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        검색결과 66

        41.
        2019.04 서비스 종료(열람 제한)
        of ordinary Portland cement. Water-cement ratio was 0.40 and cement-sand ratio was 1:3. The content of nano-TiO2 was 3% but the content of nano-SiO2 changed in cement mortars. The content of nano-SiO2 was 0%, 0.5%, 1%, 1.5% and 2% of the binder weight. Mortar prisms and beams were made in specified molds and cured in limewater. Compressive and flexural strengths, porosity and ultrasonic pulse velocity were measured. Then mortars were stored in 6 molar ammonium nitrate (NH4NO3) solution. Leaching depth, variation of mechanical and microstructural properties were measured. Presence of nano-particles decreased the leaching depth and the degradation of mechanical and microstructural properties in mortars.
        42.
        2018.08 KCI 등재 서비스 종료(열람 제한)
        Background: A soil-borne pathogenic fungus, Ilyonectria radicicola (Cylindrocarpon destructans) causes root rot on ginseng (Panax ginseng C. A. Meyer) and is known to attack many other plants. The Nectria/Neonectria radicicola complex has been renamed as the I. radicicola complex after analysis of its multi-gene relatedness and morphological characteristics. The fungi in this complex have been reclassified into 16 species under the genus Ilyonectria based on characteristics analysis Methods and Results: To obtain useful data from the Korean ginseng root rot, I. radicicola was isolated from the rhizosphere soils of the chestnut tree. They were identified through a pathogenicity test and a survey of the morphological features. The existence of I. radicicola in soil samples was confirmed by PCR detections using nested PCR with species-specific primer sets. These were subsequenctly isolated on semi-selective media from PCR-positive soils. Genetic analysis of the I. radicicola complex containing these pathogens was done by comparing the DNA sequences of the histone h3 region. These isolates originating from the rhizosphere soils of chestnut constituted a clade with other closely related species or I. radicicola isolates originating from ginseng or other host plants, respectively. Additionally, the pathogenicity tests to analyze the characteristics of these I. radicicola isolates revealed that they caused weakly virulent root rot on ginseng. Conclusions: This is the first study reporting that I. radicicola isolates from chestnut rhizosphere soils can attack ginseng plant in Korea. Thus, these results are expected to provide informations in the selection of suitable fields for ginseng cultivation.
        43.
        2018.04 서비스 종료(열람 제한)
        In this study, the performance of the self-healing with the granulated alkali activator (Ca(OH)2) manufactured in seawater environment is investigated for crack healing under 300 μm of cracks. Specimens combined with GGBFS and OPC with and without the granulated alkali activator were manufactured and immersed in seawater. After that, crack recovery on the surface of the specimens with the granulated alkali activator (Ca(OH)2) was also evaluated by the ultrasonic pulse velocity test. From the results, it was verified that cementitious materials with the granulated alkali activator, exposed in marine environments, could be able to heal or seal inside cracks
        44.
        2018.04 서비스 종료(열람 제한)
        In this study, poly-silicon sludge was used in replacement with Portland cement as SCMs. Poly-silicon sludge has an ability to improve the durability to the concrete system. Thus, the chloride penetration test of PS specimens was conducted for the confirmation of the durability. From the results, The penetration depth of the plain specimens is deepest, and gradually decreases as PS substitution rate increases.
        46.
