Thermal Nitridation of Silicon in Active Nitrogen

1984 ◽  
Vol 38 ◽  
Author(s):  
R. V. Giridhar ◽  
K. Rose
Keyword(s):  
Film Thickness ◽  
Partial Pressure ◽  
Gas Phase ◽  
Microwave Discharge ◽  
Strong Dependence ◽  
Atomic Nitrogen ◽  
Efficient Catalyst ◽  
Active Nitrogen ◽  
Thermal Nitridation

AbstractThe dissociation of N2 in a microwave discharge has been studied using a gas phase titration between N(4S) and NO. SF6 added in small concentrations (20–100 ppm of N2) is shown to be an efficient catalyst for dissociating N2. Dissociation fractions [N]/[N2 ] of 4–5% have been obtained. The studies suggest how the partial pressure of atomic nitrogen can be maximized. These results have been applied to thermal nitridation of Si in active nitrogen. A strong dependence of the film thickness on the partial pressure of atomic nitrogen (PN) has been shown. In addition to the nitridation rate, the nitrogen fraction [N]/([N] + [O]) also increases with PN.

Interaction of H2O, O2 and H2 with Proton Conducting Oxides Based on Lanthanum Scandates

2019 ◽  
pp. 88-100
Author(s):  
A. S. Farlenkov ◽  
N. A. Zhuravlev ◽  
Т. A. Denisova ◽  
М. V. Ananyev
Keyword(s):  
Water Vapor ◽  
Partial Pressure ◽  
Gas Phase ◽  
Molecular Hydrogen ◽  
Proton Magnetic Resonance ◽  
Partial Pressure Of Oxygen ◽  
Proton Conducting ◽  
Conducting Oxides ◽  
Temperature Range ◽  
Apparent Level

The research uses the method of high-temperature thermogravimetric analysis to study the processes of interaction of the gas phase in the temperature range 300–950 °C in the partial pressure ranges of oxygen 8.1–50.7 kPa, water 6.1–24.3 kPa and hydrogen 4.1 kPa with La1–xSrxScO3–α oxides (x = 0; 0.04; 0.09). In the case of an increase in the partial pressure of water vapor at a constant partial pressure of oxygen (or hydrogen) in the gas phase, the apparent level of saturation of protons is shown to increase. An increase in the apparent level of saturation of protons of the sample also occurs with an increase in the partial pressure of oxygen at a constant partial pressure of water vapor in the gas phase. The paper discusses the causes of the observed processes. The research uses the hydrogen isotope exchange method with the equilibration of the isotope composition of the gas phase to study the incorporation of hydrogen into the structure of proton-conducting oxides based on strontium-doped lanthanum scandates. The concentrations of protons and deuterons were determined in the temperature range of 300–800 °C and a hydrogen pressure of 0.2 kPa for La0.91Sr0.09ScO3–α oxide. The paper discusses the role of oxygen vacancies in the process of incorporation of protons and deuterons from the atmosphere of molecular hydrogen into the structure of the proton conducting oxides La1–xSrxScO3–α (x = 0; 0.04; 0.09). The proton magnetic resonance method was used to study the local structure in the temperature range 23–110 °C at a rotation speed of 10 kHz (MAS) for La0.96Sr0.04ScO3–α oxide after thermogravimetric measurements in an atmosphere containing water vapor, and after exposures in molecular hydrogen atmosphere. The existence of proton defects incorporated into the volume of the investigated proton oxide from both the atmosphere containing water and the atmosphere containing molecular hydrogen is unambiguously shown. The paper considers the effect of the contributions of the volume and surface of La0.96Sr0.04ScO3–α oxide on the shape of the proton magnetic resonance spectra.

The Dielectric Discharge as an Efficient Generator of Active Nitrogen for Chemiluminescence and Analysis

1983 ◽  
Vol 37 (6) ◽  
pp. 545-552 ◽  
Author(s):  
John Kishman ◽  
Eric Barish ◽  
Ralph Allen
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Band System ◽  
Electrothermal Atomization ◽  
Characteristic Radiation ◽  
Gaseous Species ◽  
Vibrationally Excited ◽  
Active Nitrogen ◽  
Excited Species ◽  
Intense Emission

A predominantly blue “active nitrogen” afterglow was generated in pure flowing nitrogen or in air by using a dielectric discharge at pressures from 1 to 20 Torr. The afterglow contains triplet state molecules and vibrationally excited ground state molecules. These species are produced directly by electron impact without the formation and recombination of nitrogen atoms. The most intense emission is the N2 second positive band system. The N2 first positive and N2+ first negative systems are also observed. The spectral and electrical properties of this discharge are discussed in order to establish guidelines for the analytical use of the afterglow for chemiluminescence reactions. The metastatic nitrogen efficiently transfers its energy to atomic and molecular species which are introduced into the gas phase and these excited species emit characteristic radiation. The effects of electrothermal atomization of Zn and the introduction of gaseous species (e.g., NO) on the afterglow are described.

