추황배(Pyrus pyrifolia Nakai cv. Chuhwangbae) 과피로부터 1종의 Sterol과 3종의 배당체 화합물의 단리·동정

이유건(Yu Geon Lee1),조정용(Jeong-Yong Cho),이현주(Hyun Joo Lee),이용현(Yong Hyun Lee),이상현(Sang-Hyun Lee),한태호(Tae-Ho Han),김월수(Wol-Soo Kim),박근형(Keun-Hyung Park),문제학(Jae-Hak Moon) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.5

본 연구에서는 배의 유용성 증명을 위한 일환으로 배의 화학성분을 분자수준에서 밝히고자 하였다. 이에 배 과피 MeOH 추출물을 용매분획하여 얻은 EtOAc-산성 분획과 EtOAc-중성분획을 대상으로 Sephadex LH-20, silica gel, 그리고 ODS colmn chromatography와 HPLC를 이용하여 정제 및 단리하였다. 그 결과, EtOAc-산성 분획과 EtOAc-중성 분획으로부터 각각 2종씩의 화합물을 단리하였다. 단리된 화합물 1-4는 1H- 및 13C-NMR 분석을 통하여 각각 (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (화합물 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone(piceoside, 화합물 2), β-sitosterol (화합물 3), 그리고 β-sitosteryl 3-O-β-D-glucopyranoside (화합물 4)로 동정되었다. 단리된 3종의 배당체 화합물(화합물 1, 2, 4)들은 본 연구에 의해 배로부터 처음 동정되었으며, 화합물 3은 추황배로부터 처음 동정되었다. 본 연구결과가 배 함유 성분연구는 물론 배의 기능성 해명 연구에도 추후 중요한 기초자료로 활용되길 기대한다. We isolated and identified antioxidants from acidic and neutral ethyl acetate fractions of the peel of pear (Pyrus pyrifolia N. cv. Chuhwangbae). We isolated 4 compounds from the methanol extract, by using 3 different types of column chromatography (Sephadex LH-20, silica gel, and octadecylsilane) and preparative HPLC. We identified the isolated compounds as (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (compound 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone (picroside, compound 2), β-sitosterol (compound 3), and β-sitosteryl 3-O-β-D-glucopyranoside (compound 4) by nuclear magnetic resonance analysis. We are the first to report the identification of compounds 1, 2, and 4 from pear.

兩端固定 圓弧 아-치의 平面內 固有振動에 關한 硏究

이병구,황학주,이원복 연세대학교 산업기술연구소 1975 논문집 Vol.6 No.1

Numerical data have been presented for the natural frequencies and modes of vibration of fixed, uniform, circular arches vibrating in their own plane, and the effects of the rotatory inertia and shear deformation affecting the response have been analyzed. The governning differential equations were solved numerically by a combination of a Holzer-type iterative procedure and an initial value integration procedure. The Runge-Kutta fifth order integration technique was used. The method was programmed for a Cyber 73-18 computer system, and all results were obtained on this computer system. A detailed study has been made of the lowest five vibration frequencies and mode shapes for a fixed arch with an angle of opening equal to 90 degrees. The effect of slenderness ratio and the influence of the rotatory inertia and shear deformation on frequencies are presented in detail in curves.

初等敎育 理念의 探索

李學周 仁川敎育大學校 1991 論文集 Vol.25 No.1

조기탈형을 위한 라텍스 개질 초속경 콘크리트의 개발 및 강도발현 특성

이봉학,홍창우,이주형,정원경 강원대학교 석재복합신소재제품연구센터 2001 석재연 논문집 Vol.6 No.-

현재 스틸렌-부타디엔 라텍스(styrene-butadiene latex)를 혼입한 콘크리트는 광범위하게 사용되고 있다. 교면포장용으로 라텍스 개질 콘크리트(LMC)의 사용은 일반 콘크리트와 다르지 않지만 라텍스에 의해 콘크리트의 특성을 향상시킨다. 그러나, 이와 같은 라텍스 개질 콘크리트와 다르지 않지만 라텍스에 의해 콘크리트의 특성을 향상시킨다. 그러나, 이와 같은 라텍스 개질 콘크리트는 장시간 양생을 요하는 문제로 인해 긴급을 요하는 곳에는 적용할 수 없다. 따라서 본 연구에서는 초속경시멘트를 사용한 라텍스 개질 콘크리트를 개발하고, 이에 따른 작업성 및 강도발현특성을 분석하는데 그 목적이 있다. 실험결과, 지연제와 소포제를 사용한 라텍스 개질 초속경 콘크리트(RSLMC)의 강도발현을 확인할 수 있었으며, 제안된 최적배합은 초속경성의 강도발현으로 인해 현장에서 긴급보수에 적용이 가능함을 알 수 있었다. 따라서 라텍스 개질 초속경 콘크리트는 교면포장, 포장체, 빌딩등의 보수에 적용이 가능할 것으로 판단된다. Concrete containing styrene-butadiene latex is widely used, nowadays, as a protective system for bridge. The usage of latex modified concrete (LMC) as an overlay system is not all that different from any quality concrete, but the improved properties impart to the concrete by the latex. However, this may not be used for repair works because the bridge lane could not be closed for several weeks for curing. Therefore, this study focused on the development of rapid-setting cement latex modified concrete (RSLMC), and on the investigation of workability and strength development. As a result, this study clearly validated the strength development of RSLMC by introducing a retarder and an antifoam agent. The proposed optimized concrete mixtures might be satisfactorily applied for the repair works in fields, because of its rapid strength development, respectively. Therefore, RSLMC could be used in many repair or overlay works such as bridge deck, pavement or building.

