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        검색결과 687

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to develop a deep learning model to monitor rice serving amounts in institutional foodservice, enhancing personalized nutrition management. The goal is to identify the best convolutional neural network (CNN) for detecting rice quantities on serving trays, addressing balanced dietary intake challenges. Both a vanilla CNN and 12 pre-trained CNNs were tested, using features extracted from images of varying rice quantities on white trays. Configurations included optimizers, image generation, dropout, feature extraction, and fine-tuning, with top-1 validation accuracy as the evaluation metric. The vanilla CNN achieved 60% top-1 validation accuracy, while pre-trained CNNs significantly improved performance, reaching up to 90% accuracy. MobileNetV2, suitable for mobile devices, achieved a minimum 76% accuracy. These results suggest the model can effectively monitor rice servings, with potential for improvement through ongoing data collection and training. This development represents a significant advancement in personalized nutrition management, with high validation accuracy indicating its potential utility in dietary management. Continuous improvement based on expanding datasets promises enhanced precision and reliability, contributing to better health outcomes.
        4,600원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Rehmannia glutinosa root and Saururus chinensis plant have been widely used in natural traditional medicines. This study was conducted to investigate the effect of the content of the main components of R. glutinosa root and S. chinensis plant by extraction method. The results of comparative analysis of extraction yield, total flavonoid, and polyphenol content by extraction method indicated that extraction yield had the best performance with hot water extraction for R. glutinosa and ultrasound-assisted extraction for S. chinensis. The total flavonoid and polyphenol content had the best performance with maceration extraction for R. glutinosa and ultrasound-assisted extraction for S. chinensis. ABTS and DPPH activity was excellent with maceration extraction for both R. glutinosa and S. chinensis. The analysis of the main components showed that maceration extraction was most effective for both S. chinensis and R. glutinosa. Specifically, maceration extraction of R. glutinosa yielded 1.5 times more than conventional ultrasound-assisted extraction.
        4,000원
        3.
        2024.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The separation of zirconium and hafnium using tributyl phosphate (TBP)-Dodecane extractants in nitric acid medium was performed. Zirconium oxychloride, used as extraction feed, was obtained from the synthesis of Kalimantan zircon sand concentrate smelted using NaOH. The extraction process was carried out by dissolving chloride-based metals in nitric acid media in the presence of sodium nitrate using TBP-Dodecane as an extractant. Some of the extraction parameters carried out in this study include variations in organic phase and aqueous phase (O/A), variations in contact time, and variations in nitric acid concentration. Extraction was carried out using a mechanical shaker according to the parameter conditions. X-ray fluorescence (XRF) was used for elemental (Zr and Hf) composition analysis of the aqueous solution. The results showed that zirconium was separated from hafnium at optimum conditions with an organic/aqueous ratio of 1:5, contact time of 75 min, and an HNO3 concentration of 7 M. The resulting separation factor of zirconium and hafnium using TBP-Dodecane was 14.4887.
        4,000원
        4.
        2024.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Broccoli and cabbage are known to have antioxidant, cholesterol-lowering, and anticancer effects due to their high bioactive component levels. This study applied 70% ethanol and hydrothermal extraction to separate bioactive components from broccoli and cabbage. 30oBrix extracts were freeze-dried and then diluted in various concentrations with distilled water for analysis. Total polyphenol contents, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric ion reducing antioxidant power, and hydrogen peroxide scavenging activity were analyzed. The diverse antioxidant assays, except DPPH radical scavenging activity, showed that hydrothermal extracts had significantly higher activity than the 70% ethanol extracts (p<0.05). In this study, it suggested that hydrothermal extraction is relatively effective in producing broccoli and cabbage extracts. Moreover, hydrothermal extraction conditions could be low-cost and environmentally friendly.