THE REACTION OF ACTIVE NITROGEN WITH PROPYLENE

1952 ◽  
Vol 30 (12) ◽  
pp. 915-921 ◽  
Author(s):  
G. S. Trick ◽  
C. A. Winkler
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Hydrogen Cyanide ◽  
Atomic Hydrogen ◽  
Atomic Nitrogen ◽  
Active Nitrogen

The reaction of nitrogen atoms with propylene has been found to produce hydrogen cyanide and ethylene as the main products, together with smaller amounts of ethane and propane and traces of acetylene and of a C4 fraction. With excess propylene, the nitrogen atoms were completely consumed and for the reaction at 242 °C., 0.77 mole of ethylene was produced for each mole of excess propylene added. For reactions at lower temperatures, less ethylene was produced. The proposed mechanism involves formation of a complex between the nitrogen atom and the double bond of propylene, followed by decomposition to ethylene, hydrogen cyanide, and atomic hydrogen. The ethylene would then react with atomic nitrogen in a similar manner.

Measurement of Flow Rate of Droplets and Liquid Film in Venturi Scrubber

2016 ◽  
Author(s):  
Yasuhiro Nakao ◽  
Naoki Horiguchi ◽  
Hiroyuki Yoshida ◽  
Tetsuya Kanagawa ◽  
Akiko Kaneko ◽  
...  
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Gas Phase ◽  
Flow Rate ◽  
Interfacial Area ◽  
Decontamination Factor ◽  
Liquid Film Thickness ◽  
Phase Flow ◽  
Radioactive Materials ◽  
Venturi Scrubber

As one of filtered venting systems which should be installed in light water reactors from viewpoint of protecting a containment vessel and suppressing the diffusion of radioactive materials, there is a system composed of venturi scrubbers. The radioactive materials in the contaminated gas are collected into liquid. By dispersed flow formed in the venturi scrubber, large interfacial area between liquid and gas was obtained, and large decontamination factor is realized. In evaluation for the decontamination performance of the venturi scrubber, interface of droplets and liquid film are important. However, there is a little knowledge about the interfacial area in the venturi scrubber for filtered venting. In this study, to obtain the interfacial area data, amount of the droplets and the liquid film in the venturi scrubber is evaluated by visualizing observation and sampling the liquid film at the outlet of the venturi scrubber. In the venturi scrubber, a pressure drop occurs in the throat part by the inflow of air from the compressor. Water flows from the tank by a pressure difference between a suctioned hole with head pressure and a throat part. An annular spray flow is then formed in the venturi scrubber. Therefore, the liquid flow rate changes according to the gas phase flow rate. To discharge separately the droplets and the liquid film, a rectangular separator is installed at the venturi scrubber outlet. The superficial gas phase flow rate is 25.2–292.3 m/s in the throat. As a result, the liquid film and the droplets through the wall were confirmed to be discharged separately by the separator. The ratio of the liquid film to the total amount of liquid is 80 to 95% and that of the droplets was estimated as 5 to 20%. However, the change of the liquid film thickness caused by the increase of gas phase flow rates was observed. When the liquid film thickness is large, it is possible that some liquid film flowing into the droplet side.

scholarly journals Spreading and oscillation dynamics of drop impacting liquid film

2019 ◽  
Vol 881 ◽  
pp. 859-871 ◽  
Author(s):  
Xiaoyu Tang ◽  
Abhishek Saha ◽  
Chao Sun ◽  
Chung K. Law
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Liquid Surface ◽  
Strong Dependence ◽  
Solid Substrate ◽  
Spreading Dynamics ◽  
Viscous Loss ◽  
Shape Oscillation ◽  
Oscillation Dynamics ◽  
The Impact

We herein report an experimental study to explore the effects of impact inertia, film thickness and viscosity on the dynamics of shape deformation of a drop impacting a liquid film. We have identified that the spreading dynamics shows a weak dependence on impact inertia, but strongly depends on the film thickness. For a thick film, the liquid surface deforms and absorbs part of the impact energy, and hence inhibits spreading of the drop. For a thin film, the drop motion is restricted by the bottom solid substrate, promoting spreading. The periodicity of the capillary controlled shape oscillation, on the other hand, is found to be independent of impact inertia and film thickness. The damping of the shape oscillation shows strong dependence on the film thickness, in that the oscillation decays faster for smaller film thicknesses, due to the enhanced viscous loss.

