Biologies composition

Wool fibers have a very complex morphological stmcture. They can be considered as biological composite materials, in which the various regions are both chemically and physically different (87). Fine wool fibers contain two types of cell those of the internal cortex and those of the external cuticle. 

Womiloju TO, Miller JD, Mayer PM et al (2003) Methods to determine the biological composition of particulate matter collected from outdoor air. Atmos Environ 37 4335-4344... 

Another interesting approach is to use nanofiber scaffolds as a crystallization matrix to mimic biological composites. Xia and coworkers were able to produce meshes with a gradient of calcium phosphate content to mimic the tendon-to-bone insertion site [206], The variation in composition led to an interesting spatial gradient in stiffness of the scaffold. This was also reflected in an activity gradient of seeded mouse preosteoblast cells. 

Assembly and mineralization processes in biomineralization strategies for forming biological composite materials... 

Wood can be considered as a biological composite of hollow tubes of cellulose fibers held together by a lignin matrix gluing material. Liquids are transported up and down the trees through the tubular plumbing system. About 90 percent of the wood tissue of softwood trees consists of fiber tracheid cells for liquid conduction and support. The hardwood trees evolved after the softwoods and have specialized water conduction cells called vessels. 

In the first section of this volume we examine the fundamentals of structure at the level of the overall composite, as well as the properties of its components. The starting materials of food derive from living biological systems, whose mechanical properties have been studied in their own right. Vincent explores the extent to which biological composites can be related to other natural and manmade composites, and emphasises the difference between the properties of components (fibres and matrix) and the structure itself This engineering approach to biological structures, whether natural or fabricated, shows the fundamental difference in the materials science approach, compared with the former recipe approach to food manufacture. 

To complete a mass balance on a chemical within the control volume, internal consumption, production, and storage of the chemical also must be quantified. In some cases source and sink strengths can be estimated based on knowledge of chemical and biological composition and physical attributes of the lake. If the lake is well mixed, storage of the chemical in the lake control volume at a given time can be estimated as the product of the chemical concentration in the lake water and the total volume of water in the lake. 

Khripounoff, A., Vangriesheim, A. Crassous, P., Segonzac, M., Colaco, A. Desbruyeres, D. and Barthelemy, R. (2001) Particle flux in the Rainbow hydrothermal vent field (Mid-Atlantic Ridge) Dynamics, mineral and biological composition. Journal of Marine Research, 59, 633-656. 

The investigation of incubation effects, i.e., that the optical, chemical, and mechanical properties of a (transparent) material can be changed during repetitive illumination of the same spot without ablation, is rather difficult because of the complicated surface structure of a biological composite material. It can be stated that one femtosecond laser pulse at F0=2.0 J cm-2 (roughly three times Fth) applied to healthy human enamel led to minor ablation (Fig. 32a). Five pulses of the same fluence resulted in a crater with a depth of 2-3 pm (Fig. 32b). The shape of the excision is well defined, and no cracks could be observed. 

Wastes and by-products from agricultural and food processing contain many potential useful bioactive compounds. It is important to determine the presence and solubility of these compounds in SC-CO2 before designing an industrial extraction plant. The objective is often to use the extracts for food/feed, pharmaceutical or cosmetic purposes. Sample preparation is particularly difficult because of the heterogeneity of the possible discarded materials in terms of chemical, physical and (micro)biological composition. 

Man-made composites fall into three broad classes, depending on whether the main part of the composite, the matrix, is a polymer, a metal or a ceramic. Often, but not always, the composite combines materials from two classes, as in glass-fibre-reinforced plastics. However, the most widely used composite material, concrete, is a ceramic -ceramic composite. The most important classes of artificial composite are described below. The mechanical properties of composites are discussed in Section 10.4. Biological composites are very varied and will not be considered here. 

The MR spectra per se can be used as a fingerprint to detect temporal or spatial changes in the chemical and biological composition of the sediment samples. The MR spectra can then be used for optimal selection of samples for further detailed analysis by other chemical or biological means. This is in line with the approach in which NIR... 

Jeronimidis, G. 1991. Learning from nature biological composites. Proceedings of Inaugural European Semirmr, Arche de la Defense, Paris. 

Raabe D, Romano P, Sachs C et al (2006) Microstmcture and crystallographic texture of the chitin-protein netwrak in the biological composite material of the exoskeleton of the lobster Homams ameiicanus. Mater Sci Eng A 421 143—153... 

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