Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Subject eliminative

The normal daily excretion of m-hydroxyhippuric acid by man ranges from 2 to 150 mg, most subjects eliminating 4-6 mg (A15). The excretion of m-hydroxyphenylhydracrylic acid ranges from 2 to 150 mg (All), whereas the values found for m-hydroxybenzoic acid are, respectively, 8.8 mg in human males and 15.0 mg in females (B31), or 10-16 mg (T22). [Pg.80]

Following exposure to 500 ppm ammonia for 10-27 minutes, healthy male subjects eliminated 70-80% of the inspired ammonia by this route (Silverman et al. 1949). Analysis of endogenous ammonia levels in the expired air of rats showed concentrations ranging from 10-353 ppb (mean=78 ppb) in nose-breathing animals (Barrow and Steinhagen 1980). [Pg.90]

The general population can tolerate high levels of dietary iodine (Pennington, 1990), but discrete populations of patients are known to be at increased risk for thyroid-related AEs as a result of iodine therapy (Braverman, 1994). The inclusion-exclusion criteria for the safety studies of I2 in iodine-naive subjects eliminated patients known to be at risk. Euthyroid patients with (a) no history of thyroid disease, (b) no previous exposure to I2, and (c) no concomitant iodine-containing medications, were eligible for inclusion in these safety trials (MX02-CLN-07 and MX02-CLN-09). The first placebo-controlled study was conducted for 6 months and the second for 12 months. [Pg.806]

In this case, no profound specialised knowledge is required for determination of the type of discontinuities. On the other hand, determination of the nature of damage using a regular flaw detector for manual UT, can be a complicated task for any flaw detection experts, in any case, its solution will require time and qualification of the operator, but. the presence of these conditions will not eliminate the subjective nature of the assessment. [Pg.790]

The pressure equipment directive was adopted by the European Parliament and the European Council in May 1997. It harmonises the national laws of the 15 Member States of the European Union relating to equipment subject to the pressure risk. That directive is one of the series of technical harmonisation directives such as for machinery, medical devices, simple pressure vessels, gas appliances and so on, which were foreseen by the Communities programme for the elimination of technical barriers to trade. It therefore aims to ensure the free placing on the market and putting into service of the equipment concerned within the European Union and the European Economic Area. At the same time it permits a flexible regulatory environment, allowing European industry to develop new techniques increasing thereby its international competitiveness. [Pg.937]

More information has appeared concerning the nature of the side reactions, such as acetoxylation, which occur when certain methylated aromatic hydrocarbons are treated with mixtures prepared from nitric acid and acetic anhydride. Blackstock, Fischer, Richards, Vaughan and Wright have provided excellent evidence in support of a suggested ( 5.3.5) addition-elimination route towards 3,4-dimethylphenyl acetate in the reaction of o-xylene. Two intermediates were isolated, both of which gave rise to 3,4-dimethylphenyl acetate in aqueous acidic media and when subjected to vapour phase chromatography. One was positively identified, by ultraviolet, infra-red, n.m.r., and mass spectrometric studies, as the compound (l). The other was less stable and less well identified, but could be (ll). [Pg.222]

Addition of several organomercury compounds (methyl, aryl, and benzyl) to conjugated dienes in the presence of Pd(II) salts generates the ir-allylpalladium complex 422, which is subjected to further transformations. A secondary amine reacts to give the tertiary allylic amine 423 in a modest yield along with diene 424 and reduced product 425[382,383]. Even the unconjugated diene 426 is converted into the 7r-allyllic palladium complex 427 by the reaction of PhHgCI via the elimination and reverse readdition of H—Pd—Cl[383]. [Pg.82]

When optically pure 2 3 dimethyl 2 pentanol was subjected to dehydration a mixture of two alkenes was obtained Hydrogenation of this alkene mixture gave 2 3 dimethylpentane which was 50% optically pure What were the two alkenes formed in the elimination reaction and what were the relative amounts of each" ... [Pg.325]

Sulfonate esters are subject to the same limitations as alkyl halides Competition from elimination needs to be considered when planning a functional group transforma tion that requires an anionic nucleophile because tosylates undergo elimination reactions just as alkyl halides do... [Pg.353]

Another anticonvulsant, formerly used as a hypnotic, is 5-ethyl-5-phenyIhydantoin [631 -07-2] (Nirvanol, Mephenytoin). Its S isomer is stereo-selectively eliminated in most subjects, a fact having clinical consequences with both desired and untoward effects (119). [Pg.256]

Ozone in the gas phase can be deterrnined by direct uv spectrometry at 254 nm via its strong absorption. The accuracy of this method depends on the molar absorptivity, which is known to 1% interference by CO, hydrocarbons, NO, or H2O vapor is not significant. The method also can be employed to measure ozone in aqueous solution, but is subject to interference from turbidity as well as dissolved inorganics and organics. To eliminate interferences, ozone sometimes is sparged into the gas phase for measurement. [Pg.503]

