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        검색결과 49

        2.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        6.
        2022.05 구독 인증기관·개인회원 무료
        In order to enhance the transparency of nuclear power, the investigation of nuclear activities is important at the right time. And investigation of North Korea, one of safety measures for such a surveillance system seems essential in the near future. However, the inspection period is limited and the possibility of revisiting is unclear, so it seems easy to install and more reliable monitoring devices are needed. The seal is a security device for monitoring forgery and alteration in the IAEA easily but simple. Since the existing seal devices used by IAEA and KINAC can only be checked through onsite inspections whether it is damaged or not, there is a limit to immediate response in the event of an emergency such as the theft of nuclear materials and loss of Continuity of Knowledge. While the North Korea-U.S. talks and inter-Korean talks are slowly approaching the North Korea’s nuclear issue, it is judged that the inspection of North Korea’s nuclear weapons is not in the distant future. Accordingly, it is necessary to develop a customized seal device for managing and monitoring spent nuclear fuel that can be used for inspection of North Korea. The real-time active seal device consists of a seal equipped with a detection sensor, a translator, and a server, and the translator use wireless communication in consideration of ease of installation and management, respectively. The translator and server use wired communication for data sustainability. The seal device is designed to maintain continuity of knowledge (COK) through wireless communication in consideration of security even in the event of equipment damage, malfunction, and loss of power, while enabling location detection in case of theft or abnormality. Therefore, in this study, a technical investigation on remote data communication was conducted accordingly, and a data communication module for a small amount of broadband data communication was manufactured and applied. In addition, several tests were conducted to determine data integrity and location accuracy according to the communication range.
        7.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험은 광 환경이 자생 Veronica속 4종 구와꼬리풀, 봉래꼬리풀, 부산꼬리풀, 큰구와꼬리풀의 생장 및 개화에 미치는 영향을 구명하기 위해 실시하였다. 이중 봉래꼬리풀은 희귀 및 특산식물로 지정되어 있는 우리나라의 자생식물이며 부산꼬리풀은 우리나라에서도 부산지역에서만 자생하는 특산식물이자 자료부족종으로 분류된다. 실험은 2018년 3월 30일부 터 2018년 8월 17일까지 수행되었으며 Veronica속 4종을 0, 40, 60, 90% 차광환경에서 재배하였다. 구와꼬리풀을 0~60% 차광환경에서 재배시 90% 차광환경에서 재배한 개체보다 지상부의 생체중이 무겁고 엽수 및 가지수가 많아 생장이 유의하게 좋았다. 큰구와꼬리풀의 줄기 두께는 90% 차광환경에서 재배시 유의하게 얇아져 생장이 불량하였다. 구와꼬리풀과 큰구와꼬리풀은 0~60% 환경에서 재배시 모든 개체가 개화하였으며 90% 차광환경에서 재배한 개체보다 개화소요일수가 짧 아졌다. 봉래꼬리풀은 0~40% 차광환경에서 재배시 60~90% 차광환경에서 재배한 개체보다 지상부 및 건물증이 유의하게 증가하여 생육이 좋았으며, 관상가치 측면에서 가장 높은 점수를 받았다. 부산꼬리풀의 관상가치는 0, 40, 60, 90% 차광환경에서 재배시 각각 4.0, 3.0, 2.2, 1.0점으로 조사되어 동일한 Veronica속이라도 종에 따라서 광 민감도가 다양한 것을 확인하였다.
