Counter‐ion‐specific helix formation of poly(γ‐methyl L‐glutamate) derivatives containing sulfonate group in aqueous alcohols

Charged polypeptides containing sulfonate groups were prepared by transesterification of poly(γ‐methyl L ‐glutamate) with isethionic acid. The coil–helix transition of the sulfonated polypeptides was investigated in aqueous alcohols. Marked counter‐ion specificity was observed for helix formation: Li⁺ < Na⁺ < Cs⁺ ≦ Rb⁺ ≦ K⁺; this was different to that for poly(L ‐glutamate) (PLG): Cs⁺ ? K⁺ < Li⁺ < Na⁺. Specific helix stabilization by counter‐ion mixing, which has been found for the PLG system, was not observed for the sulfonated polypeptides. The counter‐ion‐ and solvent‐specific helix formation is discussed and compared with that in PLG. © 2001 Society of Chemical Industry     

A novel spherical carbon

We developed a novel spherical carbon material. The spherical carbon is composed of a high density of carbon nanotubes or nanofilaments, and includes an oxidized diamond particle as a core. Syntheses of this carbon in high volume with high selectivity may be possible. It is expected that this carbon will be useful as a catalyst material for fuel cells, electric double-layer capacitors, etc.     

Vector graphics depicting marbling flow

We present an efficient framework for generating marbled textures that can be exported into a vector graphics format based on an explicit surface tracking method. The proposed method enables artists to create complex and realistic marbling textures that can be used for design purposes. Our algorithm is unique in that the marbling paint on the surface of water is represented as an enclosed contour and is advected by fluid flow to deform the marbling silhouette. In contrast to previous methods, in which the shape is tracked with a concentration density field in Eulerian grids, our approach facilitates greater complexity that is free from grid resolution and per-pixel computation while retaining real-time performance. To forestall the propagation of large vertices, we adaptively resample the contours, exploiting the curvature and the turbulence of the fluid as criteria. At the convection phase, we parallelly advect contour particles on a Graphics Processing Unit (GPU) in addition to applying volume corrections. Finally, we quickly remove extremely thin lines in shapes to remove dozens of vertices. We performed our method with an interactive prototype to demonstrate the robustness of the proposed method in several scenarios.     

Preliminary investigation of a vapor-open envelope tailored for subtropical climate

Concerning global warming and resource depletion, the impact of buildings in subtropical regions is becoming even greater due to a high growth rate of urbanized areas. From the viewpoint of building physics, the main problem concerning subtropical climate is the high level of humidity in combination with high temperature. In this study, a flexible building envelope consisting of wood and clay components was developed so that the materials and the assemblies can be easily tailored to comply with local climatic conditions. The movement and accumulation of moisture in the wall was of prime concern. This has been investigated by means of testing full scale walls in a climate chamber and the corresponding one dimensional transient heat and transfer simulation. In order to achieve a consistency between calculation and measurement, the individual materials were tested for their hygric and thermal properties. Based on these findings attempts were made to calculate the behavior of an optimized wall assembly under real climatic conditions of central Japan. As a result, it was shown that the hygrothermal behavior of the envelope is predictable by means of the models and the simulation program used, and that no risk of interstitial condensation and mold growth was predicted under the real climatic conditions of Kyoto.     

Fundamental Behavior of Direct-Coupled Submicrosecond Pulse Energization in Electrostatic Precipitators

The fundamental characteristics of the direct-coupled pulse energization in electrostatic precipitators (EP's) are investigated in a test rig comprised of a coal pulverizing facility, a furnace, a gas cooling system, and an EP. The EP consisted of a corona electrode with barbed wires and a collection electrode with 300-mm duct spacing. This simulates the type of EP normally used in a coal-fired power station. The pulse-energized collection field shows a very high collection performance of more than 99 percent collection efficiency and the performance enhancement compared to the conventional dc energization, causing very severe back corona, becomes as large as H = 2.50.H is the enhancement factor in terms of the Deutsch migration velocity in the case of the very high resistivity dust of rd = 2 x 1013 ?cm at the gas temperature of Tg = 150°C. Even at the lower level of the dust resistivity at Tg = 110°C, where no back corona occurs in the dc-energized collection field, the performance enhancement is as large as H = 1.21. The mechanism of such great performance enhancement is likely to be the result of the very uniform and very intense formation of corona plasmas on the wires as a result of the very fast rise in the pulse voltage applied and a special sawtooth waveform of the operating voltage between the corona and collection electrodes.     

