• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.3
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• pp.157-161
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• 2017

$(1-x)Bi_{0.5}(Na_{0.78}K_{0.22})_{0.5}TiO_3-xLaFeO_3$ ceramics were fabricated using a solid state reaction method. The microstructural, ferroelectric and piezoelectric properties were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and polarization hysteresis loops (P-E). XRD results indicated that BNKT ceramic crystal structure modified by $LaFeO_3$ was transformed from a ferroelectric tetragonal to a non-polar pesudo-cubic phase with increased $LaFeO_3$ content. The improved piezoelectric properties resulted from the addition of $LaFeO_3$ up to 3 mol%. The $LaFeO_3$ 3mol% sample showed markedly improved piezoelectric and strain behaviors in comparison with pure BNKT ceramic.

• The Journal of the Korea Contents Association
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• v.15 no.4
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• pp.122-138
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• 2015

This research examines factors affecting behavioral intention to use integrated platform (IP), which is one of the business models regarding paid digital contents, based on extended United Theory of Acceptance and Use of Technology (UTAUT2). IP is a service which is designed to make digital content charged. It combines digitalized format of newspaper, premium news or behind news, and additional information. The results of this paper show that effort expectancy, social influence and hedonic motivation have positive relationship with behavioral intention to use IP (BI). Satisfaction with newspaper shows negative relationship with BI, which means that newspaper and IP can be replaced with each other. Newspaper subscribers tend to have higher BI than non-subscribers. Performance expectancy, gender, age, and satisfaction with website do not have significant effect on BI.

• Journal of Gastric Cancer
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• v.14 no.4
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• pp.229-237
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• 2014

Purpose: Laparoscopic distal gastrectomy (LDG) is a well-established procedure for the treatment of early gastric cancer. Several reconstruction methods can be adopted after LDG according to tumor characteristics and surgeon preference. This study aimed to compare the remnant gastric functions after different reconstructions. Materials and Methods: In total, 221 patients who underwent LDG between March 2005 and October 2013 were reviewed retrospectively. The patients were classified into four groups based on the reconstructive procedure: Billroth I (BI) anastomosis, Billroth II (BII) with Braun anastomosis, Roux-en-Y (RY) reconstruction, or uncut RY reconstruction. Patient demographics, surgical outcomes, and postoperative endoscopic findings were reviewed and compared among groups. Results: Endoscopic evaluations at $11.8{\pm}3.8$ months postoperatively showed less frequent gastritis and bile reflux in the remnant stomach in the RY group compared to the BI and BII groups. There was no significant difference in the gastric residue among the BI, BII, and RY groups. The incidence of gastritis and bile reflux in the uncut RY group was similar to that in the RY group, while residual gastric content in the uncut RY group was significantly smaller and less frequently observed than that in the RY group (5.8% versus 35.3%, P=0.010). Conclusions: RY and uncut RY reconstructions are equally superior to BI and BII with Braun anastomoses in terms of gastritis and bile reflux in the remnant stomach. Furthermore, uncut RY reconstruction showed improved stasis compared to conventional RY gastrojejunostomy. Uncut RY reconstruction can be a favorable reconstructive procedure after LDG.

• Journal of Powder Materials
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• v.17 no.4
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• pp.289-294
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• 2010

For the aim of low-temperature co-fired ceramic microwave components, sintering behavior and microwave properties (dielectric constant ${\varepsilon}_r$, quality factor Q, and temperature coefficient of resonant frequency ${\tau}_f$) are investigated in $Bi_{18}O(Ca_{0.725}Zn_{0.275})_8Nb_{12}O_{65}$ [BCZN] ceramics with addition of $V_2O_5$. The specimens are prepared by conventional ceramic processing technique. As the main result, it is demonstrated that the additives ($V_2O_5$) show the effect of lowering of sintering temperature and improvement of microwave properties at the optimum additive content. The addition of 0.25 wt% $V_2O_5$ lowers the sintering temperature to $890^{\circ}C$ utilizing liquidphase sintering and show the microwave dielectric properties (dielectric constant ${\varepsilon}_r$ = 75, quality factor $Q{\times}f$ = 572 GHz, temperature coefficient of resonance frequency ${\tau}_f\;=\;-10\;ppm/^{\circ}C$). The estimated microwave dielectric properties with $V_2O_5$ addition (increase of ${\varepsilon}_r$, decrease of $Q{\times}f$, shift of ${\tau}_f$ to negative values) can be explained by the observed microstrucure (sintered density, abnormal grain structure) and possibly high-permittivity $Bi_{18}Zn_8Nb_{12}O_{65}$ (BZN) phase determined by X-ray diffraction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.469-473
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• 2007

