bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling the mass transfer processes in the growth of KDP crystals from solution
Authors: Verezub N. A. , Manomenova V. L. , Prostomolotov A. I. 
Published: June 2019

Finding the conditions of high-speed single crystal growth with an appropriate quality is a priority for the industrial production of crystalline materials. Crystals of potassium dihydrogen phosphate (KDP) are important optical materials, they are grown from an aqueous solution and an increase in the rate of growth and quality of a single crystal is of great practical importance.In this paper, mathematical simulation of hydrodynamic and mass transfer processes in growing KDP crystals is performed. The flow and mass transfer are modeled within the framework of continuous medium, which is considered as an aqueous solution of a special salt — potassium dihydrogen phosphate. This salt dissolves in water to a saturation level at a high temperature. Then, such supersaturated solution is used to grow crystals at lower temperatures in non-flowing and flowing crystallizers. The mathematical model is considered in a conjugate formulation with allowance for mass transfer in the«solution—crystal» system. Local features of hydrodynamics and mass transfer in a solution near the surface of a growing crystal are determined, which can affect on the local (for a particular place and direction) crystal growth rate and the formation of defects. The requirements to the crystallizers that provide the «necessary» hydrodynamics in the solution are discussed. Its validation is shown for the flow around a long horizontal plate simulating the growing facet of the crystal. The rate of precipitation of salt was evaluated by the proposed mathematical model, which matches the calculation of solution flow according to the Navier-Stokes equations for an incompressible fluid with a thermodynamic condition for the normal growth of a face under conditions of two-dimensional nucleation. The action of the flowing crystallizers was analyzed for various solution inflows (axial and ring) and its outflow through the axial bottom hole.
The getters in silicon
Authors: Kharchenko V. A. 
Published: June 2019

The processes of gettering of fast-diffusing metal impurities and structure defects in silicon, mainly used in the production of integrated circuits, power high-voltage devices, nuclear-doped silicon, are considered. The getters based on structural defects and gas-phase getters based on chlorine-containing compounds are analyzed. It is noted that for the formation of getters on the basis of structural defects, it is necessary to create internal sources for generation of dislocations and formation of precipitate — dislocation clusters. It is shown that dislocations are generated in the mouths of microfractures, which then form a sedentary dislocation grid on the non-working side of the plates. In the second case, defects are created in the area of the plate adjacent to the active layer of the electronic component. The process of creating an internal getter is based on the decomposition of a supersaturated solid oxygen solution in silicon, due to which a complex defect medium consisting of various precipitate-dislocation clusters is formed in the crystal. The packing defect as oxide precipitate with a cloud of Frank’s loops is formed. Two variants of creating an internal getter are considered — first is associated with the distillation of an oxygen impurity from the near-surface region of the plate, the second is associated with a fine adjustment of the distribution of vacancies along the plate thickness. The analysis of the influence of the getter as the defect structure reducing the magnitude of mechanical stress of the beginning of the generation of dislocations, which ultimately can determine the mechanical strength of the silicon wafer.This paper also considers the mechanism of gas-phase medium impurities and defects gettering with the addition of chlorine-containing compounds. It is shown that at elevated temperatures, due to the interaction of silicon atoms with chlorine in the near-surface region of the plate, it is possible to create vacancies that penetrate the sample volume with some probability. As a result, the case DСv > 0, DCi £ 0 is realized, that leads to a change in the composition of microdefects and their density. The examples of practical application of heat treatment in chlorine-containing atmosphere silicon wafer during application of the oxide film, in the case of the target the need for dissolution of the microdefects and of the withdrawal of fast diffusing impurities from the crystal volume, and to prevent the formation of generation-recombination centers in the manufacturing process of devices and in a nuclear doping silicon.
Contribución antropogénica a cambios geomorfológicos en una laguna costera tropical
Authors: Carrasco Navas-Parejo Juan Carlos , Benavente González Javier , Gomez-Enri Jesús , Caviedes Sánchez Verónica 
Published: June 2019

