scholarly journals Entropy of Mixing of Cadmium-based Liquid Alloys

1970 ◽  
Vol 26 ◽  
pp. 40-45
Author(s):  
S. K. Chakrabarti ◽  
B. K. Jha ◽  
I. S. Jha
Keyword(s):  
Thermodynamic Properties ◽  
Binary Alloys ◽  
The Other ◽  
Chemical Model ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Reactive Metal ◽  
Entropy Of Mixing ◽  
Binary Liquid ◽  
Other Hand

Cadmium is a highly reactive metal. At the time of formation of binary alloys in liquidphase it often forms complexes. In the present work we have considered two such complexforming binary liquid alloys of cadmium e.g. Cd-Na and Cd-Mg. The former alloy showsanomaly in its thermodynamic properties of mixing. On the other hand, the alloyingbehavior of the latter one is symmetric around the equi-atomic composition. We havecomputed their entropy of mixing (SM) for different concentrations of the ingredients byusing the quasi-lattice chemical model. The results explain the observed anomaly as well assymmetry in SM of the present alloys.Keywords: Binary liquid alloys of cadmium; Quasi-lattice chemical model; Entropy of mixingDOI: 10.3126/jncs.v26i0.3629Journal of Nepal Chemical SocietyVol. 26, 2010Page:40-45

scholarly journals Heat of Mixing of some Binary Liquid Alloys

1970 ◽  
Vol 7 (7) ◽  
pp. 96-99
Author(s):  
BK Kanth ◽  
SK Chakrabarti
Keyword(s):  
Free Energy ◽  
Successive Approximation ◽  
Chemical Model ◽  
Heat Of Mixing ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Entropy Of Mixing ◽  
Binary Liquid ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

There are a large number of binary liquid alloys the thermodynamic properties of mixing of which are not symmetrical about the equi-atomic composition-deviating maximally from those of the ideal alloys. Here we have considered three such alloys-indium-sodium, cadmium-sodium and copper-tin-and tried to calculate their heat of mixing at different concentrations of the ingredients. The liquidus lines of these alloys reveal that the constituent species form complexes. So, we have considered a quasi-lattice chemical model for computation of the thermodynamic entities. It is a statistical model in which grand partition function is used assuming that the energy of a given nearest neighbour bond is different if it belongs to the complex than if it does not. For each alloy we have started with the expression for excess free energy of mixing according to this model and computed the free energy of mixing for different concentrations of the metals within it by deriving the value of interaction parameters through successive approximation method. Thereafter, the expression for excess entropy of mixing is taken into account and the entropy of mixing is computed for different concentrations after finding out the temperature derivative of interaction parameters by the method of successive approximation. Finally the heat of mixing is calculated from these free energy of mixing and entropy of mixing on using the standard thermodynamic relation. The results explain the observed asymmetry in the heat of mixing of the said binary liquid alloys around equi-atomic composition. Key words : Binary liquid alloy; Quasi-lattice chemical model; Heat of mixing DOI: 10.3126/sw.v7i7.3836 Scientific World Vol.7(7) 2009 pp.96-99

scholarly journals Thermodynamic Properties of InNa Liquid Alloy

1970 ◽  
Vol 6 (6) ◽  
pp. 16-18
Author(s):  
SK Chakrabarti ◽  
IS Jha ◽  
BP Singh
Keyword(s):  
Thermodynamic Properties ◽  
Liquid Alloy ◽  
Heat Of Mixing ◽  
Liquid Alloys ◽  
Atomic Composition ◽  
Binary Liquid ◽  
Scientific World ◽  
Energy Of Mixing ◽  
Large Asymmetry ◽  
Free Energy Of Mixing

The large asymmetry observed in the properties of mixing of indium-sodium liquid alloy is discussed on the basis of quasi-lattice chemical model. A special attention is given to the concentration dependence of free energy of mixing, entropy of mixing and heat of mixing. The results explain the observed asymmetry in the properties of mixing of InNa liquid alloys around equi-atomic composition. Key words: Complex forming alloys; Binary liquid alloys; Quasi-lattice model; Thermodynamic properties. DOI: 10.3126/sw.v6i6.2627 Scientific World, Vol. 6, No. 6, July 2008 16-18

Interactions between cations and sugars. III. Free energies, enthalpies, and entropies of association of Ca2+, Sr2+, Ba2+, La3+, Gd3+ with D-ribose in water at 25 °C

1987 ◽  
Vol 65 (11) ◽  
pp. 2656-2660 ◽  
Author(s):  
Alfredo Maestre Alvarez ◽  
Nicole Morel-Desrosiers ◽  
Jean-Pierre Morel
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Solutions ◽  
Equilibrium Constant ◽  
The Other ◽  
Free Energies ◽  
Mean Values ◽  
Enthalpies Of Transfer ◽  
Other Hand ◽  
Solutions Of Electrolytes

