Automated determination of critical oxygen concentration for routinely active fish

1988 ◽  
Vol 23 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Timothy A. Springer ◽  
William H. Neill
Keyword(s):  
Oxygen Concentration ◽  
Critical Oxygen ◽  
Active Fish ◽  
Critical Oxygen Concentration ◽  
Automated Determination

Critical Concentrations of Atmospheric Contaminants in a-Si:H and μc-Si:H Solar Cells

2010 ◽  
Vol 1245 ◽  
Author(s):  
Tsvetelina Merdzhanova ◽  
Jan Woerdenweber ◽  
Thilo Kilper ◽  
Helmut Stiebig ◽  
Wolfhard Beyer ◽  
...  
Keyword(s):  
Solar Cells ◽  
Oxygen Concentration ◽  
Short Circuit ◽  
Red Light ◽  
Chamber Wall ◽  
Light Illumination ◽  
Critical Concentrations ◽  
Process Gas ◽  
Critical Oxygen ◽  
Critical Oxygen Concentration

AbstractWe report on a direct comparison of the effect of the atmospheric contaminants on a-Si:H and μc-Si:H p-i-n solar cells deposited by plasma-enhanced chemical vapor deposition (PECVD) at 13.56 MHz. Nitrogen and oxygen were inserted by two types of controllable contamination sources: (i) directly into the plasma through a leak at the deposition chamber wall or (ii) into the process gas supply line. Similar critical concentrations in the range of 4-6×1018 cm-3 for nitrogen and 1.2-5×1019 cm-3 for oxygen were observed for both a-Si:H and μc-Si:H cells for the chamber wall leak. Above these critical concentrations the solar cell efficiency decreases for a-Si:H solar cells due to losses in the fill factor under red light illumination (FFred). For μc-Si:H cells the losses in FFred and in short-circuit current density deteriorate the device performance. Only for a-Si:H the critical oxygen concentration is found to depend on the contamination source. Conductivity measurements suggest that at the critical oxygen concentration the Fermi level is located about 0.05 eV above midgap for both a-Si:H and μc-Si:H.

Factors Influencing Submergence and the Heart Rate in the Frog

1964 ◽  
Vol 41 (2) ◽  
pp. 417-431
Author(s):  
D. R. JONES
Keyword(s):  
Carbon Dioxide ◽  
Heart Rate ◽  
Oxygen Concentration ◽  
Carbon Dioxide Concentration ◽  
Carbon Dioxide Content ◽  
Factors Influencing ◽  
Critical Oxygen ◽  
Critical Oxygen Concentration ◽  
Main Factors ◽  
Critical Carbon Dioxide

1. The ability of the frog to remain submerged declines as the oxygen concentration in the water falls or the carbon dioxide content rises. The critical oxygen concentration appears to be about 5 mg./l. and the critical carbon dioxide concentration 100 mg./l. at temperatures around 10° C. 2. Submergence results in a decrease in heart rate which develops over a period of 15-30 min. but which disappears immediately the animal surfaces and breathes. The bradycardia is accentuated by oxygen lack or carbon dioxide excess. 3. During submergence the heart is influenced by two main factors, the shortage of oxygen and the cessation of breathing movements, both of which contribute to the decrease in rate. The former can still affect rate after vagotomy. The connexion between breathing and heart rate is dependent on the nervous system, though the detailed pathway is not worked out.

High critical oxygen concentration in microcrystalline silicon solar cells

2010 ◽  
Vol 4 (11) ◽  
pp. 323-325 ◽  
Author(s):  
Tsvetelina Merdzhanova ◽  
Jan Woerdenweber ◽  
Wolfhard Beyer ◽  
Uwe Zastrow ◽  
Helmut Stiebig ◽  
...  
Keyword(s):  
Solar Cells ◽  
Oxygen Concentration ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Critical Oxygen ◽  
Critical Oxygen Concentration
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