• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.7
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• pp.172-180
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• 2019

In this study, the microstructure and gamma-ray shielding efficiency of CRT glass mortar specimen were evaluated with replacement ratio and material properties. The results show that as the replacement ratio of CRT waste glass increases, the volume of pores with diameters below 50 nm and above 400 nm is increased. Also, the half-value layer of CRT glass mortar decreased with the increasing of linear attenuation coefficient. In addition, compressive and flexural strength were reduced when CRT waste glass was replaced as the fine aggregate, but the mechanical performance of CRT mortar specimen could be obtained by substitution of the mineral admixture.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.2
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• pp.1-6
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• 1983

The reduction of threshold voltage and punchthrough voltage of short channel MOS transistors has been measured experimentally with silicon gate NMOS transistors. The effects of the gate oxide thickness and substrate doping concentration on the threshold voltage and punch-through voltage have also been measured with sample devices with boron implantation and gate oxide thickness of 50 nm and 70 nm. Hot electron emission has been measured by floating gate method for the samples with 3 ${\mu}{\textrm}{m}$ channel length. It has been concluded from this measurement that hot electron emission is not significant for the channel length of 3${\mu}{\textrm}{m}$.

• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.29-33
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• 2004

In this paper, we investigated the ultra-low temperature(<$150^{\circ}C$) polycrystalline silicon film on plastic substrate application using RF-magnetron sputtering and excimer laser annealing. Amorphous silicon films were deposited using Ar/He mixture gas at $120^{\circ}C$ and in-film argon concentration was less than 2%, which was measured to Rutherford Backscattering Spectrometry. At energy density 320mJ/$\textrm{cm}^2$, RMS roughness was 267$\AA$ and UV crystallinity was 62%. The grain size varies from 50nm to 100nm after excimer laser irradiation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.939-942
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• 2001

We fabricated Red Organic light-emitting devices(OLED). The Basic Device Structure is ITO/hole transfer layer, TPD(50nm)/red emitting layer, Alq3 doped with DCM2 or DCM2:rubrene(xnm)/electorn transfer layer, Alq3(50-xnm)/LiF(0.8nm)/Al(8nm) . The thickness of emitting layer(xnm) changed 5, 10, 20nm. we demonstrate red emitting OLED with dependent on the thickness and concentrators of Alq3 layer doped with DCM2 or co-doped with DCM2:ruberene. The Emission color and Brightness are changed with doping or co-doping condition, dopant concentarton. In the case of rubrene:DCM2 co-doped layer structure, the red color Purity and device efficiency is improved. The CIE index of rubrene co-doped OLED is x=0.67, y=0.31. By co-doping the Alq3 layer with DCM2, rubrene, EL efficiency improved from 0.38cd/A to 0.44cd/A in comparison whit DCM2 doped Alq3 layer.

• Korean Journal of Microbiology
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• v.30 no.6
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• pp.524-527
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• 1992

Synechococcus sp. cyanophage was isolated from Baekwoon reservoir located in KyonggiDo. The cyanophage was purified by employing ultrafiltration. differential centrifugation. and sucrose density gradient centrifugation. Electron microscopic observation indicated that the sizes of its isometric head and contractile tail are 89 nm and] II nm. respectively. which means that the isolated cyanophage is included in the group. Myoviridae. The cyanophage maintained the stability of more than 50 percent from $20^{\circ}C$ to $40^{\circ}C$ and from pH 5 to 8. and had the maximal infectivity at $30^{\circ}C$ and pH 9 implying its ecological significance.

