검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 667

        221.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        플라스틱하우스 피복재의 광 이용효율을 높이기 위해 제조과정에 적색, 청색, 적색+청색 수지를 추가로 첨가하여 제조한 필름을 피복한 시설 내에서 토마토와 고추를 재배하였으며 시설 내 광 환경 변화와 작물의 생육, 수량 등을 조사하였다. 대체로 일반필름에 비하여 적색 및 청색 수지를 첨가한 필름에서 광합성유효복사의 투과량이 5~6% 많았고, 300~1,100nm의 광투과율은 0.5~1.0% 높게 나타났다. 피복재 중에는 적색+청색 혼합수지 첨가필름에서 토마토와 고추의 건물중이 높게 나타났고 일반필름에 비해 과실수량이 15~20% 많았으며 과실 당도도 약 0.5˚Bx. 높았다.
        4,000원
        222.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper describes the results of the application of Cr-Diamond-like carbon (DLC) films for efficiency improvement through surface modification of spur gear parts in the hydraulic gear pump. Cr-DLC films were successfully deposited on SCM 415 substrates by a hybrid coating process using linear ion source (LIS) and magnetron sputtering method. The characteristics of the films were systematically investigated using FE-SEM, nano-indentation, sliding tester and AFM instrument. The microstructure of Cr-DLC films turned into the dense and fine grains with relatively preferred orientation. The thickness formed in our Cr buffer layer and DLC coating layer were obtained the 487 nm and . The average friction coefficient of Cr-DLC films considerably decreased to 0.15 for 0.50 of uncoated SCM415 material. The hardness and surface roughness of Cr-DLC films were measured 20 GPa and 10.76 nm, respectively. And then, efficiency tests were performed on the hydraulic gear pump to investigate the efficiency performance of the Cr-DLC coated spur gear. The experimental results show that the volumetric and mechanical efficiency of hydraulic gear pump using the Cr-DLC spur gear were improved up to 2~5% and better efficiency improvement could be attributed to its excellent microstructure, higher hardness, and lower friction coefficient. This conclusion proves the feasibility in the efficiency improvement of hydraulic gear pump for industrial applications.
        4,000원
        223.
        2010.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        There have been many efforts to modify and improve the properties of functional thin films by hybridization with nano-sized materials. For the fabrication of electronic circuits, micro-patterning is a commonly used process. For photochemical metal-organic deposition, photoresist and dry etching are not necessary for microscale patterning. We obtained direct-patternable SnO2 thin films using a photosensitive solution containing Ag nanoparticles and/or multi-wall carbon nanotubes (MWNTs). The optical transmittance of direct-patternable SnO2 thin films decreased with introduction of nanomaterials due to optical absorption and optical scattering by Ag nanoparticles and MWNTs, respectively. The crystallinity of the SnO2 thin films was not much affected by an incorporation of Ag nanoparticles and MWNTs. In the case of mixed incorporation with Ag nanoparticles and MWNTs, the sheet resistance of SnO2 thin films decreased relative to incorporation of either single component. Valence band spectral analyses of the nano-hybridized SnO2 thin films showed a relation between band structural change and electrical resistance. Direct-patterning of SnO2 hybrid films with a line-width of 30 μm was successfully performed without photoresist or dry etching. These results suggest that a micro-patterned system can be simply fabricated, and the electrical properties of SnO2 films can be improved by incorporating Ag nanoparticles and MWNTs.
        4,000원
        224.
        2010.08 구독 인증기관 무료, 개인회원 유료
        장르 영화의 이데올로기는 이제 과감한 컴퓨터그래픽과 화려한 스펙터클 그리고 입체라는 새로운 기술전략으로 관객에게 승부를 걸고 있다. 하지만 그럼에도 불구하고 이데올로기에 봉합되지 않고 예술로서 영화의 책무를 끊임없이 보여주려는 노력 또한 여전히 존재한다. 그러한 노력은 폭로와 전복의 미학을 통해 가능한 것이다. 디지털은 바로 이러한 면에 있어서 이율배반적 기능을 수행하게 된다. 관객에게 거칠고 날카로운 그들의 삶을 여과 없이 보여주기 위해 디지털은 자기의 모든 장식적 껍질을 벗어버리게 되는 것이다. 디지털 0과 1의 픽셀미학은 이미지의 아방가르드적 현존을 가능하게 하며 관객의 능동적 참여를 이끌어 내게 한다. ‘국내 디지털 아방가르드 영화 <자본당 선언, 만국의 노동자여 축적하라>는 바로 이러한 진화의 한 축을 이루는 진보적인 국내 실험영화 중 하나이다. 이에 본 연구는 국내 디지털 아방가르드 영화<자본당 선언, 만국의 노동자여 축적하라>의 숭고미학에 있어서 탈이데올로기적 특징을 리오타르의 이론을 통하여 고찰해 볼 것이다.
