bluuebunny/crossref_metadata_2025 huggingface dataset:
Media Experiments with Jumping Word Circles in Improving Arabic Vocabulary Learning for Class IV MI Muhammadiyah Sribit
Authors: Rosyidah Rosyidah Dzunur'aini , Naimah Naimah
Published: July 2021

Mastery of Arabic vocabulary is the main key to success in learning Arabic. By using media as a bridge in distributing material, it will change the mindset of students who think learning Arabic is difficult to understand. At MI Muhammadiyah Sribit, the conventional Arabic learning process inspired researchers to conduct experimental research on the use of word hoop game media to know the differences in students' Arabic vocabulary mastery between the experimental class and the control class. This study uses a quasi-experimental research type with a quantitative approach. The research subjects were students of class IV A as the experimental class and students of class IV B as the control class. The process of collecting data using test results, observations, and interviews was then analyzed using the paired-sample t-test and independent-sample t-test with the help of SPSS. From the results of the study, it was found that the results of the application of game media in learning Arabic can improve students' vocabulary mastery. Based on the results of the independent sample t-test, the posttest significance value in the experimental class was 0.008 < 0.05, and the posttest value in the control class was 0.009 < 0.05. So it can be concluded that there is a significant difference between the mastery of Arabic vocabulary for the experimental class and the control class.

Abstrak: Penguasaan kosakata bahasa Arab merupakan kunci utama keberhasilan dalam belajar bahasa Arab. Dengan menggunakan media sebagai jembatan dalam pendistribusian materi, maka akan merubah pola pikir siswa yang menganggap pembelajaran bahasa Arab sulit untuk dipahami. Di MI Muhammadiyah Sribit proses pembelajaran bahasa Arab konvensional menginspirasi peneliti untuk melakukan penelitian eksperimental penggunaan media permainan word hoop untuk mengetahui perbedaan penguasaan kosakata bahasa Arab siswa antara kelas eksperimen dan kelas kontrol. Penelitian ini menggunakan jenis penelitian eksperimen semu dengan pendekatan kuantitatif. Subjek penelitian ini adalah siswa kelas IV A sebagai kelas eksperimen dan siswa kelas IV B sebagai kelas kontrol. Proses pengumpulan data menggunakan hasil tes, observasi, dan wawancara kemudian dianalisis menggunakan uji t sampel berpasangan dan uji t sampel independen dengan bantuan SPSS. Dari hasil penelitian diketahui bahwa hasil penerapan media game dalam pembelajaran bahasa Arab dapat meningkatkan penguasaan kosakata siswa. Berdasarkan hasil uji independent sample t-test diperoleh nilai signifikansi posttest pada kelas eksperimen sebesar 0,008 < 0,05 , dan nilai posttest pada kelas kontrol sebesar 0,009 < 0,05. Sehingga dapat disimpulkan bahwa terdapat perbedaan yang signifikan antara penguasaan kosakata bahasa Arab untuk kelas eksperimen dan kelas kontrol.
Examining Brexit: Level of Analysis and Explanations
Authors: Betti Andrea
Published: July 2021

This article analyses the scholarly debate on the Brexit phenomenon and its possible causes. By contextualizing Brexit in the International Relations Theory debate about the levels of analysis, the article focuses on some of the most recent contributions of the Brexit literature. Firstly, it analyses the contributions that explain Brexit as a problem of international and European politics, related to the adaptation of the United Kingdom to the process of European integration. Secondly, it analyses the contributions that explain Brexit as the result of causes located at the domestic level, such as the decisions and perceptions of national leaders, the decision-making process, and the impact of populist and Eurosceptic political discourse. The article identifies the advantages of an approach capable of considering both international and domestic variables. This allows a deeper understanding of the phenomenon and a potentially fruitful collaboration between political scientists from different disciplines, such as International Relations Theory and Comparative Politics.
Prevalence of Rotavirus among Iraqi children with diarrhea in Diyala province
Authors: Hameed Ali
Published: July 2021

Background: Rotavirus is the most common cause of acute gastroenteritis in children below five years.

Objectives: The aim of this study to evaluate the prevalence of rotavirus among children with diarrhea, the efficacy of Immuno Chromatography Assay (ICA) and Enzyme-linked Immunosorbent assay (ELISA) and evaluate the relationship between the demographic agent and clinical presentation associated with rotavirus.

Material and Methods: A cross-sectional study was conducted at AL-Batool Teaching Hospital in Baqubah, from the first of April 2019 to 31 of March 2020, on (300) children with diarrhea below five years of age. The patients included (n=161, 53.6%) males and (n=139, 46.3%) females. The patient’s age, gender, living area, season, mode of feeding, source of water supply and sterilization, were collected through a questionnaire prepared for this study. The Rapid Test and ELISA are used for the detection of rotavirus in fecal specimens.

