• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.545-549
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• 2001

We have produced electrolyte solution out of 1.15M LiPF$\sub$6/ EC/EMC/DEC/PC(30/55/10/5 by vol%) as a reference, and at the same time, performed basic physical property test using a single solvent of 1.15M LiPF$\sub$6/DEC, DMC, EMC and a 2 component electrolyte solution of 1.15M LiPF$\sub$6/ EC/DEC(1/2 by vo%%) and PC/DEC(1/2 by vol%). Cyclic Voltammetry Analysis showed that, compared to existing carbonate organic solvent, the addition of DEC, DMC and EMC brought the de-decomposition peak of salt anion of PF$\sub$6/$\^$-/ and the solvent at lower oxidization potential of 2.3V, 0.7V and 2.1V(vs. Li/Li$\^$+/\`). In addition, a kinetics current peak, in which intercalation of Li$\^$+/ is proceeded at 750mv, 450mv(vs. Li/Li$\^$+/), was confirmed. These findings suggest that the DEC solvent decomposition occurred at an electric potential lower than that of oxidization of existing carbonate organic solvent. Through the impedance analysis, we checked electric charge transfer resistance(R$\sub$ct/) according to the electric potential of Li$\^$+/ intercalation at 750mv(vs. Li/Li$\^$+/), which was the same as the resistance (R$\sub$f/) and cyclic voltammetry of SEI film that was formed at Reference. By doing so, we found that the significant decrease of polarization resistance(R$\sub$p/) when Reference was played a part in the formation of compact SEI layer at the initial decomposition reaction.

• 한국표면공학회지
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• 제49권1호
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• pp.81-86
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• 2016

$Eu^{3+}$-doped $MgMoO_4$ phosphor thin films were deposited on quartz substrates by radio frequency magnetron sputtering with changing various growth temperatures. The effects of growth temperature on the structure, transmittance, optical band gap, and luminescence of the phosphor thin films were characterized. All the phosphor thin films, irrespective of growth temperature, showed a monoclinic structure with a main (220) diffraction peak. The thin film deposited at a growth temperature of $400^{\circ}C$ indicated an average transmittance of 90% in the wavelength range of 500 ~ 1100 nm and band gap energy of 4.81 eV. The excitation spectra of the phosphor thin films consisted of a broad charge transfer band peaked at 284 nm in the range of 230 ~ 330 nm and two weak peaks located at 368 and 461 nm, respectively. The emission spectra under ultraviolet excitation at 284 nm exhibited a sharp emission peak at 614 nm and several weak bands. All the phosphor thin films showed high asymmetry ratio values, indicating that $Eu^{3+}$ ions incorporated into the host lattice occupied at the non-inversion symmetry sites. The results suggest that the growth temperature plays an important role in growing high-quality phosphor thin films.

• 한국정보통신학회논문지
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• 제13권7호
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• pp.1344-1356
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• 2009

DDS(Data Distribution Service)는 데이터 중심의 통신 기술로서 DDS 디스커버리(discovery) 기법을 이용하여 각 데이터(토픽: Topic)에 대한 참여자의 위치정보 자동설정을 통해 참여자의 동적 플러그 앤 플레이를 지원하는 효율적인 통신 서비스를 제공한다. 본 논문에서는 기존 DDS 디스커버리 기법들의 성능 및 문제점들을 비교 및 분석하여 대규모 분산시스템에 적합한 계층적 구조 기반의 DDS 디스커버리 기법(SPDP-TBF)을 제안한다. 제안하는 SPDP-TBF 기법은 등록/검색을 담당하는 별도의 계층별 관리자들을 두어 연관된 참여자들만의 주기적인 디스커버리를 수행함으로써 참여자 정보를 관계된 참여자에게만 전송하여 메시지 전송의 효율성을 높이며, 나아가 계층별 관리자 노드를 통해 계층적 디스커버리를 수행함으로써 대규모 분산시스템에도 적용할 수 있는 높은 확장성을 제공할 수 있다.

• 한국진공학회지
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• 제18권4호
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• pp.281-287
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• 2009

본 연구에서는 고진공 조건에서 열기화 증착 방법으로 산화막으로 덮인 Mg 리본(MgO/Mg) 위에 Pd을 증착하였다. 고진공 속에서 만든 시료의 전자구조를 in-situ X-선 광전자 분광법 (XPS)을 통하여 분석하였고, 분석 후, FE-SEM을 통해 증착량의 증가에 따른 표면구조의 변화를 확인하였다. Pd 증착량이 1 나노미터 (nm) 이하인 경우에는 증착량 증가에 따른 Pd 나노입자 크기의 증가를 확인하였으며, Pd을 1 nm 이상의 두께로 증착시킨 경우에는 Pd 입자들의 뭉침에 의해 얇은 필름이 형성됨을 관찰하였다. Pd과 기판사이의 전하이동에 의하여 산화물/금속 계면의 Pd 원자들은 부분적으로 양전하를 띔을 확인하였다.

