Effective life time

Examination of these curves suggests immediately that formulations A and C have reasonably constant rates of release and an effective life-time of possibly forty days while B has lost 90% of its active ingredient in the first week. The scatter about the curve C may be due to the difficulty of reproducibly sampling microdispersed formulations. 

There is no doubt that the extensive but dispersed literature concerned with decompositions of solids is in need of review. The nimiber of comprehensive surveys of this important, active and well-defined subject area that have been published in the last fifty years (the effective life-time of the topic) is remarkably small. Even reviews of more restricted aspects, such as the thermal properties of particular groups of reactants, are surprisingly few in number. 

The coefficient takes values between = 2 / 3 (ideal sphere) and = 1 (conditions in the MPTl (Fainerman et al. 1994a). In the moment of bubble detachment this coefficient can reach values > 1. Hence, the effective life time of the bubble during this second stage of its growth (effective dead time) results to... 

Unfortunately, these devices tend to have a short effective life-time and suffer from drift. This is due, in part, to gradual penetration of the sensor by the sample (particularly at the PVC/encapsulate seams) and a gradual leaching of the active ingredient (typically a low-molecular weight ionophore dissolved in a PVC plasticiser) into the sample. ... 

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). 

While the effective life of Norplant I is at least five years, most of the users have the implants removed at an earlier time. Norplant II was developed to have a shorter life-span, and is composed of only two rods. Levonorgestrel is dispersed in the silastic matrix which is then inserted into a thin silastic tubing. This product has an effective life-span of two to three years (36). Because it is composed of only two rods, Norplant II also is easier to implant and remove. 

A toxic reaction may take place during or soon after exposure, or it may only appear after a latency period. Chronic toxicity requires exposure of several years for a toxic effect to occur in humans. With respect to experimental animals, the animals are usually exposed for most or all of their life time to ascertain the occurrence of chronic toxicity. Acute toxic reactions that occur immediately are easy to associate with the exposure and the exposure-effect relationship can readily be demonstrated. The longer the time interval between exposure and effect, the more difficult it is to delineate the relationship between exposure and effect. 

The fact that there are no characteristic length scales immediately implies a similar lack of any characteristic time scales for the fluctuations. Consider the effect of a single perturbation of a random site of a system in the critical state. The perturbation will spread to the neighbors of the site, to the next nearest neighbors, and so on, until, after a time r and a total of / sand slides, the effects will die out. The distribution of the life-times of the avalanches, D t), obeys the power law... 

To measure the total light emission of a photoprotein sample, it was necessary to add 1-5 pM Fe2+ several times due to the short effective life of Fe2+ under the conditions involved. The total amount of light measured in this manner was always proportional to the weight of photoprotein used, with both CPA and CPC (4.7 x 1013 photons/mg at 25°C Shimomura and Johnson, 1968d). Thus, the quantum yield is estimated at roughly 0.01 for CPA, and 0.015 for CPC. 

The time of effect duration (TED) is a ftmction of the elimination half-life. Two special cases are most important, the 50% effect bisection time (TED50) and the duration of 90% of the effect (TED90). 

The effect of the life-times of radical pairs on the magnitude of polarization... 

Even under these conditions we can state that in highly developed countries HAART is cost-effective. Because of an increase of life expectancy, the life-time provider costs increase under this drug regime. But, on the contrary, the indirect... 

Effective Half-time - Biological half-time x Radioactive half-life... 

Apart from the classification based on the mode of generation of cavities, cavitation can also be classified as transient cavitation and stable cavitation [3]. The classification is based on the maximum radius reached (resonant size), life time of cavity (which decides the extent of collapse) in the bulk of liquid and the pattern of cavity collapse. Generation of transient or stable cavitation usually depends on the set of operating parameters and constitution of the liquid medium. Depending on the specific application under question, it is very important to select particular set of operating conditions such that maximum effects are obtained with minimum possible energy consumption. 

Post, R.M. Intermittent versus continuous stimulation effect of time interval on the development of sensitization. Life Sci. 26 1275, 1980. 

Contaminants Indoor contaminants are expected to compete for adsorption sites on the charcoal. We will experimentally find the effect that these contaminants have on the dynamic adsorption coefficient and on the life-time of the charcoal bed. Since the number of radon atoms in even the most seriously contaminated houses is very small, decay product buildup is not expected to pose a significant problem. 

Retention of cerium deposited in these tissues is generally considered to be very long, with a biological half-time in excess of a thousand days. Therefore, the effective half-time of retention in these internal organs will be approximately equal to the physical half-life. 

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