• Title/Summary/Keyword: As$_2$

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Preparation Nanosized TPA-Silicalite-1 with Different Silica Sources and Promoters (다양한 실리카 원과 결정화 촉진제를 이용한 나노크기의 TPA-Silicalite-1 제조)

  • Jung, Sang-Jin
    • Applied Chemistry for Engineering
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    • v.25 no.3
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    • pp.286-291
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    • 2014
  • In this study, nanosized TPA-silicalite-1 was synthesized with a suitable molar composition of TPAOH: $SiO_2$: $H_2O$ for the development of zeolite ceramic membranes to utilize as gas separation. As silica sources, TEOS, LUDOX AS-40 and CAB-O-SIL were used with the starting material of TPAOH. $NaH_2PO_4$, and a variety of acids and bases were used as promoters after TPAOH, $SiO_2$, $H_2O$ gel synthesis. To decrease synthesis time, a two step temperature change method was applied to the synthesis of TPA-silicalite-1 at a low temperature. TPA-silicalite-1 synthesized was analyzed with XRD, SEM, BET and TGA. As a result, TPA-silicalite-1 powders with a particle size of 100 nm and a specific surface area of $416m^2/g$ were obtained as optimum synthesis conditions when the two stage temperature change method was used with $NaH_2PO_4$ as promoter.

Putative Histone H2A Genes from a Red Alga, Griffithsia japonica

  • Lee, Yoo-Kyung;Lee, Hong-Kum
    • ALGAE
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    • v.18 no.3
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    • pp.191-197
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    • 2003
  • Histones are important proteins that interact with the DNA double helix to form nucleosome. Two putative histone genes, GjH2A-1 and GjH2A-2 were isolated from a red alga Griffithsia japonica. The putative open reading frame of GjH2A-1 and GjH2A-2 shared high similarity with the previously reported amino acid sequences of histone H2As. They have a motif consisting of seven amino acids A-G-L-Q-F-P-V, which matches the histone H2A motif [AC]-G-L-x-F-P-V. Phylogenetic trees were constructed from amino acid sequences of 38 histone H2As. The histone H2As were divided into two groups: major H2As and H2A.F/Z variants. The major histone H2A group consisted of animals, fungi, plants + green algae, and red algae H2A subgroups. The animal histone H2A subgroup was divided into vertebrates, echinoderms, nematodes, insects, and segmented worms H2As. The putative red algal histone genes, GjH2A-1 and GjH2A-2, constituted an independent lineage. This is the first report on red algal histone genes.

Low Temperature Deposition of the $In_2O_3-SnO_2$, $SnO_2$ and $SiO_2$ on the Plastic Substrate by DC Magnetron Sputtering

  • Kim, Jin-Yeol;Kim, Eung-Ryeol;Lee, Jae-Ho;Kim, Soon-Sik
    • Journal of Information Display
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    • v.2 no.1
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    • pp.38-42
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    • 2001
  • Thin films of $In_2O_3-SnO_2$(ITO), $SnO_2$, and $SiO_2$ were prepared on the PET substrate by DC magnetron roll sputtering. 135 nm thick ITO film on $SiO_2$/PET substrate has sheet resistance as low as 55 ${\Omega}/square$ and transmittance as high as 85%. $H_2O$gas permeation through the film was 0.35 g/$m^2$ in a day. These properties are enough on optical film for the plastic LCD substrate or touch panel. Both refractive index and sheet resistance of ITO was found to be very sensitive to $O_2$ flow rate. Oxygen flow conditions have been optimized from 4 to 5 SCCM at $10^{-3}$torr. It is also shown that both thickness of $SnO_2$ and refractive index of $SiO_2$ decrease as $O_2$ flow rate increases.

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FoxD2-AS1 is a prognostic factor in glioma and promotes temozolomide resistance in a O6-methylguanine-DNA methyltransferase-dependent manner

  • Shangguan, Wenbing;Lv, Xuyang;Tian, Nan
    • The Korean Journal of Physiology and Pharmacology
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    • v.23 no.6
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    • pp.475-482
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    • 2019
  • Glioma is the most common brain tumor with a dismal prognosis. While temozolomide (TMZ) based chemotherapy significantly improves survival in glioma patients, resistance against this compound commonly leads to glioma treatment failure. Overexpression of long-noncoding RNA (LncRNA) FoxD2 adjacent opposite strand RNA 1 (FoxD2-AS1) was identified to promote glioma development, but the role in TMZ resistance remains unclear. In this paper, we found that FoxD2-AS1 was overexpressed in recurrent glioma, high FoxD2-AS1 expression was significantly correlated with poor patient outcome. Methylation of $O^6$-methylguanine-DNA methyltransferase (MGMT) is significantly less frequent in high FoxD2-AS1 expression patients. Knockdown of FoxD2-AS1 decreased the proliferation, metastatic ability of glioma cells and promote the sensitivity to TMZ in glioma cells. Furthermore, knockdown of FoxD2-AS1 induced hypermethylation of the promoter region of MGMT. Our data suggested that FoxD2-AS1 is a clinical relevance LncRNA and mediates TMZ resistance by regulating the methylation status of the MGMT promoter region.

