524 research outputs found

    The Global Economic Crisis, Dual Polarization, and Liberal Democracy in South Korea

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    This paper aims at a theoretical reflection on and an empirical analysis of the relationship between the global economic crisis and liberal democracy in South Korea. For this, we elaborate the concept of dual polarization and construct a model of path analysis which includes such variables as socio-economic and political-ideological cleavage, political party affiliation, ideological orientation, economic (crisis) outlook, and support for an autocratic presidential rule as potential threats to liberal democracy. Descriptively, the paper examines how liberal democracy has unfolded and where South Korea stands today with regard to the quality of her democracy. Analytically, the paper examines where the potential threat to liberal democracy comes from based on a general population survey in Korea from 2014. The major findings of our analysis include: 1) The support for autocratic presidential power is stronger among citizens than among MPs. 2) Political party affiliation, ideological orientation, and economic (crisis) outlook are closely interrelated and significantly affected by the political-ideological cleavage. All independent variables contribute to explaining support for an autocratic presidential rule. 3) Yet there also exists strong support for a democratic regime among both MPs and citizens

    Controlling vibrational excitation with shaped mid-IR pulses

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    We report selective population of the excited vibrational levels of the T1u CO-stretching mode in W(CO)6 using phase-tailored, femtosecond mid-IR (5.2??m, 1923cm-1) pulses. An evolutionary algorithm was used to optimize specific vibrational populations. Stimulated emission peaks, indicative of population inversion, could be induced. Systematic truncation of each optimized pulse allowed for increased understanding of the excitation mechanism. The pulses and techniques developed herein will have broad applications in controlling ground state chemistry and enhancing vibrational spectroscopies.open514

    Copper nanofiber-networked cobalt oxide composites for high performance Li-ion batteries

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    We prepared a composite electrode structure consisting of copper nanofiber-networked cobalt oxide (CuNFs@CoOx). The copper nanofibers (CuNFs) were fabricated on a substrate with formation of a network structure, which may have potential for improving electron percolation and retarding film deformation during the discharging/charging process over the electroactive cobalt oxide. Compared to bare CoOxthin-film (CoOxTF) electrodes, the CuNFs@CoOxelectrodes exhibited a significant enhancement of rate performance by at least six-fold at an input current density of 3C-rate. Such enhanced Li-ion storage performance may be associated with modified electrode structure at the nanoscale, improved charge transfer, and facile stress relaxation from the embedded CuNF network. Consequently, the CuNFs@CoOxcomposite structure demonstrated here can be used as a promising high-performance electrode for Li-ion batteries

    Facile collection of two-dimensional electronic spectra using femtosecond pulse-shaping technology

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    This letter reports a straightforward means of collecting two-dimensional electronic (2D-E) spectra using optical tools common to many research groups involved in ultrafast spectroscopy and quantum control. In our method a femtosecond pulse shaper is used to generate a pair of phase stable collinear laser pulses which are then incident on a gas or liquid sample. The pulse pair is followed by an ultrashort probe pulse that is spectrally resolved. The delay between the collinear pulses is incremented using phase and amplitude shaping and a 2D-E spectrum is generated following Fourier transformation. The partially collinear beam geometry results in perfectly phased absorptive spectra without phase twist. Our approach is much simpler to implement than standard non-collinear beam geometries, which are challenging to phase stabilize and require complicated calibrations. Using pulse shaping, many new experiments are now also possible in both 2D-E spectroscopy and coherent control.open798

    Field modulation in Na-incorporated Cu(In,Ga)Se2 (CIGS) polycrystalline films influenced by alloy-hardening and pair-annihilation probabilities

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    The influence of Na on Cu(In,Ga)Se2 (CIGS) solar cells was investigated. A gradient profile of the Na in the CIGS absorber layer can induce an electric field modulation and significantly strengthen the back surface field effect. This field modulation originates from a grain growth model introduced by a combination of alloy-hardening and pair-annihilation probabilities, wherein the Cu supply and Na diffusion together screen the driving force of the grain boundary motion (GBM) by alloy hardening, which indicates a specific GBM pinning by Cu and Na. The pair annihilation between the ubiquitously evolving GBMs has a coincident probability with the alloy-hardening event

    Corrosion Control of Alloy 690 by Shot Peening and Electropolishing under Simulated Primary Water Condition of PWRs

