• Title/Summary/Keyword: University 2.0

Search Result 109,947, Processing Time 0.101 seconds

Crystal Structure Changes of LiNi0.5Co0.2Mn0.3O2 Cathode Materials During the First Charge Investigated by in situ XRD

  • Lee, Sang-Woo;Jang, Dong-Hyuk;Yoon, Jeong-Bae;Cho, Yong-Hun;Lee, Yun-Sung;Kim, Do-Hoon;Kim, Woo-Seong;Yoon, Won-Sub
    • Journal of Electrochemical Science and Technology
    • /
    • v.3 no.1
    • /
    • pp.29-34
    • /
    • 2012
  • The structural changes of $Li_{1-x}Ni_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode material for lithium ion battery during the first charge was investigated in comparison with $Li_{1-x}Ni_{0.8}Co_{0.15}Al_{0.05}O_2$ using a synchrotron based in situ X-ray diffraction technique. The structural changes of these two cathode materials show similar trend during first charge: an expansion along the c-axis of the unit cell with contractions along the a- and b-axis during the early stage of charge and a major contraction along the c-axis with slight expansions along the a- and b-axis near the end of charge at high voltage limit. In $Li_{1-x}Ni_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode, however, the initial unit cell volume of H2 phase is bigger than that of H1 phase since the c-axis undergo large expansion while a- and b- axis shrink slightly. The change in the unit cell volume for $Li_{1-x}Ni_{0.5}Co_{0.2}Mn_{0.3}O_2$ during charge is smaller than that of $Li_{1-x}Ni_{0.8}Co_{0.15}Al_{0.05}O_2$. This smaller change in unit cell volume may give the $Li_{1-x}Ni_{0.5}Co_{0.2}Mn_{0.3}O_2$ cathode material a better structural reversibility for a long cycling life.

Ce0.8Sm0.2O2 Sol-gel Modification on La0.8Sr0.2Mn0.8Cu0.2O3 Cathode for Intermediate Temperature Solid Oxide Fuel Cell

  • Lee, Seung Jin;Kang, Choon-Hyoung;Chung, Chang-Bock;Yun, Jeong Woo
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.22 no.4
    • /
    • pp.77-82
    • /
    • 2015
  • To increase the performance of solid oxide fuel cell operating at intermediate temperature ($600^{\circ}C{\sim}800^{\circ}C$), $Sm_{0.2}Ce_{0.8}O_2$ (SDC) thin layer was applied to the $La_{0.8}Sr_{0.2}Mn_{0.8}Cu_{0.2}O_3$ (LSMCu) cathode by sol-gel coating method. The SDC was employed as a diffusion barrier layer on the yttria-stabilized zirconia(YSZ) to prevent the interlayer by-product formation of $SrZrO_3$ or $La_2Zr_2O_7$. The by-products were hardly formed at the electrolyte-cathode interlayer resulting to reduce the cathode polarization resistance. Moreover, SDC thin film was coated on the cathode pore wall surface to extend the triple phase boundary (TPB) area.

A Study on the State of the Service-based Library 2.0 Through Web Site Analysis of Korean University Libraries (대학도서관 웹사이트 분석을 통한 도서관 2.0 기반 서비스 운영실태 분석)

  • Noh, Dong-Jo;Min, Sook-Hee
    • Journal of Information Management
    • /
    • v.42 no.4
    • /
    • pp.195-223
    • /
    • 2011
  • The purpose of this study is to determine the progress of the implementation of the Servicebased Library 2.0 in Korean university libraries. We assess the Service-based Library 2.0 based on the web site analysis of 179 different Korean university libraries. Highlights of our survey include: (1) The most accessed features of the Service-based Library 2.0, were the 'Book Review', 'RSS', 'Tag & Tagging', 'Mobile App', 'Facet' and 'Open API'. (2) Among 179 libraries, of the 16 different services offered by the Service-based Library 2.0, 145 libraries opted for 4 or fewer services offered through the Service, 3 libraries opted for 5-9 services and 3 libraries availed themselves of 10 or more services. (3) More national university libraries than private libraries are implementing Service-based Library 2.0, including such services as 'Book Review', 'RSS', 'Mobile App', 'Facet', 'Blog', 'Twitter', 'Personnel service', 'SMS', 'Facebook'.

