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        검색결과 1,259

        23.
        2023.11 구독 인증기관·개인회원 무료
        High-temperature molten salts not only demonstrate exceptional thermal and chemical stability but also offer significant advantages in catalyzing chemical reactions. Consequently, they have garnered attention as a promising medium for next-generation nuclear reactors and a wide range of electrochemical processes. Nevertheless, the challenging experimental conditions in molten salts make applying conventional analytical methods to understand reaction mechanisms a formidable task. This underscores the imperative need for more intuitive approaches to investigate molten salt chemistry. One of the simplest yet potent methods involves real-time visual monitoring of the reaction system as chemical reactions progress. In light of this, we have developed an experimental system enabling real-time visual monitoring of the internal dynamics of molten salt media. This system can capture high-resolution videos and images within molten salts, surpassing existing methodologies. We have applied this system in various electrochemical experiments using the molten LiCl-KCl eutectic salt medium. Among them, this study primarily focuses on two challenging experimental scenarios that became comprehensible through our proposed system’s application: (1) the transpassivation of Zr metal and the agglomeration of potassium hexachlorozirconate (K2ZrCl6) solid salt, and (2) the solvation of electrons during the oxidation of Li metal within the molten LiCl-KCl eutectic salt.
        24.
        2023.11 구독 인증기관·개인회원 무료
        The primary objective of radiological environmental monitoring after a radiological emergency at a nuclear facility is acquisition of background data for the determination of protective actions for the population and the comprehensive assessment of the impact on the population residing in proximity to the nuclear facility. The responsible entities engaged in the conduct of the radiological environmental monitoring encompass government organization and nuclear licensees, operating in strict adherence to the national radiological disaster prevention framework. In accordance with the national radiological disaster prevention framework, radiation environmental monitoring is executed through the deployment of emergency response organization, and recurrent exercise drills aimed at augmenting responsible capabilities. In the context of radiation environmental monitoring, it is necessary to specify measurement parameters, monitoring location, and methodological protocols for each stage, considering potential exposure pathways. In terms of equipment, it is important to utilize mobile assets such as aerial or vehicle surveys for rapid and accurate radiation environment monitoring. Radiation disaster drills are regularly conducted, and the radiation environment monitoring field is also regularly trained to enhance response capabilities. The scale of these drills may vary, ranging from exclusive participation by nuclear licensees to joint exercises conducted by governmental agencies. This iterative process of periodic drills and equipment enhancements has led to a progressive augmentation of environmental monitoring capabilities, ensuring a well-coordinated orchestration of radiation monitoring within the framework of radiation protection. Notwithstanding these achievements, challenges in public communication regarding the decision to take protective actions and the dissemination of information to the public. Considering that the purpose of radiation environmental monitoring extends beyond safeguarding public health; it also serves to alleviate public anxiety. In the future, public communication between these stakeholders should also be included in disaster drill programs to ensure proper consultation between each stakeholder during drills and to build understanding and trust in radiation environmental monitoring. This is expected to improve the quality of radiation environmental monitoring response capabilities.
        25.
        2023.11 구독 인증기관·개인회원 무료
        As the decommissioning of domestic nuclear power plants (Gori Unit 1 and Wolseong Unit 1) becomes more visible, many research projects are being conducted to safely and economically decommissioning of domestic nuclear power plants (NPPs). After permanent shutdown, decommissioning of NNPs proceeds through decontamination, cutting of main equipment, waste disposal and site restoration stages. And various technologies are applied at each stage. In particular, remote cutting of neutron induced structures (RV, RVI, etc.) is a technology used in developed countries in the cutting stage, and remote cutting has been evaluated as a core technology for minimizing workers’ radiation exposure. Generally, remote cutting technologies are divided into mechanical/thermal/electrical cutting. Among various thermal cutting technologies, plasma arc cutting (PAC) is more economical and easily to remote control than other cutting technologies, and is also effective in cutting STS304 plates. PAC is a thermal cutting technology that melts the base material at the cutting area with a plasma arc heat source and removes melted material by blowing it out with cutting gas. The cutting quality depends on the stand-off distance and power (current), material thickness, cutting speed, etc., while double arcing will occur if the cutting conditions are not suitable. A monitoring system that can confirm double arcing during remote cutting is necessary because double arcing can reduce cutting quality, increase secondary waste (increase kerf and aerosol), and cause non-cutting. In this study, we used an ultrahigh-speed camera equipped with a band-pass filter to capture clear arc shapes, and measured voltage waveforms with a data acquisition system. We studied a monitoring method that can confirm the occurrence of double arcing by synchronizing the obtained arc shape and voltage waveform, and the effects of double arcing on the STS304 plates. The results of this study are expected to be helpful in the development of the remote cutting process using plasma arc cutting when decommissioning of domestic NPPs.
