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        검색결과 9,757

        3053.
        2017.04 구독 인증기관 무료, 개인회원 유료
        Long-range visual marine aids to navigation are not required for current marine navigational practices. Therefore, the objective of this study was to develop a minimum luminous range for major lighthouses that are still in existence to sustain the operation of the lighthouses in the future. Two steps were involved in the determination of the minimum luminous range, namely the modification of the existing geographical range formula, and the finding of a strong linear correlation between the light intensity and the luminous range with the lowest gradient possible in a graph. The application of the minimum luminous range would eliminate the loom of light beyond the geographical range of the lighthouse. This approach was applied to seven major lighthouses in Peninsular Malaysia, which resulted in a minimum luminous range of between 12 nm to 14 nm, which was a reduction from the existing range of 18 nm to 25 nm. The validation of the minimum luminous range was performed in two ways; using a Full Mission Ship Simulator (FMSS), and matching the proposed minimum luminous range with the lighting system available. The results of the validation by using the FMSS between the luminous range of 25 nm and 14 nm showed that the light could be sighted and identified at 58.7 nm and 58.6 nm, respectively, which was, therefore, not significant. The validation by matching with the lighting equipment available in the market showed that the eight-tier VLB-44, which has replaced the rotating lighting system in the US since 2008, was highly matched with the proposed minimum luminous range. This further validated the minimum luminous range. The minimum luminous range is sufficient for current navigational uses and may reduce the costs for procuring and maintaining lighting systems, and will be able to sustain the operations of lighthouses in this GNSS age.
        4,000원
        3055.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carboxylated multi-wall carbon nanotubes (MWCNTs-COOH) have been used as efficient adsorbents for the removal of picric acid from aqueous solutions under stirring and ultrasound conditions. Batch experiments were conducted to study the influence of the different parameters such as pH, amount of adsorbents, contact time and concentration of picric acid on the adsorption process. The kinetic data were fitted with pseudo-first order, pseudo-secondorder, Elovich and intra-particle diffusion models. The kinetic studies were well described by the pseudo-second-order kinetic model for both methods. In addition, the adsorption isotherms of picric acid from aqueous solutions on the MWCNTs were investigated using six two-parameter models (Langmuir, Freundlich, Tempkin, Halsey, Harkins-Jura, Fowler- Guggenheim), four three-parameter models (Redlich-Peterson, Khan, Radke-Prausnitz, and Toth), two four-parameter equations (Fritz-Schlunder and Baudu) and one five-parameter equation (Fritz-Schlunder). Three error analysis methods, correlation coefficient, chi-square test and average relative errors, were applied to determine the best fit isotherm. The error analysis showed that the models with more than two parameters better described the picric acid sorption data compared to the two-parameter models. In particular, the Baudu equation provided the best model for the picric acid sorption data for both methods.
        4,200원
        3056.
        2017.04 구독 인증기관·개인회원 무료
        Having conducted numerous research and survey projects, Korea National Arboretum (KNA) has been a centre for Korean insect diversity researches in South Korea for about a decade since its first step as the first national biological collection was taken in 2003. Those projects mainly focused on specimen collection through various surveys and classical taxonomic studies on rather limited taxa. Holding slightly more than 6,000 species in our collection now, we consider it is time to take another approach that will keep insect researches going and expanding its boundary although it seems a little bit late to follow an international trend. The approach we are about to follow is a DNA barcode blitz, which aims for rapid digitization and sequencing of insects. With an integrated system of insect taxonomy we may provide faster and more reliable identification service to the public and other related biological and ecological studies. Digitized morphological and molecular data can be used in various ways such as forest insect pest monitoring, climate change related monitoring, and reverse taxonomic study.
        3057.
        2017.04 구독 인증기관·개인회원 무료
        Disheveled is a major regulator of WNT signalling pathway. It has been shown that WNT signaling is important for regulating synaptic plasticity. However, it is not still clear how Dsh is regulating synaptic plasticity. In this study, we used various methods to investigate how Dsh regulates synaptic plasticity. Our further studies will reveal unknown molecular and cellular mechanisms underlying WNT signaling dependent synaptic plasticity.
        3058.
        2017.04 구독 인증기관·개인회원 무료
        Aedes albopictus is one species of mosquito transmitting flavivirus causing Dengue, Zika, and West Nile fever. Although it is an important disease vector, the genetic study of Ae. alpopictus populations has not been undertaken yet in South Korea. Here, we investigated the genetic variation of 99 Ae. albopictus individuals collected from 29 sites in nine provinces in 2016, through mitochondrial COI gene analysis. Haplotype analyses revealed seven haplogroups in South Korea. The main haplogroup, comprising 76 individuals (77.8%), was genetically identical to the one from Nagasaki. Two groups from Jeju Island (11) and the southern coast of South Korea (nine) were closely related to different Ae. albopictus strains from Kumamoto and Guangdong/Fujian, respectively. However, the others (four) were distinct from these two countries. No geographic divisions of populations were found in the study regions. The results suggest the possibility that the currently prevalent Ae. albopictus in South Korea, represents a part of the descendants that originated from nearby countries. However, more comprehensive investigations are needed to explain its movement routes.
        3059.
        2017.04 구독 인증기관·개인회원 무료
        To replace methyl bromide (MeBr) due to its ozone depletion properties and the life-threatening to related worker as well as fumigators, ethyl formate (EF) fumigation on exported and imported fruits and vegetables has been developed by QIA in Korea since 2005. The benefits of using ethyl formate (EF) fumigant is considered as the safest practice among the commercially available chemical alternatives. The issues was that the cylinderized EF with carbon doxide (CO2) is not enough to extend their applications in terms of fumigation cost. We have developed the cost-effective liquid EF applications with nitrogen gas and demonstrated in quarantine trials (10m3) on imported bananas. We showed the new 35 gm-3 of EF applications with inert gas (nitrogen), were completely control all stage of citrus mealybug (Planoccous citri) for 4hr fumigation at 13°C. These applications meet the quarantine guidelines and protocols in terms of efficacies to target pest and safety concern as well as satisfactions of consumers showing no damages to imported bananas. Extensively, this cost effective EF technology could be acceptable to other fruit and vegetable commodities to reduce the fumigation costs and green house gas (CO2).
        3060.
        2017.04 구독 인증기관·개인회원 무료
        Pine wilt disease is currently the most deadly forest disease in the world and is known to be caused by infection of Bursaphelenchus xylophilus. Until now, no method has been developed to confirm the pine tres infected with pine wood nematodes. In order to develop a method to diagnose pine wood nematode infection, we produced a monoclonal antibody against Expansin B3, which was found to be secreted by pine wood nematodes. ELISA assay using various monoclonal antibody confirmed that the pine trees infected with the rewarming can be detected. Further studies using our antibodies may help to develop a diagnostic method that can quickly confirm infection of pine wood nematodes in the field.