The perturbation method in the problem on a nearly circular inclusion in an elastic body

The two-dimensional boundary value problem on a nearly circular inclusion in an infinity elastic solid is solved. It is supposed that the uniform stress state takes place at infinity. Contact of the inclusion with the matrix satisfies to the ideal conditions of cohesion. To solve this problem, Muskhelishvili’s method of complex potentials is used. Following the boundary perturbation method, this potentials are sought in terms of power series in a small parameter. In each-order approximation, the problem is reduced to the solving two independent Riemann – Hilbert’s boundary problems. It is constructed an algorithm for funding any-order approximation in terms of elementary functions. Based on the first-order approximation numerical results for hoop stresses at the interface are presented under uniaxial tension at infinity

Domain wall conduction in multiaxial ferroelectrics

The conductance of domain wall structures consisting of either stripes or cylindrical domains in multi-axial ferroelectric-semiconductors is analyzed. The effects of the domain size, wall tilt and curvature, on charge accumulation, are analyzed using the Landau-Ginsburg Devonshire (LGD) theory for polarization combined with Poisson equation for charge distributions. Both the classical ferroelectric parameters including expansion coefficients in 2-4-6 Landau potential and gradient terms, as well as flexoelectric coupling, inhomogeneous elastic strains and electrostriction are included in the present analysis. Spatial distributions of the ionized donors, free electrons and holes were found self-consistently using the effective mass approximation for the respective densities of states. The proximity and size effect of the electron and donor accumulation/depletion by thin stripe domains and cylindrical nanodomains are revealed. In contrast to thick domain stripes and thicker cylindrical domains, in which the carrier accumulation (and so the static conductivity) sharply increases at the domain walls only, small nanodomains of radius less then 5-10 correlation length appeared conducting across entire cross-section. Implications of such conductive nanosized channels may be promising for nanoelectronics.Comment: 39 pages, 11 figures, 3 tables, 4 appendice

Paleolimnological studies in Russian northern Eurasia: A review

© 2017, Pleiades Publishing, Ltd. This article presents a review of the current data on the level of paleolimnological knowledge about lakes in the Russian part of the northern Eurasia. The results of investigation of the northwestern European part of Russia as the best paleolimnologically studied sector of the Russian north is presented in detail. The conditions of lacustrine sedimentation at the boundary between the Late Pleistocene and Holocene and the role of different external factors in formation of their chemical composition, including active volcanic activity and possible large meteorite impacts, are also discussed. The results of major paleoclimatic and paleoecological reconstructions in northern Siberia are presented. Particular attention is given to the databases of abiotic and biotic parameters of lake ecosystems as an important basis for quantitative reconstructions of climatic and ecological changes in the Late Pleistocene and Holocene. Keywords: paleolimnology, lakes, bottom sediments, northern

Формирование и электрохимические свойства пленок оксидов никеля и кобальта

Films of cobalt oxide and nickel oxide on monocrystalline silicon substrates were obtained by electrochemical deposition from aqueous electrolyte solutions. Their structure and composition were studied by Raman microscopy and scanning electron microscopy. The results of the study by Raman spectroscopy showed that the obtained films are polycrystalline structures of cobalt (II, III) oxide and nickel (II) oxide, the crystalline perfection of which increases with an increase in the electrolyte temperature. It was found by scanning electron microscopy that nickel oxide films have a smoother surface, while cobalt oxide has a more developed structure consisting of lamellar crystals. The specific electrochemical capacity of cobalt oxide and nickel oxide films obtained under optimal conditions, measured by voltammetry, was 14.67 and 1634.08 F/g, respectively. The high specific electrochemical capacity of a nickel oxide film can be used to create efficient electrochemical devices and energy storage devices.Методом электрохимического осаждения получены пленки оксида кобальта и оксида никеля на подложках монокристаллического кремния. Проведены исследования их структуры и состава методами рамановской микроскопии и сканирующей электронной микроскопии. Результаты исследования методом рамановской спектроскопии показали, что полученные пленки представляют собой поликристаллические структуры оксида кобальта (II, III) и оксида никеля (II), кристаллическое совершенство которых возрастает с увеличением температуры электролита. Методом сканирующей электронной микроскопии было установлено, что пленки оксида никеля отличаются гладкой поверхностью, в то время как оксид кобальта обладает более развитой структурой и состоит из кристаллов пластинчатой формы. Измеренная методом вольтамперометрии удельная электрохимическая емкость пленок оксида кобальта и оксида никеля, полученных в оптимальных условиях, составила соответственно 14,67 и 1634,08 Ф/г. Высокая удельная электрохимическая емкость пленки оксида никеля может быть использована для создания эффективных электрохимических приборов и устройств накопления энергии

Genetics of Host Response to Leishmania tropica in Mice – Different Control of Skin Pathology, Chemokine Reaction, and Invasion into Spleen and Liver

Several hundred million people are exposed to the risk of leishmaniasis, a disease caused by intracellular protozoan parasites of several Leishmania species and transmitted by phlebotomine sand flies. In humans, L. tropica causes cutaneous form of leishmaniasis with painful and long-persisting lesions in the site of the insect bite, but the parasites can also penetrate to internal organs. The relationship between the host genes and development of the disease was demonstrated for numerous infectious diseases. However, the search for susceptibility genes in the human population could be a difficult task. In such cases, animal models may help to discover the role of different genes in interactions between the parasite and the host. Unfortunately, the literature contains only a few publications about the use of animals for L. tropica studies. Here, we report an animal model suitable for genetic, pathological and drug studies in L. tropica infection. We show how the host genotype influences different disease symptoms: skin lesions, parasite dissemination to the lymph nodes, spleen and liver, and increase of levels of chemokines CCL2, CCL3 and CCL5 in serum

