Replacement offers

I I Beware of a replacement offer. If someone tries to replace your policy, be suspicious—especially in health insurance. Have someone who is qualified help you make a comparison. 

Abrasives have evolved iato an essential component of modem iadustry. Sandstone, emery, and comndum were the abrasives of choice until the late 1800s when artificial materials were developed. Today synthetic abrasives offer such improved performance that the natural ones have been largely replaced except for jobs where cost is paramount. In 1987 U.S. statistics (4) showed natural abrasive production to be about 7 million while that of cmde manufactured abrasives was over 182 million. Total value of abrasives and abrasive products worldwide is estimated to be over 6 biUion dollars. 

Carbohydrates. The materials offered for fat replacement are either carbohydrate or protein and protein-like compounds (29). Table 3 fists carbohydrate fat-sparing agents. Another fisting is available (34) which includes materials offered on the European market. New compounds appear at such a rate that it is difficult to keep a current compilation proceedings from an aimual meeting are published (48). 

The mmen is not functional at birth and milk is shunted to the abomasum. One to two weeks after birth, the neonate consumes soHd food if offered. A calf or lamb that is nursing tends to nibble the mother s feed. An alternative method of raising the neonate is to remove it from its mother at a very young age, <1 week. A common example of an early weaning situation is the dairy calf that is removed from the cow soon after birth so that the cow s milk supply might be devoted entirely to production. In this instance, the neonate requires complete dietary supplementation with milk replacer. Sources of milk replacer protein have traditionally included milk protein but may also include soybean proteins, fish protein concentrates, field bean proteins, pea protein concentrates, and yeast protein (4). Information on the digestibiUty of some of these protein sources is available (4). 

Alternative feedstocks for petrochemicals have been the subject of much research and study over the past several decades, but have not yet become economically attractive. Chemical producers are expected to continue to use fossil fuels for energy and feedstock needs for the next 75 years. The most promising sources which have received the most attention include coal, tar sands, oil shale, and biomass. Near-term advances ia coal-gasification technology offer the greatest potential to replace oil- and gas-based feedstocks ia selected appHcations (10) (see Feedstocks, coal chemicals). 

Mitsubishi Rayon Co. has developed an acrylic asbestos replacement fiber with a tensile strength of almost 600 MPa (87,000 psi) (78,79). In addition, patents for acrylic asbestos replacement fibers have been obtained by Asahi (80), Wuestefeld (81), REDCO (82), and Hoechst (83). The Hoechst fiber, marketed under the trade name Dolanit (originally Dolan 10), is offered in two forms as shown in Table 4. 

Structural Components. In most appHcations stmctural foam parts are used as direct replacements for wood, metals, or soHd plastics and find wide acceptance in appHances, automobUes, furniture, materials-handling equipment, and in constmction. Use in the huil ding and constmction industry account for more than one-half of the total volume of stmctural foam appHcations. High impact polystyrene is the most widely used stmctural foam, foUowed by polypropylene, high density polyethylene, and poly(vinyl chloride). The constmction industry offers the greatest growth potential for ceUular plastics. 

In dentistry, palladium alloys are widely used as alternatives to base metal alloys in the manufacture of crowns and bridges as weU as the replacement of lost or damaged teeth (see Dental materials). Such alloys contain over 80% palladium, and hence offer significant cost benefits over alloys containing a high proportion of gold. 

Because soHd acid catalyst systems offer advantages with respect to their handling and noncorrosive nature, research on the development of a commercially practical soHd acid system to replace the Hquid acids will continue. A major hurdle for soHd systems is the relatively rapid catalyst deactivation caused by fouling of the acid sites by heavy reaction intermediates and by-products. 

Process. As soHd acid catalysts have replaced Hquid acid catalysts, they have typically been placed in conventional fixed-bed reactors. An extension of fixed-bed reactor technology is the concept of catalytic distillation being offered by CR L (48). In catalytic distillation, the catalytic reaction and separation of products occur in the same vessel. The concept has been appHed commercially for the production of MTBE and is also being offered for the production of ethylbenzene and cumene. 

In essence, the cephalosporin acts as a carrier (63) for the quinolone. The quinolone is replaced in the bacterial ceU after the action of P-lactamase on the cephalosporin portion of the molecule. This codmg combination represents a relatively new class of antibacterial agents which appear to offer advantages over the separated components (64). A good introductory discussion of these exciting agents can be found (65) (see also Antibiotics P-lactams ... 

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