arranged in good order in the
Dig + Dan 10 group.

Conclusion:

dantrolene (10 mg/kg) was cardioprotective in a model of digoxin-induced cardiotoxicity,
secondary to cardiac remodeling and hyperkalemia. However, further research is necessary
to determine dantrolene's cardioprotective and cardiotoxic doses in animal models.
Cardio Protective Approach of Unani Dietotherapy with Special
Reference to Avicenna’s Risaala Adwiyah Al Qalbiyah
Authors: Nabi Afshana , Itrat Malik , Khan Tariq Nadeem
Published: January 2023

Background and Objective:

The present paper will enlighten the role of different types
of diets in maintaining a healthy heart, as mentioned by Ibn Sina in his valuable work “Risaala
adwiyah al Qalbiyah”. Owing to an increased trend of dietotherapy in the current era, this paper is
an attempt to enhance the same (particularly the cardio-protective diets).

Methodology:

Risaala adwiyah al Qalbiyah is an important work of Ibn Sina focusing on the
maintenance of heart health. For the current study, we have selected a total of thirteen nutraceuticals
out of sixty-three that can be taken in the routine diet to avail of their benefits and avoid the risk of
cardiovascular diseases, which are at their peak at present. To meet this need, a thorough literature
survey of classical literature was conducted to collect all the necessary and relevant information.
These medicines/diets were looked upon for their proven benefits by searching them with their botanical
names using modern search engines like PubMed, Google Scholar and Research Gate to
provide an evidence-based edge to the current work.

Results:

The specific diets mentioned by Ibn Sina have proved to possess potential effects in preventing
cardiovascular diseases and thus promoting cardiac health.

Conclusion:

Dietotherapy plays a primary role in achieving the principal goal of the Unani system
of medicine (the preservation of health and prevention of diseases). Food items mentioned in this
paper can be added to the routine to get the benefits from their cardio-protective action and avoid
the risk of highly increasing cardiovascular diseases.
Dynamic analysis of arch dams considering fluid-structure interaction
Authors: Vela Calderón Yoshi Raul , Scaletti Farina Hugo Victor Luis
Published: January 2023

The social, economic, and environmental consequences of the failure of an arch dam make it essential to evaluate its dynamic response to mitigate the risk of a disaster. Since the slenderness and flexibility of these dams tend to increase the fluid-structure interaction during an earthquake, this work compares the dynamic response of a hypothetical arch dam in the Marañón river, in northern Perú, for both full and empty-reservoir conditions. Three formulations were used to estimate the hydrodynamic pressures: Westergaard’s added mass, Eulerian and Lagrangian. The comparisons were performed for earthquakes of distinct seismogenic sources, previously matched to a uniform hazard spectrum with a return period of 10000 years. The finite element method was used to derive the seismic demands of the dam-reservoir-foundation system in COMSOL Multiphysics software, carrying out time-history analyses assuming linear elastic behavior of the dam and foundation domains and a massless foundation approach, ignoring the effect of waves propagation in the foundation but considering its stiffness. The results show that the Lagrangian and Eulerian formulations produce similar seismic demands, while Westergaard’s added mass formulation is conservative. The full-reservoir condition generally increases the seismic demands, but the results will depend on the boundary conditions assumed for the fluid and the characteristics of the earthquake, among other factors. Earthquakes matched to the same uniform hazard spectrum do not necessarily produce equal dynamic responses.
Evaluación del riesgo sísmico de edificaciones mediante funciones de vulnerabilidad en la ciudad de Ayacucho – Perú
Authors: Sulca-Huaman Jhunior , Delgadillo-Ayala Rick Milton
Published: January 2023

