Estimate of the possibility of conducting mass spectrometric measurements of the matter of lunar surface

Electron beams studied for use in lunar soil spectrometric analysi

Measurements of the composition of aerosol component of Venusian atmosphere with Vega 1 lander, preliminary data

Preliminary investigation of mass spectra of gaseous products of pyrolyzed Venusian cloud particles collected and analyzed by the complex device of mass-spectrometer and collector pyrolyzer on board Vega 1 lander revealed the presence of heavy particles in the upper cloud layer. Based on 64 amu peak (SO2+), an estimate of the lower limit of the sulfuric acid aerosol content at the 62 to 54 km heights of approximately 2.0 mg/cu m is obtained. A chlorine line (35 and 37 amu) is also present in the mass spectrum with a lower limit of the chlorine concentration of approximately 0.3 mg/ cu m

Dispersion оf Multi-Walled Carbon Nanotubes in Building Science оf Materials

The paper presents that modification of binding matrices with the help of dispersions of multi-walled carbon nanotubes (MWCNT) makes it possible to increase  physical and mechanical properties of building composites

СТРУКТУРНАЯ МОДИФИКАЦИЯ НОВООБРАЗОВАНИЙ В ЦЕМЕНТНОЙ МАТРИЦЕ С ИСПОЛЬЗОВАНИЕМ ДИСПЕРСИИ УГЛЕРОДНЫХ НАНОТРУБОК И НАНОКРЕМНЕЗЕМА

Complex nanodispersed systems with multi-walled carbon nanotubes and nanodispersed silica have a significant impact on the processes of hydration, hardening and strength gain of construction composites predetermining their durability. While using a scanning electron microscope with an attachment for X-ray microanalysis and a device for infrared spectral analysis investigations have shown that the main effect of the cement matrix modification in the case of adding complex nanodispersed systems is provided by direct influence of hydration processes with subsequent crystallization of new formations. It has been noted that while adding carbon nanotube dispersion and nanosized silica a binding matrix is structured in the form of an extremely dense shell from crystalline hydrate new formations on the surface of solid phases that provides strong binding matrix in cement concrete. The addition effect of carbon nanotubes has been analyzed and quantitatively assessed through an investigation for every case of one sample with nanotubes and one sample without them with the help of a nanoindenter and scanning electron microscope. It is necessary to solve rather complicated challenging task in order to assess quantitatively the addition effect of CNT on material characteristics at a micromechanical level. At the same time it is possible to investigate surface of a concrete sample with one-micron resolution. In this case it is necessary to prepare samples for nanoindentation with exclusion of all CNT defectable effects that have been shown by a SEM. So in this case more adequate method for assessment must be a picoindenter , which combines a test method for nanoindentation with an optical SEM potential. Such equipment is in the stage of in-situ testing process at the Vienna University of Technology. The investigation is based on the fact that the main modification effect of mineral binding matrix while using incorporated complex nanodispersed systems and nanosilica is ensured by a direct influence of hydration processes and subsequent crystallization of new formations. Scanning electron microscopy and X-ray microanalysis with detection in IR spectra have revealed that adding of multi-walled carbon nanotubes dispersion together with nanodispersed silica provides structuring of rather dense shell of hydrated new formations along cement matrix on the surface of solid phase. The structured interfacial layers form separate cells in the modified cement matrix that ensures a formation of extremely filled system and predetermines structural strengthening of the modified cement matrix due to formation of spatial packaging. Consequently, the main factor increasing characteristics of cement concrete which is modified with carbon nanotubes and nanosilica is a structural modification of calcium hydrosilicates with relation to composition and morphology of new formations.Комплексные нанодисперсные системы с многослойными углеродными нанотрубками и нанокремнеземом имеют значительное влияние на процессы гидратации, твердения, набора прочности строительных композитов, предопределяя их долговечность. Исследования с использованием сканирующего электронного микроскопа и Х-лучевого микроанализа с обнаружением в инфракрасном спектре показали, что главный эффект модификации в случае добавления комплексных нанодисперсных систем обеспечивается направленным влиянием процессов гидратации с последующей кристаллизацией новообразований. Установлено, что при добавлении дисперсии углеродных нанотрубок и нанокремнезема формируется структурная матрица в виде чрезвычайно плотной оболочки из кристаллогидратных новообразований на поверхности твердой фазы, что обеспечивает прочную вяжущую матрицу в цементном бетоне. Эффект добавления углеродных нанотрубок анализировался и количественно оценивался исследованием в каждом случае одного образца с нанотрубками и одного без них с помощью наноиндентора и сканирующего электронного микроскопа. Чтобы количественно оценить эффект добавки углеродных нанотрубок на характеристики материала на микромеханическом уровне, необходимо решить сложную задачу. В то же время возможно исследовать поверхность бетонного образца с разрешением в 1 микрон. При этом необходима подготовка образцов для наноиндентирования с исключением всех эффектов дефектности углеродных нанотрубок, показанных сканирующим электронным микроскопом. Вместе с тем, более адекватным методом оценивания в данном случае должен быть пикоиндентор, который комбинирует испытательный метод наноиндентирования с оптическим потенциалом сканирующего микроскопа. Такое оборудование находится в стадии полевых испытаний в Венском техническом университете. Исследование основано на том, что главный эффект модифицирования минеральной вяжущей матрицы с использованием включенных комплексных нанодисперсных систем и нанокремнезема обеспечивается непосредственным влиянием процессов гидратации и последующей кристаллизацией новообразований. Сканирующий электронный микроскоп и Х-лучевой микроанализ с обнаружением в инфракрасном спектре показали, что введение дисперсии многослойных углеродных нанотрубок совместно с нанокремнеземом обеспечивает построение вдоль цементной матрицы очень плотной оболочки вновь образованных гидратов на поверхности твердой фазы. Структурированные поверхностные слои формируют отдельные ячейки в модифицированной цементной матрице, что обеспечивает формирование предельно наполненной системы и предопределяет структуры модифицированной цементной матрицы благодаря формированию пространственной упаковки. Следовательно, основным фактором, повышающим характеристики цементного бетона, модифицированного углеродными нанотрубками и нанокремнеземом, является структурная модификация гидросиликатов кальция относительно композиции и морфологии новообразований