Distribution of Microorganisms and Physico-Chemical Characteristics in the Chagwi-Do Coastal Waters, Jeju Island (제주 차귀도 연안해역 미생물 분포 및 이화학적 특성)

  • Moon Young-Gun;Kim Man-Chul;Lee Joon-Baek;Song Choon-Bok;Yeo In-Kyu;Kim Jong-Man;Park Guen-Tae;Son Hong-Joo;Choi Woo-Bong;Heo Moon-Soo
    • Journal of Environmental Science International
    • /
    • v.15 no.3
    • /
    • pp.271-278
    • /
    • 2006
  • To investigate the variations of physico-chemical factors and microbial population, in ten stations at water region of coastal area of Chagwi-Do, Nutritive salts, water temperature, transparency, suspended solid, salinity, COD, DO, pH, heterotrophic bacteria, coliform group and Vibrio spp. were analysed three times in September, November in 2004 and February in 2005. Heterotrophic bacteria in surface water was $3.5X10^1{\sim}1.16X10^3cfu/ml,\;1.0X10^2{\sim}5.2X10^1cfu/ml\;2.0X10^1{\sim}7.6X10^1cfu/ml$ and bottom water counted $7.0X10^2{\sim}1.0X10^3cfu/ml,\;1.4X10^1{\sim}2.5X10^2cfu/ml\;2.0X10^2{\sim}4.2X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively. The cell number of total coliform bacteria in the surface water amounted to $0{\sim}4.3X10^2cfu/ml,\;0{\sim}6.0X10^1cfu/ml,\;0{\sim}1.0X10^1cfu/ml$ and bottom water amounted $0{\sim}2.2X10^2cfu/ml,\;0{\sim}5.4X0^2cfu/ml,\;0{\sim}2.0X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively. As for Vibrio spp., the cell number in the surface water was $1.0X10^1{\sim}2.5X10^2cfu/ml,\;1.0X10^1{\sim}2.0X10^1cfu/ml,\;0cfu/ml$ and bottom water counted $1.0X10^1{\sim}5.2X10^2cfu/ml,\;0cfu/ml,\;2.0X10^1cfu/ml$ in September, November in 2004 and February in 2005, respectively.

The Study of the Fabrication and Characteristics of $n-CdS_{0.46}Se_{0.54}/p-Cu_{2-X}S_{0.46}Se_{0.54}$ heterojunction Solar Cells ($n-CdS_{0.46}Se_{0.54}/p-Cu_{2-X}S_{0.46}Se_{0.54}$ 이종접합 태양전지의 제작과 그 특성에 관한 연구)

  • You, Sang-Ha;Choi, Seung-Pyung;Lee, Sang-Youl;Hong, Kwang-Joon;Suh, Sang-Suhg;Kim, Hye-Suk;Jeon, Seung-Yong;Yun, Eun-Hee;Moon, Jong-Dae;Shin, Yeong-Jin;Jeong, Tae-Soo;Shin, Hyun-Keel;Kim, Tack-Sung;Rheu, Kee-Soo
    • Solar Energy
    • /
    • v.13 no.1
    • /
    • pp.49-58
    • /
    • 1993
  • [ $CdS_{0.46}Se_{0.54}$ ] single crystal was grown by a sublimation method. The crystal structure and the temperature dependence of carrier density and mobility of $CdS_{0.46}Se_{0.54}$ single crystal were studied. Heterojunction solar cells of $n-CdS_{0.46}Se_{0.54}/p-Cu_{2-X}S_{0.46}Se_{0.54}$ were fabricated by the substitution reaction. The spectral response, the J-V characteristics and the conversion efficiency of the $n-CdS_{0.46}Se_{0.54}/p-Cu_{2-X}S_{0.46}Se_{0.54}$ heterojunction solar cells were studied. The open-circuit voltage, short-circuit density, fill factor and conversion efficiency of $n-CdS_{0.46}Se_{0.54}/p-Cu_{2-X}S_{0.46}Se_{0.54}$ heterojunction solar cells under $80mW/cm^2$ illumination were found to be 0.48V, $21mA/cm^2$, 0.75 and 9.5%, respectively.

  • PDF

Structures and Electrochemical Properties of LiNi0.5-xCo2x}Mn0.5-xO2 as Cathode Materials for Lithium-ion Batteries

  • Choi, Hyun-Chul;Kim, Ho-Jin;Jeong, Yeon-Uk;Jeong, Soo-Hwan;Cheong, In-Woo;Jung, Uoo-Chang
    • Bulletin of the Korean Chemical Society
    • /
    • v.30 no.11
    • /
    • pp.2603-2607
    • /
    • 2009
  • $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$ (x = 0, 0.1, 1/6, 1.2, 0.3) were synthesized by the solid-state reaction method. The crystal structure was analyzed by X-ray powder diffraction and Rietveld refinement. $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$ samples give single phases of hexagonal layered structures with a space group of R-3m for x = 0.1, 1/6, 0.2, and 0.3. The lattice constants of a and c-axis were decreased with the increase in Co contents in samples. The thickness of MO2 slab was decreased and inter-slab distance was increased with the increase in Co contents in $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$. According to XPS analysis, the valence states of Mn, Co, and Ni in the sample are mainly +4, +3, and +3, respectively. The discharge capacity of 202 mAh/g at 0.1C-rate in the potential range of 4.7 - 3.0 V was obtained in $LiNi_{0.3}Co_{0.4}Mn_{0.3}O_2$ sample, and $LiNi_{0.4}Co_{0.2}Mn_{0.4}O_2$ gives excellent cycle performance in the same potential range.

