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        검색결과 39

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 Diode Array Detector (DAD)가 장착된 고성능 액체 크로마토그래피(HPLC)를 이용하여 산초나무 잎에 함유된 chlorogenic acid와 hesperidin을 동시에 분석할 수 있는 표준 정량법 개발을 확립하고자 실시하였다. 산초나무 잎의 chlorogenic acid와 hesperidin은 MS/MS 분석 및 표준물질과의 유지시간(RT), UV 흡광도 비교를 통해 확인하였고, 산초나무 잎의 지표물질로 선정하였다. 개발한 분석방법은 지표물질을 대상으로 특이성, 정확성, 정밀도, 검출한계, 정량한계, 선형성에 대해 최적화하고 검증하였다. HPLC 분석으로 두 화합물에 대한 검량선은 각각 0.99% 이상의 높은 상관계수(r2)를 보였다. Chlorogenic acid의 전체 회수율은 106.82%이었고, hesperidin의 전체 회수율은 107.37%였다. Chlorogenic acid의 검출한계(LOD)는 0.271μg/ml, Hesperidin의 검출한계(LOD)는 0.005μg/ml였다. Chlorogenic acid의 일간정밀도는 0.102% (RSD%), Hesperidin의 일간정밀도는 1.038% (RSD%)였다. 본 연구에서 개발한 HPLC-DAD 분석방법은 기능성 원료 인정을 위한 분석기준을 충족하였다. 따라서 본 연구에서 확립한 HPLC 분석법은 향후 산초나무 잎에서 유래한 생리활성물질의 대량추출 및 관련제품을 개발할 때 원료 표준화에 적용가능할 것이다.
        4,000원
        2.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the cause of mortar baseplate breakage was analyzed by diving into cross-section, material, process, and design aspects. As a result of observing the fracture surface and non-fracture suface using optical equipment, it was possible to confirm changes in the shape of disconnected line and metal surface at a specific area. In addition, a number of linear defects due to overlap were found. Flow analysis was performed using the Deform program to verify changes during the production process. According to the result, a drop test was performed on each of the lap detection baseplate, undetection baseplate, and removed product to verify the presumptive cause of the rupture of the poplite.
        4,000원
        4.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although many attempts have been made to solve the atmospheric diffusion equation, there are many limits that prevent both solving it and its application. The causes of these impediments are primarily due to both the partial differentiation term and the turbulence diffusion coefficient. In consideration of this dilemma, this study aims to discuss the methodology and cases of utilizing a passive air sampler to increase the applicability of atmospheric dispersion modeling. Passive air samplers do not require pumps or electric power, allowing us to achieve a high resolution of spatial distribution data at a low cost and with minimal effort. They are also used to validate and calibrate the results of dispersion modeling. Currently, passive air samplers are able to measure air pollutants, including SO2, NO2, O3, dust, asbestos, heavy metals, indoor HCHO, and CO2. Additionally, they can measure odorous substances such as NH3, H2S, and VOCs. In this paper, many cases for application were introduced for several purposes, such as classifying the VOCs’ emission characteristics, surveying spatial distribution, identifying sources of airborne or odorous pollutants, and so on. In conclusion, the validation and calibration cases for modeling results were discussed, which will be very beneficial for increasing the accuracy and reliability of modeling results.
        4,000원
        6.
