검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 1,231

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Landing from a step or stairs is a basic motor skill but high incidence of lateral ankle sprain has been reported during landing with inverted foot. Objects: This study aimed to investigate the effect of landing height and visual feedback on the kinematics of landing and supporting lower limbs before and after the touch down and the ground reaction force(GRF)s. Methods: Eighteen healthy females were voluntarily participated in landing from the lower (20 cm) and the higher (40 cm) steps with and without visual feedback. To minimize the time to plan the movement, the landing side was randomly announced as a starting signal. Effects of the step height, the visual feedback, or the interaction on the landing duration, the kinematic variables and the GRFs at each landing event point were analyzed. Results: With eyes blindfolded, the knee flexion and ankle dorsiflexion on landing side significantly decreased before and after the touch down. However, there was no significant effect of landing height on the anticipatory kinematics on the landing side. After the touch down, the landings from the higher step increased the knee flexion and ankle dorsiflexion on both landing and supporting sides. From the higher steps, the vertical GRF, anterior GRF, and lateral GRF increased. No interaction between step height and visual feedback was significant. Conclusion: Step height and visual feedback affected the landing limb kinematics independently. Visual feedback affected on the landing side while step height altered the supporting side prior to the touch down. After the touch down, the step height had greater influence on the lower limb kinematics and the GRFs than the visual feedback. Findings of this study can contribute to understanding of the injury mechanisms and preventing the lateral ankle sprain.
        4,200원
        2.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Using wearable passive back-support exoskeletons in workplace has attracted attention as devices that support the posture of workers, enhance their physical capabilities, and reduce physical risk factors. Objects: This study aimed to investigate the effect of a wearable passive back-support exoskeleton on the activity of the erector spinae muscles during lifting tasks at various heights. Methods: Twenty healthy adult males were selected as subjects. Electromyography (EMG) was used to assess the activity of the erector spinae muscles while performing lifting tasks at three distinct heights (30, 40, and 50 cm), with and without the application of the Wearable Passive Back Support Exoskeleton. EMG data were gathered before and after the application of the orthosis. Results: The use of the Wearable Passive Back Support Exoskeleton resulted in a significant decrease in muscle activity when lifting a 10 kg object from heights of 30 and 40 cm (p < 0.05). Additionally, there was a significant reduction in muscle activity when lifting from a height of 50 cm compared with that at lower heights (p < 0.05). Conclusion: The use of a wearable passive back-support exoskeleton led to a decrease in the activity of the erector spinae muscles during lifting tasks, irrespective of the object's height. Our results suggest that the orthosis we tested may help decrease risk of lower back injuries during lifting.
        4,000원
        3.
        2024.04 구독 인증기관·개인회원 무료
        RNAi (RNA interference, RNA 간섭)은 타겟 유전자의 mRNA 시퀀스와 상동한 이중 가닥 RNA (double-stranded RNA)에 의해 일어난다는 사실이 밝혀진 이후, 유전자의 기능을 파악하는 연구 도구로 활용되다가, 2018년에 비로소 사람의 유전자 치료제로 상용화가 되었다. 지금은 더 많은 질병들의 유전자 치료제를 만들기 위해 다양한 회사들이 임상을 진행하고 있다. 농업의 분야에서는 곤충의 ‘생존 필수 유전자’를 타겟함으로써 해충 방제제로 개발되어 서부 옥수수 뿌리벌레(Western corn rootworm)를 RNAi로 방제하기 위한 제품이 종자 형식으로 상용화 되었고, 최근에는 심각한 농약저항성을 가진 콜로라도 감자벌레(Colorado potato beetle)를 RNAi로 방제하기 위 해 ‘스프레이 방식의 뿌리는 dsRNA’가 상용화되었다. 추후에 더 많은 해충을 타겟으로 하는 제품이 개발될 예정 이다. 본 발표에서는 위에 언급한 상용화된 dsRNA 시퀀스의 환경안전성평가와 관련된 연구, off-target effect, siRNA 활용, nanoparticle 등 RNAi 기술을 보다 안전하고 유용하게 농업적으로 사용할 수 있는 방법에 대한 ‘실험 실의 역할’이 무엇인지 알아보고자 한다.