        5,500원
        225.
        2010.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        MgTiO3 thin films were prepared by r.f. magnetron sputtering in order to prepare miniaturized NPO type MLCCs.MgTiO3 films showed a polycrystalline structure of ilmenite characterized by the appearance of (110) and (202) peaks. Theintensity of the peaks decreased with an increase in the chamber pressure due to the decrease of crystallinity which resultedfrom the decrease of kinetic energy of the sputtered atoms. The films annealed at 600oC for 60min. showed a fine grainedmicrostructure without micro-cracks. The grain size and roughness of the MgTiO3 films decreased with the increase of chamberpressure. The average surface roughness was 1.425~0.313nm for MgTiO3 films prepared at 10~70mTorr. MgTiO3 films showeda dielectric constant of 17~19.7 and a dissipation factor of 2.1~4.9% at 1MHz. The dielectric constant of the films is similarto that of bulk ceramics. The dielectric constant and the dissipation factor decreased with the increase of the chamber pressuredue to the decrease of grain size and crystallinity. The leakage current density was 10−5~10−7A/cm2 at 200kV/cm and this valuedecreased with the increase of the chamber pressure. The small grain size and smooth surface microstructure of the filmsdeposited at high chamber pressure resulted in a low leakage current density. MgTiO3 films showed a near zero temperaturecoefficient and satisfied the specifications for NPO type materials. The dielectric properties of the MgTiO3 thin films preparedby sputtering suggest the feasibility of their application for MLCCs.
        4,000원
        226.
        2010.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We investigated the electrochemical properties for Langmuir-Blodgett(LB) films mixed with l-bromotetradecane(Cl4), l-bromohexadecane(Cl6), and l-bromooctadecane(Cl8). The alkyl bromides mixture was deposited by using the Langmuir-Blodgett method on the ITO glass. The electrochemical properties measured by using cyclic voltammetry with a three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) at various concentrations(0.5, 1.0, 1.5 and 2.0 N) of NaClO4 solution. A measuring range was reduced from initial potential to -1350 m V, continuously oxidized to 1650 mV. The scan rate was 100 mV/s. As a result, LB films of Cl4, Cl6, and Cl8 mixture monolayers appeared irreversible process caused by only the oxidation current from the cyclic voltammogram. The diffusivity(D) effect of LB films decreased with increasing of alkyl bromides amount.
        4,000원
        227.
        2010.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A non-volatile resistive random access memory (RRAM) device with a Cr-doped SrZrO3/SrRuO3 bottom electrode heterostructure was fabricated on SrTiO3 substrates using pulsed laser deposition. During the deposition process, the substrate temperature was 650˚C and the variable ambient oxygen pressure had a range of 50-250 mTorr. The sensitive dependences of the film structure on the processing oxygen pressure are important in controlling the bistable resistive switching of the Cr-doped SrZrO3 film. Therefore, oxygen pressure plays a crucial role in determining electrical properties and film growth characteristics such as various microstructural defects and crystallization. Inside, the microstructure and crystallinity of the Cr-doped SrZrO3 film by oxygen pressure were strong effects on the set, reset switching voltage of the Cr-doped SrZrO3. The bistable switching is related to the defects and controls their number and structure. Therefore, the relation of defects generated and resistive switching behavior by oxygen pressure change will be discussed. We found that deposition conditions and ambient oxygen pressure highly affect the switching behavior. It is suggested that the interface between the top electrode and Cr-doped SrZrO3 perovskite plays an important role in the resistive switching behavior. From I-V characteristics, a typical ON state resistance of 100-200 Ω and a typical OFF state resistance of 1-2 kΩ, were observed. These transition metal-doped perovskite thin films can be used for memory device applications due to their high ON/OFF ratio, simple device structure, and non-volatility.
