• 자원리싸이클링
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• 제28권5호
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• pp.19-29
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• 2019

최근에 들어 태양광 발전의 시설용량이 급격히 증가되고 기 설치된 태양광 패널의 수명이 다하여 폐기될 모듈의 양이 점점 많아짐에 따라, 이에 대한 처리가 환경문제 해결뿐만 아니라 유가물질의 회수차원에서도 크나큰 관심을 받고 있다. 사용 후 태양광 모듈의 처리 공정은 대부분 알루미늄 프레임의 해체, 강화유리의 분리 회수, 실리콘 웨이퍼에 부착된 에틸렌 비닐 아세테이트(EVA)의 제거 및 태양광 셀 중에 함유된 유가금속의 회수 등으로 구성되어 있다. 전술한 태양광 폐모듈의 리싸이클링 기술들을 치밀하게 검토한 다음, 물질 선별기술을 포함한 효과적인 처리 기술을 제시하였다. 그리고 리싸이클링 산업의 활성화를 위해서 필수적인 생산자 책임제도의 시행을 비롯한 종합적인 의견을 제안하였다.

• 한국자기학회지
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• 제21권6호
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• pp.208-213
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• 2011

Mori-Kawabata의 사영 연산자 방법을 $^{55}Mn$이 첨가된 $SrTiO^3$ 단 결정에 직접 적용하여, 이를 운동 방정식의 형태로 만드는 이론 체계를 사용하여 선모양 함수를 계산하였다. 외부 진동수 ${\nu}_0$ = 9.6 GHz에서 서로 다른 농도 [Mn] = 0.5 wt%와 2 wt%에 대한 온도 의존성으로 선폭을 조사하였다. 온도가 증가함에 따라 선폭은 감소하는 경향으로 확인되었고, 이는 선모양의 운동 좁아짐으로 보이며 고온영역 에서는 실험값과 비교적 일치함을 알 수 있었다. 이와 같이 계를 기술하는 스핀 해밀토니안에 연산자 방법을 이용한 선모양 함수는 실제 계의 적용에 편리한 급수전개로 하였으며, 다른 방법들에 비해 비교적 쉽게 계산할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권9호
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• pp.3172-3193
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• 2022

Cognitive radio-simultaneous wireless information and power transfer (CR-SWIPT) has attracted much interest since it can improve both the spectrum and energy efficiency of wireless networks. This paper focuses on the resource sharing between a point-to-point primary system (PRS) and a multiuser multi-antenna cellular cognitive radio system (CRS) containing a large number of cognitive users (CUs). The resource sharing optimization problem is formulated by jointly scheduling CUs and adjusting the transmit power at the cognitive base station (CBS). The effect of accessing CUs' spatial channel correlation on the possible transmit power of the CBS is investigated. Accordingly, we provide a low-complexity suboptimal approach termed the semi-correlated semi-orthogonal user selection (SC-SOUS) algorithm to enhance the spectrum efficiency. In the proposed algorithm, CUs that are highly correlated to the information decoding primary receiver (IPR) and mutually near orthogonal are selected for simultaneous transmission to reduce the interference to the IPR and increase the sum rate of the CRS. We further develop a spatial correlation-based resource sharing (SC-RS) strategy to improve energy sharing performance. CUs nearly orthogonal to the energy harvesting primary receiver (EPR) are chosen as candidates for user selection. Therefore, the EPR can harvest more energy from the CBS so that the energy utilization of the network can improve. Besides, zero-forcing precoding and power control are adopted to eliminate interference within the CRS and meet the transmit power constraints. Simulation results and analysis show that, compared with the existing CU selection methods, the proposed low-complex strategy can enhance both the achievable sum rate of the CRS and the energy sharing capability of the network.

• 한국광물학회:학술대회논문집
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• 한국광물학회.한국암석학회 2001년도 공동학술발표회 논문집
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• pp.44-44
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• 2001

구리(II)의 전자상자성공명 흉수선의 모양과 선 폭에 대한 해석을 통해 석영-물 계면에서의 구리(II) 및 흡착수와 석영 표면과의 상호 작용에 대해 연구하였다. 두 가지 흡수선이 중첩하여 흡수선을 구성하며 따라서 석영 표면에 적어도 두 종류의 구리(II)가 존재함을 알 수 있었다. 하나는 g=2.18에 중심을 둔 초미세 갈라짐이 분해되지 않는 등방성 단일 흡수선을 보여 주는 구리(II) 이온이다. 이는 수용액 중에서와 유사한 빠른 자유 회전 운동이 가능한 상태로 표면에 매우 약하게 결합된 구리 이온(Cu($H_2O$)$_{6}$$^{2+}$)인 것으로 해석된다. 다른 하나는 축 대칭 흡수선 $g_{∥}$=2.40, $g_{⊥}$=2.08)을 가지는 구리(II)로서 이는 표면에 강하게 결합된 것으로 해석된다. 본 결과는 흡착 현상에 대한 열역학적 접근법인 표면 착물화 모델들이 제시하는 광물 표면에서의 금속 이온 흡착 모델이 거시적 관점에서 흡착 현상을 잘 모사할지라도 분자 수준의 미시적 관점에서 흡착 메커니즘을 규명하기 위해서는 독립적인 분광학적 정보가 제시되어야함을 보여 준다.다.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3904-3908
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• 2011

