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        검색결과 46

        2.
        2023.11 구독 인증기관·개인회원 무료
        Within the air purification system of a nuclear power plant, specific radioactive isotopes are extracted from gases through adsorption onto activated carbon. To properly dispose of used activated carbon, it is essential to determine the concentration of radioactive nuclides within it. This study discusses the application of the pyrolysis method for analyzing the concentrations of 3H and 14C in spent activated carbon. The pyrolysis was conducted using Raddec’s Pyrolyser, with adjustments made to parameters such as temperature profiles, airflow rates, sample quantities, and trapping solution volumes. The evaluation method for the pyrolysis of activated carbon to analyze 3H and 14C involved adding 3H and 14C sources to the activated carbon before use and subsequently assessing the recovery rates of the added sources in comparison to the analysis results.
        3.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the volatile flavor components of the essential oil from Chrysanthemum coronarium var. spatiosum Bailey. The essential oil obtained from the aerial parts of the plant by the hydrodistillation extraction method was analyzed by gas chromatography and gas chromatography-mass spectrometry. One hundred and one (99.11%) volatile flavor components were identified in the essential oil from the Chrysanthemum coronarium var. spatiosum Bailey. The major compounds were hexanedioic acid, bis(2-ethylhexyl) ester (12.45%), 6.10.14-trimethyl-2-pentadecanone (7.94%), 1-(phenylethynyl)-1-cyclohexanol (6.34%), α-farnesene (5.55%), phytol (4.99%), and α-caryophyllene (4.39%). When the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey were classified by functional group, the content was high in the order of hydrocarbons, alcohols, esters, ketones, aldehydes, and phthalides. Sesquiterpene hydrocarbons were the most common hydrocarbons, mainly due to α-farnesene and α-caryophyllene. Among the alcohols, the content of aliphatic alcohols was significantly higher, mainly due to 1-(phenylethnyl)-1-cyclohexanol (6.34%) and phytol (4.99%). The analysis of the volatile flavor components of Chrysanthemum coronarium var. spatiosum Bailey in this study will provide useful information to consumers when purchasing food and to industries using fragrance ingredients.
        4,000원
        4.
        2022.05 구독 인증기관·개인회원 무료
        According to Article 4 and 5 of the Nuclear Safety and Security Commission (NSSC) Notice No. 2020-6, radioactive waste packages should be classified by radioactive levels, and finally permanently shipped to underground or surface disposal facilities. The level of the radioactive waste package is determined based on the concentrations of the radionuclides suggested in Article 8 of NSSC Notice No. 2021-26. Since most of the radionuclides in radioactive wastes are beta nuclides, chemical separation and quantification of the target nuclides are essential. Conventional methods to classify chemically non-volatile radionuclides such as Tc-99, Sr-90, Nb- 94, Fe-55 take a lot of time (about 5 days) and have low efficiency. An automated non-volatile nuclide analysis system based on the continuous chemical separation method of radionuclides has been developed to compensate for this disadvantages of the conventional method in this study. The features of the automated non-volatile nuclide separation system are as follows. First, the amount of secondary waste generated during the chemical separation process is very small. That is, by adopting an open-bed resin column method instead of a closed-bed resin column method, additional fittings and connector are unnecessary during the chemical separation. In addition, because the peristaltic pump is supplied for the sample and solution respectively, it is great effective to prevent cross-contamination between radioactive samples and the acid stock solution for analysis. Second, the factors that may affect results, such as solution amount, operating time and flow rate, are almost constant. By mechanically controlling the flow rate precisely, the operating time and additional factors required during the separation process can be adjusted and predicted in advance, and the uncertainty of the chemical separation process can be significantly reduced. Finally, it is highly usable not only in the continuous separation process but also in the individual separation process. It can be applied to the individual separation process because the user can set the individual sequence using the program. As a result of the performance evaluation of the automation system, recovery rates of about 80–90% and reproducibility within 5% were secured for all of the radionuclides. Furthermore, it was confirmed that the actual work time was reduced by more than 50% compared to the previous manual method. (It was confirmed that the operation time required during the separation process was reduced from 6 days to 3 days.) Based on these results, the automation system is expected to improve the safety of workers in radiation exposure, reduce human error, and improve data reliability.