El objetivo principal de este trabajo ha sido analizar las tasas recientes de progradación y retroceso del delta interior en la laguna de Los Micos, ubicada en el Caribe de Honduras, y determinar los factores antropogénicos y meteorológicos que han contribuido a la acelerada formación deltaica y los potenciales efectos sobre el sistema físico natural. Para ello, se han generado polígonos a partir de imágenes de satélite de la misión Landsat tomadas en los años: 1984, 1999, 2010 y 2014. Se han calculado las áreas de los polígonos y se ha analizado su evolución temporal. Se ha observado una tasa de progradación del delta de 38,45 m∙a-1, lo cual ha provocado una pérdida de superficie lagunar de ̴ 6,77 ha∙a-1, como resultado del cambio de uso del suelo en la cuenca hidrográfica y los efectos de eventos meteorológicos severos como el Huracán Mitch.
INFLUENCE OF PULMONARY DENERVATION ON THE MECHANICAL FUNCTION OF THE RIGHT HEART CHAMBERS IN PATIENTS WITH PULMONARY HYPERTENSION
Authors: Mamchur S. E. , Tokmakov E. V. , Nagirnyak O. A. , Khomenko E. A. , Chichkova T. Y. , Romanova M. P. , Mamchur I. N. 
Published: June 2019

Aim. To estimate mechanical function of the right heart chambers after the pulmonary denervation in comparison with the sham procedure using right heart catheterization (RHC) and echocardiography.Methods. Twelve patients with different clinical types of pulmonary hypertension were included in the study. All patients were randomized into two groups: Group I patients (n = 6) underwent the pulmonary denervation, Group II patients (n = 6) had sham procedure. All the patients had functional class 3 pulmonary hypertension. The patient screening was performed using echocardiography findings, and the final decision was made after RHC. After including in the study the RHC was done three times: before the procedure, immediately after it, and on the 12th months of the follow-up. Echocardiographic measurement of the right heart parameters was performed four times: a day before the procedure, immediately after it, on the 5th day and on the 12th months of the follow-up.Results. No complications during the procedure and the follow-up were registered. There were no statistically significant differences in any of the RHC parameters between groups at the second and the third control points. The same findings were determined after echocardiographic analysis.Conclusion. Pulmonary denervation does not have statistically significant effect on the mechanical function of the right heart chambers within the 12-months follow-up.
THE ROLE OF HYPOVOLEMIA AND HEMOREOLOGICAL CHANGES IN THE PATHOGENESIS OF SYSTEMIC CIRCULATION DISEASES IN THE POSTRESUSCITATION PERIOD OF ACUTE MYOCARDIAL INFARCTION
Authors: Lisachenko G. V. , Budaev A. V. , Bannih S. V. 
Published: June 2019

Aim. To determine the role of volume imbalance and alterations in the rheological properties of blood in the pathogenesis of postresuscitation hemocirculatory disorders in dogs after clinical death due to acute myocardial infarction.Methods. Changes in systemic hemodynamics, volume and dynamic viscosity of circulating blood within a 5-minute period after clinical death due to myocardial infarction were evaluated in a dog model. 152 dogs received pentobarbital anesthesia.Results. In the early postresuscitation period after myocardial infarction dogs developed phase changes in systemic hemodynamics, volume and dynamic viscosity of circulating blood with an increase in the target indicators, followed by their decrease and final normalization as compared to the baseline. The development of postresuscitation systemic hyperperperfusion (1–3 min) was associated with significantly increased blood volume and its components. The subsequently decreased perfusion volume (5–30 min) was caused by depressed contractile function of the heart. The further progression (1–9 hours) of the hypoperfusion syndrome was mainly attributed to hypovolemia, increased dynamic viscosity of the blood and the viscoelastic properties of the red blood cells. The contribution of heart rhythm disturbances (polytopic ventricular extrasystoles) to the development of circulatory failure 4–5 hours after the successful resuscitation was determined. The subsequent hemodynamic improvements were associated with the normalization of the circulating plasma volume and hemorheological properties of the blood.Conclusion. Staged disorders of the systemic circulation formed in the recovery period after clinical death following acute myocardial infarction. They were accompanied by the alterations in the volume and dynamic viscosity of the circulating blood. Immediately after the revival, elevated values of the hemodynamic parameters were attributed to the increased blood flow as well as to the increased in plasma and globular components. The initial (5–30 min) decrease in the cardiac output was caused by impaired myocardial contractility. After a recovery period of 1–9 hours, a progressive decrease in the perfusion volume demonstrated a direct linear relationship with a deficit of blood flow and its plasma component. Heart rhythm disturbances contributed to the development of insufficient blood circulation in the 4–5-hour recovery period. Thus, hypovolemia and the hyperviscous syndrome associated with it significantly contributed to the development of insufficient systemic circulation within the 1–9-hour recovery period after clinical death provoked by myocardial infarction.
BIODEGRADABLE VASCULAR GRAFT REINFORCED WITH A BIODEGRADABLE SHEATH
Authors: Antonova L. V. , Krivkina E. O. , Rezvova M. A. , Sevost'yanova V. V. , Mironov A. V. , Glushkova T. V. , Klyshnikov K. Yu. , Ovcharenko E. A. , Kudryavceva Yu. A. , Barbarash L. S. 
Published: June 2019

