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Sol-Gel법으로 제조한 PLT박막의 초전 특성 (Pyroelectric Properties of the PLT Thin Films Prepared by Sol-Gel Method)

  • 김양선;정장호;박인길;이성갑;이영희
    • E2M - 전기 전자와 첨단 소재
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    • 제10권6호
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    • pp.541-547
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    • 1997
  • (Pb$_{1-x}$ La$_{x}$)Ti$_{1-x}$ $_4$O$_3$(x=0, 0.02, 0.04, 0.08) ceramic thin films were fabricated by Sol-Gel method. A stock solution of (Pb, La)TiO$_3$ with excess Pb 10 mol% was made and spin-coated on the Pt/Ti/SiO$_2$/Si substrate at 400rpm for 30 seconds. Coated specimens were dried on the hot-plate at 35$0^{\circ}C$ for 10 min and sintered at 500~75$0^{\circ}C$ for 1 hour. The dielectric constant, remanent polarization and coercive field of the PLT(6at.%) thin films sintered at $650^{\circ}C$ were 884, 13.95$\mu$C/$\textrm{cm}^2$ and 8.7kV/cm, respectively. Pyroelectric coefficient, figure of merit of pyroelectric current, voltage responsivity and detectivity of PLT(6at.%) thin films were 3.2$\times$10$^{-8}$ C/$\textrm{cm}^2$K, 1.02$\times$10$^{-8}$ C.cm/J, 2.9 $\times$10$^{-11}$ C.cm/J, 0.29$\times$10$^{-8}$ C.cm/J, respectively.ely.

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가토의 호중성백혈구 성염색질의 정상빈도와 X선조사에 대하여 (Studies on the Normal Frequency and Effects of X-irradiation on Sex Chromatin of Neutrophil Leukocyte in the Rabbit)

  • 박대규;김무윤
    • 한국동물학회지
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    • 제9권1호
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    • pp.16-20
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    • 1966
  • The frequency of sex chromatin in neutrophil leukocyte of 14 female and 4 male normal, adult rabbits was examined and compared to those of single total X-ray irradiation. 1. The average frequency of of drumstck was 9 % in female and 0.1% in male, and that of sessile nodule was 3.35% in female and 0.9% in male , in normal condition rabbit . These results fairly determined sex ratio by sex chromatin in neutrophil leukocyte. 2. The drumstick frequency reduces to half after X-irradiaton but did not show any regular tendency or variation in morphologicla form, indicating the stability of chromatin to X-irradiation. 4. The chromatin satellite was found with a reasonable frequency in the some kinds of irradiated cells, polymorphonuclear neutrophil (above 7 lobes 0 and megakarycyte.

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입원 환자의 호칭에 관한 연구 (A Study on Appellations for Admitted Patient)

  • 강현숙;김원옥;장광자;김일원
    • 기본간호학회지
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    • 제3권1호
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    • pp.37-49
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    • 1996
  • The Purposes of this study were to understand the types of appellations used by nurses and doctors for patients in a hospital and to analyze satisfaction and reason about appellation for patient. This would enable us to provide basic data on culturally suitable appellations for admitted patients. 454 patients at K University hospital in Seoul were subjects for this study. Subjects were interviewed individually using a questionnair and frequency $X^2-test$. Results are as follows. 1. The most frequently used type of appellations in hospitals was '-ssi ; -sir' used by 88.1% of the nurses and 83.9% of the doctors. About 3 quaters of the medical staff used '-ssi' while none used job position. 2. 93.2% of the patients were satisfied with the appellations used by nurses and 93.0% of the patients were satisfied with the appellations used by the doctors 43.7% didn't think appellations were important and 44.3% thought it natural to use the appellation. The most satisfactory form of appellation used by nurses was '-ssi' to 93.3% of patients. All were satisfied with '-nim ; -sir', '-teacher' and there was no statistically significance. On the other hand, the level of satisfaction and the appellation used by doctors showed a relationship($X^2=19.72$, p=.000). Every patient was satisfied with '-nim' and '-teacher' but 19.9% were dissatisfied with the others of appellations. 3. Most patients preferred to be called '-ssi' by nurses(77.3%) and doctors(78.7%) respectively. The dominant reason being accuracy(45.8%), naturalness(33.9%) for nurses and 43.8% and 45.4% respectively for doctors. 4. The relationship between the type of appellations requested of nurses and general characteristics showed that age($X^2=83.91%$ p=.000), level of education($X^2=33.35$ p=.000), and occupation($X^2=38.22$ p=.033) were related to the type of appellation. The type of appellation requested of doctors was related to the age($X^2=72.56$ p=.000), level of education($X^2=30.01$ p=.000), and occupation($X^2$=42.90 p=.010). Generally, '-ssi' was requested of doctors and nurses, but lower age group or higher age group(over 61), those in elementary schools or elementary school graduates snd students preferred being called by their first names or grandfather, grandmother. From the results above, we can see that the most general type of appellation used for patients by the medical staff is '-ssi' and most patients were satisfied with the appellation but, the reason being that such appellations were accepted without concern. This shows that most are not adequately satisfied with the appellation. Only a small number of people use '-nim' and '-teacher' but is the preferred and frequently used types of appellation. Therfore, a continuous research of appellations used for patients with patients using '-nim' and an investigation with nurses' opinions of appellations for patients as the subject are required.

