• 제목/요약/키워드: 2D-FE analysis

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일부 성인남녀의 무기질 (Ca, P, Fe, Na, K, Zn) 섭취와 혈압 및 혈중 지질과의 관련성 (Relation among Mineral (Ca, P, Fe, Na, K,Zn) Intakes, Blood Pressure, and Blood Lipids in Korean Adults)

  • 최미경;이원영;박정덕
    • Journal of Nutrition and Health
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    • 제38권10호
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    • pp.827-835
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    • 2005
  • The purpose of this study was to investigate the relation among mineral intakes, blood pressure, and blood lipids for health management of Korean adults over 20 years old. Subjects were recruited from the district where they lived, which included rural (Yoju, n = 137) , coastal (Taean, n = 100) , and urban district (Suwon, n : 117) . hnthropornekical measurement, blood pressure measurement, dietary intake assessment using 24-hour recall method, and blood collection and analysis of blood lipids were conducted. The average age, height, weight, and BMI were 54.1 years, 168.5 cm, 67.3 kg, and 24.5 kg/$m^{2}$ for men and 53.9 years,153.8 cm,59.2 kg, and 25.0 kg/$m^{2}$ for women, respectively. The mean daily intakes of total food and energy were 1219.1 g and 1740.9 kcal for men and 1071.3 g and 1432.6 kcal for women. The mineral intakes of men and women were 448.5 mg and 400.4 mg for calcium,955.3 mg and 803.7 mg for phosphorus, 13.3 mg and 11.1 mg for iron, 4302.8 mg and 3393.3 mg for sodium,2588.0 mg and 2264.9 mg for potassium, and 8.9 mg and 7.3 mg for zinc. The daily intakes of energy, calcium, zinc, vitamin $B_{2}$, and vitamin I were $76.1\%$, $60.1\%$, $73.1\%$, $68.6\%$, and $80.4\%$ of RDAs, respectively. The intakes of energy, calcium, zinc, vitamin $B_{2}$ and I were not meet Korean RDAs. Especially, calcium, zinc, and vitamin $B_{2}$ were less than $75\%$ of RDAs. Blood pressure of the subjects was 128.3/75.5 mmHg for men and 124.1/73.7 mmHg for women. Serum lipids of men and women were 180.2 mg/dL and 184.9 mg/dL for total cholesterol, 160.8 mg/dL and 137.6 mg/dL for triglyceride,41.5 mg/dL and 44.7 mg/dL for HDL-cholesterol,106.6 mg/dL and 112.7 mg/dL for LDL-cholesterol, and 3.5 and 3.3 for atherogenic index. While serum triglyceride and AI of men was significantly higher, HDL-cholesterol was lower than those of women. In the relation among mineral intakes, blood pressure, and serum lipids, we found a significantly negative correlation of intakes of calcium, calcium/phosphorus, calcium density with systolic blood pressure. There were significantly negative correlation between intake of calcium/phosphorus and serum cholesterol, calcium density and serum cholesterol, sodium intake and serum HDL-cholesterol. Based on these results, we concluded that high intakes of calcium, calcium/phosphorus and low sodium intake were associated with favorable blood pressure and serum lipid profiles in adult men and women. (Korean J Nutrition 38(10): 827$\sim$835,2005)

페라이트 영구자석을 갖는 고속 매입형 영구자석 전동기의 특성해석 및 설계 (Design and Characteristic Analysis for High-speed Interior Permanent Magnet Synchronous Motor with Ferrite Magnet)

  • 박형일;신경훈;양현섭;최장영
    • 전기학회논문지
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    • 제65권11호
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    • pp.1806-1812
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    • 2016
  • We propose an interior permanent magnet syhchronous motor (IPMSM) with arc-shape ferrite permanent magnets (PMs) as a substitute for the rare-earth permanent magnet, and determine its optimal design through parametric study. First, we use 2D finite element analysis to analyze 4-poles and 6-slots initial model according to performance requirements and design parameters. The current angle of the maximum average torque considered in the analysis is different compared with the current angle of the minimum torque ripple. Thus, the parametric study for optimal rotor design is performed by varying the thickness and the offset radius of the PMs according to current angle. In particular, a narrow bridge is required in conventional IPMSM for reducing flux leakage; however, the increase in cogging torque in the analysis model saturates the narrow bridge (large offset radius). Therefore, we suggest an appropriate shape considering limiting conditions such as DC link voltage, average torque, torque ripple, and cogging torque taking into account performance requirements.

