• 한국재료학회지
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• 제33권4호
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• pp.159-163
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• 2023

Zinc-ion Batteries (ZIBs) are currently considered to be effective energy storage devices for wearable electronics because of their low cost and high safety. Indeed, ZIBs show high power density and safety compared with conventional lithium ion batteries (LIBs) and exhibit high energy density in comparison with supercapacitors (SCs). However, in spite of their advantages, further current collector development is needed to enhance the electrochemical performance of ZIBs. To design the optimized current collector for high performance ZIBs, a high quality graphene film is suggested here, with improved electrical conductivity by controlling the defects in the graphene film. The graphene film showed improved electrical conductivity and good electron transfer between the current collector and active material, which led to a high specific capacity of 346.3 mAh g^-1 at a current density of 100 mA g^-1, a high-rate performance with 116.3 mAh g^-1 at a current density of 2,000 mA g^-1, and good cycling stability (68.0 % after 100 cycles at a current density of 1,000 mA g^-1). The improved electrochemical performance is firmly because of the defects-controlled graphene film, leading to improved electrical conductivity and thus more efficient electron transfer between the current collector and active material.

• 한국콘텐츠학회논문지
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• 제10권2호
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• pp.381-393
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• 2010

본 연구의 목적은 영화 흥행 성과 예측 모형을 예술 영화와 상업 영화 각각에 적용하여 영화 유형별 상이한 예측 요인을 비교 분석하는 것이다. 이에 따라 예술 영화와 상업 영화 각각에 대해 영화 흥행 성과 예측 모형을 적용한 결과, 두 회귀식은 구조적으로 다른 것으로 검증되었다. 보다 구체적으로, 두 회귀식의 회귀계수의 차이를 살펴본 결과, 스크린수, 관객 평가, 장르는 예술 영화와 상업 영화 모두에 영향을 미치는 흥행요인으로 나타났다. 그러나 감독 명성, 상영등급, 전문가 평가, 배급사 영향력, 영화 제작국, 그리고 개봉 시기는 예술 영화의 흥행 성과에 대해서만 유의한 예측 변수로 검증되었다.

• The Korean Journal of Ceramics
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• 제3권2호
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• pp.105-109
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• 1997

The effects of surface conditions of the C-2 cemented carbide substrate on the adhesion of diamond film were investigated. The substrates were pretreated for different times with Murakami's reagent and then the acid solution of an H2SO4-H2O2. The adhesion strength was estimated by a peeling area around the Rockwell-A indentation. The cutting performance of the diamond-coated tools was evaluated by measuring flank wears in dry turning of Al-17% Si alloy. The morphology of deposited diamond crystallites was dominated by (111) and (220) surfaces with a cubooctahedral shape. The diamond film quality was hardly affected by the surface conditions of the substrate. The variation of tool life with longer substrate etching times resulted from a compromies between the increase of film adhesion at the interface and the decrease of toughness at the substrate surface. The coated tools were mainly deteriorated by chipping and flaking of the diamond film form a lock of adhesion strength, differently from the wear phenomena of PCD tools.

• 생물환경조절학회지
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• 제18권3호
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• pp.232-237
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• 2009

본 연구는 일반적으로 이용되는 EVA 필름과 비교하여 폴리올레핀(PO), 불소, 방적, 방무, 보온필름 등의 기능성필름이 토마토의 품질에 어떤 영향을 미치는 가를 구명하고자 하였다. 분광투과특성에 있어 자외선은 불소필름이 가장 많았고 PO필름이 가장 적었으며, PAR는 불소, 보온, PO필름 등이 많았으며, 근적외선도 EVA에 비해 기능성필름이 많은 경향이었다. 전체광선의 투과율은 불소, 방무, 방적, PO, 보온, EVA 순으로 높았다. 하우스 내 주간온도는 광투과율 차이에 의해 불소필름이 가장 높고 EVA가 가장 낮았으며, 야간온도는 필름이 두꺼운 방적 및 PO필름이 가장 높게 유지되었다. 기능성필름은 EVA에 비해 과실 당도가 $0.2{\sim}0.5^{\circ}Bx$ 더 높았고, 과실 내 라이코펜 함량이 $15{\sim}30%$ 높게 나타났다. 따라서 토마토의 당도, 라이코펜 함량 등의 품질향상을 위해서는 일반필름 대신에 기능성필름을 이용하는 것이 효과적일 것으로 판단되었다.

