• Title/Summary/Keyword: $K_w$

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[ $W_{1}/O/W_{2}$ ] Multi-emulsion Capsules Containing Ascrobic Acid-2-Glucoside Prepared Using PCL-based Amphiphilic Di- and Tri-block Copolymers

  • Cho, Heui-Kyoung;Chang, Woo-Hyuck;Cheong, In-Woo
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.262-262
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    • 2006
  • Biodegradable and amphiphilic di-block and tri-block copolymers, prepared with monomethoxy poly ethylene glycol (MPEG) and ${\varepsilon}-caprolactone\;({\varepsilon}-CL)$, were used for the application of W1/O/W2 multi- emulsion capsules. The effects of topology and the ratio of hydrophilic moiety of PCL-based polymers on the encapsulation efficiency of the $W_{1}/O/W_{2}$ multi-emulsion capsules containing Ascorbic Acid-2-Glucoside (AA-2-G) were investigated. The ratio of PEG and PCL was 1:0.5, 1:0.75, 1:1, and 1:1.25. PEG-PCL block copolymers were added to the first step of the preparation of $W_{1}/O$ emulsions. The dispersion stability, the particle size, the morphology of the $W_{1}/O/W_{2}$ multi-emulsion capsules were observed using an on-line turbidity meter, dynamic light scattering (DLS), a confocal microscopy (with FITC) and an optical microscopy. Biodegradable behavior of the PEG-PCL block copolymers and release behavior of AA-2-G were also observed by Gel Permeation Chromatography (GPC) and High Performance Liquid Chromatography (HPLC).

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OH MASERS TOWARDS THE W49A STAR-FORMING REGION WITH MERLIN AND e-MERLN OBSERVATIONS

  • ASANOK, KITIYANEE;ETOKA, SANDRA;GRAY, MALCOLM D.;RICHARDS, ANITA M.S.;KRAMER, BUSABA H.;GASIPRONG, NIPON
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.125-127
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    • 2015
  • We present preliminary results from OH ground state phase referenced observations carried out with the Multi Element Radio Linked Interferometer Network (MERLIN) and e-MERLIN towards the massive star forming region W49A. There are three active SFRs within this complex: W49 North (W49 N), W49 South (W49 S) and W49 South West (W49 SW). The first epoch of observations was obtained in 2005 with MERLIN while the second epoch was obtained in 2013 with the e-MERLIN upgraded system. In this paper, we present 1665 and 1720 MHz maser emission towards W49 S and W49 SW. Overall, both epochs show good agreement with the previous observations of Argon et al. (2000) carried out with the Very Large Array (VLA). The better sensitivity and wider velocity coverage of the MERLIN/e-MERLIN observations allowed us to discover a new 1720 MHz OH maser site in W49 S.

Bioavailability of Emulsion Containing Scutellariae Radix Extract (황금 엑스 유제의 생체이용률)

  • Yang, Jae-Heon;Kim, Young-Il
    • Journal of Pharmaceutical Investigation
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    • v.29 no.1
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    • pp.1-5
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    • 1999
  • The bioavailabilities of baicalin in water, oil, w/o and o/w emulsion were evaluated in rats. The dissolution rate of baicalin in o/w emulsion was smaller than those of w/o form in dilute hydrochloric acid solution (pH 1.2) and in PBS (pH 6.8). The absorption rate of baicalin from w/o emulsion was smaller than that of o/w emulsion in the different parts of rat intestine of the rats. Following oral administration in rats, the $C_{max}$ of baicalin from water phase, oil phase, o/w wand w/o emulsion were 2.11, 0.61, 1.57, and $1.35\;{\mu}g/ml$, respectively. The relative bioavailability of w/o emusion was 129 % when it was compared with water phase. This result suggests that the improvement of bioavailability for baicalin in w/o emulsion might be practically available.

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A study fo Al/W(110) surface structure at various annealing temperature and coverage

  • Choe, Dae-Seon;Park, Min-Geol;Park, Mi-Mi;Lee, Jeong-Hwan;Kim, Ju-Hwan;Kim, Do-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.344-344
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    • 2011
  • W(110)면에 흡착원자인 Al원자의 coverage와 annealing과정에서의 온도를 변화시켜, 여러 조건에서의 Al/W(110)계의 흡착구조를 저에너지 전자회절(LEED)과 이온산란분광법(ISS-TOF)을 이용하여 연구하였다. 여러 결과 중, annealing 온도가 900K인 1.0ML Al/W(110)면은 double domain의 p($1{\times}1$)의 흡착구조로 W(110)면의 center of hollow site에서 $0.55{\AA}$ 벗어난 위치에 흡착되었으며, W(110) 표면원자로부터 Al 원자까지의 높이는 $2.13{\pm}0.15{\AA}$이다. 또한 annealing 온도가 1100K인 0.5ML Al/W(110)면은 double domain의 p($2{\times}1$)의 흡착구조로 W(110)면의 center of bridge site에 흡착되었으며, W(110) 표면원자로부터 Al 원자까지의 높이는 $2.18{\pm}0.15{\AA}$이다.

