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        검색결과 357

        41.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The age and growth of pointhead flounder, Hippoglossoides pinetorum caught by gill nets was analyzed in this study from March 2015 to July 2017. New annuli were formed in H. pinetorum otoliths annually, and the boundary was set between the opaque and translucent zones from March and April. The relationships between total length (TL) and body weight (BW) were BW = 0.0025 TL3.409 (r2 = 0.9551) for females and BW = 0.0057 TL3.138 (r2 = 0.9163) for males. In this study, the ring of pointhead flounder, H. pinetorum was formed between 3 and 8 for females and between 3 and 6 for males. Total length (TL) and otolith radius (OR) were measured as follows: TL = 7.142 OR + 0.769 (r2 = 0.793) for females and TL = 6.498 OR + 1.706 (r2 = 0.652) for males. The mean distances of first ring (r1) were 0.92 mm and 0.91 mm for females and males respectively. The TLs at the time of annulus formation, back-calculated from the otolith-length relationship by reference to the von Bertalanffy growth curves, were Lt = 43.59 (1-e-0.15(t+0.007)) for females and Lt = 28.13 (1-e-0.26(t+0.006)) for males while the growth between female and male was different.
        4,500원
        42.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Alcoholic steatosis is a fundamental metabolic disorder and may precede the onset of more severe forms of alcoholic liver disease. In this study, we isolated enzymatichydrolysate from Semisulcospira libertine by alcalase hydrolysis and investigated the protective effect of Semisulcospira libertine hydrolysate on liver injury induced by alcohol in the mouse model of chronic and binge ethanol feeding (NIAAA). In an in vitro study, the hydrolysate protects HepG2 cells from ethanol toxicity. Liver damage was assessed by histopathological examination, as well as by quantitating activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). After the administration of S. libertina hydrolysate, fat accumulation and infiltration of inflammatory cells in liver tissues were significantly decreased in the NIAAA mouse model. The elevated levels of serum AST, ALT, and ALP activities, along with the lipid contents of a damaged liver, were recovered in experimental mice administrated with S. libertina hydrolysate, suggesting its role in blood enzyme activation and lipid content restoration within damaged liver tissues. Moreover, treatment with S. libertine hydrolysate reduced the expression rate of cyclooxygenase (COX-2), interleukin (IL)-1β, and IL-6, which accelerate inflammation and induces tissue damage. All data showed that S. libertine hydrolysate has a preventive role against alcohol-induced liver damages by improving the activities of blood enzymes and modulating the expression of inflammation factor, suggesting S. libertine hydrolysate could be a commercially potential material for the restoration of hepatotoxicity.
        4,000원
        43.
        2017.10 구독 인증기관·개인회원 무료
        농경지에서 해충발생 및 피해의‘실태조사’란 기후변화 또는 이상기상으로 야기된 현상을 조사하는 것을 말하며,농작물에서 해충실태 조사는 직접조사와 간접조사의 방법을 통하여 실시한다.‘영향평가’란 기후·기상 인자가 안정화된 현재의 농업생산시스템(적지, 생산성, 병해충, 생물다양성 등)에 변화를 일으키는 영향값을 산출하는 것이다.즉, 현재 상태를 기준으로 하여 기후변화에 따른 병해충의 피해 영향값 차이를 평가하는 것을 말한다. 농경지에서해충발생 및 이에 따른‘취약성’이란 기후변동과 극한현상을 포함한 기후변화의 부정적 영향에 대해 민감하게 반응하거나 대처할 수 없는 정도를 말한다. 따라서 ‘해충발생 취약성평가’는 기후변화의 부정적 영향값을 낮추거나 제거할수 있는 기술·정책의 유무 및 해당 기술·정책이 영향값 조절에 기여하는 정도를 차감하여 평가하는 것을 말하며,본 연구자들은 이번 주제발표에서 개별 해충에 대한 ‘실태조사, 영향평가, 취약성 평가’방법론에 관해 제안 및방법론의 정당성에 대해 논의한다.