부산지역 $PM_{2.5}$의 이온 및 미량 금속성분의 화학적 특성 (Chemical characteristics of ions and trace metallic element of PM2.5 in Busan metropolitan area)

  • 전보경;서정민;최금찬
    • 한국환경보건학회지
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    • 제27권4호
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    • pp.63-71
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    • 2001
  • PM 2.5/ samples were measured at two sites, Hadan(suburban site) and Anrak (roadside site) in Busan area. PM 2.5/ sampling was performed for 24-hour intervals by the FH9.5 particulate sampler. Aerosol samples were collected on PTFE filter. A total of 60 particulate samples were collected, dad samples were measured for Particulate mass concentration, metallic elements (Cr, Mn, Ni. Cu. Se, Fe, Pb, and Zn) and waer-soluble elements (C $l^{[-10]}$ , N $O_{3}$$^{[-10]}$ ,S $O_{4}$$^{2-}$, N $H_{4}$$^{+}$, $Ca_{2}$$^{+}$, $Mg_{2}$$^{+}$ and $^{+}$.Mass concentration in Hadan ranged 24.23~57.12 $\mu\textrm{g}$/㎥ and 60.22~72.12 $\mu\textrm{g}$/㎥m Yellow Sand Events. Major cations in Hadan and Anrak site is N $H_{4}$$^{+}$and N $a^{+}$ respectively. SO42$^{[-10]}$ was the abundant specie in the PM 2.5 fraction for Hadan site an dAnrak site. Hadan site showed igher concentration in S $O_{4}$$^{2.1}$ and N $H_{4}$ $^{+}$ In Anrak site the concentration of S $O_{4}$/sip 2-/and N $a^{+}$ was higher than other ions Prominent metallic elements were Fe and Pb in two sites. Principal component analysis showed that main source of PM 2.5 aerosol particles was non-metal related source which was resulted in relating elements as Cr, Ni, and Pb at Hadan site, Anrak site also has resulted PM2.5 aerosol paricles source, which was related its element like Zn, and Ni,. The SAS package analysis also showed that long-range transport effect at Hadan area due to Yellow Sand Event by the prevailing weaterlies.ling weaterlies.

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산업용 원심분리기의 진동저감을 위한 로터다이나믹 해석 (A Rotordynamic Analysis of a Industrial Centrifuge for Vibration Reduction)

  • 김병옥;이안성
    • 한국소음진동공학회논문집
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    • 제18권8호
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    • pp.879-885
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    • 2008
  • A rotordynamic analysis was performed with a decant-type centrifuge, which is a kind of industrial centrifuge. The system is composed of screw rotor, bowl rotor, driving motors, gear box, and support rolling element bearings. These rotors have a rated speed of 4300 rpm, and were modeled utilizing a rotordynamic FE method for analysis, which was verified through 3-D FE analysis. Design goals are to achieve wide separation margins of lateral critical speeds, and favorable unbalance responses of the rotor in the operating range. Then, a complex analysis rotordynamic analysis of the system was carried out to evaluate its forward synchronous critical speeds and mode shapes, whirl natural frequencies, and unbalance responses under various balance grade. As a result of analysis, the rotordynamic analysis performed by separating a screw rotor and bowl rotor may cause an error in predicting critical speed of entire system. Therefore, the rotordynamic analysis of a coupled rotor combining a screw and bowl rotor must be performed in order to more accurately estimate dynamic characteristics of the decanter-type centrifuge as presented in this paper. Also, rolling element bearings with suitable stiffness should be selected to keep enough separation margin. In addition, in establishing balance grade of a screw and bowl rotor, ISO G2.5 balance grade is more recommended than ISO G6.3, in particular balancing correction of a screw rotor based on ISO G2.5 grade is strongly recommended.

닥나무 추출물의 항산화 활성 및 성분 분석 (Antioxidative Activity and Component Analysis of Broussonetia kazinoki SIEB Extracts)

