Phase Relationships in the Calcium Chloride – Calcium Carbide System

1972 ◽  
Vol 50 (6) ◽  
pp. 839-843 ◽  
Author(s):  
J. F. Maillot ◽  
D. R. Morris
Keyword(s):  
Thermal Analysis ◽  
Melting Point ◽  
Calcium Chloride ◽  
Freezing Point ◽  
Eutectic Point ◽  
Calcium Carbide ◽  
Carbide System ◽  
Phase Relationships

The system calcium chloride – calcium carbide has been examined by thermal analysis. The depression of the freezing point of CaCl2 by CaC2 is ideal. The system is a eutectic one, with a eutectic point at 90 mol% CaCl2 at 740 °C. Carbon is believed to be present in the electrolyte as the so called acetylide ion [Formula: see text] The melting point of pure CaCl2 was found to be 775.2 ± 0.6 °C.

HYDROGEN PEROXIDE AND ITS ANALOGUES: V. PHASE EQUILIBRIA IN THE SYSTEM D2O–D2O2

1954 ◽  
Vol 32 (5) ◽  
pp. 550-556 ◽  
Author(s):  
Paul A. Giguère ◽  
E. A. Secco
Keyword(s):  
Hydrogen Peroxide ◽  
Melting Point ◽  
Freezing Point ◽  
Eutectic Point ◽  
Cooling Curves ◽  
Addition Compound ◽  
Concentrated Solutions ◽  
Number Of Solutions ◽  
Point Curve ◽  
Solid Liquid

The cooling curves of a number of solutions of deuterium peroxide in heavy water in the concentration range 11% to 95% were measured in order to determine the solid-liquid phase diagram for that binary system. The apparatus of Herington and Handley, which uses a pulsing pressure for stirring the solutions, and a thermistor, was found to be particularly suitable for that purpose. As could be expected the freezing-point curve of the deuterated compounds is closely similar to that of the hydrogen compounds, being shifted up only by about 4° for water-rich solutions and by 2° for peroxide-rich solutions. The melting point of the addition compound, D2O.2D2O very nearly coincides with one of the eutectic points at 46.2% D2O2 and −51.5 °C.; the other eutectic point is at 60.5% D2O2 and −55.1 °C. By extrapolation the melting point of pure deuterium peroxide is found to be 1.5 °C. as compared with −0.43 °C. for hydrogen peroxide. Concentrated solutions of deuterium peroxide exhibit an extreme tendency to supercool, resulting sometimes in formation of glasses even at liquid-air temperature. The previous results of Foley and Giguère for the system H2O–H2O2 were confirmed, specially as regards the melting point of the addition compound H2O2•2H2O.

THE PHASE DIAGRAM OF THE SYSTEM Na3AlF6–Na2SO4 AND THE DISSOCIATION OF THE CRYOLITE ANION IN MOLTEN SODIUM SULPHATE

1959 ◽  
Vol 37 (7) ◽  
pp. 1170-1175 ◽  
Author(s):  
Kai Grjotheim ◽  
Tor Halvorsen ◽  
Sigmund Urnes
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
Solid Solution ◽  
Binary System ◽  
Freezing Point ◽  
Eutectic Point ◽  
Sodium Sulphate ◽  
Freezing Point Depression ◽  
Molten Sodium

The binary system Na3AlF6–Na2SO4 has been investigated. A eutectic point was found at 91 mole % Na2SO4. On the Na3AlF6 side of the diagram extensive solid solution was found. No solid solution was observed on the Na2SO4 side, either by thermal analysis or by Debye–Scherrer diagrams. The freezing point depression of Na2SO4 caused by additions of Na3AlF6 has been used to evaluate the dissociation scheme of the cryolite anion in a sodium sulphate melt. The calculations favor the following scheme:AlF63− = AlF4− + 2F−.

