폴리머콘크리트의 내후성의 증진에 관한 연구

인교진,탁기욱,이경배 강원대학교 석재복합신소재제품연구센터 1998 석재연 논문집 Vol.3 No.-

폴리머 콘크리트의 바인더 재료로써 많이 사용되는 불포화 폴리에스테르 수지의 성분과, 물성에 대하여 조사하였다. 불포화 폴리에스테르 수지에 포함되는 각 성분과 조성의 변화에 따라 다양한 특성을 가진 수지의 제조가능성을 확인하였으며, 불포화 폴리에스테르 수지의 성능을 개선하기 위한 기초적인 자료로 이용하였다. 본 연구를 바탕으로 불포화 폴리에스테르 수지에 자외선 안정제를 첨가하거나, 바인더 수지를 변성하여 내후성을 증대시키는 방법을 추진할 계획이다. 불포화 폴리에스테르 수지를 개질하거나, 스티렌과 다른 모노머와의 공중합, 또는 커플링 제를 첨가하는 등의 방법을 적용하여 불포화 폴리에스테르 강도 및 물성을 증대하는 연구를 추진할 것이다. Properties of unsaturated polyester resins, which have been used as a binder resin of polymer concretes, were investigated. The physical and chemical properties of unsaturated polyester resins could be modified by changing the types and compositions of the constituents. These fundamental data can be applied for the improvement of cured unsaturated polyester resins. Unsaturated polyester resins with good weathering properties can be prepared by using UV stabilizer, refinement of resins. Further study will be emphasized on the development of unsaturated polyester resins with high strength and toughness by changing the component of resins, copolymerization of styrene with several monomers, developing new coupling agents, etc.

Comparison of retentive force and wear pattern of Locator® and ADD-TOC attachments combined with CAD-CAM milled bar

Sung-Ki Chae,Won-Tak Cho,Jae-Won Choi,Eun-Bin Bae,Ji-Hyeon Bae,Gang-Ho Bae,Jung-Bo Huh 대한치과보철학회 2022 The Journal of Advanced Prosthodontics Vol.14 No.1

PURPOSE. The purpose of this study was to investigate changes in retention and wear pattern of Locator® and ADD-TOC attachments on a digital milled bar by performing chewing simulation and repeated insertion/removal of prostheses in fully edentulous models. MATERIALS AND METHODS. Locator (Locator®; Zest Anchors Inc., Escondido, CA, USA) was selected as the control group and ADD-TOC (ADDTOC; PNUAdd Co., Ltd., Busan, Republic of Korea) as the experimental group. A CAD-CAM milled bar was mounted on a master model and 3 threaded holes for connecting a bar attachment was formed using a tap. Locator and ADD-TOC attachments were then attached to the milled bar. Simulated mastication and repeated insertion/removal were performed over 400,000 cyclic loadings and 1,080 insertions/removals, respectively. Wear patterns on deformed attachment were investigated by field emission scanning electron microscopy. RESULTS. For the ADD-TOC attachments, chewing simulation and repeated insertion/removal resulted in a mean initial retentive force of 24.43 ± 4.89 N, which were significantly lower than that of the Locator attachment, 34.33 ± 8.25 N (P < .05). Amounts of retention loss relative to baseline for the Locator and ADD-TOC attachments were 21.74 ± 7.07 and 8.98 ± 5.76 N (P < .05). CONCLUSION. CAD-CAM milled bar with the ADD-TOC attachment had a lower initial retentive force than the Locator attachment. However, the ADD-TOC attachment might be suitable for long-term use as it showed less deformation and had a higher retentive force after simulated mastication and insertion/removal repetitions.

증례 : 소화기 ; 총담관류에 동반되어 나타난 담낭암 1예

배기탁 ( Ki Tak Bae ),최정식 ( Jung Sik Choi ),김영구 ( Young Gu Kim ),손한백 ( Han Baek Son ),유종원 ( Chong Won Yu ),도웅정 ( Ung Jeong Do ),박나영 ( Na Young Park ) 대한내과학회 2013 대한내과학회지 Vol.85 No.1

이 증례는 소화 장애와 상복부 동통으로 내원한 환자에서 총담관류 및 담낭암을 진단한 경우이다. 내시경 역행 췌담관 조영술 등에서 총담관류를 진단하였을 때 담낭암을 비롯한 담관계 암의 동반 가능성이 있다는 점에서 이 증례는 시사하는 바가 있다. 더 나아가 총담관류를 발견하였을 때 내시경 초음파나 조직 생검의 시행을 고려하고 정기적인 초음파 또는 전산화 단층촬영 등을 통한 추적관찰이 필요하다. Choledochal cysts are congenital lesions involving cystic dilatation of the bile ducts. The choledochocele, the rarest type of choledochal cyst, is a cystic dilatation of the distal common bile duct that protrudes into the duodenum. There have been few reports concerning malignancy in the biliary tree associated with choledochoceles. We recently experienced a case of a choledochocele with gallbladder cancer. (Korean J Med 2013;85:73-76)

