Historical inversion

Bacon used the mechanical arts (engineering) to inspire the reformulation of natural philosophy, but modem memories are short and tend to think of science as the master discipline. An analogous historical inversion has occurred in business. In business today, enterprise is mn by a professional class of trained managers, and engineers are viewed merely as one instrument of a larger capitalist enterprise. It wasn t always this way. 

Consider your own dealings with business majors in college or at work. Recall whether you have experienced the historical inversion discussed. Would you now deal with such encounters differently and how so Write a short essay discussing your recollections and reflections. 

For interstitial solid solutions, too, the criteria used historically for the degree of solid solubility relates to elastic and electronic interactions. Experimentally observed maximum interstitial solubilities of H, B, C and N in Pd are inversely proportional to the sum of the s and p electrons, and hence are controlled by the valence electron concentration. Thus the electronic interactions dominate the... 

The lateral extent of the dissolved hydrocarbon plume has continued to decrease, although no significant decrease in dissolved benzene has occurred since January 1992, nor is anticipated to occur in the future as a result of continuation of conventional pump-and-treat (Figure 13.11). Aerobic biodegradation has also been documented to exist since 1992, and is ongoing as indicated by the inverse relationship between dissolved BTEX and DO. The dissolved plume is also situated hydraulically upgra-dient from a relatively larger LNAPL pool and dissolved hydrocarbon plume separation of plumes has historically been maintained and has continued to be maintained. 

Historically, the thermal transesterification of (-)-ethyl p-toluene-sulfinate 224 with n-butanol affording (+)-n-butyl p-toluenesulfinate 225 described by Phillips in 1925 (100) is the first nucleophilic substitution reaction at chiral sulfur involving a Walden-type inversion. The evidence for inversion of configuration in this reaction was based on the assumption that both (-)-esters 224 and 225 obtained from the kinetic resolution have the same configuration. 

In the first case, the concepts of urban, city, and society have typically been contrasted with their inverse others - rural, country, and nature. Historically, these oppositional categories actually emerged in the process of urbanization itself, through literary and cultural expressions during the era of industrialization. Such oppositional thinking persists in our own lives. Trying to get far from the city and get away to nature on our vacations, we constantly remind ourselves of these binaries and distinctions. 

Once a structure determination and refinement have been carried out, several tests are available for deciding whether the chosen absolute structure or its inverse is correct. The most important tests are discussed in their historical order. 

Compounds of the I—VII group in the periodic table are known to exhibit good ionic conductivity and have attracted much attention as possible candidates for solid electrolytes. A typical family of compounds is Lil, CuCl, CuBr, and Agl. Historically, polycrystalline solid electrolytes were noticed to show significantly higher ionic conductivity than bulk crystals, since a half century ago. Furthermore, a large increase in conductivity was reported for the system of the mixture of a solid electrolyte such as CuCl (1) and Agl (2) with submicrometer particles of several sorts of insulating materials. In this case, the size of the metal halide itself was on the order of a micrometer or larger. It was also reported that the enhanced conductivity was approximately proportional to the inverse of the size of the electrolyte substances (2). Hence it is natural to make an effort to obtain fine particles of metal halides in order to get better conductivity. 

Historically, H NMR spectroscopy was vital in determining the structure of the first azepines (66T81) and has since proved to be invaluable in the conformational analysis of azepines and their benzologues, and in determining ring inversion activation energies of these conformationally mobile ring systems. 

Thus, in the early days of modem enterprise, engineers were the innovators who developed the methods—the profession—of modem business. As with the scientific inversion, here there is no historical basis for business envy or a nerd inferiority complex. The businessperson who says that engineering is mere technology applied to the needs of business could more accurately be told that modern business is merely the application of engineering method to the design of commerce. 

Equation 4.51 is an integral equation that can be used to determine D(c ) by a graphical construction or numerical solution. The derivative required in Eq. 4.51 is provided by the measured concentration profile at time t and the integration is performed on the inverse of c x) [6]. However, this historically important method is only moderately accurate, and it would be preferable to obtain diffusion profiles for various assumed diffusivities as a function of concentration by computation. D(c) could be deduced by fitting calculated results for a parametric representation of D(c) to an experimentally determined diffusion profile. 

The temperature (or salinity) at which optimal temperature (or optimal salinity), because at that temperature (or salinity) the oil—water interfacial tension is a minimum, which is optimum for oil recovery. For historical reasons, the optimal temperature is also known as the HLB (hydrophilic—lipophilic balance) temperature (42,43) or phase inversion temperature (PIT) (44). For most systems, all three tensions are very low for Tlc < T < Tuc, and the tensions of the middle-phase microemulsion with the other two phases can be in the range 10 5—10 7 N/m. These values are about three orders of magnitude smaller than the interfacial tensions produced by nonmicroemulsion surfactant solutions near the critical micelle concentration. Indeed, it is this huge reduction of interfacial tension which makes micellar-polymer EOR and its SEAR counterpart physically possible. 

In the context of dilute solutions, suspensions, or vapors, we can safely regard the historically earliest idealizations of inverse-sixth-power interactions. These are for the conditions that hold in a van der Waals gas. The medium is vacuum the a s and /i s of individual particles already introduced are now those of atoms or small molecules. The vapor is so dilute that its dielectric response is that of the vacuum plus very small contributions proportional to the number density of particles. 

A few words has to be said now on the remarkable inversion order observed in the representations, when compared with the Civ ones. This inversion is due to historical rezisons when Longuet-Higgins gave for the first time in his historic paper [5] the Gse character table for ethane. 

The relationship between dose and exposure time to produce a toxic effect for any given chemical is a function of the physical and chemical properties of the substance and the unique toxicologic and pharmacologic properties of the individual substance. Historically, the relationship according to Haber (1924), commonly called Haber s law (NRC 1993) or Haber s rule (i.e., C x t = k, where C = exposure concentration, t = exposure duration, and k = a constant) has been used to relate exposure concentration and duration to a toxic effect (Rinehart and Hatch 1964). This concept states that exposure concentration and exposure duration may be reciprocally adjusted to maintain a cumulative exposure constant (k) and that this cumulative exposure constant will always reflect a specific quantitative and qualitative response. This inverse relationship of concentration and time may be valid when the toxic response to a chemical is equally dependent upon the concentration and the exposure duration. However, an assessment by ten Berge et al. (1986) of LC50 data for certain chemicals revealed chemical-specific relationships between exposure... 

The Diels-Alder reaction may be subclassified into three types of [4 + 2] cycloaddition reactions (1) the normal Diels-Alder reaction appropriately referred to as a HOMOdiene-controlled [4 + 2] cycloaddition reaction (2) the neutral Diels-Alder reaction and (3) the inverse electron demand or LUMOdiene-controlled Diels-Alder reaction (Figure 1). Historically, it has been the normal or HOMOdiene-controlled Diels-Alder reaction comprised of the [4 + 2] cycloaddition reaction of an electron-rich diene and an electron-deficient dienophile that has serviced the preparative needs of organic chemistry and has occupied the central focus of mechanistic and theoretical studies. Pertinent to the topic of this chapter and the inherent electron-deficient nature of all fundamental heterodienes (Table 1), the LUMOdiene-controlled Diels-Alder reaction possesses a characteristic rate acceleration and high levels of predictable regio- and diastereo-control comparable with those observed in the HOMOdiene-controlled Diels-Alder reaction. 

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