        4.
        2024.04 구독 인증기관·개인회원 무료
        The ovicidal effect of plant extract mixture (5% cinnamon extract + 10% citronella oil + 30% citrus oil + 10% derris extract + 20% neem extract + 25% penetrating surfactant) against several major insect pests was tested using the spraying method. In the case of stink bugs, eggs tended to die during hatching. When treated with a plant extract mixture (500-times solution), mortality for Halyomorpha halys, Riptortus clavatus, Eurydema dominulus, Trialeurodes vaprarorium, Bemisia tabaci, Spodoptera exigua, and Agrotis ipsilon reached as high as 100%. Therefore, it is believed that industrialization will be feasible in the future.
        5.
        2024.04 구독 인증기관·개인회원 무료
        To control western flower thrips (Frankliniella occidentalis), a significant pest of peppers, the control effects of eco-friendly agricultural materials were tested when treated alone and in combination. The control effects of yellow sticky roll traps installed on the stem, predatory natural enemy (Hypoaspis miles) inoculated on the stem, and plant extracts (50% custard apple seed oil + 10% cinnamon extract) sprayed on the foliage were 45.3%, 36.6%, and 50.2%, respectively, when treated individually. Meanwhile, when three eco-friendly agricultural materials were comprehensively applied, the control effect was maintained between 62.4% and 80.9% compared to untreated conditions during the pepper harvesting season. These methods can be utilized for the eco-friendly control of western flower thrips in pepper greenhouses.
        6.
        2024.04 구독 인증기관·개인회원 무료
        최근 이상기후 및 기후변화로 인해 농작물 병해충 발생이 증가하고 발생양상 또한 다양해지고 있으며, 국제 무역 및 해외 여행객 증가로 인한 외래 병해충 유입 위험성이 높아지고 있는 추세이다. 특히 대표적인 비래해충 중의 하나인 벼멸구(Nilaparvata lugens Stål, 1854)의 발생 범위, 출현율 및 빈도수가 꾸준히 증가하여 피해를 호소 하는 농가들이 많아진 반면, 이들에 대한 대응책은 피해발생의 불규칙성, 이전 자료의 부족 및 불명확성으로 인해 미비한 실정이다. 본 연구에서는 이러한 문제를 대비해 벼멸구의 온도발육모형을 이용하여, 기상자료, NCPMS와 더불어 연발생 횟수와 분포 가능 범위 및 발생 시기를 예측하였다. 또한, 벼멸구의 발생량이 많았던 충남 예산, 경남 사천, 진주의 최초발생일, 최초비래일, 최고발생일, 발생최성일 기준으로 각각 발육영점온도 및 유효적산온도를 적용하여 세대별 발생시기를 예측하였다. 최초발생일과 최초비래일은 예산 7월 9일, 7월 16일, 사천 7월 2일, 7월 19일, 진주 7월 26일, 7월 26일로 나타났으며, 최초발생일과 최초비래일 사이를 초발생일 로 적용하면 다음세대 발생이 실제 조사한 지역별 최고발생일인 예산 9월 7일, 사천 8월 9일, 진주 8월 8일과 근접 한 시기로 추정되어 효과적임을 알 수 있었다.
        7.
