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        검색결과 698

        1.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Animal experiments have demonstrated the effectiveness of fermented rice germ and soybean extracts in lowering blood alcohol concentration. A compound primarily derived from fermented soybean extract constitutes the principal component of DA-5521, an experimental dietary substance examined in this study. We investigated the possible hangover-alleviating effects of DA-5521 in individuals aged 19 to 50 who had previously experienced hangovers. Moreover, we enrolled 22 participants who met the eligibility criteria and conducted a double-blind, randomized, placebo-controlled crossover trial. Six hours after alcohol consumption, the test group exhibited a statistically significant reduction in blood acetaldehyde concentration compared with the placebo group. Further, our results displayed significantly lower levels in the DA- 5521 group at 0.50 and 0.75 h post-ingestion and substantially lower peak breath alcohol concentration compared to the placebo group. These findings confirm that consumption of DA-5521 can significantly ameliorate hangover symptoms by diminishing blood acetaldehyde concentration and reduce breath alcohol concentration.
        4,200원
        2.
        2024.01 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Korean historical literatures offer numerous records on astronomical phenomena such as eclipses, comets, and close approaches, etc. Records of close approaches often use specific terms to describe the angular distance, which lack translation into modern numerical values. We study the usage of the five commonly used terms, namely, Entry (入, En), Invasion (犯, In), Occultation (掩, Oc), Eclipse (食, Ec), as well as the unit Chi (尺). Our analysis is based on more than 2,300 records from Goryeo (918–1392 CE) and Joseon (1392–1910 CE) Dynasties. Through statistical analysis, we determine their quantitative definitions. We convert the lunisolar calendar to the Julian and Gregorian date and utilize the modern ephemeris DE431 to calculate the angular distance between celestial bodies. We find that the angular distances of the terms En, In, Oc, and Ec correspond to respectively 1.78◦+2.36 −1.11, 0.89◦+3.54 −0.51, 0.44◦+1.15 −0.31, and 0.29◦+2.61 −0.16 for the Goryeo Dynasty and 1.36◦+1.15 −0.64, 0.51◦+1.11 −0.32, 0.25◦+0.27 −0.17, and 0.21◦+0.25 −0.11 for the Joseon Dynasty. Additionally, we determine the angular size of the unit Chi by using the records from Korean chronicles along with the drawings of comets’ tails in the Daily Log (天變謄錄). We estimate the unit Chi to be 1.11◦+0.46 −0.40 and find that the numerical definition was consistent throughout the two dynasties in Korea. Furthermore, we find that the terms were used to describe the closest approach and that there is no observational bias in the angular distances against the apparent magnitudes of the objects. We show that the terms En, In, Oc, and Ec represent decreasing angular distance in that order and this ordering was consistent in both dynasties.
        4,000원
        3.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: There is a lack of research on sling neurac exercise interventions for craniovertebral angle (CVA), head rotation angle, range of motion (ROM), and neck postural alignment in adults with forward head posture Objectives: To investigate the Immediate effects of sling neurac exercise on craniosacral angulation, ROM, and neck postural alignment in adults with forward head posture. Design: Quaxi-experimental study. Methods: Fifty young adults in their 20s were divided into a sling neurac exercise group (SNEG) and a control group (CG). SNEG conducted sling neurac exercise intervention for one day, and CG did not implement intervention. Craniosacral angulation, ROM, and postural alignment before and after exercise was evaluated for each group. Results: In the sling neurac exercise group (SNEG), CVA, cranial rotation angle (CRA), ROM, and postural alignment improved significantly after intervention (all P<.01). There were no significant differences in the control group (CG) (all P>.05). After the intervention, there were significant differences between the groups in craniosacral angulation, ROM, and postural alignment (all P<.01). Conclusion: The Sling neurac exercise can significantly improve CVA, CRA, ROM, and postural alignment. Therefore, it is suggested to consider sling neurac exercise as an intervention.
