Primary structural applications

Evans, R.E. and Masters, J.E. (1987). A new generation of epoxy composites for primary structural applications materials and mechanics. In Toughened Coinpo.sites, ASTM STP 937 (N.J. Johnston ed.). ASTM. Philadelphia, PA, pp 413-436. 

Stressed skin panels of floors, walls, roofs, box beams and trusses are examples of primary structural applications where the connection is expected to carry static and dynamic design loads without failure. 

T. E. Palm, Design, fabrication and test of composite sandwich panel component for airframe primary structural applications, in Proc. 10th International Conference on Composite Materials, A. Poursartip and K. Street, eds., Woodhead Publishing Ltd., Abington-Cambridge, UK, Vol. Ill, 677-684 (1995). 

For primary structural applications, which are load bearing firstly the strength of the material should be able to support at least in-plane loads, with proper stiffnesses (if bending and shear forces are involved), and mechanical property requirements are... 

The aerospace field is a broad one and has a complex history. A comprehensive review of structural adhesive applications on currently flying aerospace vehicles alone could fill its own book. Hence this chapter will concentrate on the aerospace commercial transport industry and its use of adhesives in structural applications, both metallic and composite. Both primary structure, that is structure which carries primary flight loads and failure of which could result in loss of vehicle, and secondary structure will be considered. Structural adhesives use and practice in the military aircraft and launch vehicle/spacecraft fields as well as non-structural adhesives used on commercial aircraft will be touched on briefly as well. 

Due to the fact that the primary structure of the Ultrahydrogel packing is a hydroxylated methacrylate, the interaction of many polar polymers with the packing is minimized easily. The presence of small amounts of anionic functions on the surface of the polymer usually requires the addition of salt to the mobile phase. A common mobile phase for many applications is 0.1 M NaN03. Detailed eluent selection guidelines are given in Table 11.6. 

Thus, based on material applications, the following polymers are important natural rubber, coal, asphaltenes (bitumens), cellulose, chitin, starch, lignin, humus, shellac, amber, and certain proteins. Figure 4 shows the primary structures of some of the above polymers. For detailed information on their occurrence, conventional utilization, etc., refer to the references cited previously. 

Since nanoscale metal nanoparticles are applicable to a number of areas of technological importance, the nano-structured materials chemistry will occupy much attention of scientists. It is certain that controlling the primary structures of metal nanoparticles, that is, size, shape, crystal structure, composition, and phase-segregation manner is still most important, because these structures dominate the physical and chemical properties of metal nanoparticles. Now the liquid phase synthesis facilitates the precise control of the primary structures. 

Gorman, J.J., Corino, G.L., and Mitchell, S.J. (1987) Fluorescent labeling of cysteinyl residues. Application to extensive primary structure analysis of protein on a microscale. Eur. J. Biochem. 168, 169-179. 

Interpolymer complexes possess unique physical and chemical properties which are different from those of the initial components and have found applications in technology, medicine, and other fields (Bekturov and Bimendina, 1981). The unique properties of the complexes arise due to a higher degree of molecular ordering that is a result of secondary binding forces. The resulting secondary structures are dictated primarily by the primary structure (monomer sequence), solvent, and temperature of the system. Interpolymer complexes can be classified based on the nature of the secondary binding forces as ... 

For recycling uses, degradable polyesters are desirable for relatively small mass applications, such as glues, thin coatings or labels, in order to facilitate the rapid cleaning of the primary structure for recycling. These applications may be rigid structures such as plastic containers or modifiers for paper products. 

Electrophoresis as a method of study of molecular differences has its limitations. It can demonstrate variation of the primary structure only if it changes migration in the electric field, which is the case only for a fraction (about one third) of the conceivable variants the others are electrophoretically silent. On the other hand, different amino acid replacements may cause the same electrophoretic variant and thus be indistinguishable. Furthermore, the whole method was applicable only to selected types of proteins and could not yield a genetically satisfactory overview. 

In recent years, C-NMR spectroscopy has found extensive use in studies on carbohydrate polymers, in some series overshadowing the importance of H-NMR spectroscopy. Applications range through determination of primary structure, analysis of mixtures, monitoring of chemical and enzymic transformations or of chelation reactions, and studies on conformational change. Measurements of coupling are utilized in determining the... 

Because of the low shrinkage and the excellent adhesion, mechanical properties, and chemical resistance, epoxies have a vast variety of applications, such as adhesives (epoxyamine), structural materials in high-performance composites (epoxy-amine) (e.g., aircraft primary structure), filament wound pressure vessels, and so forth. The main disadvantage of... 

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