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        검색결과 1,429

        1.
        2024.04 구독 인증기관·개인회원 무료
        We established a soybean banker plant system and evaluated the biological control effects of aphid control in bell pepper greenhouses. The soybean banker plant was B.communis breeding system and developed as an alternative aphid control agent to the most common Barley banker(Barley-Colemani). After inoculating approximately 50 soybean aphids(Aphis glycines, aphid starter population) on 2 week old soybean seedling pot after sowing and then releasing aphid parasitoids, an average of 348.7 parasitic wasps per a soybean banker plant could be produced without additional host aphid inoculation. Common recommendation for installation in the greenhouses are about 2 soybean banker plants per 330㎡ before or immediately after planting. If the number of aphids per stem is fewer than three on 2 weeks after installation of the banker plant, additional supplementation of 20~30 aphids is necessary to maintain this system for one month. When one soybean banker plant was installed per 120㎡, the aphid control effect was about 60% on the 21st day after installation.
        2.
        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.
        3.
        2024.03 KCI 등재 구독 인증기관·개인회원 무료
        Background: Somatic cell nuclear transfer (SCNT) is a prominent technology that can preserve superior genetic traits of animals and expand the population in a short time. Hematological characters and endocrine profiles are important elements that demonstrate the stability of the physiological state of cloned animals. To date, several studies regarding cloned camels with superior genes have been conducted. However, detailed hemato-physiological assessments to prove that cloned camels are physiologically normal are limited. In this study, We evaluated the hemato-physiological characteristics of cloned male and female dromedary camels (Camelus dromedaries). Methods: Therefore, we analyzed variations in hematological characteristics and endocrine profiles between cloned and non-cloned age-matched male and female dromedary camels (Camelus dromedaries ). Two groups each of male and female cloned and non-cloned camels were monitored to investigate the differences in hemato-physiological characteristics. Results: All the animals were evaluated by performing complete blood count (CBC), serum chemistry, and endocrinological tests. We found no significant difference between the cloned and non-cloned camels. Furthermore, the blood chemistry and endocrine profiles in male and female camels before maturity were similar. Conclusions: These results suggest that cloned and non-cloned camels have similar hematological characteristics and endocrine parameters.
        4.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        현상학 연구는 질적 연구방법 중에서도 현상의 이면을 밝혀 그 본질을 도출하는 방법론이다. 이런 본래 의 현상학적 연구의 취지를 살려 연구의 성격에 맞춰 현상의 본질을 드러낼 수 있는 다양한 현상학적 방법 론이 적용될 필요가 있다. 하지만 현상학적 방법론은 현실적으로 지오르지(Giorgi)와 반마넨(Van Manen) 의 방법론에 치우쳐 있는 실정이다. 이런 문제의식을 바탕으로 본 연구자는 청소년의 학교폭력 경험에 적용 한 현상학적 자기평가방법의 분석방법을 고찰했다. 이 방법론은 환원과정이 4단계로 구체적이어서 현상학 의 본래 취지인 본질에 도달하는데 적합하다고 생각한다. 구체적으로 학교폭력 피해학생의 심층인터뷰를 활용해 현상학적 자기평가방법의 환원과정을 이 연구에서 보여주었다. 이 현상학적 자기평가방법은 사회복 지학이나 사회학에서 다루는 현상의 본질을 파악하기에 적합한 연구방법이라 할 수 있다.
        6,000원
        5.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study explores Korean EFL learner preferences and perceptions of digital composing (DC) with innovative online technology tools during the implementation of emergency remote learning measures. The research compares learner use of text-based DC and voice-based audio asynchronous online discussion (AOD). This paper investigates the following research problem: What digital modes of interactive, online instructional design can serve as appropriate, learner-accepted replacements for offline instruction? One prior finding indicated that Korean undergraduate EFL learners preferred text and audio DC to video modes. To follow up, this paper investigates 57 learners’ preferences and perceptions toward text-based and voice-based DC, and compares the results. The data analysis methods employ paired-samples Tests, and a thematic analysis to identify issues raised in student comments. The results reveal that learners’ levels of user satisfaction with voice-based audio AOD and their ratings of its perceived usefulness confirm that it can be a satisfactory, effective, and preferable task for engaging learners in digitally-mediated four-skills practice. Another finding is that utilizing a voice-based audio module did not significantly alter learners’ course satisfaction when superseding a text-based module. These findings inform pedagogical practice with empirical insights regarding learners’ use of digital technologies, levels of acceptance, and DC preferences.
