We conducted experiments to compare the catch rate of bigeye tuna and yellowfin tuna between circle hooks and straight shank hook in the Korean tuna longline fishery at the eastern and central Pacific Ocean from 2005 to 2007. We analyzed difference of fork length, survival and hooking location between a circle hook and a straight shank hook for both tunas, respectively. There was no difference in the mean fork length size of yellowfin tuna caught on the two type of hook but bigeye tuna was significant. In case of survival, there was no difference between two hook type, but the difference of hooking location was significant for both species. We also analyzed to find determinants of both tunas catch rate using generalized linear models (GLMs) which were used latitude, longitude, year, month, depth, hook type, bait type and so on as independent variables. Spatial factors, latitude and longitude, and temporal factors, year and month, affected catch rate of bigeye tuna and yellowfin tuna. And also, depth such as a marine environment factor was influenced on catch rate.

During a month, wave observation was characteristic of Suyuong bay since 16th of July. During the period, typhoons which were "Ma-on, Muifa" landed on Suyong bay. Observation point places a half-way point between Gwangan light beacon in the utmost bounds of the west and Haeundae floating buoy in east. The observation point was selected for confirming the relations of river discharge and storm surge of suyong bay. To investigate the characteristic, using meteorological data not in just Gwangan light beacon but in Haeundae floating buoy. As a result, at Gwangan light beacon the maximum significant wave observed was 3.5 m and period was 10,3 sec, at the Observation point each outcomes were 3.8 m and 10.1 sec, Haeundae floating had 2 m and 8.5 sec as consequences. The height of observation point was higher than Haeundae's or Gwangan’s and had two peaks. Although the wave direction in observation point came from southern east, being irregular in Haeundae floating buoy. Up to now, the interrelationship of weather conditions and wave characteristics have been verified, the characteristic of wave distribution

2009년 6월부터 2010년 4월에 걸쳐 전라남도 갯벌공원으로 지정되어 있는 신안군 증도 갯벌과 무안군 해제면 갯벌 공 원을 중심으로 해 저층 퇴적물의 층별 강열감량(IL), COD, 황화수소(H2S), ORP(Oxident Reduction Potential) 와 퇴적물 중금속을 측정하여 갯벌의 오염도를 평가하였고 갯벌 오염도의 등급화를 구분하였다. 두 지 역의 갯벌 오염도를 비교한 결과, COD는 증도 갯벌이 약간 높았으나 H2S와 IL치는 오히려 무안 갯벌보 다 낮은 양호한 상태를 보였고, 두 해역 퇴적물 중금속 함량의 비교에서는 Zn은 서로 비슷한 함량을 보 였으나 Cu, Cd, Cr과 Pb은 무안 갯벌보다 증도 갯벌에서 낮게 분포하였다. 다른 지역의 일반 연안의 갯 벌 상태와 비교해서는 두 지역 모두 양호한 저질 상태를 보였고 오염도의 등급으로는 1-2등급에 속하는 것으로 나타났다.

Nano-sized SnO2 thick films were prepared by a screen-printing method onto Al2O3 substrates. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a test box as a function of the detection gas. The nano-sized SnO2 thick film sensors were treated in a N2 atmosphere. The structural properties of the nano SnO2with a rutile structure according to XRD showed a (110) dominant SnO2 peak. The particle size of SnO2:Ni nano powders at Ni 8 wt% was about 45 nm, and the SnO2 particles were found to contain many pores according to the SEM analysis. The sensitivity of the nano SnO2-based sensors was measured for 5 ppm CH4 gas and CH3CH2CH3 gas at room temperature by comparing the resistance in air with that in the target gases. The results showed that the best sensitivity of SnO2:Ni and SnO2:Co sensors for CH4 gas and CH3CH2CH3 gas at room temperature was observed in SnO2:Ni sensors doped with 8 wt% Ni. The response time of the SnO2:Ni gas sensors was 10 seconds and recovery time was 15 seconds for the CH4 and CH3CH2CH3 gases.