Synthesis of Cobalt Oxide Free Black Color Spinel Pigment (CoO가 첨가되지 않은 스피넬계 흑색안료의 합성)

  • Kim, Jun-Ho;Lee, Seong-Ho;Suh, Man-Chul;Lee, Byung-Ha
    • Journal of the Korean Ceramic Society
    • /
    • v.44 no.11
    • /
    • pp.639-644
    • /
    • 2007
  • Spinel pigments, developing black color in high temperature glazes at oxidation or reduction atmosphere, without CoO because of its high price were synthesized by solid solution method. Ten mixed compositions consisted of NiO, MnO, $Fe_2O_3 and $Mn_2O_3$ were fired at $1250^{\circ}C$ for 1h. The resulting pigments were characterized by using XRD, FT-IR, SEM and UV-vis spectrometer. Structure of the pigments are spinel and particles' shape are spherical or cubic. Glazed tiles containing 5 wt% pigments were fired at $1260^{\circ}C$ and $1240^{\circ}C$ in reduction atmosphere. Color in glazes were analyzed by UV-vis spectrometer. Colors of NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole% in lime glaze showed black in oxidation, in reduction NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0125 mole% and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.55{\cdot}Mn_2O_3$ 0.0125 mole% showed black. In case of lime-barium glaze, NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.975 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black color in oxidation and NiO 0.875 MnO $0.125{\cdot}Fe_2O_3$ $0.3875{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.1125 mole%, NiO 0.925 MnO $0.075{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% and NiO 0.725 MnO $0.275{\cdot}Fe_2O_3$ $0.4375{\cdot}Cr_2O_3$ $0.50{\cdot}Mn_2O_3$ 0.0625 mole% showed black one in reduction.

Increased Serum Endoglin and Transforming Growth Factor β1 mRNA Expression and Risk of Hepatocellular Carcinoma in Cirrhotic Egyptian Patients

  • Teama, Salwa;Fawzy, Amal;Teama, Shirin;Helal, Amany;Drwish, Amira Diyaa;Elbaz, Tamer;Desouky, Eman
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.5
    • /
    • pp.2429-2434
    • /
    • 2016
  • Transforming growth factor-B1 ($TGF-{\beta}1$ )and its coreceptor endoglin (ENG) have been shown to contribute to hepatocellular tumor development and malignant progression. Our aim was to evaluate the serum expression levels of $ENG/TGF-{\beta}1$ mRNAs and risk of hepatocellular carcinoma in cirrhotic Egyptian patients. Our study included 77 subjects. Real time polymerase chain reaction was used to evaluate the expression level of ENG and $TGF-{\beta}1$mRNAs. The relative expression ratio of ENG mRNA was 0.82 (0.1 -3.2), 0.66 (0.15-5.3), 0.38(0.007-2.8) and 0.12 (0.00-0.22) and the relative expression ratio of $TGF-{\beta}1$mRNA was 1.4 (0.19 -6.2), 1.2 (0.22-4.3), 1.0 (0.15-4.4) and 0.6 (0.00-2.2) for cirrhotic HCC cirrhotic, HCC only and healthy control groups respectively. Increased ENG and $TGF-{\beta}1$ mRNA gene expression was correlated with TNM clinical stage. The expression ratio in TNM stage III-IV 1.1 (0.07-3.2), 1.55 (0.15-6.2) was statistically significantly higher than that in stage I-II 0.47 (0.007-2.8), 1.0 (0.31-4.4) (P<0.05). Our data suggested that increased ENG and $TGF-{\beta}1$ gene expression may participate in hepatocarcinogenesis and increased risk of HCC in individuals with cirrhosis. Early screening for evidence of cirrhosis and consideration of ENG and $TGF-{\beta}1$ as targets for therapy and treatment strategies are warranted.

