전이금속이 치환된 반도체 물질의 자기적 특성 연구

김재욱,차병관,지명진,권태필,박병천,경동현,진훈열,김승회,김종규,Kim, Jae-Uk,Cha, Byung-Kwan,Ji, Myoung-Jin,Kwon, Tae-Phil,Park, Byoung-Cheon,Kyoung, Dong-Hyoun,Jin, Hoon-Yeol,Kim, Seung-Hoi,Kim, Jong-Gyu 대한화학회 2010 대한화학회지 Vol.54 No.6

본 연구는 전이금속이 치환된 묽은 자성 반도체의 자기적 특성을 연구하였다. 울츠자이트(wurtzite) 구조를 가지는 화합물은 졸-겔(sol-gel)법을 이용하여 합성하였다. 열역학적 특성과 자기적 특성을 가진 $Zn_{1-x}Co_xO$은 단일상으로 나타났으며, 농도에 따라 다른 특성을 보여주었다. 묽은 자성 반도체의 특성을 조사하기 위해 X-ray diffraction (XRD), scanning electronic microscope (SEM) 및 vibrating sample magnetometer (VSM)을 사용하였다. 구조 분석을 통해 단일상이 확인된 시료에서는 모두 강자성 특성이 발견되었고, 전이금속 이온의 농도를 5%이상 치환이 되면 강자성이 감소하는 현상이 나타났다. This is the study of magnetic properties of transition metal doped diluted magnetic semiconductors(DMSs). The wurtzite structure samples were synthesized by the sol-gel method. The thermodynamic characteristics and magnetic properties of $Zn_{1-x}Co_xO$ single phase was investigated for different doping concentration (x = 0%, 1%, 2%, 3%, 4%, 5%, 10%, 15%). The property of diluted magnetic semiconductors has been comfirmed by X-ray diffraction (XRD), Scanning Electronic Microscope (SEM) and Vibrating sample magnetometer (VSM). The magnetic properties of pure $Zn_{1-x}Co_xO$ is found to be dominated by the ferromagnetic interaction between doped transition metal ions, where by the ferromagnetic coupling strength is simply increased with the concentration(>5%) of the doped transition metal.

스피넬 구조를 가지는 전이금속화합물(ZnCo₂O₄, NiCo₂O₄)의 열적 분석 및 열역학적 특성 연구

김재욱,지명진,차병관,김철현,장원철,김종규,Kim, Jae-Uk,Ji, Myoung-Jin,Cha, Byung-Kwan,Kim, Chul-Hyun,Jang, Won-Cheoul,Kim, Jong-Gyu 대한화학회 2010 대한화학회지 Vol.54 No.2

형광체나 반도체의 소자로 사용되는 전이금속화합물 중에서 나노(nano) 크기를 가지는 스피넬 화합물을 합성하였다. 스피넬 화합물의 크기, 합성여부, 열적분석과 화합물의 특성을 확인하기 위하여 열 중량 분석기(TGA), X-선 회절 분석기(XRD), 적외선 흡수 분광기(IR)를 사용하였다. Scherrer식을 이용하여 화합물의 평균 입자 크기가 13~16 nm임을 예측할 수 있었다. 본 논문에 사용된 실험방법은 졸-겔(sol-gel)법을 사용하였으며, 소성 온도는 낮은 온도에서 진행 되었다($350^{\circ}C$). Kinetic 함수인 활성화 에너지와 전환인자를 계산하기 위해서 Kissinger방법과 Arrhenius식을 이용하여 계산하였다. $ZnCo_2O_4$와 $NiCo_2O_4$의 활성화 에너지는 163.42 kJ/mol와 147.01 kJ/mol 값을 가지는 있음을 확인하였다. 그리고 spinel 화합물들의 열역학적 함수(${\Delta}G^{\varphi}$, ${\Delta}H^{\varphi}$, ${\Delta}S^{\varphi}$)를 결정하였다. The spinel compound was obtained by the thermal decomposition of Zn-Co and Zn-Ni gel prepared by sol-gel method using oxalic acid as a chelating agent. The formation of spinel compound has been comfirmed by thermogravimetric analysis (TGA), x-ray powder diffraction (XRD) and infrared spectroscopy (IR). The particle size of 13 nm~16 nm was calculated by Scherrer's equation. The sol-gel method provides a practicable and effective route for the synthesis of the spinel compound at low temperature ($350^{\circ}C$). The kinetic parameters such as activation energy (Ea) and pre-exponential factor (A) for each compound were found by means of the Kissinger method and Arrhenius equation. The decomposition of spinel compound has an activation energy about 155 kJ/mol. Finally, the thermodynamic parameters (${\Delta}G^{\varphi}$, ${\Delta}H^{\varphi}$, ${\Delta}S^{\varphi}$) for decomposition of spinel compound was determined.