A new octahedral Ru(III) complex with a tripodal tetraamine ligand, tpea = tris[2-(1-pyrazoyl)ethyl]amine, has been prepared and characterized. The single crystal X-ray crystallographic study of the complex revealed that the complex has a near octahedral geometry with the tetradentate ligand and two chloride ions. Peroxidase activity was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of the complex. Amount of $ABTS^{+{\bullet}}$ generated during the reaction was monitored by UV/VIS and EPR spectroscopies. After the initiation of the peroxidase reaction, $ABTS^{+{\bullet}}$ concentration increases and then decreases after certain time, indicating that both ABTS and $ABTS^{+{\bullet}}$ are the substrates of the peroxidase activity of the Ru(III) complex.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4021-4026
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• 2011

Functions of the luteinizing hormone releasing hormone (LHRH) and its induced release by divalent metal ions have received great attention because this neurotransmitter subsequently regulates the secretion of luteinizing hormone (LH). Metal-LHRH complexes were synthesized by addition of various Cu(II),Ni(II),Zn(II) ions into LHRH in order to understand how the induced release of LHRH is possible. The degree of complexation was monitored by $^1H$, $^{13}C$-NMR chemical shifts, and final products were identified by Mass spectrometry. Solutionstate structure determination of Zn(II)-LHRH out of metal-complexes was accomplished by using NMR and NMR-based distance geometry (DG). Interproton distance information from nuclear Overhauser effect spectroscopy was utilized for structure determination. Structure obtained in this study has a cyclic conformation exhibiting a specific ${\alpha}$-helical turn with residue numbers His[2]-Leu[7] out of 10 amino acids. Comparison of chemical shifts and EPR studies of Ni(II),Cu(II)-LHRH complexes exhibit that these metal complexes have 4-coordination geometry.

• 대한화학회지
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• 제56권2호
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• pp.217-227
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• 2012

Syntheses of some novel oxomolybdenum(V) and dioxomolybdenum(VI) complexes with an azo dye methoxyphenolazoantipyrine (HL) derived from 4-aminoantipyrine and 2-methoxyphenol are reported. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility data, IR, UV-Vis, $^1H$ NMR, EPR and FAB mass spectral studies. The physicochemical studies and spectral data indicate that HL acts as a bidentate chelating ligand. The complexes have the general formulae [$MoO(HL)XCl_2$] and [$MoO_2(HL)XCl$],where X=Cl, NCS or $NO_3$. All the complexes are found to have distorted octahedral geometry. Structural and morphological characterization of the complexes [$MoO(HL)Cl_3$](1) and [$MoO_2(HL)Cl_2$](4) before and after gamma ray irradiation,was performed by X-ray diffraction and scanning electron microscopy( SEM).The ligand and the complexes were screened for their possible antimicrobial activities.

• BMB Reports
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• 제28권4호
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• pp.311-315
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• 1995

Exogenous $Cu^{2+}$ or $Zn^{2+}$ at micromolar concentration had a strong inhibitory effect on detergent-solubilized cytochrome c oxidase. A similar effect was observed when $Cu^{2+}$ was added to vesicular cytochrome c oxidase, although the extent of inhibition was significantly larger for the uncoupled state than for the coupled state. Interestingly, the inhibition by $Zn^{2+}$ was almost negligible for both the coupled and uncoupled states. These results suggest that the binding sites for $Cu^{2+}$ ions are exposed to the extravesicular side. whereas those for $Zn^{2+}$ are exposed to the matrix side. The EPR spectra of bound $Cu^{2+}$ ions at 77 K indicate that each of the first two $Cu^{2+}$ ions is ligated by three or four histidine residues, as evidenced by distinct $^{14}N$ superhyperfine splitting. These $Cu^{2+}$ ions can not be removed readily by EDTA and inhibit the enzyme activity by as much as 80%.

• 동력기계공학회지
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• 제15권3호
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• pp.52-57
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• 2011

440A martensitic stainless steels which were modified with reduced carbon content(~0.5wt.%) and addition of small amount of vanadium, tungsten and molybdenum 0.4wt.%, 0.4wt.% and 0.68wt.% respectively were manufactured. Effects of alloying elements and tempering temperatures on the intergranular corrosion were investigated through the method of DL-EPR(Double-electrochemical potentiodynamic reactivation). It was thought that the highest DOS(Degree of sensitization) of specimens was obtained at the tempering temperature of $450^{\circ}C$ regardless of types of alloy because of the precipitation of Cr7C3. Addition of vanadium lowered DOS a little above the tempering temperature of $550^{\circ}C$. It was considered to be effected by precipitation of VC carbides. Intergranular corrosion was influenced more by tempering temperature than by alloying elements of V, W and Mo.

• 한국포장학회지
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• 제10권1호
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• pp.37-46
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• 2004

The aim of this study was to develop the recycling methode of alloyed recycling plastics. The compatibilizers have been used to improve the physical properties of recycling plastics. Eethylene propylene rubber(EPR), ethylene propylene diene monomer(EPDM), styrene ethylene butylene styrene block copolymer(SEBS), maleic anhydride modified styrene ethylene butylene styrene block copolymer(SEBS-MA) and styrene butadiene styrene block copolymer(SBS) were singled out as compatibilizers. In this study, the physical properties such as impact and tensile strength have improved above 20% by using the compatibilizers.