Dissolved oxygen removal

Extreme caution must be taken to prevent the possibility of fire when using flammable removers. Extra care must be taken when stripping on location to secure the area of ignition sources. When used on lacquer finishes, the dissolved finish and remover combined are extremely flammable. Natural mbber, neoprene, or other gloves suitable for use with the remover formula must be worn. The effect of skin contact with the remover is limited because there is immediate irritation and discomfort. Canister respirators are available for most petroleum and oxygenate remover solvents. Symptoms of long-term overexposure should be compared to symptoms of the major ingredients in the formula. 

When selecting a suitable feed symp, the main criteria are optimization of enzyme productivity and minimization of the formation of by-products. Typical feed symp specifications are shown in Table 5. Higher symp concentration and higher viscosity results in a reduced isomerization rate due to diffusion resistance in the pores of the immobilized enzyme. A deaeration step is desirable to remove dissolved oxygen that would otherwise iacrease the formation of by-products. The pH is adjusted to the optimum level for the productivity of the enzyme. 

The apparatus must be flushed with acetylene in order to remove all traces of oxygen. Acetylene dissolved in acetone is most appropriate. Acetylene obtained from tanks which contain solvents such as dimethylformamide (or other solvents) gave lower yields of carbocupration. 

If the inhibitor is not removed, dissolved oxygen reacting with the inhibitor TCB will prevent polymerization. In the absence of dissolved oxygen, polymerization will proceed at essentially the same rate as that of the uninhibited monomer. A nitrogen blanket can be used to remove the oxygen from the mixture prior to polymerization. 

Deaerators not only effectively remove dissolved oxygen and other noncondensable gases but also provide the benefit of FW heating. Also, deaerators do not add dissolved solids to the FW, as happens with sulfite-based oxygen scavengers. 

Preparation of Reactants. Reagent-grade, thiophene free benzene was stored over 4A molecular sieves and sodium ribbon in a helium atmosphere. Styrene was distilled to remove dissolved oxygen and moisture and stored under a helium atmosphere. Prior to use, styrene was injected into a copious quantity of methanol to determine if any polymerization had occurred. If there was... 

The process of oxygen removal from the metal-oxygen solid solution via the formation of carbon monoxide is known as carbon deoxidation. The terms [0]M and [C]M denote the oxygen and the carbon dissolved in the metal to be refined, for example, vanadium. The extent to which carbon deoxidation can occur in a metal under given conditions of temperature and pressure can be estimated by using the following relationship ... 

Having removed the suspended solids and dissolved salts, the water then needs to have the dissolved gases removed, principally, oxygen and carbon dioxide, which would otherwise cause corrosion in the steam boiler. The usual method to achieve this is deaeration, which removes dissolved gases by raising the water temperature1,2. 

Aluminium is added (0.1%) to molten steel to remove dissolved oxygen and nitrogen to prevent blowholes in castings. It reacts very violently with silicon steels. 

The feed brine is also a source of impurities. It can contain dissolved and entrained air and so can contribute oxygen and nitrogen. The brine may also contain carbonate that was added during chemical treatment in order to remove dissolved calcium. The carbonate will be converted to carbon dioxide in the cell environment. 

The solution was contained in a cylindrical Pyrex or silica optical cell, 2.5 cm. in diameter and 2 cm. optical depth, fitted with a side arm of diameter about 1 cm. for connection to the vacuum line (see Fig. 10). Both phosphorescence and delayed fluorescence in fluid solution at room temperature are quenched by exceedingly low concentrations of molecular oxygen, and efficient deaeration is of the utmost importance. The following procedure was found to be satisfactory. The cell was first cooled in an acetone/C02 bath and pumped out. It was then isolated from the pump, refluxed to remove dissolved gas, cooled again in the... 

For ultraviolet irradiations care is needed in choosing a solvent— water, alkanes and acetonitrile are transparent and often unreactive towards electronically excited substrates alcohols and ethers are transparent but are more likely to be reactive acetone and benzene are sometimes used even though they are not transparent to all relevant wavelengths. It may be necessary to find out by trial and error whether or not an otherwise suitable solvent interferes with the photochemical process. A similar approach can be taken to decide about the need to purge continuously with an inert gas to remove dissolved oxygen. 

Environmental Impact. Most petroleum and oxygenate removers are photochemically reactive and classed as volatile organic compounds (VOCs), Disposal of this type of remover is difficult because the dissolved finish cannot be separated from the spent remover and the whole mixture must be disposed as a liquid hazardous waste. Distillation to recover 1195... 

Potencies prepared by sonication for 30s or 5 min at every step have been mentioned. Iodine 29 was prepared without succussion but by UV radiation at every step. Some potencies were degassed for lh to remove dissolved oxygen. All other potencies were prepared by manual succussion. All the drugs including mother tinctures were in 90% ethanol. 

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