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Abstract: The diffusion process of deuterated water (D2O) in washi (Japanese traditional paper) was investigated by means of a deuterium exchange method and Fourier-transform near-infrared (FT-NIR) transmission spectroscopy. The samples were the modern (AD 2003) hand-made washi and those from an archival collection of cultural artifacts (AD 1791 and 1615). Four absorption bands were identified in the NIR spectral range from 7200 to 6000cm−1 which are due to OH groups in the amorphous, semi-crystalline and two types of crystalline regions of cellulose. The accessibility of D2O increased with decreasing state of order of cellulose, and the saturation accessibility increased with the age of the samples. It was suggested that during aging hemicellulose, which forms a composite with cellulose in paper, was progressively hydrolyzed, resulting in the expansion of inter-molecular distance between cellulose chains. The oldest sample showed a low diffusion rate compared with the others. SEM observation of the textile structures indicated that the oldest sample had two layers due to beating. It was estimated that the tight surface layer blocked the diffusant in the initial stage of the diffusion process. [Copyright &y& Elsevier]

Abstract: Cellular structures currently applied in various engineering fields are mainly made of metals and papers. To engineering design textile composite cellular structures, in this paper, comparisons of various essential structural parameters affecting energy absorption and deformation are carried out. These parameters include the opening angle, the cell-wall length, the cell-wall thickness, the bonded cell-wall length, and the bonded cell-wall thickness. The structure geometries are created by in-house computer package which exports IGES files. Two-dimensional finite element analyses are conducted by MSC.Marc Mentat 2001 which imports these IGES files to numerical calculation. Orthotropic mechanical properties of the textile composite cellular structure laminate are applied for the finite element analyses. It is found that the opening angle, the cell-wall length and the cell-wall thickness affect significantly energy absorption and deformation. Strain energy density concentrations appear very seriously around the cell corners during quasi-static impact. [Copyright &y& Elsevier]