System difference

The electronic spectra of benzenoid systems differ in a characteristic manner from their acyclic analogues. Thus benzene, unhke hexatriene. [Pg.1146]

Species Tested. In addition to the variation in susceptibiUty to chemically induced toxicity among members within a given population, there may be marked differences between species with respect to the relative potency of a given material to produce toxic injury. These species differences may reflect variations in physiological and biochemical systems, differences in distribution and metaboHsm, and differences in uptake and excretory capacity. [Pg.229]

Subsequently, other structural variations were reported encompassing compounds such as PS-5 (5) (5), carpetimycin A (6) (6), asparenomycin A (7) (7), and pluracidomycin A (8) (8), from a wide variety of streptomycete strains. Following these stmctures the simplest member of the series, having the completely unsubstituted nucleus, (1, X = CH2), was isolated from bacterial strains of Serratia and Ervinia (9). AH other natural products reported have substituents at both the C-6 and C-2 positions of the bicycHc ring system. Differences in the nature and stereochemistry of these substituents has provided a wide variety of stmctures, and over forty variations have been reported and comprehensively Hsted (10). [Pg.4]

Even the simplest detersive system is surprisingly complex and heterogeneous. It can nevertheless be conceptually resolved into simpler systems that are amenable to theoretical treatment and understanding. These simpler systems are represented by models for substrate-soHd soil and substrate-Hquid sod. In practice, many sod systems include soH—Hquid mixtures. However, removal of these systems can generally be analyzed in terms of the two simpler model systems. Although these two systems differ markedly in behavior and stmcture, and require separate treatment, there are certain overriding principles that apply to both. [Pg.531]

The ammonia-water absorption system was extensively used until the fifties when the LiBr-water combination became popular. Figure 11-103 shows a simplified ammonia-water absorption cycle. The refrigerant is ammonia, and the absorbent is dilute aqueous solution of ammonia. Ammonia-water systems differ from water-lithium bromide equipment to accommodate major differences Water (here absorbent) is also volatile, so the regeneration of weak water solution to strong water solution is a fractional distillation. Different refrigerant (ammonia) causes different, much higher pressures about 1100-2100 kPa absolute in condenser. [Pg.1119]

The electron transfer rates in biological systems differ from those between small transition metal complexes in solution because the electron transfer is generally long-range, often greater than 10 A [1]. For long-range transfer (the nonadiabatic limit), the rate constant is... [Pg.394]

Systems differ in their ability to re-enact a series of calculations or to reproduce a specific output. [Pg.274]

Variability in modeling (e.g, accounting for alternative accident mitigating. systems Differences in data used in quantifying the models... [Pg.395]

Local recirculation systems differ from central systems in that all exhausted air is passed back to the room after cleaning and that the flow rate could be larger than the flow rate through the room. [Pg.615]

One after the other, examine methanol dimer and acetic acid dimer. Do the hydrogen-bond lengths in these systems differ significantly from the optimum distance in water dimer Are the hydrogen-bond angles in these compounds significantly different from those in water dimer Rationalize your results. [Pg.49]

The outstanding feature of the preparation of 2,2 -bipyridine from pyridine under the influence of metal catalysts is the absence of isomeric bipyridines among the products. In this respect reactions using metal catalysts in a heterogeneous system differ from methods which have been used to prepare bipyridines in homogeneous sys-tems. ... [Pg.191]

Alloys with ruthenium Additions of ruthenium have a most marked effect upon the hardness of platinum, but the limit of workability is reached at about 15% ruthenium, owing to the fact that ruthenium belongs to a crystallographic system different from that of platinum. Apart from a somewhat greater tendency to oxide formation at temperatures above 800°C, the resistance to corrosion of ruthenium-platinum alloys is comparable to that of iridium-platinum alloys of similar composition. [Pg.926]

In the course of pharmacological experiments, a frequent question is Does the experimental system return expected (standard) values for drugs With the obvious caveat that standard values are only a sample of the population that have been repeatedly attained under a variety of circumstances (different systems, different laboratories, different investigators), there is a useful statistical test that can provide a value of probability that a set of values agree or do not agree with an accepted standard value. Assume that four replicate estimates of an antagonist affinity are made (pKb values) to yield a mean value (see Table 11.14). A value of t can be calculated that can give the estimate probability that the mean value differs from a known value with the formula... [Pg.249]

Shrimps of the genus Sergestes normally emit light from their photophores. However, S. lucens, a species abundantly harvested in Japan as a delicacy Sakura-ebi, has never been observed to emit light despite its specific name and the clear presence of photophores (Haneda, 1985). This species (body weight 0.4 g) undoubtedly contains some coelenterazine, but shows very little luciferase activity, which seems to be insufficient as evidence for the existence of a luciferase (Shimomura et al., 1980 see the note at the end of Section 5.2 for the reason). Thus, the luminescence of S. lucens might involve a coelenterazine luminescence system different from... [Pg.48]

This luminous brittle star has been briefly studied recently (Mallefet and Shimomura, 2004, unpublished). The animal contained a high level of coelenterazine luciferase activity (4 x 1012 photons s-1g 1), which is comparable to those in the luminous antho-zoans such as the sea pansy Renilla and sea pen Ptilosarcus (Shimomura and Johnson, 1979b). There is no evidence for the presence of a photoprotein in this brittle star. Thus, the luminescence system of Amphiura filiformis is considered to be a coelenterazine-luciferase system, differing from that of Ophiopsila californica. The luciferase has a molecular weight of 23,000 on the basis of gel filtration on Superdex 200 Prep, and catalyzes the luminescence reaction of coelenterazine in the presence of oxygen the light emission (A.max 475 nm) is optimum at pH 7.2. [Pg.307]

The various existing types of electrochemical storage system differ in the nature of the chemical reaction, structural features and form, reflecting the large number of possible applications. [Pg.3]

Single Haversian systems differ significantly in calcium-phosphorus ratio. [Pg.301]

Fig. 1. Absorption isotherms of hydrogen in palladium within a large range of temperatures and pressures of hydrogen gas. Numbers denote temperature in °C. Hydrogen pressure is given in the logarithmic scale. Broken line closes the area of the two-phase o + region of the Pd-H system. Different shapes of experimental points denote different authors data, cited by Scholten and Konvalinka (9). After Scholten and Konva-linka (9).

By essentially the same energy it is meant that the energies of the states of the unperturbed system differ by an amount less than the possible... [Pg.99]

More recently, certain MS-MS scans have been made available on the ion-trap instrument. This type of system differs from those described previously in that the MS-MS capability is associated only with the way in which the ion-trap is operated, i.e. it is software controlled, and does not require the addition of a collision cell and a further analyser. This is because ion selection, decomposition and the subsequent analysis of the product ions are all carried out in the same part of the instrument, with these processes being separated solely in time, rather than time and space as is the case for the instruments described previously. [Pg.65]

For landfill, costs vary highly across Europe. The main reason are differences in landfill quality (a point that will be quickly become less important now that the EU Landfill directive is becoming operational) and particularly landfill tax systems. Differences between some 2 per tornie in some EU countries (for inert waste) and up to 280 per tonne in, e.g., some places in Germany, may occur (though the latter value must be regarded as exceptionally high). Technically, even in countries with unfavourable circumstances like the... [Pg.22]

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