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        검색결과 526

        1.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) will provide all-sky spectral survey data covering optical to mid-infrared wavelengths with a spatial resolution of 6.′′2, which can be widely used to study galaxy formation and evolution. We investigate the galaxy-galaxy blending in SPHEREx datasets using the mock galaxy catalogs generated from cosmological simulations and observational data. Only ∼0.7% of the galaxies will be blended with other galaxies in all-sky survey data with a limiting magnitude of 19 AB mag. However, the fraction of blended galaxies dramatically increases to ∼7–9% in the deep survey area around the ecliptic poles, where the depth reaches ∼22 AB mag. We examine the impact of the blending in the number count and luminosity function analyses using the SPHEREx data. We find that the number count can be overestimated by up to 10–20% in the deep regions due to the flux boosting, suggesting that the impact of galaxy-galaxy blending on the number count is moderate. However, galaxy-galaxy blending can marginally change the luminosity function by up to 50% over a wide range of redshifts. As we only employ the magnitude limit at Ks-band for the source detection, the blending fractions determined in this study should be regarded as lower limits.
        4,000원
        2.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        산오이풀(Sanguisorba hakusanensis)은 한국의 자생식물 이며 정원소재로써 가치가 있지만, 생육 및 생리적 특성 및 정 원 적응 여부에 대하여 알려진 정보가 많지 않아 이용에 어려 움을 겪고 있다. 본 연구에서는 자생식물인 산오이풀의 관수 주기 및 NaCl 농도에 따른 생장, Fv/Fm, NPQ, 성분 변화, 무기성분 변화를 조사하여 내건 및 내염성 보유 여부, 생육 한 계 범위, 스트레스 환경에서 생육을 유지하기 위한 반응을 파 악하고자 했다. 실험 결과 NaCl 무처리구의 관수주기에 따른 성분 분석에서 엽록소 함량의 감소를 제외하고 유의한 차이가 나타나지 않았으나 이는 토양수분함량이 건조 스트레스를 유 발할 정도로 감소하지 않았기 때문으로 보인다. 염 처리에서 는 2주 이후 급격한 스트레스 반응이 나타났고 3주차부터 고 사하기 시작하여 6주차에 모든 개체가 최종 고사했다. 이러한 결과는 2주까지 염 스트레스에 의해 유발되는 2가지 스트레 스 중 초기에 나타나는 삼투 스트레스에는 저항하였으나 이후 나타나는 NPQ의 감소 등 이온 스트레스에 의해 유발된 광합 성 기구 붕괴로 인해 정상적인 생육을 유지할 수 없었기 때문 에 나타난 것으로 보인다. 그러나 무기이온 분석은 이온 스트 레스에 저항하기 위한 메커니즘의 존재 가능성을 시사하였다. 상대적으로 염 농도가 낮을 때에는 세포내 Ca2+ 및 K+ 수준이 높았는데, 이는 Ca2+ 수준이 높아짐에 따라 Na+를 세포 밖으 로 방출시키는 단백질, Na+를 K+와 함께 수송하는 단백질이 기능하여 Na+축적을 지연시키는 반응이 있었음을 시사한다. 그러나 NaCl을 고농도로 처리했을 때는 이러한 반응이 관찰 되지 않았다. 따라서 산오이풀은 염 스트레스에 의해 야기되 는 삼투 스트레스에 강한 저항성을 가지고 있고 이온 독성을 줄이기 위한 메커니즘으로 Na+ 세포내 축적을 지연시키는 것으로 보이지만, 심한 염 스트레스를 받았을 때 나타나는 급격 한 반응에서 이러한 메커니즘이 기능하지 못하고 이온독성에 매우 취약한 것으로 여겨진다. 본 연구를 통해 자생식물인 산 오이풀의 활용을 늘리는 데 기초적인 자료를 제공할 수 있을 것으로 생각된다.
