• Proceedings of the Korean Society of Developmental Biology Conference
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• 1998.07a
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• pp.32-33
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• 1998

생물체에서 유전외적 변형의 하나인 DNA 메틸화는 cis-acting factor의 조성변화를 통하여 세포특이 유전자의 발현과 virus latency, genomic imprinting, mutagenesis등과 같은 생물학적 효과를 나타내는 것으로 알려져 있다.(reviewed by Olle Heby, 1995). 5-azaCR, 5-azaCdR 그리고 6-azaCR의 처리결과는 배아자체의 DNA 메틸화의 유지가 정상발생에 필수적임을 알 수 있으며, 메틸화에 의한 배아발생 조절기작이 존재함을 암시하고 있다. 이러한 과정에서 5-azaCR과 5-azaCdR은 서로다른 경로를 통하여 배아발생에 관여함을 보여주었다. 즉, 5-azaCdR은 주로 DNA에 incorporation되어 작용하는 것으로 여겨지며, 5-azaCR은 DNA 보다는 RNA에 incorporation되어 작용하는 것으로 나타났다. 그리고, 비록 소수의 유전자만이 조사되었지만, 5-azaCdR의 incorporation에 의한 cis-acting factor의 변화는 전사인자인 c-myc proto-oncogene과 fluid 수송에 관여하는 $Na^{+}$, $K^{+}$-ATPase 유전자의 전사를 억제하지 않았다. 반면, 5-azaCR의 RNA로의 incorporation은 전사인자인 c-myc proto-oncogene의 전사를 억제하였으며, 연이어 fluid 수송에 관련되어있는 $Na^{+}$, $K^{+}$-ATPase 유전자의 전사를 억제하였다. 이것은 아마도 RNA로 incorporation된 5-azaCR은 RNA의 post-transcriptional processing에 영향을 주어 trans-acting factor의 조성을 변화, 전사적 repression을 유발한 것으로 사료된다. 생쥐 착상전 초기배아에서 DNA 메틸화는 short-term하게는 cis-acting factor로써 전사적 수준에서 유전자발현 조절하며, 그리고 유전자발현을 통하여 long-term하게는 배아발생에 관여 할 것이라고 사료된다.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.52-52
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• 2010

CIS(CuInSe2)계 화합물 태양전지는 높은 광흡수계수와 열적 안정성으로 고효율 태양전지 제조가 가능하여 태양전지용 광흡수층으로 매우 이상적이다. 미국 NREL에서는 이러한 CIGS 태양전지를 Co-evaporation 방법으로 제조 20%이상의 에너지 변환 효율을 달성하였다고 보고하였다. CIGS 태양전지의 경우 기존의 유리 기판 대신 유연한 철강 기판을 사용해 태양전지를 flexible하게 제조 할 수 있다는 장점이 있다. 이러한 flexible 태양전지의 경우 기존의 rigid 태양전지의 적용분야 뿐만 아니라 BIPV, 선박, 장난감, 군용, 자동차등 더욱더 많은 분야에 활용이 가능하다. 하지만 flexible 태양전지에 사용되는 철강기판의 경우 기존의 유리 기판인 SLG에 함유되어 있는 Na이 첨가되어 있지 않아 별도의 Na 첨가가 필요하다. Na은 CIGS 광흡수층의 결정을 증가 시키며 태양전지의 전기적 특성을 향상시킨다. 이러한 Na이 없는 경우 효율이 감소한다. 따라서 flexible 태양전지 개발을 위해서는 Na 첨가에 대한 연구가 필수적이다. 본 연구에서는 Na의 증착 순서를 변화시켜서 CIGS 증착 전, 동시증착, CIGS 증착 후로 나누어 CIGS 광흡수층 결정성의 변화를 알아보고자 한다. Na의 두께를 5nm에서 500nm 까지 단계 별로 나누어 실험을 실시하였다. 이때 CIGS 광흡수층은 미국의 NREL과 같은 3 stage 방식을 이용하였다. 1st stage의 시간은 15분으로 고정하였으며 기판온도는 약 $300^{\circ}C$로 고정 하였다. 2nd stage는 실시간 온도 감지 장치를 이용하여 Cu와 In+Ga의 조성비가 1:1이 되는 시간을 기준으로 Cu의 조성을 30%더 높게 조절하였으며 기판 온도는 약 $640^{\circ}C$로 고정 후 실험을 실시하였다. 3rd stage의 경우 Cu poor 조성으로 조절하기 위해 모든 조건을 10분으로 고정 후 실험을 실시하였다. 기판은 Na의 영향만을 비교하기위하여 Na이 첨가되어있지 않은 corning glass를 사용하였다. 후면 전극으로 약 $1{\mu}m$ 두께의 Mo을 DC Sputtering 방법을 이용하여 증착 하였다. 각각의 Na 두께에 따른 CIGS 광흡수층의 특성을 분석하기 위해 FE-SEM, XRD 분석을 실시하였다.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.515-523
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• 2015

