Noise dose, defined

Noise dose As defined by OSHA, e ratio, expressed as a percentage, of (1) the time integral, over a stated time or event, of the 0.6 power of the measured SLOW exponential time-averaged, squared, A-weighted sound pressure or (2) the product of the criterion duration (8 hours) and the 0.6 power of the squared sound pressure corresponding to the criterion sound level (90 dB). 

Hearing loss is presumed to be work-related if the employee is exposed to noise in the workplace at an 8-hour time-weighted average of 85 dBA or greater, or to a total noise dose of 50 percent, as defined in OSHA s Occupational Noise Exposure standard. Noise dose is defined as the amount of actual employee exposure to noise relative to the permissible exposure limit for noise. A dose greater than 100 percent represents exposure above the limit. For hearing loss cases where the employee is not exposed to this level of noise, refer to the rules in 1904.5 to determine if the hearing loss is work-related. 

The validity of a specific method should be demonstrated in laboratory experiments using test samples or standards that are similar to the unknown samples analyzed in the routine. For example, control tissue samples from non-treated animals, control tissue samples spiked with the analyte at several known concentrations, and dosed or incurred tissue samples from animals that have been treated with the drug, should all be available to the analyst before starting a validation process. All these samples will enable the analyst to define the background noise, to identify the amounts of the analyte added to the control tissue, and demonstrate that the method can satisfactorily recover the biologically incurred residue. 

Given the inherent statistical nature of the discrete processes (such as photon absorption, secondary electron generation, PAG excitation, acid-quencher annihilation, deprotection, etc.) involved in advanced resist imaging, say, with EUV lithography, a credible concern has been reported that resists may reach a shot noise limit whereby low doses of high-energy EUV photons may cause the number of photons to fall to such low levels that the statistical variations inevitably will cause the LER to increase beyond an acceptable limit.This acceptable limit is referred to as the shot noise limit, and it is defined as the limit imposed by the statistical probability of underexposing a pixel. ... 

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