 Results: The rotavirus antigen was detected in (47.33%) stool specimens by the ELISA test and (59%) by ICA from (300) children with diarrhea and high infection in the age group between 13-24 months at the rate (49.40%). The highest infection rate in spring was (56.00%) and lower in summer (33.33%). The infection males more than females (42.24% vs. 39.57%). High significant infection among children living in rural areas (55.68%) compared to those living in urban areas (35.48%). According to the clinical features, the results showed the rate of rotavirus infection in children with fever was (54.90%), vomiting (42.03%), those suffering from severe dehydration (48.85) some dehydration 78 (46.15%), however, rotavirus infection was significant with fever only.
High recovery of stilbene glucosides by acetone extraction of fresh inner bark of Norway spruce
Authors: Saadabadi Atefeh , Ahmed Abrar , Smeds Annika I. , Eklund Patrik C.
Published: July 2021

Stilbenes are plant polyphenols that have shown beneficial pharmacological activities in a variety of diseases. The considerable amount of stilbene glucosides in spruce inner bark encouraged us to develop a straightforward and simple method of extraction with high recovery and yield. Stilbene glucosides from fresh inner bark of Norway spruce were extracted in one simple step with acetone at 20 °C. After three weeks of soaking in acetone, the extracts were dried and the composition was determined by GC-FID using a short and a long column (HP-5) and GC-MS (HP-1). The amount of the extracted compounds was also compared with a similar extract from air dried inner bark samples. The extracts from the fresh sample contained 30–50% of stilbene glucosides and the average yield [0.185 g extract/g bark] was as good as or slightly better than in previously reported works. However, no drying, milling, or sequential extractions with different solvents in elevated temperatures were needed. Moreover, this study revealed that the drying process can decrease the amount of extractable stilbenes significantly. Therefore, this method can be considered as an alternative for preparative isolation of stilbene glucosides, especially isorhapontin and astringin from inner bark of Norway spruce.
Experimental characterization, TDDFT-DFT, and spin effect on [PEG/H2O–ZrO2/TiO2]hhybrid nanofluid 3D flow as potential ceramic industry application
Authors: Eid Mohamed R. , Ali Mohammed A. , Al-Hossainy Ahmed F.
Published: July 2021

Doped zirconium oxide nanoparticles [ZrO2]NPsin the [PEG–H2O] and [TiO2]NPsin the [PEG–H2O/ZrO2]Cmatrices to fabricated the [PEG–H2O/ZrO2+TiO2]hhybrid nanofluid films by a sol–gel method, the average crystallite size is 100 ± 5 nm. The nanofluid and hybrid nanofluid thin films are studied using combined experimental and DFT theoretical method (DMOl3), including FTIR spectrum and optical properties. Mathematically, Higher rate of reactions of rotating [PEG/H2O–ZrO2]m, and [PEG–H2O/ZrO2+TiO2]hnanofluids on an extending sheet is considered with thermal radiation and heat source. The numerical Runge–Kutta–Fehlberg of 4–5th order (RKF45) method is used to solve the issue. The results specifically determine thatΔEgOpt${\Delta}{E}_{g}^{\text{Opt}}$values decrease from 2.27 eV for [PEG–H2O/ZrO2]mmono nanofluid to 1.596 eV for [PEG–H2O/ZrO2+TiO2]hhybrid nanofluid using the DFT computations HOMO and LUMO calculation. This result concluded that the [PEG–H2O/ZrO2]mtransformed from semiconductor to [PEG–H2O/ZrO2+TiO2]has a superconductor hybrid nanofluid by addition [TiO2]NPs. The hybrid nanoparticles have a higher influence than nanoparticles on the velocity distributions.
Stochastic dynamics of dielectric elastomer balloon with viscoelasticity under pressure disturbance
Authors: Dong Hao , Du Lin , Hu Rongchun , Zhang Shuo , Deng Zichen
Published: July 2021

Dielectric elastomers are widely used in many fields due to their advantages of high deformability, light weight, biological compatibility, and high efficiency. In this study, the stochastic dynamic response and bifurcation of a dielectric elastomer balloon (DEB) with viscoelasticity are investigated. Firstly, the rheological model is adopted to describe the viscoelasticity of the DEB, and the dynamic model is deduced by using the free energy method. The effect of viscoelasticity on the state of equilibrium with static pressure and voltage is analysed. Then, the stochastic differential equation about the perturbation around the state of equilibrium is derived when the DEB is under random pressure and static voltage. The steady-state probability densities of the perturbation stretch ratio are determined by the generalized cell mapping method. The effects of parameter conditions on the mean value of the perturbation stretch ratio are calculated. Finally, sinusoidal voltage and random pressure are applied to the viscoelastic DEB, and the phenomenon of P-bifurcation is observed. Our results are compared with those obtained from Monte Carlo simulation to verify their accuracy. This work provides a potential theoretical reference for the design and application of DEs.
Few picosecond dynamics of intraband transitions in THz HgTe nanocrystals
Authors: Apretna Thibault , Massabeau Sylvain , Gréboval Charlie , Goubet Nicolas , Tignon Jérôme , Dhillon Sukhdeep , Carosella Francesca , Ferreira Robson , Lhuillier Emmanuel , Mangeney Juliette
Published: July 2021

