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        검색결과 349

        123.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Tin dioxide nanoparticles are prepared using a newly developed synthesis method of plasma-assisted electrolysis. A high voltage is applied to the tin metal plate to apply a high pressure and temperature to the synthesized oxide layer on the metal surface, producing nanoparticles in a low concentration of sulfuric acid. The particle size, morphology, and size distribution is controlled by the concentration of electrolytes and frequency of the power supply. The as-prepared powder of tin dioxide nanoparticles is used to fabricate a gas sensor to investigate the potential application. The particle-based gas sensor exhibits a short response and recovery time. There is sensitivity to the reduction gas for the gas flowing at rates of 50, 250, and 500 ppm of H2S gas.
        4,000원
        124.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Drought is one of the detrimental factors that impair plant growth and productivity. In this study, we applied annealing control primer (ACP)-based reverse transcriptase PCR (polymerase chain reaction) technique to identify differentially expressed genes (DEGs) in maize leaves in response to drought stress. Two-week-old maize seedlings were exposed to drought (DT) by suspending water supply. DEGs were screened after 3 days of DT-treated samples using the ACP-based technique. Several DEGs encoding 16.9 protein, antimicrobial protein, hypothetical protein NCLIV_068840, thioredoxin M-type were identified in maize leaves under drought stress. These genes have putative functions in plant defense response, growth and development. These identified genes would be useful for predictive markers of plant defense, and growth responses under drought stress in plants.
        4,000원
        126.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was carried out to explore possibilities of cultivating horticultural crops in the air-dome greenhouse in comparison to the common iron-frame greenhouse as the standard. The levels of carbon dioxide and atmospheric pressure measured inside the air-dome greenhouse turned out to be higher than those measured inside the iron-frame greenhouse. Contrastingly, light intensity was relatively weaker inside the air-dome greenhouse due to the air-inflated double layers. Plants of melon and cherry tomato were cultivated from May 2 to August 12, 2016, respectively in the two greenhouses. For melon plants, growth in the air-dome greenhouse effectively increased fruit weight as well as trunk circumference compared to iron-frame greenhouse. Moreover, soluble sugar content of melon fruit was significantly higher when cultivated in the air-dome greenhouse. For cherry tomato plants, fruit yield of cherry tomato was significantly increased inside the air-dome greenhouse. Furthermore, it has been found that the air-dome greenhouse was considerably effective in shortening the growing period of melon and cherry tomato plants in comparison to the iron-frame greenhouse.
        4,000원
        127.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mesenchymal stem cells (MSCs) have been considered an alternative source of neuronal lineage cells, which are difficult to isolate from brain and expand in vitro. Previous studies have reported that MSCs expressing Nestin (Nestin+ MSCs), a neuronal stem/progenitor cell marker, exhibit increased transcriptional levels of neural development-related genes, indicating that Nestin+ MSCs may exert potential with neurogenic differentiation. Accordingly, we investigated the effects of the presence of Nestin+ MSCs in bone-marrow-derived primary cells (BMPCs) on enhanced neurogenic differentiation of BMPCs by identifying the presence of Nestin+ MSCs in uncultured and cultured BMPCs. The percentage of Nestin+ MSCs in BMPCs was measured per passage by double staining with Nestin and CD90, an MSC marker. The efficiency of neurogenic differentiation was compared among passages, revealing the highest and lowest yields of Nestin+ MSCs. The presence of Nestin+ MSCs was identified in BMPCs before in vitro culture, and the highest and lowest percentages of Nestin+ MSCs in BMPCs was observed at the third (P3) and fifth passages (P5). Moreover, significantly the higher efficiency of differentiation into neurons, oligodendrocyte precursor cells and astrocytes was detected in BMPCs at P3, compared with P5. In conclusion, these results demonstrate that neurogenic differentiation can be enhanced by increasing the proportion of Nestin+ MSCs in cultured BMPCs.
        4,000원
        132.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to develop an HNS safety management system to assess and visualize hazard levels via an automated method, we have conceptualized and configured a sample system. It is designed to quantify the risk of a vessel carrying HNS with a matrix method along navigational route and indicate hazards distribution with a contour map. The basic system which provides a visualized degree of hazards in real time has been introduced for the safe navigation of HNS ships. This is useful not only for decision making and circumstantial judgment but may also be utilized for HNS safety management with a risk base. Moreover, this system could be extended to address the navigational safety of marine traffic as well as of autonomous vessels in the near future if the sensors used are connected with IoT technology.