        4,600원
        3.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Air conditioner filters purify the air of indoor environments by removing air pollutants and supporting the efficiency of the unit’s cooling function. However, an air conditioner filter can become a microenvironment in which some fungi can grow as dust continues to accumulate and favorable humidity conditions are formed. Fungal growth in air conditioner filters could lead to fungal allergies or fungal diseases, in addition to emitting a foul odor. In an effort to understand what species causes this malodorous problem, we investigated the diversity of fungi found in air conditioners. Fungi were sampled from the collected air conditioner filters and grown on DG18 agar media. After purification for pure isolates, species identification was undertaken. Colony morphology was observed on PDA, MEA, CYA, and OA media. Microstructures of fruiting body, mycelia, and spores were examined using a light microscope. Molecular identification was performed by PCR and sequencing of PCR amplicons, and molecular phylogenetic analysis of sequenced DNA markers, including the Internal Transcribed Spacer (ITS), the 28S large subunit of the nuclear ribosomal RNA (LSU rDNA), the β-tubulin (BenA) gene, the Calmodulin (CaM) gene, and the DNA-directed RNA polymerase II subunit 2 (RPB2) gene. Through this identification process, we found two fungal species, Aspergillus miraensis and Dichotomopilus ramosissimus, which are unrecorded species in Korea. We will now report their morphological and molecular features.
        4,200원
        4.
        2023.11 구독 인증기관·개인회원 무료
        This study presents a rapid and sequential radiochemical separation method for Pu and Am isotopes in radioactive waste samples from the nuclear power plant with anion exchange resin and TRU resin. After radionuclides were leached from the radioactive waste samples with concentrated HCl and HNO3, the sample was allowed to evaporate to dryness after filtering the leaching solution with 0.45 micron filter. The Pu isotopes were separated in HNO3 medium with anion exchange resin. For leaching solution passed through anion exchange column, the Am isotopes were separated with TRU resin. The purified Pu and Am isotopes were measured by alpha spectrometer, respectively, after micro-precipitation of neodymium. The sequential radiochemical separation of Pu and Am isotopes in radioactive waste samples using anion exchange resin and TRU resin was validated with ICP-MS system.
        5.
        2023.11 구독 인증기관·개인회원 무료
        The thermal treatment of radioactive waste attracts great attention. The thermal treatment offers lots of advantages, such as significant volume reduction, hazard reduction, increase of disposal safety, etc. There are various thermal technologies to waste. The developed technologies are calcination, incineration, melting, molten salt oxidation, plasma, pyrolysis, synroc, vitrification, etc. The off-gas treatment system is widely applied in the technologies to increase the safety and operation efficiency. The thermal treatment generates various by-product and pollutants during the process. The dust or fly ash are generated as a particulate from almost every radioactive waste. The treatment of PVC related components generates hydrogen chloride, which usually brings corrosion of facility. The treatment of rubber and spent resin generates sulfur oxide, SOx. The treatment of nitrile rubber generates nitrogen oxide, NOx. The incomplete combustion of radioactive waste usually generates carbon oxide, COx. The process temperature also affects the generation of off gas, such as NOx and/or COx. Various off gas treatment components are organized for the proper treatment of the previously mentioned materials. In this study systematical review on off gas treatment will be reported. Also, worldwide experiences and developed facility will be reported.
        6.
        2023.11 구독 인증기관·개인회원 무료
        The primary purpose of high temperature process of radioactive waste is to satisfy the waste acceptance criteria and volume reduction. The WAC offers the guideline of waste form fabrication process. The WAC is defined as quantitative or qualitative criteria specified by the regulatory body, or specified by and operator and approved by the regulatory body, for radioactive waste to be accepted by the operator of a repository for disposal, or by the operator of a storage facility for storage. The main objective of WAC is to protect staff and general public and environment by the containment of radioactive material, limit external radiation level, and prevent criticality. The WAC also offers systematic management of radioactive waste by standardization of waste management operations, facilitation waste tracking, ensure safe and effective operation of operating facilities, etc. Since the high temperature process for radioactive waste is considered in many countries, lots of codes and standards are considered. In many WACs, compressive strength, thermal cycle stability, radiation exposure stability, free liquid, and leachability are evaluation to understand the effect of solidified form to the disposal facility. In this paper, systematical review on waste form will be discussed. In addition, brief result of characterization of waste form will be compared.
        7.
