Fiber composition, paper testing

In the second half of the 1990s, mainly Park et al. from Korea published several papers on BF-reinforced composites. They tested polycarbonate (PC)" and epoxy resin (EP) based polymer composites with the methods of single fiber fragmentation and acoustic emission. It was found that in the case of PC matrix composite (when aminosilane was used as a treating agent), the number of acoustic events correlated well with the value of the interfacial shear strength determined from the fragmentation tests. 

Standard analytical procedures were used to evaluate the composition of ingredients. Of the proximate analyses, nitrogen, lipids, and crude fiber were measured by American Oil Chemists Society (AOCS) methods (12) and moisture and ash by Association of Official Analytical Chemists (AOAC) methods (13). Amino acid analyses were performed by gas-liquid chromatography (14) except for tryptophan, which was analyzed colormetrically Tl5). In addition to these assays, certain tests of ingredient safety or spoilage were also performed, which space does not permit to be reported in this paper, to assure that ingredients met accepted standards for food safety (16). 

The laminate construction in FRP parts can have an effect on flame spread and smoke test results. A study was conducted by Stevens15 and published in the proceedings of Composites 2007 conference. This study looked at how glass fiber content and panel thickness affected the ASTM E-84 flame spread index (FSI) and smoke developed index (SDI). The effects of fiber content and thickness on cone calorimeter results were also evaluated. Another study was conducted by Dempsey16 looking at the effect of glass content in several fire tests, and in this paper, he also found a correlation between the FR performance and glass content. 

Numerous studies have been made of the mechanical properties of fibrous composites these include recently published papers on impact properties by Izod (1,2, 3,4) and Charpy (5,6) and drop weight (7) tests. We reported the Charpy impact fracture behavior of various glass-polyester composites regarding the effects of temperature (8,9,10), specimen size (8), and fiber orientation (10). This paper describes the effects of the tough-brittle transition in the impact behavior of glass-polyester composites which occurs with a variation of temperature and specimen size. 

For an IND, the post-det world is predominantly an extrapolation of methods and measurements from radiochemical and other diagnostics developed during nuclear weapons testing. Assays are typically made of residual actinide species, major and high-value-minor fission products, and induced activation products. These data allow inferences or conclusions about device composition, design, performance, near environment, and other characteristics. Analyses of a post-det RDD would also have roots in historic radiochemistry, and would be supplemented by conventional forensic analyses. The latter would include high-explosive residues, perpetrator-specific specimens (DNA, hair, latent prints), and other possible evidence (tool marks, fibers, paints, tapes, paper, etc.). The problem of contaminated evidence (conventional criminalistics examinations of radioactively tainted exhibits) is likely most acute for a post-det RDD, as a successful IND should vaporize any such specimens proximate to the device. 

In this paper, the thermal and mechanical characteristics of balsa wood and balsa wood laminates are reviewed, and it is shown that "composite" mechanics that have been developed for the class of synthetic fiber-reinforced plastic (SFRP) materials may be useful for describing the density and direction—dependent mechanical properties of balsa wood in bulk or laminated form. It may be asked whether such advanced analytical methods, perhaps combined with specially developed methods of test, could be used effectively towards developing more applicable QA/QC procedures that will clearly qualify balsa wood as a structural material in applications where strictest code compliance is a necessity. This question has prompted the following review and discussion. 

Carbon fiber-epoxy composites (A) Solvent wipe (MEK, toluene, trichloroethylene, etc.) (B) Use peel ply during initial curing. (C) See Ref. 15 for the effect of abrasion procedures. See also Refs. 16 and 17. (A) Lightly abrade with medium-grit emeiy paper. Avoid exposing the reinforcing fibers. (A) Wipe with solvent. Check surface by water break test. Retreat, if necessaiy. 

For the majority of composites and their intended applications, the transfer of stress from the point of application throughout the remainder of the composite structure is by a shearing mechanism. The interface between fiber and matrix therefore, plays a major role. This paper examines the drawbacks from conventional micromechanical testing of model composites and introduces the benefits of fragmentation testing of aramid fibers in a thermoplastic elastomer matrix using Raman spectroscopy. Accurate and precise measurements of the interfacial shear strength between fibers and matrix are attainable. 

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