• Title/Summary/Keyword: Kinetic Study

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An Advanced Kinetic Method for HO2·/O2-· Determination by Using Terephthalate in the Aqueous Solution

  • Kwon, Bum Gun;Kim, Jong-Oh;Kwon, Joong-Keun
    • Environmental Engineering Research
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    • v.17 no.4
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    • pp.205-210
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    • 2012
  • Hydroperoxyl radical/superoxide anion radical ($HO_2{\cdot}/O_2^-{\cdot}$, $pK_a$=4.8) as an intermediate is of considerable importance in oxidation processes. Hence, the method of detecting $HO_2{\cdot}/O_2^-{\cdot}$ with high sensitivity is necessary to be developed. To achieve this objective, this study newly employed terephthalate (TA) as a probe for the measurement of $HO_2{\cdot}/O_2^-{\cdot}$ in the kinetic method presented in our previous study. This method was based on the hydroxylation of TA to produce mainly hydroxyterephthalic acid or hydroxyterephthalate (OHTA), which was analyzed by fluorescence detection (${\lambda}_{ex}$=315nm, ${\lambda}_{ex}$=425nm). The life-time of $HO_2{\cdot}/O_2^-{\cdot}$ and its concentration formed from the photolysis technique of $H_2O_2$ were reported in this study. At range of pH 2-10, the life-time of $HO_2{\cdot}/O_2^-{\cdot}$ was 51-422 sec. In particular, an increase in the life-time with pH was observed. The sensitivities of the kinetic method by using TA were always higher with 1.7-2.5 times at pH 8.0 than those by using benzoic acid. From these results, this study can contribute to understanding the basic functions of $HO_2{\cdot}/O_2^-{\cdot}$ in oxidation processes.

Relationship Between the Closed Kinetic Chain Upper Extremity Stability Test and Strength of Serratus Anterior and Triceps Brachii Muscles

  • Weon, Young-soo;Ahn, Sun-hee;Kim, Jun-hee;Gwak, Gyeong-tae;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.28 no.3
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    • pp.208-214
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    • 2021
  • Background: The CKCUES test evaluates the functional performance of the shoulder joint. The CKCUES test scores CKC exercises of the upper limbs to examine shoulder stability. Although the CKCUES test provides quantitative data on functional ability and performance, no study has determined the relationship between CKCUES scores and SA and TB muscle strength. Objects: The objective of this study is to determine the relationship between the CKCUES test scores and the strength of the SA and TB muscles in the CKCUES and unilateral CKCUES tests. Methods: Sixty-six healthy male volunteers participated in the study. A Smart KEMA strength sensor measured SA and TB muscle strength. Two parallel lines on the floor indicated the initial hand placement to start CKCUES tests. For 15 seconds, the subject raises one hand and reaches over to touch the supporting hand, then returns to the starting position. Results: The correlation between the CKCUES test scores and the strength of the SA was strong (r = 0.650, p < 0.001), and the TB was moderate (r = 0.438, p < 0.001). The correlation between the unilateral CKCUES test and the strength of the SA of the supporting side was strong (r = 0.605, p < 0.001), and swing side was strong (r = 0.681, p < 0.001). The correlation between the unilateral CKCUES test and the strength of the TB of the supporting side was moderate (r = 0.409, p < 0.001), and swing side was moderate (r = 0.482, p < 0.001). Conclusion: Our study showed that the CKCUES test had a strong association with isometric strength of SA and moderate association with that of TB. These findings suggest that the CKCUES test can evaluate the function of the SA. Moreover, the unilateral CKCUES test can evaluate unilateral shoulder function.

A Study on Pendulum Generator Using Human Body Kinetic Energy (인체 운동 에너지를 이용한 진자 발전기에 관한 연구)

  • Jee, In-Ho;Shin, Seung-Jung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.117-122
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    • 2022
  • In this study, Electromagnetic Induction Power Generation (EMG) is a structure consisting of a stator and a permanent magnet rotor, and is a method that enables power generation by using the kinetic energy of the human arm. Among them, the axial flux permanent magnet (AFPM) technique is a method that can act sensitively to the kinetic energy of the arm at a slow speed of the human body, and has a simple structure and can be designed and manufactured with an ultra-small size. Under the conditions of size of ø46×11mm, rotation speed of 7Hz (420rpm), output voltage 0.4VAC, output current 4.5mA, and output power 30mW were measured and analyzed the same as the target specification. Therefore, the purpose of this study is to study the power generation of the pendulum applying the AFPM (Axial Flux Permanent Magnet) technique to charge power to smart devices with kinetic energy of the human body.

Kinetic Study by Heating Rate Method (가열속도법에 의한 반응속도론 연구)

  • 박영수;양광규;김용태
    • Journal of the Korean Society of Tobacco Science
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    • v.4 no.2
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    • pp.57-61
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    • 1982
  • For evaluating kinetic parameters of various reactions and materials a straight- forward method has been studied by the variable heating rate method in DSC analysis. Based on the linear relationship between the logarithm of the heating rate and reciprocal Peak temperature, this method allows calculation of activation energy and the Arrhenius frequency factor by only one observation of the peak temperature versus the heating rate. According to tile D function, D=-In P(x)/dx, to x(=$\frac{E}{RT}$) we can calculate reasonably accurate activation energy, tile Arrhenius factor and the rate constant, and predict half-life times of various materials from the kinetic calculation.