The second principal advantage is that CYANEX 272 is the only one of the three above-mentioned compounds that extracts cobalt in preference to calcium (52). This property can minimise or eliminate the solvent losses that are associated with calcium extraction and the subsequent precipitation of gypsum cmds in the scmbbing or stripping circuits. This is illustrated in Eigure 1 where calcium extraction is shown as a function of pH for the three subject reagents. [Pg.321]

Phosphoms halides are subject to reactions with active hydrogen compounds and result in the elimination of hydrogen halide. They are convenient reagents in the synthesis of many esters, amides, and related compounds. However, because the involved hydrogen halide frequendy catalyzes side reactions, it is usually necessary to employ a hydrogen halide scavenger to remove the by-product. [Pg.362]

Monitoring by Electromechanical Instrumentation. According to basic engineering principles, no process can be conducted safely and effectively unless instantaneous information is available about its conditions. AH sterilizers are equipped with gauges, sensors (qv), and timers for the measurement of the various critical process parameters. More and more sterilizers are equipped with computerized control to eliminate the possibiUty of human error. However, electromechanical instmmentation is subject to random breakdowns or drifts from caUbrated settings and requires regular preventive maintenance procedures. [Pg.406]

AH vapors, including hotweH odors, are captured in a header system linked with the incineration air of a steam boiler or hot oil vaporizer. Drain seals avoid escape of odors from the sewer lines. This completely eliminates total reduced sulfur (TRS) emissions. The SO2 emissions are subject to local regulations. [Pg.306]

Photochemistry. Vinyl chloride is subject to photodissociation. Photexcitation at 193 nm results in the elimination of HCl molecules and Cl atoms in an approximately 1.1 1 ratio (69). Both vinyUdene ( B2) [2143-69-3] and acetylene have been observed as photolysis products (70), as have H2 molecules (71) and H atoms [12385-13-6] (72). HCl and vinyUdene appear to be formed via a concerted 1,1 elimination from excited vinyl chloride (70). An adiabatic recoil mechanism seems likely for Cl atom elimination (73). As expected from the relative stabiUties of the 1- and 2-chlorovinyl radicals [50663-45-1 and 57095-76-8], H atoms are preferentially produced by detachment from the P carbon (72). Finally, a migration mechanism appears to play a significant role in H2 elimination (71). [Pg.415]

In most cases, the impregnation process is followed by an electrochemical formation where the plaques are assembled into large temporary cells filled with 20—30% sodium hydroxide solution, subjected to 1—3 charge—discharge cycles, and subsequentiy washed and dried. This eliminates nitrates and poorly adherent particles. It also increases the effective surface area of the active materials. [Pg.548]

Maturing improves the taste and aroma of beer and the elimination of tannin, protein, and hop resins also has a beneficial effect. Some metaboHc products of unpleasant taste are further converted or washed out by the carbon dioxide surplus. The time for 1 agering varies with different types of beer. For every type of beer there is an optimal 1 agering time, and longer ] agering is usually detrimental to beer quaHty. The fiHed 1 agering tanks are subjected to the saturating pressure of carbon dioxide, usually 50—70 kPa (ca 0.5—0.7 atm), controUed by a safety valve. [Pg.25]

To eliminate the ambiguities in the subject of electricity and magnetism, it is convenient to add charge q to the traditional I, m and t dimensions of mechanics to form the reference dimensions. In many situations permittivity S or permeabiUty ]1 is used in Heu of charge. For thermal problems temperature Tis considered as a reference dimension. Tables 2 and 3 Hst the exponents of dimensions of some common variables in the fields of electromagnetism and heat. [Pg.104]


See other pages where Subject eliminative is mentioned: [Pg.262]    [Pg.262]    [Pg.2363]    [Pg.661]    [Pg.79]    [Pg.67]    [Pg.345]    [Pg.352]    [Pg.353]    [Pg.358]    [Pg.125]    [Pg.33]    [Pg.98]    [Pg.115]    [Pg.269]    [Pg.394]    [Pg.425]    [Pg.458]    [Pg.122]    [Pg.554]    [Pg.84]    [Pg.466]    [Pg.321]    [Pg.216]    [Pg.453]    [Pg.98]    [Pg.127]    [Pg.514]    [Pg.108]    [Pg.157]    [Pg.9]    [Pg.165]    [Pg.124]   
See also in sourсe #XX -- [ Pg.839 ]




SEARCH



Elcb elimination 838 Subject

Elimination Subject

Elimination Subject

Elimination reactions Subject

Reductive elimination 850 Subject

Subject Oxidative elimination

Subject metal halide elimination

© 2024 chempedia.info