Imidazolinium-based Multiblock Amphiphile as Transmembrane Anion Transporter

Transmembrane anion transport is an important biological process in maintaining cellular functions. Thus, synthetic anion transporters are widely developed for their biological applications. Imidazolinium was introduced as anion recognition site to a multiblock amphiphilic structure that consists of octa(ethylene glycol) and aromatic units. Ion transport assay using halide-sensitive lucigenin and pH-sensitive 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) revealed that imidazolinium-based multiblock amphiphile ( IMA ) transports anions and showed high selectivity for nitrate, which plays crucial roles in many biological events. Temperature-dependent ion transport assay using 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) indicated that IMA works as a mobile carrier. ¹H NMR titration experiments indicated that the C2 proton of the imidazolinium ring recognizes anions via a (C−H)⁺⋅⋅⋅X⁻ hydrogen bond. Furthermore, all-atom molecular dynamics simulations revealed a dynamic feature of IMA within the membranes during ion transportation.     

Superfluidity of 4He in one and three dimensions realized in nanopores

Superfluidity in one and three dimensions has been studied for 4He fluid films adsorbed in nanopores which are straight channels and three-dimensionally connected pores, respectively. We observed the superfluid in one and three dimensions where thermal phonon wavelengths are much longer than the channel diameter and the period of the pore connection, respectively, and found that the superfluid onset depends on the pore connection. In the straight channels, the observed superfluid density disappears at a temperature far below the heat capacity anomaly of the Ginzburg-Landau transition, while in the pores connected in three dimension, the adsorbed 4He films show an evident three-dimensional transition where the superfluid onset occurs at the heat capacity peak.     

Time-resolved infrared spectrometry with a focal plane array and a galvano-mirror

Time-resolved spectrometry was conducted in the mid-infrared region (2.8-4.6 microm). A galvano-mirror causes a spectrally dispersed beam to repeatedly sweep up and down a PtSi focal plane array so that each element of the array is struck by the beam only once at some point within a time frame. Transient spectra of flowing gases (hydrocarbon and carbon dioxide) were measured at 80 micros intervals.     

Plate, wire, mesh, microsphere, and microtube composed of sodium titanate nanotubes on a titanium metal template

Sodium titanate nanotube/titanium metal composites were synthesized by hydrothermal treatment of titanium metals with various morphologies such as plate, wire, mesh, microsphere, and microtube at 160 degrees C in aqueous NaOH solution and by the subsequent fixation treatment by calcination at 300 degrees C. The surface of the composite was covered with sodium titanate nanotubes with a diameter of approximately 7 nm, and the core part of the composite was titanium metal phase. The raw titanium metal acts as a template or a morphology-directing agent of micrometer size or more to arrange the nanotubes as well as a titanium source for the formation of nanotubes. The concentration of titanium species increases in the reaction solution as the dissolution of titanium metal is accelerated by the reaction between titanium and OH-. Furthermore, with an increase in concentration of titanium species in the reaction solution, the titanium species are re-precipitated as sodium titanate nanotubes onto the titanium metal. Titanium metal with a large surface area and volume can form sodium titanate nanotubes on the surface of the titanium metal, though titanium metal with a small volume and surface area tends to dissolve with the hydrothermal treatment. Even in the synthesis using titanium metal with a small volume and surface area, sodium titanate nanotubes are formed and cover the surface of the titanium metal by adding another titanium metal as a source of titanium species in the reaction solution.     

Numerical simulation of the ground effect using the boundary element method

As is well known, the lift of a wing passing over the ground becomes larger than that of a wing in a finite air field because of the ground effect. Owing to its special aerodynamic characteristics and applications, the problem of the ground effect has become increasingly common. In this paper some investigations were conducted to calculate the unsteady aerodynamic forces for long and short ground plates by means of boundary element techniques. In order to calculate the pressure variation on a long ground plate, the steady boundary element method was used. However, when using a short ground plate, the boundary element method was modified to treat the unsteady aerodynamic phenomena. Experimental studies were also made for both ground plates to confirm the validity of the numerical results. At low angles of attack the qualitative behaviour of the unsteady aerodynamic pressure on both ground plates was well predicted by the boundary element methods and qualitative agreement is found between the calculated and measured results. © 1997 John Wiley & Sons, Ltd.     

An evaluation of test statistics for detecting temporary change in Bl(1,1,1,1) models

A study is carried out to investigate the sampling properties of the outlier test statistics of a procedure developed for detecting temporary change in BL(1,1,1,1) processes. It is done with respect to the sample size, the type of outlier and the size of the coefficients of the BL(1,1,1,1) process. The results show that, in general, the outlier detection procedure is capable of detecting TC, although the performance is affected if ω is large. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Finite Element Analysis of the Dominant Mode Variation in Groove Guide

In this paper, the dominant mode in groove guide is analyzed by finite element method. For the guide with a shallow groove, the electric field lines (abbreviated as E lines) are perpendicular to the parallel plate, which is different from the literatures, and the dominant mode distribution is irrelevant to the groove width; for the guide with a narrow but deeper groove, the E lines are parallel to the plate region, which represents the characteristics of lower attenuation, for the guide with a deeper and wider groove, a complicated E lines are obtained. These results reveal that the dominant mode distribution in groove guide is varied, which replenish our understanding of groove guide, and the results have important values in design, manufacture, and application of groove guide.