감자 주식화(主食化)에 관(關)한 연구[제1보](硏究 [第一報]) - 감자쌀 제조(製造)에 관(關)한 예비시험(豫備試驗) -

김재욱,조성환,Kim, Ze-Uook,Cho, Sung-Hwan 한국응용생명화학회 1976 Applied Biological Chemistry (Appl Biol Chem) Vol.19 No.4

In order to establish methods of potato processing for mixed cooking with rice as main dish, the size and shape of potato granules and favorable ratio of potato granules to rice for cooking were studied preliminary. As the results cylindrical shaped potato granule of around 6mm in diameter and $10{\sim}13mm$ in length are more favorable than rectangular shape for mixed cooking according to panel test. Mixed cooking of 30% of treated potato granules with rice is the most favorable in the point of palatability. 농가에서 감자를 쉽게 절단 변색처리하여 주식으로 흔취 할 수 있는 감자쌀의 제조방법을 확정하기, 위한 예비시험으로서 감자의 절단 모양과 크기, 감자쌀의 혼취 기호성 및 적정 혼취량을 연구하여 다음과 같은 결과를 얻었다. 1. 건조 감자쌀을 위한 생감자의 모양은 장방형보다 원통형이 좋고 직경 6mm내외, 길이 $10{\sim}13mm$의 크기가 적당하였다. 2. 감자쌀을 혼취한 쌀밥은 백미 쌀밥보다 기호도가 약간 높으며 30%가 가장 좋았다. 3. 감자쌀과 기타 잡곡 혼취 쌀밥의 대비 식미시험 결과는 혼취량에 따라 다르나 대체로 감자 혼취 쌀밥이 좋았다.

구리봉의 연속주조금형에 사용된 아세틸렌 화염 도형의 최적화

김재욱,김영태,오규환,나형용 ( Jae Uk Kim,Young Tae Kim,Kyu Hwan Oh,Hyung Yong Ra ) 한국주조공학회 1996 한국주조공학회지 Vol.16 No.2

N/A In copper continuous casting, the soot, which is the incomplete pyrolitic product of acetylene, has been used as a mold coat. In this work, under constant acetylene pressure, the characteristics of soot and the optimum condition of sooting were investigated with different acetylene and oxygen flow rate. The soot particles deposited on the mold surface had mainly spherical shape and their sizes were about 20㎚. After reaction with melt, their shapes were changed into polygonal type due to the graphitization. With increasing oxygen flow rate up to 0.6ℓ/min, the amount of residues of soot after heat treatment were kept nearly constant. But the amount of residues increased rapidly with further increasing oxygen flow rate. Degree of graphitization was maximum at 0.4ℓ/min and 5ℓ/min of oxygen and acetylene flow rate, respectively.

과다한 육식의 피해

김재욱,Kim, Jae-Uk 한국건강관리협회 1993 건강소식 Vol.17 No.6

LAM 공정을 위한 Underpass를 갖지 않는 나선형 박막 인덕터의 주파수 특성

김재욱,Kim, Jae-Wook 한국전기전자학회 2008 전기전자학회논문지 Vol.12 No.3

본 논문에서 기존 반도체공정들이 갖는 리소그래피와 식각 등의 공정단계를 배제하는 direct-write 공정과 LAM(Laser Ablation of Microparticles) 공정을 이용하여 친환경적인 이점을 가질 수 있는 나선형 인덕터의 구조를 제안하고 주파수 특성을 확인하였다. 인덕터의 구조는 Si를 540${\mu}m$, $SiO_2$를 3${\mu}m$으로 하였으며, Cu 코일의 폭과 선간의 간격은 LAM 공정과 direct-write 공정을 이용할 수 있도록 각각 30${\mu}m$으로 설정하여 2회 권선하였다. 나선형 박막 인덕터의 성능을 나타내는 인덕턴스, quality-factor, SRF에 대한 주파수 특성을 HFSS로 시뮬레이션 하였다. Underpass와 via가 제거된 인덕터는 300-800MHz 범위에서 1.11nH의 인덕턴스, 5GHz에서 최대 38 정도의 품질계수를 가지며, SRF는 18GHz로 시뮬레이션 결과를 얻었다. 반면에 underpass와 via를 가지는 일반적인 인덕터는 300-800MHz 범위에서 1.12nH의 인덕턴스, 5GHz에서 최대 35 정도의 품질계수를 가지며, SRF는 16GHz로 시뮬레이션 결과를 얻을 수 있었다. In this study, we propose that the structures of spiral inductors have the environment advantage utilizing direct-write and LAM(Laser Ablation of Microparticles) processes without process step of lithography and etching etc. of existing semiconductor process. The structures of inductors have Si thickness of 540${\mu}m$, $SiO_2$ thickness of 3${\mu}m$. The width of Cu coils and the space between segments have 30${\mu}m$, respectively, using for direct-write and LAM processes. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The inductors without underpass and via have inductance of 1.11nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 38 at 5 GHz, SRF of 18 GHz. Otherwise, inductors with underpass and via have inductance of 1.12nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 35 at 5 GHz, SRF of 16 GHz.

