Experimental study on method of estimating strength of weld metal in steel structure

We conducted the welding experiment using three kinds of test piece, actual size, diaphragm and butt joint. Then, we examined the influence on strength, cooling time and carbon equivalent of weld metal by welding conditions on the different test pieces. We calculated an estimate of cooling time and chemical components. Consequently, we concluded that the strength of weld metal can be estimated by heat input, interpass temperature, carbon equivarent of welding wire and shape of test piece.     

Investigation for Necessity of Dispersivity and Tortuosity in the Dusty Gas Model for a Binary Gas System in Soil

Diffusion, dispersion, and advection are important processes in multi-gas systems in soils. To date, both Fick's model and the Dusty Gas (DG) model have been used to model the movement of gases in these systems. Dispersion is included in the dispersion-advection equation with Fick's Model for the movement of gases in gas-phase of soil, yet the movement of gases in multi-component gas-soil systems is considered to be expressed more accurately by the DG model than by Fick's model. However to date, no study has investigated the necessity of considering dispersion in the Dusty Gas (DG) model. We carried out column experiments for nitrogen-methane, nitrogen-carbon dioxide, and carbon dioxide-methane binary gas systems in sandy soil, and also did simulations on the same systems using both Fick's model and the DG model. A comparison of the results of the column experiments with our simulations confirmed that there was no need to consider the dispersion in the advection-diffusion equations with the DG model when the velocity of gas was 0.05-0.4 cm/s in Toyoura sand. Furthermore, our experiments and simulations with the DG model showed that, rather than dispersion, tortuosity should be taken into account in application of the DG model to the above condition.     

ATP-regulated K+ channel and cytosolic Ca2+ mobilization in cultured rat spinal neurons

ATP activated the K+ channel responsible for outwardly rectifying currents via a P2Y purinoceptor linked to a pertussis toxin-insensitive G-protein in cultured rat spinal neurons. The evoked currents were inhibited by a selective protein kinase C inhibitor, GF109203X, whereas a phospholipase C inhibitor, neomycin had no effect. These indicate that the currents are regulated by phospholipase C-independent protein kinase C activation. In addition, ATP enhanced intracellular free Ca2+ concentration. The increase in intracellular free Ca2+ concentration was inhibited by a broad G-protein inhibitor, GDP beta S, but not affected by neomycin or an inositol 1,4,5-triphosphate receptor antagonist, heparin, suggesting that the cytosolic Ca2+ mobilization is regulated by a mechanism independent of a phospholipase C-mediated phosphatidylinositol signaling. These results, thus, demonstrate that ATP has dual actions on the coupled K+ channel and cytosolic Ca2+ release.     

Copolymerization of unsaturated polyester with styrene in inverted emulsion

Copolymerization of unsaturated polyester with styrene in water-in-oil (W/O) type emulsion was carried out with the use of various basic compounds as emulsifiers. It was found that a stable, gellike W/O type emulsion of unsaturated polyester resin is formed only when pK_a's of the bases are above 6 and their concentrations are higher than some critical value. In these conditions, water can be dispersed in emulsion up to 900% to the resin. By polymerization, the stable W/O type emulsion is transformed to a white solid copolymer which is dry to the touch and which contains 90–95% of initially added water. It was confirmed that the basic compounds react with the carboxylic group of the polyester to form at the water-resin interface polyester salts, which act as true emulsifying agents. The stabilization mechanism of the emulsion at various concentrations of the polyester salt was investigated, mainly by microscopic observations, and an interpretation of the critical value of emulsifier concentration is proposed.     

Effect of Impurities on the Electronic Structure of Vortex Core Investigated by Microwave Surface Impedance Measurement

We investigated the microwave surface impedance in Zn doped YBa₂Cu₃O _y . For low Zn concentrations, crossover frequency _p and viscosity of vortex do not change significantly (at maximum, factor of 2). This is in sharp contrast to the dramatic change in the zero-field quasiparticle scattering time. The robust nature of viscosity on the impurity doping suggests that the quasiparticle scattering time in the vortex core is determined by a different mechanism from that outside the core.     

COMPUTATIONAL METHODS THROUGH GENETIC ALGORITHMS FOR OBTAINING STACKELBERG SOLUTIONS TO TWO-LEVEL MIXED ZERO-ONE PROGRAMMING PROBLEMS

In this paper, we develop computational methods for obtaining Stackelberg solutions to two-level mixed zero-one programming problems in which the decision maker at the upper level controls zero-one variables and the decision maker at the lower level controls real variables. To illustrate two-level mixed zero-one programming problems, we formulate a facility location and transportation problem as a two-level mixed zero-one programming problem. We develop computational methods through genetic algorithms for obtaining Stackelberg solutions. To demonstrate the feasibility and efficiency of the proposed methods, computational experiments are carried out and comparisons between the methods based on the branch-and-bound techniques and the proposed methods are provided.     

