Oxygen-containing Nitrogen Research Articles

Pharmacological protection of the detoxification activity of animals’ liver with the help of phospholipid and polysaccharide nature substances complex

Currently, among chemical pollutants a significant danger to the health of animals and humans represent oxygen-containing nitrogen compounds nitrates and nitrites, which are widely used as mineral fertilizers. The article presents data on the study of chronic nitrate intoxication, reproduced in laboratory animals and its pharmacological correction with a complex of substances of phospholipid and polysaccharide nature. The introduction of sodium nitrate to non-linear rats for 30 days at a dose of 3.8 mg per animal leads to the development of intoxication in rats with dominant signs of liver damage. On this background, the use of the complex of beet fiber and rapeseed lecithin leads to a weakening of nitrate toxicosis, which is demonstrated by an increase in rats’ body weight, weakening of the clinical manifestations of intoxication, a decrease in cytolytic syndrome, intrahepatic cholestasis and impaired protein synthesis function of liver.

Compositional Characterization of Expelled and Residual Oils in the Source Rocks from Oil Generation-Expulsion Thermal Simulation Experiments.

Petroleum generation–expulsion thermal simulation experiments on a low-maturity type I source rock were carried out. The composition of hydrocarbons and heteroatom-containing compounds in both expelled and residual oils was characterized by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and gas chromatography-mass spectrometry. A thorough analysis of fractionation effects was presented between expelled and residual oils. The oil composition strongly depended on the pyrolysis temperature. A significant difference in the molecular composition was found between expelled and residual oils at various pyrolysis temperatures. The difference in maturity for expelled and residual oils could be revealed clearly by the difference in the molecular composition of heteroatom-containing compounds. Carboxylic acids in the residual oil cracked quickly with the pyrolysis temperature above 350 °C (% Ro = 1.0) but part of them would survive if they were expelled out of the source rock timely. The variations between the relative abundance of oxygen compounds and nitrogen compounds indicated that the thermostability of oxygen-containing nitrogen compounds was lower than that of neutral nitrogen compounds. The variation trends in double bond equivalents and carbon number distributions of O1, O2, and N1 class species were similar. The aromaticity of heteroatom-containing polar species increased with maturity.

Formation of oxynitride layers on titanium alloys by gas diffusion treatment

Titanium alloys were oxynitrided in controlled nitrogen-oxygen gas atmospheres between 650 °C and 950 °C for 5 h to 10 h with two different techniques of gas diffusion treatment. One technique was performed in an oxygen-containing (oxygen amount ≥ 0.4 %) nitrogen environment. The other technique was performed in a deoxygenated (oxygen amount < 0.01 % to 0.0005 %) nitrogen environment with subsequent cooling in an oxygen-containing nitrogen environment (with an oxygen pressure of 1 Pa). The surface microhardness of oxynitrided samples increased due to the strengthening effect of titanium oxynitrides (TiNxOy). The maximum microhardness of the titanium oxynitrides was obtained with a near-equiatomic composition of nitrogen and oxygen in TiNxOy under optimal oxygen partial pressure and temperature-time conditions.

Influences of oxygen impurity contained in nitrogen on the reaction of titanium with nitrogen

In this work, Ti pellets were selected as a model system to investigate the influences of oxygen impurity in nitrogen gas on the reaction of a metal with the nitrogen. Analyzing changes in the in situ oxygen partial pressures when titanium specimens were annealed in the oxygen-containing nitrogen shows that the dissolution of oxygen in Ti and TiNx is exothermic, and the solubility decreases as the temperature increases. X-ray diffraction results show that nitridation of Ti occurred before oxidation, even in an oxygen-containing nitrogen atmosphere. Kinetics apparently predominates over thermodynamics at low temperatures in such a system.

Electrocatalytic oxidation of hydrazine on platinum electrodes in alkaline solutions

The mechanism and structure sensitivity of the electrocatalytic oxidation of hydrazine on platinum in alkaline solutions were investigated using cyclic voltammetry, steady-state current measurements, and on-line electrochemical mass spectrometry. The voltammetry of hydrazine oxidation on platinum in alkaline media is characterized by a single diffusion-controlled wave. The on-line electrochemical mass spectrometry measurements of hydrazine oxidation on Pt(1 1 1), Pt(1 0 0), and Pt(1 1 0) surfaces indicated the formation of molecular nitrogen. No oxygen-containing nitrogen compounds were detected under the given experimental conditions. A comparative analysis of voltammetric data for hydrazine oxidation in alkaline solutions on the three surfaces at low overpotentials points to a structure sensitivity of the reaction. The electrocatalytic activity of basal planes increases in the order Pt(1 1 0) > Pt(1 0 0) > Pt(1 1 1), as deduced from the onset of the oxidation wave. The structure of the electrocatalyst surface affects the mechanism of the reaction, although without affecting the selectivity. At low overpotentials the hydrazine oxidation on the Pt(1 1 0) and Pt(1 1 1) surfaces is limited by the rate of electrochemical steps, whereas on Pt(1 0 0) a chemical step that probably involves N 2H 2 adsorbed intermediate is the rate-determining step. Platinum is more active in hydrazine oxidation in alkaline solution than in acidic solutions. In contrast to hydrazine oxidation on platinum in acidic media, the stabilization of chemisorbed hydrazine does not occur to a significant extent in alkaline media.