        2023.11 구독 인증기관·개인회원 무료
        During the operation of nuclear power plant (NPP), the concentrates and spent resin are generated. They show relatively high radioactivity compared to other radioactive waste, such as dry active waste, charcoals, and concrete wastes. The waste acceptance criteria (WAC) of disposal facility defines the structure and property of treated waste. The concentrates and spent resin should be solidified or packaged in high integrity container (HIC) to satisfy the WAC in Korea. The Kori NPP has stored history waste. The large concrete package with solidified concentrates and spent resin. The WAC requires identification of 18 properties for the radioactive waste. Since some of the properties are not clearly identified, the large concrete packages could not satisfy the WAC in this moment. The generation of the large concrete package (rectangular type and cylindrical type), pretreatment of the package, treatment of inner drum, process development for clearance waste, etc. will be discussed in this paper. In addition, the conceptual design of whole treatment process will be discussed.
        8.
        2023.11 구독 인증기관·개인회원 무료
        For efficient design and manufacture of PWR spent fuel burnup detector, data simulated with various condition of spent fuel in the NPP storage pool is required. In this paper, to derive performance requirements of spent fuel burnup detector for neutron flux and dose rates were evaluated at various distances from CE16 and WH17 types of fuel, representatively. The evaluation was performed by the following steps. First, the specifications of the spent fuel, such as enrichment, burnup, cooling time, and fuel type, were analyzed to find the conditions that emit maximum radioactivity. Second, gamma and neutron source terms of spent fuel were analyzed. The gamma source terms by actinides and fission products and neutron source terms by spontaneous and (α, n) reactions were calculated by SCALE6 ORIGAMI module. Third, simulation input data and model were applied to the evaluation. The material composition and dose conversion factor were referred as PNNL-15870 and ICRP-74 data, respectively and dose rates were displayed with the MCNP output data. It was assumed that there was only one fuel modeled by MCNP 6.2 code in pool. The evaluation positions for each distance were selected as 5 cm, 10 cm, 25 cm, 50 cm, and 1 m apart from the side of fuel, respectively. Fourth, neutron flux and dose rates were evaluated at distance from each fuel type by MCNP 6.2 code. For WH 17 types with a 50 GWd/MTU burnup from 5 cm distance close to fuel, the maximum neutron flux, gamma dose rates and neutron dose rates are evaluated as 1.01×105 neutrons/sec, 1.41×105 mSv/hr and 1.61×101 mSv/hr, respectively. The flux and dose rate of WH type were evaluated to be larger than those of CE type by difference in number of fuel rods. The relative error for result was less than 3~7% on average secured the reliability. It is expected that the simulated data in this paper could contribute to accumulate the basic data required to derive performance requirements of spent fuel burnup detector.
        11.
        2023.10 구독 인증기관·개인회원 무료
        Seasonal occurrence and distribution of insect pests and their natural enemies were investigated in several Paprika greenhouses(different pest control histories). Even in the environmental-controlled greenhouses with natural enemies for controlling insect pests, there were differences in occurrence and distribution of insect pests and natural enemies by season. From March after planting, aphids and whiteflies(Myzus persicae and Bemisia tabaci) had partially occurred in all experimental greenhouses. During summer season, whiteflies and leaf mites primarily occurred and insect pest species occurred in this season were more diverse than the winter season. In the winter season, whiteflies predominantly occurred in both natural enemies and pesticide-treated Paprika greenhouses. Predatory mite, Amblyseius swirskii was difficult to maintain their populations under an average temperature below 18℃ and relative humidity below 60%.
        12.
        2023.10 구독 인증기관·개인회원 무료
        미국선녀벌레는 2009년 발견이후 현재 131개 시군에 15,730ha가 발생되고 있다. 주로 단감 등 10여종 이상의 작물을 흡즙하여 피해를 준다. 2017년 이탈리아 파도바 대학에서 천적인 선녀벌레집게벌(Neodryinus typhlocybae)을 도입하여 국립농업과학원에서 생태특성 조사, 대량사육 기술개발 및 미국선녀벌레 발생 현장에 방사하고 있다. 선녀벌레집게벌은 미국선녀벌레 어린약충(1~3령)에 기생하면 암컷의 비율이 낮고 수컷은 2화 성 개체가 많아져 생산이 비효율적이다. 본 연구에서 어린약충에 기생할 때 보다 노숙약충에 기생할 경우 3배정 도 암컷생산의 비율이 높아졌고, 월동하고 있는 고치들을 5월 중순 무렵에 20℃의 서늘한 곳에 보관하면 우화시 기를 상온에 놓아둔 것에 비해 10일 이상 늦추는 결과를 얻었다.
