Enhanced luminescence of europium in sol-gel derived BaTiO3/SiO2 multilayer cavity structure

We report on the sol-gel synthesis and optical properties of an Eu-doped multilayer structure consisting of a Bragg reflector/BaTiO3:Eu/Bragg reflector, with the Bragg reflector comprising of BaTiO3/SiO2 structures. Depending on the fabrication procedure two set of specimens were generated with Eu out of the cavity or Eu in the cavity. Enhanced Eu luminescence in the direction normal to the surface is observed for the most intense band 5D0 → 7F2 at 615 nm of trivalent europium in the cavity and correlates with anisotropy of the luminescence indicatrix, transmittance and reflection bands around 615 nm for the fabricated structure

Antimatter from the cosmological baryogenesis and the anisotropies and polarization of the CMB radiation

We discuss the hypotheses that cosmological baryon asymmetry and entropy were produced in the early Universe by phase transition of the scalar fields in the framework of spontaneous baryogenesis scenario. We show that annihilation of the matter-antimatter clouds during the cosmological hydrogen recombination could distort of the CMB anisotropies and polarization by delay of the recombination. After recombination the annihilation of the antibaryonic clouds (ABC) and baryonic matter can produce peak-like reionization at the high redshifts before formation of quasars and early galaxy formation. We discuss the constraints on the parameters of spontaneous baryogenesis scenario by the recent WMAP CMB anisotropy and polarization data and on possible manifestation of the antimatter clouds in the upcoming PLANCK data.Comment: PRD in press with minor change

Buildings and structures corrosion of metal structures and effectiveness of its prevention

In this article, metal structures can be partially or completely destroyed during the corrosion of building and building structures. Prepared buildings and structures, pipes, tanks, and other structural materials corrode (rust, collapse, and collapse) during operation, causing great damage to the manufacturing industry. The corrosion rate is unknown, and methods have been developed to combat corrosion

ЗОЛЬ-ГЕЛЬ СИНТЕЗ И ПЕРСПЕКТИВЫ ПРИМЕНЕНИЯ ПЛЕНОК ТИТАНАТА БАРИЯ

The sol-gel method of fabrication strontium titanate films is described. The films were characterized with scanning electron microscopy, X-ray diffraction analysis and ellipsometry. It is shown, that one layer of barium titanate films are amorphous, whereas multilayer films reveal Bragg diffraction peaks corresponding to BaTiO3 phase after annealing at 850оС. The perspective of fabrication the proposed sol for the thin film capacitive structures as well as multilayer interference filters of optical range is discussed.Изложен золь-гель метод формирования пленок титаната бария. Пленки исследовались методами растровой электронной микроскопии, рентгеновской дифракции и эллипсометрии. Установлено, что однослойные пленки ксерогеля титаната бария являются рентгеноаморфными, тогда как многослойные пленки демонстрируют четкие пики брегговской дифракции, соответствующие фазе титаната бария после отжига при температуре 850 °С. Обсуждается возможность применения разработанного золя для тонкопленочных конденсаторных структур на основе титаната бария, а также многослойных интерференционных фильтров оптического диапазона

Optical properties of multilayer BaTiO3/SiO2 film structures formed by the sol–gel method

Multi-layer film structures BaTiO3/SiO2 with a thickness of ~1 μm containing up to 14 pairs of layers were synthesized by the sol–gel method with sequential heat treatment. It is shown that the synthesized structures are X-ray amorphous. The formation of bands in the transmission and reflection spectra caused by interference effects is demonstrated. A more regular structure exhibits a photon band gap (opacity band) in the visible range with main minimum at 636 nm and corresponding maximum in the reflection spectra. Dispersion characteristics of barium titanate films with different concentrations of initial sols were studied and an increase in the refractive index with an increase in the concentration of sol was demonstrated. For a sol with a concentration of 60 mg/ml, the refractive index in the spectral range of 390–1600 nm is 1.88–1.81. The prospects of sol–gel technology for the formation of BaTiO3/SiO2 structures for nanophotonics and solar radiation converters are discussed

Sol–gel derived Ba/SrTiO3–MgF2 solar control coating stack on glass for architectural and automobile applications

Fully dielectric solar control coatings based on alternating layers of Ba (or Sr) TiO3 and MgF2 were deposited on soda lime glass substrates. Three-layered stacks BaTiO3/MgF2/BaTiO3 and SrTiO3/MgF2/SrTiO3 were generated using BaTiO3, SrTiO3 and MgF2 sols deposited on glass using dip coating technique. The multi-layered coating stack was fired at 450oC with different heating rates using a conventional muffle furnace and a conveyorized belt furnace, by which two methods of heat treatment were investigated. Heat treatment after deposition of each layer and a consolidated firing of the three-layered stack with intermediate drying between the layers were carried out and optical properties of the coatings compared. The heat treated coatings were characterized for their UV–Vis–NIR transmittance, microstructure, phase purity, thickness and refractive indices. The coating stack based on BaTiO3 as the high refractive index material in conjunction with MgF2 exhibited better solar control properties than SrTiO3 as the high refractive index material. Moreover, a fast firing of the BaTiO3/MgF2/BaTiO3 stack in a conveyorized belt furnace yielded good NIR blocking and solar control properties, whereas slow firing in a muffle furnace exhibited ~ 80% visible light transmittance with an NIR transmittance of ~ 75%