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Reduction and Spark Plasma Sintering of the W(Tungsten) Nanopowder Produced by the Electric Explosion of Wire Process (전기선폭발법으로 제조한 나노 W(텅스텐) 분말의 환원처리 및 방전플라즈마소결에 의한 조밀화)

  • Kim Ji-Soon;Kim Cheol-Hee;Park Eun-Ju;Kwon Young-Soon;Kim Jin-Chun;Lee Sung-Ho;Jung Dong-Ik
    • Journal of Powder Materials
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    • v.13 no.4 s.57
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    • pp.269-277
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    • 2006
  • [ ${\beta}-W(W_3O)$ ] oxide layer on the surface of each W(tungsten) nanopowder produced by the electric explosion of wire(EEW) process were formed during the 1vol.% air passivation process. The oxide layer hindered sintering densification of compacts during SPS process. The oxide phase was reduced to the pure W phase during SPS. The W nanopowder's compacts treated by the hydrogen reduction showed high sintered density of 94.5%. after SPS process at $1900^{\circ}C$.

Characteristic Analysis and Implementation of 30kW Portable Test Equipment for Performance Evaluation in Energy Storage System (30kW급 ESS용 이동형 성능평가 시험장치의 구현 및 특성분석)

  • Park, Jea-Bum;Kim, Mi-Sung;Rho, Dae-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.6
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    • pp.715-723
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    • 2018
  • The energy storage system consists of batteries, power conditioning system and energy management system. If ESS is installed and operated in the field, SAT(Site Acceptance Test) of ESS is being essentially required for the safety and performance of ESS. Furthermore, in order to more accurately and reliably validate the performance of the ESS in advanced countries, it has been required to perform not only performance testing by H/W equipments but also performance verification by S/W tool. Therefore, this paper proposes the modeling of portable test equipment in order to evaluate the performance and reliability of ESS by using the PSCAD/EMTDC S/W. And also, the prototype of 30[kW] scaled portable test equipments is implemented based on the S/W modeling. From the results of various simulations and testings such as power quality, LVRT and anti-islanding tests, it is confirmed that 30[kW] scaled portable test equipment is useful for SAT of ESS, because the simulation results of PSCAD/EMTDC are identical to them of 30[kW] test equipment at the same test conditions.

The characteristics of AlW thin film for TFT-LCD bus line (TFT-LCD bus line을 위한 Al-W 박막 특성에 관한 연구)

  • Dong-Sik Kim;Chong Ho Yi;Kwan Soo Chung
    • Journal of the Korean Vacuum Society
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    • v.9 no.3
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    • pp.233-236
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    • 2000
  • The structural, electrical and chemical characteristics of Al alloy thin film with low impurity concentrations AlW deposited by using dc magnetron sputtering deposition are investigated for the applications as data bus line in the TFT-LCD panel. The deposited thin films show the decrease of resistivity and the increase of grain size after the RTA at $300^{\circ}C$ for 20 min.. Moreover, the resistivity of AlW does not show appreciable grain size dependence after RTA. It is concluded that the decrease of resistivity after RTA is due to the increase of grain size. The annealed AlW is found to be hillock free. And for investigating chemical attack in TFT-LCD etching processing the electric potential of AlW alloy for Ag/AgCl were investigated by cyclic voltammetry. When W wt.% of AlW alloy was higher than about 3%, the electric potential of AlW was more positive than ITO's. Therefore AlW alloy thin film can be propose to use for data bus line.

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Ohmic Contact Formation of SiC for Harsh Environment MEMS Using a TiW Thin-film (TiW 박막을 이용한 극한 환경 MEMS용 3C-SiC의 Ohmic contact 형성)

  • Chung, Soo-Yong;Noh, Sang-Soo;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.04b
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    • pp.133-136
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    • 2004
  • In this study, the characteristics of 3C-SiC ohmic contact were investigated. Titanium-tungsten(TiW) films were used for contact metalization. The ohmic contact resistivity between 3C-SiC and TiW was measured by HP4155 and then calculated with the circular transmission line method(C-TLM). And also the physical properties of TiW and the interface between TiW and 3C-SiC were analyzed using XRD and AES. TiW films make a good role of a diffusion barrier and their contact properties with 3C-SiC are stable at high temperature.

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Classification and Design Procedure of Modules for Reuse of Embedded S/W (임베디드 S/W 재사용을 위한 모듈의 분류 및 설계 절차)

  • Yu, Mi-Sun;Cha, Jung-Eun;Yang, Yung-Jong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.11a
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    • pp.309-312
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    • 2005
  • 임베디드 시스템이 점점 복잡해지고 다양해짐에 따라 이를 지원하는 임베디드 S/W 의 비중도 계속적으로 커지고 있으며 S/W 재사용에 대한 요구도 계속적으로 증가하고 있다. 그러나 유사한 기능을 지닌 S/W 에 대한 반복적인 수요가 증가함에도 불구하고, 재사용을 위한 체계적인 방법의 부재로 인하여 유사한 부분을 재사용 하지 못하고 있는 실정이다. 그러므로 체계적으로 재사용 S/W 모듈을 관리할 수 있는 지원 시스템과 모듈의 분류 방식, 그리고 재사용 지원 시스템을 이용하여 재사용 모듈을 실제 임베디드 S/W 개발에 적용할 수 있는 절차가 정의된다면 최종적으로 S/W 개발의 생산성을 향상 시킬 수 있을 것이다. 따라서 본 논문에서는 ETRI "임베디드 시스템 개발 프레임워크 구축"의 일환으로 구현되고 있는 재사용 지원 시스템을 위한 모듈의 형태 정의 및 형태와 크기에 따른 분류 방법, 재사용 모듈의 이용 절차에 대해 설명한다.

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