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        검색결과 991

        41.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In recent years, macroalgal bloom occurs frequently in coastal oceans worldwide. It might be attributed to accelerating climate change. “Green tide” events caused by proliferation of green macroalgae (Ulva spp.) not only damage the local economy, but also harm coastal environments. These nuisance events have become common across several coastal regions of continents. In Korea, green tide incidences are readily seen throughout the year along the coastlines of Jeju Island, particularly the northeastern coast, since the 2000s. Ulva species are notorious to be difficult for morphology-based species identification due to their high degrees of phenotypic plasticity. In this study, to investigate temporal variation in Ulva community structure on Jeju Island between 2015 and 2020, chloroplast barcode tuf A gene was sequenced and phylogenetically analyzed for 152 specimens from 24 sites. We found that Ulva ohnoi and Ulva pertusa known to be originated from subtropical regions were the most predominant all year round, suggesting that these two species contributed the most to local green tides in this region. While U. pertusa was relatively stable in frequency during 2015 to 2020, U. ohnoi increased 16% in frequency in 2020 (36.84%), which might be associated with rising sea surface temperature from which U. ohnoi could benefit. Two species (Ulva flexuosa, Ulva procera) of origins of Europe should be continuously monitored. The findings of this study provide valuable information and molecular genetic data of genus Ulva occurring in southern coasts of Korea, which will help mitigate negative influences of green tide events on Korea coast.
        4,500원
        42.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon’s Hʹ values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of subsample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.
        4,200원
        43.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study collected powder extinguishers with 6-10 years of elapsed life from January 2012 to January 2017 in market, factory, and apartment areas to experiment with changes in fineness and to examine the characteristics of extinguishing power. First, in the case of ABC powder, 98.3 wt% of the 8-year market area and 98.6 wt% of the 10-year apartment complex were found to be inappropriate in the first, second, and third arithmetic average analysis of the powder extinguisher from 6 to 10 years. That is, the fine distribution and size of the powder extinguishing agent particles should be managed within an appropriate range. It is analyzed that the powder fire extinguisher may experience a change in the fineness of the powder depending on the external environment exposure, placement, management status, and age of use, resulting in a decrease in digestive power or inability to radiate. Second, the fire extinguisher cannot be used in the initial fire suppression depending on the place of deployment, the environment of deployment, the progress of the number of years of use, and maintenance, so it is necessary to strengthen the device that enables fire extinguisher maintenance and inspection. Third, in the manufacturing process, the charging method should also be reviewed in consideration of the conditions of the workplace, the humid season, and the rainy environment.
        4,000원
        44.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Korean tariff rate for fishery products is a single tax rate of 10% for live fish and frozen seafood, and 20% for all others. Since FTAs have been concluded with several countries, the tariffs is not an appropriate means to protect domestic fishery producers. The differential tariff rate according to the scientific name (genus) of the fishery products, which was implemented 30 years ago to protect fishery products produced in the Korean coastal waters has lost its original purpose. It seems that future fishery trade policy should focus on IUU prevention, hygiene and safety of consumers rather than protecting fishery producers through customs tariffs. This paper suggest that a paradigm shift in the fishery producers protection policies such as direct financial support from the state, protection and development of fishery resources, and support for fostering the 6th industry rather than indirect protection through tariffs.
        5,100원
        45.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The occurrence of Laodelphax striatellus (SBPH) in Korea ranged 0.3-19.3 individuals in 2021, and 0.3-23.3 individuals in 2022 during the investigation period. Nilaparvata lugens (BPH) was not observed in 2021, but N. lugens (BPH) showed the highest number(82.0 inds.) in late September of 2022. The occurrence of Sogatella furcifera (WBPH) was not severe during the study period. Compared to Korea’s situation, N. lugens (BPH) and S. furcifera (WBPH) in Asian regions showed high occurrence in Bangladesh and Sri Lanka. The results of the field survey could be confirmed with the occurrence pattern of about once or twice in their regions. Continuous monitoring is required for the best control of planthopper species in rice production regions of Asia. We anticipate that exchange of occurrence information and establishment of a control cooperation system will improve rice productivity in Asian regions by preventing outbreak of planthopper species and reducing damages caused by the species.
