• Title/Summary/Keyword: kinetic

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Adsorption Characteristics of Cobalt, Strontium, and Cesium on Natural Soil and Kaolin (자연토양 및 카올린에 대한 코발트, 스트론튬, 세슘의 흡착 특성)

  • Cheon, Kyeong Ho;Choi, Jeong-Hak;Shin, Won Sik;Choi, Sang June
    • Journal of Environmental Science International
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    • v.23 no.9
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    • pp.1609-1618
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    • 2014
  • In this study, as a fundamental study for the remediation of the radionuclides-contaminated soil, the adsorption of cobalt, strontium, and cesium on natural soil and kaolin were experimently investigated and adsorption characteristics were evaluated by using several adsorption kinetic and isotherm models. The pseudo-first-order kinetic model (PFOM), pseudo-second-order kinetic model (PSOM), one-site mass transfer model (OSMTM), and two compartment first-order kinetic model (TCFOKM) were used to evaluate the kinetic data and the pseudo-second-order kinetic model was the best with good correlation. The adsorption equilibria of cobalt, strontium, and cesium on natural soil were fitted successfully by Redlich-Peterson and Sips models. For kaolin, the adsorption equilibria of cobalt, strontium, and cesium were fitted well by Redlich-Peterson, Freundlich, and Sips models, respectively. The amount of adsorbed radionuclides on natural soil and kaolin was in the order of cesium > strontium > cobalt. It is considered that these results could be useful to predicting the adsorption behaviors of radionuclides such as cobalt, strontium, and cesium in soil environments.

Evaluation of Biological Kinetic Parameters in the Granular Sludge (입상슬러지의 동력학적 인자 산정)

  • 이재관;양병수
    • Journal of Environmental Science International
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    • v.4 no.2
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    • pp.201-214
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    • 1995
  • Design approach of upflow Anaerobic Sludge Blanket(UASB) process based on the biological kinetic parameters are known to be very difficult since the characteristics of the granular slut비e depends on the type of wastewater and size distribution of the granular sludge also depends on the upflow velocity in the UASB reactors. Furthermore, industrial wastewater containing toxic substances has been treated by UASB process without the clear knowledge of toxic effects on the granular slut형e. Hence, the present research was aimed on the intensive evaluation of biological kinetic parameters of the granular sludge in UASB reactor with and without toxic substance of 2, 4-dichlorophenol in order to present the basic design measures for UASB process design. The results could be summarized as follows. The biological kinetic parameters(k and Ks) considerably varied with the granular size of the sludge. Generally, 연e k and ks values of the granular sludge increased with the particle size of the granule. The biological kinetic parameters(k and Ks) of the granular sludge obtained from batch test were not applicable to design purpose of UASB process due to substrate diffusional limitation into the granular sludge in the completely mixed UASB reactors. The toxic effects on k and Ks greatly varied with the granular sixte. And as the toxicant concentration increased, the k value decreased while the Ks value increased. Inhibition constant(hi) for k with the toxicant of 2, 4-dichlorophenol varied from 0.5 to 2.3 depending on the granular sizes while the inhibition constant(Ki) for Ks varied from 20.7 to 80.1, showing the mixed inhibition.

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Energy Exchanges and Adhesion Probability of Lennard-Jones Cluster Colliding with a Weakly Attractive Static Surface (클러스터-표면 충돌시 부착 확률과 에너지 교환에 대한 분자동력학 시물레이션)

  • Jung, Seung-Chai;Suh, Dong-Uk;Yoon, Woong-Sup
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1788-1793
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    • 2008
  • Classical molecular dynamics simulations (MDS) were conducted to simulate nano-sized cluster collisions with a weakly attractive static surface. Energy exchanges associated with the cluster collision and the adhesion probability are discussed. Routes of the energy exchanges and the kinetic energy loss are vastly altered in their mode according to the cluster incident velocity. In the elastic collision regime ($V_0$<0.1), most incident kinetic energy is recovered into the rebounding kinetic energy, but a little loss in the incident kinetic energy causes the cluster adhesion. Dissipated kinetic energy is converted into the rotational energy. In the weakly plastic collision regime (0.1<$V_0$<0.3), the transition from elastic to plastic collision occurs, and a large part of the released potential energy is converted into rebounding translational energy. For strongly plastic collisions ($V_0$>0.3), permanent cluster deformation occurs with extensive collapse of the lattice structure inducing a solid-to-solid phase transition; moreover, most of the cluster kinetic energy is converted into cluster potential and thermal energy.