• 대한기계학회논문집B
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• 제20권6호
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• pp.2023-2035
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• 1996

In the present study, the characteristics of the electrical deformation of a bubble and a drop under a uniform electric field have been investigated to understand EHD heat transfer enhancement by an electric field. The deformation of the bubble and the drop have been studied theoretically using an electric normal stress acting on their interfaces and assured by the numerical analysis and the experiment. From the variation of bubble volume and free energy, it is found that a bubble is compressed in an electric field and free energy had larger value with increasing W and the permittivity of a dielectric fluid. The electric normal stress induced on the interface of the bubble and the drop is different. Because of the surface charge induced at the drop interface, the electric normal stress acting on the drop is much larger than that of the bubble. The drop is, therefore, deformed much more than the bubble. In addition, the experimental and numerical results show that the aspect ratio and the contact angle of the bubble increase with increasing W.

• 한국화재소방학회논문지
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• 제20권4호
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• pp.77-90
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• 2006

119구급대원의 응급구급활동과 관련하여 형사법적으로 문제되는 영역은 크게 세 가지이다. 첫째는 구급 요청을 거절하는 행위이며, 둘째는 요구호자를 이송하지 않는 미이송 행위이고, 셋째는 응급처치행위이다. 이러한 일련의 구급대원의 행위들이 '응급의료에 관한 법률'이나 관련 법규의 규정에 위반되어 이루어진 경우에는 이들 법률들에 규정된 범죄행위가 성립한다. 특히 정당한 이유 없이 구급요청을 거절한 행위는 응급의료법상 응급의료거부죄가 성립하고, 적법한 절차에 의하지 아니한 응급처치는 무단 응급처치죄가 성립한다. 또한 구급요청거절과 미이송 행위 그리고 응급처치나 미응급처치 등으로 인해 요구호자가 사망하거나 상태가 악화된 경우에는 형법상 살인죄나 업무상과실치사죄 또는 중상해죄가 성립할 수 있다. 이처럼 구급대원의 경우에는 구급활동과 관련하여 형사적 책임으로부터 자유로울 수가 없다. 즉 구급대원들도 직무의 소홀과 과실로 인해 발생하는 법익침해적 결과에 대해서는 당연히 형사적 책임을 져야 한다. 그러나 긴급상황에서 불가피하게 국민의 생명과 건강을 침해한 경우에는 이들을 보호할 수 있는 법적 방안도 마련되어야 하며, 특히 열악한 근무환경에서 구급대원에게만 그 책임을 전가할 수 없는 게 현실이다. 현재 구호자보호법 제정문제가 논의되고 있는데, 이 법률에 구급대원의 형사면책부분이 합리적으로 규정되어 궁극적으로 구급대원들이 국민의 생명과 건강을 지키는 파수꾼으로서 그 역할에 충실할 수 있도록 하여야 한다.

• 한국표면공학회지
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• 제47권6호
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• pp.330-334
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• 2014

In this study, the Zn-Mg alloy coatings with various Mg contents were deposited using an unbalanced magnetron sputtering process. Their surface microstructure, chemical composition, phase, and corrosion property were investigated. The microstructure of the Zn-Mg coatings changed from porous microstructure to dense one with increasing Mg contents in the coatings. As Mg contents in coatings increased, intermetallic phases such as $Mg_2Zn_{11}$ and $MgZn_2$ were detected from X-ray diffraction (XRD) results. The corrosion resistance of the Zn-Mg alloy coatings was investigated quantitatively using electrochemical impedance spectroscopy (EIS) measurement with 3.5% NaCl solution. The results of EIS measurement showed that the charge transfer resistance and the phase angle of the Zn-Mg alloy coatings were increased from $162.1{\Omega}{\cdot}cm^2$ to $558.8{\Omega}{\cdot}cm^2$ and from about $40^{\circ}$ to $60^{\circ}$ with increasing Mg contents from 5.1 wt.% to 15.5 wt.% in the coatings. These results demonstrate that the Zn-Mg coatings with increasing Mg contents showed an enhanced corrosion resistance.

