• 제목/요약/키워드: concentration effects

검색결과 14,534건 처리시간 0.044초

1990~1995 서울ㆍ수도권 지역의 광화학 오염현상 (Indication of Photochemical Air Pollution in the Greater Seoul Area, 1990 to 1995)

  • 김영성
    • 한국대기환경학회지
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    • 제13권1호
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    • pp.41-49
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    • 1997
  • Status of photochemical air pollution in the Greater Seoul Area (GSA) between 1990 and 1995 was assessed in terms of frequency distributions, number of days exceeding standards, average concentration and meteorological effects. In Seoul compared with other areas in Korea, daily maximum concentration was higher but average concentration was not so high due to lower daily minimum from April to October. The top 5th percentile was high especially in summer season. Average number of days exceeding 100 ppb at monitoring stations in GSA was highest in 1994, the hottest year, but it was only 4 days a year. Mean meteorological pattern of high ozone days could be summarized as low wind speeds, high temperatures, strong solar radiation, and low precipitation. Westerlies were more frequent on high ozone days and at Pangi station located in the eastside of GSA, both number of high ozone days and average concentration were high. Effect of precursor transport on the rise of ozone concentration was, however, not consistently important on the whole in GSA.

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The Effects of the Meditation Music and Lumbar Stabilization Exercise on Concentration, Balance and Muscle Activity in Elderly

  • Lee, Sang-Bin
    • 국제물리치료학회지
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    • 제2권1호
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    • pp.260-266
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    • 2011
  • The purpose of this study was to investigate the effects of meditation music with lumbar stabilization exercise on balance, concentration and muscle activation. Participants are divided into Group A and Group B. Group A listened to meditation music while doing 4 sets of lumbar stabilization exercise. Group B did not listen to meditation music while doing 4 sets of lumbar stabilization exercise. Surface EMG data was obtained rectus abdominis, external oblique, erector spinae, multifidus muscle during lumbar stabilization exercise. To examine the effect of before-after experiment for concentration and balance, paired t-test was adopted. Changes in EMG data of each muscles were analyzed by independence t-test. There were statistically significant increasing at concentration level and balance level in Group A. But significant difference was not shown in muscle activation. The clinical effect of the meditation music with lumbar stabilization exercise was investigated in this study with more excellent results in concentration and balance. In conclusion, these results suggest that meditation music and lumbar stabilization exercise may be useful in elderly people.

천화산가미방(天花散加味方)이 고지방식이에 의한 당뇨병 유발 쥐의 혈청 Glucose농도와 지질구성에 미치는 영향 (Effects of Cheunhwasangamibang on serum glucose concentration and lipid composition in high fat diet induced diabetic rat)

  • 김병우
    • 대한한방내과학회지
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    • 제24권2호
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    • pp.358-364
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    • 2003
  • Effects of Cheunhwasangamibang on serum glucose and lipid composition were investigated in high fat diet induced diabetic rat. Plasma glucose and free fatty acids concentration showed a high reduction in Cheunhwasangamibang groups compared to those of control group and these values decreased to increasing Cheunhwasangamibang concentration. Plasma ${\beta}$-lipoprotein and triglyceride concentration showed a low values in Cheunhwasangamibang groups, however these values showed no significantly different in 4 ml and 6 ml treatment groups. Total cholesterol concentration showed no significantly different in control group and 2 ml Cheunhwasangamibang group, however these values in 4 ml and 6 ml treatment groups showed a reduction compared to those of control group. Plasma LDL-cholesterol concentration showed a reduction in Cheunhwasangamibang group and HDL-cholesterol showed no significantly different in all treatment groups.

