The effect of air pressure on the growth of Candida lipolytica on n-hexadecane

1969 ◽  
Vol 15 (11) ◽  
pp. 1255-1261 ◽  
Author(s):  
M. Wayman ◽  
E. Wein
Keyword(s):  
Mass Transfer ◽  
Partial Pressure ◽  
Cell Mass ◽  
Air Pressure ◽  
Candida Lipolytica ◽  
Partial Pressure Of Oxygen ◽  
Gaseous Component ◽  
Air Stream ◽  
Pressure Maximum ◽  
Maximum Cell

Mass transfer of oxygen to the microbial cell is very important in hydrocarbon fermentations. One method of increasing mass transfer of oxygen is to increase its partial pressure. Increasing the total pressure of the air-feed will increase the partial pressure of oxygen, but little work has been done in this area. The present study concerns the effects of increased air pressure up to 100 pounds per square inch gauge (p.s.i.g.) on the growth of Candida lipolytica on n-hexadecane in an agitated 7-liter pressure reactor. Inhibited growth was observed with increasing pressure. Maximum cell mass yield at 100 p.s.i.g. was about one-third that at 15 p.s.i.g. Inhibition was attributed to a gaseous component fed in with the air stream.

OXYGEN SUPPLY AND PERFORMANCE IN PEROMYSCUS: METABOLIC AND CIRCULATORY RESPONSES TO EXERCISE

1967 ◽  
Vol 45 (3) ◽  
pp. 531-541 ◽  
Author(s):  
Neri P. Segrem ◽  
J. S. Hart
Keyword(s):  
Oxygen Consumption ◽  
Partial Pressure ◽  
Oxygen Supply ◽  
Peromyscus Leucopus ◽  
Work Rate ◽  
Air Pressure ◽  
Partial Pressure Of Oxygen ◽  
Running Speed ◽  
Adult Mice ◽  
And Performance

Adult mice, Peromyscus leucopus novaboracensis, were exercised on a treadmill at various running speeds up to the highest obtainable at levels of oxygen ranging from 60 to 196 mm Hg. Oxygen consumption was not directly proportional to work rate as found in man and dog, and declined with a fall in the partial pressure of oxygen [Formula: see text] at the same work rate. As noted in other species, dependence of oxygen consumption on oxygen supply in Peromyscus varied with the level of exertion. The uptake at the highest speed was reduced by a relatively small fall in [Formula: see text] below normal air pressure whereas the uptake in resting mice was relatively insensitive to a reduction in [Formula: see text]. Heart rates varied in proportion to running speed and to oxygen consumption and were increased by a fall in [Formula: see text] at the same running speed.

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.

Biorhythm of the partial pressure of oxygen in uterine and fetal tissues

1981 ◽  
Vol 92 (4) ◽  
pp. 1305-1307
Author(s):  
A. Ya. Chizhov ◽  
V. G. Filimonov ◽  
Yu. M. Karash ◽  
R. B. Strelkov
Keyword(s):  
Partial Pressure ◽  
Partial Pressure Of Oxygen ◽  
Fetal Tissues

scholarly journals Mass Transfer from a Rotating Sphere in Air Stream

1973 ◽  
Vol 37 (2) ◽  
pp. 151-157,a1 ◽  
Author(s):  
Hisaya Tanaka ◽  
Osamu Tago
Keyword(s):  
Mass Transfer ◽  
Rotating Sphere ◽  
Air Stream

Prediction of Growth Parameters of Frost Deposits in Forced Convection

1981 ◽  
Vol 103 (1) ◽  
pp. 3-6 ◽  
Author(s):  
J. E. White ◽  
C. J. Cremers
Keyword(s):  
Mass Transfer ◽  
Forced Convection ◽  
Growth Parameters ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Transfer Rates ◽  
Air Stream ◽  
Transient Period ◽  
Approximate Expressions ◽  
Frost Layer

Experimental investigations of frost deposition under forced convection conditions have shown that in most cases heat and mass transfer rates become constant after an initial transient period. It is shown that, in such cases, approximately half of the mass transfer from a humid air stream to a frost layer diffuses inward, condenses and increases the density of the frost. The other half is deposited at the surface and increases the thickness of the layer. Approximate expressions for density and thickness of the frost layer are derived and compared with data from the literature and also with experimental work reported in this paper. The correlations are shown to work well for a broad range of experimental conditions.

Quantitative Effects of Oxygen Supply on Mycelia Growth and Extracellular Polysaccharide of Ganoderma tsugae

2012 ◽  
Vol 217-219 ◽  
pp. 975-978
Author(s):  
Nukrob Narkprasom ◽  
Tzou Chi Huang ◽  
Yuan Kuang Guu
Keyword(s):  
Mass Transfer ◽  
Secondary Metabolite ◽  
Submerged Fermentation ◽  
Oxygen Supply ◽  
Cell Mass ◽  
Extracellular Polysaccharide ◽  
Mycelia Growth ◽  
High Level ◽  
Dry Cell

The quantitative effects of oxygen supply in terms of shaking speed and medium volume on the production of mycelia and extracellular polysaccharide (EPS) using Ganoderma tsugae in submerged fermentation were investigated. Mycelia growth required the proper shaking speed at 134 rpm for breaking a larger pellet into several smaller pellets. Furthermore, high level of medium volume for consumption of abundant nutrient is needed for maximum mycelia growth. For EPS, a high agitation is needed to promote a good mass transfer for achieving high product concentrations recovery. The appropriate medium volume was found to be 150.4 mL for aiding to produce a secondary metabolite by promoting the mass transfer of substrates. The dry cell mass (DCM)-EPS diagram of G. tsugae was created from the both production equations which this diagram is an useful tool for submerge fermentation industry for decision about to control the both productions.

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