Mechanism of Aggregation Colloid Centers on Surface Ionic Crystals

In this chapter, we analyze the kinetics of changes in the intensities of peaks of these aggregate defects as a function of the substrate temperature, as well as study the degradation of these aggregate F centers in order to understand the mechanisms of their formation and transformation to other types of defects, to colloids. The results obtained using methods of total current (TC) spectroscopy and secondary-ion mass spectroscopy (SIMS) under ion bombardment of LiF crystals are analyzed. The temperature dependence of the generation kinetics of F centers and their aggregates in a LiF/Si(1 1 1) thin-film system after irradiation with low-energy (80 eV) electrons was studied by TC spectroscopy. It was shown that, in all cases, low-temperature annealing results in the degradation of the formed centers followed by their coalescence. By SIMS, it is shown that the majority of the products of crystal sputtering contain point defects. A procedure for determining defects in sputtered clusters of ionic crystals is developed

Growth of ITO Films by Modified Chemical Vapor Deposition Method

Growth of ITO films on glass substrate by modified CVD method in quasi closed space with separate evaporator for formation of saturated vapor phase is investigated. The growth rate of ITO films was an order 0,5-1,0 micron/hour it is several times above than for conventional spray-pyrolysis in similar conditions. The lattice absorption spectra of fabricated ITO films shown that materials grown in temperature interval 170-500?C have identical structure, have no inclusions of secondary phase and uniform. IR absorption band in the range of 2500-3800 cm-1 which amplitude has correlation with conductivity of ITO films is found out

Magnetic Fe3O4-Ag0 nanocomposites for effective mercury removal from water

In this study, magnetic Fe3O4 particles and Fe3O4-Ag0 nanocomposites were prepared by a facile and green method, fully characterized and used for the removal of Hg2+ from water. Characterizations showed that the Fe3O4 particles are quasi-spherical with an average diameter of 217 nm and metallic silver nanoparticles formed on the surface with a size of 23-41 nm. The initial Hg2+ removal rate was very fast followed by a slow increase and the maximum solid phase loading was 71.3 mg/g for the Fe3O4-Ag0 and 28 mg/g for the bare Fe3O4. The removal mechanism is complex, involving Hg2+ adsorption and reduction, Fe2+ and Ag0 oxidation accompanied with reactions of Cl- with Hg+ and Ag+. The facile and green synthesis process, the fast kinetics and high removal capacity and the possibility of magnetic separation make Fe3O4-Ag0 nanocomposites attractive materials for the removal of Hg2+ from wate

Degradation and mineralization of 4-tert-butylphenol in water using Fe-doped TiO2 catalysts

In the present work, the photocatalytic degradation and mineralization of 4-tert-butylphenol in water was studied using Fe-doped TiO2 nanoparticles under UV light irradiation. Fe-doped TiO2 catalysts (0.5, 1, 2 and 4 wt.%) were prepared using wet impregnation and characterized via SEM/EDS, XRD, XRF and TEM, while their photocatalytic activity and stability was attended via total organic carbon, 4-tert-butyl phenol, acetic acid, formic acid and leached iron concentrations measurements. The effect of H2O2 addition was also examined. The 4% Fe/TiO2 demonstrated the highest photocatalytic efficiency in terms of total organic carbon removal (86%). The application of UV/H2O2 resulted in 31% total organic carbon removal and 100% 4-t-butylphenol conversion, however combining Fe/TiO2 catalysts with H2O2 under UV irradiation did not improve the photocatalytic performance. Increasing the content of iron on the catalyst from 0.5 to 4% considerably decreased the intermediates formed and increased the production of carbon dioxide. The photocatalytic degradation of 4-tert-butylphenol followed pseudo-second order kinetics. Leaching of iron was observed mainly in the case of 4% Fe/TiO2, but it was considered negligible taking into account the iron load on catalysts. The electric energy per order was found in the range of 28–147 kWh/m3/order and increased with increasing the iron content of the catalyst

UV LIGHT BLOCKING AND CONVERSION BY POROUS EUROPIUM-DOPED TITANIUM DIOXIDE (TIO2-EU) THIN FILMS FOR POTENTIAL PROTECTION OF PHOTOVOLTAIC DEVICES

In recent years, transparent thin films capable of screening and converting ultraviolet (UV) photons into visible spectrum gained significant interest in the protection of photovoltaic devices.We investigated the optical properties and UV screening capability of europium-doped titanium oxide (TiO2 Eu) thin films deposited by the spin-coating method from a solution precursor for the first time in this study. We showed that TiO2-Eu thin films demonstrate europium concentration-dependent optical properties, and the quantum yield of the optimized sample was found to be ~10.2%. Transmittance and photoluminescence measurements suggested that TiO2 Eu thin film can effectively block UV photons (~30.5% at 320 nm) at glass substrate and convert them to the red emission thanks to 5D0/7Fj (j ¼ 0, 1, 2, 3, and 4) Eu (III) electronic transitions. Photodegradation experiments with methylene blue dye revealed that TiO2 Eu thin films offer better UV protection compared to uncoated samples. We strongly believe that porous TiO2 Eu thin films can be effectively utilized as a UV blocking and light conversion coating

