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        검색결과 1,657

        501.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sunrise and sunset times differ depending on location and date. Previous studies conveniently but monotonously applied day and night times set up. This research defined the daytime and nighttime while considering the time of twilight according to the date and the location of ship collision accidents. Classifying the frequency of ship collision accidents with this standard, we conducted a chi-squared test for the difference between daytime and nighttime. The frequencies of ship collision accidents according to daytime and nighttime was compared by season, month, and time, and all of them showed statistically significant differences. The highest number of daytime ship collisions was 11.6 %, in June, and nighttime collisions peaked at 13.7 %, in December. The most frequent hour for daytime ship collisions was 0700h-0800h, at 10.2 %, and nighttime collisions peaked between 0400h-0500h, at 16.9 %. It is clear that the criteria used in previous studies cited was applied without any theoretical basis and likely only for the convenience of the researchers. It was found that results depend on what criteria are applied to the same research data. This study shows that statistical analyses of marine accidents, traffic volume, and congestion density should be carried out quantitatively while considering daytime and nighttime hours for each particular location and date.
        4,000원
        502.
        2018.05 구독 인증기관·개인회원 무료
        The airport concrete pavement is gradually changing from the empirical design method proposed by the FAA to the mechanical design method. However, the complete mechanical design method has not yet been developed because it is difficult to consider designing due to various break types due to environmental load. FAAFIELD, a widely used finite element analysis program in existing airport pavement design, has yet to be considered for environment loads, although it has been continuously updated. Therefore, this study used ABAQUS instead of FAARFIELD as a finite element analysis program to consider the environmental load, and carried out the load quantification work of A380 aircraft and B777 aircraft corresponding to 3DT(3 Dual Tandem) gear. The traffic load information of 3DT gear aircraft was collected, and the environmental load due to temperature and humidity was converted into the equivalent linear temperature difference. Through the finite element analysis using ABAQUS, the prediction data of maximum tensile stress and location was collected when the two loads act to slab simultaneously. The factors affecting the maximum tensile stress in the finite element analysis are slab thickness, joint spacing, aircraft load, combined bearing capacity, and equivalent linear temperature difference, respectively. In order to examine the adequacy of the selected factors, sensitivity analysis for factors which affect maximum tensile stress was performed, and the stress regression model was developed. For this, a multiple regression analysis program SPSS was used and the stress regression equations for 3DT gear aircraft were calculated considering traffic and environmental loads. Through the developed stress regression model, it is possible perform the load quantification process of the 3DT gear aircraft for the mechanical design of the airport concrete pavement. In addition, the appropriateness of the regression model is verified by securing the high decision coefficient through SPSS. This study was supported by Incheon International Airport Corporation(BEX00625)
        503.
        2018.05 구독 인증기관·개인회원 무료
        Composite pavements are constructed by placing a high functional asphalt surface layer on a high performance concrete rigid base layer and provide a more durable, high functional surface to road users. Service life of composite pavements is dependent on the bonding performance of the lower rigid base and the flexible surface layer. Accordingly, it is necessary to place an impermeability layer between the functional surface layer and the rigid base to enhance bonding performance and to prevent moisture penetration into the rigid base and deterioration of pavement. In order to use optimal composite pavement sections, two types were applied to impermeability layer: highly impermeable water-tight SMA and mastic asphalt currently in use. APT (Accelerated Pavement Testing) and experimental construction were carried out to evaluate bond strengths between the rigid base and the impermeability layer depending on the type of impermeability layers. Composite pavement sections for the APT had a 22 cm concrete rigid base layer and a 5cm functional surface, as well as either 5cm of SMA impermeability layer and 5cm of mastic layer. After applying around 8,574,000 ESALs, pull-off test was conducted, which showed that the mastic section outperformed the SMA section. In the experimental construction, three types of rigid base layers, JCP (Jointed Concrete Pavement), CRCP (Continuously Reinforced Concrete Pavement), and RCCP (Roller Compacted Concrete Pavement), were used for composite pavement sections, and as in the APT, two types of impermeability layers, SMA and mastic, were used per rigid base layer of new and deteriorated concrete pavement. Therefore, seven composite pavement sections in total were constructed. We measured the bond strength over one year or so following the construction of these composite pavement sections and found that regardless of the type of rigid base layer and whether it was new or not, those sections with a mastic impermeability layer had high bond strengths.
