Cholesterol is the central compound m any discussion of steroids Its name is a combination of the Greek words for bile (chole) and solid (stereos) preceding the characteristic alcohol suffix ol It is the most abundant steroid present m humans and the most important one as well because all other steroids arise from it An average adult has over 200 g of cholesterol it is found m almost all body tissues with relatively large amounts present m the brain and spinal cord and m gallstones Cholesterol is the chief constituent of the plaque that builds up on the walls of arteries m atherosclerosis  [c.1093]

Chrome alumina pink spinel  [c.208]

Iron chromite brown spinel  [c.524]

Spin-drawing processes Spine Spinel  [c.920]

Zinc aluminate spinel  [c.1084]

Zinc ferrite brown spinel  [c.1086]

Zinc iron chromite brown spinel  [c.1086]

Grinding fluids or coolants are fluids employed in grinding to cool the work being ground, to act as a lubricant, and to act as a grinding aid. Water is still the best Hquid for removing heat from a workpiece but it has no lubricating properties. Soluble oil coolants in which petroleum oils are emulsified in water have been developed to impart some lubricity along with mst-preventive properties. These coolants must be carefully controlled to prevent health and dermatitis problems from bacterial growth and to avoid contamination with leaking "tramp" hydrauhc oil. It should be noted that the wear rate of aluminum oxide wheels is much higher when water or water-containing coolants are used than when the same wheel is used dry. Although this has been attributed to the formation of iron spinel during the grinding process (50), the same effect has been observed in grinding kon-free refractory alloys and may be attributed to the formation of aluminum hydrate at the cutting tip of the abrasive grains, where temperatures and pressures are extremely high. The soft hydrate layer is removed on each pass through the work. This hypothesis is supported by the fact that dry and wet grinding G-ratios (volume of steel removed/volume of wheel wear) are more nearly equal in vertical spindle surface grinding, where each grit enters the work and remains buried for a long distance (protected from reaction with water) as opposed to horizontal spindle grinding, where cut-path is very short and reaction can occur at each wheel revolution.  [c.16]

Small meteoroids are not subjected to high ram pressures during entry because they decelerate at altitudes near 90 km, where the air density and corresponding ram pressure from coUisions with air molecules is smaU. Conventional meteorites are larger and penetrate deeper into the atmosphere with high velocity, where they are subjected to cmshing ram pressure. Unlike conventional meteorites which reach the Earth only by rare gravitational perturbation, dust from aU bodies beyond the Earth s orbit, if not immediately ejected from the solar system by radiation pressure, experiences the effects of radiation drag causing it to inexorably spinal toward the Sun and past the Earth s orbit.  [c.100]

Fan is the generic term for low pressure air- and gas-moving devices usiag rotary motion. Fans are subdivided iato centrifugal and axial-flow types, depending on the direction of air flow through the impeller. In centrifugal fans, the air is iatroduced iato the center of a revolving wheel or rotor with peripheral blades. Air is drawn through the blades and forced out ia centrifugal flow iato a scroU or volute housiag where a portion of the kinetic energy is converted to pressure or static head. In axial-flow fans the air continues to move directly forward through the fan along the axis of the shaft. Kinetic energy is imparted to the air by the shape and arrangement of the blades. After discharge through the blades, although the general flow direction is stiU forward, a spinal component of velocity generally has been added to the air. A propeUer-type fan is the most common axial-flow fan but more compHcated types are in use where the blades resemble vanes in a turbine.  [c.103]

Common Properties of Spinel Ferrites and M-Type Ferrites  [c.187]

Me2NCH2) C2H5)(Me)C-OOC Ph-HCI. Colourless crystalline powder with a bitter taste, m.p. 177-179"C. Prepared by the action of ethyl magnesium bromide on dimethyl-aminoaceione. It is a local anaesthetic, mainly used to produce spinal anaesthesia.  [c.33]

Chromates III). Mixed oxides, e.g. FeCr204, having spinel structures and prepared by solid state reactions.  [c.97]

Manganates III), again mixed-metal oxides present in the spinel Mn304, Mn Mn 204.  [c.249]

Rinmann s green, ZnCojO. A spinel formed when cobalt nitrate solution is placed on zinc oxide and the mixture heated to redness. The green colour forms a delicate test for Zn.  [c.346]

Spanel P and Smith D 1997 SIFT studies of the reactions of FijO", NO and Ot with a series of alcohols Int. J. Mass Spectrom. Ion Proc. 167/168 375-88  [c.1359]

Spanel P, Ji Y and Smith D 1997 SIFT study of the reactions of FijO", NO and Ot with a series of aldehydes and ketones Int. J. Mass Spectrom. Ion Proc. 165/166 25-37  [c.1359]