Background. Tissue-engineered vascular grafts can be reinforced by a biostable or biodegradable polymer sheath. A combination of electrospinning, routinely used for fabrication of biodegradable tubular grafts, and the layer-by-layer coating allows forming a polymeric sheath ensuring long-term integrity and high biocompatibility of the vascular grafts after the implantation. Aim To evaluate mechanical properties and in vivo performance of biodegradable small-diameter vascular grafts with a reinforcing sheath.Methods. Tubular grafts (4 mm diameter) were fabricated from poly(3-hydroxybutyrate-co3-hydroxyvalerate) and poly(ε-caprolactone) by emulsion electrospinning with the incorporation of vascular endothelial growth factor (VEGF) into the inner third of the graft and basic fibroblast growth factor (bFGF) along with stromal cell-derived factor-1α (SDF-1α) into the outer two thirds of the graft wall. Poly(ε-caprolactone) sheath was formed by the layer-by-layer coating. Upon graft fabrication, scanning electron microscopy was performed to assess the grafts’ surface, tensile testing allowed evaluating mechanical properties. The samples were implanted into the ovine carotid artery (n = 5 animals) for 12 months with the subsequent histological examination.Results. Sintering temperature of 160°C during the extrusion allowed effective and delicate merging of poly(ε-caprolactone) coating with the outer surface of the poly(3hydroxybutyrate-co-3-hydroxyvalerate)/poly(ε-caprolactone) tubular graft. The thickness of poly(ε-caprolactone) fiber was 380–400 μm, the increment of the reinforcing filament was 1 mm. The reinforcing sheath led to a 3-fold increase in durability and elastic modulus of the vascular grafts. At the 12-months follow-up, the grafts reported retained integrity. No signs of inflammation or calcification were found.Conclusion. The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(ε-caprolactone) vascular grafts with hierarchically incorporated growth factors and the reinforced poly(ε-caprolactone) spiral sheath demonstrated improved mechanical properties while retaining integrity and high biocompatibility after the long-term implantation into the ovine carotid artery.
Experimental study of possible development of abstinence syndrome after long use of energetic drinks
Authors: Zenkova E. A. 
Published: June 2019

Aim. To study in experiment the possible syndrome of withdrawal after a 30-day peroral use of energetic drinks.
Materials and methods.In the groups of laboratory animals, who had caffeine solution (CS) and energetic drink (ED), as the only source of drinking in free access so as to form a stable use, and in the control group of rats, who received purified water (duration of experiment – 4 weeks), one day after the withdrawal there were studied body mass indices, behavioral functions (cognitive processes, anxiety, behaviour) and rectal temperature.
Results. The 1.5-2-fold reduction of motor activity in white rats was established; it was reflected in decreased number of postures and crossed squares in the device “open field”.The increase in anxiety level against the background of energetic drink withdrawal was detected in “dark-light camera” with perforations. At the same time, no changes in motor activity and anxiety level were registered in the group of caffeine users. The following characteristic features of withdrawal syndrome as tooth chatter and gnashing, shaking arms and pads, ptosis, were registered in 87.5 %, 75 % and 37.5 %, respectively, in the group of energetic drink users, and 14.3 %, 42.9 %, 28.6 % in the group of caffeine solution users. During a 30-day period of using energetic drink by white rats, there was observed a negative dynamics of their weight.
Conclusions. The decrease in motor activity, increase in anxiety level and presence of a number of signs, does not allow excluding the presence of withdrawal syndrome after a long use of energetic drinks, and in most cases, expression of the signs of withdrawal syndrome exceeds that of caffeine. This fact, in our opinion, needs more detailed studying.
Trypanosoma evansi and “Candidatus Mycoplasma haemolamae” Co-Infection in One-Humped Camel (Camelus dromedarius) from the Northwest of Iran: A Case Report
Authors: ESMAEILNEJAD Bijan , SAADI Aram , DALIR-NAGHADEH Bahram , SAMIEI Awat , MOHAMMADI Vahid , PIRNEJAD-TALATAPEH Ali , EHTESHAMFAR Shahin 
Published: June 2019

