Players

GaAs, GaAlAs, and GaP based laser diodes are manufactured using the LPE, MOCVD, and molecular beam epitaxy (MBE) technologies (51). The short wavelength devices are used for compact disc (CD) players, whereas the long wavelength devices, mostly processed by MBE, are used in the communication field and in quantum well stmctures. 

Immunosensors promise to become principal players ia chemical, diagnostic, and environmental analyses by the latter 1990s. Given the practical limits of immunosensors (low ppb or ng/mL to mid-pptr or pg/mL) and their portabiUty, the primary appHcation is expected to be as rapid screening devices ia noncentralized clinical laboratories, ia iatensive care faciUties, and as bedside monitors, ia physicians offices, and ia environmental and iadustrial settings (49—52). Industrial appHcations for immunosensors will also include use as the basis for automated on-line or flow-injection analysis systems to analyze and control pharmaceutical, food, and chemical processing lines (53). Immunosensors are not expected to replace laboratory-based immunoassays, but to open up new appHcations for immunoassay-based technology. 

ISO-Nomi 9660), respectively. This is equivalent to 200,000 pages of text. The access time is between 200 and 600 ms. The data transfer rate of a standard audio CD player is 144 KB/s, but dedicated CD-ROM drives can transfer data at up to 300 KB/s by doubling the rotational speed of the disk. 

Fig. 2. A magnetooptical player (2). P = polarizer MC = magnetic coil (for magnetooptical writing) NBS = neutral beam spHtter PBS = polarizing beam...

The compact disk player has become a very widespread consumer product for audio reproduction. The information is stored along tracks on the disk in the form of spots of varying reflectivity. The laser beam is focused on a track on the surface of the disk, which is rotated under the beam. The information is recovered by detecting the variations in the reflected light. The compact disk offers very high fideHty because there is no physical contact with the disk. This appHcation has usually employed a semiconductor laser source operating at a wavelength of around 780 nm. Tens of millions of such compact disk players are produced worldwide every year. 

User-Related Properties. The most important element in the player s contact with the surface is traction. Shoe traction for light-duty consumer purposes need address only provision of reasonable footing. The frictional characteristics are obviously of much greater importance in surfaces designed for athletic use. For specialized surfaces such as a track, shoe traction is especially critical. With grass-like surfaces, traction is significantly affected by pile density and height, and other aspects of fabric constmction. 

Typical static friction coefficients are given in Table 1. These data demonstrate that the absolute traction values for synthetic surfaces are satisfactory in comparison with natural turf, provided that shoes with the appropriate surfaces are employed. Synthetic surfaces by virtue of their constmction are to a degree directional, a characteristic which, when substantial, can significantly affect both player performance and ball roU. This effect is evident in a measurement of shoe traction in various directions with respect to the turf—pile angle. Some traction characteristics are directiy affected by the materials. 

Game-Related Properties. Eot some activities, such as miming and wrestdng, the only consideration is the direct impact by the player. Eot others, eg, tennis, baseball, or soccer, the system must also provide acceptable bad-to-surface contact properties. Important bad-response properties on the artificial surface ate coefficients of restitution and friction, because these direedy determine the angle, speed, and spin of the bad. 

Impact Properties. Artificial playing surfaces for moderate to heavy use must provide shock absorbency for player comfort and safety. This is achieved by iacorporation of a resiUent layer, usually a shock-absorbiag underpad. 

The relevance of photonics technology is best measured by its omnipresence. Semiconductor lasers, for example, are found in compact disk players, CD-ROM drives, and bar code scaimers, as well as in data communication systems such as telephone systems. Compound semiconductor-based LEDs utilized in multicolor displays, automobile indicators, and most recendy in traffic lights represent an even bigger market, with approximately 1 biUion in aimual sales. The trend to faster and smaller systems with lower power requirements and lower loss has led toward the development of optical communication and computing systems and thus rapid technological advancement in photonics systems is expected for the future. In this section, compound semiconductor photonics technology is reviewed with a focus on three primary photonic devices LEDs, laser diodes, and detectors. Overviews of other important compound semiconductor-based photonic devices can be found in References 75—78. 

The soft drink industry is dominated by two key players. The Coca-Cola Company and Pepsico. These two companies produce eight of the ten top soft drink brands and comprise over 72% of the soft drink market in the United States (Figs. 2 and 3). 

Polaroid introduced Polavision, a Super-8-mm instant motion picture system, in 1977 (97). Polachrome CS 35-mm sHde film followed in 1982 (98), and a high contrast version, Polachrome HCP, appeared in 1987. Each of the films comprises a very fine additive color screen and an integral silver image transfer film. The Polavision system, which included a movie camera and a player that processed the exposed film and projected the movie, is no longer on the market. The Polavision film was provided in a sealed cassette, and the film was exposed, processed, viewed, and rewound for further viewing without leaving the cassette (97). 

Although water injection is still used, dry control combustion technology has become the preferred method for the major players in the industrial power generation market. DLN (Dry Low NOx) was the first acronym to be coined, but with the requirement to control NOx without increasing carbon monoxide and unburned hydrocarbons this has now become DLL (Dry Low Emissions). 

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