        4,000원
        9.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 실험은 저온처리 기간과 일장이 자생 돌마타리의 휴면타파와 생장 및 개화에 미치는 영향을 구명하기 위해 실시되었다. 노지에서 재배중인 돌마타리의 생물계절현상 반응(phenology) 을 3월부터 10월까지 조사하였다. 또한 저온처리 기간이 돌마타리 휴면타파 및 개화에 미치는 영향을 알아보기 위해 4°C 저온에 0, 3, 6, 9, 12주간 처리한 후 장일환경(16h), 25°C 온도조건에서 재배하면서 생육특성을 관찰하였다. 일장이 돌마타리의 생육 및 개화에 미치는 영향을 알아보기 위해 자연저온 처리된 돌마타리를 단일(9h), 중일(12h), 장일조건(16h)에서 재배하여 생육 특성을 관찰하였다. 야외에서 재배중인 돌마타리는 늦여름인 8월부터 9월까지 개화하는 특성을 보였다. 저온처리 기간에 따른 실험결과 9, 12주 저온처리를 받은 식물이 3, 6주간 저온처리 한 식물에 비해 개화소요일수가 유의하게 단축되었다. 돌마타리는 4°C 온도에서 9주 이상 처리시 33%의 개화율을 보이는 것으로 조사되었다. 일장에 따른 실험결과, 장일환경에서 재배된 돌마타리의 초장은 50.1cm였으나 단일 및 중일환경에서 재배된 식물의 초장은 각각 16.7, 16.1cm로 조사되었다. 돌마타리는 장일환경에서 16주간 재배 시 100% 개화하였으나 단일 및 중일 환경에서 재배 시 전혀 개화하지 않았다. 결론적으로 돌마타리 는 휴면타파 및 개화를 위해 저온을 필수적으로 요구하며 장일 환경조건에서만 개화하는 질적장일식물임을 확인하였다.
        4,000원
        10.
        2018.10 구독 인증기관·개인회원 무료
        농업용 무인멀티콥터를 활용한 방제면적은 수도작은 물론 밭작물에서도 방제 범위가 확대되고 있다. 밭작물은 작물의 형태가 다양하여 비행속도, 살포높이 등을 최적화하는 연구가 필요하다. 본 연구에서는 배추, 대파, 고추에서 발생하는 나방류에 대하여 무인멀티콥터의 살포 높이에 따른 방제효과를 확인하였다. 살포된 약제가 작물에 부착되는 정도를 조사한 결과, 배추는 2m, 대파는 3~4m, 고추는 모든 높이에서 비슷한 부착정도를 보였지만, 전체적으로 부착량이 적고 불균일 하였다. 살포 높이별 방제효과는 작물별로 각각 배추(9~10엽기)는 2m높이, 고추(약 1.2m)는 2~3m, 대파(약 60cm)는 2, 3, 4m 각각 비등한 방제효과를 보였다. 각각의 작물모두 경엽처리 대비 약효가 미흡하였으며, 고추는 4m높이 살포시 방제효과가 현저히 낮았다.
        11.
        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
        12.
        2017.04 구독 인증기관·개인회원 무료
        Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.
        13.
        2015.10 구독 인증기관·개인회원 무료
        Sweet pepper (Capsicum annuum L.) is one of the leading export greenhouse crops in South Korea. Sweetpotato whitefly, Bemisia tabaci Gennadius is one of the major pests on greenhouse pepper. This pest is conventionally managed by synthetic insecticide application, however this management tactic causes the overuse of toxic compounds and the resistance of whiteflies to insecticides. Therefore, the development of environment-friendly natural insecticides is vitally important. In this study, we evaluated the efficacy of three newly-screened insecticidal compounds for B. tabaci (Biotype Q) in laboratory. The insecticidal effects of the compounds were assessed with adult B. tabaci using leaf disc arena established in petri dish. Among the three compounds tested, JS408, a plant extract from Perilla sp., showed significant insecticidal effects on B. tabaci in one hour causing 90% mortality. However, JA408 caused phytotoxicity on sweet pepper leaf resulting in browning dead spots. The new plant-extract JA408 has promising potential as natural insecticidal compound for B. tabaci, but further study must resolve the phytotoxicity issue. Moreover, insecticidal effect should be evaluated under field conditions.
        14.
