• Title/Summary/Keyword: 정계비(定界碑)

Search Result 104, Processing Time 0.033 seconds

Pulsed Laser Deposition을 이용하여 GZO/Glass 기판상에 성장시킨 염료감응형 태양전지용 $TiO_2$ Blocking Layer의 특성 연구

  • Yeo, In-Hyeong;Kim, Ji-Hong;No, Ji-Hyeong;Kim, Jae-Won;Do, Gang-Min;Sin, Ju-Hong;Jo, Seul-Gi;Park, Jae-Ho;Mun, Byeong-Mu
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.08a
    • /
    • pp.259-259
    • /
    • 2011
  • 염료감응형 태양전지(Dye-Sensitized Solar Cells:DSSC)는 환경 친화적이며, 저가의 공정에 대한 가능성으로 기존의 고가의 결정질 실리콘 태양전지의 경제적인 대안으로 각광을 받고 있다. 최근 염료감응형 태양전지는 투명 전도성 산화막(Transparent Conducting Oxide : TCO)으로 사용되는 Fluorine Tin Oxide (FTO)가 증착된 유리기판 위에 주로 제작된다. FTO는 낮은 비저항과 가시광선 영역에서 높은 투과도를 가지는 우수한 전기-광학적 특성을 갖지만, 비교적 공정이 까다로운 Chemical Vapor Deposition (CVD)법으로 제조하며, 전체 공정비용의 60%를 차지하는 높은 생산단가로 인해 현재 FTO를 대체할 재료개발 연구가 활발히 진행되고 있다. 그 중 ZnO (Zinc Oxide)는 우수한 전기-광학적 특성과 비교적 저렴한 가격으로 새로운 TCO로써 주목받고 있다. ZnO는 넓은 energy band gap (3.4 [eV])의 육방정계 울자이트(hexagonal wurtzite) 결정 구조를 가지는II-VI족 n형 반도체 물질이며, III족 금속원소인 Al, Ga 및 In 등의 불순물을 첨가하면 TCO로서 우수한 전기-광학적 특성과 안정성을 나타낸다. 이들 물질중 $Zn^{2+}$ (0.060 nm)의 이온반경과 유사한 $Ga^{2+}$0.062 nm) 이온이 ZnO의 격자반경을 최소화 시킬 수 있다는 장점으로 최근 주목 받고 있다. 하지만 Ga-doped ZnO (GZO)의 경우 DSC에 사용되는 루테늄 계열의 산성 염료 하에 장시간 두면 표면이 파괴되는 문제가 발생하며, $TiO_2$ paste를 Printing 후 열처리하는 과정에서도 박막의 파괴가 발생할 수 있다. 이를 방지하기 위해 $TiO_2$ Blocking Layer를 GZO 투명전극 위에 증착하였다. 또한, $TiO_2$ Blocking Layer를 적용한 GZO 박막을 전면전극으로 이용하여 DSC를 제작하여 효율을 확인하였다. 2wt%의 $Ga_2O_3$가 도핑된 ZnO 박막은 20mTorr 400$^{\circ}C$에서 Pulsed Laser Deposition (PLD)에 의해 성장되었고, $TiO_2$박막은 Ti 금속을 타겟으로 이용하여 30mTorr 400$^{\circ}C$에서 증착되었다. Scanning electron microscopy (FE-SEM)을 이용한 박막 분석 결과 $TiO_2$가 증착된 GZO 박막의 경우 표면 파괴가 일어나지 않았다. Solar Simulator을 이용하여 I-V특성 측정결과 상용 FTO를 사용한 DSC 수준의 효율을 나타내었다. 이에 따라 Pulsed Laser Deposition을 이용해 제작된 GZO 기판은 $TiO_2$ Blocking Layer를 이용하여 표면 파괴를 방지할 수 있었으며, 이는 향후 염료감응형 태양전지의 투명전극에 적용 가능 할 것으로 판단된다.

  • PDF

Synthesis and Optical Properties of CaMoO4:RE3+ (RE=Eu, Dy) Phosphors (CaMoO4:RE3+ (RE=Eu, Dy) 형광체의 제조와 광학 특성)

