Concrete filled double skin circular stub columns under compression

Concrete filled double skin tubular (CFDST in abbreviation) stub columns consist of double concentric thin steel tubes and filled concrete between them. Their mechanical behaviors under axial compression were investigated experimentally. Two testing parameters considered were inner-to-outer diameters ratio and diameter-to-thickness ratio. Observed failure modes were controlled by the local buckling of both the tubes associated with shearing failure of the filled concrete. Main discussion is given on confinement effect by the outer tube to the filled concrete strength. Equations to estimate their ultimate strengths under compression were proposed based upon the yielding strengths of the tubes and the filled concrete cylinder strength.     

Microwave-hydrothermal synthesis of barium titanate under stirring condition

The role of in situ stirring under microwave-hydrothermal (M-H) conditions on the synthesis of barium titanate was investigated for the first time by powder X-ray diffraction and scanning and transmission electron microscopy. Stirring under M-H conditions in the temperature range of 150–200 °C led to enhanced crystallization of Ba titanate as revealed by yields compared to the static condition. In addition, stirring led to smaller and more uniform crystals under M-H conditions compared to those crystallized without stirring. Powder X-ray diffraction revealed the formation of only cubic polymorph of Ba titanate at or below 200 °C in 4 h with or without in situ stirring under M-H conditions. These results show that stirring is an important parameter during M-H synthesis of nanophase Ba titanate.     

Homogeneous and Disordered Assembly of Densely Packed Nanocrystals

A homogeneous and disordered assembly of densely packed nanocrystals is generated without the assistance of organic molecules, from an aqueous solution at room temperature. The densely packed nanocrystals of tin dioxide (SnO₂) and titanium dioxide (TiO₂), 2–3 nm in size, form glassy macroscopic transparent objects of 2–10 mm. The monodisperse nanocrystals, which have a surface hydrated layer and are synthesized in aqueous solution, are densely packed in an homogeneous and disordered assembly through the evaporation of water as the dispersion medium. The formation of transparent bulk objects on the macroscopic scale originates from the homogeneous and disordered nature of the densely packed nanocrystals. The resultant homogeneous architectures are distinguishable from the typical inhomogeneous and disordered aggregates of nanoparticles observed after evaporation of the dispersion medium. Among superstructures based on nanocrystals, such as superlattices and mesocrystals, the resultant homogeneous and disordered assembly can be regarded as a new class of solid‐state material.     

Case study of electrochemical metal removal from actual sediment, sludge, sewage and scallop organs and subsequent pH adjustment of sediment for agricultural use

In this paper we propose a method for chemical-free removal of metal from lake sediment, and its subsequent pH adjustment, based on electrochemical migration and precipitation. Such a method would enable the utilization of sediment as composting material. Sediment was placed in the anode side of a dual-bath electrochemical reactor separated by a thimble-shape cellulose filter from the cathode side, which was filled with pure water. When voltage was applied, contaminant metals in the sediment on the anode side migrated toward the cathode side, and precipitated due to the alkaline conditions caused by the cathodic reaction. After 10 days of electrolysis with 400 mA of constant current of 150 g wet lake sediment, the removal ratios of 13 kinds of elements after the electrochemical treatment were measured. Cd and Zn, the elements for which agricultural standards apply, showed 98% and 86% removal, respectively. The type of metal removed changed over time, and the order of removal was roughly from light metals to heavy metals. The acidified lake sediment after electrolysis could be neutralized without significant recontamination with Zn and Cd by using the alkaline cathode solution collected during electrolysis under a condition of tap water overflow at a rate of 1.5 L/h. The electrochemical metal removal method was effective not only for lake sediment, but also for municipal sludge cake, human sewage, and contaminated scallop organs. Cathode overflow during electrolysis tended to increase metal removal and decrease required voltage.     

