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        검색결과 66

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        프리지아 ‘Ruby Star’는 농촌진흥청 국립원예특작과학원 에서 보라색 홑꽃 ‘Avilla’와 흰색 반겹꽃 ‘Medeo’를 2012년 교배하여 얻은 종자로부터 2006년 향이 좋고 개화기가 빠른 적색 홑꽃 계통을 선발하여 품종으로 개발되었다. 2014년부 터 2017년까지 생육·개화 특성검정 및 육성계통평가회의 기 호도 평가를 거쳐 선발되었으며 2018년 직무육성품종심의회 를 통해 ‘Ruby Star’로 명명되어 2021년 신품종으로 등록되 었다. ‘Ruby Star’는 빨간색(RHS, R45A) 홑꽃인 절화용 프리 지아 품종으로 개화소요일수가 118.0일이며 초장이 120.5cm 로 대조품종 ‘Rapid Red’보다 약 28.7cm 더 길다. 주당 분 지수는 5.8개로 대조품종에 비해 수확량이 많고 첫번째 분지 의 길이가 32.0cm, 두께가 3.02mm로 절화 특성이 우수하 다. ‘Ruby Star’의 소화수 및 소화폭은 각각 14.8개, 6.3cm 로 소화수가 많은 중대형화이다. 절화수명은 약 8.4일이며 주 당 자구수는 3.8개, 평균 자구중은 2.9g이다. 전자코를 이용 한 PCA 분석 결과 PC1과 PC2의 설명력은 각각 97.9%, 1.8%로 전체 변이의 99.7%를 반영했으며 ‘Ruby Star’와 대 조품종 ‘Rapid Red’는 서로 다른 향기 패턴을 보였다. Radar plot 결과 총 6개의 MOS 센서에서 ‘Ruby Star’의 센서 반응 이 ‘Rapid Red’보다 강하게 나타나 ‘Ruby Star’의 향기가 더 강한 것으로 나타났다.
        4,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        백합 종간 교잡종은 다양한 교배 방법에 의해 생산되어지 고 있다. 그러나 이들 종간 교잡종은 대부분 불임이다. 2n gametes는 백합에서 종간 교잡종 F1의 불임을 극복할 수 있 을 뿐 아니라 우수한 유전형질을 지닌 2n과의 교배에 이용할 수 있고 후대 다양한 유전형질을 기대할 수 있다. 따라서 본 실험에서는 가장 효과적으로 2n gametes를 생산할 수 있는 방법을 구축하기 위하여 백합 Oriental hybrids ‘Medusa’와 ‘Marco Polo’에 N2O를 처리하였다. 같은 Oriental 그룹 내 에서도 ‘Medusa’와 ‘Marco Polo’는 화뢰 크기별 감수분열 시기가 달랐다. 감수분열 tetrad 시기에 염색체를 관찰한 결 과 sequential spindles, tripolar spindles에 의해 2가지 다른 형태가 관찰되었다. ‘Medusa’에서 2atm의 N2O를 처리 한 화뢰 길이 10~15mm와 20~25mm에서 monad, dyad, triad, tetrad가 관찰되었다. 그러나 4atm에서는 tetrad 이외에는 검경 되지 않았다. ‘Marco polo’의 경우 화뢰 길 이 10~15mm, 25~30mm 시기에 2, 4atm의 N2O를 12, 24 시간 동안 처리한 구에서 모두 dyad, triad가 관찰되었다. ‘Medusa’, ‘Marco Polo’ 모두 dyad, triad, tetrad가 관찰 된 시기는 대조구에서 interphase와 metaphase Ⅰ에 해당 하는 시기이다. 화분의 모양은 타원형으로 처리 전·후 변화가 없었으며 처리 후 화분의 크기는 n 보다 큰 화분뿐 아니라 작 은 화분도 관찰되어 전체적으로 다양했다. 화분의 임성과 발 아율은 처리구별로 차이가 없었으나 평균적으로 처리 후가 무처리구보다 임성은 약 10%, 발아는 약 20% 정도 떨어졌다. ‘Medusa’와 ‘Marco Polo’를 이용하여 N2O를 처리한 것과 처리하지 않은 것을 정역 교배하였을 때 자방이 비대 되는 형 태가 2가지이었으나 처리 별 차이는 아니었다. 획득된 식물체 를 Flow cytometry로 검정한 결과, 무처리 ‘Marco Polo’와 2atm 24시간 32mm에 처리한 ‘Medusa’의 교배를 통해 하 나의 식물체에서 2배체와 3배체가 모두 나오는 mixoploid를 확인할 수 있었다. 그 외 실험을 통해 얻은 식물체 중에서 이 수체가 4개 발견되었다. 확실한 3배체를 가진 식물체는 관찰 할 수 없었다.
