Abrasive Flow Finishing
S Santhosh Kumar, Somashekhar S. Hiremath in Role of Surface Modification on Bacterial Adhesion of Bio-Implant Materials, 2020
Kar et al. (2009a) developed and studied the performance of five different types of polymers-based abrasive media: (a) natural rubber, (b) ethylene propylene diene monomer, (c) butyl rubber, (d) silicone rubber, and (e) styrene butadiene rubber mixed with SiC abrasive particles. Out of five media styrene butadiene, rubber-based media shows better performance in terms of viscosity, thermal stability, and finishing of work surfaces. They have conducted a study on commercial media and found a composition of 66% abrasives, 34% carrier, and other ingredients in the commercial media using thermogravimetric analysis. Kar et al. (2009b) used two different rubbers for media development – (a) natural rubber + SiC abrasive particles and (b) butyl rubber + SiC abrasive particles with naphthenic oil as processing oil. The rheological properties of the media and the effect of these media on the finishing process were studied. Based on the experiments conducted, Butyl rubber-based abrasive media had shown good performance compared to natural rubber-based media. Sankar et al. (2011) developed styrene-butadiene-based media to finish the aluminium-based metal matrix composites. They have also investigated the effect of rheological properties of abrasive media on the finishing and the obtained results are explained with respect to the media properties.
Rationale and technique of malaria control
David A Warrell, Herbert M Gilles in Essential Malariology, 2017
Lining of earth drains is the best way of improving their performance and decreasing the cost of their maintenance. Open drains can be lined with cement concrete, asphalt concrete, stone or brick. When well constructed and looked after, lined drains allow for faster flow of water, less silting and reduce the growth of weeds. Concrete lining can be made on site, but the use of connecting precast slabs is more common. The slabs for the bottom of the lined drain should have a central narrow invert (cunette) to give free water flow when its level is low. Stone lining may be used where this material is plentiful and the cost of labour low. Recently, membrane lining made of asphalt felt sheeting or of butyl rubber has been introduced. However, this type of lining is more affected by weather conditions and has a life expectancy of a few years only, as opposed to the much longer duration of cement concrete. A lined drain should never be constructed without first making an earth drain to determine the requisite depth of the drain, and to see whether the flow is satisfactory.
Personal Protective Equipment (PPE): Practical and Theoretical Considerations
Brian J. Lukey, James A. Romano, Salem Harry in Chemical Warfare Agents, 2019
At least two sets of gloves should be worn with the chemical-protective ensemble, the inner usually cotton (although nitrile and latex gloves have been used) and the outer a chemical-protective glove. An intermediate-layer glove (forming three layers of gloves) may be added at the individual’s discretion. Actually, the practice of three glove layers is becoming common. Usually, these outer gloves are made of butyl rubber or halogenated butyl rubber, a substance highly resistant to permeation by chemical agents, although recently, gloves made of nitrile and Viton have been employed. However, note that petroleum products easily permeate butyl rubber. On the other hand, Viton has excellent permeation resistance to oil and gasoline products, hydraulic fluids, and hydrocarbon solvents, whereas nitrile has very good permeation resistance to oil and gasoline, superior resistance to petroleum-based hydraulic fluids, and good resistance to hydrocarbon solvents (DuPont, 2006). Any contact of butyl rubber with petroleum products (gasoline, oil, etc.) will rapidly degrade the protective effect of this material, and it should be immediately discarded. Nor should butyl rubber be used for insulation against electrical shock. Butyl rubber gloves usually come in three thicknesses: 0.007, 0.014, and 0.025 in. You may hear these referred to as 7, 14, and 25 mil gloves. Testing suggests that the 14 and 25 mil gloves can be used up to 24 h in a contaminated environment before requiring decontamination. However, the 7 mil gloves, used for operations requiring good tactile properties (medical types, typing, and computer usage), must be decontaminated and inspected within 6 h (CCCD, July 2000).
Research on the relationship between cephalosporin structure, solution clarity, and rubber closure compatibility using volatile components profile of butyl rubber closures
Published in Drug Development and Industrial Pharmacy, 2019
Xiao-Meng Chong, Xin Dong, Shang-Chen Yao, Chang-Qin Hu
Ten different types of butyl rubber closures, including chlorobutyl rubber closures (uncoated and coated with tetrafluoroethylene, copolymer of tetrafluoroethylene and ethylene, copolymer of tetrafluoroethylene and hexafluoropropylene) and bromobutyl rubber closures, were obtained from seven different manufacturers, covering the main brands of rubber closures in China.
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