Heats of transport of some aqueous nonelectrolytes

1986 ◽  
Vol 64 (4) ◽  
pp. 717-719
Author(s):  
A. K. Murkherjee ◽  
S. K. Sanyal
Keyword(s):  
Temperature Gradient ◽  
Aqueous Solutions ◽  
Thermal Diffusion ◽  
Hydrophobic Hydration ◽  
Heat Of Transport ◽  
Sintered Glass ◽  
Glass Disc

The thermal diffusion of aqueous solutions of glucose, sucrose, ethylacetate, and 1,4-dioxan (0.1 m) contained in the pores of a sintered glass disc (or porosity G4), which is subjected to a temperature gradient, has been studied. The resulting heat of transport data have been interpreted, in terms of local changes in entropy in the solvent brought forth by the presence of the solutes, and correlated to the hydrophobic hydration effects.

Heat of transport and heat capacity of transport of some aqueous electrolytes

1988 ◽  
Vol 66 (3) ◽  
pp. 435-438
Author(s):  
S. K. Sanyal ◽  
Ashis K. Mukherjee
Keyword(s):  
Heat Capacity ◽  
Aqueous Solutions ◽  
Thermal Diffusion ◽  
Aqueous Electrolytes ◽  
Heat Of Transport ◽  
Sintered Glass ◽  
A Cell ◽  
Glass Diaphragm

The thermal diffusion of aqueous solutions of NaCl, KCl, MgCl2, BaCl2, MgSO4, and CuSO4 (0.05 m) contained in the pores of a sintered glass diaphragm has been studied. A cell is designed and fabricated for this purpose, and the resulting heat of transport values are compared with those available from the literature and obtained by using independent techniques.

Thermal diffusion of aqueous alcohols

1989 ◽  
Vol 67 (5) ◽  
pp. 867-870
Author(s):  
Ashis Kumar Mukherjee ◽  
S. K. Sanyal
Keyword(s):  
Aqueous Solutions ◽  
Temperature Coefficient ◽  
Thermal Diffusion ◽  
Soret Coefficient ◽  
Local Entropy ◽  
Solvent Interactions ◽  
Solvent Water ◽  
Heat Of Transport ◽  
Sintered Glass ◽  
Experimental Values

The thermal diffusion of aqueous solutions of methanol, ethanol, propan-1-ol, butan-1-ol, ethan-1,2-diol, andpropan-1,2-diol contained in the pores of a sintered glass disc (of porosity G4) has been studied. The Soret coefficient (σ) and the heat of transport [Formula: see text] values are reported in the temperature range of 25–40 °C. The heat capacities of transport are ascertained at 30 °C from the temperature coefficient of heat of transport values. The results are explained on the basis of changes in local entropy in the solvent (water), arising out of solute–solvent interactions. Correlations of the observed experimental values with certain relevant thermodynamic parameters, taken from the literature, have also been sought, with encouraging results. Keywords: thermal diffusion, heat of transport, entropy of hydration.

The thermo-osmosis of gases through a membrane I. Theoretical

1952 ◽  
Vol 210 (1102) ◽  
pp. 377-387 ◽  
Keyword(s):  
Temperature Gradient ◽  
Diffusion Process ◽  
Temperature Coefficient ◽  
Thermal Diffusion ◽  
Stationary State ◽  
Pressure Ratio ◽  
Irreversible Processes ◽  
Heat Of Solution ◽  
Heat Of Transport ◽  
Thermal Diffusion Process

The process of thermo-osmosis is the passage of a fluid through a membrane due to a temperature gradient. Under suitable conditions it gives rise to a stationary difference of pressure. The thermo-osmosis of a gas through a membrane in which it is slightly soluble is due partly to the temperature coefficient of its solubility and partly to the existence of a thermal diffusion process inside the membrane. A theory is developed on the basis of Onsager’s treatment of irreversible processes and leads to equations giving the rate of permeation and the pressure ratio at the stationary state. The magnitude of the effect depends on the algebraic sum of the heat of solution and the heat of transport within the membrane.

Motions of water molecules in dilute aqueous solutions of tertiary butyl alcohol; a neutron scattering study of hydrophobic hydration

1970 ◽  
Vol 319 (1537) ◽  
pp. 189-208 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Water Structure ◽  
Hydrophobic Hydration ◽  
Step Length ◽  
Solute Concentration ◽  
Butyl Alcohol ◽  
Tertiary Butyl ◽  
Self Diffusion ◽  
Dilute Aqueous Solutions ◽  
Neutron Scattering Study

Cold neutron inelastic scattering experiments have been performed on dilute aqueous solutions of (CD 3 ) 3 COH and of solutions of (CH 3 ) 3 COH in D 2 O at 21 °C. From the broadening of the quasi-elastic peak and independently determined self-diffusion coefficients ( D ), diffusive lifetimes ( c ) of H 2 O molecules have been calculated as functions of solute concentration. The product Dc is insensitive to concentration, giving a mean diffusion step length of 0.14 nm. The inelastic portion of the spectrum, reflecting lattice-like hydrogen bonding modes indicates that the solute enhances the water ‘structure’ but that such structure bears no resemblance to ice.

