• Title/Summary/Keyword: Association constant

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Spectroscopic Studies on the Mechanism of Interaction of Vitamin $B_{12}$ with Bovine Serum Albumin

  • Kamat, B.P.;Seetharamappa, J.
    • Journal of Photoscience
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    • v.11 no.1
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    • pp.29-33
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    • 2004
  • The mechanism of interaction of cyanocobalamin (CB) with bovine serum albumin (BSA) has been investigated by spectrofluorometric and circular dichroism methods. Association constant for the CB-BSA system showed that the interaction is non-covalent in nature. Binding studies in the presence of an hydrophobic probe, 8-anilino-l-naphthalene sulphonic acid, sodium salt (ANS) showed that there is hydrophobic interaction between CB and ANS and they do not share common sites in BSA. Stern-Volmer analysis of fluorescence quenching data showed that the fraction of fluorophore (protein) accessible to the quencher (CB) was close to unity indicating thereby that both tryptophan residues of BSA are involved in drug-protein interaction. The rate constant for quenching, greater than $10^{10}$ $M^{-1}$ $s^{-1}$, indicated that the drug binding site is in close proximity to tryptophan residue of BSA. Thermodynamic parameters obtained from data at different temperatures showed that the binding of CB to BSA involves hydrophobic bonds predominantly. Significant increase in concentration of free drug was observed for CB in presence of paracetamol. Circular dichroism studies revealed the change in helicity of BSA due to binding of CB to BSA.

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A Study on the Dimensional plan of Kor Sork Temple(temple T) on the Preah Pithu Monument Group - A study of Preah Pithu Monument in Angkor(2) - (프레아피투 까오썩 사원(사원T) 치수계획 연구 - 앙코르유적 "프레아피투 사원" 연구(2) -)

  • Park, Dong-hee
    • Journal of architectural history
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    • v.27 no.5
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    • pp.7-16
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    • 2018
  • This study investigated the dimensional plan of Kor Sork temple in Preah Pithu complex, Angkor by civil surveying, 3D scan, measured integer ratio and regularity. According to epitaph and preceding researches, Khmer temples were built based on structural planing with the constant ratio and regularity by using special construct measure scales "Hasta" and "Byama". The study assumed the same unit method was applied in Kor Sork temple and identified the regularity of actual measurement value about the temple. The assumed construct measure scale (Hasta) used for the design of this temple is 413mm. The overall apart arrangement of the temple is different in the East-West direction and the North-South direction. In the East-West direction, the whole scale is 180 hasta, and it is divided into 20 hastas. On the other hands, it was confirmed that the North-South direction is 96 hasta and it was divided four quadrants in 24 hastas. Regarding the detailed design, the regularity according to the constant ratio was confirmed. 7 hasta was used as the basic unit on the first floor and 6 hasta were used as the basic unit on the second floor of the terrace. the basement and the central sanctuary is of 6 hasta and 8 hasta were used as the basic standard.

The electron density distribution and the structure of semiconductor HgCdTe (반도체 HgCdTe의 전자 밀도 분포와 결정 구조)

  • Kook-Sang Park;Ky-Am Lee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.4
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    • pp.388-394
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    • 1994
  • A Hg(0.79)Cd(0.21)Te single crystal has been grown by the Traveling Heater Method(THM). Its zinc blend cubic structure is identified from the X-ray diffraction patterns and its lattice constant is determined to be $6.464 {\AA}$ using the least-square method of Cohen. From the values of the lattice constant, the composition x is determined to be 0.21. The electron density is calculated from the relative intensities of the scattered X-ray and compared with the theoretically calculated values. From the electron density distribution, it is shown that the crystal binding of Hg(1-x)Cd(x)Te(MCT) is mainly covalent and has tetrahedron bonds between adjacent atoms.

