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        검색결과 182

        101.
        2009.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Silicon dioxide as gate dielectrics was grown at 400˚C on a polycrystalline Si substrate by inductively coupled plasma oxidation using a mixture of O2 and N2O to improve the performance of polycrystalline Si thin film transistors. In conventional high-temperature N2O annealing, nitrogen can be supplied to the Si/SiO2 interface because a NO molecule can diffuse through the oxide. However, it was found that nitrogen cannot be supplied to the Si/SiO2 interface by plasma oxidation as the N2O molecule is broken in the plasma and because a dense Si-N bond is formed at the SiO2 surface, preventing further diffusion of nitrogen into the oxide. Nitrogen was added to the Si/SiO2 interface by the plasma oxidation of mixtures of O2/N2O gas, leading to an enhancement of the field effect mobility of polycrystalline Si TFTs due to the reduction in the number of trap densities at the interface and at the Si grain boundaries due to nitrogen passivation.
        4,000원
        102.
        2008.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Oxide effects experiments on massive hydriding reactions of Zr alloy with hydrogen gas were carried out at 400˚C under 1 atm in a H2 environment with a thermo-gravimetric apparatus (TGA). Experimental results for oxide effects on massive hydriding kinetics show that incubation time is not proportional to oxide thickness. The results also show that the massive hydriding kinetics of pre-filmed Zr alloys follows linear kinetic law and that the hydriding rates are similar to that of oxide-free Zr alloys once massive hydriding is initiated. Unlikely microstructure of the oxide during incubation time, physical defects such as micro-cracks and pores were observed in the oxide after incubation time. Therefore, it seems that the massive hydriding of Zr alloys can be ascribed to short circuit paths and mechanical or physical defects, such as micro-cracks and pores in the oxide, rather than to hydrogen diffusion through the oxide resulting from the increase of oxygen vacancies in the hypo-stoichiometric oxide.
        4,000원
        103.
        2008.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Squid jigging fishery is very important in that there are about 1,000 jigging vessels more than 10 tonnage and about 5,000 ones less than 10 tonnage in Korea. But the cost of oil which is used to light fishing lamps, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnage. This cost has almost taken 40% of total fishing costs. That is, the fishing business condition of squid jigging fishery is recently in the very difficult situation. As oil price increases, the business condition of the fishery gets worse and worse. Therefore it is very urgent to develop an economical fishing lamp, to solve this problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery using the light emitting diode which has very excellent efficiency and durability. We made a water tank with 20 meters width which is a shape of raceway to research behavioral characteristics of Japanese flying squid to LED light, and made an experiment to investigate optimum wave of LED light to lure squid. The method is to establish LED lamps on both ends of water tank and to observe squid's behavior. Colors and wave lengths of LED lamps, used in experiment, are red(634nm), yellow(596nm), green(523nm), blue(454nm) and white(454nm+560nm). In experiment for attractive capability of LED lamp to squids, Japanese flying squid are highly attracted to blue lamp and white lamp. However, they are dispersed to red and yellow lamps. In addition, Japanese flying squid have moved and stayed in both dark ends of water tank. When compared intermittent lamp with continuous lamp, Japanese flying squid are highly attracted to intermittent lamp when intermittent interval is 0.25 second.
        4,000원
        104.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This survey was conducted to monitor the adulteration of sesame oil circulated in Gwangju, 2007. A total of 60 samples was tested by analysis of fatty acid composition. Of these samples, 22 were from large-scale manufacturer, 25 were from small-scale manufacturer and 13 from Bangagan. First of all, in goods manufactured by large-scale company, there are no sesame oils where linolenic acid (C18:3) exceed regulatory guidance (0.5%). 5 samples from small-scale manufacturer contained linolenic acid from 0.90% to 8.38%, which means that they have other cooking oil, such as corn oil, soybean oil and rape seed oil. Among Bangagan goods, only one sample have 1.20% of linolenic acid. On the other hand erucic acid (C22:1) was not detected in 60 samples at all, which means that they were not adulterated with rape seed oil. And among 6 samples of exceeding 0.5% of linolenic acid and 12 samples from Bangagan, 13 of them had benzo(a)pyrene from 0.2 μg/kg to 0.7 μg/kg and the other 5 samples did not.
