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        검색결과 40

        1.
        2023.11 구독 인증기관·개인회원 무료
        The design and fabrication of suitable waste forms with high thermal and structural stability are essential for the safe management and disposal of radioactive wastes. In particular, the thermal properties and temperature distribution of waste form containing high heat-generating nuclides such as Cs and Sr can be used to evaluate its thermal stability, but also provide useful information for the design of canisters, storage systems, and repositories. In this study, a new program code-based thermal analysis framework has been developed to facilitate the characterization, design, and optimization of the waste form. Matlab was used as a software development platform because it provides powerful mathematical computation and visualization components such as the partial differential equation (PDE) toolbox for solving heat transfer problems using finite element method, the App Designer for graphical user interface (GUI), and the MATLAB Compiler for sharing MATLAB programs as standalone applications and web applications. The thermal analysis results such as temperature distribution, heat flux, maximum/ minimum temperature, and centerline/surface temperature profile are visualized with graphs and tables. To evaluate the effectiveness of the developed program, several design and optimization studies were carried out for the SrTiO3 waste form, selected as a stable form of strontium nuclide.
        3.
        2022.05 구독 인증기관·개인회원 무료
        The fabrication of waste forms with high thermal and structural stability is an essential technology for the safe management and disposal of radioactive wastes. In particular, the thermal characteristics of waste forms containing high heat-generating nuclides such as Cs and Sr can be used for the optimized design of the waste form to secure its thermal safety, and they also provide basic design data for the safe management of canisters, storage systems, and repositories. The Korea Atomic Energy Research Institute is actively developing processes and equipment for fabricating various types of high-level wastes into a stable glass or ceramic waste form. In previous research related to the thermal analysis of the waste form, a relatively simple analysis was performed by using the analytic solution of the one-dimensional steady-state heat conduction equation considering the decay heat properties of the waste. As a specific application study, the optimized diameter of the cylindrical glass waste form was proposed by evaluating the centerline temperature of the waste form. In this study, we extended previous research by introducing a more complicated model, and the main results are summarized as follows. First, an analytical solution was derived by applying the temperaturedependent thermal conductivity expressed in the general form of polynomial function to the onedimensional heat conduction problem previously studied. Second, the two-dimensional axisymmetric steady-state heat conduction problem with a more realistic cylinder model with finite length was modeled and solved by using the finite element method via Matlab’s PDE (partial differential equation) toolbox. Third, thermal analysis was performed on the SrTiO3 waste form, selected as a stable form of strontium nuclide, using the developed analytical and numerical methods. The differences in the temperature distribution and computation time were evaluated through a comparative study of both solutions. Although the problem considered in this study could easily be solved by using commercial CFD software such as ANSYS or SolidWorks, a code-based program was developed to facilitate parametric design study in conjunction with optimization algorithms. The analysis results could be used to evaluate the thermal stability of waste form and to optimize the shape and size of the waste form in consideration of the design constraints of storage systems or repositories.
        7.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국립원예특작과학원에서는 2015년 거베라 신품종 ‘Red Velvet’ 을 육성하였다. ‘Red Velvet’은 2007년 10월부터 2008년 2월까지 주홍색 반겹꽃 스탠다드 거베라 ‘Rose’와 적색 반겹꽃 ‘Sabana’를 각각 모본과 부본으로 인공교배하여 얻은 187개체의 교배실생 분리집단으로부터 2008년부터 2015년까지 8년 동안의 개화 및 생육특성검정을 거쳐 선발된 절화용 스탠다드 거베라 품종이다. ‘Red Velvet’은 초세 강건한 갈색 화심의 적색(RHS R45B) 반겹꽃 대륜계통이다. 꽃의 평균 직경은 12.6±0.5cm이고, 내부설상화 및 통상화의 직경은 각각 5.7±0.3cm와 2.8±0.2cm이다. 꽃대는 꽃목직경이 상부 5.4±0.4mm, 중부 7.8±0.7mm 정도로 굵으며, 화경장은 60.0±8.1cm로 길다. 절화수명은 9.8±2.3일로 대조품종과 비슷하며, 연간 채화량은 48.3±4.8본/주로 많은 다수성 품종이다.
        4,000원
        8.