El Perú es uno de los países más expuestos a eventos catastróficos a nivel mundial como: inundaciones, flujo de escombros, tsunamis, terremotos. Particularmente, los terremotos son generados por la interacción de las placas de Nazca y Sudamérica conocida como proceso de subducción y de fallas poco profundas. Asimismo, otro gran problema que atraviesa el Perú es la informalidad en la construcción, que sumado a un gran terremoto, podría traer consigo grandes pérdidas económicas y vidas humanas. Por tanto, estos problemas han motivado el desarrollo de esta investigación, que tiene como objetivo evaluar el riesgo sísmico de edificaciones en el distrito de Ayacucho - Perú. En este sentido, la amenaza sísmica probabilística se evalúa mediante el programa R-CRISIS, acompañado de estudios geofísicos como MASW (Análisis Multicanal de Ondas Superficiales) que permiten caracterizar el suelo a partir de velocidades de ondas de corte. Además, la vulnerabilidad sísmica de las edificaciones se evalúa mediante el método del índice de vulnerabilidad, el cual se basa en once parámetros esenciales que caracterizan la susceptibilidad de las edificaciones a sufrir daños tras la ocurrencia de un terremoto. Finalmente, la evaluación del riesgo sísmico se realiza mediante el uso de funciones de vulnerabilidad y los resultados se reflejan en mapas representativos para diferentes escenarios sísmicos, que se elaboran utilizando los Sistemas de Información Geográfica (SIG). Los resultados muestran grandes pérdidas económicas y vidas humanas que se producirían por diferentes intensidades sísmicas en el distrito de Ayacucho. Además, más del 50% de los edificios podrían sufrir daños fuertes o severos durante la ocurrencia de un terremoto raro cuyo período de retorno es de 475 años.
Efficiency of energy dissipators in the seismic response of buildings
Authors: Saldaña Vasquez Keyvin Yuliño , Scaletti Farina Hugo Victor Luis
Published: January 2023

This paper aims to study the efficiency of energy dissipators, both fluid viscous and hysteretic, to improve the seismic responses of buildings. To quantify the ability of energy dissipators to reduce seismic responses, a series of time history analyzes were carried out on simplified models of buildings. Said simplified models consist of masses and springs with linear and elastic behavior whose properties are obtained from a shear beam model, joined by link elements with non-linear behavior to simulate energy dissipators. The main study parameters that were considered are the fundamental period of the structure without seismic control devices and the objective reduction factor. Likewise, a procedure is proposed for the dimensioning of the hysteretic dampers that will be incorporated into a building. On the other hand, the main building of the Lima airport was used as a case study, for which two alternatives are proposed, each one with a different type of energy dissipator, but both designed to have similar performance. Finally, the reductions obtained by both the simplified models and three-dimensional models are compared. It is concluded that the simplified models allow a fast and acceptable prediction of the levels of reduction of the seismic response in buildings that incorporate energy dissipators.
Implementación del espectro de curvas de diseño ramcodes de suelos no saturados de subrasantes en el diseño de pavimentos flexibles
Authors: Inga López Hainer Josué , Gutiérrez Lazares José Wilfredo
Published: January 2023

The design process for a pavement structure assumes that the subgrade will saturate at some point during the service life, however, the saturation of the subgrade depends on the conditions depending on the region in which it is located. Therefore, it is necessary to study design conditions for partially saturated subgrade. The present research aims to implement the spectrum of RAMCODES design curves for unsaturated subgrade soils, applied to the design of flexible pavements under environmental and traffic conditions associated with the Oyon-Ambo highway. To construct the RAMCODES design curves, CBR tests were performed by varying compaction energies and moisture contents.  Likewise, using the OriginPro 2019 program, the curves were obtained and a mathematical model was used to predict the variation of the degree of saturation in the subgrade over time. Subsequently, the seasonal CBR were obtained and correlated to obtain the resilient moduli. Finally, two flexible pavement structure designs were carried out, one using the traditional subgrade characterization methodology and the other according to the proposed methodology. From the results obtained, it is interpreted that the consideration of the unsaturated behavior of the subgrade optimizes the pavement design since the bearing capacity of the subgrade is increased by 28.8%, which means that the thickness of the subbase layer is reduced by 25%.
Propuesta para obtener las máximas aceleraciones de piso usando la norma sísmica peruana e.030
Authors: Sánchez Meza Roque Alberto
Published: January 2023

The collapse of some floor diaphragms during earthquakes was due to failures in connection with vertical elements or because those were not designed for seismic forces in its plane. This has made that the design of diaphragms is an issue that has been incorporated in many seismic codes. For its design, it is necessary the maximum acceleration on each floor during a strong seismic event. The seismic Peruvian code E.030 does not include any methodology about how to calculate those accelerations floor, it only refers to acceleration on floors but due to maximum base shear which does not correspond to maximum acceleration in each level.

