• Title/Summary/Keyword: Thermodynamic function

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A Study of the Curved Line as a Survival -Especially Centered on the Physical Structure- (생존으로서의 곡선(曲線)에 관한 연구 -물리적 구조법칙을 중심으로-)

  • 박규현;신기봉;박영민
    • Archives of design research
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    • v.15 no.1
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    • pp.181-190
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    • 2002
  • Every object's patterns is the balancing-relationship between the object's inner-energy and outer-stress. To see this as a balancing-relationship between an organism, inner-energy would be the occurrence of thermodynamic entropy which is for its existing maintenance. Outer-stress would be the friction that comes from the surrounding environment. Namely, we can see that object's figure exists in the balance between an extort to survive and fiction that disturb it. However, it is fourth that these figures are consisted of a curve and curved-surface which is not a straight line. So, it is impossible to find a figure made up of straight lines and surfaces in the existing object's world. It's true that we have regarded only a curve as the beautiful. Here, we have presented that in a curve, there exists an important function which protect our survival from the ancient humanity. And by closely observing the function in a physical dynamic-pattern sight, we've searched what is important in the design's origin that handle curve-patterns. Of course it would be more reasonable to analyze it in the standpoint of Mathematics, Chemistry, or Biology, and synthesize the points. However, due to the limitation of the researchability, we will concern about the physical structure in the design. Deficient details will be replenished through the study between educational systems. As a result, we have confirmed that, devoting the curve's physical structure-phenomenon (occurred in nature) to the design, is more beautiful in our eyes, too.

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Effects of Butanol Isomers on the Mixed Micellization of TTAB/Brij 35 Mixed Surfactant Systems (TTAB/Brij 35 혼합계면활성제의 미셀화에 미치는 부탄올 이성질체들의 효과)

  • Gil, Han-Nae;Lee, Byung-Hwan
    • Journal of the Korean Chemical Society
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    • v.52 no.2
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    • pp.111-117
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    • 2008
  • critical micelle concentration (CMC) and the counter ion binding constant (B) in a mixed micellar state of the trimethyltetradecylammonium bromide (TTAB) with the polyoxyethylene (23) lauryl ether (Brij 35) at 25oC in water and in aqueous solutions of butanol isomers were determined as a function of 1 (the overall mole fraction of TTAB) by the use of electric conductivity method and surface tensiometer method. Various thermodynamic parameters (Xi, i, Ci, aiM, and Hmix) were calculated by means of the equations derived from the nonideal mixed micellar model. The results say that the effects of butanol isomers on the micellization of TTAB/Brij 35 mixtures have been in the order of n-butanol>iso-butanol>t-butanol> water.

Analysis of structural and thermodynamic properties for Li-SGICs synthesized by chemical method (화학적 방법에 의하여 합성된 Li-SGICs의 구조적, 열역학적 특성 분석)

  • 오원춘
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.3
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    • pp.435-441
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    • 1998
  • Li-SGICs as a anode of lithium ion battery were synthesized by high-pressure method as a function of the Li-contents. The characteristics of these prepared compounds were determined from the studies with X-ray diffraction method and differential scanning calorimeter (DSC) analysis. From the results of X-ray diffraction, it was found that the lower stage intercalation compounds were formed with increase of Li-contents. The mixed stages in these compounds were also observed. In the case of the $Li_{30;wt%}$-SGIC, the compounds in the stage 1 structure were formed predominantly, but the structure of only pure stage 1, due to the structural defect of synthetic graphite, was not observed. The enthalpy and entropy changes of the compounds could be obtained from the differential scanning calorimetric analysis results. From the results, it was found that exothermic and endothermic reactions of Li-SGICs are related to thermal stability of lithium between artificial graphite layers.

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Mixed Micellar Properties of DPC with Other Cationic Surfactants (DTAB, TTAB, and CDEAB) (DPC와 다른 양이온성 계면활성제(DTAB, TTAB 및 CDEAB)와의 혼합마이셀화에 관한 연구)

  • Lee, Byung Hwan
    • Journal of the Korean Chemical Society
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    • v.42 no.5
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    • pp.519-525
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    • 1998
  • The critical micelle concentration $(CMC^{\ast})$ and the counterion binding constant (B) in a micellar state of the mixed surfactant systems of dodecylpyridinium chloride (DPC) with dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), and cetyldimethylethylammonium bromide (CDEAB) were determined at $25^{\circ}C$ as a function of ${\alpha}_1$ (the overall molc fraction of DPC) by the use of electric conductivity method. Various thermodynamic parameters $(X_{i},\;{\gamma}_{I},\;C_{i},\;a^{M}_{i}, \beta,\;{\Delta}H_{mix}, \;and\; {\Delta}G^{o}_{m})$ for the micellization of DPC/DTAB, DPC/TTAB, and DPC/CDEAB mixtures were calculated and analyzed for each system by means of the equations derived from the pseudophase separation model. The results show that the DPC/DTAB mixed system has the greatest deviation and the DPC/CDEAB mixed system has the smallest deviation from the ideal mixed micellar model.

