Environment safety technology of creating coated powder of technical ceramics

2020 ◽  
pp. 64-72
Author(s):  
L. V. Kozyreva ◽  
◽  
V. V. Kozyrev ◽  
I. S. Krekova ◽  
◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Abrasive Wear ◽  
Volume Ratio ◽  
Iron Pentacarbonyl ◽  
Powder Materials ◽  
Tungsten Coating ◽  
Tungsten Hexacarbonyl ◽  
Technical Ceramics ◽  
Coated Powder

Application of fuller materials for creation of the higt-strength coatings on part operating under abrasive wear is one of the promising ways of the resources increasing of road construction, emergency rescue and other types of equipment. However, in their creation process does not always comply with the environmental safety requirements, which leads to negative consequences for the natural environment and human health. The article presents the research work results of authors team created a coated powder by chemical vapor deposition of metal-organic compounds on the alumina particles surface and its applications for the wear-resistant coatings. A method of applying iron-tungsten coating on powder technical ceramics by thermal decomposition of vapors, containing iron pentacarbonyl and tungsten hexacarbonyl, is characterised by sequential application on powder particles of adhesion layer from mixture of iron pentacarbonyl and carbon monoxide in volume ratio of vapours1:5 at temperature of their thermal decomposition of 250 °С, and then surface layer from mixture of tungsten hexacarbonyl and carbon monoxide in volume ratio of vapours1:5 at temperature of their thermal decomposition of 800 °С. Metallization powder materials are carried out in a closed cycle, excluding contact workers with toxic substances and emissions of pollutants into the atmosphere, which ensures the safety of the production process. Plasma coatings obtained with the necessary physical and mechanical properties are obtained, which proves the effectiveness of the employed approach and promotes resource increase of the machines elements, subjected to abrasive wear.

The thermal decomposition of trimethylacetyl bromide

1970 ◽  
Vol 23 (3) ◽  
pp. 525 ◽  
Author(s):  
BS Lennon ◽  
VR Stimson
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Hydrogen Bromide ◽  
Transition States ◽  
Volume Ratio ◽  
Reaction Vessel ◽  
Chain Mechanism ◽  
Radical Chain ◽  
First Order ◽  
Polar Transition

Trimethylacetyl bromide decomposes at 298-364� into isobutene, carbon monoxide, and hydrogen bromide in a first-order manner with rate given by k1 = 138 x 1014exp(-48920/RT) sec-1 The rate is unaffected by addition of the products or of inhibitors, or by increase of the surface/volume ratio of the reaction vessel. The likely radical chain mechanism is considered and rejected. The reaction is believed to be a molecular one, and possible cyclic and polar transition states are discussed.

INCREASING THE WEAR RESISTANCE OF THE WORKING BODIES OF AGRICULTURAL MACHINES BY THE HDTV METHOD WITH ADDING POWDER OF THE EED METHOD

2020 ◽  
Vol 4 (141) ◽  
pp. 123-131
Author(s):  
IL’YA ROMANOV ◽  
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
High Frequency ◽  
Machine Building ◽  
Abrasive Wear Resistance ◽  
Research Purpose ◽  
Powder Materials ◽  
Agricultural Machinery ◽  
Resource Saving ◽  
Working Bodies

The development of energy and resource-saving methods and technologies for strengthening and restoring the working bodies of agricultural machinery will increase their abrasive wear resistance and durability by using materials from machine-building waste and reduce the cost by 10-30 percent without reducing operational characteristics. (Research purpose) The research purpose is in increasing the abrasive wear resistance and durability of cultivator legs by surfacing powder materials obtained by electroerosive dispersion from solid alloy waste by high-frequency currents. (Materials and methods) Authors obtained a powder for research on their own experimental installations of the CCP "Nano-Center" of electroerosive dispersion from waste of sintered hard alloys of the T15K6 brand. The microhardness of powders and coatings on microshifts was measured using the PMT-3 device, and the hardness of coatings with the KMT-1 microhardometer was measured using the Rockwell method according to GOST 9013-59. The microwave-40AV installation was used to assess the wear resistance of materials of working bodies of tillage machines. (Results and discussion) In the course of laboratory wear tests the relative wear resistance of samples hardened by high-frequency surfacing currents significantly exceeds the wear resistance of non-hardened samples made OF 65g steel, accepted as the reference standard. (Conclusions) Based on the results of experimental studies, the article proposes a new resource-saving technological process for strengthening the working bodies of agricultural machinery through the use of materials from machine-building waste, which allows increasing the abrasive wear resistance of working bodies by 1.5-2 times due to the use of tungsten-containing materials.

