Single time period

It is important not to assume that a lack of change or a very slow change will continue forever. One should not ignore the possibility that an induction period exists, particularly when durability is being assessed on the basis of degradation after a single time period (single-point data). 

In general, these occupational exposure studies poorly characterize aluminum exposure. Some of the studies reported aluminum air concentrations for a single time period (Dick et al. 1997 Sim et al. 1997 Sjogren et al. 1996 White et al. 1992), but did not have earlier monitoring data when aluminum exposures were higher. The lack of adequate exposure monitoring data and the different types of aluminum exposure makes it difficult to compare these studies and draw conclusions regarding the neurotoxic potential of inhaled aluminum in workers. 

Subtractive technique The continuous removal of material from a larger original piece in the manufacturing process examples include stone working and wood carving. Synchronic Dealing with a moment in time, a single time period. 

Acute exposure An exposure to a toxic substance which occurs in a short or single time period. 

A typical production-transportation problem can be described as follows. There are m production plants and n customers. A single product is produced at the plants and shipped from the plants to the customers. Each plant ihas a capacity limit Si, and the production cost is a concave function /(xi, X2, Xm) of the amounts produced at these plants x, X2,Xm- The transportation costs from the plants to the customers are linear the unit transportation cost from plant i to customer j is Cij. The problem involves a single time period only, and the demand of each customer j is known as dj which must be satisfied. The problem seeks a production and distribution plan that minimizes total production and transportation cost. The problem can be formulated as the following mathematical program ... 

We review results on problems with one time period separately from results on problems with multiple time periods. Cohen and Lee (1988, 1989), Zuo et al. (1991), Chen and Wang (1997), and Sabri and Beamon (2000) consider problems with a single time period but multiple products. Each of these papers is reviewed in the following paragraphs. 

OSHA says that exposures must not exceed 20 ppm except if no other measurable exposure occurs during the 8-hour work shift. Then exposures may exceed 20 ppm, but not more than 50 ppm (peak), for a single time period up to 10 minutes. However, a level of H2S gas at or above 100 ppm is immediately dangerous to life and health (IDLH). 

Subramanian, P, Ramkumar, N., and Narendran, T. T. Mathematical model for multi-echelon, multi-product, single time-period closed loop sujjply chain. International Journal of Business Performance and Supply Chain Modelling 2, no. 3-4 (2010) 216-236. 

Figure Cl.5.8. Spectral jumping of a single molecule of terrylene in polyethylene at 1.5 K. The upper trace displays fluorescence excitation spectra of tire same single molecule taken over two different 20 s time intervals, showing tire same molecule absorbing at two distinctly different frequencies. The lower panel plots tire peak frequency in tire fluorescence excitation spectmm as a function of time over a 40 min trajectory. The molecule undergoes discrete jumps among four (briefly five) different resonant frequencies during tliis time period. Arrows represent scans during which tire molecule had jumped entirely outside tire 10 GHz scan window. Adapted from...

A single-column installation is satisfactory if the unit can be shut down for regeneration. However, if flow of the stream being processed must be continuous, then two or more columns of the same resin must be installed in parallel. Regeneration of each is staged for different time periods. 

ACUTE TOXICITY Advcfse health effects occumng within a short time period of exposure to a single dose of a chemical or as a result of multiple exposures over a short time period, e.g. 24 hours. 

The calculation procedures just described are methods for predicting shortterm GLC s for single stack cases. In the calculation of short-term GLC s it is as sinned that meteorological conditions are constant throughout the measuring time period. Short-term time periods are usually considered to be 1 hour or less. The averaging times for the various methods discussed are as follows ... 

Averaging time The time period over which the measuring procedure provides a single value. 

The binomial distribution can be used to calculate tlie reliability of a redundant syslein. A redundant system consisting of n identical components is a system tliat fails only if more tlian r components fail. Familiar examples include single-usage equipment such as missile engines, sliort-life batteries, and flash bulbs, which are required to operate for one time period and are not reused. Associate "success with tlie failure of a component. Assume tliat tlie n components are independent witli respect to failure, and tliat tlie reliability of each is 1 - p. Then X, tlie number of failures, has tlie binomial pdf of Eq. (20.5.2) and the reliability of the redundtuit system is... 

How then are these ions/decompositions chosen Before considering this we must define, very carefully, the requirements of the analysis to be carried out. Is a single compound to be determined or are a number of compounds of interest If a single compound is involved, its mass spectrum and MS-MS spectra can be obtained and scrutinized for any appropriate ions or decompositions. If the requirement is to determine a number of analytes, their chromatographic properties need to be considered. If they are well separated, different ions/decompositions can be monitored for discrete time-periods as each compound elutes, thus obtaining the maximum sensitivity for each analyte. If the analytes are not well separated, this approach may not be possible and it may then be necessary to monitor a number of ions/decompositions for the complete duration of the analysis. If this is the case, the analyst should attempt to find the smallest number of ions/decompositions that give adequate performance for all of the analytes (remember the more ions/decompositions monitored, then the lower the overall sensitivity will be). 

Electrochemical nuclear magnetic resonance (NMR) is a relatively new technique that has recently been reviewed (Babu et al., 2003). NMR has low sensitivity, and a typical high-held NMR instrument needs 10 to 10 NMR active atoms (e.g., spins), to collect good data in a reasonable time period. Since 1 cm of a single-crystal metal contains about 10 atoms, at least 1 m of surface area is needed to meet the NMR sensitivity requirement. This can be met by working with carbon-supported platinum... 

Figure 3. Parent daughter disequilibrium will return to equilibrium over a known time scale related to the half-life of the daughter nuclide. To return to within 5% of an activity ratio of 1 requires a time period equal to five times the half-life of the daughter nuclide. Because of the wide variety of half-lives within the U-decay-series, these systems can be used to constrain the time scales of processes from single years up to 1 Ma.

Several equations have been developed to assess unstable kidney function. The Jelliffe equation (Table 22-1) estimates creatinine clearance by considering the change in serum creatinine over a specified time period.11 While it is more mathematically difficult to calculate, it better estimates creatinine clearance in patients with rapidly changing kidney function compared to an equation that only includes a single creatinine concentration. 

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