The effects of reducing fat levels from 30% to 20% and salt concentrations from 1.5% to 1.0% by partially substituting incorporated phosphate and sea mustard were investigated based on physicochemical properties of reduced-fat / low-NaCl meat emulsion systems. Cooking loss and emulsion stability, hardness, springiness, and cohesiveness for reduced-fat / low-NaCl meat emulsion systems with 20% pork back fat and 1.2% sodium chloride samples with incorporation of phosphate and sea mustard were similar to the control with 30% pork back fat and 1.5% sodium chloride. Results showed that reduced-fat / low-NaCl meat emulsion system samples containing phosphate and sea mustard had higher apparent viscosity. The results of this study show that the incorporation of phosphate and sea mustard in the formulation will successfully reduce fat and salt in the final meat products.

• Membrane and Water Treatment
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• v.8 no.5
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• pp.483-498
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• 2017

Novel mixed matrix membranes of Sodium Alginate (NaAlg) were developed by the incorporation ofunmodified, modified Phosphomolybdic acid (PMA) then cross-linked with glutaraldehyde externally. These membranes were prepared by the solution casting technique. Pervaporation (PV) experiments have been performed with pure NaAlg, unmodified NaAlg-PMA5, NaAlg-PMA10, modified NaAlg-mPMA5, and NaAlg-mPMA10 (wt. % of PMA 5 and 10) at 30, 40 and $50^{\circ}C$, to separate water-isopropanol feed mixtures containing 10-30 wt. % of water. Pervaporation results of NaAlg-mPMA10 produced a highest separation factor of 9028 with a flux of $0.269kg/m^2.h$ for 10 wt. % of water containing feed mixture. Both separation factor and flux for water increased significantly with increasing content of mPMA into NaAlg; a significant improvement in PV performance was observed for NaAlg-mPMA5 and NaAlg-mPMA10 membranes when compared to pure NaAlg& PMA-5, PMA-10 membrane.

• Korean Journal of Medicinal Crop Science
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• v.26 no.5
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• pp.345-353
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• 2018

Background: Some phenolics detected in the soil may inhibit the seed germination and seedling growth of ginseng (Panax ginseng). This study investigated the effect of irrigation and ginseng root residue addition on the soil microbial community and root rot disease in 2-year-old ginseng. Methods and Results: Each $20{\ell}$ pot was filled with soil infected with ginseng root rot pathogens, and irrigated daily with $2{\ell}$ of water for one month. After the irrigation treatment, ginseng fine root powder was mixed with the irrigated soil at a rate of 20 g per pot. In descending order, ${NO_3}^-$, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) decreased due to irrigation. In descending order, ${NO_3}^-$, EC, Ex. K, and available $P_2O_5$ increased with the additon of ginseng powder to the soil. The abundance of Trichoderma crassum decreased with irrigation, but increased again with the incorporation of ginseng powder. The abundance of Haematonectria haematococca increased with irrigation, but decreased with the incorporation of ginseng powder. The abundance of Cylindrocarpon spp. and Fusarium spp., which cause ginseng root rot, increased with the incorporation of ginseng powder. The abundance of Arthrobacter oryzae and Streptomyces lavendulae increased with irrigation. The abundance of Streptomyces lavendulae decreased, and that of Arthrobacter spp. increased, with the incorporation of ginseng powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot increased with the incorporation of ginseng powder. Conclusions: Ginseng root residues in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.819-821
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• 2002

Photoluminescenc (PL) and low-voltage cathodoluminescence (CL) characteristics of $[xSrTiO_3+(1-x)Li_2TiO_3]:Pr^{3+}$ and $[xSrTiO_3+(1-x)Na_2TiO_3]:Pr^{3+}$ systems were investigated. The red luminescence intensities of these compounds are enhanced remarkably by the incorporation of $Li^+$ or $Na^+$ ion as compared to that of $SrTiO_3:Pr^{3+}$. The enhanced luminescence is speculated to result from both the charge compensation of $Pr^{3+}$ site and oxygen vacancies generated in the lattices by $Li^+$ or $Na^+$ ion.