Optoelectronic devices based on intraband or intersublevel transitions in semiconductors are important building blocks of the current THz technology. Large nanocrystals (NCs) of Mercury telluride (HgTe) are promising semiconductor candidates owing to their intraband absorption peak tunable from 60 THz to 4 THz. However, the physical nature of this THz absorption remains elusive as, in this spectral range, quantum confinement and Coulomb repulsion effects can coexist. Further, the carrier dynamics at low energy in HgTe NCs, which strongly impact the performances of THz optoelectronic devices, is still unexplored. Here, we demonstrate a broad THz absorption resonance centered at ≈4.5 THz and fully interpret its characteristics with a quantum model describing multiple intraband transitions of single carriers between quantized states. Our analysis reveals the absence of collective excitations in the THz optical response of these self-doped large NCs. Furthermore, using optical pump-THz probe experiments, we report on carrier dynamics at low energy as long as 6 ps in these self-doped THz HgTe NCs. We highlight evidence that Auger recombination is irrelevant in this system and attribute the main carrier recombination process to direct energy transfer from the electronic transition to the ligand vibrational modes and to nonradiative recombination assisted by surface traps. Our study opens interesting perspectives for the use of large HgTe NCs for the development of advanced THz optoelectronic devices such as emitters and detectors and for quantum engineering at THz frequencies.
Crystal structure of (E)-7-fluoro-2-(4-methoxy-2-(trifluoromethyl)benzylidene)-3,4-dihydronaphthalen-1(2H)-one, C19H14F4O2
Authors: Meng Qing-Guo , Zhao Sheng-Nan , Sun Zhong-Hao , Shan Guang-Zhi , Meng Qing-Guo
Published: July 2021

C19H14F4O2, monoclinic, P21/c (no. 14), a = 11.8614(10) Å, b = 7.9148(6) Å, c = 16.7999(16) Å, β = 99.150(9)°, V = 1557.1(2) Å3, Z = 4, R

gt
(F) = 0.0446, wR

ref
(F
2) = 0.1150, T = 100 K.
Clause chaining and the utterance phrase: Syntax–prosody mapping in Matukar Panau
Authors: Mansfield John , Barth Danielle
Published: July 2021

Clause chaining is a form of syntactic dependency holding between a series of clauses, typically expressing temporal or causal relations between events. Prosodic hierarchy theory proposes that syntactic constituents are systematically mapped to prosodic constituents, but most versions of the theory do not account for clause chain syntax. This article presents original data from Matukar Panau, a clause-chaining Oceanic (Austronesian) language of Papua New Guinea. The clause chain is a syntactic constituent in which final-clause TAM scopes over preceding clauses. There are also other types of multi-clausal structures, encompassing subordinate adverbial clauses, and verbless copula clauses, and we analyse all these as instances of the “syntactic sentence.” The syntactic sentence maps to a distinct prosodic domain, marked by the scaling of L% boundary tones, and we equate this domain with the “utterance phrase” posited in some versions of prosodic hierarchy theory. The prosodic characteristics of the Matukar Panau utterance phrase are similar to those found in non-chaining languages, but while other languages use this prosody to mark pragmatically related groups of clauses, in Matukar Panau it most commonly maps to a syntactic sentence.
Feasibility study of cement-stabilized materials using 100% mixed recycled aggregates from perspectives of mechanical properties and microstructure
Authors: Meng Tao , Lian Songsong , Ying Kanjun , Yu Hongming
Published: July 2021

The research on the highly efficient reutilization of mixed recycled aggregates (MRA) produced from construction and demolition waste has attracted significant attention globally. In this study, the feasibility of using 100% MRA in cement-stabilized materials was investigated. The mechanical properties and microstructures of cement-stabilized MRA (CSMRA) materials containing 100% MRA were systematically examined through unconfined compressive strength (UCS) test, indirect tensile strength (ITS) test, drying shrinkage test, X-ray diffraction analysis, mercury intrusion porosimetry, and scanning electron microscopy. Results showed that the UCS and ITS of CSMRA materials were significantly enhanced with the increase of cement content and curing age, and there was almost a linear relationship between the UCS and ITS. The failure behavior of CSMRA materials under load showed three typical stages: compaction stage, elastic stage, and yield stage. The increase of the cement content caused the drying shrinkage deformation of CSMRA to increase sharply when the cement content exceeded 4%. The microstructural analysis indicated that cement had both filling and binding effects on CSMRA materials. The strength growth with cement content and curing age was because of the constant hydration of cement minerals, producing more calcium silicate hydrate binders between aggregates. Moreover, the increasing cement content could reduce the porosity and optimize the pore structure distribution of CSMRA materials. The findings of this study demonstrate that the use of 100% MRA in cement-stabilized materials as a road base is feasible, which will significantly enhance the utilization efficiency of MRA.
Assessment of Asphalt Mixture Disk-Shaped Compact Tension Test Indexes for Reflective Cracking Performance
Authors: Haslett Katie E. , Dave Eshan V. , Sias Jo E.
Published: July 2021