        2023.11 구독 인증기관·개인회원 무료
        To secure approval for a decommissioning plan in Korea, it is essential to evaluate contamination dispersion through groundwater during the decommissioning process. To achieve this, licensees must assess the groundwater characteristics of the facility’s site and subsequently develop a groundwater flow model. It is worth noting that Combustible Radioactive Waste Treatment Facility (CRWTF) is characterized by their simplicity and absence of liquid radioactive waste generation. Given these facility characteristics, the groundwater flow model for CRWTF utilizes data from neighboring facilities, with the feasibility of using reference data substantiated through comparative analysis involving groundwater characteristic testing and on-site modeling. To enable a comparison between the actual site’s groundwater characteristics and the referenced modeling, two types of hydraulic constant characterization tests were conducted. First, hydraulic conductivity was determined through long-term pumping and recovery tests. The ‘Theis’ and ‘Cooper-Jacob’ equations, along with the ‘Theis recovery’ equation, were applied to calculate hydraulic conductivity, and the final result adopted the average of the calculated values. Secondly, a groundwater flow test was conducted to confirm the alignment between the main flow direction of the referenced model and the groundwater flow in the CRWTF, utilizing the particle tracking technique. The evaluation of hydraulic conductivity from the hydraulic constant test revealed that the measured value at the actual site was approximately 1.84 times higher than the modeled value. This variance is considered valid, taking into consideration the modeling’s calibration range and the fact that measurements were taken during a period characterized by wet conditions. Furthermore, a close correspondence was observed between the groundwater flow direction in the reference model (ranging from 90° to 170°) and the facility’s actual flow direction (ranging from 78° to 95°). The results of reference data for the CRWTF, based on the nearby facility’s model, were validated through the hydraulic properties test. Consequently, the modeling data can be employed for the demolition plan of CRWTF. It is also anticipated that these comparative analysis methods will be instrumental in shaping the groundwater investigation plans for facilities with characteristics similar to CRWTF.
        7.
        2023.11 구독 인증기관·개인회원 무료
        A comparison and validation between the analysis and vibration test data of a nuclear fuel assembly were conducted. During the comparison and validation process, various parameters that govern the vibration behavior of the fuel assembly were determined, including nuclear fuel rod’s stiffness, spring constants of the dimple and spring of support structures, and damping coefficients. The calibration of the vibration analysis model aimed to find analysis parameters that can accurately simulate the vibration behavior of the test data. For calibration, power spectral density (PSD) diagrams were generated for both the measured signals from the test and the calculated signals from the analysis. The correlation coefficient between these two PSD plots was calculated. To find the analysis parameters, each parameter was defined as a variable with an appropriate range. Latin hypercube sampling was used to generate multiple sample points in the variable space. Analysis was performed for the generated sample points, and PSD plot correlation coefficients were calculated. Using the generated sample points and their corresponding results, a Gaussian Process Regression model was implemented for PSD plot correlation coefficients and the maximum PSD value. Based on the constructed surrogate model, the optimal analysis parameters were easily found without additional computations. Through this method, it was confirmed that the analysis model using the optimal parametes appropriately simulates the vibration behavior of the test.
        8.
        2023.05 구독 인증기관·개인회원 무료
        Spent nuclear fuels should be safely stored until being disposed and dry storage system is predominantly used to retain the fuels. During long-term storage, there are several mechanisms that could result in the degradation of spent nuclear fuels, and the temperature is the most important parameter to predict and estimate the degradation behaviors. Therefore, thermal analysis to estimate temperatures of spent nuclear fuel and the storage system should be performed to evaluate whether the temperatures exceed safety limit. Recently, thermal hydraulic analysis with CFD codes is widely used to investigate the temperature of spent nuclear fuel in dry storage. Herein, Explicit CFD analysis model is introduced and validated by estimating the thermal hydraulic response of the dry storage system that is Dry Cask Simulator (DCS). Extended Storage Collaborating Program (ESCP) led by the Electric Power Research Institute (EPRI) is organized to assess degradation effects of spent nuclear fuel during long-term dry storage, and DCS is the first phase of the program. The dry storage system, containing a single BWR assembly in a canister, was designed to produce validation-quality data for thermal analysis model. ANSYS FLUENT is used to simulate DCS, and the test condition of 0.5 kW decay heat and 100 kPa helium pressure was investigated in this study. In case of peak cladding temperature (PCT), PCT from the experiment was 376 K while that of CFD was 374 K. It implies CFD simulation gives good agreement with experimental measurement. Peak temperatures of channel can, basket, canister and shell predicted by CFD simulation also show good prediction and the discrepancies were less than 7 K while measurements uncertainty was 7 K.
