• Title/Summary/Keyword: region contrast

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Study on the eletronic absorption and surface morphology of phthalocyanine double layer thin films

  • Heo, Il-Su;Ryu, Il-Hwan;Hong, Da-Jeong;Im, Sang-Gyu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.337-337
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    • 2011
  • The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

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In Situ Scanning Tunneling Microscope of Cyanide and Thiocyanate Adsorption on Pt(111)

  • Yau, Shueh-Lin;Kim, Youn-Geun;Itaya, Kingo
    • Analytical Science and Technology
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    • v.8 no.4
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    • pp.723-730
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    • 1995
  • Cyclic voltammetry and in situ STM were employed to examine the interfacial structures of a Pt(111) electrode in 0.1 mM KCN (pH9.5) and 0.1 mM KSCN (pH7) solutions. In situ STM atomic resolution revealed well ordered (2${\surd}$3${\times}$2${\surd}$3)$R30^{\circ}$-6CN and ($2{\times}2$)-2SCN structures within the double layer charging region. Six CN adsorbates formed a hollow hexagon, which embraced a coadsorbed $K^+$ cation. In contrast, the coadsorbed $K^+$ cations on the SCN covered Pt(111) were poorly ordered, despite adsorbed SCN formed a long range ordered ($2{\times}2$)-2SCN adlattice. In situ STM revealed the pronounced influence of potential in controlling the structures of compact layers at the proximity of a Pt electrode. Cathodic polarization facilitated the replacement of the coadsorbed cations by protons.

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Analysis of protein-protein interaction network based on transcriptome profiling of ovine granulosa cells identifies candidate genes in cyclic recruitment of ovarian follicles

  • Talebi, Reza;Ahmadi, Ahmad;Afraz, Fazlollah
    • Journal of Animal Science and Technology
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    • v.60 no.6
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    • pp.11.1-11.7
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    • 2018
  • After pubertal, cohort of small antral follicles enters to gonadotrophin-sensitive development, called recruited follicles. This study was aimed to identify candidate genes in follicular cyclic recruitment via analysis of protein-protein interaction (PPI) network. Differentially expressed genes (DEGs) in ovine granulosa cells of small antral follicles between follicular and luteal phases were accumulated among gene/protein symbols of the Ensembl annotation. Following directed graphs, PTPN6 and FYN have the highest indegree and outdegree, respectively. Since, these hubs being up-regulated in ovine granulosa cells of small antral follicles during the follicular phase, it represents an accumulation of blood immune cells in follicular phase in comparison with luteal phase. By contrast, the up-regulated hubs in the luteal phase including CDK1, INSRR and TOP2A which stimulated DNA replication and proliferation of granulosa cells, they known as candidate genes of the cyclic recruitment.

Probing the Starburst-AGN Connection in Type I AGN based on the 3.3 micron PAH lines

  • Woo, Jong-Hak;Kim, Ji-Hoon;Imanishi, Masatoshi
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.74.1-74.1
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    • 2011
  • To probe the connection between starburst and AGN activity, we investigate the relation between the 3.3 micron~PAH emission and AGN properties based on the new AKARI observations and the data collected from the literature. Using a sample of low-z Type I AGN, we measure the global 3.3 micron PAH luminosity from the AKARI slit-less spectroscopy. The 3.3 ${\backslash}$micron~PAH emissions are detected for 7 out of 26 target galaxies, but we find no strong correlation between the 3.3 ${\backslash}$micron~PAH emission and AGN luminosity, suggesting that global star formation may not be tightlyrelated with AGN activity. In contrast the to global star formation, the nuclear 3.3 micron~PAH emission luminosity, which are measured from ground-based long slit spectroscopy with a narrow slit, correlates with AGN luminosity. These results imply that starburst and AGN activity are directly connected at the nuclear region.

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Study of radiation exposure on human body using of Computed Tomography (전산화단층촬영 검사 시 인체에 미치는 방사선피폭선량 분석연구)

  • Seon, Jong-Ryoul;Yoo, Se-Jong
    • Journal of the Korea Safety Management & Science
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    • v.17 no.4
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    • pp.193-198
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    • 2015
  • This study analyzed the total number of 19,636 patients and radiation technologists, 11,433 of male and 8,203 of female by examined body parts, age, types of detectors, the using contrast enhancement and working condition of the technologists, regular staffs or rotation-duty staffs, based on the K-DOS program distributed by FDA with the DLP value of diagnostic evaluation. The result shows that the effective radiation dose was 0.7mSv~41.7mSv for each region and male patients had more radiation exposure than females. And the amount of exposure was also affected by the types and the method of detectors. Furthermore, the regular staffs took the role of helping the patient to get reduced amount of radiation exposure than rotation duty-staffs. Computed tomography (CT) use has increased dramatically over the past several decades. In this reason, to support the patients and the workers' health in the field, the hospitals should apply specialized regular working radiation technologist system and manufacturing companies of those CTs should develop low medical radiation exposure devices.

