• Title/Summary/Keyword: $\alpha$+$\beta$상

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Corrosion properties of the 6/4 forged brass for the coupler transferring LPG between tank lorry and LPG station (LPG 충전소와 탱크로리의 가스 이$\cdot$충전 접속장치 커플러용 6/4 단조 황동의 부식특성에 관한 연구)

  • Kil Seong-Hee;Kwon Jeung-Rock;Kim Ji-Yuon;Doh Jung Man
    • Journal of the Korean Institute of Gas
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    • v.5 no.2 s.14
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    • pp.14-21
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    • 2001
  • In order to investigate the damage mechanism of the coupler transferring LPG, microstructural observation and chemical analysis of the couplers operated for the long time in the LPG stations and virgin 6/4 forged-brass corrosion-tested were conducted. Their microstructure was consisted of two phases that bright $\beta$ precipitates were irregularly dispersed in $\alpha$ matrix. The chemical compositions of oxide layer on the surface of the used coupler were composed of S, C, O, Al, Si, etc. as well as Cu and Zn. In environmental corrosion tests of both $10\%$ HCl and Mattsson solutions, no apparent deviations in mechanical impact strength of forged-brass was observed. While, in U-bend stress corrosion cracking specimen, some microcracks were observed.

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Fault Diagnosis of Solar Power Inverter Using Characteristics of Trajectory Image of Current And Tree Model (전류 궤적 영상의 특징과 트리모델을 이용한 태양광 전력 인버터의 고장진단)

  • Hwang, Jae-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.47 no.4
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    • pp.102-108
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    • 2010
  • The photovoltaic system changes solar energy into DC by solar cell and this DC is inverted into AC which is used in general houses by inverter. Recently, the use of power of the photovoltaic system is increased. Therefore, the study of 3 phase solar system to transmit large power is very important. This paper proposes a method that finds simply faults and diagnoses the switch open faults of 3-phase pulse width modulation (PWM) inverter of grid-connected photovoltaic system. The proposed method in $\alpha\beta$ plane uses the patterns of trajectory image as the characteristic parameters and differenciates a normal state and open states of switches. Then, the result is made into tree. The tree is composed of 21 fault patterns and the parameters to classify faults are a shape, a trajectory area, a distributed angle, and a typical vector angle. The result shows that the proposed method diagnosed fault diagnoses, classified correctly them, and made a pattern tree by fault patterns.

Serum Protein Concentrations and Electrophoretic Patterns by Categories of Small Opacity Profusions in Coal Workers' Pneumoconioses (탄광부 진폐증자의 흉부 방사선 사진상 소음영의 밀도에 따른 혈청 단백 농도 및 전기영동 분획상)

  • Hong, Jeong-Pyo;Chung, Ho-Keun
    • Journal of Preventive Medicine and Public Health
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    • v.24 no.1 s.33
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    • pp.1-7
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    • 1991
  • The concentrations of serum proteins fractions and their electrophoretical patterns were investigated in 135 patients with coal workers' pneumoconiosis who participated in confirmative examination for pneumoconiosis in December 1989. Their radiographical profusions were classified as 1/0 or more. Agarose film and phosphoric acid-sodium hydroxide buffer(pH 9.6) were used for electrophoresis. Concentration of each protein fractions and electrophoretical patterns seemd to be equivalent to reference values. Serum ${\alpha}_1$- and $\beta$-globulin concentrations, however, were significantly different (p<0.50) among categories of small opacity profusions and showed the lowest level in the group of category 1. Albumin concentratins decreased and ${\alpha}_2$- globulin concentrations increased significantly (p<0.05) in the group of complicated with pulmonary tuberculosis. $\gamma$-globulin concentrations were not varied by category of profusions nor by pulmonary tuberculosis complication.

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Mechanism by which periodontitis may contribute to atherosclerosis (치주염이 동맥경화에 기여하는 기전에 관한 연구)

