Tool analogy

For thousands of years, all manufacturing was limited by the power that was available to perform the task, and metal spinning was no different. Initially, power was supplied by a foot pedal that rotated the tool—analogous to the potter s wheel. Forming power for making the metal take shape was supplied by the hands and arms of the worker as he held the blunt-end tool or, in later years, the roller, against the metal. 

There are several performance characteristics of microcomputer-based laboratory instruments that make them useful tools analogous to the Crescent wrench ... 

The Diels-Alder reaction provides us with a tool to probe its local reaction environment in the form of its endo-exo product ratio. Actually, even a solvent polarity parameter has been based on endo-exo ratios of Diels-Alder reactions of methyl acrylate with cyclopentadiene (see also section 1.2.3). Analogously we have determined the endo-exo ratio of the reaction between 5.1c and 5.2 in surfactant solution and in a mimber of different organic and acpieous media. These ratios are obtained from the H-NMR of the product mixtures, as has been described in Chapter 2. The results are summarised in Table 5.3, and clearly point towards a water-like environment for the Diels-Alder reaction in the presence of micelles, which is in line with literature observations. 

Quality Control. Reproducible production of perfumes requires careful quality control of all materials used as well as the compounding process itself. The use of analytical tools has iacreased over the years with their availability, but there can be no substitute for organoleptic evaluation. The human nose is far more sensitive than any analytical instmment for certain materials, yet it is also quite limited as a quantitative tool and is subject to fatigue. There are also weU-documented examples of specific anosmias ia iadividuals, ie, iaability to smell certain odor types, which is somewhat analogous to color-blindness. 

Bioprocess Control An industrial fermenter is a fairly sophisticated device with control of temperature, aeration rate, and perhaps pH, concentration of dissolved oxygen, or some nutrient concentration. There has been a strong trend to automated data collection and analysis. Analog control is stiU very common, but when a computer is available for on-line data collec tion, it makes sense to use it for control as well. More elaborate measurements are performed with research bioreactors, but each new electrode or assay adds more work, additional costs, and potential headaches. Most of the functional relationships in biotechnology are nonlinear, but this may not hinder control when bioprocess operate over a narrow range of conditions. Furthermore, process control is far advanced beyond the days when the main tools for designing control systems were intended for linear systems. 

The z-transform is the prineipal analytieal tool for single-input-single-output dis-erete-time systems, and is analogous to the Laplaee transform for eontinuous systems. 

Despite these problems, the potential of research with conformationally restricted substrate analogs appears to be great. As yet, the use of these analogs with tools other than steady-state kinetics has been little explored. 

The conversion of diarylthallium trifluoroacetates to aromatic iodides by treatment with molecular iodine is thus analogous to the well-known conversion of diarylmercury derivatives with iodine to a mixture of an aromatic iodide and an arylmercury iodide (134), but it is much more effective as a synthetic tool because of the spontaneous disproportionation to product of the intermediate arylthallium trifluoroacetate iodide. The present procedure thus provides a practical synthetic method for the ultimate conversion of aryl Grignard reagents to aromatic iodides. 

Nonhydrolyzable Nucleoside Triphosphate Analogs Serve as Research Tools... 

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