• 제목/요약/키워드: Association constant

검색결과 1,067건 처리시간 0.03초

Salt Effects on the Critical Micelle Concentration and Counterion Binding of Cetylpyridinium Bromide Micelles

  • Jong Jae Chung;Sang Wook Lee;Joon Ho Choi
    • Bulletin of the Korean Chemical Society
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    • 제12권4호
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    • pp.411-413
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    • 1991
  • The effects of electrolyte on the critical micelle concentration (cmc) and bromide counterion binding in the micelles of cetylpyridinium bromide (CPB) have been investigated by UV spectroscopy and conductance measurements. Salts used in this study decreased cmc in the order $Cl^-\;<\;Br^-\;<\;NO3^-$ (which parallels the lyotropic series for the inorganic anions) and the effects on cmc followed the equation proposed by Shinoda: log cmc = A - B log (cmc + [NaX]). In the equation, constant B represents the counterion binding to the micelles at cmc and for the micelle of CPB at $25^{\circ}C$, B=80.76%. The association constant for the binding of counterions to long chain cations within micelles was also derived from the cmc values and counterion binding constant to the micelles.

Monte Carlo Simulation Study of Solvent Effect on Selectivity of 18-Crown-6 to between La3+ and Nd3+ Ion

  • Kim, Hag-Sung
    • Bulletin of the Korean Chemical Society
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    • 제24권6호
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    • pp.751-756
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    • 2003
  • We have investigated the solvent effects on Δlog $K_s$ (the difference of stability constant of binding) and the relative free energies of binding of $La^{3+} and Nd^{3+}$ ions to 18-crown-6 by a Monte Carlo simulation of statistical perturbation theory (SPT) in diverse solvents. We compared relative binding Gibbs free energies and the differences in stability constant (Δlog $K_s$) of binding of $La^{3+} and Nd^{3+}$ ions to 18-crown-6 in $CH_3OH$ in this study with the experimental. There is a good agreement between our study and the experimental. We noted that Borns function of the solvents, the electron pair donor properties of the solvent, the radii of host and guest and the differences in solvation dominate the differences in the stability constant (Δlog $K_s$) as well as the relative free energies of binding of TEX>$La^{3+} to Nd^{3+}$ ions to 18-crown-6. The results of this study appear promising for providing the association properties of crown ethers with alkaline earth metals among polar solvents and the less polar or non-polar solvents.

정진폭 다중 부호 이진 직교 변복조기의 FPGA 설계 및 SoC 구현 (FPGA Design and SoC Implementation of Constant-Amplitude Multicode Bi-Orthogonal Modulation)

  • 홍대기;김용성;김선희;조진웅;강성진
    • 한국통신학회논문지
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    • 제32권11C호
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    • pp.1102-1110
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    • 2007
  • 본 논문에서는 기존의 정진폭 다중 부호 이진 직교 (CAMB: Constant-Amplitude Multi-code Biorthogonal) 변조 이론을 적용한 변복조기를 프로그래밍 가능한 게이트 배열 (FPGA: Field-Programmable Gate Array)을 사용하여 설계하고 시스템 온 칩 (SoC: System on Chip)으로 구현하였다. 이 변복조기는 FPGA을 이용하여 타겟팅 한 후 보드실험을 통해 설계에 대한 충분한 검증을 거쳐 주문형 반도체 (ASIC: Application Specific Integrated Circuit) 칩으로 제작되었다. 이러한 12Mbps급 모뎀의 SoC를 위하여 ARM (Advanced RISC Machine)7TDMI를 사용하였으며 64K바이트 정적 램 (SRAM: Static Random Access Memory)을 내장하였다. 16-비트 PCMCIA (Personal Computer Memory Card International Association), USB (Universal Serial Bus) 1.1, 16C550 Compatible UART (Universal Asynchronous Receiver/Transmitter) 등 다양한 통신 인터페이스를 지원할 뿐 아니라 ADC (Analog to Digital Converter)/DAC (Digital to Analog Converter)를 포함하고 있어 실제 현장에서 쉽게 활용될 수 있을 것으로 기대된다.

아파트단지의 단위세대별 인구 및 가족형구성에 관한 분석 (The Characteristics of Population and Family Composition by the Unit Type in Apartment Houses)

  • 정사희;최승희
    • 한국주거학회논문집
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    • 제16권1호
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    • pp.97-104
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    • 2005
  • The purpose of this study is to understand changes of the population and family composition in apartment houses. The main contents of this study is to find the way of housing planning through the analysis of the population and family composition by the unit types. The population and family composition were studied by computer data base program to 11,000 residents of selection 4 apartments houses. The structure of the family types proved to be constant by the result of analyzing the 10 family types. If the family types of certain resident's groups are given, this study will be able to estimate population structure to them. The transition of the population and the family composition changes to the unit types proved to be constant by the time. The distribution of manhood and matured children is tend to change according to how large the size of house is, and to change the structure of family composition.