  • Cho, Shinho
    • Journal of the Korean Vacuum Society
    • /
    • v.22 no.2
    • /
    • pp.79-85
    • /
    • 2013
  • Rare earth ions, either $Eu^{3+}$ or $Dy^{3+}$-doped $CaMoO_4$ phosphors were synthesized by using the solid-state reaction method. The crystalline structure of all the phosphor powders, irrespective of the type and concentration of activator ions, was found to be a tetragonal system with the main diffraction peak at (112) plane. For $Eu^{3+}$-doped $CaMoO_4$ phosphors, the grain particles showed an increasing tendency and the pebble-like patterns with a very homogeneous size distribution in the range of 0.01~0.10 mol of $Eu^{3+}$ ions concentration, and the excitation spectra were composed of a broad band centered at 311 nm and weak multiline peaked in the range of 360~470 nm. The dominant emission spectrum was the strong red emission centered at 618 nm due to the $^5D_0{\rightarrow}^7F_2$ transition of $Eu^{3+}$ ions. For $Dy^{3+}$-doped $CaMoO_4$ powders, excitation spectra showed a charge transfer band centered at 303 nm and relatively weak bands resulting from the transitions of $Dy^{3+}$ ions and the main yellow emission spectrum was observed at 578 nm, which was assigned to the $^4F_{9/2}{\rightarrow}^7H_{13/2}$ transition of $Dy^{3+}$ ions.

A Study on the Effects of Parent Education Programs for Parents with Young and School-age Children through Meta-Analysis (메타분석을 통한 유아기와 아동기 자녀 부모 대상 부모교육 프로그램의 효과 연구)

  • Chung, Kai Sook;Yoo, Mee Sook;Cha, Ji Ryang;Park, Hee Kyung
    • Korean Journal of Childcare and Education
    • /
    • v.9 no.3
    • /
    • pp.365-387
    • /
    • 2013
  • This study was to analyze the general trends and the effects of parent education programs in accordance with operating methods, contents, and goals by using meta-analysis. The subjects were the studies about the effects of education programs for parents who have young and school-aged children, 41 and 15 respectively. The results showed that the trends of the operating methods in both groups did not have many differences. Also, on the contents and goals of the programs, parenting related factor was treated the most in both groups. Second, the overall effects of the parent education programs were higher on those for parents with school-aged children than parents with young children. -When parents together, not separately, participated in program, the effect size was the largest. However, the effects of other operating methods factors like number of subjects, hours per session, and number of sessions showed inconsistent results. On the effects of contents and goals, the effect of self-system competency factor as psychological characteristics was the highest in the programs for parents with young children and the effect of parenting competency factor was the highest for the ones with school-aged children. This study has implications for providing basic data for developing effective programs for parents with young and school-aged children.

Ultrastrutures of Some Selected Digestive Organs of Two Korean Freshwater Snails (한국산 담수 복족류 2종의 소화기관에 관한 전자현미경적 연구)

  • 정계헌;이훈섭;박종안
    • The Korean Journal of Malacology
    • /
    • v.9 no.1
    • /
    • pp.1-16
    • /
    • 1993
  • 한국의 담수에 광범위하게 서식하고 있으면서 역학적으로 중요한 역할을 하고 있는 두 종의 복족류 즉 쇠우렁이(Parafossarulus manchouricus)와 물달팽이(Radix auricularia coreana)의 소화기관 중에서 식도, 소화선 및 장에 대한 미세구조 관찰을 시도하였다. 이 부위들은 간흡충(간디스토마)과간질(소간디스토마)의 유생들이 그들의 생활사 중 거쳐가는 곳으로 알려진 소화관들이어서 이후 흡충류의 유충들이 위의 소화관에 주는 영향을 연구하는데 필요한 기초자료를 얻고자 수행된 것이었다. 관찰해 본 결과 다음과 같은 결론을 얻을 수 있었다. 식도의 상피조직은 두 종류에서 공히 원주세포와 원주섬모세포 및 점액분비 세포로 이루어져 있었다. 식도강상피 내에서도 어느 정도의 흡수와 소화가 이루어 지고 있음은 특이한 현상이라 하겠다. 소화선은 두 종에서 공히 복분지 관상선으로서 그 상피는 micovilli를 선강 또는 도관에 연한 유리표면에 가지고 있어 brush boredr을 이루고 있는 원주세포과 원주섬모세포로 구성되어 있었다. 이들 세포들의 내부 구조로 보아 소화세포와 배석세포로 구분할 수 있었다. 장의 상피는 원주세포와 원주섬모세포로 구성되어 있었으며 이들도 장강에 연한 유리표면에는 brush border를 이루고 있었다. 흡수와 분비기능이 활발한 것으로 사료된다. 전반적으로 보아 본 연구에서 관찰한 두 복족류의 소화관은 모든 부위에서 세포의 유리표면에 microvilli를 가지고 있어 물질의 흡수기능을 가지고 있음을 시사해주고 있었고, 이들 세포 중에는 때로 밀집한 cilia를 가지고 있어 소화관 내의 액체물질이나 이에 내포된 미세입자들의 유동을 도와주고 있음을 추측할 수 있었다.)은 결합조직으로 이루어진 근육질의 두꺼운 벽을 가지고 있었으며 내강은 돌출부위에 의해 4부분으로 갈라져 있었다. 내강에 연한 상피는 원주세포로 되어 있었다. 상음경(epiphallus)의 벽은 근섬유 다발은 벽의 외곽으로 갈수록 밀도가 높아졌다. 상부에 내강과 연결되는 함입구조(groove)를 가지며, 내강에 연한 상피는 섬모가 없는 원주세포로 이루어져 있었다. 음경(penis)은 근섬유가 산재된 두꺼운 벽을 가졌으며 상음경보다 굵은 원통형이었다. 내강은 많은 돌출부에 의해 복잡하게 나뉘어 있으며 상피세포는 원주 세포로 이루어져 있었고 섬모는 관찰되지 않았다. 내강 내의 분비물과 세포의 형태로 보아 내강상피세포는 분비기능을 가진 것으로 사료된다.술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.9%), 종격동기흉과 폐염이 병발한 경우와 폐염이 각