  • 박수아;하지훈;박수남
    • 공업화학
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    • 제24권2호
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    • pp.177-183
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    • 2013
  • 본 연구에서는 닥나무 추출물의 항산화 활성과 성분 분석에 관한 연구를 실시하였다. 닥나무 추출물은 우수한 free radical(1,1-diphenyl-2-picrylhydrazyl, DPPH) 소거활성($FSC_{50}=8.53{\mu}g/mL$)을 나타내었다. Luminol-의존성 화학발광법을 이용한 $Fe^{3+}-EDTA/H_2O_2$계에서 생성된 활성 산소종(reactive oxygen species, ROS)에 대한 에틸아세테이트 분획의 총항산화능(OSC50)은 $1.69 {\mu}g/mL$이었다. 닥나무 추출물에 대하여 $^1O_2$으로 유도된 사람 적혈구의 광용혈 실험 결과 에틸아세테이트분획은 $10{\mu}g/mL$의 낮은 농도에서 ${\tau}_{50}$이 183.3 min으로 대표적인 항산화 물질로 알려진 $\alpha$-tocopherol (${\tau}_{50}$ = 38.00 min)보다 매우 큰 세포보호 효과를 나타내었다. TLC, HPLC, LC/ESI-MS/MS 및 $^1H$-NMR을 이용하여 닥나무 추출물 에틸아세테이트 분획의 성분 분석을 수행하였다. 그 결과, 닥나무 추출물 에틸아세테이트 분획은 kazinol류의 kazinol J와 플라보노이드류인 luteolin을 함유하고 있음을 확인하였다. 이상의 결과들은 닥나무 추출물이 $^1O_2$ 혹은 다른 ROS를 소광시키거나 소거함으로써, 또는 이에 대항하여 세포막을 보호함으로써, 생체계 특히 태양 자외선에 노출된 피부에서 항산화제로서 작용할 수 있음을 가리키며 기능성 화장품 원료로서 응용 가능성이 있음을 시사한다.

X線螢光分析에 依한 珪酸鹽鑛物의 分析 (The X-Ray Fluorescent Spectrographic Analysis of Silicate Minerals)

  • 김찬국;상기남;김황암
    • 대한화학회지
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    • 제13권1호
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    • pp.49-55
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    • 1969
  • 螢光X線을 利用하여 珪酸鹽鑛物中의 主成分인 $SiO_2$, $Al_2O_3$, $Fe_2O_3$, CaO, MgO 및 $K_2O$를 迅速히 分析할 目的으로 試料의 處理 測定 및 各條件에 對하여 檢討하였다. 試料를 Lithium Tetraborate로 용융하여 300Mesh 以上의 微粉末로 한後 40,000Lb의 壓力으로 成型하여 Tungsten과 Chromium 對陰極의 X-線管과 LiF, EDDT, ADP의 分光結晶을 使用하여 測定하였다. 各成分에 對한 檢量曲線은 Matrix Effect를 고려하여 N.B.S 및 International Rock Standard를 選定 使用하였고 Lanthanum Oxide 및 Binder로서 Borie Acid를 첨가하여 얻었다. 各成分에 對하여 本法의 再現性 및 誤差를 檢討하기를 爲하여 I.R.S T-1을 使用하여 測定한 結果 0.47($SiO_2$), 0.85($Al_2O_3$), 0.05($Fe_2O_3$), 0.07(caO), 0.02($K_2O$), 0.13(MgO)의 標準偏差를 얻었다. 또한 化學分析植에 對한 偏差를 求하고져 Clay, Kaoline, Alunite, Wallastonite 및 Zeolite 等의 珪酸鹽鑛物을 選定하여 化學分析 및 本法에 依한 分析結果를 비교하였다.

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피로 자료 분산을 고려한 자동차 부품의 신뢰도 해석 (Evaluation of Chassis Component Reliability Considering Variation of Fatigue Data)

  • 남기원;이병채
    • 한국정밀공학회지
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    • 제24권2호
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    • pp.110-117
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    • 2007
  • In this paper, probabilistic distribution of chassis component fatigue life is determined statistically by applying the design of experiments and the Pearson system. To construct p - ${\varepsilon}$ - N curve, the case that fatigue data are random variables is attempted. Probabilistic density function (p.d.f) for fatigue life is obtained by the design of experiment and using this p.d.f fatigue reliability, any aimed fatigue life can be calculated. Lower control arm and rear torsion bar of chassis components are selected as examples for analysis. Component load histories which are obtained by multi-body dynamic simulation for Belsian load history are used. Finite element analysis is performed by using commercial software MSC Nastran and fatigue analysis is performed by using FE Fatigue. When strain-life curve itself is random variable, the probability density function of fatigue life has very little difference from log-normal distribution. And the cases of fatigue data are random variables, probability density functions are approximated to Beta distribution. Each p.d.f is verified by Monte-Carlo simulation.