        5.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Chrysanthemum boreal, C. indicum, and C. indicum var. albescens are well-known wild Chrysanthemum species used for traditional medicine in Korea. In this study, volatile compounds from three wild Chrysanthemums were identified according to four different flowering stages and analyzed using HS-SPME-GC-MS to determine the temporal variation of the volatiles. As a result, 132, 151, and 142 peaks were identified from C. boreale, C. indicum, and C. indicum var. albescens, respectively. Furthermore, 70 out of 132 peaks were identified in C. boreale with a matching ratio of >90% from library search. In addition, 85/151 and 76/142 peaks were identified from C. indicum and C. indicum var. albescens. Forty-nine volatile compounds were found commonly in all three wild Chrysanthemums through all four different flowering stages. However, six, seven, and five unique compounds were detected only in C. boreale, C. indicum, and C. indicum var. albescens, respectively. One hundred volatile compounds were selected for multivariate analysis considering volatile compounds overlapped with each other. The one-way ANOVA (p < 0.05) detected significant differences from 77 out of 100 volatile compounds. In addition, PLS-DA showed the different profiles of volatile compounds according to four different flowering stages in each wild Chrysanthemum. PC1 of each Chrysanthemum accounted for 45.8 56.9, and 11.9% in C. boreale, C. indicum, and C. indicum var. albescens, respectively. PC1 of C. boreale and C. indicum clearly separated the BF stage and the other three stages. Conversely, PC1 of C . indicum var. albescens showed a difference in the composition of volatile compounds between the BF/BO and HO/FO stages. In addition, the different profiles of volatile compounds could be visualized using a heatmap from three wild Chrysanthemums according to four different flowering stages. This study will help improve particular volatile compounds in three wild Chrysanthemums both in quality and quantity.
        4,000원
        6.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Volatile organic compounds (VOCs) in plants are various organic compounds with small molecular weight and high vapor pressure. The metabolomics approach was recently introduced to analyze VOCs involved in biological processes, such as abiotic and biotic stresses, spatial and temporal distribution, and genotypic differences. In addition, this approach is widely used in combination with identification of VOCs analysis and statistical analysis using multivariate analysis, such as principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA), etc. First, in this review, the current condition of the metabolomics approach to analyze VOCs synthesized in plants using head space-solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) is discussed. In addition, metabolomics approach, such as extraction and analysis of VOCs using HS-SPME-GC-MS, conversion, and processing of mass spectral (MS) data, a database for VOCs identification, useful statistical methods, and statistical tools and applications, are explained. Finally, multi-omics in combination with other omics techniques, such as genomics, transcriptomics, etc. are suggested as prospects of a metabolomics approach for VOC analysis in floricultural plants using HS-SPMEGC- MS. Therefore, the metabolomics approach of HS-SPMEGC- MS will facilitate our understanding of VOCs synthesized in plants. Furthermore, the multi-omics approach will help understand gene functions involved in the biosynthesis of VOCs and help develop new development cultivars with nicer floral scents by contributing to the development of the floricultural industry.
        4,000원
        8.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The results of gas chromatography–mass spectrometry (GC–MS) demonstrate that the volatiles captured by diamond grown by chemical vapour deposition (CVD) technology contain hydrocarbons and their derivatives (72.2 rel. %). We have identified aliphatic (paraffins and olefins), cyclic (naphthenes and arenes) and oxygenated (alcohols, aldehydes, ketones and carboxylic acids) hydrocarbons, as well as nitrogenated and sulfonated compounds. Water, negligible amounts of CO2 and Ar were also detected among the volatile components.
        4,000원
        10.