In this paper, a simplified procedure for obtaining maximum floor accelerations is shown. This procedure is based on First Mode Reduced method [1] to which a factor rW was included to consider higher modes participation in dual systems (frames / walls). The rW factor corresponds to the ratio of base moment in walls and base moment in the building. In the validation of the procedure, it was observed that the proposed procedure agrees with the results of experimental and analytical models.
Influence of the aspect ratio on seismic performance of adobe buildings
Authors: Otero Monteza Danty Alexander , Díaz Figueroa Miguel Augusto
Published: January 2023

Adobe buildings usually are characterized by having walls with small and uniform slenderness ratios; nevertheless, there are some historical adobe buildings with existing large walls, where the influence of the aspect ratio becomes quite important in the seismic behavior. This article analyzes the seismic behavior of adobe buildings with larger walls in one axis than the other orthogonal axis. Also, the influence of the aspect ratio of the wall height respects on the wall length is analyzed by varying the wall length. Finite element models were elaborated using the concrete damaged plasticity model to study the influence of the aspect ratio on the seismic behavior of adobe buildings. Four models of buildings having different aspect ratios, varying in length from eight meters to fifty-two meters have been considered. Nonlinear time history analyses with three Peruvian seismic records are conducted. Regarding material, information was collected on the parameters necessary for finite element modeling for adobe masonry. From the non-linear simulations, the cracking patterns of the four buildings were identified. The influence of the aspect ratio in the seismic capacity of these kind of adobe buildings is analyzed.  Finally, the results obtained in the numerical models are compared with the evidence of damage caused by past earthquakes.
Sputtering of metal atoms with the wake potential excited by an electron beam
Authors: Kalashnikov N.P.
Published: January 2023

The process of metal atoms sputtering during a corona discharge is considered. When an electron moves in a medium at some velocity, charge screening occurs with a delay in space and time, which leads to the emergence of a wake potential. The excited oscillations of the wake charge lead to the appearance of additional forces. The energy loss of a moving particle per unit path is determined by the work produced of the deceleration force that acts on the particle from the side of the wake potential it creates in the medium. The paper considers the effect of the wake potential on the ions (atoms) sputtering of the lattice matrix. A well-known expression is used for the wake potential excited by a charged particle moving with energy, greater than the Fermi energy. An expression for the sputtering cross-section of metal atoms under the action of the wake potential excited by the electron beam is obtained. It is shown that the result of sputtering does not depend on the charge sign of the incident particle (electron or ion). Keywords: corona discharge, nanoparticles, metal surface, inelastic scattering, wake potential.
Influence of the crystallographic orientation of silicon on the formation of "primary" cracks
Authors: Vettegren’ V. I.  , Kadomtsev A. G.  , Shcherbakov I. P.  , Mamalimov R. I.  , Oganesyan G. A.
Published: January 2023

When the silicon surface is destroyed, clusters of the smallest "primary" cracks are formed. Their formation leads to the appearance of "fractoluminescence" (FL) signals. The FL signals and spectra contained maxima, the number of which is equal to the number of "primary" cracks in the cluster. An analysis of the FL signals and spectra showed that, upon failure of the (100) and (110) surfaces, clusters of four "primary" cracks appeared, and (111) surfaces, of three "primary" cracks. Their sizes were estimated by the growth rate and time. It turned out that they are multiples of the crystal lattice constant a: ~3a, 4a, and 6a. At the moment of formation, "primary" cracks are in a nonequilibrium state and, over time, transform into defects that look like "troughs" and "tops". Their sizes are from 2 to 4 times smaller than the sizes of "primary" cracks. Keywords: silicon, fracture, "primary" cracks, fractoluminescence, interference profilometry.
Interaction of Be atoms with (111) Ir surface.
Authors: Rut'kov E. V.  , Afanas'eva E. Y.  , Gall N. R.
Published: January 2023

It is shown that, when sputtered onto the surface of the (111) Ir face in the temperature range 1100-1250 K, beryllium atoms form a surface chemical compound of stoichiometry Ir3Be with a concentration of adsorbed beryllium NBe=5·1014 cm-2, after which the newly deposited beryllium atoms dissolve metal bulk. The Ir3Be surface compound itself is destroyed due to the dissolution of beryllium in the temperature range of 1250-1400 K with an activation energy increasing from 3.2 eV to 3.7 eV with decreasing Be concentration. At T>1400 K, the thermal desorption channel is switched on. The formation of the Ir3Be surface compound significantly lowers the energy barrier E for the dissolution of Be atoms in the bulk of iridium by Delta E>1.7 eV. Keywords: iridium, beryllium, surface chemical compounds, dissolution, bulk intermetallic compounds.
Mode bistability of plasmons and dispersive jump in a structure with two graphene layers
Authors: Shutyi A. M.  , Sementsov D. I.  , Eliseeva S. V.
Published: January 2023

