REACTIONS IN DISSOCIATED WATER VAPOR

1951 ◽  
Vol 29 (11) ◽  
pp. 996-1009 ◽  
Author(s):  
R. A. Jones ◽  
C. A. Winkler
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Room Temperature ◽  
Reaction Chamber ◽  
Glass Wool ◽  
Cold Trap ◽  
Slight Effect ◽  
Reaction Chambers ◽  
Limiting Value ◽  
Water Hydrogen

Water vapor dissociated by an electric discharge and passed into a cold trap yielded products which gave off oxygen at temperatures above −120°C. and at room temperature consisted of hydrogen peroxide and water. With products formed under given conditions, the amount of oxygen evolved with warming was proportional to the total amount of product and independent of the warming procedure. The evolution proceeded to completion at −78°C. Water was found at all trap temperatures between −78°C. and −195°C. Hydrogen peroxide was formed only if the trap temperature was below −120°C., and oxygen was evolved only from products formed below −150°C. The yields of water, hydrogen peroxide, and evolved oxygen all increased with decreasing trap temperature. As the volume of reaction chambers inserted between the discharge tube and the trap was increased, the yield of hydrogen peroxide decreased continuously, while the yield of water at first decreased and then increased to a limiting value. Packing a given reaction chamber with glass wool drastically reduced the yield of hydrogen peroxide, but had little effect on the yield of water. Packing the trap itself had only a slight effect on the yields. The results are compared with those obtained by others with the H–O2 system at low temperatures, and a mechanism is proposed to correlate the two systems.

REACTIONS IN DISSOCIATED PEROXIDE VAPOR

1953 ◽  
Vol 31 (3) ◽  
pp. 262-271 ◽  
Author(s):  
J. S. Batzold ◽  
C. Luner ◽  
C. A. Winkler
Keyword(s):  
Hydrogen Peroxide ◽  
Water Vapor ◽  
Electrical Discharge ◽  
Molecular Hydrogen ◽  
Volume Ratio ◽  
Cold Trap ◽  
Gas Phase Reactions ◽  
Hydrogen Atoms ◽  
A Chain ◽  
Hydrogen Peroxide Vapor

The products of the electrical discharge through hydrogen peroxide vapor were hydrogen peroxide, water, oxygen, and hydrogen, in amounts which depended upon the arrangement and temperature of the trap, reaction time, and surface to volume ratio of the reaction vessel. Water, hydrogen, and oxygen resulted from the gas phase reactions of the dissociated hydrogen peroxide, with hydrogen peroxide produced only in a trap cooled below −120 °C. Products trapped below −150 °C evolved oxygen on warming to room temperature. The decomposition products of the electrical discharge through hydrogen peroxide correspond closely with products obtainable both from a similar discharge through water vapor and from the interaction of hydrogen atoms with oxygen molecules in a cold trap. A mechanism which accounts for their correspondence is included. Water was the only product when molecular hydrogen peroxide was caused to react with hydrogen atoms, dissociated hydrogen peroxide vapor, or dissociated water vapor in the presence or absence of molecular hydrogen. A chain mechanism is postulated for these reactions.

Hydration Chamber for Jeolco 200 Kv Microscope

1970 ◽  
Vol 28 ◽  
pp. 542-543
Author(s):  
V. R. Matricardi ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscope ◽  
Water Vapor ◽  
Vapor Pressure ◽  
Pressure Gradient ◽  
Room Temperature ◽  
List Type ◽  
Type Number ◽  
Equilibrium Vapor Pressure

In order to observe room temperature hydrated specimens in an electron microscope, the following conditions should be satisfied: The specimen should be surrounded by water vapor as close as possible to the equilibrium vapor pressure corresponding to the temperature of the specimen.The specimen grid should be inserted, focused and photo graphed in the shortest possible time in order to minimize dehydration.The full area of the specimen grid should be visible in order to minimize the number of changes of specimen required.There should be no pressure gradient across the grid so that specimens can be straddled across holes.Leakage of water vapor to the column should be minimized.