        2017.05 서비스 종료(열람 제한)
        Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. Accordingly, a chemical control system was made with the aim of effectively control gray mold, anthrax, and spotting disease which occur during growth period. fungicide resistance of gray mold rot was examined to find out whether the chemical control system can be used over the long term. Methods and Results : This experiment was conducted in three areas including Geumsan-gun, Yesan-gun, and Sejong city. The chemical control system was done to the plants of two years old or older. As for the order of the treatment, from the end of April to May Fludioxonil (A) and Pyraclostrobin (B) were used; from the mid-May to the end of July of growth stages Difenoconazole (C), Iminoctadinetris (albesilate) (D), Cyprodinil (E), Metconazole (F), Fluazinam (G) and Pyrimethanil (H); from August to September nonresidualizing polyoxinB + mancozeb (K); in November of hibernating period, Fenhexamid (I) and Carbendazim/diethofencarb (J) were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The isolation of Botrytis cinerea for examination into mycelial growth inhibition rate was conducted to 4-year old ginseng in Geumsan, 5-year old in Yesan, and 3-year old in Sejong. In Geumsan, the mycelial growth inhibition rate to Botrytis cinerea was 75.5% - 100%. Every fungicides showed good rate of mycelial growth inhibition. The lowest rate was seen in fungicide B at 75.5%. K showed the prevention rate at 76.8%, D at 82.7%, and I at 82.2%, and other fungicides at 100%. In Sejong area, the hyphal prevention rate of Botrytis cinerea was 71.0% - 100%, indicating all fungicides show good rate of mycelial growth inhibition. The lowest rate was recorded by fungicide B at 71.1%, D at 81.1%, K at 85.4%, and I at 95.4%. Yesan area also showed similar results to those of Geumsan and Sejong. Conclusion : Botrytis cinerea was isolated from ginseng and mycelial growth inhibition effect was examined in concentration of 11 kinds of fungicides. In all three areas where chemical control system were applied, resistance was not found, suggesting that the chemical control system can be applied to control diseases of ginseng.
        47.
        2017.05 서비스 종료(열람 제한)
        Background : Ginseng is a perennial plant and damaged by various diseases and insect pests. The damage lowers harvest and quality. In particular, gray mold rot occurs to plants of every year, growth duration, and hibernating stage, and decays leaves, stems, and roots, lowering the amount of harvest. This experiment was conducted with the aim of effectively preventing gray mold rot, and other major diseases such as anthrax and spotting disease, and establishing chemical control system. Methods and Results : This experiment was conducted in three areas including Geunsan-gun, Yesan-gun, and Sejong city. As for the procedure of medical treatment, from the end of April to early May of germination period, Fludioxonil and Pyraclostrobin were used. From the mid-May to the end of July of growth period, Difenoconazole, Iminoctadine tris (albesilate), Cyprodinil, Metconazole, Fluazinam, and Pyrimethanil were used. From August to September, non residualizing polyoxinB + mancozeb was used. In November of hibernating stage, Fenhexamid and Carbendazim/diethofencarb were used. As for the interval, from the end of April to the end of July the interval was 10 days, in August and September once a month, and twice in every ten days in November. The chemical control system effect was compared with conventional prevention. When chemical control system was used, stem spotting disease occurred at a lower rate of 0.34% than 1.2% of the conventional method. Leaf spotting disease occurred at a lower rate of 1.4% compared with 7.1% of the conventional method, and anthrax occurred at a lower rate by more than 10% than the conventional method. Stem gray mold rot occurred at a rate of 4.1% when the conventional method was used, but the rate stood at 5.3% in Geumsan, 8.9% in Yesan, 2.3% in Sejong when the prevention method was used, which suggest the chemical control system was effective. Conclusion : When chemical control system was applied to prevent major diseases of ginseng, spotting disease, anthrax, and gray mold occurred at lower rates compared with the case where the conventional method was used. The finding is that the chemical control system can be utilized to prevent major diseases of ginseng.
        48.
