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        검색결과 58

        1.
        2023.11 구독 인증기관·개인회원 무료
        The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.
        2.
        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
        4.
        2022.10 구독 인증기관·개인회원 무료
        With the aging of nuclear power plants (NPPs) in 37 countries around the world, 207 out of 437 NPPs have been permanently shutdown as of August 2022 according to the IAEA. In Korea, the decommissioning of NPPs is emerging as a challenge due to the permanent shutdown of Kori Unit 1 and Wolsong Unit 1. However, there are no cases of decommissioning activities for Heavy Water Reactor (HWR) such as Wolsong Unit 1 although most of the decommissioning technologies for Light Water Reactor (LWR) such as Kori Unit 1 have been developed and there are cases of overseas decommissioning activities. This study shows the development of a decommissioning waste amount/cost/process linkage program for decommissioning Pressurized Heavy Water Reactor (PHWR), i.e. CANDU NPPs. The proposed program is an integrated management program that can derive optimal processes from an economic and safety perspective when decommissioning PHWR based on 3D modeling of the structures and digital mock-up system that links the characteristic data of PHWR, equipment and construction methods. This program can be used to simulate the nuclear decommissioning activities in a virtual space in three dimensions, and to evaluate the decommissioning operation characteristics, waste amount, cost, and exposure dose to worker. In order to verify the results, our methods for calculating optimal decommissioning quantity, which are closely related to radiological impact on workers and cost reduction during decommissioning, were compared with the methods of the foreign specialized institution (NAGRA). The optimal decommissioning quantity can be calculated by classifying the radioactivity level through MCNP modeling of waste, investigating domestic disposal containers, and selecting cutting sizes, so that costs can be reduced according to the final disposal waste reduction. As the target waste to be decommissioning for comparative study with NAGRA, the calandria in PHWR was modeled using MCNP. For packaging waste container, NAGRA selected three (P2A, P3, MOSAIK), and we selected two (P2A, P3) and compared them. It is intended to develop an integrated management program to derive the optimal process for decommissioning PHWR by linking the optimal decommissioning quantity calculation methodology with the detailed studies on exposure dose to worker, decommissioning order, difficulty of work, and cost evaluation. As a result, it is considered that it can be used not only for PHWR but also for other types of NPPs decommissioning in the future to derive optimal results such as worker safety and cost reduction.
        7.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이끼의 분쇄번식 시, 가장 적합한 배양토, 광, 온도를 구명 하기 위해 날개양털이끼(Brachythecium plumosum)와 쥐꼬리이끼(Myuroclada maximowiczii)를 이용하여 실험을 수행하였다. 실험 개시 4주 후에 사진을 찍어 Photoshop에서 이끼 면적과 녹색 평균값을 구하여 이끼의 생육 정도를 나타내었다. 배양토의 경우, 두 이끼 모두 다스란 상토에서 생육이 가장 좋았고, 상토:마사토(50:50), 원예상토, 마사토:피트모스(50:50) 에서는 비슷한 수준이었다. 버미큘라이트 단용에서는 생육이 부진하였다. 광도실험에서는 날개양털이끼는 25umol・m-2・s-1 에서 100umol・m-2・s-1까지 광도가 높아질수록 생육이 조금씩 좋아지는 경향이었으나, 쥐꼬리이끼는 3개의 광환경에서 비슷한 수준이었다. 온도 실험에서는 두 이끼 모두 23℃에서 면적과 녹색값이 가장 높아 생육도 좋았다. 이러한 결과를 종합 하면, 건조한 이끼를 분쇄하여 번식할 때, 배양토로는 보습력이 좋은 다스란 상토나 원예용 상토가 무난하며, 광도는 25~100umol・m-2・s-1 범위, 온도는 20~23℃가 적당할 것으로 판단된다.
        4,000원
        9.
        2020.12 구독 인증기관 무료, 개인회원 유료
        Streptococcus mutans and Streptococcus sobrinus play important roles in dental caries. Coptis chinensis is a natural product with antimicrobial activity against enterobacteria; however, its effects on oral streptococci are still unknown. Therefore, the effects of C. chinensis on the growth and biofilm formation of the representative cariogenic bacteria S. mutans and S. sobrinus were investigated for the possible use of C. chinensis as an anticaries agent. The C. chinensis extract was diluted with sterile distilled water, and 0.1–2.5% of the extract was used in the experiment. The effects of the C. chinensis extract on the growth and glucan formation of S. mutans and S. sobrinus were measured by viable cell counting and spectrophotometry at 650 nm absorbance, respectively. Crystal violet staining was also carried out to confirm the C. chinensis extract’s inhibitory effect on biofilm formation. The C. chinensis extract significantly inhibited the growth of S. mutans and S. sobrinus at concentrations of ≥ 0.3% as compared with the control group. The viable cell count of colonies decreased by 1.7-fold and 1.2-fold at 2.5% and 1.25%, respectively, compared with the control group. The biofilm formation of S. mutans and S. sobrinus was inhibited by > 20-fold at C. chinensis extract concentrations of ≥ 1.25% as compared with the control group. In summary, the C. chinensis extract inhibited the growth and biofilm and glucan formation of S. mutans and S. sobrinus . Therefore, C. chinensis might be a potential candidate for controlling dental caries.
