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Superconducting Properties and Phase Formation of MgB2 Superconductors Prepared by the Solid State Reaction Method using MgB4 and Mg Powder (MgB4와 Mg 분말을 원료로 사용하여 고상반응법으로 제조한 MgB2 초전도체의 상생성과 초전도 특성)

  • Jeong, Hyeondeok;Kim, Chan-Joong;Jun, Byung-Hyuk;Kim, Seolhyang;Park, Hai-Woong
    • Journal of Powder Materials
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    • v.22 no.5
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    • pp.344-349
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    • 2015
  • $MgB_2$ bulk superconductors are synthesized by the solid state reaction of ($MgB_4$+xMg) precursors with excessive Mg compositions (x=1.0, 1.4, 2.0 and 2.4). The $MgB_4$ precursors are synthesized using (Mg+B) powders. The secondary phases ($MgB_4$ and MgO) present in the synthesized $MgB_4$ are removed by $HNO_3$ leaching. It is found that the formation reaction of $MgB_2$ is accelerated when Mg excessive compositions are used. The magnetization curves of $Mg_1+_xB_2$ samples show that the transition from the normal state to the superconducting state of the Mg excessive samples with x=0.5 and x=0.7 are sharper than that of $MgB_2$. The highest $J_c-B$ curve at 5 K and 20 K is achieved for x=0.5. Further addition of Mg decreases the $J_c$ owing to the formation of more pores in the $MgB_2$ matrix and smaller volume fraction of $MgB_2$.

Quality Characteristics of White Pan Bread with Ingredients of Sagoonja-Tang (사군자탕(四君子湯) 재료를 첨가한 식빵의 품질특성)

  • Cho, Jung-Soon;Nam, Hae-Young
    • Korean journal of food and cookery science
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    • v.22 no.4 s.94
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    • pp.458-467
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    • 2006
  • This study was carried out to determine the functional works and basic ingredients of Sagoonja-Tang on white pan bread. The -experimental groups consisted of 6% mixtures of five(Ed- confirm the number) kinds powders, : B1 for Sagoonja-Tang powder, B2 for Panax ginseng, B3 for Poria cocos, Koidz, B4 for Atractylodes macrocephala, and B5 for Glycyrrhiza uralensis Fisch. The volume of white pan bread somewhat decreased after adding the ingredients, and the volume differences in order from highest to lowest, were white pan bread control>B2>B3>B4>B1>B5. For white pan bread, pH of control, B3, and B5 decreased on the 2nd day during storage, but increased on the 4th and 7th days. In the texture analyses of white pan bread, B4 and B5 showed a higher degree of hardness than that of control, while B2, and B3 were the lowest. In sensory test, the overall acceptability of regular white pan bread in order from highest to lowest was control>B3>B2>B1 ${\cdot}$ B5>B4.

B2B 전자 비즈니스의 보완

  • 이현봉;홍성찬
    • Proceedings of the CALSEC Conference
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    • 1999.11a
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    • pp.232-238
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    • 1999
  • ㆍ B2B 전자 비즈니스 유형 : - EDI 와 ERP의 연계 -비즈니스 파트너를 위한 Online 상점 또는 도매점 ㆍ B2B 전자 비즈니스의 보안 위협 요소 : -내부직원, 고객, 비즈니스 파트너, 외부인 ㆍB2B 전자비즈니스 기반 기술 구조: -Application 레벨에서의 통합 (중략)

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Compressive force regulates ephrinB2 and EphB4 in osteoblasts and osteoclasts contributing to alveolar bone resorption during experimental tooth movement

  • Hou, Jianhua;Chen, Yanze;Meng, Xiuping;Shi, Ce;Li, Chen;Chen, Yuanping;Sun, Hongchen
    • The korean journal of orthodontics
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    • v.44 no.6
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    • pp.320-329
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    • 2014
  • Objective: To investigate the involvement of ephrinB2 in periodontal tissue remodeling in compression areas during orthodontic tooth movement and the effects of compressive force on EphB4 and ephrinB2 expression in osteoblasts and osteoclasts. Methods: A rat model of experimental tooth movement was established to examine the histological changes and the localization of ephrinB2 in compressed periodontal tissues during experimental tooth movement. RAW264.7 cells and ST2 cells, used as precursor cells of osteoclasts and osteoblasts, respectively, were subjected to compressive force in vitro. The gene expression of EphB4 and ephrinB2, as well as bone-associated factors including Runx2, Sp7, NFATc1, and calcitonin receptor, were examined by quantitative real-time polymerase chain reaction (PCR). Results: Histological examination of the compression areas of alveolar bone from experimental rats showed that osteoclastogenic activities were promoted while osteogenic activities were inhibited. Immunohistochemistry revealed that ephrinB2 was strongly expressed in osteoclasts in these areas. Quantitative real-time PCR showed that mRNA levels of NFATc1, calcitonin receptor, and ephrinB2 were increased significantly in compressed RAW264.7 cells, and the expression of ephrinB2, EphB4, Sp7, and Runx2 was decreased significantly in compressed ST2 cells. Conclusions: Our results indicate that compressive force can regulate EphB4 and ephrinB2 expression in osteoblasts and osteoclasts, which might contribute to alveolar bone resorption in compression areas during orthodontic tooth movement.

