Effect of initial oxygen content on the void swelling behavior of fast neutron irradiated copper

1998 ◽  
Author(s):  
S J Zinkle ◽  
F A Garner
Keyword(s):  
Fast Neutron ◽  
Oxygen Content ◽  
Swelling Behavior ◽  
Void Swelling ◽  
Initial Oxygen Content ◽  
Initial Oxygen

SOME EFFECTS OF HYPERBARIC OXYGENATION ON BACTERIA AT INCREASED HYDROSTATIC PRESSURES

1967 ◽  
Vol 13 (10) ◽  
pp. 1311-1319 ◽  
Author(s):  
Claude E. ZoBell ◽  
Leslie L. Hittle
Keyword(s):  
Hydrostatic Pressure ◽  
Dissolved Oxygen ◽  
Partial Pressure ◽  
Oxygen Content ◽  
Hyperbaric Oxygenation ◽  
Bacterial Species ◽  
Partial Pressure Of Oxygen ◽  
Nutrient Media ◽  
Initial Oxygen Content ◽  
Initial Oxygen

The adverse effects of hyperbaric oxygenation on the reproduction and survival of bacteria are augmented by increased hydrostatic pressure. Different bacterial species differ considerably in their tolerance of increased hydrostatic pressure as well as for increased partial pressure of oxygen. Although their generation times may be lengthened and their reproduction rates retarded by increased pressures, most species of well-known bacteria are able to grow at hydrostatic pressures as high as 200–400 atm. In closed systems at 1 atm, certain aerobic bacteria grow well, or sometimes better, in nutrient media in which the partial pressure of oxygen is 5 to 10 times higher than that in the normal atmosphere (-Po2ca. 0.2 atm, equivalent to a dissolved oxygen content of ca. 7 μg/ml), but such increased concentrations of oxygen (35–70 μg/ml) are injurious at substantially increased hydrostatic pressures, for example, 5–25 atm. Escherichia coli, Bacillus subtilis, Bacillus megaterium, Pseudomonas enalia, Pseudomonas perfectomarinus, and Serratia marinorubra were sterilized within a day or two by compression to 100 atm in media having a dissolved oxygen content of 35 μg/ml. All six species thrived at 100 atm in nutrient media having an initial oxygen content of 7 μg/ml and they grew well in media with an oxygen content of 35 μg/ml at 1 atm.

scholarly journals False Oxygen Consumption Effect and Factors Causing It

2011 ◽  
Vol 2011 ◽  
pp. 1-5
Author(s):  
M. V. Miniaev ◽  
M. B. Belyakova ◽  
N. V. Kostiuk ◽  
D. V. Leshchenko
Keyword(s):  
Oxygen Consumption ◽  
Low Temperature ◽  
Oxygen Content ◽  
Incubation Medium ◽  
Low Oxygen ◽  
Salting Out ◽  
Low Concentration ◽  
Initial Oxygen Content ◽  
Initial Oxygen

False oxygen consumption effect characterized by a decrease of the polarographic sensor readings by the introduction of neutral microadditives into the incubation medium was modeled and tested. These neutral microadditives neither consume oxygen nor cause its consumption by other components of the medium. It is shown that microadditives less than 3% of the volume of incubation medium can cause statistically significant effect of false oxygen consumption more than 4% of the initial oxygen content. The effect can reach more than 15% at higher volumes of additives. The most important properties of additives enhancing the effect are low oxygen content, low temperature, and low concentration of oxygen salting out components.

Influence of Dissolved Oxygen on Acid Production in Buffalo Milk by Lactic Cultures

1983 ◽  
Vol 46 (4) ◽  
pp. 321-324 ◽  
Author(s):  
S. SHEKAR ◽  
G. S. BHAT
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Acid Production ◽  
Streptococcus Thermophilus ◽  
Buffalo Milk ◽  
Milk Samples ◽  
Streptococcus Lactis ◽  
Heated Milk ◽  
Initial Oxygen Content ◽  
Initial Oxygen

