The Kinetics of Absorption and Evolution of Hydrogen by Palladium and Palladium/Platinum Electrodes

1961 ◽  
Vol 108 (5) ◽  
pp. 473 ◽  
Author(s):  
Ted B. Flanagan ◽  
F. A. Lewis
Keyword(s):  
Platinum Electrodes ◽  
Kinetics Of ◽  
Palladium Platinum

Effects of temperature and anoxia on regional cerebral blood flow in turtles

1992 ◽  
Vol 262 (3) ◽  
pp. R538-R541
Author(s):  
P. E. Bickler
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Regions ◽  
Platinum Electrodes ◽  
Regional Cerebral Blood ◽  
Blood Flows ◽  
Effects Of Temperature ◽  
Kinetics Of ◽  
Hydrogen Clearance

Regional cerebral blood flow (CBF) was measured in isoflurane-anesthetized turtles (Pseudemys scripta) by the hydrogen clearance method. Teflon-coated platinum electrodes (25 microns) were implanted in the olfactory bulbs, midcerebral cortex and cerebellum in eight adult turtles. The electrodes were voltage clamped at +0.30 V relative to a Ag-AgCl electrode implanted in the dorsal neck muscles. Washout kinetics of H2 gas administered via controlled ventilation was used to calculate local blood flow for electrodes exhibiting monoexponential washout kinetics of hydrogen (92 of 104 determinations). Data were obtained in animals with body temperatures of 15, 25, and 35 degrees C under normocapnic conditions during ventilation with 21% O2 and during ventilation with 100% N2. During normoxia, mean blood flows were 1.9 +/- 0.8, 5.0 +/- 1.9, and 6.1 +/- 1.3 (+/- SD) ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively. There were no differences between CBF values in the different brain regions. During 1-3 h of anoxia, CBF was 3.0 +/- 2.1, 7.0 +/- 3.7, and 6.6 +/- 2.9 ml.100 g-1.min-1 at 15, 25, and 35 degrees C, respectively (normoxia-anoxia difference not statistically different). Hypercarbia (ventilation with 10-20% CO2 in air or N2), or the transition from anoxia to normoxia, increased CBF up to 80% at each of these temperatures. Maintenance of CBF during anoxia likely contributes to the anoxia tolerance of the turtle brain.

Adsorption and kinetics of oxidation of ascorbic acid at platinum electrodes

1972 ◽  
Vol 40 (1) ◽  
pp. 13-17 ◽  
Author(s):  
M. Březina ◽  
J. Koryta ◽  
T. Loučka ◽  
D. Maršíková ◽  
J. Pradáč
Keyword(s):  
Ascorbic Acid ◽  
Platinum Electrodes ◽  
Kinetics Of Oxidation ◽  
Kinetics Of

scholarly journals The kinetics of electrode processes. ─Part III. The behaviour of platinum and gold electrodes in sulphuric acid and alkaline solutions containing oxygen

1933 ◽  
Vol 143 (848) ◽  
pp. 89-103 ◽  
Keyword(s):  
Sulphuric Acid ◽  
Platinum Oxide ◽  
Sulphuric Acid Solution ◽  
Alkaline Solutions ◽  
Gold Electrodes ◽  
Platinum Electrodes ◽  
Electrode Processes ◽  
Oxidizing Power ◽  
Active Condition ◽  
Kinetics Of

The first paper of this series contained a general survey of the reaction of hydrogen and oxygen at platinum electrodes in dilute sulphuric acid solution. We have now investigated in greater detail some of the phenomena which were observed, using mainly small polarizing currents, by means of which they can be more conveniently studied, and extending the scope of the experiments to other metals and solutions. In this paper an account is given of further experiments on platinum electrodes in the presence of oxygen, and of an investigation of the behaviour of gold electrodes in sulphuric acid and alkaline soutions. The experimental arrangements were similar to those previously described. Platinum Electrodes in Oxygen Saturated Solutions . Cathodic Depolarization by Oxygen .—If a platinum electrode in sulphuric acid is anodically polarized until oxygen is liberated and the current is then reversed, a marked depolarization process occurs at about ε H = + 0·05. Bowden's suggestion that this process is the reduction of a platinum oxide was shown in Part I to be untenable, because the length of the arrest of the potential is much reduced even by gentle stirring. The depolarization much be caused by some substance which is formed in the solution during the anodic polarization. Since it appeared that ordinary oxygen in the solution is not very active as a cathodic depolarizer in this region, it was suggested that the discharged oxygen remained for a time in a particularly active condition, but test of the solution failed to reveal any enhanced oxidizing power.

Kinetics of hydroquinone chemisorption at polycrystalline platinum electrodes

1987 ◽  
Vol 217 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Victor K.F. Chia ◽  
James H. White ◽  
Manuel P. Soriaga ◽  
Arthur T. Hubbard
Keyword(s):  
Platinum Electrodes ◽  
Polycrystalline Platinum ◽  
Kinetics Of
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