Switching Casimir forces with Phase Change Materials

We demonstrate here a controllable variation in the Casimir force. Changes in the force of up to 20% at separations of ~100 nm between Au and AgInSbTe (AIST) surfaces were achieved upon crystallization of an amorphous sample of AIST. This material is well known for its structural transformation, which produces a significant change in the optical properties and is exploited in optical data storage systems. The finding paves the way to the control of forces in nanosystems, such as micro- or nanoswitches by stimulating the phase change transition via localized heat sources.Comment: 7 pages, 3 figures The AFM images for the inset in Fig.2 were replaced with new ones as obtained with tips having high aspect rati

Aggregate structure of hydroxyproline-rich glycoprotein (HRGP) and HRGP assisted dispersion of carbon nanotubes

Hydroxyproline-rich glycoproteins (HRGP) comprise a super-family of extracellular structural glycoproteins whose precise roles in plant cell wall assembly and functioning remain to be elucidated. However, their extended structure and repetitive block co-polymer character of HRGPs may mediate their self-assembly as wall scaffolds by like-with-like alignment of their hydrophobic peptide and hydrophilic glycopeptide modules. Intermolecular crosslinking further stabilizes the scaffold. Thus the design of HRGP-based scaffolds may have practical applications in bionanotechnology and medicine. As a first step, we have used single-molecule or single-aggregate atomic force microscopy (AFM) to visualize the structure of YK20, an amphiphilic HRGP comprised entirely of 20 tandem repeats of: Ser-Hyp4-Ser-Hyp-Ser-Hyp4-Tyr-Tyr-Tyr-Lys. YK20 formed tightly aggregated coils at low ionic strength, but networks of entangled chains with a porosity of ~0.5–3 μm at higher ionic strength. As a second step we have begun to design HRGP-carbon nanotube composites. Single-walled carbon nanotubes (SWNTs) can be considered as seamless cylinders rolled up from graphene sheets. These unique all-carbon structures have extraordinary aromatic and hydrophobic properties and form aggregated bundles due to strong inter-tube van der Waals interactions. Sonicating aggregated SWNT bundles with aqueous YK20 solubilized them presumably by interaction with the repetitive, hydrophobic, Tyr-rich peptide modules of YK20 with retention of the extended polyproline-II character. This may allow YK20 to form extended structures that could potentially be used as scaffolds for site-directed assembly of nanomaterials

МОДЕЛИРОВАНИЕ ПРОЦЕССА ФОРМИРОВАНИЯ ТОПОЛОГИЧЕСКИХ СТРУКТУР В СЛОЯХ ВАКУУМНОГО РЕЗИСТА

The modeling of formation of topological structures with 3D elements of various sizes and configurations in а vacuum resist exposed to pulsed laser radiation with different energy density was carried out. It was found experimentally that the simulation allows predicting the actual parameters of lithography laser systems for high-quality formation of 3D topology elements in layers of vacuum resist when creating masks. Изучены методом моделирования процессы формирования топологичеких структур с 3D-элементами различных размеров и конфигурации в слоях вакуумного резиста импульсным лазерным излучением с разной плотностью энергии. Экспериментально установлено, что моделирование позволяет прогнозировать реальные параметры работы установок лазерной вакуумной микролитографии для качественного формирования 3D-элементов топологии в слоях вакуумного резиста при создании масок.