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귤피 추출물의 항균효과 (Antibacterial Effects of Extracts from Citrus Peels)

  • 최보람;강재구;강경희
    • 디지털융복합연구
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    • 제10권11호
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    • pp.559-564
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    • 2012
  • 생약제제 중에서 귤피는 항산화작용, 순환기계 질병의 예방, 항염증, 항알레르기, 항균, 항바이러스, 지질 저하 작용, 면역 증강작용, 모세혈관 강화작용 등이 있는 것으로 보고되고 있다. 본 연구에서는 귤피 추출물이 치아우식 원인균으로 알려진 S. mutans에 미치는 항균효과와 GTase활성에 미치는 영향에 대해 알아보고자 하였다. 추출물을 5, 10, 20 mg/ml의 농도로 배지에 첨가한 후 S. mutans의 성장억제효과를 확인한 결과, 농도가 높을수록 colony의 수가 현저히 줄어드는 것을 관찰 할 수 있었다. 8 시간 후 측정하였을때 5 mg/ml에서 92%, 10 mg/ml에서 95%, 20 mg/ml 에서 99%의 높은 성장억제율을 나타내었다. 또한 추출물의 GTase 활성 저해율을 측정한 결과, 추출물의 농도가 높아질수록 저해율이 급격히 증가하는 것으로 나타났으며, 5 mg/ml에서는 42%의 강한 활성 저해 효과를 보였다.

소청용장(小靑龍湯)이 생쥐의 폐(肺) 대식세포(大食細胞) Cytokine 귀전자(遣傳子) 발현에 미치는 영향 (Effects of Sochungyong-tang on Cytokine Gene Expression in Mouse Alveolar Macrophage)

  • 박인기;심성용;변학성;김경준
    • 한방안이비인후피부과학회지
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    • 제18권3호
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    • pp.1-17
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    • 2005
  • In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis of lung disease. This Experiment was conducted to investigate the effects of Sochungyong-tang on gene expressions in Mouse Alveolar Macrophage. Fer this purpose, we observed the cytokines ($IL-1{\beta}$, IL-6, IL-10, iNOS, $MIP-1{\alpha},\;MIP-1{\beta},\;MIP-1{\gamma},\;TGF-{\beta},\;TNF-{\alpha}$). We picked the alveolar macrophage out of mice and cultured it. We analyzed the cytokine gene expression by reverse transcription-PCR. The results obtained were as follows : 1 . Sochungyong-tang showed inhibitory effects on $IL-1{\beta}$ in time and concentration. 2. Sochungyong-tang showed inhibitory effects on IL-6 in time and concentration. 3. Sochungyong-tang showed inhibitory effects on IL-10 in concentration. 4. Sochungyong-tang showed inhibitory effects on iNOS. 5. Sochungyong-tang showed inhibitory effects on $TGF-{\beta}$ in time and concentration. 6. Sochungyong-tang showed on inhibitory effects on $MIP-1{\alpha},\;MIP-1{\beta},\;MIP-1{\gamma}$, $TCF-{\beta}$, $TNF-{\alpha}$. According to above results, it is supposed that Sochungyong-tang has the inhibitory effects on cytokine gene expression in mouse alveolar macrophage and can be usefully applied for curing inflammatory process of lung disease. Advanced studies are required to investigate the cure mechanism of Sochungyong-tang in the future.

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니딩 처리 시 지료농도에 따른 활엽수표백크라프트펄프의 섬유특성 변화 (Effects of Kneading Concentration on Characteristics of HwBKP Fibers)

  • 서지혜;최경화;조병욱
    • 펄프종이기술
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    • 제47권4호
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    • pp.54-59
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    • 2015
  • In this study, effects of kneading concentration on characteristics of hardwood bleached kraft pulp (HwBKP) fibers were elucidated. A laboratory two-shaft kneader was utilized for kneading. Kneading concentration was varied in the range of 15-30% (w/w) and the number of kneading treatment was adjusted between 0 and 6 passes. It was found that kneading concentration influenced fiber characteristics. At 15% of pulp concentration, fiber length slightly increased with increasing the number of kneading passes, while other morphological properties such as fiber width and curl decreased: fiber straightening occurred. In addition, the increase in WRV and the decrease in CSF were the largest at 15% kneading concentration, meanings that fibrillation mainly occurred. In contrast, at higher kneading concentration exceeding 20%, fiber deformation like curl was mainly occurred. Also, at kneading concentration of 20% and 30%, fiber length decreased with the number of kneading passes while other morphological properties such as fiber width, and WRV increased. Severe fiber entanglement was found at 30% kneading, which shall be removed during papermaking.