        7,700원
        6.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Cat-scratch disease (CSD) is a bacterial infection which primarily transmitted to humans through scratches, bites, or licks from infected cats. Even though CSD is generally a mild condition, atypical symptoms may appear and must be distinguished from other diseases. We encountered a 57-year-old woman who presented with intermittent pain in the right upper quadrant and epigastric part of the abdomen, and had lost 11 kg within a few months. She never had a cat and did not recall being scratched by a cat. Radiologic examinations strongly suggest a malignant bile duct tumor, thus liver resection was done. However, the result of histopathology was a CSD. At follow-up, the patient was stable and also showed improvement in her general condition. Hence, proper preoperative examinations of the patients are crucial in order to avoid excessive or inadequate treatment.
        4,000원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanofibers (CNFs) are promising materials for the construction of energy devices, particularly organic solar cells. In the electrospinning process, polyacrylonitrile (PAN) has been utilized to generate nanofibers, which is the simplest and most popular method of creating carbon nanofibers (CNFs) followed by carbonization. The CNFs are coated on stainless steel (SS) plates and involve an electropolymerization process. The prepared Cu, CNF, CNF–Cu, PANI, PANI–Cu, CNF–PANI, and CNF–PANI–Cu electrode materials’ electrical conductivity was evaluated using cyclic voltammetry (CV) technique in 1 M H2SO4 electrolyte solution. Compared to others, the CNF–PANI–Cu electrode has higher conductivity that range is 3.0 mA. Moreover, the PANI, CNF–PANI, and CNF–PANI–Cu are coated on FTO plates and characterized for their optical properties (absorbance, transmittance, and emission) and electrical properties (CV and Impedance) for organic solar cell application. The functional groups, and morphology-average roughness of the electrode materials found by FT–IR, XRD, XPS, SEM, and TGA exhibit a strong correlation with each other. Finally, the electrode materials that have been characterized serve to support and act as the nature of the hole transport for organic solar cells.
        4,500원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In 2022, the domestic production performance of functional cosmetics in South Korea reached 4.6 trillion won, accounting for 33.85% of the total cosmetics production. The number of functional cosmetics reviewed increased by about 7.5% from the previous year, totaling 974 items. Especially with the increasing importance of the skin barrier function due to skin sensitivity caused by various environmental pollutants, domestic cosmetic companies are showing interest in the development of new ingredients and products related to this area. This study aims to analyze academic research trends related to in vitro experiments for the development of cosmetics improving the skin barrier, to provide practical information for the cosmetic industry. The findings are as follows: Academic research mainly focused on the efficacy of natural ingredients in improving the skin barrier, but there is a significant lack of quantitative accumulation of research. For the development of skin barrier-improving cosmetic ingredients, efficacy evaluation indicators were set, including hyaluronic acid production, expression of filaggrin gene, loricrin, formation of cornified envelope (CE), and expression of ceramide synthesis enzyme genes. Moreover, effective cosmetic ingredients for improving the skin barrier included lemongrass and perilla leaf extracts, flavonoids, Lactococcus lactis subsp. lactis, Exosomelike Nanovesicles derived from apple callus, Eleutherococcus sessiliflorus, Acanthopanax sessiliflorus, Eleutherococcus gracilistylus, Acer okamotoanum extracts, Aloe vera adventitious root extract, ethanol extract of Aruncus dioicus, and organic solvent fraction of Dracocephalum argunense.
        4,000원
        9.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The economy of Tanzania relies on agriculture as the main economic activity, because agriculture provides both food and income to the population of the country, especially the rural households. Improvement of market access to crops also increases the productivity. Therefore, in this study, descriptive statistics and statistical analysis of the probit model were used to analyze the factors that determine the market accessibility of small-scale farmers in Chemba, Tanzania. Cross-sectional data collected by the systematic sampling method for 200 corn peasants in Chemba, Tanzania were used. As a result of probit regression analysis, it was found that access to improved seeds and technology had a positive statistically significant effect on the accessibility to the market, while the age of the head of the household, production cost, distance to the market, and household size had a negative statistically significant effect. Therefore, in this study, policy establishment and implementation are recommended. A policy needs to be considered to reduce the transaction costs that eventually allows the farmers to increase the accessibility to markets, enables small-scale farmers to participate in cooperatives, lowers input costs and provides educational programs on quality products to increase their competitiveness in the marketplace.
        4,000원
        13.
