Tb/Fe 다층박막의 자기 및 자기광 특성

이장로,장현숙,김미양,이용호,손봉균 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

기판회전 테이블이 부착된 DC, RF-magnetron sputtering 장치로 유리기판 위에 제작한 1000 Å정도의 8.8 ÅTb/XÅ Fe (X= 5.4∼11.0) 다층박막에 관하여 시료진동현 자기계와 타원편광 분석장치를 사용하여 자화, 수직자기이 방성, Kerr 회전각의 Fe층 두께와 열처리온도 의존성이 연구되었다. Fe층 두께가 7.8Å 기점으로하여 자화용이축의 전이가 나타나기 시작하여 6.4Å 일때 수직자기이방성을 나타낸다. 실험치로부터 계산한 Fe와 Tb층의 경계면 수직이 방성 에너지 K_s = -0.38 erg/㎠이고, Fe층만의 체적수직이방성 에너지 K_s = -8.50 × 10 exp (5) erg/㎤이다. Polar kerr 회전각은 Fe층 두께 7.8Å에서 극대값 2θ_k=1.22˚를 갖는다. Studies have been done experimentally to investigate the effects of the Fe sublayer thickness on magnetization, anisotropy, and Kerr rotation in 8.8ÅTb/X Å Fe (X = 5.4∼11) compositionally modulated films prepared in a multiple-gun sputtering chamber with rotating table. The ranges of Fe sublayer thickness required for perpendicular anisotropy were detemined. The interface and volume anisotropy energies for Tb/Fe films were estimated. The annealing temperture dependence of magnetic and magneto-optic properties has been discussed.

PHEMT소자를 이용한 K-band MMIC 발진기 설계

이지형(J. H. Lee),채연식(Y. S. Chae),조희철(H. C. Cho),윤용순(Y. S. Yoon),이진구(J. K. Rhee) 대한전자공학회 2000 대한전자공학회 학술대회 Vol.2000 No.6

경추부 후종인대의 석회침착 1예 보고 : Case report

이현재,김종현,고학종,채진,최길수,심보성 중앙대부설한국의과학연구소 1975 한국의과학 Vol.7 No.4

Influence of structural transition on the electronic structures and physical properties of the Ni2MnGa alloy films

K. W. Kim,J. Y. Rhee,N. N. Lee,Y. P. Lee,Y. V. Kudryavtsev 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

Ordered and disordered Ni2MnGa alloy lms were prepared by ash evaporation onto substrates maintained at 720 K and 150 K, respectively. The results show that the ordered lms behave in nearly the same way as the bulk Ni2MnGa ferromagnetic shape-memory alloy, including the martensitic transformation at 200 K, while the disordered lms exhibit characteristics of amorphous alloys. It was also found that the disordering in Ni2MnGa alloy lms did not change to any appreciable magnetic ordering down to 4 K. Annealing of the disordered lms restores the ordered structure with an almost full recovery of the magnetic, magneto-optical and transport properties of the ordered Ni2MnGa alloy lms. It was also understood, for the rst time, how the structural ordering in the lms in uences the physical properties, including the surprising loss of ferromagnetism in the disordered lms, as a result of performing electronic-structure calculations.

초음파 측정에 의한 한우의 도체육량 예측

이용준,전기준,최성복,석홍기,김석중,이성기,송영한 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.2

본 시험은 초음파를 이용한 한우의 도체육량등급 예측율을 향상시키기 위하여 24개월령 거세한우 573두를 대상으로 출하직전에 체중측정과 함께 실시간 초음파 진단기를 이용하여 도형체질을 측정하였다. 초음파 측정치와 도체실측치와의 비교분석에서 도출된 다양한 육량예측 기법을 이용하여 도체육량등급을 예측하였고, 그 결과를 요약하면 다음과 같다. 등지방 두께와 배최장근 단면적의 도체 실측치와 초음파 측정치간의 차이는 각각 0.6±1.65mm와 0.7±5.56㎡로 나타났다. 등지방 두께 및 배최장근 단면적의 초음파 측정치와 도체 실측치간의 상관계수는 각각 0.86 및 0.82로 높게 나타났다(p<0.001). 도체육량등급 예측율은 육량지수 산식, 등지방 보정식, 중회귀 분석 및 의사결정나무 분석에서 각각 80.3%, 81.3%, 80.1% 및 81.8%를 보여, 의사결정나무 분석이 예측율과 활용성이 가장 높은 것으로 나타났다. This study was conducted to predict the carcass yield traits using ultrasound before slaughter and to enhance the prediction accuracy of carcass yield grade by applying various strategies. For this experiment, five hundred seventy three Hanwoo steers of 24 months of age were used. Difference between ultrasound results and carcass measure of BFT and LMA was 0.6±1.65㎜ and 0.7±5.56㎤, respectively. Correlation coefficient between ultrasound result and carcass measure of BFT and LMA was 0.86 and 0.82 respectively (p<0.001). Results for improving predictions of yield grade by four methods0the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 80.3%, 81.3% 80.1% and 81.8%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

