• Textile Coloration and Finishing
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• v.10 no.3
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• pp.36-42
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• 1998

The dyeabilities of C.I. Reactive Blue 19(B19, MW ; 626), C.I. Reactive Blue 4(B4, MW ; 637) and C.I. Reactive Black 5(B5, MW : 991) were investigated. Initial dyeing rates were increased and the amount of dye on the fabric at equilibrium was decreased with temperature like other ordinary dyeing processes. Activation entropy$(\Delta{S}^*)$ was decreased because of loose bonding between dyestuffes and fiber molecules at transition state. It can be clarified that the entire reaction is exothermic and the number of molecular species at transition state becomes greater from decrease in activation enthalpy$(\Delta{H}^*)$ and the increase in activation free energy$(\Delta{G}^*)$ with temperature, respectively. The amount of B19 on the fabric at equilibrium was greater than that of B4, because B4 became unreactive towards textile substrates through hydrolysis. Due to the biggest size of the dye molecule, the reaction rate of B5 was the slowest but its difunctional group played an important role in achieving the greatest amount of dye on the fabric at equilibrium.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.1
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• pp.1-11
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• 2000

This study investigates the problem of phase change from liquid to solid in the inviscid stagnation flow. The solution of dimensionless governing equations is determined by the three dimensionless parameters of (temperature ratio/conductivity ratio), Stefan number, and diffusi-vity ratio. The solution at the initial stage of freezing is obtained by expanding it in powers of time, and the final equilibrium state is determined from the steady-state governing equations. The equilibrium state is dependent on (temperature ratio/conductivity ratio), but is independent of Stefan number and diffusivity ratio. The effect of fluid flow on the pure conduction problem can be clearly seen from the solution of the initial stage and the final equilibrium state, and the characteristics of the solidification process for all the dimensionless parameters are elucidated.

• Bulletin of the Korean Chemical Society
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• v.19 no.8
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• pp.836-840
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• 1998

The intrinsic and equilibrium isotope effects on the 13C NMR chemical shift of the cyclooctanone-2-D were investigated. Equilibrium constants and changes in the free energies, enthalpy, entropy, which are derived from the temperature dependence of the isotope shifts, are reported for this isotopomer.

• Journal of the Korean Society of Combustion
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• v.12 no.4
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• pp.57-61
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• 2007

The aim of this study is to find out the condition that generates maximum $H_2$ through the calculation of equilibrium model with conditions of pyrolysis gases of Refuse Plastic Fuel(RPF). This study deals with the computational simulation of a RPF gasification using an equilibrium model based on minimization of the Gibbs free energy. An equilibrium analysis was carried out to determine species composition of Syngas in RPF gasification and reactions to variation of temperature, $O_2/Fuel$ ratio and Steam/Fuel ratio. Calculated results shows that hydrocarbons in pyrolyzed gas are converted to synthesis gas which is formed on hydrogen and carbon monoxide.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.125.1-125.1
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• 2011

$CO_2$ separation from a flue gas by using the gas hydrate technology was suggested by Kang et al. They reported phase equilibrium conditions of mixed gases composed of $CO_2$ and N2 with THF as a thermodynamic promoter. In this study, we reported the phase equilibrium conditions of a mixed gas which had a realistic composition of the blast furnace gas (BFG) emitted from the steel-making process. The phase equilibrium measurements were done by using the "continuous" QCM method, and the results demonstrate that this method is efficient and as accurate as the conventional temperature search method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.527-535
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• 1997

Vapor-liquid equilibrium apparatus is designed and set up. The vapor-liquid equilibrium data of the binary system HFC32/134a are measured in the range between 258.15 and 283.15K at compositions of 0.2, 0.4, 0.6 and 0.8 mole fraction of HFC32. Twenty-two equilibrium data are obtained. Based upon the present data, the binary interaction parameter for Carnahan-Starling-De Santis equation of state is calculated. Temperature range of data is extended to 313.04K using the data in the open literatures. Interaction parameters are determined at nine isotherms.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.356-364
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• 2010