        4,500원
        3.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Liquid metal extraction (LME), a pyrometallurgical recycling method, is popular owing to its negligible environmental impact. LME mainly targets rare-earth permanent magnets having several rare-earth elements. Mg is used as a solvent metal for LME because of its selective and eminent reactivity with rare-earth elements in magnets. Several studies concerning the formation of Dy-Fe intermetallic compounds and their effects on LME using Mg exist. However, methods for reducing these compounds are unavailable. Fe reacts more strongly with B than with Dy; B addition can be a reducing method for Dy-Fe intermetallic compounds owing to the formation of Fe2B, which takes Fe from Dy-Fe intermetallic compounds. The FeB alloy is an adequate additive for the decomposition of Fe2B. To accomplish the former process, Mg must convey B to a permanent magnet during the decomposition of the FeB alloy. Here, the effect of Mg on the transfer of B from FeB to permanent magnet is observed through microstructural and phase analyses. Through microstructural and phase analysis, it is confirmed that FeB is converted to Fe2B upon B transfer, owing to Mg. Finally, the transfer effect of Mg is confirmed, and the possibility of reducing Dy-Fe intermetallic compounds during LME is suggested.
        4,000원
        7.
        2021.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        In recent years, the bilateral relations between the United States and Vietnam have shown a momentum of rapid development. The year 2020 marks the 25th anniversary of the normalization of bilateral relations between the two countries. Through sorting out the effects, problems and development trends of the comprehensive partnership between the two countries, this paper discusses the factors restricting the development of the bilateral relations, and then analyzes the prospects of the development of the US-Vietnam relations. The United States and Vietnam have a number of strategic convergence points to deepen cooperation, but at the same time, the two countries still face challenges in ideology, political system and other aspects. In the future, it is possible for the US-Vietnam relationship to continue to strengthen. On the one hand, Vietnam will strengthen bilateral relations with the US and implement multilateralism diplomacy to contain China. On the other hand, Vietnam will avoid stimulating China and stabilize its relations with China.
        8,700원
        8.
        2021.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We confirm whether Zr powders can restrain a rapid nitrification reaction and offer a stable oxidation reaction according to temperatures in nitrogen gas purification. A pellet-type, porous Zr getter is prepared (diameter: 10 and thickness: 3 mm) using Zr powder with an average particle size of 45 μm. While maintaining the whole system, the Zr getter reaction is confirmed with an increase in temperature from 150 to 550 oC at increments of 100 oC under 99.999 % purity nitrogen atmosphere comprising of 10 ppm of impurity. Surface color, pore size, stabilized layer, and phase change are confirmed with optical microscopy, SEM-EDS, Micro-Raman, and X-ray diffraction (XRD) according to the Zr getter temperature. The surface color of the Zr getter changes from metallic silver to dark gray as temperature increases. In the EDS results, the nitrogen component is not observed, and oxygen content increases from each surface at elevated temperatures. The Raman and XRD results show the oxidation layer as a result of 350 oC annealing. Therefore, the Zr getter can be applied as a nitrogen getter under 5-nine purity nitrogen atmosphere after appropriate oxidized pre-stabilization process to prevent rapid nitrification reaction.
        4,000원
        9.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to improve the thermal shock and ablation resistance of high thermal conductivity carbon/carbon composites, carbon nanotubes (CNTs) were introduced by electrophoretic deposition. After modification, the flexural strength of the composites increases by 53.0% due to the greatly strengthened interfaces. During thermal shock between 1100 °C and room temperature for 30 times, the strength continues to increase, attributed to the weakened interfaces in favor of fiber and CNT pull-out. By introducing CNTs at interfaces, thermal conductivity of the composites along the fiber axial direction decreases and that along the fiber radial direction increases. As the thermal shock process prolongs, since the carbon structure integrity of CNT and matrix in the modified composites is improved, the conductivity increases whatever the orientation is, until the thermal stress causes too many defects. As for the anti-ablation performance, the mass ablation rates of the CNT-modified composites with fibers parallel to and vertical to the flame decrease by 69.6% and 43.9% respectively, and the difference in the mass ablation rate related with fiber orientations becomes much less. Such performance improvement could be ascribed to the reduced oxidative damage and the enhanced interfaces.
