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Silicate 유리의 Mossbauer 분광학적 연구
홍성락,문찬호,홍치유,백승도,최달하 동국대학교 자연과학연구소 1986 자연과학연구 논문집 Vol.6 No.-
10Nio-10Fe₂O₃-30Na₂O-50SiO₂유리에 대한 Mossbauer 분광학적인 연구를 저온실험과 유리의 열처리효과에 대해 수행하엿다. center shift 와 quadrupole splitting 및 공명흡수 면적은 저온으로 갈수록 증가하였으며, 유리의 Dabye 및 Einsteine 온도는 각각 450K 와 352K 이었다. 열처리온도가 증가함에 따라 I.S. 와 Q.S. 는 감소하였으며, 특히 710℃이상에서 열처리한 시료는 NiFe₂O₄에 의한 magnetic hyperfine splitting이 관찰되었다. Using the 10Nio-10Fe₂O₃-30Na₂O-50SiO₂glass, we investigated the Mossbauer parameters of quenched glass and heat-treated glasses. The Debye and Einstein temperature of the quenched glass were determined by the center shifr and the kinetic tmeperature. According to the X-ray diffraction patterns, NiFe₂O₄was precipitated in the glass by heat treatment. Both the isomer shift and quadrupale splitting were decreased as the heat treatment temperature increased. The glasses, heat-treated above 710℃, showed magnetic hyperfine splitting for NiFe₂O₄.
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Silicate 유리의 Mossbauer 분광학적 연구
최달하,홍성락,문찬호,백승도,홍치유 濟州大學校 基礎科學硏究所 1988 基礎科學硏究 Vol.1 No.1
10Nio-10Fe₂O₃-30Na₂O-50SiO₂유리에 대한 Mossbauer 분광학적인 연구를 저온실험과 유리의 열처리효과에 대해 수행하였다. center shift와 quadrupole splitting 및 공명흡수 면적은 저온으로 갈수록 증가하였으며, 유리의 Dabye 및 Einsteine 온도는 각각 450K와 352K이었다. 열처리온도가 증가함에 따라 I. S. 와 Q. S. 는 감소하였으며, 특히 710℃이상에서 열처리한 시료는 NiFe₂O₄에 의한 magnetic hyperfine splitting이 관찰되었다. Using the 10NiO-10Fe₂O₃-30Na₂O-50SiO₂glass, we investigated the Mossbauer parameters of quenched glass and heat-treated glasses. The Debye and Einstein temperature of the quenched glass were determined by the center shift and the kinetic temperature. According to the X-ray diffraction patterns, NiFe₂O₄was precipitated in the glass by heat treatment. Both the isomer shift and quadrupale splitting were decreased as the heat treatment temperature increased. The glasses, heat-treated above 710℃, showed magnetic hyperfine splitting for NiFe₂O₄.
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최달하,김태욱 가톨릭대학산업의학센타 산업의학연구소 1978 韓國의 産業醫學 Vol.17 No.4
An electrical model for motor nerve conduction velocity was designed and constructed. This model was primarily intended for medical students in training of motor nerve conduction velocity measurements. The peroneal nerve in the lower extremity was chosen for the model. Following parameters were considered. 1. Latency. 2.0 ms, 2.5 ms or 3.0 ms selectable for distal latency. 7.5 ma, 9.0ms or 11.0 ms selectable for proximal latency. 2.Minimum effective voltage of stimulus pulse. 25v, 30v or 35v peak to peak (selectable). 3. Minimum effective duration of stimulus pulse. 0.2 ms Digital and linear integrated circuits were used to provide precise control over the model parameters, This electrical model was housed in the artificial lower limb made of rubber.
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Mossbauer 분광법을 이용한 Ni-Cd Ferrite의 미시적 연구
홍성락,최달하,백승도,이경행,문용식,홍치유 濟州大學校 基礎科學硏究所 1989 基礎科學硏究 Vol.2 No.1
Ceramic sintering 법으로 제작한 ??의 X-ray 회절선과 80 ∼ 900K의 온도영역에서 측정한 Mossbauer spectrum을 분석하였다. Ni-Cd ferrite의 격자상수는 Cd 농도가 증가함에 따라 선형적으로 증가하며, Mossbauer spectrum과 parameter의 온도의존성을 조사한 결과 자기전이온도(??)는 Cd 농도가 증가함에 따라 감소하고, Debye 온도(??)는 Cd 농도에 따른 의존성이 없다. In this study, the Mossbauer spectra of ??, prepared by a ceramic sintering method, were investigated in the temperature range of 80K∼900K. The X-ray diffraction patterns of the all samples show the single phase spinel structure and the lattice constant increases linearly as increasing Cd concentration. The center shift values of the all samples decrease as increasing temperature regardless of Fe site, but the quadrupole splitting values are indepenent of the temperature. The magnetic hyperfine field and resonant absorption area decrease as increasing temperature. From the temperature dependence of the Mossbauer parameters, it is concluded that the magnetic transition temperature decrease as increasing Cd concentration and the Debye temperature is independent of Cd concentration.
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Mo¨ssbauer 분광법에 의한 Mg-Cd 페라이트계의 자기적 성질 연구
홍치유,최달하,문용식,백승도 東國大學校 1988 論文集 Vol.27 No.-
In this study, the magnetic properties of Mg_(1-X)Cd_(X)Fe₂O₄ ferrite system has been studied by Mo‥ssbauer spectroscopy. All the samples, prepared by a ceramic sintering method, were found to be single phase spinel by X-ray diffractometry. The Mo‥ssbauer spectra. for x<=0.3, show two magnetic hyperfine splittings. one due to Fe^3+ octahedral site ions and the other due to tetrahedral site ions. While for x=0.4 spectrum shows relaxation behaviour and for x>=0.5 it exhibits quadrupole splittings. This result implicates that the magnetic properties of Mg_(1-X)Cd_(X)Fe₂O₄ferrite system change from ferrimagnetics to paramagnetics as increasing x, And the x, Cd content, dependence of Mo‥ssbauer parameters (isomer shift, quadrupole splitting, magnetic hyperfine field and line width) were investigated.
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