Effect of Anisotropy on Drained and Undrained Shear Behavior of IN-SITU Sandy Soils

Two different types of undisturbed cylindrical specimen (V-specimen: the axis is parallel to the direction of sedimentation, and H-specimen: the axis is perpendicular to the direction of sedimentation), were prepared from high quality undisturbed sand column obtained by in-situ freezing technique. A series of drained compression and extension tests (CD, test, CD, test) and cyclic undrained triaxial tests (liquefaction test) on these samples were performed in order to investigate the effect of the anisotropy on the drained and undrained shear behavior. Following were concluded. 1) The effect of anisotropy on both internal friction angle and liquefaction strength is negligible. 2) The difference in deformation characteristics between V and H-specimens for Holocene soil layer appeared in both CD and liquefaction tests implies that in-situ soil is easier to compress in horizontal direction than in vertical direction. 3) The effect of anisotropy on deformation characteristic of Pleistocene sand samples is not so remarkable as that of Holocene sand

Synthesis of Methoxy-Substituted Diazirinyl Phenylalanine – A Novel Photoreactive Aspartame Derivative for Functional Analysis of Sweet Receptors

Photoreactive phenylalanine derivatives are well known as functional analysis reagents for target biomolecules. The photophores are commonly introduced at 4-position on benzene. Aspartame, which consists of dipeptide L-Asp-L-Phe-OMe, is one of the most utilized artificial sweeteners, and substitution effects on its benzene ring have been reported. Substitution at the 4-position, however, does not maintain its sweetness properties. Trifluoromethyl- diazirine, which is one of the most reliable photophores, was introduced to a different site on phenylalanine and the new photoreactive phenylalanine was converted to aspartame derivatives. The new aspartame derivative had slightly higher sweetness potency than sucrose standard solution

SYNTHESIS OF PHOTOREACTIVE DIAZIRINYL SALICIN DERIVATIVE TO ELUCIDATE FUNCTIONAL ANALYSIS OF THE BITTER TASTE RECEPTOR

Salicin (salicyl alcohol glucoside) is a substance well known for its bitter taste. A photoreactive diazirinyl derivative of salicin will be utilized for the functional analysis of interactions between the bitter taste receptor and salicin. Glucosides of salicyl derivatives are more difficult than phenol derivatives that are unsubstituted at the ortho-position. A diazirinyl salicin derivative was synthesized at moderate yields by glucosidation of 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide and 2-hydroxy-4-[3-(trifluoromethyl)-3H-diazirin-3-yl]benzaldehyde in the presence of a phase-transfer catalyst, nBuEt(3)NBr, followed by reduction and deprotection