http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Scratch-tip-size effect and change of friction coefficient in nano / micro scratch tests using XFEM
Lee, Kwangmin,Marimuthu, Karuppasamy Pandian,Kim, Chang-Lae,Lee, Hyungyil Elsevier 2018 Tribology international Vol.120 No.-
<P><B>Abstract</B></P> <P>Compared to the experimental studies, numerical studies on scratch test have been limited due to the difficulty of numerical modeling. Here, we experimentally investigate the scratch-tip-size effect (STSE) based on coefficient of friction (COF) change to make extended finite element (XFE) models considering STSE, COF change, failure modes, yielding strength, shear strength, elastic recovery and pile-up. XFE models are then validated through nano/micro scratch tests on soda-lime glass. Finally, components of COF are extracted and then effects of tensile cracks and parameters of Drucker-Prager model on COF are investigated. We expect that proposed XFE models contribute to the understanding of damage characteristics during the scratch test.</P> <P><B>Highlights</B></P> <P> <UL> <LI> FE models for nano/micro scratch test on soda-lime glass are proposed. </LI> <LI> Scratch-tips of different size cause various failure modes. </LI> <LI> Scratch-tip size effect significantly influences friction coefficient change. </LI> <LI> Drucker-Prager model of material is calibrated considering indentation size effect. </LI> <LI> Components of coefficient of friction are extracted from experiment by using FEM. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
High-Resolution Capacitive Microinclinometer With Oblique Comb Electrodes Using (110) Silicon
Dae-Hun Jeong,Sung-Sik Yun,Byung-Geun Lee,Myung-Lae Lee,Chang-Auk Choi,Jong-Hyun Lee IEEE 2011 Journal of microelectromechanical systems Vol.20 No.6
<P>We propose a new capacitive microinclinometer where oblique comb electrodes and double-folded suspension springs are aligned parallel to the vertical (111) plane of (110) silicon. The oblique comb utilizes both the overlapped area and the gap between movable and stationary electrodes, resulting in a considerable increase in sensitivity (capacitance change/angle). The resolution becomes even higher by taking advantage of the smooth (111) sidewalls of the oblique comb electrodes, which are fabricated using silicon deep reactive ion etching followed by crystalline wet etching. The surface roughness was reduced from 200 (R<SUB>rms</SUB>) to 20 nm (R<SUB>rms</SUB>), and the verticality was improved from 88.7° to 89.7°. The capacitance change of the fabricated inclinometer experimentally ranges from -0.793 to 0.783 pF for the full range of inclination angle (from -90° to 90°). The estimated worst resolution, which is obtainable at an inclination angle of ±85°, was as low as 0.25°.</P>
Lithium과 항정신병 약물의 병합치료에 의하여 발생된 급성 뇌증후군
이창욱,채영래,백인호 大韓神經精神醫學會 1989 신경정신의학 Vol.28 No.4
The authors studied the characteristics of the acute brain syndrome induced by lithium-neuroleptic combined treatment in manic patient, admitted to the Neuropsychiatric Department of Kang-Nam St. Mary's Hospital from January 1981 to December 1987. Among 204 manic patients who had been treated with lithium and neuroleptics, 9 subjects showed acute brain syndrome. The charateristics and risk factors of acute brain syndrome subjects were analyzed, and the results were as follows; Acute brain syndrome appeared within 2 weeks follwing combined therapy of lithium and neuroleptics, even though serum lithium level were maintained within therapeutic ranges. Following the discontinuation of the drugs acute brain syndrome completely disapperared within 1 week. This findings strongly suggest that the acute brain syndrome seems to be an idiosyncratic response to the lithium-neuroleptic interaction.
실험을 통한 제방법면 보호용 식생매트의 내침식강도 평가
장창래,이경수 한국교통대학교 2014 한국교통대학교 논문집 Vol.49 No.-
The stability and erosion resistance intensity of vegetation mat for protecting bank erosion are investigated experimentally in this study. The erosion depth increases as flow velocity and discharge increase. However, the erosion velocity decreases with erosion depth. This means that the erosion decreases with time. The equation for estimating erosion resistance of vegetation mat against ground surface is derived by using the experimental results. The estimated values are compared with the erosion resistance against the vegetation roots, which covered with the river bank surface. The erosion resistance time increases as the thickness of vegetation mat increases. Moreover, the resistance velocity decreases with time in condition of the equal thickness of vegetation mat.