        2024.04 구독 인증기관·개인회원 무료
        차세대 염기서열 분석(Next Generation Sequencing, NGS)은 대량의 병렬 데이터 생산으로 유전체의 염기서열 을 고속으로 분석하는 기술이며, 이 기술은 바이러스 유전체 분석에도 광범위하게 사용되고 있다. 하지만, 바이 러스의 전장 유전체가 100kb를 넘을 경우, 동일한 raw data라도 분석 방법 및 소프트웨어 그리고 매개변수 (parameter)에 따라 유전체의 크기와 구조가 다르게 결정된다. 따라서 유전체가 큰 바이러스 분석 시, 최적화된 NGS 분석 방법을 선택하는 것이 중요하다. 본 연구는 장수풍뎅이 누디바이러스(Oryctes rhinocerous nudivirus, 120kb) 유전체를 기반으로, 다양한 Assembly 소프트웨어(metaviralSPAdes, metaSPAdes, velvet, shovill, Geneious, megahit)를 사용하여, 최적화된 NGS 분석 방법을 고안하였다. Assembly 소프트웨어에 따라 바이러스 유전체 크기와 특징(Single Nucleotide Polymorphism, Insertion&Deletion, repetitive genomic variants)의 차이를 확인하였 다. Assembly 소프트웨어 간의 차이가 있는 염기서열은 Sanger sequencing을 통해 재확인하여, 참조 유전체 (reference sequence)를 구축하였다. 이 참조 유전체를 기반으로 가장 정확한 Assembly 소프트웨어와 parameter를 평가하였다. 본 연구는 분석 방법에 따라 달라지는 유전체의 특성을 이해하고, 바이러스 유전체를 정확하게 구축 하는 분석 파이프라인을 제공할 것으로 기대된다.
        8.
        2024.04 구독 인증기관·개인회원 무료
        쌍별귀뚜라미는 국내에서 식용 및 파충류의 먹이로 사용되는 중요한 산업곤충으로 알려져있다. 2023년 국내 쌍별귀뚜라미 농가에서 쌍별귀뚜라미 덴소바이러스 감염이 확인되었으며 바이러스 억제제가 요구되는 실정 이다. RNA 간섭(RNAi)은 dsRNA를 이용해 목적 유전자의 발현을 억제할 수 있는 작용기작을 가지며, 바이러스 특이적 시퀀스를 이용한다면 효과적으로 타겟 바이러스의 증식을 저해할 수 있다. 본 연구에서는 덴소바이러스 에 감염된 귀뚜라미에 덴소바이러스 특이적 dsRNA를 제작하여 주입(injection)하고, 바이러스 발현 저해 효과를 관찰했다. 바이러스 감염 수준은 qPCR로 평가하였으며 dsRNA를 접종한 결과 체내 바이러스양이 감소함을 확인 했다. 이 연구는 향후 RNAi를 이용한 쌍별귀뚜라미 덴소바이러스 억제제 개발에 도움이 될 것으로 기대된다.
        9.
        2024.04 구독 인증기관·개인회원 무료
        한국 귀뚜라미 산업은 최근 큰 성장을 보였으며, 수직농장을 이용한 대량생산과 기술발전으로 사육수와 판매 량이 늘어나는 추세다. 그러나 귀뚜라미 사육시스템은 농가 간의 교류 및 밀집 사육으로 인해 곤충병원체에 의한 전염병에 매우 취약한 구조를 가진다. 사육 곤충의 질병을 이해하는 것이 중요함에도 곤충병원성 미생물에 대한 연구가 부족한 실정이다. 본 연구는 국내 쌍별귀뚜라미 농가에서 발견된 볼보바이러스를 식별하였으며, Gryllus bimaculatus volvovirus (GbVVV-KR)의 게놈 특성을 분석하였다. GbVVV-KR의 전체 게놈 서열은 Sanger 시퀀싱 을 통해 얻어졌으며, 게놈 크기가 2,515개 뉴클레오티드인 원형 단일가닥 DNA 바이러스임을 밝혔다. 단일 핵산 염기 다형현상 분석(Single nucleotide polymorphism, SNP)으로 정지코돈 돌연변이로 인한 ORF3 영역이 다른 귀뚜 라미 volvovirus 들에 비해 큰 변화를 확인하였다. 또한, 전국 11개 농장에서 수집한 귀뚜라미를 대상으로 PCR/qPCR을 실시하여 GbVVV-KR의 감염 정도를 확인하였다. 이러한 결과는 GbVVV-KR의 게놈 구조와 유전 적 특성, 계통발생 및 유병률에 대한 귀중한 통찰력을 제공하고 귀뚜라미 바이러스에 대한 이해를 도울 것으로 기대한다.
        10.