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Synthesis and Structural Analysis of 2-Amino-4-(4-hydroxy-3-methoxyphenyl)-7,9-dimethyl-5-oxo-4, 5, 6, 7-tetrahydropyrano [2, 3-d] pyrazolo [3, 4-b] pyridine-3-carbonitrile through X-ray Crystallography

  • Ganapathy, Jagadeesan;Jayarajan, R.;Vasuki, G.;Sanmargam, Aravindhan
    • 통합자연과학논문집
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    • 제8권1호
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    • pp.30-39
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    • 2015
  • The crystal structure of the potential active 2-amino-4-(4-hydroxy-3-methoxyphenyl)-7, 9-dimethyl-5-oxo-4, 5, 6, 7-tetrahydropyrano [2, 3-d] pyrazolo [3, 4-b] pyridine-3-carbonitrile ($C_{21}H_{22}N_5O_6S$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P-1 with unit cell dimension a=8.1201(9)${\AA}$, b=12.2684(4)${\AA}$ and c=12.387(2)${\AA}$ [${\alpha}=69.573^{\circ}$, ${\beta}=12.168^{\circ}$ and ${\gamma}=76.060^{\circ}$]. In the structure the pyrazole, pyridine and pyran are almost coplanar each other. The crystal packing is stabilized by intermolecular C-H...O and N-H... O hydrogen bond interaction.

THE FABRICATION OF A PROCESS HEAT EXCHANGER FOR A SO3 DECOMPOSER USING SURFACE-MODIFIED HASTELLOY X MATERIALS

  • Park, Jae-Won;Kim, Hyung-Jin;Kim, Yong-Wan
    • Nuclear Engineering and Technology
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    • 제40권3호
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    • pp.233-238
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    • 2008
  • This study investigates the surface modification of a Hastelloy X plate and diffusion bonding in the assembly of surface modified plates. These types of plates are involved in the key processes in the fabrication of a process heat exchanger (PHE) for a $SO_3$ decomposer. Strong adhesion of a SiC film deposited onto Hastelloy X can be achieved by a thin SiC film deposition and a subsequent N ion beam bombardment followed by an additional deposition of a thicker film that prevents the Hastelloy X surface from becoming exposed to a corrosive environment through the pores. This process not only produces higher corrosion resistance as proved by electrolytic etching but also exhibits higher endurance against thermal stress above 9$900^{\circ}C$. A process for a good bonding between Hastelloy X sheets, which is essential for a good heat exchanger, was developed by diffusion bonding. The diffusion bonding was done by mechanically clamping the sheets under a heat treatment at $900^{\circ}C$. When the clamping jig consisted of materials with a thermal expansion coefficient that was equal to or less than that of the Hastelloy X, sound bonding was achieved.

