Irradiation future research

Many interesting questions remain for future research. Cosmic rays have irradiated, albeit weakly at times, the stuff of meteorites ever since parent bodies formed 4.5 Gyr ago. In our view, the ultimate goal of CRE studies is to document the exposure histories of meteorites and their components over that entire period. We have tools for examining the earliest irradiations and the most recent. The period in between presents a major challenge. We conclude with a few questions addressable in the nearer term. 

There are, unfortunately, no studies to date of the dissolved protein content of microlayer samples. With the recent development of many sensitive techniques for the analysis of amino-acid mixtures in seawater using liquid chromatography and fluorescence detectors (e.g., Dawson and Pritchard, 1978), it should be relatively simple to analyse for combined amino acids after hydrolysis of the microlayer samples. Analyses of free amino acids in the microlayer seem not to have been performed to date either, but since considerable degradation of surface-adsorbed proteins may take place as a result of UV irradiation, this may be a fruitful area for future research. 

Future research aimed at refining SERS or SERRS spectrophotometry should be oriented towards procedures allowing surfaces to be prepared and characterized in a reproducible manner, where as many as possible of the experimental variables (especially surface charge density) can also be controlled. Furthermore, attention needs to be paid to the structural perturbations of molecules in the adsorbed state. These perturbations could occur not only as a consequence of the adsorption process, but also through photodegradation reactions occurring during laser irradiation. 

Expression (13AS), which must of course be evaluated numerically, is capable of accommodating any objective of the irradiation process. Suppose, for example, we want to be 1 % certain that all the cancerous cells have been killed. This implies that the left-hand side of (7.3.48) is 0.01. If the irradiation intensity / is known, then (7.3.48) can be used to calculate the irradiation time tjr- Another alternative is to calculate the irradiation intensity for a fixed time of irradiation. A third even more interesting alternative is the manipulation of the initial distribution which will imply some form of pretreatment of the tumor, so that one can maximize the probability of extinction at the end of irradiation. Clearly, this is an open problem that has several possibilities for future research. 

The large size of CPOs allows their direct observation. For this purpose, scanning tunneling microscopy (STM) is the best method [32,34]. Electron microscopic analysis is used for phthalocyanine 3 and its derivatives however, most of the porphyrin derivatives are decomposed by electron beam irradiation. Presently, although only a limited number of researchers are able to perform atomic-scale resolution measurement, this powerful analytical method is expected to be used widely in the future. The author reported a summary of STM studies on porphyrins elsewhere [34]. 

These examples of the use of microwave irradiation in the synthesis of heterocyclic compounds show the great versatility of this technique, which can be used under a variety of experimental conditions. Even when there is no improvement of yields, or rates, or specificity, the technique is worthwhile owing to its simplicity. It can be foreseen that microwave ovens are going to be among the basic equipment of research laboratories in the near future. Combinatorial and parallel synthesis under the action of microwave irradiation is becoming a powerful tool for discovery of new molecules and should develop very rapidly. 

Scientific research has led to significant success in the practical applications of organic ion radicals. Such applications should widen in the future. It is very important to concentrate effort on the elaboration of preparative methods of ion radical organic chemistry, including stereospecific methods. The correct choice of new developmental procedures opens up a wealth of new directions. It is hoped that interest in this area will continue to ensure the flow of new ideas and reactions, particularly in the area of organic synthesis in liquid phase and without light irradiation. 

The work performed on DNB and NB illustrates two main problems with the use of ultrasound for contaminant degradation. First, under the given experimental conditions, the process is slow. Therefore, the fate of future applied research may rest in the ability to show favorable comparisons to other treatment processes in terms of both cost and efficiency. Second, as mentioned above, the agitation produced by ultrasonic irradiation initiates more volatilization than degradation. 

---