• 한국자원식물학회지
• /
• 제23권1호
• /
• pp.38-46
• /
• 2010

메탄올을 용매로 12종 양치식물의 지상부와 근경의 건조시료를 초음파추출하여 페놀성 물질 함량 및 DPPH와 ABTS radical 소거능을 측정하였다. 총 폴리페놀의 함량은 건조시료 1 g에 $2.793{\sim}140.014\;mg{\cdot}g^{-1}$, 생시료 1 g에 $0.779{\sim}49.579\;mg{\cdot}g^{-1}$으로 다양하게 나타났으며, 넉줄고 사리와 더부살이고사리의 지상부에서 총 폴리페놀 함량이 높았다. 총 플라보노이드 함량은 건조시료 1 g에 $2.559{\sim}34.909\;mg{\cdot}g^{-1}$, 생시료 1g에 $0.714{\sim}11.487\;mg{\cdot}g^{-1}$으로 나타났다. 건조시료 중에는 관중 지상부, 생시료 중에는 더 부살이고사리의 지상부에서 총 플라보노이드 함량이 가장 높았다. 총 폴리페놀은 지상부보다 근경에 많이 함유된 경향을 보였으나, 총 플라보노이드는 지상부에 많았다. DPPH와 ABTS radical 소거능은 지상부보다 근경 추출물에서 높게 나타났다. 총 폴리페놀은 지상부보다 근경에 많이 함유된 경향을 보였으나, 총 플라보노이드는 지상부에서 함량이 많았다. DPPH와 ABTS radical 소거능은 지상부보다 근경 추출물에서 높게 나타났다. DPPH radical 소거능과 ABTS radical 소거능 모두 나도히초미 근경 추출물에서 가장 우수하였다. 그러나 시료의 수분함량과 추출수율을 고려하여 $RC_{50}$을 나타내는데 필요한 생시료의 양을 계산한 결과, 나도히초미 근경보다는 더부살이고사리 지상부가 DPPH와 ABTS radical 소거용 식물소재로 적합하였다. 양치식물의 추출물은 특히 ABTS radical 소거능이 매우 우수하였으며, 가지고비고사리 추출물을 제외한 대부분의 시료가 ascorbic acid 또는 BHT와 유사한 소거활성을 보였다.

• 한국환경보건학회지
• /
• 제46권5호
• /
• pp.548-554
• /
• 2020

Objectives: This study is to examine the polyvinyl chloride (PVC) materials in elementary school classrooms and libraries in Seoul, and to investigate phthalate contamination in indoor dust. Methods: PVC material was identified for building materials and furniture using portable x-ray fluorescence (XRF). Phthalates in dust samples (n=19) were extracted by ultrasonic extraction using cyclohexane and analyzed by GC-MS. Results: Diethyl phthalate (DEP), di-n-butyl phthalate (DBP), and Bis (2-ethylhexyl) phthalate (DEHP) were found in all collected dust samples (n=19), and diisonyl phthalate (DINP) was detected in all except for one sample (n=18). The concentration of DEHP (median: 2190 mg/kg) and DINP (2960 mg/kg) were higher than other compounds, suggesting that there are many products in the school that used these compounds. When comparing the phthalate concentration in the classroom (n=11) and library dust (n=8), the total concentration in the classroom (median: 10000 mg/kg) was higher than that in the library (8030 mg/kg). DEHP was the dominant compound in the library. The library is relatively more equipped with PVC furniture (n=83) and most floors are also identified as PVC material, suggesting that floors and furniture made of PVC materials are main sources of DEHP contamination. Conclusions: This study is a pilot survey for investigating phthalate contamination in elementary schools. As a result of the survey, phthalate contamination in elementary school was confirmed. However, further study requires risk assessment of children through analysis of phthalate metabolites in children based on sufficient number of samples and information about the site.

• Wind and Structures
• /
• 제20권6호
• /
• pp.763-791
• /
• 2015

"Wind and Ports" is a European project that has been carried out since 2009 to handle wind forecast in port areas through an integrated system made up of an extensive in-situ wind monitoring network, the numerical simulation of wind fields, the statistical analysis of wind climate, and algorithms for medium-term (1-3 days) and short term (0.5-2 hours) wind forecasting. The in-situ wind monitoring network, currently made up of 22 ultrasonic anemometers, provides a unique opportunity for detecting high resolution thunderstorm records and studying their dominant characteristics relevant to wind engineering with special concern for wind actions on structures. In such a framework, the wind velocity of thunderstorms is firstly decomposed into the sum of a slowly-varying mean part plus a residual fluctuation dealt with as a non-stationary random process. The fluctuation, in turn, is expressed as the product of its slowly-varying standard deviation by a reduced turbulence component dealt with as a rapidly-varying stationary Gaussian random process with zero mean and unit standard deviation. The extraction of the mean part of the wind velocity is carried out through a moving average filter, and the effect of the moving average period on the statistical properties of the decomposed signals is evaluated. Among other aspects, special attention is given to the thunderstorm duration, the turbulence intensity, the power spectral density and the integral length scale. Some noteworthy wind velocity ratios that play a crucial role in the thunderstorm loading and response of structures are also analyzed.

