본 연구는 부패미생물의 종류와 차이를 알아보기 위해 유기농산물과 일반농산물(깻잎, 양배추, 상추)을 구입하여 4oC에 14일 저장한 후 일반목적배지를 사용하여 미생물을 분리 및 16S rRNA sequencing방법을 이용하여 동정하였다. 유기농산물 깻잎, 양배추, 상추의 총균수는 5-7 log10 CFU/g 수준이었고, 일반농산물의 총균수는 5-8 log10 CFU/ g 수준이었다. 유기농산물보다는 일반농산물이 총균수를 더 많이 내재하고 있으나 유의적인 차이는 나타나지 않았 다(p > 0.05). 유기농산물 깻잎에서 발견된 주요 균은 Microbacterium sp.이었으며, 일반농산물 깻잎에서 발견된 주요 균은 Stenotrophomonas maltophilia이었다. 또한, 유기농산물에서 부패를 일으킬 수 있는 균인 Klebsiella pneumonia 가 발견되었으며, 일반농산물보다 유기농산물에서 발견된 균의 종류가 더 많은 것을 확인할 수 있었다. 이에 본 연구 결과는 부패미생물에 대한 이해를 높이고 농산물의 신선도 및 유통기한을 늘리기 위한 새로운 살균소독제 및 부패 억제제를 개발하는데 좋은 기초자료로 사용될 수 있을 것으로 사료된다.

인공용승류 해역에서 난자치어의 종조성 및 시공간 변동을 파악하기 위하여 2012년 6월 13일, 9월 21일 및 25일에 난자치어 네트를 이용하여 조사하였다. 조사기간 동안 출현한 어란은 4,849 ind./1,000 m3, 자치어는 641 ind./1,000 m3이였다. 출현한 어란 중 가장 우점한 종은 멸치(Engraulis japonicus)로써 총 출현량의 약 57.5 %를 차지하였다. 그 외 미동정(Unidentified) 어란 Ⅰ, Ⅱ, Ⅲ, Ⅳ이 출현하였다. 자치어는 청베도라치(Pictiblennius yatabei)가 가장 우점하였으며, 그 다음으로 돛양태류(Repomucenus sp.A, sp.B), 고등어(Scomber japonicus), 멸치(Engraulis japonicus), 전어(Konosirus punctatus) 등의 순으로 나타났다. 그리고 미동정(Unidentified) 자치어 Ⅰ, Ⅱ가 출현하였다. 대조구 해역에서는 어란은 멸치, 자치어는 돛양태류가 출현하였다. 시기별 변동에서는 어란 및 자치어 모두 7월에 가장 많았으며, 8월에 가장 낮았다. 정점별 변동에서는 인공용승이 일어나는 인근 정점인 2, 3번에서 어란 및 자치어의 출현량이 가장 많았다. 대조구 해역과의 비교하여 정점당 약 4배 이상 많은 어란 및 자치어가 출현하였다. 인공용승에 의한 영양염류 및 먹이생물의 증가로 인하여 어란 및 자치어의 출현량이 증가한 것으로 판단된다.

촉매 1,8-diazabicyclo[5,4,0]undec-7-ene(DBU)를 이용하여, poly(vinylidenefluoride-co-chlorotrifluoroethylene) P(VDF-co-CTFE) 고분자와 methacrylic acid (MAA)를 반응시켜, P(VDF-co-CTFE)-MAA 공중합체를 제조하였다. 또한 P(VDF-co-CTFE)-MAA와 2-sulfoethyl methacrylate (SEMA) 단량체를 4’,4’-azobis(4-cyanovaleric acid) (ACVA) 개시제 하에서 자유 라디칼 중합하여 수소 이온 전도성 막을 제조하였다. SEMA 함량이 많아짐에 따라 술폰산 그룹이 증가하였다. SEMA 함량이 50%일 때 최대 이온교환 용량값이 0.82 meq/g에 도달하였으며 이는 함수량 결과와 일치하였다. 또한, SEMA 함량이 50%일 때 수소이온 전도도가 0.041 S/cm까지 도달하였다. 이러한 결과는 분리막에서 SEMA 함량이 증가할수록 수소 이온을 전달시킬 수 있는 이온그룹이 증가하기 때문이다.