Effects of Glucose concentration on the production of poly(3-hydroxybutyrate) by high cell density culture of Ralstonia eutropha

  • Shang, Longan;Kim, Do-Yun;Kim, Moon-Il;Kim, Byoung-Jin;Chang, Ho-Nam
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.213-217
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    • 2003
  • The effects of glucose concentration on the production of PHB by fed-batch culture of Ralstonia eutropha were investigated. In the range of glucose concentration of $2.5\;{\sim}\;40\;g/l$, it was found that the high glucose concentration was not favorable for the PHB formation after the phosphate limitation. It was further confirmed by the specific PHB synthesis rates and yields. The PHB concentration decreased much with the increase of glucose concentration. But if the glucose concentration was very low, e.g. 2.5 g/l, the cell growth and PHB synthesis also could be limited because of inadequate glucose supply. Itwould be better to maintain the glucose concentration at about 9.0 g/l to obtain high DCW, PHB concentration and productivity.

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RHEOLOGICAL PROPERTIES OF MAGNETIC PARTICLE SUSPENSIONS

  • Kwon, T.M.;Choi, H.J.;Jhon, M.S.
    • 한국자기학회지
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    • 제5권5호
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    • pp.667-671
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    • 1995
  • The viscometric technique is used to study the effects of microstructure on the viscosity (viscosity vs. concentration or shear rate) of magnetic particle suspensions. In this characterization, measurement of suspension viscosity is used to obtain the dependence of viscous energy dissipation on microstructural state of dispersions. Microstructural shape effects which are related to particle orientation are then indirectly obtained. Empirical formulas from mean field theory and the Mooney equation, which are applicable at high concentration of magnetic particles, are used to relate viscosity to particle concentration. The validity and physical meaning of these equations are discussed.

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Experimental Study on Uranium Sorption onto Silica Colloids: Effects of Geochemical Parameters

  • Baik, Min-Hoon;Hahn, Pil-Soo
    • Nuclear Engineering and Technology
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    • 제33권3호
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    • pp.261-269
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    • 2001
  • In this study, sorption experiments of uranium onto silica colloids were carried out and the effects of important geochemical parameters such as pH, ionic strength, carbonate concentration, colloid concentration, and total concentration of uranium were investigated. The sorption coefficients of uranium for silica colloids named as pseudo-colloid formation constants were about 10$^4$~ 10$^{5}$ mL/g depending on the experimental conditions. The effects of the geochemical parameters were found to be important in the sorption of uranium onto silica colloids. A Langmuir type sorption isotherm of uranium between silica colloids and the solution phase was also presented. The sorption mechanisms were explained by analyzing the effects of the geochemical parameters.

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Prediction of solute rejection and modelling of steady-state concentration polarisation effects in pressure-driven membrane filtration using computational fluid dynamics

  • Keir, Greg;Jegatheesan, Veeriah
    • Membrane and Water Treatment
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    • 제3권2호
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    • pp.77-98
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    • 2012
  • A two-dimensional (2D) steady state numerical model of concentration polarisation (CP) phenomena in a membrane channel has been developed using the commercially available computational fluid dynamics (CFD) package CFX (Ansys, Inc., USA). The model incorporates the transmembrane pressure (TMP), axially variable permeate flux, variable diffusivity and viscosity, and osmotic pressure effects. The model has been verified against several benchmark analytical and empirical solutions from the membrane literature. Additionally, the model is able to predict the rejection of an arbitrary solute by the membrane using a pore model, given some basic knowledge of the geometry of the solute molecule or particle, and the membrane pore geometry. This allows for predictive design of membrane systems without experimental determination of the membrane rejection for the specified operating conditions. A demonstration of the model is presented against experimental results for two uncharged test compounds (sucrose and PEG1000) from the literature. The model will be extended to incorporate charge effects, transient simulations, three-dimensional (3D) geometry and turbulent effects in future work.