Influence of InGaAs Capping Layers on the Properties of InAs/GaAs Quantum Dots (InAs/GaAs 양자점의 발광특성에 대한 InGaAs 캡층의 영향)

  • Kwon, Se Ra;Ryu, Mee-Yi;Song, Jin Dong
    • Journal of the Korean Vacuum Society
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    • v.21 no.6
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    • pp.342-347
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    • 2012
  • The optical properties of InAs quantum dots (QDs) grown on a GaAs substrates by migration enhanced molecular beam epitaxy method have been investigated by using photoluminescence (PL) and time-resolved PL measurements. The luminescence properties of InAs/GaAs QDs have been studied as functions of temperature, excitation laser power, and emission wavelength. The PL peak of InAs QDs capped with $In_{0.15}Ga_{0.85}As$ layer (QD2) measured at 10 K is redshifted about 80 nm compared with that of InAs QDs with no InGaAs layer (QD1). This redshift of QD2 is attributed to the increase in dot size due to the diffusion of In from the InGaAs capping layer. The PL decay times of QD1 and QD2 at 10 K are 1.12 and 1.00 ns taken at the PL peak of 1,117 and 1,197 nm, respectively. The reduced decay time of QD2 can be explained by the improved carrier confinement and enhanced wave function overlap due to increased QD size. The PL decay times for both QD1 and QD2 are independent on the emission wavelength, indicating the uniformity of dot size.

Effects of Expander Operating Conditions on Nutrient Digestibility in Finishing Pigs

  • S.L., Traylor;K.C., Behnke;J.D., Hancock;R.H., Hines;S.L., Johnston;B.J., Chae;In K., Han
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.3
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    • pp.400-410
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    • 1999
  • Five experiments were conducted using finishing pigs (PIC L326 sires $\times$ C15 dams) to examine the effects of expander operating conditions on nutrient digestibility in finishing pigs. The effects of different expanding conditions (0, 11.7, 24.4, $32.5kg/cm^2$) for corn-SBM based diets (Exp. 1), wheat meddlings diet (Exp. 2), sorghum-SBM based diets (Exp. 3) and wheat-SBM based diet (Exp. 4). Exp. 5 was conducted as a $2{\times}4$ factorial arrangement and factors examined were 2 soy products (raw soybean and SBM) and 4 expanding conditions (0, 14.1, 28.1, $42.2kg/cm^2$). In experiment 1, total production rates (p>0.10) were similar among treatments. The amount of fines decreased (cubic effect, p<0.001) as cone pressure was increased from 0 to $11.7kg/cm^2$, with smaller differences as cone pressure was further increased to $35.2kg/cm^2$. Nutrient digestibilities increased (p<0.02) as the feed was subjected to higher cone pressures. Digestibilities of DM, N, and GE were maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet expanded at 24.4 and $35.2kg/cm^2$ increased by 172 and 109 kcal/kg, respectively, compared to the diet processed at $0kg/cm^2$ cone pressure. In experiment 2, total production and screened pellets production rates were similar among the processing treatments (p>0.21). The amount of fines decreased (quadratic effect, p<0.03) by 9 kg/h as cone pressure was increased from 0 to $11.7kg/cm^2$. Digestibilities of DM (p<0.02), N (p<0.001), and GE (p<0.002) were increased as cone pressure was increased from 0 to $35.2kg/cm^2$. DM, N, and GE digestibility in the pigs fed the midds-based diet increased by 8, 13, and 10%, respectively, at the highest processing cone pressure compared to the diets without any cone pressure. In experiment 3, the conditioned mash moistures for the treatments were numerically similar around 15% moisture. As the expander cone pressure was increased from 0 to $11.7kg/cm^2$, energy consumption for the pellet mill decreased (quadratic effect, p<0.004) from 14.1 to 12.0 kWh/t. Dry matter and gross energy digestibility increased (cubic effects, p<0.006) as cone pressure was increased from 0 to $35.2kg/cm^2$ with the largest improvement occurring as cone pressure was increased from 0 to $11.7kg/cm^2$. Nitrogen digestibility increased (cubic effect, p<0.001) from 78.3 to 81.0% as the feed was subjected to the higher cone pressures, with N digestibility being maximized at $24.4kg/cm^2$ cone pressure. The DE of the diet increased (cubic effect, p<0.001) by 225 kcal/kg as cone pressure was increased from 0 to $11.7kg/cm^2$. In experiment 4, pellet moisture decreased and moisture loss increased as cone pressure was increased from 0 to $35.2kg/cm^2$. Also, starch gelatinization of the wheat-based diets increased from 16.8 to 49.1% as the diets were processed at 0 and $35.2kg/cm^2$ cone pressure. Nutrient digestibilities were not affected (p>0.18) by any increase in cone pressure. In experiment 5, pellet moisture decreased as cone pressure was increased 0 to $35.2kg/cm^2$. The amount of moisture loss for the diets expanded at $42.2kg/cm^2$ was 3.0 and 3.8% for the SBM and raw soybean (RB) diets, respectively. Starch gelatinization for the SBM diets were 19% greater than the RB diets. The RB diets had lower DM, N and GE digestibilities as compared to the SBM diets. The DE of the RB diets were lower (p<0.02) than the SBM diets. DM (p<0.06), N (p<0.02), and GE (p<0.001) digestibilities of the dietary treatments increased as cone pressure was increased 0 to $42.2kg/cm^2$.