Plasmon modes in a symmetric structure consisting of two layers of inverted graphene separated by a dielectric barrier layer and their dispersion properties are studied for various parameters of the barrier layer. The occurrence of a bifurcation of the splitting of the branch of the dispersion dependence, which leads to the appearance of bistability and a dispersion jump with a change in the stability of the branches included in the bistability, is found. The plasmonic modes belonging to the two branches of the bistable state differ in the gain increment and phase velocity, and their group velocities are opposite in sign. Keywords: inverted graphene, three-layer structure, branching bifurcation, modal bistability, amplifying modes, dispersion dependence jump.
Conductive properties of Magneli series oxides: VO and V-=SUB=-2-=/SUB=-O-=SUB=-5-=/SUB=-
Authors: Ilinskit A.V.  , Shadrin E.B.
Published: January 2023

A comparative analysis of the electrically conductive properties of strongly correlated oxides: vanadium oxide VO and vanadium pentoxide V2O5, belonging to opposite ends of the Magneli series, is carried out. It is shown that, despite the radical difference in the symmetry of the crystal lattices of these compounds, these materials have a number of fundamental common properties, the main of which are the dependence of the width of the energy gap (gap band) on the occupation of the conduction band by electrons and the occurrence in both compounds of an electronic Mott transition extended in temperature. It is shown that vanadium pentoxide is a classic Mott insulator. Keywords: vanadium oxides, phase transition, electronic correlations.
Study of the FCC-Au properties in a wide range of temperatures and pressures
Authors: Magomedov M. N.
Published: January 2023

The properties of the FCC-of the gold crystal were calculated using an analytical method (without computer modeling) in the temperature range: T=10-1337 K and pressures: P=0-110 GPa. The following properties were calculated: state equation, Debye temperature, first and second Gruneisen parameters, elastic modulus (BT), thermal expansion coefficient (αp), isochoric (Cv) and isobaric (Cp) heat capacity, specific surface energy. Derivatives of these properties also have been calculated both by temperature along three isobars and by pressure along three isotherms. The obtained results showed good agreement with the other authors results. It was shown that there is a certain temperature TB in which the product α_pBT does not change during the crystal compression. At T>TB, the α_pBT function increases, and at T21.58 GPa, and B'(P)=7.43. At P<21.58 GPa, the C'v(P) function increases, and at P>21.58 GPa, it decreases with increasing temperature. It was shown that the isotherm of the baric derivative of the isochoric heat capacity C'v(P) has a minimum, and the isotherm of the baric derivative of the isobaric heat capacity C'_p(P) has both a minimum and a maximum. Based on the obtained dependencies, some approximations, which are used to calculate the properties of the crystal under high P-T-conditions, have been analyzed. Keywords: gold, pressure, elastic modulus, thermal expansion, heat capacity, Debye temperature, Gruneisen parameter, surface energy.
Effect of SrTiO3, KTaO-=SUB=-3-=/SUB=-, and LiTaO-=SUB=-3-=/SUB=- modifier on the dielectric properties of Ca-=SUB=-0.3-=/SUB=-Ba-=SUB=-0.7-=/SUB=-Nb-=SUB=-2-=/SUB=-O-=SUB=-6-=/SUB=- ceramics
Authors: Malyshkina O.V.  , Guseva O.S.  , Mitchenko A. S.  , Kislova I. L.
Published: January 2023

