Sulfur specimens

Mold material (19)—e.g., the seven-day strength of sulfur specimens cast in fiber molds is only 55% of the strength of specimens cast in steel molds (19). 

Figure 15. Fractured sulfur specimens—cleavage (top) and intergranular (bottom) (2X)...

Effect of Temperature on Strength. Work by Rennie et al. indicates that the flexural strength of IVz in. X 1% in. X 10 in. sulfur prisms depends markedly on the temperature at which they are equilibrated before testing (2). Other investigators (3) have noted that sulfur specimens having a substantial volume/surface area ratio may undergo thermal shock, a durability problem in which a fluctuating temperature may... 

Analytical Methods. Fluorite is readily identified by its crystal shape, usually simple cubes or interpenetrating twins, by its prominent octahedral cleavage, its relative softness, and the production of hydrogen fluoride when treated with sulfuric acid, evidenced by etching of glass. The presence of fluorite in ore specimens, or when associated with other fluorine-containing minerals, may be deterrnined by x-ray diffraction. 

In colorfastness to acid spotting, ISO 10S-E0S, drops of a solution of either acetic acid (300 g of glacial acetic acid per Hter of water), sulfuric acid (50 g of concentrated acid per Hter), or tartaric acid (100 g of crystalline acid per Hter) are spotted onto the test material, which is then dried and assessed. Colorfastness to alkaH spotting, ISO 10S-E06, is like E05 except that a solution of 100 g of anhydrous sodium carbonate per Hter of water is used. Colorfastness to water spotting, ISO 10S-E07, is like E05 but uses drops of water and assessment is made after 2 min wet and after drying. In colorfastness to hot water, ISO 10S-E08, the textile specimen and adjacents are wound around a glass rod and placed in water adjusted to pH 6 with acetic acid at 70°C... 

The reproducibility of test results between labs using the neutral salt spray tests has not been consistent, but the repeatability, within one lab, is better, and the test has value in comparing variations in coating systems. Correlation of hours of exposure in the salt spray test to actual performance of the plated part in service, even in marine atmospheres, is not consistent and usually avoided. A classic example is that cadmium deposits outlast zinc deposits on steel in salt spray tests and clean marine atmospheres, yet zinc outlasts cadmium when exposed to real, industrial atmospheres, because of the presence of sulfur-bearing corrodents in industrial environments. An important variable in salt spray testing is the position of the surface to be tested. Whereas the surface of test panels is specified to be 15—30° from the vertical (40), when salt spray testing chromated zinc-plated specimens, this range has appeared excessive (41). 

Specimen Location Outlet piping of a sulfuric acid storage tank... 

Fig. 42. AES depth profiles of copper and sulfur (top) and zinc and oxygen (bottom) for the brass-on-glass adhesion specimens as a function of curing temperature. Reproduced by permission of Gordon and Breach Science Publishers from Ref. [46].

Alkalinity. To 25ml of w, add 1 drop of 0.1% methyl red indicator soln (60% ale) and 0.0 IN acid or base until the soln is just pink. Add 25ml of specimen, mix well, then titrate with 0.01N sulfuric acid until the pink color is restored. Calc the % NH3 by wt as follows ... 

The specimen was prepared by the following method. After mixing HAF carbon black (50 phr) with natural rubber (NR) in a laboratory mixer, carbon gel was extracted from unvulcanized mixture as an insoluble material for toluene for 48 h at room temperamre and dried in a vacuum oven for 24 h at 70°C. We made the specimen as a thin sheet of the carbon gel (including carbon black) by pressing the extracted carbon gel at 90°C. The cured specimen was given by adding sulfur (1.5 phr) to the unvulcanized mixture and vulcanized for 30 min at 145°C. The dynamic viscoelastic measurement was performed with Rheometer under the condition of 0.1% strain and 15 Hz over temperatures. 

Seeligmann, Torrilhon, and Falconnet, in a treatise on rubber published in France in 1896, recorded interesting early observations on the sol and gel components now known to be present in most specimens of undegraded raw rubber. They referred to them as the two isomeric hydrocarbides of rubber, one being the adhesive principle and the other the nervous principle. It was observed that the latter refused to dissolve on repeated treatment with fresh portions of solvent and that the approximate percentage of this constituent was roughly the same when different solvents were used to extract the soluble portion. The authors called attention also to the enormous swelling capacity of the nervous hydrocarbide. Vulcanization was attributed to a reaction of sulfur with the adhesive principle whereby the adhesive characteristics are suppressed or eliminated. 