        4,000원
        4.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to prepare kombucha, a fermented tea beverage, containing Dendropanax morbiferus (DM) leaves and roots, and analyze its antioxidant and intracellular activities. We compared the pH change, total acidity, radical scavenging activity, and oxygen radical absorbance capacity (ORAC) of kombucha fermented with black tea alone and that with added DM leaves or roots during fermentation. Using RAW 264.7, we evaluated the effects of kombucha containing different DM parts on nitric oxide (NO) production and inflammation-related cytokine content in cells. Kombucha containing ethanol extracts of DM leaves (BTK-E-DML) and roots (BTK-E-DMR) showed higher radical scavenging activity and ORAC 3 d after fermentation than that prepared from black tea alone (BTK-Ori). In an in vitro experiment using RAW 264.7, samples were treated with 8 mg/mL kombucha considering cytotoxicity; the lipopolysaccharide (LPS)-induced NO content significantly reduced after BTK-E-DML and BTK-EDMR treatments compared with that after BTK-Ori treatment. Additionally, the levels of interleukin-6 and tumor necrosis factor-alpha, which were LPS-stimulated inflammatory cytokines, significantly decreased in cells treated with BTK-E-DML and BTK-E-DMR 15 d after fermentation compared with those treated with BTK-Ori. In conclusion, these results demonstrate that kombucha fermented with the leaves and roots of DM increases antioxidant activity and can significantly regulate inflammatory responses at the cellular level.
        4,000원
        11.
        2023.11 구독 인증기관·개인회원 무료
        Chelating agents, such as EDTA, NTA, and citric acid, possess the capacity to establish complexes with radionuclides, potentially enhancing the migration of such radionuclides from the disposal sites. Hence, quantification of these chelating agents in radioactive wastes is required to ensure secure disposal protocols. The determination of chelating agents in radioactive wastes is mainly composed of two steps, e.g. extraction and detection. However, there are little information on the extraction of the chelators in various radioactive wastes. We endeavored to optimize the extraction conditions for citric acid (CA) found within concrete, a prevalent component in the context of dismantled waste materials. Given the inherent high solubility of CA in water, we applied an aliquot of deionized water to the concrete and conducted a one-hour ultrasonic leaching procedure to facilitate chelate extraction. Subsequently, following the preparation of the concrete leachate via vacuum filtration and centrifugation to yield a clarified solution, we quantified the concentration of CA within the solution using Ion Chromatography (IC). To enhance leaching efficiency, we examined the % recovery variation with respect to the pH of the leaching solution. The optimized extraction method will be applied to diverse chelating agents and radioactive waste categories.
        12.
        2023.11 구독 인증기관·개인회원 무료
        Spent ion exchange resins have been generated during the operation of nuclear facilities. These resins include radioactive nuclides. It is needed to fabricate them into a stable form for final disposal. Cement solidification process is a useful method for the fabrication of them into a waste form for final disposal. In this study, proper conditions for the fabrication of them into a stable waste form were determined using the cement solidification process. In-drum waste forms were then produced at the conditions, where the stability of representative samples was evaluated for final disposal. The samples were satisfied to the Waste Acceptance Criteria for low and intermediate level radioactive waste disposal sites. This result can be utilized to derive optimal conditions for the fabrication of spent ion exchange resins into a final disposal form.
        13.
        2023.11 구독 인증기관·개인회원 무료
        Advanced countries in the field of nuclear research and technology are currently examining the feasibility of deep geological disposal as the most appropriate method for the permanent management of high-level radioactive waste, with no intention of future retrieval. Deep geological disposal involves the placement of such waste deep underground within a stable geological formation, ensuring its permanent isolation from the human environment. To guarantee the enduring isolation and retardation of radionuclides with half-lives spanning tens of thousands to millions of years from the broader ecosystem, it is imperative to comprehend the long-term evolution of deep disposal systems, especially the role of natural barriers. These natural barriers, typically consisting of bedrock, encase the repository and undergo long-term evolutions due to tectonic movements and climate variations. For the effective disposal of high-level radioactive waste, a thorough assessment of the site’s long-term geological stability is essential. This necessitates a comprehensive understanding of its tectonic evolution and development characteristics, including susceptibility to seismic and magmatic events like earthquakes and intrusions. Furthermore, a detailed analysis of alterations in the hydrogeological and geochemical environment resulting from tectonic movements over extended time frames is required to assess the potential for the migration of radionuclides. In this paper, we have examined international evaluation methodologies employed to elucidate the predictive long-term evolution of natural barriers within disposal systems. We have extracted relevant methods from international case studies and applied a preliminary scenario illustrating the long-term evolution of the geological environment at the KURT (KAERI Underground Research Tunnel) site. Nevertheless, unlike international instances, the scarcity of quantitative data limits the depth of our interpretation. To present a dependable scenario in the future, it is imperative to develop predictive technologies aimed at comprehensively studying the geological evolution processes in the Korean peninsula, particularly within the context of radioactive waste disposal.
