65 research outputs found
Characteristics Of Microflora In Patients With Chronic Purulent Rhinosinusitis
In this section, 186 patients with chronic inflammatory processes of the nasal sinuses, including 84 patients with chronic purulent inflammation (group I), 66 patients with exacerbation of chronic inflammatory process (group II), 27 patients with exacerbation of chronic purulent rhinosinusitis and. The results of bacteriological examination were shown in 9 patients with recurrent odontogenic sinusitis (group III) and 9 patients with chronic purulent odontogenic sinusitis (group IV)
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
Effect of calcium doping on the anodic behavior of E-AlMgSi (Aldrey) conducting aluminum alloy in NaCl electrolyte medium
The design of new materials intended for operation under severe conditions faces the task of rendering the materials corrosion resistant. The practical solution of this task is interrelated with the knowledge of corrosion protection of metals and alloys. The use of conducting aluminum alloys for the manufacture of thin wire may encounter specific problems. This is caused by the insufficient strength of these alloys and a small number of kinks before fracture. Aluminum alloys have been developed in recent years which even in a soft state have strength characteristics that allow them to be used as a conductive material. The E-AlMgSi (Aldrey) aluminum alloy is a well-known conducting alloy. This alloy is a heat-strengthened one, possessing good plasticity and high strength. After appropriate heat treatment this alloy acquires high electrical conductivity. Wires made from this alloy are almost exclusively used for air transmission lines. This work presents data on the corrosion behavior of calcium containing E-AlMgSi (Aldrey) aluminum conducting alloy in 0.03, 0.3 and 3.0% NaCl electrolyte medium. The anodic behavior of the alloy has been studied using a potentiostatic technique with a PI-50-1.1 potentiostat at a 2 mV/s potential sweep rate. Calcium doping of the E-AlMgSi (Aldrey) aluminum alloy increases its corrosion resistance by 15–20%. The corrosion, pitting and repassivation potentials of calcium doped alloys shift toward the positive region. An increase in the sodium chloride electrolyte concentration leads to a decrease in these potentials
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
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
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
Extracting photometric determination of antimony with 5–pyridylazo–2–monoethylaminoparacresol (PAAC)
The developed extraction-spectrophotometric method for the determination of antimony utilizing 5-(pyridylazo)-2-monoethylaminoparacresol (PAAC) stands out for its selectivity, sensitivity, and rapidity. This method proves to be effective in the determination of antimony in various complex matrices, including model solutions of silicate rocks and ores. The robustness of the method is evident as it successfully analyzes these samples without the need for preliminary separation of accompanying elements. PAAC is chosen as the complexing agent for antimony. Its selectivity and sensitivity contribute to the precision of the method. The method involves an extraction step, likely utilizing a suitable organic solvent, to selectively extract the antimony-PAAC complex from the sample matrix. The concentration of antimony in the extracted complex is determined spectrophotometrically. This involves measuring the absorbance of the complex at a specific wavelength, typically chosen based on the characteristics of the PAAC-antimony complex. The method is validated by analyzing model solutions of silicate rocks and ores. This step assesses the applicability and accuracy of the method in samples that simulate real-world conditions. The method demonstrates a reproducibility of 2-5%, indicating its reliability and precision across multiple analyses. The developed method is recommended for the analysis of chemically complex materials such as industrial wastewater, ores, concentrates, and rocks
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%
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