• Title/Summary/Keyword: EELS

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REARING OF THE EEL ANGUILLA JAPONICA IN RECIRCULATING AQUARIUMS (뱀장어 양식에 관한 연구 (순환여과식 이용))

  • KIM In-Bae;KIM Yong Uk;JO Jae-Yoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.10 no.2
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    • pp.115-124
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    • 1977
  • From August 1976 to May 1977, a series of rearing experiments of eels weighing over 5 grams were carried out utilizing indoor recirculating aquariums and the results are summarized as following: 1. The eels were instantly acclimatized in the aquarium when alive Tubifex was fed as food, resulting in the food coefficient of around 5, and the daily growth rate of $2\%$ or so (Table 2). 2. When mackerel flesh was used in combination with flour dough or commercial powdered feed, the food coefficients were 4 to 5 and daily growth rates were between 1 and $2\%$ (Tables 3 and 4). 3. The eels of 12.4-14.7g in average weight which had not shown any growth when fed processed feed, grew normally when they were fed alternately with alive Tubifex and processed feed with the results of 4.3-6.0 in food coefficient and $1.4-2.3\%$ in daily growth rate (Table 5). 4. Experimental processed feed containing North Pacific which fish meal as the main ingredient showed the food coefficient of 1.31-1. 83 as dry material and this means that there is not any significant difference between this experimental feed and the control commercial eel feed, imported front Japan which showed food coefficient of 1.34 and 1.328 (Tables 6 and 7). 5. The feed cost may be reduced by about $45\%$ (based on tile domestic prices in the spring 1977) if this experimental processed feed is used instead of imported commercial feed. 6. Uneven growth is markedly significant in eels, and those which showed retarded growth gave very poor food efficiency as well as poor growth rate until they reach the size of about 30 grams. Thereafter they recovered both the normal food coefficient and growth rate. 7. Individuals which have been showing significant retarded growth may have some inherent physiological factors but this poor growth might also be, more or less, results of some external factors which are considered necessary to be investigated.

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Studies on Fatty Acid and Lipid Components of Foods (식품중 지방산 및 기타 지질성분에 관한 연구)

  • 권혁희;김인복;김소희
    • Journal of Food Hygiene and Safety
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    • v.2 no.4
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    • pp.197-200
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    • 1987
  • Nutritive value of lipids was associated with composition of fatty acid. Unvalance diet may increase the incidence of diseases. Abundant of EPA and DHA, polyunsaturated fatty acid, were contained in fishes. Studies on 10 kinds of fishes, lipid components were determined. The results were as follows; 1. The content of crude fat 18.1% were high in eels, on the contrary the content of EPA 0.1% and DHA 0.1% were low. The content of crude fat were low in mackeral and sadrine, but the content of poly unsaturated fatty acid were high. 2. Iodine value 189 was high in sadrine, consequently, this results showed the interrelation between Iodine value and the content of polyunsaturated number. 3. The content of crude fat 1.3% in flounder(sole) were low and the content of cholesterol 20 mg% were lowest in present studies.

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Identification of Potential Species-Specific Marker in Several Fish Species by RAPD Using Universal Rice Primers (Universal Rice Primer (URP)-RAPD 방법에 의한 어류 종 특이 marker의 동정)

  • KIM Woo-Jin;KIM Kyung-Kil;LEE Jeong-Ho;PARK Doo-Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.3
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    • pp.317-320
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    • 2003
  • Morphologically similar fish species were subjected to the random amplified polymorphic DNA (RAPD) analysis using universal rice primer (URP). The fish species tested were sea basses (Lateolabrax japonicus and L. maculatus), eels (Anguilla japonica, A. bicolor bicolor, A. rostrata, and A. anguilla), and flounders (Limanda yokohamae and L. herzensteinin). Highly reproducible RAPD patterns were observed with several potential species-specific markers. The results indicate that RAPD technique using URP is useful for distinguishing fish psecies in a rapid manner.

Bonding and Physical Characteristics of Diamond-like Carbon Films Prepared by Laser Ablation (레이저 어블레이션에 의해 증착된 비정질 다이아몬드 박막의 결합및 물리적 특성)

  • Park, Hwan-Tae;Hong, Young-Kyu;Kim, Jae-Ki;Kim, Jin-Seung;Park, Chan
    • Journal of the Korean Vacuum Society
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    • v.5 no.1
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    • pp.1-5
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    • 1996
  • Noncrystalline films of diamond-like carbon (DLC) have been prepared by laser ablation technique at room temperature. A Q-switched Nd-YAG laser beam with wavelength of 1064 nm and pulse duration of 10 ns was focused onto a graphite target with power densities of about $10^9 W/\textrm{cm}^2$. The physical properties of the resulting films were analyzed with density, hardness, and resistivity measurements. The surface and bonding structure were investigated by atomic force microscopy (AFM), Raman spectroscopy, electron energy loss spectroscopy (EELS).