The standard enthalpies of transfer of ribose and arabinose from water to aqueous solutions of electrolytes (CaCl2, SrCl2, BaCl2, LaCl3, and GdCl3) have been measured at 25 °C. A method is described to calculate from these data the equilibrium constant and the enthalpy for the association between the cations and the complexing isomers of ribose. Mean values relative to these isomers are given: the constants vary from 2.0 to 4.3 and the enthalpies from −5.9 to −17.9 kJ mol−1 for the different cations studied. The thermodynamic properties of association are not related to the size nor to the charge of the complexed cation in a simple way. On the other hand, the enthalpies of reaction are linearly correlated to the entropies of reaction.

Hydrogen absorption of C14 Laves NiTiZr-NiVNb pseudo-binary alloys

2003 ◽  
Vol 801 ◽  
Author(s):  
Kazuhiro Ishikawa ◽  
Shintaro Noda ◽  
Kiyonori Suzuki ◽  
Kiyoshi Aoki
Keyword(s):  
Binary System ◽  
Hydrogen Absorption ◽  
Binary Alloys ◽  
Hydrogen Desorption ◽  
Absorption Capacity ◽  
The Other ◽  
Hydrogen Capacity ◽  
Desorption Temperature ◽  
Other Hand ◽  
Zr Alloy

ABSTRACTHydrogen absorption and desorption properties of C14 Laves NiTiZr-NiVNb and NiTiZr-NiVZr pseudo-binary alloys were investigated by using the Sieverts' apparatus, XRD and the hydrogen analyzer. The hydrogen capacity and the 50% hydrogen desorption temperature, Td, of the C14 Laves NiTiZr alloy is 1.5 (H/M) and 850 K, respectively. On the other hand, the hydrogen capacity of the C14 NiVNb alloy is 0.2 H/M. In the Ni(TiZr)1−x(VNb)x pseudo-binary system, the hydrogen capacity of the alloys is decreased with increasing x, but the 50% hydrogen desorption temperature is almost constant. The substitution of VNb reduces the hydrogen absorption capacity of the C14 Laves NiTiZr alloy. The hydrogen desorption temperature of Ni(Ti1−xVx)Zr alloy is reduced to 580 K without serious decrease of the hydrogen capacity with increasing x.

scholarly journals Influence of sub- and super-solar metallicities on the composition of solid planetary building blocks

2019 ◽  
Vol 633 ◽  
pp. A10 ◽  
Author(s):  
Bertram Bitsch ◽  
Chiara Battistini
Keyword(s):  
Planet Formation ◽  
Building Blocks ◽  
The Other ◽  
Chemical Model ◽  
Stellar Abundances ◽  
Water Ice ◽  
Other Hand ◽  
Iron Abundance ◽  
Ice Content ◽  
Ice Fraction

The composition of the protoplanetary disc is thought to be linked to the composition of the host star, where a higher overall metallicity provides the building blocks for planets. However, most of the planet formation simulations only link the stellar iron abundance [Fe/H] to planet formation and the iron abundance in itself is used as a proxy to scale all elements. On the other hand, large surveys of stellar abundances show that this is not true. Here we use stellar abundances from the GALAH surveys to determine the average detailed abundances of Fe, Si, Mg, O, and C for a broad range of host star metallicities with [Fe/H] spanning from −0.4 to +0.4. Using an equilibrium chemical model that features the most important rock-forming compounds as well as volatile contributions of H2O, CO2, CH4, and CO, we calculate the chemical composition of solid planetary building blocks around stars with different metallicities. Solid building blocks that are formed entirely interior to the water ice line (T > 150 K) only show an increase in Mg2SiO4 and a decrease in MgSiO3 for increasing host star metallicity, which is related to the increase of [Mg/Si] for higher [Fe/H]. Solid planetary building blocks forming exterior to the water ice line (T < 150 K), on the other hand, show dramatic changes in their composition. In particular, the water ice content decreases from around ~50% at [Fe/H] = −0.4 to ~6% at [Fe/H] = 0.4 in our chemical model. This is mainly caused by the increasing C/O ratio with increasing [Fe/H], which binds most of the oxygen in gaseous CO and CO2, resulting in a small water ice fraction. Planet formation simulations coupled with the chemical model confirm these results by showing that the water ice content of super-Earths decreases with increasing host star metallicity due to the increased C/O ratio. This decrease of the water ice fraction has important consequences for planet formation, planetary composition, and the eventual habitability of planetary systems formed around these high-metallicity stars.