실비늘치(6.70~5.32 cm TL)의 성장과 생산량에 대한 연구는 동대만 잘피밭에서 2006년도에 실시하였다. 실비늘치 시료는 소형 빔트롤에 의해서 총 888개체가 채집되었다. Bertalanffy 성장식을 이용하여 구한 전장의 성장식은 Lt=24.8257(1-e-0.5583(t+0.4816))이었다. 실비늘치의 밀도, 생체량, 일일생산량, 연간생산량, 그리고 P/B ratio는 각각 0.01±0.009/m2, 0.17±0.16g/m2, 0.00006±0.00006g AFDW/m2/day, 0.02g AFDW/m2/yr, 그리고 0.12이었다. 실비늘치 생산량의 월변화는 컸으며, 7월(0.000182g AFDW/m2/day), 9월(0.000127g AFDW/m2/day) 그리고 11월(0.000123g AFDW/m2/day)에 높았으며, 4월과 5월(0.000003g AFDW/m2/day)에 가장 낮았다. 실비늘치의 생산량의 월변화는 개체수와 생체량, 그리고 성장률과 양의 상관관계를 보였다.

Species composition and abundance of larval fishes in the coastal waters off Gori in the southeastern Korea were investigated from January to December in 2006. During the study period, 32 larvae species belonging to 20 families were collected. The dominant species were Engraulis japonicius, Hexagrammos agrammus, Sillago japonicus, Acropoma japonicum, Apogon lineatus, and Konosirus punctatus. These six species accounted for 87.0% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated by season. The peak numbers of species and individuals occurred in July and May, respectively. Correlation analysis showed that monthly variations in water temperature and salinity could act as an indicators of seasonal variations in the larval fish community structure and abundance of the dominant species; in particular, the abundance of S. japonicus, A. japonicum, and A. lineatus were significantly corrected with the water temperature.

광양만 대도주변에 서식하는 어류군집의 변화를 파악하기 위해서 2009년 3월부터 2010년 2월까지 소형 빔트롤을 이용하였으며, 동일 해역에서 실시된 이전 연구결과(1990~1991, 1995~1996)와 비교, 고찰하였다. 조사기간 동안 총 74종, 8,133개체가 출현하였다. 우점종은 주둥치, 보구치, 점줄망둑, 청보리멸, 열동가리돔, 풀반지, 돛양태, 베도라치, 도다리, 쥐노래미, 문치가자미 순으로 나타났다. 이들 11어종은 전체 개체수의 89.5%, 총 생체량의 58.9%를 차지하였다. 우점종이었던 개체들은 주로 작은 크기의 어종과 대형 어류의 치어였다. 종조성 및 출현량은 계절에 따라서 크게 변하였다. 2009년 5월과 10월에 가장 많은 종수가 출현하였으며, 2009년 5월에 개체수와 생체량이 가장 높았다. 출현 개체수 및 생체량은 모두 2010년 1월과 2월에 가장 낮았다. 어류군집의 계절변동은 수온변화와 연관이 있었다. 이전 연구결과와 비교하였을 때, 단위면적당 전체 개체수와 생체량은 더 높았으며, 주둥치의 출현량은 급격히 증가한 반면에 꼼치의 출현량은 감소하는 양상이었다. 어류군집의 종조성 변화는 광양만내의 전반적인 해양환경 특성의 연간변화에 기인하였다.