Nano-indium-coated ZnO:In thick films were prepared by a hydrothermal method. ZnO:In gas sensors were fabricated by a screen printing method on alumina substrates. The gas sensing properties of the gas sensors were investigated for hydrocarbon gas. The effects of the indium concentration of the ZnO:In gas sensors on the structural and morphological properties were investigated by X-ray diffraction and scanning electron microscopy. XRD patterns revealed that the ZnO:In with wurtzite structure was grown with (1 0 0), (0 0 2), and (1 0 1) peaks. The quantity of In coating on the ZnO surface increased with increasing In concentration. The sensitivity of the ZnO:In sensors was measured for 5 ppm CH4 gas and CH3CH2CH3 gas at room temperature by comparing the resistance in air with that in target gases. The highest sensitivity to CH4 gas and CH3CH2CH3 gas of the ZnO:In sensors was observed at the In 6 wt%. The response and recovery times of the 6 wt% indiumcoated ZnO:In gas sensors were 19 s and 12 s, respectively.

파프리카 신서편이 제품화 및 품질과 저장성 향상을 위해 Active MA 조건을 비교 규명 하였다. Active MA 처리구와 진공처리, 일반 MA 포장 처리를 하였으며 생체중, 산소, 이산화탄소, 에틸렌 농도와 경도, 이취 전해질 누출량을 측정하였다. 생체중은 진공처리가 가장 큰 감소를 보였고 5 : 5 : 90(CO2:O2:N2), 가장 낮은 감소 보였으며 다른 처리에서는 처리간의 큰 차이를 보이지 않았다. 산소, 이산화 탄소, 에틸렌농도 변화는 30 : 10 : 60(CO2:O2:N2) 처리가 산소 감소율과 이산화 탄소 증가율이 가장 크게 측정되었으며 그 외 처리는 감소율과 증가율에서 특별한 특징을 나타내지는 않았다. 에틸렌 농도는 30 : 10 : 60 처리 조건이 가장 크게 측정 되었으며 MA 조건이 가장적은 농도로 측정 되었다. 경도는 진공처리 조건이 가장 낮게 측정되었으며 이취의 경우 30 : 10 : 60 처리조건과 진공 포장 처리구의 이취 발생량이 가장 많은것으로 평가 되었다. 전해질 용출량은 진공조건 처리가 70%로 가장 많았고 30 : 10 : 60 처리가 35%로 Active MA 조건에서 가장 많은 누출을 보였다. 이상의 결과로 볼 때, 진공처리와 고농도 이산화탄소 처리는 파프리카 신선편이 포장 처리에 적합하지 않으며 Active MA 처리시 10 : 70 : 20(CO2:O2:N2)와 0 : 20 : 80이 가장 적합하다고 사료된다.

We have carried out a follow-up study on the students who have participated or are going to participate in either the International Astronomy Olympiad (IAO), the Asia Pacific Astronomy Olympiad (APAO) or the International Olympiad on Astronomy and Astrophysics (IOAA) from 2002 to 2011. The survey questionnaires returned from ten high school students including five who are to participate in 2011 as well as fourteen college students have been analyzed in various aspects of their backgrounds and personal characteristics. In family life, their parents tend to have high educational background along with high expectations for their children. In regard to the academic environment, most students express a general satisfaction in school life, including their relationship with teachers and classmates. In personal characteristics, they describe themselves as inquisitive, perseverant, competitive, creative, self-motivated and goal-oriented, in addition to many other traits. Most students have a strong interest in astronomy which usually begins in middle schools through exposure to astronomy books. On top of it, the astronomy olympiad has provided them with an opportunity to strengthen their self-esteem, problem-solving ability and conviction about scientific careers. Accordingly, the experience in astronomy olympiad has led a considerable number of students to continuously studying in astronomy related fields or otherwise in other science and engineering areas. In conclusion, the astronomy olympiad plays such an important role that it can make a significant contribution to astronomy as well as science in general by having positive impact on the potential career path of its participants.

