• Environmental Engineering Research
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• 제18권3호
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• pp.145-150
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• 2013

Optimal preparation guidelines of a cathode catalyst layer by non-precious metal catalysts were evaluated based on electrochemical performance in single-chamber microbial fuel cells (MFCs). Experiments for catalyst loading rate revealed that iron(II) phthalocyanine (FePc) can be a promising alternative, comparable to platinum (Pt) and cobalt tetramethoxyphenylporphyrin (CoTMPP), including effects of substrate concentration. Results showed that using an optimal FePc loading of $1mg/cm^2$ was equivalent to a Pt loading of $0.35mg/cm^2$ on the basis of maximum power density. Given higher loading rates or substrate concentrations, FePc proved to be a better alternative for Pt than CoTMPP. Under the optimal loading rate, it was further revealed that 40 wt% of FePc to carbon support allowed for the best power generation. These results suggest that proper control of the non-precious metal catalyst layer and substrate concentration are highly interrelated, and reveal how those combinations promote the economic power generation of single-chamber MFCs.

• The Journal of Korean Physical Therapy
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• 제32권2호
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• pp.70-74
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• 2020

Purpose: This study examined whether 1) the motor inhibition response as cognitive-behavioral component is learning though a stop signal task using stop-signal paradigm, and 2) whether there is a difference in the learning degree according to imagery training and actual practice training. Methods: Twenty young adults (males: 9, females: 11) volunteered to participate in this study, and were divided randomly into motor imagery training (IT, n=10) and practice training (PT, n=10) groups. The PT group performed an actual practice stop-signal task, while the IT group performed imagery training, which showed a stop-signal task on a monitor of a personal computer. The non-signal reaction time and stop-signal reaction time of both groups were assessed during the stop-signal task. Results: In the non-signal reaction time, there were no significant intra-group and inter-group differences between pre- and post-intervention in both groups (p>0.05). The stop-signal reaction time showed a significant difference in the PT group in the intra-group analysis (p<0.05). On the other hand, there was no significant intra-group difference in the IT group and inter-group difference between pre- and post-intervention (p>0.05). Conclusion: These results showed that the motor inhibition response could be learned through a stop-signal task. Moreover, these findings suggest that actual practice is a more effective method for learning the motor inhibition response.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.594-606
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• 1996

저자는 하악골의 측방 변위를 보이는 악안면 비대칭증례에서 이하두정방사선규격사진과 정모두부방사선규격사진을 이용하여 두개부 형태와 악안면부의 비대칭성과의 상호 관련성을 조사하여 다음과 같은 결론을 얻었다. 1. 이하두정방사선규격사진에서 하악골의 편위정도는 평균 $-3.12{\pm}3.80$ 이며 절대치의 평균은 $2.50{\pm}2.82$ 이였다. 2. 이하두정방사선규격사진에서 비편위측과 편위측에 대한 유의성 검정에서 통계적인 유의성은 없었으나(p>0.05), 그 차이의 평균은 전두부(Y10, Y9, Y8, Y7, Y6)에서는 편위측이 상대적으로 더 크고, 측두부(Y5, Y-1, Y-2, Y-3, Y-4, Y-5, Y-6)에서는 비편위측이 상대적으로 더 크게 나타났다. 3. 정모두부방사선규격사진에서 술전의 하악골의 평균 편위는 $1.3983{\pm}3.521$ 이며 절대치의 평균은 $3.95{\pm}2.85$ 이였다. 4. 정모두부방사선규격사진에서 수술에 의한 변화량 (PT2A-PT1A) 에 대한 재발량(PTLA-PT2A)의 상관관계분석에서 수술에 의한 이동량이 많을 수록 재발이 많은 것으로 나타났다(p<0.05). 5. 이하두정방사선규격사진에서 하악골 편위정도에 대하여 두개관 형태(비변위-변위차이)에 대한 상관관계분석에서 통계적인 유의성은 없었으나(P>0.05), 변위가 클수록 전두부에서는 비변위측이, 후두부에서는 변위측이 더 큰 경향을 보였다. 6. 정모두부방사선사진상에서 하악골의 변위 정도에 대한 두개관(비변위-변위)과의 상관관계 분석에서 Y4(P<0.05), Y3, Y2, Yl, 0, Y-1, Y-2, Y-4, Y-6(P<0,01), Y-5(p<0.001) 등의 위치에서 하악골의 변위 정도가 클수록 비변위측이 더 큰 것으로 나타났다. 7. 정모두부방사선사진상에서 하악골 재발에 대한 두개관(비변위-변위)과의 상관관계분석에서는 통계적인 유의성이 없었으나(P>0.05), 측두부에서는 비변위-변위 차이가 클수록 재발이 많은 경향을 보였다.