가토 뇌 Protein Methylase Ⅱ에 관한 연구
이창래,권기량,임규,황병두 충남대학교 의과대학 지역사회의학연구소 1990 충남의대잡지 Vol.17 No.2
Protein methylase II has been purified from rabbit brain approximately 1,600 folds with a 6% yield by the methods of homogenation, (NH_4)_2SO_4 saturation, S-adenosyl-L-homocysteine sepharose 4B column chromatography and hydroxyapatite column chromatography. The enzyme shows a pH optimun around 6. The enzyme is easily inactivated by heat treatment for 5 minutes at 60℃, and when stored at -20℃ in the presence of 10% glycerol, 40% of activity has been lost in a week. Fe^2+ and Se activate this enzyme upto 16% and 22% at 2mM concentration and Ni, Zn^2+ and Cu^2+ inhibit upto 17%, 32%, 100% at 2mM respectively. The inhibition by 250μM Cu^2+ is completely recovered by 2.5mM DTT and 40% recovered by 300μM DEDTC. The apparent Km value for S-adenosyl-L-methionine was 2.2 x 10 exp (-6)M and kinetic analysis of this enzyme in the presence of 30μM cupper ion shows that the nature of the inhibition to the enzyme is noncompetitive.
손창성,손보식,김경래,이현수 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2
The corps of engineer battalion is in the maintenance management service for about 30 battalions subordinated to the infantry division, but the maintenance management manpower is a small number because the criterion of the maintenance management manpower is in accordance with the battle organization. So, this study suggests the reasonable maintenance management manpower estimating model according to the area, the quantity and so on of army installation. In this case study, we investigate the present states and the actual conditions for the 3 infantry divisions and 3 corps of engineer battalions, and find out improvement method based on the interview with the persons concerned.
니켈기 초내열합금 RENE 80 의 크리프시험중 결정입계 균열생성 및 전파
조창용,김학민,박용조,김승언,이상래 대한금속재료학회(대한금속학회) 1991 대한금속·재료학회지 Vol.29 No.11
Two kinds of specimens with different microstructure were prepared by changing casting variables in vacuum investment casting. The effect of microstructural difference on the creep behavior, creep crack initiation and creep crack propagation was studied in Ni base superalloy RENE 80. The specimen having fine grained and uniformly distributed carbide exhibited superior creep properties to the large grained specimen tested at 760℃. However above 870℃, two kinds of specimens showed similar creep behavior. At higher temperature creep, crack initiation was principally caused by the reaction between the grain boundary exposed at the surface and the test atmosphere rather than the internal microstructural changes. The crack initiated at the surface propagated to the internal area and this kind of crack propagation leads to fracture of material.
김나영,이동호,송인성,김용일,김우호,최규완,이국래,최기영,장미수 대한소화기내시경학회 1997 Clinical Endoscopy Vol.17 No.2
Background/Aims: The aims of this study are to clarify the morphology of fundic gland polyp (FGP) and to compare the features of FGP between familial adenomatous polyposis-associated group and sporadic development group. Methods: A total of 15 endo- scopic biopsy specimens of FGP from 13 patients were divided into three groups; Group A(3 cases; familial adenomatous polyposis family, multiple FGPs), Group B(3 cases; sporadic development, multiple FGPs) and Group C(7 cases; sporadic development, single FGP), and their endoseopic /microscopic features including mucin histochemistry and immunohistoc- hemistty(for PCNA) were compared. Results: FGPs were confined to the gastric body and fundus in all 3 groups, and measured 2-8 mm. Their numbers varied even in Group A and Group B, The difference was observed in their median age: 26 years in Group A and 55 years in Group B, respectively, but there were no differences in endoscopic, histologic, mucin histochemical and immunohistochemical(for PCNA) features. Micro-scopically, all FGPs were composed of fundic glands and scattered microcysts with a spectrum of disordered glandular architecture which ranged from convoluted gland to Y-shaped gland, to stellateshaped gland, and to irregular tortuous glancl with dilated lumen. Conclusions: We assume that diversity af morphologic features of FGP may develop from progression of hyperplastic/hamartomatous fundic glandular proliferation which may end up with microcyst formation as an evolutional change. Familial adenomatous polyosis-associated FGPs were not endoscopically and histologically distingishable from sporadic deveoped FGPs.