과제 지향적 기능 훈련이 뇌졸중 환자의 균형에 미치는 영향

김재욱,김수민,박래준,Kim Jae-wook,Kim Soo-min,Park Rae-joon 대한물리치료학회 2003 대한물리치료학회지 Vol.15 No.4

The purpose of this study was to investigate the balance of stroke patient appling Task-Oriented Functional training program. Sixteen subjects were recruited from KeiMyung university Dongsan Medical Center inpatient satisfying requirement for this study. They were divided into Task-Oriented Functional training group and Conventional therapy group. They were measured by Sensory organization test and Motor control test items using EquiTest Version 8.0 machine before and after the test. The result of this study were to follow: 1. In Sensory organization test, there were no significant differences in static eguibrium score in both groups(p<.05). 2. In Sensory organization test, there were significant differences in dynamic eguibrium score in both groups(p<.05). 3. In Motor control test, there were significant differences in both groups(p<.05). 4. In exercise group, there were no significant differences in static Sensory organization test(p<.05). 5. In exercise group, there were significant differences in dynamic Sensory organization test(p<.05). 6. In exercise group, there were significant differences in Motor control test(p<.05). 7. In control group, there were no significant differences in static Sensory organization test(p<.05). 8. In control group, there were no significant differences in dynamic Sensory organization test(p<.05). 9. In control group, there were no significant differences in Motor control test(p<.05).

회원작품 - 조개전시장

김재욱,Kim, Jae-Wook 대한건축사협회 1998 建築士 Vol.1998 No.5

2층 대칭 나선형 인덕터에 대한 주파수 특성 연구

김재욱,Kim, Jae-Wook 한국정보전자통신기술학회 2022 한국정보전자통신기술학회논문지 Vol.15 No.5

In the case of a general spiral inductor, the orientation of the port is affected as it has an asymmetric structure. In this paper, double-layer spiral inductor that can have a symmetrical structure is proposed, and the simulation and frequency characteristics are analyzed. Compared to the conventional single-layer symmetrical inductor having an inductance of 3.9~4.2nH, the proposed double-layer symmetric spiral inductor has an inductance of 11~12nH in 0.3~1.2GHz frequency range, a quality factor of about 4.4 in 800MHz, and a self-resonant frequency of about 2.7~2.8GHz without changing the port. Compared to the general spiral inductor having a large difference depending on the port, it was confirmed that the influence on the port direction was small.

국민학교 학생들의 혈액, 두발 및 조갑 내의 연농도 비교

김재욱,이중정,김창윤,정종학,Kim, Jae-Uk,Lee, Jung-Jeung,Kim, Chang-Yoon,Chung, Jong-Hak 대한예방의학회 1995 예방의학회지 Vol.28 No.1

