검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 40

        2.
        2024.04 구독 인증기관·개인회원 무료
        The genus Bembidion is a prominent terrestrial group found in various regions around the world, encompassing a large number of species. Species of this genus have a reduced apical palpomere, as do all members of the tribe Bembidiini. This study reviews four species belonging to the subgenus Plataphus, which is included within the genus Bembidion. Descriptions and photos of adults are provided.
        3.
        2023.11 구독 인증기관·개인회원 무료
        Alpha activities can be used for categorization, transportation, and disposal of radioactive waste generated from the operation of nuclear facilities including nuclear power plants. In order to transport and dispose of such low- and intermediate-level radioactive waste (LILW) to the Wolsong LILW Disposal Center (WLDC) at Gyeongju, the gross alpha concentration of an individual drum should be determined according to the acceptance criteria. In addition, when the gross alpha concentration exceeds 10 Bq/g, the inventory of the comprising alpha emitters in the waste is to be identified. Gross alpha measurements using a proportional counter are usually straightforward, inexpensive, and high-throughput, so they are broadly used to assay the total alpha activity for environmental, health physics, and emergency-response assessments. However, several factors are thoughtfully considered to obtain a reliable approximate for the entire alpha emitters in a sample, which include the alpha particle energy of a particular radionuclide, the radionuclide that is used as a calibration standard, the uniformity of film in a planchet, time between sample collection and sample preparation, and time between sample preparation and counting. Korea Atomic Energy Research Institute (KAERI) have evaluated the inventory of radionuclides in low-level radioactive waste drums to send every year hundreds of them to the WLDC. In this presentation, we revisit the gross alpha measurement results of the drums transported to WLDC in the past few years and compare them with the concentrations of alpha emitters measured from alpha spectrometry and gamma spectrometry. This study offers an insight into the gross alpha measurement for radioactive waste regarding calibration source, self-absorption effect, composition of alpha emitters, etc.
        5.
        2022.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The decommissioning of nuclear facilities produces various types of radiologically contaminated waste. In addition, dismantlement activities, including cutting, packing, and clean-up at the facility site, result in secondary radioactive waste such as filters, resin, plastic, and clothing. Determining of the radionuclide content of this waste is an important step for the determination of a suitable management strategy including classification and disposal. In this work, we radiochemically characterized the radionuclide activities of filters used during the decommissioning of Korea Research Reactors (KRRs) 1 and 2. The results indicate that the filter samples contained mainly 3H (500–3,600 Bq·g−1), 14C (7.5–29 Bq·g−1), 55Fe (1.1– 7.1 Bq·g−1), 59Ni (0.60–1.0 Bq·g−1), 60Co (0.74–70 Bq·g−1), 63Ni (0.60–94 Bq·g−1), 90Sr (0.25–5.0 Bq·g−1), 137Cs (0.64–8.7 Bq·g−1), and 152Eu (0.19–2.9) Bq·g−1. In addition, the gross alpha radioactivity of the samples was measured to be between 0.32–1.1 Bq·g−1. The radionuclide concentrations were below the concentration limit stated in the low- and intermediatelevel waste acceptance criteria of the Nuclear Safety and Security Commission, and used for the disposal of the KRRs waste drums to a repository site.
        4,300원
        6.
        2022.10 구독 인증기관·개인회원 무료
        Combustion method has been widely used in the analysis of 3H and 14C in various types of radioactive wastes since X. Hou reported the analysis of 3H and 14C in graphite and concrete for decommissioning of nuclear reactor. In this work, it was demonstrated that the validation result of combustion method for the simultaneous analysis of 3H and 14C in non-combustible radioactive wastes. To validate the combustion method, 3H and 14C spiked to sea sand and soil were prepared and each simulated sample was combusted with the accordance to a combustion temperature program. The validation of combustion method was assessed by the radioactivity recovery, radioactivity deviation, and relative standard deviation of measured radioactivity. The results of radioactivity recovery, radioactivity deviation, and relative standard deviation of 14C were 100~105%, less than 7%, less than 5%, respectively. In addition, 3H showed about 90% of radioactivity recovery, less than 20% of radioactivity deviation, and less than 5% of relative standard deviation. It will be provided that the validation results of combustion method in detail.
        10.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Upgraded activated carbons (ACs) are typically synthesized by mixed methods, such as solid–solid mixing and wet impregnation of low-grade ACs with KOH. This study compares the properties of upgraded ACs prepared by different methods using elemental analysis, X-ray photoelectron spectroscopy, N2 adsorption isotherms, and X-ray diffraction. In ACs produced by the solid–solid mixing, the ratio of potassium activator is proportional to the surface area and amount of gas produced. However, in wet impregnated ACs, the potassium ratio exhibits a zero or negative correlation. It is demonstrated that potassium ions in solution are not transferred to K2O and do not contribute to the surface area and pore size, generating less amount and different composition of gases. As such, impregnated ACs exhibit similar surface areas and large pores, regardless of the potassium ratio. The physical properties, such as specific surface areas and pore size distribution, of ACs using wet impregnation were similar to the ACs generated by the water physical activation. It indicated that the KOH does not efficiently act as a chemical activator in the wet impregnation method. Therefore, a certain amount and suitable mixing method of chemical activator play an important role in the property upgrade of ACs.
        4,000원
        17.