        504.
        2018.04 구독 인증기관·개인회원 무료
        This study was performed to analyze a saltiness enhancement at the same salt content through multiple emulsion. We compared the samples with different conditions to determine the optimum stability conditions of water-in-oil through layer separation rate, microscopic observation and size analysis. Four electrolytes such as NaCl, KCl, MgCl2, and CaCl2 were used and agar contents ranged from 0 to 1% were experimented at different volume ratios including 5:5, 4:6, 3:7, 2:8, and 1:9 of water and oil. As a result of this study, the droplet size according to the electrolyte type did not show significant differences (p<0.05). Therefore, KCl was used to facilitate in-body excretion of NaCl in the outer water phase, and corn oil containing 8%(w/w) polyglycerol polyricinoleate was used as oil phase. When the volume ratio of water and oil was 3:7, 2:8, and 1:9, the layer separation rate was relatively slow and droplet size was also small. It reveals that the particle size becomes smaller as the water volume ratio decreases. However, considering the amount of water to be stored and eluted on the inner water, appropriate volume ratio of water and oil should be adopted to 3: 7. At Microscopic observation depending on agar concentrations, small particle size appeared at 0.2% and 0.4% agars. When the water and oil ratio was fixed at 3:7, the particle size was measured at 0.2% and 0.4% agar using a zeta sizer. In conclusion, the droplet size of 0.2% agar was smaller than 0.4%. Therefore, the most stable water-in-oil emulsion was obtained with 0.2% agar, when water to oil ratio was 3:7.
        505.
        2018.04 구독 인증기관·개인회원 무료
        Ochratoxin A (OTA) is one of the most important mycotoxins owing to its widespread occurrence and toxicity including nephrotoxicity and potential carcinogenicity to humans. Since OTA is stable under most food processing conditions, OTA has been detected not only in a wide range of agricultural commodities such as cereal grains but also their processed products. Nonetheless, it is known that significant reduction of OTA may be achieved under higher temperature and alkaline conditions. In this study, the effects of retorting cooking process on the stability of OTA in spiked (20 μg/kg of dry weight basis) rice and oat porridge (10% solid content; w/v) in the presence and absence of baking soda was investigated using a laboratory horizontal steam retort system. The samples were heated in a pot at 85°C central temperature until it becomes gelatinized, packed in retort pouched, and heat-processed in pressurized retort machine (at 121°C for 25 min) followed by drying in 50°C oven overnight. Samples were analyzed for OTA by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The reduction of OTA in retorted rice and oat porridge were 54% and 17%, respectively, while greater reduction of OTA was observed at increased amount of baking soda. The reduction of OTA in retorted rice porridge with 0.5% and 1% baking soda were 55% and 66%, respectively. In the retorted oat porridge, reduction of OTA was also evident to result in 30% and 48% with 0.5% and 1.0% of added baking soda, respectively. These results suggest that OTA in rice and oat may be reduced significantly by retorting process. In addition, added baking soda may positively impact the reduction of OTA.
        506.
        2018.04 구독 인증기관·개인회원 무료
        Ochratoxin A (OTA) represents one of the most widespread mycotoxins in agricultural commodities in the world and is considered a possible human carcinogen with its potent nephrotoxicity. Since OTA is stable under most food processing conditions, OTA has been detected in a wide range of cereal grains and their processed products as well. Puffed cereals are commonly used as baby snacks or as ingredients in snack formulations. We investigated the explosive puffing process effect on reduction of OTA in rice and oat. The rice and oat grains were adjusted the moisture content at 16% wet weight basis (wb) and spiked OTA (100 μg/kg), and then puffed by the explosive puffing machine at 5, 7, and 9 kgf. The temperature of chamber was 200°C and the duration times for 5, 7, and 9 kgf were 5, 6, and 9 min, respectively. The reduction of OTA in puffed rice and oat snacks were in the range of 15 – 28% and 38 – 52%, respectively, and the reduction of OTA in puffed rice and oat snacks were decreased with increasing explosive puffing pressures. The moisture content of puffed rice and oat snacks were in the range of 5 – 8% wb and 6 – 10% wb, respectively, and the moisture content in puffed rice and oat snacks were decreased with increasing of explosive puffing pressures. A decrease in bulk density of puffed rice and oat snacks was observed with increased explosive puffing pressure. In addition, increased values of degree of redness (a) in puffed rice and oat samples were observed with increasing explosive puffing pressure. These results suggest that OTA in rice and oat may be reduced significantly by explosive puffing process.