With the aim to analyze stability performance of six promising barley genotypes, eleven yield related characters were evaluated employing varied irrigation treatments under the tropical climate of Northern part in Bangladesh. Analysis of variance(ANOVA), phenotypic index, regression co-efficient(bi) and deviation from regression($s^2_d$) of the individual genotypes were estimated to evaluate the stable performance of the genotypes. A significant interaction was observed between the genotypes and irrigation period($G{\times}T$). Among all the genotypes, BSH-2 showed stable performance for plant height under different irrigation period, where $P>\bar{X},\;bi{\sim}1\;and\;s^2_d{\sim}0$. High phenotypic index, lower bi value and low deviations from regression were observed in case of spikelet number per spike and grain number per spike for genotype BSH-2 and plant height, spike length and harvest index per plant for BB-2 which suggest that those parameters were not usually affected by irrigation. On the other hand the genotype BSH-2 for tiller number and BB-1 for the fertile tiller number were not suitable for favorable moisture content, where $P<\bar{X},\;bi>1.0\;and\;low\;s^2_d$. Thus we suggest that genotype BSH-2 might have transmit high mean and increased phenotypic stability to the next progenies, which may consider as an ideal genotype for developing improved barely cultivars.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.3
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• pp.133-139
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• 2011

This study has been investigated for tensile properties with lead-free brass containing 1 wt.% of Bi. And also characteristic of corrosion resistance was analyzed by polarization test. An increase of tempering temperature was found to tend to decrease tensile strength, and percentage of elongation was shown to be the lowest value at $300^{\circ}C$. On the other hand, the elongation was increased with an increase of tempering temperature after $300^{\circ}C$. The change of mechanical properties was closely related with the content and shape of acicular Witmanst$\ddot{a}$tten ${\alpha}$ formed at the interface of ${\beta}$ phase as well as in ${\beta}$ phase. Tensile strength had a tendency to be decreased with an increase of test temperature. The elongation was shown to be the lowest value at around $300^{\circ}C$, while it began to increase as test temperature rose after $300^{\circ}C$. It might be speculated that the reason that elongation was decreased was found to form bismuth film at the interface of ${\alpha}/{\beta}$ phase leading to be easily brittle when loaded by tensile stress. The lead-free brass containing 1 wt.% of Bi had similar characteristic of corrosion resistance with a free-cutting brass with 3.4 wt. % of Pb in spite of higher fraction of ${\beta}$ phase.

• Journal of Magnetics
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• v.18 no.3
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• pp.245-249
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• 2013

A finite element model was built for MnBi/${\alpha}$-Fe nanocomposite permanent magnets, and the demagnetization curves of the magnets were simulated by micro-magnetic calculation. The microstructure of the cubic model is composed of 64 irregular grains with an average grain size of 20 nm. With the volume fraction of soft magnetic phase (t vol. %) ranged from 5 to 20 vol. %, both isotropic and anisotropic nanocomposite magnets show typical single-phase permanent magnets behavior in their demagnetization curves, illustrating good intergranular exchange coupling effect between soft and hard magnetic phases. With the increase of volume fraction of soft magnetic phase in both isotropic and anisotropic magnets, the coercive force of the magnets decreases monotonically, while the remanence rises at first to a peak value, then decreases. The optimal values of maximum energy products of isotropic and anisotropic magnets are 84 and $200kJ/m^3$, respectively. Our simulation shows that the MnBi/${\alpha}$-Fe nanocomposite permanent magnets own excellent magnetic properties and therefore good potential for practical applications.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1734-1741
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• 2023

