bluuebunny/crossref_metadata_2025_split huggingface dataset:
On optimization of technical devices based on a hierarchy of mathematical models
Authors: Суровежко А.С. , Мартыненко С.И. 
Published: August 2021

Рассмотрена задача о топливном коллекторе, которую можно отнести к обратным задачам гидродинамики: необходимо определить геометрию распределительного канала коллектора, обеспечивающего равномерную раздачу топлива. Однако профилирование коллектора на основе 3D стационарных уравнений Навье-Стокса для турбулентного течения несжимаемой вязкой среды в шероховатых каналах требует непрактичных вычислительных усилий. Использована иерархия математических моделей: 1D уравнения Навье-Стокса для профилирования и 3D уравнения Навье-Стокса для калибровки 1D модели. Показано, что используемая иерархия моделей позволяет существенно снизить объем вычислительной работы, необходимой для расчета оптимальной конструкции коллектора. Предложенный подход представляет интерес для оптимизации технических устройств различного назначения.
A fuel collector problem is considered as an inverse problem of hydrodynamics: it is necessary to determine the distribution channel geometry of a collector for a uniform fuel distribution. However, the collector profiling based on the 3D stationary Navier-Stokes equations for turbulent flow of an incompressible viscous medium in rough channels requires impractical computational efforts. A hierarchy of mathematical models (1D Navier-Stokes equations for the collector profiling and 3D Navier-Stokes equations for 1D model validation) is used in this paper. It is shown that the hierarchy of models can significantly reduce amount of computational work needed for computing the optimal collector design. The developed approach is of interest for optimizing technical devices for various purposes.
An efficient software implementation of numerical methods for solving stiff systems of delay differential equations
Authors: Желтков Д.А. , Третьякова Р.М. , Желткова В.В. , Бочаров Г.А. 
Published: August 2021

Системы уравнений с запаздываниями широко применяются в различных областях современного математического моделирования. В ходе разработки структуры математической модели и идентификации ее параметров приходится многократно решать задачу Коши для подобных систем. В случае высокой размерности системы, а также при условии жесткости задачи численное решение уравнений с запаздываниями может требовать значительных вычислительных и временных затрат. Таким образом, разработка и реализация эффективных алгоритмов численного решения различных классов уравнений с запаздывающими аргументами является актуальной задачей. В настоящей статье представлена модифицированная версия программного комплекса DIFSUBDEL, в которой реализованы методы численного решения дифференциальных уравнений с запаздываниями на основе линейных многошаговых методов. Переработанная версия разработана с применением принципов структурного программирования и является значительно более удобной в эксплуатации, чем исходная, а также обладает свойством потокобезопасности, что позволяет использовать комплекс в качестве блока в системах, основанных на технологиях параллельного программирования с общей памятью. Был проведен сравнительный анализ производительности переработанной системы DIFSUBDEL c другими существующими программными реализациями численных методов решения дифференциальных уравнений с запаздыванием и показана ее эффективность.
The systems of delay differential equation are widely used in modern mathematical modeling. The process of mathematical model development and identification requires the repeated solution of initial value problems for such systems. The numerical solution of delay differential equations may be computationally expensive, especially when the problem is stiff and high-dimensional. Therefore, it is important to develop and implement the efficient algorithms for the numerical solution of different classes of delay differential equations. In this paper, a new implementation of DIFSUBDEL program package for the numerical solution of delay differential equations based on linear multistep methods is discussed. The modified version is based on structured programming principles to make the program thread safe and user-friendly. The modified program performance is compared with the existing implementations of numerical methods for the solution of delay differential equations.
Research of migration processes in electronic social networks
Authors: Grebenyuk A. A. , Subbotin A. A. 
Published: August 2021

The article сarries out an analysis of the practices of using electronic social networks (Facebook, Twitter, Vkontakte, etc.) in the study of migration processes. The paper shows how alternative to traditional sources (administrative, surveys) data allow us to form an up-to-date idea of the spatial-temporal and socio-demographic characteristics of migration. The authors study the integration of migrants in destination countries, including difficulties of assimilation and identity preservation, geography of migration flows, migration due to natural disasters and political reasons, intellectual and labour migration. The specificity of the data generated by social networks is that they cover the entire population and are produced in real time.The paper highlights the search for the necessary information using the means of platforms – advertising plugins, geolocation in posts and information directly collected from users, the functioning of certain communities, published comments. The study also gives important methodological features, the success of the results of any research conducted through the analysis of electronic social networks depends on the consideration of which. The problem of the information obtained with their help lies in such limitations as accessibility (technical features of specific platforms), representativeness (insufficient development of statistical techniques for evaluation) and variability of user preferences. In conclusion, the authors conclude about the prospects of using digital mass communication media in the study of migration processes.The scientific and practical significance of the research paper lies in the fact that it complements the literature on the topic under consideration, being the first systematic review of it in the Russian language, and also provides recommendations on the use of the information obtained.
Entrevistas narrativas mediadas por instrumentos: investigações sobre a identidade docente
Authors: Caixeta Juliana Eugênia , Silva Delano Moody Simões da , Lima Lídia Moreira de , Alves Euler Brennequer Santos 
Published: August 2021