        4,000원
        47.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이식 과정을 통해 식재된 수목은 뿌리 절단, 수관 훼손과 같은 극단적인 교란으로 인해 식재 직후 생장량은 급격히 감소한다. 이후 시간이 경과하면서 원래의 생장량을 회복하는데 이때 소요되는 시간은 수종별로 차이가 있다. 따라서 이식 후 활착을 위한 수목관리를 위해 수종별 연간생장량의 변화를 분석하여 적정 관리 기간을 설정할 필요가 있다고 판단하였다. 이에 본 연구에서는 수변생태벨트 조성 지역에 식재된 낙엽활엽수를 대상으로 생장량을 분석하고 그 결과를 바탕으로 적정 관리 기간을 제안하고자 하였다. 이식과정에서 수목 활착율을 높이기 위해 시행하는 사전 작업인 뿌리돌림, 단근, 가지치기 등으로 인해 식재 직후의 생장량 둔화는 일반적인 현상이다. 이후 시간이 경과하면서 원래의 생장량을 회복하게 되는데, 소요되는 시간은 수종별, 식재 환경 등에 따라 차이가 존재할 수 있다. 연구결과 대부분의 수목은 이식 직후 급격한 생장량 감소를 보이는 것으로 나타났으며. 이후 수종별로 상이하긴 하나 대부분 2년 이후부터 서서히 생장량을 회복하는 것으로 나타났다. 수종별 생장량을 분석한 결과 공통적으로 이식 직후 급격한 생장량 감소를 보인 후, 이식전의 생장 수준을 회복하기 까지는 수종에 따라 2~4년 정도의 시간이 필요한 것으로 확인되었다. 결과적으 로, 생태복원 및 오염물질 저감이라는 본 사업의 목적에 부합하기 위해서는 식재한 수목의 하자율 개선이 필요하며, 이를 위해서는 적정한 기반환경을 조성하는 것 외에 최소 2년간의 수목 관리기간을 설정하는 것이 필요하다.
        4,200원
        48.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 같은 일적산광량(DLI) 조건에서 각각의 광강도 와 광주기 조합이 십자화과 식물 3종의 생육 및 글루코시놀레 이트(GSLs) 함량에 미치는 영향을 살펴보고자 수행되었다. 갓(Brassica juncea (L.) Czern.), 적겨자(Brassica juncea L.), 케일(Brassica oleracea L. var. acephala (DC.) Alef.) 종자를 암면 배지에 파종하여 3주간 육묘하였다. 육묘 후 DLI 를 10mol·m-2·d-1로 설정하여 10h-280, 14h-200, 18h-155, 22h-127μmol·m-2·s-1 처리 조합으로 3주간 처리하였다. 14h- 200μmol·m-2·s-1 처리한 결과, 적갓과 케일은 지상부 생체중/ 건물중, 엽수, 엽면적이 증가하였지만, 유의적 차이는 관찰되 지 않았다. 적갓의 GSLs 함량에서 14h-200μmol·m-2·s-1 처리 가 10h-280, 18h-155, 22h-127μmol·m-2·s-1 처리보다 각각 유의적으로 139.95, 135.87, 154.03% 증가하였으며, 케일의 경우 14h-200μmol·m-2·s-1 처리가 다른 처리구보다 각각 132.96, 122.06, 131.78% 유의하게 증가하였다. 적겨자는 18h-155μmol·m-2·s-1 처리에서 지상부 생체중/건물중, GSLs 함량이 증가하였으며, 14h-200μmol·m-2·s-1 처리에서 엽수가 10h-280, 18h-155, 22h-127μmol·m-2·s-1 처리보다 각각 15.62, 12.12, 32.14% 유의적으로 증가하였다. 유사한 십자 화과 작물이라도 종에 따라 DLI 반응이 다르기 때문에 최적의 DLI 조건 구명과 최소의 전력 소비량 및 최대 효율을 내기 위 한 광질 연구를 병행하여 더 세밀한 결과를 도출해야 할 것으 로 사료된다.
