RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: III. INFLUENCE OF OXYGEN

1964 ◽  
Vol 42 (3) ◽  
pp. 355-366 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Partial Pressure ◽  
Brook Trout ◽  
Low Oxygen ◽  
Low Level ◽  
Standard Metabolism ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

Standard oxygen consumption was determined in relation to various partial pressures of oxygen for eastern brook trout at 10° and 15 °C, and for carp and goldfish at 10° and 20 °C. Two conditions of oxygen acclimation were compared. In one case acclimation was to air saturation while in the other acclimation was to each of the partial pressures of oxygen applied.Down to a partial pressure of oxygen of approximately 80 mm Hg, standard oxygen uptake remained approximately constant, and further, the rates for the two differently acclimated groups were about equal. Below 80 mm Hg the standard rate first increased to a maximum and then, with a further reduction in the partial pressure, decreased. Below 80 mm Hg the standard rate of oxygen consumption was in all cases less for the fish acclimated to the low level of oxygen than for those acclimated to air saturation.Comparison of standard and active values suggests that the increase in standard rate of oxygen uptake in response to low oxygen does not reach the active level as suggested earlier by Fry (1947). The suggestion is made that a fraction of standard metabolism is derived anaerobically in low levels of oxygen. Further, it appears that acclimation to a low level of oxygen enhances the anaerobic fraction of standard metabolism.

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: IV. INFLUENCE OF CARBON DIOXIDE AND OXYGEN

1964 ◽  
Vol 42 (5) ◽  
pp. 847-856 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Partial Pressure ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Partial Pressure Of Oxygen ◽  
Partial Pressures ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate ◽  
Different Levels

Oxygen consumption was determined in relation to spontaneous activity and standard metabolism estimated by extrapolating the values to zero activity, Standard oxygen consumption was determined in relation to different partial pressures of carbon dioxide and oxygen for brook trout. Salvelinus fontinalis (Mitchill), at 10 °C, and carp, Cyprinus carpio Linnaeus, at 25 °C. In general, at each partial pressure of oxygen applied, standard oxygen consumption did not change significantly over the range of partial pressures of carbon dioxide followed. The relation for brook trout operated on a level characteristic of the partial pressure of oxygen. Although the effect of different levels of oxygen was not established for carp at 25 °C, it is presumed that the relation operated also in that species in a similar way.Acclimation to the different levels of carbon dioxide and oxygen to be tested was examined and, ordinarily, found not to change significantly the standard rate of oxygen consumption.

SEASONAL CHANGES IN THE STANDARD RATE OF OXYGEN CONSUMPTION OF FISHES

1964 ◽  
Vol 42 (2) ◽  
pp. 189-194 ◽  
Author(s):  
F. W. H. Beamish
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Brown Trout ◽  
Seasonal Changes ◽  
Brook Trout ◽  
Spawning Period ◽  
A Value ◽  
Late Fall ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate

The standard rate of oxygen consumption for brook and brown trout acclimated to 10 °C and exposed to natural daylight varied seasonally. For male brook trout, standard oxygen consumption increased from a low of 30 mg/kg hour during March and April to a maximum of 63 mg/kg hour during the late fall spawning period. The standard rates of the females approximated those for males. For male brown trout, standard oxygen uptake increased from a value of approximately 20 mg/kg hour during the winter and spring months to a high of roughly 30 mg/kg hour during the fall spawning period. Little change was observed in the standard oxygen consumption of female brown trout.

scholarly journals An apparent specific dynamic action in Mytilus edulis L.

1977 ◽  
Vol 57 (2) ◽  
pp. 371-378 ◽  
Author(s):  
B. L. Bayne ◽  
C. Scullard
Keyword(s):  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Metabolic Rate ◽  
Mytilus Edulis ◽  
Ammonia Excretion ◽  
Specific Dynamic Action ◽  
Dynamic Action ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate ◽  
High Level

The results of experiments recorded by Bayne & Scullard (1977) confirmed earlier studies (Bayne, 1973) in describing a decline in the rate of oxygen uptake (Vo2) by Mytilus edulis during starvation, eventually reaching a steady-state value, called the standard rate of oxygen consumption. Earlier experiments had also shown that if such starved mussels were fed, oxygen uptake increased rapidly to a high level called the active rate of oxygen consumption (Thompson & Bayne, 1972; Bayne, Thompson & Widdows, 1973). Some of this increase in metabolic rate is undoubtedly due to an increased filtration rate that is stimulated by the presence of food (the ‘mechanical cost of feeding’ discussed by Bayne et al. 1976), and part is due to the ‘physiological costs of feeding’, which includes energy utilized in digestion and assimilation of the food, and energy that is lost during deamination and other catabolic processes that accompany digestion (Warren & Davis, 1967). Increases in metabolic rate associated with feeding have been called the specific dynamic action (SDA) of the ration (see Harper, 1971, for a discussion) or the apparent SDA (Beamish, 1974)5 and they have been related to aspects of protein metabolism (Krebs, 1964). This paper describes the results of some experiments designed to examine the relationships between SDA and ammonia excretion in Mytilus edulis L.