• KIEAE Journal
• /
• 제16권6호
• /
• pp.109-114
• /
• 2016

Purpose: The underground air is the warm air discharged from the porous volcano bedrock 30-50m underground in Jeju, including excessive humidity. The temperature of the underground air is $15-20^{\circ}C$ throughout the year. In Jeju, the underground air was used for heating greenhouses by supplying into greenhouses directly. This heating method by supplying the underground air into greenhouses directly had several problems. The study was conducted to develop the heat pump system using underground air as heat source for resolving excessive humidity problem of the underground air, adopting the underground air as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) and saving heating cost for agricultural facilities. Method: 35kW scale(10 RT) heat pump system using underground air installed in a greenhouse of area $330m^2$ in Jeju-Special Self-Governing Province Agricultural Research & Extension Services, Seogwipo-si, Jeju. The inlet and outlet water temperature of the condenser, the evaporator and the thermal storage tank and the underground air temperature and the air temperature in the greenhouse were measured by T type thermocouples. The data were collected and saved in a data logger(MV200, Yokogawa, Japan). Flow rates of water flowing in the condenser, the evaporator and the thermal storage tank were measured by an ultrasonic flow meter(PT868, Panametrics, Norway). The total electric power that consumed by the system was measured by a wattmeter(CW240, Yokogawa, Japan). Heating COP, rejection heat of condenser, extraction heat of evaporator and heating cost were analyzed. Result: The underground air in Jeju was adopted as a farm supporting project by Ministry of Agriculture, Food and Rural Affairs(MAFRA) in 2010. From 2011, the heat pump systems using underground air as a heat source were installed in 12 farms(16.3ha) in Jeju.

• 한국컴퓨터정보학회논문지
• /
• 제16권2호
• /
• pp.55-60
• /
• 2011

본 논문에서는 요부 영상에서 근육을 추출하는 방법을 제안한다. 제안된 방법은 초음파 영상에서 왜곡이 존재하지 않는 영역을 측정할 근육 영역으로 설정한 후, 초기 초음파 영상에서 불필요한 잡음을 제거하고 Ends-in Search Stretching 기법을 적용하여 근육 영역의 명암 대비를 강조한다. 그리고 형태학적 특징을 이용하여 등뼈 영역과 피하지방을 분리한 후, 4 방향 윤곽선 추적 알고리즘을 적용하여 피하지방의 하단 부분을 추출한다. 또한 최대 및 최소 명암도를 조정하여 얻어진 등뼈의 후보 영역에서 형태학적 특징을 이용하여 잡음을 제거하고 최종적으로 등뼈 영역을 추출한다. 추출된 등뼈 영역을 기반으로 피하지방층과 등뼈 사이를 근육의 두께로 측정한다. 본 연구에서 제안된 방법을 368개의 요부 초음파 영상에 적용하여 근육 영역을 추출한 결과, 제안된 방법이 초음파 영상에서 근육 영역들의 두께를 측정하는데 기존의 근육 측정 방법보다 효과적인 것을 확인할 수 있었다.

• Journal of Ginseng Research
• /
• 제44권4호
• /
• pp.552-562
• /
• 2020

Background: Ginsenosides are the unique and bioactive components in ginseng. Ginsenosides are affected by the growing environment and conditions. In New Zealand (NZ), Panax ginseng Meyer (P. ginseng) is grown as a secondary crop under a pine tree canopy with an open-field forest environment. There is no thorough analysis reported about NZ-grown ginseng. Methods: Ginsenosides from NZ-grown P. ginseng in different parts (main root, fine root, rhizome, stem, and leaf) with different ages (6, 12, 13, and 14 years) were extracted by ultrasonic extraction and characterized by Liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Twenty-one ginsenosides in these samples were accurately quantified and relatively quantified with 13 ginsenoside standards. Results: All compounds were separated in 40 min, and a total of 102 ginsenosides were identified by matching MS spectra data with 23 standard references or published known ginsenosides from P. ginseng. The quantitative results showed that the total content of ginsenosides in various parts of P. ginseng varied, which was not obviously dependent on age. In the underground parts, the 13-year-old ginseng root contained more abundant ginsenosides among tested ginseng samples, whereas in the aboveground parts, the greatest amount of ginsenosides was from the 14-year-old sample. In addition, the amount of ginsenosides is higher in the leaf and fine root and much lower in the stem than in the other parts of P. ginseng. Conclusion: This study provides the first-ever comprehensive report on NZ-grown wild simulated P. ginseng.

