Kinetics of ionization of molecular hydrogen on platinum electrodes

1959 ◽  
Vol 8 (2) ◽  
pp. 188-197 ◽  
Author(s):  
A. N. Frumkin ◽  
�. A. Aikazyan
Keyword(s):  
Molecular Hydrogen ◽  
Platinum Electrodes ◽  
Kinetics Of

scholarly journals Kinetics of D/H isotope fractionation between molecular hydrogen and water

2018 ◽  
Vol 242 ◽  
pp. 191-212 ◽  
Author(s):  
Nicholas J. Pester ◽  
Mark E. Conrad ◽  
Kevin G. Knauss ◽  
Donald J. DePaolo
Keyword(s):  
Molecular Hydrogen ◽  
Isotope Fractionation ◽  
Kinetics Of

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.

The mercury (63P1) photosensitized hydrogenation of ethylene. Kinetics of the reaction C2H5 + H2 = C2H6 + H

1968 ◽  
Vol 46 (20) ◽  
pp. 3275-3281 ◽  
Author(s):  
L. E. Reid ◽  
D. J. Le Roy
Keyword(s):  
Gas Phase ◽  
Molecular Hydrogen ◽  
Mercury Vapor ◽  
Experimental Conditions ◽  
Working Pressure ◽  
Extinction Coefficients ◽  
Secondary Reactions ◽  
Ethyl Radicals ◽  
Kinetics Of ◽  
Hydrogenation Of Ethylene

A quantitative study has been made of the reaction of ethyl radicals with molecular hydrogen in the gas phase in the temperature range 240 to 320 °C. The mercury (63Pi) photosensitized decomposition of hydrogen in the presence of ethylene was used to generate ethyl radicals. Extinction coefficients for the absorption of 2537 Å by mercury vapor were measured and Beer's law was shown to be obeyed under the experimental conditions used. The corrections required to allow for the nonuniformity of radical concentrations in the cell were small. After delineating the experimental conditions necessary to minimize secondary reactions, the rate constant (cm3 mole−1 s−1) for the reaction C2H5 + H2 = C2H6 + H was found to be given by log10k = 12.57 − 13.7/θ. Experiments in the presence of added carbon dioxide showed the absence of hot radical effects at the working pressure of 92 Torr of hydrogen.

CATALYTIC ACTIVATION OF HYDROGEN IN AQUEOUS SOLUTION BY THE CHLOROPALLADATE(II) ION

1959 ◽  
Vol 37 (9) ◽  
pp. 1446-1450 ◽  
Author(s):  
J. Halpern ◽  
J. F. Harrod ◽  
P. E. Potter
Keyword(s):  
Aqueous Solution ◽  
Ferric Chloride ◽  
Molecular Hydrogen ◽  
Homogeneous Catalyst ◽  
Rate Law ◽  
Catalytic Activation ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reduction of ferric chloride by molecular hydrogen in aqueous solution, in the presence of chloropalladate(II), were examined. The latter acts as a homogeneous catalyst for the reaction. The rate-law was found to be,[Formula: see text]where[Formula: see text]The mechanism of the reaction is discussed.

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
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