Multi-component co-condensation model of Ti-based boride/silicide nanoparticle growth in induction thermal plasmas

Numerical analysis is conducted for the titanium-based boride and silicide nanoparticle synthesis using an induction thermal plasma including the material evaporation process and the nanoparticle growth process with nucleation and co-condensation. Both systems present the nano-scaled particle size distributions. Ti-B system shows the smaller particle diameter, sharper distribution, larger particle number density, and wider range of the composition than Ti-Si system. Ti-Si system provides a narrower range of the silicon content due to the simultaneous co-condensation of titanium and silicon. Finally the correlation between the particle size and the nonmetal content of the synthesized nanoparticles is presented on a chart.     

Improvement in stabilization of launching performance and launching velocity using linear accelerator

This paper describes the improvements in launching stability and launching velocity of the linear accelerator (LAC). The authors have designed and produced a railgun using the LAC for weaving loom shuttles. The LAC is an electromagnetic launcher which enables a projectile to be launched at a speed of more than 50 m/s. Basically, it consists of a unipole linear dc motor and operates the same principle as dc rotary motors, the most difficult problem in this system being the stabilization of the current collection on the projectile. Then, various launch experiments have been conducted. As a result, the carbon projectile was launched at a speed of 73 m/s using double-state-type LAC.     

Hybrid nanocomposite based on NbWO6 nanosheets and polyaniline

Synthesis and characterization of the hybrid nanocomposite based on polyaniline and NbWO₆ nanosheets is reported here. Formation of the nanocomposite is reflected by the increase of interlayer distance of NbWO₆ nanosheets and the XRD pattern depicts the formation of NbWO₆/polyaniline nanostructure with interlayer separations of 1.6 nm and 0.9 nm which is consistent with a bilayer and a monolayer of polyaniline molecules within the gallery of nanosheets. Transmission electron micrographs, infrared spectra and thermograms support the formation of the hybrid nanocomposite. Electrochemical investigations on the nanocomposite reveal the presence of polyaniline and the data is compared also with those of polyaniline and host.     

Effects of interferon-alpha on serum hepatitis C virus in patients with chronic hepatitis C

Interferon is beneficial in some patients with chronic hepatitis C. To assess the efficacy of interferon, we used the polymerase chain reaction (PCR) to measure HCV RNA in serial serum samples from 13 chronic hepatitis C patients who were treated with interferon-alpha. Serum alanine aminotransferase (ALT) values normalized in association with the disappearance of serum HCV RNA in nine cases during the therapy. Serum HCV remained negative after the therapy in the three patients who had no relapse, while serum HCV RNA reappeared in the six patients with elevation of ALT values. The persistence of normal ALT levels appears to be correlated with the clearance of the serum HCV. There were two patients whose ALT became normal immediately after the cessation of interferon. Serum HCV was detectable at the end of treatment when serum ALT was elevated, and thereafter serum HCV disappeared. This result suggests an immunomodulatory effect of interferon in the clearance of HCV in some cases. Furthermore, the semiquantitative PCR assay showed that all five patients in whom ALT values were normal at the end of follow-up without detectable serum HCV genome had lower HCV titers in the pretreatment sera than the other eight patients. The detection of HCV RNA by the PCR assay is useful in determining the efficacy of interferon and its mechanisms.     

Simultaneous measurement of liquid velocity and interface profiles of horizontal duct wavy flow by ultrasonic velocity profile meter

A simultaneous measurement of the liquid velocity and interface profiles was performed for stratified-smooth and wavy flows in a horizontal duct using a ultrasonic velocity profile (UVP) meter. The influences of the reflections of ultrasonic pulses at the gas–liquid interface and channel bottom were reduced by using an absorbent for the ultrasonic pulses on the duct bottom wall and optimization of the liquid level and time interval between pulses. For a smooth–stratified flow, good comparison was obtained with a velocity profile obtained by particle tracking velocimetry (PTV) for video pictures taken simultaneously at the UVP measurement. Polystyrene beads were used as the reflector and tracers respectively, for the UVP and PTV measurements. The velocity profiles measured for a wavy flow with periodically-generated interfacial waves agreed well with the theoretical prediction for solitary waves. Turbulence component appeared in the velocity profiles of both the smooth–stratified and wavy flows.     

