Oxygen negative influences

Small amounts of molecular oxygen can influence the value of ff=0.675 With the rise of the 02 concentration in the electrolyte solution, the form of the Z", E curve changes and the value of (7=0 shifts toward less negative values. However, the effect is weak after saturation of the solution with molecular hydrogen and holding the pc-Bi electrode for 30 min at E = -1.35 V (SCE), the original shape of the Z", E curves and the original value of Eff=0 is restored. This indicates that oxidation and reduction of a pc-Bi electrode surface are reversible processes. 

Dogadkin, Skorodumova, and Kovaleva (127) studied the reaction of carbon black with sulfur at low temperatures. A solution in toluene was used at 145° in the presence of an accelerator. The sulfur sorption was negatively influenced by surface oxides. The oxygen-containing groups were not affected by the reaction, since no change in the water vapor adsorption was detected. No hydrogen sulfide was evolved under the reaction conditions. 

Surfactant concentrations also exert a negative influence on the bio-oxidation of certain substances, as evidenced in studies with even readily biodegradable substances [7]. It should be noted that this protection of substances from bio-oxidation is only temporary and it slowly reduces until its virtual disappearance in about a week for most substances. This phenomenon serves to retard the self-purification process in organically polluted rivers, even in the presence of high concentrations of dissolved oxygen. 

The conversion of 3-chloropentafluoropropene to 2-(chlorodifluoromethyI)-2,3,3-trifluoro-oxirane (33) can be carried out64 by heating the mixture of the alkene and oxygen in 1,1,2-trichlorotrifluoroethane (CFC-113) in an autoclave.64 The oxidation with hydrogen peroxide in alkaline solution is negatively influenced by the high nucleophilic reactivity of allylic chlorine.65 66 The reaction is performed at very low temperatures that favor the attack of the hydroperoxy anion in competition with the hydroxy anion. Acceptable yields of 31 -38 % are obtained in the presence of a phase-transfer catalyst.66... 

Bone and co-workers [4] studied the formation of nitric oxide in the combustion of carbon monoxide and arrived at some very strange results, e.g., yields of nitric oxide exceeding equilibrium values, a sharply negative influence of water vapor and hydrogen, etc. Bone concluded that the reaction of nitrogen with oxygen is caused by activation of the nitrogen by radiation from the carbon monoxide flame. 

For the oxidation of CO, methane and olefins, Pd is a better catalyst than Pt. For the oxidation of paraffins higher than propane, Pt is better than Pd. Under conditions of hydrocarbon oxidation, the metal surface is fully covered with oxygen. Hence there is no influence of oxygen pressure on the reaction rate (sometimes there is even a slight negative influence on the rate). 

Negative influences of pigments on polymer light stability are due to sensitization of singlet oxygen formation, initiation of polymer photooxidation by photo-exdted pigment chromophore formation of other photo-excited species with adverse effects on... 

However, the explosion pressure of oxygen-negative explosive would be increased with the increase of the density thus, the above-mentioned two secondary reaction equilibriums are moved to the right, leading the volume reduce of gaseous products and increase of the relative amount of CO2, thus leading the increase of explosion heat. The influence of charging density of condensed explosive on explosion heat was shown in Table 3.5. 

Tetrahydrophthalic acid has the specific effect of reducing the negative influence of oxygen on the curing of the resin surface,... 

Treatment with petrolatum in order to improve waterproof resistance of PE insulating cables, or the production of insulations with cellular structure having superior dielectric properties, influences negatively their stabilization. The negative influence of foamed insulation is probably not so much caused by the residues of the blowing agent as by faster diffusion of oxygen to the PE/copper interphase... 

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