        4,000원
        8.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lycium barbarum extract has a high potential to be developed as a health functional food due to the various health-promoting effects of Lycium barbarum. This study analyzed changes in nutritional and functional components depending on the extraction solvent (purified water and a mixture of purified water and alcohol) and the condition of the sample. The nutritional components (carbohydrates, protein, fat, ash), organic acids, amino acids, total phenolic compounds, and total flavonoids of the extract produced during the extraction process were analyzed. The nutritional composition and functional substances of the extracts showed some differences depending on the type of solvent and the condition of the sample. The amounts of crude protein (7.61%), crude fat (1.63%), carbohydrate (90.22%), and ash (0.54%) of dried Lycium barbarum extract using purified water as a solvent were similar to those of the powder sample extract. The highest content of citric acid was 4.31 mg/mL, similar to the case of acetic acid, when the powder sample used a mixture of purified water and alcohol as a solvent. The highest amino acid content was 357.39 mg/mL when the powder sample was mixed with purified water and alcohol as a solvent. The total amount of phenolic compounds was 686.16 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent. The highest total flavonoid content was 111.32 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent.
        4,000원
        9.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the ultrasonication-assisted extraction conditions that maximize the DPPH radical scavenging activity of extracts obtained from the stems of Lespedeza bicolor Turcz through the application of the Response Surface Methodology (RSM). Before delving into the analysis of extraction conditions using the RSM model, we conducted efficiency validation of ultrasonication-assisted extraction and executed single-factor experiments for ethanol concentration, extraction time, and extraction temperature. The data obtained from these single-factor experiments were employed to construct the Box-Behnken Design (BBD). In these results, in the single-factor experiments, it was evident that the parameters for ethanol concentration, extraction time, and extraction temperature exhibited quadratic trends. The single-factor experiments allowed us to discern the trends for each parameter leading to the maximum antioxidant capacity, and this data was subsequently applied to the BBD. Following the completion of initial experiments, a Response Surface Methodology (RSM) model was constructed based on Box-Behnken Design (BBD). According to the predictive model developed in this study, it was anticipated that performing ultrasonic-assisted extraction for 85.0412 minutes at an ethanol concentration of 32.573% and an extraction temperature of 51.5608°C will result in a DPPH radical scavenging activity of 79.7146%. The predictive results were statistically verified through a comparative analysis with actual measurements and ANOVA analysis, confirming the statistical significance of the model. The finding of this study underscore the significance of optimizing extraction conditions in the precise quantification of the antioxidant potential for economic advantages in both experimental and industrial contexts.
        4,900원
        10.
        2024.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        총담관결석의 치료는 내시경역행담췌관조영술을 시행하여 결석을 제거하는 것이 표준적인 방법이며 내시경유두부 괄약근절개술 및 내시경유두부풍선확장술을 시행한 후 바스켓 및 풍선도관, 기계석 쇄석술 등의 여러가지 방법을 사용하여 그 성공률은 90% 이상으로 알려져 있다. 그러나 일부 거대담석이나 담도협착이 동반된 경우 등에서는 담석의 제거에 실패하는 경우가 있다. 본 저자들은 방사선 비투과성 담석에 대해서 일반적인 담석제거를 위한 방법을 사용한 후에도 담석제거에 실패하고 기계적 쇄석술을 시행하던 중 바스켓의 철선이 끊어지면서 담석과 함께 총담관 내에 잔류하게 된 환자에서 체외충격파 쇄석술을 시행하여 담석을 파쇄한 후 담석의 제거에 성공하였던 증례를 문헌고찰과 함께 보고한다.
        4,000원
        11.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        빠르게 발전하는 이미지 인식 기술에도 불구하고 표 형식의 문서와 수기로 작성된 문서를 완벽하게 디지털화하기에는 아직 어려움이 따른다. 본 연구는 표 형식의 수기 문서인 선박 항해일지를 작성하는 데에 사용되는 규칙을 이용하여 보정 작업을 수행함으로 써 OCR 결과물의 정확도를 향상시키고자 한다. 이를 통해 OCR 프로그램을 통하여 추출된 항해일지 데이터의 정확성과 신뢰성을 높일 것 으로 기대된다. 본 연구는 목포해양대학교 실습선 새누리호의 2023년에 항해한 57일간의 항해일지 데이터를 대상으로 OCR 프로그램 인 식 후 발생한 오류를 보정하여 그 정확도를 개선하고자 하였다. 이 모델은 항해일지 기재 시 고려되는 몇 가지 규칙을 활용하여 오류를 식별한 후, 식별된 오류를 보정하는 방식으로 구성하였다. 모델을 활용하여 오류를 보정 후, 그 효과를 평가하고자 보정 전과 후의 데이터 를 항차별로 구분한 후, 같은 항차의 같은 변수끼리 비교하였다. 본 모델을 활용하여 실제 셀 오류율은 약 11.8% 중 약 10.6%의 오류를 식 별하였고, 123개의 오류 중 56개를 개선하였다. 본 연구는 항해일지 중 항해정보를 기입하는 Dist.Run부터 Stand Course까지의 정보만을 대 상으로 수행하였다는 한계점이 있으므로, 추후 항해정보 뿐만 아니라 기상정보 등 항해일지의 더 많은 정보를 보정하기 위한 연구를 진 행할 예정이다.
