• 농업과학연구
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• 제38권3호
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• pp.421-428
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• 2011

Of the countries where Korea has advanced for overseas afforestation investments, Indonesia might be the most important country. As the end of 2010, nine Korean companies have been implementing afforestation projects in Indonesia, covering a total area of one hundred and fifty thousand hectares roughly. Following the Memorandum Of Understanding (MOU) on afforestation investment covering five hundred thousand hectares (A/R CDM / industrial afforestation) signed between Korea and Indonesia, the two countries concluded in 2009 an additional MOU covering two hundred thousand hectares for biomass afforestation, thus securing a total afforestation area of seven hundred thousand hectares. Further it was guaranteed that afforestation license would have validity for maximum 95 years, which laid the foundation for long-term stable investments for afforestation projects. Forest law of Indonesia consists of Presidential decree and Governmental decree as superior regulations and Minister's decree as subordinate regulations, being made up of total 17 chapters. Forestry Minister's decree was amended at end of last year, as regards license for exploitation of timber and forestry products in afforestation area. In the past, such license to develop and use timber and forestry products had been granted under Forestry Minister's decree No. P 11 / Menhut-II / 2008. After the amendment in 2010, however, the ground was shifted to Forestry Minister's decree No. P 50 / Menhut-II / 2010, trimming the procedure to obtain afforestation license into a little simplified one.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제29권2호
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• pp.215-239
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• 2015

본 연구는 다양한 표상활동을 중심으로 한 분수학습이 분수의 이해 및 수학적 태도에 미치는 영향을 알아보기 위한 것으로서 서울 소재 B초등학교 4학년 33명 전체학생을 대상으로 실시하였다. 활동적, 영상적, 상징적 표상활동으로 이루어진 분수학습을 6주간 15차시에 걸쳐 진행한 결과 관계적 이해에 도달한 학생들의 비율이 증가하였으며, 분수 학업성취도 검사 I, II, III에서 평균 90점 가까이 또는 그 이상의 높은 성취도를 보였다. 수학적 태도 변화를 알아보기 위해서 두 종속표본 t검정을 실시한 결과, 유의수준 .01에서 통계적으로 유의미한 차이가 있는 것으로 나타났다. 결론적으로 다양한 표상활동 중심의 분수학습은 학생들의 관계적 이해도와 분수 이해력을 향상시키고, 학생들의 학습지향성, 자기통제, 흥미, 가치인식, 자신감을 높이며, 불안감을 감소시키는 등의 수학적 태도면에서도 긍정적 영향을 미쳤다고 할 수 있다.

• 공업화학
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• 제8권2호
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• pp.161-171
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• 1997

인쇄회로기판의 식각폐수를 전기화학적 방법을 이용하여 양극에서 이를 재생하고, 음극에서 구리를 석출하기 위한 실험을 행하였다. 양극에서의 Cu(I)의 산화에 따른 Cu(I)/Cu(II) 변화는 Pt와 Ag/AgCl/4M KCl 전극사이의 전위차를 이용하여 측정하였으며, 반응의 진행에 따른 양극에서의 염소기체 발생은 용액내에 Cu(I)의 농도를 일정치 이상으로 유지시키고, 비다공성 흑연전극을 이용하여 억제할 수 있었다. 그리고, 음극에서의 구리석출은 전류밀도 $360mA/cm^2$, 구리이온농도 12g/l 일때 가장 효율적이며 석출된 구리는 dendrite구조임을 알 수 있었다. 또한 석출효율과 회수방법을 고려할 때 음극으로서 Ti전극을 사용할 경우 가장 우수한 효율을 얻을 수 있었다. 전해온도가 증가함에 따라서 전류효율은 낮아졌으며, 전력효율은 $50^{\circ}C$에서 최대값을 나타내었다.

• 대한수의학회지
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• 제56권2호
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• pp.67-74
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• 2016