Disk-shaped compact tension (DCT) testing is a commonly used low-temperature fracture test to determine the cracking resistance of asphalt mixtures. The current testing specification only considers the fracture energy (Gf) from load-crack mouth opening displacement test data. However, Gf does not directly take into consideration the behavior of the post peak region of the curve, which may indicate the mixture’s ability to resist crack propagation and provide insight into fracture processes (e.g., crack growth velocity). It is possible to have two DCT specimens with similar Gf values but dramatically different load-displacement responses. The main focus of this paper is to make a comparative evaluation of various performance indexes developed for DCT fracture testing with respect to field reflective cracking performance of 10 full-scale asphalt concrete overlay test sections. This study evaluates Gf in addition to three other indexes: fracture strain tolerance (FST), rate-dependent cracking index (RDCI) and a proposed DCTIndex from Minnesota Department of Transportation that considers the post peak load-displacement behavior. An equivalent performance index approach is adopted to make comparisons of test sections with varying overlay structures in terms of thickness and material properties. Results from this study showed there was relatively good agreement between all equivalent laboratory performance indexes in identifying the best and worst performing overlay sections, according to normalized field performance indexes after approximately three years of service. In general, the equivalent FST and RDCI laboratory indexes rank test sections similarly, while equivalent Gf and DCTIndex have comparable ranking.
Thermodynamic properties of the GdTe3 compound
Authors: Imamaliyeva Samira
Published: July 2021

The alloys of the Gd-Te system in the range of compositions > 75 at% Te were studied by the methods of X-ray diffraction (XRD) and electromotive forces (EMF). From the EMF measurements of the concentration cells relative to the GdTe electrode in the 300-450 K temperature range, the partial thermodynamic functions of GdTe in alloys were determined. By combining these data with the corresponding functions of Gd in GdTe, the partial molar functions of gadolinium in GdTe3+Te alloys, and standard thermodynamic functions of formation and standard entropy of the GdTe3 compound were calculated. The obtained results were compared with the literature data.
Un acercamiento a la correlación entre habilidades tecnológicas de los docentes y su intención de uso de la tecnología en la enseñanza en el aula
Authors: Rodríguez Pinzón Heivar Yesid , Galvis López Jhon Jairo
Published: July 2021

En la búsqueda de encontrar La finalidad de este documento es utilizar un diseño de muestreo estratificado MAS a una población de 1724 de docentes de tiempo completo de tres universidades en Colombia (Tecnológica de Pereira, Quindío y Francisco José de Caldas), con el fin de presentar un modelo de ecuaciones estructurales basadas en la varianza SEM-PLS. El modelo establece cinco constructos (tres exógenos que corresponden a las creencias en las habilidades tecnológicas del docente y dos endógenos que corresponden a la intensión del uso de la tecnología en el aula) y 16 items o variables indicadoras, el instrumento y modelo usado se basa en el estudio previo propuesto por (Teo, 2009). Los resultados muestran que existe una relación positiva significativa entre la habilidad del uso de la tecnología para la pedagogía y la intención del uso constructivista y tradicional en el aula. Así mismo, el modelo de medida reflectivo muestra AVE mayores a 0.5 para los constructos, consistencia interna y fiabilidad mayor a 0.6 y validez discriminante HTMT mediante intervalo de confianza que no incluya 1 en todos los constructos. Por otro lado, en el modelo estructural no se evidencia multicolinealidad, los coeficientes path o de trayectoria tienen magnitud fuerte y signo acorde a las hipótesis planteadas, en el caso del constructo TP (Tecnología para la pedagogía) hacia los constructos UCT (Intención del uso de la tecnología de forma constructivista) y UTT (Intención de uso de la tecnología de forma tradicional), el coeficiente de determinación de los constructos endógenos son mayores a 0.6 y se muestra un grado del constructo exógeno TP que explica los constructos endógenos UCT y UTT.
European values in the axiological space of modern Ukrainian youth
Authors: Borets'ka Marta
Published: July 2021

The article provides a brief overview of the theoretical field of socio-humanitarian sciences in terms of definition and features of disciplinary approaches to the study of values as a scientific category. The topicality of sociology is established in this discourse, i.e. it is a comprehensive study of values, which involves their analysis in relation to other elements of the social system, taking into account the current social context. Emphasis is placed on the expediency of creating a theoretical and methodological basis for research by combining consistent provisions of structuralism and hermeneutics as well as the use of qualitative methods relevant to non-classical theorizing. The dialectic of the concepts of world and European values is explained, the correctness of the use of the latter is substantiated. The leitmotif of the article is the idea of a direct relationship between the quality of modernization of Ukraine and the speed of transformation of the axiological space of Ukrainians towards the (Western)European model. Therefore, based on the data of the World Values Survey, the tendencies of modification of the modern axio-sphere of the Ukrainian society in accordance with the changes of the European and world value spaces are analyzed. It is emphasized that in Ukraine there is a slow departure from the still dominant traditional values to the values of secularization and self-expression (according to R. Inglehart). It is most obvious in the value orientations of young people as the most progressive and adaptive socio-demographic group of the population. In view of this, the author studied the value orientations of the I. Franko Lviv National University students to check them on the availability of European values, the specifics of the internalization of the latter and the search for subjects who are their repeaters. It has been established that the state of the value space of the respondents can be characterized as one that is basically specified by a dominant tradition, in which the fundamental values of a united Europe are already slowly being internalized. The determinants of this process are the active transformations of the political and economic situation in the country and the world at the macro-level as well as the influences of the closest surroundings, friends, educational courses, travelling at the meso- and micro-level of the social system.
Sociology of generation’s social structure
Authors: Kovalisko Natalia , Makeiev Serhii
Published: July 2021