        9.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 동백나무 종자에 함유된 생리활성물질인 camelliaside B의 표준정량화를 위해 고성능 액체 크로마토그래피 (HPLC-DAD) 분석법을 확립하고자 실시하였다. 동백나무 종자에 함유된 주요화합물은 MS/MS 분석, UV 흡광도, 화합물의 유지시간 등을 통해 얻은 결과에 바탕을 두어 camelliaside B를 동백나무 종자 추출물의 지표물질로 선정하였다. Camelliaside B의 HPLC 분석법에 대한 특이성, 정확성, 정밀도 및 정량한계 등을 검증하였다. Camelliaside B 분석을 위해 표준화된 HPLC 분석법은 0.99% 이상의 상관계수(R2)로 높은 선형성을 가지는 것을 보여주었다. Camelliaside B의 회수율은 100.42-108.00%였으며, 검출한계 (LOD)와 정량한계 (LOQ)는 각각 0.084㎍/㎖, 0.254㎍/㎖였다. 동백나 무 종자 지표물질 (camelliaside B)의 일중 정밀도는 각각 0.09-0.16 RSD였으며, 일간정밀도는 0.123 RSD였다. 표준화된 분석법으로 지역별로 수집한 동백나무 종자의 camelliaside B의 함량은 0.279-2.05㎎/g 으로 다양하였다. HPLC 분석법으로 확인한 모든 매개변수는 기능성 원료 인정을 위한 제출자료 작성 기준을 충족하였다. 따라서 본 연구에서 확립한 HPLC 분석법은 동백나무 종자 추출물 유래 건강 관련 기능성 제품 또는 의약품 개발의 첫 단계를 제공할 수 있을 것이다.
        4,000원
        10.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Putrescine은 일반적으로 미생물의 활동에 의해 발생되며, 신선함의 척도로서 사용된다. 그러나 동결건조된 로열젤리에 대한 putrescine 의 분석법은 아직 확립되지 않은 실정이다. 본 연구에서는 C18 컬럼을 이용하여 동결건조 로열젤리 내 putrescine을 분석하기 위한 UPLC 분석 법을 확립하고자 하였다. 새롭게 확립된 분석법은 7분 이내에 putrescine을 분석 가능하였으며, 이러한 분석법을 검증하기 위해 특이성, 직선성, 정밀성, 정확성, 정량한계, 정성한계 등을 평가하였다. 본 연구를 통해 동결건조 로열젤리의 신선한 정도를 평가하기 위한 분석법을 제공하였으 며, 추후 안전성의 척도에 대한 자료로서 활용 가능할 것으로 기대되어진다.
        4,000원
        11.
        2022.10 구독 인증기관·개인회원 무료
        Combustion method has been widely used in the analysis of 3H and 14C in various types of radioactive wastes since X. Hou reported the analysis of 3H and 14C in graphite and concrete for decommissioning of nuclear reactor. In this work, it was demonstrated that the validation result of combustion method for the simultaneous analysis of 3H and 14C in non-combustible radioactive wastes. To validate the combustion method, 3H and 14C spiked to sea sand and soil were prepared and each simulated sample was combusted with the accordance to a combustion temperature program. The validation of combustion method was assessed by the radioactivity recovery, radioactivity deviation, and relative standard deviation of measured radioactivity. The results of radioactivity recovery, radioactivity deviation, and relative standard deviation of 14C were 100~105%, less than 7%, less than 5%, respectively. In addition, 3H showed about 90% of radioactivity recovery, less than 20% of radioactivity deviation, and less than 5% of relative standard deviation. It will be provided that the validation results of combustion method in detail.