  • Han, Seung-Hee;Kim, Kyung-Hwa;Yang, Seung-Min;Chung, Hyun-Ju;Choi, Yoon-Sik;Han, Soo-Boo;Chung, Chong-Pyoung;Rhyu, In-Chul
    • Journal of Periodontal and Implant Science
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    • v.32 no.4
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    • pp.837-846
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    • 2002
  • 그람 음성균의 감염에 의한 만성 염증질환인 치주염이 동맥경화를 동반한 허혈성 심장질환 (협심증이나 심근 경색)을 일으킬 수 있는 위험인자로 작용할 수 있다는 보고가 있었다. 그러나, 그 기전에 관해서는 명확하게 알려져 있지 않다. 작용기전의 하나로서, 치주염에 의해 치주조직에서 국소적으로 생긴 염증성 싸이토카인(IL-1${\beta}$, IL-6, $PGE_2$, TNF-${\alpha}$)이 혈행을 따라 이동하여 심혈관에서 동맥경화를 일으킬 수 있다는 가설이 제시되고 있는데, 이 가설을 검증해 보고자 한다. 서울대학교 병원 순환기 내과에 불안정 협심증이나 심근경색으로 입원한 환자 및 과거 이 질환의 병력을 갖고 있거나 검진 목적으로 내원하여 관상동맥 조형술을 받은 환자들 중 동맥경화로 진단받은 사람을 실험군(24명)으로 하고, 동맥경화로 진단받지 않은 사람을 대조군(12명)으로 하였다. 치주질환의 활성도를 나타내는 치은 지수, 치태 지수, 치주낭 깊이, 부착 상실을 측정하였다. Paper strip을 실험대상 치아(Ramfjord's teeth)들 중에서 가장 깊은 치주낭을 가진 두 개의 치아를 택하여 각 치아의 가장 깊은 치주낭에 30초간 삽입한 후 밀폐된 plastic tube에 넣고 ELISA kit를 이용하여 IL-1${\beta}$, IL-6, TNF-${\alpha}$, $PGE_2$의 농도를 측정하였다. 환자의 plasma에서도 동일한 싸이토카인의 농도를 측정하였다. 설문조사를 통해 동맥경화의 위험 인자로 간주되어온 고혈압, 당뇨, 가족력, 심근경색이나 협심증의 기왕력, 흡연의 유무를 기록하였다. 혈액검사를 하여 total cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, WBC, CRP (C-reactive protein)의 농도를 측정하였다. 치주조직에 대한 임상 검사 결과 치은의 염증상태를 나타나는 지표인 치은 지수에서만 실험군이 대조군에 비해 유의할 정도 (p=0.0174)로 높게 나타났고, 만성적인 염증의 결과로 인한 치조골의 사실 정도를 나타내는 치주낭 깊이나 부착 상실에서는 유의할 만한 차이를 보이지 않았다. 치주낭에서 측정한 염증성 싸이토카인 중 IL-1${\beta}$, $PGE_2$가 실험군에서 유의할 만한 차이 (p=0.005, 0.022)를 보이며, 더 높은 농도로 나타났고, TNF-${\alpha}$는 대조군에서 유의성 있게 (p=0.009) 높게 나타났다. 그러나, plasma의 싸이토카인이나, serum lipid/lipoprotein, C-reactive Protein, WBC는 유의할 만한 차이를 보이지 않았다. 또한 치은열구액내의 싸이토카인과 이에 상흥하는 싸이토카인 간에 상관관계는 관찰되지 않았다. 다변량 로지스틱 회귀분석 결과, 치은열구액내의 IL-1${\beta}$와 TNF-${\alpha}$ 만이 동맥경화와 유의성 있는 관련성을 보였고, 특히 IL-1${\beta}$와 교차비는 273으로 상당한 관련성을 보여주었다. 결론적으로, 치주조직에서 국소적으로 생긴 염증성 싸이토카인이 그대로 혈행으로 이동하여 혈장내의 싸이토카인 농도를 높이는 것은 아니다. 그러나, 치주염으로 인해 치은열구내액내에 국소적으로 증가된 염증성 싸이토카인은 동맥경화와 상당한 관련성을 가진다.

Sex-Related Differences of EEG Coherences between Patients with Schizophrenia and Healthy Controls (조현병 환자와 건강한 대조군에서 성별에 따른 뇌파 동시성의 차이)