        4,200원
        12.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to investigate antioxidant and anti-inflammatory activities of perilla(Perilla frutescens L.) seed, flower and leaf according to extraction condition. Perilla seed extracts(PSE), perilla flower extracts(PFE), perilla leaf extracts(PLE) was extracted by stirring extraction (STE, 25°C), shaking extraction (SHE, 80°C), and sonication assisted extraction(SAE, , 25°C) with 94% ethanol, 60% ethanol and distilled water, followed by analysis of total polyphenol and flavonoid and testing radical scavenging activities. The highest total polyphenol content (5.47, 9.36, 38.58 mg gallic acid equivalent/g), total flavonoid content(5.77, 8.62, 46.44 mg catechin equivalent/g), ABTS(10.68, 19.46, 63.56 mg trolox equivalent/g) and DPPH(6.51, 7.69, 79.73 mg trolox equivalent/g) radical scavenging activity of PSE, PFE and PLE was observed in the HWE with 60% ethanol,. Among the three extraction method, SHE provided the best results for yield, polyphenol, flavonoid content of perilla seed, flower, leaf in comparison to STE or SAE. SHE with 60% ethanol of perilla seed, flower, leaf more effectively inhibited secretion of nitric oxide(NO) and pro-inflammatory cytokine in RAW 264.7 macrophage exposed to LPS compared to other extraction solvent and method. Therefore, these extracts obtained from perilla seed, flower, leaf could be used antioxidant and anti-inflammatory ingredients in the food industry.
        4,000원
        13.
        2023.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to examine the possibility of upcycling extracts of Angelica keiskei and Oenanthe javanica juice by-products through comparing enzyme extraction (EE) and complex extraction (CE) methods to increase the extraction yield and flavor of materials. A higher extraction yield was obtained for free amino acid content with EE and CE for A. keiskei and O. javanica juice by-products, respectively, and a higher extraction efficiency was achieved with juice by-products than with extracts prepared from raw materials before juice production. The content of major amino acids varied depending on the extraction method used. When used according to the characteristics of the extract, their use as a functional material was confirmed along with improvement in the flavor of the food. Consistently high extraction yields for organic acid and sugar levels were obtained with CE in A. keiskei and O. javanica juice by-products. The DPPH radical scavenging ability and TPC were consistently high with CE in A. keiskei and O. javanica juice by-products; the increase in extracted content was likely because of the reaction between the ethanol used for CE and the phenolic compounds. However, because the antioxidant capacity of the juice by-product extracts was somewhat lower than that of the extracts from raw materials before juice production, the amount used should be reviewed. The TFC was found to be higher in extracts obtained with EE than with CE for A. keiskei juice by-products; however, no significant difference was observed between EE and CE in the O. javanica juice by-products. Through this study, the taste compounds and antioxidant properties of extracts obtained from juice by-products produced after the production of A. keiskei and O. javanica green juice were analyzed, and the availability of high value-added materials was confirmed. Based on these research results, expanding specific R&D for practical use should be explored.
        4,200원
        15.
        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.
        16.
