Evaporation induced flow inside circular wells

Flow field and height averaged radial velocity inside a droplet evaporating in an open circular well were calculated for different modes of liquid evaporation.Comment: 5 page, 3 figures, submitted to European Physical Journal

Interest to future professional activity as category of pedagogics

The aim of the investigation is to study the interest to future professional activity of students of higher education institution of physical culture. Methods. The methods involve theoretical analysis of psychology and pedagogical literature; a method of the system description. Results. The various points of view concerning a phenomenon of interest and different lines of thought to definition of essence and structurization of interest to professional work are considered. Scientific novelty. The concept «interest in future professional activity» as important component of a professional orientation of the identity of the student is defined; it includes three components: cognitive, emotional and behavioural. Practical significance. The research implications can be useful while developing of pedagogical conditions on formation of students’ interest in future professional activity Целью представленного в статье исследования было изучение интереса к будущей профессиональной деятельности у студентов вуза. Методы, использованные в работе, – теоретический анализ психолого-педагогической литературы и системное описание. Результаты. Рассмотрены различные точки зрения по поводу феномена интереса и разные подходы к определению сущности и структурированию интереса к профессиональной деятельности. Научная новизна исследования состоит в том, что в качестве важной составляющей профессиональной направленности личности студента уточнено понятие «интерес к будущей профессиональной деятельности», определена его структура, включающая три компонента: когнитивный, эмоциональный и поведенческий. Практическая значимость исследования состоит в разработке педагогических условий формирования интереса у студентов к будущей профессиональной деятельности

Internal scheme of the body assessment in an experiment with environmental uncertainty

The aim of the work was to analyze the influence of various environmental factors forming environmental uncertainty on the nature of the transformation of the "internal scheme of the body". Materials and methods. For the study, a group of healthy volunteers (n = 90) was selected. The results in this paper are median, 75 and 25 percentiles (Me [UQ / LQ]). The study was conducted in several stages. At the first stage, the criteria for excluding potential participants from the experiment were formed. At the second stage of the study, a video analysis of the main anatomical orientations of the pelvic region in static and dynamic samples was conducted for all participants. Conclusion. In the course of the study, specific patterns of spatial deviations of biomechanical blocks of the pelvic region were established, triggered by changes in the qualitative and quantitative parameters of the external environment. So, in conditions of static equilibrium, coordination is activated with involvement of the anterior and posterior half-rings of the pelvis (frontal biomechanical blocks); in conditions of dynamic equilibrium, diagonal biomechanical blocks of the pelvic region are activated; in conditions of deprivation of visual afferentation, the compensatory reactions of the lateral semirings of the pelvic region (lateral biomechanical blocks) are formed

Классификация криогенно-оползневых форм рельефа для целей картографирования и прогноза

A classification of cryogenic-landslide landforms is developed for mapping their distribution and dynamics. It is based on the previously suggested classification subdividing cryogenic landsliding into two main types: cryogenic translational landslides (or active-layer detachment slides), and cryogenic earth flows (or retrogressive thaw slumps). The increased proportion of retrogressive thaw slumps compared to active layer detachments in the North of West Siberia in the last decade creates the need for an expanded classification of cryogenic earth flows. One of the important issues is separating the process of landsliding and resulting landforms, which in English are covered by one term ‘retrogressive thaw slump’. In dealing with the landforms, we distinguish (1) open and (2) closed ones. Open cryogenic-landslide landforms are those formed by the retreating of the coast bluff due to the thaw of ice or ice-rich deposits with an additional impact from wave or stream action. Closed cryogenic-landslide landforms are those initiated on a slope landward, and thawed material is delivered to the coast or stream through an erosional channel. Morphologically we distinguish thermocirques and thermoterraces depending on the shape of the retreating headwall, crescent or linear, respectively. An important issue is the type of ground ice subjected to thaw: tabular, ice-wedge or constitutional ground ice are distinguished. Landforms can be active, stabilized or ancient. One can find both single landforms and their combination. The classification is based on a significant amount of field studies and interpretation of remote sensing data. Mapping of the cryogenic-landslide landforms is suggested using the proposed classification and indication features. The classification is based on the experience obtained mainly in the north of West Siberia. Applying it to other regions may require additional studies.Разработана классификация криогенно-оползневых форм рельефа, сформированных криогенными оползнями течения (КОТФР), для картографирования их распространения и динамики. В основе лежит значительный объем полевых исследований и интерпретации данных дистанционного зондирования Земли. Классификация включает генетические, морфологические и криолитологические особенности пород, определяющие морфологию и динамику КОТФР, их положение в рельефе, степень их активности, сочетание и комплексирование единичных КОТФР. Предложенная классификация и индикационные признаки используются для картографирования КОТФР на севере Западной Сибири

Correlation effects during liquid infiltration into hydrophobic nanoporous mediums

Correlation effects arising during liquid infiltration into hydrophobic porous medium are considered. On the basis of these effects a mechanism of energy absorption at filling porous medium by nonwetting liquid is suggested. In accordance with this mechanism, the absorption of mechanical energy is a result expenditure of energy for the formation of menisci in the pores on the shell of the infinite cluster and expenditure of energy for the formation of liquid-porous medium interface in the pores belonging to the infinite cluster of filled pores. It was found that in dependences on the porosity and, consequently, in dependences on the number of filled pores neighbors, the thermal effect of filling can be either positive or negative and the cycle of infiltration-defiltration can be closed with full outflow of liquid. It can occur under certain relation between percolation properties of porous medium and the energy characteristics of the liquid-porous medium interface and the liquid-gas interface. It is shown that a consecutive account of these correlation effects and percolation properties of the pores space during infiltration allow to describe all experimental data under discussion

