Technical complexity

After sulfuric acid work-up (accompanied by the formation of sodium sulfate), the resorcinol is extracted and isolated in a 94% yield based on y -benzenedisulfonic acid [98-48-6]. In addition to the technical complexity that goes along with the manipulation of soHds at high temperature, this process produces large amounts of salts (sulfite and sulfate salts) which economically as well as environmentally are not always desired. 

Many filtration requirements are fiilfilled by spunbonded stmctures and a growing but technically complex market has developed since the 1970s... 

Protection of the environment from pollution caused by wastes is a matter of increasing concern. It can be a technically-complex exercise because the variety of waste is extremely wide, the volumes may be large, and the levels permissible for release may be very low. 

Overall, the technical complexity of the Deans switch system is considerably greater than that of a mechanical switching valve and it is accepted that reliability and ease of use is reduced as the system complexity increases. For many compound types, however, the completely non-intrusive nature of the Deans method offers sufficient advantages to justify its application. However, the use of modern electronic pressure and flow controls integrated into the overall computer control of the chromatographic system does now make the operation of Deans switches significantly easier or more reliable than has been reported in its earlier applications. 

Mammalian cell culture is more technically complex and more expensive than microbial cell fermentation. Therefore, it is usually only used in the manufacture of therapeutic proteins that show extensive and essential post-translational modifications. In practice, this usually refers to glycosylation, and the use of animal cell culture would be appropriate where the carbohydrate content and pattern are essential to the protein s biological activity, its stability or serum half-life. Therapeutic proteins falling into this category include EPO (Chapter 10), the gonadotrophins (Chapter 11), some cytokines (Chapters 8-10) and intact monoclonal antibodies (Chapter 13). 

This practice supports the CSB observation that effective process hazard analysis for a reactive system is essentially more data driven than conventional process hazard analysis given the technical complexity of the reactive hazard. Three of the five visited companies use reactivity test data when conducting process hazard analysis two use qualitative hazard evaluation methods only. 

Traditionally protein-protein interactions studies have been performed in vitro after isolation and purification of individual proteins. While some in vivo or in situ protein-protein interaction studies can be performed by traditional methods using microinjection of purified proteins into oocytes, technical complexities limit the number of proteins that can be studied. Furthermore, many putative proteins of interest, predicted by genomic analysis, are not characterized and cannot be used in such studies. Some of the limitations posed by traditional methods have been overcome by use of yeast two-hybrid systems. These systems allow studies of many recombinant test proteins... 

The Technology Clearinghouse Unit is currently in the process of developing a series of industry-specific waste reduction guidance documents and fact sheets. These fact sheets are aimed at informing industry of the waste reduction options available, and encouraging industry to request and implement the more technically complex industry-specific waste reduction audit reports chat have been developed and published by the Alternative Technology Section over the last two years. 

Overall, therefore, too much theoretical and computational effort, often used with insufficient data, was producing increasing technical complexity and minimal chemical insight. It is this conclusion that prompted Nyholm s criti-cizms and, for that matter, the opening sentence of this chapter. Over the past few years, however, the situation has been enormously improved in each respect as I now try to demonstrate. 

Inhalation. The respiratory system is an important portal of entry, and for evaluation purposes animals must be exposed to atmospheres containing potential toxicants. The generation and control of the physical characteristics of such contaminated atmospheres is technically complex and expensive in practice. The alternative—direct instillation into the lung through the trachea—presents problems of reproducibility as well as stress and for these reasons is generally unsatisfactory. 

Below, different reactor designs are discussed in order of increasing technical complexity, and thus, increasing cost. Char quality also improves through the list, but none produce a quality char comparable to carbon black in most applications, even after upgrade. 

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