A Micropowered Chemoresistive Sensor Based on a Thin Alumina Nanoporous Membrane and SnxBikMoyOz Nanocomposite

This work presents and discusses the design of an efficient gas sensor, as well as the technological process of its fabrication. The optimal dimensions of the different sensor elements including their deformation were determined considering the geometric modeling and the calculated moduli of the elasticity and thermal conductivity coefficients. Multicomponent SnxBikMoyOz thin films were prepared by ionic layering on an anodic alumina membrane and were used as gas-sensitive layers in the sensor design. The resistance of the SnxBikMoyOz nanostructured film at temperatures up to 150 ◦C exceeded 106 Ohm but decreased to 104 Ohm at 550 ◦C in air. The sensitivity of the SnxBikMoyOz composite to concentrations of 5 and 40 ppm H2 at 250 ◦C (10 mW) was determined to be 0.22 and 0.40, respectively

Конструкционные упрочняющие композитные покрытия на алюминиевых сплавах из матричных углеродных и металлоксидных наноструктур

Использование современных конструкционных материалов обычно ограничивается тем, что увеличение прочности приводит к снижению пластичности. Однако более глубокое изучение физики деформационных процессов наноструктурированных материалов показало, что уменьшение их микроструктуры и наноструктурирование приводят к появлению в них новых качеств и созданию новых видов материалов с повышенной прочностью и пластичностью. Проведенные исследования при разработке конструкционных композитных покрытий с наполнителями из матричных наноструктур на основе металлооксидных и углеродных материалов показали перспективы для их применения в качестве упрочняющих покрытий на алюминии при изготовлении литых изделий точной формы из цветных сплавов с повышенной износостойкостью и ударной вязкостью, создании наноструктурированных защитных термо- и коррозионностойких покрытий, обладающих повышенной прочностью и низкой воспламеняемостью

Synthesis of matrix nanostructures from oxides and sulfides of transition metals

An original technology for the formation of spatially ordered planar TiO2/Bi2O3 and TiO 2 /CdS nanosystems is proposed, which based on the electrochemical anodization of titanium through anodic alumina mask and ionic cyclic layering of composite films based on Bi2O3 and chemical deposition of CdS on nanostructured TiO 2 surface. Comprehensive studies of multicomponent composites with three-dimensional architecture specified for practical use have been carried out, and prospects for the creation of effective photovoltaic and sensoric devices on their basis have been determined

Features of electrochemical formation of metal and semiconductor nanowires in anodic alumina matrices with variable pores

Methods for the porous membranes formation from anodic alumina with periodically alternating pore diameters along the membrane depth and the electrochemical nanowires formation of complex morphology from various materials have been developed and tested. The features of the electrochemical deposition of indium and copper antimonide into pores with varying diameters under different chemical conditions and electrical modes have been investigated. The electron microscopic studies of the created nanosystems have been carried out, the elemental composition has been investigated, the current-voltage characteristics of InSb nanowires of complex morphology have been measured

Incidence of multiple myeloma among cleanup workers of the chornobyl accident and their survival

The study presents the updated data on the multiple myeloma (MM) incidence in Ukrainian cleanup workers after the Chornobyl accident and their survival. The epidemiological analysis is based on the extended follow-up period to identify new MM cases for higher statistical power and to collect additional data on the disease course and outcome for the survival analysis. The objective of the study was to analyze the MM incidence and survival in Chornobyl cleanup workers in 1996–2013 in comparison with the national MM statistical data. Materials and Methods: A study cohort consisted of 152,520 male cleanup workers resided in one of 6 regions of Ukraine or Kyiv city and registered in the Ukrainian State Chornobyl Registry (SChR). The Cohort Database was linked to the Ukrainian National Cancer Registry (NCR) Database to identify MM cases and to analyze MM incidence in 1996– 2013. Standardized incidence ratios (SIR) for MM over the period 1996–2013 were calculated as compared to the general population of Ukraine. A 10-year lag period (when incident cases are not considered radiation-related) was applied. One-year and 5-year cause-specific survival of MM cases were calculated as percentage of those who were alive correspondingly for 1 or 5 years after diagnosis among overall diagnosed. By the moment, the 5-year survival rate either for the sub-period 2008–2013 or for the whole study period 1996–2013 cannot be determined. Vital status data were updated according to the recent SChR and NCR information. Results: 75 MM cases diagnosed in 1986–2013 were identified in the studied cohort. 69 of them were included to the incidence analysis considering a 10-year lag period. While the incidence over 15 years after the accident did not differ significantly from the corresponding rate in general population of Ukraine, a tendency to increase was seen in the period from 16 to 21 years after the accident, and significantly increased SIR estimate was revealed for 2008–2013 (SIR 1.86, 95% confidence interval (CI) 1.27–2.44). The highest incidence was detected in 2008–2013 among cohort members diagnosed over the age of 50 years mostly due to the significant excess among those aged 60–69 (SIR 2.46, 95% CI 1.32–3.59). Survival rates in cleanup workers were shown to be higher than in the general population of Ukraine (73.9% and up to 65.0%, respectively). Conclusions: SIR for the 2008– 2013 period, 22–27 years after the accident, demonstrated the significant excess of MM incidence among male cleanup workers. Survival of MM cases is higher in cleanup workers in comparison with that in general population. This article is a part of a Special Issue entitled “The Chornobyl Nuclear Accident: Thirty Years After”

Матричные наносистемы на основе оксида висмута для рентгеноконтрастной диагностики и защиты от ионизирующего излучения

