검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 87

        63.
        1997.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        전자빔 용해법에 의해 고순도 티타늄잉고트 및 버튼시편을 제조하였다. 이들 중 18개의 금속불순물을 GDMS(Glow Discharge Mass Spectrometry)로 그리고 탄소, 질소, 산소의 함량을 고온연소법으로 측정한 후 이들과 전기비저항, 경도와의 관계를 조사하였다. 99%와 99.6%스폰지를 용해한 경우 대부분의금속불순물들이 대폭 감소하는 큰 휘발 정련효과가 나타났으며 비금속불순물들의 경우는 장비의 진공상태에 따라 큰 영향을 받으며 정련효과를 기대할 수 없었다. 금속 불순물중 철은 가장 제거하기 어려운 원소로 밝혀졌으며 이는 원료 스폰기중에서 철이 주불순물이기 때문이며 추가적인 예비정련이 필요한 것으로 나타났다. 상온 및 액체질소온도에서의 전기비저항은 가스불순물의 량이 증가함에 따라 직선적으로 증가하였으며 이들의 저항비(ρRT /ρN2)는 가스불순물의 총량이 1,000ppm이하의 경우 불순물량이 감소함에 따라 급격하게 저하하였으며 이 이상인 경우 완만하게 감소하였다. 이들의 경도는 가스불순물의 량이 증가하였으며 산소당량의 평방근에 비례하는 것으로 나타났다.다.
        4,000원
        65.
        1995.02 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        30KV 전자빔리소그래피 장치를 사용하여 PMMA 3000Å/P(MMA/MAA) 6000Å의 이중구조에서 foot width 0.1μm이하, head width 0.4μm의 T-gate를 형성하였다. PMMA/P(MMA/MAA)/GaAS 구조에 대한 Monte Carlo 시뮬레이션 결과, 산란반경 0.1μm에서 전방산란전자와 후방산란전자의 에너지 비는 19.5:1로 나타났다. 전자빔리소그래피 공정에 필요한 PMMA 및 P(MMA/MMA)의 열처리 조건, 설게 선폭에 대한 패턴감도를 구하였다. MIBK : IPA = 1 : 1 현상액에 대한 PMMA 및 P(MMA/MAA)의 감마값(gamma value)은 2.3이었다. 광 및 전자빔리소그래피 장치의 혼합사용(mix-and-match) 결과 층간정렬도 (alignment accuracy)는 0.1μm(3σ) 이하를 얻었다.
        4,000원
        66.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        Based on the results of the prior study, we conducted a study of the DRE (destruction and removal efficiency) and carbonization of xylene using high electron beam energies. The irradiation intensity of electron beam energy was 30 mA, and the irradiation times were 5.7, 11.4, 22.8, and 45.6 sec. The absorbed dose were 124.23, 248.46, 496.91, and 993.83 kGy. Xylene was completely removed at 248.46 kGy, and the main by-products were carbon particles. Carbon particle formation was increased with increased absorbed dos. The carbon particles were generated as fine particles with a size of 0.5 to 1.0 μm. The most common oby-products of these particle were carbon black and graphite.
        67.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        This study is to identify the effects of DRE (destruction and removal efficiency) and carbonization of Xylene when using the electron beam energy. The irradiation intensity of electron beam energy was 10 mA, 20 mA and irradiation time was 5.7, 11.4, 22.8, 45.6 sec (Absorbed dose are 41.41, 82.82, 165.64, 331.28, 662.55 kGy). The Xylene was completely removed at 331.28 kGy. Main by-products was carbon particles. Carbon particle formation was increased with irradiation intensity increasing. Most of the by-products of particle were Carbon black and Graphite.
        68.
