Authors:L. Pérez-Maqueda, V. Balek, J. Poyato, J. Pérez-Rodríquez, J. Šubrt, I. Bountsewa, I. Beckman, and Z. Málek
Emanation thermal analysis (ETA), thermogravimetry, DTA and XRD were used in thermal characterization of natural vermiculite
(Santa Olalla, Huelva, Spain) and of Na+- and - exchanged vermiculite samples during heating in air in the range 25-1100C. A good agreement between the results of
these methods was found. Changes in the radon release rate measured by ETA, which reflected the decrease and collapse of the
interlayer space after the release of water as well as the formation of new crystalline phases were evaluated using a mathematical
model. The model used for the evaluation was found suitable for the quantitative characterization of microstructure changes
during in situ conditions of heating of vermiculite samples.
Authors:D Montecchio, O Francioso, P Carletti, D Pizzeghello, S Chersich, F Previtali, and S Nardi
acids (HAs) extracted from soils developed under two Norwegian spruce (Picea
abies, (L.) Karst) subalpine forests of northern Italy were characterized
using chemical, thermal (TG-DTA) and spectroscopic (DRIFT) analyses. The samples
were taken from five sites which differed in orientation (northern and southern
exposure) and vegetal cover at different old age: grassland, regeneration,
immature and mature stands. In general, the thermal patterns of HAs were similar
(three exothermic reactions appeared around at 300, 400 and 500C) in
both sites in grasslands and regeneration while a considerable modification
appeared in HA from stands of different age at northern and southern exposure
site. DRIFT spectroscopy confirmed the differences observed through TG-DTA
analysis. In particular the main structural changes were ascribed to modification
of carbonyl group and of CH stretching in aliphatic components in each HAs
from different sites.
Reaction kinetics of the formation of TiC by calciothermic reduction of TiO2 in presence of carbon have been investigated using thermal analysis (TG-DTA) of a powder mixture of TiO2, Ca, and C in argon atmosphere at different heating rates. Both the reaction initiation and the peak temperatures are found
to increase with heating rates. The appearance of exothermic peaks in the DTA plots after Ca melting indicates the reduction
of TiO2 by liquid calcium and formation of TiC by in-situ reaction of Ti with C. The apparent activation energy of the process has
been found to be 170.80.5 kJ mol-1.
simultaneous thermogravimetry and differential thermalanalysis (TG–DTA) systems. The experiments were carried out with ~10 mg, crude oil-limestone sample (15 wt% crude oil in the mixture) at 10 °C/min heating rate. Air flow rate through the sample pan was kept
Authors:Rodica Olar, Andreea Dogaru, Dana Marinescu, and Mihaela Badea
mode for biguanide derivatives.
Thermalanalysis (TG, DTA) of these complexes confirms the complexes composition and allows the number and nature of the water molecules determination. It was also evidenced that the intermediate steps correspond
Authors:XiuYan Wang, JieMin Liu, QiShan Yang, Jian Du, FengE Wang, and Wu Tao
weight and enthalpy during reaction were obvious [ 10 – 15 ].
In this paper, the thermogravimetry–differential thermalanalysis (TG–DTA) and Fourier transform infrared spectroscopy (FTIR) were used to real time monitor the reaction process of
Authors:Maurizio Ferrante, Morena Petrini, Paolo Trentini, and Giuseppe Spoto
the thermalanalysis (TG-DTA) the light-curing composites polymerization quality (monomer/polymer), carried out at different times and distances of irradiation (0–8 mm; 20–60 s).
Materials and methods
The materials used were
Authors:Mihaela Badea, Rodica Olar, Valentina Uivarosi, Dana Marinescu, Victoria Aldea, Stefania Felicia Barbuceanu, and George Mihai Nitulescu
square-pyramidal stereochemistry for metallic ion was proposed based on the electronic spectra, while the IR spectra features indicated a chelate coordination mode of flavones.
Thermalanalysis (TG, DTA) of these complexes elucidated the
Authors:P. R. Dametto, F. J. Caires, B. Ambrozini, and M. Ionashiro
and differential thermalanalysis (TG-DTA), differential scanning calorimetry (DSC) and TG coupled to FTIR.
The folic acid (C 19 H 19 N 7 O 6 ) with 99% purity was obtained from Aldrich. Aqueous solution of Na 2
Authors:Mihaela Badea, Rodica Olar, Valentina Uivarosi, Dana Marinescu, and Victoria Aldea
synthesised and characterised. Spectral data indicate a square pyramidal stereochemistry for complexes and a chelate coordination mode for flavonoid molecules.
Thermalanalysis (TG, DTA) of these complexes confirms the complexes composition and allows