대구시내 중심가의 국민학교 4학년 학생 남녀 각 50명씩들을 대상으로 혈액, 두발 및 조갑 내의 연농도를 정량분석하고 이들 각 시료 내의 연농도의 상관관계를 조사한 연구결과를 요약하면 다음과 같다. 혈액, 두발 및 발들의 평균 연농도는 각각 $6.00{\pm}2.44{\mu}g/dl,\;7.17{\pm}3.28{\mu}g/g,\;7.33{\pm}3.18{\mu}g/g$이었다. 혈중 연농도는 남학생이 $6.43{\pm}2.77{\mu}g/dl$, 여학생이 $5.59{\pm}2.01{\mu}g/dl$, 두발 중 연농도는 남학생이 $7.66{\pm}2.97{\mu}g/g$, 여학생이 $6.68{\pm}3.54{\mu}g/g$로 남학생에서 높았으나 통계적으로 유의하지 않았으며, 발톱의 경우는 남학생에서 $8.19{\pm}3.54{\mu}g/g$, 여학생에서 $6.47{\pm}2.59{\mu}g/g$로 남학생에서 유의하게 높았다. 혈액, 두발과 발톱 중 연농도에 따른 학생들의 분포는 혈액은 남학생에서 $5.0\sim7.4{\mu}g/dl(38%)$, 여학생에서는 $2.5\sim4.9{\mu}g/dl(42%)$에 전체적으로는 $5.0\sim7.4{\mu}g/dl(41%)$에 가장 많이 분포하였다. 두발의 경우 남학생에서 $5.0\sim7.4{\mu}g/g(32%)$, 여학생에서 $2.5\sim4.9{\mu}g/g(34%)$에 전체적으로는 $2.5\sim4.9{\mu}g/g(28%)$에 가장 많이 분포하였다. 발들에서는 남학생에서 $5.0\sim7.4{\mu}g/g(34%)$, 여학생에서 $7.5\sim9.9{\mu}g/g(30%)$에 전체적으로는 $5.0\sim7.4{\mu}g/g(31%)$에 가장 많이 분포하였다. 또한 남학생의 8%, 여학생의 4%로 전체 학생들의 6%에서 혈액 중 연농도가 $10{\mu}g/dl$을 넘었다. 혈액, 두발과 발톱 사이의 연농도의 상관관계를 보면 남학생에서 혈액과 두발의 연농도 사이의 상관계수는 0.4909(p<0.001)(regression equation : Y(두발 중 연농도)=0.5255X(혈액 중 연농도)+4.2810)였으며, 여학생에서의 상관계수는 0.3778(p<0.001) (regression equation : Y(두발 중 연농도)=0.6655X(혈액 중 연농도)+2.9632)이었다. 남학생에서 혈액과 발톱 중 연농도 사이의 상관계수는 0.5533(p<0.01) (regression equation : Y(발톱 중 연농도)=0.7076X(혈액 중 연농도)+3.6472)였으며 여학생에서의 상관계수는 0.2738(regression equation : Y(발톱 중 연농도)=0.3431X(혈액 중 연농도)+4.5570이었다. 남학생에서 두발과 발톱 중 연농도 사이의 상관계수는 0.4148(p<0.001) (regression equation : Y(발들 중 연농도)=0.4956X(두발 중 연농도)+4.3986)였으며, 여학생에서의 상관계수는 0.1159(regression equation : Y(발톱 중 연농도)=0.0825X(두발 중 연농도)+5.9214)이었다. 본 연구의 결과에서 여학생의 두발과 발톱간을 제외하고, 대도시 남자 국민학교 학생들의 혈액, 두발, 발들의 연농도간의 유의한 관련성이 있으므로 혈액, 두발및 발톱을 연 폭로평가의 상호보완, 혹은 대체시료로써 이용의 가능성이 있다고 생각된다. This study was conducted to measure the lead level in the blood, scalp hair and toenail of the elementary schoolchildren and assess the relationship among those samples. Lead concentration of the blood, scalp hair and toenail was measured for 100(male 50, female 50) fourth grade elementary schoolchildren in Taegu city. The mean lead level in the blood, scalp hair and toenail was $6.00{\pm}2.44{\mu}g/dl,\;6.68{\pm}3.54{\mu}g/g,\;and\;7.33{\pm}3.18{\mu}g/g. The mean lead level in the blood of schoolboys was $6.43{\pm}2.77{\mu}g/dl$, and that of schoolgirls was $5.59{\pm}2.01{\mu}g/dl$. The mean lead level in the scalp hair of schoolboys was $7.66{\pm}2.97{\mu}g/g$ and that of schoolgirls was $6.88{\pm}3.54{\mu}g/g$. The mean lead level in the toenail of schoolboys was $8.19{\pm}3.5{\mu}g/g$ and that of schoolgirls was $6.47{\pm}2.52{\mu}g/g$ and their difference was statistically significant. In schoolboys, the correlation coefficient between the lead level in the blood and scalp hair was 0.4909, and the data were fitted best by the regression equation Y = 0.5255X+4. 2810, where Y and X are scalp hair and blood concentration. In schoolgirls the correlation coefficient between the lead level in the blood and scalp hair was 0.3778, and the data were fitted best by the regression equation Y = 0.6655X+2.9632, where Y and X are scalp hair and blood concentration. In schoolboys, the correlation coefficient between the lead level in the blood and in the toenail was 0.5533, and the data were fitted best by the regression equation Y = 0.7076X+3. 6472, where Y and X are toenail and blood concentration. In schoolgirls the correlation coefficient between the lead level in the blood and in the toenail was 0.2738, and the data were fitted best by the regression equation Y = 0.3431X+4.5570, where Y and X are toenail and blood concentration In schoolboys, the correlation coefficient between the lead level in the scalp hair and in the toenail, in the schoolboys was 0.4148, and the data were fitted best by the regression equation Y = 0.4956X+4.3986, where Y and X are toenail and scalp hair concentration. In schoolgirls, the correlation coefficient between the lead level in the scalp hair and in the toenail was 0.1159, and the data were fitted best by the regression equation Y = 0.0825X+5. 9214, where Y and X are toenail and scalp hair concentration. Correlation among lead concentration in the blood, scalp hair and toenail of schoolchildren were statistically significant except between scalp hair and toenail in schoolgirls. These finding suggest that blood, scalp hair and toenail can be used as substitutive samples between each others.