• Title/Summary/Keyword: thermodynamics

Search Result 431, Processing Time 0.038 seconds

Separation of Heavy Metal Ions across Novel Mosaic Membrane (하전모자이크 막을 사용하여 중금속이온의 분리)

  • Song, Myung-Kwan;Lee, Jang-Oo;Yang, Wong-Kang
    • Proceedings of the Membrane Society of Korea Conference
    • /
    • 2005.11a
    • /
    • pp.96-101
    • /
    • 2005
  • A theory for the material transports through ion exchange membrane has been developed on the basis of nonequilibrium thermodynamics by removing the assumption of solvent flow in the previous paper and applied to a detailed study of the ionic transport properties of new charged mosaic membrane(CMM) system. The CMM having two different fixed charges in the polymer membrane indicated unique selective transport behavior then ion-exchange membrane. The separation behavior of ion transport across the CMM with a parallel array of positive and negative functional charges were investigated. It was well-known the analysis of the volume flux and solute flux based on nonequilibrium thermodynamics. Our suggests preferential salt transport across the charged mosaic membranes. Transport properties of heavy metal ions, $Mg^{2+}$, $Mn^{2+}$and sucrose system across the charged mosaic membrane were estimated. As a result, we were known metal salts transport depended largely on the CMM. The reflection coefficient indicated the negative value that suggested preferential material transport and was independent of charged mosaic membrane thickness.

  • PDF

Detection and Analysis of DNA Hybridization Characteristics by using Thermodynamic Method (열역학법을 이용한 DNA hybridization 특성 검출 및 해석)

  • Kim, Do-Gyun;Gwon, Yeong-Su
    • The Transactions of the Korean Institute of Electrical Engineers C
    • /
    • v.51 no.6
    • /
    • pp.265-270
    • /
    • 2002
  • The determination of DNA hybridization reaction can apply the molecular biology research, clinic diagnostics, bioengineering, environment monitoring, food science and application area. So, the improvement of DNA hybridization detection method is very important for the determination of this hybridization reaction. Several molecular biological techniques require accurate predictions of matched versus mismatched hybridization thermodynamics, such as PCR, sequencing by hybridization, gene diagnostics and antisense oligonucleotide probes. In addition, recent developments of oligonucleotide chip arrays as means for biochemical assays and DNA sequencing requires accurate knowledge of hybridization thermodynamics and population ratios at matched and mismatched target sites. In this study, we report the characteristics of the probe and matched, mismatched target oligonucleotide hybridization reaction using thermodynamic method. Thermodynamic of 5 oligonucleotides with central and terminal mismatch sequences were obtained by measured UV-absorbance as a function of temperature. The data show that the nearest-neighbor base-pair model is adequate for predicting thermodynamics of oligonucleotides with average deviations for $\Delta$H$^{0}$ , $\Delta$S$^{0}$ , $\Delta$G$_{37}$ $^{0}$ and T$_{m}$, respectively.>$^{0}$ and T$_{m}$, respectively.

A Study on Explosive Limits of Flammable Materials - Explosive Limits of Ternary System by Means of Solution Thermodynamics and MRSM Model - (가연성물질의 폭발한계에 관한 연구 - 용액열역학 및 MRSM 모델에 의한 3성분계 폭발한계 -)

  • Ha, Dong-Myeong
    • Journal of the Korean Society of Safety
    • /
    • v.20 no.3 s.71
    • /
    • pp.91-97
    • /
    • 2005
  • The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

Effects of Pre-learning Attitude on Academic Achievement in the Flipped Learning Methodology (A Case of Applied Thermodynamics) (플립러닝 교수법에서 사전학습태도가 학업성취도에 미치는 영향 (응용열역학 교과목 적용 사례))

  • Ryu, Kyunghyun
    • Journal of Engineering Education Research
    • /
    • v.26 no.6
    • /
    • pp.51-61
    • /
    • 2023
  • In this study, the effects of pre-learning attitude on learning participation and academic achievement was analyzed when applying the flipped learning methodology to engineering subject education. The modified PARTN teaching and learning model was applied, and pre-class survey, assessment on learning in pre-class, and post-class survey were conducted to analyze the effectiveness of flipped learning. The results were analyzed for 24 students who took the applied thermodynamics lecture. They were asked to take the course with the videos provided in the pre-class stage, and a pre-learning assessment was conducted to measure the completeness and understanding of the learning. As a result of the study, it was found that students with relatively excellent learning ability had excellent pre-learning evaluation results and excellent final academic achievement. In addition, the lower the pre-learning completion rate within the pre-learning period or the higher the learning rate using mobile devices, the more difficult it was to faithfully complete pre-learning, leading to poor pre-learning evaluation results. Meanwhile, the survey revealed that conducting pre-learning assessments were helpful in encouraging individual learning. In addition, cases reflecting pre-learning evaluation results to course grades showed higher pre-learning evaluation results than cases not reflecting pre-learning evaluation results to course grades, and in flipped learning classes, pre-learning evaluations act as a factor that promotes pre-class learning.

