Directly measured index numbers

The start temperature of evaporation for bitumens and vacuum residues is in the range from 180-300 °C (Tl %) or 237 to 365 °C (T5 %) respectively. Atmospheric residues start to evaporate between 97 °C and 165 °C Tl %) or 182 °C and 215 °C (T5 %). For the products from conversion processes, the evaporation start temperature depends on the degree of distillation which took place after tile conversion process. Therefore the start temperatures of the samples of this investigation show wide ranges from 98-261 °C (Tl %) and 154-324 °C (T5 %). 

The coefficient 0.771 is the arithmetical mean of 22 samples with a coefficient of variation V -13% (relative). 

The weight loss up to 400 °C (A G400) which is the fraction of the sample subject to distillation, decreases when the evaporation temperature increases. The limits found for AG400 are  

The residue at 800 °C (/ 8(X)) depends on the concentration of colloids in the samples. Samples which still have a distillable fraction, have a smaller / 8(X) than samples without this fraction  

Bitumens and Vacuum Residues Products from Conversion Processes 8.0 19.5 

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Directly measured index numbers in comparison with the simulated distillation... 

Con osition and Physical Properties Many composition measurements are obtained indirecdy. Physical properties such as temperature, viscosity, vapor pressure, electric conductivity, density, and refractive index are measured and used to infer the conposition of a stream, in place of a direct measurement. A number of other measurement techniques have become commonplace for the on-line analysis of composition. These include gas chromatography and mass and infrared spectrometry. These instruments are very accurate but are expensive and often fail to provide the continuous measurements that are required for rapid regulation. 

All the quantities in equation (9) are susceptible of direct measurement except v, the number of molecules per cc. This can, therefore, be deduced from measurements of refractive index and of turbidity, if the wavelength of the light employed is known. 

Several investigators have demonstrated that there is no direct correlation between numbers of SRB and the likelihood that corrosion has occurred or will occur. Jack and coworkers [41] prepared a review of 30 months of electrochemical measurements, weight-loss data, water chemistry and microbiological data for an oilfield waterflood operation in which produced brine was injected to displace oil from the reservoir. They concluded that SRB numbers could be used as an index of biocide performance in these field systems. No other correlations between corrosion measurements and microbial numbers were found. 

Strength (Hammett Indicators) is not strictly applicable to microporous solids, although the Hammett scale is a convenient comparative index. As a result, a number of alternative approaches have been taken to determine the concentration, type and strength of acid sites within these solids. Most of these methods give relative scales of acidity, but it is broadly possible to calibrate these acidities to those observed for other acids. The methods fall into three broad categories direct measurements, measurement of interaction with un-reactive probe molecules and the use of catalytic test reactions. 

Where N is the number of beads per molecule and d. is the number of bonds separating site / and j of the molecule. This parameter only describes the connectivity and is not a direct measure of the size of the molecules. Larger Wiener index numbers indicate higher numbers of bonds separating beads in molecules and hence more open structures of polymer molecules [28]. Table 2 shows the DB of polymers with different architectnre and the same degree of polymerization. 

With sucking insects that produce honeydew, the amount of honeydew excreted is assumed to be proportional to feeding. Honeydew production can be measured as number of droplets (using bromocresol blue or ninhydrin as a stain Auclair 1958), or the stained honeydew can be collected, extracted from the collection chamber, and measured colorimetrically (Nisbet et al. 1994). Several problems must be addressed with the use of honeydew as an index of consumption. First, some aphids will produce nymphs when feeding on artificial diet, and the production of honeydew by nymphs may inflate the quantity recorded for the test insect. The simplest solution here is to frequently remove any nymphs that are produced. Second, because aphids may scatter their honeydew, the droplets will not always fall directly below the aphid. Thus, collection dishes must be sufficiently large to collect all of the honeydew that might be produced. Alternatively, the entire chamber must be lined with material used to collect the honeydew, from which it is extracted subsequently (e.g., Nisbet et al. 1994). 

One of the advantages of GC-MS over an IR spectroscopic analyzer is the ability to measure distillation characteristics as well as predict other properties. There are several other materials that can be directly measured and reported. These include benzene, total aromatics, oxygenates, certain sulfur compounds and additives. The properties that can be predicted include (among others) cetane number and index, research and motor octanes, refractive index, distillation properties, aniline point, cloud point, pour point, volatility, flash point, density, conductivity, and viscosity [57]. 

A titration procedure, ASTM Test Method D1159, Bromine Number of Petroleum Distillates and Commercial Aliphatic Olefins by Electrometric Titration, provides an approximation of olefin content within a sample, while ASTM Test Method D2710, Bromine Index of Petroleum Hydrocarbons by Electrometric Titration, can be valuable for determining trace olefin levels. These methods do not directly measure total olefins, and the results are affected by the type of olefinic compound present. 

Employed as an index of lead exposure, the inhibition of 5-ALA-D in erythrocytes would appear to offer little advantage over direct measurement of PbB. In erythrocytes the enzyme is vestigial, and its inhibition requires the presence of lead ion interacting with the sulphydryl group in the proximity of the active site (Mitchell ei al, 1977). In addition, a number of methodological problems abound that would further serve to minimize this measure s attraction as a substitute for PbB. 

If measurements are made in thin oxide films (of thickness less than 5 nm), at highly polished Al, within a small acceptance angle (a < 5°), well-defined additional maxima and minima in excitation (PL) and emission (PL and EL) spectra appear.322 This structure has been explained as a result of interference between monochromatic electromagnetic waves passing directly through the oxide film and EM waves reflected from the Al surface. In a series of papers,318-320 this effect has been explored as a means for precise determination of anodic oxide film thickness (or growth rate), refractive index, porosity, mean range of electron avalanches, transport numbers, etc. 

To date, there have only been a limited number of studies directly examining PKC in bipolar disorders [77], Although undoubtedly an oversimplification, particulate (membrane) PKC is sometimes viewed as the more active form of PKC, and thus an examination of the subcellular partitioning of this enzyme can be used as an index of the degree of activation. Friedman etal. [78] investigated PKC activity and PKC translocation in response to serotonin in platelets obtained from bipolar-disorder patients before and during lithium treatment. They reported that the ratios of platelet-membrane-bound to cytosolic PKC activities were elevated in the manic patients. In addition, serotonin-elicited platelet PKC translocation was found to be enhanced in those patients. With respect to brain tissue, Wang and Friedman [74] measured PKC isozyme levels, activity and translocation in postmortem brain tissue from patients with bipolar disorder, and reported increased PKC activity and translocation in the brains of bipolar patients compared with controls, effects which were accompanied by elevated levels of selected PKC isozymes in cortices of bipolar disorder patients. 

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