The chemical and biological reaction of the aquatic organism is closely related with temperature variation and water temperature is one of the most important factors that should be considered in establishing sustainable reservoir operation scheme to minimize adverse environmental impacts related with dam construction. This paper investigates temperature variation in the downstream of Yongdam Reservoir using sampled data collected from total 8 temperature monitoring stations placed along the main river and the major tributaries. Using KoRiv1, 1-dimensional dynamic water quality simulation model, temperature variation in the downstream of Yongdam Reservoir has been simulated. The simulated results were compared with sampled data collected from May 15 to August 1 2008 by applying two different temperature modeling schemes, equilibrium temperature and full heat budget method. From the result of statistical analysis, seasonal temperature variation has been simulated by applying the equilibrium temperature scheme for comparison of the difference between the reservoir operation and the natural conditions.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.7 no.2
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• pp.19-24
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• 2001

The design criteria of ventilating container is not provided yet in Korea. This caused strength reduction due to the ventilating hole and bad ventilating performance. The purposes of this study were to survey the present situation of ventilating container in Korea, to analyze the strength reduction on the atmosphere condition variation, and to provide the criteria for the optimum design of ventilating container. The ventilating area of container was $1.41{\sim}2.65%$, and strength reduction due to the varied pattern, size and location of ventilating hole was $8.5{\sim}20.2%$. The effect on the strength reduction from the pattern and location of ventilating hole was bigger than that from the ventilating area. Equilibrium arrival time of temperature and relative humidity was shorter as the ventilating area was bigger, and temperature reached to the equilibrium state earlier than the relative humidity. There was no significant difference on the ventilating hole pattern between equilibrium arrival time of temperature and relative humidity and equilibrium arrival temperature and relative humidity if the ventilating area was the same.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.89-96
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• 2006

The combustion temperature in gas generator should be kept below around 1,000K to avoid any possible thermal damages to turbine blade by adopting either fuel rich or oxidizer rich combustion. Thus, non-equilibrium chemical reaction dominates in the gas generator. Meanwhile, Kerosene is a compounded fuel mixed with various types of hydrocarbon elements and difficult to model the chemical kinetics. This study focus to model the non-equilibrium chemical reaction of kerosene/LOX with detailed kinetics developed by Dagaut using PSR(Perfectly stirred reactor) assumption. Also, droplet evaporation time is taken into account by calculating for the residence time of droplet and by decoupling reaction temperature from the reactor temperature. In Dagaut’s surrogate model for kerosene, chemical kinetics of kerosene consists of 1592 reaction steps with 207 chemical species. The comparison of calculation results with experimental data could provide very reliable and accurate numbers in the prediction of combustion gas temperature, species fraction and other gas properties.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1920-1926
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• 2010

Yoon et $al.^1$ presented an approximate mathmatical model to describe ammonia removal from an experimental batch reactor system with gaseous headspace. The development of the model was initially based on assuming instantaneous equilibrium between ammonia in the aqueous and gas phases. In the model, a "saturation factor, $\beta$" was defined as a constant and used to check whether the equilibrium assumption was appropriate. The authors used the trends established by the estimated $\beta$ values to conclude that the equilibrium assumption was not valid. The authors presented valuable experimental results obtained using a carefully designed system and the model used to analyze the results accounted for the following effects: speciation of ammonia between $NH_3$ and $NH^+_4$ as a function of pH; temperature dependence of the reactions constants; and air flow rate. In this article, an alternative model based on the exact solution of the governing mass-balance differential equations was developed and used to describe ammonia removal without relying on the use of the saturation factor. The modified model was also extended to mathematically describe the pH dependence of the ammonia removal rate, in addition to accounting for the speciation of ammonia, temperature dependence of reactions constants, and air flow rate. The modified model was used to extend the analysis of the original experimental data presented by Yoon et $al.^1$ and the results matched the theory in an excellent manner.