This work presents the synthesis and preparation of a new glass system described by the equation of (70-x) B₂O₃-5TeO₂ -20SrCO₃-5ZnO -xBi₂O₃, x = 0, 1, 5, 10, and 15 mol. %, using the melt quenching technique at a melting temperature of 1100 ℃. The photon-shielding characteristics mainly the linear attenuation coefficient (LAC) of the prepared glass samples were evaluated using Monte Carlo (MC) simulation N-particle transport code (MCNP-5) at gamma-ray energy extended from 59 keV to 1408 keV emitted by the radioisotopes Am-241, Ba-133, Cs-137, Co-60, Na-22, and Eu-152. Furthermore, we observed that the Bi₂O₃ content of the glasses had a significantly stronger impact on the LAC at 59 and 356 keV. The study of the lead equivalent thickness shows that the performance of fabricated glass sample with 15 mol.% of Bi₂O₃ is four times less than the performance of pure lead at low gamma photon energy while it is enhanced and became two times lower the perforce of pure lead at high energy. Therefore, the fabricated glasses special sample with 15 mol.% of Bi₂O₃ has good shielding properties in low, intermediate, and high energy intervals.

• Progress in Superconductivity and Cryogenics
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• v.16 no.1
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• pp.19-22
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• 2014

The effects of Mg content on the pore formation, density and critical properties were investigated in in-situ reacted $MgB_2$ superconductors. The $Mg_{1+x}B_2$, (x=-0.2, 0.0, 0.05, 0.3, 1.0) bulk samples with different Mg contents were heat-treated at $900^{\circ}C$ for 1 h in an Ar atmosphere. The dimensional changes of a pellet's mass and volume after heat-treatment were measured. After heat-treatment process, the sample mass was decreased by Mg evaporation, but the sample volume was expanded by pore formation at the Mg site; therefore, the apparent density was decreased. Spherical pores the same as Mg particles were developed after heat-treatment in all samples, and the pore density was increased with increasing Mg content. As the x of Mg content was increased to 1.0, the apparent density of $Mg_{1+x}B_2$ samples was decreased due to a relatively larger reduction in a mass change. The critical current density of Mg excessive sample of x=0.05 showed the highest values over the applied magnetic fields because the excessive Mg may compensate Mg loss and enhance grain connectivity.

• Korean journal of food and cookery science
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• v.32 no.5
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• pp.648-655
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• 2016

Purpose: This study investigated the salt and sodium content of lunch meals served at foodservice center for children in Gyeongsan-si, Gyeongsangbuk-do. Methods: Five foodservice centers for children registered at Center for Children's Foodservice Management were investigated for salt and sodium content and salt content contributing rate per meal. Results: Average salt content of every meal was $1.78{\pm}0.54g$, and average sodium content was $680.99{\pm}175.97mg$. The 98 of 100 meals served in 5 foodservice centers for children exceeded the dietary reference intakes for Koreans' recommendation for adequate intake of sodium per meal of 333 mg. The highest sodium content was 1,369.85 mg. Samples from lunch meals were classified into 14 food items and investigated for one serving size, salinity, salt and sodium content. Total average salinity was 0.31%, kimchi (0.49%), followed by soup (0.45%), hard-boiled foods (0.39%), stir-fried foods (0.39%), and fresh-vegetables (0.32%). Total average salt content was 0.39 g, the most salty dishes were one-dish rice noodles, followed by soup (0.65 g), hard-boiled foods (0.49 g), stir-fried foods (0.48 g), and broth stew (0.43 g). Samples from lunch meals were classified into 6 menu groups, including cooked rice, one-dish rice noodles, soup stew, main dish, side dish, and kimchi. Contributing rate for total average salt content was high in one-dish rice noodles (48.97%), soup stew (38.47%), main dish (27.28%), side dish (21.02%), kimchi (18.56%), and cooked rice (3.95%). Conclusion: These results can be useful for reducing total dietary sodium content to less than 333 mg in children who are provided lunch meals at foodservice centers. To achieve this goal, development of low-sodium recipes, and nutrition education for foodservice employees is required.