Tomato extract has been shown to exert antiplatelet activity in vitro and to change platelet function ex vivo, but with limitations. In this study, antiplatelet activity of water soluble tomato concentrate (Fruitflow I) and dry water soluble tomato concentrate (Fruitflow II) was investigated using rat platelets. Aggregation was induced by collagen and adenosine diphosphate and granule-secretion, $[Ca^{2+}]_i$, thromboxane B2, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) levels were examined. The activation of integrin ${\alpha}_{IIb}{\beta}_3$ and phosphorylation of signaling molecules, including mitogen-activated protein kinase (MAPK) and PI3K/Akt, were investigated by flow cytometry and immunoblotting, respectively. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were examined. Moreover, in vivo thrombus weight was tested by an arteriovenous shunt model. Fruitflow I and Fruitflow II significantly inhibited agonist induced platelet aggregation, adenosine triphosphate and serotonin release, $[Ca^{2+}]_i$, and thromboxane B2 concentration, while having no effect on cAMP and cGMP levels. Integrin ${\alpha}_{IIb}{\beta}_3$ activation was also significantly decreased. Moreover, both concentrates reduced phosphorylation of MAPK pathway factors such as ERK, JNK, P38, and PI3K/Akt. In vivo thrombus formation was also inhibited. Taken together, these concentrates have the potential for ethnomedicinal applications to prevent cardiovascular ailments and can be used as functional foods.

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.62-68
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• 1999

Ferroelectric $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$(x=0, 0.1, 0.2, 0.3) thin films were deposited on $Pt/SiO_2/Si$ substrate by MOD(Metalorganic Decomposition) process. Metal carboxylate and metal alkoxide were used as precursors, and 2-methoxyethanol, xylene as solvents. After spin coating, thin films were pre-annealed at $400^{\circ}C$, followed by RTA(Rapid Thermal Annealing) and final annealing at $800^{\circ}C$ in oxygen atmosphere. These procedures were repeated three times to obtain thin films with the thickness of $2000{\AA}$. To enhance the nucleation and growth of layered-perovskite phase, thin films were rapid-thermally annealed above $720^{\circ}C$ in oxygen atmosphere. As RTA temperature increased, fluorite phase was transformed to layered-perovskite phase. And the change of Nb contents affected dielectric / electrical properties and microstructure. The ferroelectric characteristics of $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$ thin film were Pr=8.67 $\mu{C}/cm^2$, Ec=62.4kV/cm and $I_{L}=1.4\times10^{-7}A/cm^2$ at the applied voltage of 5V, respectively.

• Journal of Chest Surgery
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• 제29권9호
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• pp.964-970
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• 1996

1986년 2월부터 1996년 1월까지 108명의 환자에게 SJM 판막을 이용한 판막치환수술을 시행하고 1996년 2월까지 10년 동안 임상적으로 추적, 분석하였다. 성별은 남자 55명, 여자 53명이 였고 연령분포는 최소 11세에서 최고 60세로 평균 36.3 $\pm$ 10.4세였다. 치환된 판막은 승모판에 88개 대동맥 판에 54개 삼첨판에 1개였는데 승모판막치환에는 31mm(32), 33mm (23), 29inm(20), 27mm(10), 25mm(2), 그리고 35rnrn(1) 등이 사용되었고 대동맥 판치환에는 23rnm(21), 21min(18), 19mm(7), 25mm(5), 27mm(2), 그리고 33inm(1) 등이 사용되 었으며 삼첨판에 31mm(1)가 사용되었다. 술전 NYHA 기능적 분류는 II(14례), III(73례), IV(21례)였으나 술후에는 I(89례), II(16례)로 대부분 호전되었다. 술후 조기합병증은 15례(13.9%)에서 발생하였는데 저심박출증이 5례(4.6%)로 가장 많았고 3례(2.8%)의 술후 조기사망이 있었다. 술후 조기사망자를 포함한 전체 추적기간은 108례에서 평균 4.1$\pm$2.9년(437.6환자-년)이 었으며 후기 합병증은 5례(1.14%/환자-년)에서 발생하였는데 혈전색증(2례), 판막주위누출(1례), 혈전색과 판막주위누출(1례)및 판막염증(1례)등이었으 \ulcorner판막실패 례는 없었다. 재수술은 2례에서 시행되었고 2례가 사망하여 10년간 생존율은 93.6$\pm$3.1%였고 10년간 합병증이 없을 확율은 91.4$\pm$3.4%였다.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.299-309
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• 2013

