Use in New Tires

The tire is a complicated composite product consisting of tread, undertread, carcass, innerliner, bead, and sidewall. Many different types of rubber and carbon black reinforcement are used in manufacturing tires. Therefore, GRT is a blend of various rubbers and carbon blacks. Accordingly, in using GRT powder and devulcanized GRT in new tire manufacturing, many factors should be considered. Evidently, scrap tire powder can be used as a filler for virgin rubbers and devulcanized GRT can be used in blends with virgin rubbers. This market consumed approximately 1.354 x 10 tons of scrap tire rabber in 2009 (US Scrap Tire Markets, 2009). 

Until recently, it was generally understood that only a few percent of ground rubber can be used in new tires. Scrap Tire Management Council reports that 5% of recycled tire rubber is used in an original equipment tire for the Ford Windstar. Although no other information on the amount of devulcanized rubber used in new tires is available in open literature, a possibility exists for the use up to 10 wt.% of recycled tire rubber in new tire compounds (Myhre and MacKillop, 2002). It was reported that actual road tests of buck tire containing 10 wt.% of the devulcanized rubber in the tread exhibited tread wear behavior almost equal to that for standard type with the new rubber compound (Fukumori et al., 2002). The increase in the amount of recycled mbber in tires is growing but it is likely that results will not be available for a number of years. 

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It turns out that there is another branch of mathematics, closely related to tire calculus of variations, although historically the two fields grew up somewhat separately, known as optimal control theory (OCT). Although the boundary between these two fields is somewhat blurred, in practice one may view optimal control theory as the application of the calculus of variations to problems with differential equation constraints. OCT is used in chemical, electrical, and aeronautical engineering where the differential equation constraints may be chemical kinetic equations, electrical circuit equations, the Navier-Stokes equations for air flow, or Newton s equations. In our case, the differential equation constraint is the TDSE in the presence of the control, which is the electric field interacting with the dipole (pemianent or transition dipole moment) of the molecule [53, 54, 55 and 56]. From the point of view of control theory, this application presents many new features relative to conventional applications perhaps most interesting mathematically is the admission of a complex state variable and a complex control conceptually, the application of control teclmiques to steer the microscopic equations of motion is both a novel and potentially very important new direction. 

The microscopic understanding of tire chemical reactivity of surfaces is of fundamental interest in chemical physics and important for heterogeneous catalysis. Cluster science provides a new approach for tire study of tire microscopic mechanisms of surface chemical reactivity [48]. Surfaces of small clusters possess a very rich variation of chemisoriDtion sites and are ideal models for bulk surfaces. Chemical reactivity of many transition-metal clusters has been investigated [49]. Transition-metal clusters are produced using laser vaporization, and tire chemical reactivity studies are carried out typically in a flow tube reactor in which tire clusters interact witli a reactant gas at a given temperature and pressure for a fixed period of time. Reaction products are measured at various pressures or temperatures and reaction rates are derived. It has been found tliat tire reactivity of small transition-metal clusters witli simple molecules such as H2 and NH can vary dramatically witli cluster size and stmcture [48, 49, M and 52]. 

Almost all IDA derived chain extenders are made through ortho-alkylation. Diethyltoluenediamine (DE I DA) (C H gN2) (53), with a market of about 33,000 t, is the most common. Many uses for /-B I DA have been cited (1,12). Both DE I DA and /-B I DA are especially useful in RIM appHcations (49,53—55). Di(methylthio)-TDA, made by dithioalkylation of TDA, is used in cast urethanes and with other TDI prepolymers (56). Styrenic alkylation products of TDA are said to be useful, eg, as in the formation of novel polyurethane—polyurea polymers (57,58). Progress in understanding aromatic diamine stmcture—activity relationships for polyurethane chain extenders should allow progress in developing new materials (59). Chlorinated IDA is used in polyurethane—polyurea polymers of low hysteresis (48) and in reinforced polyurethane tires (60). The chloro-TDA is made by hydrolysis of chloro-TDI, derived from TDA (61). 

Another furnace that does not require fuel preparation is the stoker boiler, which was used by New York State Electric Gas Corporation (NYSEG) in its TDE tests. At NYSEG, the stoker boiler, which has a 1649°C (3000°E) flame temperature (as does the cyclone boiler), has routinely blended low quaUty coal, and more recently, wood chips with its standard coal to reduce fuel costs and improve combustion efficiency. In the tire-chip tests, NYSEG burned approximately 1100 t of tire chips (smaller than 5x5 cm) mixed with coal and monitored the emissions. The company determined that the emissions were similar to those from burning coal alone. In a second test-bum of 1900 t of TDE, magnetic separation equipment removed metal from the resulting ash, so that it could be recycled as a winter traction agent for roadways. 

A new class of solvents called ionic liquids has been developed to meet this need. A typical ionic liquid has a relatively small anion, such as BF4, and a relatively large, organic cation, such as l-butyl-3-methylimidazolium (16). Because the cation has a large nonpolar region and is often asymmetrical, the compound does not crystallize easily and so is liquid at room temperature. However, the attractions between the ions reduces the vapor pressure to about the same as that of an ionic solid, thereby reducing air pollution. Because different cations and anions can be used, solvents can be designed for specific uses. For example, one formulation can dissolve the rubber in old tires so that it can be recycled. Other solvents can be used to extract radioactive waste from groundwater. 

NMR microscopy is ultimately an innovative method of research and it is not surprising that most of the commercially installed systems, approximately 80%, are installed in public scientific research centers, where new applications are continuously being developed. The method is not particularly widely distributed in industry, where standardized methods are more often used. However, NMR microscopy is mainly used in the pharmaceutical industry for the development of new drugs, in the food industry for the development of new types of food, in the chemical industry for creating and characterizing new materials and in the polymer industry, e.g., for creating new mixtures for tires. 

Using the information in table 1.4, the used-car ad can be divided into five moves. In the first move (included in all six ads), the seller states the essential facts about the car (year, make, and model). In the second move (included in all but two ads), the seller highlights select features of the car (e.g., new tires, air bags, five speeds). In the third move (interchangeable with the second), the writer offers a subjective description of the car (e.g., good cond or fun ). In the fourth move, the writer states the price. Finally, in the fifth move, the seller provides contact information (1) a phone number, (2) a contact name (optional), and (3) when to call (optional). 

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