        2019.04 구독 인증기관·개인회원 무료
        해충방제용 미생물 선발을 위해 2018년도에 공원·산림·유기농 근권 토양 87지점을 수집하여 갈색거저리를 이용한 insect-bait법 및 자연조건에서의 감염사충으로부터 곤충병원성 곰팡이를 132균주 분리하였다. 분리된 균주는 점박이응 애, 복숭아혹진딧물에 대한 살충활성 스크리닝을 통하여 각 해충별 살충활성을 보이는 56균주를 선발하였다. 선발된 균주들은 rDNA의 ITS영역을 이용하여 분류동정 하였다. 추가 적용범위 확대를 위해 무잎벌(종령 유충), 거세미나방류 (3~6령 유충)와 같은 지하부 이동성 해충의 방제 가능성을 탐색하기 위해 선발 곤층병원성 곰팡이의 포자 현탁액의 관주처리 방법으로 살충활성을 검정 중이다.
        10.
        2018.10 구독 인증기관·개인회원 무료
        경기지역에 발생하는 돌발 및 남방계 해충의 발생실태 조사결과, 겨울철 경기지역 평균기온이 전년보다 3.7℃, 평년보다는 1.2℃ 낮게 경과함에 따라 포도 재배지 꽃매미 평균 월동난 부화율은 35.6%로 전년 대비 60% 감소하였음. 블루베리 재배지 갈색날개매미충의 평균 월동난 부화율은 26.9%로 전년 대비 50% 감소하였으며, 겨울철 피해가지 제거로 부화약충의 밀도는 매우 낮았음. 저온 적응성이 강한 미국선녀벌레의 경우 6월 중순 안성지역 평야 블루베리에서 약충이 가지당 최대 6.64마리 발견되었으나, 하절기 고온 등으로 성충의 밀도는 크게 감소되었음. 남방계 해충인 볼록총채벌레는 포도 재배지에서 5월 하순부터 발견되기 시작하여 7월 상순부터 급격히 증가하는 양상을 보인 가운데 지역별로는 남부지역(안성), 지대별로는 중산간지 > 산간지 > 평야지 순으로 높은 경향을 보였음.
        11.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to evaluate the effect of treating dairy cattle with exogenous human chorionic gonadotrophin (hCG), five (5) days post artificial insemination (AI) on serum progesterone (P4) concentration and pregnancy rate. In this experiment, five days after AI, cows were assigned randomly to two groups namely: a) treated group (67) which were administrered with 1500 IU hCG (Chorulon) and b) control group (61), which received no treatment. On day 5, 10, 15 and 20 after the artificial insemination, blood samples from a total of 8 cows (4 from each group) were collected and were analyzed for serum P4 concentration. Cows were detected for estrus according to standing heat by visual observation. Cows that were detected still in estrus after days 18-24 were re-inseminated and recorded as not pregnant (open). Pregnancy diagnosis was conducted by ultrasonographic examination and transrectal palpation of the uterus on approximately 60 days in cows that observed to be not in estrus. The conception rate in hCG treated and control groups were 52.5 and 36.1%, respectively. The results proved that there were no significant differences in conception rate between two groups (p=0.0568). However, pregnancy rates were reduced by hCG treatment. Average serum P4 concentrations did not differ between Hcg-treated and control groups on day 5 (0.377 versus 0.375 ng/ml). On day 20 serum P4 concentrations were greater in the treated group compared with the control group (3.085 versus 2.010 ng/ml). The treatment with hCG seemed to increase P4 level compared with the control. In conclusion, the results of this study showed that 1500 IU of hCG administered on 5 day post AI increased conception rate in dairy cows. This was supported by the results on serum P4 concentration which was greater in hCG treated group.
        4,000원
        12.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국립원예특작과학원에서 2011년 거베라 신품종 ‘Pink Melody’를 육성하였다. ‘Pink Melody’는 2007년 10월부터 2007년 12월까지 분홍색 반겹꽃 ‘Eta’와 ‘Pascal’을 교배하여 획득한 97개체의 실생계통으로부터 2008년부터 2011년까지 4년 동안의 개화 및 생육특성검정을 거쳐 선발된 절화용 대륜 거베라 품종이다. ‘Pink Melody’는 초세강건한 녹색화심의 파스텔톤 분홍색(RHS R55D) 반겹꽃 대륜계 품종이다. 꽃은 평균 직경이 11.4±0.9cm이고, 내부설상화와 화반의 직경은 각각 7.3±0.8cm와 2.6±0.5cm, 외부 설상화의 길이와 폭은 각각 5.3±0.4cm와 1.0±0.1cm로 꽃잎이 비교적 좁고 긴 도란형이다. 꽃대는 꽃목직경이 상부 4.2±0.4mm, 중부 6.4±0.8mm 정도로 강건하며, 꽃대의 길이는 45.2±5.5cm이다. 절화수명은 10.8±1.6일로 대조품종 ‘Pascal’보다 약 1.5일이 길며, 연간 채화량은 52.9±4.3본/주로 대조품종보다 5.0본/주 많은 다수성 품종이다.
