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        검색결과 16

        1.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tomatoes in greenhouse are a widely cultivated horticultural crop worldwide, accounting for high production and production value. When greenhouse ventilation is minimized during low temperature periods, CO2 enrichment is often used to increase tomato photosynthetic rate and yield. Plant-induced electrical signal (PIES) can be used as a technology to monitor changes in the biological response of crops due to environmental changes by using the principle of measuring the resistance value, or impedance, within the crop. This study was conducted to investigate the relationship between tomato growth data, vital response, and PIES resulting from CO2 enrichment in greenhouse tomatoes. The growth of tomato treated with CO2 enrichment in the morning was significantly better in all items except stem diameter compared to the control, and PIES values were also higher. The growth of tomato continuously applied with CO2 was better in the treatment groups than control, and there was no significant difference in chlorophyll fluorescence and photosynthesis. However, PIES and SPAD values were higher in the CO2 treatment group than control. CO2 enrichment have a direct relationship with PIES, growth increased, and transpiration increased due to the increased leaf area, resulting in increased water absorption, which appears to be reflected in PIES, which measures vascular impedance. Through this, this study suggests that PIES can be used to monitor crops due to environmental changes, and that PIES is a useful method for non-destructively and continuously monitoring changes of crops.
        4,000원
        3.
        2023.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        AZO/Cu/AZO thin films were deposited on glass by RF magnetron sputtering. The specimens showed the preferred orientation of (0002) AZO and (111) Cu. The Cu crystal sizes increased from about 3.7 nm to about 8.5 nm with increasing Cu thickness, and from about 6.3 nm to about 9.5 nm with increasing heat treatment temperatures. The sizes of AZO crystals were almost independent of the Cu thickness, and increased slightly with heat treatment temperature. The residual stress of AZO after heat treatment also increased compressively from -4.6 GPa to -5.6 GPa with increasing heat treatment temperature. The increase in crystal size resulted from grain growth, and the increase in stress resulted from the decrease in defects that accompanied grain growth, and the thermal stress during cooling from heat treatment temperature to room temperature. From the PL spectra, the decrease in defects during heat treatment resulted in the increased intensity. The electrical resistivities of the 4 nm Cu film were 5.9 × 10-4 Ω ‧ cm and about 1.0 × 10-4 Ω ‧ cm for thicker Cu films. The resistivity decreased as the temperature of heat treatment increased. As the Cu thickness increased, an increase in carrier concentration resulted, as the fraction of AZO/Cu/AZO metal film increased. And the increase in carrier concentration with increasing heat treatment temperature might result from the diffusion of Cu ions into AZO. Transmittance decreased with increasing Cu thicknesses, and reached a maximum near the 500 nm wavelength after being heat treated at 200 °C.
        4,000원
        4.
        2022.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A spin coating process for RRAM, which is a TiN/TiO2/FTO structure based on a PTC sol solution, was developed in this laboratory, a method which enables low-temperature and eco-friendly manufacturing. The RRAM corresponds to an OxRAM that operates through the formation and extinction of conductive filaments. Heat treatment was selected as a method of controlling oxygen vacancy (VO), a major factor of the conductive filament. It was carried out at 100 oC under moisture removal conditions and at 300 oC and 500 oC for excellent phase stability. XRD analysis confirmed the anatase phase in the thin film increased as the heat treatment increased, and the Ti3+ and OH- groups were observed to decrease in the XPS analysis. In the I-V analysis, the device at 100 oC showed a low primary SET voltage of 5.1 V and a high ON/OFF ratio of 104. The double-logarithmic plot of the I-V curve confirmed the device at 100 oC required a low operating voltage. As a result, the 100 oC heat treatment conditions were suitable for the low voltage driving and high ON/OFF ratio of TiN/TiO2/FTO RRAM devices and these results suggest that the operating voltage and ON/OFF ratio required for OxRAM devices used in various fields under specific heat treatment conditions can be compromised.
        4,000원
        5.
