SrCl₂:Eu²⁺,Na⁺ X-선 영상저장 형광체의 발광특성

김성환,김완,강희동,도시홍,서효진,김영국,김도성,Kim, Sung-Hwan,Kim, Wan,Kang, Hee-Dong,Doh, Sih-Hong,Seo, Hyo-Jin,Kim, Young-Kook,Kim, Do-Sung 한국재료학회 2003 한국재료학회지 Vol.13 No.6

Photoluminescence(PL), photostimulated luminescence(PSL) and thermoluminescence(TL) in $SrC1_2$:$Eu^{2+}$ , $Na^{+}$ phosphor powder were measured, and the activation energies(trap depth) of traps associated with TL and PSL were investigated. The PL and PSL in the studied sample is due to the $4f^{6}$ 5d\longrightarrow$4f^{7}$transition of $Eu^{ 2+}$. TL glow curve is single peak, and its peak temperature is about 377.2 K. The PL, PSL and TL emission spectra of the phosphors are located in the range of 380∼440 nm, peaking at 408 nm. The activation energy of the PSL trapping center is 0.78 eV and that of the TL trapping center is 0.79 eV. We, thus, suggest that the trapping centers giving rise to the PSL are identical to those giving rise to the TL.

랫드에서 amitraz의 출생 전후 발생 시험

김성환,임정현,박나형,문창종,박수현,강성수,배춘식,김성호,신동호,김종춘,Kim, Sung-Hwan,Lim, Jeong-Hyeon,Park, Na-Hyeong,Moon, Changjong,Park, Soo-Hyun,Kang, Seong-Soo,Bae, Chun-Sik,Kim, Sung-Ho,Shin, Dong-Ho,Kim, Jong-Choon 대한수의학회 2010 大韓獸醫學會誌 Vol.50 No.2

This study investigated the potential effects of amitraz on the pre- and postnatal development, behavior, and reproductive performance of offspring of parent rats given amitraz during pre-mating, gestation, and lactation. The test chemical was administered via the drinking water containing 0, 40, 120, and 360 ppm to male rats from 2 weeks before mating to the end of 14-day mating period and to females from 2 weeks before mating, throughout mating, gestation and lactation up to weaning. Based on fluid consumption, the male rats received an average of $0,\;5.7{\pm}1.33,\;13.2{\pm}2.08,$ and $35.8{\pm}3.42$ mg/kg/day amitraz, and the female rats received an average of $0,8.7{\pm}4.42,\;20.1{\pm}9.60,\;and\;47.6{\pm}22.38$ mg/kg/day amitraz, respectively. At 360 ppm, an increase in the incidence of abnormal clinical signs, a suppression in the body weight gain, a decrease in the food consumption and litter size, an increase in the post-implantation loss, and a decrease in the seminal vesicle weight were observed in the parent animals. In addition, a suppression in the body weight gain, a decrease in the grip strength, a delay in the negative geotaxis, an increase in the pre- and post-implantation loss, and a decrease in the number of live embryos were observed in the offspring. At 120 ppm, suppressed body weight gain and reduced food consumption were observed in the parent rats. Suppressed body weight gain and decreased grip strength were also observed in the offspring. There were no signs of either reproductive or developmental toxicity at 40 ppm. Under these experimental conditions, the no-observed-adverse-effect level of amitraz for parent rats and their offspring was estimated to be 40 ppm in rats.

마이크로웨이브 조사를 이용한 반도체성 단일벽 탄소나노튜브의 선택적 분리

김성환,송우석,김유석,김수연,박종윤,Kim, Sung-Hwan,Song, Woo-Seok,Kim, Yoo-Seok,Kim, Soo-Youn,Park, Chong-Yun 한국진공학회 2011 Applied Science and Convergence Technology Vol.20 No.4

본 연구에서는 열화학기상증착법과 나노구조의 Fe/$Al_2O_3$/Si 촉매층을 이용하여 단일벽 탄소나노튜브를 합성하고 마이크로웨이브 조사를 통해 금속성 단일벽 탄소나노튜브를 선택적으로 제거하고 반도체성 단일벽 탄소나노튜브를 분리하였다. 조사시간의 변화에 따른 단일벽 탄소나노튜브의 전기적, 구조적 특성을 분석한 결과, 조사시간이 120초인 경우, 금속성의 단일벽 탄소나노튜브가 선택적으로 제거되어 약 95%의 반도체성 단일벽 탄소나노튜브를 분리할 수 있었으며, 뿐만 아니라 남아있는 반도체성 단일벽 탄소나노튜브가 손상 없이 우수한 결정성을 지니는 것을 확인할 수 있었다. 이러한 방법은 반도체성 단일벽 탄소 나노튜브를 기반으로 한 전계효과 트랜지스터 및 다양한 나노전자소자의 응용에 유용한 정보를 제공하리라 기대한다. In this study, single-walled carbon nanotubes (SWCNTs) were synthesized on a Fe/$Al_2O_3$/Si layer by thermal chemical vapor deposition. Metallic SWCNTs were selectively removed by microwave irradiation. Electrical and structural characterizations of the SWCNTs clearly revealed that the metallic SWCNTs were almost removed by microwave irradiation for 120 sec. The remained semiconducting SWCNTs with a high crystalline structure were obtained over 95%. This method would provide useful information for applications to SWCNTs-based field effect transistors and multifaceted nanoelectronics.