• Journal of Periodontal and Implant Science
• /
• 제42권6호
• /
• pp.243-247
• /
• 2012

Purpose: The effects of magnetostrictive and piezoelectric devices on tooth surfaces seem to differ with regard to the root surface roughness they produce. This study aimed to compare the results of scaling using magnetostrictive and piezoelectric devices on extracted teeth. Methods: Forty-four human extracted teeth were assigned to four study groups (n=11). In two groups (C100 and C200), the teeth were scaled using a magnetostrictive device and two different lateral forces: 100 g and 200 g, respectively. In the other two groups (P100 and P200), the teeth were scaled with a piezoelectric device with 100 g and 200 g of lateral force, respectively. The teeth were scaled and the data on the duration of scaling and the amount of surface were collected and analyzed using the t-test. Results: The mean time needed for instrumentation for the piezoelectric and magnetostrictive devices was 50:54 and 41:10, respectively, but their difference was not statistically significant (P=0.171). For root surface roughness, we only found a statistically significantly poorer result for the C200 group in comparison to the P200 group (P=0.033). Conclusions: This study revealed that applying a piezoelectric scaler with 200 g of lateral force leaves smoother surfaces than a magnetostrictive device with the same lateral force.

• 한국정보통신학회논문지
• /
• 제21권9호
• /
• pp.1818-1825
• /
• 2017

ADCP(Acoustic Doppler Current Profiler) 는 초음파의 도플러 효과를 이용하여 수중에서 유속의 측정 및 교란 정도를 분석한다. 따라서 수신되는 각 공간 영역에 대한 속도 정보를 추출하기 위하여 수신 펄스 신호에 대한 자기 상관 함수나 FFT(Fast Fourier Transform) 스펙트럼을 추정한다. 그러나 자기 상관 함수 추정은 수신되는 반사 신호가 가우시안 형태의 대칭적인 도플러 스펙트럼을 가진다는 가정이 필요하며 이러한 조건이 만족 되지 않는 경우 추정치에서의 큰 편향오차가 발생할 수 있다. 또한 유속의 변화가 빠르게 나타나는 경우 신호 획득시간이 짧아 유속을 측정하기 위한 자기 상관 함수 나 FFT 스펙트럼의 정확한 추정이 어렵다. 따라서 본 논문에서는 반사 신호가 대칭형 또는 비대칭형 가우시안 형태의 스펙트럼을 보이면서 상대적으로 짧은 반사 획득 신호인 경우에도 정확한 유속 추정이 가능한 AR(Autoregressive) 스펙트럼 첨두치 추정 방법을 제안하였다. 이러한 방법을 이용하면 기존 방법에 비하여 그 정확도를 개선할 수 있음을 보였다. 제안된 방법의 평가를 위하여 다양한 환경에서의 모의 신호들을 구현하였으며 그 결과들을 비교하고 분석하였다.

• 약학회지
• /
• 제56권5호
• /
• pp.280-287
• /
• 2012

A high-performance liquid chromatography (HPLC) combined with ultraviolet (UV) method for the simultaneous determination of ${\alpha}$-cyperone and nootkatone was developed for the quality control of Cyperus rotundus Linne. The separation was performed on a KR100-$5C_{18}$ ($4.6{\times}250mm$) column, and an elution gradient composed of methanol and water with a flow-rate of 1.0 ml/min. Detection wavelength was set at 254 nm. The optimum extraction for the detection of the ${\alpha}$-cyperone and nookatone was achieved by ultrasonic with methanol for an hour. Two marker compounds ${\alpha}$-cyperone and nootkatone in Cyperi Rhizoma showed good linearity ($R^2$ >0.999) in the concentration range of $12.5{\mu}g/ml$ to $200{\mu}g/ml$. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.04~1.23% and 0.08~0.68%, respectively, and the overall recoveries of 97.45~105.58% for the two compounds analyzed. Additionally, a difference was observed in the cluster analysis and principal component analysis between Cyperi Rhizoma in Korea and China. The result demonstrated that the principal component analysis is useful to distinguish between Cyperi Rhizoma in Korea and China.

• Journal of Plant Biotechnology
• /
• 제47권1호
• /
• pp.90-99
• /
• 2020

This study aimed to screen for plants with antimicrobial potential among the evergreen woody species of South Korea that are used for horticulture and landscaping and to provide basic information about plants with proven antimicrobial activity to underpin future research. The plant materials were extracted under various conditions, and the antimicrobial activities of the extracts were evaluated by agar diffusion assay. The screening tests demonstrated that the crude extracts of 43 species had inhibitory effects against S. aureus. The inhibitory activities of four species (Elaeocarpus sylvestris, Camellia japonica, Cleyera japonica, and Quercus salicina) were relatively higher than that of the synthetic antimicrobial agents methylparaben and phenoxyethanol. The highest inhibitory activity was observed with the leaf extracts (extracted with methanol for 30 minutes) of E. sylvestris, based on induction of the largest inhibition zone of 23.3 mm in size. In addition, solvent fractions of E. sylvestris were evaluated. The largest inhibitory zone of 23.1 mm was observed for the n-butanol fraction, which is likely to contain effective compounds that exhibit inhibitory activity against S. aureus. In contrast, n-hexane and residual aqueous fractions showed no antimicrobial activity. Overall, our findings confirm that evergreen woody plants native to South Korea have potential antimicrobial activity.