RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
        • 원문제공처
          펼치기
        • 등재정보
          펼치기
        • 학술지명
          펼치기
        • 주제분류
          펼치기
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재
      • 폭풍시 사구의 침식각에 따른 해안단면의 침식에 관한 연구

        이보형,표순보,이홍식,조원철 中央大學校 建設環境硏究所 1999 環境科學硏究 Vol.9 No.2

        This EDUNE model developed by Kriebel was used for predicting storm-induced beach and dune erosion due to elevated water levels and waves. This model was based on the convolution integral involving a erosion-force function and an exponential erosion-response function. This numerical model adopted the equation of sediment continuity and a dynamic equation governing the cross-shore sediment transport due to a disequilibrium of wave energy dissipation levels. These equations are solved numerically by an implicit, double-sweep method to obtain the changes in position of elevation contours in the profile. In this study, the changes of a beach profile and dune erosion have been simulated for varying the dune erosion angle due to storm. The range of angle was 0.1~0.4 radian. It is shown that erosion rate is increasing according to the decrease of erosion angle.

      • 흑연 표면에 흡착된 Kr의 이차원 지름 분포 함수

        안운선,이순보,함경희,이광순 成均館大學校 1983 論文集 Vol.33 No.-

        The radial distribution function for 2D fluid of Kr adsorbed on graphite surface is calculated using cluster integrals. The interaction energy between a Kr molecule and graphite surface is assumed as a pairwise addition of Lennard-Jones(12, 6) potentials. From this radial distribution function spreading pressure of the adsorbed layer is calculated. The results agree very well with experimental results and boundary conditions. The isosteric heat of adsorption is also calculated using 2D virial equation of state, and found to agree very well with experimental results.

      • 효모에서 분리한 단백 메틸레스의 특성에 관한 연구

        김보경,백운기,조만희,김창세 순천향의학연구소 1997 Journal of Soonchunhyang Medical Science Vol.3 No.2

        A cytochrome C - specific protein methylase Ⅲ was purified approximately 63 - fold from Saccharomyces cerevisiae. The unmethylated cytochrome C served as substrate for the enzyme. Horse heart apocytochrome C was found to be a better substrate than the native horse heart cytochrome C. This observation suggests that the in vivo methylation of cytochrome C in the yeast probably occurs before cytochrome C become attached to the mitochondria. In partly purified protein methylase Ⅲ the optimun pH is about 9.0, the enzyme activity is linearly proportional to the amount of enzyme protein up to about 30㎍ and also to time up to 15min. The Km values for horse heart cytochrome C and S - adenosyl - L- methionine were 1.33mM and 40㎛, respectively. S - adenosyl - L - homocysteine was found to be a competitive inhibitor for S - adenosyl - L - methionine, and the Ki value was 2.7 μM. The molecular weight of the enzyme was approximately 97,000, determined on sephadex S- 200 gel filtration. The regulation of cellular cytochrome C and the protein methylase Ⅲ are not coordinately related in a parallel manner.

      • Ni添加 CV黑鉛鑄鐵의 祖織과 機械的性質 및 熱物性値에 關한 硏究

        南泰運,許甫寧,徐弘三 慶尙大學校 1987 論文集 Vol.26 No.1

        In this sthdy, an easy production method of CV graphite cast with iron with small adition of NI which is known as the elements of the graphitizon was inverstigated. And so, the effects of physical, mechanical and thernal properties by fading time, carbon equivalent and Ni addition after the treatments with spheroidizer(Fe-Mg), were also investigated. The results obtained from this study were as follows: 1. With an increase of carbon equivalent the CV ratio was a little increased but with an increase of addition of Ni plus Mg the graphite numbers and CV rato were greatly increased. And so, the form and distribution of graphite were homogenized. 2. With an addition of Ni the ferrire ratio were decreased and the parlite ratio were a little increased. 3. With an increase of CE and fading time the mechanical properties (tensile strength, ased. And so, in case of Mg an Ni plus Mg addition the mechanical properties were greatly increased. 4. With an incease of CE and fading time the thermal properties(thermal diffusivity and conductivity ) were increased but with addition of Ni plus Mg the thermal properties were speroidal graphite ratio. 5. For the addition of Ni plus Mg the results were obtained that the decrease of lading effect the increase of inoculation effect, the increase of CV graphite ratio.