        13.
        2023.10 구독 인증기관·개인회원 무료
        2022년 10월부터 2023년 5월까지 친환경 딸기재배 농가에서 점박이응애는 칠레이리애응애와 사막이리응애, 진딧물은 콜레마니진디벌을 대상으로 하는 천적처리구와 유기농자재를 사용하는 관행방제구에서 천적의 해 충 밀도억제 효과를 조사하였다. 천적처리구에서 점박이응애 성충 밀도는 잎당 1.5마리 이하, 알은 4개 이하로 관리되었고, 사막이리응애는 잎당 최대 0.4마리까지 증가하여 점박이응애 밀도억제에 많은 영향을 미친것으로 보인다. 반면, 관행방제구에서 점박이응애 밀도는 천적 방사구에 비하여 오히려 많은 발생량을 보였지만, 3월 9일부터는 사막이리응애의 증가와 유기농자재의 효과로 점박이응애 밀도는 급격하게 감소하였다. 진딧물 천적 처리구에서 진딧물 밀도는 1월부터 발생하였으며 3월 상순에 잎당 0.3마리까지 증가하였으나 이후 감소하였고, 콜레마니진디벌은 진딧물 발생이 많지 않아 3.9마리/㎡(2회) 방사하는 데 그쳤다. 한편, 관행방제구 포장의 진딧 물은 유기농자재의 영향으로 거의 발생하지 않았다.
        14.
        2023.10 구독 인증기관·개인회원 무료
        Plant biosecurity refers to measures that aim to prevent the introduction and spread of pests that pose potential risks to plant health. This core concept underpins the approach undertaken by the National Plant Protection Organization (NPPO), where pre-border, border, and post-border biosecurity activities focus on early detection and rapid response. The approach recognizes the continuum from pre- to post-border, resource allocation is currently being reviewed to ensure an appropriate balance for effective risk mitigation. National Priority Plant Pests with contingency plans highlight the types of threats facing the Korean peninsula faces from exotic plant pests. This will lead to transparency of NPPO activities and ensure that it has the people, resources, tools and systems to address its most important priorities and effectively manage current and future biosecurity challenges.
        16.
        2023.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        During the operation of a nuclear power plant (NPP), the generation of radioactive waste, including dry active waste (DAW), concentrates, spent resin, and filters, mandates the implementation of appropriate disposal methods to adhere to Korea’s waste acceptance criteria (WAC). In this context, this study investigates the potential use of polymer concrete (PC) as a high-integrity container (HIC) material for solidifying and packaging these waste materials. PC is a versatile composite material comprising binding polymers, aggregates, and additives, known for its exceptional strength and chemical stability. A comprehensive analysis of PC’s long-term integrity was conducted in this study. First, its compressive strength, which is crucial for ensuring the structural stability of HICs over extended periods, was evaluated. Subsequently, the resilience of PC was tested under various stress conditions, including biological, radiological, thermal, and chemical stressors. The findings of this study indicate that PC exhibits remarkable long-term properties, demonstrating exceptional stability even when subjected to diverse stressors. The results therefore underscore the potential viability of PC as a reliable material for constructing high-integrity containers, thus contributing to the safe and sustainable management of radioactive waste in NPPs.