Tensile Properties and Creep Behavior of SiC-Based Fibers under Various Oxygen Partial Pressures

2005 ◽  
Vol 475-479 ◽  
pp. 1333-1336 ◽  
Author(s):  
Jan Ji Sha ◽  
J.S. Park ◽  
Tatsuya Hinoki ◽  
Akira Kohyama ◽  
J. Yu
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Tensile Properties ◽  
Creep Behavior ◽  
Elevated Temperatures ◽  
Low Oxygen ◽  
X Ray Diffraction ◽  
Sic Fibers ◽  
Partial Pressures ◽  
Ar Gas

Three kinds of atmospheres (air, highly-pure Ar and ultra highly-pure Ar gas) with different oxygen partial pressures were applied to investigate the tensile properties and creep behavior of SiC fibers such as Hi-NicalonTM and TyrannoTM-SA. These fibers were annealed and crept at elevated temperatures ranging from1273-1773 K in such environments. After annealing at 1773 K, the room temperature tensile strengths of SiC-based fibers decreased with decreasing the oxygen partial pressure and the near stoichiometric fiber TyrannoTM-SA shows excellent strength retention. At temperatures above the 1573 K, the creep resistance of SiC fibers evaluated by bending stress relaxation (BSR) method under high oxygen partial pressure was lower than that of in low oxygen partial pressure. The microstructural features on these fibers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

The relationship between cirral activity and oxygen uptake in Balanus balanoides

1965 ◽  
Vol 45 (2) ◽  
pp. 387-403 ◽  
Author(s):  
R. C. Newell ◽  
H. R. Northcroft
Keyword(s):  
Body Weight ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Mantle Cavity ◽  
The Body ◽  
Effect Of Temperature ◽  
Zero Rate ◽  
Rate Of Oxygen Consumption ◽  
The Relationship ◽  
Balanus Balanoides

The rate of cirral beat of Balanus balanoides is related to the logarithm of the body weight as an exponential function. In any one animal, there is little effect of temperature on cirral activity between 7·5° and 10° C. Between 10° and 20° C, however, there is a rapid increase in cirral beat with temperature followed by a fall at temperatures above 20° C.Balanus balanoides exhibits a fast, medium and zero rate of oxygen consumption. These rates of oxygen consumption correspond with (a) normal cirral beating, (b) ‘testing’ activity with no cirral movement, and (c) with the closure of the mantle cavity. Both of the possible levels of oxygen uptake are related to the logarithm of the body weight in a logarithmic fashion over the temperature range 7·5°–22·5° C. Temperature affects the two rates of oxygen consumption differently. In the slower rate (rate B) there is an increase in the rate of oxygen consumption between 7·5° and 14° C but there is no significant increase in the rate of oxygen consumption between 14° and 22·5 C°.

scholarly journals Process-Parameter-Dependent Structural, Electrical, and Optical Properties of Reactive Magnetron Sputtered Ag-Cu-O Films

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
P. Narayana Reddy ◽  
A. Sreedhar ◽  
M. Hari Prasad Reddy ◽  
S. Uthanna ◽  
J. F. Pierson
Keyword(s):  
Optical Properties ◽  
Substrate Temperature ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Rf Magnetron Sputtering ◽  
Low Oxygen ◽  
Electrical And Optical Properties ◽  
Partial Pressures ◽  
Effect Of Oxygen ◽  
Parameter Dependent

Silver-copper-oxide thin films were formed by RF magnetron sputtering technique using Ag80Cu20target at various oxygen partial pressures in the range 5 × 10−3–8 ×10−2 Pa and substrate temperatures in the range 303–523 K. The effect of oxygen partial pressure and substrate temperature on the structure and surface morphology and electrical and optical properties of the films were studied. The Ag-Cu-O films formed at room temperature (303 K) and at low oxygen partial pressure of 5 × 10−3 Pa were mixed phase of Ag2Cu2O3and Ag, while those deposited at 2 × 10−2 Pa were composed of Ag2Cu2O4and Ag2Cu2O3phases. The crystallinity of the films formed at oxygen partial pressure of 2 × 10−2Pa increased with the increase of substrate temperature from 303 to 423 K. Further increase of substrate temperature to 523 K, the films were decomposed in to Ag2O and Ag phases. The electrical resistivity of the films decreased from 0.8 Ωcm with the increase of substrate temperature from 303 to 473 K due to improvement in the crystallinity of the phase. The optical band gap of the Ag-Cu-O films increased from 1.47 to 1.83 eV with the increase of substrate temperature from 303 to 473 K.

RESPIRATION OF FISHES WITH SPECIAL EMPHASIS ON STANDARD OXYGEN CONSUMPTION: I. INFLUENCE OF WEIGHT AND TEMPERATURE ON RESPIRATION OF GOLDFISH, CARASSIUS AURATUS L.