Transforming growth factor (TGF) family is well known to induce the chondrogenic differentiation of mesenchymal stem cells (MSC). However, the precise signal transduction pathways and underlying factors are not well known. Thus the present study aims to evaluate the possible role of C2 domain in the chondrogenic differentiation of human mesenchymal stem cells. To this end, 145 C2 domains in the adenovirus were individually transfected to hMSC, and morphological changes were examined. Among 145 C2 domains, C2 domain of protein kinase C eta ($PKC{\eta}$) was selected as a possible chondrogenic differentiation factor for hMSC. To confirm this possibility, we treated $TGF{\beta}3$, a well known chondrogenic differentiation factor of hMSC, and examined the increased-expression of glycosaminoglycan (GAG), collagen type II (COL II) as well as $PKC{\eta}$ using PT-PCR, immunocytochemistry and Western blot analysis. To further evaluation of C2 domain of $PKC{\eta}$, we examined morphological changes, expressions of GAG and COL II after transfection of $PKC{\eta}$-C2 domain in hMSC. Overexpression of $PKC{\eta}$-C2 domain induced morphological change and increased GAG and COL II expressions. The present results demonstrate that $PKC{\eta}$ involves in the TGF-${\beta}3$-induced chondrogenic differentiation of hMSC, and C2 domain of $PKC{\eta}$ has important role in this process.

• 대한화학회지
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• 제56권1호
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• pp.34-46
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• 2012

Dopants and defects can be introduced as well as the intercalation of metals into single wall carbon nanotubes (SWCNTs) to modify their electronic and magnetic properties, thus significantly widening their application areas. Through spinpolarized density functional theory (DFT) calculations, we have systemically studied the following: (i) (10,0) and (5,5) SWCNT doped with nitrogen ($CN_xNT$), (ii) (10,0) and (5,5) SWCNT with pyridine-like defects (3NV-$CN_xNT$), and (iii) chemical functionalization of (10,0) and (5,5) 3NV-$CN_xNT$ with 12 different transition metals (TMs) (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, and Pt). Attention was done in searching for the most stable configurations, deformation, calculating the formation energies, and exploring the effects of the doping concentration of nitrogen and pyridine-like nitrogenated defects on the electronic properties of the nanotubes. Also, calculating the corresponding binding energies and effects of chemical functionalization of TMs on the electronic and magnetic properties of the nanotubes has been made. We found out that the electronic properties of SWCNT can be effectively modified in various ways, which are strongly dependent not only on the concentration of the adsorbed nitrogen but also to the configuration of the adsorbed nitrogen impurities, the pyridine-like nitrogenated defects, and the TMs absorbed; due to the strong interaction between the d orbitals of TMs and the p orbitals of N atoms, the binding strengths of TMs with the two 3NV-$CN_xNT$ are significantly enhanced when compared to the pure SWCNTs.

• 대한화학회지
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• 제58권2호
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• pp.169-178
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• 2014

A new series of metal complexes of V(IV), Pd(II), Pt(IV), Ce(IV) and U(VI) with 3-[(3-chlorophenyl)-hydrazono]-pentane-2,4-dione (Cphpd) were synthesized and characterized by elemental analysis, molar conductivity, magnetic moment measurements, UV-vis, FT-IR and $^1H$ NMR as well as TG-DTG techniques. The data indicated that the Cphpd acts as a bidentate ligand through the hydrazono nitrogen and one keto oxygen. The kinetic parameters have been evaluated by using Coats Redfern (CR) and Horowitz-Metzeger (HM) methods. The thermodynamic data reflected the thermal stability for all complexes. The calculated bond length and the bond stretching force constant, F(U=O), values for $UO_2$ bond are $0.775{\AA}$ and $286.95Nm^{-1}$. The bond lengths, bond angles, dipole moment and the lowest energy model structure of the complexes have been determined with DFT calculations. The antimicrobial activity of the synthesized ligand and its complexes were screened.

• Current Photovoltaic Research
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• 제2권1호
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• pp.18-27
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• 2014

Dye-sensitized solar cells (DSSCs), developed two decades ago, are considered to be an attractive technology among various photovoltaic devices because of their low cost, accessible dye chemistry, ease of fabrication, high power conversion efficiency, and environmentally friendly nature. A typical DSSCs consists of a dye-coated $TiO_2$ photoanode, a redox electrolyte, and a platinum (Pt)-coated fluorine-doped tin oxide (FTO) counter electrode. Among them, redox electrolytes have proven to be extremely important in improving the performance of DSSCs. Due to many drawbacks of iodide electrolytes, many research groups have paid more attention to seeking other alternative electrolyte systems. With regard to this, one-electron outer sphere redox shuttles based on cobalt complexes have shown promising results: In 2014, porphyrin dye (SM315) with the cobalt (II/III) redox couple exhibited a power conversion efficiency of 13% in DSSCs. In this review, we will provide an overview and perspectives of cobalt redox electrolytes in DSSCs.