Extreme-case scenario

For each specific relief all possible scenarios are identified and cataloged. This step of the relief method is extremely important The identification of the actual worst-case scenario frequently has a more significant effect on the relief size than the accuracy of relief sizing calculations. 

Yet just as all people are not alike, neither are all food crises alike. They can vary in their familiarity, severity, proximity, consequence, and the extent to which they can be avoided. This review covers a wide range of crises from bacteria contamination, to product tampering, to fears related to irradiation and biotechnology. Different types of crises will be evaluated differently by different groups of consumers. What has been done in this review is to focus on worst-case scenarios involving initial responses to food safety issues. These will provide the most clear and illustrative profiles of consumer response. Less extreme scenarios will elicit less extreme responses. 

Less extreme plans can be reached with the two-phase optimization strategy compared to the one-phase optimization approach scenario profits are nearer by and the worst case scenario is comparably better than in the one-phase-optimization strategy. The overall plan in sales, production and procurement is more cautious with lower sales quantities and lower expected profits as the pay-off for better minimum profits. 

The most extreme case of gamma radiation dose would arise from explosion of a nuclear weapon. Nuclear weapons release intense gamma radiation that can produce fatal doses miles from an explosion (see Chapter 5). A less extreme but more likely scenario involves radioactive materials dispersed via conventional explosives (dirty bombs), where only the immediate area is contaminated with gamma-emitting radionuclides. 

Within realistic conditions of operation, the shortest lifetime (1200 y) represents the worst case, which is certainly difficult to envision for this situation, HT granules would have the smallest possible size (1 mm) and would dissolve at the fastest rate (10-3 g/m2 x day). Likewise, the longest lifetime (6 x 105 y) is the best case scenario, which might never happen HT granules would have the greatest size and dissolve at the lowest corrosion rate. These two extreme lifetimes are thus not considered to be plausible. For the most realistic estimates, one would expect the hypothetical HT material to last for ca. 104-105 years, which is remarkably favourable. 

The same Australian study estimated total farm incomes under the assumption of an adoption rate of 30%. Under the worst-case scenario, where premiums for crops were assumed to decrease from 15% to 0% with no premiums for livestock products at all stages (extreme assumptions) total returns to the sector would drop by 7% when 30% of farmers had converted. In the best-case scenario, with premiums decreasing from 15% to 7.5% (probably more realistic), total returns to the cereal-livestock sector would have a 3% decrease at the 30% adoption rate. 

In the chapters devoted to reactors, it was considered that a situation is thermally stable due to the relatively high heat removal capacity of reactors compensating for the high heat release rate of the reaction. We considered that in the case of a cooling failure, adiabatic conditions were a good approximation for the prediction of the temperature course of a reacting mass. This is true, in the sense that it represents the worst case scenario. Between these two extremes, the actively cooled reactor and adiabatic conditions, there are situations where a small heat removal rate may control the situation, when a slow reaction produces a small heat release rate. These situations with reduced heat removal, compared to active cooling, are called heat accumulation conditions or thermal confinement. 

At the same time, across all the sectors and policies, there was a reduction in volume of production, in most cases by much less than 1%. In two extreme cases - steel and cement - under the toughest policy scenario, the output reductions were of 10% and 5%. This supports the suggestion, made for example by the CBI, that the EU ETS might cause a reduction in employment in some sectors. 

Flame retardants or flame retardancy mechanisms, respectively, influence different fire properties quite differently, and, what is more, show different effectiveness in different fire scenarios, and thus fire tests. In extreme cases, flame retardancy with respect to a specific fire property or specific test is achieved with little or no improvement in performance in another fire property or fire test. This fundamental understanding in fire science sometimes may be overlooked in materials development, but is worth addressing. The influence on different fire risks and the dependency of effectiveness on the scenario addressed is discussed subsequently based on the fire retardancy mechanisms accompanying charring and barrier formation. 

The typical end-use product and application method chosen as representative of the extreme-case exposure scenario must be used to attain the highest permissible rate allowed by label directions. Sampling for indoor residues should consider all potential sites where appreciable residues are expected and are accessible. For instance, dermal contact may come from exposure to the pesticide as a residue on carpets, vinyl tile, upholstery and counter tops, while airborne residue (vapor- or particle-phase) may provide the source of inhalation exposure. The measurements taken are linked specifically to the method of application. 