        44.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study described the spatial distribution of dinoflagellate cyst assemblages in the Ulsan Coastal Waters (UCW). Surface sediment samples from 15 stations revealed the occurrence of 33 species involving the Groups Protoperidinioid (51.5%), Gonyaulacoid (30.4%), Calciodineloid (9.1%), Gymnodinioid (3.0%), Diplopsallid (3.0%) and Tuberculodinioid (3.0%). The recorded cyst abundance in the UCW recorded was low (260~1,680 cysts g-dry-1) compared to Korean coastal waters. The abundance of heterotrophic cysts is higher in the Ulsan harbour and northwestern parts of UCW with eutrophic areas, however autotrophic species are more prevalent in the southern parts with open sea environments. The dinoflagellate cyst assemblages in the UCW were characterized by the dominance of Gonyaulax scrippsae, Protoperidinium sp. (Brigantedinium sp.), and Gonyaulax spinifera complex. The advent of the toxic dinoflagellate, Pyrodinium bahamense var. bahamense was recorded for the first time in the East-south sea of Korea. Therefore, as a result of ongoing monitoring and management for new toxic dinoflegallates from tropical or subtropical regions, analysis of dinoflagellate cyst assemblages in the UCW has been deemed necessary.
        4,300원
        46.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A cold-work tool steel powder is used to fabricate 3-dimensional objects by selective laser melting using a high-pressure gas atomization process. The spherical powder particles form continuous carbide networks among the austenite matrix and its decomposition products. The carbides comprise Nb-rich MC and Mo-rich M2C. In the SLM process, the process parameters such as the laser power (90 W), layer thickness (25 μm), and hatch spacing (80 μm) are kept fixed, while the scan speed is changed from 50 mm/s to 4000 mm/s. At a low scan speed of 50 mm/s, spherical cavities develop due to over melting, while they are substantially reduced on increasing the speed to 2000 mm/s. The carbide network spacing decreases with increasing speed. At an excessively high speed of 4000 mm/s, long and irregularly shaped cavities are developed due to incomplete melting. The influence of the scan pattern is examined, for which 1 × 1 mm2 blocks constituting a processing layer are irradiated in a random sequence. This island-type pattern exhibits the same effect as that of a low scan speed. Post processing of an object using hot isostatic pressing leads to a great reduction in the porosity but causes coarsening of the microstructure.
        4,000원
        47.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, H13 tool steel sculptures are built by a metal 3D printing process at various laser scan speeds. The properties of commercial H13 tool steel powders are confirmed for the metal 3D printing process used: powder bed fusion (PBF), which is a selective laser melting (SLM) process. Commercial H13 powder has an excellent flowability of 16.68 s/50 g with a Hausner ratio of 1.25 and a density of 7.68 g/cm3. The sculptures are built with dimensions of 10 × 10 × 10 mm3 in size using commercial H13 tool steel powder. The density measured by the Archimedes method is 7.64 g/cm3, similar to the powder density of 7.68 g/cm3. The hardness is measured by Rockwell hardness equipment 5 times to obtain a mean value of 54.28 HRC. The optimum process conditions in order to build the sculptures are a laser power of 90 W, a layer thickness of 25 μm, an overlap of 30%, and a laser scan speed of 200 mm/s.
        4,000원
        48.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Selective laser melting (SLM) can produce a layer of a metal powder and then fabricate a three-dimensional structure by a layer-by-layer method. Each layer consists of several lines of molten metal. Laser parameters and thermal properties of the materials affect the geometric characteristics of the melt pool such as its height, depth, and width. The geometrical characteristics of the melt pool are determined herein by optical microscopy and three-dimensional bulk structures are fabricated to investigate the relationship between them. Powders of the commercially available Fe-based tool steel AISI H13 and Ni-based superalloy Inconel 738LC are used to investigate the effect of material properties. Only the scan speed is controlled to change the laser parameters. The laser power and hatch space are maintained throughout the study. Laser of a higher energy density is seen to melt a wider and deeper range of powder and substrate; however, it does not correspond with the most highly densified three-dimensional structure. H13 shows the highest density at a laser scan speed of 200 mm/s whereas Inconel 738LC shows the highest density at 600 mm/s.