The perturbation method in the problem on a nearly circular inclusion in an elastic body

The two-dimensional boundary value problem on a nearly circular inclusion in an infinity elastic solid is solved. It is supposed that the uniform stress state takes place at infinity. Contact of the inclusion with the matrix satisfies to the ideal conditions of cohesion. To solve this problem, Muskhelishvili’s method of complex potentials is used. Following the boundary perturbation method, this potentials are sought in terms of power series in a small parameter. In each-order approximation, the problem is reduced to the solving two independent Riemann – Hilbert’s boundary problems. It is constructed an algorithm for funding any-order approximation in terms of elementary functions. Based on the first-order approximation numerical results for hoop stresses at the interface are presented under uniaxial tension at infinity

Risicobeoordeling van grondwaterverontreiniging ten gevolge van verlaten opslagplaatsen op landbouwbedrijven in Oekraïne : Afsluitend projectrapport.

Dit is het hoofdrapport. Het bijlagenrapport heeft nummer 680272001-ADit is het hoofdrapport. Het bijlagenrapport heeft rapportnummer 680272001A Oekraïne kampt met een groot aantal puntbronnen van pesticiden en meststoffen die de landbouwgronden en het drinkwater bedreigen. Risicobeoordeling biedt de mogelijkheid om het grote aantal verontreinigde locaties te identificeren en prioriteren als een eerste stap naar sanering van de locaties Toenemende behoeften en afnemende budgetten Centerderzhrodyuchist, het Oekraïense Staatsinstituut voor Bodemvruchtbaarheid en Productkwaliteit, is verantwoordelijk voor zowel de monitoring van bodemkwaliteit als voor bodemvruchtbaarheidanalysen en bemestingsadvies. Het budget voor beide taken neemt af, terwijl de behoefte aan gedetailleerde monitoring en informatieverzameling toeneemt om een voldoende en een veilige voedselproductie voor de toekomst zeker te stellen. Het veiligstellen van landbouwgrond en voedselveiligheid De risico's van grondwaterverontreiniging zijn reëel door uitspoeling van pesticiden en meststoffen uit verlaten en onbeheerde opslagplaatsen voor deze producten in het landelijk gebied. De verontreiniging van het grondwater vormt een bedreiging voor zowel de landbouwproductie (gewasopbrengst en de voedselveiligheid) als voor de drinkwatervoorziening van kleine dorpen. Deze dorpen zijn voor hun drinkwater meestal afhankelijk van locale drinkwaterputten. Prioriteren en differentiëren van puntbronnen Teruglopende budgetten en de hoge kosten gerelateerd aan het saneren van al deze locaties vragen om een methodologie voor risicobeoordeling van puntbronnen. Hieronder wordt verstaan, ten eerste, het uitvoeren van een inventarisatie van relevante puntbronnen en/of processen die de mobiliteit van verontreinigingen beïnvloeden. Ten tweede betekent dit het bepalen in welke mate verontreinigingen in het freatische grondwater terechtkomen en op welke wijze deze worden getransporteerd via grondwaterstroming door de ondergrond. Ten derde houdt het in het uitvoeren van een risicobeoordeling met betrekking tot de land- en watergebruiksfuncties in de nabijheid van puntbronnen. Deze methodologie is uitgewerkt door de Nederlandse en Oekraïense deskundigen en vastgelegd in een leidraad. Financiering en team Bovenstaande bevindingen zijn het resultaat van een project, gefinancierd door Agenschap NL, om de opties te onderzoeken voor het gebruik van aardobservatie en GIS in de bodemkwaliteitsmonitoring in de Oekraïne. Een team van Nederlandse experts, afkomstig van het RIVM, het Planbureau voor de Leefomgeving (PBL) en het adviesbureau Acacia Water BV, heeft dit project in 2011 en 2012 uitgevoerd samen met experts van Centerderzhrodyuchist en experts van twee andere Oekraïense instituten en organisaties, zowel overheid als bedrijfsleven.Ukraine faces large challenges, as point sources of contamination endanger its highly productive, but vulnerable soils and drinking water wells. Risk assessment provides a methodology to prioritize and differentiate the vast amount of potentially contaminated sites in a first step towards remediation. Increasing needs and decreasing budget Centerderzhrodyuchist, the Ukrainian State Centre for Soil Fertility and Product Quality, is responsible for soil quality monitoring in Ukraine as well as soil fertility analysis and advises. The budget for both tasks is decreasing, while the need for detailed monitoring and information collection is increasing to assure sufficient and safe food production in the near future. Safeguarding the agricultural area and food security The risk of groundwater contamination by abandoned on-farm storage sites endangers the agricultural area and drinking water wells. This in turn endangers crop production and as a consequence food security. Prioritizing and differentiate point sources of pollution Decreasing budgets and high costs involved with remediation demand a methodology for risk assessment of point-source contamination. This involves an inventory of relevant point sources and/or contaminant mobilisation processes; secondly, an assessment of the leaching of contaminants into phreatic groundwater and transport in aquifers due to groundwater flow and, thirdly, a risk assessment as regard to land and water use functions in the vicinity of a pointsource of contamination. The Dutch and Ukrainian experts have elaborated this methodology and have laid it down in a guidance document. Sponsor and teams These findings are the result of a project, developed by NL Agency and financed by the Ditch Ministry of Economic Affairs, Agriculture and Innovation, to enable Ukrainian experts to carry out risk assessments for the abandoned on-farm storage sites in Ukraine. A Dutch team, with experts from the National Institute for Public Health and the Environment (RIVM), PBL Netherlands Environmental Assessment Agency and the consultancy firm Acacia Water BV, carried out this project together with experts of Centerderzhrodyuchist and with experts of two other Ukrainian institutes and organisations, both public and private, in 2011 and 2012.NL Agenc