        4,000원
        133.
        2017.04 구독 인증기관·개인회원 무료
        Chewing and swallowing disorders such as dysphagia are common in the elderly people whose number is reported to continuously increase throughout the world. With this trend, the aging populations have recently become the global focus of substantial research interest in a variety of industrial fields and the food industry is also no exception. Further studies are also necessary to establish the guidelines or criteria for controlling the food texture for the elderly with different living and cultural backgrounds. An experimental attempt was made to bridge the gap between instrumental and sensory texture in a model solid food system, providing a reference texture range for the elderly diets. For doing so, uniaxial compression was applied to measure the instrumental hardness of corn starch gels that was correlated with their sensory properties perceived by the elderly aged 60 and older. A polynomial trend line was satisfactorily obtained with the formula (y=0.2188x2-5.7917x+38.14) describing the relationship between instrumental hardness and starch concentration. When the instrumental hardness (stress) was correlated with the sensory hardness, a linear correlation was observed with a coefficient of determination (R2=0.879). However, the use of logarithmic transformation exhibited the improved correlation of coefficients. A fairly linear correlation (R2>0.96) was thus observed between the instrumental and sensory hardness by a semi-logarithmic relationship known as Weber-Fechner’s law scale. In principal component analysis, two principal components that accounted for 86.71% of the total variance, separated the gel samples in terms of hardness/springiness and moistness, respectively. The categories of the starch gel samples were subdivided into five groups with different stress ranges. As a result, five categories of food texture could be successfully provided with corresponding stress range and consumer languages that can be used as a reference tool to establish the guideline or criteria for developing the elderly foods.
        134.
        2017.04 구독 인증기관·개인회원 무료
        The gastro-intestinal behaviors of foods influence their physiological functions in the human body. In-vitro methods simulating digestion processes have been extensively used to study the gastro-intestinal behaviors of foods due to more rapid and less expensive advantages. However, there is a lack of systematic studies to monitor the rheological changes of the food digesta in real time. In this study, rice-based products (specifically, extruded noodles) were prepared with three varieties of rice flours with different contents of amylose and their physicochemical properties and in-vitro digestibility were then characterized from a rheological point of view. The rice flours with higher amylose contents exhibited greater stability to dual mixing and higher degrees of starch gelatinization and retrogradation in thermo-mechanical measurements. In addition, greater elastic properties were clearly observed in the high amylose rice samples. The noodles which were produced with high amylose rice flour had a harder texture and reduced cooking loss. When the rheological changes of the extruded rice noodles were monitored in real time during the in-vitro starch digestion, the rice noodle digesta with higher amylose content exhibited greater viscosities throughout the simulated oral-gastric-intestinal digestion steps. The flow behavior of the rice noodle digesta consisted of the Power-law region and infinite shear plateau that were satisfactorily characterized by the Sisko model (R2>0.99). Hence, this study was conducted to investigate the physicochemical and in-vitro digestibility of extruded rice noodles with different amylose contents. These results can provide a promising opportunity for the food industry to research in-vitro digestion and physicochemical characteristics of rice-based products.
        136.
        2017.04 구독 인증기관·개인회원 무료
        We performed a survey for flavivirus infection and distribution of Aedes albopictus that known as Zika and Dengue virus vector using black–light trap and BG-sentinel trap around urban area in Korea. Mosquitoes were collected in 27 cities during March to November (twice a month) year 2016. Total numbers of mosquitoes collected 102,102 including 19 species 8 genera during collecting period. Total 21,467 Ae. albopictus was collected that 20,961(24.3%) by BG-sentinel trap and 506 (3.2%) by Black-light trap in urban area. Trap index(trap/night) of Ae. albopictus was showed highest in Hamyang (TI:992.3) and lowest in Taebaek (TI:0.3) there was only collected by Black-light trap. A total of 894 pools from all collecting Ae. albopictus were performed a Flavivirus detection. Flavivirus was not detected during study period. This study may provide basic information for surveillance of imported diseases (include Zika virus) and vectors in Korea.
