기계적 분쇄화법으로 제조된 (Ti52Al48)100-xBx(X=0,0.5,2,5) 합금의 미세조직 및 기계적 성질

표성규,김낙준,정현호,황승준 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.12

The present study is concerned with γ-(Ti_(52)Al_(48))_(100-x)B_x(x=0, 0.5, 2, 5) alloys produced by mechanical milling/vacuum hot pressing using melt-extracted powders. Microstructure of as-pressed alloys exhibit dual phase equiaxed microstructure of α₂ and γ with a mean grain size of 200 ㎚. Besides α₂ and γ phase, binary and 0.5%B alloys contains Ti₂AlN and Al₂O₃ phases located along the grain boundaries and show appreciable coarsening in grain and dispersoid sizes during annealing treatment at 1300℃ for 5 h. On the other hand, 2%B and 5%B alloys contains fine boride particles within the γ grains and show minimal coarsening during annealing. Room temperature compression tests of as-pressed alloys reveal low ductility, but very high yield strength >2100 ㎫. After annealing treatment, mechanically milled alloys show much higher yield strength than conventional PM and IM processed alloys, with equivalent ductility to IM processed alloys. 5%B alloy with smaller grain size shows higher yield strength than binary alloy at room temperature. When test temperature is increased to 850℃ 5%B alloy shows much lower strength than binary alloy, indicating the deformation of fine 5%B alloy is dominated by the grain boundary sliding mechanism.

한국어 마찰음과 파찰음의 음향학적 및 공기역학적 특성에 관한 연구

표화영,이주환,최성희,심현섭,최홍식 한국음성과학회 1999 음성과학 Vol.6 No.1

21 normal Korean native speakers participated as subjects to investigate the acoustic and aerodynamic study of Korean fricatives and affricated and to make good use of the results for the patients with articulation problems. Their productions of [sa], [s'a], [ca], [c^ha],[c'a] [asa], [as'a], [aca], [ac^ha] , and [ac'a] were analyzed with CSL and AP II instruments. The results are as followings : (1) Fricative showed higher frequency in minimum and maximum frequency and longer duration than affricates. (2) Fricatives showed higher peak flow rate and longer rise time than affricates. (3) When we compared the different phonemes with each other, their differences were usually statistically significant, but when we compared CV and VCV syllables, they did not show significant difference, even VCV's showed higher and longer values than CV syllables. (4) Normaly, lax fricatives and affricates showed lower frequency and higher peak flow rate, shorter frication duration, and longer rise time. Keywords: Fricatives, affricates, acoustics, aerodynamics.