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Low-value Fish used as Feed is a Source of Disease in Farmed Fish

  • Kim, Do-Hyung
    • Fisheries and Aquatic Sciences
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    • v.18 no.2
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    • pp.203-209
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    • 2015
  • Low-value fish is the most commonly used feed in Asian fish farms despite the fact that its application is controversial in regard to the sustainability and biosecurity of aquaculture. In this study, the causal agent of a disease outbreak at a Korean rockfish Sebastes schlegeli farm was investigated to determine whether the low-value fish used at the farm was the source. Infected Korean rockfish and Pacific sand eel used as feed were sampled from the farm, and bacterial cultures recovered from the internal organs of all sampled rockfish were isolated as pure cultures and later identified as Vibrio harveyi. The causal agent of the disease was also isolated from the kidneys of some of the sampled Pacific sand eels. This study provides additional evidence that the low-value fish used as feed at fish farms can be a key source of infectious diseases.

Characterization of Boron Nanoparticles Synthesized with a Thermal Plasma System

  • Shin, Weon-Gyu;Girshick, Steven L.;Oh, Dong-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.369-369
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    • 2011
  • In the current work, we demonstrate the gas phase plasma synthesis of ultrafine boron nanoparticles by decomposing boron trichloride (BCl3) gas in an argon-hydrogen thermal plasma and quenching the hot plasma by expansion through a ceramic nozzle, driving the homogeneous nucleation of nanoparticles. It is shown that ultrafine nanoparticles can be produced from the experiments. We also show the characterization results regarding the oxidation of boron nanoparticles at room temperature using X-ray Photoelectron Spectroscopy (XPS) and the combined Scanning Transmission Electron Microscope (STEM) and Electron Energy Loss Spectroscopy (EELS).

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Quantitative characteristics of a new high-voltage CCD camera (신규 설치된 HVEM용 고전압 CCD 카메라의 정략 특성 평가)

  • Kim, Yeong-Min;Kim, Yun-Jung
    • 한국전자현미경학회:학술대회논문집
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    • 2007.05a
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    • pp.84-89
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    • 2007
  • 카메라의 정량 평가 결과로부터 신규 설치된 HVEM용 고전압 CCD 카메라 (SPUS1000 HV-IF)는 기존의 HV-MSC 카메라에 비해 read-out noise level과 shot noise 발생거동, average gain, dynamic range, uniformity, DQE 등이 향상된 결과를 보여 주었고 MTF는 전과 유사한 결과를 나타내었다. 그러나 linearity가 HV-MSC 카메라에 비해 그 범위가 좁으며 낮은 전자 조사 조건하에서는 전반적인 카메라 성능이 오히려 HV-MSC 카메라의 경우보다 낮은 결과를 나타내었다. 따라서 본 신규 카메라는 낮은 전자 조사 조건이 필요한 실험에서는 기록 성능의 개선을 나타내지 않지만 고속 영상 기록 기능을 활용한 재료의 역동적 분석과 함께 원자분해 영상 작업과 EELS 분석에 있어선 이전 보다 기록 성능의 뚜렷한 개선을 나타낼 것으로 기대할 수 있다.

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H13소재의 쇼트피닝과 이온질화에의한 표면경화

  • Jo, Gyun-Taek;Son, Seok-Won;Yu, Gwang-Chun;Lee, Yeong-Guk;Lee, Won-Beom
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.11a
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    • pp.58-59
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    • 2012
  • Surface hardening mechanism of H13 steel was investigated when ion niriding after shot peening process was applied. Severe plastic deformation induced nanocrystallized grains at surface region. Higher nitrogen concentration was achieved in ion nitrided specimen with shot peening treatment than in single nitrided specimen. The elemental mapping on chromium and nitrogen by TEM-EELs showed chromium dissolved in matrix enhanced bulk nitrogen diffusion at surface region. Higher nitrogen diffusion also caused lattice distortion. Nano-sized grains, higher nitrogen concentration, and lattice diffustion contributed to the surface hardening.

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Deformation and crystallization of Cu-base BMG alloy in the supercooled liquid region (과냉각 액상 구간에서 Cu-based BMG 합금의 결정화와 변형 거동)

  • Park, E.S.;Lee, J.H.;Kim, H.J.;Bae, J.C.;Huh, M.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.10a
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    • pp.143-145
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    • 2007
  • The correlation between crystallization and deformation behavior in the supercooled liquid region (SLR) of a $Cu_{54}Ni_{6}Zr_{22}Ti_{18}$ bulk metallic glass (BMG) alloy is investigated by compression tests, differential scanning calorimetry (DSC), electron energy loss spectrometry (EELS) and high resolution transmission electron microscopy (HRTEM). In the SLR, This BMG alloy was strongly depended on the deformation temperature and the alloy exhibits important change in deformation behavior after a given time which is directly connected to the development of crystallization. Compressive stress impeded decomposition and consequently retarded forming of nano-crystal, which led to enlarge the homogeneous deformation region of the BMG alloy in SLR during compression test.

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