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Impact of $CO_2$ Increase on East Asian Monsoon

  • Kripalani, R.H.;Oh, J.H.;Chaudhari, H.S.
    • The Korean Journal of Quaternary Research
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    • v.19 no.2
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    • pp.50-54
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    • 2005
  • Some basic summer precipitation features over East Asia during the $20^{th}-21^{st}$ century as simulated / projected by the 22 coupled climate models under the IPCC AR4 program are investigated. Keeping in view that these are climate runs without prescribed SSTs, models perform well in simulating the regional annual cycle, spatial patterns (not shown) and the inter-annual variability. The projections under the 1% increase in $CO_2$ compounded until reaching double and held constant thereafter reveal that (a) Precipitation is likely to increase in all the months in particular during the summer monsoon (JJA) months. (b) The mean summer monsoon rainfall can increase from 4.2 to 13.5% and its variability is also likely to increase in the warming world due to increase in $CO_2$ (c) Extreme excess and deficient seasonal monsoons are likely to become more intense (not shown here) (d) Once the increase in $CO_2$ is cut-off, the system will reach a state of equilibrium, and then the rate of increase in precipitation is also expected to remain constant.

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Analysis of Stratified Lake using an Eddy Diffusion and a Mixed-Layer Models (와확산 및 혼합층 모델을 이용한 성층화 호수 해석)

  • 김경섭
    • Water for future
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    • v.29 no.5
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    • pp.235-244
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    • 1996
  • A one-dimensional eddy diffusion model and a mixed-layer model are developed and applied to simulate the vertical temperature profiles in lakes. Also the running results of each method are compared and analyzed. In an eddy diffusion model, molecular diffusivity is neglected and eddy diffusivity which does not need lake-specific fitting parameter and constant lake's level are applied. The heat exchanges at the water surface and the bottom are formulated by the energy balance and zero energy gradient, respectively. In a mixed-layer model, two layers approach which has a constant thickness is adopted. Application of these models which use explicit finite difference an Runge-Kutta methods respectively demonstrates that the models efficiently simulate water temperatures.

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The relation of dielectric properties and structure change with temperature for $(Na_{0.5}Sr_{0.5})(Ti_{0.5}Nb_{0.5})O_{3}$ ($(Na_{0.5}Sr_{0.5})(Ti_{0.5}Nb_{0.5})O_{3}$의 온도변화에 따른 유전특성과 구조 상전이의 관계)

  • 정훈택
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.4
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    • pp.394-399
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    • 1995
  • Dielectric properties and crystal structure changes with temperature were observed on $(Na_{0.5}Sr_{0.5})(Ti_{0.5}Nb_{0.5})O_{3}$ which had a superstructure due to oxygen octahedron tilting. Dielectric loss peak observed at 380 K was found to have a relation with a primitive cell change from tetragonal to cubic, however, in this case, dielectric constant variation was not observed. Therefore it was found that the dielectric loss was more senstive than the dielectric constant for detecting the structure change. After the structure change of primitive cell from tetragonal to cubic, X-ray diffraction peaks of superstructure, which completely disappear above 500 K, were still observed. And no dielectric property variations were found with the disappearence of superstucture.

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A STUDY ON THE MECHANICAL PROPERTIES OF ORTHODONTIC OPEN COIL SPRINGS (교정용 open coil spring의 역학적 특성에 관한 연구)

  • Park, Kyu-Chan;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.22 no.1
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    • pp.135-146
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    • 1992
  • It was the purpose of this study to analyze and compare the mechanical properties of ortho dontic open coil springs. Four variable factors were presented - wire diameter (.008", .009", .010"), lumen size (.030", .032", .036"), arch wire size and shape (.016" round, $ .016^{{\prime}{\prime}}{\times}.022^{{\prime}{\prime}}$ rect.) and alloy type (HiT II, Elgiloy, Sentalloy). The total 104 specimens were divided into 13 groups, and compression test was performed on an Instron test machine. The load deflection curve of each open coil spring was obtained, from which, the load-deflection relations, stiffnesses, percent recoveries were computed statistically. The results were obtained as follows: 1. When the lumen size of the coil spring remained constant, stiffness and percent recovery increased as the wire diameter increased. 2. When the wire diameter of the coil spring remained constant, stiffness and percent recovery decreased as the lumen size increased. 3. The effect of size and shape of arch wire on the coil spring was not statistically significant. 4. In alloy types, stiffness was the greatest in HiT II (55.21), Elgiloy (42.61) and Sentalloy (7.74) in that order. Sentalloy exhibited superior percent recovery and long range of action.

