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Preparation of nanoparticles CuInSe2 absorber layer by a non-vacuum process of low cost cryogenic milling (저가의 cryogenic milling 비진공법을 이용한 나노입자 CuInSe2 광흡수층 제조)

  • Kim, Ki-Hyun;Park, Byung-Ok
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.2
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    • pp.108-113
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    • 2013
  • Chalcopyrite material $CuInSe_2$ (CIS) is known to be a very prominent absorber layer for high efficiency thin film solar cells. Current interest in the photovoltaic industry is to identify and develop more suitable materials and processes for the fabrication of efficient and cost-effective solar cells. Various processes have been being tried for making a low cost CIS absorber layer, this study obtained the CIS nanoparticles using commercial powder of 6 mm pieces for low cost CIS absorber layer by high frequency ball milling and cryogenic milling. And the CIS absorber layer was prepared by paste coating using milled-CIS nanoparticles in glove box under inert atmosphere. The chalcopyrite $CuInSe_2$ thin films were successfully made after selenization at the substrate temperature of $550^{\circ}C$ in 30 min, CIS solar cell of Al/ZnO/CdS/CIS/Mo structure prepared under various deposition process such as evaporation, sputtering and chemical vapor deposition respectively. Finally, we achieved CIS nanoparticles solar cell of electric efficient 1.74 % of Voc 29 mV, Jsc 35 $mA/cm^2$ FF 17.2 %. The CIS nanoparticles-based absorber layers were characterized by using EDS, XRD and HRSEM.

Antimicrobial Activity of Black Garlic Pomace Extract and Its Application to Cleansing of Fresh Spinach Leaves for Microbial Control (흑마늘박 추출물의 항균 활성과 미생물 제어를 위한 시금치 세척에의 이용)

  • Kang, Ji Hoon;Son, Hyeon Jeong;Min, Sea Cheol;Oh, Deog Hwan;Song, Kyung Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.4
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    • pp.450-458
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    • 2017
  • In this study, the antimicrobial activity of black garlic pomace extract (BGPE) was examined, and its washing applicability to spinach was investigated. BGPE had antimicrobial activity against both Gram-positive (Listeria monocytogenes and Staphylococcus aureus) and Gram-negative (Escherichia coli O157:H7 and Salmonella Typhimurium) food-borne pathogens. In particular, antimicrobial activities of BGPE against Gram-positive bacteria were higher than those against Gram-negative bacteria. Spinach samples were treated with 0.5% BGPE to determine the effect of BGPE on reducing naturally existing microorganisms on the surface of spinach leaves. BGPE treatment reduced populations of total aerobic bacteria and yeast/molds in spinach by 1.23~1.35 log CFU/g and 0.82~1.12 log CFU/g during 9 days of storage, respectively, compared with those of control samples. After treatment, there were no significant differences in color quality such as Hunter L, a, and b values and total color difference (${\Delta}E$). These results clearly indicate that BGPE treatment can be useful for improving microbiological safety and maintaining color quality of spinach during storage.

Nanolayered CuWO4 Decoration on Fluorine-Doped SnO2 Inverse Opals for Solar Water Oxidation

  • Cho, Ha Eun;Yun, Gun;Arunachalam, Maheswari;Ahn, Kwang-Soon;Kim, Chung Soo;Lim, Dong-Ha;Kang, Soon Hyung
    • Journal of Electrochemical Science and Technology
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    • v.9 no.4
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    • pp.282-291
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    • 2018
  • The pristine fluorine-doped $SnO_2$ (abbreviated as FTO) inverse opal (IO) was developed using a 410 nm polystyrene bead template. The nanolayered copper tungsten oxide ($CuWO_4$) was decorated on the FTO IO film using a facile electrochemical deposition, subsequently followed by annealing at $500^{\circ}C$ for 90 min. The morphologies, crystalline structure, optical properties and photoelectrochemical characteristics of the FTO and $CuWO_4$-decorated FTO (briefly denoted as $FTO/CuWO_4$) IO film were investigated by field emission scanning electron microscopy, X-ray diffraction, UV-vis spectroscopy and electrochemical impedance spectroscopy, showing FTO IO in the hexagonally closed-pack arrangement with a pore diameter and wall thickness of about 300 nm and 20 nm, respectively. Above this film, the $CuWO_4$ was electrodeposited by controlling the cycling number in cyclic voltammetry, suggesting that the $CuWO_4$ formed during 4 cycles (abbreviated as $CuWO_4$(4 cycles)) on FTO IO film exhibited partial distribution of $CuWO_4$ nanoparticles. Additional distribution of $CuWO_4$ nanoparticles was observed in the case of $FTO/CuWO_4$(8 cycles) IO film. The $CuWO_4$ layer exhibits triclinic structure with an indirect band gap of approximately 2.5 eV and shows the enhanced visible light absorption. The photoelectrochemical (PEC) behavior was evaluated in the 0.5 M $Na_2SO_4$ solution under solar illumination, suggesting that the $FTO/CuWO_4$(4 cycles) IO films exhibit a photocurrent density ($J_{sc}$) of $0.42mA/cm^2$ at 1.23 V vs. reversible hydrogen electrode (RHE, denoted as $V_{RHE}$), while the FTO IO and $FTO/CuWO_4$(8 cycles) IO films exhibited a $J_{sc}$ of 0.14 and $0.24mA/cm^2$ at $1.23V_{RHE}$, respectively. This difference can be explained by the increased visible light absorption by the $CuWO_4$ layer and the favorable charge separation/transfer event in the cascading band alignment between FTO and $CuWO_4$ layer, enhancing the overall PEC performance.