        2023.11 구독 인증기관·개인회원 무료
        During the initial cooling period of spent nuclear fuel, Cs-137 and Sr-90 constitute a large portion of the total decay heat. Therefore, separating cesium and strontium from spent nuclear fuel can significantly decrease decay heat and facilitate disposition. This study presents analytical technique based on the gas pressurized extraction chromatography (GPEC) system with cation exchange resin for the separation of Sr, Cs, and Ba. GPEC is a micro-scaled column chromatography system that allows for faster separation and reduction volume of elution solvent compared to conventional column chromatography by utilizing pressurized nitrogen gas. Here, we demonstrate the comparative study of the conventional column chromatography and the GPEC method. Cation exchange resin AG 50W-X12 (200~400 mesh size) was used. The sample was prepared at a 0.8 M hydrochloric acid solution and gradient elution was applied. In this case, we used the natural isotopes 88Sr, 133Cs, and 138Ba instead of radioactive isotopes for the preliminary test. Usually, cesium is difficult to measure with ICP-OES, because its wavelengths (455.531 nm and 459.320 nm) are less sensitive. So, we used ICP-MS to determine the identification and the recovery of eluate. In this study, optimized experimental conditions and analytical result including reproducibility of the recovery, total analysis time and volume of eluents will be discussed by comparing GPEC and conventional column chromatography.
        17.
        2023.11 구독 인증기관·개인회원 무료
        To address the pressing societal concern in Korea, characterized by the imminent saturation of spent nuclear fuel storage, this study was undertaken to validate the fundamental reprocessing process capable of substantially mitigating the accumulation of spent nuclear fuel. Reprocessing is divided into dry processing (pyro-processing) and wet reprocessing (PUREX). Within this context, the primary focus of this research is to elucidate the foundational principles of PUREX (Plutonium Uranium Redox Extraction). Specifically, the central objective is to elucidate the interaction between uranium (U) and plutonium (Pu) utilizing an organic phase consisting of tributyl phosphate (TBP) and dodecane. The objective was to comprehensively understand the role of HNO3 in the PUREX (Plutonium Uranium Redox Extraction) process by subjecting organic phases mixed with TBPdodecane to various HNO3 concentrations (0.1 M, 1.0 M, 5.0 M). Subsequently, the introduction of Strontium (Sr-85) and Europium (Eu-152) stock solutions was carried out to simulate the presence of fission products typically contented in the spent nuclear fuel. When the operation proceeds, the complex structure takes the following form. 􀜷􀜱􀬶 􀬶􀬾(􀜽􀝍) + 2􀜰􀜱􀬷 􀬿(􀜽􀝍) + 2􀜶􀜤􀜲(􀝋􀝎􀝃) ↔ 􀜷􀜱􀬶(􀜰􀜱􀬷)􀬶 ∙ 2􀜶􀜤􀜲(􀝋􀝎􀝃) Subsequently, separate samples were gathered from both the organic and aqueous phases for the quantification of gamma-rays and alpha particles. Alpha particle measurements were conducted utilizing the Liquid Scintillation Counter (LSC) system, while gamma-ray measurements were carried out using the High-Purity Germanium Detector (HPGe). The distribution ratio for U, Eu (Eu-152), and Sr (Sr-84) was ascertained by quantifying their activity through LSC and HPGe. Through the experiments conducted within this program, we have gained a comprehensive understanding of the selective solvent extraction of actinides. Specifically, uranium has been effectively separated from the aqueous phase into the organic phase using a combination of tributyl phosphate (TBP) and dodecane. Subsequently, samples containing U(VI), Eu(III), and Sr(II) underwent thorough analysis utilizing LSC and HPGe detectors. Our radiation measurements have firmly established that the concentration of nitric acid enhances the selective separation of uranium within the process.
        18.