Using the method of solid-phase synthesis, we obtained ceramic samples with a structure like tetragonal tungsten bronzes, pure Ca0.3Ba0.7Nb2O6 (CBN30) and with modifying additives SrTiO3, KTaO3, or LiTaO3. The dispersion of the permittivity in the frequency range from 1 Hz to 10 MHz, the temperature dependences of the permittivity (in the given frequency range) and the pyroelectric coefficient are studied. It is shown that if the introduction of the LiTaO3 impurity into the composition of CBN30 destabilizes the dielectric characteristics at frequencies above 100 kHz, then the SrTiO3 impurity increases both the permittivity and the pyroelectric coefficient, significantly reducing dielectric losses at low (1-10 Hz) frequencies. At the same time, both of these impurities (SrTiO3 and LiTaO3) lead to sample depolarization during heating above 150oC, while the KTaO3 impurity, which slightly increases the permittivity and pyroelectric coefficient, does not affect the stability of the polarized state during heating up to higher temperatures. Keywords: piezoelectric ceramics, barium-calcium niobate, lead-free materials, permittivity dispersion, pyroelectric effect.
Synthesis, crystal structure and thermodynamic properties of apatite Pb-=SUB=-3-=/SUB=-Bi-=SUB=-2-=/SUB=-(GeO_4)-=SUB=-3-=/SUB=-
Authors: Denisova L. T.  , Molokeev M. S.  , Golubeva E. O.  , Belousova. N. V.  , Denisov V. M.
Published: January 2023

Apatite Pb3Bi2(GeO_4)3 was obtained by the solid-phase method from the initial oxides of PbO, Bi2O3 and GeO2 by sequential firing in air at temperatures of 773-1003 K. Its crystal structure has been refined by X-ray diffraction. The high-temperature heat capacity (350-1000 K) of this compound was measured by differential scanning calorimetry. Based on these data, the main thermodynamic functions are calculated. Keywords: apatite bismuth-lead germanate, solid-phase synthesis, high-temperature heat capacity, thermodynamic properties Keywords: apatite bismuth-lead germanate, solid-phase synthesis, high-temperature heat capacity, thermodynamic properties.
Formation of "primary" cracks upon fracture of quartz
Authors: Vettegren V I  , Kadomtsev A G  , Ponomarev A V  , Mamalimov R I  , Shcherbakov I P
Published: January 2023

The spectrum was obtained and the time dependences of the fractoluminescence signals were studied during the destruction of the quartz surface by "microcutting" perpendicular to the (0001) axis. An analysis of the obtained data showed that clusters of the 4 smallest "primary" cracks appear during fracture. The formation of cracks is associated with the destruction of barriers that prevent the movement of dislocations along slip planes. The crack sizes are several nm, and the growth rate is several m/s. The size distribution of cracks has a power law form. Keywords: "primary" nanocracks, fractoluminescence, quartz.
Features of remagnetization of the two-layer film structure of the YIG/FeNi
Authors: Svalov A. V.  , Ivanov V. E.  , Lepalovskij V. N.  , Feshchenko A. A.  , Gorkovenko A. N.  , Makarochkin I. A.  , Vas’kovskiy V. O.  , Kurlyandskaya G. V.
Published: January 2023

The results of magneto-optical and magnetometric measurements carried out on two-layer film structures of YIG/FeNi are presented. YIG films were grown by liquid-phase epitaxy, and FeNi films were deposited by magnetron sputtering. It has been established that an interlayer magnetic coupling takes place in the YIG/FeNi system, which is mainly due to magnetostatic interaction. Keywords: yttrium-iron-garnet, permalloy, interlayer coupling, magnetostatic and exchange interaction, magnetic domain structure.
Hysteresis of resistivity tensor in rare-earth polytellurides
Authors: Grigoriev P.D.  , Sinchenko A. A.  , Mogilyuk T. I.  , Vorobyov P. A.  , Akparov D.  , Alisultanov S. S.  , Dyugaev A. M.
Published: January 2023

Possible reasons for the temperature hysteresis of the Hall and diagonal components of resistivity tensor in tritellurides and tetratellurides of rare-earth metals, respectively, are analyzed. The width of this hysteresis exceeds 100 K in both families. This hysteresis is related to the charge density wave (CDW), but its detailed nature is still being discussed. It is known that it cannot be explained by a temperature variation in the CDW wave vector. In this paper, we discuss various interpretations of the observed hysteresis, present new experimental data showing a strong dependence of the hysteresis value on the temperature range, and propose new experiments (or a detailed analysis of unpublished data from existing ARPES measurements) that can substantiate or refute the proposed explanations for this unusual effect. Keywords: charge density wave, hysteresis, conductivity, Hall coefficient, anisotropy.
Magnetic sensor based on spin waves
Authors: Kozhevnikov A. V.  , Vysotskii S. L.  , Dudko G. M.  , Khivintsev Yu. V.  , Nikulin Yu. V.  , Filimonov Yu.A.
Published: January 2023

