旭硝子財団助成研究成果報告2018

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94Supachok Tanpichai95Sontipee AimmaneePreparation of Cellulose Nanofibers Isolated from Agricultural Wastes(Project 2017)Analysis of Electrical Energy Harvesting Using a Piezoelectric Laminated Belleville Spring(Project 2017)68旭硝子財団　助成研究成果報告（2018）locus. Lastly, a recombinant B. subtilis, designated strain BPJ06, which was designed to be able to express PEDVSME in both vegetative cell and spore, was generated by integrating the PrrnO-pgsA-PEDVSME gene into amyE locus of the strain BPJ05 chromosome. Western blot analysis and immunofluorescence staining confirmed a successful expression and spore surface display of CotB-PEDVSME. However, when expressed by vegetative cell, only cleaved products with low amount of PgsA-PEDVSME could be detected. Thus, antigen modification may be needed to make the antigen more stable in vegetative cell. This study reveals a strategy to generate recombinant B. subtilis that can express antigen in both cell stages and thus may enhance induction of antigen-specific immune response. A large amount of pineapple leaf fibers has been left as agricultural wastes after pineapple cultivation. Therefore, the aim of this research was to use these fibers as a raw cellulose material to prepare cellulose nanofibers using the steam explosion treatment without any usage of chemical solvents. The pineapple leaf fibers were treated with different conditions in terms of the steam pressure and treatment cycles. Results showed that the steam explosion treatment could reduce lignin and hemicellulose contents, and increase a cellulose composition in the treated fibers. The decreased lignin and hemicellulose contents resulted in higher thermal properties of the steam exploded fibers by 13°C, and increased degree of crystallinity. Moreover, a larger amount of the cellulose nanofibers fibrillated from the original fibers could be observed when the fibers were treated with the higher steam pressure or were steam exploded for several times. The as-prepared cellulose nanofibers from the pineapple leaf fibers could be beneficial for applications such as composites, cosmetics and packaging. This article presents a study of an energy harvesting from a smart Belleville spring composed of composite and piezoelectric materials. Electrical energy can be generated by employing direct piezoelectric effect. A total potential energy model including strain energy and electric enthalpy energy are developed in order to calculate the ordinary spring characteristic under quasi-static mechanical loadings, i.e. load-deflection relationship and the extraordinary spring electromechanical performance, namely electrical energy generated during snap-through buckling. This study focuses on the effect of geometric parameters that involve metastability of the composite spring on the harvested electrical energy. The numerical results show that snap-through buckling plays a very important role in the amount of energy generated, which can be eight times as much as that produced from a monostable spring at the same level of applied loads. The final outcomes could lead to the design guideline for energy harvesting from a smart composite Belleville spring.