        2016.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study investigated the effect of electron beam (EB) treatment on the microbial reduction of dried laver (Porphyra tenera) and identified EB-resistant bacteria from the treated dried laver. After EB treatments of 4 kGy and 7 kGy, the numbers of total bacteria and EB-resistant bacteria were measured using tryptic soy agar and mannitol salt agar, respectively. The morphological and biochemical characteristics of each isolated EB-resistant bacteria were investigated and these bacteria were identified. Compared to the control (1.5±0.2)×106 CFU/g, the total bacterial number was significantly decreased to (5.4±0.5)×104 CFU/g and (1.1±0.6)×104 CFU/g after EB treatments of 4 kGy and 7 kGy, respectively. With a higher EB dosage, the number of red colonies was almost same, whereas the number of yellow colonies was significantly decreased to (3.3±1.2)×103 CFU/g and 0 CFU/g for 4 kGy and 7 kGy, respectively. All red and yellow colonies were gram-positive cocci, catalase-positive, and resistant to 3% and 5% NaCl media. From the 16S rDNA sequence analysis, yellow and red colonies were identified as either Micrococcus flavus or M. luteus, with 99% similarity for the yellow colonies, and Deinococcus proteolyticus and D. piscis, with 99% and 97% similarity for the red colonies, respectively.
        69.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        집속이온빔(FIB, focused ion beam)법은 광물 및 지질시료의 분석 대상 위치로부터 투과전자현 미경(TEM, transmission electron microscope) 관찰을 위한 박편을 정밀하게 제작할 수 있는 방법으로 널리 보급되고 있다. 그러나 박편 제작과정에서 Ga 이온빔에 의한 구조 손상이나 인위적 효과들이 발 생하여 전자빔에 의한 손상과 함께 TEM 분석에서의 난점들 중 하나이다. 광물 시료 FIB 박편의 TEM 관찰에서 석영과 장석의 비정질화, 커튼 효과, Ga 오염 등이 확인되었으며, 특히 입자 경계 부근 이나 두께가 얇은 곳에서 이들 현상이 보다 뚜렷하다. 박편 제작 시의 가속전압 및 전류 조정 등의 분 석절차 개선으로 이온빔 손상을 줄일 수 있으나, 어느 정도의 손상이나 오염은 피할 수 없으므로 TEM 박편 관찰과 해석에서 유의하여야 한다.
        70.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        Volatile Organic Compounds in Urban Atmosphere are contributing largely at significant risks to human health andhave caused serious problems such as ozone formation. This study is to identify the effects of DRE (destruction andremoval efficiency) and carbonization of styrene when using the electron beam energy. The irradiation intensity of electronbeam energy was 1mA, 5mA and irradiation time were 5sec and 10sec. The styrene was completely destroyed at 5mA.Main by-products was aerosol particles. Aerosol particle formation was increased with increasing irradiation intensity.Most of the by-products of particle were carbon.
        71.
        2015.01 KCI 등재 서비스 종료(열람 제한)
        Nitrogen trifluoride (NF3) and Sulfur hexafluoride (SF6) are usually used as novel etching and cleaning gases in semiconductor industry and electrical equipments. Recently, the many studies about PFCs decomposition have been performed due to high global warming potential (GWP). This study is to identify the effects of the hydrogen on the destruction and removal efficiency (DRE) of NF3 and SF6 when using the electron-beam. The experiment was conducted at a flow rate of 10 LPM with NF3 and SF6 of 1,000 ppm. Absorbed dose (electric current) was 1,028 kGy (5 mA). The DREs of NF3 and SF6 gases increased about 54% and 68% respectively with hydrogen injection. By-products formed by NF3 and SF6 destruction were mainly HF and F2 gases. In addition, the particles were generated during the NF3 and SF6 destruction due to corrosion of reactor and SF6 decomposion, respectively.
        72.
        2014.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        식품의 방사선 조사는 식품 저장을 위한 성공적인 현대기술의 하나이지만 매우 신중하게 이루어져야 한다. 조사된 식품의 확인은 국제무역에서 소비자의 안전한 선택과 보호를 위해 가장 중요하다. 따라서 본 연구는 건조된 오징어와 문어에 전자선을 조사하여 선량별로 유도 생성되는 hydrocarbon류의 함량 및 분해패턴을 확인하였다. 비조사 시료와 선량별로 전자선 조사된 시료에서 지방을 추출한 뒤 solid phase extraction(SPE)방법을 이용하여 GC/MS로 확인하였다. 1, 3, 5, 7 및 10 kGy의 선량으로 전자선 조사된 건조 오징어와 문어에서 유도된 hydrocarbon류는 동일 선량에서 시료들의 지방산 조성에 따른 다른 생성률을 나타내었으며, 조사선량에 따라 증가하였다. 시료들에 다량 함유되어 있는 palmitic acid와 stearic acid로부터 생성된 1-tetradecene(C14:1), pentadecane(C15:0), 그리고 1-hexadecene(C16:1), heptadecane(C17:0)이 전자선 조사에 의해 유도된 주요 hydrocarbon류로 확인되었으며, 건오징어에서 hydrocarbon류 생성량이 건문어의 hydrocarbon류 생성량 보다 더 많음을 확인하였다. 이는 시료의 지방산 함유량에 따라 hydrocarbon류 생성량이 비례함을 알 수 있었다. 전자선 조사된 건오징어와 건문어에서 분석된 hydrocarbon류 중 1-tetradecene(C14:1), 1-hexadecene(C16:1) 그리고 heptadecane(C17:0)은 전자선 조사여부를 판별할 수 있는 지표로 활용될 수 있을 거라 사료된다.