Suppose we are at the point A in Fig. 9 or Fig. 13. By heating the specimen in an atmosphere of sulfur, as was done by Stephens and co-workers (69), we enrich it in sulfur, which involves an increase both in 8- and in ev because sulfur is an acceptor. In this case we are transferred, for example, from the point A to the point G in Fig. 9 or Fig. 13, which weakens the effect. This is what has been observed by Stephens and his associates. 

CM sulfur compounds in specimens from Villefranche-sur-mer, France, strongly inhibit feeding by the amphipod A. logimana (Schnitzler et al. 1998)... 

Hugo, R.C. and Cady, S.L (2004) Preparation of geological and biological TEM specimens by embedding in sulfur. Microsc. Today, 12, 28-30. 

Analysis of the urine specimens of a 3-year-old boy who had been playing with 1,4-dichlorobenzene yielded 2,5-dichlorophenol as well as 4 other unidentified phenols. These compounds were shown to be conjugated with glucuronic and sulfuric acids (Hallowell 1959). 

Society of Edinburgh that lie had discovered soda in several varieties of Scottish whinstone and m lava from Mt, Aetna (25). He used the term whinstone to include basalt, trap, and certain kinds of porphyry, wacke, and other argillaceous stones. When he analyzed a specimen which had been broken from one of the famous basaltic columns of Staffa, he found that the sum of the earths, silica, and iron never amounted to more than 94 per cent. Suspecting the presence of an alkali, he heated the pulverized mineral with pure sulfuric acid and extracted a salt which he identified as sodium sulfate (25). He proved, moreover, that the sodium compounds had not been dissolved from his glass apparatus. Dr. Kennedy also found 4 per cent of soda in a specimen of lava brought to him by Sir James Hall and Dr. James Home from the famous current of Mt. Aetna which in 1669 had destroyed part of the town of Catania. He published these analyses in 1800 in Nicholsons Journal (25). 

In 1771 G. W. Scheele investigated a green variety of fluorspar from Garpenberg and a white one from Gislof in Scania. He found that the green specimen contained a trace of iron but that the white one did not. When he heated the pulverized mineral with oil of vitriol [sulfuric acid], he noticed that the inner surface of the glass retort became corroded,... 

Determination of acidity. The soln retained from the detn of the pH value shall be titrated with a 0.05N NaOH soln to a reading of 7,6 on the pH meter, A blank detn shall be conducted on an equal volume of distd w and the volume of NaOH used for the specimen shall be corrected. The percent acid present in the soln shall be ealed to sulfuric acid as follows ... 

Figure 3. Marshall stability as a function of sulfur and asphalt contents in sand-asphalt-sulfur mixes (15,). Materials used were medium-coarse sand and 150/180 pen. asphalt. All specimens were prepared with 2 hammer blows on one face only.

Wohler143 first described the formation, from concentrated aqueous thiocyanic acid, of a compound, C2H2N2S3 later named isoperthiocyanic acid, and now formulated as 3-imino-5-thiono-l,2,4-dithia-zolidine (144). Solutions of isoperthiocyanic acid in alkali deposit sulfur this redissolves presently giving a liquid containing144-147 the salt of an isomeric acid, later named perthiocyanic acid, for which the 3,5-dimercapto-l,2,4-thiadiazole structure is now accepted (see Section III, J, 1). This acid, isolated from its barium salt by treatment with mineral acid and ether extraction,144,145 readily reverts to isoperthiocyanic acid,144 but fairly stable specimens are obtainable under carefully controlled conditions.148 148... 

When satisfactory crystals have been obtained, bring them quickly upon a Witte plate, washing them on with the mother liquor. Wash the crystals with successive small portions of concentrated hydrochloric acid, being careful that none escapes the washing. Pump off the liquid each time, then spread the crystals upon absorbent paper, press them lightly with a wad of absorbent paper, and transfer them to a desiccator over sulfuric acid. As soon as they are dry, put them in a perfectly dry bottle and seal with paraffin, since they are deliquescent. They should be bright green in color and not at all yellow. It is very hard to get a perfect specimen, but it can be done, and, when successful, the specimen will keep indefinitely. 

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