A 4-year-old male one-humped camel (Camelus dromedarius) was referred to Veterinary Teaching Hospital of Urmia University, Iran in 2017 with anorexia, weakness, depression and pale mucosa. Decreased red blood cell count, packed cell volume and hemoglobin concentration were detected by complete blood cell count. In Giemsa-stained peripheral blood smears Trypanosoma spp. trypomastigotes scattered between erythrocytic spaces and Mycoplasma-like organisms were observed attached to the surface of erythrocytes. Species-specific PCR assay confirmed T. evansi and Candidatus Mycoplasma haemolamae (CMhl) co-infection. Administration of diminazene aceturate, oxytetracycline 20%, flunixin meglumine and phosphorus-vitamin B12 were not effective in treatment. Hemoplasmosis should be considered as an important differential diagnosis of conditions associated with hemolytic anemia in camel.
HANNAH ARENDT E A QUESTÃO NEGRA NA DESSEGREGAÇÃO DA ESCOLA DE LITTLE ROCK, 1957
Authors: Briskievicz Danilo Arnaldo , Ferreira Amauri Carlos 
Published: June 2019

RESUMO. O objetivo deste artigo é discutir o caso de dessegregação racial educacional acontecido na capital do Arkansas, Little Rock, nos Estados Unidos da América, em 4 de setembro de 1957. Para iluminar o contexto social e político das discussões sobre o polêmico caso, retomamos o controverso ensaio de Hannah Arendt publicado em 1959, intitulado Reflexões sobre Little Rock. Contamos, brevemente, a luta dos movimentos sociais norte-americanos ligados à questão negra até o caso Little Rock. Apresentamos variadas relações entre o caso Little Rock e algumas categorias do pensamento arendtiano como igualdade de direitos, mundo comum, responsabilidade, ação, discurso, visibilidade e crise do mundo moderno. Esclarecemos que o mundo comum é uma história comum tecida como resultado da ação e do discurso, em que os agentes se revelam pela palavra, pela voz e pelo gesto. Por fim, evidenciamos que duas mulheres foram escolhidas para narrar Little Rock: Elizabeth Eckford, a estudante de 15 anos que foi hostilizada publicamente e teve seu gesto imortalizado numa fotografia; e outra, Hannah Arendt. A imagem de Eckford foi republicada em diversos jornais, foi vista por Hannah Arendt que reconheceu Little Rock como um caso emblemático para a política e escreveu seu artigo. ABSTRACT. The purpose of this article is to discuss the case of educational racial desegregation that took place in Arkansas, Little Rock, United States of America, on September 4, 1957. To illuminate the social and political context of the controversial case, we resume the controversial essay by Hannah Arendt published in 1959, entitled Reflections on Little Rock. We briefly recount the struggle of the American social movements linked to the black issue until the Little Rock case. We present various relationships between the Little Rock affair and some categories of Arendtian thought as equal rights, common world, responsibility, action, discourse, visibility and crisis of the modern world. We clarify that the common world is a common history woven as a result of action and discourse, in which agents are revealed by word, voice and gesture. Finally, we note that two women were chosen to narrate Little Rock: Elizabeth Eckford, the 15-year-old student who was publicly harassed and had her gesture immortalized in a photograph; and another, Hannah Arendt. The Eckford’s image was republished in several newspapers, was seen by Hannah Arendt who recognized Little Rock as an emblematic case for politics and wrote her article.
FOTOCATÁLISE HETEROGÊNEA APLICADA NO TRATAMENTO DO CORANTE RODAMINA B – USO DE CATALISADOR DE TIO2 SOB RADIAÇÃO UV
Authors: Bellido Jorge David Alguiar , Almeida Maysa Martins , Cotta Anna Luisa Silva , Júlio Júlia Paula Oliveira , Vaz Carlos Alberto Santos 
Published: June 2019