        137.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Our understanding of dust emission, interaction, and evolution, is evolving. In recent years, electric dipole emission by spinning dust has been suggested to explain the anomalous microwave excess (AME), appearing between 10 and 90 Ghz. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at polycyclic aromatic hydrocarbon molecules (PAHs). We present data from the AKARI/Infrared Camera (IRC) due to its high sensitivity to the PAH bands. By inspecting the IRC data for a few AME regions, we nd a preliminary indication that regions well- tted by a spinning- dust model have a higher 9 m than 18 m intensity vs. non-spinning-dust regions. Ongoing e orts to improve the analysis by using DustEM and including data from the AKARI Far Infrared Surveyor (FIS), IRAS, and Planck High Frequency Instrument (HFI) are described.
        3,000원
        138.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 ‘상주둥시’ 감을 3개월동안 -1, 0.5, 3oC에 저장하면서 감 과실의 과실품질 변화와 저장장해 증상에 미치는 영향을 구명하고자 실시하였다. 저장온도에 따른 감 과실의 에틸렌 발생량은 저장온도가 낮을수록 그 발생량이 낮았으나 호흡율은 영향을 받지 않았다. 과실의 경도는 모든 처리구들에서 저장기간이 길어지면서 감소하였고 저장온도가 높을수록 과실 경도의 저하는 더 빠르게 진행되었다. 또한 저장기간이 길어지고 저장온도가 높을 수록 과실의 연화가 급속히 진행되었다. 과실의 감모율도 저장온도가 높을수록 증가하였고, 가용성 고형물 함량도 저장온도가 낮을수록 더 높게 유지되었다. 감 과실의 과정부와 과실측면의 과피색 L*, a*, b* 값의 변화는 저장온도 -1oC와 0.5oC에서는 저장기간에 따른 차이를 거의 보이지 않았으나, 3oC처리구에서는 과피색의 변화가 현저히 적었다. 저장중 발생하는 생리장해증상인 과피흑변, 과실연화 및 부패정도는 온도가 높을수록 그 증상이 심하게 발생하여 과실품질이 현저히 감소하였다.
        4,000원
        139.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Activated carbon fiber (ACF) surfaces are modified using an electron beam under different aqueous solutions to improve the NO gas sensitivity of a gas sensor based on ACFs. The oxygen functional group on the ACF surface is changed, resulting in an increase of the number of non-carbonyl (-C-O-C-) groups from 32.5% for pristine ACFs to 39.53% and 41.75% for ACFs treated with hydrogen peroxide and potassium hydroxide solutions, respectively. We discover that the NO gas sensitivity of the gas sensor fabricated using the modified ACFs as an electrode material is increased, although the specific surface area of the ACFs is decreased because of the recovery of their crystal structure. This is attributed to the static electric interaction between NO gas and the non-carbonyl groups introduced onto the ACF surfaces.
        4,000원
        140.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구에서는, 전기방사법을 이용하여 산화철-산화그래핀(Fe3O4/GO, metallic graphene oxide; MGO)이 도입된 PVdF/MGO 복합나노섬유(PMG)를 제조하였으며, 이를 활용하여 비소제거에 대한 특성 평가를 진행하였다. MGO의 경우 In-situ-wet chemical 방법으로 제조하였으며, FT-IR, XRD분석을 진행하여, 형태와 구조를 확인하였다. 나노섬유 분리막의 기 계적 강도 개선을 위하여 열처리과정을 진행하였으며, 제조된 분리막의 우수한 기계적 강도 개선 효과를 확인할 수 있었다. 그러나, PMG 막의 경우, 도입된 MGO의 함량이 증가할수록 기계적 강도가 감소되는 경향성을 보여주었으며, 기공크기 분석 결과로부터, 0.3~0.45 μm의 기공크기를 가진 다공성 분리막이 제조되었음을 확인할 수 있었다. 수처리용 분리막으로의 활용 가능성 조사를 위해, 수투과도 분석을 실시하였다. 특히, PMG2.0 샘플의 경우 0.3 bar 조건에서, PVdF 나노섬유막(91 kg/m2h)에 비해 약 70% 향상된 결과값(153 kg/m2h)을 나타내었다. 또한, 비소 흡착실험 결과로부터, PMG 막의 경우, 비소3 가와 5가에 최대 81%, 68%의 높은 제거율을 보여주었으며, 흡착등온선 분석으로부터, 제조된 PMG 막의 경우 비소3가, 5가 모두 Freundlich 흡착거동을 따른다는 것을 확인하였다. 위 모든 결과로부터, PVdF/MGO 복합 나노섬유 분리막은 비소제거 및 수처리용 분리막으로 충분히 활용할 수 있을 것으로 판단된다.
        4,000원