Proton-Induced Effects in CeBr₃ Single Crystals

김성환,Heeding Kang,H. Park,H. J. Kim,Hong U,Sih-Hong Doh,Wan Kim 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.3

A CeBr₃ single crystal is a useful inorganic scintillator with properties of high light yield and fast decay time and is a good candidate for applications such as high-energy physics, space missions, nuclear physics, medical imaging, industrial radiation sensors etc. In this research, CeBr₃ single crystals were grown with the dimension of 4 × 4 × 8 mm³ by using the Bridgman method. The crystals were irradiated with the 45 MeV proton beam of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Science. The scintillation properties of the crystal were investigated before and after proton irradiations. The proton induced activation of the crystals was also studied. A CeBr₃ single crystal is a useful inorganic scintillator with properties of high light yield and fast decay time and is a good candidate for applications such as high-energy physics, space missions, nuclear physics, medical imaging, industrial radiation sensors etc. In this research, CeBr₃ single crystals were grown with the dimension of 4 × 4 × 8 mm³ by using the Bridgman method. The crystals were irradiated with the 45 MeV proton beam of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Science. The scintillation properties of the crystal were investigated before and after proton irradiations. The proton induced activation of the crystals was also studied.

The Comparison of Image Quality Using Body Contour and Circular Method with L-mode in Myocardial Perfusion SPECT

김성환,남기표,류재광,윤순상,Kim, Sung-Hwan,Nam, Ki-Pyo,Ryu, Jae-Kwang,Yoon, Soon-Sang The Korean Society of Nuclear Medicine Technology 2012 핵의학 기술 Vol.16 No.1

심근관류 SPECT의 영상획득 방법에는 Body contour와 Circular 방식이 있고, 환자와 검출기 사이의 거리를 줄이기 위해 Body contour 방식을 주로 사용한다. 그러나 이중(Dual) 검출기 장비에서 수직방식으로 검출기를 설정하여 영상을 획득하는 경우에는 환자와 검출기 사이의 거리가 Body contour 방식이 Circular 방식에 비해 더 증가하는 경향이 있다. 본 연구의 목적은 이중 검출기 장비에서 수직방식으로 검출기를 설정하여 영상을 획득하는 경우, Body contour 방식과 Circular 방식에서 환자와 검출기 사이의 거리를 비교하고, 거리에 따라 영상에 미치는 영향을 파악하여 영상의 질을 높이기 위한 방안을 제시하고자 시행하였다. 실험에 사용된 장비는 GE INFINIA Gamma Camera와 Anthropomorphic torso 모형에 심장 모형을 삽입하여 영상을 획득하였고, 2011년 8월 본원에서 심근관류 SPECT를 시행한 환자 40명을 대상으로 하였다. 모형 제작은 실제 환자조건과 동일하게 하기 위하여 심근에 74 kBq (0.22 mCi)/cc, 폐에 2.59 kBq ($60{\mu}Ci$)/cc, 연부조직에 11.1 kBq (2.2 mCi)/cc의 201-Tl을 주입하여 제작하였고, 영상획득 조건은 회전각 $6^{\circ}$, 50 sec/frame으로 환자와 동일한 조건으로 하였다. 영상획득 방식에 따른 차이를 확인하기 위해 Body contour와 Circular 방식으로 영상을 획득하여 환자와 검출기 사이의 거리를 각각 측정하여 비교하였고, 정상군과 비 정상군의 영상을 육안 분석하였다. 거리에 따라 영상에 미치는 영향을 확인하기 위해, 모형 실험에서 Circular 방식으로 회전반경을 18.8, 21.8, 23.8, 25.8, 28.8 cm 로 다르게 설정하여 영상을 획득하였고, 각 영상에서 심첨(Apex)에 관심영역을 설정하여 반치폭을 비교하였다. 모형 실험 결과, Body contour를 이용한 실험에서 산출된 반치폭은 6.23 mm이고, Circular mode에서 18.8, 21.8, 23.8, 25.8, 28.8 cm의 회전반경으로 산출된 반치폭은 각각 5.41, 6.24, 6.33, 6.42, 6.93 mm이다. 환자 데이터에서 Body contour의 회전반경이 -3.5 cm ~ 9.5 cm으로 차이를 보였고, Circular mode에 비해 평균 2.5 cm 더 큰 차이를 보였다. 본 연구를 통해, INFINIA 장비에서 Circular mode가 Body contour를 사용한 영상 획득 방법보다 낮은 반치폭을 보였다. 비록 INFINIA장비의 두 가지 영상 획득 방식에 대한 비교였지만, INFINIA장비를 이용한 심근관류 검사에서는 Circular mode 의 영상 획득 방식이 더 적합하다고 사료된다. Purpose : In myocardial perfusion SPECT, the type of orbit (circular vs. body contouring) that affect the image quality is still on the debate. Presently in the nuclear medicine field, the body contouring orbit acquisition is widely used to improve the image quality on the myocardial perfusion SPECT. But in case of body contouring acquisition using the vertical method with dual detect machine, there is a tendency of increasing the radius. In this research, we compared body contouring orbit acquisition with circular orbit acquisition, so we suggest ideal method that reduces the radius for improving image quality. Materials and Methods : Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on equally with counts from patient's body. The study was performed under six different conditions. To compare image quality according to the radius, we increased radius sequentially per step during circular orbit acquisition. On the other hand, sensors that protect a collision and reduce the radius automatically were used to acquire image during body contouring orbit acquisition. So we compared FWHM value of apex. In clinical studies, we analyzed the 40 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center in August 2011. To acknowledge the differences according to the radius, we acquired the results two times using circular orbit acquisition and body contouring orbit acquisition. Results : In phantom study, we analyzed that increase of radius resulted in changes of FWHM value. It was 5.41, 6.24, 6.33, 6.42, 6.93 mm. On the other hand, using the body contouring orbit acquisition, FWHM value was 6.23 mm. In clinical study, difference of average radius between two methods was 2.5 cm (circular orbit acquisition was more close to patients). Conclusion : Through the experiments using Anthropomorphic torso phantom and patients data, we found that FWHM value of circular orbit acquisition was lower than body contouring orbit acquisition. As a result, if the difference of average radius exists approximately 3 cm, circular orbit type acquisition is better than body contouring type acquisition. But clinical investigation is only aimed to average radius, so it needs more investigation in comparison of patient's image.