        4,000원
        49.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        토양수분은 지면환경에서 일어나는 수문 순환을 이해하기 위한 중요한 기상인자일 뿐만 아니라 가뭄, 홍수, 산불 등과 같은 자연재해와 밀접하게 연관되어 있다. 그러나 위성기반 토양수분 자료는 공간해상도가 매우 떨어져서 국지규모 분석에 직접적 으로 적용하기에는 한계가 있다. 이 연구에서는 마이크로파 위성센서로부터 산출된 토양수분 자료가 가지는 공간해상도의 제약을 완화하기 위하여, 다양한 지면 변수와 공간통계법을 활용한 다운스케일링 기법을 도입하였다. 가장 정교한 다운스케일링 기법으로 평가되는 회귀크리깅을 이 연구를 통하여 토양수분 자료에 처음으로 적용하였다. 우리나라의 2013년과 2014년의 4월부터 10월까지 의 일자별 AMSR2(Advanced Microwave Scanning Radiometer 2) 공간해상도 10km와 25km의 토양수분 자료를 각각 2km와 4km로 다운스케일링한 결과, 고해상도로 다운스케일링된 자료와 저해상도 원자료와의 일관성이 우수하게 유지되어, 다운스케일링 전후의 공간패턴과 자료특성이 잘 보존되는 것을 확인할 수 있었다. 이 연구에서 제시한 다운스케일링 기법은 토양수분뿐만 아니라 여러 기상요소에 적용될 수 있으며, 위성영상이나 모형자료의 공간해상도 한계를 극복하기 위한 방편이 될 수 있을 것으로 기대된다.
        4,300원
        50.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Information about time spent in microenvironments plays a critical role in exposure assessment of the person concerned, considering that personal exposure relies on the characterization of time-activity patterns of the population at risk as human activities impact the timing, location, and level of personal pollutant exposure. The purpose of this paper was to present the time-activity patterns of Korean adults from a population-based study, and to determine the time spent each day in microenvironments. The population-based study collected time-activity data of about 46,000 adults for two consecutive days on weekdays (n=28,152) and weekends (n=18,800). The mean times spent at one’s own house, workplace or school, other’s house house, restaurant or bar, other places, and transportation related to the whole sample of 28,152 people were 14.90 hrs (62.08%), 4.28 hrs (17.81%), 0.24 hrs (1.01%), 0.51 hrs (2.14%), 2.45 hrs (10.21%), and 1.62 hrs (6.74%) on weekdays, respectively. Looking at the total time spent indoors by adults in different countries, the following four countries were ranked as follows, from lowest to highest: USA > Canada > Korea > Hong Kong. Due to cultural, socioeconomic and climatic differences, it may not be appropriate to directly apply statistical data of other countries to the Korean situation. This paper provides information on how the proportion of persons in different locations changes by time of day, on weekdays and weekends. Here, we can see that over 90% of respondents were in a residence from about 11 PM to 5 AM, and the largest proportion of respondents in workplaces or schools and other places is found between 8 AM and 5 PM.