  • Jung, Hye Min;Lee, Yu Sang;Kim, Seongsu;Kim, Seongkyun;Jeong, Jaeseung;Oh, Jin-Seok;Lee, Seungyeoun;Kim, Bum Joon;Chang, Jae Seung
    • Korean Journal of Biological Psychiatry
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    • v.20 no.4
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    • pp.166-178
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    • 2013
  • Objectives Alteration of epigenetic effects of testosterone during early development was suggested as an ancillary mechanism for the genesis of schizophrenia. EEG coherence was thought to be a marker for cerebral laterality of which important determinant was testosterone during early development. We studied sex-related differences of EEG coherences between patients with schizophrenia and controls to examine the sex effects in the genesis of schizophrenia. Methods EEG was recorded in 35 patients with schizophrenia and 46 healthy controls in the eyes closed resting state. Pair-wise EEG coherences were calculated over delta, theta, alpha, beta and gamma frequency bands. To examine the differences of EEG coherence according to sex in each group, ANCOVA was performed using Statistical Analysis system (SAS, Ver 9.3) and R (Ver 2.15.2). Results Healthy control males showed more increased right intrahemispheric coherences than healthy control females in delta, theta, alpha and beta frequency bands. In patients with schizophrenia, this male dominant pattern in right intrahemispheric coherences was attenuated especially in alpha and beta bands. Healthy control females showed more increased interhemispheric coherences than healthy control males in delta, theta, beta and gamma frequency bands. In patients with schizophrenia, these female dominant patterns in interhemispheric coherences were attenuated especially in delta, theta, and beta bands, which were commonly observed in frontal to central areas. Conclusion Sex differences in resting EEG coherences were attenuated in schizophrenia patients. These results imply that sex-related aberrant cerebral lateralization might exist in patients with schizophrenia, which are partly due to sex hormones via epigenetic mechanisms.

Effect of Dietary Protein on the Changes of Lipoprotein Fractions in Carbon Tetrachloride-Treated Rats (식이성 단백질 함량에 따른 흰쥐에 사염화탄소 투여시 Lipoprotein 분획비의 변동)

  • 이혜자;윤종국;이상일
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.2
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    • pp.127-131
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    • 1993
  • To evaluate an effect of dietary protein on lipoprotein profile serum of carbon tetrachloride-treated rats, carbon tetrachloride (50% in olive oil) was twice given at 0.1ml/100g body weight at intervals of 24hours to the male rats and then the degree of liver damage in carbon tetrachloride-treated animals fed a low protein diet was compared with that fed a high protein diet. The increasing rate of liver weight/body weight and the serum levels of alanine aminotransferase in carbon tetrachloride-treated rats to the control group were higher in rats fed high protein diet than those fed low protein diet. In the serum levels of lipid (total lipid, total cholesterol and triglyceride) remarkable differences were not found between low protein diet group and high protein diet group. But these serum lipids in carbon tetrachloride-treated rats were decreased and the decreasing rate of serum lipids to control group were higher in carbon tetrachloride-treated rats fed high protein diet than those fed low protein diet. Under the animal model as identified by the present data herein, serum pre $\beta$-lipoprotein and $\alpha$-lipoprotein fractions were decreased in carbon tetrachloride-treated rats, but the serum levels of $\beta$-lipoprotein were rather increased in the both group by the injection of carbon tetrachloride. Especially, the decreasing rate of $\alpha$-lipoprotein fraction was higher in $CCl_4$-treated rats fed a high protein diet than those fed a low protein diet to its control group and the increasing rate of serum $\beta$-lipoprotein fraction was also higher in $CCl_4$-treated rats fed high protein diet than those fed low protein diet.

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Preparation and Electrical Properties of Electro-conducting Glasses Containing $\textrm{V}_{2}\textrm{O}_{5}$ ($\textrm{V}_{2}\textrm{O}_{5}$계 전자 전도성 유리의 제조 및 전기적 특성)

  • Kim, Il-Gu;Park, Hui-Chan;Son, Myeong-Mo;Lee, Heon-Su
    • Korean Journal of Materials Research
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    • v.7 no.1
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    • pp.81-88
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    • 1997
  • Vanadate glasses using $B_2O_3$ as a network former and with CuO additive were mainly investigated in relation to electrical properties. Crystalline phases formed by heat-treatment in each composition were examined and dc electrical conductivity changes of the glasses were analyzed. Crystalline phases were identified as $V_3O_5,\;a-CuV_2O_6\;and\;{\beta}-CuV_2O_6$ by XRD analysis. Crystallization degrees of $V_2O_5$ and ${\beta}-CuV_2O_6$ were little changed with heat-treatment time, but those of ${\alpha}u-CuV_2O_6$ were changed sharply with heat-treatment time. The more crystallization of ${\alpha}u-CuV_2O_6$ occurred, the higher electrical conductivity was observed. Electrical conductivities with $10^{-2}~10^{-4}/{\Omega}/cm$ at room temperature(303K) could be obtained by controlling the glass compositions. The electrical conductivities were increased with increasing of $V_20_5$ content and decreasing of alkality($CuO/B_2O_3$). In this study, electron was proved to be charge carrier by seebeck coefficient measurement. Accordingly, the glasses are believed to be n-type semiconductor. Calculated activation energies for the conduction were in the range 0.098-0.124 eV. Electrical conduction mechanism was small polaron hopping without showing variable range hopping in the temperature range $30~200^{\circ}C$.