        507.
        2018.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Morphological differences in multi-layered graphene flakes or graphene nanoplatelets prepared by oxidative (rGO-NP, reduced graphene oxide-nanoplatelets) and non-oxidative (GIC-NP, graphite intercalation compound-nanoplatelets) routes were investigated with various analytical methods. Both types of NPs have similar specific surface areas but very different structural differences. Therefore, this study proposes an effective and simple method to identify structural differences in graphene-like allotropes. The adsorptive potential peaks of rGO-NP attained by the density functional theory method were found to be more scattered over the basal and non-basal regions than those of GIC-NP. Raman spectra and high resolution TEM images showed more distinctive crystallographic defects in the rGO-NP than in the GIC-NP. Because the R-ratio values of the edge and basal plane of the sample were maintained and relatively similar in the rGO-NP (0.944 for edge & 1.026 for basal), the discrepancy between those values in the GIC-NP were found to be much greater (0.918 for edge & 0.164 for basal). The electrical conductivity results showed a remarkable gap between the rGO-NP and GIC-NP attributed to their inherent morphological and crystallographic properties.
        4,000원
        510.
        2018.04 구독 인증기관·개인회원 무료
        Feeding effects of the honeybee pollen products from both domestic, China, Spain and mixture of different origin on the colony development of earth bumblebee, Bombus terrestris L., were surveyed to evaluate efficient nutritional resources for commercial bombiculture in Korea. As the results, the domestic pollen was most effective to achieve high rates of oviposition (88%), colony foundation (70%), and queen production. While feeding with domestic pollens during the egg-laying period, and domestic+Chinese mixture (5:2) during the breeding period (Plot-2), it revealed high oviposition rate of 75%, colony foundation of 65%, and large numbers of adult queen production, indicating its suitability for generation subculturing. In the Plot-3, the same high oviposition rate (75%) was obtained except for feeding with the domestic+Chinese mixture (2:5) during the breeding period, which produced large number of workers.
        511.
        2018.04 구독 인증기관·개인회원 무료
        The tobacco cutworm, Spodoptera litura(Fabricius) is serious pest that hurts tomato crops, actives long time of the year. Without pesticide applications, sex pheromone delta traps through experiment first and second half setting during cultural seasons in glasshouse and greenhouse. We investigated captured number of S. litura both in and out side of the two type of tomato cultivated greenhouse. As a result of investigation, captured number of S. litura showed the wave and three high peak typed graph throughout 10 months experiment. First time expression of S. litura was late April in outside installed traps and after that occurrence rate increased gradually until late August. In september, the rate decreased remarkably to middle November in both in and out side treated traps. The result also expressed that captured average number of S. litura in inside of the greenhouse were 8~10 units, and were 15~20units in outside treated traps. Simultaneous installation of internal and external sex pheromone traps succeeded in eliminating a considerable number of S. litura male moths, and the number of larvae was expected to be considerably reduced. Consequently in the experiment, captured male number of S. litura were about 220 units in outside, on the other about 80 of S. litura captured in inside installed traps.
        512.
        2018.04 구독 인증기관·개인회원 무료
        Pine wilt disease (PWD) induced by the pinewood nematode (PWN), Bursaphelenchus xylophilus, is a great threat to pine forests in Europe and East Asia. Identification of interrelation between Monochamus spp., the major vectors of PWD and PWN is the key factor for effective control of PWD because PWN is trasmitted to healthy pine trees only by Monochamus vectors. In this study, direct injection system is designed to apply PWN artificially to M. alternatus just before emergence to adults. After injection of PWN (300~500 nematodes in 10 μl of 1X PBS) using adapted glass pipets, the survival rate of M. alternatus and detection rate of live PWN were 80.0% and 68.8% at 168 h respectively. As a result, we demonstrated the artificial injection methods of nematode to Monochamus vectors for further study of coeffect between vectors and specific stage of PWN including 3rd stage dispersal juvenile.
        513.