The Study of Dissolution Kinetics of the Phosphate Concentrate from Rivat Deposit

Проведено кинетическое исследование растворения концентрата, полученного из фосфатной руды Риватского месторождения в технической фосфорной кислоте. Показана зависимость скорости растворения от скорости перемешивания (300, 500 и 700 оборотов в минуту), концентрации фосфорного ангидрида (25, 30 и 35 % P2O5) и температуры (60, 70 и 80 °C). Установлено, что при увеличении скорости перемешивания от 300 до 700 об/ мин, концентрации от 25 до 35 % и температуры от 60 до 80 °C степень растворения увеличивается в 1,27; 1,3; 1,34 раза соответственно. Из-за сложности исследования растворения фосфатов в минеральных кислотах этот процесс не до конца изучен. Все же существует несколько различных опубликованных материалов по кинетической модели для описания данного процесса, дающих разные выражения скорости в зависимости от времени. Для изучения данного процесса наиболее подходящей моделью является модель сжимающегося ядра. В нашей работе для расчета константы скорости k и энергии активации применялась данная модель с использованием растворов, не содержащих сульфата кальцияConducted kinetic study of dissolution of the concentrate obtained from the phosphate ore of the Rivat deposit in technical phosphoric acid. To determine the kinetics and their interaction mechanism, we studied certain parameters, such as the stirring speed (300, 500 and 700 rpm), the concentration of phosphoric anhydride (25, 30 and 35 % P2O5), as well as the temperature (60, 70 and 80 °C). It should be noted that the rate of dissolution of phosphorite concentrate increases with an increase of studied parameters. Due to the complexity of the dissolution of phosphates in mineral acids, this process has not fully explored. However, there are several different published materials on the kinetic model to describe this process, giving different expressions of the rate as a function of time. To study this process, the most suitable model is the shrinking core model. In this work, to calculate the rate constant k and the activation energy, we used solutions free of calcium sulfat

Optimized approach to the treatment of fractures by taking into account the derangements some aspect of lipid profile in patients with concomitant of traumatic brain injury

The authors analyzed the results of diagnostics and treatment of 183 patients with concomitant brain injury. Through research of lipid spectrum of venous blood plasma of patients and the use of modified isovolumic hemodilution was managed to optimize the treatment of traumatic brain injury and limb fractures in patients of the main group. Was reduced the number of complications by 9.9% (respectively 15.7% and 25.6%), and unsatisfactory results of treatment by 10.9% (respectively 5% and 15.9%). The positive effect of treatment results in patients of the main group due to: an optimized approach to the treatment of the manifestations of traumatic brain injury and fractures of the extremities according to the severity of injuries, the state of the victim, the severity of traumatic brain injury, lipidic spectrum observation, using isovolumic hemodilution and using attenuated methods of osteosynthesis. Modified isovolumic hemodilution allows to move out the patient's state of shock, reduces the hypoxia hematic and prevents interstitial edema, minimizes blood loss and the degree of endogenous intoxication, reduces the risk of fat embolism syndrome and other vital disorders.Авторы проанализировали результаты диагностики и лечения 183 пациентов с сочетанной черепно-мозговой травмой. Благодаря исследованиям липидного спектра плазмы венозной крови у больных и использованию модифицированной изоволемической гемодиллюции удалось оптимизировать лечение ЧМТ и переломов конечностей у больных основной группы. Снижено количество осложнений на 9,9% (соответственно 15,7% и 25,6%) и неудовлетворительных результатов лечения на 10,9% (соответственно 5% и 15,9%). Положительный эффект результатов лечения больных основной группы обусловлен: оптимизированным подходом к лечению проявлений ЧМТ и переломов конечностей с учетом тяжести травм, состоянием пострадавшего, тяжестью ЧМТ, исслндованием липидного спектра, применением изоволемической гемодиллюции и использование щадящих способов остеосинтеза. Модифицированная изоволемическая гемодиллюция позволяет вывести больного из состояния шока, снижает гемическую гипоксию и препятствует интерстициальному отёку, минимизирует объем кровопотери и степень эндогенной интоксикации, снижает риск развития синдрома жировой эмболии и других витальных нарушений

Sol–Gel Fabrication and Luminescence Properties of Multilayer Eu-Doped BaTiO3–SiO2 Xerogel Nanostructures

With the use of sol–gel method BaTiO3–SiO2 multilayer structures were fabricated on glass or fused silica substrates employing dipping or spinning procedure. The photonic stop band was observed in the reflection and transmission spectra of the multilayer structure annealed at 450∘C. It is redshifted with an increase of the thicknesses of BaTiO3 and SiO2 layers. For structures comprising Eu-doped BaTiO3 layers of different thicknesses photoluminescence with the main band at 614nm was detected. It is characterized with the double-exponential decay with the lifetimes of about 0.5ms and 1.1ms which do not depend significantly on the photonic stop band position