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Drag Reduction Characteristics of Surfactant by a Rotating Disk Apparatus (회전원판장치를 이용한 계면활성제의 마찰저항감소)

  • Kim, C.A.;Choi, H.J.;Yoon, H.K.;Park, S.Y.;Kim, J.Y.
    • Applied Chemistry for Engineering
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    • v.9 no.1
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    • pp.149-154
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    • 1998
  • The characteristics of drag reduction and rheological behaviors were investigated using cationic surfactants, whose microstructures are known to change when concentration of the surfactant exceeds CMC. The firstly formed spherical micelles change to rodlike or disklike micelles because of packing between surfactants micells, and of thermodynamic perference. The drag reduction becomes significant when the concentration increases over this micellar transient point. Drag reductions were measured as a function of concentration, and rheological characteristics of the surfactant were further investigated to understand the correlation between their rheological properties and drag reduction. Micelles show the non-Newtonian behavior, and shear thickening behaviors were observed due to the structural development. In addition, structural developments were determined by adding the counter-ion in case of DOBON-G.

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Poly(4-vinylpyridine)/Vinyl Acetate-Vinyl Alcohol Copolymer Blends : 9. Phase. Behavior (폴리(4-비닐피리딘)/비닐아세테이트-비닐알코올 공중합체 블렌드 :2. 상 거동)

  • Lee, Joon-Youl;Choi, Dong-Hoon;Lee, Hyeok
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.649-656
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    • 2001
  • Miscibility of poly(4-vinylpyridine) (P4VP) blends with poly(vinyl acetate-co-vinyl alcohol) (VAc-VAL copolymers) was investigated as a function of comonomer composition of VAc-VAL copolymers. Differential scanning calorimetry (DSC) and thermo-optical microscopic (TOM) analysis confirmed that P4VP is miscible with VAc-VAL copolymers containing more than 30 mole% VAL. Fourier transform inflated (FT-IR) spectroscopic analysis revealed that the strong intermolecular hydrongen bonding interaction between the vinylpyridine and VAL hydroxyl group was formed. Theoretical phase diagram was constructed by the calculation using the Association model, a thermodynamic model for hydrogen-bonded polymer blend systems developed by Coleman et al. The calculated theoretical binodal phase diagrams were in good agreement with the experimentally determined cloud point curves.

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Surface Segregation of Hydroniums and Chlorides in a Thick Ice Film at Higher Temperatures

  • Lee, Du Hyeong;Bang, Jaehyeock;Kang, Heon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.263-263
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    • 2013
  • This work examines the dynamic properties of ice surfaces in vacuum for the temperature range of 140~180 K, which extends over the onset temperatures for ice sublimation and the phase transition from amorphous to crystallization ice. In particular, the study focuses on the transport processes of excess protons and chloride ions in ice and their segregative behavior to the ice surface. These phenomena were studied by conducting experiments with a relatively thick (~100 BL) ice film constructed with a bottom $H_2O$ layer and an upper $D_2O$ layer, with excess hydronium and chloride ions trapped at the $H_2O$/$D_2O$ interface as they were generated by the ionization of hydrogen chloride. The migration of protons, chloride ions, and water molecules to the ice film surface and their H/D exchange reactions were measured as a function of temperature using the methods of low energy sputtering (LES) and Cs+ reactive ion scattering (RIS). Temperature programmed desorption (TPD) experiments monitored the desorption of water and hydrogen chloride from the surface. Our observations indicated that both hydronium and chloride ions migrated from the interfacial layer to segregate to the surface at high temperature. Hydrogen chloride gas desorbs via recombination reaction of hydronium and chloride ions floating on the surface. Surface segregation of these species is driven by thermodynamic potential gradient present near the ice surface, whereas in the bulk, their transport is facilitated by thermal diffusion process. The finding suggests that chlorine activation reactions of hydrogen chloride for polar stratospheric ice particles occur at the surface of ice within a depth of at most a few molecular layers, rather than in the bulk phase.

