K₂O-CaO-SiO₂-P₂O₅계 유리의 형성 및 용출특성

윤태민,윤영진,이용수,강원호,Yoon Tae Min,Yoon Young Jin,Lee Yong Soo,Kang Won Ho 한국재료학회 2004 한국재료학회지 Vol.14 No.1

The glass-forming conditions are investigated in the $K_2$O-CaO-$SiO_2$ $-P_2$$O_{5}$ system with 10~65 mole% of$ P_2$$O_{5}$. Thermal properties and dissolution properties were investigated according to variation of the SiO and KO contents in selected compositions. The glass formation condition was determined when $K_2$O/$P_2$$O_{5}$ mole ratio 0~0.24, $SiO_2$/($SiO_2$+$P_2$$O_{5}$ ) mole ratio 0~0.29, and CaO/$P_2$$O_{5}$ mole ratio 0~1.00. In the result of the thermal properties, the glass transition temperature($T_{g}$) and softening temperature($T_{s}$ ) were gradually shifted to the lower temperature range with increase of $K_2$O contents. The maximum value of the chemical durability was shown in $K_2$$PO_2$$O_{5}$ mole ratio 0.17 when the $SiO_2$ contents were changed, and $K_2$O was fixed at 10 mole%. Hence the change of the $K_2$O/$P_2$$O_{5}$ mole ratio was found that a new main factor of the chemical durability.

인산염계 수용성 유리의 용출 및 구조 분석

윤영진,윤태민,이용수,강원호,Yoon, Young-Jin,Yoon, Tae-Min,Lee, Yong-Soo,Kang, Won-Ho 한국재료학회 2002 한국재료학회지 Vol.12 No.7

Potassium-Calcium-Phosphate glasses in range $XCaO\cdot(50-X)K_2O$ \cdot $50P_2$$O^{5}$were investigated. Glass transition temperature(Tg) of prepared glasses were below $520^{\circ}C$, thermal expansion coefficient from $270.3$\times$10^{7}$ to $604.5$\times$10^{7}$/$^{\circ}C$. The structure of XCaO.(50-X)$K_2$O\cdot$50P_2$$O^{5}$ glasses were examined by FT-IR spectroscopy indirectly. As CaO was increased, Ts, Tg, P-O-P bonding strength and chemical durability were increased. Glass surface change was observed with increasing dissolution time using bulk specimen, weight loss and pH change were measured as function of the dissolution time.

K₂O·CaO·P₂O₅계 유리의 열적특성과 구조분석

윤영진,윤태민,이용수,강원호,Yoon, Young-Jin,Yoon, Tae-Min,Lee, Yong-Soo,Kang, Won-Ho 한국세라믹학회 2002 한국세라믹학회지 Vol.39 No.2

$K_2O{\cdot}CaO{\cdot}P_2O_5$를 기본조성으로 하여 용융법에 의해 유리 형성범위를 정의하고자 하였다. TG-DTA와 DSC를 이용하여 열적 특성을 관찰하고자 하였으며, FT-IR과 Raman Spectroscopy를 이용하여 구조를 분석하였다. $K_2O{\cdot}CaO{\cdot}P_2O_5$의 함량이 증가함에 따라 유리전이온도 및 연화온도는 감소하였다. $K_2O{\cdot}CaO{\cdot}P_2O_5$ 유리의 기본 구조는 이웃한 구조와 상호 결합을 위한 $PO_2$와 $PO_4^{3-}$ 구조와 유리의 골격구조를 이루는 P-O-P 결합이며, CaO의 함량이 증가함에 따라, 유리내의 P-O-P의 결합력은 점차적으로 증가하였으며, $PO_2$와 $PO_4^{3-}$의 intensity는 점차적으로 감소하였다. Various composition of $K_2O{\cdot}CaO{\cdot}P_2O_5$ glasses were studied by melting process to identify glass forming region. Thermal properties were observed by DSC and TG-DTA, structural properties were investigated by FT-IR and Raman Spectroscopy. The glass transition temperature (Tg) and softening temperature (Ts) were decreased with increasing $K_2O\;and\;P_2O_5$ contents. The basic structural unit of phosphate glasses is the $PO_2\;and\;PO_4^{3-}$ groups to make a cross-link and P-O-P group to form skeleton structure. As CaO content was increased, the P-O-P field strength in these glass was increased and intensity of $PO_2\;and\;PO_4^{3-}$ stretch was decreased.