СОСТАВ И ФИЗИКО-ХИМИЧЕСКИЕ СВОЙСТВА ПОРОД-КОЛЛЕКТОРОВ СПАНОВСКОЙ СВИТЫ ПРИБУГСКОЙ СТРУКТУРЫ ПОДЛЯССКО-БРЕСТСКОЙ ВПАДИНЫ

The results of laboratory studies of the composition and physical properties of span series rocks of the Pribug structure within the eponymous underground gas storage (UGS), have been presented. The rocks are represented by a finegrained quartz sandstone with various sorting and grain roundness, type of cementation and clay content. The character of section suites changes for the material composition of the rocks and their physical properties have been set. The examined properties specify reservoir rocks characteristics which are widely used for integrated geophysics well data interpretation, geological and hydrogeological UGS modeling, making recommendations for increasing efficiency of pore volume usage during gas storage operation. Rock intervals with poor porosity and permeability are detected inside the examined rock series.Приведены результаты лабораторных исследований вещественного состава и физико-химических свойств пород спановской свиты Прибугской структуры в пределах одноименного подземного хранилища газа (ПХГ). Породы представлены кварцевым мелкозернистым песчаником с различной степенью сортировки и окатанности зерен, типом цементации, глинистости. Установлен характер изменения состава пород и их физических свойств по разрезу свиты. Исследованные свойства характеризуют фильтрационно-емкостные параметры пород-коллекторов, которые используются при интерпретации данных комплексных геофизических исследований скважин, построении геологических и гидродинамических моделей ПХГ, выработке рекомендаций по повышению эффективности использования порового пространства пород при эксплуатации газовых залежей. В пределах свиты выявлены интервалы пород с низкой пористостью и проницаемостью

Структура и оптические свойства покрытий алмазоподобного углерода

Using a hybrid method of cathodic arc (PVD) and chemical (CVD) deposition from the gas phase, a new type of coatings containing high amount of sp3 bonds of carbon, capable of absorbing effectively light has been developed.This thin film material is a promised one for optical devices operating in open space environment as antireflective coating  for photoreceiver bodies. The hybrid method permits to obtain effective light absorbing coatings having excellent mechanical and tribological properties and is able to sustain temperature cycling in a range from plus 150 to minus 100 oC.  The optical characteristics of DLC coatings were studied depending on the content of sp2bound content. The combined physical and chemical deposition of DLC coatings allows to achieve a sufficiently high light absorption (a~10 5 cm–1) and low reflection with a relatively small coating thickness about 1 mm. It has been established that the antireflective properties of such coatings depend on the conditions for their preparation, first of all on hydrocarbon gas pressure С использованием гибридного метода катодно­дугового (PVD) и химического (CVD) осаждения из газовой фазы разработан новый тип покрытий с большим содержанием sp2­химически связанных атомов углерода, способных эффективно поглощать видимое оптическое излучение.Аморфный тонкопленочный углеродный материал является перспективным для нанесения поглощающих антибликовых покрытий на корпусные детали фотоприемников оптического излучения, работающих в открытом космосе. Гибридный метод позволяет получать сильнопоглощающие покрытия, обладающие также высокими механическими и трибологическими свойствами и способные выдерживать термоциклирование от + 150 до – 100 °С.Проведено исследование оптических характеристик АПУ покрытий в зависимости от содержания sp2­связанных атомов углерода. Полученный комбинированным способом физического и химического осаждения АПУ в виде тонких слоев позволяет достичь достаточно высокого поглощения и низкого отражения при сравнительно малой толщине покрытия (a ~ 105 см–1). Установлено, что антибликовые свойства таких покрытий зависят от условий его получения, и прежде всего – от давления газа углеводородов

Shower development of particles with momenta from 15 GeV to 150 GeV in the CALICE scintillator-tungsten hadronic calorimeter

We present a study of showers initiated by electrons, pions, kaons, and protons with momenta from 15 GeV to 150 GeV in the highly granular CALICE scintillator-tungsten analogue hadronic calorimeter. The data were recorded at the CERN Super Proton Synchrotron in 2011. The analysis includes measurements of the calorimeter response to each particle type as well as measurements of the energy resolution and studies of the longitudinal and radial shower development for selected particles. The results are compared to Geant4 simulations (version 9.6.p02). In the study of the energy resolution we include previously published data with beam momenta from 1 GeV to 10 GeV recorded at the CERN Proton Synchrotron in 2010.Comment: 35 pages, 21 figures, 8 table

WEST NILE FEVER WORLDWIDE AND IN THE TERRITORY OF THE RUSSIAN FEDERATION IN 2016, AND FORECAST OF EPIDEMIC SITUATION DEVELOPMENT IN 2017

