• Title/Summary/Keyword: Size selectivity

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Size selectivity of tooth spacing and mesh size of dredge for Gomphina melanaegis (형망 어구에 대한 민들조개의 어획선택성)

  • 조태현;김인옥;박창두
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.39-40
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    • 2001
  • 민들조개(Gomphina melanaegis)는 우리 나라의 동해안 및 남해안에 널리 분포하고 있으며, 주로 연안에서 소형 선박을 이용하여 형망으로 어획하고 있다. 최근, 우리나라에서도 연안 어업자원의 관리 및 지속적 유효이용이 중요한 관심사항으로 부각되었으며, 이와 관련된 다양한 연구가 수행되고 있으나, 대부분 어류를 대상으로 하는 어구의 연구가 대부분을 차지하고 있으며 패류를 포획 대상으로 하고 있는 형망 어업과 관련된 연구는 매우 적다. (중략)

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Vapor Permeation Characteristics of TiO2 Composite Membranes Prepared on Porous Stainless Steel Support by Sol-Gel Method

  • Lee, Yoon-Gyu;Lee, Dong-Wook;Kim, Sang-Kyoon;Sea, Bong-Kuk;Youn, Min-Young;Lee, Kwan-Young;Lee, Kew-Ho
    • Bulletin of the Korean Chemical Society
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    • v.25 no.5
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    • pp.687-693
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    • 2004
  • Composite membranes with a titania layer were prepared by soaking-rolling method with the titania sol of nanoparticles formed in the sol-gel process and investigated regarding the vapor permeation of various organic mixtures. The support modification was conducted by pressing $SiO_2$ xerogel of 500 nm in particle size under 10 MPa on the surface of a porous stainless steel (SUS) substrate and designed the multi-layered structure by coating the intermediate layer of ${\gamma}-Al_2O_3$. Microstructure of titania membrane was affected by heat-treatment and synthesis conditions of precursor sol, and titania formed at calcination temperature of 300$^{\circ}C$ with sol of [$H^+$]/[TIP]=0.3 possessed surface area of 210 $m^2$/g, average pore size of 1.25 nm. The titania composite membrane showed high $H_2/N_2$ selectivity and water/ethanol selectivity as 25-30 and 50-100, respectively. As a result of vapor permeation for water-alcohol and alcohol-alcohol mixture, titania composite membrane showed water-permselective and molecular-sieve permeation behavior. However, water/methanol selectivity of the membrane was very low because of chemical affinity of permeants for the membrane by similar physicochemical properties of water and methanol.

Mesh selectivity of monofilament and multifilament nylon trammel net for marbled sole(Pleuronectes yokohamae) in the western sea of Korea (서해안 문치가자미 삼중망의 망지 재료에 따른 망목선택성)

  • KIM, In-Ok;PARK, Chang-Doo;CHO, Sam-Kwang;KIM, Hyun-Young;CHA, Bong-Jin;LEE, Gun-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.3
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    • pp.302-311
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    • 2015
  • A series of field tests to estimate the size selectivity of monofilament and multifilament gill net for marbled sole, Pleuronectes yokohamae, were carried out 12 times with five different mesh sizes (86.6, 101.0, 121.2, 137.7 and 151.5mm) in the western sea of Korea from 2007 to 2009. The master selection curve was estimated by the extended Kitahara's method. The total number of catch species was 23 and that of catch was 1,688 in the field tests. Marbled sole of total catch was 1,150 with 68.1 percent. In the monofilament trammel net, the optimum value of total length (TL) per mesh size (m) for 1.0 of retention probability was estimated 0.280 and the values of TL/m were estimated to be 0.187, 0.201, 0.210, 0.218 and 0.226 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. In the multifilament trammel net, the optimum value of TL/m for 1.0 of retention probability was estimated 0.307 and the values of TL/m were estimated to be 0.195, 0.211, 0.222, 0.232 and 0.241 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

Mesh selectivity of drum net traps for Buccinum opisoplectum Dall using SELECT model with unequal fishing and sampling efforts: A preliminary analysis (비균등한 어획노력량 및 샘플량인 경우의 SELECT 모델을 이용한 세고리물레고둥(Buccinum opisoplectum Dall)의 장구형 통발에 대한 망목선택성 : 예비분석)