        4,000원
        17.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents a study on the design and implementation of a secure contactless system leveraging Quick Response (QR) codes as a core component. The main goal of this system is to bridge the gap between strong security and improved user experience within the realm of digital interaction. The system's versatility can be expanded with broad compatibility with a variety of applications. Utility can be expanded to areas such as contactless payments, electronic ticketing, secure identity verification, and convenient access to medical records. The international standardization of QR codes ensures seamless cross-platform compatibility, strengthening their role in the digital ecosystem. We actually create and develop a non-contact security QR code system and check the expandability of the system. This study highlights the pivotal role of QR codes within the realm of secure contactless systems. Through its effective balance of digital security and user convenience, QR codes are emerging as an important element in the continued development of a secure and user-friendly digital environment. The potential for future research lies in exploring more complex use cases and further advancements that improve both security and user-centered design.
        4,000원
        18.
        2023.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        There are many types of foam molding methods. The most commonly used methods are the pressure foaming method, in which foam resin is mixed with a foaming agent at high temperature and high pressure, and the normal pressure foaming method, which foams at high temperature without pressure. The polymer resins used for foaming have different viscosities. For foaming under normal pressure, they need to be designed and analyzed for optimal foaming conditions, to obtain resins with low melt-viscosity or a narrow optimal viscosity range. This study investigated how changes in viscosity, molding temperature, and cross-link foaming conditions affected the characteristics of the molded foam, prepared by blending rubber polymer with biodegradable resin. The morphologies of cross sections and the cell structures of the normal pressure foam were investigated by SEM analysis. Properties were also studied according to cross-link/foaming conditions and torque. Also, the correlation between foaming characteristics was studied by analyzing tensile strength and elongation, which are mechanical properties of foaming composites.
        4,000원
        19.
        2023.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        A study was conducted on the vitrification of the rare earth oxide waste generated from the PyroGreen process. The target rare earth waste consisted of eight elements: Nd, Ce, La, Pr, Sm, Y, Gd, and Eu. The waste loading of the rare earth waste in the developed borosilicate glass system was 20wt%. The fabricated glass, processed at 1,200℃, exhibited uniform and homogeneous surface without any crystallization and precipitation. The viscosity and electrical conductivity of the melted glass at 1,200℃ were 7.2 poise and 1.1 S·cm−1, respectively, that were suitable for the operation of the vitrification facility. The calculated leaching index of Cs, Co, and Sr were 10.4, 10.6, and 9.8, respectively. The evaluated Product Consistency Test (PCT) normalized release of the glass indicated that the glass satisfied the requirements for the disposal acceptance criteria. Furthermore, the pristine, 90 days water immersed, 30 thermal cycled, and 10 MGy gamma ray irradiated glasses exhibited good compressive strength. The results indicated that the fabricated glass containing rare earth waste from the PyroGreen process was acceptable for the disposal in the repository, in terms of chemical durability and mechanical strength.
        4,200원
        20.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        주방세제의 진딧물 살충효과와 분국화 생육에 미치는 영향 을 알아보기 위해 실험을 수행하였다. 복숭아혹진딧물과 목화 진딧물을 대상으로 주방세제 100, 200, 400배액 단용처리와 주방세제 400배액 100mL에 소주 10mL 또는 20mL를 혼용 하여 분무 처리하였다. 그 결과 주방세제 400배 이하의 모든 농도에서 복숭아혹진딧물은 85%, 목화진딧물은 90%의 살충 률을 보였다. 주방세제와 소주 혼용처리에 의한 살충효과 상 승은 보이지 않았다. 하우스안에서 진딧물이 많이 발생한 분 국화 잎에 400배액 이하의 농도로 3일 간격으로 2회 처리함 으로써 90% 이상의 진딧물이 감소되는 효과를 얻을 수 있었 다. 또한 분국화를 재배하면서 3~4일 간격으로 5주간 지속적 으로 주방세제를 처리했을 때, 대조구에서는 90% 잎에서 진 딧물이 발생한데 비해, 모든 주방세제 단독 처리구에서는 발 생율이 15% 이하로 낮게 유지되었다. 또한 국화의 생체중, 초 장, 엽수는 주방세제 농도가 높아질수록 조금씩 낮아지는 경 향이었으나, 초폭이나 분지수에서는 차이가 없었다. 그러나 주방세제 200배 이하의 농도에서는 국화의 잎이 갈변되거나 꽃잎 끝이 백화되는 약해가 관찰되었다.
        4,000원
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