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        검색결과 1,071

        161.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plant regeneration from stems and leaves was carried out for the growth of biomass, hybrid poplar(Populus alba x P. glandulosa)clone, which has various uses for plant purification. Callus was well induced when stem and leaf tissues were cultured in 1.0 mg/L 2,4-D containing MS medium. Shoot regeneration was best induced by zeatin among growth regulators, and Plant regeneration was more regenerated in leaf-derived callus than in stem-derived callus. The growth of regenerated shoots at high and low concentrations of zeatin was similar to that of the control at low concentrations. As the concentration of growth regulators increased, the growth of regenerated shoots showed a big difference among individuals. Hybrid poplar showed color variation of plant stem in medium containing high concentration of growth regulator. Regenerated individuals were in vitro rooted in MS medium containing 0.5 mg/L IBA after 2 weeks of culture. and transferred to the greenhouse for acclimatization. The study is believed to be widely used for the induction of in vitro variants through organogenesis.
        4,000원
        162.
        2020.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Two different casting speeds of 60 and 80mm/min are adopted to determine the effect of casting speed on the microstructure and mechanical properties of Al-Mg-Si/Al hybrid material prepared by duo-casting. The obtained hybrid material has a uniform and straight macro-interface between the pure Al side and the Al-Mg-Si alloy side at both casting speeds. When the casting speed is increased to 80mm/min, the size of primary α phases in Al-Mg-Si alloy decreases, without change of shape. Although the Al-Mg-Si alloy produced at higher casting speed of 80mm/min shows much higher ultimate tensile strength (UTS) and 0.2 % proof stress and lower elongation, along with higher bending strength compared to the case of the 60mm/min in casting speed, the tensile properties and bending strength of the hybrid material, which are similar to those of pure Al, are the same regardless of the increase of casting speed. Despite the different casting speeds, deformation and fracturing in hybrid materials are observed only on the pure Al side. This indicates that the macro-interface is well-bonded, allowing it to endure tensile and bending deformation in all hybrid materials.
        4,000원
        163.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to evaluate the effects of different nitrogen levels on the yield and nutrient quality of a newly developed domestic hybrid of Teosinte, Geukdong 6〔Zea mays L. subsp. mexicana (Schrad.) H. H. Iltis〕. The field experiment was conducted in a randomized block design with three replicates and consisted of four nitrogen (N) application rates, T1 (200 kg/ha), T2 (300 kg/ha), T3 (400 kg/ha), and T4 (500 kg/ha). No differences were found in plant length, leaf length, leaf width, leaf number, dead leaves, stem hardness, tiller number, and fresh yield (p>0.05). The T3 showed significantly greater dry matter yield at harvest (heading stage) compared to the other treatments (p<0.05). The crude protein content of T4 (10.49%) was higher than those of T1 and T2 (p<0.05). However, there was no significant difference between T4 (10.49%) and T3 (9.63%). The effects on crude fat, crude ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber were not significant (p>0.05). The sugar content was higher in the T2 treatment than the other treatments (p<0.05). For Ca, T3 showed significantly greater content (p<0.05). However, no significant effects were found in the contents of Cu, Fe, K, Mg, Mn, Mo, and Zn (p>0.05). Na content was higher in order of T2 > T4 > T3 > T1 (p<0.05). Total mineral contents were not significantly different among the treatments (p>0.05). Given these results, we recommend the amount of nitrogen fertilization necessary for “Geukdong 6” to be around 400 kg per ha (T3), when considering, high fresh yield, dry matter yield, number of leaves and content of crude protein.
        4,000원
        164.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험에서 아질산 급성노출은 대왕범바리의 혈액학적 성상 및 혈장성분에 유의적 변화를 나타내었다. 혈액학적 성상인 Hct와 Hb는 아질산 노출에 의한 유의적 감소를 확인하였다. 혈장 성분인 glucose, cholesterol, GPT 및 ALP는 아질산 노출에 의해 유의적으로 변화를 나타냄을 확인 하였다. 본 실험의 결과 아질산 노출 100 mg L-1 이상의 농도는 대왕범바리의 혈액 성상 및 혈장 성분의 유의적 영향을 미치며, 800 mg L-1의 아질산 급성 노출은 대량 폐사를 유발할 수 있으나, 기존 국내 양식 대상종인 Olive flounder, P. Olivaceus는 171.043 mg L-1 (Kim et al. 2018), Yellow tail, Seriola quinqueradiata는 147 mg L-1 (Sugiyama et al. 1991)에 비해 상대적으로 높은 값을 보여 아질산 내성이 상대적으로 강함을 확인할 수 있었다.