• 한국표면공학회지
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• 제48권2호
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• pp.38-42
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• 2015

Atomic layer deposition (ALD) is essential for the fabrication of nanoscale electronic devices because it has excellent conformality, atomic scale thickness control, and large area uniformity. Metal thin films are one of the important material components for electronic devices as a conductor. As the size of electronic devices shrinks, the thickness of metal thin films is decreased down to few nanometers, and the metal films become non-continuous due to inherent island growth of metal below a critical thickness. So, fabrication of continuous metal thin films by ALD is fundamentally and practically important. Since ALD films are grown through self-saturated reactions between precursors on surface, initial growth characteristics significantly depend on the surface properties and the selection of precursors. In this work, we investigated ALD Pt on $TiO_2$ substrate by using trimethyl-methyl-cyclopentadienyl-Platinum ($MeCpPtMe_3$) precursor and $O_3$ reactant. By using $O_3$ instead of $O_2$, initial nucleation rate of ALD Pt was increased on $TiO_2$ surface, resulting in formation of continuous thin Pt films. Morphologies of ALD Pt on $TiO_2$ were characterized by using Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). Crystallinity of ALD Pt on $TiO_2$ correlated with its growth characteristics was analyzed by X-Ray Diffraction (XRD).

• 한국세라믹학회지
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• 제32권12호
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• pp.1408-1416
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• 1995

Microstructure and ferroelectric properties of sol-gel derived PZT(52/48) and PT interlayered PZT(52/48) thin films on Pt/Ti/SiO2/Si substrates were investigated. Films were fabricated using Acetylacetone chelated PT and PZT(52/48) sols. PZT(52/48) thin films annealed at $700^{\circ}C$ for 20 min showed the rosette structure with the size of 1.2~1.6${\mu}{\textrm}{m}$ and the pyrochlore phse was contained. PT interlayered PZT thin films, which is inserted by PbTiO3 thin layer with the thickness of 130 $\AA$ between PZT thin film and electrode, consisted of a single perovskite phase after annealing above 55$0^{\circ}C$. They exhibited the uniform and columnar grains of 0.1~0.16${\mu}{\textrm}{m}$, which are applicable for microelectronic device including non-volatile memory. Typical P-E hysteresis loops could be obtained from PT interlayered PZT thin film at as low as the annealing temperature of 50$0^{\circ}C$. Ferroelectric properties of PT interlayered PZT thin films were improved as increasing annealing temperature up to $700^{\circ}C$, and then deteriorated at 75$0^{\circ}C$. PZT(52/48) and PT interlayered PZT(52/48) thin film annealed at $700^{\circ}C$ for 20 min displayed Ps=38.8$\mu$C/$\textrm{cm}^2$, Pr=10.0$\mu$C/$\textrm{cm}^2$, Ec=65.3 kV/cm and Ps=28.5$\mu$C/$\textrm{cm}^2$, Pr=9.8$\mu$C/$\textrm{cm}^2$, Ec=76.1 kV/cm, respectively.