  • PDF

Effects of Biomedical Ethics Education on Moral sensitivity, Critical thinking and Biomedical ethics Awareness of Nursing Students (생명의료 윤리교육이 간호학생의 도덕적 민감성, 비판적 사고성향, 생명의료 윤리의식에 미치는 효과)

  • Kim, Kyung-Ah;Jeong, Gye-Seon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.20 no.2
    • /
    • pp.240-249
    • /
    • 2019
  • The purpose of this study was to find the effect of systemic biomedical ethics education program on moral sensitivity, critical thinking disposition and consciousness of biomedical ethics nursing student. This study is a quasi-experimental research design and repeated measured ANOVA was used to analyzed the collected data statistically on this study. Data was collected from 1st September to 31 of December 2014. Nursing students and nurses in A and S cities participated in this study as subjects. 32 nursing students were assigned to an experimental group, and 33 nursing students were assigned to control group A, 26 nurses were assigned control group B, total subjects were 91. There are significant different in consciousness of biomedical ethics(F=3.432, p=.037). In the category of consciousness of biomedical ethics, there are significant different in 'right to life of fetus'(F=4.476, p=.014) and 'prenatal diagnosis of fetus'(F=6.207, p=.003), and 'right to life of newborn(F=6.207, p=.003) between experimental group and two control groups. The biomedical ethics education influenced the positive effect on moral sensitivity, critical thinking disposition and consciousness of biomedical ethics of nursing students, and shown the significant effect to enhance the consciousness of biomedical ethics for nursing students.

Monocentric Derivative Y Chromosome with Duplication of the SRY Gene in an Azoospermic Male (무정자증 불임남성에서 관찰된 SRY 유전자의 중복을 동반한 일동원체성 derivative Y 염색체)

  • Choi, Eun-Young;Lee, Bom-Yi;Park, Ju-Yeon;Lee, Yeon-Woo;Oh, Ah-Rum;Lee, Shin-Young;Kim, Shin-Young;Han, You-Jung;Lee, Mee-Bum;Ryu, Hyun-Mee;Seo, Ju-Tae;Park, So-Yeon
    • Journal of Genetic Medicine
    • /
    • v.7 no.2
    • /
    • pp.160-164
    • /
    • 2010
  • Structural abnormalities of the Y chromosome affect normal testicular differentiation and spermatogenesis. The present case showed a rare monocentric derivative Y chromosome with partial duplication of Yp including the SRY gene and deletion of Yq12 heterochromatin. The karyotype was 46,X,der(Y)(pter${\rightarrow}$q11.23::p11.2${\rightarrow}$pter).ish der(Y)(DYZ3+,DYZ1-,SRY++), confirmed through a FISH study. Even though the patient possessed an abnormal Y chromosome, testicular biopsy showed normal testicular volumes in the proband, with gonadal hormonal levels in the normal range but bilateral varicocele and hypospermatogenesis. We speculate that the abnormal Y chromosome arose from sister chromatids during Y chromosome recombination or intra chromosomal NAHR (non-allelic homologous recombination) during meiosis in the patient's father or in the very early stages of embryogenesis. The derivative Y chromosome might interfere in the meiotic stage of spermatogenesis, leading to the developmental arrest of germ cells. The present case illustrates that the infertility phenotype can have various causes. Also, it emphasizes the importance of accurate and various genetic analyses and could aid in male infertility treatment.