The thermal degradation of μ-Diphenylacetylene-bis(tricarbonylcobalt)

1973 ◽  
Vol 26 (8) ◽  
pp. 1791 ◽  
Author(s):  
RS Dickson ◽  
LJ Michel
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Thermal Degradation ◽  
Organic Compounds ◽  
Degradation Mechanism ◽  
Scanning Calorimetry ◽  
Organic Products ◽  
Suitable Temperature ◽  
Degradation Reaction

The thermal decomposition of Co2(CO)6(PhC2Ph) has been investigated in detail. Differential scanning calorimetry was used to determine the most suitable temperature range for the study. At 180�, Co2(CO)6(PhC2Ph) decomposes to form cobalt, carbon monoxide, tetraphenylcyclopentadienone, hexaphenylbenzene, and other organic compounds. Variation in the temperature, the time, and the solvent used for the degradation reaction causes significant changes in the yields of the organic products. An investigation of the effects of adding stoichiometric amounts of free alkyne, tetra-phenylcyclopentadienone, and hexaphenylbenzene has been initiated in an attempt to understand the degradation mechanism.

Exergy and Energy Analysis of α-Fe2O3-Doped Al2O3 Nanocatalyst-Based Biodiesel Blends—Performance and Emission Characteristics

2021 ◽  
Vol 143 (12) ◽  
Author(s):  
A. Anderson ◽  
Amal M. Al-Mohaimeed ◽  
Mohamed Soliman Elshikh ◽  
T. R. Praveenkumar ◽  
M. Sekar
Keyword(s):  
Carbon Monoxide ◽  
Energy Analysis ◽  
Unsaturated Fatty Acids ◽  
Engine Performance ◽  
Volume Ratio ◽  
Emission Characteristics ◽  
Biodiesel Blends ◽  
Performance And Emission ◽  
High Area ◽  
Load Conditions

Abstract The current study emphasis on the engine performance and emission characteristics of rapeseed and soya biodiesel dispersion on a novel nanocatalyst at different concentrations of 25 ppm and 50 ppm. The results of this study were compared with those of conventional diesel at varying load conditions on a combustion ignition engine. An α-Fe2O3-doped Al2O3 was mixed with rapeseed biodiesel and soya biodiesel using an ultrasonicator at a frequency of 25 kHz. This study revealed that the incorporation of nanoparticles in biodiesel enhanced the performance of the blends by reducing the content of lignin and other unsaturated fatty acids. The improvement in the performance of the engine is mainly attributed to the high area-to-volume ratio of the nanocatalyst. Emissions of NOx. hydrocarbon and carbon monoxide during the combustion reaction increased significantly when nanoparticles were added at higher concentrations. Contrastingly, the emission of NOx in pure biodiesel was higher than that in conventional diesel. The addition of nanoparticles reduced CO emissions due to the presence of extra oxygen molecules and converted carbon monoxide into carbon dioxide. Soya seed biodiesel blends with 50 ppm nanoparticles showed better engine performance and emission characteristics as compared with all other blends.

COMPARATIVE ANALYSIS OF THE CONTENT OF TOXIC SUBSTANCES IN THE GAS PHASE OF AEROSOL OF CIGARETTES AND HEATED TOBACCO STICKS FOR ELECTRIC TOBACCO HEATING SYSTEMS

2020 ◽  
Author(s):  
С.Н. МЕДВЕДЕВА ◽  
Т.А. ПЕРЕЖОГИНА ◽  
Е.В. ГНУЧИХ
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Comparative Analysis ◽  
Gas Phase ◽  
Control Sample ◽  
Toxic Substances ◽  
Heating Systems