A hybrid approach to keyframe extraction from motion capture data using curve simplification and principal component analysis

In this paper, we propose a novel method to extract keyframes from motion capture data. A hybrid approach, which combines a curve‐simplification algorithm with an initialization procedure including principal component analysis, is adopted. The developed method automatically extracts an appropriate number of keyframes at high speed without performance degradation. Experimental results prove the effectiveness of the present method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Improved polyhydroxybutyrate (PHB) production in transgenic tobacco by enhancing translation efficiency of bacterial PHB biosynthetic genes

Polyhydroxybutyrate [P(3HB)] was produced in the transgenic tobacco harboring the genes encoding acetoacetyl-CoA reductase (PhaB) and polyhydroxyalkanoate synthase (PhaC) from Ralstonia eutropha (Cupriavidus necator) with optimized codon usage for expression in tobacco. P(3HB) contents in the transformants (0.2mg/g dry cell weight in average) harboring the codon-optimized phaB gene was twofold higher than the control transformants harboring the wild-type phaB gene. The immunodetection revealed an increased production of PhaB in leaves, indicating that the enhanced expression of PhaB was effective to increase P(3HB) production in tobacco. In contrast, codon-optimization of the phaC gene exhibited no apparent effect on P(3HB) production. This result suggests that the efficiency of PhaB-catalyzed reaction contributed to the flux toward P(3HB) biosynthesis in tobacco leaves.     

Full‐duplex analogue/digital data transmission using lasers coupled to GI fibre and its application

This paper describes a low‐cost version of a full‐duplex optical fibre analogue/digital data transmission link whose practical implementation is simplified by using a pair of laser diodes, each having a built‐in photodiode for monitoring the laser output power, and its application to vibration test data transmission. The transmission link sends digital data of up to 9600 bps in one direction, and analogue data of DC to 100 kHz and image data specified by an NTSC colour video signal in the opposite direction, all at the same time through one GI optical fibre. Being simple in configuration and stable against noise, this type of link has a variety of applications within factory, home and offices. Copyright © 2001 John Wiley & Sons, Ltd.     

Heat transfer characteristics of a reservoir embedded loop heat pipe (Heat transfer characteristics of a deployable radiator for use on the ETS‐VIII satellite while in orbit)

As heat generation in satellites increases, ensuring that they are provided with sufficient radiator panel area is an important problem. Deployable radiators, with radiator panels that are deployed post‐launch in space to increase the satellite's effective radiator panel area of the satellite, are becoming an important thermal control technology. A reservoir embedded loop heat pipe (RELHP) is used in deployable radiators as a heat transport device. A deployable radiator of this type was mounted on the ETS‐VIII satellite, which was launched on December 18, 2006 and injected into a geostationary orbit. The satellite is still operating without any significant issues over two years later. This paper investigates the heat transport characteristics of an RELHP system used in a deployable radiator in a geostationary orbital environment. This system can be successfully started up in a micro gravity environment. We also found that the sub‐cooling region is shorter in a micro gravity environment than in a terrestrial gravity environment, because there is less heat leakage into the reservoir in a micro gravity environment. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20346     

Micro-/nanostructural investigation of laser-cut surfaces of single- and polycrystalline diamonds

Micrometer- to nanometer-scale structures of the cut surfaces of single- and polycrystalline diamonds by a pulsed ultraviolet laser have been thoroughly investigated by scanning and transmission electron microscopy. Within the laser-cut grooves, the processed diamond surfaces are extensively covered with laser-modified debris which consists of complex layered units of graphite with various crystallinities. The units consist of 1) highly oriented graphite, 2) corrugated graphite, and 3) nanocrystalline graphite, which are sequentially located from the surface of the underlying diamond substrate to the center of the grooves. Detailed textural examinations revealed that the highly oriented graphite unit is a product of the initial graphitization of diamond by a solid-state diffusion process, whereas the latter two units are deposition products from the liquid and/or vapor phases of carbon in the later stage. The present study demonstrates that the laser-cutting of diamonds proceeds in a two-step process: 1) extensive graphitization of laser-scanning path and 2) subsequent sublimation of the pre-formed graphite. These processes are basically identical among the three different types of diamonds (single crystal type Ib, single crystal type IIa and nano-polycrystalline aggregate) tested in this study.