전기분해수조를 위한 풀-브릿지 DC-DC 컨버터의 설계와 제어 방법

이병섭(Seung-Joo Lee),윤태민(Tae-Min Yoon),김종훈(Jong-Hoon Kim),이교범(Kyo-Beum Lee) 대한전기학회 2015 전기학회논문지 Vol.64 No.4

Hydrogen is commonly used in many industrial field. However, hydrogen should be filled in a high pressure container to use it. Therefore, many researches have been conducted about an electrolyzer. The operating principle of the electrolyzer is that the electrolyzer can separate water molecules into hydrogen and oxygen. To use the electrolyzer, a power conversion system is needed because the current of the electrolyzer increases exponentially depending on the voltage of the electrolyzer. Thus, this paper proposes the power conversion system for the electrolyzer using a full-bridge DC-DC converter topology.

K2O , CaO , P2O5 조성의 구조와 용출특성에 관한 연구

윤영진(Young Jin Yoon),윤태민(Tae Min Yoon),이영수(Yong Soo Lee),강원호(Won Ho Kang) 단국대학교 산업기술연구소 2001 산업기술연구 Vol.2 No.-

K₂O·CaO·P₂O_5조성의 구조와 용출특성에 관한 연구

윤영진,윤태민,이영수,강원호 단국대학교 2001 산업기술연구 Vol.2 No.-

Various composition of K_2O·CaO·P_2O_5 glasses were studied by melting process to identify glass forming region. Thermal properties were observed by DSC and TG-DTA, structural properties were investigated by FT-IR and Raman Spectroscopy. Dissolution mechanism was observed by pH meter and Optical Microscopy. The glass transition temperature(Tg) and softening temperature(Ts) were decreased with decreasing CaO content. Tgand Ts was increased from 318℃ to 536℃, Ts was from 350℃ to 563℃ respectively with increasing CaO content, α was decreased from 201.5×10 exp (7) to 90.1×10 exp (7), as CaO content was increased, dissolution properties was decreased, pH has been changed acid as the times.

교정용 미니스크류의 디자인에 따른 식립 및 제거 토오크

차정열,윤태민,황충주 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.1

교정용 미니스크류의 원추 형태가 식립 후 시기별 안정성에 미치는 영향을 알아보기 위해, 시기별 제거 토오크 및 동요도와 조직시편분석을 시행하였다. 성견 6마리의 하악 협측골에 원통형과 원추형 교정용 미니스크류(Biomaterials Korea, Seoul, Korea) 48개를 식립하고, 식립 시 식립 토오크와 동요도를 측정하고 3주, 12주 동안 교정력을 부여한 후, 제거 시 제거 토오크와 동요도를 측정하였다. 식립 토오크는 원통형 미니스크류에서 13.6 Ncm, 원추형 미니스크류에서 22.3 Ncm로 원추형 미니스크류에서 높은 식립 토오크가 측정되었다 (P < 0.001). 식립 3주째 제거 토오크는 원통형 미니스크류에서 5.7 Ncm, 원추형 미니스크류에서 9.1 Ncm로 유의한 차이가 관찰되었다(P < 0.05). 식립 12주째 원추형 미니스크류의 제거 토오크는 3.6 Ncm로 유의하게 감소하여(P < 0.05) 원통형 미니스크류의 4.2 Ncm와 유의한 차이를 보이지 않았다. 이상의 결과로 미니스크류의 원추 구조는 식립 토오크를 유의하게 증가시켜 식립 후 3주간 안정성에 도움이 되었으나, 12주 후 안정성에 있어서는 원통형 미니스크류와 유사하였음을 시사한다. Objective: This study was designed to analyze the primary and secondary stability characteristics of orthodontic mini-screws of tapered design when compared with the cylinder mini-screw. Methods: A total of 48 mini-screws were placed into the buccal alveolar bone of the mandible in 6 male beagle dogs. Comparison was made between tapered and cylinder type mini-screws (Biomaterials Korea, Seoul, Korea). Maximum insertion torque (MIT) was measured using a torque sensor (Mark-10, MGT50, USA) during installation, and maximum removal torque (MRT) was recorded after 3 and 12 weeks of loading. Results: Taper mini-screws showed a higher MIT value of 22.3 Ncm compared with cylinder mini-screw showing 13.6 Ncm (P < 0.001). The MRT of the taper mini-screw showed a significantly higher value of 9.1 Ncm than those of cylinder mini-screw of 5.7 Ncm at 3-weeks after installation (P < 0.05). However, there was no difference in the MRT value between the taper and cylinder mini-screws at 12 weeks of loading. Conclusions: These results showed that the high insertion torque of the taper mini-screw design increases initial stability until 3 weeks of loading, but does not have any effect on the secondary stability at 12 weeks of loading.

