Thermal conductivity of a dendritic ice layer

Measurements of the thermal conductivities of the frozen layer of aqueous binary solutions have been performed using the transient hot-wire method. Solutions of ethylene glycol and sodium chloride were utilized as the testing fluids, and they were frozen up in the test section in which the platinum wires 40 m in diameter and 170 mm in length were strung. Measurements were carried out under equilibrium at a variety of both the initial concentration of the solution and the temperature of the frozen layer. The expressions of the thermal conductivity of the frozen layer were determined. It was found that the thermal conductivity of the dendritic ice layer was favorably assessed with the Lichteneker's model by introducing the solid fraction under an assumption of the equililbrium within the range of parameters examined.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Heat extraction characteristics by coaxial heat exchanger

This study was performed to investigate the heat extraction characteristics from shallow geothermal resources using a coaxial heat exchanger. First, a computer simulation program for a coaxial heat exchanger was checked and verified by laboratory experiments. After inspecting the effectiveness of the computer program described herein, a numerical simulation for a real scale model was conducted under the condition that the heat transfer mechanism in the stratum was heat conduction. Unsteady heat extraction characteristics are presented herein, and the effects of the tube material, inner diameter, and circular modes on the heat extraction rate are discussed. From the computer results it was found that the heat extraction performance using a coaxial heat exchanger greatly depended on the factors mentioned above in the range of the parameters covered in this study. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(7): 496–513, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20083     

Synthesis of silica-coated rhodium nanoparticles in reversed micellar solution

Silica (SiO₂)-coated rhodium (Rh) nanoparticles were prepared using a water-in-oil microemulsion of polyoxyethylene (15) cetyl ether, cyclohexane and water. SiO₂-coated Rh nanoparticles were obtained by hydrolyzing metal alkoxide (tetraethylorthosilicate, TEOS) in the solution containing Rh complex nanoparticles followed by thermal and reduction treatments. In the SiO₂-coated Rh nanoparticle, a Rh particle with an average diameter of 4.1 nm was located nearly at the center of each spherical SiO₂ particle. The SiO₂ layer was approximately 15 nm thick. Since the Rh particle was wholly surrounded by SiO₂, the Rh particle of the SiO₂-coated Rh nanoparticle exhibited an extremely high thermal stability. Furthermore, the porous structure of the SiO₂ layer could be controlled by the hydrolysis conditions of TEOS.     

Occurrence of two genotypes of tetracycline (TC) resistance gene tet(M) in the TC-resistant bacteria in marine sediments of Japan

The tetracycline (TC) resistance gene tet(M) was monitored in bacteria isolated from Japanese coastal and off-shore marine sediments. The high rate of occurrence of TC resistant (TC(r)) bacteria (120 microg mL(-1) TC) was observed at frequency ranges between 0.0-0.08% in Tokyo Bay, 1.67-1.82% in Sagami Bay and 0.0-4.35% in the open Pacific Ocean. The tet(M) gene was PCR amplified from the TC(r) isolates, showing 127 of 209 isolates (60.8%) as positive. The rate of occurrence of tet(M) was between 32.0-96.0%, 21.1 -28.0% and 0.0-83.3% in the isolates from Tokyo Bay, Sagami Bay and the open Pacific Ocean, respectively. The tet(M) positive isolates belonged to 4 orders of bacteria. Bacillales was the most dominant order (121 strains) among tet(M) possessing bacteria, followed by Actinomycetales (three strains), Flavobacteriales (one strain) and Pseudomonadales (one strain). This indicates that tet(M) is present in various bacterial species and suggests that marine sediments are a natural reservoir of the tet(M) gene. Nucleotide sequence of the tet(M) revealed that two genotypes of tet(M) were found in the bacteria. The two genotypes were placed in genetically distant branches of the phylogenetic tree, suggesting that the two tet(M)s have different origins.     

Real-time video-based modeling and rendering of 3D scenes

Our work targets 3D scenes in motion. In this article, we propose a method for view-dependent layered representation of 3D dynamic scenes. Using densely arranged cameras, we've developed a system that can perform processing in real time from image pickup to interactive display, using video sequences instead of static images, at 10 frames per second. In our system, images on layers are view dependent, and we update both the shape and image of each layer in real time. This lets us use the dynamic layers as the coarse structure of the dynamic 3D scenes, which improves the quality of the synthesized images. In this sense, our prototype system may be one of the first full real-time image -based modelling and rendering systems. Our experimental results show that this method is useful for interactive 3D rendering of real scenes     

Development of a New Conversion Process Consisting of Hydrothermal Treatment and Catalytic Reaction Using ZrO2–FeO X Catalyst to Convert Fermentation Residue into Useful Chemicals

Conversion of coliform-fermented residue to useful chemicals such as ketone was carried out by a new conversion process consisting of hydrothermal treatment and catalytic reaction using ZrO₂–FeO _X , resulting in the selective production of acetone. Moreover, catalytic reactions using a model compounds were carried out to clarify the reaction mechanism and kinetics for the fermentation residue conversion.     

Vector unit architecture for emotion synthesis

Two vector units embedded in the emotion engine chip support high-quality 3D graphics, emotion synthesis, and 300-MHz, 5.5-GFLOPS operation for the recently introduced PlayStation2 game entertainment system     

Preparation for Size-Controlled MOR Zeolite Nanocrystal Using Water/Surfactant/Organic Solvent

Recently, the synthesis of nanometer-sized zeolite crystals has attracted considerable attention from many researchers. In this study, the preparation of Mordenite (MOR zeolite) nanocrystals via hydrothermal synthesis in water/surfactant/organic solvent was carried out. Polyoxyethylene-(15)-oleylether (O-15, non-ionic surfactant) and cyclohexane were employed as a surfactant and organic solvent, respectively. Interestingly, it was found that the crystal sizes and morphology of MOR zeolites depended on the surfactant concentration regardless of the same concentrations of Si and Al sources and template in the water solution. The MOR zeolite nanocrystals with average sizes of approximately 80 nm could be obtained. Moreover, the column-like morphology of MOR zeolite was also observed at a high surfactant concentration (0.75 mol/L). Accordingly, the crystal size and morphology of MOR zeolite can be controlled by the surfactant concentration. This result appears to be due to the difference in the nucleation and growth rates of MOR in the solution.     

A 1 Tb/s 3 W Inductive-Coupling Transceiver for 3D-Stacked Inter-Chip Clock and Data Link

A 1 Tb/s 3 W inter-chip transceiver transmits clock and data by inductive coupling at a clock rate of 1 GHz and data rate of 1 Gb/s per channel. 1024 data transceivers are arranged with a pitch of 30 mum in a layout area of 1 mm². The total layout area including 16 clock transceivers is 2 mm² in 0.18 mum CMOS and the chip thickness is reduced to 10 mum. Bi-phase modulation (BPM) is employed for the data link to improve noise immunity, reducing power in the transceiver. Four-phase time division multiple access (TDMA) reduces crosstalk and the bit-error rate (BER) is lower than 10^-13