In sociology, the concept of “generation” is usually applied to a wide variety of social categories. This is a cohort of peers, and a cohort of several years of birth — as in studies of social mobility, as well as a community of those who share acceptable values, simultaneously experienced significant events, is a bearer of similar experiences and memories. Theoretical reflection in modern literature continues to excite the fundamental essay of K. Mannheim “The Problem of Generations”. The cognitive intuitions it contains have a priority status, but the published reviews state that the empirical potential of the concept outlined there is minimal, and new times require new approaches to analyzing the role of generations in the intensification of social dynamics and the movement of history. Sociology of the social structure of a generation is mainly a way of observing, fixing and describing the transformations of the morphological structure of a community. The heterogeneity of the age cohort is prescribed by origin from different types of families and birth in a particular region and type of settlement. In the course of primary socialization, general patterns of worldview and worldview are formed, an attitude to the past, present and future on the basis of internalized values, standards and norms of behavior. The degree of stratification of life chances and opportunities given by birth is subsequently corrected or fixed by institutions of secondary and higher education, which is monitored in studies of professional and status mobility. Events are capable of elevating an age cohort to the status of a generation, constructing an identity (“we,” shared ways of feeling, thinking, acting) and, almost synchronously, differentiating peers, establishing differences and distances.
Global dimension of labor inequality
Authors: Butkaliuk Vitalina
Published: July 2021

The transition of the world economy from Keynesianism to neoliberalism at the end of the twentieth century entailed tectonic shifts in the sphere of labor and employment. The organization of the production process on neoliberal principles under the conditions of the post-Fordist regime of capital accumulation has led to instability and insecurity of employment, a high level of labor underutilization, widespread labor poverty, as well as the rapidly increasing inequality that threatens social development today and stability of society. Based on the economic-sociological approach the author examines the reasons for the expansion and the specifics of the manifestation of inequality in the world of work in the context of the post-Fordist neoliberal reform of the global economic system. The article characterizes the key trends in the functioning of the labor market, contributing to the increase in inequality over the past decades (a decrease of the labor share in the national income, a reduction in the relationship between productivity and wages growth, the erosion of the trade union movement and the destruction of the welfare state). The main attention is paid to the study of the phenomenon of labor income inequality, its dynamics and forms of manifestation in the modern world, as well as to identify the impact on this type of inequality, both individual characteristics of workers and the characteristics of the industry, size of the enterprise, as well as the level of socio-economic development of the country. Based on the study of these processes, the author concludes that the redistribution of income in favor of capital and their high differentiation are the quintessence of neoliberal capitalism. The economic and political depletion of nation states in the context of neoliberal reforms led to their low resources, insufficient either to carry out a broad social policy and help those in need, or to adequately combat the consequences of crises characteristic of capitalism or any force majeure situations, such as, for example, the current COVID-19 pandemic. To get the global economy out of the current crisis requires the implementation of fundamental changes not only in the field of economic policy, but also in the entire system of distribution of public goods.
Our friend Melvin Kohn
Authors: Paniotto Volodymyr
Published: July 2021

In the genre of oral history of sociology, the author narrates his experience of communication with the famous American sociologist, former president of the American Sociological Association (1987), honorary doctor of the Kiev-Mohyla Academy Melvin Lester Kohn (1928–2021). It is about the friendship and cooperation of Melvin Cohn with Ukrainian colleagues, his participation in the organization and holding of international research with the participation of Ukraine. The creative heritage of the American sociologist is important for the development of sociology in the world and in Ukraine, in particular for better understanding the social structure of Ukrainian society.
On approximation of two-variable function by linear positive polynomial operators
Authors: Bugaets V.P.
Published: July 2021

On approximation of two-variable function by linear positive polynomial operators.
On linear methods of summation of double Fourier series
Authors: Grishin V.B.
Published: July 2021

On linear methods of summation of double Fourier series.
Iterative methods of solving Theodorsen's equation
Authors: Gubar I.G.
Published: July 2021

Iterative methods of solving Theodorsen's equation.
Tauberian theorems for $(W^{(\alpha)}, P, Q)$-methods of integration of two-variable functions
Authors: Novikova N.S.
Published: July 2021

Tauberian theorems for $(W^{(\alpha)}, P, Q)$-methods of integration of two-variable functions.
Some properties of curvature of Riemannian spaces
Authors: Fedishchenko S.I.
Published: July 2021

Some properties of curvature of Riemannian spaces.
Some iteration formulae of inversion of linear operations
Authors: Dubovik L.I.
Published: July 2021

Some iteration formulae of inversion of linear operations.
To synthesis of optimizing digital-analog device by dynamic programming method in continuously-discrete form
Authors: Ivakhnenko M.M. , Zlatkin A.A.
Published: July 2021

To synthesis of optimizing digital-analog device by dynamic programming method in continuously-discrete form.
On realization of generalized separated differences in vector spaces
Authors: Ogneva V.A. , Chernyshenko V.M.
Published: July 2021

On realization of generalized separated differences in vector spaces.
On the best approximation of multivariable function by means of step functions
Authors: Ryshchenko N.D.
Published: July 2021

