• Title/Summary/Keyword: KCT

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Development of a TL pellet based on $CaSO_4:Dy$ for Neutron Measurement ($CaSO_4:Dy$ 물질 기반 중성자 측정용 TL소자 개발)

  • Yang, Jeong-Seon;Lee, Jeong-Il;Kim, Jang-Lyul;Kim, Bong-Hwan;Sou, Dong-Sup
    • Journal of Radiation Protection and Research
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    • v.31 no.3
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    • pp.129-134
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    • 2006
  • A TL pellet for a neutron dose measurement (KCT-306) by embedding a $^6Li$-compound into a $CaSO_4:Dy$ phohphor was developed based upon the technical information of KCT-300. The KCT-300 is an another kind of $CaSO_4:Dy$ TL detector shich was developed at KAERI, in which small amounts of $NH_4H_2PO_4$ have been emvedded as a binding material. This paper presented the optimized manufacturing condition of KCT-306 and compared its sensitivity with that of the commercialized neutron TL pellets. $CaSO_4:Dy$ Phosphor with grain size ranging less than $45{\mu}m$ are used for the KCT-306. The optimum $CaSO_4:Dy$ TL phosphor, $^6Li$-compounds and P-compound as the binding material are determined as 20-40wt%, 50-70wt% and 20wt%. The TL pellet combination of our KCT-306/KCT-300, TLD-600/TLD-700 and TLD-600H/TLD-700H(Harshaw) have been irradiated in the neutron/gamma mixed fields from a $D_2O$ moderated $^{252}Cf$ neutron source. The KCT-300, TLD-700 and TLD-700H were used at the same time as gamma ray discriminators in the neutron/gamma mixed fields. It was found that the neutron/gamma response ratios of KCT-306/KCT-300, which were developed in this study, were approximately 4 times higher than those of the commercial TLD-600H/TLD-700H.

Effects of Keukhachukeo-Tang on the Development of Experimentally-induced Endometriosis in Rats (격하축동탕(膈下逐疼湯)이 실험적으로 유발된 흰쥐의 자궁내막증에 미치는 영향)

  • Kim, Chul-Soo;Lee, Dong-Nyung;Seo, Il-Bock;Kim, Hyung-Jun
    • The Journal of Korean Obstetrics and Gynecology
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    • v.20 no.1
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    • pp.61-83
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    • 2007
  • Purpose: This study was performed to investigate the effects of Keukhachukeo-Tang (KCT) on the development of experimentally-induced endometriosis in rats. Methods : Endometriosis was induced in rats by autotransplanting uterine tissue to the peritoneum and devided them into three groups: (1) sham-operated group (n=8), (2) surgically induced endometriosis and untreated control group (n =8), (3) surgically induced endometriosis and KCT treated group. KCT (1,200 mg/head) was orally administrated for 15 days after operation. Then we measured the body weight, the volumes of endometriotic implants. The weight (body, left uterus and ovaries) and concentrations of cytokines (MCP-1, TNF-${\alpha}$, IL-l${\beta}$) in serum and peritoneal fluid were also measured. Histopathology, immunohistochemistry for COX-2, and histochemistry for mast cells in transplanted uterine tissue were performed. Results : - The volumes(mm$^3$) of endometriotic implants in KCT-treated group (107${\pm}$66) were significantly decreased (p<0.05) compared with control group (405${\pm}$318). - The contents(pg/ml) of MCP-1 in peritoneal fluid in KCT-treated group (6,940${\pm}$893) were significantly decreased (p<0.01) compared with control group (8,632${\pm}$1,245). - The contents(pg/ml) of TNF-${\alpha}$ in peritoneal fluid in KCT-treated group (847${\pm}$330) were significantly decreased (p<0.05) compared with control group (1,245${\pm}$362). - The percentages(%) of positive epithelial layers for COX-2 in KCT-treated group (31${\pm}$10) were significantly decreased (p<0.01) compared with control group (50${\pm}$8). - The numbers of mast cells in adjacent tissue of transplanted uterine tissue in KCT-treated group (69${\pm}$18) were significantly decreased (p<0.01) compared with control group (109${\pm}$30). - The numbers of mast cells in stroma of transplanted uterine tissue in KCT-treated group(16${\pm}$5) were significantly decreased (p<0.01) compared with control group (26${\pm}$8). - Histopathologically, proliferation of endometriotic epithelia and stroma, and infiltration of inflammatory cells in transplanted uterine tissue of KCT-treated group were weakly observed than those of control group. Conclusion : From the above results, Keukhachukeo-Tang (KCT) have inhibiting effects on the development of transplanted uterine tissue. And these effects are related to the decreased concentration of MCP-1 and TNF-${\alpha}$, decreased expression of COX-2, and decreased infiltration of mast cells by administration of Keukhachukeo-Tang.

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A study on pre-service mathematics teachers' MKT (예비수학교사의 MKT에 관한 연구)

  • Han, Hyesook
    • Communications of Mathematical Education
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    • v.30 no.1
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    • pp.101-120
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    • 2016
  • The purposes of the study were to analyze pre-service mathematics teachers' MKT and to examine the perceptions of MKT to find implications for the improvement of pre-service mathematics teacher education program in the aspect of teachers' content knowledge. Twenty-six pre-service mathematics teachers participated in the survey to examine the perceptions of MKT and they also finished two MKT tasks which focused on a specific area of middle school geometry. According to the survey results, the participants thought that they have enough knowledge in all categories of MKT except KCT-2 and they appreciated the importance of MKT education in pre-service mathematics teacher education program. However, the participants showed difficulties in MKT task items which required SCK, KCS, KCT, especially, the proportions of those who showed appropriate knowledge on the items required SCK and KCT was less than 50%. These results show disagreement between the perceptions of pre-service mathematics teachers' MKT and practice of MKT.