Compton-emissive hafnium detector of neutrons for in-core monitoring

The work is devoted to substantiating the use of metallic hafnium as the emitter of the Compton (prompt-response) in-core detector of thermal and resonant neutrons. The main trends in the development of nuclear power engineering, which raise the interest in the use of hafnium, are considered. The known data on the behavior of both Compton and β-emission self-powered neutron detectors (SPND) are generalized. The Compton SPND signal formation mechanism for the case of the irradiation by reactor-type fluxes of neutrons and gamma quanta is considered. The paper presents the calculation result of the hafnium burning-out degree for the conditions of WWER and RBMK reactors. The influence of the gamma radiation “sources”, which provide the largest contribution to the electrons production in the detector is considered

Структурная модификация новообразований в цементной матрице с использованием дисперсии углеродных нанотрубок и нанокремнезема

Complex nanodispersed systems with multi-walled carbon nanotubes and nanodispersed silica have a significant impact on the processes of hydration, hardening and strength gain of construction composites predetermining their durability. While using a scanning electron microscope with an attachment for X-ray microanalysis and a device for infrared spectral analysis investigations have shown that the main effect of the cement matrix modification in the case of adding complex nanodispersed systems is provided by direct influence of hydration processes with subsequent crystallization of new formations. It has been noted that while adding carbon nanotube dispersion and nanosized silica a binding matrix is structured in the form of an extremely dense shell from crystalline hydrate new formations on the surface of solid phases that provides strong binding matrix in cement concrete. The addition effect of carbon nanotubes has been analyzed and quantitatively assessed through an investigation for every case of one sample with nanotubes and one sample without them with the help of a nanoindenter and scanning electron microscope. It is necessary to solve rather complicated challenging task in order to assess quantitatively the addition effect of CNT on material characteristics at a micromechanical level. At the same time it is possible to investigate surface of a concrete sample with one-micron resolution. In this case it is necessary to prepare samples for nanoindentation with exclusion of all CNT defectable effects that have been shown by a SEM. So in this case more adequate method for assessment must be a picoindenter , which combines a test method for nanoindentation with an optical SEM potential. Such equipment is in the stage of in-situ testing process at the Vienna University of Technology. The investigation is based on the fact that the main modification effect of mineral binding matrix while using incorporated complex nanodispersed systems and nanosilica is ensured by a direct influence of hydration processes and subsequent crystallization of new formations. Scanning electron microscopy and X-ray microanalysis with detection in IR spectra have revealed that adding of multi-walled carbon nanotubes dispersion together with nanodispersed silica provides structuring of rather dense shell of hydrated new formations along cement matrix on the surface of solid phase. The structured interfacial layers form separate cells in the modified cement matrix that ensures a formation of extremely filled system and predetermines structural strengthening of the modified cement matrix due to formation of spatial packaging. Consequently, the main factor increasing characteristics of cement concrete which is modified with carbon nanotubes and nanosilica is a structural modification of calcium hydrosilicates with relation to composition and morphology of new formations

Структурная модификация новообразований в цементной матрице с использованием дисперсии углеродных нанотрубок и нанокремнезема

Complex nanodispersed systems with multi-walled carbon nanotubes and nanodispersed silica have a significant impact on the processes of hydration, hardening and strength gain of construction composites predetermining their durability. While using a scanning electron microscope with an attachment for X-ray microanalysis and a device for infrared spectral analysis investigations have shown that the main effect of the cement matrix modification in the case of adding complex nanodispersed systems is provided by direct influence of hydration processes with subsequent crystallization of new formations. It has been noted that while adding carbon nanotube dispersion and nanosized silica a binding matrix is structured in the form of an extremely dense shell from crystalline hydrate new formations on the surface of solid phases that provides strong binding matrix in cement concrete. The addition effect of carbon nanotubes has been analyzed and quantitatively assessed through an investigation for every case of one sample with nanotubes and one sample without them with the help of a nanoindenter and scanning electron microscope. It is necessary to solve rather complicated challenging task in order to assess quantitatively the addition effect of CNT on material characteristics at a micromechanical level. At the same time it is possible to investigate surface of a concrete sample with one-micron resolution. In this case it is necessary to prepare samples for nanoindentation with exclusion of all CNT defectable effects that have been shown by a SEM. So in this case more adequate method for assessment must be a picoindenter , which combines a test method for nanoindentation with an optical SEM potential. Such equipment is in the stage of in-situ testing process at the Vienna University of Technology. The investigation is based on the fact that the main modification effect of mineral binding matrix while using incorporated complex nanodispersed systems and nanosilica is ensured by a direct influence of hydration processes and subsequent crystallization of new formations. Scanning electron microscopy and X-ray microanalysis with detection in IR spectra have revealed that adding of multi-walled carbon nanotubes dispersion together with nanodispersed silica provides structuring of rather dense shell of hydrated new formations along cement matrix on the surface of solid phase. The structured interfacial layers form separate cells in the modified cement matrix that ensures a formation of extremely filled system and predetermines structural strengthening of the modified cement matrix due to formation of spatial packaging. Consequently, the main factor increasing characteristics of cement concrete which is modified with carbon nanotubes and nanosilica is a structural modification of calcium hydrosilicates with relation to composition and morphology of new formations