내의류의 수분특성 및 착용감에 관한 연구 (II) -내의 착용시 생리적 반응과 착용감- (A Study on Moisture Related Properties and Human Sensations of under wear (II) -The Physiological Responses and Subjective Wearing Sensations of Underwear-)

  • 이순원
    • 대한가정학회지
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    • 제27권3호
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    • pp.29-38
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    • 1989
  • The purpose of this study is to investigate the physiological respones and subjective wearing sensations of the body of different materials of underwears. Experimental underwears were round neck-line shirts made of 100% cotton (60's plain stitch), 100% untreated nylon and hydrophillic finished 100% nylon (140 D. tricot). Four healthy female served as subjects. The experimental chamber was controlled at a constant temperature (23±1℃), constant relative humidity (53±3%) and air velocity of 0.25m/sec. The skin temperature, rectal temperature, pulse rate, clothing climate of temperature and humidity, and subjective wearing sensations were measured every five minutes during 75min. The results showed the level of the fiber hygroscopic properties was most relevant in the sensations of wearing: thus, cotton and treated nylon were felt by the subjects as more confortable fabrics, than untreated nylon.

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Delignification Kinetics of Trema orientalis (Nalita) in Kraft Pulping

  • Jahan, M. Sarwar;Rubaiyat, A.;Sabina, R.
    • 펄프종이기술
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    • 제39권5호
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    • pp.7-11
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    • 2007
  • Kraft pulping of Trema orientalis (Nalita) was studied in order to find kinetic data for delignification. Pulping runs were carried out in the temperature range of $160-180\;^{\circ}C$ under constant and well-defined conditions. The delignification was found to be first order with respect to residual lignin and was chemically controlled. The rate of delignification reaction was increased 1.11-1.23 for $10\;^{\circ}C$ temperature increase in the range of $160-180\;^{\circ}C$ range. A mean value of 93% of lignin was removed at the transition between bulk and residual delignification. The influence of cooking temperature on the rate constant was expressed by an Arrhenius-type equation. The obtained activation energy of the delignification reaction was 6,164 cal/mol. The transition point between bulk and residual phase was shifted to lower lignin and carbohydrate yield with the increase of temperature.

FINITE ELEMENT MODEL TO STUDY TWO DIMENSIONAL UNSTEADY STATE CYTOSOLIC CALCIUM DIFFUSION

  • Tewari, Shivendra Gajraj;Pardasani, Kamal Raj
    • Journal of applied mathematics & informatics
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    • 제29권1_2호
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    • pp.427-442
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    • 2011
  • Calcium is a vital second messenger for signal transduction in neurons. Calcium plays an important role in almost every part of the human body but in neuronal cytosol, it is of utmost importance. In order to understand the calcium signaling mechanism in a better way a finite element model has been developed to study the flow of calcium in two dimensions with time. This model assumes EBA (Excess Buffering Approximation), incorporating all the important parameters like time, association rate, influx, buffer concentration, diffusion constant etc. Finite element method is used to obtain calcium concentration in two dimensions and numerical integration is used to compute effect of time over 2-D Calcium profile. Comparative study of calcium signaling in two dimensions with time is done with other important physiological parameters. A MATLAB program has been developed for the entire problem and simulated on an x64 machine to compute the numerical results.

월강우의 시간분포에 따른 유출량 변화 (Changes of Outflow with Time Varied Monthly Rainfall Data)

  • 황만하;강신욱
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2007년도 학술발표회 논문집
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    • pp.1967-1971
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    • 2007
  • In general, outflow is larger with rainfall but it is various in the initial moisture condition of basin and condition of rainfall distribution in both time and space. In this study, changes of outflow with time varied rainfall data were analyzed in the basin in which the moisture distribution is constant. Outflow differences with rainfall intensive of first period, middle period, and last period of month are 6.1% in January, 7.8% in February, 9.8% in March, 22.6% in April, 15.7% in May, 19.1% in June, 22.6% in July, 22.4% in August, and 16.8% in september respectably. The results show that 10 days outflow differences are ranged from 6.1% to 22.6% under the constant moisture condition, Outflow differences in the flood seasons are larger than them in the drought seasons.

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Drug-biomacromolecule interaction 1

  • Kim, Chong-Kook;Ahn, Hae-Young
    • Archives of Pharmacal Research
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    • 제4권2호
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    • pp.99-107
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    • 1981
  • To investigate the protein binding characteristics of ibuprofenlysine, the effects of drub conentration, pH, ionic strength and protein concentration on the binding of drug to protein concentration on the binding of drug to protein were studied by fluorescence probe method. The conformational change of protein was investigated by circular dichroism (CD) measurement. As the concentration of drug increases, the association constant decreases. These may be due to complex formation of the probe and drug, or the interaction of the protein-probe complex and drug. The association constant for ibuprofenlysine increased with increasing protein concentration. These finding suggest a sharing of one ibuprofenlysine molecule by more than one protein molecule in the binding. The binding between ibuprofenlysine and protein was dependent on pH and ionic strength. It seems that both hydrophobic binding and some electrostatic forces are involved in the binding of ibuprofenlysing to protein.

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노자 "도덕경"과 건축학의 정의고 (The Lao-tsu's Tao-te-ching and the Definition of the Science of Architecture)

  • 장백기
    • 한국주거학회논문집
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    • 제12권3호
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    • pp.97-108
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    • 2001
  • This study is to find out the definition of the science of architecture which agree with the ideal of architecture form the roots of Lao-tsus Tao-te-ching. The science of architecture is that of which the architect wants to realise the ideal of architecture in the realities of life. Lao-tsu says that the roots of man and universe is nothing and doing of nothing. Nothing makes sense with constant-nothing and constant-existance, and is named with bright. And becomes the light. We can say that the definition of the science of architecture of nothing. And architecture of nothing is the foundation of the architecture for man. When the architecture of nothing for man agrees with the realities, the action becomes doing of nothing. And it is the very architecture of doing of nothing.

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