• Title/Summary/Keyword: Scallop

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Effect of Stocking density on Growth and Survival rate of the Scallop, Chlamys farreri (Jones & Preston, 1904) cultured in Hanging culture in the West coast of Korea (비단가리비, Chlamys farreri 수하양식에서 수용밀도에 따른 성장과 생존)

  • Park, Kwang-Jae;Yoon, Sang-Pil;Park, Young-Je;Song, Hong-In
    • The Korean Journal of Malacology
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    • v.28 no.1
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    • pp.1-6
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    • 2012
  • We studied that the effect of stocking density on growth and survival rate of the scallop, Chlamys farreri (initial shell height 32.97 mm and total weight 5.63 g) from June 2002 to October 2003 in the west coast of Korea. C. farreri is usually the west coast of Korea and northern China in the natural habitat of the coastal species. Range of surface water temperature in the study area was $4.3^{\circ}C$ to $25.3^{\circ}C$, salinity 29.2 psu to 32.1 psu, dissolved oxygen 5.32 mg/L to 7.51 mg/L and pH was 7.84 to 8.12, respectively. The stocking densities were 20, 30, 40 and 50 individuals per a compartment of suspension cage in culture beginning. After 16 months from initiation, ranges of shell height and mean total weight were from 64.35 mm to 76.23 mm and from 41.53 g to 64.85 g. The survival rate was from 82% to 100%. The growth rate of the scallop was negatively correlated with the stocking density. The growth of the shell height and total weight were decreased with decreasing of water temperature. Most of mortality of scallop occurred during March to April and September to October. Survival rate in the stocking density was decreased by density increase and was highest in 20 individual a compartment.

A study on the Oil Contents of Phytoplankton and Bay Scallop, Argopecten irradians (해만가리비와 먹이생물 Phytoplankton의 지질함량에 관한 연구)

  • Kim, Sook-Yang;Kang, Seok-Joong;Choi, Byeong-Dea;Jun, Sang-Ho
    • The Korean Journal of Malacology
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    • v.26 no.3
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    • pp.217-225
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    • 2010
  • The total oil proportion of bay scallop by areas during the growing period was the highest (2.8%) at Tongyong in August, then it decreased to 1.88% in September and 0.62% in October, and it was the lowest (0.22%) in November. The total oil proportion of phytoplankton by areas was the highest at Tongyong, where it was decreased from 5.02% in August and 3.29% in September to 2.48% in October and 1.66% in November. For the composition of fatty acid of bay scallop by areas and seasons during the growing period, the major composition was 16:0 and 18:0 as saturated fatty acid, and 16:1n-7, 18:1n-7, 20:1n-9, ARA (20:4n-6), EPA (20:5n-3), DHA (22:6n-3) as monoenic acid. TMTD (4,8,12-trimethyltridecanoic acid) was detected in a little amount as special fatty acid. For the composition of fatty acid of prey by areas during the growing period of bay scallop from August to November 1998, n-3HUFA, Omega-3 highly unsaturated fatty acid, in August was 47.11% at Namhae in slowest growth, while it was distinctively low with 34.26% at Tongyong and 14.06% at Nammeon.

A Study on the Production of Artificial Seed and Intermediate culture for Attached Spats of the Chinese Stock of a Scallop, Patinopecten yessoensis (중국산 참가리비, Patinopecten yessoensis의 인공종묘 생산 및 부착치패 중간양성에 관한 연구)

  • Oh, Bong-Se;Lee, Jeong-Yong;Park, Se-Ku;Lee, Chu;Jo, Q-Tae
    • The Korean Journal of Malacology
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    • v.24 no.2
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    • pp.153-159
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    • 2008
  • We investigated artificial mass seed production of a Chinese scallop, Patinopecten yessoensis, in 2004. The GSI(gonad somatic index) of the Chinese scallop, P yessoensis was 17.2 on mid-February, 20.2 on mid-March, while that of Korean scallop, P yessoensis was 6.9 on mid-February, 10.8 on mid-March. Matured 120 females and 350 males were selected for artificial mass production. They were exposed in air for 1 hr at over $20^{\circ}C$, and placed into a spawning tank(20 ton) containing sea water treated with UV radiation at $12^{\circ}C$. We gained a total of 228,000 thousand scallop embryos between March 10th and 15th, and reared larvae at the indoor tank during 25 days. When the mean shell length of larvae reached 250 ${\mu}m$ and they have eye-spots, the number of pre-settling larvae was 47,500 thousand. We gained 1,850 thousand attached scallop spats from two kinds of collectors. Attached spats were reared in indoor tank for different periods from 5 days to 60 days. They were divided into 5 groups according to the length of reared days. Each group of attached spats was moved to intermediate rearing sites at Yangyang fishing port in Gangreung-city for acclimation to ocean environments. The highest survival rate of attached spats was 13.0% shown at the group reared for 12 days, but the significant difference in their growth was not found between the groups. The shell length of artificial attached spats increased from 0.9 ${\mu}m$ on July 10th to 24.7 ${\mu}m$ on December 16th with the survival rate of 85.0% while that of natural attached spats increased from 0.6 ${\mu}m$ on July 10th to 23.9 ${\mu}m$ on December 16th with the survival rate of 85.7%.

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The Optimum leaf width of Multileaf Collimator (Multileaf Collimator의 적정 폭에 관한 연구)

  • 이병용;조병철;장혜숙
    • Progress in Medical Physics
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    • v.5 no.2
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    • pp.49-55
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    • 1994
  • Multileaf Collimator is an essential tool for conformal therapy. We have measured the scallop penumbars of a poligon-shape field produced by Multileaf Collimator(MLC) with various leaf widths and the penumbra from conventional block, and compared the difference between them for the energy of photons, leaf widths, and angle of filed edges in order to find out the optimum leaf width. In addition, we have simulated a treatment of 20 factionations with errors of patient positioning. Optimum cost-benefit balanced leaf width is 8 mm.

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A Toolpath Generation for CNC Machining of Free-form Surfaces (자유 곡면의 CNC 가공을 위한 가공경로의 생성)

  • Seong, Wan;Choi, Chong-Ho;Song, O-Sok
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.4 s.97
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    • pp.129-137
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    • 1999
  • A parametric curve interpolator has been proposed for machining curves instead of a linear interpolator in which curves are approximated by a set of line segment. The parametric curve interpolator is superior to linear interpolator in machining time and contour error and generate exact position commands directly from curve equations. In this paper, a new toolpath generation method is proposed based on the parametric curve interpolator. This method retains all the benefits of parametric curve interpolator and can bound the scallop height within a specified value. By interpolating curves and surfaces directly from the mathematical equations, the amount of data from CAD/CAM system to CNC controller can be significantly reduced. The proposed method was implemented on a CNC controller and was confirmed to give a better result than the other existing method.

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Development of Modified Atmosphere Packaging for Scallop (세계의 포장 - 가리비 조개 선도유지에 탁월한 EPS상자 개발)

  • 한국발포스티렌재활용협회
    • 환경사랑
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    • s.55
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    • pp.6-7
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    • 2009
  • 수산물 EPS상자의 용도가 날로 확대되는 가운데 일본 아오모리현 수산 종합연구센터 증양식 연구소는 가리비 조개의 선도유지를 위한 EPS상자를 개발했다. <월간 포장계> 2009년 2월호에 소개 된 개발 용기 내용을 요약했다.

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