      • 다결정 니켈표면과 산소 기체와의 상호 작용

        안운선,이순보,부진효,박유용 성균관대학교 기초과학연구소 1986 論文集 Vol.37 No.2

        The interaction of the gaseous oxygen molecule with polycrystalline nickel surface has been studied by the XPS through the wide range above the room temperature. For relatively lower oxygen exposure, only an O(1s) peak was observed at 530.2 eV, which is associated with the dissociative adsorption. On the other hand, with increasing oxygen exposures, two peaks was appeared at 529.7eV and 531.3eV. These peaks are attributed to nickel oxide and Ni_2O_3, respectively. The latter oxide is ascribed due to the excess adsorption over the NiO stoichiometry. However at high temperatures above 423K, the dissociative adsorption and oxidation was found to take place simultaneously. As a whole, through these XPS study it is found that the interaction of the oxygen with the polycrystalline nickel surface commences through three steps: the fast dissociative adsorption following slow initiation process, rapid oxidation corresponding to the epitaxial NiO formation, and finally the bulk oxide formation.

      • KCI등재

        엔진구동형 NiTi 파일의 근관성형능력 비교

        김보혜,최경규,박상혁,최기운 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.2

        The purpose of this study was to compare the root canal shaping ability of 4 rotary NiTi instruments in simulated root canals. For the preparation of thirty two curved root canals, Mtwo instruments using “single length”technique, and Profile, ProTaper Universal, and K3 using crown-down technique (N = 8) were used. All canal samples were prepared by reaching an apical canal size of #30. Pre- and post-instrumentation digital images were recorded and an assessment of canal shape was determined using a computer image analysis program SigmaScan Pro (Systat Software Inc., San Jose, CA, USA). The changes of the dimension of inner walls of canals, (2) the changes of the dimension of outer walls of canals, and (3) the centering ratio were measured at 7 measuring points, and then data were statistically analyzed using one-way ANOVA and Duncan’s test. The results were as below; 1. The root canal shaping ability of Profile was significantly faster than that of other rotary NiTi instruments (p < 0.05). 2. The deformation and fracture of all instruments used for this study were not experienced. 3. In the degree of changes of the dimension of inner walls of canals, Profile demonstrated the lowest changes of the dimension of inner walls of canals except at the measuring points of the 1 and 2 mm (p < 0.05). However, the ProTaper Universal showed the highest changes of the dimension of inner walls of canals at all measuring points (p < 0.05). 4. In the degree of changes of the dimension of outer walls of canals, Mtwo demonstrated the lowest changse of the dimension of outer walls of canals except at the measuring point of the 1 mm (p < 0.05). However, Profile exhibited the highest changes of the dimension of outer walls of canals at the measuring points of 3 and 4 mm and ProTaper Universal and K3 showed the largest changes of the dimension of outer walls of canals at the measuring points of 1, 2, 6, and 7 mm (p < 0.05). 5. In degree of centering ratio, Profile demonstrated the least centering ratio comparing with the centering ratio shown by other NiTi instruments at the measuring points of 1, 4, 5, and 6 mm. Results suggest that in the coronal part of canal preparation, active cutting files such as ProTaper Universal may efficiently flare the canal orifice and form a better taper, and in the apical part of the canal, files which have a better centering ability such as Profile may maintain the original canal curvature and reduce the shaping time. 이 연구의 목적은 4가지 엔진구동형 NiTi 기구의 근관성형력을 비교하는 것이다. 32개의 투명레진모형을 사용하여 파일의 단면도가 S자 형태이고“single length”방법으로 근관성형을 시행하는 Mtwo와 crown-down 방법으로 근관성형을 하는 Profile, ProTaper Universal 및 K3로 근관성형을 하였다 (n = 8). 모든 근관은 한사람의 술자가 근단공 크기가 #30이 될때까지 성형하였다. 기구 사용 전과 후 근관 모양을 디지털 영상을 기록하였고, 컴퓨터 영상 분석 프로그램(Expression Scanner와 Adobe Photoshop CS)으로 평가하였다. 다음과 같은 결론을 얻었다. 근첨으로부터 1, 2, 3, 4, 5, 6, 7 mm 떨어진 부위의 내측과 외측으로 삭제된 레진 양을 측정하였고, 자료는 SPSS법으로 비교 분석하였다. 1. 근관형성 시간은 Mtwo가 84.50초로 가장 짧았으며, 총 작업시간은 K3가 269.37초로 가장 길었다(p < 0.05). 2. 기구의 변형과 파절은 모든 구동형 NiTi 파일에서 발생하지 않았다. 3. 근관 내측 폭경의 변화는 Profile이 1, 2 mm 부위를 제외한 다른 부위에서 가장 적었으며, ProTaper Universal은 모든 부위에서 가장 많았다(p < 0.05). 4. 근관 외측 폭경의 변화는 Mtwo이 1 mm 부위를 제외한 모든 부위에서 가장 적었으며, Profile은 3, 4 mm 부위에서 가장 많았다(p < 0.05). ProTaper Universal와 K3는 1, 2, 6, 7 mm 부위에서 가장 많았다(p < 0.05). 5. 근관중심변위율(centering ratio)은 Profile이 1, 4, 5, 6 mm 부위에서 가장 적었다(p < 0.05). 이상의 결과, 구동성 NiTi 파일을 이용한 만곡 근관의 근관형성은 치경부는 ProTaper와 같은 삭제력이 높은 파일을 사용하는 것이 근관 입구를 효과적으로 넓히고 더 나은 taper를 형성하며, 근단부는 Profile과 같은 근관 중심 변위가 적은 파일을 사용하는 것이 근관형성 시간을 단축하고 근단부의 근관 변형(transportation)을 줄일 수 있다고 판단된다.