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    This work clarifies the effect of surface modifications on the corrosion rate of Alloy 690, a nickel-based alloy for steam generator tubes, under the simulated test conditions of the primary water chemistry in nuclear power plants. The surface stress was modified by the shot peening and electropolishing methods. The shot peening treatment was applied using ceramic beads with different intensities by varying the air pressure and projection angle. The corrosion rate was evaluated by gravimetric analysis and the surface was analyzed by scanning electron microscopy (SEM). The corrosion rate of Alloy 690 was evaluated from the influence of the stress state on the metal surface. Based on the observation of the surface after the corrosion test, the oxide composition and its structure were affected by the surface modifications. The corrosion behavior of Alloy 690 was distinguished by the shot peening intensity on the surface, and additional electropolishing was effective at reducing the dissolution of nickel ions from the metal surface

    Molecular lens applied to benzene and carbon disulfide molecular beams

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    A molecular lens of the nonresonant dipole force formed by focusing a nanosecond IR laser pulse has been applied to benzene and CS2 molecular beams. Using the velocity map imaging technique for molecular ray tracing, characteristic molecular lens parameters including the focal length (f ), minimum beam width (W), and distance to the minimum beam width position (D) were determined. The laser intensity dependence of the observed lens parameters was in good agreement with theoretical predictions. W was independent of the laser peak intensity (I-0), whereas f and D varied linearly with 1/I-0. The differences in lens parameters between the molecular species were well correlated with the polarizability per mass values of the molecules. A high chromatographic resolution of Rs = 0.84 was achieved between the images of benzene molecular beams undeflected and deflected by the lens. The possibilities for a new type of chromatography are discussed.open293

    Revisiting the Seasonal Variations of Sea-Air CO2 Fluxes in the Northern East China Sea

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    Temperature, salinity, chlorophyll a (Chl-a), nitrate, and sea-air differences of CO2 partial pressure (ΔpCO2) were extensively investigated in the northern East China Sea (ECS) during seven research cruises from 2003 to 2009. The ΔpCO2 showed large intraseasonal variation in the spring and summer. In spring, the areal mean ΔpCO2 in May 2004 was almost half of that in April 2008, probably associated with differences in sea surface temperature (SST). In summer, the areal mean ΔpCO2 in August 2003 was also twice as large as that in July 2006. In addition, ΔpCO2 exhibited large seasonal variation with positive values in autumn and negative values in other seasons. The positive ΔpCO2 in autumn was ascribed to vertical mixing with CO2-enriched subsurface waters and relatively high SST in this season. The annually integrated sea-air CO2 flux in the northern ECS was -2.2 ± 2.1 mol m-2 yr-1, indicating CO2 absorption from atmosphere to the sea, which was more than two times lower than the previous estimate (Shim et al. 2007) reported for the same region. This large difference was presumably responsible for the underestimation of winter CO2 influx by Shim et al. (2007) and the large interannual variation of CO2 flux. The CO2 influx in the ECS was twice that estimated for continental shelves worldwide, suggesting that the ECS acts as a strong sink of atmospheric CO2 compared to other continental shelves

    Is Cognitive Function in Adults with Hearing Impairment Improved by the Use of Hearing Aids?

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    ObjectivesIn the present study, we investigated whether speech-related cognitive function and speech recognition ability under background noise in adults with hearing impairment are improved with the use of hearing aids.MethodsParticipants were recruited from the ENT Department of Eulji Hospital from September 2008 to July 2009. The study group comprised 18 participants (mean age, 69.5±8.3 years) with sensorineural hearing loss who were fitted with hearing aids, and the control group comprised 11 participants of equivalent age (mean age, 63.1±11.8 years) who were not fitted with hearing aids. All participants were assessed using the computerized Korean visual verbal learning test (VVLT) and words-in-noise (WIN) test prior to fitting of hearing aids for the study group and initially for the control group. Both groups were reassessed in both tests after 6 months. For each group, differences in the results between the two assessments were compared using the Friedman test.ResultsThere was no difference in mean age between the study group and control group. In the study group, total VVLT score (reflecting short-term memory) was significantly improved from before hearing aid use to 6 months after hearing aid use (P0.05).ConclusionThe speech-related cognitive function of individuals with hearing impairment improved after using hearing aids. This finding indicates that hearing aids may induce acclimatization of the central auditory system
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