        73.
        2014.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구에서는 후춧가루의 위생화를 위해 감마선, 전자선 및 X-선을 조사한 후 이에 따른 미생물학적 및 관능적 품질변화를 평가하였다. 후춧가루에 감마선, 전자선 및 X-선을 2, 4, 6, 8 및 10 kGy로 각각 조사한 후 미생물 변화와 관능품질 변화를 평가한 결과, 미생물의 경우 선종에 관계없이 흡수선량이 증가할수록 미생물 제어 효과가 증가하는 것으로 나타났으며, 선종별 D10값의 경우 2.24-2.75 kGy범위를 보였으며 방사선 선종에 따른 유의차가 없는 것으로 나타났다. 색도의 경우 명도, 적색도 및 황색도 모두 방사선 선종에 따른 변화가 없는 것으로 판단하였다. 관능적 품질 역시 방사선 선종에 관계없이 흡수선량에 따라 품질저하가 발생되는 것으로 나타났다. 이상의 결과를 종합하여 볼 때 방사선 선종에 따른 후춧가루의 품질변화 차이가 없는 것으로 판단하였으며, 이상의 결과는 X-선의 상업적 이용을 위한 기초 연구 자료로 활용될 수 있을 것으로 사료되었다.
        74.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        The decomposition of NF3 using only an electron beam, and an electron beam in the presence of hydrogen are assessedin terms of the destruction and removal efficiency (DRE, %). Experiments were conducted at a flow rate of 500LPM.The inlet concentration of NF3 in nitrogen gas was about 1,000ppm, and the concentration of hydrogen ranged from 1,500to 8,000ppm, respectively. Absorbed dose (kGy) and electric current ranged from 33.87 (5mA) to 203.21kGy (30mA).The results in this study indicate that the DRE increased about 35% with hydrogen addition at electric current 30mA.Additionally hydrogen gas played a significant role in the constituents of byproducts.
        76.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        Nitrogen trifluoride (NF3) has been used as a novel etching and cleaning gas in semiconductor industry. Recently, the many studies about NF3 decomposition have been performed due to high global warming potential (GWP : 17,000). In this study, the role of conditioning agents such as H2, O2, and H2O (water vapor) in the destruction of NF3 gas using electron-beam technology is assessed in terms of the destruction and removal efficiency (DRE, %). The inlet concentration of NF3 was 1,000 ppm and the concentration of conditioning agents ranged from 250 to 1,500 ppm respectively and electron beam current was 5 mA. From the result, the by-products of NF3 decomposition were NO, N2O, and HF.
        77.
        2013.06 KCI 등재 서비스 종료(열람 제한)
        The effect of sewage sludge irradiation and addition of starfish as a dewatering agent on the efficiency of composting was investigated using saw dust as a bulking agent. Results indicates that the temperature of EB sludge cake (electron beam irradiated sludge cake) and EB-SF sludge cake (electron beam irradiated sludge cake mixed with star fish powder) composting piles rose up to 62 ~ 66oC within 1 day and maintained high temperature of 52 ~ 55oC for more than 3 days, which was much higher than that of the control. The electron beam irradiation and addition of star fish accelerate the composting. The control sludge cake composting pile needed 35 days to reach the criteria of mature rate for composting, (Final C/N ratio)/(Initial C/N ratio) of 0.75, while EB-SF sludge cake composting plie required 11 days. This means that maturing compost could be highly improved by irradiating sludge cake or by adding star fish powder. The pH of the composting pile of sludge cake with addition of waste star fish powder rose 1 pH unit higher than that of the control during the entire operation, showing that the star fish has a good buffering capacity. The pH of the final matured compost was above pH 7, satisfying the standard of soil conditioner. The G.I. values of Chinese cabbage and lettuce with composts from EB sludge cake and EB-SF sludge cake composting pile ranged 88 ~ 99, satisfying a safety level (G.I. 80) in plant growth. After 60 days operation for composting 4 different types of sludge cakes, each compost was able to meet the Ministry of Agriculture's Standards of Compost.
