Impedance를 이용한 전도성고분자 센서의 가스감응특성

이경문,유준부,이병수,전희권,이상태,이덕동,허증수 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

SnO₂/TiO₂후막형 습도센서의 제조 및 특성

이건동,이재현,박효덕,이덕동,최흥문 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

SnO_(2) doped with TiO_(2) and other activating agents, is used as a raw material to prepare humidity sensors. SnO_(2) is an n-type semiconductor whose resistance is described as a function of relative humidity. SnO_(2)/TiO_(2) thick film humidity sensors have been fabricated by using typical silk screen printing techniques. The humidity sensitivity of SnO_(2)/TiO_(2) thick film has been investigated. And the sensing characteristics of the fabricated SnO_(2)/TiO_(2) sensors such as resistance change and response time, has been investigated from R.H.20 % to 90 %. Experimental results show that the impedance-humidity characteristics of the humidity sensors depend on the microstructure of surface roughness and pore size distribution.

단일전극을 가진 마이크로 가스센서의 제작 및 특성

송갑득,박영일,이상문,이윤수,최낙진,주병수,서무교,허증수,이덕동 한국센서학회 2002 센서학회지 Vol.11 No.6

센서의 안정도와 감도를 개선시킬 수 있는 단일전극을 가진 열선형 마이크로 가스센서를 제작하였다. 일반적으로, 금속산화물 반도체를 이용한 가스센서는 히터전극과 감지전극의 두 개의 전극을 가지고 있다. 제작된 센서는 히터전극위에 감지물질을 형성하여 단일 전극을 가지는 구조를 가지고 있다. 히터와 감지전극으로 사용되는 Pt는 glass 기판위에 스퍼터링법으로 형성하였으며, SnO_2 감지물질은 제작된 Pt 전극위에 열증착시켜 형성하였다. SnO_2막은 lift-off 공정을 이용해서 패턴을 형성하고 1시간 동안 산소분위기에서 열산화하였다. 제작된 소자의 크기는 1.92x.1 mm^2 이다. CO 가스에 대한 감지특성을 조사한 결과 1,000 ppm에 대해 100 mV의 출력변화를 나타내었으며, 넓은 농도범위(0 ~ 10,000 ppm에서 선형적인 전압출력을 나타내었다. 또한 가스 반응 전과 반응 후의 전압출력을 비교해 볼 때, 1 % 이내의 편차를 나타내는 우수한 회복성을 나타내었다. Micro gas sensor with single electrode was proposed for improving stability and sensitivity, Generally, metal oxide gas sensors have two electrodes for heating and sensing. This fabricated new type sensor have only a single electrode by forming a sensing material onto heating electrode. Pt as a heating and sensing electrode was sputtered on glass and a SnO_2 sensing material was thermally evaporated on Pt electrode. SnO_2 was patterned by lift-off process and then thermally oxidized in O_2 condition for 1 hr., 600 ℃. The size fabricated sensor was 1.9 x 2.1 mm^2. As a result of CO gas sensing characteristics, this sensor showed 100 mV change for 1,000 ppm and linearlity for wide range(0 ~ 10,000 ppm) of gas concentrations. And the sensor shows a good recovery characteristics of 1 % deviation compared to initial resistance.