In Europe, as in Russia and Canada, outlined was a tendency to the increase in the morbidity rates, while in the US – the incidence was somewhat lower as compared to previous years. On the whole, West Nile fever incidence rates in the Russian Federation by regions during the epidemic season, 2016 were below the average long-term index. Above the average regional annual incidence rates were registered in the Saratov region only and accounted for 64 % of all reported cases in Russia. Analysis of the monitoring results indicated the circulation of WNF virus markers in carriers of the pathogen in 10 constituent entities of the Russian Federation, and the presence of IgG antibodies in healthy population cohorts in 30 RF entities. According to molecular-genetic typing of WNF virus samples from a deceased patient in the Astrakhan Region and mosquito Culex samples from the Volgograd Region, WNF virus genotype I was established. Forecasting of epidemiological situation development for the year 2017 does not rule out the possibility of local increase in WNF incidence in certain regions of Russia

Peculiarities of Epidemiological Situation on the West Nile Fever in 2012 in the Territory of the Russian Federation

During the epidemic season of 2012 453 cases of West Nile fever (WNF) were registered in the territory of the 21 constituent entities of the Russian Federation. Epidemic process is spreading itself towards the northern regions of Russia. The presence of markers of West Nile fever virus in carriers and vectors of the disease as well as acquired immunity among the population against the West Nile virus (WNV) have been identified in the territory of 53 constituent entities of the Russian Federation. The epidemic process is characterized by a number of peculiarities concerning both its epidemiological and clinical aspects. With the intensification of diagnostic works among the patients with clinical symptomatology similar to WNF, first and foremost in the territories where WNV markers have been detected, prognosticated is the registration of WNF incidence among the population extending over a large area of the Russian Federation

КАРБАМИДОФОРМАЛЬДЕГИДНЫЕ СМОЛЫ, НАПОЛНЕННЫЕ ТЕХНИЧЕСКИМ ДИОКСИДОМ КРЕМНИЯ

The effect of silicon dioxide (SDO) on the physico-chemical properties of urea-formaldehyde resins and plywood made with the modified resins, has been studied. SDO addition to the resin increases its acidity and reactivity. This reduces the consumption of catalyst for resin curing 1,5−2,0 times, and plywood, obtained using SDO, has higher mechanical strength.Изучено влияние диоксида кремния (ДОК) на физико-химические свойства карбамидоформальдегидных смол (КФС) и фанеры, изготовленной с использованием наполненных смол. Добавка ДОК в смолу приводит к увеличе­нию ее кислотности и повышению реакционной способности. При этом снижается расход катализатора отверждения смолы в 1,5−2,0 раза, а фанера, полученная с использованием ДОК, имеет более высокую механическую прочность

Best practice guidelines for cetacean tagging

Animal-borne electronic instruments (tags) are valuable tools for collecting information on cetacean physiology, behaviour and ecology, and for enhancing conservation and management policies for cetacean populations. Tags allow researchers to track the movement patterns, habitat use andother aspects of the behaviour of animals that are otherwise difficult to observe. They can even be used to monitor the physiology of a tagged animal within its changing environment. Such tags are ideal for identifying and predicting responses to anthropogenic threats, thus facilitating the development of robust mitigation measures. With the increasing need for data best provided by tagging and the increasing availability of tags, such research is becoming more common. Tagging can, however, pose risks to the health and welfare of cetaceans and to personnel involved in tagging operations. Here we provide ‘best practice’ recommendations for cetacean tag design, deployment and follow-up assessment of tagged individuals, compiled by biologists and veterinarians with significant experience in cetacean tagging. This paper is intended to serve as a resource to assist tag users, veterinarians, ethics committees and regulatory agency staff in the implementation of high standards of practice, and to promote the training of specialists in this area. Standardised terminology for describing tag design and illustrations of tag types and attachment sites are provided, along with protocols for tag testing and deployment (both remote and through capture-release), including training of operators. The recommendations emphasise the importance of ensuring that tagging is ethically and scientifically justified for a particular project and that tagging only be used to address bona fide research or conservation questions that are best addressed with tagging, as supported by an exploration of alternative methods. Recommendations are provided for minimising effects on individual animals (e.g. through careful selection of the individual, tag design and implant sterilisation) and for improving knowledge of tagging effects on cetaceans through increased post-tagging monitoring.Publisher PDFPeer reviewe