        4,500원
        11.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Heteroatoms in situ-doped hierarchical porous hollow-activated carbons (HPHACs) have been prepared innovatively by pyrolyzation of setaria viridis combined with alkaline activation for the first time. The micro-morphology, pore structure, chemical compositions, and electrochemical properties are researched in detail. The obtained HPHACs are served as outstanding electrode materials in electrochemical energy storage ascribe to the particular hierarchical porous and hollow structure, and the precursor setaria viridis is advantage of eco-friendly as well as cost-effective. Electrochemical measurement results of the HPHACs electrodes exhibit not only high specific capacitance of 350 F g−1 at 0.2 A g−1, and impressive surface specific capacitance (Cs) of 49.9 μF cm−2, but also substantial rate capability of 68% retention (238 F g−1 at 10 A g−1) and good cycle stability with 99% retention over 5000 cycles at 5 A g−1 in 6 M KOH. Besides, the symmetrical supercapacitor device based on the HPHACs electrodes exhibits excellent energy density of 49.5 Wh kg−1 at power density of 175 W kg−1, but still maintains favorable energy density of 32.0 Wh kg−1 at current density of 1 A g−1 in 1-ethy-3-methylimidazolium tetrafluoroborate ( EMIMBF4) ionic liquid electrolyte, and the excellent cycle stability behaviour shows the nearly 97% ratio capacitance retention of the initial capacitance after 10,000 cycles at current density of 2 A g−1. Overall, the results indicate that HPHACs derived from setaria viridis have appealing electrochemical performances thus are promising electrode materials for supercapacitor devices and large-scale applications.
        4,600원
        12.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Highly active, stable and low-cost noble metal-free electrocatalysts are essential for production of hydrogen. However, preparation of such catalysts is still highly challenging so far. In this work, the Mo2C– carbon nanomaterials have been prepared by controlled thermal technique. By controlling concentration of the reactants in the experimental condition, the Mo2C– carbon nanomaterials have been fabricated, which leads to decreases in contact resistance b/w Mo2C– carbon nanomaterials and graphitic carbon atoms. As a result, the Mo2C– carbon nanomaterial electrode shows remarkable activity for hydrogen evolution reactions with a small onset overpotential of 95 mV, a Tafel slope of 62 mV dec−1, an high exchange current density of 0.32 mA cm−2, good stability during long-term 1000 cycles and exhibits long-term durability for several days. This study opens a new method for the preparation of highly active non-noble electrode for production of hydrogen from water splitting.
        4,000원
        14.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In Korea, the daily waste production in 2015(excluding specified waste) was 404,812 tons, of which household waste accounted for 12.7%(51,247 tons/day). Total household food and vegetable waste amounted to 1,120 tons/day; of this, 70% of was ultimately used as feed or fertilizer and 30% was buried. In this study, a drying unit was developed to enable the production of solid refuse fuel using high-moisture food waste, and its performance was examined through an experiment. Thus, a laboratory pyrolysis system with a drying capacity of 500 kg/hr was manufactured. Food wastes were collected from a company cafeteria and from Changwon City and used for experiment. The drying characteristics of the food waste were examined depending on the input temperature of the drying air. The results of the food waste drying experiment showed that the total required drying time was approximately 20 hours, and the drying speed was approximately 2.90 %/hr. The drying time was five hours longer than the research target value(15 hours per batch). However, the time was approximately 16 hours when the preheating and cooling times required for the input and output were excluded, which was close to the research target value. The drying time did not show a large difference depending on the temperature of the input drying air. Drying time was 21 hours at 155℃, and thus drying operation would be possible without the use of high-temperature air(more than 200℃) when waste heat is utilized in the future. It is thought that rather than the temperature of the input air, it is the contact area between the input air and the food waste that has a significant effect on reducing the drying time.
        4,000원
        16.
        2017.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Oxide layers were formed by an environmentally friendly plasma electrolytic oxidation (PEO) process on AZ91 Mg alloy. PEO treatment also resulted in strong adhesion between the oxide layer and the substrate. The influence of the KF electrolytic solution and the structure, composition, microstructure, and micro-hardness properties of the oxide layer were investigated. It was found that the addition of KF instead of KOH to the Na2SiO3 electrolytic solution increased the electrical conductivity. The oxide layers were mainly composed of MgO and Mg2SiO4 phases. The oxide layers exhibited solidification particles and pancake-shaped oxide melting. The pore size and surface roughness of the oxide layer decreased considerably with an increase in the concentration of KF, while densification of the oxide layers increased. It is shown that the addition of KF to the basis electrolyte resulted in fabricating of an oxide layer with higher surface hardness and smoother surface roughness on Mg alloys by the PEO process. The uniform thickness of the oxide layer formed on the Mg alloy substrates was largely determined by the electrolytic solution with KF, which suggests that the composition of the electrolytic solution is one of the key factors controlling the uniform thickness of the oxide layer.