        14.
        2023.11 구독 인증기관·개인회원 무료
        The effectiveness of a crystalline natural barrier in providing sealing capabilities is based on the behavior of numerous fractures and their intersections within the rock mass. It is important to evaluate the evolving characteristics of fractured rock, as the hydro-mechanical coupled processes occurring through these fractures play a dominant role. KAERI is actively developing a true tri-axial compression test system and concurrently conducting hydro-mechanical experiments using replicated fractured rock samples. This research is focused on a comprehensive examination of coupled processes within fractures, with a particular emphasis on the development of true tri-axial testing equipment. The designed test system has the capability to account for three-dimensional stress conditions, including vertical and both maximum and minimum horizontal principal stresses, realizing the disposal conditions at specific underground depths. Notably, the KAERI-designed test system employs the mixed true tri-axial concept, also known as the Mogi-type, which allows for fluid flow into fractures under tri-axial compression conditions. This system utilizes a hydraulic chamber to maintain constant stress in one direction through the application of oil pressure, while the other two directional stresses are applied using rigid platens with varying magnitudes. Once these mechanical stress conditions are established, control over fluid flow is achieved through the rigid platens in contact with the specimen section. This pioneering approach effectively replicates in-situ mechanical conditions while concurrently observing the internal fluid flow patterns within fractures, thereby enhancing our capacity to study these coupled phenomena. As future research, numerical modeling efforts will be proceeding with experimental data-driven approaches to simulate the coupled behavior within the fractures. In these numerical studies, two distinct fracture geometry domains will be generated, one employing simplified rough-walled fractures and the other utilizing mismatched rough-walled fractures. These investigations mark the preliminary steps in the process of selecting and validating an appropriate numerical model for understanding the hydro-mechanical evolution within fractures.
        15.
        2023.11 구독 인증기관·개인회원 무료
        The solid-state chemistry of uranium is essential to the nuclear fuel cycle. Uranyl nitrate is a key compound that is produced at various stages of the nuclear fuel cycle, both in front-end and backend cycles. It is typically formed by dissolving spent nuclear fuel in nitric acid or through a wet conversion process for the preparation of UF6. Additionally, uranium oxides are a primary consideration in the nuclear fuel cycle because they are the most commonly used nuclear fuel in commercial nuclear reactors. Therefore, it is crucial to understand the oxidation and thermal behavior of uranium oxides and uranyl nitrates. Under the ‘2023 Nuclear Global Researcher Training Program for the Back-end Nuclear Fuel Cycle,’ supported by KONICOF, several experiments were conducted at IMRAM (Institute of Multidisciplinary Research for Advanced Materials) at Tohoku University. First, the recovery ratio of uranium was analyzed during the synthesis of uranyl nitrate by dissolving the actual radioisotope, U3O8, in a nitric acid solution. Second, thermogravimetric-differential thermal analysis (TG-DTA) of uranyl nitrate (UO2(NO3)2) and hyper-stoichiometric uranium dioxide (UO2+X) was performed. The enthalpy change was discussed to confirm the mechanism of thermal decomposition of uranyl nitrate under heating conditions and to determine the chemical hydrate form of uranyl nitrate. In the case of UO2+X, the value of ‘x’ was determined through the calculation of weight change data, and the initial form was verified using the phase diagram for the U-O system. Finally, the formation of a few UO2+X compounds was observed with heat treatment of uranyl nitrate and uranium dioxide at different temperature intervals (450°C-600°C). As a result of these studies, a deeper understanding of the thermal and chemical behavior of uranium compounds was achieved. This knowledge is vital for improving the efficiency and safety of nuclear fuel cycle processes and contributes to advancements in nuclear science and technology.