Resumo: Os efluentes dos processos de tingimento na indústria têxtil apresentam uma complexa composição, incluindo principalmente corantes de diferente natureza química, portanto o tratamento destes tem como finalidades necessárias a remoção da cor e a degradação dos compostos orgânicos presentes. Dessa forma, este projeto teve por objetivo apresentar uma alternativa frente ao descarte de efluentes têxteis, usando como modelo o corante rodamina B, um corante resistente à fotodegradação natural. O projeto consistiu na construção de um reator fotocatalítico usando uma placa de vidro jateada e impregnada com catalisador de TiO2. Essa placa foi fixada com inclinação estabelecida. Além disso, foram utilizadas duas lâmpadas germicidas de radiação UV e potência de 15 W. Foram analisados a influência da concentração inicial, tempo de residência no reator e pH da solução para remoção de cor do corante. A descoloração da solução foi acompanhada pela medida da absorbância das amostras coletadas durante o ensaio. A eficiência do reator foi avaliada em relação à descoloração da solução. Os melhores resultados foram obtidos para uma solução de 7,80 mg L-1 a pH 5.0 foi tratada por 430 min alcançando um 97,84% de descoloração. AbstractThe effluents from the dyeing processes in the textile industry have a complex composition, including mainly dyes of different chemical nature, so the treatment of these has the necessary purposes of removing the color and the degradation of the organic compounds present. In this way, this project aimed to present an alternative to the disposal of textile effluents, using as a model the rhodamine B dye, a dye resistant to natural photodegradation. The project consisted in the construction of a photocatalytic reactor using a blasted glass plate and impregnated with TiO2 catalyst, It was fixed in a pre-established inclination, besides that, two germicide UV lamps at 15 W were employed. The influence of the initial concentration, residence time in the reactor and pH of the solution for color removal of the dye were analyzed. Solution discoloration was followed by absorbance measurement of the sample solution collected along the assay. The reactor efficiency was evaluated in relation to the discoloration of the sample solution. Best results were achieved when a solution of 7.80 mg L-1 at pH 5.0 was treated for 430 min reaching 97.84% of discoloration.
UMA ABORDAGEM CONSTRUTIVISTA NO ENSINO DE ALGORITMOS E LÓGICA DE PROGRAMAÇÃO COM O AUXÍLIO DE UMA FERRAMENTA GAMIFICADA
Authors: Perlin Rodrigo , Macedo Ricardo Tombesi , Silveira Sidnei Renato 
Published: June 2019

Ao analisar os esforços para apoiar os processos de ensino e de aprendizagem de algoritmos e lógica de programação, encontram-se estudos envolvendo a aplicação de diferentes ferramentas, tais como o Scratch e o Algo+. Além disso, existem trabalhos que propõem uma reorganização dos conteúdos e a aplicação de metodologias de ensino inovadoras. Nesse contexto, este artigo propõe uma abordagem para apoiar os processos de ensino e de aprendizagem de algoritmos e lógica de programação baseada na teoria construtivista, utilizando a ferramenta P.e.p.y, a qual implementa o conceito de gamificação. Para validar essa proposta, bem como a ferramenta desenvolvida, foi realizado um estudo de caso. A aplicação dos instrumentos no início e no final do estudo de caso, apontam percentuais elevados de compreensão dos conceitos de lógica de programação e da linguagem de programação Python. Os resultados apontam que a aplicação da ferramenta auxiliou os alunos a desenvolver o pensamento computacional, uma área que vem sendo estimulada pela SBC (Sociedade Brasileira de Computação) e que a abordagem proposta estimula os processos de ensino e de aprendizagem por meio da ferramenta P.e.p.y. AbstractBy analyzing efforts to support learning process applied to logic and programming courses, there are studies involving the employment of different tools, such as Scratch and Algo+. Besides, there are works proposing the content reorganization and the employment of innovative teaching methodologies. In this context, this paper proposes an approach to support algorithms learning process based on constructivist theory through the use P.e.p.y tool, which implements the gamification concept. In order to validate this proposal, as well as the implemented tool, it was performed a case study. The instruments application in the beginning and in the end of the case study indicates elevated perceptual of comprehension of logic and Python programming languages concepts. Results indicate that the tool application supported students to develop the computational thinking, a field highly stimulated by the SBC, the Brazilian Computing Society, and that the proposed approach stimulates the learning processes through the P.e.p.y tool employment.