Surface versus bulk characterization of the electronic inhomogeneity in a VO_{2} film

We investigated the inhomogeneous electronic properties at the surface and interior of VO_{2} thin films that exhibit a strong first-order metal-insulator transition (MIT). Using the crystal structural change that accompanies a VO_{2} MIT, we used bulk-sensitive X-ray diffraction (XRD) measurements to estimate the fraction of metallic volume p^{XRD} in our VO_{2} film. The temperature dependence of the p$^{XRD}$ was very closely correlated with the dc conductivity near the MIT temperature, and fit the percolation theory predictions quite well: $\sigma$ $\sim$ (p - p_{c})^{t} with t = 2.0$\pm$0.1 and p_{c} = 0.16$\pm$0.01. This agreement demonstrates that in our VO$_{2}$ thin film, the MIT should occur during the percolation process. We also used surface-sensitive scanning tunneling spectroscopy (STS) to investigate the microscopic evolution of the MIT near the surface. Similar to the XRD results, STS maps revealed a systematic decrease in the metallic phase as temperature decreased. However, this rate of change was much slower than the rate observed with XRD, indicating that the electronic inhomogeneity near the surface differs greatly from that inside the film. We investigated several possible origins of this discrepancy, and postulated that the variety in the strain states near the surface plays an important role in the broad MIT observed using STS. We also explored the possible involvement of such strain effects in other correlated electron oxide systems with strong electron-lattice interactions.Comment: 27 pages and 7 figure

Prioritization of water management under climate change and urbanization using multi-criteria decision making methods

This paper quantifies the transformed effectiveness of alternatives for watershed management caused by climate change and urbanization and prioritizes five options using multi-criteria decision making techniques. The climate change scenarios (A1B and A2) were obtained by using a statistical downscaling model (SDSM), and the urbanization scenario by surveying the existing urban planning. The flow and biochemical oxygen demand (BOD) concentration duration curves were derived, and the numbers of days required to satisfy the environmental flow requirement and the target BOD concentration were counted using the Hydrological Simulation Program-Fortran (HSPF) model. In addition, five feasible alternatives were prioritized by using multi-criteria decision making techniques, based on the driving force-pressure-state-impact-response (DPSIR) framework and cost component. Finally, a sensitivity analysis approach for MCDM methods was conducted to reduce the uncertainty of weights. The result indicates that the most sensitive decision criterion is cost, followed by criteria response, driving force, impact, state and pressure in that order. As it is certain that the importance of cost component is over 0.127, construction of a small wastewater treatment plant will be the most preferred alternative in this application

The scale of typhoon RUSA

International audienceIn August 2002, Typhoon RUSA hit Korea with severe gale and storm, causing extensive damage throughout the whole country and especially in the Gangneung area. Even on a single day, Typhoon RUSA recorded up to 879.5 mm of rainfall in the Gangneung area. Quantitative and qualitative analyses of the scale of Typhoon RUSA are performed in this study. Most of the inland affected by RUSA in the Korean Peninsula recorded heavy rainfall, equivalent to a return period of more than 200 years. Especially, rainfall of 24 h duration exceeded the maxima observed so far. Although areal rainfall showed a rapidly decreasing trend with increasing area, it reached 96 percent of the existing PMP within a 2000 km2 area and recorded the maximum observed value of Korea according to a DAD analysis of rainfall. Re-estimated PMP values obtained from a hydro-meteorological approach compared with existing PMP estimates revealed a discrepancy between the two values, which showed that re-estimated PMP values of 12 to 24 h duration within 2000 km2 exceeded the existing PMP estimates of Korea. Therefore, modification of the existing PMP is required, which is used as a design hydrological variable of hydraulic structure

