Development of sample holder for in situ neutron measurement of hydrogen absorbing alloy

We developed a sample holder for in situ measurement of hydrogen absorbing alloy. In order to prevent the hydrogen absorption by vanadium, copper is coated with 2 μm thickness on inner surface of the vanadium holder. The effect of copper coating and the performance of the holder were evaluated by neutron diffraction and PDF profiles. The lattice parameters a and c of La₂Ni₇ with Ce₂Ni₇-type structure were refined as 0.505921(4) and 2.468608(4) nm by Rietveld analysis. The Cu-Cu correlation peak around r = 0.255 nm was not observed in the PDF profile. Thus the holder is useful for in situ measurement of hydrogen absorbing alloy. The diffraction and PDF profiles of La₂Ni₇D_x (0 < x < 10.5) were collected using a deuterium pressure of 3.7 MPa, and the changes of crystal and local structures were clearly observed.     

NOx reduction and NO2 emission characteristics in rich-lean combustion of hydrogen

Hydrogen is a clean alternative to conventional hydrocarbon fuels, but it is very important to reduce the nitrogen oxides (NO_x) emissions generated by hydrogen combustion. The rich-lean combustion or staged combustion is known to reduce NO_x emissions from continuous combustion burners such as gas turbines and boilers, and NO_x reduction effects have been demonstrated for hydrocarbon fuels. The authors applied rich-lean combustion to a hydrogen gas turbine and showed its NO_x reduction effect in previous research. The present study focused on experimental measurements of NO and NO₂ emissions from a coaxial rich-lean burner fueled with hydrogen. The results were compared with diffusion combustion and methane rich-lean combustion. Significant reductions in NO and NO₂ were achieved with rich-lean combustion. The NO and NO₂ reduction effects by rich-lean combustion relative to conventional diffusion combustion were higher with hydrogen than with methane.     

(Eu-Nb)-codoped TiO2 nanopowders synthesized via Ar/O2 radio frequency thermal plasma oxidation processing: Phase composition and photoluminescence properties through energy transfer

(Eu³⁺-Nb⁵⁺)-codoped TiO₂ nanopowders have been prepared by Ar/O₂ radio frequency (RF) thermal plasma oxidizing liquid precursor mists, with various addition contents of dopants (molar ratio of Eu³⁺:Nb⁵⁺ = 1:1). Characterizations have been performed by the combined studies of XRD, TEM, Raman spectra, UV-vis spectroscopy, and excitation and PL spectra. The plasma-generated nanopowders mainly consist of anatase and rutile polymorphs. Doping Nb⁵⁺ cannot have appreciable influence on Eu³⁺ solubility (0.5 at.%) in the TiO₂ host lattice, but can significantly inhibit the increase of rutile weight fraction for TiO₂. 617 nm PL intensity at 350 nm indirect excitation through energy transfer is considerably weaker than that at 467 nm direct excitation, indicating that a defect state level in the TiO₂ host lattice might be lowered below the excited state of Eu³⁺ by doping Nb⁵⁺, which is conceivable from a relatively large amount of oxygen deficiencies yielded in the TiO₂ host lattice.     

In-Flight Nitridation of Molybdenum Disilicide Powders by an Induction Plasma

The in-flight nitridation of MoSi₂ powder particles was attempted in an argon-nitrogen induction plasma, with and without tail gas quenching. The inductive power level, reactor pressure, plasma-gas composition, and quantity of quench gas, as well as the species of quench gas, were investigated to obtain substantial nitridation of the MoSi₂ powder particles. Under investigated conditions, ∼2.8 wt% of nitrogen was incorporated into the MoSi₂ powder particles.     