        26.
        2023.11 구독 인증기관·개인회원 무료
        The high-level nuclear waste (HLW) repository disposes of high-level nuclear waste at a depth of 500 m to 1,000 m underground. Structural health monitoring must be accompanied by the complex environmental conditions of high temperature, high humidity, radiation, and mechanical stress. A thermocouple for measuring temperature, total stress meter and pore pressure meter for measuring stress and water pressure, relative hygrometer and electrical resistivity sensor (TDR or SUS) for measuring humidity, accelerometer for measuring crack signals, and strain gauge for measuring displacement are used. For safety, after disposing of HLW in the HLW repository, access to the disposal tunnel gets blocked, making it impossible to replace or remove the monitoring sensors. So, it is necessary to evaluate the effect of the HLW repository’s environmental conditions on the monitoring sensors and enhance their durability through quantitative life evaluation and shielding. Before evaluating the life of accelerometers and strain gauges used in the HLW repository, an experimental study is conducted to determine failure modes and failure mechanisms under radiation conditions, which are unique environmental conditions of the HLW repository.
        27.
        2023.11 구독 인증기관·개인회원 무료
        In the nuclear environment, sensors ensure safety, monitoring, and operational efficiency under various operating conditions. These sensors come in various forms, each tailored to specific purposes, including nuclear safety and security, waste treatment and storage, gas leak detection, temperature and humidity monitoring, and corrosion detection. Ensuring the longevity of sensors without the need for frequent replacements is a vital goal for researchers in this field. This paper explores materials that can act as shields to protect sensors from harsh environmental conditions (high radiation and temperatures) to enhance their lifetime. The types of material that had been explored were divided into categories: metal and non-metal. Fourteen types of metal and seven different plastic materials were studied and focused on their characteristics and current applications. Considering properties like melting point, intensity, and conductivity, plastic materials are chosen to be examined as sensor shielding material. A preliminary experiment was conducted to verify signal characteristics changes by shielding material. Metal material and plastic material each were placed in the middle of the granite and the target sensor. The result showed that when metal is between the granite and the sensor, the density and impedance are higher in granite than in the metal. This leads to signal attenuation and a shift in resonance frequency, while plastic does not. Therefore, PPS (Polyphenylene sulfide) and PAI (Polyamide-imide) have lower density and impedance than granite while also possessing heat, moisture, and radiation resistance for effective shielding.
        28.
        2023.11 구독 인증기관·개인회원 무료
        Over the past decades, particle physics has made significant progress in characterizing neutrinos even if neutrinos have extremely small cross-section (~10-44 cm2), allowing them to penetrate any object. More recently, neutrino detection and analysis have indeed become valuable tools in various aspects of nuclear science and technology. Neutrinos are detected using various methods, including Inverse Beta Decay (IBD), Neutrino-electron scattering, and Coherent Neutrino-Nucleus Scattering (CNNS). For the detection of anti-neutrinos from nuclear reactor, the Inverse Beta Decay (IBD) is commonly considered with scintillators. Notable experiments in Korea, such as RENO and NEOS, have been conducted using the IBD method at the Hanbit Nuclear Power Plant since 2006. Additionally, the NEON experiment, which employs CNNS, which has a significantly larger reaction cross-section than IBD but its low-energy signal detection difficulty, has been ongoing since 2021. Based on the results of NEOS (2015-2020) the signal to noise is ~30 and IBD detection rate is ~2000 counts per day. The IBD event in nuclear power plants provides valuable information about reactor behavior. IBD count rates are in good agreement with the thermal power of the reactor. Furthermore, the neutrino energy spectrum can be used to estimate the fission isotope ratio of the reactor core, showing promise for obtaining reactor core information from antineutrino detection techniques. Neutrino detection in nuclear facilities provides valuable information about reactor behavior. However, as a surveillance technology neutrino detection faces challenges due to the very low cross-section, requiring efforts to overcome limitations related to detector size and signal acquisition time. In 2008, the International Atomic Energy Agency (IAEA) included neutrino detection in its Research and Development (R&D) program for reactor safeguards. In January 2023, the IAEA organized a “Technical Meeting on Nuclear Data Needs for Antineutrino Spectra Applications” to discuss the latest developments and research results in this field. In summary, the use of neutrino detection in the nuclear field, particularly for reactor monitoring and safeguarding, has advanced significantly. Ongoing research and collaboration are expected to enhance our understanding of neutrinos and their applications in nuclear science and technology.