Application of Highly Functional Ti-Oxide-Based Photocatalysts in Clean Technologies

Various Ti-oxide based photocatalysts such as the highly dispersed Ti-oxide species within zeolite frameworks, TiO₂ nano-particles hybridized with hydrophobic zeolite adsorbents as well as visible light responsive TiO₂ thin films have been successfully prepared. Characterization studies at the molecular level, such as X-ray absorption fine structure (XAFS) and photoluminescence (PL), revealed that the highly dispersed Ti-oxide species within the nano-spaces of zeolites possess a tetrahedral coordination and that they demonstrate unique and high performance for the photocatalytic decomposition of NOx and the photocatalytic reduction of CO₂ with H₂O. A high photocatalytic reactivity for the TiO₂ semiconducting photocatalysts could be achieved by blending them with hydrophobic siliceous zeolites which was equal to the performance of TiO₂ deposited with expensive Pt particles. The role of the siliceous zeolites can be described as a so-called “catch and release effect of organic compounds”, i.e., (i) the condensation of the reactants within the hydrophobic cavities of zeolites and; (ii) the efficient diffusion of the reactant onto the TiO₂ photocatalytic sites. Furthermore, a novel photocatalytic system which can convert abundant solar energy into renewable H₂ energy by the decomposition of H₂O into H₂ and O₂ can also be achieved by using visible light responsive TiO₂ thin film photocatalysts prepared by a RF-magnetron sputtering deposition method. The conversion efficiency of solar energy into H₂ energy may be estimated at ca. 0.1% from the initial rate of H₂ evolution.     

Morphologic Control of Pt Supported Titanate Nanotubes and Their Photocatalytic Property

Morphologic control of Pt supported titanate nanotubes was attempted by the hydrothermal hot-pressing (HHP) technique in order to improve the handleability as a photocatalyst. The bulk of Pt-nanocrystal supported titanate nanotubes was successfully fabricated without the H₂ reduction process by applying the HHP technique. The bulky Pt-nanocrystal supported titanate nanotubes possessed dense microstructures, significantly sharp distributions of mesopores, and high Brunauer–Emmett–Teller (BET) surface area. Furthermore, the bulky Pt-nanocrystal supported titanate nanotubes showed the photocatalytic degradation activities of 2-propanol aqueous solution under UV-light irradiation.     

Surface temperature of Pd/C catalyst under microwave irradiation in dechlorination process of PCBs

In recent years, a new effective method of processing for polychlorinated biphenyls (PCBs) has been developed: It enables PCBs to become harmless by dechlorinating them using a 2.45 GHz microwave (MW). Compared with conventional thermal heating, MW processing hardly produces any harmful byproduct materials, and has high reaction velocity. To investigate such promotion of chemical reaction by MW irradiation, the surface temperature of the catalyst is measured by an infrared camera just after the irradiation by MW. It is recognized that there are some heated regions on the catalyst and the temperature is not uniform. It is natural to say that chemical reaction is promoted well on such a heated region. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Dielectrics loss of PCBs leading to microwave heating

A new effective processing for polychlorinated biphenyls (PCBs) has been recently developed. PCBs become harmless by dechlorination using 2.45 GHz-microwave (MW). To investigate such chemical reaction by MW irradiation, the dielectric loss of pure PCBs solutions and an isomer mixture in MW band is measured. Some PCBs and isopropyl alchol, added as a source of hydrogen supply have high dielectric loss in MW band. This suggests that MW heats PCBs and isopropyl alchol, and then the temperature of the solvent consisting mainly of insulating oil rises by the thermal conduction. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Hardware‐oriented ant colony optimization and its application to dynamic route guidance problem

Ant colony optimization (ACO) is based on the behavior of food gathering of ants and it is a powerful search tool particularly when applying it to combinatorial optimization problems. However, ACO has the inherent problem of substantial processing time, because it requires a lot of repetitive calculations. In this article, we propose novel hardware‐oriented ACO (H‐ACO) to reduce processing time. H‐ACO adopts new integer arithmetic instead of conventional floating point arithmetic in the optimization process and it achieves high‐speed processing while keeping the quality of solutions. In addition, H‐ACO reduces the hardware resources, accelerates the clock frequency, and improves the latency, if it is implemented as a dedicated hardware. Furthermore, we also propose a new route guidance algorithm which combines H‐ACO with Dijkstra's algorithm and it can be applied to a dynamic route guidance problem. Experiments using actual map data demonstrate the validity of the proposed route guidance algorithm. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.