Warm and freeze-fracture of cotton seed radicles

1987 ◽  
Vol 45 ◽  
pp. 984-985
Author(s):  
E. L. Vigil ◽  
E. F. Erbe
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
Fracture Surface ◽  
Membrane Structure ◽  
Room Temperature ◽  
Freeze Fracture ◽  
Longitudinal Axis ◽  
Fracture Plane ◽  
Cotton Seeds ◽  
Condensed Water

In cotton seeds the radicle has 12% moisture content which makes it possible to prepare freeze-fracture replicas without fixation or cryoprotection. For this study we have examined replicas of unfixed radicle tissue fractured at room temperature to obtain data on organelle and membrane structure.Excised radicles from seeds of cotton (Gossyplum hirsutum L. M-8) were fractured at room temperature along the longitudinal axis. The fracture was initiated by spliting the basal end of the excised radicle with a razor. This procedure produced a fracture through the tissue along an unknown fracture plane. The warm fractured radicle halves were placed on a thin film of 100% glycerol on a flat brass cap with fracture surface up. The cap was rapidly plunged into liquid nitrogen and transferred to a freeze- etch unit. The sample was etched for 3 min at -95°C to remove any condensed water vapor and then cooled to -150°C for platinum/carbon evaporation.

scholarly journals A Mn(iii) polyoxotungstate in the oxidation of organosulfur compounds by H2O2 at room temperature: an environmentally safe catalytic approach

2016 ◽  
Vol 6 (9) ◽  
pp. 3271-3278 ◽  
Author(s):  
Tiago A. G. Duarte ◽  
Sónia M. G. Pires ◽  
Isabel C. M. S. Santos ◽  
Mário M. Q. Simões ◽  
M. Graça P. M. S. Neves ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Organosulfur Compounds ◽  
Keggin Type ◽  
Environmentally Safe

A manganese monosubstituted Keggin-type polyoxometalate was used as a catalyst in the oxidation of recalcitrant organosulfur compounds by hydrogen peroxide at room temperature.

scholarly journals Ein Wasserstoffisotopieeffekt im CuSO4 * 5H2O

1969 ◽  
Vol 24 (10) ◽  
pp. 1502-1511
Author(s):  
Karl Heinzinger
Keyword(s):  
Water Vapor ◽  
Aqueous Solutions ◽  
Separation Factor ◽  
Room Temperature ◽  
Copper Ion ◽  
Hydrogen Isotopes ◽  
Bulk Water ◽  
Water Molecules ◽  
Hydration Water ◽  
Sulfate Solutions

Abstract There are two kinds of water in CuSO4·5H2O differing by their binding in the crystal. The oxygen of four water molecules is bonded to the copper ion, that of the fifth molecule is hydrogen bonded. It is shown that the D/H ratios of these two kinds of water differ by 5.7%, the light isotope being enriched in the water molecules coordinated with the copper ion. The results show that there is no exchange of the hydrogen isotopes during the time needed for dehydration at room temperature which takes several days. The assumption has been confirmed that the water coordinated with the copper ion leaves the crystal first on dehydration at temperatures below 50 °C. Additional measurements of the separation factor for the hydrogen isotopes between water vapor and copper sulfate solutions allow conclusions on the fractionation of the hydrogen isotopes between bulk water and hydration water in aqueous solutions.

Characterization of HfO2/Si Exposed to Water Vapor at Room Temperature

2006 ◽  
Vol 917 ◽  
Author(s):  
Carlos Driemeier ◽  
Elizandra Martinazzi ◽  
Israel J. R. Baumvol ◽  
Evgeni Gusev
Keyword(s):  
Water Vapor ◽  
Metal Oxide ◽  
Room Temperature ◽  
Gate Dielectric ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Dielectric Films ◽  
Nuclear Reaction Analysis ◽  
Environmental Air

AbstractHfO2-based materials are the leading candidates to replace SiO2 as the gate dielectric in Si-based metal-oxide-semiconductor filed-effect transistors. The ubiquitous presence of water vapor in the environments to which the dielectric films are exposed (e.g. in environmental air) leads to questions about how water could affect the properties of the dielectric/Si structures. In order to investigate this topic, HfO2/SiO2/Si(001) thin film structures were exposed at room temperature to water vapor isotopically enriched in 2H and 18O followed by quantification and profiling of these nuclides by nuclear reaction analysis. We showed i) the formation of strongly bonded hydroxyls at the HfO2 surface; ii) room temperature migration of oxygen and water-derived oxygenous species through the HfO2 films, indicating that HfO2 is a weak diffusion barrier for these oxidizing species; iii) hydrogenous, water-derived species attachment to the SiO2 interlayer, resulting in detrimental hydrogenous defects therein. Consequences of these results to HfO2-based metal-oxide-semiconductor devices are discussed.

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