        2023.11 구독 인증기관·개인회원 무료
        Recently, the status of North Korea’s denuclearization has become an international issue, and there are also indications of potential nuclear proliferation among neighboring countries. So, the need for establishment of nuclear activity verification technology and strategy is growing. In terms of ensuring verification completeness, sample collection-based analysis is essential. The concepts of Chain of Custody (CoC) and Continuity of Knowledge (CoK) can be defined in the process of sample extraction as follows: CoC is interpreted as the ‘system for managing the flow of information subjected by the examinee’, and CoK is interpreted as the ‘Continuity of information collection through CoC subjected by the inspector’. In the case of sample collection process in unreported areas for nuclear activity verification, there are additional risks such as worker exposure/kidnapping or sample theft/tampering. Therefore, the introduction of additional devices might be required to maintain CoC and CoK in the unreported area. In this study, an Environmental Geometrical Data Transfer (EGDT) was developed to ensure the safety of workers and the CoC/CoK of the samples during the collection process. This device was designed for achieving both mobility and rechargeability. It is categorized into two modes based on its intended users: sample mode and worker mode. Through the sensors, which is positioned in the rear part of device, such as radiation, gyroscope, light, temperature, humidity and proximity sensors, it can be easily achievable various environmental information in real-time. Additionally, GPS information can also be received, allowing for responsiveness to various hazardous scenarios. Moreover, the OLED display positioned on the front gives us for checking device information such as the current status of the device such as the battery level, the connectivity of wifi, and etc. Finally, an alarm function was integrated to enable rapid awareness during emergency situations. These functions can be updated and modified through Arduino-based firmware, and both the device and the information collected through it can be remotely controlled via custom software. Based on the presented design conditions, a prototype was developed and field assessments were conducted, yielding results within an acceptable margin of error for various scenarios. Through the application of the EGDT developed in this study to the sample collection process for nuclear activity verification purposes, it is expected to achieve a stable maintenance of CoC/CoK through more accurate information transmission and reception.
        19.
        2023.11 구독 인증기관·개인회원 무료
        Uranium extraction from seawater has been a topic of considerable interest over the past decades. However, Commercial facilities for uranium extraction from seawater have not yet been constructed due to its lack of economic feasibility. With the increasing demand for sustainable energy sources, there is a growing interest in eco-friendly uranium extraction methods. Despite this, the safeguards associated with these extraction techniques remain relatively under-researched, necessitating comprehensive studies that address both the economic feasibility and safeguards approach. The Korea Hydro & Nuclear Power Central Research Institute is poised to elucidate the economic value of uranium extraction from seawater and embark on research to extract Yellow Cake from seawater on a laboratory scale. Given these advancements, it becomes imperative to consider the approach to safeguards. In this study, a comprehensive review was conducted to understand the relevant regulations that encompass both international obligations in partnership with the IAEA and domestic guidelines, specifically the Nuclear Safety Act. Emphasis was placed on a detailed examination of the IAEA’s comprehensive safeguards agreement and its additional protocol, focusing on deriving the necessary regulatory timings, subjects, and methodologies for effective reporting and verification. We reviewed the safeguards guidelines and the IAEA policy to confirm the international non-proliferation obligations. The study also reviewed the impact of the State-Level Approach promoted by the IAEA and its implications on state-specific factors and evaluations of state technological advancement. Additionally, the regulatory aspects of extracted uranium as an internationally regulated material under the Nuclear Safety Act were critically assessed. In conclusion, this study explains the international and domestic regulatory considerations for uranium extraction from seawater. Ultimately, this study will provide valuable understanding for policymakers, researchers, and practitioners involved in uranium extraction from seawater. Additionally, we expect that this study will contribute to establishing the safeguards approach and regulatory framework for the commercialization of uranium extraction from seawater in the ROK.
        20.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The spherical mesophases are the main precursors for the high tap density of carbonaceous anode batteries. However, it is challenging to control mesophase size without coalescence and no deformation since it quickly coalesces into a regular large sphere. Here, we propose a feasible extraction method to refine the spherical size of mesophase using benzene. Thermogravimetric and differential scanning calorimetry analysis of untreated pitch revealed that the maximum temperature for mesophase nucleation should not exceed 410 °C to provoke the nucleation of mesophase spheres while maintaining a high pyrolysis yield. The extraction results showed that the extraction weight tends to decrease with an increase in the solvent ratio. There is an exponential relationship between the influence of solvent ratio and the ability for extraction. The solubility of the spherical mesophase in benzene is size-dependent and can dissolve selectively spherical mesophases smaller than 5 μm. Consequently, a monodisperse spherical mesophase was obtained. The reason for forming uniform mesophase spheres can be explained by their thermodynamic state, as described by the “two-step” classical nucleation theory. Benzene effectively improves the size distribution of spherical mesophase by dissolving small sizes while retaining large ones.
        4,000원
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