Effect of osmotic potential on germination of tomato seed

  • Kim, Min Geun;Park, Sunyeob;Kim, Du Hyun
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.214-214
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    • 2017
  • Seeds of Tomato (Lycopersicon esculentum Mill.) have demanded high quality because of their high cost of seed. The optimization of the seed priming techniques that have positive effect on fast and uniform germination becomes important at the commercial level. Several factors such as solution composition, osmotic potential, and treatment duration affect seed priming response. In this study, osmotic potentials of priming solution and germination characteristics of primed seed were investigated to clarify the effects different inorganic salt types and the duration. Tomato seeds were primed in osmotic solutions that were osmotic potential ranged -1.54 to -0.45 MPa in an aerated solution of PEG 8000 (17%, 22%, 27%), and inorganic salt solution of $KNO_3$, $Na_2SO_4$, and $K_2SO_4$ (100, 200, 300mM). The seeds were treated at $20^{\circ}C$ for 2, 4, and 6 days. After each treatment, the seeds were dried to moisture content ranged 5-8% at $25^{\circ}C$. Four replications of 25 seeds per each treatments were placed in 10-cm petri dishes containing two filter papers and 3 ml of $dH_2O$ and incubated at $20^{\circ}C/30^{\circ}C$ and $15^{\circ}C$ and seedlings evaluated for abnormality after 14 days of incubation. Seed water potential (${\psi}$) was correlated with water potential of priming solution ($r^2=0.86$). Seeds primed in 100mM $KNO_3$ resulted the highest germination rate (GR, $63.9 %{\cdot}day^{-1}$) and lowest mean germination time (MGT, 2.0 days) comparing to untreated control ($23.9%{\cdot}day^{-1}$ of germination rate and 4.1 days of MGT) at $20/30^{\circ}C$, even though 96% of germination percentage were not different. Seeds primed in 100mM $KNO_3$ (${\psi}=-0.45MPa$) for 4 days showed ${\psi}=-0.38MPa$. Priming in $Na_2SO_4$, $K_2SO_4$, and PEG solution for 6 days improved MGT and GR, but not significantly than 4 days of treatment. Additionally, stepwise osmotic solution treatment with 100mM and 300mM concentration for 6 day did not showed differences with single treatment. In relation to osmotic potentials, identical osmotic potential in different inorganic salt solution showed different effect on germination characteristics.

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High-Pressure Synthesis and Chemistry of Amphibole Solid Solutions along the Joint Tremolite-Tschermakite (투각섬석-처마카이트 각섬석 고용체의 고압합성 및 화학적 성질)

  • 조문섭
    • Journal of the Mineralogical Society of Korea
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    • v.3 no.1
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    • pp.1-6
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    • 1990
  • Clacic amphiboles along the tremolite (Tr)-tschermakite(Ts) joint were synthesized using a piston-cylinder appratus. At 750-85$0^{\circ}C$and 12-2 kb, amphibole+corundum coexist with zoisite($\pm$talc, chlorite, and Mg-staurolite), but with anorthite($\pm$cholorite, spinel, pyroxenes, and sapphirine) at lower P. At 90$0^{\circ}C$, amphibole+corundum+clinopyroxene($\pm$anorthite, forsterite, sapphirine, and garnet) are stable over the P range 12-18 kb. These amphibole-bearing assemblages are replaced at high P by clcinopyroxene+talc+chlorite+zoisite at 650-75$0^{\circ}C$, and at higher temperatures by garnet+clinopyroxene($\pm$zoisite, orthopyroxene, and Mg-staurolite). Synthetic amphiboles with Ts>~45 mol% contain as much as 0.15 excess cations per formula unit(pfu) based on 23 oxygens(anhydrous formula), whereas less tschermakitic ones are deficient in cation occupancy by up to 0.18 pfu. This trend is attributed to the 야/trioctahedral substitution in Ca-amphiboles. Compositions of synthetic amphiboles display systematic changes with P and T governed by coexisting mineral assemblages. The Ts content (=[8-Si-Na]/2) increases with increasing T( Ts/ T=~0.1 nik% K-1) in the range 750-85$0^{\circ}C$, but remains nearly constant at 850-90$0^{\circ}C$. Pressure dramatically affects the Ts content of Ca-amphiboles:it increases with P at 8-12 kb( Ts/ T=2-3 mol% K-1), but significantly decreases at 12-21 kb( Ts/ P=-2.5 mol% Kb-1). Hence, the most tschermakitic amphiboles, containing 60$\pm$5 mol % Ts, or 1.2$\pm$0.1 tetrahedral Al, occur at 12 kb and 850-90$0^{\circ}C$. Compositions of Ca-amphiboles defined by a simple reaction, 3 Tr+2 zoisite+7 corundum+H2O=5 Ts, are reversed and used to estimate thermodynamic parameters of tschermakite assuming ideal mixing of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$of Tr-Ts solid solutions. Predicted standard molal entropy and enthalpy of tschermakite are : S$^{\circ}$=566.9$\pm$13.7 J mol-1K, -1and H$^{\circ}$=-12518.36$\pm$15.17 kJ mol.-1

