• Title/Summary/Keyword: kinetic studies

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The effects of closed kinetic chain exercise and open kinetic chain exercise in improving the balance of patients with hemiplegia (닫힌 사슬운동과 열린 사슬운동이 편마비 환자의 균형에 미치는 영향)

  • Kim, Yong-Jeong;Kim, Taek-Yean;Oh, Duck-Won
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.15 no.1
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    • pp.22-31
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    • 2009
  • Purpose The purpose of this study was to compare the effects of closed kinetic chain exercise and open kinetic chain exercise in improving the balance of patients with hemiplegia. Methods Ten patients with stroke were randomly allocated to either a closed kinetic chain exercise (CKC) group(n=5) or an open kinetic chain exercise(OKC) group(n=5). The subjects of each group followed the exercise regimen of their respective groups, and each exercise was performed for 50 mins per day, 3 days per week, for 4 weeks. Assessment was made using Berg Balance Scale (BBS), One Leg Standing(OLS) test, and Timed up and go(TUG) test. The 2 groups were assessed twice: before and after the intervention. Results The TUG test score was significantly different in the CKC group between before and after intervention (p<.05); however, there was no such deference in the OKC group (p>.05). Further, the scores of the BBS and OLS tests were not significantly different for the 2 groups between before and after intervention (p>.05). The hanges in these BBS and OLS score were not significantly different(p>.05); however, there was a significant difference in the change in the TUG scores (p<.05). Conclusion On the basis of the results of this study, we found that the closed kinetic chain exercise is more effective in improving the walking ability and dynamic balance in patients with stroke. Future studies are warranted in this regard.

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Oxidation of Benzyl Alcohols with Extraordinarily High Kinetic Isotope Effects

  • Jo, Myeong-Ran;Seok, Won-K.
    • Bulletin of the Korean Chemical Society
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    • v.32 no.spc8
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    • pp.3003-3008
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    • 2011
  • Reactions of benzyl alcohol and its derivatives by [Ru$^{IV}$(tpy)(dcbpy)(O)]$^{2+}$ (tpy = 2,2':6',2"-terpyridine; dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) leading to the corresponding benzaldehydes in acetonitrile and water have been studied. Kinetic studies show that the reaction is first-order in both alcohol and oxidant, with k = 1.65 (${\pm}$ 0.1) $M^{-1}s^{-1}$ at $20^{\circ}C$, ${\Delta}H^{\ddag}$ = 4.3 (${\pm}$ 0.1) kcal/mol, ${\Delta}S^{\ddag}$ = -22 (${\pm}$ 1) eu, and $E_a$ = 4.9 (${\pm}$ 0.1) kcal/mol. High ${\alpha}$ C-H kinetic isotope effects are observed, but O-H solvent isotope effects are negligible. Spectral evidences with the isotope effects suggest that oxidation of benzyl alcohols occurs by a two-electron, hydride transfer. The catalytic cycles of aerobic benzyl alcohol oxidation are employed.

Analysis of Kinetic Data of Pectinases with Substrate Inhibition

  • Gummadi, Sathyanarayana-N.;Panda, T.
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.332-337
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    • 2003
  • Enzyme kinetics data play a vital role in the design of reactors and control of processes. In the present study, kinetic studies on pectinases were carried out. Partially purified polymethylgalacturonase (PMG) and polygalacturonase (PG) were the two pectinases studied. The plot of initial rate vs. initial substrate concentration did not follow the conventional Michaelis-Menten kinetics, but substrate inhibition was observed. For PMG, maximum rate was attained at an initial pectin concentration of 3 g/l, whereas maximum rate was attained when the initial substrate concentration of 2.5 g/l of polygalacturonic acid for PG I and PG II. The kinetic data were fitted to five different kinetic models to explain the substrate inhibition effect. Among the five models tested, the combined mechanism of protective diffusion limitation of both high and inhibitory substrate concentrations (semi-empirical model) explained the inhibition data with 96-99% confidence interval.

