Threshold proximity

Methods that cluster data on the basis of a single scan of the data set are referred to as single-pass. A proximity threshold is typically used to decide... 

Idcntificalion of facilities at which an c.xlremcly hazardous substance is present in an amount in e. ccss of the threshold plamiing quantity, whether it is being produced, used, or stored. Transportalion routes of any extremely haztirdous substance lo or from the facility must be given, as well. Also lo be identified were other facilities contributing or subjected lo addilioiuil liazards because of tlieir proximity to facilities such as hospitals or natural gas facilities... 

Bilger has documented ozone and other oxidant measurements in Australia and compared them with those in other cities. Table 4-6 shows the portion of hours during which threshold concentrations were exceeded in Sydney in 1971, 1972, and 1973. Low concentrations were recorded before 1970, probably because of the proximity to nitric oxide emission sources in the central portion of the city. It is also noteworthy that, despite the calm conditions and strong inversion in the winter months (in the Southern Hemisphere), high-oxidant days were relatively infrequent. Figure 4-8 outlines this seasonal variation in oxidant concentration. In Melbourne, Australia, however, a high-ozone episode was observed during... 

It is important to note that the information obtained by each of the above techniques is very useful for understanding the composition and behaviour of a particular sample. A particularly appropriate example was the investigation of ground-water pollution by arsenic in the Lower Ganga Plain of West Bengal in India and Bangladesh. At one location, arsenic concentration was clearly well above the safe drinking threshold, while at another in the close proximity it was not toxic [24]. In this... 

This chapter will focus on infinitely-extended suspensions in which potential complications introduced by the presence of walls are avoided. The only wall-effect case that can be treated with relative ease is the interaction of a sphere with a plane wall (Goldman et ai, 1967a,b). The presence of walls can lead to relevant suspension rheological effects (Tozeren and Skalak, 1977 Brunn, 1981), which result from the existence of particle depeletion boundary layers (Cox and Brenner, 1971) in the proximity of the walls arising from the finite size of the suspended spheres. Going beyond the dilute and semidilute regions considered by the authors just mentioned is the ad hoc percolation approach, in which an infinite cluster—assumed to occur above some threshold particle concentration—necessarily interacts with the walls (cf. Section VI). 

Compound A is nephrotoxic in rats at thresholds estimated at 180 ppm/hour [67]. Renal toxicity is characterized histologically by proximal tubular cell degeneration and necrosis in the corticomedullar region of die kidney and biochemically by proteinuria, glucosuria, and enzymuria (NAG and a-GST) with increased serum creatinine and BUN concentrations occurring with severe toxicity [67-70]. 

Arbisi, R A., A. S. Levine, J. Nerenberg and J. Wolf (1996). Seasonal alteration in taste detection and recognition threshold in seasonal affective disorder the proximate source of carbohydrate craving. Psychiatry Res 59(3) 171-82. 

In contrast to the calcium-conserving effect of PTH on the kidneys, PTH increases renal phosphate excretion at the proximal tubule by directly lowering the renal phosphate threshold. Approximately 6.5 g (210 mmol) of phosphate is filtered by the kidneys each day. Normally, 85% to 90% is reabsorbed by the renal tubules (proximal and distal convoluted tubule). PTH is one of the most important factors regulating the renal phosphate threshold and hence the serum phosphate concentration. 

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