Evaluation of quasi-isotropic plate and cylindrical shell fabricated with green composite sheets

Conventional fiber reinforced plastics (FRPs) have some problems in the case of disposal. Their combustion disposal discharges the carbon dioxide in the air because resins of FRPs are made of fossil fuel. In the case of disposal into the ground, these FRPs remain semi-permanently without decomposing. Therefore, green composites are now developed and are studied as one of less the environmental burden materials. In this study, two kinds of continuous green composite sheets, which were composed of Kenaf fibers or Linen fibers as reinforcement and biodegradable poly butylene succinate (PBS) resin as a matrix, were fabricated with a pultrusion molding. Since the PBS resin is a thermoplastic resin, the PBS/KENAF or PBS/LINEN composite sheets can be treated as intermediate materials such as Carbon Fiber Reinforced Plastic prepregs. In order to apply the PBS/KENAF or PBS/LINEN composite sheets to structural components, quasi-isotropic plates and cylindrical shells were fabricated and evaluated.     

In situ Raman spectroscopy analysis of local structure in dry gel for zeolite beta synthesis

To investigate faster crystallization of zeolite beta by the dry-gel conversion method, the local structure of the dry gel before synthesis was quantitatively evaluated using in situ Raman spectroscopy during the drying process. The dry gel prepared from Si and Al sources, and tetraethylammonium hydroxide solution was crystallized after several hours by the dry-gel conversion method. The conformational change of TEA⁺ cations was observed during the drying process by the deconvolution of the spectrum, and the conformational change was larger than that during the synthesis process. The rate of conformational change was increased with the drying temperature, and the apparent activation energy was estimated to be 68.2 kJ/mol. The generation and transformation of double three-membered silicate rings (D3Rs) and 4-2 type secondary building units (SBUs), which are essential for the crystallization of zeolite beta, were observed during the drying process. The transformation from D3R to 4-2 SBU in the dry gel during drying process could be confirmed quantitatively by the difference of the time variation for the amounts of these silicate building units estimated by in situ observation.     

Tetraphenylporphyrin Enters the Ring: First Example of a Complex between Highly Bulky Porphyrins and a Protein**

Tetraphenylporphyrin (TPP) is a symmetrically substituted synthetic porphyrin whose properties can be readily modified, providing it with significant advantages over naturally occurring porphyrins. Herein, we report the first example of a stable complex between a native biomolecule, the haemoprotein HasA, and TPP as well as its derivatives. The X-ray crystal structures of nine different HasA-TPP complexes were solved at high resolutions. HasA capturing TPP derivatives was also demonstrated to inhibit growth of the opportunistic pathogen Pseudomonas aeruginosa. Mutant variants of HasA binding FeTPP were shown to possess a different mode of coordination, permitting the cyclopropanation of styrene.