• 제목/요약/키워드: Kinetic Parameters

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정속가열(定速加熱)조건에서 표준온도상당시간(相當時間)을 이용한 비효소적 갈색화 반응의 동력학 파라미터 추정(推定) (Estimation of Kinetic Parameters of Nonenzymatic Browning Reaction Using Equivalent Time at Reference Temperarture with Linearly Increasing Temperature Profile)

  • 조형용;권윤중;김인규;변유량
    • 한국식품과학회지
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    • 제25권2호
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    • pp.178-184
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    • 1993
  • 식품의 품질변화에 미치는 온도의 영향을 분석하기 위한 kinetic parameters를 추정하는데 있어서 표준온도 상당시간이 유효함을 밝히기 위하여 비효소적 갈색반응 액체 모델 및 식품시스템을 직선적으로 온도를 증가시키는 조건$(6^{\circ}\;/h)$에서 반응시켰다. 표준온도 상당시간은 $t_E=-{\exp}[-(E_a/R)\;(1/T-1/T_{ref})]$로 정의되며, 임의의 온도 T에서 1일 동안에 일어난 품질변화는 표준온도 $T_{ref}$에서 몇일 동안에 일어난 변화에 상당하는가를 의미한다. 이와 같이 정의되는 표준온도 상당시간을 이용하여 glucose-lysine모델, 여러종류의 아미노산과 당의 액체모델 및 액체 음료 식품시스템의 실험자료로부터 비선형 최소자승법으로 kinetic parameter, n, $k_{ref}$$E_a$를 추정하였다. Glucose와 lysine의 손실속도는 1차 반응, 갈색물질 형성속도는 0차 반응이었다. 추정한 kinetic parameters를 이용하여 computer simulation한 결과 실험값과의 상관계수가 0.96 이상으로 잘 일치하여 $t_E$를 이용한 1단계 비선형 최소자승법으로 kinetic parameters를 효율적으로 정확히 추정할 수 있음을 확인하였다.

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우리나라 연령별 보행분석 비교연구 (The Comparative Study on Age-associated Gait Analysis in Normal Korean)

  • 윤나미;윤희종;박장성;정화수;김건
    • The Journal of Korean Physical Therapy
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    • 제22권2호
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    • pp.15-23
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    • 2010
  • Purpose: This study was done to establish reference data for temporo-spatial, kinematic and kinetic parameters for normal Koreans as they age. Methods: Normal adults and children without a previous history of musculoskeletal problems were enrolled in this study. The normal subjects were divided by age into three groups: Group I: children ($11.95{\pm}0.29$ years); Group II: young adults ($23.90{\pm}3.67$ years); Group III: older adults ($71.40{\pm}4.08$ years). The temporo-spatial and kinematic data were measured using 6 MX3 cameras while each subject walked through a 10 m walkway at a self-selected speed. The kinetic data were measured using 2 force plates and were calculated by inverse dynamics. Results: Motion patterns are typically associated with a specific phase of the gait cycle. Our results were as follows: 1. There were significant differences between the different age groups in temporo-spatial parameters such as cadence, double support, time of foot off, stride length, step length, and walking speed. 2. There were significant differences between the groups in kinematic parameters such as range of motion (ROM) of the hip, knee and ankle in the sagittal plane, ROM of the pelvis, hip and knee in the coronal plane and ROM of the pelvis, hip and ankle in the transverse plane. 3. There were significant differences between the groups in kinetic parameters such as joint moments of force, joint mechanical power generation or absorption and ground reaction forces. Conclusion: The results of this study can be utilized (a) as a reference for kinematic and kinetic data of gait analysis in normal Koreans, and (b) as an aide in evaluating and treating patients who have problems relating to gait.

TGA를 이용한 폴리프로필렌의 연소반응에서의 열적 특성 연구 (Thermal Characteristics of Polypropylene in Combustion Reaction Using TGA)

  • 강윤진;서수은;서규석;강경식
    • 대한안전경영과학회지
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    • 제10권4호
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    • pp.111-120
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    • 2008
  • The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

정상 성인의 운동역학적 보행분석 (A Study on Kinetic Gait Analysis of the Normal Adult)

  • 김건;윤나미
    • The Journal of Korean Physical Therapy
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    • 제21권2호
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    • pp.87-95
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    • 2009
  • Purpose: This study reports the basic reference data of the specific gait parameters for Korean normal adults. Methods: The basic gait parameters were extracted from 73 Adults (35 men and 38 women), 18 to 33 years of age, using a Vicon MX motion analysis system. The segment kinetics, such as joint moment and power, was analyzed at the hip, knee and ankle. Results: The motion patterns are typically associated with a specific phase of the gait cycle. The temporal-spatial gait parameters of Korean normal adults, such as cadence, walking speed, stride length, single support and double support, were similar to the other western reference data. The kinetic parameters of Korean normal adults, such as joint moments of force, joint mechanical power generation or absorption and ground reaction forces, were also similar to other western reference datasets. Conclusion: This study demonstrates that objective gait analysis can be used to document the gait patterns of normal healthy adults. The techniques of 3-dimensional temporal-spatial gait parameters and kinematic parameters analysis can provide a detailed biomechanical description of a normal and pathological gait.