        4,000원
        10.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop a lifestyle scale for one-person hair salon users and to identify differences in store choice factors and hairstyle pursuit behaviors according to lifestyle types. Data was collected by survey, with 225 responses being included in the analysis. Data analysis was performed using cross-analysis, factor analysis, Cronbach’s α, cluster analysis, ANOVA and the Duncan-test using SPSS 23.0 analysis software. The results of the study were as follows. First, one-person hair salon users were classified according to the following lifestyle groups: The rational appearance management group, the passive appearance management group, and the discriminative appearance management group. Second, store choice factors according to lifestyle group showed significant group-specific differences in relation to store atmosphere, accessibility, and promotion. Conversely, comfort of space in store and word-of-mouth recommendation message were high for all three groups, indicating that these are important factors in relation to store selection. Third, with regard to hairstyle pursuit behaviors according to lifestyle, the discriminative appearance management group showed the same characteristics as high involvement groups that regard all dimensions of hairstyle pursuit behavior as important. The results of this study can be used to suggest efficient operations for one-person hair salons and to suggest differentiated marketing strategies to increase the demand of one-person hair salon users.
        4,900원
        11.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chamaecyparis obtusa is one of the economical conifers planted in Korea due to its good quality timber and wood characteristics. Individuals of C. obtusa containing high terpenes (HT) and low terpenes (LT) were selected for by colorimetric method. The HT of C. obtusa was delayed in wilting against various abiotic stresses compared to the LT plants. The HT group exposed to UV did not significant influence the chlorophyll content, and the chlorophyll value was higher in the HT group than the LT group. Also, chilling treatment (5℃) did not significant influence on the chlorophyll content. However treatment at -4℃ showed relatively low chlorophyll content in the LT group than the HT group. Plants exposure to high temperature was not a difference between the HT and the LT group. However, treatment at 38℃ influenced the chlorophyll content that was increased exposure time-dependently. In salt treatments, chlorophyll in the HT group was lower at high concentrations (300 and 500 mM) of NaCl. However, chlorophyll content increased to slightly in treatment time-dependently, which is 6.7% to 40%. H2O2 treatment has been a negative effect on the chlorophyll content in the HT group. All concentration of H2O2 decreased the chlorophyll content of 5% to 35%. Plants containing high terpenoids were resisted against some abiotic stress such as salt and H2O2. Our results implied that terpenoids could cause various abiotic stress resistance. These results could be utilized for efficient management and biomass production during forest silvicultures.
        4,000원
        12.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pesticide application in agriculture provides significant benefits such as protection from disease, prevention of harmful insects, and increased crop yields. However, accurate toxicological tests and risk assessments are necessary because of many related adverse effects associated with pesticide use. In this review, we discuss and analyze residual pesticides contained in livestock feed in Korea. A pesticide residue tolerance standard for livestock feed has not been precisely established; so, risk assessments are required to ensure safety. Standards and approaches for animal criteria and appropriate methods for evaluating residual pesticides are discussed and analyzed based on technology related to animal product safety in Korea. The safety of livestock feed containing pesticides is assessed to establish maximum residue limits relative to pesticides. Analysis of residual pesticides in milk, muscle, brain, and fat was performed with a livestock residue test and safety evaluation of the detected pesticide was performed. Efficacy of organic solvent extraction and clean-up of feed was verified, and suitability of the instrument was examined to establish if they are effective, rapid, and safe. This review discussed extensively how pesticide residue tolerance in livestock feed and hazard evaluation may be applied in future studies.
        4,000원
        13.