On the best approximation of multivariable function by means of step functions.
Occlusal Trauma Restored with a Fiber-Reinforced Composite Resin System (FRC)
Authors: Ramírez Barrantes Juan Carlos , Calvo Barillas John
Published: July 2021

Fiber-reinforced composite resin systems (FRC) are widely used materials in engineering and biomedicine. For approximately 40 years they have been investigated demonstrating their excellent mechanical properties. From a clinical perspective, they are suggested in different disciplines of dentistry, where their applications are evidenced-based. With the introduction of new technologies and bonding protocols, these types of materials can be used as substructures. The attempt to explore the properties and applications of FRC's materials in non-everyday clinical cases, allows us to provide a viable alternative in the planning of complex restorative treatments.
PIBID-Química sob o olhar do professor supervisor
Authors: Borges Marcia Narcizo , Chacon Eluzir Pedrazzi
Published: July 2021

O Programa Institucional de Bolsa de Iniciação à Docência visa envolver licenciandos na realidade escolar sob a supervisão de professores da Escola Básica, produzindo conhecimentos e alternativas metodológicas centradas em um ensino-aprendizagem dinâmico e significativo. O trabalho objetiva avaliar a visão do candidato a supervisor sobre sua pretensão de atuar no PIBID-Química analisando sua carta de intenção, através da metodologia de Análise Textual Discursiva e também, observar se a sua participação trouxe alguma contribuição para sua formação docente e para a comunidade escolar, através da análise das respostas dadas a um questionário avaliativo. Foram analisadas 8 cartas de intenção que demonstram crenças de que a experiência profissional pregressa seja o fator mais importante para a atuação como professor supervisor e que não apresentam propostas concretas de como atuar na construção de valores éticos e metodológicos. Os questionários avaliativos foram respondidos por 7 supervisores que mostraram a importância do Programa em sua formação docente e da comunidade escolar, através do desenvolvimento de atividades diferenciadas que proporcionaram um dinamismo no ensino-aprendizagem da Química.
Palavras-chave: PIBID; avaliação; supervisor.
Effect of ultrafine natural steatite powder, super plasticizer and VMA on the fresh and hardened properties of self-compacting cement paste and mortar
Authors: Christopher Gnanaraj S. , Chokkalingam Ramesh Babu , Thankam G. Lizia , Pothinathan S.K.M.
Published: July 2021

For the past few decades innovation in construction material has grown a lot. This leads to special concrete such as self-compacting concrete, geopolymer concrete, self-healing concrete, etc. To prepare a special concrete apart from regular concreting material some sort of special materials was also needed, like mineral and chemical admixtures. Hence it is necessary to study the effect of these admixtures in cement paste and mortar before studying the same in concrete. Hence an attempt is made to study the effect of mineral and chemical admixtures in the fresh and hardened properties of cement paste and mortar. For this study ultrafine natural steatite powder is taken as mineral admixture and polycarboxylic based superplasticizer and glenium stream 2 were taken as chemical admixtures. Ultrafine natural steatite powder was used as additive to cement in various percentages like 0%, 5%, 10%, 15%, 20% and 25%. Superplasticizer and viscosity modifying admixture were taken as 1.5% and 0.5%, respectively. Then various combinations were worked out. To study the fresh property of cement paste consistency, initial setting time and miniature slump cone test were done based on the results yield stress of cement paste also calculated empirically. To study the hardened property compression test on cement mortar was done. Based on the test results it is clear that the addition of ultrafine natural steatite powder increases the water demand hence reduces the workability. On the other hand, it increases the compressive strength up to a certain limit. Adding superplasticizer increases the workability and reduces the water demand and viscosity modifying admixture reduces the bleeding and segregation effects hence increases the compressive strength.
Bio-inspired and computer-supported design of modulated shape changes in polymer materials
Authors: Bäckemo Johan , Liu Yue , Lendlein Andreas
Published: July 2021

The Venus flytrap is a fascinating plant with a finely tuned mechanical bi-stable system, which can switch between mono- and bi-stability. Here, we combine geometrical design of compliant mechanics and the function of shape-memory polymers to enable switching between bi- and mono-stable states. Digital design and modelling using the Chained Beam Constraint Model forecasted two geometries, which were experimentally realized as structured films of cross-linked poly[ethylene-co-(vinyl acetate)] supported by digital manufacturing. Mechanical evaluation confirmed our predicted features. We demonstrated that a shape-memory effect could switch between bi- and mono-stability for the same construct, effectively imitating the Venus flytrap.

