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Lifetime, units

The variable delay can be as simple as an RC network. Often the variable delay line is calibrated directly in terms of lifetime units (nanoseconds). When the reference and comparison signals are in phase the fluorescence lifetimes can simply be read off the calibrated variable delay. [Pg.24]

Heinrich, U., M. Roller, and F. Pott, Estimation of a Lifetime Unit Lung Cancer Risk for Benzol a Ipyrene Based on Tumour Rates in Rats Exposed to Coal Tar/Pitch Condensation Aerosol, Toxicol. Lett., 72, 155-161 (1994). [Pg.534]

Heinrich U, Pott F, Roller M. 1994a. Estimation of a lifetime unit lung cancer risk for benzo(a)pyrene (BAP) based on tumor rates in rats exposed to coal tar/pitch condensation aerosol (CTP). Zentral Hyg Umwelt 195 155-156. [Pg.327]

Arzhaev A T, Kiselyov VA., Badalyan V.G., Vopilkin A.Kb., Strelkov B.R,Vanukov V.N., Aladinsky V. V, Makhanev V.O. Field application of Augur)> ultrasonic system during RBMK NPP Unit ISI and its impact on pressure boundary integrity. In Ageing of Materials and Methods for the Assessment of Lifetimes of Engineering Plant, R K. Penny (Ed.), 1997, pp. 97-104. [Pg.197]

In 1976 the United States banned the use of CFCs as aerosol propellants. No further steps were taken until 1987 when the United States and some 50 other countries adopted the Montreal Protocol, specifing a 50% reduction of fully halogenated CFCs by 1999. In 1990, an agreement was reached among 93 nations to accelerate the discontinuation of CFCs and completely eliminate production by the year 2000. The 1990 Clean Air Act Amendments contain a phaseout schedule for CFCs, halons, carbon tetrachloride, and methylchloroform. Such steps should stop the iacrease of CFCs ia the atmosphere but, because of the long lifetimes, CFCs will remain ia the atmosphere for centuries. [Pg.381]

Thus the ADI in mg per kg per day is an estimate of the daily pesticide dietary intake that appears to be without risk over the entire human lifetime. ADI values are estabHshed and periodically reviewed by joint committees of the Eood and Agricultural Organization (EAO) and WHO of the United Nations. [Pg.309]

Another nonregenerative drying appHcation for molecular sieves is their use as an adsorbent for water and solvent in dual-pane insulated glass windows. The molecular sieve is loaded into the spacer frame used to separate the panes. Once the window has been sealed, low hydrocarbon and water dew points are maintained within the enclosed space for the lifetime of the unit. Consequently, no condensation or fogging occurs within this space to cloud the window. [Pg.456]

Anxiety disorders and insomnia represent relatively common medical problems within the general population. These problems typically recur over a person s lifetime (3,4). Epidemiological studies in the United States indicate that the lifetime prevalence for significant anxiety disorders is about 15%. Anxiety disorders are serious medical problems affecting not only quaUty of life, but additionally may indirecdy result in considerable morbidity owing to association with depression, cardiovascular disease, suicidal behavior, and substance-related disorders. [Pg.217]

Depression is a common psychiatric disorder. The lifetime risk of developing a depressive episode is estimated to be as high as 8—12% for men and 20—26% for women (116). Depression, one of the most widespread of all life-threatening disorders, is almost always a factor in the mote than 30,000 suicides that occur annually in the United States alone (117). [Pg.228]

Very early in the study of radioactivity it was deterrnined that different isotopes had different X values. Because the laws of gravity and electromagnetism were deterministic, an initial concept was that when each radioactive atom was created, its lifetime was deterrnined, but that different atoms were created having different lifetimes. Furthermore, these different lifetimes were created such that a collection of nuclei decayed in the observed manner. Later, as the probabiUstic properties of quantum mechanics came to be accepted, it was recognised that each nucleus of a given radioactive species had the same probabiUty for decay per unit time and that the randomness of the decays led to the observed decay pattern. [Pg.446]