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Structure Determination of Glucosyltransferase Inhibitors from Cacao Bean Husk (Cacao Bean Husk로부터 Glucosyltransferase 저해물질 구조결정)

  • An, Bong-Jeun;Choi, Cheong
    • Applied Biological Chemistry
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    • v.37 no.6
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    • pp.498-502
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    • 1994
  • For glucosyltransferase(GTase) inhibitors, two flavan-3-ols were isolated from Theobroma cacao beam husk. They showed positive reaction with $anisaldehyde-H_2SO_4$ solution, $FeCl_3$ to be confirmed as dimeric flavan-3-ols on TLC and were identified as procyanidin B-1 [(-)-epicatechin-$(4{\beta}{\rightarrow}8)$-catechin] and procyanidin B-3 [(+)-catechin-$(4{\beta}{\rightarrow}8)$-catechin by spectroscopic analysis. Their inhibitory effect on glucosyltranaferase activity was also investigated and procyanidin B-1 showed 50% inhibition at 0.3 mM. They inhibited on the glucosyltransferasa noncompetitively and dimeric flavan-3-ol containing (-)-epicatechin had higer inhibitory activity.

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Comparing Quantitative EEG and Low Resolution Electromagnetic Tomography Imaging between Deficit Syndrome and Non-Deficit Syndrome of Schizophrenia (정신분열병의 결핍증후군과 비결핍증후군에서 QEEG와 sLORETA를 이용한 비교연구)

  • Lee, Sang-Eun;Yim, Seon-Jin;Lee, Mi-Gyung;Lee, Jae-Won;Han, Kyu-Hee;Lee, Jong-Il;Sim, Min-Young;Yoon, Hai-Joo;Shin, Byoung-Hak
    • Sleep Medicine and Psychophysiology
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    • v.17 no.2
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    • pp.91-99
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    • 2010
  • Objectives: Deficit schizophrenia (DS) constitutes a disease separate from non-deficit schizophrenia (NDS). The aim of the current study was to compare the quantitative EEG and low resolution electromagnetic tomography (LORETA) imaging between DS and NDS. Methods: This study was performed by 32 channels EEG for 42 schizophrenia patients who we categorized into DS and NDS using proxy instrument deficit syndrome (PDS). We performed the absolute power spectral analyses for delta, theta, alpha, low beta and high beta activities. We compared power spectrum between two groups using Independent t-test. Partial correlation test was performed with clinical parameters. Standardized LORETA (sLORETA) was used for comparison of cortical activity, and statistical nonparametric mapping (SnPM) was applied for the statistical analysis. Results: DS showed significantly increased delta and theta absolute power in fontal and parietal region compared with NDS (p<0.05). Power spectrum showed significant correlation with 'anergia' and 'hostility/suspiciousness' subscale of brief psychiatric rating scale (BPRS)(p<0.05). sLORETA found out the source region (anterior cingulate cortex/limbic part) that delta activity was significantly increased in DS (p=0.042). Conclusions: DS showed different cortical activity compared with NDS. Our results may suggest QEEG and LORETA could be the marker in differentiating between DS and NDS.

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Optimal Drive Algorithm Research for Three-Phase BLDC Motor with Double Rotor (이중 회전자 구조를 갖는 3상 BLDC 전동기 최적운전 알고리즘 연구)

  • Jung, Hyun-woo;Kim, Jang-sik;Kim, Jang-mok
    • Proceedings of the KIPE Conference
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    • 2011.11a
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    • pp.10-11
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    • 2011
  • 단일 회전자 전동기와 달리 동일한 크기에서 높은 출력 밀도와 높은 토크의 장점이 있는 이중 회전자 구조를 갖는 전동기는 공간적 제약을 받는 전기 자동차, 전기 이륜차 등의 분야에 활발히 연구되고 있다. 이중 회전자 구조를 갖는 전동기는 고 토크 운전을 위해 이중 인버터 운전 방식이 요구된다. 이때, 내부와 외부전동기의 역기전력이 다를 때 이를 고려하지 않고 운전한다면 발생하는 동손이 증가하여 운전효율 저하로 이어진다. 본 논문에서는 이중 회전자 구조를 갖는 3상 BLDC 전동기에서 내부와 외부전동기의 역기전력비(${\alpha}$)와 고정자 저항 비(${\beta}$)를 고려한 전류분배방식을 통해 동손을 최소화하는 최적운전 알고리즘을 제안하였다.

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