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Measurement time, effective

Experimentally, it is sometimes difficult to detect differences between a shear-thinning Hquid in which the viscosity decreases with increasing shear, and a thixotropic material in which the viscosity decreases with time, because of the combined shear and time effects that occur during a series of measurements. This is especially tme if only a few data points are collected. In addition, most materials that are thixotropic are also shear thinning. In fact. [Pg.168]

Administration of 5 ppm barium, the acetate, to mice in the drinking water in a life-time study had no observable effects on longevity, mortality, and body weights, or on the incidence of tumors (53). Long-term studies in rats exposed to Ba " in drinking water containing 5 mg/L, as acetate, or 10—250 mg/L, as chloride, resulted in no measurable toxic effects (47). [Pg.483]

Measure of averaging time Cyclic factor measured Measurement method with same averaging time Effect with same averaging time... [Pg.47]

Another important factor in diffusion measurements that is often encountered in NMR experiments is the effect of time on diffusion coefficients. For example, Kinsey et al. [195] found water diffusion coefficients in muscles to be time dependent. The effects of diffusion time can be described by transient closure problems within the framework of the volume averaging method [195,285]. Other methods also account for time effects [204,247,341]. [Pg.584]

A number of laboratory tests are available to measure the phases of hemostasis described above. The tests include platelet count, bleeding time, activated partial thromboplastin time (aPTT or PTT), prothrombin time (PT), thrombin time (TT), concentration of fibrinogen, fibrin clot stabifity, and measurement of fibrin degradation products. The platelet count quantitates the number of platelets, and the bleeding time is an overall test of platelet function. aPTT is a measure of the intrinsic pathway and PT of the extrinsic pathway. PT is used to measure the effectiveness of oral anticoagulants such as warfarin, and aPTT is used to monitor heparin therapy. The reader is referred to a textbook of hematology for a discussion of these tests. [Pg.608]

The na/ outcomes which are changes over time in the symptoms, welfare and quality of life of patients (and their families if relevant to the context), relative to some baseline position, standard or comparator. Final outcomes are clearly measures of effectiveness. They can equivalently be defined as reductions in need. [Pg.7]

The relatively small percentage resonance effects require measuring times on the order of 1 week. A representative Pt (99 keV) Mossbauer spectrum, that of Pt02 taken at 4.2 K [332], is shown in Fig. 7.71. [Pg.343]

If the inhibition is found to be rapidly reversible, we must next determine if the approach to equilibrium for the enzyme-inhibitor complex is also rapid. As described in Chapter 4, some inhibitors bind slowly to their target enzymes, on a time scale that is long in comparision to the time scale of the reaction velocity measurement. The effect of such slow binding inhibition is to convert the linear progress curve seen in the absence of inhibitor to a curvilinear function (Figure 5.10). When nonlinear progress curves are observed in the presence of inhibitor, the analysis of... [Pg.127]

A new experimental method has been introduced to measure the effect of the crystal anapole moment on p decay. The basic hypothesis is very similar to that assumed by Zel dovich. The special idea is to introduce the description of solid-state physics (crystallography) into the process of weak interaction. The p decay rate will be modified due to the presence of crystal anapole moment. If this modification could be detected, the hypothesis for the anapole moment and its coupling to weak interaction will be verified for the first time if this modification could not be detected by this method, an upper limit of up to 1(T6 for the coupling of anapole moment to weak process should be given. This experiment will give direct verification to Zel dovich s assumption. [Pg.313]

Although it is clear that H2S plays an important physiological role in mammalian systems, it must be realized that many investigations have been carried out at 02 and H2S concentrations that do not represent physiological levels. In-situ H2S levels have not been monitored partly because continuous physiological H2S measurements have not been possible until recently. Without the benefit of real time H2S measurements, the effects of H2S under physiological conditions remain largely undefined. [Pg.239]

Permeabilities measured for pure gases can serve as a rough guide for selection of membrane materials. For design, data must be obtained on gas mixtures, where selectivities are often found to be much lower than those calculated from pure-component measurements. This effect is often due to plasticisation of the membrane by sorption of the most soluble component of the gas. This allows easier penetration by the less-permeable components. The problem of concentration polarisation, which is often encountered in small-scale flow tests, may also be responsible. Concentration polarisation results when the retention time of the gas in contact with the membrane is long. This allows substantial depletion of the most permeable component on the feed side of the membrane. The membrane-surface concentration of that component, and therefore its flux through the membrane, decreases. [Pg.108]

He stressed the significance of measurements of molecular dipole moment, the principles of which had been established in 1912 by Debye.52 Ingold predicted that mesomeric systems would display measurable dipole effects. 53 He later said that he realized at this time that the theory of dipolar charge and intermediate form was... [Pg.226]


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