        2018.04 구독 인증기관·개인회원 무료
        꽃노랑총채벌레는 국화, 장미, 고추, 토마토 등 여러 작물의 잎, 꽃, 과실을 흡즙 및 산란을 통해 피해를 주며 토마토반점위조바이러스(TSWV)와 국화줄기괴저바이러스(CSNV) 등을 매개한다. 재배작기, 환경, 품종등에 따라 총채벌레류의 발생과 피해가 다양하게 나타나는 국화는 총채벌레류 및 매개 바이러스병으로 인해 약 20∼30%의 생산량이 감소된다. 또한 총채벌레류에 대한 약제저항성 계통의 출현이 지속적으로 보고되어 살충제의 교호사용에 주의가 필요한 방제가 어려운 해충 중 하나이다. 살충력이 높은 살충제를 선정하기 위하여 시판하는 국화 총채벌레류 등록 살충제 Acetamiprid, Acetamiprid+Spinetoram, Acrinathrin, Benfuracarb, Buprofezin+Thiamethxam, Chlorfenapyr+ lothiandin, Chlorfenapyr+Imidacloprid, Emamectin+Benzoate, Imidacloprid, Thimethoxam 10종을 꽃노랑총채벌레에 살포 한 결과 유효성분으로 Pyrroles계인 Chlorfenapyr를 함유한 살충제의 살충력이 가장 높았다. 총채벌레류의 화학적 방제 시 Chlorfenapyr가 함유한 살충제를 사용하는 것이 효과적이다.
        514.
        2018.04 구독 인증기관·개인회원 무료
        2017년 한해 동안 9개 공항만에서 중국 등 32개국, 120개 품목 8,660건을 조사한 결과, 523건에서 해충 검출이 있었다. 반입빈도가 높은 품목은 사과, 망고, 감귤, 배, 복숭아, 바나나, 오렌지, 오이, 고추. 호두(미탈각), 자두, 드래곤프릇, 포멜로, 토마토, 풋콩, 망고스틴, 대추 등의 순이었으며, 중국, 베트남, 일본, 필리핀, 대만, 태국 등의 나라에서 반입건수가 많았다. 해충 검출 빈도가 높은 품목은 망고스틴, 망고, 사과, 슈가애플, 람부탄, 고추, 자두, 구아바 등이며, 해충 검출 빈도가 높은 국가는 중국, 베트남, 태국 등이었다. 검출 해충류 중 금지해충으로 오리엔탈과실파리류(Bactrocera dorsalis sp. complex) 52건, 오이과실파리(Bactrocera cucurbitae) 1건, Bactrocera latifrons 2건이 있었으며, 과실파리류 32건이 동정중이며, 코드린나방(Cydia pomonella)이 1건 검출되었다.
        515.
        2018.04 구독 인증기관·개인회원 무료
        Delphacidae is the most diverse group in the Superfamily Fulgoroidea (Hemiptera: Auchenorrhyncha: Fulgoromorpha) with more than 2000 reported species worldwide. This group is commonly called planthoppers, because most members are grass-feeding species. Some members are known as vectors of economically important plant viruses, and damage to several crops in many countries. Stenocranus is one of the biggest groups in the Delphacidae. In Korea, there have been eight recorded species. In this presentation, we present taxonomic review of the Stenocranus with a new record in Korea. Morphological characters and key to Korean species are presented.
        516.
        2018.04 구독 인증기관·개인회원 무료
        Subfamily Asopinae (Heteroptera: Pentatomidae) is known to have a unique behaviour among congeners of the family Pentatomidae. Their predatory behavior towards Lepidoptera and Coleoptera larvae has been numerously studied as some of the species have been used as biological control agents against insect pests. In this presentation a morphological taxonomical revision of the Korean Asopinae is made. New records and the first key from Korea are presented together with illustrations of all their habitus. Their possible role as Biological control agents in Korea is also discussed.
        517.
        2018.04 구독 인증기관·개인회원 무료
        The economic contribution of the pollinators is often estimated in order to understand the importance of the pollinator population, particularly insects. Also declining of the pollinator population would be a potential threat to food production which in turn affects nutritional security negatively. Unlike the economic contribution in terms of currency, seldom the contribution has been addressed in terms of nutrients. In the present paper, we estimated the contribution of pollinator population in the micronutrients viz. minerals and vitamins supply of the country. A higher pollinator dependency than present global average was noted in connection with all minerals deemed nutritionally important and most of the vitamins. Pollinator-dependent (PD) crops provide a substantial share of micronutrients to the population, especially with regard to vitamins C and E and elements iron. A positive trend was found in the PD supply of all micronutrients over the last 30 years in Korea, but the rate of increment was somewhat lower for vitamins C and K as well as folate.