        2017.11 구독 인증기관·개인회원 무료
        In South Korea, increase in kimchi import from China has emphasized the importance of noticing the origin of production area, largely because of the price and safety concerns. Nevertheless, identification of it depends on a complex physicochemical method. Hence, the objective of this study is to develop a statistical algorithm applicable for analyzing volatile compounds measured by electronic nose so that the device can be used for simple classification of kimchi by its production origin. Discriminant function analysis (DFA), one of multi-variate analysis, was mainly used for analyzing big-size data of volatile compounds detected from kimchi produced either in South Korea or China. Result showed that DFA could completely separate 69 varieties of kimchi by its origin of production (39 from South Korea and 30 from China). This result suggests that volatile compounds can be an index for identifying origin of kimchi and consequently, electronic nose is an optimal option for identifying origin of kimchi production when combined with multi-variate statistics.
        12.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        There has been growing concern over the emissions of formaldehyde and VOCs from automotive interior materials, as these could have an important impact on the in-vehicle air quality (IVAQ) of automotive vehicles. Odor along with VOCs refers to the automotive interior smell emitted directly or indirectly from any part of an automotive interior, based on human olfactory senses and a comfort evaluation of vehicle quality. The objective of this paper is to compare the odor intensity using GC/MS analysis method and odor sensory test in accordance with ISO 12219-2. For the compounds having low odor threshold value and high VOC concentration, it was found that there was the same tendency in each field of odor whether the instrument analysis method or the odor sensory test method was used.
        4,000원
        13.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To increase the availability of Maxillaria species and cultivars, we investigated the volatile floral scents in eight species and cultivars of M. tenuifolia, M. variabilis, M. variabilis 'Alba', M. variabilis 'NxO', M. variabilis 'Brown', M. variabilis 'Red', M. variabilis 'Nana', and M. sangnine. The volatile components were analyzed using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). We identified 46 volatiles in eight species and cultivars of Maxillaria. α-pinene, eucalyptol, trans-β-ocimene, α-copaene, and β-caryophyllene were major flavor components in the eight Maxillaria species and cultivars. A principle component analysis (PCA) showed that M. tenuifolia, M. variabilis, M. variabilis 'NxO', M. variabilis 'Brown', M. variabilis 'Nana', and M. sangnine (major components: sesquiterpenes) were located closely together on t he s core p lot. However, M. variabilis 'Alba' and M. variabilis 'Red' (major components: monoterpenes) were located closely on the score plot and not analyzed coconut flavor.
        4,000원
        15.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        삼채의 잎과 뿌리로부터 휘발성 화합물과 아미노산을 분석하였다. 휘발성 향기성분은 Headspace GC-MS방법으로 분석하였다. 잎 조직으로부터 18종의 휘발성화합물이 검출되었고, 21종의 화합물은 뿌리조직으로부터 분석되었다. 주요 향기성분은 diallyl disulphide였고, 잎(27.9%)과 뿌리(17.41)에서 가장 많이 함유하고 있었다. 또 다른 주요 황화합물은 methyl 2-propenyl disulfide, dimethyl disulfide, methyl 1-propenyl disulfide과 methyl 2-propenyl trisulfide이 잎과 뿌리에 모두 함유하고 있었다. 전체 46종 화합물 중 가장 많이 함유하고 있는 물질군은 황화합물이었다. 황화합물은 엽조직에 6종, 뿌리조직에는 5종이 함유되어 있었다. 또한 유리아미노산과 polyphenol성 화합물은 잎과 뿌리 조직에서 분석하였다. 잎과 뿌리 조직에서 아미노산은 20종과 19종이 각각 검출되었다. 총아미노산의 함량은 잎에서 0.134 mg/g, 뿌리조직에서 0.105 mg/g 함유하고 있었다. 총 polyphenol성 화합물 함량은 잎에서 0.28 mg/g, 뿌리에서 1.08 mg/g 함유하고 있었다. 이 결과는 삼채의 이용과 효율적인 재배에 기초자료를 제공할 수 있다.
