• 제목/요약/키워드: 수산

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수산화인회석의 다양한 합성법과 용매에 따른 결정의 크기 변화에 관한 연구

  • 김영용;권기영
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.269-269
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    • 2012
  • 수산화인회석(Hydroxyapatite)는 뼈와 이빨의 무기물 주성분으로서, 칼슘과 인산염으로 구성된다. 우리는 수산화인회석의 합성에 용융열 합성법(molten salt method), 수열 합성법(hydrothermal method), 용매열 합성법(solvothermal method)을 사용하였으며, pH 조절과 각기 다른 용매를 사용하여 다양한 형태의 수산화인회석을 합성하였다. TEM과 SEM을 이용하여 크기와 모양이 제어된 수산화인회석임을 확인할 수 있었다. 합성된 수산화인회석을 이용하여, 전이금속 Ruthenium cation을 Hydroxyapatite 표면에 ion-exchange 반응을 통하여 도입하였으며, ICP를 통하여 Ru 함양을 정량하였다. 합성된 Ruthenium Hydroxyapatite (Ru-HAP)를 이용하여 dimethylamine borane를 통한 수소 발생을 확인하였다.

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한국 남해안에 서식하는 보구치(Pennahia argentata)의 이석을 이용한 연령 및 성장 (Age and Growth of White Croaker Pennahia argentata in the Southern Sea of Korea by Otolith Analysis)

  • 전복순;최정화;김두남;임양재;이해원
    • 한국수산과학회지
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    • 제54권1호
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    • pp.53-63
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    • 2021
  • Age structure and growth of white croaker Pennahia argentata were estimated an analysis of otoliths. Fish specimens were collected from the Southern Sea of Korea from January to December 2018. A thin section method was used for age determination because otoliths of white croaker are oval in shape and large in size. Otoliths were cut vertically into 0.4-0.5 mm thick sections with an electric saw (Micracut 125). Monthly changes in the marginal index indicated that rings (opaque zone) were formed once a year in August. The estimated von Bertalanffy growth equation estimated by a non-linear regression were L∞=34.71 (1-e0.38(t+0.80)). In the present study, the oldest female was 8 years old and the male was 7 years old.

봄철 제주 남부해역 난·자치어의 수직 분포 (Vertical Distribution of Icthyoplankton in the Southern Waters of Jeju Island During Spring)

  • 이보람;지환성;유효재;황강석;김두남
    • 한국수산과학회지
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    • 제55권2호
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    • pp.146-153
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    • 2022
  • The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

서해안 수산생물에서 분리한 대장균(Escherichia coli)의 항생제 내성 및 다제 내성 양상 비교 (Comparison of Antimicrobial Resistance and Multi-Drug Resistance Patterns of Escherichia coli Isolated from Aquatic Organisms Off the West Coast of South Korea)

  • 정연겸;박보미;김민주;박진일;정연중;오은경
    • 한국수산과학회지
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    • 제54권4호
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    • pp.388-396
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    • 2021
  • Antimicrobial resistance patterns of Escherichia coli were investigated. Strains were isolated from 310 shellfish, 36 crustaceans, and 12 fish collected off the West Coast of Korea from April 2019 to October 2020. Two hundred and ninety-five E. coli strains were isolated from shellfish, 100 from crustaceans, and 54 from fish. Strains isolated from shellfish showed the highest resistance to ampicillin (27.5%), whereas those from crustaceans were resistant to sulfisoxazole (30.0%) and those from fish were resistant to ampicillin (59.3%) and sulfisoxazole (59.3%). Ceftazidime resistance was observed in strains isolated from short neck and hard clams, whereas gentamicin resistance was observed in strains from fish. Multi-drug resistance was observed in 56 strains (48.7%) isolated from shellfish, 11 (28.2%) from crustaceans and 27 (73.0%) from fish. Depending on the source of isolation, the strains showed specific antimicrobial resistance tendency. Strains isolated from shellfish showed 12 different multi-drug resistance patterns, whereas those from crustaceans showed high resistance (59%) to a single antimicrobial agent and those from fish showed a broad trend of multi-drug resistance to more than eight antimicrobials.

사료 공급횟수가 어린 강도다리(Platichthys stellatus)의 성장에 미치는 영향 (Effect of Feeding Frequency on the Growth of Juvenile Starry Flounder Platichthys stellatus)

  • 김희성;최진;임현정;정민환;이채성;변순규
    • 한국수산과학회지
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    • 제52권1호
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    • pp.87-91
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    • 2019
  • Effects of feeding frequency on the growth performance of juvenile starry flounder Platichthys stellatus were investigated. One thousand fifty fishes were distributed into 15 of 500-L flow-through tanks. Triplicate groups of were fed experimental diet with five feeding frequency (one meal every two days, one meal a day, two meals a day, three meals a day and four meals a day) for 9 weeks. Weight gain and specific growth rate (SGR) of fish fed two meals a day were higher than those of fish fed one meal 2 days and one meal a day, but not different from those of fish fed three meals a day and four meals a day. Feed consumption of fish fed two meals a day was not different from that of fish fed three meals a day and four meals a day. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed two meals a day were higher than those of fish fed all other diets, except for three meals a day. These results suggest that the optimal feeding frequency is two meals a day for the optimum growth performance of juvenile starry flounder under the experimental conditions.

천수만 주변해역에 출현하는 부유성 어란 및 자치어의 분포특성 (Distribution characteristics of egg and ichthyoplankton in the Cheonsu Bay, Korea)

  • 윤병일;최동혁;최윤석;이승환;권대현;김맹진
    • 수산해양기술연구
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    • 제58권4호
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    • pp.326-333
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    • 2022
  • To provide information needed for managing fish resources and protecting the ecosystem of Cheonsu Bay, bimonthly variations in species composition and abundance of fish eggs and larvae were investigated. The samples were collected by using bongo net at three different stations from February 2020 to December 2021. Fish eggs were divided into Engrualis japonicas and unidentified eggs, of which Engragulis japonicus accounted for 85.6% of the total eggs collected. A total of 21 species representing 17 families and 6 orders were collected. The three dominant species were Gobiidae spp, Thryssa hamiltonii and E. japonicus and these three species accounted for 74.1% in the total number of individuals. The number of species was highest in August, 2020 and lowest in February, 2020 and 2021; the number of individuals was highest in August, 2020 and lowest in February, 2020. Temporal changes in the abundances of pelagic eggs and larval fishes corresponded with temperature.