        4,000원
        13.
        2018.05 구독 인증기관·개인회원 무료
        Subsurface cavities in the asphalt pavement which can cause road depression and cave-in accidents influence on the safety of pedestrians and vehicle drivers in the urban area. The existence of subsurface cavity can increase the tensile strain at the bottom of asphalt layer which is an indicator of fatigue cracking potential, and leads to the weakening of the pavement structural capacity. In this study, the finite element (FE) analysis was conducted to examine the relationship between the critical pavement responses and influencing factors, such as cavity depth and size, asphalt layer thickness, and asphalt concrete modulus. The surface deflections and tensile strains calculated from the ABAQUS FE program were compared to those from ILLIPAVE. It is found from this comparison that there are a good relationship between two analysis results. A three dimensional finite element model which is essential to simulate the hexahedral cavity were used to generate the synthetic database of critical pavement responses. To validate the developed model, the deflection data obtained from field Falling Weight Deflectometer (FWD) testing in four different locations were compared to FE deflections. It is found that the center deflections obtained from the FWD testing and FE analysis are similar to each other with an error values of 2.7, 4.4, 5.5, and 11.9 % respectively. The FE model developed in this study seems to be acceptable in simulating actual field cavity condition. On the basis of the data in the database, various analyses were conducted to estimate the effect of influencing factors on the critical pavement responses. It was found that the tensile strain at the bottom of asphalt layer is affected by all the factors but the most affected by the cavity depth and asphalt concrete modulus. Further studies are recommended to properly account for the effect of cavity’s geometry to pavement response.
        14.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to observe the fermentative quality and anthocyanin content in whole crop colored barley silage during storage periods and anthocyanin stability in in vitro ruminal fluid. Silages of colored barley cultivar “Boanchalbori” and normal barley cultivar “Yuyeonbori” were stored during 0, 2, 4, 6, and 12 months. The in vitro ruminal fluid was fermented for 0, 6, 12, 24, and 48 hrs. For the feed value, crude protein of colored barley silage was slightly increased in the silage compared to that of normal barley silage, and being increased up to 2 months after ensiling and thereafter maintained at the similar level. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of both the barley significantly increased by prolonged storage of 2 months (p<0.05), but they were maintained at the constant level after 2 months of storing silage. Whereas TDN (total digestible nutrients) contents of them were decreased by the prolonged storage of 2 months (p<0.05), then maintained at the constant levels. The fermentative quality and pH values in both the barley silages were slightly decreased during the storage time. Lactic acid and acetic acid contents were increased during prolonged storage period, but not significantly different among treatments. Butyric acid was not detected. In the colored barley silage, pH value showed slightly lower compared to that of the normal barley silage but not significant, and lactic acid content was significantly higher than the normal barley silage (p<0.05). The total anthocyanin content in the whole crop colored barley silage decreased to 42% after 2 months of ensilage, however maintained at the constant level until 12 months of ensilage. In the case of anthocyanin stability on in vitro ruminal fluid digestion, the pH value of the ruminal fluid was slightly lower at 6, 12, 24, 48h incubation time and the content of anthocyanin was at similar levels. These results indicated that the colored barley showed higher fermentation quality, and total anthocyanin content was maintained stable at 42% level of the first value in storing silage. As the anthocyanin had higher stability in the ruminal fluid, the colored barley has a potential as functional feeds for Ruminants.
        4,000원
        15.