당뇨병에서의 혈장 Renin 활성에 관한 연구

이정상,이문호,김성권,최강원,표희정,박정식 대한핵의학회 1979 핵의학 분자영상 Vol.13 No.1

당뇨병에서의 고혈압 및 신합병증에 따른 Renin Angiotensin-Aldosterone계의 동태를 밝히기 위하여 40예의 당뇨병 환자에서 기저 및 furosemide 정주 2시간 후의 PRA를 측정하였다. 1) 40예의 당뇨병 환자는 신합병증과 고혈압의 유무에 따라 4군으로 분류하였으며, 임상적인 합병증이 없는 Ⅰ군에는 15명, 신합병증이 있는 Ⅱ군에는 7명, 신합병증과 고혈압이 같이 있는 Ⅲ군에는 8명, 고혈압만 있는 Ⅳ군에는 10명의 환자가 속하였다. 2) 각 군의 24시간 요중 Na배설량의 평균치 사이에는 유의한 차이가 없었다. 3) 기저 PRA치는 Ⅰ군이 1.53±1.09ng/ml/hr(Mean±S.D), Ⅱ군이 0.63±0.59ng/ml/hr, Ⅲ군이 0.79±0.62ng/ml/hr, Ⅳ군이 1.11±0.80ng/ml/hr로서 Ⅱ군과 Ⅲ군은 Ⅰ군에 비하여 유의하게 저하되어 있으나(P$lt;0.05), 다른 군들 간에는 유의한 차를 볼 수 없었다. 4) furosemide 정주 2시간 후의 PRA치는 Ⅰ군이 2.72±1.96ng/ml/hr, Ⅱ군이 0.92±0.78ng/ml/hr, Ⅲ군은 1.03±0.76ng/ml/hr, Ⅳ군은 1.73±1.39ng/ml/hr로써 Ⅰ군과 Ⅱ군사이에서만 유의한 차이를 보이고(P$lt;0.05), 다른 당뇨병 환자군 사이에서는 유의한 차를 볼 수 없었다. 5) furosemide 정주에 의한 Renin 분필 자극시험에 대한 반응도 Ⅱ군과 Ⅲ군에서는 둔화되어 있는 양상을 보이나, 시험대상도 적고하여 통계적 유의성에는 미치지 못하였다. 이상의 성적에서 신합병증이 있는 당뇨병에서는 혈장 Renin활성이 저하되며 furosemide 정주에 의한 Renin 분필자극시험에 대한 반응도 둔화됨을 알 수 있었다. 또한 당뇨병성 신합병증에 의한 고혈압에서도 혈장 Renin활성은 저하되는 경향을 보여서 이 경우의 고혈압은 Renin이외의 다른 요인이 작용할 것으로 보인다. To evaluate the renin-angiotensin-aldosterone system in diabetes mellitus, basal plasma renin activity(PRA) and its response to intravenous furosemide were determined in 40 diabetic subjects. The diabetics were divided into 4 groups according to the pressence of nephropathy and/or hypertension. Uncomplicated diabetics(Group I) were taken as control group and the results of the other groups were compared to this group. In diabetics viith nephropathy alone(Group Ⅱ), and with nephropathy and hypertension (Group Ⅲ), basal PRA values were 0.63±0.59ng/ml/hr., and 0.79±0.62ng/ml/hr., respectively, both significantly lower than control group. (1.53±1.09ng/ml/hr.). (P$lt;0.05) In both of the above groups, the responses to intravenous furosemide tended to be blunted. On the other hand, in diabetics, with hypertension only (Group Ⅳ), the basal and stimulated PRA were not significantly different from control. Above results suggests that nephropathy may be one of the factors which suppress renin activity in diabetes me.

Low-temperature adsorption of hydrogen on ion-exchanged Y zeolites

Jhung, S.H.,Sun Lee, J.,Woong Yoon, J.,Pyo Kim, D.,Chang, J.S. Pergamon Press 2007 International journal of hydrogen energy Vol.32 No.17

Ion-exchanged Y zeolites with several alkali metal cations and proton have been used to analyze the effect of electrostatic field or basicity on the hydrogen adsorption at low temperature and low pressure. The adsorption capacity per surface area, isosteric heat of adsorption (-ΔH<SUB>ads</SUB>), surface coverage and micropore occupancy increase with the decreasing electronegativity of the metals that are introduced in the zeolite. Ion-exchanged zeolites also favorably adsorb hydrogen at relatively low pressures when the electronegativity of the metal is low. This work demonstrates that zeolites with strong electrostatic fields or high basicity are beneficial for high hydrogen uptake especially at low pressure and low temperature.

Metal bonding strength in low-temperature processed titanium using atomic force microscopy with single-wall carbon nanotube tip

Choi, E. M.,Cui, Y. H.,Kwon, S. H.,Kim, A. R.,Choi, H. S.,Lee, S. J.,Pyo, S. G. John Wiley Sons, Ltd 2014 Physica Status Solidi. Rapid Research Letters Vol.8 No.2

We report the development of a Ti-Ti bonding process at a low bonding temperature below 200 degrees C using chemically surface-activated Ti thin films and a reliable evaluation method for measuring the Ti-Ti bond strength by means of atomic force microscopy (AFM). Using Ti as an interlayer enables void-free bonding because Ti exhibits fast diffusion and oxide solubility. On the other hand, wafer bonding is an important processing step for 3D circuit integration that requires a high reliability of the process. However, the reliability of bonding-strength values obtained by employing conventional measurement devices is limited by comparably large measurement errors and restricted the availability of suitable sample material. In this study, the use of AFM to measure the bonding strength is proposed. The interfacial bonding properties depend on the Ti deposition parameters. A bonding temperature of 200 degrees C was found to be appropriate for the development of a low bonding temperature wafer-bonding process. The pretreatment methods like plasma activation and chemical activation at 200 degrees C result in a Ti bonding strength of approximately 8.22 J/m(2), sufficient for applications in 3D circuit integration. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