        2013.10 구독 인증기관·개인회원 무료
        Most traditional genome sequencing projects involving infectious viruses include culturing and purification of the virus. This can present difficulties as an analysis of multiple populations from multiple locations may be required to acquire sufficient amount of high-quality DNA for sequence analysis. The electrophoretic method provides a strategy whereby the genomic DNA sequences of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) were analyzed by purifying it from host DNA by pulsed-field gel electrophoresis, thus simplifying sampling and labor time. The genomic DNA of infected P. rapae was embedded in agarose plugs, digested with a restriction nuclease and methylase, and pulsed-field gel electrophoresis (PFGE) was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the separated viral DNA. The double-stranded circular genome of PiraGV-K encodes 120 open reading frames (ORFs), covering 92% of the sequenced genome. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF11), involved in the liquefaction of the host, were found in the genome. The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the pulsed field electrophoretic method. The method appears to be applicable to the analysis of genomes of large viruses. The chitinase, identified by PiraGV-K genome sequence, was functionally characterized by quantitative PCR, Western blot analysis, immunohistochemistry and transmission electron microscopy.
        17.
        2012.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 심지층 처분장 부지선정 시에 고려되는 요소를 지질, 수리지질, 지화학 등으로 분류하고 그 첫 번째 단계로 지질분야의 세부 항목을 지형, 토양층, 암종, 구조지질, 역학적 안정성, 지질학적사건으로 분류하였으며, 이들 항목에 대한 국외 기준분석을 수행하였다. 부지선정요소(Siting factor)에 대한 기준(Criteria)은 각 국가의 처한 지질환경에 따라 다른 조건혹은 값을 제시하고 있다. 화산 및 지진활동이 빈번한 일본에서는 이에 대한 기준을 상대적으로 자세히 기술하고 있으며, 빙하작용이 예상되는 스웨덴에서는 빙하작용에 의한 지반 융기·침식에 대한 영향을 상세히 분석하였다. 따라서, 본 논문 결과는 향후 국내의 심지층 처분장 부지선정 기준 수립시에 중요한 참고자료로 활용될 수 있을 것으로 판단된다.
        4,000원
        19.
        2008.09 구독 인증기관 무료, 개인회원 유료
        수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드 스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동 방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색 특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율 면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위 칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.
        4,000원
        20.
        2006.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oral squamous cell carcinoma is the 1st most common malignancy in oral and maxillofacial area. HPV 16 has been strongly linked to progression of cervical carcinoma. E6 and E7 as a small DNA virus encoding two major oncoproteins of HPV 16 can act together to produce efficient immortalization of primary human epithelial cells. Thus it is important to pursue the development of Immortalized human oral keratinocyte(IHOK) culture model which could be related to the pathogenesis of oral squamous cell carcinoma. If we establish IHOK transfected by E6/E7 genes, IHOK will be accepted as a model system for HPV-linked oral carcinogenesis. The purpose of this study were to culture primary normal human oral keratinocyte(NHOK), and to establish IHOK for studying oral carcinogenesis in the future. NHOK was primarily cultured under normal culture condition, and transformed into IHOK by transfection of E6/E7 genes. After 100 passages depend on Ca++ condition, cultured IHOK was confirmed by growth curve, cornified cell envelope measurement, TGase 1activity, mRNA detection, tumorogenecity and anchorage independence assay. After 100 passages, cultured IHOK showed most basal cell and monolayer of polyhedral cells under 0.15mM Ca++, and small area of stratification and flattened epithelial cells with irregular border under 1.2mM Ca++. The cultured IHOK showed relatively resistant growth under high calcium condition. The E6/E7 mRNA was detected in cultured IHOK by RT-PCR. During the terminal differentiation in cultured IHOK, increased insoluble cornified cell envelope formation was accompanied with induction of TGase 1 activity. But the cultured IHOK showed less CEM and TGase 1 activity than those of cultured NHOK. Cultured IHOK showed non-tumorogenecity, but slight anchorage independence. We had developed a technique to transform NHOK into IHOK by transfection of E6/E7 genes. Cultured IHOK was established as intermediate stage cell to study the pathogenesis of human oral squamous cell carcinoma.
        4,200원
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