• Bulletin of the Korean Chemical Society
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• 제15권2호
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• pp.122-126
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• 1994

Corrosion of brass coated steel cords in the acetonitrile solution of sulfenamide derivatives, N-Cyclohexylbenzothiazole-2-sulfenamide (CBTS), N,N'-Dicyclohexylbenzothiazole-2-sulfenamide (DCBS), N-tert-Butylbenzothiazole-2-sulfenamide (TBBS), N-tert-Amylbenzothiazole-2-sulfenamide (TABS), and N-Oxydiethylbenzothiazole-2-sulfenamide (OBTS) was investigated by potentiostatic anodic and cathodic polarization (Tafel plot), DC polarization resistance, and AC impedance measurements. The corrosion current densities and rates are 1.236 ${\mu}A /cm^2$ and 0.655 MPY for CBTS; 1.881 ${\mu}A/cm^2$ and 0.988 MPY for DCBS; 2.367 ${\mu}A/cm^2$ and 1.257 MPY for TBBS; 3.398 ${\mu}A /cm^2$ and 1.809 MPY for TABS, respectively. OBTS among derivatives under study shows the lowest corrosion density (0.546 ${\mu}A /cm^2$) and the slowest corrosion rate (0.288 MPY). Also, the charge transfer resistances and the double layer capacitances are 275.21 $k{\Omega}{\cdot}cm^2$ and 7.0 ${\mu}F{cdot}cm^{-2}$ for CBTS; 14.24 ${\mu}F{\cdot}cm^2$ and 26 ${\mu}F{\cdot}cm^{-2}$ for DCBS; 54.15 $k{\Omega}{\cdot}cm^2$ and 26 ${\mu}F{\cdot}cm^{-2}$ for TBBS; 0.96$k{\Omega}{\cdot}cm^2$ and 83 ${\mu}F{\cdot}cm^{-2}$ for TABS, respectively. The weaker the electron donating inductive effect of derivatives is and the smaller the effect of steric hindrance is, the more the corrosion of brass coated steel cords in the acetonitrile solution of sulfenamide derivatives is prevented. The above results agree with that observed in the field of tire industry.

• 대한금속재료학회지
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• 제50권2호
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• pp.159-163
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• 2012

A TCO-less ruthenium (Ru) catalytic layer on glass substrate instead of conventional Ru/TCO/ glass substrate was assessed as counter electrode (CE) material in dye sensitized solar cells (DSSCs) by examining the effect of the Ru thickness on the DSSC performance. Ru films with different thicknesses (34, 46, 69, and 90 nm) were deposited by atomic layer deposition (ALD) on glass substrates to replace both existing catalyst and electrode layer. In order to make our comparison, we also prepared an Ru catalytic layer by a similar method on FTO/glass substrate. Finally, we prepared the $0.45cm^2$ DSSC device the properties of the DSSCs were examined by cyclic voltammetry (CV), impedance spectroscopy (EIS), and current-voltage (I-V) method. CV measurements revealed an increase in catalytic activity with increasing film thickness. The charge transfer resistance at the interface between the electrolyte and Rudecreased with increasing Ru thickness. I-V results showed that the energy conversion efficiency increased up to 1.96%. Our results imply that TCO-less Ru/glass might perform as both catalyst and electrode layer when it is used in counter electrodes in DSSCs.

• 대한금속재료학회지
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• 제50권3호
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• pp.243-247
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• 2012

A ruthenium (Ru) catalytic layer and a conventional Pt layer were assessed as counter electrodes (CE) for dye sensitized solar cells (DSSCs). Ru films with different thicknesses of 34, 46, and 90 nm were deposited by atomic layer deposition (ALD). Pt layers with the same thicknesses were prepared by sputtering. $0.45cm^2$ DSSCs were prepared and their properties were characterized by FE-SEM, cyclic voltammetry (CV), impedance spectroscopy (EIS), and current-voltage (I-V). FE-SEM revealed that the crystallized Ru films and Pt films had been deposited quite conformally. CV showed that the catalytic activity of Pt was much greater than that of Ru. In addition, although the catalytic activity of Pt did not depend on the thickness, that of Ru showed an increase with increasing thickness. Impedance analysis revealed high charge transfer resistance at the Ru interface and a decrease with increasing Ru thickness, whereas Pt showed low resistance with no thickness dependence. Despite the relatively small catalytic activity of Ru, the I-V result revealed the average energy conversion efficiency of Ru and Pt to be 2.98% and 6.57%, respectively. These results suggest that Ru can be used as counter electrodes in DSSCs due to its extremely low temperature process compatibility.