        16.
        2023.11 구독 인증기관·개인회원 무료
        Once discharged, spent nuclear fuel undergoes an initial cooling process within deactivation pools situated at the reactor site. This cooling step is crucial for reducing the fuel’s temperature. Once the heat has sufficiently diminished, two viable options emerge: reprocessing or interim storage. A method known as PUREX, for aqueous nuclear reprocessing, involves a chemical procedure aimed at separating uranium and plutonium from the spent nuclear fuel. This separation not only minimizes waste volume but also facilitates the reuse of the extracted materials as fuel for nuclear reactors. The transformation of uranium oxides through dissolution in nitric acid followed by drying results in uranium taking the form of UO2(NO3)2 + 6H2O, which can then be converted into various solid-state configurations through different heat treatments. This study specifically focuses on investigating the phase transitions of artificially synthesized UO2(NO3)2 + 6H2O subjected to heat treatment at various temperatures (450, 500, 550, 600°C) using X-ray Diffraction (XRD) analysis. Heat treatments were also conducted on UO2 to analyze its phase transformations. Additionally, the study utilized XRD analysis on an unidentified oxidized uranium oxide, UO2+X, and employed lattice parameters and Bragg’s law to ascertain the oxidation state of the unknown sample. To synthesize UO2(NO3)2 + 6H2O, U3O8 powder is first dissolved in a 20% HNO3 solution. The solid UO2(NO3)2 + 6H2O is obtained after drying on a hotplate and is subsequently subjected to heat treatment at temperatures of 450, 500, 550, and 600°C. As the heat treatment temperature increases, the color of the samples transitions from orange to dark green, indicating the formation of different phases at different temperatures. XRD analysis confirms that uranyl nitrate, when heattreated at 500 and 550°C, oxidizes to UO3, while the sample subjected to 600°C heat treatment transforms into U3O8 due to the higher temperature. All samples exhibit sharp crystal peaks in their XRD spectra, except for the one heat-treated at 450°C. In the second experiment, the XRD spectra of the heat-treated UO2 consistently indicate the presence of U3O8 rather than UO3, regardless of the temperature. Under an oxidizing atmosphere within a temperature range of 300 to 700°C, UO2 can be oxidized to form U3O8. In the final experiment, the oxidation state of the unknown UO2+X was determined using Bragg’s law and lattice parameters, revealing that it was a material in which UO2 had been oxidized, resulting in an oxidation state of UO2.24.
        17.
        2023.10 구독 인증기관·개인회원 무료
        참깨는 건전 유기 종자생산을 위해서는 Corynespora cassicola 등과 같은 종자전염 병원균의 감염을 최소화해 야 하므로 비가림하우스 내에서의 종자생산이 필수적이다. 그러나 비가림하우스 재배 시 진딧물의 대발생으로 참깨의 생산량 저하 되므로 본 연구에서는 참깨 비가림하우스 내 유기 재배 시, 진딧물에 대한 효과적인 유기농업 자재를 선발하고자 한다. 등록된 유기농업자재 8종 중 4종을 기내에서 선발하였으며 선발된 유기농업자재 4종을 참깨 재배기간 중 주 1회 처리한 결과, 처리 간 유의한 차이가 나타났다. 수확기인 8월 3일 기준 무처리구 대비 데리스추출물 70%와 데리스 20%+시트로넬라 30%+계피추출물 10%은 12.3%, 9.0%만이 고사하여 우수한 방제 효과를 나타냈다. 본 연구 결과는 참깨 재배 시 농림현장에서 발생하는 복숭아혹진딧물에 대한 유기농업자재 효과를 검정함으로써 유기재배 농가의 자재 선택에 대한 정보를 제공하고자 한다
        18.