The spectrum of spin waves (SW) of tangentially magnetized films of yttrium iron garnet (YIG) with a surface metastructure in the form of gratings of etched grooves with a period close to the film thickness d (~ d) has been experimentally and numerically studied. It has been found that the spectrum of the signal reflected from a microstrip transducer with a width w>> d, located on the YIG film contains absorption lines associated with the excitation of the SW of the surface metastructure. In the case when the magnetic field H and the transducer are oriented along the grooves, the absorption lines of the metastructure are located at frequencies f* near the short-wavelength edge of the spectrum of the surface magnetostatic (Damon--Eshbach) wave fs. It is shown that f* linearly depends on H, which can be used to develop magnetic field sensors. The results of measurements of dependences f*(H) are in qualitative agreement with the results of micromagnetic modeling. Keywords: magnetostatic waves, one-dimensional grating, surface structure, sensor of magnetic field.
Spin wave propagation in a YIG/FeRh composite structure as a system of coupled microwaveguides
Authors: Salomatova E. I.  , Odintsov S. A.  , Sakharov V. K.  , Khivintsev Yu. V.  , Amirov A. A.  , Sadovnikov A. V.
Published: January 2023

In this paper present that it is possible to control the characteristics of spin waves (SW) in a system of lateral magnetic waveguides made of iron yttrium garnet (YIG) by changing the characteristics of the antiferromagnetic iron-rhodium (FeRh) layer located above these waveguides. In particular it is shown that by changing the geometric parameters and magnetization of the FeRh layer one can control the amplitude and phase of SW propagating in lateral microwaveguides. The modes under which dips appear on the transmittance amplitude-frequency response (AFR) due to redistribution of the SW power are revealed, and their location can be controlled by changing the properties of the FeRh layer. The results obtained can be used to create microwave demultiplexers and taps based on the proposed structure. Keywords: spin waves, antiferromagnetic, magnonics, lateral structures
Bistability of magnetic skyrmions in a multilayer ferromagnetic/heavy metal structure
Authors: Gubanov V. A.  , Mruczkiewicz M.  , Sadovnikov A. V.
Published: January 2023

The effect of the Dzyaloshinskii-Moriya interface interaction on the stability of magnetic skyrmions in the ferromagnet-heavy metal multilayer structure depending on the number of multilayer repetitions was investigated by micromagnetic modeling. The parameters of the multilayer structure for the stabilization of magnetic skyrmions in nanodisks formed by Ir/Co/Pt layers are selected. It is shown how the value of the Dzialoszynskii--Moriya exchange interaction affects the type, stability, and radius of magnetic skyrmions in multilayer nanopillars. The results obtained can be used to create devices for processing and storage information signals. Keywords: spin waves, magnonics, magnetic skyrmions, ferromagnetic, heavy metal, Dzialoshinskii--Moriya interaction, multistability.
Investigation of the interference of magnetostatic surface waves using the inverse spin Hall effect
Authors: NikulinYu. V.  , Kozhevnikov A. V.  , Vysotskii S. L.  , Seleznev M.E.  , Khivintsev Yu. V.  , Filimonov Yu. A.
Published: January 2023

The effect of EMF generation due to the inverse spin-Hall effect during the propagation of magnetostatic surface waves (MSSW) in the structure of yttrium iron garnet (YIG) --- platinum based on a two-layer YIG film with different saturation magnetizations of the layers ((4π M1>4π M2) has been experimentally studied. It was shown that the magnitude of the EMF resonantly increases at the frequencies of hybridization of the MSSW with the exchange modes of the structure. At the same time, at the frequencies of the MSSW of the layer with a higher magnetization, oscillations of the EMF are observed, caused by its hybridization with the exchange modes of both the layer with 4π M1 and the layer with lower magnetization, which indicates the influence of interlayer exchange on the efficiency of spin pumping in the structure under consideration. The influence of the interference of counterpropagating MSSWs on the generated EMF has been studied. It has been shown that the EMF value is sensitive to the phase difference between counterpropagating MSSWs and oscillates. In this case, the amplitude of the oscillations is determined by the ratio of the wavelength of the MSSW and the length of the platinum film. Keywords: magnetostatic waves, yttrium iron garnet, platinum, interference, inverse spin Hall effect.
Mg-=SUB=-2-=/SUB=-Ge germanide under pressure: first principle evolutionary search results
Authors: Lunyakov Yu. V.
Published: January 2023