TI2O3/TIO2-ASSISTED SOLAR PHOTOCATALYTIC DEGRADATION OF 4-TERT-BUTYLPHENOL IN WATER

Colored Ti2O3 and Ti2O3/TiO2 (mTiO) catalysts were prepared by the thermal treatment method. The effects of treatment temperature on the structure, surface area, morphology and optical properties of the as-prepared samples were investigated by XRD, BET, SEM, TEM, Raman and UV–VIS spectroscopies. Phase transformation from Ti2O3 to TiO2 rutile and TiO2 anatase to TiO2 rutile increased with increasing treatment temperatures. The photocatalytic activities of thermally treated Ti2O3 and mTiO were evaluated in the photodegradation of 4-tert-butylphenol (4-t-BP) under solar light irradiation. mTiO heated at 650 C exhibited the highest photocatalytic activity for the degradation and mineralization of 4-t-BP, being approximately 89.8% and 52.4%, respectively, after 150 min of irradiation. The effects of various water constituents, including anions (CO2 3 , NO3, Cl and HCO 3 ) and humic acid (HA), on the photocatalytic activity of mTiO-650 were evaluated. The results showed that the presence of carbonate and nitrate ions inhibited 4-t-BP photodegradation, while chloride and bicarbonate ions enhanced the photodegradation of 4-t-BP. As for HA, its effect on the degradation of 4-t-BP was dependent on the concentration. A low concentration of HA (1 mg/L) promoted the degradation of 4-t-BP from 89.8% to 92.4% by mTiO-650, but higher concentrations of HA (5 mg/L and 10 mg/L) had a negative effect

VAR - analysis of Global financial economic crisis impact on public budget and unemployment: evidence from the economy of the Kyrgyz Republic

The Global financial crisis hit the economy of the Kyrgyz Republic by the third wave of its transmission in the early of 2009. The article examines the impact of the Global financial economic crisis on the public budget and unemployment of the Kyrgyz Republic. We analyzed the transmission of the crisis on the public budget firstly and its effect on unemployment level by using the vector autoregression approach (VAR) and quarterly data for 2005-2013 within the framework of IS-LM model for small open economies with floating exchange rate. There is an inverse relationship between the public budget and remittances inflow, liquidity level, volume of deposits, and exchange rate. As a result of the study, the fall in remittances inflows, liquidity level of the banking system, depreciation of the national currency lead to an increase in public revenue. Therefore, the increase in public spending during the crisis period, with the aim of unemployment reduction, may be considered as a crucial policy. The study result allows to policy-makers to exactly know what channels of transmission mechanism transfer the Global crisis on the public budget and its effect on unemployment level of the republic in order to undertake anticrisis macroeconomic policy. The final result of the study indicates that the increase of unemployment level by 1 % requires the increase of public spending by 0.63 %. © Copyright 2005-2016 Institute of Economics, the Ural branch of the RAS. All rights reserved

Comprehensive solution to environmental problems of ceramic production by recycling their waste in cement industry

The paper presents the results of studies to determine the suitability of the dump battle of fired ceramic products based on kaolin clays of the Angren deposit, the positive effect of the addition of fractionated ceramic battle on the formation of the structure and physico-mechanical properties of portland cement stone is established. For use as an additive in cement, the need for fractionation of ceramic production waste with separation of the burnt part of ceramic waste was noted; its chemical and mineralogical compositions and hydraulic activity were determined according to the Student’s criterion, the value of which was t=21.21, which is higher than its regulated value of at least 15 according to GOST (State Standard) 31108-2020. Based on the obtained research results, ceramic waste is recommended as an active mineral additive in cement. The positive effect of the addition of fractionated ceramic waste on the process of origin and evolution of neoplasms in terms of acceleration of hydrolysis, hydration of clinker minerals, and cement hardening with the formation of a low-porous structure of cement stone, which, despite a decrease in the proportion of high-temperature Portland cement clinker up to 20%, is characterized by high hydraulic activity corresponding to the grade of cement PC400-D20

Foreign portfolio investment and monetary policy: A disaggregated analysis In Nigeria

The study used Toda-Yamamoto causality framework, an augmented vector autoregressive model, to examine the response of foreign portfolio investment to monetary policy decisions in Nigeria. The results indicated no causality running from any of the monetary policy tools to aggregate foreign portfolio investment. However, a unidirectional causality was found running from the total foreign portfolio investment to the policy rate and cash reserve ratio. This suggests that monetary policy is reactive, as developments in the foreign portfolio markets influence it. The results also showed that each key component response to specific monetary policy instruments with varying levels of magnitudes