Saturation rule

The ferritin vaiue corresponds well to the total value of body iron, whereby 1 qg/l ferritin is equivalent to about 7.5 mg body iron. The sensitivity of the ferritin value in HC is 85% and the specificity is 95%. A value of >700 ig/l points both to the presence of HC and to the development of liver fibrosis or cirrhosis. In contrast, a normal ferritin value and normal transferrin saturation rule out HC in about 95% of cases, (s. tab. 31.18)... 

It is felt that the analytical method presented here is distinctly superior to any of the empirical methods for estimating gas consumption, such as the so-called "saturation rule." Application of the analytical method, however, is somewhat more difficult. The method should be suitable for all tank systems that use cryogens (such as hydrogen, oxygen, nitrogen, fluorine, carbon monoxide and neon) and that are equipped with a gas diffuser to prevent direct jetting of the gas into the liquid. In addition, the method is set up so that large variations in system operation may be incorporated by a person reasonably well versed in the principles of thermodynamics and heat transfer. 

By the saturation rule of thumb the gas consumption AM, in any transfer run can be estimated by the following equation ... 

Estimation of gas requirements to pressurize and transfer cryogenic fluids is best made with the saturation rule. This rule is on the average 10 to 15 per cent conservative if only pressurization and transfer are considered. It will still predict gas consumption quite well if a hold period up to 1 hour after transfer is included. 

The so-called saturation rule [1], derived from experiments with liquid oxygen and nitrogen, permits the prediction of the pressurized rapid transfer gas requirements for those liquids. However, this rule has limitations that are demonstrated clearly by a comparison of the results obtained with its use with those obtained from the "worst case" analysis. The rule can be stated approximately as follows for pressurization and transfer process ... 

For the case of negligible initial ullage, with all liquid displaced from a tank, the saturation rule gives... 

Table V with those obtained from the saturation rule, for pressurized transfer at 100 psia.

The pressurizing-gas mass requirements for the transfer of liquid oxygen and nitrogen can be estimated quickly by utilizing the saturation rule... 

Solution. Since the fluid transferred is liquid nitrogen, the saturation rule can be applied to determine the mass of gas required for the transfer. The original volume of the vapor is the ullage volume, given as 10% of the vessel volume. Thus... 

Using the saturation rule, determine the pressurization mass requirement for a nominal 117.77 m liquid oxygen storage vessel with a 10% ullage volume. The pressurization is to be maintained at 405 kPa for a 30-min transfer period at a rate of 0.025 m s. Assume that the vessel initially contains 106 m of liquid oxygen at a pressure of 101.3 kPa before it is suddenly pressurized to initiate the cryogen transfer. 

The hydrogenolyaia of cyclopropane rings (C—C bond cleavage) has been described on p, 105. In syntheses of complex molecules reductive cleavage of alcohols, epoxides, and enol ethers of 5-keto esters are the most important examples, and some selectivity rules will be given. Primary alcohols are converted into tosylates much faster than secondary alcohols. The tosylate group is substituted by hydrogen upon treatment with LiAlH (W. Zorbach, 1961). Epoxides are also easily opened by LiAlH. The hydride ion attacks the less hindered carbon atom of the epoxide (H.B. Henhest, 1956). The reduction of sterically hindered enol ethers of 9-keto esters with lithium in ammonia leads to the a,/S-unsaturated ester and subsequently to the saturated ester in reasonable yields (R.M. Coates, 1970). Tributyltin hydride reduces halides to hydrocarbons stereoselectively in a free-radical chain reaction (L.W. Menapace, 1964) and reacts only slowly with C 0 and C—C double bonds (W.T. Brady, 1970 H.G. Kuivila, 1968). 

The subsequent literature shows the rule to be generally valid, within a few pet cent, amongst systems which give Typje IV isotherms in the typical example of Table 3.1, the data refer to adsorptives differing widely in their physical and chemical properties, yet the deviation of the saturation volume y, from the mean is within 6 per cent. 

Evidence of a different kind is furnished by the fact that the Gurvitsch rule (p. 113) is often obeyed by systems showing Type I isotherms " the amounts of different adsorptives taken up by a given adsorbent, when expressed as a volume of liquid, agree within a few per cent. The order of agreement is illustrated by the typical examples in Table 4.1 for the adsorption of n-alkanes on ammonium phosphomolybdate, and in Table 4.2 which refers to a variety of adsorptives on a silica gel. It must be admitted, however, that there are cases where considerable deviations from the Gurvitsch mle are found, even though the isotherms are of Type 1. Thus, in Table 4.3 the variation in values of the saturation uptake is far outside... 

