228 research outputs found
Considering the Cultural Issues of Web Design in Implementing Web-Based E-Commerce for International Customers
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
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.
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Immobilization of Saccharomyces Cerevisiae in Rice Hulls for Ethanol Production
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
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 decays using a partial reconstruction technique
We report results on time-dependent CP asymmetries in decays based on a data sample containing 657 {\times}
pairs collected with the Belle detector at the KEKB
asymmetric-energy collider at the resonance. We use a
partial reconstruction technique, wherein signal
events are identified using information only from the fast pion from the B
decay and the slow pion from the subsequent decay of the , where the
former (latter) corresponds to final states. We obtain CP
violation parameters and .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
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 and
We have searched for CP violation in the charmed meson decays and using 673 fb of data
collected with the Belle detector at the KEKB asymmetric-energy
collider. No evidence for CP violation is observed. We report the most
sensitive CP asymmetry measurements to date for these decays: , , , and , where the first uncertainties are statistical and
the second are systematic
Measurement of the decay and determination of
We present a measurement of the charmless semileptonic decay
using a data sample containing 657
events collected with the Belle detector at the KEKB
asymmetric-energy collider operating near the
resonance. We determine the total branching fraction of the decay,
. We also report a new precise measurement
of the differential decay rate, and extract the Cabibbo-Kobayashi-Maskawa
matrix element using model-independent and -dependent approaches.
From a simultaneous fit to the measured differential decay rate and lattice QCD
results, we obtain , where the error
includes both statistical and systematic uncertainties.Comment: 8 pages, 3 figures, Submitted to PRD(RC
Search for Decays at Belle
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 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 at Belle
We present a measurement of the branching fraction for the Cabibbo- and
color-suppressed decay based on a data sample of
events collected at the resonance
with the Belle detector at the KEKB asymmetric-energy collider. We
observe a signal of events with a significance of
including systematic uncertainties. The measured branching fraction is
.Comment: 5 pages, 5 figure
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