        2022.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Ti3C2Tx MXene, which is a representative of the two-dimensional MXene family, is attracting considerable attention due to its remarkable physicochemical and mechanical properties. Despite its strengths, however, it is known to be vulnerable to oxidation. Many researchers have investigated the oxidation behaviors of the material, but most researches were conducted at high temperatures above 500 oC in an oxidation-retarding environment. In this research, we studied changes in the structural and electrical properties of Ti3C2Tx MXene induced by low-temperature heat treatments in ambient conditions. It was found that a number of TiO2 particles were formed on the MXene surface when it was mildly heated to 200 oC. Heating the material to higher temperatures, up to 400 oC, the phase transformation of Ti3C2Tx MXene to TiO2 was accelerated, resulting in a TiO2/ Ti3C2Tx hybrid. Consequently, the metallic nature of pure Ti3C2Tx MXene was transformed to semiconductive behavior upon heat-treating at ≥ 200 oC. The results of this research clearly demonstrate that Ti3C2Tx MXene may be easily oxidized even at low temperatures once it is exposed to air.
        4,000원
        6.
        2015.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, in order to improve the thermal and electrical properties of epoxy/graphene nanoplatelets (GNPs), surface modifications of GNPs are conducted using silane coupling agents. Three silane coupling agents, i.e. 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (ETMOS), 3-glycidoxypropyltriethoxysilane (GPTS), and 3-glycidoxypropyltrimethoxysilane (GPTMS), were used. Among theses, GPTMS exhibits the best modification performance for fabricating GNP-incorporated epoxy composites. The effect of the silanization is evaluated using transmission electron microscopy (TEM), scanning electron microscopy, thermogravimetric analysis, and energy dispersive X-ray spectroscopy. The electrical and thermal conductivities are characterized. The epoxy/silanized GNPs exhibits higher thermal and electrical properties than the epoxy/raw GNPs due to the improved dispersion state of the GNPs in the epoxy matrix. The TEM microphotographs and Turbiscan data demonstrate that the silane molecules grafted onto the GNP surface improve the GNP dispersion in the epoxy.
        4,000원
        7.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 뇌경색으로 인한 연하장애 환자를 운동자극군과 감각자극군으로 나누어 전기자극치료를 적용하였을 때에 각각의 치료 효과를 확인하고 두 치료간의 효과 차이를 비교해보고자 하였다. 연구방법 : 본 연구는 뇌경색으로 연하장애가 발생하였고, 전기 자극의 강도를 결정하기 위하여 의사표현이 가능한 사람 을 대상으로 하였다. 전기자극치료는 1일 1회, 30분 동안, 일주일에 5회, 4주간 실시하였으며 전기자극치료 전에 운동 자극군과 감각자극군 모두에게 구강운동치료를 30분씩 적용하였다. 전기자극치료의 효과를 알아보기 위해 전기자극 치료 전과 4주 간의 치료 후에 비디오투시검사를 실시하였으며, 기능적 연하곤란 척도, 침습-흡인 척도, 미국언어청 각협회 연하척도를 이용하여 평가하였다. 결과 : 전기자극치료 전에 두군 사이에서 삼킴 기능에는 차이가 없었고(p>.05), 4주간의 전기자극치료 후에 두군 모두에 서 기능적 연하곤란 척도의 인두기 총점, 미국언어청각협회 연하 척도에서 삼킴 기능의 유의한 향상을 보였으며 (p<.05), 삼킴 후 잔여물이 유의하게 감소하였다(p<.05). 침습-흡인 척도는 운동자극군은 연식에서만 유의하게 향상 되었으나(p<.05), 감각자극군에서는 모든 검사식에서 유의하게 향상되었다(p<.05). 자극 강도에 따른 치료 효과를 비 교하였을 때에는 두군 사이에 삼킴 기능의 향상 정도는 유의한 차이가 없었다(p>.05). 결론 : 본 연구를 통해 연하장애의 치료를 위한 전기자극치료 시에 감각자극만으로도 삼킴 기능의 향상에 효과가 있으며 감각자극이 침습과 흡인의 감소에 효과적이라는 것을 알 수 있으므로 임상에서 전기 자극 강도를 조절하여 적용할 수 있을 것이라 기대한다.