Neste artigo, temos o objetivo de analisar o uso da entrevista narrativa mediada por instrumentos em pesquisas sobre a identidade docente em dois contextos: PIBID ”“ Programa Institucional de Bolsas de Iniciação Ã Docência e Educação de Jovens e Adultos. Para tanto, usamos a análise temática dialógica para analisar uma dissertação de mestrado, dois artigos e um relatório de pesquisa. O uso da entrevista narrativa mediada por instrumentos tem favorecido a construção de contextos investigativos que provocam o falar de si por meio da interação do/a entrevistado/a com um objeto que se remete Ã sua história. No caso das pesquisas sobre a identidade docente, o uso de instrumentos tem favorecido o posicionamento da pessoa como professor/a.
Narrativas, infância e educação: reflexões e perspectivas
Authors: Pulino: Lúcia Helena Cavasin Zabotto 
Published: August 2021

Este artigo, inspirado em texto poético-filosófico de Walter Benjamin, propõe-se a tratar criticamente as narrativas sobre educação e crianças, num sentido amplo, envolvendo formas de relações em contextos educativos, expressas por palavras, práticas e afetos. Por meio de reflexões filosóficas relacionadas Ã perspectivas teóricas e metodológicas nos campos do desenvolvimento humano e da educação, problematiza-se a formação de educadores da infância. Criticam-se propostas de formação por se sustentarem em narrativas prescritivas de como deve ser o humano que não abrangem a sua complexidade e a singularidade das pessoas, nem tampouco aceitam a diferença como possibilidade do humano e não como desvio da normalidade. A partir dessa crítica, busca-se traçar uma proposta teórico-metodológica que possa superar as contradições apontadas e que se defina a partir de uma narrativa aberta a novas possibilidades de relações, ao conflito, ao desacordo, Ã diversidade da experiência humana. Que seja, enfim, uma metodologia de pesquisa e intervenção que possa dar espaço para uma narrativa gestada em “lugares de infância”, marcada pela pergunta, pelo não saber, pelo encontro com o outro, especialmente com a infância.
Obrigatoriedade de matrícula na pré-escola: análise do ponto de vista das famílias
Authors: Lira Aliandra Cristina Mesomo , Machado Leandra Souza 
Published: August 2021

O artigo tem como objetivo problematizar a obrigatoriedade de matrícula na pré-escola para crianças de 4 e 5 anos de idade, proposta pela Lei 12.796, e compreender qual a percepção dos pais com relação aos encaminhamentos envoltos no cumprimento da lei. A pesquisa é de cunho qualitativo, partindo de referencial teórico e análise documental, e entrevistas com os responsáveis pelas crianças matriculadas na pré-escola. Foi possível reconhecer que a obrigatoriedade não necessariamente significa uma pré-escola de qualidade, e que os responsáveis interpretam a implementação da lei como direito ‘de aprender’ mais cedo, a despeito das condições de atendimento.
Pemberian Pisang Ambon Untuk Meningkatkan Kadar Hemoglobin Pada Ibu Hamil Trimester III Dengan Anemia
Authors: Widayati Enny , Aisah Siti 
Published: August 2021