Poly(4-diphenylaminostyrene) with a well-defined polymer chain structure: Controllable optical and electrical properties

The effect of polymer chain structure on the optical and electrical properties are reported for poly(4-diphenylaminostyrene) (PDAS), which was prepared by the living anionic polymerization of 4-diphenylaminostyrene (DAS) with the benzyllithium (BzLi)/N,N,N′,N′-tetramethylethylenediamine (TMEDA) system. The optical properties of PDAS are strongly affected by the stereoregularity of the PDAS polymer chain; intramolecular excimer-forming fluorescence was observed from PDAS with a syndiotactic-rich configuration. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of PDAS were approximately −5.4 and −2.0 eV, respectively, regardless of the polymer chain structure. The hole and electron drift mobilities for PDAS were in the order of 10⁻⁴ to 10⁻⁵ (cm²/V s) and 10⁻⁵ (cm²/V s), respectively, with negative slopes. The distance of each triphenylamino (TPA) group in the polymer chain was a major factor influencing the drift mobility of PDAS. The current-voltage (I-V) characteristics of PDAS were controllable according to the polymer chain structure of PDAS.     

Synthesis of porphyrin-end-functionalized poly(p-phenylene) as a leaf-green-colored soluble semiconducting polymer: Control of π–π interactions for visible-light absorption

The synthesis of tetraphenylporphyrin (H₂TPP)-end-functionalized poly(p-phenylene) (H₂TPP-PPP) as a leaf-green-colored soluble semiconducting polymer with a well-controlled and defined polymer chain structure was achieved for the first time. Chloromethyl-end-functionalized poly(1,3-cyclohexadiene) (CM-PCHD) was prepared by the living anionic polymerization of 1,3-cyclohexadiene and the post-polymerization reaction of poly(1,3-cyclohexadienyl)lithium and chloro(chloromethyl)dimethylsilane. H₂TPP-end-functionalized PCHD (H₂TPP-PCHD) was then prepared by the addition of 5-(4-hydroxyphenyl)-10,15,20-triphenylporphyrin to CM-PCHD. The dehydrogenation of H₂TPP-PCHD with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone was performed under ultrasonic irradiation, and H₂TPP-PPP was obtained as a target polymer in almost quantitative yield. The –Si(CH₃)₂–CH₂–O– bond in H₂TPP-PPP effectively inhibited the coordination of the H₂TPP end-group onto the PPP moiety, and the aggregation of H₂TPP-PPP with the accumulation of the H₂TPP end-group was formed. H₂TPP-PPP exhibited a leaf-green color and had a very broad absorption band overlapping the visible-light region, similar to chlorophyll a.     

Reactivity of quinones for the dehydrogenation of poly(1,3‐cyclohexadiene)

The reactivity of three types of quinones (3,4,5,6‐tetrachloro‐1,2‐(o‐)‐benzoquinone (TOQ), 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ), and 2,3,5,6,‐tetrachloro‐1,4‐(p‐)‐benzoquinone (TCQ)) was examined for the dehydrogenation of poly(1,3‐cycohexadiene) (PCHD) composed of 1,2‐cyclohexadiene and 1,4‐cyclohexadiene units. The order of reactivity was TOQ > DDQ > TCQ. The steric hindrance of C?O groups in the quinones appeared to be an important factor in determining their reactivity. DDQ was found to be an appropriate dehydrogenation reagent for PCHD. The reactivity of TCQ was considerably low for PCHD containing 1,2‐cyclohexadiene units. The reactivity of TOQ was too high and side reactions occurred, causing the formation of structural defects. Copyright © 2007 Society of Chemical Industry     

Degradation of the covalent carbon–carbon bond between fullerene‐C60 and poly(1,3‐cyclohexadiene)

The degradation of fullerene‐C₆₀ (C₆₀) end‐capped poly(1,3‐cyclohexadiene) (C₆₀‐PCHD) with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) was examined to reveal the nature of the covalent carbon–carbon bond between C₆₀ and PCHD (C₆₀‐PCHD bond). The number average molecular weight (M_n) of C₆₀‐PCHD decreased with an increase in the degree of dehydrogenation, and the elimination of a PCHD arm from a C₆₀ occurred. The degradation of the C₆₀‐PCHD bond via a 1,4‐CHD unit was faster than that via a 1,2‐CHD unit, whereas the C₆₀‐poly(cyclohexane) bond was stable. The degradation of the C₆₀‐PCHD bond with DDQ was caused by the dehydrogenation of a CHD unit adjoining a C₆₀ core. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010