도라지 재배환경 및 토양 형태학적 특성 (Survey on Cultural Environment and Soil Morphological Characteristics of Platycodon grangiflorus)

  • 이영한;박상렬;류재산;임선택;고병구;윤한대
    • 한국토양비료학회지
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    • 제32권3호
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    • pp.215-222
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    • 1999
  • 토양 이화학적 성질에 따른 도라지 재배적지를 경남 진주 6, 김해 7, 고성 3, 함안 6, 거창 4개소 강원도 홍천 6개소 등 32개소를 대상으로 분석한 결과는 다음과 같다. 기온은 발병율과 $Y=3.07X^2-87.16X+649.26(R^2=0.947^{**})$, 수량과 $Y=-478.68X^2+13403X-90836(R^2=0.763^*)$의 유의성 있는 상관이 있었다. 재배년수는 진주 8.0년으로 다년생이었고 홍천 1.30ha로 가장 넓었으며 김해가 0.08ha로 좁았다. 평균 퇴비시용량은 홍천이 $108Mg\;ha^{-1}$로 과다시용하는 경향이었고 김해지역이 $4.96Mg\;ha^{-1}$로 적게 시용하였다. 경사는 고성이 35.0%로 급경지였고 거창은 28%로 구릉지이며 진주, 김해, 홍천은 경사가 11.7 11.0, 7.5%로 기복지를 나타냈다. 배수상태는 거창, 김해, 진주, 고성지역이 양호한 반면 홍천, 함안은 불량한 편이었고 농가재배지의 포장방향은 거창, 진주, 고성이 동남향이었으며 김해, 함안, 홍천지역은 북서방향이었다. 재배년수가 긴 진주지역이 근경 4.20cm, 주당 근중 57g으로 수량이 $36.17Mg\;ha^{-1}$로 높게 나타났다. 발병율은 함안, 홍천지역이 각각 56.8, 52.5%로 높게 나타났고 고성 진주지역이 30.0. 32.2%로 낮게 나타났다. 발병율은 배수등급과 Y=19.1X-5.26($R^2=0.592{***}$)지형과는 Y=9.68X+10.77($R^2=0.205^{**}$)의 고도의 유의성 있는 정의상관을 나타냈고, 수량은 배수등급과 Y=-10X+42($R^2=0.348^{**}$), 지형과는 Y=-5.34X+34.5 ($R^2=0.134^*$)의 부의상관을 나타냈다.

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CPS 급전 방식의 광대역 Yagi-Uda 안테나 (A Broadband CPS-Fed Yagi-Uda Antenna)

  • 한경호;박용배;추호성;박익모
    • 한국전자파학회논문지
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    • 제20권7호
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    • pp.608-616
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    • 2009
  • 본 논문에서는 CPS 급전 방식의 광대역 Yagi-Uda 안테나를 제안하였다. 제안한 안테나는 CPS 급전 선로를 사용하여 기존에 설계된 Yagi-Uda 안테나들에 비하여 간단한 급전 구조를 가지며 기판에 접지면이 필요 없기 때문에 reflector의 설계를 자유로이 할 수 있다. 정합 선로를 설계하기 위하여 선폭이 두꺼운 선로와 선폭이 얇은 선로 사이에 테이퍼된 선로를 삽입하여 최적의 CPS 급전 선로 구조를 설계하였다. 제안한 Yagi-Uda 안테나는 -10 dB 반사 손실을 기준으로 $3.9{\sim}5.9$ GHz의 대역폭을 가지고 대역폭 내에서 $6.5{\sim}8$ dBi의 이득을 가진다. 중심 주파수인 4.9 GHz에서 이득은 7.4 dBi 이고, 반전력 빔폭은 x-z 평면에서 $98^{\circ}$, x-y 평면에서 $73^{\circ}$이다.