        29.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The evaluation of the low-temperature performance of an asphalt mixture is crucial for mitigating transverse thermal cracking and preventing traffic accidents on expressways. Engineers in pavement agencies must identify and verify the pavement sections that require urgent management. In early 2000, the research division of the Korea Expressway Corporation developed a three-dimensional (3D) pavement condition monitoring profiler vehicle (3DPM) and an advanced infographic (AIG) highway pavement management system computer program. Owing to these efforts, the management of the entire expressway network has become more precise, effective, and efficient. However, current 3DPM and AIG technologies focus only on the pavement surface and not on the entire pavement layer. Over the years, along with monitoring, further strengthening and verification of the feasibility of current 3DPM and AIG technologies by performing extensive mechanical tests and data analyses have been recommended. METHODS : First, the pavement section that required urgent care was selected using the 3DPM and AIG approaches. Second, asphalt mixture cores were acquired from the specified section, and a low-temperature fracture test, semi- circular bending (SCB) test, was performed. The mechanical parameters, energy-release rate, and fracture toughness were computed and compared. RESULTS : As expected, the asphalt mixture cores acquired from the specified pavement section ( poor condition – bad section) exhibited negative fracture performances compared to the control section (good section). CONCLUSIONS : The current 3DPM and AIG approaches in KEC can successfully evaluate and analyze selected pavement conditions. However, more extensive experimental studies and mathematical analyses are required to further strengthen and upgrade current pavement analysis approaches.
        4,000원
        30.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the semiconductor manufacturing clean room, contamination that directly affects process yield is managed through the operation of a monitoring system that measures molecular contamination in the air. In this study, I presented the component inspection method, test conditions, and judgment criteria through the life test of the solenoid valve that will be applied to the sampling module of the AMC Monitoring System.
        4,000원
        31.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The sampling test module of the existing AMC Monitoring System is constructed using tubes and fittings, so there has been a problem with molecular contaminants remaining in the system. This study demonstrated how a new manifold-type sampling test module without connecting tubes and fittings, and with super-hydrophobic coating improves residual molecular contaminants in the AMC Monitoring System through CDA purge when molecular contamination occurs in a clean room with a Semiconductor Fabrication.
        4,000원
        32.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 기존 식품첨가물 분석법에서 합으로써 분 석되는 락색소를 laccaic acid A, B, C, E 4가지 성분으로 분류하고 개별적으로 정량 할 수 있는 분석법을 확립하였 다. Natural red 25를 사용하여 구조적으로 비슷한 laccaic acid A와 B를 1차적으로 분취한 후 2차로 A와 B를 분리 했다. 같은 방식으로 C와 D를 1차, 2차에 걸쳐 각각의 개 별 표준품으로 사용하였다. 락색소 불검출 시료 3가지 시료 (햄, 토마토 주스, 고추장)를 확보하여 0.05-107.2 μg/mL 범 위에서 결정계수(r2) 0.995 이상의 직선성을 확인하였다. 3 가지 시료에서 정밀도와 정확성을 측정한 결과, 일내 정 밀도는 0.2-12.3%, 정확도는 90.6-112.7% 범위 내에서 확인 되었으며 일간 정밀도는 0.3-13.3%, 정확도는 90.3-113.0% 범위내로 확인 되었다. 락색소를 사용하는 식품과 사용 금 지 식품에 대해 회수율을 측정한 결과, 사용 가능 식품에서 는 91.6-114.9% 범위의 회수율을 보였으며, 사용 불가 식품 의 경우 92.5-113.5% 범위의 회수율을 보였다. 락색소의 검 출 한계는 3가지 시료에서 검출한계 0.01-0.15 μg/mL, 정량 한계 0.02-0.47 μg/mL로 확인되었다. 락색소의 4가지 성분중 laccaic acid A와 C에 대한 측정 불확도를 산출한 결과, laccaic acid A의 측정 불확도는 13.65±0.39 mg/kg(신뢰수준 95%, K=2), laccaic acid C의 측정 불확도는 4.19±0.39 mg/kg(신뢰 수준 95%, K=2)로 비교적 낮은 측정불확도 값을 산출하 였다. 따라서 본 연구에서는 식품 중 락색소의 개별 분석 과 정성 및 정량분석을 위해 유효성이 검증된 분석법을 확립으로 식품 중 잔류물질 기준규격 설정 및 관리에 참 고 자료가 될 수 있고, 향후 매트릭스 효과에 따른 laccaic acid 개별 분석과 개별 활성 및 독성시험 연구의 근거 지 표가 될 수 있다고 판단된다.
