B Solved Problems

If a molecule contains several asymmetric C atoms, then the diastereomers show diastereotopic shifts. Clionasterol (28a) and sitosterol (28b) for example, are two steroids that differ only in the absolute configuration at one carbon atom, C-24 Differing shifts of C nuclei close to this asymmetric C atom in 28a and b identify the two diastereomers including the absolute configuration of C-24 in both. The absolute configurations of carboxylic acids in pyrrolizidine ester alkaloids are also reflected in diastereotopic H and C shifts which is used in solving problem 54. 

The E-Z Solve software may also be used to solve Example 12-7 (see file exl2-7.msp). In this case, user-defined functions account for the addition of fiesh glucose, so that a single differential equation may be solved to desenbe the concentration-time profiles over the entire 30-dry period. This example file, with die user-defined functions, may be used as the basis for solution of a problem involving the nonlinear kinetics in equation (A), in place of the linear kinetics in (B) (see problem 12-17). 

Figure 4.26 (a) DNA replication at low resolution (for example as seen by electron microscopy). Only one replication fork is visible and it appears that both strands of the parental DNA replicate continuously in the same direction, which cannot be the case, since the two strands of parental DNA are anti-parallel, (b) The problem is solved by the priming of DNA synthesis with short RNA primers, whose 3 -hydroxyl can be used by DNA polymerase, producing Okazaki fragments, while on the other strand, DNA synthesis is continuous. (From Voet and Voet, 2004. Reproduced with permission from John Wiley Sons., Inc.)... 

Key factors in solving problems associated with crystalline materials not meeting purity requirements are (a) the location of the impurities— i.e., on the surface or incorporated in the crystal—and (b) the nature of the impurity. Impurities are on the surfaces or, more generally, the exterior of host crystals due to adsorption, wetting by a solvent that contains the impurities, or through entrapment of impure solvent in cracks, crevices, agglomerates and aggregates. Incorporation... 

B) This problem can be easily solved using the factor-label method ... 

Described below is a technique taken from the book written by Charles H. Kepner and Benjamin B. Tregoe entitled The New Rational Manager, Princeton Research Press, 1981. This straightforward process of problem analysis is excellent in providing steps to help identify and focus on the vital information needed to identify and solve problems. 

However, a method using ion-exchange has been developed and considered to solve a B-pollution problem at Kizildere in Turkey (Badruk Kabay 2003). 

In the earlier studies of problem solving in the physical sciences, attention was centered on the differences in the methods and procedures used by students and by experts when solving problems (111-113). The basic differences were (a) the comprehensive and complete scheme of the experts in contrast to the sketchy one of the novices and (b) the extra step of the qualitative analysis taken by the experts, before they move into detailed and quantitative means of solution. 

The restricted space of this introductory article does not allow us to give further attention to Ya.B. s papers on the physical chemistry of combustion and detonation.4 In Ya.B. s own words, the science of combustion and detonation is dear to him because it provided him, at the beginning of his life and career, with a wide-open field of activity both as a theorist and as a bold experimenter. Important problems of a fundamental nature were being solved, problems which were related to important technological applications. The tremendous contribution which Ya.B. made to this science is the pride and showpiece of the Soviet school of combustion. Ya.B. s work on the theory of detonation and combustion was recognized by awarding him the State Prize of the USSR in 1943. 

In contrast to the technology described in item 2.2 the present one has yet no experience of commercial usage, but only prototype tests at realistic flow rates ( 500 MMscm/y) for solving problems A), B) from the list above. 

Farrell, R. L., Hata, K., Wall, M. B. Solving Pitch Problems in Pulp and Paper Processes. Vol. 57, p. 197... 

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