The Structure of Polyvinyl Alcohol Adsorption Layers at Interfaces with Benzene in Connection with Stability of Concentrated Emulsions

Determination of PV A adsorbtion on interfaces between PV A and benzene was performed. Adsorbed layers are formed under dynamic conditions emulsions were prepared by vibrocomminution and ultrasonic dispergation). Adsorbtion data are used in calculation of the area per adsorbed molecule and the thickness of interfacial adsorpbtion layers. Adsorption isotherms are compared with rheological parameters of adsorbed layers. On the basis of reported data on the distribution of adsorbed segments of PV A molecules, the interfacial thickness of the adsorbed layer is estimated to be several hundreds of A in a fo rm of gel. The formation of the gel is a result of condensation and phase deemulgation which is in agreement with a similar mechanism of gel formation in solution with diffuse distribution of polymer segments in the adsorbed layer. It is shown that at least one monolayer must cover drops of benzene in order to obtain stable emulsions. Kinetic parameters and the energy of activation of coalescence are dependent on PV A adsorption

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

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

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

Data Reduction and Error Analysis for the Physical Sciences

ABSTRACT Polycrystalline thin films (PTF) of p-WSe2, p-WS2, and p-MoSe2 have been prepared and characterized with respect to their photoelectrochemical properties, p-WS2 showed the highest open-circuit photovoltages and the highest conversion efficiencies in various redox couples. In addition, the band structure of all the films has been determined experimentally and compared to those reported for single crystals. Over the last two decades a great deal of interest has developed in the area of photoelectrochemistry, particularly in the application of photoelectrochemical systems to the problem of solar energy conversion and storage. The interest is to develop new energy sources to supplement and eventually replace fossil fuels. The first photoelectrochemical experiment was performed in 1839 by Becquerel (1), who demonstrated that a voltage and current are generated when a silver chloride electrode, immersed in an electrolytic solution and connected to a counterelectrode, is illuminated. Although the concept of a semiconductor did not exist at that time, it is now clear that the electrode which Becquerel used had semiconducting properties. In 1955, Brattain and Garett (2) used germanium as the first semiconductor electrode in photoelectrochemistry. Since then, the knowledge of semiconductors has grown steadily. Fujishima and Honda (3) were the first to point out the potential application of photoelectrochemical systems for solar energy conversion and storage. They demonstrated that the photo-oxidation of water to 02 was possible by utilizing an n-type semiconducting titanium dioxide photoanode. Since then, there has been a large and rapidly growing international interest in the study of photoelectrochemistry of semiconductors (4). The effective use of solar energy in photovoltaic or photoelectrochemical applications depends in part on the development of materials that can show high conversion efficiencies and long-term stability under operation. In ad-*Electrochemical Society Active Member. **Electrochemical Society Student Member. dition, the desirable materials should have a bandgap that closely matches the solar spectrum and be made of readily available and inexpensive materials. We have focused our attention on the transition metal dichalcogenides (e.g., WSe2, WS2, MoSe2, and others), also known as layered or d-d semiconductors. Tributsch's (5, 6) pioneering work on the use of these materials has stimulated intensive research in this area, and single Crystals of a number of materials have been studied extensively in both aqueous and nonaqueous solvents and in photovoltaic and photoelectrosynthetic cells. The advantages of using these materials are that they have bandgaps (1.1-1.6 eV) that closely match the solar spectrum and exhibit high conversion efficiencies as single crystals. In addition, they can achieve long-term stability due to the fact that the transitions are localized in the nonbonding d orbitals of the metal. These materials consist of metal dichalcogenide sandwiches (e.g., Se-W-Se) held together by van der Waals forces. The fact that there is strong covalent bonding within the layers, but only weak interactions between layers, makes these materials highly anisotropic in their properties. For example, the surface parallel to the C axis (IIC) is more conducting than the surface perpendicular to the C axis (• Therefore, edges and surface imperfections on the surface parallel to the C axis act as efficient recombination centers for photogenerated carriers or products (7

Scrub typhus ecology: a systematic review of Orientia in vectors and hosts

Abstract Scrub typhus, caused by Orientia tsutsugamushi, is an important and neglected vector-borne zoonotic disease with an expanding known distribution. The ecology of the disease is complex and poorly understood, impairing discussion of public health interventions. To highlight what we know and the themes of our ignorance, we conducted a systematic review of all studies investigating the pathogen in vectors and non-human hosts. A total of 276 articles in 7 languages were included, with 793 study sites across 30 countries. There was no time restriction for article inclusion, with the oldest published in 1924. Seventy-six potential vector species and 234 vertebrate host species were tested, accounting for over one million trombiculid mites (‘chiggers’) and 83,000 vertebrates. The proportion of O. tsutsugamushi positivity was recorded for different categories of laboratory test and host species. Vector and host collection sites were geocoded and mapped. Ecological data associated with these sites were summarised. A further 145 articles encompassing general themes of scrub typhus ecology were reviewed. These topics range from the life-cycle to transmission, habitats, seasonality and human risks. Important gaps in our understanding are highlighted together with possible tools to begin to unravel these. Many of the data reported are highly variable and inconsistent and minimum data reporting standards are proposed. With more recent reports of human Orientia sp. infection in the Middle East and South America and enormous advances in research technology over recent decades, this comprehensive review provides a detailed summary of work investigating this pathogen in vectors and non-human hosts and updates current understanding of the complex ecology of scrub typhus. A better understanding of scrub typhus ecology has important relevance to ongoing research into improving diagnostics, developing vaccines and identifying useful public health interventions to reduce the burden of the disease.</jats:p

