Subject index sampling

A wide variety of compounds can be used as curing agents, and a typical sample as gleaned from a Chemical Abstracts subject index is listed below [100-111]. 

Thoms has isolated an alcohoH from Peru balsam oil, which he termed peruviol. This body was stated to have powerful antiseptic properties, but has not been further investigated until Schimmel Co. took up the subject. The sample of oil upon which they have worked had the following characters.- Specific gravity, 1-1200 optical rotation, -b 0 55 refractive index, 1-57177 -, acid value, 36-4 and ester value, 228-2. The oil after saponification was fractionated, and after benzyl alcohol had distilled over, a light oil with characteristic balsamic odour passed over. It boiled at 125 to 127 at 4 mm., and had a specific gravity, 0 8987 optical rotation, -h 12 22 and refractive index, 1-48982. This body appeared to be identical with Hesse s nerolidol, whilst in physical and chemical properties it closely resembles Thoms peruviol. The characters of the various preparations were as follows — . ... 

Sample handling and preparation techniques associated with HPIEC of proteins and peptides, are critical to the success of the separation. The field of sample preparation for biopolymer. separation has been reviewed by Wehr (6) and Majors (7). Further details can be found in works by Suelter (8), Brewer, Pesce and Ashworth (9) and in the subject indexes of Methods in Enzymology (10). 

We begin the mathematical analysis of the model, by considering the forces acting on one of the beads. If the sample is subject to stress in only one direction, it is sufficient to set up a one-dimensional problem and examine the components of force, velocity, and displacement in the direction of the stress. We assume this to be the z direction. The subchains and their associated beads and springs are indexed from 1 to N we focus attention on the ith. The absolute coordinates of the beads do not concern us, only their displacements. 

Films containing about 10% CIRh(PPh3)3 in PMMA were prepared and subjected to oxygen index, TGA, and DSC measurements. The oxygen index, bottom ignition (1 1), increases from about 14 for pure PMMA to about 20 for the rhodium compound in PMMA. TGA analysis indicates that about 25% of the sample is non-volatile at 600°C and the glass transition temperature increases by about 15°C by DSC. 

It is not surprising that the data produced as total petroleum hydrocarbons (EPA 418.1) suffer from several shortcomings as an index of potential ground-water contamination or health risk. In fact, it does not actually measure the total petroleum hydrocarbons in the sample but rather, measures a specific range of hydrocarbon compounds. This is caused by limitations of the extraction process (solvents used and the concentration steps) and the reference standards used for instrumental analysis. The method specifically states that it does not accurately measure the lighter fractions of gasoline [benzene-toluene-ethylbenzene-xylenes fraction (BTEX)], which should include the benzene-toluene-ethylbenzene-xylenes fraction. Further, the method was originally a method for water samples that has been modified for solids, and it is subject to bias. 

In concentrated sulfuric acid, aromatic polyisocyanides are subject to sulfona-tion. Poly(isopropyl isocyanide) is dissolved in 97%H2S04, and is reprecipitated by the addition of water. Infrared spectra show that some structural change, e.g. hydrolysis, has taken place (26). Poly(sec-butyl isocyanide) is dissolved by the acidic hexafluoroisopropanol with some attendant browning of the solution (7). In spite of the theoretical complexities of polyelectrolytic character introduced into the solution characterization of polyisocyanides in strongly acidic media, such media at least allow viscometric indexing of the various samples of the otherwise insoluble polyisocyanides. 

Attrition index (AI, wt%). A fresh catalyst sample is subjected to high-velocity fluidization for a long time. In this process, wear on the particles occurs as they are... 

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