Composite material patching

Heslehurst. R. B.. Baird. J. P.. Williamson. H. M.. and Clark. R. (1993). Portable holographic interferometry testing system Application to crack patching quality control. Proc. of the Inter. Conf. on Advanced Composite Materials, pp. 687 692. 

Other important variables are patch structure (composite material, layup and thickness according to the analytical results) and fastener stiffness which should be determined by test or analysis and subsequently used in the analysis of the overall repair. Fastener tensile and shear stresses should be determined as to their adequacy for static strength and for fatigue loading. Fastener selection is addressed in Chapter 11. 

Cheng P, Gong XJ, Aivazzadeh S. Design and optimization of composite laminates repaired by external patches. In 18th international conference on composite materials, Korea 2011 August, pp. 21—6. 

Koh Y, Jang S, Kim J, ICim S, Ko YC, Cho S, Sohn H (2008) DBR PSi/PMMA composite materials for smart patch application. Colloids Surf A Physicochem Eng Asp 313-314 328 Krepker MA, Segal E (2013) Dual-functionalized porous Si/hydrogel hybrid for label-free biosensing of organophosphorus compounds. Anal Chem 85 7353 ICruk M, Dufour B, Celer EB, Kowalewski T, Jaroniec M, Matyjaszewski K (2008) Grafting monodisperse polymer chains from concave surfaces of ordered mesoporous silicas. Macromolecules 41 8584... 

When comparing patch tests, it is surprising to see how many different delivery systems have been developed and are still used to apply products to the skin. These so-called chambers vary in size, the volume of their content, their composition material, and their more or less occlusive character. This latter factor has been shown to be extremely influential in determining the overall skin reaction [59]. Furthermore, the tape used to keep the chambers on the skin also has its importance if the skin reacts to the tape, skin will also become more responsive to the test products which are in the chambers. This is a variable too often underestimated by many experimentators. 

Madelpech, P., Juaneda, S., Pradels, M., 2009. Bonded composite patch to repair metallic structures fatigue behaviour of a dishond. In Proceeding of 17th International Conference on Composite Materials, July. 

A host of bioadhesive controlled release systems have been proposed in recent years. Among the most commonly studied applications of bioadhesive materials is the area of buccal controlled delivery [408], The buccal delivery of small peptides from bioadhesive polymers was studied by Bodde and coworkers [409], and a wide range of compositions based on poly(butyl acrylate) and/or poly(acrylic acid) gave satisfactory performance. Bioadhesive poly(acrylic add)-based formulations have also been used for oral applications [402,410] for the sustained delivery of chlorothiazide [410] and for a thin bioadhesive patch for treatment of gingivitis and periodontal disease [411]. Other bioadhesive applications of polyelectrolytes include materials for ophthalmic vehicles [412,413], and systems for oral [410,414,415-419], rectal [420,421] vaginal [422] and nasal [423] drug delivery. 

In terms of overall composition, traditional transdermal patch systems have changed little in the past few years. The modifications that have been made are, for the most part, refinements of the materials used in their construction (Table 3). This is the case for the soft patches that consist of thin flexible films containing a known amount of drug. The soft patch is designed to be flexible and to conform to various body flexures. 

If the analyte occurs in clumps or patches, the sampling strategy becomes more complicated. The patches can be considered as separate strata and sampled separately. If bulk materials are segregated or stratified, and the average composition is desired, then the number of samples from each stratum should be in proportion to the size of the stratum. 

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