• Journal of the Korean Ceramic Society
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• v.52 no.1
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• pp.72-76
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• 2015

150-nm-thick In-Zn-Tin-Oxide (IZTO) films were deposited by RF magnetron sputtering after a 10 to 50-nm-thick $SiO_2$ buffer layer was deposited by plasma enhanced chemical vapor deposition (PECVD) on polyethylene terephthalate (PET) substrates. The electrical, structural, and optical properties of the IZTO/$SiO_2$/PET films were analyzed with respect to the thickness of the $SiO_2$ buffer layer. The mechanical properties were outstanding at a $SiO_2$ thickness of 50 nm, with a resistivity of $1.45{\times}10^{-3}{\Omega}-cm$, carrier concentration of $8.84{\times}10^{20}/cm^3$, hall mobility of $4.88cm^2/Vs$, and average IZTO surface roughness of 12.64 nm. Also, the transmittances were higher than 80%, and the structure of the IZTO films were amorphous, regardless of the $SiO_2$ thickness. These results indicate that these films are suitable for use as a transparent conductive oxide for transparency display devices.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.5
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• pp.495-501
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• 2011

We present an experimental study of electrical discharge in nanoscale gaps. The discharge occurred between a cathode made of sharpened Pt-Ir wire and a gold-plated anode. Electric discharges were detected for electric potentials from 10 V to 80 V, and their gaps ranged from 50 nm to 800 nm. The spark signals indirectly showed spark phenomena such as discharges or shortages in the system. The sparks and discharges strongly depended on the electric potential (voltage) and the radius of the tips. For small gaps, the electrical discharge was random and strongly depended on the radius of the cathode tips.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.4
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• pp.1-6
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• 2012

This paper presents the extraction and analysis of small-signal parameters of tunneling field-effect transistors (TFETs) by using TCAD device simulation. The channel lengths ($L_G$) of the simulated devices varies from 50 nm to 100 nm. The parameter extraction for TFETs have been performed by quasi-static small-signal model of conventional MOSFETs. The small-signal parameters of TFETs with different channel lengths were extracted according to gate bias voltage. The $L_G$-dependency of the effective gate resistance, transconductance, source-drain conductance, and gate capacitance are different with those of conventional MOSFET. The $f_T$ of TFETs is inverely proportional not to $L_G{^2}$ but to $L_G$.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.780-783
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• 2002

We report very efficient white OLEDs consisting of a blue-emitting 4,4'bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl (${\alpha}$-NPD), a hole-blocking layer of 2,9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP) doped with red fluorescent dye of 4-dicyanomethylene-2-methyl-6-[2-(2,3,6,7-tetrahydro- 1H, 5H-benzo[i,j]quinolizin-8-yl) vinyl]-4H-pyran) (DCM2), and green-emitting tris(8-hydroxyquinoline) aluminum ($Alq_3$). The device with the structure of ITO/${\alpha}$-NPD (50 nm)/BCP:DCM2 (0.8 %, 4 nm)/$Alq_3$ (50 nm)/LiF (0.5 nm)/Al shows a white emission with the CIE coordinates (0.329, 0.333). The maximum luminance of 20,800 cd/$m^2$ is obtained at 15.4 V. The power efficiency is 2.6lm/W and the external quantum efficiency is 2.1 % at a luminance of 100 cd/$m^2$ at the bias voltage of 6 V.

• Korean Journal of Materials Research
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• v.13 no.9
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• pp.606-612
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• 2003

Surface and mechanical properties of thin films with submicron thickness was characterized by nanoindentation with Berkovich and Vickers tips, and scanning probe microscopy. Nanoindention was made in a depth range of 15 to 200 nm from the surface by applying tiny force in a range from 150 to $9,000 \mu$N. Stiffness, contact area, hardness, and elastic modulus were determined from the force-displacement curve obtained. Reliability was first tested by using fused quartz, a standard sample. Elastic modulus and hardness values of fused quartz measured were the same as those reported in the literature within two percent of error. Mechanical properties of ITO thin film were characterized in a depth range of 15∼200nm. As indentation depth increased, elastic modulus and hardness decreased by substrate effect. Ion beam deposited DLC thin films were indented in a depth range of 40∼50 nm. The results showed that the DLC thin film using benzene and bias voltage 0∼-50 V has elastic modulus and hardness value of 132 and 18 GPa respectively. Pure DLC thin films showed roughnesses lower than 0.25 nm, but silicon-added DLC thin films showed much higher roughness values, and the wavy surface morphology.