        4,000원
        228.
        2010.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We investigated the carbon monoxide (CO) gas-sensing properties of nanostructured Al-doped zinc oxide thin films deposited on self-assembled Au nanodots (ZnO/Au thin films). The Al-doped ZnO thin film was deposited onto the structure by rf sputtering, resulting in a gas-sensing element comprising a ZnO-based active layer with an embedded Pt/Ti electrode covered by the self-assembled Au nanodots. Prior to the growth of the active ZnO layer, the Au nanodots were formed via annealing a thin Au layer with a thickness of 2 nm at a moderate temperature of 500˚C. It was found that the ZnO/Au nanostructured thin film gas sensors showed a high maximum sensitivity to CO gas at 250˚C and a low CO detection limit of 5 ppm in dry air. Furthermore, the ZnO/Au thin film CO gas sensors exhibited fast response and recovery behaviors. The observed excellent CO gas-sensing properties of the nanostructured ZnO/Au thin films can be ascribed to the Au nanodots, acting as both a nucleation layer for the formation of the ZnO nanostructure and a catalyst in the CO surface reaction. These results suggest that the ZnO thin films deposited on self-assembled Au nanodots are promising for practical high-performance CO gas sensors.
        4,000원
        229.
        2010.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Transparent conductive films of single wall carbon nanotube (SWCNT) were prepared by spray coating method. The effect of acid treatment on the SWCNT films was investigated. The field emission scanning electron microscope (FESEM) shows that acid treatment can remove dispersing agent. The electrical and optical properties of acid-treated films were enhanced compared with those of as deposited SWCNT films. Nitric acid (HNO3), sulfuric acid (H2SO4), nitric acid:sulfuric acid (3:1) were used for post treatment. Although all solutions reduced sheet resistance of CNT films, nitric acid can improve electrical characteristics efficiently. During acid treatment, transmittance was increased continuously with time. But the sheet resistance was decreased for the first 20 minutes and then increased again. Post-treated SWCNT films were transparent (85%) in the visible range with sheet resistance of about 162Ω/sq. In this paper we discuss simple fabrication, which is suitable for different types of large-scale substrates and simple processes to improve properties of SWCNT films.
        3,000원
        230.
        2010.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        CuInSe2 (CIS) thin films were electrodeposited on Mo-coated glass substrates in acidic solutionscontaining Cu2+, In3+, and Se4+ ions, depending on deposition parameters such as deposition potential (-0.4 to-0.8V[SCE]) and pH (1.7 to 1.9). The influences of PH and deposition potential on the atomic composition ofCu, In, and Se in the deposited films were observed. The best chemical composition, approaching 1:1:2 atomicratio for the elements, was achieved at -0.5V (SCE) and pH 1.8. The as-deposited films showed low crystallinityand were annealed at 300 to 500oC for 30 min to improve crystallization. The surface morphologies,microstructures, and crystallographic structures of the annealed films as well as the as-deposited films wereanalyzed with AFM, SEM, and XRD. The defects of spherical particles appeared on the surfaces of CIS thinfilms in the as-deposited state and decreased in size and number with increasing annealing temperatures.Additionally, the crystallization to chalcopyrite structure and surface roughness (Ra) of the as-deposited thinfilms were improved with the annealing process.
        4,000원
        231.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This cycloaddition of [70]fullerene with methyl azidoacetate in benzene under ultrasonic irradiated condition afforded the closed [5,6]-bridged aziridino[70]fullerene derivative, which was unusual product of cycloaddition to the 5,6-junction of fullerene. Its structure was determined by FAB-MS, UV-vis, 1H- and 13C-NMR spectral data. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films were self-assembled using the layer-by-layer method on the reactive of glass slides functionalized with 3-mercaptopropyl trimethoxysilane. The functionalized glass slides were alternately soaked in the solution containing closed the [5,6]-bridged aziridino[70]fullerene and 4-aminothiophenoxide/hexanethiolate-protected gold nanoparticles. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films have grown up to 5 layers depending on the immersion time. The self-assembled nanoparticle multilayer films were characterized using UV-vis spectroscopy showed that the surface plasmon band of gold at 527 nm gradually became more evident as successive layers were added to the films.
        3,000원
        232.