        2018.10 구독 인증기관·개인회원 무료
        상주는 귀농 도시이자 농업 중심 도시로써 농업기술원을 유치할 만큼 생태학적 연구가치가 있는 친환경 도시이다. 특히 경천섬은 낙동강 본류에 있는 상주보 인근에 위치하고 있어 낙동강 생태 환경 연구의 중요 지역 중 하나이다. 하지만, 아직 경천섬에 대한 생물다양성 연구가 부족한 상태이다. 섬과 산지의 생태환경이 다르기 때문에 생물의 다양성도 다를 것이라 간주하고, 경천섬 주변의 생태학적 가치를 재조명할 기초자료를 조사하고자 한다. 이에 경천섬과 인근에 위치한 청룡사 길목 산지에 서식하는 곤충 채집을 통해 생물다양성을 조사하여 비교분석하는 것을 목적으로 한다. 채집방법은 직접잡기, 쓸어잡기, 함정트랩, 흡충관을 이용하였으며, 함정트랩에 사용된 유인제는 소주1.8ℓ와 빙초산350㎖를 혼합하여 사용하였다. 2018년 4월~8월 중 3회 채집과정을 수행하여 목표개체수를 확보하였고, 채집된 곤충은 에탄올을 채운 conical tube에 넣어 냉동실에 보관하여 보존성을 높였다. 채집과정에서 잡은 곤충들을 건조시키고 유사종끼리 분류하고 동정하는 과정을 거쳐 다양도지수, 우점도지수, 종풍부도지수, 종균등도지수, 유사도지수를 계산할 것이다. 기존에 알려지지 않았던 경천섬 일대의 생물다양성을 세세하게 분석하는 과정을 통해 경천섬의 생태학적 가치를 드러내고, 경천섬 일대의 자연환경관리와 보존에 필요한 정보나 체계적인 관리체계를 구축할 기초자료를 제공하고자 한다.
        18.
        2016.10 구독 인증기관·개인회원 무료
        The Chrysomelid species of the genus Morphosphaera, M. japonica Hornstedt, 1788 is reported for the first time from South Korea. The genus Morphosphaera Baly, 1861, within subfamily Galerucinae, contains eighteen species, and is distributed Palearctic region. In the present study we report on the genus Morphosphaera Baly, 1861 from Korea for the first time, based on M. japonica Hornstedt, 1788. We provide the habitus photographs, illustrations of diagnostic features and a key to the genus in S. Korea.
        19.
        2016.10 구독 인증기관·개인회원 무료
        White rice with grains is a nutritious meal that richly contains fiber, vitamin and mineral, but it is difficult for elderly people to masticate some grains and beans due to its hardness. This study was aimed to find the optimal mixing ratio of rice with texture modified grains and beans by comparing rheological properties. Beans were soaked in tap water for 24 hr at 20°C, cooked under pressure (1hr at 121°C), frozen for 24 hr at -18°C, and thawed in water bath for three hr at 30°C. The samples were submerged in macerating enzyme solution, left under vacuum at 60 mmHg for 5 min to infuse the enzyme into the intercellular spaces of samples, and rapidly returned to the atmospheric pressure. The samples were removed from enzyme solution, sealed in plastic bag, placed at 70°C for 20 min for enzyme activation and inactivated at 95°C for 15 min. The grains and texture modified beans were added to white rice with different ratio, soaked for one hr in enzyme solution under warming condition at 70°C, and steamed with electric pressure cooker. Cooked meals were rapidly cooled at -18°C for one hr, placed at 20°C for another one hr, and then rheological properties were measured with texture analyzer. The hardness of texture modified rice with grains was reduced to 2.3 ~ 4.1 × 104 N/m2 and the hardness of rice with beans was reduced to 3.8 ~ 4.8 × 104 N/m2 depending on mixing ratio. The cohesiveness was reduced by 1/3 ~ 2/3 respectively, while adhesiveness was not changed significantly, compared to those of cooked rice. These results suggest that cooked rice mixed with 30 ~ 40% of grain and 6 ~ 10% of bean would be appropriate for elderly people to consume without chewing difficulty.
        20.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        미꾸라지에서의 Nitrofuran계 대사물질인3-amino-2-oxazolidone (AOZ), 5-morpholinomethyl-3-amino-2-oxazolidinone (AMOZ), 1-ammino-hydantoin (AHD)와 semicarbazide (SEM)의 잔류량을 검사하기 위해HPLC-MS/MS를 이용한 신속한 정량법이 개발되었다. 2-nitrobenzaldehyde (2-NBA)를 이용해 50℃에서 1시간 동안 산 가수분해와 유도체화 과정을 거친 뒤에, 액-액 분배로 정제와 추출을 하였다. 회수율은 음성시료에 3가지 농도 0.5, 1.0, 2.0 μg/kg의 표준액을 첨가하여 평가하였고 평균 회수율은 75.1-108.1% 이었다. 정밀성(%RSD)은 일내 8.7% 이하, 일간 8.5% 이하였다. 직선성은 NBAOZ는 0.2-20 μg/Kg, NBAMOZ는 0.8-20 μg/Kg, NBAHD는 0.2-20 μg/Kg, NBSEM 는 0.1-20 μg/Kg 범위에서 모두 상관계수 0.99이상이었다. 검출한계(LOD)는 NBAOZ 0.06 μg/Kg, NBAMOZ 0.24 μg/Kg, NBAHD 0.06 μg/Kg, NBSEM 0.03 μg/Kg이었고, 정량한계(LOQ)는 NBAOZ 0.2 μg/Kg, NBAMOZ 0.8 μg/Kg, NBAHD 0.2 μg/Kg, NBSEM 0.1 μg/Kg 이었다. 가수분해 및 유도체화 소요시간을 1시간으로 줄여 만든 신속 간편한 이 시험법이미꾸라지 중 nitrofuran metabolites잔류량 분석에 적합함을 확인할 수 있었다.
        4,000원
        1 2