The International Olympiad on Astronomy and Astrophysics (IOAA) initiated by the Thailand Astronomical Society in 2007 is an annual competition for high school students. One of its aim is to enhance the development of international exchange in the field of school education in astronomy and astrophysics. This paper first provides the overview of the IOAA in terms of key regulations based on its statutes, history and current status. Secondly, the published syllabus of the IOAA is used for content analysis according to subject areas regarding the exam questions of the IOAA in theoretical, observational and data analysis parts from 2007 to 2010. Also, a scientific inquiry framework is applied to the same questions for assessment based on scientific inquiry in the cognitive aspect with two sub-classes of scientific knowledge and scientific reasoning. Among a dozen astronomy subject areas listed on the syllabus, the theoretical part of the IOAA makes more frequent use of the Sun, the solar system, properties of stars, and concept of time. In content knowledge, a factor of scientific knowledge, the IOAA questions, especially in the theoretical part have a lesser degree in difficulty than the IAO (International Astronomy Olympiad) exam questions for the same period whose degree in difficulty is comparable to college level. With regard to scientific reasoning, the IOAA questions tend to involve convergent rather than divergent thinking. Lastly, in light of these findings, discussions are given on the outcome of Korean participation in the previous IOAAs and ways to help better in preparing Korean students for future astronomy Olympiads.

본 연구에서는 자연분해재 펠릿과 polyethylene들을 이용해 LDPE와 신장율과 인장강도가 유사한 생붕괴성 플라스틱 필름들을 제조하였다. 식품 포장재로서의 안전성, 광분해성, 열분해성 및 곰팡이 생분해성을 평가한 결과 제작된 생붕괴성 플라스틱 필름들은 식품 포장재로 사용하기에 안전하고 LDPE 필름에 비해 상대적으로 우수한 분해 특성을 나타내어 환경친화적인 식품 포장 소재로 사용될 가능성을 보여주었다.

[ Zn2(1-x)MnxSiO4 ]0.07≤x≤0.15) green phosphor was prepared by solid state reaction. The first heating was at 900˚C-1250˚C in air for 3 hours and the second heating was at 900˚C in N2/H2(95%/5%) for 2 hours. The size effect of SiO2 in forming Zn2SiO4 was investigated. The temperature for obtaining single phase Zn2SiO4 was lowered from 1100˚C to 1000˚C by decreasing the SiO2 particle size from micro size to submicro size. The effect of the activators for the Photoluminescence (PL) intensity of Zn2SiO4:Mn2+ was also investigated. The PL intensity properties of the phosphors were investigated under vacuum ultraviolet excitation (147 nm). The emission spectrum peak was between 520 nm and 530 nm, which was involved in green emission area. MnCl2·4H2O, the activator source, was more effective in providing high emission intensity than MnCO3. The optimum conditions for the best optical properties of Zn2SiO4:Mn2+ were at x = 0.11 and 1100˚C. In these conditions, the phosphor particle shape was well dispersed spherical and its size was 200 nm.

[ WO3 ]powders were ball-milled with an alumina ball for 0-72 hours. In2O3 doped WO3 was prepared by soaking ball-milled WO3 in an InCl3 solution. The mixed powder was annealed at 700˚C for 30 min in an air atmosphere. A paste for screen-printing the thick film was prepared by mixing the WO3:In2O3 powders with α-terpinol and glycerol. In2O3 doped WO3 thick films were fabricated into a gas sensor by a screen-printing method on alumina substrates. The structural properties of the WO3:InO3 thick films were a monoclinic phase with a (002) dominant orientation. The particle size of the WO3:InO3 decreased with the ball-milling time. The sensing characteristics of the In2O3 doped WO3 were investigated by measuring the electrical resistance of each sensor in the test-box. The highest sensitivity to 5 ppm CH4 gas and 5 ppm CH3CH2CH3 gas was observed in the ball-milled WO3:InO3 gas sensors at 48 hours. The response time of WO3:In2O3 gas sensors was 7 seconds and recovery time was 9 seconds for the methane gas.