Two-Phase Multicomponent Diffusion and Convection for Reservoir Initialization

2006 ◽  
Vol 9 (05) ◽  
pp. 530-542 ◽  
Author(s):  
Hadi Nasrabadi ◽  
Kassem Ghorayeb ◽  
Abbas Firoozabadi
Keyword(s):  
Thermal Conductivity ◽  
Porous Medium ◽  
Natural Convection ◽  
Temperature Gradient ◽  
Thermal Diffusion ◽  
Multicomponent Diffusion ◽  
Compositional Variation ◽  
Horizontal Temperature Gradient ◽  
Two Phase ◽  
Thermogravitational Column

Summary We present formulation and numerical solution of two-phase multicomponent diffusion and natural convection in porous media. Thermal diffusion, pressure diffusion, and molecular diffusion are included in the diffusion expression from thermodynamics of irreversible processes. The formulation and the numerical solution are used to perform initialization in a 2D cross section. We use both homogeneous and layered media without and with anisotropy in our calculations. Numerical examples for a binary mixture of C1/C3 and a multicomponent reservoir fluid are presented. Results show a strong effect of natural convection in species distribution. Results also show that there are at least two main rotating cells at steady state: one in the gas cap, and one in the oil column. Introduction Proper initialization is an important aspect of reliable reservoir simulations. The use of the Gibbs segregation condition generally cannot provide reliable initialization in hydrocarbon reservoirs. This is caused, in part, by the effect of thermal diffusion (caused by the geothermal temperature gradient), which cannot be neglected in some cases; thermal diffusion might be the main phenomenon affecting compositional variation in hydrocarbon reservoirs, especially for near-critical gas/condensate reservoirs (Ghorayeb et al. 2003). Generally, temperature increases with increasing burial depth because heat flows from the Earth's interior toward the surface. The temperature profile, or geothermal gradient, is related to the thermal conductivity of a body of rock and the heat flux. Thermal conductivity is not necessarily uniform because it depends on the mineralogical composition of the rock, the porosity, and the presence of water or gas. Therefore, differences in thermal conductivity between adjacent lithologies can result in a horizontal temperature gradient. Horizontal temperature gradients in some offshore fields can be observed because of a constant water temperature (approximately 4°C) in different depths in the seabed floor. The horizontal temperature gradient causes natural convection that might have a significant effect on species distribution (Firoozabadi 1999). The combined effects of diffusion (pressure, thermal, and molecular) and natural convection on compositional variation in multicomponent mixtures in porous media have been investigated for single-phase systems (Riley and Firoozabadi 1998; Ghorayeb and Firoozabadi 2000a).The results from these references show the importance of natural convection, which, in some cases, overrides diffusion and results in a uniform composition. Natural convection also can result in increased horizontal compositional variation, an effect similar to that in a thermogravitational column (Ghorayeb and Firoozabadi 2001; Nasrabadi et al. 2006). The combined effect of convection and diffusion on species separation has been the subject of many experimental studies. Separation in a thermogravitational column with both effects has been measured widely (Schott 1973; Costeseque 1982; El Mataaoui 1986). The thermogravitational column consists of two isothermal vertical plates with different temperatures separated by a narrow space. The space can be either without a porous medium or filled with a porous medium. The thermal diffusion, in a binary mixture, causes one component to segregate to the hot plate and the other to the cold plate. Because of the density gradient caused by temperature and concentration gradients, convection flow occurs and creates a concentration difference between the top and bottom of the column. Analytical and numerical models have been presented to analyze the experimental results (Lorenz and Emery 1959; Jamet et al. 1992; Nasrabadi et al. 2006). The experimental and theoretical studies show that the composition difference between the top and bottom of the column increases with permeability until an optimum permeability is reached. Then, the composition difference declines as permeability increases. The process in a thermogravitational column shows the significance of the convection from a horizontal temperature gradient.

Temperature dependence of thermal diffusion for aqueous solutions of monosaccharides, oligosaccharides, and polysaccharides

2012 ◽  
Vol 14 (29) ◽  
pp. 10147 ◽  
Author(s):  
Yuki Kishikawa ◽  
Haruka Shinohara ◽  
Kousaku Maeda ◽  
Yoshiyuki Nakamura ◽  
Simone Wiegand ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Temperature Dependence ◽  
Thermal Diffusion

Unified Effect of Hydrophobic Hydration on the Dynamics and the Structure of Water Molecules in Lower Alcohol Aqueous Solutions

2011 ◽  
Vol 80 (4) ◽  
pp. 044604 ◽  
Author(s):  
Masaru Nakada ◽  
Kenji Maruyama ◽  
Osamu Yamamuro ◽  
Tatsuya Kikuchi ◽  
Masakatsu Misawa
Keyword(s):  
Aqueous Solutions ◽  
Hydrophobic Hydration ◽  
Water Molecules ◽  
Structure Of Water ◽  
Lower Alcohol

Heat of transport in thermal diffusion of hydrogen in titanium

1969 ◽  
Vol 3 (8) ◽  
pp. 583-584 ◽  
Author(s):  
Masahiro Kitada ◽  
Shigeyasu Koda
Keyword(s):  
Thermal Diffusion ◽  
Heat Of Transport ◽  
Diffusion Of Hydrogen
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