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Abstract  

In order to identify the kinetic process of self-heating in DSC experiment for Ti+3Al→TiAl3 reaction, two approaches, linear-fitting approach developed from Semenov"s theory of spontaneous ignition and variation of Friedman method, were carried out with cylindrical Ti-75 at% Al samples. Following these approaches, two identical activation energies are obtained as 16915 kJ mol-1 and 1705 kJ mol-1, respectively. Compared with the activation energies of reactions and interdiffusions between Ti and Al, the possible rate-controlling process of self-heating in DSC experiment for Ti+3Al→TiAl3 reaction is the interdiffusion between Ti and Al through TiAl3-layer.

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Journal of Thermal Analysis and Calorimetry
Authors: Abduljelil Iliyas, Kelly Hawboldt, and Faisal Khan

Introduction With safety issues associated with processing, storage, and transportation of sulfide mineral ores/concentrates due to their self-heating propensity in the presence of air, increasing emphasis is placed upon

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Abstract  

It has been shown that the exothermic decomposition of KMnO4 in vacuum is accompanied by a significant self-heating effect. It manifests itself in the reduction of the molar enthalpy of the reaction, determined by the third-law method. In comparison with the value 138.3±0.6 kJ mol−1 that is valid for the decomposition of KMnO4 under atmospheric pressure at 493–553 K, the molar enthalpy in vacuum (10−4-10−7 bar) at 484–511 K varies in the range of 136 to 126 kJ mol−1. This is related to the reduction of the thermal conductivity of residual air in the furnace and, as a result, to the self-heating of the reactant, that accelerates the exothermic reaction. A simple method of evaluation of the self-heating effect has been developed. By analogy with the known method for evaluation of the self-cooling effect, it is based on the determination of the molar enthalpy by the third-law method at two different temperatures. The increase of sample temperature above the furnace temperature Tf in the case of the exothermic decomposition of KMnO4 in a high vacuum and T f≥490 K reaches a few tens of degrees.

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Results of testing the liability of various samples of fertilizer grade ammonium nitrate (AN) to self-heating are presented. Test methods applied comprises: DTA, TG, determination of mass loss at constant temperature, pH-measurement of aqueous solutions. The assessment of liability to self-heating is based on comparison to the relevant results of a standard AN product.

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Metastable effects onmartensitic transformation in SMA

Part 4. Thermomechanical properties of CuAlBe and NiTi observations for dampers in family houses

Journal of Thermal Analysis and Calorimetry
Authors: C. Auguet, A. Isalgué, F. Lovey, F. Martorell, and V. Torra

Abstract  

The behavior of shape memory alloys (SMA) allows their use as a passive smart material. In particular, the existence of a hysteretic cycle in the domain of the elementary coordinates strain-stress-temperature (σ, ε, T) suggests its application for damping in mechanical and/or in civil engineering. We are working in the application of SMA as dampers for earthquakes in small houses as family homes. For dampers installed in the inner porticos of the house, the suggested SMA is the CuAlBe and, eventually, the NiTi. At room temperature the used SMA wires induces forces situated between 2–3kN/wire. The properties related with the damping applications for CuAlBe and NiTi, i.e., the SMA creep and the self-heating will be presented, together with some other minor stress and temperature effects on NiTi modifying the hysteretic behavior.

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Abstract  

This paper explains why directly agitated test cells are sometimes required in order to obtain good adiabatic calorimetry data that can be used with confidence to predict large scale plant behaviour. Experiments for methyl methacrylate polymerisation are reported. Simple procedures are presented for calculating genuine thermo-kinetic parameters from data which includes energy dissipation from the stirrer drive system.

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commercial Sanyo 18650 lithium-ion batteries under adiabatic condition by VSP2 calorimeter method and obtained the essential parameters of thermal hazard via VSP2, such as initial exothermic temperature ( T 0 ), self-heating rate (d T d t −1 ), d P d t −1

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data, such as temperature and pressure traces versus time. A PC-controlled adiabatic calorimeter (VSP2), the well-known turn-on heat-wait-search (H–W-S) mode for detecting the self-heating rate, was adopted for VSP2. Under heating conditions, the main

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temperature ( T 0 ), heat of decomposition (Δ H d ), maximum temperature ( T max ), maximum pressure ( P max ), self-heating rate (d T d t −1 ), pressure rise rate (d P d t −1 ), etc., by using differential scanning calorimetry (DSC) and vent sizing package

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