228 research outputs found

    Considering the Cultural Issues of Web Design in Implementing Web-Based E-Commerce for International Customers

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    The web design for international e-commerce sites is becoming an increasingly important issue. This paper addresses issues about cultural differences in web design and designers’ views. The summary of research work includes understanding of designers’ attitudes and approaches in designing web sites for different countries. Some suggestions about important aspect of localized design are made from case studies conducted during this research

    A highly active and durable lanthanum strontium cobalt ferrite cathode for Intermediate-Temperature solid Oxide fuel cel

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    Solid oxide fuel cells (SOFCs) are promising techniques for high energy efficiency, fuel flexibility, and low pollutant emissions. For commercialization of SOFCs, it is required to decrease the operating temperature. At this intermediate temperature region, the cathodic polarization resistance significant due to the thermally activated oxygen reduction reaction (ORR). To compensate this, highly active cathode materials have been considered and lanthanum strontium cobalt ferrite (LSCF6428, La0.6Sr0.4Co0.2Fe0.8O3-δ) has been attracted as a cathode material for SOFCs because of its high mixed electronic and ionic conducting (MIEC) nature. However, one of the major concerns of LSCF6428 is the degradation during the long-term operation. Currently, Sr segregation has been reported as one of the major reasons for the LSCF degradation. In this study, we investigated LSCF2882 (La0.2Sr0.8Co0.8Fe0.2O3-δ) and compared with LSCF6428 as a SOFC cathode. X-ray diffraction (XRD) and Rietveld refinement were applied to analyze phase structures. By electrical conductivity relaxation (ECR) technique, Oxygen surface exchange coefficients (kchem) and chemical diffusion coefficients (Dchem) of LSCF2882 were evaluated and we observed enhancements compare to LSCF6428. For interpretation of enhanced oxygen transport kinetics, we tried to visualize the interstitial oxygen conduction pathways and the bond valence sum (BVS) mapping method was utilized by Valence program. BVS mapping results show clearly demonstrating the 3D network of the interstitial pathways at 600oC in LSCF2882. Electrochemical performances were investigated by EIS (Electrochemical Impedance Spectroscopy) and single cell performance was also evaluated. In addition, long-term stability test was performed for over 500 hours. LSCF2882 showed better performances and it exhibited no degradation during the stability test. Please click Additional Files below to see the full abstract

    Immobilization of Saccharomyces Cerevisiae in Rice Hulls for Ethanol Production

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    The whole cell immobilization in ethanol fermentation can be done by using natural carriers or through synthetic carriers. All of these methods have the same purpose of retaining high cell concentrations within a certain defined region of space which leads to higher ethanol productivity. Lignocellulosic plant substance represents one of highly potential sources in ethanol production. Some studies have found that cellulosic substances substances can also be used as a natural carrier in cell immobilization by re-circulating pre-culture medium into a reactor. In this experiment, ricehulls without any treatment were used to immobilize Saccharomyces cerevisiae through semi solid state incubation combined with re-circulating pre-culture medium. The scanning electron microscopy (SEM) pictures of the carrier show that the yeast cells are absorbed and embedded to the rice hull pore. In liquid batch fermentation system with an initial sugar concentration of 50 g/L, nearly 100% total sugar was consumed after 48 hours. This resulted in an ethanol yield of 0.32 g ethanol/g glucose, which is 62.7% of the theoretical value. Ethanol productivity of 0.59 g/(L.h) is 2.3 fold higher than that of free cells which is 0.26 g/(L.h). An effort to reuse the immobilized cells in liquid fermentation system showed poor results due to cell desorption in the first batch which led to high sugar concentration inhibitory effect in the second batch fermentation. This might be solved by using semi solid fermentation process in the future work

    Effects of warming and eutrophication on coastal phytoplankton production

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    Phytoplankton production in coastal waters influences seafood production and human health and can lead to harmful algal blooms. Water temperature and eutrophication are critical factors affecting phytoplankton production, although the combined effects of warming and nutrient changes on phytoplankton production in coastal waters are not well understood. To address this, phytoplankton production changes in natural waters were investigated using samples collected over eight months, and under 64 different initial conditions, established by combining four different water temperatures (i.e., ambient T, + 2, + 4, and + 6 degrees C), and two different nutrient conditions (i.e., non-enriched and enriched). Under the non-enriched conditions, the effect of warming on phytoplankton production was significantly positive in some months, significantly negative in others, or had no effect. However, under enriched conditions, warming affected phytoplankton production positively in all months except one, when the salinity was as low as 6.5. These results suggest that nutrient conditions can alter the effects of warming on phytoplankton production. Of several parameters, the ratio of initial nitrate concentration to chlorophyll a concentration [NCCA, mu M (pg L-1)(-1))] was one of the most critical factors determining the directionality of the warming effects. In laboratory experiments, when NCCA in the ambient or nutrient-enriched waters was >= 1.2, warming increased or did not change phytoplankton production with one exception; however, when NCCA was < 1.2, warming did not change or decreased production. In the time series data obtained from the coastal waters of four target countries, when NCCA was 1.5 or more, warming increased phytoplankton production, whereas when NCCA was lower than 1.5, warming lowered phytoplankton production, Thus, it is suggested that NCCA could be used as an index for predicting future phytoplankton production changes in coastal waters.11Ysciescopu

    Measurements of time-dependent CP asymmetries in BDπ±B \to D^{*\mp} \pi^{\pm} decays using a partial reconstruction technique