        2024.04 구독 인증기관·개인회원 무료
        귀뚜라미는 단백질 함량이 높고 필수아미노산이 풍부하여 세계적으로 식용과 사료용 곤충으로서 가치가 높 다. 국내에서 쌍별귀뚜라미(Gryllus bimaculatus)는 사육이 용이하다는 장점이 있고 주로 파충류, 물고기 등의 사료로 대량 소비되고 있기 때문에 매우 중요한 산업곤충으로 자리매김하고 있다. 그러나 최근 쌍별귀뚜라미의 활동성이 저하되고 다리가 마비되는 등 이상 증상이 발생하여 대량 폐사된 농가가 급증하였다. 이에 대한 원인을 규명하기 위해 질병 발생 농가로부터 귀뚜라미 시료를 수집하여 RNA를 추출하고 metatranscriptomic analysis 를 수행하였다. 그 결과, 신규한 덴소바이러스(Densovirus)가 대량 폐사의 원인임을 밝혀내었고, 이 바이러스를 Gryllus bimaculatus densovirus (GbDV)로 명명하였다. 또한, GbDV의 유전체 분석 결과, genome size는 5,643 bp로 5개의 ORFs(Open Reading Frames)을 포함하며, 왼쪽에는 세 개의 Non-structural proteins을 포함하는 유전자(NS1, NS2, NS3)가 존재했고 오른쪽에는 두 개의 Structural proteins을 포함하는 유전자(VP1, VP2)가 존재했다. 본 연구 는 알 수 없는 곤충 질병의 원인을 밝혀내어 해당 질병에 대한 모니터링을 가능케 함으로써 산업곤충 질병의 예찰하고 확산을 방지하는 데 기여할 것으로 사료된다.
        11.
        2024.04 구독 인증기관·개인회원 무료
        전 세계적으로 RNA 간섭(RNA interference, RNAi)을 활용한 해충방제제 연구가 활발히 진행되고 있다. 대표적 으로 Monsanto의 서부 옥수수 뿌리벌레(Diabrotica virgifera virgifera) 특이적 방제용 dsRNA (DvSNF7)를 발현하 는 옥수수 종자가 상용화 되었고, 2016년 이 종자가 국내 사료 및 식품용으로 수입이 승인 되었다. 본 연구는 국내 에 서식하는 좁은가슴잎벌레(Phaedon brassicae)를 Non-target 곤충으로 사용하여, 옥수수 종자에 사용된 DvSNF7 dsRNA의 잠재적 위해성을 평가했다. P. brassicae의 SNF7 유전자와 DvSNF7 dsRNA 간 Sequence유사성 을 확인했다. 다음으로 P. brassicae가 DvSNF7 dsRNA를 섭식할 수 있는 환경을 조성하여, 치사 효과 실험과 Sequence특이적인 Knockdown효과를 확인하였다. 그 결과, DvSNF7 dsRNA는 P. brassicae생존에 영향을 미치지 않았으며, P. brassicae의 SNF7유전자를 Knockdown시키지 않음을 확인했다. 이번 연구를 통해 D. virgifera virgifera와 같은 과인 P. brassicae 는 SNF7유전자 간 Sequence유사성이 있지만, Sequence특이성이 부족하여 생존과 유전자 발현에 영향을 주지 않음으로써 위해성이 낮음을 확인했다.
        12.