Temperature dependence of thermodynamic properties of Si–Ti binary liquid alloys

2011 ◽  
Vol 519 (1-2) ◽  
pp. 1-5 ◽  
Author(s):  
O.E. Awe ◽  
Y.A. Odusote ◽  
L.A. Hussain ◽  
O. Akinlade
Keyword(s):  
Thermodynamic Properties ◽  
Temperature Dependence ◽  
Liquid Alloys ◽  
Binary Liquid

scholarly journals Calculation of activities in some gallium-based systems with a miscibility gap

2003 ◽  
Vol 68 (8-9) ◽  
pp. 665-675 ◽  
Author(s):  
Dragan Manasijevic ◽  
Dragana Zivkovic ◽  
Iwao Katayama ◽  
Zivan Zivkovic
Keyword(s):  
Thermodynamic Properties ◽  
Phase Diagrams ◽  
The Other ◽  
Miscibility Gap ◽  
Liquid Alloys ◽  
Duhem Equation ◽  
Coexisting Phases ◽  
Temperature Ranges

The calculations of thermodynamic properties in some gallium-based systems with a miscibility gap ? Ga?Tl, Ga?Hg and Ga?Pb are presented in this paper. The determination of the gallium activities in the mentioned liquid alloys was based on their known phase diagrams using the Zhang-Chou method for calculating activities from phase diagrams involving two liquid or solid coexisting phases. The activities of gallium in Ga?Tl, Ga?Hg and Ga?Pb system were calculated in the 973?1273 K, 573?873 K and 1000?1100 K temperature ranges, respectively. The activities of the other component in all the investigated systems were obtained by the Gibbs-Duhem equation. The results of the calculations are compared with literature data.

Classification and Characterization of the Shape Memory Binary Alloys

2006 ◽  
Vol 980 ◽  
Author(s):  
Mitsuo Notomi ◽  
Krystyn J Van Vliet ◽  
Sidney Yip
Keyword(s):  
Crystal Structure ◽  
Shape Memory ◽  
Shape Recovery ◽  
Major Element ◽  
Binary Alloys ◽  
Major Elements ◽  
The Other ◽  
Atomic Composition ◽  
Group 5

AbstractAll shape memory binary alloys (SMBA) that exhibit not only perfect shape recovery but also partial shape recovery were reviewed and classified into three groups, B2, A2 and A1 type, according to the parent phases. There are the thirteen, six and eleven alloys belonging to B2, A2 and A1 type, respectively. In the group of B2 type SMBA the alloys are divided into two categories due to the combination of the elements. Over A1 and A2 type SMBA the atomic composition of one element is larger than the other so the larger one is called a major element. The major elements, Ti, U, Fe, and Cu, of A2 type SMBA do not belong to the group 5 and 6 in which the elements have a typical BCC (A2) crystal structure. In the A1 type SMBA there are four major elements, Mn, Fe, Co, and In and the SMBA except for In-based SMBA have ferromagnetic or antiferromagnetic natures. The shape memory effect (SME) for A1 (FCC) type SMBA might need the magnetic properties.

A QUASI-LATTICE THEORY FOR COMPOUND FORMING TERNARY LIQUID ALLOYS

2006 ◽  
Vol 20 (23) ◽  
pp. 3319-3340
Author(s):  
O. E. AWE ◽  
O. AKINLADE ◽  
L. A. HUSSAIN
Keyword(s):  
Thermodynamic Properties ◽  
Binary Mixtures ◽  
Lattice Model ◽  
Lattice Theory ◽  
Short Range ◽  
Short Range Order ◽  
Liquid Alloys ◽  
Binary Liquid ◽  
Limiting Case ◽  
Liquid Binary Mixtures

A Quasi-lattice model of liquid binary mixtures has been used to establish a model for calculating some thermodynamic properties of compound forming ternary liquid alloys. The effect of varying Z on the concentration fluctuations was also investigated. Results obtained for limiting case of the model are presented and compared with that obtained by Bhatia and Singh for binary liquid alloys. A framework for calculating the Warren Cowley short range order for ternary liquid alloys as a function of Z is also formulated.

scholarly journals The Difference between the Chemical Short Range Orders of Binary Liquid Alloys Using Different Models

2021 ◽  
Vol 5 (2) ◽  
pp. 1-6
Author(s):  
Abodunrin OW
Keyword(s):  
Thermodynamic Properties ◽  
Short Range ◽  
Short Range Order ◽  
Range Order ◽  
Concentration Fluctuation ◽  
Liquid Alloys ◽  
Thermodynamic Models ◽  
Stability Functions ◽  
Binary Liquid ◽  
The Difference

The thermodynamic models based on cluster of two and four atoms were considered to obtain the thermodynamic properties of liquid binary alloys. The four liquid alloys are candidates of homo-coordination / self-coordination. The values of chemical short range order, Concentration fluctuation and excess stability functions and the differences in models computed for Cu-Pb, Li-Mg, Cd-Ga and Bi-Cd binary liquid alloys are presented.

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