Chlorination activator

Active alkali Active chlorine Active dry yeast Active dry yeasts Active oxygen (AO)... 

ProducL Sulfur, Chlorine, Active Copper strip 40° 100° Density, at Total acid Pour... 

The ability of MPO to catalyze the nitration of tyrosine and tyrosyl residues in proteins has been shown in several studies [241-243]. However, nitrite is a relatively poor nitrating agent, as evident from kinetic studies. Burner et al. [244] measured the rate constants for Reactions (24) and (25) (Table 22.2) and found out that although the oxidation of nitrite by Compound I (Reaction (24)) is a relatively rapid process at physiological pH, the oxidation by Compound II is too slow. Nitrite is a poor substrate for MPO, at the same time, is an efficient inhibitor of its chlorination activity by reducing MPO to inactive Complex II [245]. However, the efficiency of MPO-catalyzing nitration sharply increases in the presence of free tyrosine. It has been suggested [245] that in this case the relatively slow Reaction (26) (k26 = 3.2 x 105 1 mol-1 s 1 [246]) is replaced by rapid reactions of Compounds I and II with tyrosine, which accompanied by the rapid recombination of tyrosyl and N02 radicals with a k2i equal to 3 x 1091 mol-1 s-1 [246]. 

Due to the limited extent of this paper, we mention only some positive results achieved in the orientation to two main directions i.e. to oxidative principles and to alcoholates in aprotic solvents. The research of oxidative principles (see e.g. [9]), involved the use of compounds with active chlorine, active iodine, peroxo-compounds, various mixtures of these compounds, as well as the use of oxidative agents with enhancing solubility and thus decontamination efficiency by adding detergents. It can... 

Lightox A photochemical process for destroying organic materials in aqueous solution by oxidation with chlorine, activated by ultraviolet radiation. Developed by the Taft Water Research Center, United States in the 1960s. 

Zhang, R., M.-T. Leu, and L. F. Keyser, Heterogeneous Chemistry of HONO on Liquid Sulfuric Acid A New Mechanism of Chlorine Activation on Stratospheric Sulfate Aerosols, . /. Phys. Chem., 100, 339-345 (1996). 

TABLE 12.5 Some Values of Reaction Probabilities (y) for the Heterogeneous Chlorine Activation Reactions under... 

De Haan, D. O., I. Flpisand, and F. Stordal, Modeling Studies of the Effects of the Heterogeneous Reaction CIOOCI + HCI - Cl2 + HOOCI on Stratospheric Chlorine Activation and Ozone Depletion, J. Geophys. Res., 102, 1251-1258 (1997). 

Muller, R., P. J. Crutzen, J.-U. GrooB, C. Briihl, J. M. Russell III, and A. F. Tuck, Chlorine Activation and Ozone Depletion in the Arctic Vortex Observations by the Halogen Occultation Experiment on the Upper Atmosphere Research Satellite, J. Geophys. Res., 101, 12531-12554 (1996). 

Activated charcoal is a hydrocarbon rather than an elemental carbon because it contains hydrogen chemically bound to carbon. We observed that when exposed to chlorine, activated charcoal evolves HC1 the substitution of hydrogen by chlorine, i.e., the reaction of the type... 

It is possible to calculate the net uptake coefficient for small sulfuric aerosols in the atmosphere, and thus derive the effectiveness of direct chlorine activation, from basic physical and chemical parameters [43]. The net uptake coefficient for the atmosphere, y, can be expressed by ... 

Tables on the "reaction probalility or "uptake coefficient" have been summarized for various heterogeneous reactions in a recent review article [87], and by the IUPAC [88] and NASA-JPL [86] evaluation teams. For the purpose of this article, a rough comparison is made of the uptake rates for the reactions (1) to (5) on the different type surfaces. Three major type of surfaces have been considered a) NAT, or Type I PSC, b) Water ice, or Type II PSC and c) sulfuric acid aerosol, which is normally a liquid surface generally composed of 60-80 wt % H,S04 and 40-20 wt % H,0 also considered is the solid form SAT (sulfuric acid tetrahydrate) with a composition of 57.5 wt % H,S04. The importance of chlorine activation on sulfuric acid solutions has been demonstrated in a recent article [89]. Halogen activation on seasalt material will shortly be reviewed as part of the tropospheric processes.

The hydrolysis of C10N02 (reaction 2) is expected to be important for chlorine activation if and when the HQ reservoir becomes depleted via reaction (1) and (4). The uptake coefficient on NAT surfaces ranges between 7x1 O 3 and 4x10 [90,94]. The reaction probability however depends on the partial HjO pressure. The uptake coefficient y over pure water-ice is very high and is of the order of 0.3. Older measurements have indicated much lower values, which are explained by the use of too large QONO, concentrations. Recently, a value of 0.03 was obtained at ice temperatures ranging 75-140 K [95]. 

Urban, J., A.H P. Goede, H. Kullmann, K. Ktlnzi, G. Schwaab, N. Whybom and J. Wohlgemuth (1998) Chlorine activation and ozone destruction in the Arctic winter stratosphere 1996, as measured by an Airbome-Submillimetre SIS Radiometer. Geophysical Research Letters (in press). 

Process D. PVC, kept in the fluidized bed state, was chlorinated at 50 °C, with gas chlorine activated by ultraviolet light. 

Zuurbier KWM, Bakkenist AR, Wever R, Muijsers AO (1990) The chlorinating activity of human myeloperoxidase high initial activity at neutral pH value and activation by electron donors. Biochim Biophys Acta 1037 140-146... 

Kettle AJ, Winterboum CC (1994) Assays for the chlorination activity of myeloperoxidase. Methods Enzymol 233 502-512... 

HOC1 chlorinating activity appears in reactions with free amino moieties to produce the respective chloramines (S36, S53) ... 

Figure 32 The Winter vortex over Antarctica. The cold core is almost isolates from the rest of the atmosphere, and acts as a reaction vessel in which chlorine activation may take place in the polar night (after ref 3)...

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