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Introduction The European Symposium on Thermal Analysis and Calorimetry (ESTAC) owes it origins to a decision by the UK Thermal Methods Group (TMG) to hold an international meeting on thermal analysis in the UK, following a
calorimeter [ 6 ], heat flow or isothermal calorimeters [ 7 – 9 ]. The method of differential scanning calorimetry (DSC) is also applied for determination of the specific heat [ 10 ]. Limitations to the application of DSC method result mostly from difficulties
Abstract
A microcalorimetric method was applied to study microbial soil activity of ornamental flower (Dahlia pinnata) plantations when irrigated with potable water and wastewaters. The samples were irrigated with potable water PW sample (reference) and treated wastewaters from Municipal Wastewater Treatment Station of Asa Norte in Brasilia City (Brazil). Three different water treatments were applied to irrigate soil samples, named TW1, TW2, and TW3 samples. The increase of the microbial soil activity observed in TW1 sample must have occurred because of the high amount of organic waste dissolved in wastewater used for irrigation. This rise indicates that the present treated wastewater can affect natural life cycle. However, only a low alteration in microbial soil activity was observed in the TW2 and TW3 samples, which suggests that these wastewater treatments can be normally used to irrigate soils without bringing environmental consequences, once they offer a great opportunity to upgrade and protect the environment.
key role in the hydration of PC/CAC mixtures, and especially affect the formation of ettringite. Calorimetry shows that without calcium aluminate addition, the second exothermic peak appears almost 50 h later than that of
Abstract
Calorimetry deals with the energetics of atoms, molecules, and phases and can be used to gather experimental details about one of the two roots of our knowledge about matter. The other root is structural science. Both are understood from the microscopic to the macroscopic scale, but the effort to learn about calorimetry has lagged behind structural science. Although equilibrium thermodynamics is well known, one has learned in the past little about metastable and unstable states. Similarly, Dalton made early progress to describe phases as aggregates of molecules. The existence of macromolecules that consist of as many atoms as are needed to establish a phase have led, however, to confusion between colloids (collections of microphases) and macromolecules which may participate in several micro- or nanophases. This fact that macromolecules can be as large or larger than phases was first established by Staudinger as late as 1920. Both fields, calorimetry and macromolecular science, found many solutions for the understanding of metastable and unstable states. The learning of modern solutions to the problems of materials characterization by calorimetry is the topic of this paper.
Modulated differential scanning calorimetry
III. Applications to measurements of the glass transition temperature and increment of heat capacity
Abstract
Modulated-temperature differential scanning calorimetry was used to measure the glass transition temperature,T g, the heat capacity relaxation in the glassy state and the increment of heat capacity, δCp, in the glass transition region for several polymers. The differential of heat capacity with respect to temperature was used to analyseT g and δCp simply and accurately. These measurements are not affected by complex thermal histories.
Modulated differential scanning calorimetry
Transitions between monotropic and enantiotropic phases of a cholesteric liquid crystal
The Modulated Differential Calorimetry (MDSC) is applied to the determination of the reversibility in the cholesteryl chloride, which presents a cholesteric monotropic phase between the isotropic and crystalline states. The experimental modulation parameters that govern this method i.e. frequency, amplitude and heating/cooling rate, are determined. MDSC curves and complementary thermomicroscopical observations assign melting, crystallization and liquid cholesteric transition as ‘non reversing’, and clarification as ‘reversing’.
Introduction Differential scanning calorimetry (DSC) is extensively used in chemistry and physics to analyze, e.g. phase transitions of different compounds [ 1 , 2 ]. Recently this technique has been used with increasing
Pulsed bed calorimetry
A jump in speed and sensitivity
Abstract
Conventional calorimetry has always the difficulty of choosing between near to equilibrium working conditions and high thermal ramp rates. Thus, either the transport phenomena and sample homogeneities are good but the signals become weak due to thermal losses, or the signals are sharp, but strong gradients across the sample lead to chemical and thermal heterogeneities. The described pulsed fluidized bed technique, by strongly stirring the sample, allows good sample homogeneities even at high ramp rates. Moreover, the permanently regenerated cover gas allows as well a good heat transfer towards the thermocouples as a constant atmosphere composition leading to very precise onset temperatures.
explained. Aims The aim of this study is to investigate fireline intensity at the laboratory scale by means of oxygen consumption (OC) calorimetry and to test Byram’s formulation. Effective heat of combustion and combustion