      • CV黑鉛鑄鐵의 黑鉛型態 및 機械的 性質에 미치는 Ni첨가 효과에 관한 연구

        許甫寧,金水泳,南泰運,徐弘三,金學權 慶尙大學校 1985 論文集 Vol.24 No.1

        In this study, an easy production method of CV (Compacted/vermicular) graphite cast iron with small addition of a Ni which is known as the element of the graphitization was investigated. And so, the effects of fading (holding) time and of Ni addition after the treatments with spheroidizer (Fe-Si-Mg-Ca-Al-Ti-Ce) were also investigated. The results obtained are as follows. 1. According as Ni contents in CV molten cast iron increase, the graphite No. and CV radio were increased. And so, graphite form and the distribution of the graphite were homogenized. 2. When the addition treated with Ni, the tensile strength were increased, and the effect of fading time were decreased.

      • 유육종증 1례

        전수영,정운태,황성보,류종철,최수전,고일향 인제대학교 1993 仁濟醫學 Vol.14 No.4

        저자들은 폐결핵 추정하에 치료를 받았던 Sarcoidosis 환자 1례를 경험했기에 문헌적 고찰과 함께 보고하는 바이다. Sarcoidosis is a granulomatous disease of unknown etiology In which pulmonary manifestations typically predominate with protean extrapulmonary and systemic manifestations. In sarcoidosis, pulmonary symptoms include dyspnea on exertion, non-productive cough and wheezing. Typical radiologic finding is a diffuse infiltration with or without bilateral symmetric hilar lymphadenopathy. Sarcoidosis should be differentiated with pulmonary tuberculosis because of its clincal and radiological slmilarity in Korea, an endemic area of pulmonary tuberculosis. We report a case of sarcoidosis patient whose symptoms were not improved by treatment with anti-tuberculous medication, but by steroid therapy following the diagnosis of sarcoidosis made by biopsy.