Differential Cytotoxicity of Penta-O-galloyl-β-D-glucose in Human Cancer and Normal Cell Lines of Various Origins (사람의 다양한 조직에서 기원하는 암세포 및 정상세포에 대한 penta-O-galloyl-β-D-glucose의 세포독성 효과)

  • Lee, Hyeon-Jeong;Kim, Min-Gyeong;Lee, Song-Yeong;Song, Min-Hyock;Kim, Yoon-Dong;Ha, Jeong-Sook;Jeong, Gie-Joon;Rho, Gyu-Jin;Jeon, Byeong-Gyun
    • Journal of Life Science
    • /
    • v.26 no.11
    • /
    • pp.1320-1329
    • /
    • 2016
  • The present study examined the cytotoxic effects of 1, 2, 3, 4, 6-penta-O-galloyl-${\beta}$-D-glucose (PGG), known as the pentahydroxy gallic acid ester of glucose, in the various human cancer cell lines (A-549, MDA-MB-231, U87-MG, MCF-7 and PANC-1), normal MRC-5 fetal fibroblasts, and dental papilla tissue- derived mesenchymal stem cells (DPSCs). Significantly (p<0.05) lower half maximal inhibitory concentration ($IC_{50}$) values were observed in the A-549 and MDA-MB-231 cells showing a high proliferation capacity, compared with other cancer and normal cell lines with a relatively low proliferation capacity. The population doubling time (PDT) was significantly (p<0.05) higher in the $10{\mu}M$ PGG-treated cell lines than those of untreated control cell lines. The present study demonstrated that the $IC_{50}$ value increases proportionally to the extending PDT. A high cell number with senescence-associated ${\beta}-galactosidase$ activity was also observed in the $10{\mu}M$ PGG-treated cells compared with those of untreated control cells. Moreover, the level of telomerase activity was significantly (p<0.05) decreased with $10{\mu}M$ PGG treatment, especially in A-549 and MDA-MB-231 cells showing a high proliferation capacity. Based on these observations, PGG could serve as a potent agent for cancer chemotherapy, as its treatment was more effective in cells with a high proliferation capacity.

Beam Shaping by Independent Jaw Closure in Steveotactic Radiotherapy (정위방사선치료 시 독립턱 부분폐쇄를 이용하는 선량분포개선 방법)

  • Ahn Yong Chan;Cho Byung Chul;Choi Dong Rock;Kim Dae Yong;Huh Seung Jae;Oh Do Hoon;Bae Hoonsik;Yeo In Hwan;Ko Young Eun
    • Radiation Oncology Journal
    • /
    • v.18 no.2
    • /
    • pp.150-156
    • /
    • 2000
  • Purpose : Stereotactic radiation therapy (SRT) can deliver highly focused radiation to a small and spherical target lesion with very high degree of mechanical accuracy. For non-spherical and large lesions, however, inclusion of the neighboring normal structures within the high dose radiation volume is inevitable in SRT This is to report the beam shaping using the partial closure of the independent jaw in SRT and the verification of dose calculation and the dose display using a home-made soft ware. Materials and Methods : Authors adopted the idea to partially close one or more independent collimator jaw(5) in addition to the circular collimator cones to shield the neighboring normal structures while keeping the target lesion within the radiation beam field at all angles along the arc trajectory. The output factors (OF's) and the tissue-maximum ratios (TMR's) were measured using the micro ion chamber in the water phantom dosimetry system, and were compared with the theoretical calculations. A film dosimetry procedure was peformed to obtain the depth dose profiles at 5 cm, and they were also compared with the theoretical calculations, where the radiation dose would depend on the actual area of irradiation. Authors incorporated this algorithm into the home-made SRT software for the isodose calculation and display, and was tried on an example case with single brain metastasis. The dose-volume histograms (DVH's) of the planning target volume (PTV) and the normal brain derived by the control plan were reciprocally compared with those derived by the plan using the same arc arrangement plus the independent collimator jaw closure. Results : When using 5.0 cm diameter collimator, the measurements of the OF's and the TMR's with one independent jaw set at 30 mm (unblocked), 15.5 mm, 8.6 mm, and 0 mm from th central beam axis showed good correlation to the theoretical calculation within 0.5% and 0.3% error range. The dose profiles at 5 cm depth obtained by the film dosimetry also showed very good correlation to the theoretical calculations. The isodose profiles obtained on the home-made software demonstrated a slightly more conformal dose distribution around the target lesion by using the independent jaw closure, where the DVH's of the PTV were almost equivalent on the two plans, while the DVH's for the normal brain showed that less volume of the normal brain receiving high radiation dose by using this modification than the control plan employing the circular collimator cone only. Conclusions : With the beam shaping modification using the independent jaw closure, authors have realized wider clinical application of SRT with more conformal dose planning. Authors believe that SRT, with beam shaping ideas and efforts, should no longer be limited to the small spherical lesions, but be more widely applied to rather irregularly shaped tumors in the intracranial and the head and neck regions.

