황동광의 초미세 자기장 연구

金哲聖 空軍士官學校 1978 論文集 Vol.8 No.-

CuFeS_2의 이온 상태와 무반조 상수에 관한 연구

金哲聖 空軍士官學校 1978 論文集 Vol.9 No.-

직접 합성법에 의해 CuFeS_2를 제조하여 여러 자기적 특성 가운데 Mossbauer 효과를 이용하여 액체질소 온도에서 800˚K의 온도 범위에서 취한 Spectrum으로 Isomer Shift와 Debye Temperature를 구했다. S-Charge에 의한 Isomer Shift는 실온(298˚K)에서 금속철을 기준하여(0.35±0.02) mm/sec로 CuFeS_2에서 Fe 이온이 Fe^+3상태임을 밝혔으며, Cu^+1Fe^+3S_2와 Cu^+2Fe^+2S^2의 공존설이나, Cu^+Fe^+3(S^-2)_2←→Cu^-3Fe^-(S^+2)_2공명설이 부정된다. Mossbauer Recoilless Fraction으로부터 Debye Temperature가 537˚K가 됨을 결정하였다.

Fe-Si-B-Nb-Cu 합금의 Mossbauer 연구

김철성,이희민,김성백 국민대학교 1998 기초과학연구소 논문집 Vol.16 No.-

Enhanced Ferrimagnetism in Zn½Fe½Cr₂S₄

김철성,Sung Hwan Bae,김삼진 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

We have synthesized Zn½Fe½Cr₂S₄ and studied it by using with X-ray diffraction, magnetic susceptibility and Mossbauer spectroscopy measurements. The crystal structure was found to be a cubic spinel with space group Fd3m by using a Rietveld refinement of X-ray diffraction data. The lattice constant of Zn½Fe½Cr₂S₄ was determined to be a0 = 9.992 Å. The magnetization curves followed a Curie-Weiss law, with a positive θcw = 107 ± 1 K showing a ferrimagnetic behavior. The Neel temperature (TN) of Zn½Fe½Cr₂S₄ was determined to be 105 K. The Mossbauer spectra of Zn½Fe½Cr₂S₄ were obtained at various temperatures ranging from 4.2 to 300 K. The magnetic anomaly observed below TN is caused by a weakening of the spin-orbit coupling. The isomer shift value of the sample at room temperature was 0.65 mm/s, which means that the charge state of the Fe ions was ferrous in character. We have synthesized Zn½Fe½Cr₂S₄ and studied it by using with X-ray diffraction, magnetic susceptibility and Mossbauer spectroscopy measurements. The crystal structure was found to be a cubic spinel with space group Fd3m by using a Rietveld refinement of X-ray diffraction data. The lattice constant of Zn½Fe½Cr₂S₄ was determined to be a0 = 9.992 Å. The magnetization curves followed a Curie-Weiss law, with a positive θcw = 107 ± 1 K showing a ferrimagnetic behavior. The Neel temperature (TN) of Zn½Fe½Cr₂S₄ was determined to be 105 K. The Mossbauer spectra of Zn½Fe½Cr₂S₄ were obtained at various temperatures ranging from 4.2 to 300 K. The magnetic anomaly observed below TN is caused by a weakening of the spin-orbit coupling. The isomer shift value of the sample at room temperature was 0.65 mm/s, which means that the charge state of the Fe ions was ferrous in character.