Gas-phase reaction of iron carbonyl cations with atomic hydrogen and atomic nitrogen

1992 ◽  
Vol 114 (2) ◽  
pp. 771-773 ◽  
Author(s):  
Helene Mestdagh ◽  
Christian Rolando ◽  
Michel Sablier ◽  
Nicolas Billy ◽  
Gerard Gouedard ◽  
...  
Keyword(s):  
Gas Phase ◽  
Atomic Hydrogen ◽  
Iron Carbonyl ◽  
Phase Reaction ◽  
Atomic Nitrogen ◽  
Gas Phase Reaction

scholarly journals Dependence of mitochondrial and cytosolic adenine nucleotides on oxygen partial pressure in isolated hepatocytes. Application of a new rapid high pressure filtration technique for fractionation

1988 ◽  
Vol 250 (3) ◽  
pp. 641-645 ◽  
Author(s):  
H Hummerich ◽  
H de Groot ◽  
T Noll ◽  
S Soboll
Keyword(s):  
High Pressure ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Adenine Nucleotide ◽  
Intact Cell ◽  
Adenine Nucleotides ◽  
Strong Dependence ◽  
Isolated Hepatocytes ◽  
Pressure Filtration ◽  
Filtration Technique

By using a new rapid high pressure filtration technique, mitochondrial and cytosolic ATP and ADP contents were determined in isolated hepatocytes at different oxygen partial pressures. At 670 mmHg, subcellular adenine nucleotide contents and ATP/ADP ratios were comparable with values obtained with the digitonin fractionation technique. However at lower oxygen partial pressure ADP appears to be rephosphorylated during digitonin fractionation whereas with high pressure filtration fractionation rephosphorylation of ADP is avoided due to shorter fractionation times. Cytosolic and mitochondrial ATP/ADP ratios decrease if oxygen partial pressure is lowered. However the absolute values of ATP/ADP ratios depend critically on the incubation conditions. Thus incubation of hepatocytes in an oxystat system, where oxygen partial pressure is maintained constant by infusing oxygen-saturated medium and the hepatocyte suspension is continuously stirred, yields much higher subcellular and overall ATP/ADP ratios than incubation in Erlenmeyer flasks gassed with different gas mixtures and shaken in a water bath. This is ascribed to limited diffusion of oxygen from the medium into the cell if the suspension is not mixed thoroughly by stirring. The strong dependence of subcellular ATP/ADP ratios on incubation conditions indicates that oxygen may be one rate-controlling factor for oxidative phosphorylation in the intact cell.

Evaluation of Carbon Dioxide Corrosion on N80 Steel

2014 ◽  
Vol 490-491 ◽  
pp. 311-314
Author(s):  
Zhen Zhong Fan ◽  
An Qi Tong ◽  
Yan Cui ◽  
Jun Feng Yang
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Corrosion Rate ◽  
Partial Pressure ◽  
Gas Phase ◽  
Test Temperature ◽  
Microscopic Analysis ◽  
Carbon Dioxide Corrosion ◽  
Large White ◽  
N80 Steel

The carbon dioxide corrosion on N80 steel was evaluated under the gas phase and the liquid phase. With the test temperature improved, the corrosion rate increases. Under the condition of gas phase, the corrosion peak is 0.2942mm/a when the temperature is 110°C and pressure is 24 MPa. Under the condition of liquid phase, the corrosion peak is 26.5325mm/a when the temperature is 50°C and pressure is 24 MPa. With the increase of CO2 partial pressure, the corrosion rate of N80 steel was falling. Microscopic analysis shows that the corrosion products of CO2 on N80 steel have a large white flocculent compounds and the corrosion surface have a lot of cracks and holes.

scholarly journals Reaction of active nitrogen with oxygen

1967 ◽  
Vol 45 (22) ◽  
pp. 2837-2840 ◽  
Author(s):  
A. S. Vlastaras ◽  
C. A. Winkler
Keyword(s):  
Reaction Time ◽  
Oxygen Atom ◽  
Gas Phase ◽  
Rate Constant ◽  
Analytical Method ◽  
Order Rate Constant ◽  
Maximum Amount ◽  
Active Nitrogen ◽  
Tube Reactor ◽  
Different Levels

The maximum yields of oxygen atoms, estimated at different levels in a long-tube reactor by gas-phase "titration" with NO2, were equal for the reactions of active nitrogen with NO and O2. In this reactor, the maximum oxygen-atom production from the oxygen reaction, determined by the amount of N2O3 produced with excess NO2, was found to correspond to the NO "titration" value for the active nitrogen and not to the maximum amount of HCN produced in the active nitrogen – ethylene reaction. A second-order rate constant, [Formula: see text] [Formula: see text]was obtained for the active nitrogen – oxygen reaction.Experiments in a short reactor showed that the validity of the analytical method based on the trapping of N2O3 depended upon adequate reaction time for the NO + NO2 reaction to occur.

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