        2023.11 구독 인증기관·개인회원 무료
        The nuclear fuel that melted during the Fukushima nuclear accident in 2011 is still being cooled by water. In this process, contaminated water containing radioactive substances such as cesium and strontium is generated. The total amount of radioactive pollutants released by the natural environment due to the nuclear accident in Fukushima in 2011 is estimated to be 900 PBq, of which 10 to 37 PBq for cesium. Radioactive cesium (137Cs) is a potassium analog that exists in the water in the form of cations with similar daytime behavior and a small hydration radius and is recognized as a radioactive nuclide that has the greatest impact on the environment due to its long half-life (about 30 years), high solubility and diffusion coefficient, and gamma-ray emission. In this study, alginate beads were designed using Prussian blue, known as a material that selectively adsorbs cesium for removal and detection of cesium. To confirm the adsorption performance of the produced Prussian blue, immersion experiments were conducted using Cs standard solution, and MCNP simulations were performed by modeling 1L reservoir to conduct experiments using radioactive Cs in the future. An adsorption experiment was conducted with water containing standard cesium solution using alginate beads impregnated with Prussian blue. The adsorption experiment tested how much cesium of the same concentration was adsorbed over time. As a result, it was found that Prussian blue beads removed about 80% of cesium within 10-15 minutes. In addition, MCNP simulation was performed using a 1 L reservoir and a 3inch NaI detector to optimize the amount of Prussian blue. The results of comparing the efficiency according to the Prussian volume was shown. It showed that our designed system holds great promise for the cleanup and detection of radioactive cesium contaminated seawater around nuclear plants and/or after nuclear accidents. Thus, this work is expected to provide insights into the fundamental MCNP simulation based optimization of Prussian blue for cesium removal and this work based MCNP simulation will pave the way for various practical applications.
        14.
        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.
        15.
        2023.11 구독 인증기관·개인회원 무료
        The primary heat transport system consists mainly of the in-core fuel channels connected to the steam generators by a system of feeder pipes and headers. The feeders and headers are made of carbon steel. Feeders run vertically upwards from the fuel channels across the face of the reactor and horizontally over the refueling machine to the headers. Structural materials of the primary systems of nuclear power plants (NPPs) are exposed to high temperature and pressure conditions, so that the materials employed in these plants have to take into accounts a useful design life of at least 30 years. The corrosion products, mainly iron oxides, are generated from the carbon steel corrosion which is the main constituent of the feeder pipes and headers of this circuit. Typical film thickness on CANDU-PHWR surface is 75μm or 30mg/cm2. Deposits on PHWR tends to be much thicker than PWR due to use of carbon steel and also for the source of corrosion products available on the carbon steel surface. Degradation of carbon steel for the feeder pipes transferring the primary system coolant by flow-assisted corrosion in high temperature has been reported in CANDU reactors including Point Lapreau, Gentully-2, Darlington and Bruce NPPs. The formation of Fe3O4 film on a carbon steel surface reduces the dissolution rate of steel substantially. The protectiveness of the Fe3O4 film over the carbon steel is affected by the environmental factors and the operational parameters of the feeder pipes, including the velocity, wall shear stress, solution pH, temperature, concentration of dissolved iron, quality of solution, etc. For effective chemical decontamination of these thick oxides containing radionuclides such as Co-60, it is necessary to understand the corrosion behaviors of feeder pipes and the characteristics of oxide formed on it. In this work, we investigated the growth of oxide films that develop on type SA-107 Gr. B carbon steel in high temperature water and steam environment by scanning electron microscopy (SEM) and glow discharge optical emission spectrometry (GD-OES) for the quantification and the solidstate speciation of metal oxide films. This study was especially focused to set the experimental tests conditions how to increase the oxide thickness up to 50 m by changing the oxidation conditions, such as solution chemistry and thermo-hydraulic conditions both temperature and pressure and so on.
        16.
        2023.11 구독 인증기관·개인회원 무료
        It is crucial to be sure about the safety of nuclear facilities for human resources who are in danger of radioactive emission, also diminishing the volume of the wastes that are buried under the ground. Chemical decontamination of nuclear facilities can provide these demands at the same time by dissolving the oxide layer, which radionuclides such as 60Co and 58Co have been penetrated, of parts that are utilized in nuclear plants. Although there are many commercial methods to approaching its aim and they perform a high decontamination factor, they have some issues such as applying organic acids which have the ability to chelate with radionuclides that can be washed by underground water, have large quantities of radioactive waste and damage to the surface by severe intergranular attack. A new method has been introduced by KAERI’s scientist which is named the HyBRID Process, in this process the main solution is the acidic form of Hydrazine. In this process, like other acid-washing processes, there is a chance of corrosion on the metal surface which is not desired. The metal surface is able to be protected during dissolving process by adding some organic and inorganic corrosion inhibitors such as PP2 and PP3. There is a very new research topic about ionic liquids (ILs) as corrosion inhibitors which illustrates a vast potential for this application due to their tunable nature and the variety of options for cationic and anionic parts. The key factors for ILs corrosion inhibitors such as the hardness properties are summarized. In this study, we review to the fundamentals and development of corrosion inhibitors for chemical decontamination and give an prospect with emphasis on the challenges to be overcome.
        17.