• Journal of Electrochemical Science and Technology
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• v.14 no.3
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• pp.222-230
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• 2023

Capacitive deionization of saline water is one of the most promising water purification technologies due to its high energy efficiency and cost-effectiveness. This study synthesizes porous carbon composites composed of reduced graphene oxide (rGO) and activated carbon (AC) with various rGO/AC ratios using a facile chemical method. Surface characterization of the rGO/AC composites shows a successful chemical reduction of GO to rGO and incorporation of AC into rGO. The optimized rGO/AC composite electrode exhibits a specific capacitance of ~243 F g^-1 in a 1 M NaCl solution. The galvanostatic charging-discharging test shows excellent reversible cycles, with a slight shortening in the cycle time from the ~260^th to the 530^th cycle. Various monovalent sodium salts (NaF, NaCl, NaBr, and NaI) and chloride salts (LiCl, NaCl, KCl, and CsCl) are deionized with the rGO/AC electrode pairs at a cell voltage of 1.3 V. Among them, NaI shows the highest specific adsorption capacity of ~22.2 mg g^-1. Detailed surface characterization and electrochemical analyses are conducted.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.12-12
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• 2009

We weal know that PbO was poisonous and prone to volatilize, then to pollute the circumstance and hurt to people, so we should dope other innocuous additives instead of lead to increase Tc of composite PTC material. In order to prepare lead-free $BaTiO_3$-based PTC with middle Curie point, the incorporation on $(BaNaK)(TiNb)O_3$ into $BaTiO_3$-based ceramics was investigated on samples containing 0.05, 0.07 and 0.1mol% of $(BaNaK)(TiNb)O_3$. $(BaNaK)(TiNb)O_3$ was compounded as standby material by conventional solid-state reaction technique. The starting materials were $Na_2O_3$,$K_2CO_3$, $BaCO_3$, $TiO_2$ and $Nb_2O_5$ powder, and using solid-state reaction method, too. The microstructure of samples were investigated by SEM, DSC, XRD and dielectric properties. Phase composition and lattice parameters were investigated by X-ray diffraction. Also, we are measure the resistivity of sintered bodies with calcinations condition.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.129-130
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• 2021

In order to solve the problem of low early-age compressive strength of high volume fly ash concrete. This paper studies the effect of 2% sodium sulfate (Na₂SO₄) as a chemical activator on the paste with 40% fly ash content and a water-binder ratio of 0.30. The results indicate that the addition of Na₂SO₄ can effectively improve the early-age compressive strength of the fly ash-cement system, and the strength improvement rate on the first day reached nearly 70%. In addition, calorimetric analysis reveals that the incorporation of Na₂SO₄ promotes the early hydration of cement and fly ash, increases the cumulative hydration heat and delays the heat peak of the aluminum phase.

• Current Photovoltaic Research
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• v.2 no.1
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• pp.28-35
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• 2014

High-efficiency in $Cu(In,Ga)Se_2$ (CIGS) solar cells were usually achieved on soda-lime glass substrates due to Na incorporation that reduces deep-level defects. However, this supply of sodium from sodalime glass to CIGS through Mo back electrode could be limited at low deposition temperature. Na content could be more precisely controlled by supplying Na from known amount of an outside source. For the purpose, an $Na_2S$ layer was deposited on Mo electrode prior to CIGS film deposition and supplied to CIGS during CIGS film. With the $Na_2S$ underlayer a more uniform component distribution was possible at $350^{\circ}C$ and efficiency was improved compared to the cell without $Na_2S$ layer. With more precise control of bulk and surface component profile, CIGS film can be deposited at low temperature and could be useful for flexible CIGS solar cells.