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The finite element FE analysis of quasi-static indentation event of various nose shape rigid indenters into woven fabric composite with carbon fiber as reinforcement has been performed and discussed in detail. It was found that indenter nose shape has large influence in terms of absorbed energy, indentation at failure and damage area. The FE software, ABAQUS® was employed to simulate quasi-static response of woven composite unit cell. Exhaustive parametric studies have been conducted with an aim to analyze the effect of change in indenter geometry on the indentation response of the woven composite unit cell. The developed FE model for the purpose of validation was compared with available experimental results and was found to be in reasonably good agreement. The failure morphologies, damage shape and damage size were evaluated, compared and deeply discussed for different nose shape indenters. Largest damaged areas were observed for flat and truncated indenters while the smallest for the conical one. [ABSTRACT FROM AUTHOR]

Textile composite are used extensively in aerospace as they offer a 3D reinforcement in a single layer providing better mechanical properties in both in-plane and transverse directions. This paper reports on the mechanical behavior of a plain weave textile fabric under the compressive loading. Unit cell geometry of the plain weave fabric structure is identified and its model is created using TexGen geometric modeling scheme developed by the University of Nottingham (U.K.). Later on its mechanical behavior is predicted using finite element modeling (FEM) based simulation software ABAQUS® incorporating a transversely isotropic material law. Strain energy of the developed model has been compared with that of the published results and shows very good agreement. The analysis indicated that transverse-longitudinal shear (TLS) modulus plays an important role in characterizing the behavior of the woven fabric under compression, while the friction between the yarns and longitudinal stiffness has less significant influence on compaction behavior. In order to ascertain the effectiveness of the developed model, exhaustive parametric studies have also been conducted to investigate the effect of transverse-longitudinal shear modulus on some of the important parameters such as artificial strain energy, external work, frictional dissipation, internal energy, kinetic energy, strain energy and total energy of the model. The developed model has the capacity to predict and simulate the behavior of variety of fabric architectures based on their constituent yarn properties under various regimes of service loads. [ABSTRACT FROM AUTHOR]

In this article, we are discussing the synthesis and characterization of poly(vinyl alcohol)-based multiwalled carbon nanotubes (MWCNT) hydrogels and its evaluation studies for toxic metal ion removal. The functionalized MWCNT serves the purpose of toxic ion adsorbent and PVA is functioning as the substrate for the stable dispersion of MWCNT. We have carried out the evaluation studies using lead ions Pb(II) in batch experimental mode. The percentage removal of Pb(II) was examined by varying experimental conditions viz. dosage of adsorbent, pH of the solutions, and contact time. It was found that 80% removal was achieved under optimal conditions. This adsorption potential is found to be far better than that of simply dispersing MWCNT in water. The equilibrium adsorption follows the Freundlich adsorption isotherm model. After Pb(II) adsorption, the ions were easily desorbed using a high pH solution, completely regenerating for further removal process. This novel approach of dispersing MWCNT in hydrogel and their re-use after desorption is expected to have promising outcome in the water purification application. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 [ABSTRACT FROM AUTHOR]

Sunfish specimens (genus Lepomis) collected from Pinehurst Lake, Ontario, Canada, were identified as bluegill (L. macrochirus), pumpkinseed (L. gibbosus) and their hybrids. Hybridization was studied on the basis of the constants of cross-sectional allometry as, to the best of our knowledge, no attempt has ever been made to study hybridization quantitatively from the relative growth aspect. Two sets of data—one on the pair Y1/X (head length/standard length) and the other on the pair Y2/X (body depth/standard length)—were analysed, with the following objectives: (i) A statistical method of analysing hybrid index based on cross-sectional allometry was first presented and then Y1/X-data analysed by this method, and (ii) data Y2/X were analysed to show that in some particular situations analysis for hybridization by methods other than the hybrid index approach may be more appropriate. Results of the analyses were discussed. [ABSTRACT FROM AUTHOR]

Necessity of a thorough study of hybridization, following the breakdown of reproductive isolating mechanisms between naturally occurring populations, has been felt by biologists in general and ichthyologists in particular. In this connection a formula for ‘hybrid index’ developed mainly by Hubbs & Kuronuma (1942) and Hubbs, Hubbs & Johnson (1943) has widely been in use, to test the assumption of hybridity and to study the mode of inheritance. Misra, Bateson & Keenleyside (1970) gave statistical methods of analysing hybrid indices estimated for characters of the ‘continuous’ type, and also provided a numerical example. Recently Misra (1971) gave a method of doing similar analysis for hybrid indices estimated for meristic characters, but no example was provided, as data were not available to him. This paper presents a study of hybridization in the sunfishes (genus Lepomis) of Pinehurst Lake, Ontario, Canada, based on the number of scales below the lateral line; the primary purpose of the study is to show the complete computational procedure involved in the application of the method of Misra (1971), so that those users of the method who are mainly interested in the applied aspects of the method, can bypass the mathematics easily. [ABSTRACT FROM AUTHOR]