Ionic liquid enables simple and rapid sample preparation of human culturing cells for scanning electron microscope analysis

Ionic liquid is a kind of salt that stays in a molten state even at room temperature. It does not vaporize at all in vacuum and facilitates electrical conductivity to the sample surfaces for observations with a scanning electron microscope (SEM). In this study, we used an ionic liquid in SEM for the first time to observe fixed human culture cells. The condition for the cell culture using wrapping sheets and SEM settings were varied to elucidate the optimized protocol. Compared to samples prepared by the conventional way, the ionic liquid‐treatment of samples gave SEM images of the cellular ultra structures in more detail, enabling observation of microvilli that made bridges between separated cells. In addition, the ionic liquid treatment is less time consuming as well as less laborious compared with the conventional way that includes dehydration, drying, and conductivity treatments. Totally, we concluded the ionic liquid is a useful reagent for SEM sample preparation. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Garlic extract and its selected organosulphur constituents promote ileal immune responses ex vivo

The effects of garlic extract and three organosulphur compounds of garlic on intestinal immune responses in mice were investigated. Peyer’s patch (PP) cells were isolated from mice orally administered with garlic extracts or one of three organosulphur compounds (alliin, allicin, diallyl disulphide (DADS)). PP cells isolated from mice that had been orally injected with ethanol extract significantly produced interferon (IFN)-γ and interleukin (IL)-4. IL-2 production in PP cells was significantly reduced by hot-water and ethanol extracts from garlic. PP cells from mice administered with two organosulphur compounds, alliin or DADS (5 mg/kg/day), could produce IL-2, IFN-γ and IL-4, whereas allicin showed moderate activity. The enhancement activity of IL-2 and IFN-γ productions in PP cells by DADS was higher than those obtained by administration of alliin or allicin. Comprehensive analyses of genetic profiles in PP tissue from mice administered with ethanolic extracts, allicin or alliin revealed that oral administration of samples increased 68–144 genes and decreased 50–52 genes by ?1.8-fold. Analyses of clustering profiles of microarrays indicated that ethanol extract and alliin upregulated the expression of IFN-γ. These data showed that garlic and its organosulphur compounds stimulate de novo IFN-γ biosynthesis in PP cells, thereby promoting ileal immune responses.     

Development of a separable search-and-rescue robot composed of a mobile robot and a snake robot

Abstract

In this study, we propose a new robot system consisting of a mobile robot and a snake robot. The system works not only as a mobile manipulator but also as a multi-agent system by using the snake robot's ability to separate from the mobile robot. Initially, the snake robot is mounted on the mobile robot in the carrying mode. When an operator uses the snake robot as a manipulator, the robot changes to the manipulator mode. The operator can detach the snake robot from the mobile robot and command the snake robot to conduct lateral rolling motions. In this paper, we present the details of our robot and its performance in the World Robot Summit.     

Instantaneous control method with a GTO converter for active andreactive powers in superconducting magnetic energy storage

A new type of GPG (gate pulse generator) is presented to give GTO power converters quick response firing angle control and PWM control functions. Using the GPG, an instantaneous control method of active and reactive powers for an SMES (superconducting magnetic energy storage) employing one GTO converter is studied     

The study on radiation grafting of acrylic acid onto fluorine-containing polymers. III. Kinetic study of preirradiation grafting onto poly(tetrafluoroethylene–hexafluoropropylene)

A kinetic study has been made on the preirradiation grafting of acrylic acid (AAc) onto poly(tetrafluoroethylene–hexafluoropropylene) (FEP) film. The effect of grafting conditions was investigated. The dependencies of the grafting rate on preirradiation dose and monomer concentration were found to be 0.58 and 1.25 order, respectively. The overall activation energy for the graft polymerization was 7.4 kcal/mol. The final degree of grafting increased with preirradiation dose and monomer concentration and slightly decreased as the grafting temperature was elevated. The relationship between the grafting rate and film thickness gave a negative first-order dependency, which is in agreement with that obtained for polytetrafluoroethylene—AAc grafting system. It was reasonably concluded that this grafting proceeds from the surface to the center of film with progressive monomer diffusion through the grafted layer which swells in the monomer solution.     

Iodine-initiated,solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. I. Fundamental study on beaker-scale copolymerization

The iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal has been studied on a beaker scale. It was found that tetraoxane can be easily copolymerized with 1,3-dioxolane by a small amount of iodine as initiator and gives oxymethylene copolymer with excellent thermal stability in a high yield. The copolymerization was largely influenced by the concentrations of iodine, 1,3-dioxolane, and methylal, i.e., the polymerization rate increased with increase not only in iodine but also in 1,3-dioxolane, and the thermal stability and the molecular weight of the copolymer were mainly affected by 1,3-dioxolane and methylal concentration, respectively.