        4,800원
        8.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this present work, the effect of additional heat-treatment (AHT) in the range from 1800℃ to 2400℃ on the chemical composition, morphology, microstructure, tensile properties, electrical resistivity, and thermal stability of commercial polyacrylonitrile (PAN)-based carbon fibers was explored by means of elemental analysis, electron microscopy, X-ray diffraction analysis, single fiber tensile testing, two-probe electrical resistivity testing, and thermogravimetric analysis (TGA). The characterization results were in agreement with each other. The results clearly demonstrated that AHTs up to 2400℃ played a significant role in further contributing not only to the enhancement of carbon content, fiber morphology, and tensile modulus, but also to the reduction of fiber diameter, inter-graphene layer distance, and electrical resistivity of "as-received" carbon fibers without AHT. The present study suggests that key properties of commercial PAN-based carbon fibers of an intermediate grade can be further improved by proprietarily adding heat-treatment without applying tension in a batch process.
        4,000원
        10.
        2006.03 구독 인증기관 무료, 개인회원 유료
        Electrical treatment has been widely used for porcine oocytes activation. However, developmental rates following electrical activation of porcine oocytes is relatively inefficient compared to other domestic animals. To investigate the effects of porcine oocytes on combined activation by both chemical and electrical treatment, in-vitro matured oocytes were activated by combined cycloheximide and electrical pulses treatment. Cumulus-free oocytes were exposed with NCSU-23 medium containing cycloheximide (10μgml) for 0, 5, 10, 20, 30 min and then activated by electrical pulse treatment and cultured in PZM-3 for 8 days. Also effects of exposure to 6.25μM calcium ionophore for 2 min for cumulus-free oocytes were tested. The percentage of blastocyst formation in 10 min exposure to 10μgml cycloheximide and electrical pulse treatment was significantly increased (P<0.05) than in the control group. And exposure to 6.25μM calcium ionophore for 2 min with 10μgml cycloheximide for 10min and electrical pulse treatment significantly increased (P<0.05) the percentage of blastocyst developmental rates than the control group. In conclusion, activation by combined cycloheximide and electrical stimulation treatment promoted the subsequent development of porcine oocytes and improved the subsequence blastocyst development
        4,000원
        13.
        2002.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to investigate the effect of irradiation by 60Co-γrays as well as the e thermal treatment on the dielectric deterioration in ethylene propylene rubber, insulating material for electric cables used in atomic power plants, charging discharging current, residual built- up voltage and dielectric properties are measu discussed in this study. Variance in the characteristic of relative dielectric constant as a function of tem was observed in relatively high dose of irradiation. Since glass transition tem appeared at tens of degree Celsius below zero, the characteristic is attributed orientation polarization. Dielectric loss is generally increased, with increasing d irradiation in the characteristic of dielectric loss as a function of temperature, No d loss by thermal treatment was observed. Dielectric resistance decreases with increa of irradiation in the characteristic of charging current as a function of temperature be considered that dielectric resistance seems to be recovered by thermal treatm characteristic of discharging current as a function of time in the specimen less ir become similar to that of the unirradiated, when thermal treated. A peak is shown residual built- up voltage as a function of time, and the corresponding time of the shorten as increasing dose of irradiation. It is also observed that the corresponding the peak is lengthened by thermal treatment.
        4,000원
        15.
        1995.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        BST 박막을 Pt/SiO2/Si 기판위에 co-sputtering 방법으로 형성할 때 열처리 조건이 BST 박막의 결정성과 전기적 특성에 미치는 영향에 관하여 연구하였다. BST 박막의 특성은 급속 열처리나 관상로 열처리과 같은 후열처리 온도보다 증착시의 기판온도에 따라서 민감하게 변화하였고, 기판 온도를 550˚C로 하여 증착할대 Perovskite상이 가장 안정적으로 성장하여 유전율 1100, 유전손실계수 0.02로 우수한 유전특성을 나타내는 막을 형성할 수 있었다. BST 박막은 기판온도를 증가하면 정합에너지와 표면에너지를 최소로하는 (111) 방향으로 우선방위를 나타내었고 결정립의 조대화 현상으로 누설전류가 증가하였다.
        4,000원