판상형 충전제의 함량과 배향에 따른 PP복합체의 영률 변화 연구

서상범(Sang Bum Seo),이용현(Yong Hyun Lee),정선경(Sun Kyoung Jeong),이승구(Seung Goo Lee),이기윤(Kee Yoon Lee) 한국고분자학회 2012 폴리머 Vol.36 No.2

이 논문은 판상형 충전제의 함량과 배향에 따라 폴리프로필렌 복합체의 영률 변화에 미치는 영향을 연구 하였다. 이론적인 예측은 Lee와 그의 연구자들에 의해 제안된 두 개의 종횡비, ρα=a1/a3과 ρβ=a1/a2 를 이용하여 3차원 타원체의 형상을 계산하였고 실험값과 비교 분석하였다. 판상형 충전제로 운모와 탈크를 사용하였다. 충전제의 형태는 SEM을 이용해 관찰하였고, 종횡비는 고분자의 흐름을 기준으로 좌표축을 설정하여 통계적 방법으로 계 산하였다. 충전제가 운모인 경우에 ρα=13.5와 ρβ=1.8이었고, 탈크의 경우는 ρα=3.8과 ρβ=1.4이었다. 또한 충전제 의 2개의 종횡비와 함량이 기계적 물성에 미치는 영향을 실험적으로 연구하였다. 운모의 경우 30 wt% 함량일 때 E11이 약 2.7배 향상되었다. 탈크의 경우는 E11이 약 2.3배 향상하였다. This paper studied the effects of the content and the orientation of the disk shape fillers on the modulus of PP composites. The experimental results were compared with the theoretical calculations which included the three dimensional ellipsoids and analyzed by two aspect ratios, ρα=a1/a3 and ρβ=a1/a2 proposed by Lee and his researchers. Mica and talc were used as disk shape fillers in the composites. The shapes of mica and talc were observed by SEM and aspect ratios were statistically calculated. For the case of mica, the average aspect ratios were ρα=13.5 and ρβ=1.8, and for the case of talc, they were ρα=3.8 and ρβ=1.4. Also, the effects of two aspect ratios and the content of filler on the mechanical properties were studied: For 30 wt% of mica, E11 increased up to about 2.7 times, and for the other case of talc, E11 increased up to about 2.3 times, respectively.

8.3% Carbamide Peroxide 함유 펜 형 자가미백제인 BIancTis Forte의 색조개선 및 안전성에 관한 임상연구

이진경,민선홍,홍성태,오소람,정신혜,황영혜,유성엽,배광식,백승호,이우철,손원준,금기연 대한치과보존학회 2009 Restorative Dentistry & Endodontics Vol.34 No.2

This clinical study evaluated the whitening effect and safety of polymer based-pen type BlancTis Forte(NIBEC) containing 8.3% carbamide peroxide. Twenty volunteers used the BlancTis Forte whitening agent for 2 hours twice a day for 4 weeks As a control. Whitening Effect Pen (LG) containing 3% hydrogen peroxide was used by 20 volunteers using the same protocol. The change in shade (ΔE^(*) color difference) was measured using Shadepilot™ (DeguDent) before, during and after bleaching (2 weeks, 4 weeks and postbleaching 4 weeks). A clinical examination for any side effects (tooth hypersensitivity or soft tissue complications) was also performed at each check-up. The following results were obtained. 1 Both the experimental and control groups displayed a noticeable change in shade (ΔE) of over 2 No significant differences were found between the two group (p>0.05) implying that the two agents have a similar whitening effect. 2 The whitening effect was mainly due to changes in a and b values rather than in L value (brightness). The experimental group showed a significantly higher change in b value thus yellow shade than the control(p < 0.05) 3 None of the participants complained of tooth hypersensitivity or soft tissue complications confirming the safety of both whitening agents 8.3%의 carbamide peroxide를 함유한 펜형 코팅용 미백제인 BlancTis Forte (NIBEC, Seosul & JinCheon)를 실험군으로, 3% hydrogen peroxide를 함유한글 Whitening Effect Pen (LG. Seoul) 제재를 대조군으로 각각 피험자 20명에게 2시간씩 1일 2회 제조사의 지시대로 치아표면에 4주간 적용하도록 지시하고 색조개선 효능과 안전성을 평가하였다. 미백 효과는 미백 전 및 미백 2주, 4주 및 미백 종료 4주 후에 Shadopilot™을 이용하여 색 변화를 측정하였고, 매 내원시기마다 모든 환자는 치수생활력 검사와 치주 및 치태 검사를 통해 부작용 여부 (치아과민증 및 구감 내 연조직의 부작용)를 기록한 후 다음과 같은 결과를 얻었다. 1.실험군 및 대조군의 색 변화량 (ΔE)은 2이상으로 인지할 수 있는 색 변화를 보였으며, 두 제품 간에는 통계적으로 유의한 차이를 보이지 않아 (p > 0.05) 유사한 미백효능을 나타냄을 알 수 있었다. 2,미백효과는 명도의 개선보다는 주로 a. b값의 변화에 의한 것으로 특히 실험군에서 b값의 변화, 즉 황색조의 개선효과가 대조군에 비해 유의성 있게 높은 것으로 나타났다 (p <0.05). 3.치아나 치은의 과민증이나 이상증상을 호소하는 피험자는 없어 두 제품 모두 안전성을 확인할 수 있었다.

