Danger prediction

Hu Qian-ting, et al. 2007. New technology of outburst danger prediction by gas content. Journal of China Coal Society 32(3) 276-280. 

We are aware of tire dangers inherent in predicting tire future. It is much safer to summarize tlie present and to extrapolate to tlie near tenn only. 

Semiempirical correlations are often preferred to purely empirical or purely theoretical correlations. Purely empirical correlations are dangerous to use for extrapolation. Purely theoretical correlations may predict trends accurately but they can be several orders of magnitude off in the value of k. 

Other Effects Stream concentration can have important effects on corrosion rates. Unfortunately, corrosion rates are seldom linear with concentration over wide ranges. In equipment such as distillation columns, reactors, and evaporators, concentration can change continuously, makiug prediction of corrosion rates rather difficult. Concentration is important during plant shutdown presence of moisture that collects during cooling can turn innocuous chemicals into dangerous corrosives. 

A list of danger categories is given in Table 14.2. Note that chemicals may possess several hazards, e.g. nitric acid is classed as both an oxidizer and a conosive. If a chemical is not in one of these categories it is not generally considered to be dangerous. If the hazards of a new chemical have not been established it should be labelled Caution - substance not yet fully tested . Mixtures can be classified either from results from tests on the preparation, or by calculation to predict the healtli effects of the product based on the properties of individual components and tlieu concentration in the mixture. Preparations need to be classified for both physico-chemical and health effects but, to date, not for environmental effects. 

The preservation processes should be designed to prolong the life of the product by inhibiting the effect of natural elements. While the conditions in the factory can be measured, those outside the factory can only be predicted. Markings on packaging are therefore essential to warn handlers of any dangers or precautions they must observe. 

Localised corrosion The various forms of localised corrosion are a greater source of concern to the plant designer (and operator) since it is usually difficult to predict an accurate rate of penetration, difficult to monitor, and consequently can be (especially in the case of stress-corrosion cracking) catastrophically rapid and dangerous. 

My design here is to bypass reactions declared dangerous merely because they have provoked an accident, in order to provide the means of predicting the potential danger of a reaction, by virtue of global treatment of products that have structures in common. 

Finally, there was a detonation, which involved molten copper and water. It is not a properly dangerous reaction and the consequences of such a thermal shock are rather predictable. 

Descriptors used to characterize molecules in QSAR studies should be as independent of each other (orthogonal) as possible. When using correlated parameters there is an increased danger of obtaining non-predictive, chance correlation [56]. To examine the correlation between PSA (calculated according to the fragment-based protocol [10]) and other descriptors, we studied a collection of 7010 bioactive molecules from the PubChem database [57]. In addition to PSA, the following parameters were used ... 

Intravenous medication is injected directly into a vein either to obtain an extremely rapid and predictable response or to avoid irritation of other tissues. This route of administration also provides maximum availability and assurance in delivering the drug to the site of action. However, a major danger of this route of administration is that the rapidity of absorption makes effective administration of an antidote very difficult, if not impossible, in most instances. Care must often be... 

Because herbicides have been used for many years, soil will almost always simultaneously accumulate residual amounts of several stable pesticides. The number of possible combinations of residual pesticides is so great (hundreds, maybe even thousands), that it is impossible theoretically to predict the effect. However, it is theoretically possible to draw a general conclusion founded in fact the consequences of using any pesticide are always more varied and dangerous than the regulations state. 

The need to balance costs against benefits both in the public and private sectors resulted in a search for methods of predicting the fate and effects of chemicals in the environment. Actual field testing of all cases of interest is both too costly and too dangerous to perform. Mathematical models, therefore, have been developed to provide descriptive tools and predictive approaches to this problem. At the symposium on which this book is based, a collection of user-oriented information was presented and covered the following aspects of environmental fate modeling ... 

The finger prick technique is invasive, painful, and potentially dangerous, because of the risk of infection. Also, since it is not continuous, it is not possible to predict a blood glucose pattern over the day nor the exact dose of insulin needed. In addition, depending on the training of the individual performing the test, the results are subject to inaccuracy. 

---