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        검색결과 45

        1.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내 절화류 표준규격은 장미, 카네이션, 국화 등 17개 품 목에 대하여 고시되어 있으나 이에 대한 생산자들의 인지도 및 활용도가 낮을 뿐만 아니라, 공영도매시장별 품질등급의 결정기준이 서로 달라 표준규격 운영의 실효성도 낮은 수준이 다. 이에 본 연구에서는 국내 도매시장의 화훼류 출하 실태를 조사하고 국내 시장 환경에 적합한 절화류 표준규격 개선 방 안을 모색하고자 하였다. 지난 10년간 국내 공영도매시장에서 거래된 절화류 품목의 수는 평균 228개 품목으로 꾸준히 증 가하는 추세이며, 주요 거래품목의 종류도 해마다 변화되고 있어 현재 절화류 표준규격에 고시된 품목만으로는 빠르게 변 화하는 화훼 시장에 대응하는데 한계가 있다. 2022년 기준 20대 절화류 가운데 라넌큘러스와 루스커스를 포함한 7개 품 목의 표준규격이 고시되어 있지 않다. 따라서 주요 거래품목 들을 대상으로 표준규격 고시 품목의 확대가 필요하며 품목별 표준규격 이외에 절화류 전체에 공통적으로 적용 가능한 절화 (공통) 표준규격 제정이 필요하다. 또한 현행 화훼류 표준규격 에서 품질평가 지표가 주관적 기준에 따라 평가될 수 있는 항 목들로 구성됨에 따라 aT화훼공판장에 상장된 절화의 68.1% 가 ‘특’으로 거래되는 등 실제 품질보다 높게 평가되고 있다. 이에 절화의 무게나 줄기의 굵기 등 절화의 내적 품질을 객관 적으로 평가할 수 있는 지표를 도입하고 개화정도나 결점 등 외적 품질을 판단할 수 있는 등급도감의 도입도 필요하다. 크 기구분 역시 aT화훼공판장에 상장된 절화의 18.5%만이 ‘1급’ 으로 출하되는 등 국내 생산환경에 적합한 수준으로 설정되어 있지 못할 뿐만 아니라, 온라인 유통 확대 등 절화 유통환경의 변화에 맞춰 실제 특성값을 표기할 수 있도록 표시방법을 변 경하고 절화의 길이 이외에도 꽃의 크기, 꽃 수 등 다양한 항 목의 정보를 제공할 수 있도록 개선할 필요가 있다.
        4,000원
        3.
        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
        5.
        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
        11.
        2018.10 구독 인증기관·개인회원 무료
        수출입 묘목류에 있어서 깍지벌레류는 주요한 해충으로 다양한 묘목류에서 검출되고 있다. 깍지벌레류 중 우리나라의 소나무에 피해를 주고 있는 소나무굴깍지벌레는 연 2회 발생하는 해충으로 1세대는 4월, 2세대는 8월에 발생하여 소나무 잎에 피해를 준다. 따라서 본 연구에서는 수출입 묘목류에서 검출되는 깍지벌레류의 소독효과에 대한 정보를 제공하기 위하여 포스핀과 에틸포메이트 그리고 메틸브로마이드를 이용하여 소나무굴깍지벌레를 대상으로 훈증효과를 검정하였다. 포스핀을 소나무굴깍지벌레 알을 대상으로 0.06 mg/L 이상 처리시 난부화억제율은 100%였으며, 에틸포메이트 처리의 경우 성충은 2.6 mg/L, 알은 7.4 mg/L에서 100% 살충활성을 보였다. 그리고 메틸브로마이드를 40 g/㎥으로 2시간 훈증처리시 소나무굴깍지벌레 성충은 100% 치사하였으며, 알의 경우 26.0 mg/L을 처리했을 때 100%부화억제 효과를 보였다.
        13.
        2016.04 구독 인증기관·개인회원 무료
        Oxalic acid has a nematicidal activity against the root-knot nematode Meloidogyne incognita. High producer of oxalic acid was isolated, and then named as Aspergillus niger F22. Oxalic acid production was investigated under various temperatures from 20 – 33oC and rotational speeds in 5 L jar fermenters. Yield of oxalic acid increased with decreasing temperature. The highest yield was obtained at 23oC, showing the yield of oxalic acid of 8.7 g/L, whereas oxalic acid production was least at 33oC. At 20oC, the yield was lower than that of 23oC. At a rotational speed of 300 rpm, serious oxygen depletion was present from 48 - 72 h, resulting in low productivity of 26.2 mg /L·h. When a rotational speed was set at 600 rpm, dissolved oxygen tension was over 40% and oxalic acid production increased up to approximately 55%. Viscosity during the culture differed with temperatures. Viscosity increased with the increment of temperatures. When A. niger F22 was cultured at 23oC, viscosity was 810 cP, which was favorable for oxalic acid production.