        12.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 발효노니 다당체 추출물(Vitalbos)을 건강기능 식품 소재로 활용하기 위해 DAA, 총당 함량, 단당류 3종 (galacturonic acid, glucose 및 galactose)을 지표성분으로 설정하고, 지표성분에 대한 효과적인 분석법 설정 및 검 증을 위해 수행되었다. 기존에 보고된 분석법 검증 방법 을 수정하여 특이성, 직선성, 정밀성, 정확성, 검출한계 (LOD) 및 정량한계(LOQ)를 고성능 액체크로마토그래피와 페놀-황산법을 이용하여 측정하였다. 그 결과 DAA 및 단 당류 3종의 표준용액과 Vitalbos의 머무름 시간이 일치하 였으며 스펙트럼 또한 동일하여 분석법의 특이성을 확인 하였다. 지표성분의 검량선 상관계수(R2)는 0.9995-0.9998 범위로 0.99 이상의 우수한 직선성을 나타냈다. Intra-day 및 inter-day 정밀도는 0.14-3.01%의 범위로 5% 미만의 우 수한 정밀도를 나타냈고 회수율은 95.13-105.59% 범위에 서 우수한 정확도를 보였다. DAA 분석의 LOD와 LOQ는 각각 0.39 μg/mL 및 1.18 μg/mL이었으며 총당 함량의 LOD 및 LOQ는 각각 0.84 μg/mL 및 2.55 μg/mL로 측정 되었다. 단당류 3종에 대한 LOD는 0.48-0.81 μg/mL의 범 위였으며, LOQ는 1.45-2.44 μg/mL 범위에서 정량분석이 가능한 것으로 나타났다. 분석법 검증 결과, 특이성, 직선 성, 정밀성 및 정확성 모두 우수한 분석법임을 검증하였 으며, LOD와 LOQ 또한 Vitalbos 분석에 적합하였음을 확 인하였다. 검증된 분석법을 이용하여 Vitalbos의 지표 성분 함량을 측정하였을 때, DAA, 총당 함량, galacturonic acid, glucose 및 galactose의 함량은 각각 2.31±0.06 mg/dry weight g, 475.92±5.95 mg/dry weight g, 72.83±1.05 mg/dry weight g, 71.63±2.44 mg/dry weight g 및 67.30±2.31 mg/dry weight g으로 측정되었다. 본 연구에서 검증된 분석법을 사용했을 때 Vitalbos의 지표성분 3종에 대하여 우수한 재현성으로 정 량분석이 가능하였으며, 건강기능식품 소재로의 품질관리에 기여할 수 있을 것으로 판단된다.
        4,000원
        14.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        서양종 꿀벌(Apis mellifera L.)의 봉독은 예로부터 항염증과 탁월한 진통 효과로 인해 많은 질병 치료에 이용되어 왔다. 이러한 기능성은 멜리틴과 같은 봉독의 다양한 활성물질로부터 기인하며 약리기전에 대한 연구도 활발하다. 그러나 아직까지 봉독 내에 존재하는 생체아민에 대한 연구는 미흡하다. 본 연구에서는 초고성능액체크로마토그래피를 이용하여 봉독 내에 존재하는 생체아민인 putrescine의 존재 여부를 확인하였으며 이에 대한 밸리데이션을 수행하였다. 밸리데이션은 특이성, 정확성 및 정밀도를 평가하고 분석법을 검증하였다. Putrescine 분석의 선형성은 R≥0.99로 높은 선형성을 나타냈으며, 검출한계는 0.9 μg/ml, 정량한계는 2.7 μg/ml였으며, 회수율은 96.4%-99.9%로 나타났다. Intra-day 정밀도와 inter-day 정밀도의 상대표준편차(RSD) 값은 각각 0.16%-0.23%와 0.09%-0.36%였으며, 이는 RSD 값이 5%이하의 우수한 정밀도 를 보였다. 따라서 본 분석법은 putrescine 분석에 있어서 선형성, 검출한계, 정량한계 및 회수율을 모두 만족하는 것으로 확인되었다. 또한 봉독 내에 존재하는 putrescine의 함량을 조사해본 결과 3.1 ± 0.09 mg/g 존재하였으며 본 연구를 통해 봉독 내 putrescine 함량에 대한 기본적인 데이터를 제공하며, 이는 다양한 생물 활성에 대한 추가 연구에 유용할 것으로 사료된다.