국내 분리 일본뇌염 바이러스 유전자에 대한 항체생성 연구(Ⅰ) : cloning of JEV viral genes

박찬,최우영,이호동,채수림,신은진,김인범,표재환,박근용,조해월 국립보건연구원 1999 국립보건원보 Vol.36 No.-

적외선 우주배경복사 관측 실험 2(CIBER2) 국제 공동 연구

이대희,박원기,문봉곤,박성준,김민규,김건희,남욱원,표정현,정웅섭,박영식,김일중,한원용,Lee, D.H.,Park, W.K.,Moon, B.G.,Park, S.J.,Kim, M.G.,Kim, G.H.,Nam, U.W.,Pyo, J.,Jeong, W.S.,Park, Y.S.,Kim, I.J.,Han, W. 한국천문학회 2015 天文學論叢 Vol.30 No.1

First light galaxies have predictable linear clustering, and are expected to produce fluctuations with a characteristic spatial power spectrum, which peaks at an angular scale of ~ 10 arcminutes and in the $1-2{\mu}m$ spectral regions. The Cosmic Infrared Background ExpeRiment 2 (CIBER2) is a dedicated sounding rocket mission for measuring the fluctuations in the extragalactic infrared background light, following up the previous successful measurements of CIBER1. With a 28.5 cm telescope accompanied with three arms of camera barrels and a dual broadband filter on each H2RG (${\lambda}_c=2.5{\mu}m$) array, CIBER2 can measure 6 bands of wide field ($1.1{\times}2.2$ degrees) up to 3 AB magnitudes deeper than CIBER1. This project is leaded by California Institute of Technology/Jet Propulsion Laboratory, collaborating internationally with Institute of Space and Astronautical Science in Japan, Korea Astronomy and Space Science Institute, Korea Basic Science Institute, and Seoul National University. The Korean team is in charge of 1) one H2RG scientific array, 2) ground station hardware and software, 3) telescope lenses, and 4) flight and test bed electronics fabrication. In this paper, we describe the detailed activities of the Korean participation as well as the current status of the CIBER2 project.

만성신부전증에서 혈청 CEA치에 관한 연구

이정상,신영태,정순일,고창순,김성권,표희정,권인순 대한핵의학회 1980 핵의학 분자영상 Vol.14 No.2

저자들은 1979년 3월부터 1980년 10월까지 서울대학교병원내과에 입원하여 만성신부전증으로 진단받고 혈액투석요법을 받지 않은 환자 15예, 혈액투석요법을 시행중인 환자 39예 및 신장이식술을 받고 신장능이 호전된 환자 23예에서 혈청 CEA치를 방사면역측정법으로 측정하여 정상대조군과 비교하여 다음과 같은 결과를 얻었다. 1) 정상 성인 65명의 혈청 CEA치의 범위는 1.0∼4.3 ng/ml이었으며 평균은 1.6±0.66 ng이었다. 2) 혈액투석요법을 시행치 않은 만성신부전증 환자 15예의 혈청 CEA치는 0.3∼8.3 ng/ml이었고 평균은 3.6±2.10 ng/ml로써 정상대조군에 비하여 유의하게 증가되어 있었다(p$lt;0.001). 3) 혈액투석요법으로 치료중인 만성신부전증 환자 39예의 혈청 CEA치는 0.7∼6.7 ng/ml로 평균이 3.0±1.52 ng/ml이며, 정상대조군에 비하여 유의하게 상승되어 있으나(p$lt;0.001), 혈액투석을 받지 않은 환자군과는 유의한 차이가 없었다. 4) 신이식 환자 23예의 혈청 CEA치의 분포는 1.8∼10.8 ng/ml이고 평균은 3.8±1.96 ng/ml로 역시 정상대조군에 비하여 유의하게 증가되어 있으나(p$lt;0.001), 만성신부전증 환자군과는 유의한 차이가 없었다. 5) 이상의 혈청 CEA치가 정상범위 이상으로 상승된 49명��환자중 이학적 소견이나 검사소견상 악성종양은 발견되지 않았다. The serum CEA levels were measured by radioimmunoassay technique in 15 patients with chronic renal failure, who were not treated with hemodialysis, in 39 patients under hemodialysis and in 23 patients who received renal transplantation. The results were compared with those in 65 normal adults and the following results were obtained. 1) Serum CEA concentrations in 65 normal adults were in the range of 1.0 to 4.3 ng/ml with a mean value of 1.6±0.66 ng/ml. 2) Serum CEA concentrations in 15 chronic renal failure patients who were not treated with hemodialysis, were in the range of 0.3 to 8.3 ng/ml with a mean value of 3.6±2.10 ng/m1 which was significantly higher than those of normal controls(P$lt;0.001). 3) Serum CEA concentrations in 39 chronic renal failure patients under hemodialysis were also much higher than normal controls(p$lt;0.001), but not significantly different from those of the patients who were not under hemodialysis(P$gt;0.05). 4) In 23 patients who received renal transplantation, serum CEA levels were snificantly higher than normal controls(P$lt;0.001), but not significantly different from those of chronic renal failure patients.