Osmotic Cross Second Virial Coefficient ($B_{23}$) of Unfavorable Proteins: Modified Lennard-Jones Potential

  • Choi, Sang-Ha;Bae, Young-Chan
    • Macromolecular Research
    • /
    • v.17 no.10
    • /
    • pp.763-769
    • /
    • 2009
  • A chromatographic method is used to measure interactions between dissimilar proteins in aqueous electrolyte solutions as a function of ionic strength, salt type, and pH. One protein is immobilized on the surface of the stationary phase, and the other is dissolved in electrolyte solution conditions flowing over that surface. The relative retention of proteins reflects the mean interactions between immobile and mobile proteins. The osmotic cross second virial coefficient calculated by assuming a proposed potential function shows that the interactions of unfavorable proteins depend on solution conditions, and the proposed model shows good agreement with the experimental data of the given systems.

Thermodynamics of Micellzation of Aminosugar Derivatives (아미노당(糖) 유도체(誘導體)의 미셀형성(形成)에 관(關)한 동력학적(動力學的) 연구(硏究))

  • Nam, Gi-Dae;Lee, Chang-Seop;Park, Gwan-Seon
    • Journal of the Korean Applied Science and Technology
    • /
    • v.8 no.1
    • /
    • pp.85-89
    • /
    • 1991
  • The thermodynamics of micellization of a new series of ionic surface-active agents, dimethyl alkyl-2-deoxy-2-epi-inosityi-ammonium chlorides, has been examined, A minimum in the critical micelle concentration versus temperature has been observed at $25^{\circ}C$ It has been found that the standard entropy of micellization is always positive showing that miceliization is governed by the gain in entropy associated with the removal of the monomer from an aqueous environment to the micelle over a $15^{\circ}C$ to $45^{\circ}C$ temperature while governed by enthalpy directed process below $25^C{\circ}$.

Thermodynamics for Formation of Each Stable Single Phase in BSCCO Thin Films

  • Yang, Sung-Ho;Park, Yong-Pil;Kim, Gwi-Yeol
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2000.11a
    • /
    • pp.104-105
    • /
    • 2000
  • High quality BSCCO thin films have been fabricated by means of an ion beam sputtering at various substrate temperatures, T$_{sub}$, and ozone gas pressures, PO$_3$. The correlation diagrams of the BSCCO phases appeared against T$_{sub}$ and PO$_3$are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 phases as well as Bi2212 one come out as stable phases depending on T$_{sub}$ and PO$_3$. From these results, the thermodynamic evaluations of ΔH and ΔS which are related with Gibbs'free energy change for single Bi2212 or Bi2223 phase are performed.ormed.i2212 or Bi2223 phase are performed.

  • PDF

Thermodynamics of the binding of Substance P to lipid membranes

  • Lee, Woong Hyoung;Kim, Chul
    • Analytical Science and Technology
    • /
    • v.30 no.2
    • /
    • pp.89-95
    • /
    • 2017
  • The thermodynamic functions for the binding of the peptide Substance P (SP) on the surface of lipid vesicles made of various types of lipids were obtained by using isothermal titration calorimetry. The reaction enthalpies measured from the experiments were -0.11 to $-4.5kcal\;mol^{-1}$. The sizes of the lipid vesicles were measured with dynamic light scattering instrument in order to get the correlation between the reaction enthalpies and the vesicle sizes. The bindings of SP on the lipid vesicles with diameter of 37 to 108 nm were classified into the enthalpy-driven reaction or the entropy-driven reaction according to the size of the lipid vesicles. For the enthalpy-driven binding reaction, the significance of the electrostatic interactions between SP and lipid molecules was affirmed from the experimental results of the DMPC/DMPG/DMPH and DMPC/DMPS/DMPH vesicles as well as the importance of the hydrophobic interactions between hydrophobic groups of SP and lipid molecules.