Production of monoclonal antibody(MAb) for lymphocytes of Korean native cattle 2. MAb to E-rosette forming lymphocytes. (한우 림프구에 대한 단일항체 생산 2. E-rosette형성 림프구에 대한 단일항체)

  • Song, Hee-jong;Woon, Jae-ho;Kim, Tae-joong
    • Korean Journal of Veterinary Research
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    • v.35 no.4
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    • pp.777-783
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    • 1995
  • A monoclonal antibody(MAb), KCT-23ER, with specificity for E-rosetted T cells of Korean native cattle was prepared by cell hybridization of myeloma P3/NS-1/1-Ag-4-1 and spleen cells from BALB/c mice hyperimmunized with E-rosetted lymphocytes. The isotype of KCT-23ER to T lymphocytes was mouse $IgG_{2b}$. KCT-23ER was reacted with 53.6% to peripheral blood lymphocytes and with 67.8% to nylon wool nonadherent blood lymphocytes. And it was reacted with 72.2%, 59.2% and 35.3% to thymocytes, prescapular lymph node cells and splenocytes, respectively. Immunocytological reactive rates to E-rosetted and non-E-rosetted cells were 72.5% and 22.4%, respectively. These results indicated that KCT-23ER reacted to E-rosetted cells was one of the MAb for investigate of $CD_2$ receptor positive cell subset in the Korean native cattle.

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KCT첨가에 따른 $(Na,K)NbO_3$ 세라믹스의 압전특성

  • No, Jeong-Rae;Lee, Yu-Hyeong;Ryu, Ju-Hyeon;Yun, Hyeon-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.93-93
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    • 2009
  • In this study, in order to develop excellent lead-free composition ceramics for piezoelectric transformer, $(K_{5.4}Cu_{1.3}Ta_{10}O_{29})$ added $(K_{0.5}Na_{0.5}](Nb_{0.97}Sb_{0.03})O_3$ were fabricated using conventional mixed oxide method. At the 0.9mol% KCT added specimen, electromechanical coupling factor(kp) and mechanical quality factor ($Q_m$) showed the optimal values of 0.437 and 727.07, respectively, for piezoelectric transformer application.

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A Study on the development and effect of the MKT development program for pre-service mathematics teachers (예비수학교사의 MKT 함양을 위한 프로그램 개발 및 효과에 관한 연구)

  • Ok, Bo-myoung;Han, Hyesook
    • Communications of Mathematical Education
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    • v.34 no.3
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    • pp.257-276
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    • 2020
  • In this study, the MKT level of pre-service mathematics teachers in the area of permutations and combinations was investigated, and MKT-Development Program(MKT-DP) focused on improving the MKT of pre-service mathematics teachers was developed and implemented to examine the effects of the program on the MKT in the area of permutations and combinations. Twenty-nine pre-service mathematics teachers participated in a four-week MKT-DP and MKT pre and post tests. According to the MKT pre test results for permutation and combination areas, pre-service teachers who participated in this study showed low levels of MKT in the permutation and combination areas, especially, the level of SCK and KCT was quite low. In order to examine the effects of MKT-DP, the results of pre- and post-MKT tests were analyzed, and a significant difference between pre- and post-tests was found only in the KCT sub-category. This shows that the MKT-DP developed in this study is effective in improving pre-services teachers' KCT in the area of permutation and combination. Although there were no statistically significant differences between the three remaining sub-categories(CCK, SCK, and KCS), the positive influence of MKT-DP can be expected throughout MKT, as a result of some level increase in post-test compared to the pre-test.

Teacher Knowledge Necessary to Address Student Errors and Difficulties about Ratio and Rate (비와 비율에 관한 학생의 오류와 어려움 해결을 위해 필요한 교사지식)

  • Kang, Hyangim;Choi, Eun Ah
    • School Mathematics
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    • v.17 no.4
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    • pp.613-632
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    • 2015
  • In this study, we hope to reveal teacher knowledge necessary to address student errors and difficulties about ratio and rate. The instruments and interview were administered to 3 in-service primary teachers with various education background and teaching experiments. The results of this study are as follows. Specialized content knowledge(SCK) consists of profound knowledge about ratio and rate beyond multiplicative comparison of two quantities and professional knowledge about the definitions of textbook. Knowledge of content and students(KCS) is the ability to recognize students' understanding the concept and the representation about ratio and rate. Knowledge of content and teaching(KCT) is made up of knowledge about various context and visual models for understanding ratio and rate.

Pre-service and In-service Teachers' MKT about the Concept of Vector (예비교사와 현직교사의 벡터 개념에 대한 이해: MKT 중심으로)

  • Yoon, Hyun-Kyoung;Kwon, Oh-Nam
    • School Mathematics
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    • v.13 no.4
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    • pp.615-632
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    • 2011
  • The purpose of the study was to investigate the mathematical knowledge for teaching (MKT) of pre-service and in-service mathematics teachers on the concept of vector. 80 pre-service and 124 in-service mathematics teachers were asked to perform three questions based on MKT's subdomain. The results show that pre-service teachers have stronger common content knowledge(CCK). On the other hand, in-service teachers have stronger specialized content knowledge(SCK), knowledge of content and teaching(KCT) compared to those of pre-service teachers. The paper proposes CCK, SCK and KCT about the concept of vector and discusses the relationships between subdomains of MKT.

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