국내외 하천복원사업 성공사례

김성환,Kim, Seong-Hwan 한국상하수도협회 2006 한국상하수도협회지 Vol.15 No.-

분무 열분해법으로 제조된 미세 Bi-2223 전구분말의 특성

김성환,유재무,고재웅,김영국,Kim S. H.,Yoo J. M.,Ko J. W.,Kim Y. K. 한국초전도학회 2005 Progress in superconductivity Vol.6 No.2

Homogeneous and fine powders for Bi-2223 tape were prepared by ultrasonic spray pyrolysis (SP) method from an aqueous solution of metal nitrates. Bi-2223 precursor powders were synthesized with various solutes concentration and pyrolysis temperature. The synthesized precursor powders had a narrow particle size distribution and an average particle size was $\~{\cal}um$. The reactivity of precursor powder by SP method is very high, attributed to the fine and narrow particle size distribution. Bi-2223/Ag tape was prepared using PIT method and followed by various sintering conditions. The precursor powder by SP method promoted a very quick formation of the Bi-2223 phase for short sintering time while the secondary phase such as large AEC phase and $Ca_2PbO_4$ were minimized for SP tapes.

병원감염 예방기술 - 공기청정기의 미생물 제거 특성

김성환,Kim, Seong-Hwan 한국공기청정협회 2015 空氣淸淨技術 Vol.28 No.3

Interferon과 Ribavirin 병용요법 시행중인 만성 C형간염 환자에서 발생한 부작용에 대한 침구치료 증례

김성환,홍상훈,박동일,Kim, Sung-hwan,Hong, Sang-hoon,Park, Dong-il 대한침구의학회 2003 대한침구의학회지 Vol.20 No.1

Objective : Interferon-alpha and Rivabirin are much used at the same time to treat Chronical C viral hepatitis. But interferon caused lots of unexpected side effects, Acupuncture Treatment for them will be an alternative plan. Methods : We first posed questions to a 4 year-old man who ha skin flare, fatigue, itching, insomnia, pronounced a diagnosis based on overall of symptoms and signs and then treated Acupuncture, Moxibustion and Electroacupuncture. We acupunctured a BL17, BL18, BL20 and removed it at once. We electroacupunctured at GV20, Yin tang(Ex-HN3) form 20 minutes, acupunctured at Bi yi(鼻翼, Extra-point), S36, P6. Pizhengge(脾定格) was acupunctured for 10 minutes. Results : The symptoms of fatigue, insomnia, itching are reduced after acupuncture treatments and they made a person keep interferon treatment on. Conclusions : We confirmed that acupuncture treatments make a patient of chronic C viral hepatitis reduce and improve side effects of interferon treatment. We should keep on studying the various and efficient method of acupuncture treatment to improve living quality and treatment efficiency of patients.

해외건축동향: 일본 - 오키 사토와 넨도 Part II

김성환,Kim, Sungwhan 대한건축사협회 2018 建築士 Vol.587 No.-