Представлены результаты анализа содержания монооксида углерода, бензола, 1,3-бутадиена в газовой фазе аэрозоля (ГФА) образцов нагреваемых табачных палочек (стики) для электрических систем нагревания табака, пяти марок коммерческих сигарет, контрольной сигареты 3R4F с помощью тестирования на курительной машине в стандартном режиме прокуривания ISO и интенсивном ISO Intense. Установлено значительное снижение содержания монооксида углерода, бензола и 1,3-бутадиена в аэрозоле образцов стиков по режиму ISO Intense и ISO. Количество образующегося монооксида углерода в ГФА образцов стиков составляет 2% от его содержания в ГФА образца контрольных сигарет 3R4F, что подтверждает отсутствие процессов термического разложения (пиролиза) табака. Определено, что в ГФА образцов стиков содержится значительно меньше вредных и потенциально опасных соединений. Установлено снижение содержания бензола и 1,3-бутадиена более чем на 99% по сравнению с контрольным образцом 3R4F и пятью образцами популярных в России марок сигарет. The results of the analysis of the content of carbon monoxide, benzene, 1,3-butadiene in the aerosol gas phase (AGPh) of heated tobacco sticks for electric tobacco heating systems, five brands of commercial cigarettes, 3R4F control cigarette using testing on a Smoking machine in standard ISO smoking mode and ISO Intense are presented. A significant decrease in the content of carbon monoxide, benzene and 1,3-butadiene in stick aerosols according to the ISO Intense and ISO modes was found. The amount of carbon monoxide produced in the effluent AGPh is 2% of its content in the AGPh of 3R4F control cigarettes, which confirms the absence of thermal decomposition (pyrolysis) of tobacco. It was determined that the AGPh of verses contains significantly fewer harmful and potentially dangerous compounds. A decrease in the content of benzene and 1,3-butadiene was found by more than 99% compared to the control sample of 3R4F cigarettes and five brands of cigarettes popular in Russia.

Reactions of 1,1,3,3-tetramethyldisilazane with dicobalt octacarbonyl and iron pentacarbonyl. Thermal decomposition of the cobalt and iron carbonyl silazane complexes

1998 ◽  
Vol 47 (12) ◽  
pp. 2455-2462 ◽  
Author(s):  
V. V. Semenov ◽  
E. Yu. Ladilina ◽  
S. Ya. Khorshev ◽  
N. P. Makarenko ◽  
Yu. A. Kurskii ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Iron Pentacarbonyl ◽  
Iron Carbonyl ◽  
Dicobalt Octacarbonyl

The gas-phase photochemistry and thermal decomposition of glyoxylic acid

1985 ◽  
Vol 63 (2) ◽  
pp. 542-548 ◽  
Author(s):  
R. A. Back ◽  
S. Yamamoto
Keyword(s):  
Thermal Decomposition ◽  
Carbon Monoxide ◽  
Absorption Spectrum ◽  
Gas Phase ◽  
Singlet State ◽  
Glyoxylic Acid ◽  
Static System ◽  
First Order ◽  
Increasing Temperature ◽  
Homogeneous Formation

The photolysis of glyoxylic acid vapour has been studied at five wavelengths, 382, 366, 346, 275, and 239 nm, and pressures from about 1 to 6 Torr, at a temperature of 355 K. Major products were CO2 and CH2O, initially formed in almost equal amounts, while minor products were CO and H2. Except at 382 nm, the system was complicated by the rapid secondary photolysis of CH2O. Three primary processes are suggested, each involving internal H-atom transfer followed by dissociation.The absorption spectrum is reported and shows the three distinct absorption systems. A finely-structured spectrum from about 320 to 400 nm is attributed to a transition to the first excited π* ← n+ singlet state; a more diffuse absorption ranging from about 290 nm to a maximum at 239 nm is assigned to the π* ← n− state, while a much stronger absorption beginning below 230 nm is attributed to the π* ← π transition. Product ratios vary with wavelength and depend on which excited state is involved.The thermal decomposition was studied briefly in a static system at temperatures from 470 to 710 K and pressures from 0.4 to 8 Torr. Major products were again CO2 and CH2O, but the latter was always less than stoichiometric. First-order rate constants for the apparently homogeneous formation of CO2 are described by Arrhenius parameters log A (s−1) = 7.80 and E = 30.8 kcal/mol. Carbon monoxide and H2 were minor products, and the CO/CO2 ratio increased with increasing temperature and showed some surface enhancement at lower temperatures. The SF6-sensitized thermal decomposition of glyoxylic acid, induced by a pulsed CO2 laser, was briefly studied, with temperatures estimated to be in the 1100–1600 K range, and the CO/CO2 ratio increased with increasing temperature, continuing the trend observed in the static system.

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