• 대한기계학회논문집
• /
• 제19권12호
• /
• pp.3372-3381
• /
• 1995

An equilibrium analysis was carried out to determine principal species of heavy metals in waste incineration and their behaviors with variation of temperature, chlorine concentration, excess air ratio, and C/H ratio. The waste was assumed as a compound of hydrocarbon fuel, chlorine, and metals. Calculated results showed that the most important parameter to determine the principal species was temperature. Chlorine concentration also affected on mole fractions of the principal species. Generally principal species at high temperature were chlorides while there were some metals of which principal species were oxides. At low temperature mole fractions of the principal species increased, but at high temperature mole fractions of some metal species decreased. C/H ratio of the hydrocarbon fuel and excess air ratio had little effect on mole fractions of the metal species, compared to the temperature and chlorine concentration.

• 한국연소학회지
• /
• 제1권1호
• /
• pp.31-39
• /
• 1996

An equilibrium analysis was carried out to determine principal species in the incineration of hazardous waste, which was assumed as a compound of hydrocarbon fuel, chlorine, sulfur, and heavy metals, and their behaviors with variation of temperature, chlorine and sulfur concentrations. Calculated results showed that the most important parameter influencing the principal species was temperature. Chlorine concentration affected on mole fractions of the species, especially at high temperature. Existence of sulfur had a significant effect on the species at low temperature, regardless of surfur concentration. Generally, principal species at high temperature were chlorides and oxides, while the principal species at low temperature were sulfides. As temperature increased, mole fractions of the principal species increased at low temperature, however, mole fractions of some metal species decreased at high temperature.

• International Journal of Aeronautical and Space Sciences
• /
• 제17권4호
• /
• pp.455-466
• /
• 2016

Chemical-kinetic parameters of the equilibrium constants to evaluate the reverse rate coefficients in the shock layer of a blunt body and the expanding flows are derived for the temperature range from 300 K to 20,000 K. The expanded equilibrium constants for the chemical reactions of the dissociation, ionization, associative ionization, and neutral and charge exchange reactions of the atmospheric species and carbon materials are proposed in the present work. In evaluating the equilibrium constants, the inter-nuclear potential energies of the molecular species are calculated by the analytical potential function of the Hulburt-Hirschfelder model, and the parameters of the analytical model are determined from the semi-classically calculated RKR potentials. The electronic states and energies of the atoms are calculated by the electronic energy grouping model, and the rovibrational states and energies of each electronic states of the molecules are evaluated by the WKB method. The expanded equilibrium constants for 31 types of the reactions are provided for the best curve-fit functions, and the recombination reaction rate coefficients evaluated from the present equilibrium constants are compared with existing measured values.

• Ocean and Polar Research
• /
• 제36권1호
• /
• pp.71-76
• /
• 2014

This study aims to analyze the market interactions among the main farmed fish species in Korea, using both multivariate and bivariate cointegration analysis. For the analysis of market interactions among farmed fish species, major four farmed fish species, olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), red seabream (Pagrus major), and grey mullet (Mugil cephalus) were selected as the analytical target species. And their real price data by month from January 2000 to December 2011 were used in the analysis. The results of the multivariate cointegration test for four farmed fish showed that there would be no long-term equilibrium relationships among farmed fish species, and consequently they do not share the same market. The results of bivariate cointegration test indicated that there was little evidence to suggest that all farmed fish species were cointegrated each other. However, it was only analyzed that olive flounder and grey mullet might have a long run equilibrium relationship.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2000년도 춘계 학술대회논문집
• /
• pp.166-171
• /
• 2000

A two-dimensional/axisymmetric CSCM upwind flux difference splitting Wavier-Stokes method has been developed to study the finite rate chemically react-ing invisicd and viscous hypersonic flows over blunt-body. A upwind method was chosen due to its robustness in capturing the strong bow shock waves. For the nonequilibrium chemically reacting air, NS-I species conservation equations were strongly coupled with flowfield equations through convection and species production terms. The nonequilibrium wall pressure and heat transfer rate distributions along the vehicle were compared with those from equilibrium and perfect gas calculations. The nonequilibrium species distribution shows the reduced concentrations of O and N species when compared with equilibrium species distribution. The solutions resolved strong bow shock waves md heat transfer rate very accurately when compared with central difference schemes.