The features of the bismuth oxide deposition by the ion layering method on matrices of anodic alumina and anodic titania have been studied. The formed nanostructured systems have been studied by means of electron micros copy, X-ray microanalysis, and X-ray spectroscopy. Two-layer nanocomposites consist of porous matrix or TiO2 island film with vertically oriented Bi2O3 plates placed on the surface. The photoluminescence spectrum of Al2O3/Bi2O3 oxide structure contains two photoluminescence channels with peaks at 460 and 560 nm upon excitation at 345 nm. Analysis of the EDX spectra showed that the atomic ratio of Bi, Ti and O was 31.46 % Bi : 3.78 % Ti : 51.05 % O. The possibility of using complex nanocomposite as contrast agents in X-ray diagnostics and for protection against ionizing radiation is shown.Исследованы особенности нанесения оксида висмута на матрицы анодного оксида алюминия и оксида титана методом ионного наслаивания. Сформированные наноструктурированные системы изучены с помощью электронной микроскопии, рентгеновского микроанализа и рентгеновской спектроскопии. Нанокомпозиты представляют собой двухслойные системы из пористой матрицы или островковой пленки TiO2, на поверхности которых находятся вертикально ориентированные пластинки Bi2O3. В спектре фотолюминесценции структуры Al2O3/Bi2O3 присутствуют два канала фотолюминесценции с пиками на 460 и 560 нм при 345 нм возбуждения. Анализ EDX-спектров показал, что атомарное соотношение Bi, Ti и O составило 31,46 % Bi : 3,78 % Ti : 51,05 % O. Показана возможность использования сложного нанокомпозита в качестве контрастирующего агента в рентгеновской диагностике и для защиты от ионизирующего излучения

Spatially Ordered Matrix of Nanostructured Tin–Tungsten Oxides Nanocomposites Formed by Ionic Layer Deposition for Gas Sensing

The process of layer-by-layer ionic deposition of tin-tungsten oxide films on smooth silicon substrates and nanoporous anodic alumina matrices has been studied. To achieve the film deposition, solutions containing cationic SnF2 or SnCl2 and anionic Na2WO4 or (NH4)2O·WO3 precursors have been used. The effect of the solution compositions on the films deposition rates, morphology, composition, and properties was investigated. Possible mechanisms of tin-tungsten oxide films deposition into the pores and on the surface of anodic alumina are discussed. The electro-physical and gas-sensitive properties of nanostructured SnxWyOz films have been investigated. The prepared nanocomposites exhibit stable semiconductor properties characterized by high resistance and low temperature coefficient of electrical resistance of about 1.6 × 10 −3 K −1. The sensitivity of the SnxWyOz films to 2 and 10 ppm concentrations of ammonia at 523 K was 0.35 and 1.17, respectively. At concentrations of 1 and 2 ppm of nitrogen dioxide, the sensitivity was 0.48 and 1.4, respectively, at a temperature of 473 K. At the temperature of 573 K, the sensitivity of 1.3 was obtained for 100 ppm of ethanol. The prepared nanostructured tin-tungsten oxide films showed promising gas-sensitivity, which makes them a good candidate for the manufacturing of gas sensors with high sensitivity and low power consumption

ЧУВСТВИТЕЛЬНОСТЬ КЛЕТОК КРОВИ И ЭПИДИДИМАЛЬНЫХ СПЕРМАТОЗОИДОВ КРЫС К ВОЗДЕЙСТВИЮ МАГНИТНОГО ПОЛЯ ПРОМЫШЛЕННОЙ ЧАСТОТЫ (50 Гц)

The article discusses the data on the long-time effect of low frequency magnetic fields (IF MF 50 Hz, 0.4 mT, 4h/day, 5 days/week, 26 days) on blood cells and spermatozoa of Wistar rats. It was determined that at different times after exposure (3th, 15th and 30th days) the changes in different quantitative and qualitative indicators of test cells were revealed, some of which are kept in 30 days after exposure. В сообщении обсуждаются данные исследований длительного воздействия магнитного поля промышленной частоты (МП ПЧ 50 Гц, 0,4 мT, 4 ч/день, 5 дней в неделю, суммарное количество 26 дней) на клетки крови и эпидидимальные сперматозоиды крыс Вистар. Установлено, что в различные сроки после воздействия (3-и, 15-е и 30-е сутки) выявляются изменения различных количественных и качественных показателей исследуемых клеток, некоторые из которых сохраняются в отдаленном периоде (30-е cутки после экспозиции).

Diffusion tensor imaging with deterministic error bounds

Errors in the data and the forward operator of an inverse problem can be handily modelled using partial order in Banach lattices. We present some existing results of the theory of regularisation in this novel framework, where errors are represented as bounds by means of the appropriate partial order. We apply the theory to diffusion tensor imaging (DTI), where correct noise modelling is challenging: it involves the Rician distribution and the nonlinear Stejskal-Tanner equation. Linearisation of the latter in the statistical framework would complicate the noise model even further. We avoid this using the error bounds approach, which preserves simple error structure under monotone transformations.While at the Center for Mathematical Modelling of the Escuela Politécnica Nacional in Quito, Ecuador, T. Valkonen has been supported by a Prometeo scholarship of the Senescyt (Ecuadorian Ministry of Science, Technology, Education, and Innovation). In Cambridge, T. Valkonen has been supported by the EPSRC grants Nr. EP/J009539/1 “Sparse & Higher-order Image Restoration”, and Nr. EP/M00483X/1 “Efficient computational tools for inverse imaging problems”. A. Gorokh and Y. Korolev are grateful to the RFBR (Russian Foundation for Basic Research) for partial financial support (projects 14-01-31173 and 14-01-91151)