TECHNOLOGY DEVELOPMENT REQUIREMENTS

Once the inhalation exposure questions have been identified, the specifications for each personal monitor must be determined and the monitor must be validated for the contaminant being measured. Table I, updated from Samet et al. (14), identifies currently available personal monitors, and Table II, taken from an Environmental Protection Agency (EPA) report (15), shows the projected needs in the 1990s. There are a number of opportunities for research on personal monitors Table II indicates that relatively few commercial units are currently available for either particulate or gas-phase species. For compounds such as polycyclic aromatic hydrocarbons (PAHs), a two-stage sampler is required because some PAHs exist simultaneously in the gaseous and particulate phase (16). Consequently, research must be ranked with respect to the significance of the air pollution problem, and the technological developments required to provide reliable samplers must be defined. 

Fusion. Molten salts are a leading candidate for cooling the first wall of fusion energy machines. Hence there are similar technological development requirements for this program. 

Secondary Lead. The emphasis in technological development for the lead industry in the 1990s is on secondary or recycled lead. Recovery from scrap is an important source for the lead demands of the United States and the test of the world. In the United States, over 70% of the lead requirements are satisfied by recycled lead products. The ratio of secondary to primary lead increases with increasing lead consumption for batteries. WeU-organized collecting channels are requited for a stable future for lead (see BATTERIES, SECONDARY CELLS Recycling NONFERROUS METALS). 

Heat Recovery and Seed Recovery System. Although much technology developed for conventional steam plants is appHcable to heat recovery and seed recovery (HRSR) design, the HRSRhas several differences arising from MHD-specific requirements (135,136). First, the MHD diffuser, which has no counterpart ia a conventional steam plant, is iacluded as part of the steam generation system. The diffuser experiences high 30 50 W/cm heat transfer rates. Thus, it is necessary to allow for thermal expansion of the order of 10 cm (137) ia both the horizontal and vertical directions at the connection between the diffuser and the radiant furnace section of the HRSR. 

The disclosure requirement provides that the patent be a teaching document, and enhance the breadth of knowledge held by the pubHc. By increasing the breadth of knowledge within the pubHc sector, a given patent faciHtates further technological development and growth, which in turn results in the issuance of additional patents. 

Future technology developments in paraffin alkylation will be greatly influenced by environmental considerations. The demand for alkylate product will continue to increase because alkylate is one of the most desirable components in modern low emission gasoline formulations. Increased attention will be focused on improving process safety, reducing waste disposal requirements, and limiting the environmental consequences of any process emissions. 

The most efficient processes in Table I are for steel and alumintim, mainly because these metals are produced in large amounts, and much technological development has been lavished on them. Magnesium and titanium require chloride intermediates, decreasing their efficiencies of production lead, copper, and nickel require extra processing to remove unwanted impurities. Sulfide ores produce sulfur dioxide (SO2), a pollutant, which must be removed from smokestack gases. For example, in copper production the removal of SO, and its conversion to sulfuric acid adds up to 8(10) JA g of additional process energy consumption. In aluminum production disposal of waste ciyolite must be controlled because of possible fiuoride contamination. 

Physical realizability is often the most difficult of the above three corollary questions to answer. In general, to answer this question it is necessary to know 1) whether the materials and components required by the engineering design are available and 2) whether the manufacturing (and/or fabrication) techniques and skilled craftsmen needed to fabricate the product are also available. These two assessments are difficult to make because they often involve the projection of future technological developments. Technological developments usually do not occur according to schedule. 

Although a clear objechve, extreme AO at visible wavelength will certainly require more technology development, delaying its implementation to later stages. MOEMS (Micro-Opto-Electronical Mechanical devices) constitute a promising avenue, however not the only one (see Ch. 10). Piezo-stacks, combined with thin shells and moderate segmentahon in a pupil, may offer a more conservahve baseline. 

In conclusion, adaptive optics is the only control system that still requires extensive but not unreasonable technology development. The project is cautiously allocahng more than 10% of its total budget to adaptive optics. Last but not least, an aptly named MAD (Mulh-conjugate Adaptive optics Demonstrator) instrument is currently under construction at ESO to demonstrate the... 

As a practice-based subject, the formation and development of tribology have always been associated with the requirement from society and technology development. Tribology experienced several different stages in its history. Its developing process indicates an obvious trend of integration and combination of multi-scientific subjects in a multi-scale nature from macroscopic dimension to nanometre. 

The thickness of the active layer is about 100-300 nm, while the source-drain distance (channel length) amounts to a few micrometers. The channel length is determined by the current requirements and usually exceeds 10 /xm. Other manufacturing schemes as well as alternative stmctures are described elsewhere [619, 621]. Technology developments for the next generation TFTs that are to be used for high-resolution displays have been summarized by Katayama [627]. 

With the increasing costs of new product development, industry concentrates on specific materials and chemistries, and on meeting specific regulatory requirements. Technological developments (Table 10.6)... 

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