意味辨別法으로 測定한 敎師像에 관한 一硏究

李恩玉,李學柱 울산대학교 1985 연구논문집 Vol.16 No.2

本 硏究는 大學生이 갖는 敎師像을 意味 辨別法으로 測定·分析하기 위하여 40쌍의 대칭되는 形容詞間項을 사용하였다. 標集은 서울과 지방에서 4개 대학을 선정, 모두 579명으로부터 資料를 募集하였고. 資料는 全體, 性別, 系列別로 平均, 標準偏差를 算出하고, t-檢證 및 要因分析 하였으며 그 結果는 다음과 같다. 1. 全體的으로 大學生이 갖는 敎師像은 肯定的이나, 그 지지정도는 多小 中立的이어서 鮮明하지 않다. 部分的으로 活動, 力能次元에서는 否定的인 경향도 나타내고 있다. 가장 肯定的인 반응을 보인 문항은 '중요하다', '自尊心이 강하다', '精神的', '깨끗하다' 등이었고, 가장 否定的인 반응을 보인 문항은 '소심하다', '보수적이다', '방어적', '고지식하다' 등이었다. 2. 大學生의 性別에 따른 敎師像은 男學生이 女學生에 비해 훨씬 强하게 肯定皓일 경향을 나타내고 있다. 이런 경향은 '순진하다', '깨끗하다', '옳다', '똑똑하다', '헌신적이다'라는문항에서 두드러지게 나타났다. 3. 大學生의 系列別에 따른 敎師像은 非師範系가 師範系 學生에 비해 다소 肯定인 경향을 나타내고 있다. 이런 경향은 '깨끗하다', '새롭다', '의욕적'이라는 문항에서 나타나고 있다. 4. 大學生이 갖는 敎師像의 栗因構造는 "進取性"과 "誠實性"이 대부분을 차지하고 있는데, 이중 진취성에는 부정적인 경향을, 성실성에는 긍정적인 경향을 나타내고 있다. 以上의 結果를 토대로 볼때, 大學生에게 비쳐진 敎師의 이미지는 全般的으로는 肯定的이나, 倫理·道德的인 側面에서는 보다 肯定的 方向에서, 活動·力能面에서는 多小 否定的일 方向에서 知覺되고 있으며, 이런 경향은 男學生이나 比師範系 學生보다는 女學生, 師範系 學生에게서 더욱 두드러지게 나타나므로, 漸增하고 있는 敎職의 女性化 추세에 비추어 現行의 師範·敎職敎育에서 이에 대한 적절한 對策 마련이 있어야 할 것이다. This study is an attempt to measure college students' image on "teacher", and to determine the factor structure of the image. This study used a semantic differential scale that was constructed with 40 bipolar adjective items. The scale was administered to 579 college students. Mean scores were computed for every adjective pair for the male group, the female group, the teacher-training course students, non-teacher-training course students and the combined group. This analysis showed a tendency that 1) the college students, generally, had positive images on "teacher". Only on 7 items, they showed negative tendencies such as "narrow-minded, " "conservative" , "defensive" , "simple-minded" etc. The most positive responses were "important", "self-respectful", "spiritual", "clean" act. 2) Significance tests for the sex difference showed that the male students had more strongly positive images on 16 items and more negative images on 1 item on teacher than the female students. That is, the male students' images on "teacher" were more incline toward "pure", "clean", "right", "clever", "self-sacrificing", and less toward "talkative". 3) Significance tests for the course difference showed that the non-teacher-training course students had more positive images on 7 items and more negative images on 2 items on teacher than the teacher-training course students. That is, the non-teacher-training course students' images on ."teacher" were more inclined toward "clean", "new", "willingly" and less toward "difficult" , "talkative". And the data were subjected to factor analysis. Using a criterion of eigenvalue greater than, 1, followed by the varimax rotation, 9 factors were selected. The common variance of 56.5% in the meaning or image of "teacher" were calculated for all these 9 factors. Items that had factor score coefficient of .10 or greater on a single factor were arbitrarilly selected to represent that factor. The 9 factors have been named "Progressiveness", "Sincerity", "Nobility", "Self-Fulfilment", "Sagacity" , "Quickness" , "Complexity" , "Faithfulness" . Among the factors, the 1st factor (Progressiveness) accounted for 25.6% of the common variance, 55% of the common variance accounted for 9 factors. This implies that "Progressiveness" dimension is the most important for assessment of the "teacher" image. But the students showed negative tendency in 1st dimension. The 2nd factor (Sincerity) accounted for 7.7% of the common variance, 14.2% of the common variance accounted for 9 factors. In 2nd dimension, the students showed positive tendency. The results imply that students have image on "teacher" who was "negative", "narrow-minded", "conservative", "defensive", "simple-minded", "weak", but "selfsacrificing", "sincere", "responsible", "clean", "believable"

