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        검색결과 12

        1.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In alignment with South Korea's “3020 Renewable Energy Expansion Plan,” this study focuses on the developing large-scale floating wind turbines. It addresses the challenges of increased size and cost in floating structures for wind turbines over 10MW. This paper details the preliminary design of a novel floating substructure utilizing composite materials(ie, EVA). Structural analysis was performed using ABAQUS, accounting for both typical and extreme wind conditions. Results from the analysis validate that the substructure design is adequately feasible for implementation.
        4,000원
        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study focused on improving the phase stability and mechanical properties of yttria-stabilized zirconia (YSZ), commonly utilized in gas turbine engine thermal barrier coatings, by incorporating Gd2O3, Er2O3, and TiO2. The addition of 3-valent rare earth elements to YSZ can reduce thermal conductivity and enhance phase stability while adding the 4-valent element TiO2 can improve phase stability and mechanical properties. Sintered specimens were prepared with hot-press equipment. Phase analysis was conducted with X-ray diffraction (XRD), and mechanical properties were assessed with Vickers hardness equipment. The research results revealed that, except for Z10YGE10T, most compositions predominantly exhibited the t-phase. Increasing the content of 3-valent rare earth oxides resulted in a decrease in the monoclinic phase and an increase in the tetragonal phase. In addition, the t(400) angle decreased while the t(004) angle increased. The addition of 10 mol% of 3-valent rare-earth oxides discarded the t-phase and led to the complete development of the c-phase. Adding 10 mol% TiO2 increased hardness than YSZ.
        4,000원
        3.
        2018.10 구독 인증기관·개인회원 무료
        Momordica charantia is therophyte vine plants. It is called natural insulin and contains carantine and vitamin C and so on. Momordica charantia is one of the representative subtropical crops as a functional crop, showing efficacy on improvement of diabetes, cancer, abdominal obesity and improvement of hypertension. According to climate change, Momordica charantia is growing cultivation area, but there is still insufficient research for insect pest occurrence and insecticides. Due to the lack of proper control measures, the damage caused by insect pests is increasing as the year goes by. This study was conducted to investigate the occurrence and damage of insect pests in Momordica charantia and utilize it as basic data for development of insect pest control technology. As a result, 5 orders of 13 species of insect pests were investicated. Among them, Aphis gossypii, Frankliniella intonsa, and Frankliniella occidentalis showed high density. In particular, Aphis gossypii showed the highest density in mid-May, also Frankliniella intonsa and Frankliniella occidentalis showed high density in the middle of June. The leaf damage caused by the larvae of Palpita indica was observed in late June. After mid July, the biginning of the high temperature period, the insect pest density decreased, but the damages caused by moths were severe.
        4.
        2018.04 구독 인증기관·개인회원 무료
        우리나라는 1996년 WTO/SPS(동식물검역협정)에 따라 검역병해충제도를 정비하였으며, 해외병해충의 위험으로부 터 자국내 생물자원과 자연환경을 보호하기 위하여 다양한 노력을 하고 있다. 현재까지의 수입식물 검역과정에서 검출된 병해충을 분석한 결과 병해충 검출건수는 수입량이 늘어나면서 증가하는 추세이다(00년 6,233건 → 17년 12,749건). 하지만 식물의 수입 유형에 따라 곡류, 사료류 등 비재식용 식물의 경우 병해충 검출률은 07년 이후 감소하고 있으며(07년 9.8% → 17년 3.3%), 묘목류, 종자류 등 재식용 식물의 경우 11년 이후로 지속적으로 증가하고 있어(11년 7.9% → 17년 22.0%) 재식용 식물을 통한 해외 병해충의 유입 위험도가 가증되고 있는 상황이다. 따라서 우리는 검역본부에서 운영하고 있는 자체 전산시스템인 병해충정보시스템(PIS)을 이용하여 2000년 이후 식물검역과 정에서 발견된 병해충 검출동향과 수입 유형에 따른 검출동향을 비교분석하고, 2016년 대비 2017년 병해충 검출동향을 파악하였다.
        5.