EDTA를 사용한 납 오염 토양에서의 효율적인 납 추출

김철성 한국지하수토양환경학회 1999 지하수토양환경 Vol.4 No.1

4종류의 서로 다른 납 처리시설 주변토양과 인위적으로 납을 오염시킨 토양에서 토양 내에 존재하는 주요 양이온과 토양 질량 대 EDTA 용액부피 비 및 납과 EDTA의 정량비(stoichiometric ratio)가 EDTA를 사용한 납 추출에 미치는 영향을 연구하였다. 납 오염토양으로부터의 납 추출은 EDTA용액 부피 대 토양 질량 비를 3$m\ell$/g까지 감소시켜도 영향을 받지 않았으며 단지 용액 내에 존재하는 EDTA의 몰수에 의존하는 것으로 밝혀졌다. 본 연구결과에 의하면 각각의 토양에 대한 납 추출효과는 서로 다른 독립적인 경향을 보였으며 납 광산시설 주변토양을 제외하고는 다량의 EDTA가 유입되면 모든 납이 추출되었다. 이러한 결과는 Fe, Cu. Zn, Al과 같은 토양 내에 존재하는 주요 양이온이 EDTA 의 ligand site에 반응하기 위하여 Pb와 경쟁하기 때문인 것으로 추정되어진다. 납 추출을 위한 EDTA의 도입은 여러 음이온 용해도의 증가를 동반하여 토양내 금속의 용해도를 증가하는 결과를 나타내었으며 용해되어진 금속의 양은 유입된 EDTA 몰수에 최대 20배에 이루는 것으로 나타났다. 납오염된 토양에서의 EDTA를 이용한 납 추출은 토양내의 주요 양이온, 납의 종류(species)및 납의 결합 형태와 위치에 의하여 영향을 받는 것으로 나타났으며 이러한 영향이 복합적으로 작용할 때에는 EDTA의 납 추출효과가 현저히 감소하는 것으로 밝혀졌다. The effects of major cations in soils, soil : extractant ratio, and EDTA : lead stoichiometric ratio on the extraction efficiency of lead using EDTA were studied for 4 different actual lead-contaminated soils and one artificially lead-contaminated soil. Extraction of lead from the lead-contaminated soil was not affected by a soil : extractant ratio as low as 1 : 3 but instead was dependent on the quantity of EDTA present. Results of the experiments showed that the extraction efficiency for each soil was different, but if sufficiently large amount of EDTA was applied, all the lead may be extracted except for a soil from lead mining area. The differences in extraction efficiencies nay be due to the major cations present in soils which may compete with lead for active sites on EDTA. The total molar amount of major cations extracted was as muck as 20 times more than the added molar amount of EDTA. For some of the soils tested, the extraction efficiency of lead may be affected by being occluded in the Fe and Mn oxides present in the soil. While major cations present in the soil may be one of the factors affecting lead extraction efficiency, the type of lead species present may also play a role. When these factors affect severely, the using of EDTA to extract lead from lead-contaminated soil might be non-effective method.

전립선대비증 평가에서 이행대 용적지수와 증상점수 및 요류속도와의 상관관계

김철성,전상준,정치영,소영석,노준,장대수 조선대학교 2001 The Medical Journal of Chosun University Vol.26 No.2

Purpose : otal prostate volume has been known to be poorly correlated with other parameters used to assess benign prostatic hyperplasia(BPH), including international prostatic symptom score(IPSS), peak flow rate(Qmax). This study was aimed to investigate the possible correlation between transition zone index(TZI), IPSS and Qmax in patients with clinical benign prostatic hyperplasia(BPH). Materials and methods : From September 1999 to December 2000, A total of 95patients with clinical BPH were evaluated total prostate volume(TV), transition zone volume(TZV), TZI, IPSS and Qmax. TZI was determined as the ratio between transition zone volume(TZV) and total prostate volume(TV). Results : The relationships between IPSS and TV, TZV, and TZI were not statistically significant. A statistically significant relationship was observed between TZV, TZI and Qmax and between TV, TZV, TZI and age. Conclusion : These results suggest that TZV, TZI may not be a useful method to assess symptom severity in BPH patients but may be limited clinical parameters.

요관경하 배석술

김철성 메디메디아코리아(주) 1998 유로트렌드 Vol.3 No.1

음경골절 치험 3례

김철성,문재선,김춘곤 朝鮮大學校 附設 醫學硏究所 1986 The Medical Journal of Chosun University Vol.11 No.1

Generally, penile fracture is rare. Fracture of the penis is a lesion occurring after blunt trauma to the erect penis and the characteristic pathology consists of a rupture of the tunica albuginea with hemorrhase followed by a large hematoma formation and distortion of the penis. Many authors advocatea immediate operative intervention for fracture of the penis. Herein we report three cases of penile fracture with review of literatures.