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    We report results on time-dependent CP asymmetries in BDπ±B \to D^{*\mp}\pi^{\pm} decays based on a data sample containing 657 {\times} 10610^6 BBˉB\bar{B} pairs collected with the Belle detector at the KEKB asymmetric-energy e+ee^+ e^- collider at the Υ(4S)\Upsilon(4S) resonance. We use a partial reconstruction technique, wherein signal BDπ±B \to D^{*\mp}\pi^{\pm} events are identified using information only from the fast pion from the B decay and the slow pion from the subsequent decay of the DD^{*\mp}, where the former (latter) corresponds to D+(D)D^{*+} (D^{*-}) final states. We obtain CP violation parameters S+=+0.061±0.018(stat)±0.012(syst)S^+ = +0.061 \pm 0.018(\mathrm{stat}) \pm 0.012(\mathrm{syst}) and S=+0.031±0.019(stat)±0.015(syst)S^- = +0.031 \pm 0.019(\mathrm{stat}) \pm 0.015(\mathrm{syst}).Comment: 8 pages, 5 figures, 2 tables, submitted to Physical Review D (RC

    Search for CP violation in tau -> K^0_S pi nu_tau decays at Belle

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    We report on a search for CP violation in tau -> K^0_S pi nu_tau decays using a data sample of 699 fb^{-1} collected in the Belle experiment at the KEKB electron-positron asymmetric-energy collider. The CP asymmetry is measured in four bins of the invariant mass of the K^0_S pi system and found to be compatible with zero with a precision of O(10^{-3}) in each mass bin. Limits for the CP violation parameter Im(eta_S) are given at a 90 % confidence level. These limits are |Im(eta_S)|<0.026 or better, depending on the parameterization used to describe the hadronic form factors and improve upon previous limits by one order of magnitude

    Search for CP violation in the decays D(s)+KS0π+D^+_{(s)} \to K_S^0\pi^+ and D(s)+KS0K+D^+_{(s)} \to K_S^0K^+

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    We have searched for CP violation in the charmed meson decays D(s)+KS0π+D^{+}_{(s)}\to K^0_S\pi^+ and D(s)+KS0K+D^{+}_{(s)}\to K^0_S K^+ using 673 fb1^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. No evidence for CP violation is observed. We report the most sensitive CP asymmetry measurements to date for these decays: ACPD+KS0π+=(0.71±0.19±0.20)A_{CP}^{D^+\to K^0_S\pi^+}=(-0.71\pm0.19\pm0.20)%, ACPDs+KS0π+=(+5.45±2.50±0.33)A_{CP}^{D^+_s\to K^0_S\pi^+}=(+5.45\pm2.50\pm0.33)%, ACPD+KS0K+=(0.16±0.58±0.25)A_{CP}^{D^+\to K^0_S K^+}=(-0.16\pm0.58\pm0.25)%, and ACPDs+KS0K+=(+0.12±0.36±0.22)A_{CP}^{D^+_s\to K^0_S K^+}=(+0.12\pm0.36\pm0.22)%, where the first uncertainties are statistical and the second are systematic

    Measurement of the decay B0π+νB^0\to\pi^-\ell^+\nu and determination of Vub|V_{ub}|

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    We present a measurement of the charmless semileptonic decay B0π+νB^0\to\pi^-\ell^+\nu using a data sample containing 657×106\times 10^6 BBˉB\bar{B} events collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider operating near the Υ(4S)\Upsilon(4S) resonance. We determine the total branching fraction of the decay, B(B0π+ν)=(1.49±0.04(stat)±0.07(syst))×104\mathcal{B}(B^0\to\pi^-\ell^+\nu)=(1.49\pm 0.04{(\mathrm{stat})}\pm 0.07{(\mathrm{syst})})\times 10^{-4}. We also report a new precise measurement of the differential decay rate, and extract the Cabibbo-Kobayashi-Maskawa matrix element Vub|V_{ub}| using model-independent and -dependent approaches. From a simultaneous fit to the measured differential decay rate and lattice QCD results, we obtain Vub=(3.43±0.33)×103|V_{ub}|=(3.43\pm 0.33)\times 10^{-3}, where the error includes both statistical and systematic uncertainties.Comment: 8 pages, 3 figures, Submitted to PRD(RC

    Search for Bπ+B \to \pi \ell^+\ell^- Decays at Belle

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    We present a search for the B-> pi e^+ e^- and B-> pi \mu^+ \mu^- decays, with a data sample of 657 million BBbar pairs collected with the Belle detector at the KEKB e+ee^+e^- collider. Signal events are reconstructed from a charged or a neutral pion candidate and a pair of oppositely charged electrons or muons. No significant signal is observed and we set the upper limit on the isospin-averaged branching fraction BF(B -> \pi \ell^+\ell^-) < 6.2x10^-8 at the 90% confidence level.Comment: 8 pages, 3 figures, accepted by PRD(RC

    Evidence for B0χc1π0B^0 \to \chi_{c1} \pi ^0 at Belle

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    We present a measurement of the branching fraction for the Cabibbo- and color-suppressed B0χc1π0B^0 \to \chi_{c1}\pi^0 decay based on a data sample of 657×106657\times 10^6 BBˉB\bar B events collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. We observe a signal of 40±940\pm9 events with a significance of 4.7σ4.7\sigma including systematic uncertainties. The measured branching fraction is B(B0χc1π0)=(1.12±0.25(stat.)±0.12(syst.))×105\mathcal {B}(B^0 \to \chi_{c1} \pi^0) = (1.12\pm 0.25(\rm {stat.})\pm 0.12({\rm syst.}))\times 10^{-5}.Comment: 5 pages, 5 figure
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