        4,000원
        50.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fungi are organisms that must be monitored and controlled in order to preserve valuable paper records. They reduce the quality of paper records by degradation and/or discoloration. As an effort to understand fungal contamination in the National Archives of Korea, the concentration of fungi in the indoor air of the unsterilized record rooms has been reported. However, what species are present in the facilities is not much known. In the present study, we examined the fungi isolated from the National Archives of Korea and found among them that there are fungal species which are newly documented in Korea. They were identified based on morphological properties and nucleotide sequences analysis of the polymerase chain reaction-amplified the internal transcribed spacer region of rDNA, calmodulin gene, and beta-tubulin gene. We report Cladosporium parahalotolerans, Cladosporium subuliforme, Ochroconis mirabilis, Penicillium angulare, and Penicillium fundyense as new instances of fungal species in Korea. Among these five species, P. angulare is known to able to produce cellulase and O. mirabilis as an opportunistic pathogen of human and animals.
        4,000원
        51.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 2013년 1차 솎아베기 및 가지치기를 시행한 35년생 종가시나무 인공림을 대상으로 2014년과 2021년에 임분조사를 실시하여 임목 생장⋅형질 반응 특성을 분석하였다. 가지치기 시업임분에 대한 솎아베기 강도별 임목생장 특성을 비교 분석한 결과, 평균수관면적은 강도구가 대조구보다 유의적으로 넓으며(p<0.05), 정기생장률도 높아 흉고직경과 유사한 경향을 보였다. 가지치기 시업임분에 대한 솎아베기 처리구별 가지발 달 특성을 분석한 결과, 약도구를 제외한 모든 처리구의 지하고는 가지치기 처리구에서 대조구보다 유의적으로 높게 분석되었다(p<0.05). 고사지 발생률의 경우 가지치기 처리구에서 29.6∼36.7%, 대조구에서 40.0∼53.3%로 각각 나타났다. 활엽수 입목형질등급평가 기준에 따른 연구대상지의 형질등급 분석 결과, 1등급 입목의 비율은 가지치기 처리구에서 21.0%, 대조구에서 11.6%로 각각 나타나 유의적인 차이를 보였으며, 이로부터 가지치기 시업에 따른 임목형질개선 효과에 대한 실증적 시험연구결과를 도출할 수 있었다.
        4,000원
        52.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, newly improved Ferron assay test haved on timed spectrometry was used for the determination of hyolrolytic Al species presented in PACl coagulant. The color development reagent ferron was prepared by using conventional method and two newly developed methods. Then the ferron assay test was used to compare and analyze the distribution of Al(III) hydrolyzed species presented in the prepared PACl and alum. The preparing method of reagent A required an aging period of 7 days by adding a hydroxylamine hydroxide and a 1,10-phenanthroline monohydrate reagent, whereas the preparing method of reagent B was used as a coloring agent immediately without aging time. The regression analysis between UV absorbance and Al concentrations of conventional method and newly developed method of ferron reagents in low-concentration aluminum solutions and high-concentration aluminum solutions, showed the correlation coefficients of 0.999 or higher, as showing high correlations of conventional method and newly developed method. Applying Ferron assay test, Al species in the PACls and alum were classified as Ala(monomeric Al), Alb (polymeric Al), and Alc (colloidal and precipitated Al). Distribution of Al(III) hydrolyzed species according to the preparation of ferron colorimetric reagents was similar.