        2009.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        BiFeO3 (BFO) thin films were prepared on Pt/TiO2/Si substrate by r.f. magnetron sputtering. The effects of deposition pressure on electrical properties were investigated using measurement of dielectric properties, leakage current and polarization. When BFO targets were prepared, Fe atoms were substituted with Mn 0.05% to increase electrical resistivity of films. (Fe+Mn)/Bi ratio of BFO thin films increases with increasing partial pressure of O2 gas. The deposited films showed the only BFO phase at 10 mTorr, the coexistence of BFO and Bi2O3 phase at 30-50 mTorr, and the only Bi2O3 phase at 70 mTorr. The crystallinity of BFO films was reduced due to the higher Bi contents and the decrease of surface mobility of atoms at high temperature. The porosity and surface roughness of films increased with the increase of the deposition pressure. The films deposited at high pressure showed low dielectric constant and high leakage current. The dielectric constant of films deposited at various deposition pressures was 84~153 at 1 kHz. The leakage current density of the films deposited at 10~70 mTorr was about 7×10.6~1.5×10.2A/cm2 at 100 kV/cm. The leakage current was found to be closely related to the morphology and composition of the BFO films. BFO films showed poor P-E hysteresis loops due to high leakage current.
        4,000원
        233.
        2009.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Thin films of single-wall carbon nanotubes (SWNT) with various thicknesses were fabricated, and their optical andelectrical properties were investigated. The SWNTs of various thicknesses were directly coated in the arc-discharge chamberduring the synthesis and then thermally and chemically purified. The crystalline quality of the SWNTs was improved by thepurification processes as determined by Raman spectroscopy measurements. The resistance of the film is the lowest for thechemically purified SWNTs. The resistance vs. thickness measurements reveal the percolation thickness of the SWNT film tobe ~50nm. Optical absorption coefficient due to Beer-Lambert is estimated to be 7.1×10-2nm-1. The film thickness for 80%transparency is about 32nm, and the sheet resistance is 242Ω/sq. The authors also confirmed the relation between electricalconductance and optical conductance with very good reliability by measuring the resistance and transparency measurements.
        4,000원
        234.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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 0.2~0.5˚Bx 더 높았고, 과실 내 라이코펜 함량이 15~30% 높게 나타났다. 따라서 토마토의 당도, 라이코펜 함량 등의 품질향상을 위해서는 일반필름 대신에 기능성필름을 이용하는 것이 효과적일 것으로 판단되었다.
        4,000원
        235.
        2009.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO wire-like thin films were synthesized through thermal oxidation of sputtered Zn metal films in dry air. Their nanostructure was confirmed by SEM, revealing a wire-like structure with a width of less than 100 nm and a length of several microns. The gas sensors using ZnO wire-like films were found to exhibit excellent H2 gas sensing properties. In particular, the observed high sensitivity and fast response to H2 gas at a comparatively low temperature of 200˚C would lead to a reduction in the optimal operating temperature of ZnO-based H2 gas sensors. These features, together with the simple synthesis process, demonstrate that ZnO wire-like films are promising for fabrication of low-cost and high-performance H2 gas sensors operable at low temperatures. The relationship between the sensor sensitivity and H2 gas concentration suggests that the adsorbed oxygen species at the surface is O-.
        4,000원
        236.
        2009.08 구독 인증기관 무료, 개인회원 유료
        현재 방송 영화 기록물은 수집 관리 체계가 미흡하여 망실의 위험이 상존하고 있다. 또한 수집 관리 기관의 이해관계에 따라 국가 기록물의 접근이 폐쇄적이다. 따라서 영구보존 가치를 지닌 방송프로그램 영화 기록정보 수집관리를 체계화하여, 국가의 역사 문화 기록유산으로 보존 및 활용을 위한 중장기 계획을 수립하여 추진하여야 할 것이다. 본 연구는 선진 국가의 방송 영화 기록물 체계를 비교 분석하여 우리나라 기록물 수집 관리 제도의 문제점을 도출하고 개선 방안을 제시하고자 한다. 연구결과, 방송프로그램의 경우 프랑스와 미국 등은 방송프로그램에 대한 법적 의무납본 및 자발적 납본을 채택하고 전문적인 공공방송영상아카이브를 운영, 안정적으로 수집 관리하고 있다. 영화의 경우엔, 거의 모든 선진 외국이 의무 납본제를 통해 체계적으로 관리하고 있다. 이에 우리나라에서도 총괄 관리 기능을 수행할 독립적인 성격의 국립 방송 영화 아카이브 설립될 필요가 있으며 안정적인 방송영화 기록물의 수집을 위해 의무 납본제를 실시하여 국가기록물의 멸실을 방지해야 할 것이다. 이를 위해서는 법, 제도의 개정이 필수적으로 이루어져야 할 것이다.