한약에 의해 유발된 급성 간질성 신염 2례

김덕윤,박동건,김응석,강영모,양창헌,이정호,이동철,이영현,김정란 동국대학교 경주대학 1996 東國論集 Vol.15 No.-

간질성 신염은 신장의 간질을 선택적으로 침범하는 염증성 질환으로 여러가지 원인에 의해 유발되며, 이 중 약물에 의한 경우는 각종 항생제, 비스테로이드성 진통제, 항경련제, 이뇨제, 면역억제제등에 의한 증례들이 보고되고 있다. 현재 각종 질환-특히 만성질환-의 치료에서 한약이 차지하는 비중이 적지 않으나, 그 각각의 성분들이 유발할 수 있는 부작용들에 대한 연구는 거의 없는 실정이다. 저자들은 관절염 치료를 위해 중국산 한약을 복용한 후 복통, 피로감 및 육안적 혈뇨를 주소로 내원한 두 환자에서, 단백뇨와 신기능 장애를 보여 시행한 신조직 생검상 급성 간질성 신염에 합당한 병리학적 소견을 보이고, 한약 복용 중지 후 급속한 회복을 보여, 한약에 의해 유발된 것으로 사료되는 급성 간질성 신염 2예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Acute interstitial nephritis is a disease characterized by renal interstitial inflammatory cell infiltration and acute renal functional deterioration. This is caused mainly by antibiotics, NSAID and diuretics such as thiazide, but cases induced by herb medication are rare. We experienced two cases of acute interstitial nephritis after treatment with herb medication. One 71-year-old female patient and the other 60-year-old female were admitted to the hospital because of general weakness and gross hematuria. Microscopic hematuria, pyuria, and proteinuria were presented. After definitive diagnosis with a renal biopsy, we noted rapid recovery of renal function by drug withdrawal and steroid therapy. We report these cases with a review of the referenced literatures. Key Words : Herb medication, Acute Interstitial nephritis.

열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구

배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.

열적 변화를 이용한 실내환경 가스의 분류

최낙진,심창현,송갑득,주병수,이윤수,이상문,이덕동,허증수 한국센서학회 2002 센서학회지 Vol.11 No.5

단일 기판위에 온도측정용 Pt 박막과 Pt 히터 그리고 가스 감지를 위하여 순수한 SnO_2 박막과 Pt가 첨가된 SnO_2박막을 설계하고 제작하였다. 제작된 소자는 실내환경가스인 이산화탄소, 프로판 그리고 부탄의 분류에 응용되었다. 동작 온도를 가변하기 위하여 히터의 입력 전압을 사다리꼴로 인가하면서 SnO_2 감지막의 반응특성과 실내환경가스들에 대한 분류여부를 조사하였다. 감지막 반응특성곡선에서 여러 변수들을 추출한 후 주성분분석(principal component analysis : PCA)을 통하여 가스 분류 특성을 검증하였다. Two SnO_2 based sensing films(pure SnO_2 and SnO_2/Pt) and a Pt thin film for temperature sensor on an alumina substrate were designed and fabricated for classifying the indoor environmental gases. By controlling the heating power in the shape of trapezoid, unique four sensing response curves created from both SnO_2 film and SnO_2/Pt film. Then, various parameters were extracted from sensing response curves and carried out principal component analysis(PCA). The results confirm that a sensor array with the proposed operating mode was extremely effective in classifying indoor environmental gases such as CO_2, C_3H_8, C_4H_10.

산화코발트계 산소센서의 제작 및 그 특성

이재현,전춘배,이덕동 경북대학교 센서기술연구소 1990 센서技術學術大會論文集 Vol.1 No.1

Co_(1-x)Mg_(x)O ceramic oxygen sensors were prepared by pressing at 0.3 ~ 1.5 ton/cm^(2) with or without binder, intending to change porosity and average grain size on the surface purposely. Microstructures of prepared Co_(1-x)Mg_(x)O ceramics were observed, the electrical properties and the sensitivity characteristics for oxygen gas were investigated in the specimen temperature range of 700~1000 °C and for oxygen partial pressure range of 1~10^(-4) atm. Temperature dependence of the resistivity of the specimen showed NTC behavior, average grain size increased and porosity decreased with increasing compaction pressure. The slopes of the resistivity of the specimens on the oxygen partial pressure decreased with increasing average grain size and with decresing porosity. Particularly, specimen pressed by 0.3 and 0.5 ton/cm^(2) showed the highest sensistivity to oxygen gas. In general optimum operating temperature was 800 °C.

Short n-channel MOSFET의 특성

李德東 경북대학교 공과대학 1982 工大硏究誌 Vol.11 No.-

Short n-channel metal gate MOSFETs have been fabricated with the channel length of 1 um. The source and drain were formed by implanting As with the energy of 150 keV and the dose of 5 x 10^15/㎠. And Boron was implanted into the channel to define the enhancement mode. Photolithography technique was used to define each pattern. The experimental value of threshold voltage of short channel device was about 0.8v. And it was suggested that Yau's model structure could be used to calculate the threshold voltage of short channel device. The drain characteristics and the mobility versus gate voltage were also obtained.