        2016.04 구독 인증기관·개인회원 무료
        The cabbage whitefly Aleyrodes proletella L. (Hemiptera: Aleyrodidae) is a specialized insect that uses its mouthparts(stylets) to feed from the phloem of its host plants, which are found among the Brassicaceae and Asteraceae. Female whiteflies lay their eggs in circular patterns embedded in wax on the underside of the leaves. These were collected from the leaf of triangular lettuce, Crepidiastrum sonchifolium throughout the whole Chungnam province, 2013. We reared the cabbage whitefly on the egg-plant. The elongate-oval eggs are laid upright in a semicircle on the underside of Brassica leaves but didn’t in lab. Initially pale and translucent, the eggs become darker. Nymphs are scale-like and covered with wax; their color is white with two yellow spots on the abdomen. On the dorsal surface of the last abdomial segment is the vasiform orifice charactersitic of the group. The fourth instar is called the “pupa”. The pupa is thicker, immobile, and pale in color with red eyes. The adults are tiny, about 1.5 mm long, and moth-like. The head and thorax are dark. The abdomen is yellow and covered by a conspicuous white waxy layer. The forewings have a faint, dark bar. If disturbed, the adults fly readily. The duration of development of immature stages of Aleyrodes proletella decreased with increase in temperature, the mortality was higher below 16 ℃ and above 28 ℃.
        6.
        2014.10 구독 인증기관·개인회원 무료
        We collected the unknown species of whiteflies throughout the Chungnam districts. Crepidiastrum sonchifolium (Bunge) Park & Kawano, Korean youngia was major plant to Cabbage whitefly and discovered throughout the Chungnam province in 2013. The unknown other species was collected on leaf of Morus alba L.(White mulberry) in September, 2014. We are attributing this species to Parabemisia sp. It has been known that plants affected by Aleyrodes proletella Linnaeus, cabbage whitefly are leafy brassicas, including kale cabbage, broccoli and Brussels sprout and a minor pest of cabbage, bruseels sprouts and broccoli in Europe, being seldom a pest of agriculture but often troublesome to home gardeners. In cage of pupal, lingular head is simple, dorsal submargin without row of papillae and body not boxshaped. The pupal shape of Parabemisia sp.(attributted) is as follows. The fourth nymphal skin has 30 to 32 marginal setae including the caudal setae. The anterior spiracular furrows are scarecely visible, but the caudal furrow is slightly ridged longitudinally. The vasiform orifice is elongate triangular with the lingula included. The lingula has two blunt lateral tubercles and two long caudal lingular setae. The operculum covers only the anterior one-third of the vasiform orifice. In vivo, the nymphs are surrownded by a marginal fringe of clear wax.
        7.
        2014.06 구독 인증기관 무료, 개인회원 유료
        This paper studies on the effects of new biological control system, particularly on banker plants of Orius laevigatus to control Frankliniella occidentalis on rose. Orius banker plants for Frankliniella occidentalis were investigated under the conditions of photoperiod 16L:8D, 70 ± 5% RH and 22 ± 2oC. Three types of plants(Sedum sarmentosum, ortulaca grandiflora, Mentha rotundifolia) were used to effectiveness verification of egg taking. And P. grandiflora has been selected as the banker plants for O. laevigatus. Result from this banker plants clearly demonstrated that the population of F. occidentalis was kept under the economic threshold level (1.9 per flower).
        3,000원
        8.
        2013.10 구독 인증기관·개인회원 무료
        F. occidentalis causes to decrease the yield of chrysanthemum flower economically because it is the major crop pest injuring the flower directly at flowering period in chrysanthemum artificial houses. The control of it with chemicals is very difficult because the resistance of it to chemicals is so high. F. occidentalis began to occur at early-May and increased rapidly mid-May after in standard chrysanthemum artificial houses, Yesan, Chungcheongnam-do. In case of a farm, the density of it increased continuously in spite of chemical control . The times of chemical control to depress the density of it was 6 or 7th for cultivation period of chrysanthemum. We put the flowering yellow pot-mum already (trap plant attracting F. occidentalis) in standard chrysanthemum PVC-houses and set the yellow sticky cards up at an interval of 5m from trap plant(TP). The more yellow sticky trap near to trap plant, the more F. occidentalis was attracted to yellow sticky trap. TP was more attractive to adult F. occidentalis up to distances of 10m. The numbers of it attracted to yellow sticky traps at different distance from TP was not different significantly when standard chrysanthemum bloomed. We put the TP in standard chrysanthumum PVC-house at an distance of 20m and released the natural enemies (Orius laevigatus) on TP at 3 times, an interval of 7 days. And then we set yellow sticky traps up at an distance of 5m from TP and compared the plot with TP+natural enemy(NE) to the plot without them. The density of F. occidentalis was rather lower at TP+NE plot than the plot without at the formative period of flower bud of standard chrysanthemum. Therefore, The yellow flowering chrysanthemum possesses great value of TP attracting F. occidentalis in chrysanthumum PVC-house up to flowering period of cultivating chrysanthemum, and if it is used with natural enemy and chemicals simultaneously, farmers can minimize the quantity of chemicals used.
