Profitability study

The molecules most profitably studied in connection with purely steric isotope effects have been isotopically substituted biphenyl derivatives. Mislow et al. (1964) reported the first more or less clearcut example of this kind in the isotope effect in the configurational inversion of optically active 9,10-dihydro-4,5-dimethylphenanthrene (7), for which an isotopic rate ratio ( d/ h) of 1-17 at 295-2°K in benzene solution was determined. The detailed conformation of the transition state is not certain in this case, as it involves the mutual passage of two methyl groups, and thus it is difficult to compare the experimental results with... 

Reganold, J.P. 1995. Soil quality and farm profitability studies of biodynamic and conventional farming. In Cook, H.F. and Lee, H.C. (eds) Soil Management in Sustainable Agriculture. Wye College Press, Wye. pp. 1-11. 

Aside from the possession of a permanent dipole moment and sufficient volatility, a molecule must be reasonably small for its microwave spectrum to be profitably studied. Large molecules have many low-frequency vibrational modes these modes will be appreciably populated at room temperature, giving many strong pure-rotation transitions between levels with nonzero vibrational quantum numbers. The microwave spectrum of a large molecule will thus have so many lines that assignment of the lines will be virtually impossible. 

Sulphuric acid has not, until recently, been industrially prepared in this way. Its preparation is not well adapted to the laboratory, but its properties may be profitably studied. 

Decomposition of acidified solutions of thiosulphate forms sulphur dioxide, colloidal sulphur (S8,Ss), polythionic acids and hydrogen sulphide. The reaction kinetics have been examined several times ° and profitable studies of the conditions under which colloidal sulphur is formed were made 3,714, 716-718. acceptable interpretation was first given by Davis , in terms of the steps (7)-(15). These involve successive steps of nucleophilic displacement by thiosulphate, viz. 

The contractor s comparative profit study is silent on the question of whether a 2 to 3 percentage point difference in rates of return is due to differences in the cost of capital between... 

Baber and Kang submitted a second draft of their contract report to OTA in January 1991, based on the criticisms raised at the workshop. OTA contracted with two of the country s foremost experts on profit measurement, Franklin Fisher (Massachusetts Institute of Technology) and Gerald Salamon (Indiana University), as well as the panel chairman, to provide a thorough review and critique of the second draft. These two reviews formed the basis for a third revised draft of the profit study in March 1991, which was then submitted for further review not only to the Advisory Panel but also to Professors Fisher and Salamon and a... 

One outside economist who specializes in the pharmaceutical industry submitted a detailed critique of the third draft of the profit study in July 1991. OTA asked Baber and Kang to reply to the critique. The entire file of comments and replies was then sent back to the two contract reviewers and the panel chair for a final review. These reviews convinced OTA that the methods employed by Baber and Kang to measure profitability in the industry are sound and represent an important advance over previous methods. OTA compiled the entire history of review for the profit study into a single document that is available upon request to interested parties. 

In their comparative profitability study, Baber and Kang did not address the question of whether a 2 to 3 percentage point difference in IRRs can be explained by a difference in risk (and, therefore, in costs of capital) between the pharmaceutical industry and other companies. To investigate this issue, OTA estimated the relative riskiness and differences in the cost of capital between the pharmaceutical firms and the nonpharmaceutical firms studied by Baber and Kang. 

Preoccupation with the occurrence and behavior of minute amounts of nitrosamines in the human environment will probably divert skills from more profitable studies of the behavior of nitrosamines in experimental systems... If [this essay] leaves the reader with the impression that nitrosamines have a much greater potential as research tools than they have as health hazards, it will have served its purpose. 

The reaction chemistry observed to date amply confirms this expectation. Because of the rich chemistry that can stem from ipso ions, it seemed important to us to select a tractable system and proceed to build a data base by examination of that system. With reference points established one can more profitably study structural variations and changes in reaction chemistry that attend such variation. The acetyl nitrate adducts derived from hemimellitene (1,2,3-trimethylbenzene) are particularly useful for this purpose. Both the cis and trans isomers may be rather easily isolated from nitration mixtures by low temperature crystallization procedures. The crystalline dienes thus obtained axe stable in the cold and may be stored for long periods. The intent of the discussion that follows is to exenplify some of the chemistry of ipso ions by reference to some of our studies of the adducts of hemimellitene. 

To visualize some of the effects described in the previous section, Poincare showed that the behavior of two degree-of-freedom nonlinear systems can be profitably studied by mapping the dynamics onto a well-chosen plane. This is because the conservation of energy requires all trajectories to wander on a three-dimensional hypersurface. In his honor, these maps are often referred to as Poincare maps. The plane chosen to map the dynamics onto is referred to as a surface of section. 

The emission spectra of substances added to flames, e.g. sodium atoms added in the form of a spray of sodium chloride solution, was a much more profitable study. In the first place, the amount of additive could readily be varied by altering the concentration of the solution sprayed, and in the second place, it was possible, by comparing the intensity of first and second resonance lines, to demonstrate that the... 

The errors encountered with a given level of theory in calculation of vibrational intensities are considerably more profound than those in the frequencies. Meaningless results are common unless the basis set is of double-C quality and contains polarization functions. The double-harmonic approximation is another source of error. Nonetheless, the effects of H-bonding upon the intensity of each mode can be profitably studied within this framework. Analysis of these intensities sheds light upon the electronic density perturbations caused by formation of the bond. 

Details are provided on the RingExtruder, which is equipped with 12 intermeshing co-rotating screws arranged in a stationary circular configuration, for the continuous mixing of mbber. The advantages of this continuous mixer over twin-screw extmders are demonstrated and the results of extmsion trials on various robbers and a profitability study are presented and discussed. 7 refs. 

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