• Journal of the Korean Wood Science and Technology
• /
• 제22권4호
• /
• pp.37-42
• /
• 1994

The adsorption of water vapor and equilibrium moisture content(EMC) of the specimens for four softwood species dried by conventional- and high temperature method and equilibrated to 15% of the target EMC condition at 25$^{\circ}C$ were determined by oven drying method and with moisture meters. The amount of adsorption for high temperature dried red pine was significantly higher than that of conventional kiln dried wood, while those of eastern white pine, eastern hemlock and Norway spruce were not significantly different between drying methods. EMCs of these four species determined by oven drying method and with capacitive admittance moisture meter were not significantly different between drying methods. EMC of high temperature dried red pine determined with resistance moisture meter was significantly higher than that of conventional kiln dried wood. But EMCs of other species did not show significant difference between drying methods. EMCs of conventional and high-temperature dried wood determined with electronic moisture meters, especially in the case of the capacitive-admittance moisture meter measurement, were lower than that determined by oven drying method.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2010년도 제35회 추계학술대회논문집
• /
• pp.447-450
• /
• 2010

$CH_4-O_2$ vitiated 공기가열기에서의 유동 오염도 분석을 위해 가열기 및 노즐 영역에 대한 평형 및 평형 유동장 계산을 수행하였다. 유동장은 일차원 비점성 유동으로 가정하였으며 계산 결과는 측정값과 비교하였다. 연구결과 연소 지연이나 중단 현상에 영향을 주는 오염원으로써 NO 성분의 존재를 파악하기 위해서는 비평형 유동장 계산이 고려되어야 함을 알 수 있었다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2002년도 추계학술발표회
• /
• pp.161-166
• /
• 2002

Bioremediation of trace metals in groundwater may require the manipulation of redox conditions via the injection of a carbon source. To simulate the numerous biogeochemical processes that will occur during the bioremediation of trace-metal-contaminated aquifers, a reactive transport model has been developed. The model consists of a set of coupled mass balance equations, accounting for advection, hydrodynamic dispersion, and a kinetic formulation of the biological or chemical transformations affecting an organic substrate, electron acceptors, corresponding reduced species, and trace metal contaminants of interest, uranium in this study. The redox conditions of the domain are characterized by estimating the pE, based on the concentrations of the dominant terminal electron acceptor and its corresponding reduced specie. This pE and the concentrations of relevant species we then used by a modified version of MINTEQA2, which calculates the speciation/sorption and precipitation/dissolution of the species of interest under equilibrium conditions. Kinetics of precipitation/dissolution processes are described as being proportional to the difference between the actual and calculated equilibrium concentration.

• Bulletin of the Korean Chemical Society
• /
• 제10권3호
• /
• pp.270-272
• /
• 1989

The polymeric species formed on the hydrolysis of Th(IV) from solubility experiments of $ThO_2$ in 0.1M $NaClO_4$ and $Th(OH)_4\;in\;0.5M\;NaClO_4$ were removed by ultrafiltration using 1 nm ultrafilters. The resultant equilibrium concentrations of mono-hydroxy Th(IV) species in solutions between pH 1.5 to 13 were measured by the NAA method. From these data solubility product of thorium dioxide and the stability constants of mono-hydroxy Th(Ⅳ) were determined. The values obtained were log $K_{sp}\;-\;50.76\;{\pm}\;0.08, log\;{\beta}_{1,1}\;12.42\;{\pm}\;0.02,\;log\;{\beta}_{1,2}\;22.46\;{\pm}\;0.15, log\;{\beta}_{1,3}\;34.36\;{\pm}\;0.07,\;log\;{\beta}_{1,4}\;42.58\;{\pm}\;0.08$, which are in good agreement with the values given in the literature. In addition, several dimeric species, $Th_2(OH)_2\;^{6+},\;Th_2(OH)_3\;^{5+} and\;Th_2(OH)_4\;^{4+}$ have been identified.

• Kyungpook Mathematical Journal
• /
• 제47권1호
• /
• pp.31-56
• /
• 2007

In this paper, we consider a delay differential equation model of two competing species with harvesting of the mature and immature members of each species. The time delay in the model represents the time from birth to maturity of that species, which appears in the adults recruitment terms. We study the dynamics of our model analytically and we present results on positivity and boundedness of the solution, conditions for the existence and globally asymptotically stable of equilibria, a threshold of harvesting, and the optimal harvesting of the mature populations of each species.