        4,000원
        105.
        2008.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sea experiment for this study was carried out to develop a Trawl Escapement Net(TEN) using net material to improve the survival rate of undersized fishes that escaped from trawls in the Korean southern sea in May and November, 2005. Three kinds of Trawl Escapement Net(TEN) were examined to increase the escapement rate for fishes escaped from the TEN, and total catches in the codend and cover-net were investigated. The main catch species in the experimental fishing trials using a V shape TEN(A type) in May were Korean pomfret(Pampus echinogaster), slimy(Leiognathus nuchalis), gizzard shad(Konosirus punctatus), white croaker(Pennahia argentata) and smelt(Sillago sihama). In the experimental fishing trials using a V shape TEN with a protector for undersized fishes(B type) and a panel shape TEN with a protector(C type) in November, the main catch species were horse mackerel(Trachurus japonicus), sea pike (Sphyraena japonica), large-head hairtail(Trichiurus lepturus), kammal thryssa(Thryssa kammalensis), white croaker(Pennahia argentata), butterfish(Psenopsis anomala) and red gurnard(Lepidotrigla microptera). Most of large-sized fish species like Korean pomfret and Spanish mackerel could not escape through the TEN in the B type and C type. Catches of horse mackerel were highest in the experimental fishing of November and escapement rates for most fish species including horse mackerel were higher in the C type compared with B type.
        4,000원
        106.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2007년 3월부터 11월까지 광주지역에 소재하는 재래시장과 할인마트에서 구입한 건과류 채소류와 건포류 등 94건, 전통 막걸리 판매점 등에서 구입한 탁류 23건, 모두 117건을 구입하여 식품첨가물인 이산화황, 타르색소와 인공감미료를 조사하였다. 건과류 채소류와 건포류 등 94건에서 이산화황을 조사한 결과 17건에서 11.5~4,452.3;mg/kg이 검출되었으며, 식품공전의 기준을 적용한 결과 건조과실류인 대추채 2건이 각각 2,476.6 mg/kg, 4,452.3 mg/kg이 검출되어 부적합하였고, 중국산 건방울 토마토에서 88.9 mg/kg, 국내산 건호박에서 1,653.7 mg/kg이 검출되어 부적합 판정되었다. 또한, 주류 23건을 구입하여 인공감미료와 타르색소를 검사한 결과, 탁주에서 사용할 수 없는 인공감미료인 삭카진나트륨이 2건에서 0.4 mg/kg, 11.1 mg/kg이 검출되었으며, 합성 착색료로 주류에서 많이 사용할 가능성이 있는 황색5호 등 타르색소는 검출되지 않았다.
        4,000원
        108.
        2007.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed not only to develop the gill net and trap made of biodegradable monofilaments in order to prevent a ghost fishing and to protect marine ecosystem, but also to analyze their spinning process and physical properties. Results showed that the spinning speed of biodegradable polybutylene succinate(PBS) monofilament was estimated to be approximately 100m/min when spinning temperature and cooling water temperature were adjusted at 180℃ and 3℃, respectively. The breaking loads of PBS monofilaments were estimated to be 35.3kg/mm2 at Φ0.2mm, 46.5kg/mm2 at Φ0.3mm, and 49.7kg/mm2 at Φ0.4mm in the dry condition, respectively. However, its breaking loads in the wet condition were reduced by 2.4-5.5%, compared to those in the dry condition. The knotted strength of PBS monofilament at Φ0.2mm was estimated to be 98.6% of PE in the dry condition. The breaking load of PBS monofilament at Φ0.3mm was evaluated to be 81.8% of PA, and its softness showed 3 times less than that of PA in the wet condition. The breaking load of PBS monofilament at Φ0.4mm was 95.3% of PA, and its softness showed 1.6 times less than that of PA in the wet state. However, the load elastic elongations of two kinds of monofilaments were estimated to be 1% higher than that of PA.
        4,000원
        113.