Properties Electric of AIN Thin Film on the Si and GaAs Substrate (Si와 GaAs기판 위에 AIN 박막의 전기적 특성)

  • Park, Jung-Cheul;Chu, Soon-Nam;Kwon, Jung-Youl;Lee, Heon-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.1
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    • pp.5-11
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    • 2008
  • To study the effects of $H_2$ gas on AIN insulation thin film, we prepared AIN thin film on Si and GaAs substrate by means of reactive sputtering method using $H_2$ gas as an additives, With treatment conditions of $H_2$ gas AIN thin film shows variable electrical properties such as its crystallization and hysterisis affected to electrical property, As a results, AIN thin film fabricated on Si substrate post-treated with $H_2$ gas for 20 minutes shows much better an insulation property than that of pre-treated, And AIN film treated with $H_2$ gas comparing to non-treated AIN film shows a flat band voltage decreasment. But In GaAs substrate $H_2$ gas does not effect on the flat band voltage.

Electrical Characteristics of Ultra-Shallow n+/p Junctions Formed by Using CoSi$_2$ as Diffusion Source of As (CoSi$_2$를 As의 확산원으로 형성한 매우 얇은 n+/p 접합의 전기적 특성)

  • 구본철;정연실;심현상;배규식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.242-245
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    • 1997
  • Co single layer and Co/Ti used to form a CoSi$_2$ contact. We fabricated the n+/p diodes with this CoSi$_2$ contact as diffusion source of As. The diodes wish CoSi$_2$ formed by Co/ri bilayer had more Bo7d electrical characteristics than CoSi$_2$ formed by Co single layer. This shows that the flatness of interface which is a parameters to affect the diodes\` electrical characteristics. And the electrical characteristics of diodes are more good when the second thermal activation processing temperature was low as much as 50$0^{\circ}C$ than the temperature high over than 80$0^{\circ}C$, it was thought as that the silicide was degradated at high temperature.

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Degradation of the Herbicide, Alachlor, by Soil Microorganisms -Part I. Degradation in the flooded paddy soils- (제초제 Alachlor의 토양미생물에 의한 분해 -제일보(第一報). 담수답토양에서의 분해-)

  • Lee, Jae-Koo
    • Applied Biological Chemistry
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    • v.27 no.2
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    • pp.64-72
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    • 1984
  • Alachlor, 2-chloro-2, '6'-diethyl-N-(methoxymethyl) acetanilide, which had been incubated in the flooded paddy soils yielded 1-formyl-2,3-dihydro-7-ethylindole, 2,6-diethylaniline, 2,6-diethylacetanilide, 2,6-diethyl-N-(methoxymethyl) acetanilide, 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide, and three unidentifiable compounds as its degradation products. The water-soluble products of Alachlor in soil suspensions increased with incubation periods and similar results were obtained from the incubation of Rhizoctonia solani, as verified by use of the ring $-^{14}C-$labeled Alachlor. Streptomyces lavendulae Ru 3340-8 produced 2-hydroxy-2, '6'-diethyl-N-(methoxymethyl) acetanilide as the major degradation product as much as 25%, whereas Bacillus brevis IFO 3331, Bacillus cruciviae, and Pseudomonas putida did not produce it.

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Thermal Performance Assessment of Insulated door by experiment. (실측 실험을 통한 단열문의 열성능 평가)

  • Jang, Cheol-Yong;Kim, Chi-Hoon;Ahn, Byung-Lip;Hong, Won-Hwa
    • Journal of the Korean Solar Energy Society
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    • v.31 no.2
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    • pp.47-52
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    • 2011
  • Currently, Exterior wall's U-value about building envelope is 0.36 W/$m^2K$(Central Region), but window's one is 2.1 W/$m^2K$ according to air gap of glazing, filling gas, coating and type of windows. The door"s one is 1.6~5.5 W/$m^2{\cdot}K$ depending on material and configuration of door. As such, energy loss per unit of door is considerably larger like windows. The door for the recognition was relatively low because energy loss through the door is relatively small compared to window area. In this paper, thermal performance was analyzed through simulation targeting the door which has thermal break that can improve the insulation performance and doesn't have one. As a results of simulations, case1 was calculated as the average of 1.63 w/m2k and case 2 was calculated as the average of 4.14 w/m2k. The thermal performance of door depends on the type and condition of insulations. As a results of final simulations, Case1 was calculated as 1.06 w/m2k and Case2 was calculated as 1.27 w/m2k. As a results of the experiments, thermal performance of case 1 was measured as 1.28 w/m2k. Error between experiments and simulations is considered problems encountered when creating the samples. The effect of door frame on the overall thermal performance is slight because it's a small proportion of the door frame.