응급실 환자의 내원 및 응급처치 소요에 관한 조사연구

탁기천,배대경,고영관,손명숙,정두채 대한응급의학회 1993 대한응급의학회지 Vol.4 No.1

This study consists of time consuming of arrival and emergency treatment of the 495 patients, who were admitted to the emergency rooms of 3 university hospitals in Seoul from July 6, 1992 to July 29, 1992. These results were obtained by investigating and analysing the questionaires through the patients, or/and their accompanist by the emergency room nurses. 1. Distribution of time consuming. 1) Consumed time from development of the symptom to visiting emergency room was 31.5 hours. 2) Male patients visited much earlier than female patients.(statistically significant) 3) The patients of under the age of 6 visited earlier than any other age group.(Nearly 30% of them came within 60 minutes.(Statistically significant) 4) The patients visted most early when a symptom developed on road.(42.9%: significant) 5) A taxi was the most frequently used transportation.(45.9%) In case of visiting by walking, patients arrived within 60 minutes(48.4%: significant) 6) Fourty three % of injured patients arrived within 60 minutes and they visited much earlier than diseased patients. 7) Orthopedic patients visited within 60 minutes, which was earlier than other department patients and occupied 45.3%.(significant) 8) Non-first-aided patients at home visited earlier than first aided ones at home. (nonsignificant) 2. Time interval from arrival to initial emergency care. 1) Seventy % of the patients were initially cared within 30 minutes. 2) Time to initial care according to the symptoms and signs was not statistically significant. 3) Fifty nine % OB/GYN patients were cared within 10 minutes and earlier than other department patients, however, statistcally nonsignificant. 3. Time interval from initial care to completion. 1) Emergency care was completed within 180 minutes in sixty three % of the patients. 2) Although, a distribution of the time to completion of emergency care was statistically nonsignificant, diseased patients were completed a little bit earlier than injured patients. 3) Pediatric patients were completed earlier than any other department patients and 37.3% of them were completed within 60 minutes.

A correlation between pelvic node metastasis and clinical symptoms in the patient underwent staging surgery for the early-stage cervical cancer

( Ki Jin Ryu ),( Ye Won Chung ),( Hyo Sook Bae ),( Jae Kwan Lee ),( Nak Woo Lee ),( Tak Kim ),( Jae Yun Song ) 대한산부인과학회 2012 대한산부인과학회 학술대회 Vol.98 No.-

This study was conducted to evaluate the clinical factors which can expect pelvic nodal metastasis in patients with early-stage invasive cervical cancer, when nodal involvement had not been detected by pretherapeutic CT, MRI, with or without PET-CT. The medical records of 233 early-stage cervical cancer patients who had undergone staging surgery between November 1990 and February 2012 were reviewed. The incidence of histologically proved nodal metastasis was compared with the clinical factors that include age, BMI, initial symptom, clinical stage, histology, serum SCC and CEA, and postoperative complications. Statistical analysis was performed using SPSS program. Out of a total of 233 patients, nodal involvement was detected in 31(13.3%) by pathological examination. 65(28%) patients were asymptomatic, and among the 168(72%) symptomatic patients, vaginal bleeding and/or discharge was evident in 153(65%), and lower abdominal pain in 15(6%). The node-involved group showed higher rate of presenting lower abdominal pain as the initial symptom (p-value = 0.034). Clinical stage was statistically relevant to nodal involvement, but not to a type of clinical symptom. Neither the histology, age, BMI, tumor markers were, the postoperative complications (lymphedema, lymphocele) were not statistically related to pelvic nodal involvement. There was significant correlation between the histological nodal metastasis and the presentation of lower abdominal pain as initial symptom in early-stage cervical cancer patients. Although the reliability and pathophysiology of this finding are certainly need to be investigated by further studies, it might be worthwhile to consider a more active surgical lymph node dissection for management of patient with lower abdominal pain rather than vaginal bleeding or no symptom.