        2016.10 서비스 종료(열람 제한)
        Background : Ginseng is a perennial, and damage occurs due to various diseases and pests. As a result, yield decreases and quality deteriorates. In particular, it is impossible to be repeatedly cultivated due to root rot, soil-borne disease. For this, in order to control root rot and repeatedly cultivate ginseng by using soil fumigation from virgin soil, this experiment was conducted. Methods and Results : This experiment was performed in ginseng farm field, Geumsan-gun, Chungnam province. And total area was 3ha. And the experiment was conducted in soil where apple trees had been grown. Apple trees were rooted up in 2006. And soil was fumigated in May 2007. With regard to soil fumigant, soil was treated with Basamid of 40kg/10a. After soil fumigation, 5 ton/10a of cattle manure fermented for 1 year was put in the soil in June, and then the soil was cared for by being plowed and rotary-tilled as occasion. Ginseng seeds were sowed in the soil cared for in October 2007. And 4-year-old ginseng was harvested in 2011. The soil from which ginseng was harvested was fumigated by the same method in May 2012, and then ginseng seeds were sowed in 1.5ha in October 2012 and in 1.5ha in October 2013. In October 2013, 3-year-old and 4-year-old ginseng was harvested. And ginseng growth characteristics and root rot incidence was examined. It was shown that 4-year-old ginseng yield after the fumigation of virgin soil was nearly 2 times as high as that of conventional virgin soil cultivation. And root rot didn't occur. After that time, the soil was fumigated again. And when ginseng was cultivated, 3-year-old and 4-year-old ginseng yield was 650kg and 960kg per 10a. And it was shown that root rot incidence was 1.3% and 15.3% in 3-year-old and 4-year-old ginseng respectively. Conclusion : This study showed the results where ginseng can be cultivated repeatedly if soil was fumigated again after ginseng was harvested following the soil fumigation from virgin soil so as to control the ginseng root rot and cultivate ginseng repeatedly.
        49.
        2016.10 서비스 종료(열람 제한)
        In this study, to evaluate the performance of fire resistance of the mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) which has a RCC (Radiant Control Capability) as repair material to the steel structure, temperature evaluation of mortar was conducted by increasing 500°C in the furnace. The performance of RCC can decrease a temperature to external and internal mortar. As a result, it is confirmed that temperatures of mortar with magnesium hydroxide(MH) and aluminium hydroxide(AH) were more decreased than general mortar due to the RCC effect of MH and AH. Therefore, it can be possible to apply to a repair material at the steel structure.
        51.
        2015.10 서비스 종료(열람 제한)
        This experiment can maximize the decline of the heat on steel structure by using the magnesium hydroxide and aluminum hydroxide which generally used to resistant or retardant. These materials can delay a temperature rise due to the generation of vapors around the fire resistive covering, when reacting with heat by a creating moisture. Therefore, applicability of the fire resistance mortar used magnesium hydroxide and aluminum hydroxide was studied and experimented. As a result, in case of the workability is satisfied with the condition of site, but in case of the bonding strength is not satisfied with the standard with fire resistance mortar.
        52.
        2015.08 KCI 등재 서비스 종료(열람 제한)
        Eliot was impressed with Charles Baudelaire’s technical mastery and particularly with his employment of symbolic imagery as a means of representing a spiritual or emotional state of modern man. This paper makes it clear that Baudelaire’s decadent metropolitan settings appear in Eliot’s early poetry including “The Love Song of J. Alfred Prufrock.” This paper argues that Eliot not merely presents the imagery of the sordid common life of a metropolis but attempts to transform such imagery to disclose the symbolic landscape in the protagonist’s mind. Eliot recalls from his past life memory and daily observations concrete physical equivalents for intangible feelings of modern humans. This paper shows how all the scenery of the poem, indoor and outdoor, is transferred to the psychological landscape of Prufrock himself. And this paper also argues that the symbolist device of objective correlative, then, in Eliot’s hands, renders the complexity of modern human experience as well.
        53.
        2015.04 서비스 종료(열람 제한)
        In this study, cement-based accelerators, which have an advantage of preventing early frost and in developing early strength in cold-weather. Then, whether it can be secured the operating time by controlling the response time in early-stage and can be developed due to the accelerator's function, as evaluated by testing.
        54.