        4,000원
        53.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는, 5가지 식물의 메탄올 추출물을 이용하여 모기기피 효과 실험을 진행하고 누드 쥐를 모델로 하여 흰줄숲모기에 대한 모기기 피제의 유효용량 및 유효시간을 평가하였다. 그리고 식물의 휘발성분을 GC-MS로 분석하였다. 유효용량은 개박하가 10, 50, 100, 200 μg/mL 에서 72.9, 83.7, 86.4, 97.3%의 효율로 가장 높았다. 누드 쥐를 대상으로 한 유효시간 연구에서는 5가지 식물의 메탄올 추출물 중 개박하, 개다 래 및 개똥쑥이 90.5%로, 30분까지만 지속하였다. 각 식물의 휘발성분을 분석한 결과, 애플민트 28개 성분, 개다래 19개 성분, 개똥쑥 27개 성분, 개박하 26개 성분, 민들레 19개 성분이 확인 되었다. 특히 모기기피제의 유효 성분으로 알려진 네페탈락톤(nepetalactone)이 개박하의 휘발성분 중 한 성분으로 확인 되었다(27.95 mg/Kg). 본 연구결과는 다양한 휘발성분을 함유한 식물을 이용한 모기기피제 재료로서 가능성을 제시한다.
        4,000원
        54.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 장흥지역에서 자생 및 재배한 총 3가지 식물을 수증기 증류 추출(편백, 석창포, 라벤 더)을 통해 얻은 각 천연 에센셜 오일에 대한 GC-MSD 향기 성분 분석 후 추출된 오일들과 시판 오일(클 라리세이지, 시나몬, 프랑킨센스)을 조합하여 세포독성, 항산화, 항염, 미백 효과를 확인하여 화장품 소재로 서의 가능성을 확인하였다. 향기 성분 분석 결과 편백 오일의 주요 성분으로는 Sabinene, 석창포 오일은 Asarone, 라벤더 오일은 L-Linalool이 동정되었다. 6종 에센셜 조합 오일의 세포독성이 확인되지 않은 100 μL/mL의 농도에서 NO 생성은 27.76% 억제, DPPH 라디칼 소거능은 99.69%, ABTS 라디칼 소거 능은 94.66%, 티로시나아제 저해활성은 55.9%를 보여 기능성 화장품 원료로서 유용하게 활용할 수 있는 가능성을 제시하였다.
        4,200원
        60.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Volatile organic compounds (VOCs) are chemicals to which humans are exposed frequently via various mediums, including vehicle emissions that contain fine dust and heavy metals, use of organic solvent building materials, furniture, and smoking. Exposure to high concentrations of VOCs may result in loss of consciousness, paralysis, convulsions, and, in the most severe cases, death. Therefore, the present study investigated the indoor and outdoor concentrations of total volatile organic compounds (TVOC) and five types of VOCs (benzene, toluene, styrene, m,p-xylene, and o-xylene) in apartments, a representative residential environment accounting for ~55% of the housing in the Seoul metropolitan area. The research was conducted over four seasons from May 2020 to February 2021, and the levels of VOC concentrations were analyzed by classifying them by season, weekday/weekend, and indoor/outdoor locations. The seasonal trend in VOC concentrations showed that TVOC concentration was highest in summer, with values of 1630.93 ± 1184.10 μg/m3 and 1610.36 ± 1363.43 μg/m3 for indoor and outdoor environments, respectively. The seasonal trends of the concentrations of the five types of VOCs showed that concentrations of benzene and toluene were highest in spring, the concentrations of m,p-xylene and o-xylene were highest in summer, and the concentration of styrene was highest in winter, irrespective of spatial characteristics such as indoor/outdoor environments. In all four seasons, the indoor concentrations were higher than the outdoor concentrations. These results reveal the spatial and temporal distribution characteristics of the VOCs and so can serve as useful basic data for managing indoor and outdoor levels of VOCs.
        4,500원
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