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Shelf Life Prediction of Seasoned Anchovies packaged with PET/EVOH Film (포장(PET/EVOH Film) 멸치조미가공품의 유통기한 예측)

  • Lee, Eui-Seok;Lee, Hyong-Ju;Bae, Jae-Seok;Kim, Yong-Kuk;Lee, Jong-Hyeouk;Hong, Soon-Taek
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.6
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    • pp.827-832
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    • 2013
  • An attempt is made to predict the shelf life of seasoned anchovies packaged with laminated film, composed of polyethylene terephthalate (PET) and ethylene vinyl alcohol (EVOH). First, a descriptive sensory analysis is carried out to determine the principal sensory quality index in seasoned anchovies. Then, the physicochemical quality index with high correlation to the principal sensory quality index is determined accordingly. Subsequently, with the physicochemical quality index, the shelf-life is estimated by using the Arrhenius equation. As for the sensory quality index, 'color' is determined as a principal sensory quality index. For all samples stored at 3 different temperatures (25, 35, $45^{\circ}C$), it is observed that the sensory score is shown to be over 2.5 until 60 days of storage period, which is the lowest acceptable level. In addition, the b-value, as a physicochemical quality index, is determined to have a high correlation to the sensory quality index. Further, the activation energy and the Q10 value for the b-value by the Arrhenius equation is found to be 11.24 kcal/mol, 1.385~2.011, respectively. Thus, it can be concluded that the shelf life of seasoned anchovies packaged with PET/EVOH film is estimated to be 279.44 days when stored at $20^{\circ}C$.

Effect of Telmisartan on the Pharmacokinetics of Ebastine (Ebastine의 약동학에 미치는 Telmisartan의 영향)

  • Baek, SangHoon;Park, Sunkyoung;Jang, Yoo-Jeong;Lim, Misun;Kang, Wonku
    • Korean Journal of Clinical Pharmacy
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    • v.23 no.4
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    • pp.322-326
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    • 2013
  • Purpose: Telmisartan, an angiotensin receptor blocker has been known to be a potent blocker of both CYP2J2 and P-glycoprotein (P-gp) in vitro. This study aims to investigate the drug-drug interactions between telmisartan and ebastine, a CYP2J2 and P-gp substrate in rats. Method: Ebastine (10 mg/kg) was orally given in the presence and absence of telmisartan (4 mg/kg, p.o.). Heparinized blood was serially taken and the plasma concentrations of ebastine and its three metabolites (hydroxyebastine, carebastine and desalkylebastine) were determined using LC-MS/MS, and their pharmacokinetic parameters were compared. Results: Peak concentrations ($C_{max}$) and AUC of ebastine were significantly (p<0.05) increased in the presence of telmisartan by 2.1 and 1.9 times, respectively. While $C_{max}$ of hydroxyebastine was significantly increased by 1.9 times, the half-life of hydroxyebasteine was decreased significantly with telmisartan (p<0.05). There was no change in the pharmacokinetic parameters of carebastine, the active metabolite of ebastine, and desalkylebastine was not detected in plasma. The systemic exposure of ebastine was significantly augmented by telmisartan, indicating that telmisartan may enhance the absorption of ebastine by blocking P-gp. Conclusion: Although telmisartan may also partially contribute to inhibit the biotransformation to hydroxyebastine, the inhibitory action seemed to be overridden by the enhancement of absorption, because the generation of hydroxyebastine was not diminished. In spite of such interactions between telmisartan and ebastine, no clinical consequence could be expected due to no significant change of the active metabolite, carebastine.

