If Modifications and Practical Problem Solving

Jeff L. Joseck, Trevor A. Kletz, and an unknown author on the Internet each communicate a different clever story within the first part of this chapter. 

Jeff is a talented staff engineer employed by a major chemical plant in West Virginia he has a solid background in Loss Prevention. Jeff Joseck s article was written to spark interest and discussion of process safety in safety meetings. It is also very skillfully worded to spark readers into thinking about acceptable risks and minimal risks. 

Trevor Kletz is the most published Loss Prevention Engineer of all time with nine process safety books and over 100 technical articles. Professor Kletz s topics in this chapter assume that. some of the modem synthetic materials we u.se daily have been available since the dawn of time and that some ordinary materials are being examined in a sort of hazards review session. These are Kletz s most classic, clever illustrations of how we can sometimes be overzealous and too narrow in our focus on a problem. 

All three of these short articles show that it is easy to overexaggerate the dangers of unfamiliar conditions and it is also ea.sy for us to forget that humans have learned to live comfortably with many of the hazards that surround us. The author thanks both of these writers for their permission to freely copy their work. 

This first article was originally published in 1976 in the Imperial Chemical Industries Limited (ICI) Safety Newsletter. It later appeared in Critical Aspects of Safety ami Imss Prevention (11 in 1990. It assumes that water, in the pure fonn, has been unknown — there are no seas, no rivers, no lakes—and it has just been discovered. 

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Applications Research. Specialty chemical producers devote a larger share of their time and costs to appHcations research than do producers of most commodity chemicals. As noted earHer, the most successful specialty chemical producers have been those companies that ate able to respond quickly to customer needs and problems under the conditions found in the customer s plant. This entails having, at the specialty chemical plant, equipment and procedural knowledge which closely approximate those found among customers. Tests can then be mn and a solution to the problem or need may result. If successful, even in part, it can be brought to the customers and tried there. In practice, of course, each customer s plant has some variables which make a single answer or product quite unlikely. Fortunately, slight modifications by the suppHer will often solve the next customer s problem. 

The third advantage, the chemical stability of DNA aptamers, can solve the main problem of protein-based biosensors. The chemical and physical instability of protein-based biosensors is always claimed in practical use, and this limits the range of biosensor application. However, DNA is chemically stable. It is stable within the pH range 2 to 12 and is thermally renaturable Even if it is denatured at 100°C, it is refolded at room temperature. Even RNA aptamers can gain stability upon 1 modification therefore, aptamers have the potential to enhance the applicability of biosensors in practical contexts. Additionally, aptamers can be immobilized onto substrates using DNA microarray fabrication technology, and aptamer microarrays can be created. 

Deposition has serious effects in practical applications. To solve this problem, at this point, we can only suggest to choose proper channel wall material for the reaction system. The material can be chosen based on affinity balance between particle-particle, particle-solvent, and solvent-wall. Besides the physical or physicochemical affinities, chentical affinities such as solidification by surface reaction between adsorbed ions and dissolved ions can also induce deposition. If the affinity between particle and wall is smaller than that between solvent and wall, particles are expected not to be deposited on the wall. Therefore, the proper choice of reactor wall or surface modification can be good optifMis (Fig. 9) [9]. Also, the proper choice of surfactants is also helpful. However, as far as our knowledge is concerned, it is very difficult to obtain general solutions to the deposition problem, and a good combinatimi of reactor material, reaction system, and operation conditions is required. 

The nature of problems to be solved by an analyst is often such that the basic ideas mentioned are sometimes superposed or appear in various modifications. What is required from organic analysis may vary widely, and if we take into account the enormous variety of organic compounds in general, it will become evident that a true picture of the whole range of problems can only be gained through actual practice. 

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