Preparation of Anisotropic/Isotropic Pitches from NCC-PFO

Hwang, J.-S 한국화학공학회 1995 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.33 No.5

複合 抗指肝劑에 關한 硏究 (第2報)

沈應基,李圭松,全性文,李吉哲,禹濟昇,李啓胄 國立保健硏究院 1971 국립보건연구원보 Vol.8 No.-

Sorption of aqueous Pb²⁺ ion on synthetic manganese oxides-intercalated with exchangeable cations

Kang, K.C.,Ju, J.H.,Kim, S.S.,Baik, M.H.,Rhee, S.W. Korean Society of Industrial and Engineering Chemi 2011 Journal of industrial and engineering chemistry Vol.17 No.3

This paper describes the preparation, characterization, and application of three different synthetic manganese oxides (K-MO, H-MO, and Mg-MO). K-MO was synthesized by the reduction of potassium permanganate in an aqueous acidic medium. H-MO was prepared by an ion exchange reaction of K-MO with H<SUP>+</SUP>, while Mg-MO was prepared by reaction of H-MO and an aqueous Mg<SUP>2+</SUP> salt solution under reflux. The subsequent solid products were characterized by a chemical composition analysis, XRD, XPS, FT-IR, SEM, and BET measurements. XPS spectra revealed that only tetravalent manganese ions coordinated octahedrally with oxygens. XRD patterns showed that K-MO turned into a layer-structured material while Mg<SUP>2+</SUP> ions were incorporated into the gallery space of the tunnel-structured Mg-MO. Each type of manganese oxide was used in a sorption study of aqueous Pb<SUP>2+</SUP> at 25<SUP>o</SUP>C. The sorption of Pb<SUP>2+</SUP> ions by manganese oxide resulted in increases of the concentrations of pre-intercalated ions (potassium ions, protons, or magnesium ions) and Mn<SUP>2+</SUP> ions. In spite of the smaller surface area and pore volume, K-MO showed greater sorption capacity for Pb<SUP>2+</SUP> ions than that of Mg-MO under the present experimental conditions, thus suggesting that ion exchange is the main mechanism for the sorption of Pb<SUP>2+</SUP> ions on manganese oxides. The results are anticipated to be applicable to the removal of heavy metal ions from wastewater and the prevention of migration of ions in landfill leachates.

Dynamic Mesh 기법을 통한 X-형 제어판 배치 잠수함의 가상구속모형시험

천기현(K.H. Cheon),석우찬(W.C. Seok),박종열(J.Y. Park),서정화(J.H. Seo),이신형(S.H. Rhee) 한국전산유체공학회 2018 한국전산유체공학회지 Vol.23 No.2

X-form configuration of a submarine has advantages of better manoeuvrability than the cruciform configuration, which has been traditionally used. The X-form configuration has a much longer span of control planes than those of the cruciform configuration, so it has the advantage of generating larger control force. Its control system, however, is complex, because horizontal and vertical forces induced by control planes were coupled. For the reason above, its dynamic characteristics should be analysed by identifying a dynamic modelling and deriving hydrodynamic derivatives. The present study carried out for a submarine with an X-form configuration. The test model was BB2, of which design was open most recently by Maritime Research Institute Netherlands. The hydrodynamic force on the BB2 model was estimated using virtual Planar Motion Mechanism test using Computational Fluid Dynamics(CFD). To to this, SNUFOAM, an object-oriented open source CFD tool-kit, was used as a solver for Unsteady Reynolds-Averaged Navier-Stokes simulation. Standard k-ε was selected for turbulence model and dynamic mesh methods was used for dynamic PMM tests.

한국 성인에서 비알콜성 지방간의 중증도에 따른 대사이상의 특징

김형진,김대중,김수경,김세화,이유미,안철우,차봉수,송영득,임승길,김경래,이현철,허갑범 대한내분비학회 2002 Endocrinology and metabolism Vol.17 No.4