Structural and thermodynamic properties of nanocrystalline fcc metals prepared by mechanical attrition

1992 ◽  
Vol 7 (7) ◽  
pp. 1751-1761 ◽  
Author(s):  
J. Eckert ◽  
J.C. Holzer ◽  
C.E. Krill ◽  
W.L. Johnson
Keyword(s):  
Thermal Analysis ◽  
Grain Size ◽  
Melting Point ◽  
Grain Boundary ◽  
Bulk Modulus ◽  
Atomic Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fcc Metals ◽  
Mechanical Attrition

Nanocrystalline fcc metals have been synthesized by mechanical attrition. The crystal refinement and the development of the microstructure have been investigated in detail by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The deformation process causes a decrease of the grain size of the fcc metals to 6–22 nm for the different elements. The final grain size scales with the melting point and the bulk modulus of the respective metal: the higher the melting point and the bulk modulus, the smaller the final grain size of the powder. Thus, the ultimate grain size achievable by this technique is determined by the competition between the heavy mechanical deformation introduced during milling and the recovery behavior of the metal. X-ray diffraction and thermal analysis of the nanocrystalline powders reveal that the crystal size refinement is accompanied by an increase in atomic-level strain and in the mechanically stored enthalpy in comparison to the undeformed state. The excess stored enthalpies of 10–40% of the heat of fusion exceed by far the values known for conventional deformation processes. The contributions of the atomic-level strain and the excess enthalpy of the grain boundaries to the stored enthalpies are critically assessed. The kinetics of grain growth in the nanocrystalline fcc metals are investigated by thermal analysis. The activation energy for grain boundary migration is derived from a modified Kissinger analysis, and estimates of the grain boundary enthalpy are given.

scholarly journals RESEARCH OF STABLE TETRAHEDRON OF LiF-LiVO3-NaBr-NaVO3 QUATERNARY MUTUAL SYSTEM OF Li,Na||F,Br,VO3

2018 ◽  
Vol 59 (4) ◽  
pp. 47
Author(s):  
Ivan K. Garkushin ◽  
Inna N Samsonova ◽  
Tatiana V. Gubanova
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Equilibria ◽  
Quaternary System ◽  
Eutectic Point ◽  
Analysis Method ◽  
Thermal Analysis Method ◽  
Mutual System

Phase equilibria of quaternary system LiF-LiVO3-NaBr-NaVO3 were studied with differential thermal analysis method. The temperature and composition of eutectic point was determined: Е 458 ºС: 11.2% LiF, 57.2% LiVO3, 16% NaBr, 15.6% LiVO3.

scholarly journals Synthesis of N-benzothiazole derivative imide on polymeric chain, have possible biological activity

2013 ◽  
Vol 10 (3) ◽  
pp. 673-685
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermal Analysis ◽  
Biological Activity ◽  
Melting Point ◽  
13C Nmr ◽  
Uv Spectroscopy ◽  
Polymeric Chain ◽  
Thermal Stabilities ◽  
Triethyl Amine ◽  
Ft Ir ◽  
Structure Confirmation

In this reserch Some new substituted and unsubstituted poly imides compounds. were synthesized by reaction of acrylol chloride with different amides (aliphatic and aromatic) in a suitable solvent in the presence amount triethyl amine (Et3N) with heating. The Structure confirmation of all polymers were confirmed using FT-IR,1H-NMR,13C-NMR and UV spectroscopy. Thermal analysis (TG) for some polymers showed their thermal stabilities. Other physical properties including softening points, melting point and solubility of the polymers were also measured

Thermal Analysis of Nomex® and Kevlar® Fibers

1977 ◽  
Vol 47 (1) ◽  
pp. 62-66 ◽  
Author(s):  
J. R. Brown ◽  
B. C. Ennis
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Glass Transition ◽  
Melting Point ◽  
Transition Region ◽  
High Temperatures ◽  
High Performance ◽  
Polymer Melt ◽  
Glass Transition Region ◽  
Dta Curves

DTA, TG, and TMA curves of commercial Kevlar® 49 and Nomex® fibers have been used to assess their behavior at high temperatures. The fibers lost absorbed water around 100°C, and a glass transition was reflected in the DTA and TMA curves in the region of 300°C. Difficulties in the interpretation of DTA and TMA curves in the glass-transition region and in the assignments of Tv‘s for these high-performance fibers are discussed. Whereas Kevlar 49 showed both a crystalline melting point (560°C) and a sharp endothermal thermal decomposition (590°C), Nomex showed only the latter (440°C) and no evidence of melting from the DTA curves. The endothermal decomposition peaks apparently correspond to “polymer melt temperatures” reported for related materials, and correlate well with the TG and TMA features. During thermal analysis of Kevlar 49, oxidation occurs more readily than thermal decomposition, but the latter predominates for Nomex. Differences between dyed and undyed Nomex were due to differences in yarn constitution.