Evaluation of refused tea waste activated carbon for color removal: Equilibrium and kinetic studies

  • Wijetunga, Somasiri;Gunasekara, Chathurika DFA
    • Advances in environmental research
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    • v.6 no.1
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    • pp.1-14
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    • 2017
  • New technologies or improvement of the existing technologies are required to enhance the efficiency of removal of pollutants from wastewater. In this study we attempted to produce and test the activated carbon produced from the refused tea waste for the removal of dyes from wastewater. The objectives of this investigation were to produce activated carbon from refused tea waste by chemical activation, evaluate its performance for the removal of color produced from Acid Yellow 36, and the modeling of its dye removal with the kinetic study. The activation was performed in two steps namely carbonization at $375{\pm}25^{\circ}C$ and chemical activation with HCl at $800^{\circ}C$ under the absence of Oxygen. Adsorption isotherms and kinetic studies were performed with a textile dye, Acid Yellow 36, at different concentrations (20-80 mg/L). The maximum dye removal (~90%) observed at 80 mg/L dye concentration and it reduced at low dye concentrations. Maximum adsorption (71.97 mg/g) was recorded at 96 h at $29{\pm}1^{\circ}C$. Low pH increased the dye adsorption (pH=2; 78.27 mg/g) while adsorption reduced at high pH levels indicating that the competition occurs in between OH- ions and AY36 molecules for the adsorption sites in RTAC. The Langmuir isotherm model clearly explained the dye adsorption, favorably, by RTAC. Moreover, kinetic studied performed showed that the pseudo second order kinetic model clearly describes the dye adsorption. Based on the results obtained in this study, it can be concluded that RTAC can be used for the removal of textile dyes.

A Study on Kinetic Typography's Communicational Function (키네틱 타이포그래피의 정보전달 기능에 관한 연구)

  • Hong Young-Rae
    • Journal of Science of Art and Design
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    • v.8
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    • pp.267-296
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    • 2005
  • Typography, as the median for communication, has expanded its roles according the attributes of the media where it Is used, and the change of media follwing the change of times is presenting new directions to the field of typography. The attempts of 20C experimental typography prioritize visual formativeness, free typography and language started to appear on printed matters and different kinds of prints put pep in magazines. Thus, experiments in the aspects of effective delivery of inpormation that letters have and aesthetic side of shapes of letter are continuing. Today with the appearance of multimedia, development of visual colture and rapid development of digital technology, the range of experimental typography has expanded even wider and therefore, different kinds of expressions became possible. As seen above, unlike the existing static printed media that carries linguistic information only, letters in the multimedia environment is shown in the movie titles, TV or web not only as a basic visual media such as type and image, but as a dynamic and complex factor that contains additional information of motion and sound factor. This study will attempt to find the historic context of focus of moment from the kinetic art and define the moving letters as kinetic typography. Therefore, this paper will have an understanding on kinetic typography's background, concept and characteristics following the change of communication environment in the multimedia era and tried to study the basic theories of kinetic typography and the information delivery and imagery function of letters. Also, this paper attempted to carry out a study on whether kinetic typography is delivering information smoothly from the aspect of communication through the image role as delivering information by studying major works of artists who have influenced kinetic typography. Based on this study, I would like to suggest new direction for effective delivery of information and value of use.

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Oxidation Effect on the Critical Velocity of Pure Al Feedstock Deposition in the Kinetic Spraying Process (저온분사 공정에서 알루미늄 분말의 산화가 임계 적층 속도에 미치는 영향)

  • Kang, Ki-Cheol;Yoon, Sang-Hoon;Ji, Youl-Gwun;Lee, Chang-Hee
    • Journal of Welding and Joining
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    • v.25 no.4
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    • pp.35-41
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    • 2007
  • In kinetic spraying process, the critical velocity is an important criterion which determines the deposition of a feedstock particle onto the substrate. In other studies, it was experimentally and numerically proven that the critical velocity is determined by the physical and mechanical properties and the state of materials such as initial temperature, size and the extent of oxidation. Compared to un-oxidized feedstock, oxidized feedstock required a greater kinetic energy of in-flight particle to break away oxide film during impact. The oxide film formed on the surface of particle and substrate is of a relatively higher brittleness and hardness than those of general metals. Because of its physical characteristics, the oxide significantly affected the deposition behavior and critical velocity. In this study, in order to investigate the effects of oxidation on the deposition behavior and critical velocity of feedstock, oxygen contents of Al feedstock were artificially controlled, individual particle impact tests were carried out and the velocities of in-flight Al feedstock was measured for a wide range of process gas conditions. As a result, as the oxygen contents of Al feedstock increased, the critical velocity increased.