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Kinematic and Kinetic Analysis of the Soft Golf Swing using Realistic 3D Modeling Based on 3D Motion Tracking

  • Kim, Yong-Yook;Kim, Sung-Hyun;Kim, Nam-Gyun
    • 대한의용생체공학회:의공학회지
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    • 제28권6호
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    • pp.744-749
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    • 2007
  • Kinematic and kinetic analysis has been performed for Soft Golf swings utilizing realistic three dimensional computer simulations based on three dimensional motion tracking data. Soft Golf is a newly developed recreational sport in South Korea aimed to become a safe and easy-to-learn sport for all ages. The advantage of Soft Golf stems from lighter weight of the club and much larger area of the sweet spot. This paper tries to look into kinematic and kinetic aspects of soft golf swings compared to regular golf swing and find the advantages of lighter Soft Golf clubs. For this purpose, swing motions of older aged participants were captured and kinematic analysis was performed for various kinematic parameters such as club head velocity, joint angular velocity, and joint range of motions as a pilot study. Kinetic analysis was performed by applying kinematic data to computer simulation models constructed from anthropometric database and the measurements from the participants. The simulations were solved using multi-body dynamics solver. Firstly, the kinematic parameters such as joint angles were obtained by solving inverse dynamics problem based on motion tracking data. Secondly, the kinetic parameters such as joint torques were obtained by solving control dynamics problem of making joint torque to follow pre-defined joint angle data. The results showed that mechanical loadings to major joints were reduced with lighter Soft Golf club.

혼합 액체 연료의 화학반응 인자 계측에 관한 실험적 연구 (An Experimental Study on Measurement of Chemical Kinetic Parameters of a Liquid Fuel with Various Components)

  • 최효현;임준석;김철진;손채훈
    • 한국연소학회지
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    • 제16권3호
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    • pp.21-26
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    • 2011
  • Thermal analyses are conducted to measure chemical kinetic parameters of an unknown liquid fuel with various components. Thermal Analyses are divided into two different methods such as TGA(Thermo-Gravimetric Analysis) and DSC(Differential Scanning Calorimety). Non-isothermal experimental results are analyzed by adopting TGA and they are filtered by Freeman-Carroll method. As a results of the analysis, chemical parameters of the activation temperature and the reaction order are measured to be 6128.2 K and 1.4, respectively. Furthermore, the chemical kinetic parameters are obtained by a variety of mathematical processing methods. It has been found that they show a little difference depending on the processing method.

Effect of Kinetic Parameters on Simultaneous Ramp Reactivity Insertion Plus Beam Tube Flooding Accident in a Typical Low Enriched U3Si2-Al Fuel-Based Material Testing Reactor-Type Research Reactor

  • Nasir, Rubina;Mirza, Sikander M.;Mirza, Nasir M.
    • Nuclear Engineering and Technology
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    • 제49권4호
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    • pp.700-709
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    • 2017
  • This work looks at the effect of changes in kinetic parameters on simultaneous reactivity insertions and beam tube flooding in a typical material testing reactor-type research reactor with low enriched high density ($U_3Si_2-Al$) fuel. Using a modified PARET code, various ramp reactivity insertions (from $0.1/0.5 s to $1.3/0.5 s) plus beam tube flooding ($0.5/0.25 s) accidents under uncontrolled conditions were analyzed to find their effects on peak power, net reactivity, and temperature. Then, the effects of changes in kinetic parameters including the Doppler coefficient, prompt neutron lifetime, and delayed neutron fractions on simultaneous reactivity insertion and beam tube flooding accidents were analyzed. Results show that the power peak values are significantly sensitive to the Doppler coefficient of the system in coupled accidents. The material testing reactor-type system under such a coupled accident is not very sensitive to changes in the prompt neutron life time; the core under such a coupled transient is not very sensitive to changes in the effective delayed neutron fraction.

고구마 조직의 가열변화에 대한 반응속도론적 상수 결정 (Determination of Kinetic Parameters for Texture Changes of Sweet Potatoes during Heating)

  • 이정주;임종환
    • 한국식품과학회지
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    • 제33권1호
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    • pp.66-71
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    • 2001
  • 가열에 의한 품종별 고구마 조직의 변화에 대한 반응속도론적 상수를 biphasic model과 fractional conversion method를 사용하여 결정하였다. Biphasic model에 따라 고구마의 가열에 의한 조직의 변화는 2단계의 연속적인 1차 반응식으로 표시할 수 있었으며, 활성화에너지는 고구마의 품종에 따라 $71.0{\sim}75.1\;kJ/mol$$48.4{\sim}59.6\;kJ/mol$이었다. 또한 고구마의 가열에 의한 조직변화를 fractional conversion method를 사용하여 1개의 1차 반응식으로 표시할 수 있었는데, 이 때의 활성화에너지는 $67.5{\sim}75.3\;kJ/mol$로서 biphasic model에 의한 제 1단계의 반응에 대한 값과 유사한 값을 나타냈다. 이들 방법으로 결정된 반응속도론적 상수들 사이에는 kinetic compensation 효과가 있었으며, 두 방법 모두 고구마의 가열에 의한 조직변화에 대한 반응속도론적 상수들을 결정하는데 적용할 수 있음을 알 수 있었다.

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

  • 주종효;김명준;조형태;이재원;김정환
    • 한국수소및신에너지학회논문집
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    • 제33권5호
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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.

Determination of Kinetic Parameters in Coal Weathering Processes

  • Yun, Yongseung
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 1993년도 추계학술발표회 초록집
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    • pp.31-36
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    • 1993
  • Three different methods were employed to measure the degree of aerial oxidation in coal and the resulting oxidation/weathering indices were applied to obtain kinetic parameters of aerial oxidation processes, The index (i.e., slurry pH, Free Swelling Index, weight gain) values were subjected to kinetic analysis based on power-law Arrhenius type reaction model. The results show that activation energy of the aerial oxidation in 20-29$0^{\circ}C$ is in the range of 12-16 ㎉/㏖ and the agreement among three techniques is remarkable. The first order kinetic model is suitable in describing low temperature aerial oxidation process, except in the FSI case where the zero order expression is the best one.

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