Growth of 12CaO·7Al 2O 3 single crystal with tetragonal symmetry by Czochralski method

Single crystals of 12CaO·7Al 2O 3 (C12A7) have been grown by the Czochralski method with three different growth directions of <100>, <110>, and <111>. Employment of a 2.0% oxygen-containing nitrogen atmosphere and use of an iridium crucible were the critical factors for obtaining the single crystal. The crystal exhibited orange color resulting from the incorporation of Ir 4+ ions of ∼ 5 × 10 17 cm − 3 , presumably occupying at Ca 2+ sites. High resolution X-ray diffraction analyses indicated that the C12A7 single crystal shows the tetragonal symmetry belonging to the space group I 4 ― 2 m .

Forming carbonitride coatings on titanium by thermochemical treatment with C-N-O-containing media

The formation of TiCxNy coatings on titanium alloys through thermochemical treatment of graphite in nitrogen was investigated in this study. The presence of oxygen in saturating media was found to lower the nitrocarburizing temperature from 1,100°C to 850°C. Two methods to accumulate oxygen in a saturating medium have been proposed: using oxygen-containing nitrogen or oxygensaturated graphite. The sequence of stages of carbonitride formation in the Ti-C-N-O system is explained in this paper.

Czochralski Growth of 12CaO·7Al2O3 Crystals

Single crystals of nanoporous 12CaO·7Al2O3 (C12A7) as large as 27 mm in diameter, 120 mm in length, and 207 g in weight have been successfully grown by the Czochralski method. We found that a 2.0% oxygen-containing nitrogen atmosphere and an iridium crucible are the critical factors for success. The crystal ingot exhibited an orange color resulting from the incorporation of Ir4+ ions of ca. 5 × 1017 cm-3, which presumably occupy Ca2+ sites. X-ray diffraction analysis indicated that the ingot obtatined was a single crystal with few domains.

Thermodynamic Analysis of the Possibility of Hydrogen Production by Oxidation of n -Butane, n -Pentane, and Carbon by Oxygen-Containing Nitrogen Compounds

A thermodynamic analysis is performed to study the reactions of hydrogen production by oxidation of hydrocarbons of natural gas and carbon of solid fuels by unconventional oxidants—oxygen-containing nitrogen compounds. The analysis suggests the possibility of developing a new hydrogen production method, which in comparison with existing methods can provide higher efficiency, lower energy and material consumption, and higher conversion of the initial reactants.

Electrical properties of undoped BaTiO3 ceramics annealed in a fluorine containing atmosphere

Air-sintered and atmospherically reduced BaTiO 3 ceramics were fluorinated by the introduction of a CF 3 CH 2 OH fluorination agent into a hot furnace using a supporting gas: either pure nitrogen or nitrogen containing a low concentration of oxygen. The nitrogen-supported fluorination resulted in a decrease in the resistivity of the insulating air-sintered samples to semiconducting values, primarily due to atmospheric reduction. When air-sintered samples were fluorinated using oxygen-containing nitrogen as the supporting gas, their resistivity remained very high. The exposure of fluorinated samples to air at high temperatures (1200°C) resulted in a decrease of their resistivity and a remarkable PTCR effect.

Activated nitriding of TiCN-based cermets

Computer modelling in the Ti-C-N and Ti-C-O-N systems shows that the thermodynamic potential for nitriding TiC in pure nitrogen is low whereas adding small amounts of oxygen leads to a considerable increase in the potential for nitriding TiC. A new technology for nitriding the TiCN-Ni-Mo cermets in an oxygen-containing nitrogen flow is developed. Adding small amounts of oxygen to nitrogen utilized for carrying out the nitridation process allows substantial intensification of the process. This results in formation of a TiN-enriched surface layer on the surface of the cermets and substantial improvement in their performance properties.

Thermoelectric Power of Crystalline Sodium Chloride

The thermoelectric power of single crystals of pure NaCl and of SrCl2-doped NaCl was measured in the temperature range 550°–755°C using Pt electrodes and a nitrogen atmosphere. The results for the pure crystals differ significantly from previous measurements on polycrystalline material. Current theories of the heterogeneous thermoelectric power do not adequately describe the results. Part, but probably not all, of this discrepancy may be due to errors in transport numbers used, which were calculated from diffusion data. The thermoelectric power of pure NaCl is decreased by heating the crystals in oxygen-containing nitrogen.