연구배경: 30세 이상의 성인 한국인에서 지방간의 중증도와 대사증후군의 여러 요소들 (특히 인슐린저항성 및 중심성비만)과의 관련성을 분석하고자 하였다. 방법: 대상자는 2001년 4월부터 6월까지 건강검진센터를 방문한 사람들 중 만성 바이러스성 간염이나 일주일에 2회 이상 음주력이 있는 사람들을 제외한 1074명 (남자 502, 여자 572)에서 문진, 신체검사, 채혈 그리고 복부초음파를 시행하였다. 결과: 1074명중 522명에서 지방간이 양성이어서 양성율은 49%였으며 남성은 여성에 비해 높은 유병률을 보였다. (57 vs 42%, p<0.05). 당뇨병, 비만 그리고 이상지질증을 가지지 않은 사람들에서 비알콜성 지방간의 유병률은 20%였다. 지방간이 양성인 522명중 218명은 경도, 273명은 중등도, 31명은 중증의 지방간 소견을 보였다. 체질량지수, 허리둘레, 체지방률, 수축기혈압, aspartate aminotransferase, alanine aminotransferase, 총콜레스테롤, 중성지방, 그리고 총콜레스테롤/고밀도지단백 비는 지방간의 중증도에 따라 의미있게 증가하는 양상을 보였다(p<0.05). 다중회귀분석을 시행하였을 때 지방간의 중증도를 잘 반영하는 인자로는 허리둘레, alanine aminotransferase, HONA_IR, 총콜레스테롤/고밀도지단백비, aspartate aminotransferase, 그리고 수축기혈압의 순서로 나타났다. 공복혈당장애, 고혈압 및 인슐린저항성은 지방간을 가진 군에서 대조군보다 의미있게 높은 빈도를 보였을 뿐만 아니라 지방간의 중증도에 따라 차이를 보였다(p<0.05). 인슐린저항성은 심한 지방간에 비교위험도가 14.7(CI; 6.8∼32.0), 중등도의 지방간에서 6.9(CI; 4.6∼10.3), 경도의 지방간에서 5.7(CI; 3.6∼8.8)이었으며 HOMA_IR의 상위 1/4을 인슐린저항성이 있는 군으로 정의하였을 때 각군에 인슐리저항성을 가진 비율은 7.6, 32.0, 36.0, 그리고 55%였다(p<0.05). 지방간의 중증도에 따른 비알콜성 지방간염의 고위험군 비율은 각각 5.0, 21.6, 27.8, 그리고 58.1%였다(p<0.05). 결론: 우리나라의 비알콜성 지방간의 빈도는 서구인에 비해 높은 것으로 나타났다. 또한 비알콜성 지방간이 있을 경우 대사증후군과 관련된 여러인자들(특히 인슐린저항성과 중심성비만)과 비알콜성 지방간염의 위험이 현저히 증가하며 초음파의 중증도 분류에 따라 비례하였다. Background: We evaluated the frequency of non-alcoholic fatty liver disease, and the associations between the metabolic abnormalities and severity of non-alcoholic fatty liver disease in Korean adults using ultrasonography. Methods: We examined 1074 Korean adults above the age of 30 years, comprising of 502 men and 572 women, participating in medical check-ups at the Health Promotion Center. Hepatitis B and C serologies were negative, and the average weekly alcohol intake was ≤ 2 standard drinks. A standard interview, physical exam and biochemical study, were conducted, and an experienced operator carried out ultrasound liver studies. Results: 522 of the subjects had non-alcoholic fatty liver disease, and the remaining 552 did not. The frequency in the men was higher than that in the women (57 vs 42%, p<0.05). The frequency of non-alcoholic fatty liver disease in the subjects without diabetes, obesity or dyslipidemia was 20%. We classified subjects into 4 groups: the controls (n=552) and those with mild (n=218), moderate (n=273) or severe fatty liver disease (n=31), according to their ultrasonographic findings. BMI, waist circumference, body fat, systolic blood pressure, aspartate aminotransferase, alanine aminotransferase, total cholesterol, triglyceride, the total-to HDL-cholesterol ratio, impaired fasting glucose, hypertension and insulin resistance, were all significantly increase with the increased severity of non-alcoholic fatty liver disease (p<0.05). Following the multiple regression analyses, waist, alanine, aminotransferase, HOMAIR, the total- to HDL-cholesterol ratio, aspartate aminotransferase and systolic blood pressure, were all associated with the severity of non-alcoholic fatty liver disease. Odd ratios of insulin resistance in the mild, moderate and severe non-alcoholic fatty liver disease were 14.7 (CI: 6.8∼32.0), 6.9 (CI: 4.6∼10.3) and 5.7 (CI 3.6∼8.8), respectively. The percentages of subjects with insulin resistance in each group were 7.6, 32.0, 36.0 and 55.0% (p<0.05), respectively. The percentages of subjects with risk of non-alcoholic steatohepatits in each groups were 5.0, 21.6, 27.8 and 581% (p<0.05) respectively. Conclusion: The frequency of non-alcoholic fatty liver disease was relatively high in Korean adults. Proportional differences in metabolic abnormalities, relation to the severity of non-alcoholic fatty liver disease, were found by ultrasonography (J Kor Soc Endocrinol 17:514∼525, 2002).