糖尿病을 合倂한 上腹部臟器의 部分傳位症

朴俊明,李公錫,表潤浩,李鍾星 中央醫學社 1940 中央醫學 Vol.9 No.1

Effects of dextrorotatory morphinans on brain Na⁺ channels expressed in Xenopus oocytes

Lee, J.H.,Shin, E.J.,Jeong, S.M.,Lee, B.H.,Yoon, I.S.,Lee, J.H.,Choi, S.H.,Kim, Y.H.,Pyo, M.K.,Lee, S.M.,Chae, J.S.,Rhim, H.,Oh, J.W.,Kim, H.C.,Nah, S.Y. North-Holland ; Elsevier Science Ltd 2007 european journal of pharmacology Vol.564 No.1

We previously demonstrated that dextromethorphan (DM; 3-methoxy-17-methylmorphinan) analogs have neuroprotective effects. Here, we investigated the effects of DM, three of its analogs (DF, 3-methyl-17-methylmorphinan; AM, 3-allyloxy-17-methoxymorphian; and CM, 3-cyclopropyl-17-methoxymorphinan) and one of its metabolites (HM; 3-methoxymorphinan), on Na<SUP>+</SUP> channel activity. We used the two-microelectrode voltage-clamp technique to test the effects of DM, DF, AM, CM and HM on Na<SUP>+</SUP> currents (I<SUB>Na</SUB>) in Xenopus oocytes expressing cRNAs encoding rat brain Nav1.2 α and β1 or β2 subunits. In oocytes expressing Na<SUP>+</SUP> channels, DM, DF, AM and CM, but not HM, induced tonic and use-dependent inhibitions of peak I<SUB>Na</SUB> following low- and high-frequency stimulations. The order of potency for the inhibition of peak I<SUB>Na</SUB> was AM-CM > DM=DF. The DM, DF, AM and CM-induced tonic inhibitions of peak I<SUB>Na</SUB> were voltage-dependent, dose-dependent and reversible. The IC<SUB>50</SUB> values for DM, DF, AM and CM were 116.7+/-14.9, 175.8+/-16.9, 38.6+/-15.5, and 42.5+/-8.5 μM, respectively. DM and its analogs did not affect the steady-state activation and inactivation voltages. AM and CM, but not DM and DF, inhibited the plateau I<SUB>Na</SUB> more effectively than the peak I<SUB>Na</SUB> in oocytes expressing inactivation-deficient I1485Q-F1486Q-M1487Q (IFMQ3) mutant channels; the IC<SUB>50</SUB> values for AM and CM in this system were 8.4+/-1.3 and 8.7+/-1.3 μM, respectively, for the plateau I<SUB>Na</SUB> and 43.7+/-5.9 and 32.6+/-7.8 μM, respectively, for the peak I<SUB>Na</SUB>. These results collectively indicate that DM and its analogs could be novel Na<SUP>+</SUP> channel blockers acting on the resting and open states of brain Na<SUP>+</SUP> channels.