        2018.07 구독 인증기관·개인회원 무료
        This research explored antecedents of stickiness of m-commerce sites, based on the push–pull–mooring (PPM) framework, which was developed to explain what leads people to move from one original location to another. In the current study, the stickiness of m-commerce sites was used as the opposite concept to switching. Therefore, pull effects refer to the positive factors which make consumers stick to an m-commerce site, while push effects refer to the negative factors which make consumers not stick with an m-commerce site. After reviewing the literature, responsiveness, ubiquity, enjoyment, and effectiveness were selected as the pull effects, while privacy concern and efficiency were selected as the push effects. The amount of money spent in specific mobile sites was considered as a mooring effect. According to the results of the structural equation modeling analysis, efficiency actually had a negative impact on stickiness of m-commerce sites. Also, a test of the mooring effect suggested that the negative impact of efficiency on stickiness of m-commerce sites was greater for people who spent more money in their mobile shopping compared to those who spent less. For both the high and low spending groups, responsiveness was the important pull effect as it was the strongest predictor of enjoyment for the low spending group and the strongest predictor of effectiveness for the high spending group (note that enjoyment and effectiveness had the strongest positive impacts on stickiness of m-commerce sites for the low and high spending groups, respectively.). Therefore, the fast response and feedback on m-commerce sites should increase consumers’ stickiness to these sites regardless of the amount consumers spend on these sites. On the other hand, the duration and retention of the low spending group of consumers were influenced by enjoyment the most.
        14.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        현재 농가에서 이용되고 있는 보광등과 난방등의 특성을 조사하고 하우스내 기상 환경과 절화장미의 개화와 품질에 미치는 영향을 알아보기 위해 실험을 수행하였다. 보광등으로는 LED등(light emitting diode lamp, LED), 메탈할라이드등(metal halide lamp, MH), 고압나트륨등(high pressure sodium lamp, HPS)을, 난방등으로는 나노탄소섬유 적외선등(nano-carbon fiber infrared lamp, NCFI)을 절화장미 재배상 위에 설치하였다. 그 결과 LED와 NCFI의 광도는 각각 6.8μmol·m-2·s-1과 0.4μmol·m-2·s-1으로 매우 낮은 반면, MH와 HPS는 79 ~ 100μmol·m-2·s-1 범위로 높은 편이었다. 또한 LED와 MH는 적외선역에 파장이 없어 발열량이 거의 없었으나, HPS와 NCFI는 적외선역에 파장이 많아 발열이 많은 것으로 나타났다. 동일한 공간에서 칸막이로 실험구간을 나누어 실험이 수행되었음에도 불구하고 MH, HPS, NCFI에 의해 온도는 2°C 정도 상승되는 결과를 얻었으나, 습도에서는 처리간 차이가 보이지 않았다. 광도에 상관없이 모든 전등들은 절화장미의 개화를 촉진시켜 무처리구에 비해 적게는 5 ~ 7일, 많게는 12 ~ 14일 개화가 촉진되는 것으로 나타났다. 광량이 충분한 봄철에는 전조처리에 의해 개화소요일수가 짧아지는 만큼 절화장도 대조구보다 짧아졌지만, 광량이 부족한 겨울철에는 전조처리에 의해 절화장이 길어져 품질이 향상되는 결과를 얻을 수 있었다.
        4,000원
        15.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to investigate the effects of foot position adjuster on body alignment and weight loads in chronic stroke patients. The subjects were 15 chronic stroke patients who were admitted to KHospital in Daegu, South Korea. The study compared the body alignment and weight load changes on flat ground with the foot position adjuster using Foot scan and Dartfish video analysis software. In the results of this study, posterior superior iliac spine (PSIS) alignment decreased significantly after use of the foot position adjuster and center pressure was significantly increased after use of the foot position adjuster. This study suggests that foot position adjuster influences body alignment and weight distribution.
        4,000원
        16.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chrysanthemums (Dendranthema grandiflorum ‘Iwanohakusen’) were grown in a greenhouse with complete nutrient solution system to investigate the effect of silicon (Si) supplement on salt induced deleterious effects in chrysanthemum plants. The experiment was conducted in plastic pots supplemented with a mixture of upland soil : leaf mold : river sand (3:3:4, v:v:v). Si and salinity were treated in combination with two levels of NaCl (0 and 100 mM) and two sources of silicon (K2SiO3, KSi and silicate fertilizer, SiF) at the same concentration (1.8 mM Si) by weekly-drenching for 12 weeks. Chrysanthemum plants supplemented with Si increased in fresh and dry matter enhancing water content and salinity tolerance. The plants grown under salt stress produced less fresh and dry matter than control plant. However, Si supplement to plants under salt stress ameliorated negative effects of salt stress. In soil, EC and NaCl increased by salt stress were mitigated by Si supplement. Salt stress significantly decreased the contents of K and P in leaf, but Si supplement under salt stress significantly recovered the decreased contents with enormous desorption of K and P in soil. Added Si significantly increased content of available SiO2 with its adsorption by salt stress in soil, which was directly related to Si accumulation in leaf. However, Si uptake by roots was suppressed by salt stress irrespective of Si supplement. Si supplement did not ameliorated the negative effects of salt stress on chlorophyll content and membrane integrity in leaf of chrysanthemum plant although significantly increased Si content in leaf, but reversed pest (Liriomyza trifolii) resistance to above-control level.