The static and dynamic behavior of a very long shaft made of a composite

A very long rubbing roller with a small deflection is required the manufacture of large LCD thin films. In order to accomplish this, the shaft for the roller is often made with a composite material. As composite material shafts are expensive and require a long time to manufacture, a simulation to check the deflection of the shaft should be conducted during the design step. However, simulations of extremely long composite materials are seldom reported. Thus, an accurate simulation technique should be studied. Therefore, this report presents the static and dynamic simulations of a very long composite material shaft. The simulation was in good agreement with the test data; hence, the simulation technique can help model other composite material shafts

Extreme cavity expansion in soft solids: damage without fracture

Cavitation is a common damage mechanism in soft solids. Here, we study this using a phase-separation technique in stretched, elastic solids to controllably nucleate and grow small cavities by several orders of magnitude. The ability to make stable cavities of different sizes, as well as the huge range of accessible strains, allows us to systematically study the early stages of cavity expansion. Cavities grow in a scale-free manner, accompanied by irreversible bond breakage that is distributed around the growing cavity, rather than being localized to a crack tip. Furthermore, cavities appear to grow at constant driving pressure. This has strong analogies with the plasticity that occurs surrounding a growing void in ductile metals. In particular we find that, although elastomers are normally considered as brittle materials, small-scale cavity expansion is more like a ductile process. Our results have broad implications for understanding and controlling failure in soft solids

DEVELOPMENT OF A PULLING-REAPING TRAINING & MEASUREMENT INSTRUMENT TO ENHANCE JUDO PERFORMANCE

The purpose of this study was to develop a judo-doll uke (partner) for training and measurement applicable to pulling, pushing and sweeping in Judo. In Judo the most common techniques consist of the pulling, pushing and reaping which all need to be practiced with a partner. So research needs to develop a measurement system that can be used to evaluate the forces involved with these techniques. The Doll-Uke was developed so that Judoists can train alone. After the manufacture of Doll-Uke the strengths and weaknesses were recorded and evaluated. The height of a Doll-Uke is 170cm and has a weight of 70kg. Doll-Uke was developed with a trunk angle of 55° and the lower extremities of an angle of 45°. The Doll-Uke can also measure the forces developed during the pulling, pushing and reaping. Due to the ability of the system to measure the forces while performing Judo techniques, feedback can be provided to the Judoists to improve their performance during training

Inhibition of Inducible Nitric Oxide Synthase, Cycleooxygenase-2 and Lipid Peroxidation by Methanol Extract of Pericarpium Zanthoxyli

Purpose: To explore the antioxidant properties of the methanol extract of Pericarpium Zanthoxyli and its effect on inducible nitric oxide synthase (iNOS), cycleooxygenase-2 (COX-2) and lipopolysaccharides (LPS)-induced cell damage in macrophage cells.Methods: Anti-oxidant activities were tested by measuring free radical scavenging activity (DPPH, NO) and lipid peroxidation levels. The mechanism of anti-oxidant action of Pericarpium Zanthoxyli extractwas determined by Western blot analysis for iNOS and COX-2 expression in LPS-stimulated RAW 264.7 cells.Results: Pericarpium Zanthoxyli extract contained anti-oxidant   components including phenolics (2.456 mg/g), flavonoids (0.127 mg/g) and anthocyanins (20.34 mg/g). The extract exerted significant radicalscavenging activity in a dose-dependent manner. It also inhibited lipid peroxidation and exerted dramatic reducing power (28.9-fold compared with control at a concentration of 1 mg/ml). Production of iNOS induced by LPS was significantly (p < 0.05) inhibited by the extract, suggesting that the extract inhibits nitric oxide (NO) production by suppressing iNOS expression. Strikingly, COX-2 induced by LPS was also significantly (p < 0.05) inhibited by the extract.Conclusion: These results suggest that the methanol extract of Pericarpium Zanthoxyli exerts significant anti-oxidant activity via inhibiting free radicals, iNOS and lipid peroxidation as well as by inhibition of COX-2 enzyme.Keywords: Pericarpium Zanthoxyli, Nitric oxide, iNOS, COX-2, Lipid peroxidation, Antioxidan