Защитные свойства Zr-содержащих конверсионных покрытий на цинке

The aim of the study is to develop an environmentally friendly chromium-free passivation technology for galvanized steel. Passivation of zinc coatings was carried out by deposition of conversion coatings from solutions containing ZrO(NO3)2, Na2SiF6 and oxidizer H2O2 or K2S2O8. The effect of the solution pH, the concentration of Na2SiF6 and the type of oxidizer on the protective properties of coatings was studied by the drop method and electrochemical method of linear voltammetry in 3 % NaCl using the full factor experiment 23 . The main effects and effects of the interaction of the studied factors for the darkening time of the droplet and the dissolution potential of zinc are calculated. The solution pH in the presence of the oxidizing agent K2S2O8 influences the both parameters in the most extent. Concentration of Na2SiF6 has a significant effect on the dissolution potential of zinc and the least effect on the darkening time of the droplet. An increase in the solution pH and the concentration of Na2SiF6 increases the protective properties of the coatings. Measurements of the mass loss and open circuit potential during the resource testing of conversion coatings in 3% NaCl showed an increase in the corrosion rate over time.Цель исследования − разработка экологически безопасной бесхромовой технологии пассивации гальванически оцинкованной стали. Пассивация гальванических цинковых покрытий проводилась осаждением на них конверсионных покрытий из растворов, содержащих ZrO(NO3)2, Na2SiF6 и окислитель H2O2 или K2S2O8. Изучалось влияние pH раствора, концентрации Na2SiF6 и типа окислителя на показатели защитных свойств покрытий методом капли и электрохимическим методом линейной вольтамперометрии в 3 %-ном NaCl с использованием полного факторного эксперимента 23 . Рассчитаны главные эффекты и эффекты взаимодействия исследованных факторов для времени потемнения капли и потенциала растворения цинка. Наибольшее влияние на оба показателя оказывает pH раствора в присутствии окислителя K2S2O8. Концентрация Na2SiF6 оказывает значительное влияние на потенциал растворения цинка и наименьшее влияние на время потемнения капли. Увеличение pH раствора и концентрации Na2SiF6 увеличивает показатели защитных свойств покрытий. Измерения потери массы и потенциала разомкнутой цепи в процессе ресурсных испытаний конверсионных покрытий в 3 %-ном NaCl показали возрастание скорости коррозии со временем

Evidence of a Louse-Borne Outbreak Involving Typhus in Douai, 1710-1712 during the War of Spanish Succession

Background: The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. Methods: We identified a mass grave in Douai, France dating from the early XVIII th century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. Results and Discussion: In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XX th century. Conclusion: Louse-borne outbreaks were raging during the XVIII th century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America

Nonlinear dynamics of magnetohydrodynamic flows of heavy fluid over an arbitrary surface in shallow water approximation

The magnetohydrodynamic equations system for heavy fluid over an arbitrary surface in shallow water approximation is studied in the present paper. It is shown that simple wave solutions exist only for underlying surfaces that are slopes of constant inclination. All self-similar discontinuous and continuous solutions are found. The exact explicit solutions of initial discontinuity decay problem over a flat plane and a slope are found. It is shown that the initial discontinuity decay solution is represented by one of five possible wave configurations. For each configuration the necessary and sufficient conditions for its realization are found. The change of dependent and independent variables transforming the initial equations over a slope to those over a flat plane is found.Comment: 43 pages, submitted to Theoretical and Computational Fluid Dynamic

Adipose Tissue Serves as a Reservoir for Recrudescent Rickettsia prowazekii Infection in a Mouse Model

Brill-Zinsser disease, the relapsing form of epidemic typhus, typically occurs in a susceptible host years or decades after the primary infection; however, the mechanisms of reactivation and the cellular reservoir during latency are poorly understood. Herein we describe a murine model for Brill-Zinsser disease, and use PCR and cell culture to show transient rickettsemia in mice treated with dexamethasone >3 months after clinical recovery from the primary infection. Treatment of similarly infected mice with cyclosporine failed to produce recrudescent bacteremia. Therapy with doxycycline for the primary infection prevented recrudescent bacteremia in most of these mice following treatment with dexamethasone. Rickettsia prowazekii (the etiologic agent of epidemic typhus) was detected by PCR, cell culture, and immunostaining methods in murine adipose tissue, but not in liver, spleen, lung, or central nervous system tissues of mice 4 months after recovery from the primary infection. The lungs of dexamethasone-treated mice showed impaired expression of β-defensin transcripts that may be involved in the pathogenesis of pulmonary lesions. In vitro, R. prowazekii rickettsiae infected and replicated in the murine adipocyte cell line 3T3-L1. Collectively these data suggest a role for adipose tissue as a potential reservoir for dormant infections with R. prowazekii

Синтез и свойства новых азотсодержащих производных зерумбона

A series of potential bioactive nitrogen zerumbone derivatives by carbonyl group containing terpene ring, has been synthesized. For the first time, microwave irradiation method has been used for their preparation. The structures of the obtained compounds have been determined by 1Н NMR and IR spectroscopy.Синтезирован ряд потенциальных биологически активных азотсодержащих производных зерумбона по карбонильной группе с сохранением терпенового цикла. Впервые такой синтез проведен с использованием метода микроволнового излучения. Методами ЯМР1Н и ИК спектроскопии установлено строение полученных соединений