Reference

Sulfide detection device

Sulfide detection device. Logan, Douglas Patton (Calgon Corp., USA). U.S. US 4026667 31 May 1977, 3 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: G01N031-22. NCL: 023230000R. APPLICATION: US 76-713543 11 Aug 1976. DOCUMENT TYPE: Patent CA Section: 51 (Fossil Fuels, Derivatives, and Related Products) Section cross-reference(s): 79 Sulfide or hydrosulfide ions are detected in alk. aq. drilling muds during drilling for petroleum or natural gas by contact with a solid compn. that turns black in the presence of the ions. The solid compn. comprises a C5-22 fatty carboxylic acid 40-50, Pb, Co, Ni, Cu, or Fe acetates 30-40, a solid wax 9-29, a nonionic surfactant 0-1, and an oil-sol. dye 0-0.05 wt.%. Thus, a solid detector compn. is prepd. by stirring stearic acid [57-11-4] (m.p. 70.degree.) at 100.degree. and adding Pb acetate trihydrate [6080-56-4] . The soln. is heated to 118-20.degree. to remove HOAc, and candle wax, surfactant Plurafac A 38 [64060-02-2], and dye (Sudan Red O [53124-92-8]) are added with stirring. Cooling and solidifying the mixt. in a mold gives the product in the form of a tubular stick.

Development and validation of a material-labeling method for powder process characterization using X-ray computed tomography

Development and validation of a material-labeling method for powder process characterization using X-ray computed tomography. Yang, Chia-Yi; Fu, Xi-Yong (Merck Research Laboratories, West Point, PA 19486, USA). Powder Technology, 146(1-2), 10-19 (English) 2004 Elsevier B.V. CODEN: POTEBX. ISSN: 0032-5910. DOCUMENT TYPE: Journal CA Section: 63 (Pharmaceuticals) The material-labeling method presented in this paper, coupled with x-ray computed tomog. (XRCT), allows in situ non-invasive 3D characterization of certain pharmaceutical processes using relevant materials and process geometry. Microcryst. cellulose (MCC, Celphere) particles were used in expts., and lead (II) acetate trihydrate was used to label the MCC particles because it has both high water soly. and high x-ray attenuation coeff. A 0.5-M lead acetate soln. was used to impregnate the Celphere particles, and thus to deliver sufficient contrast in the XRCT shadow images. Selected phys. properties of the impregnated particles were examd. and found to be similar to the as-received material. The mixt. 9004-34-6 and 6080-56-4 are also in the experiment. of Pb-impregnated and as-received Celphere particles constituted a model pharmaceutical system to investigate die compaction and blending. Lead impregnation allows particles of low at. wt. to become visually traceable on XRCT by enhancing their x-ray absorption. For the compaction study, the in-die positions of Pb-impregnated particles were monitored as a function of compaction pressure. For the mixing study, a linear correlation between the gray scale of the cross-section images and the percentage of Pb-impregnated particles in the mixt. was demonstrated. Two different initial fill configurations were compared: column-filling and layer-filling. Results show that the layer-filled configuration leads to better mixing than the column-filled configuration. .