Wall Ceramics Products Based on Opoka and Coal Slurry

AbstractThe article shows high prospects of high-performance wall ceramics products with average density less than 700-800kg / m3 and thermal conductivity less than 0.15–0.20W/(m · °C) manufacturing with minimum costs. There is a brief description of siliceous opal-cristobalite rocks - opoka and by-products of coal processing - dehydrated coal slurries being valuable man-caused raw material. The results of studies on the production of ceramic stones of high efficiency compression molding based on clay and clay-carbonate opoka with the addition of coal slurry are shown. The main technological factors and regularities affecting the properties of products are defined. The results of research on the impact of the amount of coal slurry on the strength, density and water absorption of products taking into account the firing temperature are given. The phase-logical and mineralogical transformations occurring during firing were examined. The recommended process scheme for the production of highly efficient ceramic stones is given. The feasibility study for the products manufacturing of this type on the basis of opoka and coal slurry is give

Examination ofmulti-layer silicon detector in measurementofelectron spectrumfor beta-decayof ⁹⁰SR- ⁹⁰Y

Brief survey of recent achievements in investigations of nuclear beta decays is given with some emphasis on superallowed 0⁺→ 0⁺ Fermi transitions between T=1 nuclear states. Progress in construction of a detecting system for registration of electrons and positrons in studies of beta transitions is discussed. The spectra of electrons emitted in decay of ⁹⁰Sr and ⁹⁰Y nuclides are measured with the help of double-sided silicon detector. The spectra obtained are compared with results of computer simulation.У доповіді коротко обговорюються досягнення в недавніх дослідженнях бета-розпадів атомних ядер. Основна увага приділяється понаддозволеним 0⁺→ 0⁺ переходам Фермі між ядерними станами з ізотопічим спіном, що дорівнює одиниці. Виконано виміри спектрів електронів, що випускаються в розпадах ядер ⁹⁰SR та ⁹⁰Y, за допомогою розроблювального двостороннього кремнієвого детектора. Отримані спектри порівнюються з результатами комп'ютерного моделювання.В докладе кратко обсуждаются достижения в недавних исследованиях бета-распадов атомных ядер. Основное внимание уделяется сверхразрешенным 0⁺→ 0⁺ переходам Ферми между ядерными состояниями с изоспином Т=1. Выполнены измерения спектра электронов, испускаемых в распадах ядер стронция-90 и иттрия-90, с помощью разрабатываемого двухстороннего кремниевого детектора. Полученные спектры сравниваются с результатами компьютерного моделирования

Sharp focusing of on-axis superposition of a high-order cylindrical vector beam and a beam with linear polarization

In this work, the sharp focusing of a laser beam whose initial polarization pattern is formed by superposition of a cylindrical mth-order vector beam and a homogeneous linearly polarized beam is considered theoretically and numerically. Although in the source plane of such a beam both the angular spin momentum and the third Stokes parameter are equal to zero, we reveal that given odd m, subwavelength local regions are formed in the focal plane, where transverse vortex energy flows occur and the third Stokes parameter (the on-axis component of the angular spin momentum) is non-zero. Thus, at odd m, at the focus of such a beam there are – sub-regions with elliptical polarization of light with alternating handedness in the adjacent sub-regions (clockwise and counterclockwise). This phenomenon can be interpreted as a variant of an optical Hall effect. We note that at even m, the field at the focus is linearly polarized at every point and no transverse energy flow is observed

Circular polarization before and after the sharp focus for linearly polarized light

We consider sharp focusing of a linearly polarized light beam. Using the Richards-Wolf formalism, we show that before and after the focal plane there are cross-section regions in which the polarization is circular (elliptical). When passing through the focal plane, the direction of rotation of the polarization vector is reversed. If before the focus the light is left-hand circular polarized at a definite region of the beam cross-section, then exactly at the focus the polarization becomes linear at this cross-section region, before becoming right circular polarized after the focus at this region. This effect allows linearly polarized light to be used to rotate weakly absorbing dielectric microparticles around their center of mass