It is likely that the use of CO remains from the early atmospheric conditions when life first evolved around 4 billion years ago. This follows from the hypothesis that the first organisms were autotrophic (Huber and Wachtershauser, 1997 Russell et al., 1998). Volcanic gases can contain as high as 1% CO. Early life forms evolving in volcanic sites or hydrothermal vents could have used CO as their carbon and energy source. If this scenario is correct, CO metabolism today can be viewed as the extant survivor of early metabolic processes (Huber and Wachtershauser, 1997). The ability to metabolize CO is still important today since about 10 tons of CO are removed from the lower atmosphere of the earth by bacterial oxidation every year (Bartholomew and Alexander, 1979). This helps to maintain CO below toxic levels, except in extreme cases. 

If uncertainty is not in the range of the proactive model scenarios (Table 2), the reactive approach gives better evaluation criterion values in all cases. The last scenario in Table 2 is an extreme case and demonstrates the superiority of the reactive model (a 67,5% better) if the uncertainty takes place very close to the end of time horizon (Fig. 1). 

This assessment included the estimate of the residues of PBO following application at the recommended application rate and at 10 times the single application rate- This incorporates two highly conservative assumptions. First, the I OX rate simulates the maximum number of applications allowed on the label and incorporates the unrealistic assumption that no degradation or dissipation occurs in the field (or all 10 applications are made at the same lime). This is a worst-case scenario considering the degradation predicted by the environmental fate studies and the actual levels of PBO observed in the field, as well as the low likelihood that 1U applications of PBO would ever be made prior to harvest. The second extremely conservative assumption used in this exposure assessment is that I009f- of the avian diet is derived from treated crop,... 

Each simulation included 100 hypothetical subjects. The model parameters used were derived from an adult population and there were no covariate distribution models for the virtual trial population. Subjects were assumed to be healthy and on valproate monotherapy (31). The simulations assumed that the extended release (ER) formulation was administered once daily and the delayed release (DR) preparation was administered twice daily. Unbound and total valproic acid concentrations were simulated from the time of dose administration to 280 h and the simulations were based on the administration of 1000 mg ER once daily, 500 mg DR twice daily, 2500 mg ER once daily, and 1000 mg DR twice daily. For once-daily regimens, simulation scenarios included doses taken 6, 12, 18, and 24h late from schedule and then two doses taken 24h late (replacement dose for the missed dose). For the twice-daily regimens, doses were simulated 3,6,9, and 12 h later than the scheduled times and then two doses were simulated 12 h later than scheduled to mimic replacement dosing for a missed dose. More extreme cases where two doses are delayed at various times or missed were also simulated. 

Whilst it is hoped that the issue of polymorphism is resolved during prenomination and early development, it can remain a concern when the synthesis of the drug is scaled-up into a larger reactor or transferred to another production site. In extreme cases, and despite intensive research, work may have only produced a metastable form, and the first production batch produces the stable form. Dunitz and Bernstein (1995) have reviewed the appearance of, and subsequent disappearance of, polymorphs. Essentially, this describes the scenario whereby, after nucleation of a more stable form, the previously prepared metastable form could no longer be made. 

Consider the phenomenon referred to as spontaneous human combustion (SHC), as publicized from time to time (e.g., as was reported in Arthur C. Clarke s Mysterious Universe, shown on the Discovery Channel, for instance, on October 22,1996, and was mentioned in Charles Dickens Bleak House). If this weird phenomenon does indeed occur, it could instead be referred to as spontaneous ignition, followed by combustion. And if it is at least conceivable for aberrations to occur among the enzyme-catalyzed reactions involved in the metabolism of glucose or other carbohydrates to yield CO2 and H2O, then conceivably there may be a case. Ordinarily, body metabolism reaction rates are miniscule as compared to the direct combustion or combustive oxidation of conventional fuels. If enzyme promoters exist, however, there is the possibility that runaway metabolic processes occur, similar to those in the ignition and further combustion of carbonaceous materials. If so, ample air or oxygen supply would also be required for this extremely unlikely scenario. 

SCCP concentrations in river water were approximately half of those in effluents from sewage treatment plants, which indicates that the measured concentrations of river water were extremely high, considering that usual concentrations are about 10% of those in effluents. Thirdly, based on the assumption that the measured concentrations have distribution with the mean of measured concentrations and the standard deviation of SS, the 95th percentile is calculated extremely high. Therefore, it is considered relevant to assume this as a worst case scenario for risk assessment. 

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