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Well Loss of Shallow Water in South Korea (국내 천정의 정호 수두 손실)

  • 한정상
    • Water for future
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    • v.10 no.1
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    • pp.20-24
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    • 1977
  • 43,000 shallow water wells have been installed as a part of all weather irrigation water supply project executed during 1969 to 1970 in all over Korea penninsula in order to solve water shortage problem of farming land by developing shallow ground water reserved in unconsolidated materials. But after 3 years later it was reported that 34% of the wells were abandoned by the reasons of artificial and natural defects. 48 wells distributed uniformly in the penninsula are selected to determine their well loss constants, relation between well loss and specific capacity, and tophographic classification of the well loss on the shallow water well. The results show that average well loss consatnt and the value of $CQ^2/S_w$ is ranged from $5.95{\times}10^{-5}\;to\;3.65{\times}10^{-8}Day^2M^{-5}$ and from 35.5% to maximum 68.48% respectvely and that relation between specific capacity and well loss constant can be approximately formulated as $C=0.61S_p2.246$ However this result indicates that most wells installed in this time have too high value of well loss constant $CQ^2/S_w$ in comparison with properly deseigned well. The most favorable and producable water bearing formation among unconsolidated deposits such as sand & gravel, boulderly gravel, clayey boulderly gravel, and sand formation in Korea is sand formation deposited in center of valley.

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Synthesis, Protonation Constants and Stability Constants for $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, and $Zn^{2+}$ Ions of 1,15-bis(2-pyridyl)-2,5,8,11,14-pentaazapentadecane

  • Kim, Sun-Deuk;Kim, Jun-Kwang;Jung, Woo-Sik;Chung, Koo-Chun
    • Analytical Science and Technology
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    • v.9 no.4
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    • pp.411-415
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    • 1996
  • The new potentially heptadentate $N_7$ ligand 1, 15-bis(2-pyridyl)-2, 5, 8, 11, 14-pentaazapentadecane(pytetren) has been synthesized and characterized by EA, IR, NMR, and mass spectrometry. Its proton association constants (log $K{_H}^n$) and stability constants(log $K_{ML}$) for $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, and $Zn^{2+}$ ions were determined at 298.1K and ionic strength=0.100M($KNO_3$) by potentiometry: log $K{_H}^1=9.36$, log $K{_H}^2=9.12$, log $K{_H}^3=8.09$, log $K{_H}^4=6.62$, log $K{_H}^5=4.02$, log $K{_H}^6=2.54$: log $K_{ML}(CO^{2+})=22.67$, log $K_{ML}(Ni^{2+})=26.25$. log $K_{ML}(Cu^{2+})=28.46$, log $K_{ML}(Zn^{2+})=19.90$.

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Kinetic analysis of the elbow joint in human motion (인체운동에 있어서 주관절의 운동학적 분석)

  • Noh, Tae-Hwan;Kim, Sik-Hyun;Kim, Jae-Hun
    • PNF and Movement
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    • v.5 no.1
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    • pp.49-56
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    • 2007
  • Objectives : We find that the reaction force on the elbow joint during elbow flexion, extension with and without an object in the hand can be calculated the equations of motion that the sum of the torque and the sum of the force acting on the elbow joint must be zero and (moment of inertia x angular acceleration) and (mass x acceleration). Methods : we have calculated the equations of motion (${\Sigma}F=0$, ${\Sigma}{\tau}=0$, ${\Sigma}F=ma$, ${\Sigma}{\tau}=Ia$) to investigate the reaction force on the elbow joint during elbow flexion, extension by means of the simplified free-body technique for coplanar forces. Results : we found that the reaction force on the elbow joint during elbow flexion, extention as constant acceleration motion is more than constant velocity, static motion. Also, we found that the relation between during flexion and during extension like this ; $J_{flexion}$ < $J_{extension}$.

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