        4,000원
        51.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이상 고수온을 감지하기 위한 생물모니터링 시스템(BMS) 연구를 위해, 4단계의 수온(5, 10, 20와 30℃)에서 참굴 패각운동을 측정하였다. 모든 참굴은 실험시작 전에 3일 동안 절식을 통하여, 먹이섭이 및 배출에 따른 패각운동의 요인을 제거하였다. 5℃ 실험구에서는 패각운동이 관찰되지 않았지만, 수온의 증가와 함께 패각운동은 증가하였다(10℃ : 6.31±2.18 times/hr, 20℃ : 22.0±10.0 times/hr). 30℃에서는 5℃와 같이 패각운동이 전혀 보이지 않았던 실험구와 20℃와 유사한 패각운동이 실험구가 나타났다. 이는 30℃ 이상에서도 20℃와 같은 신진대사를 보이는 개체군이 있었으나, 대부분이 신진대사의 활력의 감소에 기인하여 폐각상태가 지속되는 것으로 나타났다. 따라서 참굴 양식장에 고수온 감지를 위한 참굴 패각운동 BMS를 설치한다면, 경계단계는 빠른 패각운동(약 30.0회/hr 이상)일 때, 심각단계는 수시간 이상 폐각상태일 때, 조기경보(early warning)를 내릴 수 있을 것이다. 따라서 참굴 패각운동을 활용한 BMS는 이상고수온의 조기경보에 대하여 효과적으로 활용이 가능할 것으로 판단된다.
        4,000원
        52.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fecralloy coating layer with large surface area is suitable for use as a filter media for efficient removal of hot gaseous pollutants exhausted from combustion processes. For uniform preparation of a Fecralloy coating layer with large surface area and strong adhesion to substrate, electrospray coating and thermal treatment processes are experimentally optimized in this study. A nano-colloidal solution with 0.05 wt% Fecralloy nanoparticles is successfully prepared. Optimized electrospraying conditions are experimentally discovered to prepare a uniform coating layer of Fecralloy nanocolloidal solution on a substrate. Drying the electrospray coated Fecralloy nano-colloidal solution layer at 120oC and subsequent heating at 600oC are the best post-treatment for enhancing the adhesion force and surface roughness of the Fecralloy coating layer on a substrate. An electrospray coating system, consisting of several multi-groove nozzles, is also experimentally confirmed as a reasonable device for uniform coating of Fecralloy nano-colloid on a large area substrate
        4,000원
        53.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This present study investigated characteristics of distribution and community structure of macrobenthic invertebrates through the survey of commercial Danish seine fisheries from 2011 to 2013. In this study, a total of 28 species were sampled with a mean density of 32,568 ind./km2 and mean biomass of 1,649.5 kg/km2. The dominant species, comprising over 1.0% of the total number of individuals, were Chionoecetes opilio (11,203 ind./km2, 34.4%), Pandalus eous (9,247 ind./km2, 28.4%), Ophiuridae spp. (5,750 ind./km2, 17.7%), Argis lar (2,631 ind./km2, 8.1%), Neocrangon communis (994 ind./km2, 3.1%), Berryteuthis magister (612 ind./km2, 1.9%), Sepiola birostrata (499 ind./km2, 1.5%) and Strongylocentrotidae sp. (424 ind./km2, 1.3%). The dominant species, in terms of biomass, comprising over 1.0% of the total biomass, were C. opilio (1,167.2 kg/km2, 70.8%), B. magister (130.3 kg/km2, 7.9%), P. eous (102.4 kg/km2, 6.2%), Ophiuridae spp. (84.6 kg/km2, 5.1%), Enteroctopus dofleini (45.5 kg/km2, 2.8%), A. lar (35.7 kg/km2, 2.2%), Strongylocentrotidae sp. (25.0 kg/km2, 1.5%) and S. birostrata (22.1 kg/km2, 1.3%). Among them, S. birostrata, E. dofleini, Strongylocentrotidae sp. and Ophiuridae spp. were higher abundance and biomass in the shallow water (<200 meters in depth), whereas C. opilio, P. eous, A. lar, N. communis and B. magister were higher in the deep water (301 ~ 500 meters in depth).As the results of cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, the macrobenthic invertebrates community by Danish seine survey was divided into two groups of station in the shallow water (<200 meters in depth, Group A) and the deep water (201 ~ 500 meters in depth, Group B). The major individual-dominant species was S. birostrata, Ophiuridae spp. and immature C. opilio in group A. But Group B was P. eous, A. lar, B. magister and mature C. opilio.