G292 세포에서 세포막 신장으로 활성화되는 K^+통로의 특성

이상국,정동근,서덕준,박수병 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.2

본 연구에서는 인체 골종양에서 유래한 G292세포를 이용하여 압력으로 세포막을 신장(stretch)시켰을 때 K+ 통로의 전기적 활성 변화를 연구하였다. 배양된 세포에서 유리전극을 이용하여 세포막 내측이 유리전극의 외부로 향하도록 inside-out patch를 얻어 단일이온통로전류를 막전압고정법 (patch clamp recording)으로 기록하였다. G292세포의 세포막 내외에 140 mM KCl용액이 있는 상태에서 유리전극내 전압을 -80 mV로 고정했을 때 전도성이 270±27 pS, 113±12 pS, 48±8 pS인 3가지 종류의 K+통로를 관찰하였다. 전도성이 낮은 48 pS의 K+ 통로는 모든 세포막에서 관찰하였으며 270 pS 및 113 pS의 K+ 통로는 일부 세포에서만 관찰하였다. 48 pS의 K+ 통로는 세포막 외측에 음의 전압을 가하면 활성화되고 양의 전압을 가하면 활성화되지 않는 외향성 정류특성을 보였다. 세포막 외측에 음압을 가하면 48pS의 K+통로는 활성화되었으며 이온 통로가 열리는 확률(Popen)이 가하는 압력에 비례하여 증가하였다. 이러한 결과는 G292세포주에 3가지 종류의 K+통로가 존재하며 전도성이 낮은 48pS의 K+통로만이 세포막 신장에 의하여 직접적으로 활성화되는 특성을 보였다. 이러한 K+ 통로의 활성화는 세포가 기계적 자극을 받아 세포막이 신장되면 세포막전압을 과분극시키며 조골세포에서 기계적 강수기로서의 기능을 수행하여 조골세포의 골개조에 관여할 것으로 추측된다. K+-selective ion channels were studied in excised inside-out membrane patches from human osteoblast-like cells (G292). Three classes of K- channels were present and could be distinguished on the basis of conductance. Conductances were 270±27 pS, 113± 12 pS, 48±8 pS according to their approximate conductances in symmetrical 140 mM KCI saline at holding potential of -80 mV. It was found that the small conductance (48 pS) K+ channel activation was dependent on membrane voltage. In current-voltage relationship, small conductance K+ channel showed outward rectification, and it was activated by the positive potential inside the membrane. In recordings, single channel currents were activayed by a negative pressure outside the membrane. The membrane pressure increased Popen of the K+ channel in a pressure-dependent manner. In the excised-patch clamp recordings, G292 osteoblast-like cells have been shown to contain three types of K+ channels. Only the small conductance (48 pS) K+ channel is sensitive to the membrane stretch. These findings suggest that a hyperpolarizing current, mediated in part by this channel, may be associated with early events during the mechanical loading of the osteoblast. In G292 osteoblast-like cells, K+ channel is sensitive to membrane tension, and may represent a unique adaptation of the bone cell membrane to mechanical stress.

스트레스와 운동상해의 예측과 예방을 위한 모델

이동재,장덕선 群山大學校 1997 論文集 Vol.25 No.-

A theoretical model of stress and athletic injury is presented. The purpose of this paper is to propose a framework for the prediction and prevention of stress-related injuries that includes cognitive, physiological, attentional, behavioral, interpersonal, social, and stress history variables. Development of the model grew from a synthesis of the stress-illness, stress-accident, and stress-injury literatures. The model and its resulting hypotheses offer a framework for many avenues of research ingo the nature of injury and reduction of injury risk. Other advantages of the model are that it addresses possible mechanisms behind the stress-injury relationship and suggests several specific interventions that amy help diminish the likelihood of injury. The model also has the potential of being applied go the investigation of injury and accident occurrence in general.