        4,000원
        165.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험에서 암모니아 급성 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 유의적 변화를 나타내었다. 본 실험의 결과 20 mg L-1 이상의 급성 암모니아 노출은 대왕범바리의 혈액학적 성상 및 혈장 성분에 영향을 주어 생리적 변화를 일으키며, 40 mg L-1의 급성 암모니아 농도는 대량 폐사를 유발할 수 있음을 나타낸다. 향후 대왕범바리바이오플락 양식기술 적용을 위한 양식연구에 이러한 결과를 지표로 활용할 수 있을 것이다.
        4,000원
        166.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyaniline–graphene quantum dots (PANI–GQDs) are considered as an important candidate for applications in photovoltaic cells. In this work, GQDs were prepared using sono-Fenton reagent from reduced graphene oxide (rGO). PANI–GQD hybrid was also synthesized using the chemical in situ polymerization method. The synthesized materials were characterized using UV–visible (UV–Vis) spectroscopy, photoluminescence (PL) spectroscopy, current–voltage (I–V) characteristic, thermal gravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction (XRD). Dynamic light scattering was also used to estimate the lateral size of GQDs. The enhanced visible-light absorbance in the hybrid was confirmed by UV–Vis analysis and the decrease in intensity around 3461 cm−1 in FT-IR spectra was due to the interaction between functional groups of PANI with GQDs. This led to improved thermal stability and conductivity as observed from TGA and I–V analysis, respectively. Moreover, the Raman spectrum for PANI–GQDs showed a decrease in the peak at ~ 1348 and ~ 1572 cm−1 as compared to PANI and GQDs. Similarly, from the XRD profile of PANI–GQDs, a shift in peak was observed due to an alteration in the microstructure. A sandwich device with cell structure glass/ITO/PANI–GQDs/Al was fabricated and its application was tested. Current density–voltage (J–V) curve of the device was measured with a Keithley SMU 2400 unit under an illumination intensity of 100 Wm−2 simulating the AM 1.5 solar spectrum. The hybrid exhibited photovoltaic properties, and 0.857% efficiency was observed in response to the applied voltage. This work suggests that PANI can be used as an alternative material for photovoltaic cells.
        4,200원
        167.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: This study aims to evaluate the resistance to chemical attack of combined organic and inorganic hybrid mortars as the repair materials (i.e., HRM mortar) used for concrete road facilities through a comparison with mortars made from cement repair materials (i.e., IRM mortar). METHODS: Inorganic materials used as a binder and two mineral fillers were adopted to produce HRM mortars. The ratio of the main resin versus the hardener was fixed at 2:1. For comparison, IRM mortars made of cement repair materials were also manufactured. The mortars were exposed to chemical solutions, such as NaCl, MgSO4, Na2SO4, and H2SO4, with the same concentration of 5% after 7 days of curing. The compressive strength, compressive strength loss, mass ratio, and relative bulk density of the mortar samples exposed to the chemical solutions were measured at predetermined periods. In addition, a scanning electron microscope observation was performed to evaluate the microstructures and the products formed by the chemical reaction of the mortar samples. RESULTS : As a result, the resistance to chemical attack of the HRM mortars was found to be much better than that of the IRM mortars, regardless of the types of attacking sources. This finding implies that HRM is a highly promising and versatile material because of its excellent resistance to chemical attack. CONCLUSIONS: The application of the combined organic and inorganic hybrid mortars is a possible option for repair of concrete road facilities exposed to aggressive environments.
        4,000원
        170.
        2019.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원전 일차계통 HyBRID 제염공정에서 발생되는 제염폐액에는 황산이온과 방사성 핵종을 포함한 금속이온 및 발암성 물질의 하이드라진을 포함하고 있어 이를 안전한 수준으로 처리할 수 있는 기술개발이 필요하다. 본 연구에서는 모의 제염폐액 내 황산 및 금속이온의 제거와 하이드라진의 분해시험을 실시하여 황산이온, 금속이온 및 하이드라진을 효과적으로 제거할 수 있는 HyBRID 제염폐액 처리공정을 도출하였으며, 1 L 규모에서의 반복실험과 Pilot 규모(300 L/batch)에서의 평가시험을 통해 도출한 HyBRID 제염폐액 처리공정의 성능 재현성과 적용성을 검증하였다.