        4,200원
        17.
        2013.11 구독 인증기관·개인회원 무료
        We have used bulked segregant analysis to screen the strain-specific DNA marker associated thermophilic strain of Pleurotus eryngii. Bulked genomic DNAs of Pleurotus eryngii were amplified by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S primers to screen the strain-specific DNA marker. A unique DNA fragment of 500 bp was amplified with OP-A11 primer from the psychrophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-A11-1. The PCR analysis with the OP-A11-1 primer showed that this SCAR marker clearly distinguish the psychrophilic strains from the control strains.
        18.
        2013.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ampelopsis brevipedunculata, a porcelain berry that is a kind of Korean domestic wild berry (Viticeae), has been known to be resistant to diseases and insects. A total of 2,622 unigenes containing 912 contigs and 1,710 singletons were obtained by sequencing 5,839 expressed sequence tag (EST) clones derived from the cDNA library of wild grape, A. brevipedunculata. In the gene ontology analysis, 1,175 genes related to biological process, 1,516 genes related to molecular function, and 1,413 ones related to cell components were annotated. Among the genes showing molecular function, 17 clones were classified into defense-related genes, and 102 were known to be related with responses to stress in plants. Domains, such as leucine-rich repeat, Serine/threonine protein kinase-related, WD40 repeat, EF-hand calcium-binding, pentatricopeptide repeat, and pathogenesis-related transcriptional factor were highly expressed. Genes encoding defense related proteins, such as chitinase, catalase, protein-serine/threonine kinases, were also clustered into an abundant group in cDNAs from A. brevipedunculata. Approximately, 80 simple sequence repeats with 2~5 nucleotides were detected in the cDNAs of A. brevipedunculata. These data could provide useful information for the genetic analysis of wild grapevines and in programs for breeding grape cultivars.
        4,500원
        19.
        2013.10 구독 인증기관·개인회원 무료
        Haemaphysalis longicornis (Hl) as members of the ixodid tick inhabits lots of grass thicket of field and mountain. Ticks are blood-feeding ectoparasites that can mediate a variety of diseases to human and animals, causing Lyme disease, Rocky Mountain spotted fever, and human monocytic ehrlichiosis. Particularly, ticks can trigger an inflammatory response representing symptoms about swelling and itching in human. The aim of this study is to investigate the effect of H. longicornis extract (HlE) on production of inflammatory cytokines and their mRNA in human monocytic THP-1 cells. In a time- and dose-dependent manner, human monocytic THP-1 cells was treated with HlE. Supernatants were analyzed for the production of cytokines using enzyme-linked immunosorbent assay (ELISA). mRNA level in the culture cells was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR). As a result of this study, HlE significantly induced secretion of IL-6, IL-8, and MCP-1 in THP-1 cells. These results suggest that HlE increase the release of proteins and mRNAs level of inflammatory cytokines in THP-1 cells. HlE may play a role in contributing to inflammatory diseases through stimulation of immune cells. Further research of H. longicornis is needed to better understand the elucidation of the pathogenic mechanism.
        20.
        2013.10 구독 인증기관·개인회원 무료
        Tyrophagus putrescentiae (Tp) as a storage mite inhabitats in stored grains, hay, and straw at agricultural areas. T. putrescentiae stimulates an immune response and triggers inflammatory cytokines release, and thus it is a source of allergen that sensitize and induce allergic reactions. Also, T. putrescentiae has been reported to cause asthma and atopic disease by cross-reactivity with Dermatophagoides pteronyssinus (Dp). The study on T. putrescentiae in human monocytic THP-1 cells is not enough to understand cytokine expression and pathological mechanisms. The aim of this study is to investigate the effect of T. putrescentiae extract (TpE) on production of inflammatory cytokines and expression of mRNA level in THP-1 cells. THP-1 cells are treated with TpE and supernatants were analyzed for the production of cytokines using enzyme-linked immunosorbent assay (ELISA). mRNA level in the culture cells was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR). As a result of this study, TpE significantly induced secretion of interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (MCP-1) in THP-1 cells in time- and dose-dependent manner. These results suggest that TpE may play a role in contributing to inflammatory disease through stimulation of immune cell. Further research of T. putrescentiae is needed to understand the elucidation of the pathogenic mechanism.
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