        2023.11 구독 인증기관·개인회원 무료
        The radiation field generated in the primary cooling system of a nuclear power plant tends to increase in intensity as radionuclides bind to the oxide film on the internal surface of the primary system, which is operated at high temperature and pressure, and as the number of years of operation increases. Therefore, decontamination of the primary cooling system to reduce worker exposure and prevent the spread of contamination during maintenance and decommissioning of nuclear power plants uses the principle of simultaneous elution of radionuclides when the corrosion oxide film dissolves. In general, a multi-stage chemical decontamination process is applied, taking into account the spinel structure of the corrosion oxide film formed on the surface of the primary cooling system, i.e. an oxidative decontamination step is applied first, followed by a reductive decontamination step, which is repeated several times to reach the desired decontamination goal. Currently, permanganic acid is commonly used in oxidative decontamination processes to remove Cr from corrosion oxide films. In the reductive decontamination step to remove iron and nickel, organic acids such as oxalic acid are commonly used. However, organic acids are not suitable for the final radioactive waste form. A number of multi-stage chemical decontamination technologies for primary cooling systems have been developed and commercialized, including NP-CITROX, AP/NP-CANDECON, CANDERM, AP/NP-LOMI and HP/CORD-UV. Among these, HP/CORDUV is currently the most actively applied primary cooling system chemical desalination process in the world. In this study, KAERI has developed a new chemical decontamination technology that does not contain organic chemical decontamination agents, with a focus on securing an original technology for reducing the amount of decontamination waste while having equivalent or better decontamination performance than overseas commercial technologies, and compared it with the inorganic chemical agent-based HyBRID (Hydrazine Based Reductive Metal Ion Decontamination) chemical decontamination technology.
        18.
        2023.11 구독 인증기관·개인회원 무료
        There are analytical methods used for measuring activity when light photons are emitted for scintillating-based analytical application. When this electron returns to the original stable state, it releases its energy in the form of light emission (visible light or ultraviolet light), and this phenomenon is called scintillation. Scintillator is a general term for substances that emit fluorescence when exposed to radiation such as gamma-rays. Radioactivity is all around us and is unavoidable because of the ubiquitous existence of background radiations emitted by different sources. The scintillator contributes to these sensing, and it is expected that the inspection accuracy and limit of detection will be improved and new inspection methods will be developed in the future. Moreover, scintillators are chemical or nanomaterial sensors that can be used to detect the presence of chemical species and elements or monitor physical parameters on the nanoscale. In this study, it includes finding use in scintillating-based analytical sensing applications. A chemical and nanomaterial based sensors are self-contained analytical tools that could provide information about the chemical compositions or elements of their environment, that is, a liquid or even gas condition. Herein, we present an insightful review of previously reported research in the development of high-performance gamma scintillators. The major performance-limiting factors of scintillation are summed up here. Moreover, the 2D material has been discussed in the context of these parameters. It will help in designing a prototype nanomaterial based scintillators for radiation detection of gamma-ray.
        19.
        2023.11 구독 인증기관·개인회원 무료
        Radioactive contamination distribution in nuclear facilities is typically measured and analyzed using radiation sensors. Since generally used detection sensors have relatively high efficiency, it is difficult to apply them to a high radiation field. Therefore, shielding/collimators and small size detectors are typically used. Nevertheless, problems of pulse accumulation and dead time still remain. This can cause measurement errors and distort the energy spectrum. In this study, this problem was confirmed through experiments, and signal pile-up and dead time correction studies were performed. A detection system combining a GAGG sensor and SiPM with a size of 10 mm × 10 mm × 10 mm was used, and GAGG radiation characteristics were evaluated for each radiation dose (0.001~57 mSv/h). As a result, efficiency increased as the dose increased, but the energy spectrum tended to shift to the left. At a radiation dose intensity of 400 Ci (14.8 TBq), a collimator was additionally installed, but efficiency decreased and the spectrum was distorted. It was analyzed that signal loss occurred when more than 1 million particles were incident on the detector. In this high-radioactivity area, quantitative analysis is likely to be difficult due to spectral distortion, and this needs to be supplemented through a correction algorithm. In recent research cases, the development of correction algorithms using MCNP and AI is being actively carried out around the world, and more than 98% of the signals have been corrected and the spectrum has been restored. Nevertheless, the artificial intelligence (AI) results were based on only 2-3 overlapping pulse data and did not consider the effect of noise, so they did not solve realistic problems. Additional research is needed. In the future, we plan to conduct signal correction research using ≈10×10 mm small size detectors (GAGG, CZT etc.). Also, the performance evaluation of the measurement/analysis system is intended to be performed in an environment similar to the high radiation field of an actual nuclear facility.
        20.
        2023.10 구독 인증기관·개인회원 무료
        In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.
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