The reproductive ecology of the glowbelly, Acropoma japonicum was examined using 637 specimens collected monthly from January to December 2006 in the coastal waters off Gori, Korea. The specimens ranged in standard length (cm, SL) from 2.9 to 11.4cm for female, 2.7 to 10.5cm for male. The gonadosomatic index (GSI) of female was highest in September and decreased until December, and the spawning season lasted from August to November. The monthly sex was not different significantly (2-test, p〉0.05). The size at 50% maturity was estimated at 6.0cm SL. A. japonicum was multiple spawner that spawn on more than one occasion in a single spawning season, and the maximum egg diameter was 0.75mm. Fecundity (F) ranged from 12,052 to 104,246 eggs, with the mean of 38,321 eggs. The relationships between fecundity and standard length (cm, SL), body weight (g, BW) were estimated as F=86.278SL2.9652 (R2=0.7970) and F=3036BW1.0081 (R2=0.7992), respectively.

In this study, mechanical tests and microstructural analyses including TEM analyses with EDX of precipitates in modified 9Cr-1Mo steel were carried out to determine the cause of embrittlement observed after heat-treatment, which limits the usage of the alloy for power plants. Mod. 9Cr-1Mo steel specimens at austenite temperature were quenched to the molten salt baths at 760˚C and 700˚C, in which the specimens were kept for 10 min ~ 10 hr with subsequent air-cooling. Impact tests showed that the impact value dropped abruptly when the specimens were kept longer than 30 min at ~760˚C reaching to minima in about 1 hr, and then increasing at further retention. The tensile strength of the specimens reached the minimum value without much change afterward, whereas the values of elongation showed the same trend as that of the impact value. The isothermally heat-treated steel at 700˚C also showed a minimum impact value in about 1 hr. These results suggest that the isothermal heattreatment at 760 and 700˚C for about 1 hr induces temporal embrittlement in Mod. 9Cr-1Mo steel. The microstructural examination of all the specimens with extraction replica of the carbides revealed that the specimens with temporal embrittlement had Cr2C, indicating that the cause of the embrittlement was the precipitation of the Cr2C. In addition, TEM/EDX results showed that the Fe/Cr ratio was 0.033 to 0.055 for Cr2C, whereas it was 0.48 to 0.75 for Cr23C6, making the distinction of the Cr2C and Cr23C6 possible even without direct electron diffraction analyses.

In2O3 films were deposited by RF magnetron sputtering on a glass substrate and then the effect of post depositionannealing in nitrogen atmosphere on the structural, optical and electrical properties of the films was investigated. Afterdeposition, the annealing process was conducted for 30 minutes at 200 and 400oC. XRD pattern analysis showed that the asdeposited films were amorphous. When the annealing temperature reached 200-400oC, the intensities of the In2O3 (222) majorpeak increased and the full width at half maximum (FWHM) of the In2O3 (222) peak decreased due to the crystallization. Thefilms annealed at 400oC showed a grain size of 28nm, which was larger than that of the as deposited amorphous films. Theoptical transmittance in the visible wavelength region also increased, while the electrical sheet resistance decreased. In this study,the films annealed at 400oC showed the highest optical transmittance of 76% and also showed the lowest sheet resistance of89Ω/□. The figure of merit reached a maximum of 7.2×10−4Ω−1 for the films annealed at 400oC. The effect of the annealingon the work-function of In2O3 films was considered. The work-function obtained from annealed films at 400oC was 7.0eV. Thus,the annealed In2O3 films are an alternative to ITO films for use as transparent anodes in OLEDs.

It is well known that modified 9Cr-1Mo steel has a low thermal expansion and high thermal conductivity with excellent high temperature properties compared to austenitic stainless steel. For these advantages, the steel is very popular for the boiler tube of thermal power plants. Normalizing is commonly utilized to obtain martensite in this steel, which shows an unusual toughness for martensite. However, some accidents related to this steel have been reported recently, opening the necessity for further study. As a particular behavior of the steel, an abrupt drop of the impact value has been identified upon tempering at 750˚C for about 1 hour. It is well known that Fe3C forms during autotempering and turns to Cr2C at an early stage and then transforms to Cr23C6. In this study, the cause of the abrupt drop of the impact value was investigated with an impact test, microstructural observation, nanodiffraction and phase analyses using instruments such as optical and transmission electron microscopes (TEM) with an extraction carbon replica of the carbides. The analyses revealed that the M2C that formed when retained for about 1 hour at 750˚C causes a drastic decrease in the mechanical properties. The sharp drop in mechanical properties, however, disappeared as the M2C transformed into M23C6 with longer retention.

