Process without after-effect

A Markovian description can be naturally introduced by generalising deterministic systems modelled by ordinary differential equations. In other words, the stochastic version of a deterministic process without after-effect is a Markov process. 

A stochastic process is a collection of random variables teJ, Two important cases are the discrete parameter process, when J cz = 0, 1, 2,. .. and the continuous parameter process, when T ci IR We shall mostly consider the second case, and, in addition, restrict ourselves to Markov processes (processes without after-effect). 

Fig. 26. SEM micrographs illustratiag the effects of airborne basic chemical contamination, (a) This image was formed when a positive-tone CA resist was processed without any delay after coating, (b) This image was formed when an identical film was stored after coating for 15 minutes in an atmosphere containing 10 parts per billion on A/-methylpyrrohdone, and then processed identically to the first film.

The supercritical fluid carbon dioxide, C02, is of particular interest This compound has a mild (31°C) critical temperature (Table 1) it is nonflammable, nontoxic, and, especially when used to replace freons and certain organic solvents, environmentally friendly. Moreover, it can be obtained from existing industrial processes without further contribution to the greenhouse effect (see Air pollution). Carbon dioxide is fairly miscible with a variety of organic solvents, and is readily recovered after processing owing to its high volatility. It is a small linear molecule and thus diffuses more quickly than... 

Effect of de-sintering observed during two-step sintering process (without and with pressure applied) on reference sample, two samples with 0.1 wt% carbon content after oxidation at 800°C from batch with carbon black, and one sample from batch with graphite and with no graphite content after oxidation at 800°C. 

It transpired that the toxic oil was rapeseed oil that had been adulterated by the addition of 2 per cent of a chemical called aniline, as required by law in Spain for imported rapeseed oil so that it cannot be used for cooking. This oil had been refined and was sold for human consumption, as had been done before without adverse effects. It would appear that a batch of oil may have been refined differently or somehow became contaminated. The toxic oil was found to come from only one source within a particular refinery. The Spanish government agreed to replace the suspect oil with pure olive oil, after which the number of new cases subsided. Collection of contaminated oils known to be associated with the syndrome for analysis was a difficult task due to the government exchange programme. The results showed that the oil associated with the syndrome had a similar composition to rapeseed oil and contained contaminants as a result of the added aniline and the subsequent refining process. 

The concoction took some 40 days to prepare, after which the process of maturation began. Twelve years was considered by Galen the proper period to keep it before use. Galen records that Marcus Aurelius consumed the preparation within two months of its being compounded without ill effect. 

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