Anemia merupakan suatu kondisi tubuh dengan jumlah dan ukuran sel darah merah atau kadar hemoglobin (Hb) lebih rendah, sehingga akan mengakibatkan distribusi oksigen oleh darah ke seluruh tubuh terganggu. Anemia pada ibu hamil akan berisiko tinggi terjadi persalinan prematur, kematian janin, atau bayi lahir dengan berat rendah. Mengkonsumsi buah pisang 2 kali sehari pagi dan sore selama 7 hari bersamaan dengan mengkonsumsi tablet Fe dapat meningkatkan kadar Hb pada ibu hamil yang mengalami anemia. Studi kasus ini bertujuan untuk meningkatkan kadar Hb pada ibu hamil dengan anemia. Studi kasus ini menggunakan metode deskriptif dengan pendekatan proses asuhan keperawatan. Subjek studi kasus adalah pasien ibu hamil yang mengalami anemia dengan Hb <10 g/dl. Subjek studi kasus berjumlah 2 pasien kelolaan yang kemudian diberikan intervensi pemberian buah pisang ambon 2 kali sehari pagi dan sore selama 7 hari bersamaan dengan mengkonsumsi tablet Fe. Pasien telah menandatangani informed consent sebelum dilakukan pengambilan data. Hasil studi kasus ini mengalami kenaikan kadar Hb, pasien I Hb semula 9,7 g/dl menjadi 11,3 g/dl dan pasien II Hb semula 8,8 g/dl menjadi 9,9 g/dl. Pemberian buah pisang ambon 2 kali sehari pagi dan sore selama 7 hari bersamaan dengan mengkonsumsi tablet Fe mampu menaikkan kadar Hb ibu hamil trimester III dengan anemia.
Penurunan Intensitas Rasa Haus Pasien Penyakit Ginjal Kronik Yang Menjalani Hemodialisa Dengan Menghisap Es Batu
Authors: Dewi Riana , Mustofa Akhmad 
Published: August 2021

Penyakit ginjal kronik adalah gangguan fungsi pada ginjal yang bersifat progresif dan tidak dapat pulih kembali, dimana tubuh tidak mampu memelihara metabolisme, keseimbangan cairan, dan elektrolit yang berakibat pada peningkatan ureum. Terapi pengganti pada penyakit ginjal kronik (PGK) yang banyak dipilih yaitu hemodialisis. Pasien yang menjalani hemodialisis sering merasakan haus akibat adanya program pembatasan cairan yang dianjurkan. Menghisap es batu merupakan salah satu dari banyak metode manajemen rasa haus pada pasien PGK. Tujuan studi ini adalah menganalisis intervensi menghisap es batu terhadap penurunan intensitas rasa haus pada pasien PGK. Penerapan studi kasus ini menggunakan pendekatan asuhan keperawatan dengan mengaplikasikan evidence based practice nursing pada dua pasien PGK yang menjalani hemodialisis. Hasil pemberian intervensi terjadi penurunan intensitas rasa haus. Hasil penerapan menunjukkan intensitas rasa haus turun dari intensitas sedang ke intensitas ringan. Intervensi ini dapat menjadi salah satu manajemen terapi yang dapat diaplikasikan untuk mengurangi keluhan rasa haus baik di rumah maupun di rumah sakit.
Keterampilan Berpikir Kritis dalam Pembelajaran Berbasis Masalah Berbantuan Situs Jejaring Sosial Edmodo
Authors: Rosiyanah Siti 
Published: August 2021

Perkembangan teknik informatika dan komputer (TIK) yang semakin pesat membawa dampak terhadap dunia pendidikan saat ini. Perubahan paradigma pendidikan yang dulunya menganut teacher-centered learning menjadi student-centered learning, membawa perubahan yang sangat signifikan terhadap metode-metode pembelajaran yang dikembangkan saat ini. Penelitian ini bertujuan untuk mengetahui keefektifan model pembelajaran berbasis masalah berbantuan situs jejaring sosial Edmodo terhadap keterampilan berpikir kritis dan hasil belajar peserta didik. Penelitian ini dilakukan di kelas VIII SMP Negeri 6 Jepara pada semester gasal Tahun Pelajaran 2019/2020 pada materi tekanan dan penerapannya dalam kehidupan sehari-hari. Desain penelitian yang digunakan adalah pre-test and post-test control group design. Pengambilan data dilakukan dengan metode observasi, dokumentasi, dan tes. Hasil penelitian menunjukkan bahwa nilai thitung keterampilan berpikir kritis dan hasil belajar peserta didik > nilai ttabel (1,99). Nilai thitung keterampilan berpikir kritis dan hasil belajar secara berturut-turut adalah 11,12 dan 2,757. Hasil penelitian menyimpulkan bahwa model pembelajaran berbasis proyek berbantuan situs jejaring sosial Edmodo efektif untuk meningkatkan keterampilan berpikir kritis dan hasil belajar peserta didik. Hasil penelitian menyimpulkan bahwa model pembelajaran berbasis masalah berbantuan situs jejaring sosial Edmodo efektif untuk meningkatkan keterampilan berpikir dan hasil belajar peserta didik.
The Effectiveness of Hybrid Learning in Improving of Teacher-Student Relationship in Terms of Learning Motivation
Authors: Aristika Ayu , Darhim . , Juandi Dadang , Kusnandi . 
Published: August 2021