        4,000원
        17.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Assays for detecting pregnancy-associated glycoproteins (PAGs) levels in the blood of pregnant cattle have been developed and commercialized to determine pregnancy status. This study was conducted to determine the accuracy of a PAG-based ELISA test for pregnancy detection in Hanwoo. The anticoagulated treated whole blood was sampled from 595 Hanwoo that were 28-71 d (mean 49) and 85-128 d (mean 106) after artificial insemination. At the 2nd blood collection time, a transrectal palpation test was used as the standard for pregnancy diagnosis. For PAGs and the transrectal palpation test (n=595), the sensitivity was 98.4% (pregnancy, 481/489), the specificity was 100% (open, 106/106), and the accuracy was 98.7% (pregnancy+open, 587/595). In conclusion, the rapid PAG-based ELISA pregnancy test was highly sensitive and specific for pregnancy detection in Hanwoo.
        3,000원
        18.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        에너지 음료는 카페인을 주성분으로 타우린, 비타민 같은 다른 energy-enhancing 성분을 함유하고 있다. 미국과 유럽에서는 글루쿠로노락톤이 에너지 음료에 첨가될수 있으나, 국내에서 의약품으로는 허가되어 있다. 따라서 식품 첨가물로는 그 사용이 금지 되어 있어, 지속적으로 수입 및 유통 음료에서 시험검사를 하여 규제하고 있다. 현재 분석법으로 사용하는 LC-PDA 법은 복잡한 유도체화 과 정을 거치고, 음료 중에 당류들이 위양성 결과를 나타내 기도 한다. 이런 기존 방법의 단점을 개선하기 위해 HILICESI- MS/MS (hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry) 를 이용한 분석법을 개발하고, 선택성, 직선성, 검출한계, 정량한계, 정밀도, 정확성, 재현성에 대하여 분석법 유효성 검증을 수행했고, AOAC, EURACHEM 가이드라인에 부합되는 결과를 얻었다.
        4,000원
        19.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study aimed to evaluate the damage persistence during subsequent years in kiwifruit vines defoliated by strong wind such as typhoons. Artificial defoliation was treated on five-year-old ‘Jecy Gold’ kiwifruit vines grown in a plastic house in year 2013 and 2014 by applying four levels of defoliation, i.e., 0, 50, 75, and 100% in August 23, 2013 and 100% defoliation in July 28 and August 29, 2014, respectively. Return bloom and fruit quality were investigated in the following two years, 2014 and 2015. A significant reduction in number of flowers per shoot in the following year, 2014 was recorded for the vines with 50%, 75%, and 100% defoliations treated in 2013 compared to the control vines. The number of flowers per florescence was significantly reduced for defoliated vines. Nevertheless, the fruit quality parameters, i.e., fruit length, width, weight, firmness, TSS, acidity, and dry matter content were not significantly different for the defoliated vines compared to the control vines. The vines defoliated in 2013 at 75% and 100% levels showed a significant reduction of number of flower per inflorescence in 2015 compared to the 0% defoliation. However, the number of flowers per shoot and fruit quality were not significantly different. Also, the number of flowers per inflorescence in 2015 was significantly reduced by July 28, 2014 or August 29, 2014 defoliation compared to non-defoliated vines while the number of flowers per shoot, and fruit quality in 2015 were not significantly different between treatments and control vines. Accordance with the present findings, the flowering is considerably affected by the shortage of carbohydrate supply than the fruit quality of ‘Jecy Gold’ kiwifruit. In addition, the negative impacts of severe defoliation in flowering of ‘Jecy Gold’ kiwifruit might be persisted more than one season from the time of defoliation and consequently, the total yield might be reduced in the following seasons after defoliation.
        4,000원
        20.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most previous studies on dinoflagellates in Korean coastal areas were conducted without morphological descriptions and illustrations of the observed dinoflagellates. This indicates that the species and diversity of dinoflagellates may have been respectively misidentified and underestimated in the past, probably due to cell shrinkage, distortion and loss caused by sample fixation. This study provides information on the morphological observations of four dinoflagellate orders (Prorocentrales, Dinophysiales, Gonyaulacales and Gymnodiniales) from Jangmok Harbour in Jinhae Bay, Korea. The unfixed samples were collected weekly from December 2013 to February 2015. A total of 13 genera and 30 species were identified using light and scanning electron microscopy, although some samples were not clarified at the species level. Harmful dinoflagellates, Prorocentrum donghaiense, Tripos furca, Alexandrium affine, A. fundyense, Akashiwo sanguinea and Cochlodinium polykrikoides, were identified based on the morphological observations. The results also reflect the occurrence and identification of dinoflagellates that had not been previously recorded in Jangmok Harbour.
        4,000원
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