Discharge and Luminous Characteristics of Coplanar Type Xe Plasma Flat Lamp (면방전형 Xe 플라즈마 평판 램프의 방전 및 발광 특성)

  • Kim, Hyuk-Hwan;Lee, Won-Jong
    • Korean Journal of Materials Research
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    • v.21 no.10
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    • pp.532-541
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    • 2011
  • The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

Speckle Reduction in Near-field Image of Multimode Fiber with a Piezoelectric Transducer

  • Ha, Woo-Sung;Lee, Se-Jin;Oh, Kyung-Hwan;Jung, Yong-Min;Kim, Jun-Ki
    • Journal of the Optical Society of Korea
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    • v.12 no.3
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    • pp.126-130
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    • 2008
  • We propose and experimentally demonstrate an effective method to reduce near-field speckle noise at the output of a 50 ${\mu}m$ graded index multimode fiber using a short cylindrical piezoelectric transducer(PZT) vibrating in the radial direction. The fiber was coiled as tightly as possible around the mandrel of the PZT and a periodic stretching effect was caused by the radial oscillations of the actuator. The output of the optical fiber using the He-Ne laser source was intensively observed by a CCD camera. By counting all the pixels corresponding to relative intensity graded into 256 levels in the selected area and by calculating standard deviation and mean value of the intensity, we could measure the speckle contrast and vibration effect quantitatively with reduction ratio of pixels and line profile of the illuminated region. It was clearly observed that the characteristics of the speckle pattern in the vibration-on state were significantly improved over that of the vibration-off state due to time-averaged smoothing.

Colorectal Adenocarcinoma in a Dog (개에서 발생한 결장직장 선암종 1례)

  • Choi, Ho-Jung;An, Ji-Young;O, I-Se;Jeong, Seong-Mok;Park, Seong-Jun;Cho, Sung-Whan;Lee, Young-Won
    • Journal of Veterinary Clinics
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    • v.25 no.5
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    • pp.429-433
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    • 2008
  • An 8-year-old, female Pointer dog was presented with weight loss, hematochezia, and dyschezia. For the diagnosis, physical examination, complete blood counts, serum chemistry, radiography, ultrasonography, computed tomography, colonoscopy, cytology and histopathological examination were performed. The complete blood counts and serum biochemistry results were within the reference range. Ultrasonographic findings were presented with the thickened wall of the colon and rectum. Colonoscopy revealed irregular and ulcerated mucosal surface, mass and luminal narrowing of colorectal lesions. There were thickened wall and contrast enhancement of the lesion in colorectal region on the computed tomography. The cytologic examination suggested the adenocarcinoma. Postmortem histopathologic examination revealed adenocarcinoma. Based on these findings, the dog was diagnosed with annular colorectal adenocarcinoma.

Fabrication and Characteristics of Reflection Type InGaAs MQW SEED (반사형 InGaAs MQW SEED 소자의 제작 및 특성)

  • Kim, Sung-Woo;Park, Sung-Soo;Park, Jong-Cheol;Kim, Taek-Seung;Kwon, O-Dae;Kang, Bong-Koo
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1216-1219
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    • 1994
  • A reflection type SEED from LP-MOCVD grown InGaAs/GaAs ESQW structures, with 5% In fraction, has been fabricated and its basic characteristics were investigated. Its intrinsic region consists of 50 pairs of alternating $100{\AA}$ $In_{0.05}Ga_{0.95}As$ barrier and $100{\AA}$ GaAs layers. And a multilayer reflector stack of $Al_{0.12}Ga_{0.88}As(641{\AA})-/AlAs(774{\AA})$ was vertically integrated below the p-i-n structures. The device processing includes the mesa etching, insulator deposition, indium metallization, and thermal alloy for Ohmic contact. Photocurrent spectrum measurement showed the exciton absorption peak at 905nm and availability as a optical switching device. This device showed a contrast ratio of 2:1 by the reflectance spectrum measurement.

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Hydrodynamic Investigation of a Floating-type Monoleaflet Polymer Valve under Steady Flow Condition (정상유동에서 유동형 단엽폴리머 인공판막의 수력학적 성능평가)

  • 김준우;박복춘
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.49-60
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    • 1996
  • An experimental investigation was performed under steady flow condition to assess hydrodynamic performance of floating-type monoleaflet polymer valves (MLPV) withdifferent leaflet thickness. The St. Jude Medical valve (SJMV) was also used for comparison test. Pressure drops of MLPVS are larger than those for other types of polymer valves and mechanical valves. Furthermore, the thicker is the leaflet thickness of the polymer valve, the larger are the corresponding pressure drop. The velocity profiles for MLPs reveal a large reversed flow region downward to the valve position. The maximum wall shear stresses of MLPVS at a flow rate of $30{\ell}$/min are in the range 50-130 dyn/$cm^2$, and the corresponding maximum Reynolds shear stresses are in the range of 100-500 dyn/$cm^2$, respectively, which are beyond the allowable limit clinically. In contrast, floating-type monoleaflet polymer valves show better hydrodynamic performance in leakage volume. From the designing point of view, it may be concluded that the optimum thickness of leaflet for better hydrodynamic performance is one of the Important parameters.

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