A nonapeptide with an Ala–(HO)Gly–Ala sequence has been synthesized via condensation of appropriately protected tripeptide units. 1H NMR and CD spectral data indicate that the nonapeptide has a disordered structure in DMSO and water. The peptide forms a 1 : 3 complex of iron(III) with hydroxamate groups at neutral pH when mixed with an aqueous iron(III) solution. The complex shows λmax at 410 nm with an ε of 2160 at pH 7. Alanine residues influence the hydroxamate groups to produce a chiral complex, the CD spectrum of which reveals bands at 355 nm (Δε+0.8) and 435 nm (Δε−1.8), showing a preference for the Δ-configuration around the iron.
The purpose of this study is to investigate the deformation property, under a high strain rate, of high strength steel sheets. The influence of strain rate on the Bauschinger effect is clarified, and the relation between the mechanical property and this influence is formulized. In this study, three kinds (590MPa, 780MPa, 980MPa) of high strength steel sheets of the Dual Phase type were applied. Both the rolling direction and the transverse direction specimens are created, and the compressive-tensile tests are conducted on three conditions of strain rate 7.0x10 -3 , 10 and 100/s. As a result, it is shown clearly in Dual Phase steels that the dependence of strain rate on the Bauschinger effect exists. In addition, with the transformation of material into high strength, it is demonstrated that consideration of the influence of the Bauschinger effect becomes increasingly important; however, the need for consideration of the dependence of the strain rate and the influence of strength anisotropy on the Bauschinger effect decrease for a material model in a numerical simulation.
A bottle with a vacuum insulation structure is generally called a thermos bottle. It has a dual structure with inner and outer cylinders and a vacuum layer between them. The bottle with the structure maintains the heat and cold. It has been found useful for many years as a container that carries drinking water. Recently, the lightweight design of a vacuum bottle has been required to meet consumer demand. However, the bottle's wall collapses during the process of drawing a vacuum if the stiffness of the cylinder is not enough. To construct the design guide that can prevent the collapse of a double-structured bottle induced by the pressure difference, a numerical simulation was performed. The critical thickness t c , which is the thickness of the bottle when the bottle starts to deform under 1 atm, was defined. t c depends on the length and diameter of the bottle. The index to determine t c from the length and diameter of the bottle was suggested. To evaluate the validity of the analysis, vacuum bottles were prepared and experiments were conducted. The index we suggested showed good agreement with the experimental results. The shift of index within the increase of Young's modulus can be formulated.
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