난소를 절제한 rats에서 폐경증후군에 대한 석류추출물의 효과

안기훈 ( Ki Hoon Ahn ),이경욱 ( Kyong Wook Yi ),박현태 ( Hyun Tae Park ),신정호 ( Jung Ho Shin ),허준용 ( Jun Young Hur ),김영태 ( Young Tae Kim ),김선행 ( Sun Haeng Kim ),이규완 ( Kyu Wan Lee ),배춘식 ( Chun Sik Bae ),김탁 ( Tak 대한산부인과학회 2010 Obstetrics & Gynecology Science Vol.53 No.4

목적: 난소를 절제한 폐경모델 rats에서 석류추출물이 폐경증후군에 대해 효과가 있는지 알아보고자 하였다. 연구 방법: 79마리의 암컷 rats을 이용하였다: A, 난소 절제하지 않고 약물 투여하지 않은 군; B, 가장수술 후 증류수 투여군; C, D, E, F는 각각 난소 절제 후 증류수, 10%, 20%, 40% 석류 투여군. 약물 투여 4주째에 각 개체를 대상으로 실험을 진행하였다. 비뇨생식기 상피세포층의 수, 꼬리온도, 혈청 성호르몬, 지질대사, homocysteine, thiobarbituric acid reactive substances를 측정하였다. 결과: 20% 석류에서 방광상피세포층수의 유의한 증가가 관찰되었다. 간헐적으로 석류추출물이 쥐꼬리온도를 낮추었으나 일관된 효과를 발견하기 힘들었다. 석류추출물은 혈청 homocysteine의 감소 효과를 보여주었다. 또한 혈중 고밀도 지단백을 증가시켰다. 결론: 일부 석류추출물은 난소를 절제한 rats에서 방광상피세포의 변화를 회복시켰다. 또한 혈중 고밀도 지단백 증가 및 homocysteine 감소 효과를 관찰할 수 있었다. Objective: To determine whether or not pomegranate extract can affect postmenopausal syndrome in ovariectomized rats. Methods: Seventy-nine female Sprague-Dawley rats were used: A, no intervention; B, sham operation and distilled water; C, ovariectomy and distilled water; D, ovariectomy and 10% dilute pomegranate; E, ovariectomy and 20% pomegranate; and F, ovariectomy and 40% pomegranate. The study samples were obtained 4 weeks later. The following parameters were investigated for analyses: the thickness of urogenital epithelium, tail skin temperature, serum levels of sex hormones, lipid profile, homocysteine, and thiobarbituric acid reactive substances. Results: 20% pomegranate had a transient thickening effect of bladder epithelial layer. There was an intermittent lowering effect of tail skin temperature of pomegranate extract, however, it was not consistent. There were lowering effect in serum homocysteine and elevating effect in serum high density lipoprotein-cholesterol. Pomegranate did not reverse post-ovariectomy reduced sex hormone levels. Conclusion: Pomegranate extract showed a tendency to reverse ovariectomy-related urothelial changes. Also pomegranate had a serum homocysteine-lowering effect.

Compact Ferrite Antenna for T-DMB Applications

Seok Bae,Yang-Ki Hong,Jae-Jin Lee,Jeevan Jalli,Gavin S. Abo,In-Tak Nam,Jun-Sig Kum,Jun-Sig Kum,Sang-Hoon Park,Won-Mo Seong 한국자기학회 2009 한국자기학회 학술연구발표회 논문개요집 Vol.2009 No.5

Cascaded H-bridge Multilevel Inverter employing Front-end Flyback Converter with Single Independent DC Voltage Source

Kim, Ki-Du,Bae, Gyou-Tak,Kang, Feel-Soon Journal of International Conference on Electrical 2013 Journal of international Conference on Electrical Vol.2 No.2

Cascaded H-bridge multilevel inverter requires independent DC voltage sources to produce multi output voltage levels. When it needs to generate more levels in the output voltage wave, the number of independent DC voltage sources usually limits its extension. To solve this problem, we propose a cascaded H-bridge multilevel inverter employing a front-end flyback converter for unifying input DC voltage sources. After theoretical analysis of the proposed circuit, we verify the validity of the proposed inverter using computer-aided simulations and experiments.

黃連과 구성 생화합물의 약리작용에 대한 고찰

김기배(Ki Bae Kim),이형탁(Hyung Tak Lee),구경회(Kyung Howi Ku),홍진우(Jin Woo Hong),조수인(Su In Cho) 대한한의학회 2012 대한한의학회지 Vol.33 No.3

Study of Oxygen Additive Effect in High Aspect Ratio Contact Etching using High Polymer Forming Hydrofluorocarbon Isomers

Hyun Woo Tak,Seong Bae Kim,Chan Hyuk Choi,Seul Ki Kim,Dong Woo Kim,Geun Young Yeom 한국표면공학회 2023 한국표면공학회 학술발표회 초록집 Vol.2023 No.11-1