Analysis Of Gas Phase Composition Research Articles

Experiments on tritium generation and yield from lithium ceramics during neutron irradiation

The vacuum extraction method with a mass spectrometry registration of tritium is presented in paper. It can provide a full-range analysis of gas phase composition in the chamber with samples under neutron irradiation. Lithium ceramics Li2TiO3 in the form of pebbles with lithium enrichment on 6Li isotope of 96% was examined.The paper shows the results of reactor experiments on study the extraction of tritium-containing molecules from lithium ceramics Li2TiO3 at various temperatures and reactor power levels at the WWR-K research reactor (Almaty, Kazakhstan). The time dependences of tritium yield from the ampoule with ceramics during reactor irradiation were obtained. Near-surface concentrations of tritium and hydrogen atoms on the ceramics surface under reactor irradiation were estimated.

Thermodynamic Characteristics of the Cadmium Pivalate Phenanthroline Complex Cd2Piv4Phen2

Evaporation of the cadmium pivalate phenanthroline complex Cd2Piv4Phen2 was studied by the Knudsen effusion method with mass spectral analysis of gas phase composition. The evaporation is congruent, and the gas phase consists of CdPiv2Phen molecules. The standard enthalpy of sublimation of these molecules was found. The energy of dissociation of CdPiv2Phen molecules to cadmium pivalate and phenanthroline was determined on the basis of experimental data on ionization.

Gas Phase Composition and Vaporization Thermodynamics of Cobalt(II) Pivalate Complexes

Vaporization of cobalt(II) pivalate [Co(Piv)2] (1, HPiv = HO2CCMe3) and cobalt(II) oxopivalate [Co4O(Piv)6] (2) complexes has been studied by Knudsen effusion technique in combination with mass-spectral analysis of gas phase composition. The congruent sublimation of the prepared compounds has occurred, it has been accompanied by partial thermal decomposition in the case of complex 1. Saturated vapor over complex 1 has been found to consist mainly of monomeric Co(Piv)2, dimeric Co2(Piv)4, and small amount of tetrameric Co4(Piv)8 molecules, as well as Co4O(Piv)6, CO2, and 2,2,4,4-tetramethylpentanone ones. Saturated vapor over complex 2 contains only Co4O(Piv)6 species. The absolute values of partial pressure and sublimation enthalpies of gas phase components have been calculated.

Pyrolysis of Olive Mill Waste with On-line and Ex-post Analysis

Olive mill wastes constitute a serious environmental problem in the Mediterranean region due to the unique features associated with this type of agricultural waste. Therefore, it is not surprising that research efforts have been directed towards developing efficient treatment technologies including various physical–chemical processes. In this paper we present a thermo-chemical degradation method (pyrolysis) to produce biochar. The large part of work is devoted to understand the pyrolysis processes using on-line analysis of thermal parameters and chemical composition. The originality of our work resides in the on-line analysis in the form of temperature measurements during individual pyrolysis cycles as well as the whole pyrolysis process, accompanied with on-line measurements of component concentrations during the whole pyrolysis process. On-line and ex-post analysis of gas phase composition provides important information about environmental impacts of the pyrolyzing process. The concentration profiles of CO, CO2, CH4, H2 and NOX were measured at four locations within the pilot system with a high sampling frequency (every 8 s) during whole pyrolysis process. In terms of the general aspects and possible future application of pyrolysis and its products we propose a novel method capable to reduce carbon dioxide concentrations in pyrolysis gas. The average CO2 removal efficiency during the whole pyrolysis process was as high as 65%. The final product is solid proteinoid. The pyrolysis process decrease the amont of waste to 10% of input amount of material. The carbon char produced in the system may find several applications especially in the agriculture.

Pulse CVD Deposition of Ru Films from Ru(II) ή3-Allylic Complex

A ruthenium(II) ή3-allylic complex Ru(nbd)(allyl)2 (nbd = norbornadiene) was used as precursor for pulse CVD thin Ru films on silicon substrates. Preliminary study of thermal behavior of precursor was carried out: temperature dependence of vapor pressure was measured by means of Knudsen method with mass spectrometric analysis of gas phase composition; thermodynamic parameters of sublimation process were calculated. By means of high temperature mass spectrometry in situ the process of vapor thermo destruction was investigated in vacuum: vapor decomposition starts at relatively low temperature (about 180оC); the major gas by-products are the radicals of ligands - allyl, norbornadiene and their combinations. Deposition of Ru films was carried out in vacuum and hydrogen. XPS, AFM and HREM study have shown metal state of Ru in films. In the presence of hydrogen the film consists of Ru particles with size of 3.5 nm. Sample surface is smooth; mean square roughness is 0.17 nm.