ZnS:Mn, Dy yellow phosphors for White Light Emitting Diode were synthesized by a solid state reaction methodusing ZnS, MnSO4·5H2O, S and DyCl3·6H2O powders as starting materials. The mixed powder was sintered at 1000oC for 4h in an air atmosphere. The photoluminescence of the ZnS:Mn, Dy phosphors showed spectra extending from 480 to 700nm,peaking at 580nm. The photoluminescence of 580nm in the ZnS:Mn, Dy phosphors was associated with 4T1→6A1 transitionof Mn2+ ions. The highest photoluminescence intensity of the ZnS:Mn, Dy phosphors under 450nm excitation was observedat 4mol% Dy doping. The enhanced photoluminescence intensity of the ZnS:Mn, Dy phosphors was explained by energytransfer from Dy3+ to Mn2+. The CIE coordinate of the 4 mol% Dy doped ZnS:Mn, Dy was X=0.5221, Y=0.4763. Theoptimum mixing conditions for White Light Emitting Diode was obtained at the ratio of epoxy:yellow phosphor=1:2 formCIE coordinate.

캐나다까지 장거리 수출조건은 선적 후 통관까지 20일 동안은 7±1℃와 90% 상대습도가 유지되었고, 이후 저장창고 이송전에 3시간만에 13℃까지 상승한 후 저장창고 이송후 3일간 3~4℃와 90% 상대습도를 나타내었다. 이후 상온조건의 판매소에서는 16℃에 60% 이하의 상대습도를 나타내었다. 이상의 유통조건을 기초로 7℃, 90% 상대습도에서 15일간 저장한 후 20℃, 55% 상대습도에서 7일간 저장하는 조건에서 MA저장 실험을 실시하였다. 포장방법에는 무처리와 기존의 유공포장(6mm 직경의 구멍이 18holes/m2) 그리고 레이저로 가공한 3가지 비천공 필름 (산소 투과도 5,000과 20,000 그리고 100,000cc/m2·day·atm)로 하였다. 저장 중 생체중 감소는 3가지에서는 1% 이하였으나, 유공처리과 무처리는 4% 이상으로 품질 저하가 나타났다. 상온으로 이동한 저장 15일 후 포장재내 대기조성이 5,000cc/m2·day·atm비천공필름처리는 산소 5%, 이산화탄소 15%를 나타내었고, 20,000cc/m2·day·atm 비천공필름처리는 산소 16%, 이산화탄소 4~5%를 나타내어, 이들처리에서는 이산화탄소 농도가 파프리카의 적정 범위를 상회하였다. 포장재내 에틸렌 농도는 처리간 큰차이가 없었다. 저장 중 외관상 품질은 이산화탄소 농도가 적절하게 유지되었던 100,000cc/m2·day·atm 비천공필름처리에서 가장 높게 유지되었으며, 경도와 당도는 비천공 필름간 차이에 통계적 유의성은 없었다. 이상의 결과로 보아 20일 이상의 장기 유통 중 판매가 상온에서 이루어질 경우 포장내 이산화탄소 농도가 3% 이하로 유지될 수 있는 100,000cc/m2·day·atm의 통기성을 가장 포장재가 파프리카 MAP에 적합하다고 사료된다.

ZnO nanorods for gas sensors were prepared by a hydrothermal method. The ZnO gas sensors were fabricated on alumina substrates by a screen printing method. The gas-sensing properties of the ZnO nanorods were investigated for CH4 gas. The effects of growth time on the structural and morphological properties of the ZnO nanorods were investigated by X-ray diffraction and scanning electron microscope. The XRD patterns of the nanocrystallized ZnO nanorods showed a wurtzite structure with the (002) predominant orientation. The diameter and length of the ZnO nanorods increased in proportion to the growth time. The sensitivity of the ZnO sensors to 5 ppm CH4 gas was investigated for various growth times. The ZnO sensors exhibited good sensitivity and rapid response-recovery characteristics to CH4 gas, and both traits were dependent on the growth time. The highest sensitivity of the ZnO sensors to CH4 gas was observed with the growth time of 7 h. The response and recovery times were 13 s and 6 s, respectively.