        2010.05 구독 인증기관·개인회원 무료
        Cambodia covers an area of 181,035 sq km among them, forests cover 53 percent. As a tropical monsoon climate, average annual rainfall is about 1,400 mm(about 55 in) on the central plain and increases to as much as 3,800 mm (150 in) in the mountains and along the coast. The average annual temperature is about 27°C (about 80°F). There are many wildlife diversity in Cambodia, but regulated or unregulated logging and mining have diminished the country's wildlife rapidly. This expedition was conducted three times in 2009 (7.2-7.11, 10.16-22, 12.25-12.30). Central Cadamon Protected Forest (N 11° 41' 13" E 103° 26' 31.3") and Seima Biodiversity Conservation Area (N 12° 08' 20.8", E 106° 55' 2.7") were main area surveyed by pitfall trap, light trap and sweeping etc. As the result, totally 611 individuals of 11 families in Coleoptera was collected, among them Gonocephalumspecies of Tenebrionidae was highest number and species in Melonthidae, Chrysomelidae and Dynastidae etc., were collected, specially kind of Hydrophilidae species from wetland was surved in the expedition.
        16.
        2009.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 poly(vinyl chloride) (PVC)가지형 공중합체 전해질과 헤테로폴리산(HPA)을 이용하여 유무기 합성 전해질막을 제조하였다. poly(vinyl chloride)-g-poly(styrene sulfonic acid) (PVC-g-PSSA)는 PVC의 이차 염소의 직접적인 개시를 이용한 atom transfer radical polymerization (ATRP)로 합성하였다. 이때, HPA 나노입자는 수소 결합을 통해 PVC-g-PSSA 가지형 공중합체와 결합하는 것을 FT-IR spectroscopy를 통하여 확인하였다. 전해질막의 수소이온 전도도는 HPA의 질량 분율이 0.3이 될 때까지 상온에서 0.049에서 0.068 S/cm로 증가하였다. 이것은 HPA 나노입자 고유의 전도도와 가지형 공중합체가 가지고 있는 술폰산의 강화된 산도 때문이라고 추정된다. 합습률은 HPA의 질량 분율이 0.45까지 증가할수록 130에서 84%로 감소하였다. 이것은 HPA나노입자와 고분자 메트릭스 사이의 수소 결합의 상호작용 때문에 물을 흡수하는 site의 수가 감소한 결과라고 볼 수 있다. 열중량 분석결과 HPA의 농도가 증가할수록 전해질막의 열적 안정성이 강화된다는 것을 알 수 있었다.
        4,000원
        18.
        2006.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        우라늄 변환시설 가동 중 발생하여 라군(lagoon)에 저장중인 방사성 슬러지 폐기물에 대한 처리는 시설 해체과정에서 매우 중요한 업무 중 하나이다. 슬러지 구성성분 중 다량을 차지하는 질산암모늄의 폭발 위험성 등으로 인해 미생물을 이용한 질산염의 분해는 질산염을 안정적으로 처리할 수 있는 효과적인 방법이라 할 수 있다. 본 연구에서는 라군 슬러지의 약 60 wt%를 차지하는 질산염을 혐기성 균주의 하나인 Pseudomonas halodenidificans를 이용하여 탈질하기위한 공정 변수에 대한 영향을 평가하였다. 온도, 질산염 농도, 전자공여체의 영향, C/N 비율, 초기 접종하는 균주의 비율, pH등의 공정변수에 대하여 실험한 이번 결과는 향후 연속식 공정 설계를 위한 기초 자료로 사용될 것이다.
        4,000원
        19.
        2005.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        우라늄 변환시설의 라군 슬러지에 함유된 질산염의 안정적 처리를 위해 물 첨가 용해를 실시한 뒤, 여과 케이크의 안정화 특성에 대하여 알아보았다. 물 용해에 의해 대부분의 질산염은 고농도 질산염 용액으로 제거되었으므로, 여과 케이크의 열분해는 에서 하나의 단계로 수행하였다. Muffle furnace를 이용하여 에서 5시간동안 여과 케이크의 열분해를 실시한 결과 라군 1 슬러지에 포함된 U은 의 열분해와 함께 의 형태로 안정화 되었다. 라군 2 열분해 잔류물의 경우에는 열분해 시 생성된 CaO가 냉각과정에서 수분과 반응하여 로 전환되는 것을 TG/DTA 분석과 XRD 분석을 통해 확인할 수 있었지만, 처분장에서 대기중 노출이나 지하수의 침출 등에는 안정한 화합물로 알려져 있으므로, 특별한 첨가제의 첨가 없이 단순 열분해 후 처분이 가능할 것으로 판단된다.
        4,000원
        20.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was 23.0°C and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.
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