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The Effect of Density Gradient on the Self-modulated Laser Wakefield Acceleration with Relativistic and Kinetic Effects

  • Yoo, Seung-Hoon;Kim, Jae-Hoon;Kim, Jong-Uk;Seo, Ju-Tae;Hahn, Sang-June
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.42-47
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    • 2009
  • The propagation of an intense laser pulse through an upward density-gradient plasma in a self-modulated laser wakefield acceleration (SM-LWFA) is investigated by using particle-in-cell (PIC) simulations. In the fully relativistic and kinetic PIC simulations, the relativistic and kinetic effects including Landau damping enhance the electron dephasing. This electron dephasing is the most important factor for limiting the energy of accelerated electrons. However, the electron dephasing, which is enhanced by relativistic and kinetic effects in the homogeneous plasma, can be forestalled through the detuning process arising from the longitudinal density gradient. Simulation results show that the detuning process can effectively maintain the coherence of the laser wake wave in the spatiotemporal wakefield pattern, hence considerable energy enhancement is achievable. The spatiotemporal profiles are analyzed for the detailed study on the relativistic and kinetic effects. In this paper, the optimum slope of the density gradient for increasing electron energy is presented for various laser intensities.

Effects of Visual Feedback Closed Kinetic Chain Exercise on the Lower Limb Muscles Activity and ankle Instability in Adult men with Chronic Ankle Instability (시각적 피드백을 이용한 닫힌 사슬 운동이 만성 발목 불안정성 성인남성의 하지 근활성도 및 발목 불안정성 지수에 미치는 영향)

  • Nam, Seung-Min;Lee, Do-Youn
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.1
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    • pp.131-138
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    • 2019
  • PURPOSE: This study examined the effects on muscle activation and ankle instability following sudden ankle inversion of the closed kinetic chain exercise using visual feedback to evaluate chronic ankle instability in adult males. METHODS: In this study, 28 subjects with chronic ankle instability were recruited and randomly divided into a closed kinetic chain exercise using a visual feedback group(n=13) and an open kinetic chain exercise group(n=15). Each group underwent 30 minutes of exercise three times a week for 8 weeks. The electromyographic(EMG) values of the rectus femoris, biceps femoris, tibialis anterior, peroneus longus, peroneus brevis, and lateral gastrocnemius muscles were measured to analyze muscle activity. The Cumberland ankle instability tool(CAIT) was used to measure ankle instability. RESULTS: Both groups showed improvements in tibialis anterior, peroneus longus and CAIT score(p<.05). In the experimental group, there were significant improvements in the rectus femoris, biceps femoris, and lateral gastrocnemius muscle activation(p<.05). CONCLUSION: The results suggest that closed kinetic chain exercise using visual feedback can be a useful treatment method for patients with chronic ankle instability.

Kinetic Parameter Estimation of Ru Catalyst for Steam Methane Reforming (증기 메탄 개질 반응의 Ru 촉매 Kinetic Parameter 예측)

  • JOO, CHONGHYO;KIM, MYUNGJUN;CHO, HYUNGTAE;LEE, JAEWON;KIM, JUNGHWAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.5
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    • pp.499-506
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    • 2022
  • This study proposes kinetic parameters of Ru catalyst for steam methane reforming (SMR). First, extensive experiments are performed under different SMR conditions to evaluate performance of the catalyst in SMR. Second, a kinetic model is designed and developed for parameter estimation and validation using gPROMS. Finally, estimated parameters are fitted to the kinetic model and then, the model results are compared with the experimental data. The model results are in a good agreement with the experimental data.

Effect of Hip Adduction Position on the Vastus Medialis Oblique and Vastus Lateralis During Closed Kinetic Chain Exercise in Sitting Posture

  • Cha, Yong-su;Jeon, Hye-seon;Yi, Chung-hwi;Kwon, Oh-yun;Choi, Bo-ram
    • Physical Therapy Korea
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    • v.23 no.2
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    • pp.75-83
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    • 2016
  • Background: Several studies have discussed diverse exercise methods considered to be useful for the selective contraction of the vastus medialis oblique (VMO) muscle for the treatment of patellofemoral pain syndrome. Some studies have reported that exercise methods, including hip adduction, in closed kinetic chain exercises are more effective in terms of the muscle activation of the VMO and the timing of the muscle's initial contraction. We focused on isometric contraction during a closed kinetic chain exercise with hip adduction. Objects: The purpose of this study was to examine muscle activation in the VMO and the vastus lateralis (VL) and the onset time difference between their initial contractions via closed kinetic chain isometric quadriceps femoris exercises including hip adduction. Methods: In total, 36 healthy subjects adopted two hip positions during isometric contraction of the quadriceps femoris in a closed kinetic chain exercise (hip neutral and hip adduction position). Statistical analyses were conducted using a paired t-test (${\alpha}=.05$). Results: Isometric contraction of the quadriceps femoris in a closed kinetic chain exercise caused a greater increase in VMO muscle activity in the hip adduction position [$52.68{\pm}22.21$ percentage of maximal voluntary isometric contraction (%MVIC)]than the hip neutral position ($43.43{\pm}19.85%MVIC$). The onset time difference (VL-VMO) decreased more in the hip adduction position ($-82.14{\pm}34.2ms$) than the hip neutral position ($73.94{\pm}2.94ms$). Conclusion: We recommend this exercise as a clinically useful therapeutic method for patients with patellofemoral pain syndrome due to weakening of the VMO muscle and lateral inclination of the patella.