Estimation of the Kinetic Energy of Raindrops for Hourly Rainfall Considering the Rainfall Particle Distribution (강우입자분포를 고려한 시강우의 강우에너지 산정 연구)

  • Kim, Seongwon;Jeong, Anchul;Lee, Giha;Jung, Kwansue
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.15-23
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    • 2018
  • The occurrence of soil erosions in Korea is mostly driven by flowing water which has a close relationship with rainfalls. The soil eroded by rainfalls flows into and deposits in the river and it polluted the water resources and making the rivers become difficult to be managed. Recently, the frequency of heavy rainfall events that are more than 30 mm/hr has been increasing in Korea due to the influence of climate change, which creating a favourable condition for the occurrence of soil erosion within a short time. In this study, we proposed a method to estimate the distribution of rainfall intensity and to calculate the energy produced by a single rainfall event using the cumulative distribution function that take into account of the physical characteristics of rainfall. The raindrops kinetic energy estimated by the proposed method are compared with the measured data from the previous studies and it is noticed that the raindrops kinetic energy estimated by the rainfall intensity variation is very similar to the results concluded from the previous studies. In order to develop an equation for estimating rainfall kinetic energy, rainfall particle size data measured at a rainfall intensity of 0.254~152.4 mm/hr were used. The rainfall kinetic energy estimated by applying the cumulative distribution function tended to increase in the form of a power function in the relation of rainfall intensity. Based on the equation obtained from this relationship, the rainfall kinetic energy of 1~80 mm/hr rainfall intensity was estimated to be $0.03{\sim}48.26Jm^{-2}mm^{-1}$. Based on the relationship between rainfall intensity and rainfall energy, rainfall kinetic energy equation is proposed as a power function form and it is expected that it can be used in the design of short-term operated facility such as the sizing of sedimentation basin that requires prediction of soil loss by a single rainfall event.

Adsorption of Pb(II) Ions from Aqueous Solution Using Activated Carbon Prepared from Areca Catechu Shell: Kinetic, Isotherm and Thermodynamic Studies

  • Muslim, A.;Aprilia, S.;Suha, T.A.;Fitri, Z.
    • Journal of the Korean Chemical Society
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    • v.61 no.3
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    • pp.89-96
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    • 2017
  • This study proposed adsorption of Pb(II) ions from aqueous solution using activated carbon prepared from areca catechu shell (ACS AC) using Timphan Method. The effects of independent variables on adsorption kinetic and isotherm have been investigated by conducting experiments in batch mode at neutral pH. The structural characterization of adsorbent was done by FT-IR and SEM analysis. The Pb(II) adsorption was correlated very well with the pseudo second-order kinetic (PSOKM) and Langmuir isotherm models (LIM). Increasing NaOH mass for activation and adsorption temperature increased weakly all the parameters of adsorption kinetic and isotherm. The Pb(II) ions adsorption capacity of the ACS AC at 27 and $45^{\circ}C$ was 50.51 and 55.25 mg/g, respectively. Thermodynamic parameters were determined, and the results confirmed the Pb(II) ions adsorption should be endothermic and spontaneous process, and both physical and chemical adsorption should be taken place.

Kinetics and Equilibrium Adsorption Studies of Cd Adsorption by the Activated Carbon Containing Hydroxyapatite (Hydroxyapatite 첨가 활성탄을 이용한 Cd의 동역학적 흡착과 흡착평형에 관한 연구)

  • An, Sangwoo;Choi, Jaeyoung;Park, Jaewoo
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.1
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    • pp.45-51
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    • 2010
  • Cadmium (Cd) adsorption by the activated carbon containing hydroxyapatite (HAP) was investigated. Cd adsorption with different HAP mass ranged from 10% to 30%. With more HAP, more Cd was adsorbed. These results suggest that the higher HAP dose causes an increase of the ion exchange potential in HAP sorbent. Kinetics and equilibrium studies were investigated in series of batch adsorption experiments. Langmuir and Freundlich isotherm models were fit to the equilibrium data and Cd adsorption on HAP sorbent were found to follow the Freundlich isotherm model well in the initial adsorbate concentration range. The simple kinetic model, the pseudo first order kinetic model and the pseudo second order kinetic model, were used to investigate the adsorption. The adsorption reaction of Cd followed the pseudo second order kinetic model, and the adsorption pseudo second order kinetic constants ($k_2$) increased with increasing initial HAP amounts onto activated carbon. Also, intraparticle diffusion model was used to investigate the adsorption mechanism between adsorbate and adsorbent in the aqueous phase. Surface adsorption reaction and intraparticle diffusion occur simultaneously Cd adsorption mechanism from aqueous phase in this study.