Graphic Abstract
Late Stage Decomposition of Embalmed Cadavers
Authors: Mata Tutor Pilar , Villoria Rojas Catherine , Benito Sánchez María
Published: July 2021

Decomposition is a natural process that begins approximately four minutes after death and continues until the body is degraded to simpler biochemical components which are gradually recycled back to the environment. This process is dependent on extrinsic and intrinsic factors. Embalming is a chemical preservation technique that aims to preserve the external appearance of the body in good condition for an indeterminate period. In Spain, there is a lack of experimental studies carried out to analyse the variables that affect decomposition in embalmed bodies, therefore, in accordance with the conclusions reached by previous authors, it is hypothesised that embalmed bodies show quantifiable characteristics during the late stage decomposition which distinguish them from control, unembalmed, cadavers. An anthropological and statistical analysis was performed on 14 individuals from Cementerio Sur de Madrid exhumed after ten years according to the Mortuary Health Law of the Autonomous Region of Madrid. The preliminary results obtained showed that there is a qualitative and statistically significant relationship between the variables evaluated, being the presence or absence of soft tissue the most notable difference. The mortuary or thanatopraxy treatments performed before the burial and the microenvironmental conditions of the burial positively influence the soft tissue preservation on embalmed bodies. These results contribute to the understanding about the decomposition rate of an embalmed cadavers in cemeteries, and the related extrinsic variables.
Vibrations of a Cantilevered Thick Plate
Authors: Papkov S. O
Published: July 2021

It has been for the first time that an analytical solution to the problem of free vibrations of a cantilevered thick orthotropic plate is presented. This problem is quite cumbersome for using the exact methods of the theory of elasticity; therefore, methods based on the variational approach were developed to solve it. The paper suggests using the superposition method to construct a general solution of the vibration equations of a plate in the series form of particular solutions obtained with the help of a variables separation. The particular solutions of one of the coordinates are built in the form of trigonometric functions of a special type (modified trigonometric system). The constructed solution, in contrast to the solutions known in the literature on the basis of the variational approach, accurately satisfies the equations of vibrations. The use of a modified trigonometric system of functions makes it possible to obtain uniform formulas for even and odd vibration shapes and to reduce the quantity of boundary conditions on the plate sides from twelve to nine ones, while five of the nine boundary conditions are also accurately satisfied. The structure of the presented solution on the plate boundary is such that, each of the kinematic or force characteristics of the plate is represented as a sum of two series, i.e. a trigonometric series and a series in hyperbolic functions. Remaining boundary conditions make it possible to obtain an infinite system of linear algebraic equations with respect to the unknown coefficients of the series representing the solution. The convergence of the solution by the reduction method of the infinite system is investigated numerically. Examples of the numerical implementation are given; numerical studies of the spectrum of natural frequencies of the cantilevered thick plate were carried out based on the obtained solution, both with varying elastic characteristics of the material and with varying geometric parameters.
Modeling the Effective Conductive Properties of Polymer Nanocomposites with a Random Arrangement of Graphene Oxide Particles
Authors: Tashkinov M. A , Dobrydneva A. D , Matveenko V. P , Silberschmidt V. V
Published: July 2021

Сomposite materials are widely used in various industrial sectors, for example, in the aviation, marine and automotive industries, civil engineering and others. Methods based on measuring the electrical conductivity of a composite material have been actively developed to detect internal damage in polymer composite materials, such as matrix cracking, delamination, and other types of defects, which make it possible to monitor a composite’s state during its entire service life. Polymers are often used as matrices in composite materials. However, almost always pure polymers are dielectrics. The addition of nanofillers, such as graphene and its derivatives, has been successfully used to create conductive composites based on insulating polymers. The final properties of nanomodified composites can be influenced by many factors, including the type and intrinsic properties of nanoscale objects, their dispersion in the polymer matrix, and interphase interactions. The work deals with modeling of effective electric conductive properties of the representative volume elements of nanoscale composites based on a polymer matrix with graphene oxide particles distributed in it. In particular, methods for evaluating effective, electrically conductive properties have been studied, finite element modelling of representative volumes of polymer matrices with graphene oxide particles have been performed, and the influence of the tunneling effect and the orientation of inclusions on the conductive properties of materials have been investigated. The possibility of using models of resistive strain gauges operating on the principle of the tunneling effect is studied. Based on the finite-element modeling and graph theory tools, we created approaches for estimating changes in the conductive properties of the representative volume elements of a nanomodified matrix subjected to mechanical loading.
Tuning acoustic performance of multi-chamber hybrid mufflers
Authors: Trinh Van-Hai
Published: July 2021

In this paper, we investigate the functional acoustic performance of multi-chamber mufflers using a numerical approach. The wave propagation governing in expansion chamber domains is first introduced and solved by the finite element method. Our numerical results of selected muffler configurations are compared with the reference predictions model and experiments in order to validate the present procedure. Then, the influence of the geometry characteristics of typical and hybrid configurations of multi-chambered mufflers (number of sub-chambers, micro-perforated tube structure) on their sound transmission loss is studied. The obtained results indicate that the structure of the considered muffler has a strong effect on their acoustical performance, and the location and the high level of resonances of the sound transmission loss behavior are strongly related to the number of sub-chambers as well as micro-perforated tube characteristics. By tuning geometrical parameters (e.g., having a small perforation ratio), we enable to design mufflers having a higher sound transmission loss (up to 110 dB) at low frequencies (~ 195 Hz) but a constraint space (e.g., acoustic chamber length of 300 mm).
Free vibration and buckling of bidirectional functionally graded sandwich plates using an efficient Q9 element
Authors: Ich Le Cong , Dung Tran Quang , Nam Pham Vu , Kien Nguyen Dinh
Published: July 2021

