Temporal Factors Time pressure

Temporal factors include system design recommendations relating to the temporal factors that impact workload, including time pressure, shiftwork, and the temporal distribution of workload. 

From the development of a comprehensive model of the factors leading to instabilities in molecular discharges, Haas [87] has found that these systems are prone to several modes of instability. Of these modes, the conditions leading to the development of ionization and neutral particle energy transfer modes of instabilities have been found to be most easily satisfied under laser conditions. Ionization instabilities are produced when conditions enhance the temporal amplification of an imbalance between electron production and loss processes. The characteristic growth time for this type of instability that has been found to be independent of pressure and power density is in the 10-8-10 4 sec range [53, 78, 87], In contrast, neutral particle energy transfer instability modes that occur due to amplification of disturbances in translational... 

Simple models have been developed to screen for consequences of worst-case exposures (van de Meent et al., 1995 USEPA, 1997b). For example, these models calculate worst-case exposure by dividing the amount of active ingredient by the room size. When better estimates of exposure are needed, simple models are advanced based on mechanistic processes or statistical relations, in conjunction with experiments aimed at quantifying exposnre factors (Jayjock, 1994 Matoba et al., 1998a,c van Veen, 1996) (see the model overview below). These models describe the mechanisms of exposure and inclnde key factors that influence exposure, such as ventilation rates of rooms and vapor pressures of chemicals. In addition, they provide a more precise temporal and spatial scale of exposure and dose. These scales enable identification and exposnre assessment of persons at various distances from the application and of persons having varions time-intervals of contact with the pesticide. 

When time irreversibility is incoq)orated, evolutionary chemical systems are generated, representing the induction of chemical evolution. This opens perspectives towards systems that would undergo progressive change of internal structure under the pressure of environmental factors. It implies also the passage from closed systems to open systems that are connected spatially and temporally to their surroundings. 

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