Space effect

There is no reason why interaction should not more than offset the spacing effect and this is consistent with descriptions of antiplasticisation which have recently found their way into a number of research publications. 

In the rubber industry hydrocarbon oils are often used to reduce the softness and facilitate the processing of hydrocarbon rubbers. These appear to have a small interaction with the polymer but spacing effects predominate. Such materials are generally referred to as softeners. The rubber industry, like the plastics industry, commonly uses the term plasticisers to describe the phthalates, phosphates and sebacates which are more commonly used with the more polar rubbers. 

In the above example, 1 lb of initial steam should evaporate approximately 1 lb of water in each of the effects A, B and C. In practice however, the evaporation per pound of initial steam, even for a fixed number of effects operated in series, varies widely with conditions, and is best predicted by means of a heat balance.This brings us to the term heat economy. The heat economy of such a system must not be confused with the evaporative capacity of one of the effects. If operated with steam at 220 "F in the heating space and 26 in. vacuum in its vapor space, effect A will evaporate as much water (nearly) as all three effects costing nearly three times its much but it will require approximately three times as much steam and cooling water. The capacity of one or more effects in series is directly proportional to the difference between the condensing temperature of the steam supplied, and the temperature of the boiling solution in the last effect, but also to the overall coefficient of heat transfer from steam to solution. If these factors remain constant, the capacity of one effect is the same as a combination of three effects. 

This sharp decrease is attrihutahle to the fiee space effect, which is described in Section ni.5(//). When such a decrease does not occur, the system is classified as type Ib. 

It is sometimes difficult to distinguish between the free space effect and the tranquilization effect the former is usually more pronounced at lower temperatures. However, if the two effects are superimposed, for example, possibly for at very low concentration in (Li, K)(CO,)(i/2), it is nearly impossible to deconvolute them. 

Despite having been the earliest attempted prediction, proton prediction remains relatively poor. The reasons for this have been alluded to earlier but to summarise the proton chemical shift is often highly dependant on through-space effects (anisotropy) and has a very small distribution. There are four main commercial approaches to proton prediction currently Incremental parameters, HOSE code databases, semi-empirical and cib initio methods. 

The aziridine-coupling reaction had the ability to introduce bridge-substituents X or Y on either side of the iV-bridge in fused 7-azanorbomanes 87 and allowed a rare opportunity to study through-space effects on A-bridge hybridisation and JV-alkyl invertomerisation in fused 7-aza norbomanes. 

Anisotropic effect (Also called space effect). The 8 value (chemical shift) in each case can be justified by explaining the manner in which n electrons circulate under the influence of the applied. 

Keren, R., Meiri, A., Kalo, Y. Plant spacing effect on yield of cotton irrigated with saline waters. Plant and Soil 74(3), 461 65 (1983)... 

Table 4. Nearest interatomic U-U spacings, effective paramagnetic moments, and estimated 7 eV XPS satellite intensities for various binary uranium compounds (from Ref. 122). The references for the intensities and distances are given in ...

In aliphatic compounds, 3JCC is related to the dihedral angle according to a Karplus cosine function as portrayed in Fig. 3.18. Similar to 3JHH, the maximum at = 180° is larger than that at 4> — 0° for carboxylic acids. A reversed pattern is found for aldehydes and alcohols, due to heteroatom through-space effects [129]. 

Our result thus demonstrates that C3 has a cyclic structure. The estimated cyclic/linear separation is larger than the QCISD(T) results, mainly as a result of N-particle space effects. It is somewhat smaller than the best CCSD(T) results of Scuseria [91], although our uncertainty range includes his values. While these observations seem to suggest a much larger difference between QCISD(T) and CCSD(T) than might have been expected, it should be kept in mind that the QCI calculations are based on a UHF reference, while the CC calculations are based on RHF. Examination of CISD results suggests that half the difference can be attributed directly to reference treatments. 

Enolization of cationic ketones is accelerated by electrostatic stabilization of the enolate anion. Rate constants for water-, acetate-, and hydroxide ion-catalysed enolization of 2-acetyl- 1-methylpyridinium ion (94) have been measured13811 and compared with a 2-acetylthiazolium ion (95), a simple analogue of 2-acetylthiamine pyrophosphate.13811 For (94), qh = 1.9 x 102 M-1 s 1, about 1.1 x 106 times that for a typical methyl ketone such as acetone. Thermodynamically, it is >108 times more acidic (pAa values of 11.1 vs 19.3). These increases in kinetic and thermodynamic acidity are derived from through-bond and through-space effects, and the implications for enzymatic catalytic sites with proximal, protonatable nitrogen are discussed. The results for (94) suggest a pAa value of 8.8 for (95), a value that cannot be measured directly due to competing hydrolysis. 

In contrast to the results (entries 25-29 and 31), saturated n-pentanoic acid is preferentially incorporated in CA cavities as compared with 2-pentenoic acid. This implies that the separation depends not only on the space effect of the cavities but also on host-guest hydrogen-bond interaction, which is observed in the inclusion crystals of CA with acetic acid [26a], This indicates that the separation mechanism of protic compounds cannot be understood only in the terms of the fit between the host cavity and guest molecule. 

The hyperfine paramagnetic contribution (LIS, Spara) corresponding to the sum of contact (through-bond) and pseudo-contact (through-space) effects is easily obtained from the experimental NMR data ... 

The adsorption of CO on a site is also accompanied by backrelaxation of the surrounding ions. This is a through-solid effect, which must be added to the through-space effects (static dipole-dipole interactions, etc.) to explain the larger Avstat shift (53, 499, 500). 

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