A puzzling feature is that obedience to the Gurvitch rule is by no means universal, the (liquid) volume of water at saturation usually being less than that of the other adsorbate. In Fig. 5.14 for example, the volume of water at... 

Commercially, HEC is available in a wide range of viscosity grades, ranging from greater than 500 mPa-s(=cP) at 1% soHds to less than 100 mPa-s(=cP) at 5% total soHds. Because HEC is nonionic, it can be dissolved in many salt solutions that do not dissolve other water-soluble polymers. It is soluble in most 10% salt solutions and in many 50% (or saturated) salt solutions such as sodium chloride and aluminum nitrate. As a rule, the lower substitution grades are more salt-tolerant. 

The photolysis of 1,2-benzisoxazole in the absence of air in acetonitrile gave salicylonitrile and benzoxazole (67AHC(8)277). When air-saturated acetonitrile was employed, 2,2 -dimeriz-ation to (38) occurred, accompanied by benzoxazole. Photolysis of the 2,2 -dimer (38) and benzoxazole did not alter the ratio, thus indicating that neither one arose from the other. Selective excitation also ruled out dimer formation from benzoxazole under the reaction conditions (Scheme 9). This dimerization is similar to that observed for benzimidazole, except that in that series no 2,2 -dimerization was observed (74TL375). 

The constants Cj and C9 are both obtained from Fig. 2-40 Ci, usually from the saturated liquid line and C2, at the higher pressure. Errors should be less than 1 percent for pure hydrocarbons except at reduced temperatures above 0.95 where errors of up to 10 percent may occur. The method can be used for defined mixtures substituting pseiidocritical properties for critical properties. For mixtures, the Technical Data Book—Fehvleum Refining gives a more complex and accurate mixing rule than merely using the pseiidocritical properties. The saturated low pressure value should be obtained from experiment or from prediction procedures discussed in this section for both pure and mixed liquids. 

The two most commonly applied systems for naming polycyclic parents are in some ways complementary. Fusion nomenclature provides names for structures containing the maximum number of non-cumulative double bonds von Baeyer nomenclature (Section 1.02.3.4) names fully saturated structures. Thus names for partially hydrogenated structures can be arrived at either by adding hydro prefixes to fusion names or ene , diene , etc. suffixes to von Baeyer names (see examples 29 and 30). If needed, rules are available for... 

Miller et al. [9] hypothesized rules on the regioselectivity of addition from the study of the base-catalyzed addition of alcohols to chlorotnfluoroethylene. Attack occurs at the vinylic carbon with most fluorines. Thus, isomers of dichloro-hexafl uorobutene react with methanol and phenol to give the corresponding saturated and vinylic ethers The nucleophiles exclusively attack position 3 of 1,1-dichloro-l,2,3,4,4,4-hexafluoro-2-butene and position I of 4,4-dichloro-l,l,2,3,3,4-hexafluoro-1-butene [10]. In I, l-dichloro-2,3,3,4,4,4-hexafluoro-l-butene, attack on position 2 is favored [J/] (equation 5) Terminal fluoroolefms are almost invariably attacked at tbe difluoromethylene group, as illustrated by the reaction of sodium methoxide with perfluoro-1-heptene in methanol [/2J (equation 6). 

Just as the saturated solubility of sugar in water is limited, so the solid solubility of element B in metal A may also be limited, or may even be so low as to be negligible, as for example with lead in iron or carbon in aluminium. There is extensive interstitial solid solubility only when the solvent metal is a transition element and when the diameter of the solute atoms is < 0 6 of the diameter of the solvent atom. The Hume-Rothery rules state that there is extensive substitutional solid solubility of B in >1 only if ... 

There are other, more complex, variants of this minimal model. FHP-II, for example, is a 7-bit variant of FHP-I, adding a zero-velocity rest particle and a few collision extra rules involving that rest particle [frischS ]. FHP-III is a collision-saturated version of FHP-II ([frischST], [d HumSTc]). There are also 8-bit variants that include up to three rest particles per site and use particles of different mass ([d Hum87c], [wolf86c]). For simplicity, we will not consider models with rest particles. 

Alkanes are a class of saturated hydrocarbons with the general formula C H2n. -2- They contain no functional groups, are relatively inert, and can be either straight-chain (normal) or branched. Alkanes are named by a series of IUPAC rules of nomenclature. Compounds that have the same chemical formula but different structures are called isomers. More specifically, compounds such as butane and isobutane, which differ in their connections between atoms, are called constitutional isomers. 

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