Molecular dynamics simulation of 〈<Emphasis Type="Bold">c</Emphasis>+<Emphasis Type="Bold">a</Emphasis>〉 dislocation core structure in hexagonal-close-packed metals

The core structures of 〈c+a〉 dislocations in hexagonal-close-packed (hcp) metals have been investigated by molecular dynamics (MD) simulation using a Lennard-Jones-type pair potential. The 〈c + a〉 edge dislocation has two types of core at 0 K; one is a perfect dislocation (type A), and the other has two 1/2 〈c+a〉 partials (type B). Type A transforms to type B by abruptly increasing temperature from 0 K to 293 K, while type B is stable in temperature range from 0 K to 293 K. In contrast, type A extends parallel to (0001) at 30 K, and this extended core is still stable at 293 K. These results suggest that the 〈c+a〉 edge dislocation glides on the {11 2} as two 1/2 〈c+a〉 partial dislocations and becomes sessile due to changes of the core structure. The 〈c+a〉 screw dislocation spreads over two {10 1} planes at 0 K. The core transforms into a unsymmetrical structure at 293 K, which is spread over {11 2} and {10 1}, and core spreading occurs parallel to {11 2} at 1000 K. A critical strain to move screw dislocations depends on the sense of shear strain. The dependence of the yield stress on the shear direction can be explained in terms of these core structures. This article is based on a presentation made in the symposium entitled “Defect Properties and Mechanical Behavior of HCP Metals and Alloys” at the TMS Annual Meeting, February 11–15, 2001, in New Orleans, Louisiana, under the auspices of the following ASM committees: Materials Science Critical Technology Sector, Structural Materials Division, Electronic, Magnetic & Photonic Materials Division, Chemistry & Physics of Materials Committee, Joint Nuclear Materials Committee, and Titanium Committee.     

Simultaneous three-dimensional step-height measurement and high-resolution tomographic imaging with a spectral interferometric microscope

A noncontact, nonmechanical scanning, wide-field spectral interference microscope is developed for simultaneous measurement of three-dimensional step-height of discontinuous objects and tomographic imaging. A superluminescent diode (SLD) is used as a broadband light source and a liquid-crystal Fabry-Perot interferometer (LC-FPI) as a frequency-scanning device. By means of changing the injection current to the SLD, the spectral profile of the SLD is equalized, and a constant light input to the interferometer is achieved over the entire frequency-scan range. The Fourier-transform technique is used to determine both the amplitude and the phase of spectral fringe signals. Three-dimensional height distribution of a discontinuous object is obtained from the phase information, whereas optically sectioned images of the object are obtained either from the amplitude information alone or from the combination of both the amplitude and phase information. Experimental results with submicrometer resolution are presented for both step-height measurement and tomographic sectioning.     

Travel Time Reliability in Vehicle Routing and Scheduling with Time Windows

This paper presents calibration of the Vehicle Routing and scheduling Problems with Time Windows-Probabilistic (VRPTW-P) model which takes into account the uncertainty of travel times. Probe vehicle data of travel times were obtained from usual operation of pickup-delivery trucks in South Osaka area. The optimal solution of the VRPTW-P model resulted in reducing total cost, running times and CO₂, NOx and Particle Materials (PM) emissions compared with the usual operation. This is attributed to better routing of VRPTW-P to choose more reliable roads. Therefore, VRPTW-P can contribute to establish efficient and environmentally friendly delivery systems in urban area.     

COCOVILA – Compiler-Compiler for Visual Languages

A compiler-compiler for visual languages is presented. It has been designed as a framework for building visual programming environments that translate schemas into textual representation as well as into programs representing the deep meaning of schemas. The deep semantics is implemented by applying attribute grammars to schema languages; attribute dependencies are implemented as methods of Java classes. Unlike compiler-compilers of textual languages, a large part of the framework is needed for support of interactive usage of a visual language.