토양훈증제 처리가 2년생 인삼의 생육과 화학적 조성에 미치는 영향 (Effect of soil fumigation treatment on the growth and the chemical composition of Korea ginseng, Panax ginseng C.A. Meyer)

  • 안용준;김요태;김명수;최승윤
    • 한국응용곤충학회지
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    • 제20권1호
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    • pp.31-36
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    • 1981
  • D-D외 3종의 토양훈증제를 인삼의 연작토에 15cm, 30cm 깊이로 처리하였을 때 2년생인삼의 생육과 화학적조성에 미치는 영향을 알아보기 위해서 본 시험을 실시하였다. 1980년 3월 7일 처리, 4월 1일 이식, 8월 19일에 채취하여 근, 경, 엽으로 나누어 일반 무기성분(N, P, K, Ca, Mg, Na, Fe, Mn, Zn)을 분석한바 그 결과는 다음과 같았다. 1. 훈증제처리가 2년생인삼의 지상하부의 생육을 촉진하였는데, 지하부 생체중의 경우 $2.8\~58.4\%$, 건물중의 경우 $8.1\~63.8\%$ 증가하였다. 2. 지상하부의 질소와 인산의 함량은 훈증제처리구에서 무처리구에 비하여 증가하였으나, a의 경우에는 오히려 감소하는 경향을 보였다. K의 경우에 있어서는 지하부에서는 함량이 감소하였으나, 지하부에서는 증가하였다. 3. 미량요소의 경우에 있어서는 Mn, Fe의 함량은 훈증제처리구에서 증가하였으나, Na, Zn의 함량에는 큰 영향을 미치지 못하였다. 4. 훈증제의 처리깊이(15cm, 30cm)에 따른 차이에서 보면 2년생인삼의 생육과 화학적조성에는 별다른 차이를 볼 수 없었다.

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수치해석과 현장계측을 통한 병렬터널의 최소 필라폭과 보강에 대한 평가 (Assessment of minimum pillar width and reinforcement of parallel tunnel using numerical analysis and field monitoring)

  • 안용관;공석민;이용주
    • 한국터널지하공간학회 논문집
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    • 제16권3호
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    • pp.299-310
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    • 2014
  • 국가적으로 국토의 효율적 활용과 친환경성 등으로 인해 터널과 같은 지하공간 건설이 필요하다. 친환경적 요소의 중요성을 감안할 때, 산악지에 형성되는 도로건설에 대해 2-아치 및 대단면 터널로 계획되나 경제성, 시공성, 공사기간, 유지관리 등의 문제점을 가지고 있다. 따라서 본 연구에서는 2차로의 국도터널을 기준으로 현장조건과 지반조건을 고려하여 터널별 이격거리와 토피고를 변화시켜 경험식과 수치해석적으로 필라부의 안전성을 평가하였으며, 해석 프로그램으로 유한요소법을 적용한 Plaxis 2D를 활용하여 터널의 최소 필라폭 선정과 전체적인 터널의 거동특성을 분석하였다. 분석결과, Tie-Bolt에 의한 필라보강은 연직하중을 분산시켜 안전적인 근접병렬터널 계획이 가능하며, 터널 필라의 거동은 현장계측 결과와 잘 일치하는 것으로 나타났으며, 지반조건에 따라 터널 필라폭을 축소시킨다면 이전의 터널에 비해 효율적인 터널 활용이 가능하다.

Levitation and Thrust Forces Analysis of Hybrid-Excited Linear Synchronous Motor for Magnetically Levitated Vehicle

  • Cho, Han-Wook;Kim, Chang-Hyun;Han, Hyung-Suk;Lee, Jong-Min
    • Journal of Electrical Engineering and Technology
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    • 제7권4호
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    • pp.564-569
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    • 2012
  • This paper proposes a hybrid-excited linear synchronous motor (LSM) that has potential applications in a magnetically levitated vehicle. The levitation and thrust force characteristics of the LSM are investigated by means of three-dimensional (3-D) numerical electromagnetic FEM calculations and experimental verification. Compared to a conventional LSM with electromagnets, a hybrid-excited LSM can improve levitation force/weight ratios, and reduce the power consumption of the vehicle. Because the two-dimensional (2-D) FE analysis model describes only the center section of the physical device, it cannot express the complex behavior of leakage flux, which this study is able to predicts along with levitation and thrust force characteristics by 3-D FEM calculations. A static force tester for a hybrid-excited LSM has been manufactured and tested in order to verify these predictions. The experimental results confirm the validity of the 3-D FEM calculation scheme for the description of a hybrid-excited LSM.