        2023.10 구독 인증기관·개인회원 무료
        본 연구는 벼 화분에 잔류한 네오니코티노이드계 약제가 꿀벌 봉군 내로 유입하여 만성적으로 피해를 주는지 에 대해 실험적으로 검증하고자 한다. 벼 꽃 개화기에 맞춰 논 인근의 세 지역에 각 6개 봉군을 설치하였다. 3개의 지역 중 두 지역은 벼 꽃 개화기 항공 방제 수행지역이고, 1개 지역은 미수행 지역이다. 지역마다 봉군 3개에는 채분기를 설치하여 벌통 내 화분 유입을 차단한 그룹과 미설치 그룹 간 봉세와 꿀벌 면역 및 수명 관련 유전자 발현량을 비교하였다. 약제 방제가 수행된 지역에서 채분기를 설치한 봉군의 봉세는 미설치 봉군보다 상대적으 로 강한 것을 확인하였다. 또한, 약제 처리 지역에서 채분기 설치 봉군에서 채분기를 설치한 봉군의 봉세는 미설치 봉군보다 상대적으로 강한 것을 확인하였다. 또한, 약제 처리 지역에서 채분기 설치 봉군에서 채집된 꿀벌의 면역 및 수명 관련 유전자 발현량이 미설치 그룹과 차이가 있는 것을 확인하였다.
        19.
        2023.10 구독 인증기관·개인회원 무료
        생활권 수목이란 주민들이 생활하는 지역에 식재된 수목으로, 가로수, 학교수목, 아파트 수목 등 종류가 다양 하며 도시경관과 생활환경 개선의 이점을 제공한다. 그러므로 생활권 수목의 유지와 관리에 있어서도 인근 주민 에 혐오감이나 피해가 없도록 방제를 수행하는 것이 매우 중요하다. 일반적인 경엽살포의 경우, 약액 비산에 의해 주민들의 활동 제한, 안전사고 및 재산상 피해가 발생할 수 있으므로 사용이 제한적이다. 이러한 문제를 해결하기 위해, 나무에 약제를 직접 주입하는 나무주사(trunk injection)가 보편적인 생활권 수목 방제법으로 주목 받고 있으며, 이는 주입물질의 손실이 없고, 외부환경에 크게 영향 받지 않는다는 장점이 있다. 하지만 생활권 수목 전반에 대한 나무주사 처리방법이 명확하지 않아 약효가 일부 가지에서만 나타나는 등 사후 검증 및 관리가 미흡한 실정이다. 본 연구는 생활권 수목 병해충 방제 나무주사 제품의 효과제고를 위한 기존 처리방법 개선 및 최적의 약제처리 방법을 검증하였다. 느티나무외줄면충(Colopha moriokaensis)을 대상으로 시험을 진행하였 으며, Acetamiprid을 시험약제로 사용하였다. 느티나무에 대하여 약제처리 위치, 주입량, 천공수, 주사시기에 따른 약효 및 약해를 확인하였으며, 이를 바탕으로 최적의 약제처리 방법을 제시하였다.
        20.
        2023.10 구독 인증기관·개인회원 무료
        Climate change and biological invasions are the greatest threats to biodiversity, agriculture, health and the global economy. Tomato leafminer(Tuta absoluta) (Meyrick) (Lepidoptera: Gelechiidae) is one of the most important threats to agriculture worldwide. This pest is characterized by rapid reproduction, strong dispersal ability, and highly overlapping of generations. Plants are damaged by direct feeding on leaves, stems, buds, calyces, young ripe fruits and by the invasion of secondary pathogens which enter through the wounds made by the pest. Since it invaded Spain in 2006, it has spread to Europe, the Mediterranean region, and, in 2010, to some countries in Central Asia and Southeast Asia. In East Asia, Tomato leafminer was first detected in China in Yili, Xinjiang Uygur Autonomous Region, in 2017. There is a possibility that this pest will invade South Korea as well. This study provides this by the use of MaxEnt algorithm for modelling the potential geographical distribution of Tomato Leafminer in South Korea Using presence-only data.
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