불소화된 $YBa_2Cu_3O_{7-y}$ 초전도체의 구조적, 전기적 성질에 관한 연구 (A study on the structural and electric properties of fluorinated $YBa_2Cu_3O_{7-y}$)

  • 김재욱;김채옥
    • E2M - 전기 전자와 첨단 소재
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    • 제9권4호
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    • pp.404-409
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    • 1996
  • The structural and electric properties of $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$(x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) have been investigated by using XRD(X-ray diffraction), TMA(thennomechanical analysis), NMR(nuclear magnetic resonance) analysis and four probe method. $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$ samples were prepared by conventional solid-state reaction method using $Y_{2}$O$_{3}$, BaCO$_{3}$, CuO and YbF$_{3}$ power. TMA and high temperature XRD results shows that orthorhombic to tetragonal phase transition occurs in the unfluorinated 1-2-3 sample while the phase change is not observed in the fluorinated 1-2-3 samples. Superconducting transition temperature(T$_{c}$) increases with increasing YbF$_{3}$ content ; T$_{c}$, of the sample reaching maximum of 102K for x=0.3, and then decreases with further increasing YbF$_{3}$ content. The structural analysis and T$_{c}$ results shows that the fluorine doping stabilize the orthorhombic phase, together with the increase in T$_{c}$.}$ c/.TEX> c/.

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MOD법을 이용한 BLT박막의 제초 및 특성에 관한 연구 (The Preparation and Characterization of BLT Thin Films by MOD Process)

  • 이진한;장건익
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.186.1-189
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    • 2001
  • Ferroelectric $Bi_{4-x}$La$_{x}$Ti$_3$O$_{12}$ (BLT)thin films with various compositions(x=0.65, 0.70, 0.75) were prepared on Pt//Ti/SiO$_2$/Si(100) substrate by metal-organic deposition. The electrical and structural characteristics of BLT thin films were investigated to develop ferroelectric thin films for capacitor layers of FRAM. After spin coating, thin films were annealed at $650^{\circ}C$ for 1hour in oxygen atomosphere. Scanning electron micrographs showed uniform surfaces composed of rod-like grains. The $Bi_{4-x}$La$_{x}$Ti$_3$O$_{12}$ (x=0.70) thin film capacitors with a Pt top electrode showed better ferroelectric properties than other films. At the applied voltage of 5V, the dielectric constant($\varepsilon$$_{r}$), dissipation factor(tan$\delta$),remanent polarization(2Pr), and coercive field(2Ec) of the $Bi_{4-x}$La$_{x}$Ti$_3$O$_{12}$ (x=0.70)thin films were about 272.54, 0.059, 32.4 $\mu$C/cm$^2$, 2Ec=119.9kV/cm. Also the capacitor did not show any significant fatigue up to 4.8$\times$10$^{10}$ read/write switching cycles.hing cycles.s.

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Effects of Al2O3 addition on nanocrystal formation and crystallization kinetics in (1-x)Li2B4O7-xAl2O3 glasses

  • Choi, Hyun Woo;Kim, Su Jae;Yang, Hang;Yang, Yong Suk;Rim, Young Hoon;Cho, Chae Ryong
    • Journal of Ceramic Processing Research
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    • 제20권1호
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    • pp.63-68
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    • 2019
  • We investigated the effects of Al2O3 addition on (1-x)Li2B4O7-xAl2O3 (LBAO; x = 0, 0.005, 0.01, 0.05, 0.07, and 0.1) glasses. The glasses were synthesized by a conventional melt-quench method. Structural transformations of the LBAO glasses were assessed via X-ray diffraction analysis. Estimations of ΔT, KGS = (Tc-Tg)/(Tm-Tc), activation energy, and the Avrami parameter were performed using differential thermal analysis and differential scanning calorimetry. An interpretation of non-isothermal kinetics of the crystallization process is presented using the modified Ozawa equation. The activation energy E increased from 3.3 to 3.5 eV for the LBAO (x < 0.01) glasses whereas those of the LBAO (x > 0.05) glasses slightly increased from 3.75 to 4.05 eV. The exponent n was estimated to be 3.9 ± 0.1 for the LBAO (x < 0.01) glasses and 3.2 ± 0.02 for the LBAO (x > 0.05) glasses. Microstructural characterization of the glassy and crystalline phases using atomic force microscopy was investigated. The effects of Al2O3 on the LBAO glasses include a decreased nucleation rate in the crystallization process and a significantly reduced crystal size.