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1998 Calculating phase diagrams involving solid solutions via non-linear equations, with examples using THERMOCALC Journal of Metamorphic Geology 16 577 588

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Introduction In the present article, the results of investigations pertaining to the equilibria which occur in the system Rb 3 PO 4 –Ba 3 (PO 4 ) 2 are described. Its phase diagram was not published previously. There is

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Abstract  

Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. The robustness and sensitivity of instrumentation, the introduction of automation and of reliable software according to the industrial needs widened considerably the areas of applications in the last decade. Calibration of instruments and validation of results follow the state of the art of cGMP as for other analytical techniques. Thermal analysis techniques are especially useful for the study of the behavior of the poly-phasic systems drug substances and excipients and find a unique place for new delivery systems. Since change of temperature and moisture occur by processing and storage, changes of the solid state may have a considerable effect on activity, toxicity and stability of compounds. Current requirements of the International Conference of Harmonisation for the characterization and the quantitation of polymorphism in new entities re-enforce the position of thermal analysis techniques. This challenging task needs the use of complementary methods. Combined techniques and microcalorimetry demonstrate their advantages. This article reviews the current use of thermal analysis and combined techniques in research and development and in production. The advantage of commercially coupled techniques to thermogravimetry is emphasized with some examples.

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analysis results for samples after the final heating stage On the ground of all presented results a phase diagram of the system CuO–V 2 O 5 –Fe 2 O 3 in subsolidus area was worked out. Figure 5 shows a

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Journal of Thermal Analysis and Calorimetry
Authors: Masoud Nazarian-Samani, Ali Reza Kamali, Mahboobeh Nazarian-Samani, Roohallah Mobarra, and Saber Naserifar

Introduction Ni–B binary phase diagram ( Fig. 1 ) [ 1 ] shows several intermetallics of NiB, m -Ni 4 B 3 , o -Ni 4 B 3 , Ni 2 B, and Ni 3 B, respectively. These intermetallics have found interesting applications such as

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molecular weights and structures of either or both components in the blends. Our present study aimed at probing the phase behavior, phase diagrams, and temperature dependence of blends systems composed of PLLA of two different molecular weights (low and high

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Journal of Thermal Analysis and Calorimetry
Authors: A. Caneiro, L. Mogni, N. Grunbaum, and F. Prado

transformations occurring under the working conditions. For this reason, the resolution of the phase diagram of SOFC materials results very important in the understanding of these properties. The thermal analysis involves powerful methods that permit the

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The diastereoisomeric salt pair formed between α-phenyl-ethyl-amine and R-1-phenylethylsuccinamic acid were investigated by physico-chemical methods. Melting and solubility phase diagrams were determined, the coincidence of the eutectic points of the two phase diagrams were demonstrated. The large difference in physico-chemical properties of the salt pair explains the efficient enantiomer separation.

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Differential scanning calorimetry (DSC) was used to construct phase diagrams of binary mixtures of alkylcyclohexanes and to characterize metastable phases formed in the binary mixtures. The experimentally measured liquidus curves were compared to the liquidus curves calculated using ideal solution theory. The measured phase diagrams of pentadecylcyclohexane/nonadecylcyclohexane and octadecylcyclohexane/nonadecylcyclohexane binary mixtures are consistent with theoretical phase diagrams constructed based on the assumption that these mixtures form eutectic systems. It was also observed that a metastable phase formed in some binary mixtures of pentadecylcyclohexane/nonadecylcyclohexane under fast cooling conditions. It is hypothesized that this metastable phase recrystallizes into the eutectic phase upon heating.

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The phase equilibria in the system AlVMoO7-V2O5 were investigated over the whole component concentration range up to 1000C. A phase diagram was constructed from the results of DTA and XRD methods.

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