        2024.04 구독 인증기관·개인회원 무료
        Scrub typhus is a zoonotic bacterial disease caused by Orientia tsutsugamushi (Rickettsiales: Rickettsiaceae) and trombiculid mite larvae, also known as chigger, are known vector. Until recently, O. tsutsugamushi is the only species of the genus. However, two new species Candidatus O. chuto and Candidatus O. chiloensis that causes scrub typhus were reported recently in the Middle East, southern Chile, and Africa. In addition, Orientia spp. bacteria detected from field collected free-living Eutrombicula chigger mites in the United States. Despite these trends, research on new species is insufficient in the Republic of Korea. Therefore, we focused on finding the presence of novel species or strains from chiggers. Specimen chiggers harvested from rodents collected in 16 regions in October 2022 collaborating with the Regional Center for Vector Surveillance against Climate Change were selected. A total of 1,249 specimen belonging 4 genera and 14 species were identified by using a fluorescence microscope and 266 pools were produced by pooling up to 10 individuals per species chiggers. To detect Orientia spp., we screened by using a real-time PCR targeting the 16S rRNA gene. Overall minimum infection rate was 0.56% (7 pools/1,249 tested specimen). After screening, conventional nested-PCR for targeting 47-kDa htrA gene was conducted to obtain sequences, and four of the positive pools were amplified. Through phylogenetic analysis, three pools were clustered with O. tsutsugamushi Gilliam and UT221 strain, and the other pool was formed a clade that was distinct from O. tsutsugamushi. These results suggest that novel species of Orientia may exist in the Republic of Korea.
        13.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The morphological features of germling cells were examined to identify an unspecified resting cyst (described as Cochlodinium cf. polykrikoides-like resting cyst) in the Korean coastal area. LSU rRNA gene sequences were also obtained from a strain established from the germling cells. The resting cysts isolated from Korean coastal sediment were characterized as being brown in color, having a large dark-red body, and fibrous lobed ornaments. The germling cells were ellipsoidal with an irregular outline and had an open comma-shaped ASC (apical structure complex), a wide and deep cingulum, and a deep sulcus. These morphological features were consistent with those of previously described harmful dinoflagellate Pseudocochlodinium profundisulcus. The molecular phylogeny revealed that the germling cells and P. profundisulcus were conspecific. Based on these morphological and phylogenetic data, this study documents the occurrence of P. profundisulcus in a Korean coastal area for the first time.
        4,000원
        14.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자생 부추속 식물 중 강부추(Allium thunbergii for. rheophytum ined.)와 갯부추(A. pseudojaponicum Makino)는 관상용, 식 용 및 약용자원으로 가치가 있으나 육묘를 위한 생육환경조건 구명이 미비하여 연구할 필요성이 있다. 본 연구는 강부추와 갯부추의 육묘에 미치는 플러그 셀 크기, 차광률, 시비처리에 따른 영향을 구명하기 위하여 실험을 수행하였다. 강부추와 갯부추를 육묘한 결과, 플러그 셀 크기에서는 50, 72, 105, 128, 162, 200셀 처리 중 용적이 가장 큰 50셀에서 초장, 엽 수, 근수, 그리고 근장의 생육이 우수하였다. 그러나 생산비용 과 플러그 육묘의 효율성을 고려하여 105셀 이상의 플러그 트레이 중에서 선택하여 육묘하는 것이 효과적이라 판단된다. 차광률에 따른 유묘는 0, 30, 60, 90% 처리 중 30~60% 차 광처리에서 초장, 근수, 그리고 근장이 유의적으로 높게 측정 되어 생육이 양호하였다. 시비처리에서 생중량과 건중량을 제 외한 생육지표를 검토했을 때, 강부추의 적정 시비처리는 속 효성 고형비료(DO-PRO) 0.1g, 갯부추는 속효성 액체비료 (Peters) 주 1회 8mL 엽면시비처리였고 두 종 모두 속효성 시비처리가 효과적이었다. 강부추와 갯부추의 초기 생육에는 30~60% 차광처리가 된 재배플롯에서 원예상토가 충진된 128셀 플러그 트레이에 종자를 파종한후, DO-PRO 0.1g 또 는 Peters 8mL를 주 1회 엽면시비하면서 재배하는 것이 효 과적이라 판단된다.
        4,000원
        15.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents factors to consider when designing DeFi regulations. DeFi regulations may be established by imposing obligations on developers and operators, who exist even in extreme decentralization cases. However, the requirements in current financial legislation, which heavily rely on intermediaries’ organization and personnel, are difficult to apply to DeFi. Instead, under DeFi, information can be obtained, analyzed, and aggregated on the blockchain and reported to the authority automatically and regulatory requirements may be reflected in the smart contract and automatically executed. This may require mandatory code audits by supervisory authorities and civil technology experts prior to execution, to check whether legal requirements are embedded in the code. In addition, measures addressing the risk-contagion effects in macroeconomic crisis, potentially arising from DeFi’s connectivity with traditional finance, must be considered.