We have seen that 10" M s is about the fastest second-order rate constant that we might expect to measure this corresponds to a lifetime of about 10 " s at unit reactant concentration. Yet there is evidence, discussed by Grunwald, that certain proton transfers have lifetimes of the order 10 s. These ultrafast reactions are believed to take place via quantum mechanical tunneling through the energy barrier. This phenomenon will only be significant for very small particles, such as protons and electrons. [Pg.136]

Dose Rate This represents the dose per unit time, for example in mg/day, sometimes also called dosage. Dose rates are often expressed on a per-imit-bodyweight-basis. yielding units such as mg/kg-d. They are often expressed as at erages over some time period, e.g., a lifetime. [Pg.317]

Generally, the slope factor is a plausible upper bound estimate of the probability of a response per unit intake of a ehemieal over a lifetime. The slope factor is used in risk assessments to estimate an upper-bound lifetime probability of an individual developing cancer as a result of e.xposure to a particular level of a potential carcinogen. Slope factors should always be accompanied by the weight-of-evidence classification to indicate the strength of the evidence that the agent is a human carcinogen. Calculational details are presented below. [Pg.335]

When using animal inhalation e.xpcrimcnts to estimate lifetime human risks for partially soluble vapors or gases, the air concentration (ppm) is generally considered to be the equivalent dose between species based on cqui alcnt c.xposure times (measured as fractions of a lifetime). For inhalation of particulates or completely absorbed gases, the amount absorbed per unit of body surface area is considered to be the equivalent dose between species. [Pg.337]

Toxicity alucs for carcinogenic effects also can be c.xprcsscd in terms of risk per unit concentration of the substance in the medium where human contact occurs. These measures, called unit risks, are calculated by dividing the slope factor by 70 kg and multiplying by the inhalation rate (20 m /day) or the water consumption rate (2 L/day), respecti ely, for risk associated with unit concentration in air or water. Where an absorption fraction less than 1.0 has been applied in deriving the slope factor, an additional conversion factor is necessary in the calculation of unit risk so that the unit risk will be on an administered dose basis. The standardized duration assumption for unit risks is understood to be continuous lifetime c.xposure. Hence, when there is no absorption conversion required ... [Pg.337]

C, = amnial average air concentration of pollutant i UR, = unit risk value by inhalation for pollutant i L = operational lifetime of a facility, yr usually assumed to be 70 year... [Pg.420]

The CCE spreads the investment over the lifetime of the measure into equal annual payments with the familiar capital recovery factor. The annual payment is then divided by the annual energy savings to yield a cost of saving a unit of energy. It is calculated using the following formula ... [Pg.288]

If one just concentrates on the radioactive material in SNF, the volume is very small, especially compared to waste from other power production practices. However, one can only discuss the separated radioactive material if it has undergone extensive reprocessing. If SNF is to be isolated, as in a place such as Yucca Mountain, with perhaps 70 miles of tunnels, the volume is that of the interior of this minor mountain. Isolation of up to 100,000 metric tons of SNF in Yucca Mountain means that for the United States, approximately all the SNF made to date and that expected in the operating lifetime of all current reactors can be put there. Approximately 2,000 metric tons of SNF are produced each year in the United States. Waste volume and placement depend on the amount of compaction and consolidation at the sites. The plans for the Yucca Mountain present a realistic and understandable picture of the volume of SNF. [Pg.884]


See other pages where Lifetime, units is mentioned: [Pg.180]    [Pg.212]    [Pg.180]    [Pg.212]    [Pg.96]    [Pg.481]    [Pg.1426]    [Pg.2446]    [Pg.2501]    [Pg.2857]    [Pg.367]    [Pg.538]    [Pg.273]    [Pg.456]    [Pg.499]    [Pg.149]    [Pg.111]    [Pg.100]    [Pg.188]    [Pg.45]    [Pg.270]    [Pg.509]    [Pg.184]    [Pg.267]    [Pg.547]    [Pg.336]    [Pg.357]    [Pg.241]    [Pg.270]    [Pg.849]    [Pg.1034]   
See also in sourсe #XX -- [ Pg.11 ]




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