      • Streptozotocin-당뇨병 백서에서 당뇨병 이환기간에 따른 대동맥의 이완능 저하 및 Oxygen-Free Radical에 의한 이완능의 손상정도

        김정국,김신우,김수동,서예경,하승우,김보완,백운이,권삼,강승완 경북대학교 병원 1997 경북대학교병원의학연구소논문집 Vol.1 No.1

        목적: 당뇨병의 이환기간이 혈관의 내피세포 의존성 및 비의존성 이완능의 저하에 미치는 영향과 이환기간에 따라 oxygen-free radical(OFR)에 의한 동맥이완능의 손상정도에 차이가 있는지를 알아보고자 하였다. 방법: Streptozotocin(STZ)으로 당뇨병이 유도된 3 주 및 10주째의 백서군과 연령이 비슷한 정상 대조백서군의 적출 대동맥환을 norepinephrine으로 수축시킨 상태에서 내피세포 의존성 이완제인 acetylcholine(ACh) 및 비의존성 이완제인 nitroglycerine(NTG)에 대한 이완능을 즉정하여 비교 관찬하였다. 또한 xanthine과 xanthine oxidase의 혼합으로 생성된 H₂O₂에 대동맥환을 노출시킨뒤 역시 ACh과 NTG에 대한 이완능의 손상정도를 비교하였다. 결과: 3주및 10주째 당뇨병 백서의 대동맥환은 모두 대조군 백서의 대동맥환에 비해 ACh에 대한 이완능이 유의하게 감소하였으며 10주째 당뇨병 백서군에서의 ACh에대한 이완능의 저하는 3 주째 당뇨병 백서군에 비해 유의하게 심하였다.H₂O₂에 노출시킨 뒤 ACh에대한 이완능은 3주 및 10주 째 당뇨병 백서군에서 모두 대조군에 비해 유의하게 심한 손상을 보였으나 3주와 10주째 당뇨병 백서군 사이의 손상정도의 차이가 통계학적으로 유의하지는 않았다. 한편 3주 및 10주째 당뇨병 백서군 모두 NTH에 대한 대동맥환의 이완능은 대조 백서군과 별다른 차이가 없었으며 또 H₂O₂에 노출시킨 뒤에도 NTG에 대한 이완능의 손상은 관찰되지 않았다. 결론: STZ-당뇨병백서에서 대동맥의 이완능은 당뇨병에 이환된지 3 주째에 이미 ACh에 대한 내피세포 의존성 이완능이 선택적으로 저하되며 당뇨병의 이환기간이 길수록 이완능의 저하가 심하였고, OFR에 의한 동맥 이완능의 손상도 내피세포 의존성 이완능에만 선택적으로 나타나나 이환기간에 따라 OFR에 의한 이완능 손상정도에는 뚜렷한 차이가 없음을 시사하고 있다. Objectives: Diabetes mellitus produces histological evidence of endothelial as well as changes in vascular function in experimental animal. Oxygen free radicals interfere with of destroy endothelium-dependent relaxation in normal and diabetic blood vessels. The present study was investigated whether the duration of diabetic state can affect the severity of impairment in endothelium-dependent and/or independent relaxation and the sensitivity to oxygen free fadical (OFR)-induced damage in diabetic rat vasculature. Methods: The relaxative responses of aortic ring precontracted with norepinephrine in vitro to cumulative concentrations of acetylcholine (ACh) and nitroglycerine (NTG) were conducted in 3- and 10- week streptozotocin (STZ)-diabetic rats and agematched controls. After exposure to H₂O₂generated by mixing xanthine and xanthine oxidase, the degree of impairment in relaxative responses to ACh and NTG were also compared between 3- and 10-week diabetic rats. Results: The relaxative responses of aortic rings produced by cumulative concentrations of ACh were significantly lower in both 3- and 10-week diabetic rats than in the age-matched controls. The impairments of relaxative responses to ACh in 10-week diabetic rats were significantly greater than those in 3-week ones. After H₂O₂ exposure, the impairments of relaxative responses to ACh in 3- and 10-week diabetic aortas was also significantly greater than those in the control in the control ones. However, the severity of H₂O₂-induced damage in 10-week diabetic aortas was not significantly different than that in 3-week ones. In contrast, aortic rings of 3- and 10-week diabetic rats could still be fully relaxed by NTG, even after exposure to H₂O₂. Conclusion: These findings suggest that in SRZ-diabetic rat aortas selective impairment of endothelium-dependent relaxation to Ach can be found early even over a 3-week period after the induction of diabetes and the impairment may be greater in those with the longer duration of the diabetic state and that the impairment of the vascular relaxation by OFR is also selective to endothelium-dependent response but the sensitivity of OFR-induced damage may not be related to the duration of the diabetic state.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