FeS_(1-x)Se_x의 X선 및 Mo"ssbauer 분광학적 연구

김철성,박용환,옥항남 연세대학교 자연과학연구소 1985 學術論文集 Vol.15 No.-

혼성 계열 FeS_(1-x)Se_x를 제조하여 그 자성과 결정학적 성질을 연구하였다. FeS_(1-x)Se_x(0.6≤x≤0.9) 시료의 Mo¨ssbauer Spectrum과 X선 회절도를 취해 본 결과 0.6≤x≤0.8 영역에서는 열처리 방법에 따라 두가지 다른 형태의 결정구조를 나타낸다. 시료를 quenching한 경우 hexagonal NiAs 구조로 결정화되며 slow cooling한 경우 작은 양의 NiAs 구조가 섞인 tetragonal PbO 구조로 결정화된다. FeS_0.1Se_0.9는 열처리 방법에 관계없이 NiAs 구조가 약간 섞인 PbO구조로 결정화된다. Mo"ssbauer spectrum을 측정함으로써 FeS_(1-x)Se_x는 대략 345k 부근에서 NiAs구조로부터 PbO구조로 바뀌는 Phase transition이 일어나는 것을 알았다. 음이온 Se의 농도가 증가함에 따라 전기사중극자 분열 ??E_Q는 증가하며 초미세자기장 H_hf는 감소한다. The mixed series FeS_(1-x)Se_x have been prepared in order to study their magnetic and crystallographic properties. Examination of all the samples FeS_(1-x)Se_x (0.6≤x≤0.9) by Mo¨ssbauer and X-ray measurements show that the samples in the range of 0.6≤x≤0.8 crystallize with two different structures depending on the heat treatments. The samples prepared by quenching crystallize with a NiAs structure of hexagonal system and the those prepared by slow cooling process crystallize mainly with a PbO structure of tetragonal system, which is always mixed with a small amount of the NiAs structure. FeS_0.1Se_0.9 crystallizes always with the PbO structure mixed slightly with NiAs structure regardless of the heat treatments. Mo"ssbauer measurements show that the NiAs structure of FeS_(1-x)Se_x is transformed to the PbO structure with increasing temperature around 345K. As the selenium concentration increases, electric quadrupole splitting ??E_Q tends to increase and hyperfine field H_hf does to decrease.

알루미늄 산화물을 치환한 Garnet 물질의 자기적 성질에 관한 연구

김철성,민병기,금준식 국민대학교 2002 기초과학연구소 논문집 Vol.21 No.-

Sol-gel법을 이용하여 Y₃Fe_(4.75)Al_(0.25)O_(12) 분말을 합성하였다. 열시차 중량 분석장치(TG-DTA), X-선 회절기(XRD), 시료진동 자화율 측정기(VSM) 및 Mo¨ssbauer 분광기를 이용하여 물질의 결정구조 및 자기적 성질을 연구하였다. Y₃Fe_(4.75)Al_(0.25)O_(12)의 결정구조는 cubic이며, 격자상수는 α_(0)=12.3612Å로 결정하였다. Mo¨ssbauer spectrum을 20 K로부터 Ne´el 온도 (T_(N))까지 여러 온도에서 측정을 하였다. Ne´el 온도는 555 K로 측정되었다. Mo¨ssbauer spectrum은 Ne´el 온도로 접근함에 따라 바깥쪽 팔면체 자리의 선폭이 점점 넓어지는 것을 관측할 수 있다. 이러한 현상을 설명하기 위해 양이온의 확률적 분포를 이용하여 분석을 수행하였다. Al은 tetrahedral site를 선호한다고 알려져 있으며 Fe^(3+)과 Al^(3+)이 tetrahedral site에서 (_(6)C_(n))의 분포로 존재함을 알 수 있었다. 이성질체 이동 값의 분석 결과 tetrahedral site와 octahedral site의 Fe 이온이 모두 +3 상태로 존재함을 알 수 있었다. 전기4중극자 분열값으로부터 사면체적 대칭성과 팔면체적 대칭성을 잘 유지하고 있음을 알 수 있었다. 상온에서 외부 자장을 5 kOe 인가하여 측정한 포화 자화(M_(s))값은 21.537emu/g, 보자력(H_(c)) 값은 41.5 Oe 이었다. Al^(3+) substituted garnet Y₃Fe_(4.75)Al_(0.25)O_(12) was fabricated by a sol-gel method. The crystallographic and magnetic properties of Y₃Fe_(4.75)Al_(0.25)O_(12) have been studied by Mo¨ssbauer spectroscopy, X-ray diffraction (XRD), thermogravimetry analysis (TGA), differential thermal analysis (DTA), and vibrating sample magnetometer (VSM). The crystal structure is found to be a cubic with the lattice constant a_(0)= 12.3612 Å. Mo¨ssbauer spectra of Y₃Fe_(4.75)Al_(0.25)O_(12) measured at various absorber temperatures from 20 to Ne´el temperature. It's the Neel temperature (T_(N)) is found to be 555 K. As the temperature increased toward T_(N), a systematic line broadening effect in the Mo¨ssbauer spectra was observed and interpreted to originate from different temperature dependencies of the magnetic hyperfine fields at various iron sites. It results from the distribution (_(6)C_(n)) of Fe^(3+) and Al^(3+) at tetrahedral site. The isomer shifts indicated that the iron ions were ferric at the octahedral 16a-site and the tetrahedral 24d-sites. The quadrupole splits showed that the orientation of the magnetic hyperfine field with respect to the principal axes of the electric field gradient was random. The saturation magnetization (M_(s)) was 21.537 emu/g and coercivity (H_(c)) is 41.5 Oe at room temperature under the applied field of 5 kOe.