        5,200원
        16.
        2023.11 구독 인증기관·개인회원 무료
        When decommissioning of nuclear facilities happens, large amounts of radioactive wastes are released. Because costs of nuclear decommissioning are enormous, effective and economical decontamination technologies are needed to remove radioactive wastes. During NPP operation, corrosion product called Chalk River Unidentified Deposits (CRUD) is generated. CRUD is an accumulation of substances and corrosion products consisting of dissolved ions or solid particles such as Ni, Fe, and Co on the surface of the NPP fuel rod coating. CRUD is slowly eroded by the circulation of hot pressurized water and later deposits on the fuel rod cladding or external housing, thereby reducing heat production by the nuclear fuel. Decontamination of radiologically contaminated metals must be performed before disposal, and several methods for decontaminating CRUD are being studied in many countries. Decontamination technology is an alternative to reducing human body covering and reducing radioactive waste disposal costs, and much research and development has been conducted to date. Currently, the importance of decontamination is emerging as the amount of waste stored in radioactive waste storage is close to saturation, and the amount of radioactive waste generated must be minimized through active decontamination. In this study, a preliminary study was conducted on the removal of CRUD by multiple membrane in an electro-kinetic process using an electrochemicalbased decontamination method. Preliminary research to develop a technology to electrochemically remove CRUD by using a self-produced electrochemical cell to check the pH change over time of the CRUD cell according to voltage, electrolyte, membrane and pH change.
        17.
        2023.11 구독 인증기관·개인회원 무료
        During the operation of a nuclear power plant (NPP), corrosion products called CRUD (Chalk River unidentified deposit) accumulate on the surface of the primary system. The CRUD components of pressurized light water reactors or heavy water reactors, represented by (NixFe1-x)(FeyCr1-y)2O4, are composed of Fe3O4, NiFe2O4, FeCr2O4, NiCr2O4, etc. Radionuclide such as Co-60 are deposited within this CRUD, so the entire deposited material must be dissolved and removed for decontamination. Chemical decontamination has the advantage of being able to decontaminate a wide metal surface, but has the disadvantage of generating a large amount of secondary waste. Recently, chemical decontamination methods that add an electrodynamic process are being studied to overcome these shortcomings. This technology is a method of dissolving CRUD by applying an electric field in the anodic compartment of a cell separated by CEM. It is a method of accelerating CRUD dissolution by generating a large amount of hydrogen ions in the anodic compartment. Dissolved metal ions pass through the CEM (cation exchange membrane) and move to the cathodic compartment (pH > 12), where they are removed by adsorption or precipitation process. Therefore, the speciation characteristics between decontamination agent (oxalic acid) and metal ions are very important. In this study, we investigated the speciation characteristics of Fe(II), Ni(II), Co(II) - oxalate, which are important complex species in CRUD dissolution cells. The thermodynamic equilibrium constant for hydrolysis of each ion and of M(II)-oxalate were collected and speciation characteristics were analyzed using the MINEQL 5.0 program. From the speciation characteristics of M(II)-oxalate, effective radionuclide removal methods in an electrodynamic cell were considered.
        18.