        4,000원
        171.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        스테인레스 스틸에 대한 합성된 폴리우레탄-에폭시 수지의 기계적 특성은 SEM, FT-IR, 인장특성, 그리고 EIS에 의한 특정질량손실량, 입도분석 등에 의해 물성을 측정하였다. 친환경적인 중방식 도료에 관한 관심이 고조됨에 따라 스테인레스 등의 금속에 코팅하는 무용제 도료를 합성하였다. 폴리올, IPDI, 충진제, 실리콘 계면활성제, 촉매 등이 함유된 기존 중방식수지보다 폴리올, MDI, 충진제, 실리콘 계면활성제, 촉매가 함유되어 합성된 중방식수지의 도료가 온도변화에 따른 인장강도가 증가하였고, 전해성이 높은 용액 속에서 저헝력이 크게 측정되었으며, 내구력과 강도가 양호하였다. 견고한 중방 식수지의 기계적 특성은 가교와 부식환경의 차단력이 증가함에 따라 강도가 증가하였다. 결론적으로 중방식의 가교된 미세조직은 방청코팅이 어려운 스테인레스 스틸 같은 금속물질 코팅에도 좋은 실험결과를 보여주었다.
        4,000원
        172.
        2019.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The performance of Li-ion hybrid supercapacitors (asymmetric-type) depends on many factors such as the capacity ratio, material properties, cell designs and operating conditions. Among these, in consideration of balanced electrochemical reactions, the capacity ratio of the negative (anode) to positive (cathode) electrode is one of the most important factors to design the Li-ion hybrid supercapacitors for high energy storing performance. We assemble Li-ion hybrid supercapacitors using activated carbon (AC) as anode material, lithium manganese oxide as cathode material, and organic electrolyte (1 mol L−1 LiPF6 in acetonitrile). At this point, the thickness of the anode electrode is controlled at 160, 200, and 240 μm. Also, thickness of cathode electrode is fixed at 60 μm. Then, the effect of negative and positive electrode ratio on the electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors is investigated, especially in the terms of capacity and cyclability at high current density. In this study, we demonstrate the relationship of capacity ratio between anode and cathode electrode, and the excellent electrochemical performance of AC/LiMn2O4 Li-ion hybrid supercapacitors. The remarkable capability of these materials proves that manipulation of the capacity ratio is a promising technology for high-performance Li-ion hybrid supercapacitors.
        4,000원
        173.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the effect of offering eco-friendly fashion items on consumers’ perceived image of stores and their intention to purchase food in a hybrid cafe setting. The data were collected using an online survey of 465 adults aged 20 to 49 years. In order to compare ‘a general cafe’ where only food is sold and ‘a hybrid cafe’ which offers eco-friendly fashion items as well as food, we developed two store types (general×hybrid) with two store designs (modern×eco-friendly) as stimuli, resulting in four scenarios. The results indicated that offering eco-friendly fashion items at a cafe did not significantly affect consumers’ perceived eco-friendly image of the store. Further, this negatively affected consumers’ perceived healthy and tasty images of the store and intention to purchase food. Such negative effects on the healthy and tasty images of the store increased in the store with a modern design. In conclusion, offering eco-friendly fashion items at cafes may not contribute to enhancing the stores’ images or sales.
        4,000원
        174.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Titanium dioxide (TiO2) is a typical inorganic material that has an excellent photocatalytic property and a high refractive index. It is used in water/air purifiers, solar cells, white pigments, refractory materials, semiconductors, etc.; its demand is continuously increasing. In this study, anatase and rutile phase titanium dioxide is prepared using hydroxyl and carboxyl; the titanium complex and its mechanism are investigated. As a result of analyzing the phase transition characteristics by a heat treatment temperature using a titanium complex having a hydroxyl group and a carboxyl group, it is confirmed that the material properties were different from each other and that the anatase and rutile phase contents can be controlled. The titanium complexes prepared in this study show different characteristics from the titania-formation temperatures of the known anatase and rutile phases. It is inferred that this is due to the change of electrostatic adsorption behavior due to the complexing function of the oxygen sharing point, which crystals of the TiO6 structure share.