Interaction between Cholesterol and Calcium Ions in Solution

1975 ◽  
Vol 30 (11-12) ◽  
pp. 718-721 ◽  
Author(s):  
S. P. Marfey ◽  
R. Van Meter ◽  
M. E. Bartlet
Keyword(s):  
Calcium Chloride ◽  
Freezing Point ◽  
Cellulose Membrane ◽  
Aqueous Dioxane ◽  
Freezing Point Depression ◽  
Three Solutions ◽  
Chloride Dihydrate ◽  
Natural Protein ◽  
Protein Membrane ◽  
Calcium Chloride Dihydrate

Abstract Dialysis rates of cholesterol, calcium chloride dihydrate and of their mixture in 90% aqueous dioxane through Visking cellulose membrane were characterized by half-escape times (t½) of 2.2, 1.0 and 10.5 hours, respectively. Slow dialysis rate observed with the mixture was due to complex formation between four molecules of cholesterol and two molecules of calcium chloride dihydrate, molecular weight 1800 to 2000. The association constant for this complex in 90% aqueous dioxane was estimated to be 3.9 × 1014. Rates of dialysis obtained with a natural protein membrane were in the reverse order to those obtained with cellulose membrane. Half-escape times for cholesterol, calcium chloride dihydrate and for their mixture were 0.6, 6.7 and 1.4 hours, respectively. Determinations of milliosmolality of the three solutions by freezing point depression indicated that in the mixture there were fewer osmotically active same molarity, also suggesting formation of the complex which was detected by dialysis experiments.

System triethylamine–water: the equilibrium diagram and some physical properties

1967 ◽  
Vol 45 (10) ◽  
pp. 1089-1091 ◽  
Author(s):  
E. M. Kartzmark
Keyword(s):  
Thermal Analysis ◽  
Physical Properties ◽  
Freezing Point ◽  
Equilibrium Diagram ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Viscosity Measurements ◽  
Volume Of Mixing ◽  
Negative Volume

The freezing-point diagram, determined by the method of thermal analysis, corroborates the existence of a dihydrate, first discovered by Pickering (1). Density and viscosity measurements at 16.0 °C, slightly below the critical solution temperature of 18.3 °C, show marked non-ideality. The negative volume of mixing reaches a maximum at 50 mole % and the maximum in the viscosity (4.00 relative to water) occurs at 12 mole %.

scholarly journals An investigation of the dissociation pressures and melting points of the system Copper-cuprous oxide

1912 ◽  
Vol 87 (598) ◽  
pp. 524-534 ◽  
Keyword(s):  
Melting Point ◽  
Solid Solutions ◽  
Cuprous Oxide ◽  
Eutectic Temperature ◽  
Eutectic Point ◽  
Cooling Curve ◽  
Melting Points ◽  
Platinum Crucible ◽  
Dissociation Pressures

E. Heyn determined the melting points of mixtures of copper and cuprous oxide of compositions varying between 100 per cent. Cu and 88·24 per cent. Cu, 11·76 per cent. Cu 2 O. The results of his experiments are shown by the points marked + in fig. 1. These points fall on two curves intersecting at the eutectic point 1065° C., Cu 2 O 3·5 per cent., Cu 96·5 per cent. Heyn found that all his mixtures showed a halt in the cooling curve at this eutectic temperature, so that within the range of his experiments there is no evidence of the existence of solid solutions. C. N. Otin has lately published some experiments on the melting points of the system cuprous oxide-silica. He attempted to determine the melting point of cuprous oxide, but as some oxidation always took place in his experiments, and as he did not analyse the solid obtained (on account of having to remelt it to get it out of the platinum crucible), there is some doubt as to the actual composition of the substance of which he determined the melting point. The highest temperature at which he found a halt in the cooling curve was 1205° C.

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