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A Study on a Configuration of the Load Characteristic Evaluation Device Using Hydraulic Power for the Analysis of the Tilting Kinetic Mechanism (틸팅 부하메커니즘 특성 분석을 위한 유압식 부하특성 평가 장치구성에 대한 연구)

  • Lee, Jun-Ho;Kim, Ho-Yeon;Han, Seong-Ho
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.12
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    • pp.1152-1158
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    • 2011
  • In this paper a configuration of the load evaluation device for the tilting actuator using hydraulic power is presented, which makes it possible to measure the force action on the tilting actuator. It is possible to measure only current using the conventional electro-mechanical actuator when the bogie is in the process of the tilting. This makes impossible to measure the force acting on the tilting actuator. In order to overcome this problem a kinetic mechanism test system using hydraulic cylinder is proposed. The system are consisted of hydraulic cylinder for the tilting actuation, control system to control hydraulic power, sensors to measure for force and displacement and monitoring system for the user interface.

Formation Kinetic Study of Thermal Products of Tocopherols

  • Chung, Hae-Young
    • Preventive Nutrition and Food Science
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    • v.12 no.3
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    • pp.131-134
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    • 2007
  • The kinetic analyses for thermal products of alpha-, gamma- and delta-tocopherols during heating as functions of temperature and time were studied. Alpha-, gamma- and delta-tocopherols dissolved in glycerol were heated at $100{\sim}200^{\circ}C$ for $5{\sim}60$ min. The thermal products were separated by hexane extraction and analyzed by HPLC using a reversed phase ${\mu}-Bondapak$ $C_{18}-column$ with two kinds of elution solvents in a gradient mode. The formation kinetics of thermal products of tocopherols followed a first-order kinetic model. The formation rate of thermal products of tocopherols was dependent on heating temperatures and heating times. The activation energy and enthalpy for the thermal products of ${\gamma}-and$ ${\delta}-tocopherols$ were higher than those for ${\alpha}-tocopherol$ as in the case of the oxidative degradation kinetics of tocopherol. The magnitude order of the activation energy was ${\gamma}->{\delta}->{\alpha}-tocopherol$.

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

  • Choi, Hyo-Hyun;Lim, Jun-Seok;Kim, Chul-Jin;Sohn, Chae-Hoon
    • Journal of the Korean Society of Combustion
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    • v.16 no.3
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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.

Kinetic Modeling of Non-Isothermal Anionic Styrene-Butadiene Block Copolymerization And Its Industrial Applications

  • Park, Seung-Young;Yeon, Young-Joo;Lee, Jong-Ku
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.380-380
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    • 2006
  • Styrene-Butadiene diblock or styrene-butadiene-styrene triblock copolymers are industrially important materials for asphalt modification and adhesives. A kinetic modeling study on non-isothermal anionic styrene-butadiene diblock copolymerization system is presented. The model deals with the association/dissociation reaction of initiator and propagating ion pairs in its kinetic scheme. By comparing model calculation results with real plant data, it is possible to obtain useful ideas for more efficient plant operation. For example, the model clearly provides important relation between the reaction temperature profile and the conversion of monomers.

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Kinetic Study of Milk Gellation by the Electrical Resistance Measurement

  • LEE Keun Tai
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.22 no.6
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    • pp.391-396
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    • 1990
  • Changes in electric resistance was measured to carry out the kinetic analysis of milk gellation upon addition of rennet. Using pasteurized milk and commercial rennin, kinetic properties were investigated during milk gellation in terms of initial hydrolysis and coagulation steps. Specially designed reactor with two platinum electrodes was used throughout the experiments. As a function of either milk concentrations or reaction temperatures, gel time exhibited directly proportional relations: on the contrary, gel time was inversely pro-portional to enzyme concentration. Activation energies for enzymatic degradation and cogulation were 16.3, 4.6 and 34, 8.6 Kcal/mol, repectively. This simple analytical method proved to be very effective to characterize the mechanism of milk gellation. Moreover, unlike other methods, this method reguired simple apparatus and short time of analysis.

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Capacity Design of Accumulator in Hydraulic Hybrid Drive Brake System (유압 하이브리드 구동 시스템의 축압기 용량 설계)

  • 이재구;김정현;김성동
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2001.04a
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    • pp.15-21
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    • 2001
  • An accumulator in hydraulic systems stores kinetic energy during braking action, and then that controls hasty surge pressure. An energy recovery system using accumulator seems to be advantageous for ERBS due to its high energy density. This study suggests a method to decide suitable accumulator volume for ERBS. The method is based upon energy conservation between kinetic energy of moving inertia and elastic energy of accumulator. The energy conversion was analyzed and a simple formula was derived. A series of computer simulation was done to verify effectiveness of the formula. The results of the simulation work were compared with those of experiments and these results show that the proposed design is effective for decision accumulator volume in ERBS.

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