Effects of Phytezyme Supplementation on the Growth Performance and Nutrient Digestibility in Growing Pigs

  • Hong, J.W.;Kim, I.H.;Kwon, O.S.;Lee, S.H.;Bae, H.D.;Kang, S.J.;Yang, U.M.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.10
    • /
    • pp.1440-1443
    • /
    • 2001
  • Forty eight $Duroc{\times}Yorkshire{\times}Landrace$ pigs ($15.2{\pm}0.3kg$ average initial BW) were used conducted to evaluate the effects dietary phytase (Phytezyme, WOOJIN, Co. Ltd) supplementation on the growth performance and nutrient digestibility in growing pigs. There were three pigs per pen and four pens per treatment. Treatments were 1) Con (corn-wheat-SBM), 2) PE0.1 (low-P iet+0.1% Phytezyme), 3) PE0.2 (Iow-P diet+0.2% Phytezyme), 4) PE0.3 (low-P diet+0.3% Phytezyme). During d 0 to 28, average daily gain was not significantly different among the treatments. Pigs fed PE0.3 diet significantly decreased (p<0.05) their average daily feed intake compared to pigs fed Con diet. Also, gain/feed in pigs fed PE0.1 and PE0.3 diet was improved (p<0.05) compared to pigs fed Con and PE0.2 diet (p<0.05). For d 28 to 56, pigs fed PE0.2 diet grew significantly faster (p<0.05) than pigs fed Con and PE0.1 diet. Gain/feed was greater (p<0.05) for PE0.2 and PE0.3 treatments than for Con. For overall period, average daily gain was increased (P<0.05) by the addition of 0.2% Phytezyme compared with Con. Gain/feed was significantly improved (p<0.05) by supplementation of PE0.3. Pigs fed PE0.2 showed increased DM and N digestibilities compared to pigs fed other treatments. Supplemented diets PE0.2 and PE0.3 improved (p<0.05) the apparent digestibility of Ca and P compared to other treatments. In conclusion, the results obtained from these feeding trials suggest that the Phytezyme supplementation of diets for growing-finishing pigs had improved growth performance and nutrient availability.

A New Method for Aortic Valve Planimetry with High-Resolution 3-Dimensional MRI and Its Comparison with Conventional Cine MRI and Echocardiography for Assessing the Severity of Aortic Valvular Stenosis

  • Hae Jin Kim;Yeon Hyeon Choe;Sung Mok Kim;Eun Kyung Kim;Mirae Lee;Sung-Ji Park;Joonghyun Ahn;Keumhee C. Carriere
    • Korean Journal of Radiology
    • /
    • v.22 no.8
    • /
    • pp.1266-1278
    • /
    • 2021
  • Objective: We aimed to compare the aortic valve area (AVA) calculated using fast high-resolution three-dimensional (3D) magnetic resonance (MR) image acquisition with that of the conventional two-dimensional (2D) cine MR technique. Materials and Methods: We included 139 consecutive patients (mean age ± standard deviation [SD], 68.5 ± 9.4 years) with aortic valvular stenosis (AS) and 21 asymptomatic controls (52.3 ± 14.2 years). High-resolution T2-prepared 3D steady-state free precession (SSFP) images (2.0 mm slice thickness, 10 contiguous slices) for 3D planimetry (3DP) were acquired with a single breath hold during mid-systole. 2D SSFP cine MR images (6.0 mm slice thickness) for 2D planimetry (2DP) were also obtained at three aortic valve levels. The calculations for the effective AVA based on the MR images were compared with the transthoracic echocardiographic (TTE) measurements using the continuity equation. Results: The mean AVA ± SD derived by 3DP, 2DP, and TTE in the AS group were 0.81 ± 0.26 cm2, 0.82 ± 0.34 cm2, and 0.80 ± 0.26 cm2, respectively (p = 0.366). The intra-observer agreement was higher for 3DP than 2DP in one observer: intraclass correlation coefficient (ICC) of 0.95 (95% confidence interval [CI], 0.94-0.97) and 0.87 (95% CI, 0.82-0.91), respectively, for observer 1 and 0.97 (95% CI, 0.96-0.98) and 0.98 (95% CI, 0.97-0.99), respectively, for observer 2. Inter-observer agreement was similar between 3DP and 2DP, with the ICC of 0.92 (95% CI, 0.89-0.94) and 0.91 (95% CI, 0.88-0.93), respectively. 3DP-derived AVA showed a slightly higher agreement with AVA measured by TTE than the 2DP-derived AVA, with the ICC of 0.87 (95% CI, 0.82-0.91) vs. 0.85 (95% CI, 0.79-0.89). Conclusion: High-resolution 3D MR image acquisition, with single-breath-hold SSFP sequences, gave AVA measurement with low observer variability that correlated highly with those obtained by TTE.