  • Park, Hae-Hoon;Millar Russell B.;An Heui-Chun;Kim, Hyun-Young;Jeong, Eui-Cheol;Shin, Jong-Keun;Cha Bong-Jin;Kim, In-Ok
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.4
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    • pp.279-288
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    • 2005
  • The mesh selectivity of drum net traps for Buccinum opisoplectum Dall caught in the eastern sea of Korea was described. Several experiments were conducted between July 2003 and March 2004 and the data obtained from the experiment was fitted by SELECT (Share Each Length class's Catch Total) model with unequal fishing and sampling efforts. The selection curve was determined to be 'estimated fishing efficiency' by model deviance rather than AIC. However the fishing efficiency between 20mm and 35mm mesh size did not seem to be different. The $L_{50}$ lengths of the selectivity for the 55mm and 75mm mesh size were 65.4mm and 96.0mm, respectively.

Mesh selectivity of gill net for swimming crab Potunus trituberculatus in the western coastal waters of Korea (서해 꽃게 자망의 망목 선택성 연구)

  • Park, Chang-Doo;Cho, Sam-Kwang;Kim, Hyun-Young;Park, Seong-Wook
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.2
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    • pp.106-115
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    • 2013
  • A series of fishing experiments were carried out in the western coastal waters of Korea from May, 2006 to September, 2007, using gill nets of different mesh sizes (m=101, 121.8, 152.5, 176.8, and 191 mm) to determine the mesh selectivity of gill net for swimming crab, Potunus trituberculatus. The catch species was composed of swimming crab (87%), Thomas's rapa whelk Rapana venosa (5%), arthritic neptune Neptunea cumingi (2%), Japanese swimming crab Charybdis japonica (2%), marbled sole Pleuronectes yokohamae (1%), pen shell Atrina pectinata, ocellate spot skate Okamejei kenojei, and so on. The carapace length (CL) of each swimming crab caught in the experimental nets was measured. Sponge crab (egg-bearing female crab) was appeared from the end of June to August in the coastal waters. The master selection curve was estimated by applying the extended Kitahara's method. The selection curve showed that the gill nets of larger mesh size allowed more crabs of small carapace size to escape. The optimum value (CL/m) was 0.645 and the CL/m was estimated to be 0.301, 0.354, 0.391, 0.422, and 0.450 when the retention probabilities were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

Mesh selectivity of gill net for female Japanese sandfish (Arctoscopus japonicus) in spawning season (산란기 도루묵(Arctoscopus japonicus) 암컷의 자망에 대한 망목선택성)

  • Park, Hae-Hoon;Jeong, Eui-Cheol;Bae, Bong-Seong;Yang, Jae-Hyeong;Chol, Soo-Ha;Lee, Sung-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.4
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    • pp.274-280
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    • 2007
  • The mesh selectivity of gill net for Japanese sandfish (Arctoscopus japonicus) caught in the East Sea, Korea was described. The experiment was conducted with five different kinds of mesh size (39.4, 45.5, 51.5, 53.0, 57.6mm) between November and December 2006 in spawning season. The catch was mostly Japanese sandfish (93.3%) and some others (6.7%), and almost all of the female Japanese sandfish were larger than the fork length at 50% maturity (16.7cm). The selection curve for the female Japanese sandfish caught from the experiments was fitted by the Kitahara's method to a polynomial equation which was $s(R)={\exp}\{(0.2584R^3-5.3445R^2+32.269R-59.868)-0.6585\}$ where R=l/m, and l and m are fork length and mesh size, respectively.

Adsorption Characteristics of $CH_4/CO_2$ Mixed Gases on Activated Carbon Fibers (활성탄소섬유상에서 CH4/CO2 혼합가스의 흡착 특성)

  • Moon, Seung-Hyun;Shim, Jae-Woon
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.5
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    • pp.655-662
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    • 2004
  • An adsorption process to recover the pure $CH_4\;and\;CO_2$ from its mixture was examined. In this study, activated carbon fibers were used as a selective adsorbent. The activated carbon fibers has 78~94% micropore volume and 10.5~20.3${\AA}$ narrow pore size, and showed high adsorption rate and the good selectivity for $CO_2$ under the ambient pressure. The ACF with high surface area showed short mass transfer zone and long breakthrough time and, its adsorption capacity depended on the microporosity. Compared with single component adsorption, the amount adsorbed $CO_2$ on ACF increased by the roll-up of $CH_4$ in mixed gases. The adsorption selectivity increased as now rate and $CO_2$ concentration of mixed gases increased, showing 5.2 selectivity for 75% $CO_2$ concentration.