Catastrophic effect

Manganese, copper, iron, cobalt and nickel ions can all initiate oxidation. Untinned copper wire can have a catastrophic effect on natural rubber compounds with which it comes into contact. Inert fillers for use in rubbers are usually tested for traces of such metal ions, particularly copper and manganese. The problem is perhaps less serious in saturated hydrocarbon polymers but still exists. 

Secondly, accidents of the second type liave a catastrophic effect on production. Not only will tlie entire facility be demolished (in all likelihood), but a large fraction of the pool of trained personnel will be lost all at once. Who will train replacement persomiel if everyone is lost in tlie disaster Similar concerns make disruption in Uie community much greater for accidents of the second type. Some of these considerations can be factored into decision making as direct economic losses tliat increase the burden to both Uie company and Uie community for accidents of the second type. 

Although natural selection is the only evolutionary agent that adapts organisms to their environments, the course of evolution has been profoundly influenced by major environmental changes, some of which had catastrophic effects. Some of these events resulted from Earth s internal processes, such as the activity of volcanoes and the shifting and colliding of continents. Others were the result of external events, such as collision of meteorites with Earth. 

Other factors that determine the catastrophic effects of an explosion are the initial density of the explosive (which is more than three orders of magnitude higher for TNT than for hydrogen-air mixture) and detonation velocity (which is three to five times higher in TNT). Therefore, the resulting pressure wave from a hydrogen explosion is considerably flatter (longer duration and lower maximum overpressure) than TNT, and destruction effects are mainly caused by impulse rather than overpressure. 

Opik, E. S., On the catastrophic effects of collisions with celestial bodies, Irish Astronomical Journal 5, No. 1, 34, 1978. 

Life evolved soon after Earth s formation, befiare any continents were present, during a time when the oceans were chemically and thermally controlled by tectonic processes. Thus, it has been proposed that the life evolved in hot anaerobic submarine environments similar to present-day hydrothermal vent systems. This hypothesis is supported by the observation of structures, thought to be the remains of protocells, in rocks formed by hydrothermal processes 3.5 to 3.8 billion years ago. Thus, the first organisms on Earth were probably anaerobic hyperthermophiles. Hydrothermal vent habitats probably offered an additional benefit by providing a stable environment relatively isolated from the catastrophic effects of bolide impacts. In other words, submarine hydrothermal vents coifld have acted as refugia enabling survival of early life forms. 

Despite the remarkable natural defence mechaifisms that have evolved, they have not always been successful and infections have, on occasions, produced catastrophic effects on the human population (Box 17.6). Two examples are the plague pandemic of the mid-1300s (Box 17.7), and the influenza pandemic of the early 1900s. This is due, in part, to the ability of the pathogen to avoid detection or killing by the immune system. 

When a gas is compressed, it heats up. When it expands, it cools. Anyone who uses a bicycle pump knows this. However, it is no longer true for electron or neutron gases at very high densities. This deviation from the ideal gas laws has a catastrophic effect on stars. Moreover, the behaviour of a photon gas with regard to volume changes differs from that of a typical gas made up of atoms,... 

Deficiency of adrenal medullary catecholamines appears to give no ill effects, and replacement therapy is therefore not used, but adrenal medullary tumours, phaeochromocytomas, secrete excess catecholamines often causing hypertension with dramatic episodes of headache, palpitations, pallor, sweating and anxiety. This condition is normally treated surgically, but preoperative preparation is mandatory to avoid catastrophic effects of surges of catecholamine release. A combination of alpha- and beta-adrenergic receptor blockade is normally used, with drugs such as phenoxybenzamine or doxazosin as alpha-blockers, and propranolol as a non-selective beta-blocker. 

The results of a recent study have called this into question. The primary walls of a double mutant of Arabidopsis thaliana in which two xyloglucan xylosyltransferase genes were not expressed were found to contain no detectable xyloglucan (Cavalier et al., 2008). Compared to the wild type, the double mutant was slightly smaller and had abnormal root hairs, yet there was no catastrophic effect on cell-wall integrity as would be predicted from current cell-wall models. A possible explanation is that the pectic polysaccharide network between the... 

The increasing use of the precautionary principle is stifling development in Europe and to a lesser, but increasing, extent in America and around the world.29 In rich countries, the precautionary principle costs money, and because of its inflexible application, it is unlikely to provide benefits. In poorer countries, it is likely to be harmful, sometimes causing catastrophic effects on human health. Concerns about chlorination and the push for a DDT ban are the most obvious examples of this phenomenon. 

HCFCs are viable substitutes for CFCs, but they can have catastrophic effects on some polymeric substrates, owing to increased polarity and solvent strength. To reduce or eliminate substrate attack, PFCs can be combined widi HCFCs. PFCs are miscible with most HCFCs, such as HCFC-141b (1,1-dichloro-l-fluoroethane) and HCFC-225 (pentafluorodichloropropane) and therefore can be mixed in any proportion to obtain the desired inerting behavior. 

As we will see later, the release of acids is characteristic of the breakdown of esters in the presence of water. This acidity, in alcoholic fragrances, can in turn result in the formation of acetals between the ethanol and any aldehydes that may be present in the perfume. Although this reaction is reversible in principle, where there is a large excess of alcohol in the product as opposed to aldehydes, as is usually the case, the aldehydes can be almost entirely lost, with a catastrophic effect on the odor. 

In view of the catastrophic effects and the increasingly severe legal and economic implications of a disastrous explosion, a large amount of effort is devoted to the safety of operations, while keeping control costs at an acceptable level. This work has been given increased impetus in the United States by the military plant modernization now underway and the development of a variety of new or improved processes for making explosives. 

A specialized case of air pollutant modeling pertains to the transport and dispersion of very dense vapors that sink to the ground surface and are driven in large part by gravity forces. Such situations are uncommon, but may have catastrophic effects when they do occur examples include release of very cold natural gas from liquified natural gas (LNG) carriers, massive venting of toxic vapors from chemical plants, or release of cold ammonia gas. 

The publicity concerning the catastrophic effects of marihuana smoking in New York City is unfounded. 

It is therefore advisable to use the doping elements in quantities compatible with complete solubility in the host oxide, and to check that they do not segregate during the catalytic reaction. Cobalt, mentioned above as a useful dopant, could exert a catastrophic effect if segregated as cobalt oxide, because of the high activity of the latter in complete oxidation. 

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