Alkaline destruction

This corrosion risk is especially high when the cooling water has little inherent buffering capacity (say, because of alkalinity destruction by the... 

Johansson, M. H., and Samuelson, O. (1977). Alkaline destruction of birch xylan in the light of recent investigations of its structure. Sven. Papperstidn. 80, 519-524. 

A classical example of the application of chlorine in industrial waste treatment is the alkaline destruction of cyanide wastes. The process is maintained at pH greater than 10 and cyanide is destroyed in a two step process using separate... 

The reduction wave in alkaline media enables the simultaneous determination of cystine, t steine (care must be taken to prevent oxidation) and sulphide in the alkaline destruction of keratin. 

Table 5 Inhibition of Polyethylene Thermal Destruction by Filler—Fiberglass of Varying Alkalinity...

Sodium hydroxide (NaOH) and potassium hydroxide (KOH) solutions do not dissolve tantalum, but tend to destroy the metal by formation of successive layers of surface scale. The rate of the destruction increases with concentration and temperature. Damage to tantalum equipment has been experienced unexpectedly when strong alkaline solutions are used during cleaning and maintenance. 

Welds on steelwork need special attention because of the different composition of weld metal and adjacent steelwork, the rough surface and spatter caused by welding and the presence of welding flux. The latter is often alkaline and destructive to many paints. It is necessary to clean thoroughly, preferably by reblasting for 25-50 mm each side of the weld, fare the rough metal and wash off residual flux. The cleaned surface should then be stripe coated with the primer used on the remainder of the surface. 

In architectural work, particular care must be taken to avoid destructive attack of the anodic film by alkaline mortar or cement during erection, and temporary coatings of spirit-soluble waxes, or acetate-butyrate lacquers are frequently applied to window frames and the like to protect against mortar splashes, which in any event should be removed at the earliest possible moment. 

Wood has a good resistance to a wide range of chemicals. The acid resistance is superior to that of most common metals. Iron begins to corrode at pH 5, whereas attack on wood commences at pH 2, and even at lower values proceeds at a very low rate. Wood has excellent resistance to acetic acid which is particularly destructive to most common metals. In alkaline conditions wood has good resistance up to pH 11. 

Most pancreatic enzyme supplements are enteric coated to release enzymes in the alkaline environment of the intestine this minimizes enzyme destruction in the stomach. Enteric-coated pancreatic enzyme supplements require fewer daily dosage units, but delivery of the drug to the site of action and effectiveness may be delayed by gastric emptying time.41... 

Elevated alkaline phosphatase may indicate bone destruction. 

Theory Selenium is very toxic and its contamination is usually controlled by an absorptiometric method after destruction of the organic compound with fuming nitric acid. The latter converts selenium (Se) as selenous acid (H2Se03), which on subsequent treatment with 3,3 -diaminobenzidinc under controlled experimental parameters, results into the formation of a highly coloured compound known as 3,4-diaminophenylpiazselenol. The latter is consequently extracted with toluene after making the aqueous solution alkaline, and the colour compared with a standard prepared likewise from a known amount of selenium. The various reactions involved may be expressed as follows ... 

The method of protein hydrolysis was important acid hydrolysis caused destruction of tryptophan but alkaline treatment gave even greater losses of other amino acids especially cystine. The amino acids were usually separated by then standard chemical procedures based on differences in solubility, selective precipitation by agents such as Reinecke salt (proline and hydroxyproline), or flavianic acid (arginine). 

Changes in phosphate, nitrate, ammonia, and silicate concentrations associated with the biogenic production and destruction of POM can alter seawater alkalinities. These effects are usually so small in scale that they can be ignored. Since the largest biotic impact on alkalinity in oxic seawater is exerted by the formation and dissolution of... 

Both alkali metal and alkaline earth atoms are reactive with oxygen-bearing terminal groups but the latter appear to be far more destructive. K deposition on -COOCH3 and -COOH terminated SAMs results in a 1 1 reaction to form -COO species, which in the ester case requires cleavage of the -CH3 group [45, 46, 58, 59, 61]. Walker and co-workers have reported that Ca deposition on OCH3... 

Promotion and deactivation of unsupported and alumina-supported platinum catalysts were studied in the selective oxidation of 1-phenyl-ethanol to acetophenone, as a model reaction. The oxidation was performed with atmospheric air in an aqueous alkaline solution. The oxidation state of the catalyst was followed by measuring the open circuit potential of the slurry during reaction. It is proposed that the primary reason for deactivation is the destructive adsorption of alcohol substrate on the platinum surface at the very beginning of the reaction, leading to irreversibly adsorbed species. Over-oxidation of Pt active sites occurs after a substantial reduction in the number of free sites. Deactivation could be efficiently suppressed by partial blocking of surface platinum atoms with a submonolayer of bismuth promoter. At optimum Bi/Ptj ratio the yield increased from 18 to 99 %. 

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