        2014.11 서비스 종료(열람 제한)
        화력발전소에서 2011년 약 123백만톤의 석탄을 소비하고 있다. 이 석탄을 연소하는 과정에서 석탄회가 발생되는데 이러한 석탄회는 Fly Ash(비산재)의 형태로 배가스와 함께 배출되거나 Bottom Ash(바닥재)의 형태로 보일러 하부에 잔류하게 된다. Fly Ash는 그 크기가 대략 10-30 μm으로 발생량은 시스템에 따라 다르나 전체회 발생량의 약 80~85%를 차지하며 나머지 약 15~20%에 상당하는 석탄회는 대략 1~2.5mm 크기의 Bottom Ash로 보일러 하부에 모인다고 보고되어 진다. 이러한 석탄회의 발생량은 계속 증가하여 2007년에는 한국의 석탄회 발생량이 620만톤이었지만 2011년에는 910만톤으로 증가하는 추세이다. Fly Ash는 전기집진기나 여과 집진기 등에서 배가스로부터 분리되어 콘크리트 혼화재나 시멘트 클링커 등으로 재활용되고, 보일러 하부에 모인 Bottom Ash는 Grinder로 분쇄 후 해수를 이용하여 대부분 회사장으로 폐기되고 있다고 보고되어 진다. 이와 같이 재활용되지 못하고 폐기되는 석탄회는 여러 가지 환경문제를 야기하고 있어 이의 재활용률을 높이고자 많은 연구와 개발이 수행되었다. 하지만 국내 석탄회의 재활용은 대부분 Fly Ash의 재활용에 의한 것으로서 Bottom Ash의 재활용은 매우 미미하며 대부분 회사장으로 폐기되고 있는 실정이다. 본 연구자는 회사장에 폐기되고 있는 Bottom Ash를 대상으로 미연탄소를 에너지자원으로 회수 하기 위하여 Bottom Ash 내의 미연탄소 회수 연구를 진행하였다. Bottom Ash내에 함유되어 있는 미연탄소를 비중분리와 체가름, 자력선별 등 물리적선별을 통하여 3283cal/g로 달성하였으며, 이후 물리화학적 선별인 부유선별을 통하여 pH변화, 기포제 첨가량 변화, 포수제 첨가량 변화, 광액의 농도, 부유시간에 따라 실험을 진행해본 결과 회수된 미연탄소가 5000cal/g을 넘는 부유물을 회수할 수 있었다.
        55.
        2014.11 서비스 종료(열람 제한)
        국내에서는 매년 약 1900만 톤가량의 항만준설토가 발생하고 있다. 항만공사과정에서 발생되는 준설토는 대부분 투기장 매립재로 활용되고 있으나, 정기적인 항로유지 준설 및 오염해역 준설사업에서 발생되는 준설토는 육상 투기장에 매립하거나 외해에 투기하는 방법으로 처분하고 있다. 이러한 투기장은 반면, 국제적으로 폐기물의 외해투기가 해양생태계에 미치는 악영향으로 인하여 금지되는 추세를 보이고 있으며 육상의 매립지 조성이 곤란하기 때문에 준설토의 적절한 재활용 방안 및 투기 시 해양생태계에 미치는 영향을 정량적으로 검토하는 연구가 수행되고 있다. 그러나 우리나라의 경우 아직까지 준설토의 오염현황 파악 및 정부 차원의 준설토 재활용을 위한 정책 및 오염 준설토의 유효한 관리 방안이 없는 실정이다. 따라서, 본 연구자들은 준설토의 중금속 제거를 위하여 각 해역 중에서도 중금속의 함량이 비교적 높은 영도 남항의 준설토를 대상으로 연구를 진행하였다. 먼저, 중금속의 제거를 위하여 비중선별을 실시한 결과, 비중이 작아질수록 중금속 제거율이 높아지는 경향이 나타났다. 이 후 중액선별을 이용하여 중금속이 농축된 부분을 대상으로 XRD 분석을 실시한 결과 Fe2O3, CuFe2O4 등 중금속이 철과 공존하여 존재하는 것으로 나타나 500~5000Gauss로 자력의 세기를 변화하여 자력선별을 실시한 결과, 자력의 세기가 증가할수록 제거효율이 증가하는 것으로 나타났고, 효율이 가장 높은 5000Gauss일 때 Fe, Cu, Pb, Zn의 제거율이 각각 약 30, 27, 28, 16%로 나타났다.