        2023.11 구독 인증기관·개인회원 무료
        General phases in the plan and implementation of an environmental remediation of radioactively contaminated sites are planning for remediation, site characterization, remediation criteria, remediation strategy, implementing remediation actions, and conducting post-remediation activities. Environmental remediation should commence with a planning stage. It is helpful to prepare reports which detail all the supporting activities related to these elements before significant levels of funds and efforts are committed. Site characterization is needed to provide sufficient data to make strategic decisions on the environmental remediation activities. The source characterization should include both waste characterization and facility or site characterization and should provide reliable estimates of the release rates of radioactive constituents as well as constituent distribution. During the preliminary site characterization, an engineering study should be conducted to develop remediation options which address the specific contaminant problem and are aimed to reduce radiological and chemical exposure. Options will include engineering approaches and associated technologies. A preliminary selection of options may be made based on several factors including future sites use, technical considerations, public acceptability, cost, and regulatory requirements. The implementation of remediation actions includes procurement of the selected technology, preparation of the site, development of a health and safety plan, development of operations procedures, staff selection and training, completion of site cleanup, verification, waste disposal, and release of the site for any future use. Once remediation activities have been completed and verified, the remediated site can be released for restricted or unrestricted use. Remediation of radioactively contaminated sites may require special adaptation to address sites covering very large surface areas or those which are deep and difficult to access. Quality assurance may be very important to the verification of environmental remediation activities. The selection of optimal remediation technologies to solve or mitigate the safety of an environmental contamination problem should be taken into account several factors. The several factors include performance (the ability of the technology to reduce risk to the health and safety of the public and to the environment), reliability and maintenance requirements for the technology, costs of implementing the technology, infrastructure available to support the technology, availability(the ease of accessing the technology and associated services), risk to workers and public safety, environmental impacts of the technology, ability of the technology to meet regulatory acceptance, and communication of stakeholder.
        19.
        2023.11 구독 인증기관·개인회원 무료
        Wet solid wastes including spent ion exchange resins, evaporator concentrates and sludges require solidification to transform wastes into an acceptable solid, monolithic form for final disposal. The development of the process control program for the solidification of radioactive sludges generated at nuclear power plants has been in progress to provide reasonable assurance that the solidified product will meet the established waste acceptance criteria for solidified waste. A mobile solidification system to produce the solidified waste in the size of a 200 L drum was used, which adopts the in-line mixing method where the waste and binder are mixed and then transferred to the disposable container. To simulate radioactive sludges, non-radioactive sludges are synthesized and the specimens are prepared by using them. The qualification tests on the prepared specimens including the compressive strength test, the thermal cycling test, the irradiation test, the leach test, the immersion test, etc. have been performed to qualify recipes for a range of waste compositions. The results of the tests will be analyzed and discussed.
        20.
        2023.11 구독 인증기관·개인회원 무료
        Structural stability of a waste form can be provided by the waste form itself (steel components, etc.), by processing the waste to a stable form (solidification, etc.), or by emplacing the waste in a container or structure that provides stability (HICs or engineered structure, etc.). The waste or container should be resistant to degradation caused by radiation effects. In accordance with the requirements for the domestic waste acceptance criteria, irradiation testing of solidified waste forms containing spent resin should be conducted on specimens exposed to a dose of 1.0E+6 Gy and other material 1.0E+7 Gy. Expected cumulative dose over 300 years is about 1.770E+6 Gy for spent resin and 0.770E+6 Gy for dried concentrated waste generated from NPPs generally. According to NRC Waste Form Technical Position, to ensure that spent resins will not undergo adverse degradation effects from radiation, resins should not be generated having loadings that will produce greater than 1E+6 Gy total accumulated dose. If it necessary to load resins higher than 1E+6 Gy, it should be demonstrated that the resin will not undergo radiation degradation at the proposed higher loading. This is the recommended maximum activity level for organic resins based on evidence that while a measurable amount of damage to the resin will occur at 1E+6 Gy, the amount of damage will have negligible effect on disposal site safety. Cementitious materials are not affected by gamma radiation to in excess of 1E+6 Gy. Therefore, for cement-stabilized waste forms, irradiation qualification testing need not be conducted unless the waste forms contain spent resins or other organic media or the expected cumulative dose on waste forms containing other materials is greater than 1E+7 Gy. Testing should be performed on specimens exposed to IE+6 Gy or the expected maximum dose greater than 1E+6 Gy for waste forms that contain ion exchange resins or other organic media or the expected maximum dose greater than 1E+7 Gy for other waste forms. This is suggestion as a review result that requirement for irradiation testing of solidified waste forms has something to be revise in detail and definitively.
        1 2 3 4 5