        14.
        2013.05 구독 인증기관 무료, 개인회원 유료
        This paper is a case study of reliability assessment with field warranty data of Clutch Master Cylinder(CMC) in hydraulic clutch system. We estimate lifetime distribution using field warranty data which contain much useful information for understanding reliability of the system in the real-world environments. However, the estimated parameters are far from existing reference values, which seems to be caused right censored field warranty data. To modify the parameters, we use the information of the durability test which is performed to verify that the lifetime of the item meets the required level. After that, we can observe that the modified parameters are closer to the existing reference values. This case study shows a possible idea to supplement lack of right censored field warranty data and its applicability
        4,000원
        15.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Recent studies indicate that reactive oxygen species (ROS) can act as modulators of neuronal activity, and are critically involved in persistent pain primarily through spinal mechanisms. In this study, we investigated the effects of NaOCl, a ROS donor, on neuronal excitability and the intracellular calcium concentration ([Ca2+]i) in spinal substantia gelatinosa (SG) neurons. In current clamp conditions, the application of NaOCl caused a membrane depolarization, which was inhibited by pretreatment with phenyl-N-tert-buthylnitrone (PBN), a ROS scavenger. The NaOCl-induced depolarization was not blocked however by pretreatment with dithiothreitol, a sulfhydrylreducing agent. Confocal scanning laser microscopy was used to confirm whether NaOCl increases the intracellular ROS level. ROS-induced fluorescence intensity was found to be increased during perfusion of NaOCl after the loading of 2′,7′-dichlorofluorescin diacetate (H2DCF-DA). NaOCl-induced depolarization was not blocked by pretreatment with external Ca2+ free solution or by the addition of nifedifine. However, when slices were pretreated with the Ca2+ ATPase inhibitor thapsigargin, NaOCl failed to induce membrane depolarization. In a calcium imaging technique using the Ca2+-sensitive fluorescence dye fura-2, the [Ca2+]i was found to be increased by NaOCl. These results indicate that NaOCl activates the excitability of SG neurons via the modulation of the intracellular calcium concentration, and suggest that ROS induces nociception through a central sensitization.
        4,000원
        18.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Recent studies indicate that reactive oxygen species (ROS) are critically involved in persistent pain primarily through spinal mechanisms, and that mitochondria are the main source of ROS in the spinal dorsal horn. To investigate whether mitochondrial ROS can induce changes in mem¬brane excitability on spinal substantia gelatonosa (SG) neurons, we examined the effects of mitochondrial electron transport complex (ETC) substrates and inhibitors on the membrane potential of SG neurons in spinal slices. Application of ETC inhibitors, rotenone or antimycin A, resulted in a slowly developing and slight membrane depolarization in SG neurons. Also, application of both malate, a complex I substrate, and succinate, a complex II substrate, caused reversible membrane depolarization and enhanced firing activity. Changes in membrane potential after malate exposure were more prominent than succinate exposure. When slices were pretreated with ROS scavengers such as phenyl-N-tert-buthylnitrone (PBN), catalase and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), malate-induced depolarization was significantly decreased. Intracellular calcium above 100 µM increased malate-induced depolarization, witch was suppressed by cyclosporin A, a mitochondrial permeability transition (MPT) inhibitor. These results suggest that enhanced production of spinal mitochondrial ROS can induce nociception through central sensitization.
        4,000원
        20.
        2006.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        연구로 2호기 해체과정에서 발생한 방사화된 수조 콘크리트 내의 깊이에 따른 및 의 방사능 분포를 고온연소로와 액체섬광계수기를 이용하여 분석하였다. 또한 향후 연구로 2호기 해체과정에서 발생된 콘크리트폐기물의 핵종재고량 평가에 활용하기 위하여 및 측정결과와 감마방출핵종과의 상관관계를 도출하였다. 및 의 검출하한값은 0.048 및 0.028 Bq/g이다. 연구로 2호기 수조 콘크리트 내의 및 의 깊이별 방사능 분포는 콘크리트 표면으로부터 멀어질수록 지수적으로 감소하는 경향을 보여주었다. 또한, 및 의 비방사능은 콘크리트에 존재하는 의 비방사능과 좋은 상관관계를 나타내었다.
        4,000원
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