        4,600원
        54.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of development new variety ‘Miho’ (Hordeum vulgare L.) is a favorite with livestock feed and develop varieties resistant to disease and lodging. ‘Miho’ was carrying out the growth habit of group Ⅲ with green and mid-wide leaf. Awn that is related to preference of livestock is a semi-smooth awn. This cultivar had 96 cm of culm length, 650 of spikes per m2. Heading date of ‘Miho’ was April 27, and maturing date on May 30, which were later than cultivar ‘Youngyang’. It also showed strong winter hardiness, and similar resistance to shattering and bariy yellow mosaic virus (BaYMV) compared with those of check one. The best thing among the traits of a good quality with the plant green at the latter growing period. The average forage dry matter yield in the regional yield trial was about 13.1, 12.1 MT per ha in upland and paddy field, respectively, which were 9%, 2% higher than that of the check cultivar. It’s also showed 6.8% crude protein, 27.1% ADF (acid detergent fiber), and 67.5% TDN (total digestible nutrients), including higher silage quality for whole crop barley. This cultivar would be suitable for the area whose average minimum temperature was above -8℃ January in Korean peninsula.
        4,000원
        55.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study described the spatial distributions of marine environmental factors such as water temperature, salinity, chlorophyll a concentration and turbidity, and characteristics of phytoplankton community such as species composition, standing crops and dominant species at 19 fishing ports around Jeju Island during the early summer of 2016. I analyzed bio-oceanographical characteristics using principal component analysis (PCA) of the environmental factors and biological parameters. Water temperature, salinity, chlorophyll a and turbidity ranged from 17.6 to 20.7℃, from 26.19 to 32.33 psu, from 0.76 to 7.13 μg L-1, and from 0.51 to 14.49 FTU, respectively. A total of 51 species of phytoplankton belonging to 35 genera were identified. In particular, diatoms and dinoflagellates accounted for more than 56.8% and 27.4% of all the species, respectively. Moreover, the number of phytoplankton species was controlled by salinity. Phytoplankton cell density ranged from 2.9 cells mL-1 to 185.9 cells mL-1. The dominant species were Navicula spp. Stephanopyxis turris, Eutreptiella gymnastica and Mesodinium rubrum. Environmental factors and the phytoplankton community varied greatly between sampling sites. According to PCA, the biological oceanographic characteristics of the around Jeju Island were characterized by meteorological factors such as air temperature, precipitation and discharge of ground water during early summer.
        4,300원
        57.
        2016.10 구독 인증기관·개인회원 무료
        농촌진흥청 작물보호과에 1962년 이래로 보관되어 온 전국 159개 예찰답의 유아등 성적을 분석하여 그간 국내의 기후변화와 벼멸구, 흰등멸구, 혹명나방 등의 주요 벼 비래해충의 초기 비래일 변화를 살펴보았다. 토착해충과 달리 비래해충은 유아등에 유인되는 날짜의 변화가 기후변화와 반드시 일치하거나 연관성이 높음을 단정지을 수 있는 이론은 아직까지 없으나, 그럼에도 불구하고 국내에서 월동가능하며 중국에서의 비래량 또한 무시할 수 없는 애멸구의 경우에는 유아등에 유인되는 초기 개체수의 피크 밀도가 지구온난화에 따른 해충발생시기 변화의 중요한 단서를 제공할 수 있다. 우리나라 남한지역을 편의상 9등분하여 조사한 결과 경남 및 전남지역 등 남부지역의 경우 애멸구의 본답이동시기가 1960년대에 비해 2010년대에는 약 10일정도 더 빨라짐을 알 수 있었고, 경기, 강원 등 북부지역의 경우에는 3~5일 정도 이동시기가 빨라졌음을 알 수 있었다. 따라서 지구온난화에 따른 해충발생상 변화 속도는 남부지역이 북부지역보다 더 빠르게 진행되고 있음을 알 수 있었다.