• Tribology and Lubricants
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• 제24권3호
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• pp.147-153
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• 2008

The effect of oil supply pressure on the performance of vapor cavitated short squeeze film dampers is examined. Vapor cavitation is characterized by film rupture occurring as a result of evaporating oils. The pressure of vapor cavity in the film is almost zero in absolute pressure and nearly constant. Pan's model about the shape of vapor cavity is utilized for studying the effect of vapor cavitation on the damping capability of a short squeeze film damper. As the level of oil supply pressure is increasing, vapor cavitation is suppressed so that the direct damping coefficient increases and the cross coupled damping coefficient decreases. Futhermore, the analysis of the unbalance responses of a rigid rotor supported on cavitated squeeze film dampers shows that a significant reduction in rotor amplitude and force transmissibility is possible by controlling the oil supply pressure into short squeeze film dampers.

• 한국전기전자재료학회논문지
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• 제35권2호
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• pp.190-193
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• 2022

In this work, the effect of sputtering working pressure for the tellurium film and its thin-film transistor was investigated. The transfer characteristics of tellurium thin-film transistors were improved by increasing the working pressure during sputtering process. As increasing working pressure, physical and optical properties of Te films such as crystallinity, transmittance, and surface roughness were improved. Therefore, the improved transfer characteristics of Te thin-film transistors may originate from both improved interface properties between the silicon oxide gate dielectric layer and the tellurium active layer with an improved quality of Te film. In conclusion, the control of working pressure during sputtering would be important for obtaining high-performance tellurium-based thin film transistor

• Carbon letters
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• 제14권4호
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• pp.255-258
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• 2013

Flexible transparent conducting films (TCFs) were fabricated by dip-coating single-wall carbon nanotubes (SWCNTs) onto a flexible polyethylene terephthalate (PET) film. The amount of coated SWCNTs was controlled simply by dipping number. Because the performance of SWCNT-based TCFs is influenced by both electrical conductance and optical transmittance, we evaluated the film performance by introducing a film property factor using both the number of interconnected SWCNT bundles at intersection points, and the coverage of SWCNTs on the PET substrate, in field emission scanning electron microscopic images. The microscopic film property factor was in an excellent agreement with the macroscopic one determined from electrical conductance and optical transmittance measurements, especially for a small number of dippings. Therefore, the most crucial factor governing the performance of the SWCNT-based TCFs is a SWCNT-network structure with a large number of intersection points for a minimum amount of deposited SWCNTs.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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• pp.75-80
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• 2008

Recently, Energy savings in buildings has received much attention in response to the increased needs for global warming and better comforts of the occupants in apartment housing. This study proposes the method which uses the sun control window film to reduce the cooling load and heating load improving the thermal performance of the building and it improves an energy efficiency. The film which used in actual measurement has a low shading coefficient and a solar energy transmission. so we measured the surface temperature of the triple Low-e glazing system used and inside temperature according to the change of outside temperature and solar energy to study thermal performance evaluation. As a result, it was helpful to use window film insulation to reduce inside temperature in summer and to keep room warm in winter.

• 설비공학논문집
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• 제7권3호
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• pp.512-520
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• 1995

This study investigates the simultanceous heat and mass transfer between a falling desiccant film and air in cross flow at the interface. The application of this work is the optimization of falling film evaporators for use in potential hybrid air conditioning systems. The specific geometry considered is liquid TEG films falling along the vertical cooled surfaces of a channel with air in cross flow. The equations to describe the coupled heat and mass transfer between a falling desiccant film and air in cross flow for a falling film evaporator have been presented and solved numerically. The effects of important design and operating variables on the evaporator performance predicted by the parametric numerical analysis and suggestions for performance improvements of the evaporator are presented.

• 설비공학논문집
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• 제19권11호
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• pp.797-802
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• 2007

The effects of window cover on the performance of the plate type radiant cooling test system are studied. The cover materials tested are 2mm, 1mm, 0.7mm glass, Cokin 007 filter, and PVC film. The measurements are performed during the September nights of 2005 at the rooftop of the building in Seoul. The equivalent height of the building is about a building with twelve floors. The radiant cooling performance of the black painted and aluminum film coated plate are compared under no cover condition. Also the results are compared when the system has cover over the plate. In general, the covers reduce the radiant cooling temperature differences during the nighttime. Among these covers, the PVC film cover shows the best performance. In some cases, the plate with PVC film cover shows lower temperatures than the system without cover.