        4,000원
        16.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 감꽃의 주요 향기성분을 알아보기 위해서 감나무 수령별로 감꽃의 향기성분을 SPME를 이용하여 분석하고, 기관을 꽃과 꽃받침으로 분류하여 향기성분을 비교하였다. 감나무 수령별 감꽃의 만개율은 15년생 이상, 10-14년생, 5-9년생 순으로 수령이 오래될수록 초기 만개율이 높았다. 감나무 수령에 따른 감꽃 향기성분 분석 시 동정된 주요 향기 성분은 a-pinene, butene, caryophyllene, cubebene, lavandulol, D-limoneneylangene, ylangene 등의 성분을 얻을 수 있었다. 대부분이 green 향, fruit계, floral계의 옅은 향도 포함하고 있었다. 감꽃에 존재하는 휘발성 향기성분의 수는 5-9년생은 30종, 10-14년생은 24종, 그리고 15년생 이상에서는 32종으로 수령이 5년 미만과 15년 이상에서 많은 향기성분이 조사되었다. 감꽃을 꽃받침과 나누어 향기성분을 비교하면 단감 ‘부유’ 품종 중 꽃의 향기 성분은 10개이고 상대적인 총 함량은 26.35%이며, 꽃받침은 향기 성분은 14개 이고 상대적인 총 함량은 46.28%로 꽃에 비해서 더 다양한 향기성분이 존재하는 것으로 조사되었다. 반면 떫 은감 ‘둥시’ 품종은 꽃에서는 6개의 향기성분이 17.58%, 꽃받침에서는 9개의 향기 성분이 50.27%로, ‘부유’ 품종 에 좀더 다양한 향기성분이 존재하였다. 본 연구는 감꽃 향기를 이용하고자 하는 향기산업에 기초자료를 제공하 는데 기여할 것이다.
        4,000원
        17.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        pH의 변화는 10%, 15%, 20% 염도 고추장에서는 숙성기간이 지나면서 약간의 pH의 감소 현상이 일어나기는 했지만, 수치에 큰 변화는 없었다. 그러나 염도가 낮은 3%와6% 고추장은 급격한 pH의 감소를 보여주었다. 호기성 세균수는 숙성기간 동안 큰 변화가 없었지만, pH의 감소 경향과 비슷하게 3%와 6% 염도 고추장에서 생균수가 더 많이 감소했다. 모든 염도에서 B. licheniformis와 B. subtilis가 큰 비중으로 차지하였다. 그러나 염도가 낮은 3%와 6% 염도 고추장에서는 이외에도 다양한 균주가 확인되었다. 호염성 세균수의 변화 추이는 호기성 세균의 생균수 변화 추이와 비슷했다. 호염성 세균도 B. subtilis가 모든 염도에서 전 숙성기간 동안 가장 큰 비중으로 확인되었다. 그러나 호염성 세균에서는 B. licheniformis 대신 Peanibacillus 속이 많은 부분에서 지배균주였다. 이외에도 3% 염도 고추장에서는 숙성 기간 동안 다양한 균주가 확인되었다. 효모는분리 유무가 숙성기간에 따라 다르게 나타났는데, 이는 pH의 급격한 저하에 의해 낮은 pH에도 생육이 가능한 균주만 숙성후기에 분리되는 것으로 판단된다. 20% 이상의 염도에서는 pH보다 고염에 의한 영향으로 효모의 증식이 어려운 것으로 보인다. 모든 염도에서 Candida 속과 S.cerevisiae가 가장 많이 분리되었으며, 이외에도 다양한 균종이 확인되었다. 검출된 휘발성 향기성분은 ester류가 26종으로 가장 많고, 그 다음 alcohol류가 12종, ketone류가 6종등 총 70종이 검출되었다. 이 중 alcohol류의 ethanol, ester류의 ethyl acetate와 3-methyl-1-butyl acetate, ketone류의 3-hydroxy-2-butanone, acid류의 acetic acid 등이 10-40% 정도의 면적비율로 검출되면서 주요한 성분으로 나타났다. 효모의 대사산물이면서 고추장의 고소한 향미를 내는ethanol은 10%와 15%에서 상대적으로 높은 비율로 검출되었고, 과실향에 기여하는 ethyl acetate는 3%, 6%, 10% 염도 고추장에서 상대적으로 높게 나타났으며, 반대로 발효유의 중요한 향기성분인 3-hydroxy-2-butanone은 염도가높아질수록 높은 비율로 검출되었다. 바나나의 향기에 중요한 3-methyl-1-butyl acetate와 초산발효에 중요한 기여를하는 acetic acid는 3%와 6% 염도 고추장에서 매우 높은수치로 검출되면서 고추장의 이취를 내는 것으로 보인다.결론적으로, 일반적인 고추장의 미생물 균총과 휘발성 향미가 달라지지 않게 제조하기 위한 고추장의 최저 염도는10%가 가장 적절할 것으로 사료된다.