        58.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To understand size fractioned chlorophyll a and material cycles of coastal ecosystem in Uljin marine ranching area (JMRA) of East Sea, 4 times of survey were conducted from April to November 2008. Picoplankton, nanoplankton and netplankton in the surface of UMRA fluctuated with an annual mean of 0.26 μg L-1 between the lowest value of 0.03 μg L-1 and the highest value of 0.87 μg L-1, annual mean 1.32 μg L-1 between 0.11 μg L-1 and 5.60 μg L-1, annual mean 0.45 μg L-1 between no detected (nd) and 4.68 μg L-1, respectively. And the relative ratio of picoplankton, nanoplankton and netplanktons on the phytoplankton biomass was on annual average 12.9%, 65.0% and 22.1%, respectively. The 10 m layer was similar to the surface. The relative ratio of pico- and nano-plankton was higher throughout the year. That is, the material cycle of UMRA consists of a microbial food web rather than traditional food chain at a lower trophic levels. Primary production is deemed to have a higher possibility of being adjusted by top-down dynamics, such as micro-zooplankton grazing pressure rather than nutrients supply.
        4,000원
        59.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted for recycling the waste MDF(Medium-density fibreboard) to investigate the enzymatic saccharification characteristics using two enzymes Novozyme Cellic® CTec2 and HTec2 (Novozymes, Bagsvaerd, Denmark) after the delignification by pretreatment using sodium chlorite. The chemical composition of the waste MDF are lignin, holocellulose, ash, and other extracts 28.40, 60.20, 0.10, and 11.30%, after pretreatment with sodium chlorite were 5.20, 53.10, 0.03, and 41.67%. The Lignin interferes with enzymatic saccharification of 23.2% was removed, 7.1% of holocellulose was lost. The times of sodium chlorite pretreatment and saccharification of the waste MDF was finished between 48-72 hours, the saccharification speed was fast when the concentration of the enzyme by 10% and the HTec2 CTec2 ratio 9:1. Sugar ratio of the solid content of the waste MDF is the highest as 69.6% when it comes out of 8% and a viscosity was as high as 34.8% when the 12-FB%. Therefore, the pre-treatment with sodium chlorite is more advantageous when enzymatic saccharification to lignocellulosic biomass. The amount of the enzyme, the solid-liquid ratio, and the reaction time showed a proportional relationship with saccharification efficiency. The studies for increasing the solids content of waste MDF to improve the economic efficiency more than 12% should accompanied.
        4,000원
        60.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, in Korea various kinds of genetically modified (GM) crops have been imported and used as a raw material to manufacture foods and livestock feeds, but the different social concerns about the benefits and the potential risks of GM crops are being shown with a different reaction from the public. Thus a persistent management is required for the safe utilization of genetically modified organism (GMO). PCR analysis of transgene into crop is generally performed for the efficient post management of GMOs. The most important prerequisite for the application of nucleic acid detections is to decide the effective DNA-extraction methods. Particularly, in the case of processed feeds, the nucleic acids of which may be damaged by heating, high pressure, pH treatments, fermentation, etc. in processing, DNA must be extracted with high sensitivity from the samples to perform the PCR successfully. In this study, seven of DNA-extraction methods used commercially and non-commercially were compared with respect to the yields and quality of DNA extracted from livestock feeds and those crop materials. Amounts of genomic DNA obtained from the extraction methods varies according to feed configurations and crop materials. The DNA yield and uniformity of samples extracted with PG, CTAB, and QF method is greater than that obtained from other extraction methods. In the DNA integrity of the selected extraction methods, PCR analysis showed distinct amplifications and similar patterns in detecting crop endogenous genes and GMO genes. These results would be applicable for the selection of an adequate DNA-extraction method in extracting processed feeds and/or crop materials.
        4,000원
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