Stearic acid from

The adsorption of stearic acid from n-hexane solution on a sample of steel powder is measured with the following results ... 

When tallow fatty acids are the feed, stearic acid (actually 60/40 C16/C18) and oleic acids are the products. Solvent separation is also used to separate stearic acid from isostearic acid when hydrogenated monomer is the feed, and oleic acid from linoleic acid when using tall oil fatty acids as feed. 

Fig. 8 Optimizing values of stearic acid and starch as a function of restrictions on tablet friability (A) percent starch (B) percent stearic acid. (From Ref. 15.)...

Figure 31. ir-A curves for D-12-hydroxy-stearic acid (- - -), D,L-12-hydroxyste-aric acid (- - - -) and stearic acid ( ). From Tachibana and Hori (82). Permission of Academic Press, Inc. 

Subtract percent of Stearic Acid from 100 percent... 

What can be done to prevent atherosclerosis For persons with a high LDL level there is little doubt that a decreased dietary intake of cholesterol and a decrease in caloric intake are helpful. While such dietary restriction may be beneficial to the entire population, controlled studies of the effect of dietary modification on atherosclerosis have been disappointing and confusing.33 A diet that is unhealthy for some may be healthy for others. For example, an 88-year old man who ate 25 eggs a day for many years had a normal plasma cholesterol level of 150-200 mg / deciliter (3.9-5.2 mM) bb Comparisons of diets rich in unsaturated fatty acids, palmitic acid, or stearic acid have also been confusing.cc cd/dd Can it be true that palmitic acid from tropical oils and other plant sources promotes atherogenesis, but that both unsaturated fatty acids and stearic acid from animal fats are less dangerous ... 

FIGURE 6.35 The release of stearic acid from a pie-shaped device. [Graph reconstructed from data by Lipper and Higuchi, J. Pharm. Sci., 66, 159 (1977).]... 

In 1973, Van Dorp et al. found a number of interesting macro-cyclic compounds, including some with both double and triple unsaturated bonds (26), but made no attempt to determine their biological significance. They compared the macrocyclic ketones and the fatty acids found in civet and muskrat gland and concluded that there is evidently no correlation between the macrocyclic ketone composition and the fatty acid composition. For example, cycloheptadecanone was the most prominent peak in the muskrat gland (41% of the macrocyclic ketones), whereas the stearic acid from which it could have been formed, was among the minor components (3%) of the fatty acids. 

The presence of surface OH groups or H2 O molecules can play a primary role in adsorption. For example, a microcalorimetric study of the adsorption of stearic acid, from heptane solution, on ferric oxide (Husbands et al., 1971) revealed that preadsorbed water enhanced adsorption of stearic acid. When adsorption takes place from a dry organic liquid, residual surface water may act as special agent. This was shown for the adsorption of a silane coupling agent (y-amino-propyl-triethoxysilane) on silica covered with water molecules for 6 < 1 (Trens and Denoyel, 1996). By the simultaneous determination of adsorption isotherms and the enthalpies of displacement (of heptane by various silanes) it was demonstrated that the amine function was able to displace some of the surface water and make it available for the hydrolysis of the silane into trisilanol, whereas the residual water was able to promote the formation of siloxane bonds between the trisilanol molecules and the surface. 

One of the traditional raw materials used for the production of stearic acid is taUow, and very often, consumers or customers will ask for products equivalent to stearic acid from tallow. Single, double, and triple pressed stearic acids from pahn oil are in fact produced via distillation processes, but similar terminologies were used to indicate their similar characteristics. Besides their fight color, fatty acids derived from palm products have a low content of unsaponifiables, indicating excellent purity. 

Solutes used for this determination by solution adsorption include stearic acid from benzene solution (Daniel, 1951 Kipling, 1962) and p-nitrophenol from aqueous or xylene solution (Giles, 1962). Giles (op. cit.) has discussed the requirements for a suitable adsorbate for the purpose. 

Direct study of the desorption of stearic acid from platinum and from NiO was carried out by Timmons and Zisman [10]. Their findings are shown in Table 10-5. The methylene iodide contact angle and the surface potential measurements indicate that a stearic acid monolayer adsorbed on platinum can be removed completely by heating to 130 C or by extraction with diethyl ether. But if the adsorbent is nickel oxide, heating to 150 C or extraction with diethyl ether fails to restore the original contact angle behavior or the surface potential of the adsorbent surface. 

Stearic Acid-czs-Decalin Series. The adsorption process of stearic acid from Decalin (Figure 3) is similar to that of the first two acids, with the trend being to still smaller average island diameters for the several stages of monolayer completion. 

The formation of discrete islands in all of the films from Decalin and in the cerotic acid from hexadecane indicates little solvent incorporation in these films. The increasing tendency toward solvent incorporation suggested for behenic and stearic acid from hexadecane is in agreement with the Bewig and Zisman statement [4] that "adlineation of the solvent is most marked" when the solvent and solute chains are the same length. 

Hydroxy-Stearic acid (from OA) O2 Multistep biocatalysis 48 (22) >... 

The relative content of linoleic acid was reduced by 11%, that of linolenic acid by 29%. The content of stearic acid increased by 41% which resulted in the decrease in the total content of C unsaturated fatly acids relative to the content of stearic acid from 16.61 0.30 to 10.59 0.20. Similar effect of the water deCbit on the fatty acid composition of the mitochondrial membranes from maize, potato, and leaves of Ara-bidopsis thaliana and apricot was observed earlier [2, 15-18], The anthors detected a considerable decrease of the levels of linoleic and linolenic acids and an increase of the level of stearic acid in the membranes. 

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