        78.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        기내배양한 양란 심비디움 원괴체에 전자빔(2 MeV/n, 0.5 mA)을 10 Gy~300 Gy로 조사하여 생장 변화와 유전적 변이의 다양성을 검토하였다. 전자빔을 조사 후 배양 10주째에 선량의 증가에 따라 원괴체로부터 신초유도가 감소하였고, 200 Gy 이상의 선량을 조사한 처리구에서는 신초분화가 크게 억제되었다. 원괴체 18개체를 ISSR 분석한 결과 대조구는 12.5% 다형성을 나타내었고, 전자빔 조사구에서는 42.2%의 다형성을 나타내었다. RAPD 분석한 결과 대조구에서 13%의 다형성을 나타내었고, 전자빔 조사구에서는 43.8%의 다형성을 나타내었다. 따라서 RAPD 및 ISSR 분석 모두에서 전자빔 조사시 대조구보다 3.5배 정도 다형성이 증가한 것으로 나타났다. 유전적 유사도 지수(GSM)는 전자빔 처리가 대조구보다 낮게 나타나 전자빔 처리에 의하여 개체들 간의 유전적 다양성이 높아진 것으로 보인다. 군집분석 결과 RAPD와 ISSR 분석 모두 대조구와 전자빔 처리구가 분리되어 그룹을 이루었다. 이와 같이 전자빔 조사로 기내 배양 양란 심비디움의 유전적 다형성이 증대됨을 확인하였다.
        79.
        2013.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to evaluate the changes in the quality of rice wine (Makgeolli) treated with UV-C and electron beam (EB) irradiation during its storage at 4℃ for 15 days. The EB irradiation was found to be more effective than the UV-C irradiation for microbiological control. The pH tended to be increased by UV-C, EB irradiation, and storage period. Acidity was significantly higher in rice wine treated with EB irradiation than those of control and UV-C irradiation during storage period. The L*-value of the samples treated with UV-C and EB irradiation tended to be proportionately higher than that of the control, but this was not consistent during storage period. The a*-value of the sample treated with EB was higher than that of the others, but this was not consistent during the storage period. The reducing sugar content was higher in the control at day 0, but it rapidly decreased compared with the control during the storage. The results indicate that EB irradiation was more effective than UV-C irradiation in controlling microorganisms of rice wine. However, a further study is needed to minimize the rice wine quality deterioration caused by UV-C or EB irradiation during storage.
        80.
        2012.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The changes in the volatile organic compounds in plum after its electron beam irradiation and storage were determined using the simultaneous distillation extraction method and gas chromatograph-mass spectrometry. There were 44, 46, 45, 47, and 38 volatile compounds in the 0-, 0.25-, 0.5-, 0.75-, and 1 kGy irradiated samples, respectively. Also, the volatile flavor components of the plum that was stored for 30 days were identified as 48, 40, 40, 39, and 40 components. The compositions of the volatile compounds of the control and irradiated samples showed a similarity after the storage. Especially, the more important volatile flavor of the plum was identified as hexanal of the C6compounds, (E)-2-hexenal and (Z)-3-hexenal. In particular, hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-ol increased in all the doses, where as hexanol and (E)-2-hexen-1-ol decreased. Among the lactone compounds, γ -hexalactone, γ-octalactone, and γ-decalactone were identified during the storage period in the raw samples. Hexanonic acid and 2-hexenoic acid were not identified during the storage of the samples, and 2-methylprrole was detected only when the storage samples were irradiated at a dose higher than 0.5kGy. Therefore, it was shown that there was no effect on the variation of the volatile organic component suntil 1 kGy in the plum was irradiated with an electron beam.
        1 2 3 4 5