  • PDF

Spectral Response of $TiO_{2}$/Se : Te Heterojunction for Color Sensor (컬러센서를 위한 $TiO_{2}$/Se : Te 이종접합의 스펙트럼 응답)

  • Woo, Jung-Ok;Park, Wug-Dong;Kim, Ki-Wan;Lee, Wu-Il
    • Journal of Sensor Science and Technology
    • /
    • v.2 no.1
    • /
    • pp.101-108
    • /
    • 1993
  • $TiO_{2}$/Se : Te heterojunction for color sensor has been fabricated by RF reactive sputtering and thermal evaporation methods onto glass substrate. The optimum deposition condition of $TiO_{2}$ films was such that RF power was 120 W, substrate temperature was $100^{\circ}C$, oxygen concentration was 50%, working pressure was 50 mTorr for the $TiO_{2}$ film thickness of $1000{\AA}$. In this case, the optical transmittance of $TiO_{2}$ film at 550 nm-wavelength was 85%, resistivity was $2{\times}10^9{\Omega}{\cdot}cm$, refractive index was 2.3, and optical bandgap was 3.58 eV. The composition ratio of 0 to Ti by AES analysis was 1.7. When $TiO_{2}$ films were annealed at $400^{\circ}C$ for 30 min. in $O_{2}$ ambient, the optical transmittance of $TiO_{2}$ films at the wavelength range of $300{\sim}580$ nm was improved from 0 to 25%. When Se : Te films were annealed at $190^{\circ}C$ for 1 min., photosensitivity under illumination of 1000 lux was 0.75. The optical bandgap of Se : Te films was 1.7 eV. The structures of Se : Te films were the hexagonal with (100) and (110) orientation. The spectral response of a-Se was improved by the addition of Te, especially in the long wavelength region. The $TiO_{2}$/Se : Te heterojunction showed wide spectral response, and more improved one than that of a-Si film in the blue light region.

  • PDF

Comparative Compressional Behavior of Zeolite-W in Different Pressure-transmitting Media (제올라이트-W의 압력전달매개체에 따른 체적탄성률 비교 연구)

  • Seoung, Donghoon;Kim, Hyeonsu;Kim, Pyosang;Lee, Yongmoon
    • Korean Journal of Mineralogy and Petrology
    • /
    • v.34 no.3
    • /
    • pp.169-176
    • /
    • 2021
  • This study aimed to fundamentally understand structural changes of zeolite under pressure and in the presence of different pressure-transmitting media (PTM) for application studies such as immobilization of heavy metal cation or CO2 storage using pressure. High-pressure X-ray powder diffraction study was conducted on the zeolite-W (K6.4Al6.5Si25.8O64× 15.3H2O, K-MER) to understand linear compressibility and the bulk moduli in different PTM conditions. Zeolite-w is a synthetic material having the same framework as natural zeolite merlinoite ((K, Ca0.5, Ba0.5, Na)10 Al10Si22O64× 22H2O). The space group of the sample was identified as I4/mmm belonging to the tetragonal crystal system. Water, carbon dioxide, and silicone-oil were used as pressure-transmitting media. The mixture of sample and each PTM was mounted in a diamond anvil cell (DAC) and then pressurized up to 3 GPa with an increment of ca. 0.5 GPa. Pressure-induced changes of powder diffraction patterns were measured using a synchrotron X-ray light source. Lattice constants, and bulk moduli were calculated using the Le-Bail method and the Birch-Murnaghan equation. In all PTM conditions, linear compressibility of c-axis (𝛽c) was 0.006(1) GPa-1 or 0.007(1) GPa-1. On the other hand, the linear compressibility of a(b)-axis (𝛽a) was 0.013(1) GPa-1 in silicone-oil run, which is twice more compressible than the a(b)-axis in water and carbon dioxide runs, 𝛽a = 0.006(1) GPa-1. The bulk moduli were measured as 50(3) GPa, 52(3) GPa, and 29(2) GPa in water, carbon dioxide, and silicone-oil run, respectively. The orthorhombicities of ac-plane in the water, and carbon dioxide runs were comparatively constant, near 0.350~0.353, whereas the value decreased abruptly in the silicone-oil run following formula, y = -0.005(1)x + 0.351(1) by non-penetrating pressure fluid condition.