        4,000원
        175.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내에서 가장 많이 재배되고 있는 버섯은 느타리류로 일반느타리와 큰느타리(새송이) 두 품목이 대부분을 차지한다. 그 중에서 큰느타리는 자동화 시설이 확대되면서 생산량이 크게 증가하였으며, 저장성이 우수하여 수출되는 버섯의 주요 품목 중 하나로 자리잡았다. 그러나, 생산량이 점차 증가하면서 가격이 다소 하락하였고 이에 생산자는 큰느타리를 대체할 수 있는, 소비자는 버섯 시장의 선택의 폭을 넓힐 수 있는 새로운 버섯 품목 개발을 요구해 왔다. 이에 따라, 국립원예특작과학원에서는 중국 등 아시아 에서 맛과 향이 우수하여 고품질로 생산되고 있는 백령느 타리와 아위느타리를 종간교잡하여 ‘크리미’라는 품종을 개발하였다. 기존에 육성된 품종 및 수집된 유전자원을 재배하여 형태적 특성검정을 하였고, 아위느타리 품종 ‘비산2 호(KMCC00430)’ 와 백령느타리 유전자원 ‘KMCC00461’ 을 모본으로 선발한 뒤 각 모본으로부터 단포자를 분리하여 mono-mono 교잡하였다. 약 1,000 조합의 교잡을 하였 고, 그 중 73계통이 교잡이 확인되어 재배시험 및 자실체 특성조사를 수행하였다. 그 중 갓이 밝은 연백색이며 대가 굵고 곧아 품질이 우수한 ‘7773’ 계통을 최종선발하였고 ‘크리미’라고 명명하였다. ‘크리미’의 균사생장 적온은 25~30 ̊C이고, 자실체 생육온도는 16 ̊C이다. 농가에서 대량생산시험 후 현장평가회 및 시식회를 개최해 본 결과, ‘크리미’의 수량이 대조구 ‘백황’보다 약 5% 증수되었고, 기존 아위느타리 품종 ‘비산2호’에 비해 식감과 맛이 더 우수하며, 아위x백령느타리 품종 ‘백황’보다 자실체 형태 가 더 우수하여 고품질로 판매가 가능할 것이라는 평가를 얻었다. 큰느타리와 다르게 밝은 연백색인 갓을 가졌으며, 식감과 향이 더 우수한 아위x백령느타리 신품종 ‘크리미’가 앞으로 버섯 농가의 새로운 소득 창출과 버섯 시장의 품목 다변화에 이바지할 것을 기대해 본다.
        4,000원
        176.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        하이브리드 감압 열펌프 건조기의 효과를 파악하기 위하여 건조된 굴 제품을 8주간 저장하면서 일반 성분의 변화와 글리코겐 함량의 변화 등을 조사하였다. 일반세균의 변화는 18~19×103 CFU/g으로 기존제품의 27~30×103 CFU/g 보다 안전하였다. 주요 지방산의 함유량은 건조기에서 건조한 시료의 DHA 및 EPA 함량은 L1-1, L1-3 및 R2-2에서 각각 17.87% 및 14.80%, 17.46% 및 14.38%, 17.89% 및 14.99%이었고, 반면 CD-1은 각각 15.41% 및 13.20%로 약간의 차이를 보였다. 각 시료의 유리아미노산 함량에는 큰 차이를 보이지 않아 1325.2~1360.4 mg/100 g으로 나타났다. 그리고 선도를 나타내는 K 값에서는 하이브리드 건조기에서 건조한 시료가 저장기간 동안 매우 우수한 신선도를 나타낸 반면, 시판 굴의 시료에서는 34.0~42.1%로 나타났다.
        4,000원
        177.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES: The objective of this study is to evaluate the durable performance of combined organic and inorganic hybrid mortar as repair material (HRM mortar) for concrete road facilities via comparison with that of cement repair materials (IRM mortar). METHODS : To produce HRM mortars, inorganic materials as binder and 2 mineral fillers were adopted. The ratio of main resin versus hardener was fixed at 1:2. For comparison, IRM mortars made with cement repair materials were also manufactured. Compressive, flexural, and bonding strengths were measured at predetermined periods. For durability assessment, the scaling resistance, freezing & thawing resistance, rapid chloride penetration resistance, and acid attack resistance of those mortars were experimentally monitored. RESULTS: The durability performances of HRM mortars, especially with respect to freezing & thawing, rapid chloride penetration and acid attack, were identified to be much better than those of IRM mortars. This result implies that HRM is a highly promising and versatile material because of its excellent durability. CONCLUSIONS: It is concluded that the application of the combined organic and inorganic hybrid mortars is possibly an option for the repair of concrete road facilities exposed to aggressive environments.
        4,000원