The search of optimal structures of magnesium germanide Mg2Ge under pressure has been performed using the software suite USPEX implementing the evolution algorithm combined with the density functional theory (DFT) approach. It is found that at pressures P≥15 GPa the triclinic P1 and P-1, monoclinic P21/c, orthorhombic Amm2 and trigonal P3m1 structures can coexist besides the well-known cubic Fm3m, orthorhombic Pnma and hexagonal P63/mmc ones. The new discovered structures are unstable due to potential relief complexity. They transform into orthorhombic Pnma structure at pressures P<14 GPa or hexagonal P63/mmc structure at pressures P>17 GPa. Keywords: Mg2Ge, crystal structure, phase transitions, hydrostatic pressure, evolutional search, Density Functional Theory.
X-ray Flashes and Pulsating Electron Flow in X-Ray Generators Based on SBN-61 Crystals
Authors: Andrianov V. A.  , Erzinkian A. L.  , Ivleva L. I.  , Lykov P. A.
Published: January 2023

In an X-ray generator based on a ferroelectric crystal of barium-strontium niobate Sr0.61Ba0.39Nb2O6 (SBN-61) at a temperature of about 50oC, pulsations of the electron flux and X-ray radiation were detected with an increase in gas pressure in the range 2·10-2-10-1 Torr. The electron flux had the shape of a cross in the crystal plane. The flash duration did not exceed 0.04 seconds. The pulsation period varied from 0.2 seconds at the beginning and up to 5-10 s at the end at a pressure of ~0.1 Torr. The observed effect is explained by the movement of domain boundaries on the depolarized crystal face in vacuum conditions, resulting in a large surface charge and, accordingly, an electric potential, leading to the formation of a pulsed electron flux. Keywords: X-ray radiation, electron flux, SBN-61 crystal, ferroelectric domains.
Ab initio study of the compressibility and electronic properties of a molecular organic crystal C-=SUB=-8-=/SUB=-H-=SUB=-10-=/SUB=-O-=SUB=-2-=/SUB=-
Authors: Korabel’nikov D. V.  , Fedorov I. A.
Published: January 2023

The structure and electronic properties of a molecular organic crystal octa-3,5-diyn-2,7-diol (C8H10O2) were studied in the pressure range from 0 to 1 GPa on the basis of ab initio calculations in the framework of the density functional theory taking into account the dispersion interaction. The compressibilities of C8H10O2 were calculated and a significant negative linear compressibility (-44 TPa-1) was established, which is caused by a change in the orientation and linear dimensions of molecular structural units relative to the crystallographic axes. Based on a topological analysis of the electron density, it is shown that hydrogen bonds are partially covalent in nature, and their energies are relatively high. It is shown that the upper valence and lower unoccupied electronic states correspond mainly to the states of carbon atoms. The band gap of C8H10O2 is calculated and its decrease with increasing pressure is predicted. Keywords: molecular crystal, negative compressibility, pressure, band gap, electron density, density functional theory.
Pressure-Dependent Elastic, Mechanical, and Ultrasonic Analysis of CaAuBi Compound
Authors: Prajapati A. K.  , Rai S.  , Yadawa P. K.
Published: January 2023

The Lennard-Jones potential model is used to investigate the effects of pressure on the elastic and ultrasonic properties of CaAuBi half-Heusler compound. Potential model technique approaches is used to evaluate second- and third-order elastic constants of CaAuBi compound at various pressures (0-15 GPa). The pressure dependence of elastic constants is studied and it has been observed that the elastic constants of the half-Heusler CaAuBi compound increase monotonically as pressure is increased. The hexagonal half-Heusler CaAuBi compound is mechanically stable at different pressures according to Born's elastic stability criteria. The Voigt-Reuss-Hill method was used to compute elastic parameters such as Young's modulus Y, shear modulus G, bulk modulus B, and Poisson's ratio ν under various pressures. For the provided pressure range, the second-order elastic constants were also utilized to determine ultrasonic velocities along with z-axis at various angles. The half-Heusler CaAuBi compound's hardness, ultrasonic attenuation, melting temperature, and anisotropy are also determined. The computation have been also satisfactory in estimating the thermal conductivity k(min) and Debye average velocity under varied pressure. Keywords: elastic properties, thermal conductivity, ultrasonic properties, thermo-physical properties.