Modem composite technologies

Infrared spectroscopy was widely used in the second half of the 20th century, and this technique has allowed some advances to be made in awareness of functionalities in, and of complexes formed by, humic molecules. However, the greatest advances in determinations of functionalities, in aspects of compositions and structures, and now in aspects of humic interactions have been made since the introduction of solid-state 13C NMR spectroscopy (Wilson, 1987 Malcolm, 1989). Chapter 15 in this book (by Simpson and Simpson) has reviewed in detail the applications of NMR in the solid and liquid states to studies of compositions and interactions of NOM. We now have a good indication of the types of functionalities that compose HS, and combinations of modem NMR technologies and principal component analysis (PCA) techniques allow us to deduce the origins of some of the functionalities (Novotny et al., 2007). 

Investigations to date of the charge distribution on the HTSC/ionic electrolyte and HTSC/semiconductor (p- and n-) interfaces [145,147], and also similar studies of the HTSC/conducting polymer type of composition [28,50], relate directly to fundamental aspects that arise in modem electronics technology [164]. Of particular interest is analysis of the so-called proximity effect, a sharp increase in metal conductivity as a result of its contact with a superconductor. 

However, functional foods are not the exclusive preserve of modem food technology. The concept implies the recognition and promotion of the positive health properties of a food product, traditional or novel, and thus could include a variety of conventional foods (e.g. fermented milk drinks and yoghurts) as well as compositionally enhanced foods. 

Because of this continued emphasis on adhesive bonding technology development over the years, the airframes of modem front-line aircraft such as the B-2 bomber and the F-117 and F-22 fighters are largely structurally bonded advanced composites. They tend to be comprised of materials that are more advanced (expensive) than commercial aircraft such as carbon and boron fiber reinforcements with cyanate esters, bismaleimides, polyimides or other high-temperature resin matrices and adhesives. 

As described earlier, concerns around water and air pollution have transformed landfill technology. Figure 17.4 is an illustration of a modem lined landfill with a gas recovery system, leachate collection and treatment, a cap to prevent rain water entry, and ground water monitoring to confirm the integrity of the liner. The composition of landfills have been characterized by various garbologists and... 

As a result of the type approval legislation manufacturers have been required to develop increasingly effective emission-control technologies, and these were described earlier in this chapter. Table 3 provides an overview of the different devices which are typically required for light-duty diesel vehicles in each Euro category. In modem vehicles various elements are used in combination, and these have different effects on the properties and composition of the exhaust gas. 

The technology to fabricate ultrathin high-performance membranes into high-surface-area membrane modules has steadily improved during the modem membrane era. As a result the inflation-adjusted cost of membrane separation processes has decreased dramatically over the years. The first anisotropic membranes made by Loeb-Sourirajan processes had an effective thickness of 0.2-0.4 xm. Currently, various techniques are used to produce commercial membranes with a thickness of 0.1 i m or less. The permeability and selectivity of membrane materials have also increased two to three fold during the same period. As a result, today s membranes have 5 to 10 times the flux and better selectivity than membranes available 30 years ago. These trends are continuing. Membranes with an effective thickness of less than 0.05 xm have been made in the laboratory using advanced composite membrane preparation techniques or surface treatment methods. 

The modem technological needs of stmctural materials are not fulfilled entirely by these two types of materials. There is also a need for materials that exhibit properties in between cement and sintered ceramics. That need can be met by CBPC matrix composites—materials that are produced like cements at ambient or at slightly elevated temperatures, but exhibit properties of ceramics. These composites are attractive for many stmctural applications, including architectural products, oil-field drilling cements, road repair materials that set in very cold environments, stabilization of radioactive and hazardous waste streams, and biomaterials. 

The interaction of light with matter has fascinated people since ancient times. The color of an object is the result of this interaction. In modem terms, this interaction is described as spectroscopy. In this chapter, how the optical properties of a material are the result of its chemical composition and stmcture are examined. Several examples of technologically relevant applications are then presented of the manipulation of the optical properties to achieve a desired performance. 

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