Free vibration and buckling of three-phase bidirectional functionally graded sandwich (BFGSW) plates are studied in this paper for the first time by using an efficient nine-node quadrilateral (Q9) element. The core of the sandwich plates is pure ceramic, while the two skin layers are of a three-phase bidirectional functionally graded material. The element is derived on the basis of the Mindlin plate theory and linked interpolations. Fundamental frequencies and buckling loads are computed for the plates with various boundary conditions. Numerical result shows that convergence of the linked interpolation element is faster compared to the conventional Lagrangian interpolation Q9 element. Numerical investigations are carried out to highlight the influence of the material gradation and the side-to-thickness ratio on the vibration and buckling behaviour of the plates.
New Chromosome Numbers and Karyotype Analysis of Tordylium (Apiaceae) Species with Emphasis on Their Systematics and Evolutionary Significance
Authors: GÖMÜRGEN Nihal , DOĞRU KOCA Aslı , ÖZMEN BAYSAL Edibe , DOĞAN Cahit , ALTINÖZLÜ Haşim
Published: July 2021

In Turkey, there are eighteen Tordylium (Apiaceae) species out of twenty in the worldwide and seven of them are endemic. In this research, karyotypes of T. apulum, T. pestalozzae, T. syriacum, T. trachycarpum and karyotypes and chromosome numbers of T. cappadocicum, T. aegaeum, T. hasselquistiae, T. ketenoglui (endemic), T. macropetalum (endemic), T. pustulosum (endemic) are provided for the first time. Tordylium species were separated into five cytotypes according to chromosome numbers as 2n=8, 16, 18, 20 and 22. Besides, idiograms of haploid chromosome set, length of the chromosome arms, arm ratios, centromeric index, relative length and haploid karyotype formulas are given. T. ketenoglui has longest chromosome lengths (3,39–1,66 µm) while T. aegaeum has shortest (1,10–0,59 µm). Additionally, principal component analysis (PCA) was performed by quantitified karyological characters. PCA results showed that the median type and haploid chromosome length have significant variants among karyological characters. Also, it is discussed correlation among karyological data, current infrageneric classification and the phylogenetic hypothesis based morphological dataset of Tordylium. Karyological characters are incompatible with current infrageneric classification, similarly with conflict between the phylogenetic hypothesis and infrageneric classification. In the light of the phylogeny, it can be said that the ancestral number is 2n=16.
Síndrome Dyke Davidoff Masson Aspectos Clínico-Radiológicos: Reporte de Caso
Authors: Avellaneda Luis Carlos , Castro Luis E. , Vargas R Ledmar J.
Published: July 2021

Introducción: El síndrome de Dyke Davidoff Masson (DDM) es una rara entidad. Este síndrome tiene una presentación clínica variable desde casos leves a severos, por lo que constituye un reto diagnóstico en edades tempranas y el personal tratante. Sin embargo, dentro de los hallazgos característicos estos pacientes pueden cursar con hemiparesia, asimetría facial, convulsiones, retraso mental y hemiatrofia cerebral en neuroimagen. Caso clínico: Paciente de 17 años de edad con antecedente de epilepsia bajo manejo médico, ingreso a urgencias por cuadro de 3 días de cefalea, emesis, fonofobia y síntomas focales por lo que se realizó tomografía craneal, la cual evidencia hallazgos característicos de este síndrome. Discusión: El síndrome de DDM es una patología poco descrita en la literatura médica, con presentación variable en su sintomatología. Este puede debutar tanto en edad adulta como en edades tempranas. Sinembargo, hasta el momento no se ha encontrado predisposición según el sexo o el hemisferio afectado. El diagnostico se basa en hallazgos al examen físico y estudios imagenologicos que sirven para confirmar dicho diagnóstico. El manejo para este síndrome es sintomatológico y tiene como objetivo mejorar la calidad de vida de los pacientes. Conclusiones: Se presenta el caso de un paciente con inicio tardío de síntomas, sin antecedentes perinatales de relevancia y hallazgos tomográficos compatibles con dicho síndrome. El síndrome de DDM es una entidad poco común con una presentación clínica variable desde casos leves a severos, por lo que constituye un desafío diagnóstico en edades tempranas y para el personal tratante.
Anthropologist and Tourist: Mobility of the Udehe Image in Ethnographic Space
Authors: Degtiar Vladimir
Published: July 2021

The article tries to trace the formation, transformation, and deconstruction of the image of the author’s studied object. At the same time, it is proposed to consider the movement of the subject in the ethnographic space, that is, a temporal and geographically unified space that includes field research, presentations, conversations with colleagues, writing the text of an article, etc. The concept of imaginaries, which is central to the representation of the object, is considered in comparison with tourism practices, where the image is a central element, which gives a better understanding of the practices of both. It is argued that when deconstructing an image, the researcher’s position on the object and the ethnographic space change. The method of self-ethnography and mobility as a concept metaphor serve as tools for deconstructing the image. The main result of such a deconstruction is the ethical conclusions of the relationship of the subject to the object, as well as the performative effect of auto–ethnography. The author at the same time tries to find a solution to establish a reciprocity in relation to the object, as a kind of mandatory ethical action. One of the possible solutions seems to be the use of anthropological knowledge in the commodification of the object’s culture in its economic interests.