Mad2B forms a complex with Cdc20, Cdc27, Rev3 and Rev1 in response to cisplatin-induced DNA damage

  • Ju Hwan Kim;Rajnikant Patel
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.5
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    • pp.427-436
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    • 2023
  • Mitotic arrest deficient 2 like 2 (Mad2L2, also known as Mad2B), the human homologue of the yeast Rev7 protein, is a regulatory subunit of DNA polymerase ζ that shares high sequence homology with Mad2, the mitotic checkpoint protein. Previously, we demonstrated the involvement of Mad2B in the cisplatin-induced DNA damage response. In this study, we extend our findings to show that Mad2B is recruited to sites of DNA damage in human cancer cells in response to cisplatin treatment. We found that in undamaged cells, Mad2B exists in a complex with Polζ-Rev1 and the APC/C subunit Cdc27. Following cisplatin-induced DNA damage, we observed an increase in the recruitment of Mad2B and Cdc20 (the activators of the APC/C), to the complex. The involvement of Mad2B-Cdc20-APC/C during DNA damage has not been reported before and suggests that the APC/C is activated following cisplatin-induced DNA damage. Using an in vitro ubiquitination assay, our data confirmed Mad2B-dependent activation of APC/C in cisplatin-treated cells. Mad2B may act as an accelerator for APC/C activation during DNA damage response. Our data strongly suggest a role for Mad2B-APC/C-Cdc20 in the ubiquitination of proteins involved in the DNA damage response.

Phase Orientation of TiC-$TiB_2$-SiC Ternary Eutectic Composite Prepared by an FZ Method

  • Tu, Rong;Li, Wenjun;Goto, Takashi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.859-860
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    • 2006
  • TiC-$TiB_2$-SiC system was a ternary eutectic, whose eutectic composition was 34TiC-$22TiB_2$-44SiC (mol%). TiC-$TiB_2$-SiC ternary eutectic composite were synthesized by a floating zone method using TiC, $TiB_2$ and SiC powders as starting materials. The TiC-$TiB_2$-SiC eutectic composite showed a lamellar texture. TiC(022), $TiB_2(010)$ and SiC(111) of the eutectic composite were perpendicular to the growth direction. TiC-$TiB_2$-SiC ternary eutectic composite had specific relationship among the crystal planes: TiC[011]//$TiB_2[010]$//SiC[112], TiC(200)//$TiB_2$(001)//SiC(402) and $TiC(1\bar{1}1)$//$TiB_2(101)$//SiC(220).

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MINIMUM DEGREE AND INDEPENDENCE NUMBER FOR THE EXISTENCE OF HAMILTONIAN [a, b]-FACTORS

  • Zhou, Sizhong;Pu, Bingyuan
    • Journal of applied mathematics & informatics
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    • v.28 no.1_2
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    • pp.325-331
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    • 2010
  • Let a and b be nonnegative integers with 2 $\leq$ a < b, and let G be a Hamiltonian graph of order n with n > $\frac{(a+b-5)(a+b-3)}{b-2}$. An [a, b]-factor F of G is called a Hamiltonian [a, b]-factor if F contains a Hamiltonian cycle. In this paper, it is proved that G has a Hamiltonian [a, b]-factor if $\delta(G)\;\geq\;\frac{(a-1)n+a+b-3)}{a+b-3}$ and $\delta(G)$ > $\frac{(a-2)n+2{\alpha}(G)-1)}{a+b-4}$.

An empirical study on RFM-T model for market performance of B2B-based Technology Industry Companies (B2B 중심의 기술 산업 기업의 수익성 성과를 위한 RFM-T 모형 실증 연구)

  • Miyoung Woo;Young-Jun Kim
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.2
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    • pp.167-175
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    • 2024
  • Due to the Fourth Industrial Revolution, ICT(Information and Communication Technology) industry is becoming more important and sophisticated than ever. In B2B based ICT industry demand forecasting by analyzing the previous customer data is so important. RFM, one of customer relationship management models is a marketing technique that evaluates Recency, Frequency and Monetary value to predict customers behavior. RFM model has been studied focusing on the B2C based industry. On the other hand there is a lack of research on B2B based technology industry. Therefore this study applied it to B2B based high technology industry and considered T(technology collaboration) value, which are identified as important factors in the technology industry. To present an improved model for market performance in B2B technology industry, an empirical study was conducted on comparing the accuracy of the traditional RFM model and the improved RFM-T model. The objective of this study is to contribute to market performance by presenting an improved model in B2B based high technology industry.

Study on the Properties of $B_2O_3$-$SiO_2$and $Al_2O_3$-$SiO_2$Coating Films by the Sol-Gel Method (Sol-Gel법으로 제조한 $B_2O_3$-$SiO_2$$Al_2O_3$-$SiO_2$ 박막의 특성에 관한 연구)

  • 황규석;김병훈;최석진
    • Journal of the Korean Ceramic Society
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    • v.27 no.5
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    • pp.583-588
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    • 1990
  • Glass films in the binary system B2O3-SiO2 and Al2O3-SiO2 were prepared on soda-lime-silica slide glass by the dip-coating technique from TEOS and boric acid or aluminum nitrate. Thickness of the films varying with viscosity and withdrawal speed were measured and effect of composition and firing temperature on the properties such as transmittance and refractive index were investigated. nM2O3.(100-n)SiO2(M=B or Al) films containing up to 20mol% B2O3 and 40mol% Al2O3 were transparent. Maximum transmittance at visible range were obtained for the sample containing 15mol% Ba2O3 and 32.5mol% Al2O3 and heat-treated at 50$0^{\circ}C$, respectively. Refractive index of the film containing 15mol% B2O3 was mininum in the B2O3-SiO2 binary system and minimal refractive index was appeared at the film containing 32.5mol% Al2O3. In IP spectra, addition of B2O3 were increased absorption peak intensity of B-O and Si-O-B bond and addition of Al2O3 were decreased absorption peak intensity of Si-O bond, respectively.

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