The Advanced Mathematical Thinking (AMT) ability is one of the prioritized mathematical abilities needed to be developed in learning mathematics during tertiary education. The present study sought to test the effectiveness of hybrid learning in improving students' advanced mathematical thinking. The research used a quasi-experimental design with a non-equivalent control group design. The subject of this study was students of a mathematics education study program at a university in Bandung who attended lecture for the multi-variable in a calculus course. The sampling technique used was purposive sampling. Of the many variable calculus classes consisting of 2 classes, one class was chosen as the experiment group and the other class as the control group. The sample consists of 40 people for each group. Data analysis used the MANOVA test with normality and homogeneity tests as a prerequisite test. The results showed a difference in AMT's significance between the hybrid learning and conventional groups, where hybrid learning had a higher AMT. Other than that, there is a difference in the significance of AMT between the high motivation group and the low motivation group, where high motivation has a higher AMT, and there is an interaction of learning models and motivational factors to increase AMT. Doi: 10.28991/esj-2021-01288 Full Text: PDF
Confidence Intervals for the Coefficient of Quartile Variation of a Zero-inflated Lognormal Distribution
Authors: Yosboonruang Noppadon , Niwitpong Sa-Aat 
Published: August 2021

There are many types of skewed distribution, one of which is the lognormal distribution that is positively skewed and may contain true zero values. The coefficient of quartile variation is a statistical tool used to measure the dispersion of skewed and kurtosis data. The purpose of this study is to establish confidence and credible intervals for the coefficient of quartile variation of a zero-inflated lognormal distribution. The proposed approaches are based on the concepts of the fiducial generalized confidence interval, and the Bayesian method. Coverage probabilities and expected lengths were used to evaluate the performance of the proposed approaches via Monte Carlo simulation. The results of the simulation studies show that the fiducial generalized confidence interval and the Bayesian based on uniform and normal inverse Chi-squared priors were appropriate in terms of the coverage probability and expected length, while the Bayesian approach based on Jeffreys' rule prior can be used as alternatives. In addition, real data based on the red cod density from a trawl survey in New Zealand is used to illustrate the performances of the proposed approaches. Doi: 10.28991/esj-2021-01289 Full Text: PDF
Cañoneo auto desprendible, análisis de presión y caudal transiente, en la optimización de la completación inicial y producción definitiva de pozos
Authors: Dorian Jaramillo 
Published: August 2021

Se presenta una iniciativa operativa para la completación y evaluación inicial de reservorios que utiliza los conceptos del análisis de declinación de presión y caudal transiente para el cálculo del potencial de pozo y solicitud de tasa al Ministerio de Energía y Recursos Naturales No Renovables (MERNNR) sin la necesidad de realizar una prueba de restauración de presión y reduciendo el tiempo para la puesta en producción definitiva. El procedimiento se basa en el uso de cañones auto desprendibles, BHA’s con equipos BES y sensores de presión con transmisión a tiempo real. Previo a la activación de los cañones, se desplaza la BES, se evacua el fluido para generar el “Bajo Balance” y una vez que los cañones se activen, el pozo entra en fase de surgencia y por equilibrio hidrostático se alcanza condiciones cercanas a la presión estática de reservorio. Luego de 12h del cañoneo, se enciende el equipo BES a frecuencia y con parámetros de superficie constantes. Los datos de presión y caudal permiten calcular el potencial de pozo. El uso de tecnologías de cañoneo auto desprendible y equipos BES con sensores de presión y monitoreo en “real time”, permite diseñar una propuesta diferente para la evaluación inicial de pozos, previo a la solicitud de fijación de tasa por parte del MERNNR en el Ecuador. La propuesta tradicional incluía el uso de BHA’s de evaluación con bomba jet más el uso de memorias para el Build Up. Bajo esta metodología se lograba estimar el potencial del pozo antes de bajar completación definitiva (BES en la mayoría de los casos). El tiempo promedio transcurrido entre la terminación del registro de cemento y la puesta en producción definitiva era de +/- 16 días asumiendo que se usa el mismo equipo de perforación en la completación lo cual resulta costoso. En el caso de usar un Rig de Reacondicionamiento para la fase de completación, se debe considerar el tiempo asociado al cambio de Rig (+/- 15 días). El objetivo de ENAP desde el 2018 fue optimizar los tiempos de completación y determinar el potencial del pozo para obtener la fijación de tasa por parte del MERNNR. El resultado obtenido permitió reducir a 7 días el tiempo entre la culminación del registro de cemento y la puesta en producción definitiva
Modelos de depósitos tipo VHMS para las divisiones de la Cordillera Real: Alao y Salado
Authors: Calero-Gómez Kevin , Albacura-Chuquín Laura , Solano-Yépez Stalin , Viteri-Santamaría Francisco 
Published: August 2021

