Claim severity quantitative results

In a different example, traceability in the amount-of-substance analysis of natural potassium, thorium, and uranium by the method of passive gamma-ray spectrometry was demonstrated by Nir-El (1997). For an absolute quantitative determination, accurate values of two parameters were required (i) the emission probability of a gamma-ray in the decay of the respective indicator radionuclides, and (2) the detection efficiency of that gamma-ray. This work employed a number of CRMs in the critical calibration of the detection efficiency of the gamma-ray spectrometer and the establishment of precise emission probabilities. The latter results compared well with literature values and provided smaller uncertainties for several gamma-rays that were critical for the traceabUity claim. The amount-of-substance analytical results of the long lived naturally occurring radionucHdes K, Th, and... 

A fair correlation of log(Zj,/Zo) with a was found for several mass-spectrometric processes. One of these is shown in Fig. 18 (Bursey and McLafferty, 1966 for a review see Bursey, 1968). The correlations are usually improved by use of mass spectra at energies below 20 eV when competing fragmentation is reduced. As in solution chemistry, there appears to be considerable uncertainty about the correct choice of a values, and both the Hammett a and Brown values have been tried. On the basis of the results a quantitative correlation with solution chemistry was claimed (Bursey and McLafferty, 1966 Bursey, 1968). 

The researches have dealt with each phase of the pentosan determination. Many modifications have been introduced in the distillation procedure, in attempts to obtain ma.ximal yields of furfural. For e.xample, some workers prefer to distil with 23 % hydrobromic acid, rather than with the conventional 12% hydrochloric acid. Others distil in the presence of added sodium chloride, to avoid changes in acid concentration. Steam distillation has been used by a number of workers, who claim theoretical yields of furfural from pentoses, but Launer and Wilson found no advantage either in salts or in steam in the analysis of pulps and papers. Interfering substances are of two types materials other than pentosans which form furfural in the pentosan analysis, and substances which yield products which may be determined as furfural. TJronic acids and polyuronides yield furfural, although not quantitatively, and, in the case of materials containing appreciable quantities of these substances, it is usual to make a correction. The value of the correction to be applied has been determined experimentally by several workers, with somewhat differing results. 

The process concept involves the extraction of light hydrocarbon oils from asphaltic petroleum supercritical solvents followed by a subsequent fractionation and separation of the oil from the solvent. It is stated that the metal compounds which are present in the asphaltic petroleum do not dissolve in the solvent under the conditions of operation. The primary difference claimed for this new process relative to the old processes is that the solvent is at or above the critical temperature rather than below the critical temperature as is described in prior art. The operation is explained in the patent with the aid of a simple distillation-like extraction vessel. Asphaltic feedstock is heated and introduced into the extraction vessel. The solvent is also heated and introduced into the vessel and the two streams are mixed. The temperature is maintained at or above the critical temperature of the solvent. In the extractor, the non-soluble components of the feed setde and are removed and sent to a stripper to recover and recycle the solvent. Several examples give quantitative information when an asphaltic feedstock containing 28 ppm Ni, 220 ppm V is used. The oil yield and metal content results are given below for two cases where the solvent is catalytic cracker gasoline and propane, resf>ectively. 

H, CHj, NHz, OH, 0CH3, F, NO2, CN, CHO, CF3, Li, O", NH, and NH3" ). Some of the work reported herein has been previously published (6,8-11) but a large part of our discussion refers to previously unpublished data accumulated over a number of years from several different laboratories. The primary goal of this study has been to draw together this wide body of computational data and to attempt to understand the diverse behavior observed within a relatively simple PMO (7) framework. There are undoubtedly other frameworks within which the results could be analyzed and we make no claim that our interpretation is necessarily unique. However, regardless of the qualitative picture of substituent effects which we develop here, the quantitative data stand on their own and hopefully may be utilized by other workers to prove or disprove alternative or supplementary hypotheses concerning substituent effects in aromatic systems. 

The finding of low 5HIAA excretion in Parkinson s disease [158] has not been confirmed [159, 160]. The protean pink spot has been reported [161], refuted [162], suggested to be due to 3,4-dimethoxyphenylethylamine [161] (dimethyl DA), or tyramine [163] and has recently been correlated with tea drinking [164]. Urinary tyramine was also found to be significantly increased in severely but not in mildly affected subjects with Parkinson s disease [165]. Finally, elevated tryptamine excretion has been claimed [165, 166] but even if confirmed is unlikely, for quantitative reasons, to result from or cause defective hydroxylation of tryptophan to 5HT as originally suggested [166]. 

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