scholarly journals Measurement of Oxygen Potential and Temperature in Liquid Slag, Metal and Gas Phase of Q-BOP Converter by Oxygen Concentration Cell

1982 ◽  
Vol 68 (2) ◽  
pp. 277-283 ◽  
Author(s):  
Kazuhiro NAGATA ◽  
Kyoji NAKANISHI ◽  
Fumio SUDO ◽  
Kazuhiro S. GOTO
Keyword(s):  
Gas Phase ◽  
Oxygen Concentration ◽  
Liquid Slag ◽  
Oxygen Potential ◽  
Concentration Cell

Chemisorption of ethylene on nickel surfaces with preadsorbed oxygen

1981 ◽  
Vol 46 (2) ◽  
pp. 340-353
Author(s):  
Pavel Zachař ◽  
Zdeněk Bastl ◽  
Jakub Adámek
Keyword(s):  
Gas Phase ◽  
Phase Analysis ◽  
Oxygen Concentration ◽  
Electrical Resistance ◽  
High Vacuum ◽  
Volumetric Method ◽  
Surface Oxygen ◽  
Oxygen Chemisorption ◽  
Thin Polycrystalline ◽  
Total Adsorption

Chemisorption of ethylene was studied on thin polycrystalline layers of nickel prepared by metal deposition in high vacuum and modified by preadsorbed oxygen. The volumetric method combined with the gas-phase analysis and the measurement of the electrical resistance changes of these layers were used. Already small amounts of preadsorbed oxygen of the order of 10-2 of the monolayer affect rather substantially the extent of ethylene chemisorption. The extent of the initial irreversible chemisorption and also the total adsorption of ethylene as a function of the amount of preadsorbed oxygen have a maximum at the surface oxygen concentration of 3 . 1013 molecule cm-2. The adsorption accompanied by the extensive dissociation of ethylene C-H bonds proceeds predominantly on nickel atoms with lower coordination (atoms on the microcrystal edges, corner atoms, etc.), where also oxygen chemisorption proceeds preferentially.

Control of Oxygen Content in Heavily Sb-Doped CZ Si Crystal by Adjusting Ambient Pressure

1995 ◽  
Vol 378 ◽  
Author(s):  
Koji Izunome ◽  
Xinming Huang ◽  
Shiniji Togawa ◽  
Kazutaka Terashima ◽  
Shigeyuki Kimura
Keyword(s):  
Single Crystals ◽  
Gas Phase ◽  
Oxygen Concentration ◽  
Evaporation Rate ◽  
Ambient Pressure ◽  
Silicon Crystals ◽  
Silicon Melt ◽  
Sb Doping ◽  
Gas Phase Transport ◽  
Phase Transport

AbstractIn Czochralski-grown (CZ) silicon single crystals, antimony (Sb) doping decreases the oxygen concentration by enhancing oxygen evaporation from the melt surface. In this study, Ar ambient pressures of around 100 Torr over the silicon melt were found to suppress evaporation of oxide species. To clarify the effect of the growth chamber ambient pressure on oxygen concentration, heavily Sb-doped CZ silicon crystals were grown under Ar pressures of 30, 60, and 100 Torr. Increasing Ar pressure increases the oxygen and Sb concentrations at the melt surface. The oxygen concentration under an Ar pressure of 100 Torr was 1.2 times higher that under 30 Torr when the solidified fractions are 0.5 or larger. The oxygen evaporation rate is controllable by gas phase transport of Sb2O at high Ar pressures.

Effects of Salt Corrosion on the Adhesion of Brass Plated Steel Cord to Rubber

1986 ◽  
Vol 59 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Yasuhiro Ishikawa ◽  
Shinji Kawakami
Keyword(s):  
Oxygen Concentration ◽  
Corrosion Test ◽  
Nacl Solution ◽  
Concentration Cell ◽  
Open Type ◽  
Salt Corrosion ◽  
Steel Cord ◽  
Brass Plating ◽  
Electrochemical Oxygen

Abstract Adhesion loss caused by salt corrosion is proposed to occur by the following process: 1) During a salt corrosion test, the NaCl solution rises in the cavity located at the steel-cord center. 2) An electrochemical oxygen concentration cell is formed. 3) OH− is produced by the reduction of oxygen. 4) An increase of the NaOH concentration causes the reverse of ion tendency between brass and steel. 5) Dezincification and dissolution of brass take place in the brass plating. The same process also occurs in the corrosion of a bare brass plated steel cord immersed in NaCl solution. Compounds containing cobalt stearate and a compound free from cobalt show adhesion deterioration by the process described above. Many other cobalt salts suppress the corrosion of brass in NaCl solution. At the same time, the underlying steel changes to become ignoble compared with brass, leading to the production of a large amount of rust. In view of the above considerations, it is desirable to remove the cavity located at the steel-cord center in order to suppress the steel-cord corrosion. Use of an open type of steel cord is useful in this respect.

scholarly journals Sensitivity to Oxygen of Nitrogenase Activity in Rhizobium Strain ANU289 of the Non-legume Parasponia (Ulmaceae)

1984 ◽  
Vol 37 (2) ◽  
pp. 31 ◽  
Author(s):  
S S Mohapatra ◽  
PM GresshoffA
Keyword(s):  
Carbon Source ◽  
Gas Phase ◽  
Cell Density ◽  
Oxygen Concentration ◽  
Oxygen Tension ◽  
Nitrogenase Activity ◽  
Rhizobium Strain ◽  
Low Oxygen ◽  
Liquid Cultures ◽  
Low Oxygen Tension

Nitrogenase activity can be detected in Rhizobium strain ANU289 of Parasponia in shaken liquid cultures. A combination of consistently low oxygen tension and appropriate cell density was found to be essential for rapid initiation and high specific rates (in the range of 50-60 nmoles of ethylene per milligram protein per hour). In the presence of succinate as carbon source and an oxygen concentration of 0�25% (v/v) in the gas phase, nitrogenase activity developed after incubation for 24 h. The requirement for an oxygen concentration in the range of O� 1 to 0�35% for derepression indicated a lack of any inherent tolerance to higher oxygen levels and thus suggests that plant-derived mechanisms are responsible for protection by oxygen in the nodule.

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