Controversies

These marginal costing approaches to costing steam are unsatisfactory. Within operating companies, few subjects generate more controversy than the value placed on different steam levels. 

In the context of the structural perturbations at fluid-solid interfaces, it is interesting to investigate the viscosity of thin liquid films. Eaily work on thin-film viscosity by Deijaguin and co-workers used a blow off technique to cause a liquid film to thin. This work showed elevated viscosities for some materials [98] and thin film viscosities lower than the bulk for others [99, 100]. Some controversial issues were raised particularly regarding surface roughness and contact angles in the experiments [101-103]. Entirely different types of data on clays caused Low [104] to conclude that the viscosity of interlayer water in clays is greater than that of bulk water. 

In principle, nucleation should occur for any supersaturation given enough time. The critical supersaturation ratio is often defined in terms of the condition needed to observe nucleation on a convenient time scale. As illustrated in Table IX-1, the nucleation rate changes so rapidly with degree of supersaturation that, fortunately, even a few powers of 10 error in the preexponential term make little difference. There has been some controversy surrounding the preexponential term and some detailed analyses are available [33-35]. 

Where do you stand on the controversy between Neumann and co-workers [221-223] and those who have criticized this approach [219, 220] ... 

The mechanism of the Fischer-Tropsch reactions has been the object of much study (note Eqs. XVI11-55-XV111-57) and the subject of much controversy. Fischer and Tropsch proposed one whose essential feature was that of a metal carbide—patents have been issued on this basis. It is currently believed that a particular form of active adsorbed carbon atoms is involved, which is then methanated through a series of steps such as... 

Comparing this to the fonn chosen by Slater, we note that this fonn, known as Kolm-Sham exchange, differs by a factor of = i.e. = 2 /3- For a number of years, some controversy existed as to whether the... 

Figure B2.5.7 shows the absorption traces of the methyl radical absorption as a fiinction of tune. At the time resolution considered, the appearance of CFt is practically instantaneous. Subsequently, CFl disappears by recombination (equation B2.5.28). At temperatures below 1500 K, the equilibrium concentration of CFt is negligible compared witli (left-hand trace) the recombination is complete. At temperatures above 1500 K (right-hand trace) the equilibrium concentration of CFt is appreciable, and thus the teclmique allows the detennination of botli the equilibrium constant and the recombination rate [54, M]. This experiment resolved a famous controversy on the temperature dependence of the recombination rate of methyl radicals. Wliile standard RRKM theories [, ] predicted an increase of the high-pressure recombination rate coefficient /r (7) by a factor of 10-30 between 300 K and 1400 K, the statistical-adiabatic-chaunel model predicts a...

There is a controversy about tire bonding state of tire sulphur. Most evidence suggests tliat it is bound in tire fonn of a tliiolate [122], while x-ray diffraction suggests tliat tire sulphur atoms may dimerize [147]. Flowever, not all of tire observed overstmctures can be explained witli tliis latter assumption. 

All of the contributions to the energy function presented above assume that pairwise interactions are sufficient to describe the situation within a molecule or molecular system. Whether or not multi-centered interactions are negligible is controversial. On the other hand, failure or success of a force field with its functional form and corresponding parameter set is not a matter of mathematics... 

This point was taken up by Reynolds in a letter addressed to G. G. Stokes, in the latter s capacity as Secretary of the Royal Society [83]. Reynolds pointed out that Maxwell s theory evaluated the effects of thermal transpiration only in circumstances where they were too small to be measured, and complained that Maxwell had misrepresented his own theoretical treat ment of the phenomenon. However, this incipient controversy never developed... 

In discussing science we also need to define its scope, as well as the methods and views (concepts) involved in its pursuit. It is also useful to think about what science is not, although this can sometimes become controversial. Significant and important studies such as those concerned with the fields of sociology, politics, or economics increasingly use methods that previously were associated only with the physical and biological sciences or mathematics. However, I believe these... 

One of the major contemporary chemical controversies in which I was inadvertently involved developed in the 1950s, surprisingly over the structnre of a deceptively simple seven carbon-containing bicyclic carbocation, the 2-norbornyl (bicyclo[2.2.1]heptyl) cation. The in-... 

The Brown-Winstein nonclassical ion controversy can be summed up as differing explanations of the same experimental facts (which were obtained repeatedly and have not been questioned) of the observed significantly higher rate of the hydrolysis of the 1-exo over the 2-endo-norbornyl esters. As suggested by Winstein, the reason for this is participation of the Ci-Q single bond leading to delocalization in the bridged nonclassical ion. In contrast. Brown maintained that the... 

As the norbornyl ion controversy evolved, it became a highly public and frequently very personal and bitter pnblic debate. Saul Winstein suddenly died in the fall of 1969, shortly after the Salt Lake City sym-posinm. To my regret, I seemed to have inherited his role in repre-... 

Before our controversy in 1965 with Herbert Brown and Heinz Staab in Heidelberg... 

Intensive, critical studies of a controversial topic also help to eliminate the possibility of errors. One of my favorite quotations is by George von Bekesy, a fellow Hungarian-born physicist who studied fundamental questions of the inner ear and hearing (Nobel Prize in medicine, 1961) ... 

Clearly there was no lack of devoted adversaries (perhaps a more proper term than enemies) on both sides of the norbornyl ion controversy. It is to their credit that we today probably know more about the structure of carbocations, such as the norbornyl cation, than about most other chemical species. Their efforts also resulted not only in rigorous studies but also in the development or improvement of many techniques. Although many believe that too much effort was expended... 

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