        4,300원
        33.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        식량 작물의 확보 및 생산량 예측은 국가 발전에 있어 필수적이며, 국가 경제뿐만 아니라 전 세계 식량 안보에 기여 한다. 최근 환경오염으로 인한 이상기후는 식량 작물 생산량에 직ㆍ간접적으로 부정적 영향을 끼치고 있어, 작물 수확량 예측 불확실성이 높아지고 있다. 특히, 노지 작물의 경우 생산량 감소와 품질 저하 문제가 화두 되고 있다. 이러한 문제는 농가들뿐만 아니라 소비자들에게도 큰 피해를 안겨주고 있다. 이러한 생산량 예측 이슈를 해결하기 위해 최근에는 인공지능 기술이 농업 분야에도 활발히 적용되고 있다. 작물 수확량의 정확한 예측을 위한 머신러닝 기반 연구가 집중적으로 수행되고 있다. 따라서, 본 연구에서는 이와 같은 인공지능 기반의 노지 작물 수확량 예측 기술(머신러닝, 딥러닝, 하이브리드 모델 등) 현황 및 작물 수확량에 가장 영향을 많이 끼치는 모델 파라미터 등을 조사하였다.
        4,200원
        35.
        2023.10 구독 인증기관·개인회원 무료
        Insects, including aphids, caterpillars, and beetles, have a significant impact on biodiversity, ecology, and the economy by consuming various plant tissues like leaves, stems, and fruits, leading to issues such as holes, defoliation, and impaired growth. Consequently, our study's primary goal was to establish a model system capable of identifying and tracking insects, covering aspects like their behaviors, movements, sizes, and patterns. Our research has successfully produced a 3D monitoring system specifically designed for continuous insect tracking by applying it to brown planthopper. This technology allows for in-depth exploration of insect behaviors and their interactions with plants and crops. The potential applications of this technique are highly promising, offering valuable assistance to researchers in unraveling insect behavior and ecological dynamics and driving further advancements in these crucial research areas.
        36.
        2023.10 구독 인증기관·개인회원 무료
        최근 기후변화, 국제교역량, 여행객 및 외국 이주민 증가 등으로 고위험 식물병해충의 유입이 증가하고 있으 며, 고위험해충에 대한 국내 유입여부를 상시 조사하여 외래식물해충을 발견하고 발생시 조기 대응하는 전문지 식과 경력을 갖춘 민간 전문가를 활용한 예찰시스템 구축의 필요성이 요구되고 있다. 침입우려 고위험 해충인 오리엔탈과실파리(Bactrocera dorsalis)는 광식성 해충으로 파프리카, 망고, 바나나, 감귤류 등 약 80종의 과실 농작물에 피해를 입히고 있으며, 해당 종의 국내정착 시 큰 경제적 피해를 입을 것으로 예상된다. 2023년 조기 방제 및 선제적 대응과 국내 확산 정착을 방지하기 위해 4개도(강원, 전북, 전남, 경남) 18개 시군 90개소에 유인트 랩(스테이너)을 설치하여 설치장소별 월 1회 정밀조사를 실시하였다. 트랩에 포획된 해충을 수거 후, 동정한 결과 오리엔탈과실파리는 발견되지 않았다.
        37.