        4,200원
        18.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A comparison of essential oils composition of Aster tataricus L. (gaemichwi), Ligularia fischeri (gomchwi), Solidago virga-aurea var. asiatica Nakai (miyeokchwi), and Aster scaber (chamchwi) was performed by gas chromatography and mass spectrometry for the identification of volatile flavor characteristics in chwi-namuls. The essential oils were extracted by the hydro distillation extraction method. One hundred volatile flavor components were identified from gaemichwi essential oil. α-Pinene (11.5%) was the most abundant compound, followed by myrcene (8.9%) and β pinene (7.5%). Ninety-one volatile flavor components were identified from the essential oil of gomchwi. Aromadendrene (14.8%) was the most abundant component, followed by β-caryophyllene (7.6%) and 1-methyl-4-(1-methylethylidene) cyclohexene (7.3%). Ninety-five volatile flavor constituents were detected in the essential oil of miyeokchwi, moreover, spathulenol (15.7%) was the most abundant component. Ninety-six volatile flavor constituents were detected in the essential oil of chamchwi. Epi-bicyclosesquiphellandrene (21.9%) was the most abundant component, followed by β-caryophyllene (9.5%) and δ terpinene (8.9%). The essential oil composition of gaemichwi was characterized by a higher contents of pinenes. The essential oil composition of gomchwi can be easily distinguished by the percentage of aromadendrene. Spathulenol and epi bicyclosesquiphellandrene were regarded as the characteristic odorants of miyeokchwi and chamchwi, respectively.
        4,200원
        19.
        2009.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국내 주요 복분자 산지인 고창, 정읍, 횡성, 순창산 복분자로 복분자주를 제조하여 제조 복분자주의 휘발성 향기성분 분석과 기호도 조사를 통해 산지별 차이를 파악하였다. 복분자주의 주요 향기성분으로 phenylethyl alcohol, isoamyl alcohol, diethyl succinate, isobutyl alcohol, acetic acid, octanoic acid, benzoic acid, α-terpineol, myrtenol, pcymene-8-ol이 동정되었고 특히 적포도주에 비해 terpene류가 많이 검출되어 복분자주의 odor-active compounds를 분석하기 위해 gas-chromatography-olfactometry를 포함한 다양한 향기성분 분석 연구가 필요한 것으로 보인다. Ester류는 횡성산과 정읍산 복분자주에서 많이 검출되었고 alcohol과 acid류도 횡성산에서 가장 많은 농도를 나타내었다. Terpene류는 정읍산에서 가장 높게 나타났다. 차후 이들 시료에 대한 묘사분석을 통해 향기성분과의 상관관계 분석이 필요하리라 여겨진다. 전반적인 기호도에서는 제조 복분자주에서 고창, 순창, 횡성, 정읍순으로 나타났고 특히 횡성과 정읍 시료의 경우 단맛은 약하고 신맛은 너무 강한 것으로 나타나 당산비 조절이 필요한 것으로 여겨진다.
        4,000원
        20.
        2008.06 구독 인증기관 무료, 개인회원 유료
        This study identified and compared the volatile flavor components of two commercial rice wines: one fermented using the mycelium of Phellinus linteus and a regular commercial rice wine. The volatile flavor components were isolated from the infusions by Porapak Q (50-80 mesh) column adsorption. The concentrated aroma extracts were then analyzed and identified by GC and GC-MS. Thirty-four kinds of flavor components were identified in the mycelium-fermented rice wine, including 11 alcohols, 8 esters, 3 ketones, 6 acids, 3 hydrocarbones, and 4 others. In the regular commercial rice wine, 36 kindss of flavor compounds were identified, including 9 alcohols, 6 esters, 4 ketones, 6 acids, 9 hydrocarbones, and 2 others. Therefore, the data indicate that the primary flavor components in the rice wines were alcohols and esters.
        4,000원
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