        4,000원
        15.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In addition to physical risks such as electrical, chemical, and mechanic ones in the workplace, psychosocial risks are also raising as an important issue in recent years in connection with human rights and work-life balance policies. The purpose of this study is to confirm the degree of effect of the psychosocial risk management plan at the workplace on workers through logistic regression analysis. Input data for logistic regression analysis is the results of a survey of 4,558 people conducted by the Institute for Occupational Safety and Health were used. There are 9 independent variables, including the change a workplace and confidential counseling, and the dependent variable is whether the worker feels the effect on the psychosocial risk management plan. As a result of this study, changes in work organization, dispute resolution procedures, provision of education program, notification of the impact of psychosocial risks on safety and health, and the persons in charge of solving psychosocial problems are shown effective in reducing worker’s psychosocial risks. This study drives which of the management plans implemented to reduce the psychosocial risk of workers in the workplace are effective, so it can contribute to the development of psychosocial risk management plans in the future.
        4,000원
        17.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to design a diesel engine system and predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. A gas flow analysis in three-dimensional (3D) format needs a high-resolution workstation and enormous time for analysis. Therefore, the method of characteristics (MOC) was used for a gas flow analysis with a fast calculation time and a low-resolution workstation. An experiment was conducted on a single cylinder diesel engine to measure pressure in cylinder, intake pipe and exhaust pipe. The one-dimensional (1D) gas flow was analyzed under the same conditions as the experiment. The engine speed, valve timing and compression ratio were the same conditions and the intake pressure was inputted as the experimental results. Bent pipe such as an exhaust port that cannot be realized in 1D was omitted. As results of validation, the cylinder pressure showed accuracy, but the exhaust pipe pressure exhibited inaccuracy. This is considered as an error caused by the failure to implement a bent pipe such as an exhaust port. When analyzed in 3D, calculation time required 61 hours more based on a model of this study. In the future, we intend to implement a bent pipe that cannot be realized in 1D using 3D and prepare a method to supplement reliability by using 1D-3D coupling.
        4,000원
        19.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Given the view of tests as mechanisms within a language policy framework (Shohamy, 2006), Korean proficiency tests are not only used as a way to measure language knowledge, but rather as tools to impose national ideologies about langage use and diversity. The field of Korean language testing needs to embrace sociopolitical dimensions, and engage what is going on value and consequence in test development and validation. By drawing upon a combined approach of Messick’s (1989) validity framework, Fairclough’s (2001) Critical Discourse Analysis (CDA), Bachman and Palmer’s Assessment Use Arugment (AUA), this study aims to illustrate how the practice of testing can be discursively interpreted as a multilayered phenomenon, constituted through discourse. It discussed the applicability of AUA’s two claims (decisions, consequences) to the validation of Korean language proficiency or related certification testing for immigrants with foci of value implications and consequences. The interconnectedness of test validation and CDA is modelled through the procedure of Faircough’s (2001) analytic methodology. In an effort to illustrate that language testing is discursively value-laded, this study not only offer a theoretical and methodological addition to the current inquiry of test validation, but also re-emphasize that language testing is sociopolitically driven from a discursive angle.
        6,600원
        20.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to select compounds for the standardization of fermented Kalopanax pictus Nakai (KP-F), to develop the analysis method using HPLC-PDA and to perform method validation. KP-F is a fermented powder developed to improve the original physiological activities and create a new functionality. Eleutheroside E, Acanthoside B, and Syringaresinol were selected as the standard compounds and developed our own method for simultaneous analysis. The analyte was isolated using C18 column with a gradient elution of 0.05 M phosphoric acid in water and methanol as the mobile phase at a flow rate of 1 mL/min and detected at 210 nm. As a result, all standard compounds showed good linearity with an R2 (coefficient of correlation) of 1.000 and for the limit of detection range of 0.710~0.831 μg/mL, and the limit of quantification as 2.150~2.520 μg/mL. The precision was RSD (%) of less than 4.80%, while the accuracy was 4.70%>RSD (%) for the range 102.44~110.48%. In conclusion, the developed analysis method is suitable for the detection of Eleutheroside E, Acanthoside B, and Syringaresinol in KP-F.
        4,000원
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