Rates of acid production in buffalo milk by lactic cultures increased with the decrease of oxygen content to 2.90 ppm. Rates of production in milk samples containing less than 2.90 ppm dissolved oxygen did not vary. Incorporating oxygen into milk to raise the initial oxygen content from 5.50 to 9.00 ppm strongly inhibited acid production by all lactic cultures. Development of acidity by lactic cultures was more rapid in milk subjected to prior heat treatment and was maximum in milk heated at 90°C for 10 min. This was attributed to a slight descrease in oxygen content and increase in free sulfhydryls in heated milk. The free sulfhydryls and dissolved oxygen content decreased considerably in milk samples inoculated with lactic cultures but not in uninoculated control samples incubated for up to 2 h. The decrease in free sulfhydryls corresponded with the decrease in dissolved oxygen in all inoculated samples. Acidification of milk with lactic acid to the same extent as that found in inoculated milk samples showed no decrease in either free sulfhydryls or dissolved oxygen content, suggesting that lactic cultures catalyze the oxidation of free sulfhydryls with dissolved oxygen thereby effecting a more rapid rate of acid production during microbial fermentation of heated milk. The rate of decrease in free sulfhydryls and dissolved oxygen content and increase in acidity corresponded well with growth of lactics, being greatest in Streptococcus lactis-and least in Streptococcus thermophilus-inoculated milk.

Formation of Alumina Inclusions during Counter Diffusion of Aluminum and Oxygen Dissolved in Molten Iron

2013 ◽  
Vol 315 ◽  
pp. 260-267
Author(s):  
Yokoyama Seiji ◽  
Nik Hisyamudin Muhd Nor
Keyword(s):  
Oxygen Content ◽  
Diffusion Front ◽  
Supersaturation Ratio ◽  
X Ray ◽  
Irreversible Reaction ◽  
Inclusion Formation ◽  
Initial Oxygen Content ◽  
Critical Supersaturation ◽  
Initial Oxygen ◽  
Counter Diffusion

The formation of alumina (Al2O3) inclusions was experimentally investigated with the capillary-reservoir method. The inclusions were observed with a SEM (scanning electron microscope). The compositions of iron matrix and inclusion were measured with an EDX (energy dispersive X-ray analysis). The content profile of aluminum was discussed by the counter-diffusion model of aluminum and oxygen with an instantaneous irreversible reaction for alumina formation. The inclusions of spherical and polygonal alumina and spherical hercynite (FeOAl2O3) were observed in the vicinity of the diffusion front of aluminum. The hercynite was detected when the initial oxygen content was 0.075 mass% and higher. When the initial oxygen content was more than 0.045 mass% and higher, dendritic alumina formed at the position that was nearer to the interface than the position of spherical and polygonal inclusions. No inclusion was observed around the interface because of the re-dissolution of the inclusions. The initiating position of the inclusion formation was approximated by the reaction position, Zr, obtained from the model on the assumption that aluminum and oxygen contents at the reaction position were zero. Empirically, 0.9×Zr and 0.17×Zr expressed the initiating positions of formation and re-dissolution of inclusions respectively. The critical supersaturation ratio was estimated to be from 1 to 7.4×105, depending on the initial aluminum and oxygen contents.

Chlorine Release Characteristics During Biomass Reburning in an Entrained Flow Reactor

2017 ◽  
Author(s):  
Ping Lu ◽  
Jiateng Shi ◽  
Xinyi Yin
Keyword(s):  
Oxygen Content ◽  
Reaction Temperature ◽  
Flue Gas ◽  
Flow Reactor ◽  
Stoichiometric Ratio ◽  
Cotton Stalk ◽  
Entrained Flow ◽  
Initial Oxygen Content ◽  
Initial Oxygen ◽  
Entrained Flow Reactor

Five biomass including cotton stalk (CS), sunflower stalk (SS), wheat stalk (WS), rice husk (RH) and maize stalk (MS) were pyrolyzed in an entrained flow reactor under reburning condition. The chlorine release fraction was determined based on the analysis of each biomass and the relevant bio-coke measured by digital ion meter. The effects of biomass species, reaction temperature (T), residence time (τ), stoichiometric ratio (SR2), and initial oxygen content in the simulated flue gas on chlorine release were analyzed. The obtained results indicated that the chlorine release fraction increases with the increasing of reaction temperature, and all biomass have a higher chlorine release fraction of 94.6%–100% at high reaction temperature. Stoichiometric ratio has little influence on chlorine release. The chlorine release fraction shows a significant increase from 80.3% to 97.1% with increasing initial oxygen content in the simulated flue gas from 0% to 4%.

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