實踐的 行爲의 敎育的 意味에 관한 硏究

李學周 仁川敎育大學校 1990 論文集 Vol.24 No.1

부순모래를 사용한 고강도 콘크리트의 배합설계에 관한 연구

이봉학,김동호,홍창우,이주형 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.A

The amount used of aggregates for concrete is increasing rapidly since the mid-1980s in Korea. The natural gravels from river are already displaced with crushed stone, and use of crushed sand as a substitute of natural river sands, also, is getting increased day by day. This paper is presented for mixture of high strength concrete using crushed sands. Mixing design of concretes alee various water-cement ratios(w/c) such as 25%, 40%, 55% and different replacement radio of crushed sands to natural sands such as 0%, 20%, 40%, 60%. As a results, it has been shown that compressive strength of concretes with w/c lower than 40% and 25% is higher than 400 kgf/cm2 and 600 kgf/cm2 respectively.

항고형암제의 활성평가를 위한 in vitro 삼차원 암세포 배양계의 확립

이상학,이주호,구효정 한국약제학회 2004 Journal of Pharmaceutical Investigation Vol.34 No.5

For the efficient determination of activity against solid tumors, an in vitro tumor model that resembles the condition of in vivo solid tumors, is required. The purpose of this study was to establish a rapid culture method and viability assay for an in vitro 3-dimensional tumor model, multicellular spheroid (MCS). Among 12 human cancer cell lines, a few cell lines including DUD-1 (human colorectal carcinoma cells) formed fully compact MCS which was adequate for in vitro viability assay. DLD-1 MCS showed steady growth reaching 700 pm diameter after 11 day culture. DUD-1 cells grown as MCS showed significant increase in G_(0)/G₁ phase compared to the monolayer cells (73.9% vs 45.7%). but necrotic regions or apoptotic cells were not observed. The cells cultured as MCS showed resistance to 5-FU (10.3 fold higher IC_(50)) compared to monolayers. however, tirapazamine (a hypotoxin) showed similar activity in both culture systems. In summary, MCS may be a valid in vitro model for activity screening of anticancer agents against human solid tumors and also exploitable for studying molecular markers of drug resistance in human solid tumors.

鐵筋콘크리트 보의 附着擧動에 관한 硏究

이주형,이봉학,홍창우,김동호 江原大學校 産業技術硏究所 1998 産業技術硏究 Vol.18 No.-

Cracking is considered to be one of the important factors in determining the durability of reinforced concrete structures. When the bending stress exceeds the modulus of rupture of the concrete, cracking fom along the length of members. The total load is transferred across these cracks by the reinforcement, but the concrete between craks is still capable of carrying stresses due to the bond between steel and concrete. This phenomenon is called the tension stifening effect. The tension stiffening effect is affected by many variables, such as the bond stress, strength of concrete, interrocking of aggregate, type of steel, and dowel action of steel. Also, this tension stifening effect is usually quite significant in beams under service loading, and must be taken into account in the calculation of deflection and crack widths. In this study, the experiment was carried out on types of specimen, strength of concrete, and steel ratio and finite element analysis were compared in terms of load-deflection relationship, crack pattern.

소포제 종류 및 혼입률에 따른 초속경 라텍스개질 모르타르의 역학적 특성

이봉학,홍창우,이주형,김동호 江原大學校 産業技術硏究所 2001 産業技術硏究 Vol.21 No.B

The purpose of this study was to remove the excessive air foaming which was produced in mixing the RSLMC(latex-modified concrete with rapid-setting cement) by choosing the best antifoam agent type. A series of RSLMM(latex-modified mortar with rapid-setting cement) experiments were carried out as a basic experiments for RSLMC with the main experimental variables such as antifiamer types (A, B, C, D), antifoamer contents(0, 1, 2, 3%), and latex contents(10, 15%). Air content test and compressive strength tests were carried out to measure the improved properties of RSLMM. SEM analysis, also, was carried to observe the formation of latex film. The results of RSLMM showed that the decrease of 50% air content was obtained by admixturing an antifoam agent by 1%. This made the strength enhanced and the workability be within the purposed. The best properties of compressive strengths was obtained at latex content of 15% and D antifoam agent of 1%. compressive strength increased about 32.6%. The analysis of SEM results no difference in a formation of later film.