Growth and Photocurrent Properties of CuGaTe2 Single Crystal Thin Films by Hot Wall Epitaxy (Hot Wall Epitaxy (HWE) 방법에 의한 CuGaTe2 단결정 박막 성장과 광전류 특성)

  • 백승남;홍광준
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.158-158
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    • 2003
  • 수평 전기로에서 CuGaTe2 다결정을 합성하여 HWE 방법으로 CuGaTe2 단결정 박막을 반절연성 GaAs(100) 위에 성장하였다. CuGaTe2 단결정 박막은 증발원과 기판의 온도를 각각 67$0^{\circ}C$, 41$0^{\circ}C$로 성장하였다. 이때 단결정 박막의 결정성이 10K에서 측정한 광발광 스펙트럼은 954.5nm (1.2989eV) 근처에서 exciton emission 스펙트럼이 가장 강하게 나타났으며, 또한 이중결정 X-선 요동곡선(DCRC)의 반폭치(FWHM)도 139arcsec로 가장 작게 측정되어 최적 성장 조건임을 알 수 있었다. Hall 효과는 van der Paw방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 8.72$\times$$10^{23}$개/㎥, 3.42$\times$$10^{-2}$$m^2$/V.s였다. 상온에서 CuGaTe2 단결정 박막의 광흡수 특성으로부터 에너지 띠간격이 1.22 eV였다 Band edge에 해당하는 광전도도peak의 온도 의존성은 Varshni 관계식으로 설명되었으며, Varshni 관계식의 상수값은 Eg(0) = 1.3982 eV, $\alpha$= 4.27$\times$$10^{-4}$ eV/K, $\beta$= 265.5 K로 주어졌다. CuGaTe2 단결정 박막의 광전류 단파장대 봉우리들로부터 10K에서 측정된 $\Delta$cr (crystal Field splitting)은 0.0791eV, $\Delta$s.o (spin orbit coupling)는 0.2463eV였다. 10K에서 광발광 봉우리의 919.8nm (1.3479eV)는 free exciton(Ex), 954.5nm (1.2989eV)는 donor-bound exciton 인 I2(DO,X)와 959.5nm (1.2921eV)는 acceptor-bound exciton 인 I1(AO,X) 이고, 964.6nm(1.2853eV)는 donor-acceptor pair(DAP) 발광, 1341.9nm (0.9239eV)는 self activated(SA)에 기인하는 광발광 봉우리로 고찰되었다.

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Studies on the Red Pigment Produced by Monascus sp. in Submerged Culture. Part I Isolation of Strain and Cultural Conditions of Pigment Produced (액침진탕 배양에 의한 Monascus sp..가 생산하는 적색색소에 관한 연구 제1보 균주의 분리 및 색소생산 배양 조건)

  • 김현수;김두현;양호석;변유량;유주현
    • Microbiology and Biotechnology Letters
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    • v.7 no.1
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    • pp.23-30
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    • 1979
  • Fungi which produce red pigment were isolated from tapioca chips, Korean Koji, air, and plant leaves. Among the Fungi, T-1 strain was selected as test strain. This strain was identified as a Monatcus sp. by the morphological propeties. Various culture conditions, and physical and physiological characteristics of red pigment were studied. According to the studies of culture conditions, optimum condition was found to be pH 6.5; 4 days of incubation; temperature, 32~33 c: 3.5% of Tapioca chips powder as carbon source, 0.2% of sodium nitrate as nitrogen source and 100 ml of medium in the 500 ml Erlenmyer flask at a rotary shaker (rpm180) as aeration condition. Also effective levels of vitamins, amino acids and inorganic compounds was found to be l$\mu\textrm{g}$/ml of folic acid and niacin; 0.3% of L-arginine, L-glutamic acid and L-proline; and 0.001% of manganese dioxide giving good results.

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Implementation of Parallel Volume Rendering Using the Sequential Shear-Warp Algorithm (순차 Shear-Warp 알고리즘을 이용한 병렬볼륨렌더링의 구현)

  • Kim, Eung-Kon
    • The Transactions of the Korea Information Processing Society
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    • v.5 no.6
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    • pp.1620-1632
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    • 1998
  • This paper presents a fast parallel algorithm for volume rendering and its implementation using C language and MPI MasPar Programming Language) on the 4,096 processor MasPar MP-2 machine. This parallel algorithm is a parallelization hased on the Lacroute' s sequential shear - warp algorithm currently acknowledged to be the fastest sequential volume rendering algorithm. This algorithm reduces communication overheads by using the sheared space partition scheme and the load balancing technique using load estimates from the previous iteration, and the number of voxels to be processed by using the run-length encoded volume data structure.Actual performance is 3 to 4 frames/second on the human hrain scan dataset of $128\times128\times128$ voxels. Because of the scalability of this algorithm, performance of ]2-16 frames/sc.'cond is expected on the 16,384 processor MasPar MP-2 machine. It is expected that implementation on more current SIMD or MIMD architectures would provide 3O~60 frames/second on large volumes.

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