• 한국응용과학기술학회지
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• 제40권3호
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• pp.579-588
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• 2023

본 연구는 퍼스널트레이너-고객 간의 라포형성이 운동성과에 미치는 영향관계를 커뮤니케이션 스타일을 중심으로 인과 관계(SEM)를 밝히고자 하였다. 이에 2022년 10월 1일부터 4월 28일까지 표본계획에 의해 PT고객 187명을 대상으로 모바일 프로그램 '서베이몽키'를 통해 다음과 같은 결과를 도출 하였다. 첫째, 커뮤니케이션 스타일은 라포형성에 영향(+)을 미치는 것으로 나타났다. 둘째, 커뮤니케이션 스타일은 운동성과에 부분적으로 영향(+)을 미치며, 통제형은 영향관계가 성립되지 않았다. 셋째, 라포형성이 운동성과에 영향을 미치는 것으로 나타났다. 따라서 PT는 일반적인 서비스가 아닌 인적 서비스이기에 그 중요성이 더욱히 강조되어야 될 것이다. 또한, 치열한 PT시장에서 우위를 점하는 것은 바로 고객이 반응할 수 있는 표현방식 언어적 측면과 비언어적 측면을 적절하게 반영된다면 운동성과와 경영성과 둘 동시 영향을 줄 것으로 판단된다.

• 한국군사과학기술학회지
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• 제5권3호
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• pp.105-112
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• 2002

A combined process of non-thermal plasma and catalytic techniques has been investigated to treat toxic gas compounds in air. The treated gas in the present study is $CH_3$CN that has been known to be a simulant of toxic chemical agent. A planar type dielectric barrier discharge(DBD) reactor has been used to generate non-thermal plasma that produces various chemically active species, O, N, OH, $O_3$, ion, electrons, etc. Several different types of adsorbents and catalysts, which are MS 5A, MS 13X, Pt/alumina, are packed into the plasma reactor, and have been tested to save power consumption and to treat by-products. Various aspects of the present techniques, which are decomposition efficiencies along with the power consumption, by-product analysis, reaction pathways modified by the adsorbents and catalysts, have been discussed in the present study.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.383-385
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• 2009

비백금계 코발트 전이금속 촉매를 탄소지지체에 담지한 뒤, 암모니아 분위기에서 $500^{\circ}C$에서 3시간 동안 열처리하는 과정을 통해 코발트 질화물 촉매를 제조했다. 제조된 촉매들의 구조와 형태를 각각 XRD, HE-TEM등을 통해 분석하였고, 전위 측정기를 이용한 CV, LSV 결과로부터 촉매의 전기화학적 산소 환원특성을 분석하여, 기존의 연료전지 양극 촉매로 사용되는 고가의 백금촉매를 대체하기 위한 비백금계로서의 가능성을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.620-623
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• 2003

Non-linear behaviors of multilayer piezoelectric ceramic actuator (MCA) were investigated under electrical and mechanical stress. DC 100 V bias was applied to the MCA to obtain displacement. Laser vibrometer, which using Doppler effect, was employed to characterize displacement caused by $d_{33}$ mode of MCA. To understand this non-linear behavior of MCA, displacement was measured and compared under different load states. By increasing load, electric field-induced strain and piezoelectric constant($d_{33}$) of MCA was decreased. We attribute this phenomenon to the domain wall motion and depoling of MCA under heavy load.

• 한국진공학회지
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• 제10권3호
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• pp.368-373
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• 2001

N형 InGaAs에 대한 Pd/Si/Ti/Pt 오믹 접촉 특성을 조사하였다. 증착 상태에서는 접촉 비저항을 측정할 수 없을 정도의 비오믹 특성을 보였으며, $375^{\circ}C$에서 10초 동안 열처리한 경우 $5\times10^{-3}\Omega\textrm{cm}^2$의 높은 접촉 비저항을 나타내었다. 그러나 열처리 시간을 60초로 연장할 경우 접촉 비저항이 $1.7\times10^{-6}\Omega\textrm{cm}^2$로 급격히 감소하였고, 열처리 조건을 $425^{\circ}C$, 10초로 변화시킬 경우 $2\times10^{-6}\Omega\textrm{cm}^2$의 접촉 비저항을 나타내었다. 또한 $450^{\circ}C$까지도 오믹 재료와 InGaAs의 평활한 계면을 유지하면서 우수한 오믹 특성을 나타내어, 화합물 반도체 소자의 오믹 접촉으로 충분히 응용가능하다.