1964 ◽  
Vol 42 (2) ◽  
pp. 161-175 ◽  
Author(s):  
F. W. H. Beamish ◽  
P. S. Mookherjii
Keyword(s):  
Oxygen Consumption ◽  
Spontaneous Activity ◽  
Carassius Auratus ◽  
Goldfish Carassius Auratus ◽  
Simultaneous Measurements ◽  
Proportionate Change ◽  
Rate Of Oxygen Consumption ◽  
Standard Rate ◽  
The Mean ◽  
External Stimuli

Standard oxygen consumption of goldfish was estimated in relation to weight and temperature from simultaneous measurements of routine oxygen uptake and spontaneous activity. The relation between weight and standard oxygen consumption was expressed as a logarithmic linear regression. For a given shift in temperature, the proportionate change in standard oxygen consumption appears to be independent of weight. The mean slope of the regressions was found to be 0.850.The standard rate of a 100-g goldfish increased linearly, on a semilogarithmic grid, over the temperature range of 10 to 35 °C. The estimates found in the present study were less than the lowest applicable values that could be found in the literature.The average routine rate of oxygen consumption suggests that goldfish display a considerable amount of spontaneous activity despite the elimination of external stimuli.

Role of Oxygen Vacancies on the Ferroelectric Properties of Pzt Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Chi Kong Kwok ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Vacancy Concentration ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Low Oxygen ◽  
Partial Pressures ◽  
Pzt Films

AbstractThe properties of ferroelectric thin films can be significantly influenced by the presence of point defects. The concentration of vacancies presented in these thin films is known to be one of the key parameters causing the degradation of these films when these films are subjected to polarization reversals.To study the effects of the vacancy concentration on the ferroelectric properties, sol gel PZT films and powders were annealed in different oxygen partial pressures. For the PZT films, the reduction of oxides to pure metals was not observed even with films annealed at 2×10−5 atmosphere of oxygen partial pressure. Samples annealed at low oxygen partial pressure (for instance, 10−3 and 2×10−5 atmosphere), which has more Pb and O2 depletions and consequently has more Pb and O2 vacancies, cannot be switched easily. The ratios of coercive field after and before fatigue increase as the defect concentrations of the annealed samples increase.

Si-N nanowire formation from Silicon nano and microparticles.

2003 ◽  
Vol 789 ◽  
Author(s):  
Chandana Rath ◽  
A. Pinyol ◽  
J. Farjas ◽  
P. Roura ◽  
E. Bertran
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Crystalline Silicon ◽  
Silica Layer ◽  
Whisker Formation ◽  
Low Oxygen ◽  
Partial Pressures ◽  
Precursor Material ◽  
Different Temperatures ◽  
First Time

ABSTRACTWe report silicon nitride whisker formation from hydrogenated amorphous silicon (a-Si:H) nanoparticles grown by PECVD for the first time. We compared the results with the kinetics of whisker formation from ball milled crystalline silicon (c-Si) microparticles. Whisker formation is analyzed at different temperatures (900–1440 °C) and oxygen partial pressures. At temperatures equal or above 1350 C and at low oxygen partial pressure we observe monocrystalline α-Si3N4 whiskers having 30–100 nm diameter and several microns length. By increasing the oxygen partial pressure, the structure of whiskers is completely changed, as shown by electron microscopy. In this case we observe α-Si3N4 whiskers covered by an amorphous silica layer at 1350 C. Finally, when the precursor material is silicon microparticles, thicker (170–330 nm) and longer whiskers are formed.

Ovine ill-thrift in Nova Scotia. 4. The survival at low oxygen partial pressure of fungi isolated from the contents of the ovine rumen

1972 ◽  
Vol 18 (7) ◽  
pp. 1119-1128 ◽  
Author(s):  
D. Brewer ◽  
J. M. Duncan ◽  
S. Safe ◽  
A. Taylor
Keyword(s):  
Carbon Dioxide ◽  
Nova Scotia ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Oxygen ◽  
Mucor Rouxii ◽  
Permanent Pasture ◽  
Method Of Determination ◽  
Partial Pressures

Aspergillus fumigatus, Mucor rouxii, and Sporormia minima have been isolated from the rumen contents of sheep grazing permanent pasture at Nappan, Nova Scotia. To determine the ability of these fungi to survive and grow at the low oxygen partial pressure present in the rumen, a method of determination of oxygen, nitrogen, and carbon dioxide has been developed. The lowest partial pressures of oxygen [Formula: see text] and nitrogen that could be detected were 0.0005 cm Hg and the precision of the determination was ±0.001 cm Hg. Carbon dioxide was determined with slightly less precision than achieved for oxygen and nitrogen. Using this method, respiration was detected in cultures of all the fungi named at [Formula: see text] Hg and growth was observed at [Formula: see text] Hg in the case of M. rouxii. It is concluded that all these fungi are capable of survival in the ovine rumen.

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