        9.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 토마토의 주요해충인 토마토녹응애(Aculops lycopersici Massee)의 조기 예찰을 위한 새로운 예찰법 개발에 관한 것이다. 토마토 녹응애는 4월경 최초 발생하여 토마토의 아래 줄기부터 감염시키며 엽병을 타고 잎으로 이동한다. 발생이 심할 경우 줄기는 다소 광택이 나면서 녹이 낀 색을 보이며, 잎은 은빛을 띠다가 점차 녹슨 형태를 띠고 잎 끝이 말린다. 성숙된 과실보다 푸른색을 띠는 시기에 피해를 주며 과실에 피해가 보일 경우는 밀도가 상당히 높아야 하기 때문에 과실 피해를 보기란 쉽지 않다. 녹색의 라벨스티커에서 최초로 토마토녹응애를 찾아내는데 걸리는 시간은 약 7.0초로 가장 짧았으며 청색, 주황색, 백색의 경우 각각 17.1, 19.8, 12.3초의 시간이 걸렸다. 투과현미경에 측광을 주었을 때 가장 관찰이 용이하였다. 토마토녹응애는 4월 하순부터 발생하여 5월 중순 이후 급격히 밀도가 증가하였으며, 6월 중하순경 최대 발생 양상을 보이고 기온이 높아지면서 6월 하순 이후 밀도가 급격히 감소하였다. 토마토녹응애 접종 후 개체군 증가를 보았을 때, 접종 20일 후 하단부 줄기에서 최초로 관찰되었고 60일 후에는 상단부 줄기에서도 관찰되었다. 접종 후 최대의 발생량을 보이는 시기는 줄기의 경우 40일부터 60일까지였으며 잎의 경우는 약 80일 후였다. 라벨스티커는 토마토재배지에서 토마토녹응애의 발생을 예찰하기에 충분하였다
        4,000원
        10.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        복숭아혹진딧물에 기생하는 목화면충좀벌의 발육기간, 머미율, 번데기 사망률, 성비를 20, 25, 30, 25℃ 인큐베이터에서 수행하였다. 실험을 위하여 피망잎이 놓인 콤팩트샤레를 사용하였다. 각각의 4개 온도에서 발육단계별로 복숭아혹진딧물을 사육하였고 기생을 유도하기 위하여 12시간 동안 목화면충좀벌에 제공하였다. 목화면충좀벌의 알에서 성충까지 발육기간은 20℃ 18.3일, 25℃ 14.7일, 30℃ 10.4일, 35℃ 9.3일 이었다. 복숭아혹진딧물에 기생한 목화면충좀벌의 머미율은 20℃와 25℃, 1령과 2령에서 가장 높았으나 30℃와 25℃에서는 3령충에서 84.4~85.0%로 가장 높았다. 목화면충좀벌의 기주섭식률은 20~35℃까지 각각 12.5%, 17.3%, 16.0%, 10.9%였다. 목화면충좀벌 암컷의 성비는 온도별로 각각 49%, 46%, 69%, 60% 였다.
        4,000원
        11.
        2006.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The periodontal ligament (PDL) is that soft, specialized connective tissue situated between the cementum covering the root of the tooth and bone forming the socket wall. The PDL is a connective tissue particularly well adapted to its principal function, supporting the teeth in their sockets and at the same time permitting them to withstand the considerable force of mastication. During the life time, PDL is usually exposed to mechanical stress by mastication. However, little is known about the gene which is related to the mechanical stress in PDL. UNC-50 (PDLs22) was identified and isolated from D. melanogater and C. elegance. This gene was also regulated in sensory bristle for mechanotransduction in D. melanogaster. In this study, to uncover the relationship between UNC-50 and mechanical stress, we induced the mechanical stress by medium displacement in cementoblast cell line. After mechanical stress induction UNC-50 expression was analyzed by RT-PCR, Real-time PCR, and western analysis. The expression of UNC-50 was increased after medium displacement of cementoblast in vitro. Collagen type I, type III, and osteonection mRNAs were also strongly expressed after mechanical stress induction. The results of this study suggest that UNC-50 might responsible for molecular event in PDL inducing cementoblast under mechanical stress.
        4,000원
        12.
        1994.12 KCI 등재 서비스 종료(열람 제한)
        The environmental regulation violation of the Korean firms is causing severe environmental pollution lately. Nevertheless, there are few studies on the firm`s pattern of environmental regulation violation. In this paper, for the pattern of environmental regulation violation of the Korean firms, we give a type of statistical data analysis using the correspondence analysis. Therefore, with more effective control and inspection based on this, we have an effective and enforceable system decreasing the violative firms.