Spanel P and Smith D 1998 SIFT studies of the reactions of FijO", NO and Ot with a series of volatile carboxylic acids and esters Int. J. Mass Spectrom. Ion Proc. 172 137-47  [c.1359]

By a mutually agreeable arrangement with Case Western I was able to take most of my laboratory equipment, chemicals, and instrumentation with me to LA. I again got help from Dow Chemical, which donated an additional NMR spectrometer. We packed up our laboratories in Cleveland in late May, with my graduate students John Welch and Surya Prakash spearheading and organizing the effort. Our small convoy, including moving vans, started out across the country to California in the best spirit of westward migration. Most of my group drove to LA, but Judy and I decided to fly out with our cocker spaniel Jimmy in the baggage compartment. My sons drove out in our car, getting to know each other better during the long trip than they had in years.  [c.112]

The most abundant natural steroid is cholesterol. It can be obtained in large quantides from wool fat (15%) or from brain or spinal chord tissues of fat stock (2-4%) by extraction with chlorinated hydrocarbons. Its saturated side-chain can be removed by chromium trioxide oxidation, but the yield of such reactions could never be raised above 8% (see page 118f.).  [c.285]

Sillimanite, see Aluminum silicon oxide (1/1) Smithsonite, see Zinc carbonate Soda ash, see Sodium carbonate Spelter, see Zinc metal Sphalerite, see Zinc sulflde Spherocobaltite, see Cobalt(II) carbonate Spinel, see Magnesium aluminate(2—)  [c.275]

Adrenocortical insufficiency Organ transplants Liver disease Adrenogenital syndrome Nephrotic syndrome Acute spinal cord injury Hyp ere alemia Hematologic disorders Myasthenia gravis Neoplastic disease  [c.94]

Prevention of Osteoporosis. Another health benefit associated with the consumption of a diet high in cereals is the maintenance of bone-mineral content, especially among older women. After the menopause, women are subject to deminera1i2ation of bones, especially in the pelvis and spinal column. This condition, called osteoporosis, leaves them vulnerable to hip fractures. Some degree of deterioration in total life adjustment is a nearly inevitable occurrence in the five sixths who survive a hip fracture (25). Osteoporosis in women has been associated with a reduced estrogen production after the menopause. That plus the fact that animal studies indicated an involvement of estrogen in depositing calcium in the bones led to use of this hormone in treatment of osteoporotic women (26). Reports suggest, however, a connection between estrogen therapy and endometrial cancer (27).  [c.352]

The cubic ferrites, perovskite, garnet, and spinel, have quite different crystal stmctures and correspondingly different properties and appHcations. Perovskite ferrites, isostmctural with the mineral perovskite [9003-99-0] CaTiO, contain iron in unusually high valency states, eg, +4, +5, +6 (8), giving rise to high and almost metallic electrical conductivity. Representatives ate (CaSr)Fe02 (8) and (PbCa)Fe20 (9). AppHcations are mainly in the field of electroceramic devices, eg, electrical transducers (see Ceramics AS ELECTRICAL MATERIALS). Closely related to the perovskite ferrites are orthoferrites where the  [c.186]

Spinel ferrites, isostmctural with the mineral spinel [1302-67-6] MgAl204, combine interesting soft magnetic properties with a relatively high electrical resistivity. The latter permits low eddy current losses in a-c appHcations, and based on this feature spinel ferrites have largely replaced the iron-based core materials in the r-f range. The main representatives are MnZn-ferrites (frequencies up to about 1 MH2) and NiZn-ferrites (frequencies 1 MHz).  [c.187]

The soft magnetic spinel ferrites, by far the most important cubic ferrites, were first introduced by Philips under the trade name Ferroxcube (14) and are now widely commercially available under various trade names. The world market for soft magnetic ferrites amounts to about one biUion dollars (1991), about 350 million dollars of which is in the United States.  [c.187]

The commercial sintered spinel and M-type ferrites have a porosity of 2—15 vol % and a grain size in the range of 1—10 ]lni. In addition, these materials usually contain up to about 1 wt % of a second phase, eg, CaO + Si02 on grain boundaries, originating from impurities or sinter aids.  [c.187]

See pages that mention the term Sabinol : [c.24]    [c.26]    [c.96]    [c.98]    [c.104]    [c.188]    [c.218]    [c.223]    [c.247]    [c.250]    [c.350]    [c.369]    [c.369]    [c.400]    [c.429]    [c.829]    [c.1757]    [c.287]    [c.920]    [c.920]    [c.98]    [c.186]    [c.188]   
The chemistry of essential oils and artificial perfumes Volume 2 (1922) -- [ c.135 ]