        518.
        2018.04 구독 인증기관·개인회원 무료
        The potato tuber moth (PTM) is an oligophagous insect pest on solanaceous crops. Potato tuber is regarded as the main host of PTM but it can also feed, develop and reproduce on other solanaceous crops such as tomato. We tested adult olfactory behavior and larval development on 5 cultivated tomato varieties namely Money maker, Campari, Ailsa craig, LA 3475 (M82) and E-6203, and one wild species, S. pimpinellifolium. Tomato leaf hydro-distilled oils of Money maker, Campari, Ailsa craig, S. pimpinellifolium and E-6203 leaves showed strong attractiveness for mated adult PTM of both sexes (> 70%) in two-armed bioassay. LA 3475 (M82) oil showed repulsive response (83.7% for males and 87.3% for females). GC-MS analysis of the hydro-distilled oils of all tomato leaves contain the fatty acid n-hexadecanoic acid (Palmitic acid) as a major compound with relative percentage as S. pimpinelifollium (32.1%) > E-6203 (26.5%) > money maker (26.1%) > LA-3475 (16.3%) > Campari (15.0%) > Ailsa craig (10.4%). LA 3475 consists of (1-hexyltetraecyl)cyclohexane (10.5%) as the second major compound which was absent in all other tomato varieties. In no choice test, PTM larvae showed highest developmental performances such as number of mines, headcapsule size, pupal weight and survival in Ailsa craig, and lowest in LA 3475. In choice test, similar results were observed. This study indicates the leaf volatile of n-hexadecanoic acid might be responsible for PTM attractiveness and (1-hexyltetraecyl)cyclohexane for repulsiveness. And varieties of tomato leaves could support suitable nutritional contents to PTM, posing pest potential in the future where higher exposure is expected.
        519.
        2018.04 구독 인증기관·개인회원 무료
        The potato tuber moth Phthorimaea operculella (Zeller) is an important pest for solanaceous crops mainly potatoes. There is an increasing concern on host expansion to tomato which is higher cash crop. We monitored PTM population dynamics in potato dominated area and tomato greenhouse area in Andon, South Korea for 2 years using delta sticky trap with sex pheromone lure. PTM population was higher in potato growing area and low in tomato area; 19.82 PTM/trap/week and 0.8 PTM/trap/week, respectively. Peak occurrence time was related to the crop phenologies; August in potato field and November in tomato field. Land scape analysis showed that there was significant positive correlation between habitat potato field itself and green house with the number of moth catch during the monitoring period.
        520.
        2018.04 구독 인증기관·개인회원 무료
        The potato tuber moth (PTM) is a cosmopolitan insect pest and hosts various solanaceous crops including tomato. We tested olfactory behavior and larval development of PTM on different varieties of tomato fruit namely, Money maker, Campari, Ailsa craig, LA 3475 (M82) and E-6203, and one wild species, S. pimpinellifolium. We also analyzed essential oil of the tomato fruits through GC/MS. There were significance differences in immature developmental period and head capsule size among the tested varieties. PTM larvae showed highest survival on Ailsa craig (66.0±6.0) and E-6203 (64.0±4.0) and lowest on S. pimpinellifolium (14.0±6.0). The major compounds found in the tomato fruit’s essential oils include n-hexadecanoic acid (14.2%) and 2-octylcyclopropaneoctanal (8.7%) in Money makers; hexadecanoic acid, 2-hydroxy -1-(hydroxymethyl) ethyl ester (13.1%) in Campari; tert-hexadecanethiol (6.8%) and 1,4-benzenedicarboxylic acid, bis (2-ethylhexyl) ester (6.2%) in Ailsa craig; (Z)-13-docosenamide (13.39) in S. pimpinellifolium; Eicosane (4.4%,), (Z)-9 -octadecenamide (4.2%), and n-hexadecanoic acid (4.1%) in E-6208. The larval development result on tomato fruit could support its suitable nutritional contents to PTM, posing pest potential in the future where higher exposure is expected.