Application of Monte Carlo Simulation to Intercalation Electrochemistry II. Kinetic Approach to Lithium Intercalation into LiMn2O4 Electrode

  • Kim, Sung-Woo;Pyun, Su-Il
    • Journal of the Korean Electrochemical Society
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    • v.5 no.2
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    • pp.86-92
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    • 2002
  • The present article is concerned with the application of the kinetic Monte Carlo simulation to electrochemistry of lithium intercalation from the kinetic view point. Basic concepts of the kinetic Monte Carlo method and the transition state theory were first introduced, and then the simulation procedures were explained to evaluate diffusion process. Finally the kinetic Monte Carlo method based upon the transition state theory was employed under the cell-impedance-controlled constraint to analyse the current transient and the linear sweep voltammogram for the $LiMn_2O_4$ electrode, one of the intercalation compounds. From the results, it was found that the kinetic Monte Carlo method is much relevant to investigate kinetics of the lithium intercalation in the field of electrochemistry.

The Effect of an Integrated Kinetic Program on the Change of Body Composition and Blood Lipid Components in Middle-aged Women (복합운동프로그램이 중년여성의 신체구성 및 혈중지질의 변화에 미치는 영향)

  • Ji, Yang;Wan-Hee, Lee
    • The Journal of Korean Physical Therapy
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    • v.24 no.1
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    • pp.41-50
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    • 2012
  • Purpose: This study examined the effect of an integrated kinetic program on the body composition of middle-aged and their associated blood lipid components. Methods: The subjects included 50 middle-aged women who resided at J city. Upon their agreements, the subjects were divided into either an experimental group or the control group. There were 25 subjects in each. The integrated kinetic program was conducted during the 6 weeks, and the experimental group was underwent its associated program 5 times a week. There were 3 subjects from each group that were excluded. The extensions were measured with the extensometer, the weights were taken with the body ingredient analysis instrument, and the blood lipid consistency with the blood autoanalyzer. Results: Pre- and Post- the integrated kinetic program, there were statistically significant differences between the body fat mass and the BMI in the experimental group. However, this difference was not significantly different in the control group. Further, there were no statistically significant differences between the two groups of all items in blood lipid components. But the experimental group showed the decrement from TC and TG items after accomplishing the program. Conclusion: The results of this study showed that this kinetic program helps the prevention and functional control of bodily functional decrement to middle-aged women. It is considered that follow-up studies on practically integrated kinetic programs are needed so that they include exercise accomplishments of proper period and good quality nutrition intake. This is in order to maintain muscular quantity and prevent muscle function decrement for the healthy middle-aged women, preparing in aging and menopause.

Prediction of energy expenditure from a tri-axial accelerometer during treadmill walking (트레드밀 보행 시 단일 3축 가속도센서를 사용한 대사에너지 소모량 예측)

  • Lee, H.Y.;Park, S.W.;Kim, S.H.;Lee, D.Y.;Kim, Y.H.
    • Journal of Biomedical Engineering Research
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    • v.32 no.2
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    • pp.79-84
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    • 2011
  • The purpose of this study was to investigate the relevance of the prediction equations derived from the relationship between metabolic energy expenditure and kinetic energy, for different speeds of walking and running over the treadmill. Seven male subjects participated in this study. A tri-axial accelerometer was attached on between the left and right posterior superior iliac spines. Kinetic energy was calculated by the integration of acceleration data and compared with the metabolic energy measured by a gas analyzer. Correlation coefficients were determined to find a relationship between the kinetic energy and the metabolic energy expenditure. Also, the difference between measured and predicted values was used to find the relevance for individual and group equations. Results showed a relatively good correlation between the measured metabolic energy and the calculated kinetic energy. In addition, a dramatic increase in kinetic energy was observed at the transition speed of walking and running (6 km/h). There was no difference in how to predict the kinetic energy expenditure for individual and group even though people have different physical characteristics. This study would be useful to predict metabolic energy expenditures by the regression analysis with acceleration data.