교정력 부하시기에 따른 교정용 미니 임플란트의 안정성

이승연,차정열,윤태민,박영철 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.3

본 연구는 미니 임플란트 식립 후 교정력 부하시기와 관련하여 임플란트 주위골의 치유과정을 조사하였다. 성견8마리의 하악 협측골에 교정용 미니 임플란트(ORLUS, Ortholution CO, Korea) 48개를 식립한 후 교정력을 주지 않은 대조군과 식립 후 즉시 교정력을 준 즉시 부하군, 그리고 식립 후 3주간의 치유기간을 두고 교정력을 준 지연 부하군으로 나누어 각각의 군에 대해 3주, 6주, 12주가 경과된 시점에 임플란트 주위골의 변화를 조직 계측학적으로 관찰하였다. 골 접촉률은 즉시 부하군에서 시기에 따른 유의한 변화가 없었으며 지연 부하군은 3주에 비해 12주에서 유의하게 증가하였다 (p < 0.05). 각 시점에서 군 간의 골 접촉률을 비교했을 때 12주째 지연 부하군이 즉시 부하군보다 유의하게 높았다 (p < 0.05). 골 면적비율은 즉시 부하군의 경우, 시기에 따른 유의한 변화가 없었으며, 지연 부하군과 대조군은 6주에 비해 12주째 유의한 증가를 보였으며 (p < 0.05), 12주째 실험군 간에 유의한 차이는 관찰되지 않았다 (p > 0.05). 동요도는 12주째 즉시 부하군과 지연 부하군 간에 유의한 차이는 없었다 (p > 0.05). 위의 결과에서 즉시 부하가 self drilling형 미니 임플란트 주위골의 안정성에 부정적인 영향을 주지 않았으므로 식립 즉시 교정력을 부여하여 사용하는 데 임상적으로 문제가 없을 것으로 판단된다. Objective: The purpose of this study was to investigate the stability of mini-implants in relation to loading time. Methods: A total of 48 mini-implants (ORLUS, Ortholution, Korea) were placed into the buccal alveolar bone of the mandible in 8 male beagle dogs. Orthodontic force (200 - 250 gm) was applied immediately for the immediate loading group while force application was delayed for 3 weeks in the delayed loading group. For the subsequent loading periods (3, 6, 12 weeks), BIC (bone implant contact) and BV/TV (bone volume/total volume) and mobility test were carried out. Results: The immediate loading group showed no changes in BIC from 3 to 12 weeks, while the delayed loading group showed a significant increase in BIC between 3 and 12 weeks (p < 0.05). The BV/TV of the delayed loading group significantly increased from 6 to 12 weeks of loading (p < 0.05), while the BV/TV of the immediate loading group decreased from 3 to 12 weeks of loading. However, there was no significant difference in BV/TV between experimental groups. The mobility of the immediate loading group was not significantly different from that of the delayed loading group after 12 weeks of loading (p < 0.05). Conclusions: These results showed that immediate loading does not have a negative effect on the stability of mini-implants compared to the early loading method in both the clinical and histomorphometric point of view.