        2023.10 구독 인증기관·개인회원 무료
        담배가루이(Bemisia tabaci)는 국내 주요 농업 해충으로서 고추, 오이, 토마토 등의 시설재배 작물에 큰 피해를 입힌다. 담배가루이는 작물을 흡즙하여 식물체의 상태를 악화시키고 TYLCV(tomato yellow leaf curl virus)등 100 여 종의 바이러스를 매개하며, 배설물을 통해 그을음병을 유발한다. 가장 일반적인 담배가루이의 방제방법은 빠르고 높은 효과를 지닌 살충제 살포이다. 하지만, 지속적인 화학적 방제는 해충의 살충제 저항성을 야기한다. 살충제 저항성은 방제 효율 감소와 농가의 경제적 손실을 일으킨다. 본 연구는 국내 지역별 시설 고추 재배지에서 발생한 담배가루이의 약제별 저항성을 조사하여, 지역별로 효과적인 약제 선정 및 대체 약제 추천 등 지속 가능한 해충관리법을 제시하고자 한다. 담배가루이는 전국 13개(파주, 양평, 화성, 횡성, 당진, 천안, 공주, 예천, 구미, 사천, 남원, 나주, 고흥) 지역에서 채집되었다. 작용기작 별 사용량이 많은 8종을 선정하였으며, 엽침지법을 사용 하여 살충률을 확인하였다. 곤충생장조절제(insect growth regulators, IGR)인 피리프록시펜계 약제는 알을 대상 으로, 그 외 7개 약제는 2령약충을 대상으로 살충률을 확인하였다. 높은 살충력을 보인 약제는 아버멕틴, 밀베마 이신계, 스피노신계, METI살충제, 디아마이드계 약제이다. 아버멕틴, 밀베마이신계는 권장사용농도로 처리 시 최소 84.5%, 최대 100% 살충률을 보였다. 스피노신계는 최소 86.3%, 최대 90.6% 살충률을 보였으나 천안, 파주, 사천에서 각각 59.7%, 66.6%, 79%로 다른 지역에 비해 상대적으로 낮은 살충률을 보였다. METI살충제는 최소 81.1%, 최대 98% 살충률을 보였으나 나주, 예천, 천안, 사천이 각각 61.6%, 68.8%, 68.9%, 69.2%의 상대적으로 낮은 살충률을 보였다. 디아마이드계는 최소 83.9%, 최대 91.9% 살충률을 보였으나 천안과 구미가 각각 56.6%, 59.8%로 상대적으로 낮은 살충률을 보였다. 낮은 살충력을 보인 약제는 네오니코티노이드계, 설폭시민계, 테트 론산 및 테트람산 유도체, 피리프록시펜계 약제이다. 네오니코티노이드계는 최소 14.1%, 최대 41.9% 살충률을 보였다. 설폭시민계는 최소 17%, 최대 42.8% 살충률을 보였다. 테트론산 및 테트람산 유도체는 최소 30.5%, 최대 54.9% 살충률을 보였으나 천안이 14.4%로 특히 낮은 살충률을 보였다. 피리프록시펜계는 최소 55.3%, 최대 64.3% 살충률을 보였으나 횡성이 72.2%로 상대적으로 높은 살충률을 보였으며, 파주가 35%로 상대적으로 낮은 살충률을 보였다. 실험 결과를 통해 살충제 별 살충력의 차이와 지역별로 살충률의 차이를 확인하였다. 본 연구결 과를 통해 효과적인 약제 추천과 지역에 따라 다른 방제 전략 제시에 도움이 되고자 한다.
        38.
        2023.10 구독 인증기관·개인회원 무료
        최근 기후변화로 인해 외래 무척추동물(곤충)의 돌발발생 가능성이 높아지고 있는 추세를 감안할 때 이들에 대한 확산 및 변화예측 진단을 통한 조기방제의 중요성이 대두되고 있다. 그러나, 외래곤충의 종 정보 및 정확한 침입경로가 충분치 않아 문제해충이 될 가능성이 매우 높은 것이 사실이다. 또한, 신속정확한 정책결정을 위해서 는 현장조사자료가 체계적으로 수집되어 종합되어야만 정확한 진단 및 방제에 활용될 것이므로 이에 대한 다양 한 장치가 필요하다. 현재 국내 서식 중인 주요 산림해충 일부를 제외한 종들은 대부분 외래곤충으로 돌발적으로 대발생한 해충이 많이 포함되어 있어 국내에 유입된 외래 곤충에 대한 체계적인 데이터 확보를 통해 정착, 확산, 생태계 영향 예측모델 개발 및 활용시스템의 구축이 요구되는 실정이다. 따라서, 본 연구는 외래 곤충의 전국적인 모니터링을 통해 분포정보 및 생태정보 등의 중요 데이터 수집과 최신 정보를 활용하여 국내 유입된 외래 곤충의 정착, 확산, 생태계 영향 및 변화예측을 위한 전략수립과 모바일 등을 이용한 전자야장의 사용에 대해 논하고자 한다.
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