Miscellaneous Composite Structures

The best today s composite structure with 2-2-0 (air cavity) connectivity - Moonie - uses flextensional principle (Dogan et al. 1997 Fernandez et al. 1998 Xu et al. 1991 Zhang et al. 1999). Composite is made from the ceramic disc (PZT ceramics) and from two metallic plates (e.g. brass) with small air cavities (Fig. 7.29) glued together. By means of the metallic caps the hydrostatic pressure on major transducer surface is transferred to the longitudinal tension of the ceramic disc. This stress transfer will improve significantly the effective hydrostatic piezoelectric coefficient of the structure due to the different signs of ( 33 and d-n coefficients in PZT ceramics. The effective hydrostatic coefficient d could be further tuned in the value by the 

Another example of the piezoelectric composite stmctures either with 3-0 or 3-1 connectivity is the miniature piezoelectric hollow sphere transducer (Alkoy et al. 1997 Fernandez et al. 1996 Meyer et al. 1994). Technique allowing for the manufacturing of the extremely small thin-walled bubbles (1-6 mm in diameter and 80 xm wall thickness) from PZT slurry has been developed. Such bubbles could be electroded and poled either radially (3-0 coimectivity) or cylindrically (3-1 connectivity) if the hole is drilled through the bubble (Fig. 7.30). Composite stracture vibrates in radial (breathing) or in thickness mode. Effective hydrostatic piezoelectric coefficient as well as significantly enhanced with 

Similar to 2-2 composite more comphcated geometiy was reported for 3-1 connectivity pattern (Zhang et al. 1996). Honeycomb PZT stracture was manufactured by the extrusion technique. Consequently the inner faces are electroded and the voids are either hlled by the polymer (which results in stiffer stmcture) or left empty and end-capped by the additional polymer plate. This configuration allows for higher effective hydrostatic figure of merit. Values as high as  

50000 X 10 m N were reported on the samples (Zhang et al. 1996) however the stmcture is less resistant to the mechanical damage. 

Also 3-3 composites were reported (Bowen et al. 2001). Such stmctures exhibit better poling properties due to the piezoelectric phase cormected in all 3 dimensions however the technology of making it is more comphcated. 

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In Secs. 13.2-13.3 the principles of toughening of thermosets by rubber particles, and the role of morphologies, interfacial adhesion, composition, and structural parameters on the toughening effect are analyzed. Section 13.4 is devoted to the use of initially miscible thermoplastics for toughening purposes. The effect of core-shell rubber particles is discussed in Sec. 13.5 and, in Sec. 13.6, miscellaneous ways of toughening thermosets (liquid crystals, hybrid composites, etc.), are analyzed. 

In the Landolt-Bdmstein data collection, ferroelectric and antiferroelectric substances are classified into 72 families according to their chemical composition and their crystallographic structure. Some substances which are in fact neither ferroelectric nor antiferroelectric but which are important in relation to ferroelectricity or anti-ferroelectricity, for instance as an end material of a solid solution, are also included in these families as related substances. This subsection surveys these 72 families of ferroelectrics presented in Landolt-Bornstein Vol. III/36 (LB III/36). Nineteen of these families concern oxides [5.1,2], 30 of them concern inorganic crystals other than oxides [5.3], and 23 of them concern organic crystals, liquid crystals, and polymers [5.4]. Table 4.5-1 lists these families and gives some information about each family. Substances classified in LB 111/36 as miscellaneous crystals (outside the families) are not included. 

The textile industry still constitutes one of Europe s most relevant industrial sectors for both the economy and society. The very latest trend in textile and linked industries is to create miscellaneous new products which possess the potential of interacting with the surrounding environment through active feedback. This class of new interactive material is termed intelligent textile structures or smart textiles. In order to make interactive fabrics available at the industrial level it is necessary to apply a multidisciplinary approach. The route to develop and optimise multifunctional material involves in the same way textile engineering and colloid chemistry. The complexity of the production process for modern composite materials is a real challenge to textile engineering but the fundamentals of interfacial and colloid science are indispensable to characterise and control the... 

There are a number of books available that deal with lipids and their structures, and the author has found those cited to be of particular value [319,367]. Literally thousands of papers have appeared over the last 25 years detailing the structures and compositions of lipids from particular tissues and species, as determined by modem chromatographic methods, but there appears to have been very little effort to collate and critically compare these data in any systematic way, or to relate the compositions of lipids to their functions. Among other consequences of this, there remain anomalies and gaps in our knowledge. Comprehensive accounts of the lipids of the tissues of ruminant animals [162], tissue and membrane phospholipid compositions [395,970] and triacylglycerol compositions [125,553,686,824] have appeared, however, and there are miscellaneous reviews of the compositions of specific lipid classes or tissues in the literature. The author recently attempted to summarise the essential features of lipid composition in a succinct manner [168]. This cannot be repeated here, and a brief summary only of lipid structure and composition follows. 

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