        6,100원
        237.
        2009.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Indium Tin Oxide (ITO) thin films on Polyethylene Terephtalate (PET) substrate were prepared by Roll-to-Roll sputter system with targets of 5 wt% and 10 wt% SnO2 at room temperature. The influence of the chromaticity (b*) and transmittance properties of the ITO Films were investigated. The ITO thin films were deposited as a function of the DC power, rolling speed, and Ar/O2 gas flow ratio, and then characterized by spectrophotometer. Their crystallinity and surface resistance were also analyzed by X-ray diffractometer and 4-point probe. As a result, the chromaticity (b*) and transmittance of the ITO films were broadly dependent on the thickness, which was controlled by the rolling speed. When the ITO films were prepared with the DC power of 300 W and the Ar/O2 gas flow ratio of 30/1 sccm using 10 wt% SnO2 target as a function of the rolling speeds 0.01 through 0.10 m/min, its chromaticity (b*) and transmittance were about -4.01 to 11.28 and 75.76 to 86.60%, respectively. In addition, when the ITO films were deposited with the DC power of 400W and the Ar/O2 gas flow ratio of 30/2 sccm used in 5 wt% SnO2 target, its chromaticity (b*) and transmittance were about -2.98 to 14.22 and 74.29 to 88.52%, respectively.
        4,000원
        238.
        2009.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The deposition behavior and structural and magnetic properties of electroless Co-B and Co-Fe-B deposits, as well as the amorphous ribbon substrates, were investigated. These Co-based alloy deposits exhibited characteristic polycrystalline structures and surface morphology and magnetic properties that were dependent on the type of amorphous substrates. The catalytic activity sequence of the amorphous ribbon electrodes for anodic oxidation of DMAB was estimated from the current density-potential curve in the anodic partial electrolytic bath that did not contain the metal ions. Both the deposition rate and potential in the initial region were obtained in order of the catalytic activity, depending on the alloy compositions of the substrates. The deposition rate linearly varied against the deposition time. The initial deposition potential may have also determined the structural and magnetic properties of the deposit based on the thickness of μm order. Furthermore, a basic study of the electroless deposition processes on an amorphous ribbon substrate has been carried out in connection with the structural and magnetic properties of the deposits.
        4,000원
        239.
        2009.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        ZnO thin film was grown on a sapphire single crystal substrate by plasma assisted molecular beamepitaxy. In addition to near band edge (NBE) emissions, both blue and green luminescences are also observedtogether. The PL intensity of the blue luminescence (BL) range from 2.7 to 2.9eV increased as the amountof activated oxygen increased, but green luminescence (GL) was weakly observed at about 2.4eV without muchchange in intensity. This result is quite unlike previous studies in which BL and GL were regarded as thetransition between shallow donor levels such as oxygen vacancy and interstitial zinc. Based on the transitionlevel and formation energy of the ZnO intrinsic defects predicted through the first principle calculation, whichemploys density functional approximation (DFA) revised by local density approximation (LDA) and the LDA+Uapproach, the green and blue luminescence are nearly coincident with the transition from the conduction bandto zinc vacancies of V2-Zn and V-Zn, respectively.
        4,000원
        240.
        2009.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study we investigated the effect of the multi-step texturing process on the electrical and optical properties of hydrogenated Al-doped zinc oxide (HAZO) thin films deposited by rf magnetron sputtering. AZO films on glass were prepared by changing the H2/(Ar+H2) ratio at a low temperature of 150˚C. The prepared HAZO films showed lower resistivity and higher carrier concentration and mobility than those of non-hydrogenated AZO films. After deposition, the surface of the HAZO films was multi-step textured in diluted HCl (0.5%) for the investigation of the change in the optical properties and the surface morphology due to etching. As a result, the HAZO film fabricated under the type III condition showed excellent optical properties with a haze value of 52.3%.
        4,000원