Психологічний статус дітей з атопічним дерматитом

Purpose of the study: assessment of psychological status of children with atopic dermatitis. Materials and methods. Conducted psychological examination of 77 children with atopic dermatitis and 56 healthy children. In the industrial city of Zaporizhia population of 40 patients and 29 healthy subjects. In ecologically clean regions of 37 children with atopic dermatitis and 27 healthy people. Psychological features of the person of children were evaluated using a questionnaire for these criteria: «The state of health», «Active» and «Mood». Results. Revealed that 42.5% of children with atopic dermatitis from the city Zaporozhye pointed to decrease health. In 43.24% of patients with regions marked increase in health. Children with atopic dermatitis from the field, often there is a decrease, «Activity» (45.95%). Increased «Activity» was typical for inner-city children with atopic dermatitis (57.5%). Reducing the mood was recorded in 60% of urban and 18.92% of regional patients. Conclusions. The study results showed that to improve the quality of life of children with atopic dermatitis is necessary to carry out their social and psychological adaptation. Key words: psychological status, self-concept, atopic dermatitis, children. Цель: оценка психологического статуса детей с атопическим дерматитом. Пациенты и методы. Проведено психологическое обследование 77 детей с атопическим дерматитом и 56 здоровых детей. В промышленном городе Запорожье проживали 40 больных и 29 здоровых детей и 37 детей с атопическим дерматитом и 27 здоровых проживали в относительно экологически благоприятных районах Запорожской области. Психологические особенности личности детей оценивались с использованием опросника «САН» за такими критериями: «Самочувствие», «Активность» и «Настроение». Результаты. На снижение самочувствия указали 42,5% детей с атопическим дерматитом из г. Запорожье. У 43,24% больных из области, наоборот, отмечалось его повышение, что может свидетельствовать о меньшем жизненном опыте, связанном с преодолением заболевания. Дети с атопическим дерматитом из области достоверно чаще, чем из г. Запорожье, отмечали сниженную «Активность» (45,95% против 22,5%). И наоборот — повышенная «Активность» была характерна для городских детей с атопическим дерматитом (57,5% против 5,41%). Это связано как с неспособностью детей из области объективно оценить себя, так и с более активным способом жизни в урбанизированном городе. Снижение настроения регистрировалось у 60% городских и 18,92% больных из области, p&lt;0,05. Высокая самооценка настроения больных из области свидетельствовала о повышении механизмов компенсации и субъективного ощущения собственного здоровья. Выводы. Перспективным направлением повышения качества жизни детей с атопическим дерматитом является включение в комплекс лечения методов социальной и психологической адаптации. Ключевые слова: психологический статус, самооценка, атопический дерматит, дети.Мета: визначення психологічного статусу дітей з атопічним дерматитом. Пацієнти і методи. Проведено психологічне обстеження 77 дітей з атопічним дерматитом та 56 здорових. У промисловому місті Запоріжжя мешкали 40 хворих та 29 здорових дітей, а 37 дітей з атопічним дерматитом і 27 здорових проживали у відносно екологічно сприятливих районах Запорізької області. Психологічні властивості та стан особистості всіх обстежених дітей досліджували за допомогою запитальника САН для оперативної оцінки «Самопочуття», «Активності» та «Настрою» як засобу психодіагностики особистості дитини. Результати. Серед хворих на атопічний дерматит мешканців м. Запоріжжя 42,5% дітей вказували на зниження самопочуття. У 43,24% хворих з області, навпаки, відмічалось його підвищення, що може свідчити про їх менш тривалий життєвий досвід, пов'язаний з подоланням захворювання. Серед хворих з області достовірно частіше, ніж з м. Запоріжжя, реєструвалися знижена активність (45,95% проти 22,5%). І навпаки — підвищена активність була більш притаманною городянам, ніж мешканцям області (57,5% проти 5,41%). Це, з одного боку, було пов'язане з нездатністю дітей з області об'єктивно оцінити себе, а з іншого — з більш активним способом життя дітей в урбанізованому місті. Знижений настрій мали 60% міських і тільки 18,92% хворих з області, p&lt;0,05. Висока самооцінка настрою хворих з області свідчила про підвищення механізмів компенсації та суб'єктивного відчуття себе здоровими, незважаючи на хворобу. Висновки. Перспективним напрямком підвищення якості життя дітей з атопічним дерматитом є включення у комплекс лікування методів соціальної та психологічної адаптації. Ключові слова: психологічний статус, самооцінка, атопічний дерматит, діти