        57.
        2014.10 서비스 종료(열람 제한)
        Although accelerators can be utilized for the prevention of early frost by developing the strength of concrete in cold weather, no security of workability occurs because early hydration makes them react rapidly. In this study, granulation was used as a method as it can control the response time of the accelerator to secure the workability of fresh concrete.
        58.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        시설오이로 많이 재배되고 있는 4 품종을 선발하여 생육단계별로 DPPH radical 소거활성, 아질산염 소거활성, ABTS 소거활성 그리고 항산화효소 활성에 대하여 비교 분석하였다. 장죽청장 품종이 모든 생육단계에서 DPPH radical 소거활성이 상대적으로 높게 나타났으며, 그 외 품종들 간에는 큰 차이를 보이지는 않았다. 또한 생육단계별로는 수확기에 못 미친 미성숙단계에서 DPPH radical 소거 활성이 높게 나타났다. 아질산염 소거활성은 pH가 1.2일 경우 모든 품종과 생육단계에서 40% 이상 분해시켰으며, 특히 장형낙합과 신조은백다다기 품종이 상대적으로 높은 활성을 보였다. 또한 pH 4.0에서는 추출물 모두에서 30% 이상의 아질산염 소거활성을 나타냈으며, pH 6.0에서는 대부분 활성이 없었다. ABTS 소거활성은 장죽청장과 늘푸른 청장 품종이 다른 품종보다 상대적으로 다소 높은 소거능을 나타냈고, 생육단계별로는 대부분의 품종에서 ABTS 소거능에 큰 차이를 보이지는 않았다. SOD 활성은 모든 품종과 전 생육단계에서 95% 이상의 높은 활성을 보였으며, 품종 간에 거의 유의한 차이를 나타내지 않았다. CAT 활성은 전체적으로 장죽청장과 늘푸른청장 품종이 그리고 APX 활성은 늘푸른청장, 장형낙합 품종에서 상대적으로 높은 활성을 나타냈고, POX 활성은 생육단계별로 뚜렷한 경향을 보여 수확기에 이를수록 활성이 현저히 감소하는 결과를 나타냈다. 본 실험의 결과, 오이의 높은 항산화능을 확인함으로서 향후 향장소재 및 식품소재로서의 이용 가치성을 증대시킬 수 있음을 시사한다.
        59.
        2013.10 서비스 종료(열람 제한)
        Set-controlling admixtures via granulation method may be secured the operation time by adjusting the response time. therefore, mortar with Set-controlling admixtures via granulation is measured setting-time. As a result, the possibility of initial reaction control confirmed and also was developed the required properties of setting-time.
        60.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        현재 와이파이가 지원되는 스마트폰 시장이 급격히 증가하면서 스마트 폰을 기반으로 하는 네트워크 콘텐츠 가 빠르게 보급되고 있다. 하지만, 아직까지 와이파이가 지원되지 않거나 블루투스 환경만을 제공하는 피처폰이나 기타 멀티미디어 기기 등에서는 네트워크 콘텐츠를 제공하기 힘든 환경이다. 본 논문에서는 블루투스, 와이파이 등의 기술보다도 저전력, 저가격, 사용의 용이성, 다채널, 브로드캐스팅을 지원하는 지그비 기술을 이용하였다. 근거리 네트워크 게임에 지그비 기술을 이용함으로써 다양한 형태의 네트워크 게임을 개발할 수 있을 것이다. 또한, 이를 이용한 다양한 무선 네트워크 컨텐츠의 개발을 기대할 수 있을 것이다.
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