La Cordillera Real comprende terrenos alóctonos y autóctonos acrecionados al continente, representados de oeste a este por las divisiones litotectónicas Guamote, Alao, Loja, Salado y Zamora. En este estudio se realiza la identificación de los posibles depósitos tipo VHMS (Sulfuros Masivos Volcanogénicos) relacionados a las divisiones Alao y Salado, basado en estudios previos de petrología, petrografía y evolución de estas divisiones. Los parámetros que se utilizaron para comparar los tipos de modelos VHMS con los posibles depósitos de las divisiones mencionadas son: entorno geológico y tectónico, rocas encajantes, características texturales y mineralógicas de los cuerpos masivos, alteración y características geoquímicas. De esta manera se puede establecer que los depósitos de la Unidad Peltetec no se asocian a modelo alguno de depósitos VHMS, al existir diferencias con respecto a la litología y geoquímica. Por el contrario, el modelo asociado a un depósito VHMS tipo Kuroko coincide con las características de un depósito VHMS en la Unidad Alao-Paute. A su vez se asoció depósitos de la División Salado a un depósito de VHMS tipo Besshi, al encontrar similitudes en cuanto al entorno geológico-tectónico, mineralogía y semejanza de las huellas geoquímicas, sin embargo, las características de formación y evolución de la División Salado ha dificultado el desarrollo completo de estos VHMS tipo Besshi, pero no se descarta la existencia de los mismos.
Accumulation of photosynthetic pigments and indicators of fluorescence of chlorophyll in leaves of <i>Dioscorea alata</i> L. during vegetative reproduction of plants on ion-exchange substrates
Authors: Karasiova A. N. 
Published: August 2021

The content of photosynthetic pigments and fluorescence of chlorophylls in leaves of Dioscorea alata L. plants grown on a modified ion-exchange substrate were studied. It was found that in the variant with the addition of a fine fraction to the hydrogel substrate in an amount of 1 g/l, the Chl а content is 15 % higher than in the control. The content of Chl b and carotenoids in comparison with the control differed insignificantly. When the hydrogel was added at a concentration of 0.5 g/l, the Chl а content in all studied variants was significantly lower than the control.Based on the investigated parameters of chlorophyll fluorescence, the most favorable conditions for the productivity of photosynthesis were in the variant with the addition of 1 g of a fine fraction and illumination of DNaT-400.
Induced pluripotent stem cells. Obtaining, properties and application prospects in biology and medicine
Authors: Tishuk O. I. , Poleshko A. G. , Volotovsky I. D. 
Published: August 2021

This review dedicated to induced pluripotent stem cells discovery of which became one of the outstanding achievements of biomedical science at the beginning of 21th century. These cells are in fact a artificially induced analogue of embryonic stem cells. They are the progenitors of all cells contained in organism of animals and human. The pool of embryonic stem cells forms in fertilized cell and they are involved in extremely complex processes of organogenesis. The position of these cells in general and of induced pluripotent stem cells in particular in hierarchy of cells in organism is described.The main properties of these cells, similarities and differences between embryonic and induced pluripotent stem cells, prospects for their practical use in biology and medicine including treatment of human diseases are considered.The mechanisms of induced dedifferenciation in both unipotent cells, for example fibroblasts and keretotinocytes, and multipotent cells as hemopoetic or mesenchimal stromal stem cells are described.In this review the information on used in the world approaches for obtaining of induced pluripotent stem cells is presented, the ways of reprogramming different in the methods of delivery of genetic material into the cells and conditions of their cultivation during dedifferentiation process and efficacy. As an example, description of all dedifferentiation cycle of human fibroblasts in induced pluripotent stem cells is provided. Besides, the data on unique properties of induced pluripotent stem cells what allowed to study ontogenesis processes, pathophysiology of various diseases both in vitro and in animals' models to be obtained using induced pluripotent stem cells and also on approaches of these cells application for medicine screening when they are synthesized and tested are given.