        2007.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The sciaenid species, which has swimbladder, generates sounds by vibrating in its length wards when spawning or getting stimulus from something else. This research analyzed on sound frequency characteristics relatives to their swimbladder length of three sciaenid species, yellow croaker(Larimichthys polyactis), brown croaker(Miichthys miiuy), and white flower croaker(Nibea albiflora). As results, the dominant frequency for yellow croaker ranged over 38.08 to 141.60Hz in wide frequency band, and the averaged pulse duration expressed in 280.3±156.0ms. For brown croaker, the dominant frequency ranged in 49.80 to 59.57Hz, and the averaged pulse duration was 129.1±36.9ms. Moreover, the dominant frequency of white flower croaker ranged in 73.24 to 86.91Hz, and the averaged pulse duration was 88.0±15.9ms, it has shorter pulse duration than any two species. Therefore, the dominant frequency relatives to swimbladder length of sciaenidae showed that it had widely resonant characteristics and long pulse duration as in shorter swimbladder length. Additionally, for white flower croaker, we could confirm their behavior and sounds in response to production of recorded sounds using underwater speaker.
        4,000원
        114.
        2007.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The investigation for the species composition and catch in the deep East Sea was carried out with commercial trawlers from 2004 to 2006. The catches were 6,043kg and were composed of 43 species with 34 hauls between 250m and 1,030m in depth. The principal species caught were Allolepis hollandi, red crab (Chionoecetes japonicus), Careproctus rastrinus, Argis lar, Chionoecetes opilio, Malacocottus gibber, Petroschmidtia toyamensis, Pandalus eous Makarov, and Dasycottus setiger. The rate of discarded catches in situ was about 50%. The diversity indexes of 2005 and 2006 were 1.152 and 0.878, respectively, and the evenness indexes at those years were 0.752 and 0.583, respectively, which implied one dominant species caught in 2006.
        4,000원
        116.
        2006.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper introduces an auto-feeding system to exactly control the feeding time and the amount to cultured fishes in aquaculture industrial field. To reduce expensive costs or labors in this field, it was designed by the concept of controlling feed quantity exactly on the basis of fish's feeding behavior pattern in water tank. A feed control method of this system was developed for controlling feed amount by rotor capacity and motor rotated number. Moreover, a scattering section was selected by rotate way of propeller wing to scatter dried feed to designated site, and then, the diameter of its wing was 250mm and maximum scattering distance was 7.6m for 600rpm. Furthermore, the scattering ways were embodied 2 types such as a simplified way and a multistage shift way looks like a manual scattering. As a results, the multistage shift way is more effective to discharge the dried feed widely than the simple way in the water tank.
        4,000원
        120.
        2006.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to develope a fishing technology for fisheries management for improving the survival rate of young fishes escaped from trawl net. Sea experiments were carried out to investigate the survival rate of the fishes in off Geomun island and Korean southern sea. Cover-net fish cage was designed and manufactured to collect fishes escaped from COD(codend) and TED(trawl escapement device). Fish cage was installed in a shallow site where scuba diver can observe the surviving fishes after separating the cage from trawl net. Most of fishes except horse mackerel(Trachurus japonicus) and mackerel(Scomber japonicus) could escaped through TED(bar space 35mm) easier than COD(mesh size 54mm). Especially, escapement rate of redlip croaker(Pseudosciaena polyactis) escaped from TED was the highest as 73.9%. Survival rate of horse mackerel(Trachurus japonicus) escaped from TED was 85.5% at the point of 96 hours over, while the survival rate for COD showed a rapid decrease according to the time elapse as 85.0% at the point of 24 hours, 76.4% for 48 hours, 62.7% for 72 hours and 56.1% for 96 hours. Over 90% of red seabream(Pagrus major) and rock bream(Oplegnathus fasciatus) escaped from TED were survived 96 hours over and the survival rate of those fishes were excellent compared with the other fish species. All korean pomfret(Pampus echinogaster) escaped from both COD and TED were died within 48 hours. Most of redlip croaker(Pseudosciaena polyactis) were also died within 12 hours because of the weak physiological characteristics by water pressure change. Survival rate of fishes like as horse mackerel(Trachurus japonicus) having hard skin was high while it was low for the fishes like as squid(Todarodes pacificus) and hair-tail(Trichiurus lepturus) having soft skin. We could know that there were big differences in the survival rate offish species escaped from trawl net.
        4,000원
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