Technology-based approach

In order to assess the target concentrations of air contaminants both human risk-based and technology-based approaches can be used (Fig. 6.7). The various approaches are dealt with in more detail elsewhere. F" ... 

Physical chemistry is known for its heavy use of mathematics, which can makes the subject seem abstract. Therefore, it is no surprise that mathematics ability has been found to be a good predictor of student success in physical chemistry (House 1995 Bers 1997 Nicoll and Francisco 2001). The emphasis on mathematics, combined with a traditional focus on the early development of thermodynamics and quantum mechanics, leads to the impression that physical chemistry is a theoretical science, with only tenuous connections to real science. However, making connections to concepts or applications that are known to or relevant to students can be difficult or impossible if attempted through a hands-on approach. Equipment costs and availability, time limitations, and expertise can all hinder such efforts. There again, a technology-based approach can provide a solution. 

Under the Federal Clean Water Act s National Pollutant Discharge Elimination System (NPDES) permitting program, two approaches exist for controlling pollutant discharges from individual and municipal waste water treatment facilities the technology-based approach and the water-quality based approach... 

In the absence of a practical, effective way of determining how much lead dust has been added to a carpet and whether it has been fully removed, EPA is adopting a technology-based approach for carpets that differs from the approach used for hard-surfaced floors, by requiring use of a HEPA vacuum with a beater bar. EPA is not aware of, and commenters have not identified, a practicable approach similar to the one EPA has adopted for floors as a basis to evaluate the results of the application of work practice standards to carpets. In the absence of such an approach, EPA believes the approach adopted in the final rule is the most effective, reliable approach available for minimizing potential lead-based paint hazards in carpets created by renovations. 

The Japanese program system AlPHOS is developed by Funatsu s group at Toyo-hashi Institute of Technology [40]. AlPHOS is an interactive system which performs the retrosynthetic analysis in a stepwise manner, determining at each step the synthesis precursors from the molecules of the preceding step. AlPHOS tries to combine the merits of a knowledge-based approach with those of a logic-centered approach. 

The content of a curriculum must be functional when dealing with societal activities necessary chemical concepts, skills and attitudes with respect to macro-micro thinking must be included. This can be derived from representative authentic tasks. The content of the curriculum should be considered as a chemical toolbox. The traditional content of the present chemistry curriculum, such as the stmcture of atoms, ionic theoiy, fundamental acid-base calculations, are not necessarily part of the chemical toolbox when addressing chemical and technological tasks. The validity of the toolbox (philosophical substmcture) is determined by the representative practices and tasks related to chemistry (cf need-to-know principle in context-based approaches). 

An additional example includes the intracellular transcription and translation of virally encoded genes during intracellular viral replication. In all such instances, the medical consequences of such inappropriate gene (over)expression could be ameliorated/prevented if this expression could be down-regulated. A nucleic-acid-based approach to achieve just this is termed antisense technology . 

The conversion of PS to SiOz by thermal oxidation was reported in 1971 by Watanabe and Sakai [Wa7]. Arita in 1978 [Ar3] and Unagami in 1980 [Uni] performed thermal oxidation experiments on PS, which a few years later led to an sil-icon-on-insulator (SOI) technology based on oxidized PS [Hoi, Iml]. Another approach to manufacturing SOI structures was developed in 1986 by Lin and coworkers [Lil], by growing a Si molecular beam epitaxy (MBE) film on PS and subsequent oxidation. However, a major drawback of PS-based SOI technologies is the need for windows in the Si film to carry out the oxidation of the underlying PS. 

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