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Effectiveness of Feather Waste for Orange II Removal from Aqueous Solutions (수용액 중 Orange II 흡착 제거를 위한 우모폐기물의 이용가능성)

  • Park, Soo-Yeun;Yoo, Ji-Yeon;Son, Hong-Joo
    • Journal of Environmental Science International
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    • v.27 no.9
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    • pp.743-751
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    • 2018
  • The objective of this study was to investigate the adsorption potential of chicken feathers for the removal of OrangeII (AO7) from aqueous solutions. Batch experiments were performed as a function of different experimental parameters such as initial pH, reaction time, feather dose, initial OrangeII concentration and temperature. The highest OrangeII uptake was observed at pH 1.0. Most of the OrangeII was adsorbed at 2 h and an adsorption equilibrium was reached at 6 h. As the amount of chicken feather was increased, the removal efficiency of OrangeII increased up to 99%, but its uptake decreased. By increasing the initial concentration and temperature, OrangeII uptake was increased. The experimental adsorption isotherm exhibited a better fit with the Langmuir isotherm than with the Freundlich isotherm, and maximum adsorption capacity from the Langmuir constant was determined to be 0.179244 mmol/g at $30^{\circ}C$. The adsorption energy obtained from the Dubinin-Radushkevich model was 7.9 kJ/mol at $20^{\circ}C$ and $30^{\circ}C$ which indicates the predominance of physical adsorption. Thermodynamic parameters such as ${\Delta}G^0$, ${\Delta}H^0$, and ${\Delta}S^0$ were -12.28 kJ/mol, 20.64 kJ/mol and 112.32 J/mol K at $30^{\circ}C$, respectively. This indicates that the process of OrangeII adsorption by chicken feathers was spontaneous and endothermic. Our results suggest that as a low-cost biomaterials, chicken feather is an attractive candidate for OrangeII removal from aqueous solutions.

Experimental Study on Peak-Pressure Variation Due to Compression by Using RCM (급속 압축장치(RCM)의 압축 조건에 따른 최대 압력 변화에 관한 실험적 연구)

  • Kim, Hye-Min;Kim, Hak-Young;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.2
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    • pp.197-204
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    • 2011
  • RCM is used to clarify the complex phenomena of engine combustion. In order to describe engine combustion, several significant experimental studies are considered. Prediction of the peak pressure is very important since it has a significant influence on engine combustion. In addition, peak-temperature variation can be calculated from the measured peak pressure by using the fundamental thermodynamic relation. When the RCM is in operation, heat transfer occurs through the cylinder wall. Because of this phenomenon, it is difficult to determine the peak pressure without employing the case by case experimental method. The goal of this study is to evaluate the peak pressure analytically. We conduct an experiment to confirm the relationship between the peak pressure and some parameters. Using the results of the peak pressure variation experiment, we develop a general equation that be used to calculate the peak pressure as a function of operation time and compression ratio.

Study on Metal Cupferrate Complex (Part III) Study on Distribution Ratio of Hydrogen Cupferrate in $H_2O-CHCl_3$ System (Metal Cupferrate Complex 에 關한 硏究 (第 3 報) $H_2O$-Chloroform 系에서의 Hydrogen Cupferrate 의 分配係數에 關한 硏究)

  • Si-Joong Kim;Doo-Soon Shin
    • Journal of the Korean Chemical Society
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    • v.7 no.4
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    • pp.283-287
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    • 1963
  • The distribution ratio of hydrogen cupferrate in $H_2O-CHCl_3$ system was considered as a function of pH ($HClO_4$), ionic strength ($NaClO_4$), and cupferron concentration in perchloric acid media, respectively. The values were independent upon pH (1.50∼3.00 range) and ionic strength (0.1∼2.00 range), but they increased as increasing the cupferron concentration in the acidic media. At the infinite dilution, the thermodynamic distribution ratio between chloroform and aqueous phase was 120. 0. The activity coefficients of hydrogen cupferrate in chloroform solution were determined by the distribution ratio. This activity coefficient may be calculated by using the empirical equation, $-log\;f_{CHCl3}=0.1285C_{CHCl3}+{7.775C^2}_{CHCl3}$ which represents the experimental data quite well for the solution in 0.1 mole/l order of hydrogen cupferrate concentration.

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