High-pressure water

Another consequence of the effect of pressure on gas solubility is the painful, sometimes fatal, affliction known as the bends. This occurs when a person goes rapidly from deep water (high pressure) to the surface (lower pressure), where gases are less soluble. The rapid decompression causes air, dissolved in blood and other body fluids, to bubble out of solution. These bubbles impair blood circulation and affect nerve impulses. To minimize these effects, deep-sea divers and aquanauts breathe a helium-oxygen mixture rather than compressed air (nitrogen-oxygen). Helium is only about one-third as soluble as nitrogen, and hence much less gas comes out of solution on decompression. 

Boiler feed water high pressure, 167 Brake horsepower, 200 Capacity-head ranges, 165 Casing, 165... 

Molecular weights were determined using a Waters high-pressure GPC instrument (Model 6000 A pymp, a series of five p-Styragel columns (10s, 10s, 10, 103, 500 A), Differential Refractometer 2401 and UV Absorbance Detector Model (440) and a calibration curve made by well fractionated polyisobutylene standards. 

M.J. Cocero, J.L. Soria, F. Fdez-Polanco, Behaviour of a Cooled Wall Reactor for Supercritical Water, High Pressure Chemical Engineering, Ph. Rudolf Ch Trepp Eds. 121, Elsevier (1996). 

The isoxazole-to-oxazole rearrangement has been also used in the synthesis of benzocondensed derivatives. The irradiation of benzisoxazoles 81 in water (high-pressure Hg lamp) produces almost quantitative yields of the corresponding ben-zoxazoles 82 (Scheme 12.24) [53]. Benzoxazolin-2-ones 83 are similarly obtained [54], Furthermore, oxazolo[5,4-b]pyridines 84 and oxazolo[5,4-b]quinoline 85 are obtained by preparative-scale photolysis in ether with a high-pressure Hg lamp of the corresponding isoxazolo[5,4-b]pyridines or isoxazolo[5,4-b]quinoline, respectively (Scheme 12.24) [55]. 

Waters High Pressure Liquid Chromatography apparatus (pump 6000 A, injector U6K, UV detector 440, u-styragel columns set 10 - 10 - 10 - 500 A), =254 nm, flow rate ... 

Proton NMR spectra were obtained from a Varian T-60 spectrometer. The solvent used was 99.8% CDCl containing trime-thylsilane as a marker. Infrared spectra were obtained with a Beckman Acculab-6 spectrometer. The elementary analyses were determined by Elek Microanalytical Laboratories, Torrance, California. A Waters high pressure liquid chromatograph was... 

High-pressure reactions in specific dry conditions. In some cases, the synthesis of materials requires the elimination of all traces of water. High-pressure cells are usually made of pyrophyllite and the high-temperature treatment of such material leads to the in situ formation of water, which induces hydrolysis. 

MEASUREMENT METHODS XAD tube methanol/water high pressure liquid chromatograph with UV detection. 

MEASUREMENT METHODS Particulate filter water high pressure liquid chromatography with ultra violet detection. 

Polymerization was carried out at 60 °C for 24 h in chlorobenzene. [M]o (initial monomer concentration) = 0.25. Monomer to catalyst mole ratio. Methanol-insoluble polymer. " Values were obtained by GPC analysis with polystyrene standards calibration (Waters high-pressure GPC assembly Model M590 pump /<-Styragel columns of 10 , 10, 10, 500, and 100 A refractive index detectors, solvent, THF). 

Boiler feed water (high-pressure or low-pressure boiler water)... 

Hardness elements can form deposits because of the inverse solubilities of silicates and carbonates, and organics can foul surfaces or lead to corrosion. Some low-pressure systems can operate on softened water. High-pressure boilers (>6 MPa), on the other hand, require the equivalent of a three-bed demineralizer for the treatment of fresh water. To avoid the potential for contamination by regenerant chemicals, external regeneration is often chosen. 

FIGU RE 5.6 A reverse osmosis system for the removal of ions and other impurities from water. Highly pressurized water is forced through a membrane selectively permeable to water so that desalinated purified water penetrates the membrane and a waste brine is rejected. Membrane filtration processes that employ filters with... 

The molecular weights and molecular weight distributions were determined by a Waters High Pressure GPC instrument (Model 600 E). DSC analysis was performed on a Dupout Instrument DSC 910s. Elemental analysis was performed on a Perkin Elmer Elemental Analyzer (Model 240). The infrared spectra were recorded on a Perkin Elmer Infrared Spectrophotometer (Model 1430). 

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