국내 개발 재배품종인 코스피드 이탈리안 라이그라스의 최적 배양조건을 확립하기 위하여 성숙종자로부터 캘러스 유도조건 및 식물체 재분화 조건을 조사하였다. 캘러스 유도시 첨가되는 auxin으로는 2,4-D가 NAA 보다 효율적이었으며, 5 mg/L 2,4-D가 첨가된 N6 배지에서 캘러스가 가장 높은 빈도로 유도되었다. 캘러스로부터 식물체 재분화는 1 mg/L 2,4-D와 5mg/L BA가 첨가된 N6 배지에서 배양했을 때 67% 이상의 재분화율을 나타내었

This study was investigated seasonal variation and species composition of fish species at artificial reefs (octangle three-stage compartment type and dice type)and natural rock in the Shinyang-Ri coastal waters off Jeju Island with visual census method in January 2009, April 2009, July 2009, September 2009, December 2009, March 2010, June 2010, and September 2010. A total of 44 fish species was occurred, and the dominant fish species were Apogon semilineatus, Chromis notata, Trachurus japonicus, Sebastes thompsoni and Apogon doederleini. The number of individuals of fishes was higher at April 2009 and March 2010, however, lower at June 2010 and September 2010. The number of fish speices was higher at artificial reefs than those of at natural rock. Apogon semilineatus was dominant at octangle three-stage compartment type and the dice type artificial reefs, whereas Chromis notata was for natural rock. These results indicated that artificial reefs were good habitats for a variety of fish species in the Shinyang-Ri coastal waters off Jeju Island.

ZnO thin films were prepared on a glass substrate by radio frequency (RF) magnetron sputtering without intentional substrate heating and then surfaces of the ZnO films were irradiated with intense electrons in vacuum condition to investigate the effect of electron bombardment on crystallization, surface roughness, morphology and hydrogen gas sensitivity. In XRD pattern, as deposited ZnO films show a higher ZnO (002) peak intensity. However, the peak intensity for ZnO (002) is decreased with increase of electron bombarding energy. Atomic force microscope images show that surface morphology is also dependent on electron bombarding energy. The surface roughness increases due to intense electron bombardment as high as 2.7 nm. The observed optical transmittance means that the films irradiated with intense electron beams at 900 eV show lower transmittance than the others due to their rough surfaces. In addition, ZnO films irradiated by the electron beam at 900 eV show higher hydrogen gas sensitivity than the films that were electron beam irradiated at 450 eV. From XRD pattern and atomic force microscope observations, it is supposed that intense electron bombardment promotes a rough surface due to the intense bombardments and increased gas sensitivity of ZnO films for hydrogen gas. These results suggest that ZnO films irradiated with intense electron beams are promising for practical high performance hydrogen gas sensors.

Feeding habits of Acentrogobius pellidebilis collected from in an eelgrass(Zostera marina) bed from January to December 2006 were studied. A. pellidebilis ranged form 1.6 to 6.9 cm in standard length were determined. A. pellidebilis was a carnivore which consumed mainly copepods, polychaetes, and amphipods. Its diets included small quantities of isopods, seaweeds, nematods, and gastropods. It showed ontogenetic changes in feeding habits. Smaller individuals (<2.0cm SL) fed mainly on copepods. While the consumption of copepods decreased with increasing fish size, the consumption of polychaetes and amphipods were increased. Dietary breadth index was varied with fish size.