β-Carotene 이 혈중 효소활성도에 미치는 영향

이상한,우기민,조만희,장예진,김창세,김현철 순천향의학연구소 1997 Journal of Soonchunhyang Medical Science Vol.3 No.2

This study was carried out in order to observe the effects of ethanol and β-carotene on the cholesterol, Triglyceride, LDL-cholesterol, HDL-cholesterol, glutathione peroxidase and catalase activities. The normal white S.D rats were classified into 4 group: 0.9% NaCl administration and 20% ethanol administration were referred to as group A, 20% ethanol and 50% β-carotene mixture administration was group B and 50% β-carotene administration was group C for the 30 day-feeding experiment. The results were obtained as following: 1. The blood lipid concentration was most highly increased in group A, was almost normal in group B, but significantly decreased in goup C. 2. The blood antioxidant enzyme activities were significantly decreased in group A, but significantly increased in goup B and C. 3. The blood β-carotene concentration were significantly decreased in group A, and slightly decreased in group B. Surprisingly it was increased in group C.

사립체 DNA 뉴클레오타이드 3243 A→G 돌연변이 [MTTL1^*MELAS3243G]에 의한 MELAS 증후군

박기형,김승현,이영주,김희태,김주한,김명호,박성섭 대한신경과학회 1998 대한신경과학회지 Vol.16 No.4

친환경건축물 인증기준의 분류체계 비교 연구

이승민,박상동,신기식,최무혁 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

Energy problem of our country is very serious and the energy import is being increased continuously. To solve the problems related to energy and environment, many countries including our country have prepared and carried out various certification programs to disseminate environmentally friendly buildings. The purpose of this study is to investigate the basics and category systems of domestic green building certification criteria and to utilize it as reference materials for developing integrated criteria applicable to all buildings.

포도에 대한 Captafol 수화제의 안전사용기준 설정

李載球,慶箕性,金學南 충북대학교 농업과학기술연구소 1993 農業科學硏究 Vol.11 No.1

In order to establish the criteria for the safe use of the fungicide captafol on grapes, 12 plots with different spray frequency and different spray time were placed and sprayed on stems and leaves with the captafol wettable powder up to 3, 7, 15, 30, 45, 60 days before harvest. The results of the analysis of captafol residues on the sample grapes were as follows : 1- Recovery values obtained from fortified control samples were 85.3 and 90.0%, respectively, at the 0.1 and 1.0 ppm levels, the detection limits being 0.06 ng(0.015 ppm). 2. Captafol residues were detected in all samples, ranging from 0.25 to 5.79 ppm. 3. Captafol residues had a tendency to become the more, the more spray frequency and the closer spray time to harvest. 4. The captafol residues on grapes were within the maximum residue limits in the samples sprayed 4 times involving those sprayed up to 3 days before harvest, whereas the residues in the samples sprayed 5 times were beyond the limits. 5. It was recommended that the captafol WP should be sprayed on grapes 4 times up to 7 days before harvest.

재무제표 구조 개선에 관한 연구 : 국제비교 중심으로

이대선,고완석,유청을,송기신,박성환 서강대학교 경영학연구원 2002 서강경영논총 Vol.13 No.1

객체에 근거한 선호도 제약 중심 스케줄링 언어와 성능향상 기법

이기철,문정모,송성헌 한국경영과학회 1995 經營 科學 Vol.12 No.2

For a complex scheduling system like time table construction, its optimal solution, if exists, is hard to obtain. In this paper, the scheduling environment is reasonably confined as where objects have their own events competing for better slots on boards, and objects have their own board slot preferences and belong to one or more classes of the society which globally constrains them. Here, two phase method is suggested, where the first phase is human-like preference dirven and the second phase is for fine tuning by considering all the factors given. Designed and implemented in our system HI-SCHED are dynamic object switching, temporal-constraint-driven intelligent backtracking, case-based revisions, object-based approach, and so on. Some satisfaction degrees are also defined to measure the usefulness of our method. In addition, look-ahead dynamic object switching is considered, and additional global constraints are introduced and processed. A simple scheme is also used to verify the usefulness of the post processing scheme.

Mannitol 투여에 의한 핍뇨성 급성 신부전 1례

이홍준,나기찬,정은경,박상기 朝鮮大學校 附設 醫學硏究所 1992 The Medical Journal of Chosun University Vol.17 No.2

Mannitol, a hexahydroxy chemically related to mannose, is a non-electrolytic, osmotic agent, It has been known that mannitol may cause serious life-threatening situation if administered in a patient with renal problem. Recently, it has been published that mannitol itself may be nephrotoxic in a patient without preexisting nephrologic disorders. We experienced a case of acute oliguric renal failure caused by long use of mannitol in order to reduce intracranial pressure and cerebral edema after operation of left posterior communicating aneurysm, and reported with recent literature review.

高果糖 誘導 고지혈증 흰쥐에 대한 薏苡仁의 효과

이영종,손영종,임덕빈,이은섭,박중수,김성기 대한본초학회 2005 大韓本草學會誌 Vol.20 No.1

Objective : In order to examine the effects of Coicis Semen on the hyperlipidemia, the extracts of Job's Tears were given to hyperlipidemic rats induced by fructose-rich chow. Method : The hyperlipidea was induced by fructose-rich chow during five weeks in rats. And the rats were administered with the extracts prepared from husk layer, bran layer, polished rice, unpolished rice or unhulled grain of Job's Tears each others during three weeks. And then, the effects of the extracts on body weight gain, total cholesterol, triglyceride and blood glucose were examined. Results and Conclusion : The extracts prepared from polished rice, unpolished rice or unhulled grain of Job's Tears had no effects on the body weight gains of the corpulent rats induced by a high fructose diet. Meanwhile, the extracts prepared from the unhulled grain (Coicis Semen), unpolished rice, and bran layer of Job's Tears decreased the levels of blood total cholesterol. and triglyceride, each others. And the effect of unhulled grain was more stronger than those of the others. The results suggested that unhulled grain had some materials useful for alleviating the hyperlipidemia, and the effective molecule is existed in the surface of unhulled grain.