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Melting Range (melting + range)
Selected AbstractsSpeciation of zinc in secondary fly ashes of municipal solid waste at high temperaturesJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2009Meijuan Yu The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273,K, 1423,K and 1523,K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. [source] FTIR Microanalysis and Phase Behaviour of Ethylene/1-Hexene Random CopolymersMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 14 2007Mariano Pracella Abstract Ethylene/1-hexene random copolymers with 1-hexene content in the range of 1,5 mol-%, synthesised in the presence of new heterogeneous catalyst systems based on bis-carboxylato and -bis-chloro-carboxylato titanium chelate complexes, have been characterised by FTIR microspectroscopy (FTIR-M), DSC calorimetry and X-ray scattering. The co-monomer content and sequence distribution in the various samples were determined by means of both FTIR-M and 13C NMR spectroscopy. The deformation bands of methyl groups in the region of 1,400,1,330 cm,1 were used for the structural analysis of these copolymers. The effect of composition on the crystallinity and phase transitions of copolymers was analysed both in 1,500,1,300 and 760,690 cm,1 frequency ranges as a function of the annealing temperature. A neat variation of the absorbance ratio of methyl band at 1,378 cm,1 was recorded between 110 and 130,°C corresponding to the melting range of the copolymer crystals. The crystallisation behaviour of the copolymers was examined by DSC in dynamic and isothermal conditions; the isothermal kinetics were analysed according to the Avrami model. A marked decrease in the bulk crystallisation rate, accompanied by changes in the nucleation and growth of crystals, was found with an increase in the co-monomer content. The melting behaviour of isothermally crystallised samples was also investigated and the melting temperatures of the copolymers at equilibrium conditions were related to the composition; the experimental data were consistent with the Flory exclusion model of side branches from the crystalline phase. The lowering of crystal growth rate in the copolymers has been accounted for by an increase in the free energy of formation of critical size nuclei due to the effect of the side branches. [source] High-Temperature Crystalline Phases in Nylon 6/Clay NanocompositesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 13 2005Xiaohui Liu Abstract Summary: Nylon 6/clay nanocomposites (N6CN) with different cooling histories were investigated by differential scanning calorimetry (DSC) and variable-temperature X-ray diffraction (XRD). Above the melting temperature, new endothermic peaks appeared in the DSC trace for N6CN. All the neat nylon 6 samples presented amorphous XRD patterns when heated up to the melting range. However, for N6CN samples, undefined crystalline structures remained in the substantially molten polymer matrix up to 300,°C. XRD patterns of a quenched nylon 6 sample annealed at 210,°C and N6CN samples annealed at 210, 230, and 300,°C, respectively. [source] Polymer Morphology: A Guide to Macromolecular Self-OrganizationMACROMOLECULAR SYMPOSIA, Issue 1 2004D.C. Bassett Abstract The study of polymer morphology continues to be the principal means of acquiring knowledge and understanding of macromolecular self-organization. Longstanding problems of the nature of melt-crystallized lamellae and spherulitic growth have been resolved, bringing understanding of how characteristic properties such as a broad melting range and spatially-varying mechanical response are inherent in spherulitic morphologies. This reflects the distinctive features of the crystallization of long molecules, i.e. that they impede each other and, for faster growth, form rough basal surfaces. Knowledge of morphology is an essential accompaniment to the informed development of advanced polymeric materials and a full understanding of their structure/property relations. [source] Thermoaktive Bauteilsysteme mit integrierten Phasenwechselmaterialien , eine SimulationsstudieBAUPHYSIK, Issue 1 2007Doreen Kalz Dipl.-Ing. Gegenstand der vorliegenden Arbeit ist die Analyse und Evaluierung von thermoaktiven Bauteilsystemen (TABS) und einem Nachtlüftungskonzept hinsichtlich des thermischen Raumkomforts auf Grundlage einer modellbasierten Simulationsstudie. Das Gebäude- und Anlagenmodell wurde in der Simulationsumgebung ESP-r mit Meßdaten aus Experimenten in einem Niedrigenergie-Bürogebäude validiert. Die Untersuchung umfaßt: Betonkerntemperierung (BKT), Kapillarrohrmatten ohne und mit 20% mikroverkapselten latenten Wärmespeichermaterialien (PCM) im Deckenputz. Zentrale Ergebnisse sind: Die Konditionierung mit Kapillarrohrmatten ermöglicht ein zufrieden stellendes Raumklima vergleichbar mit BKT, die Verwendung von PCM trägt entscheidend zur Reduzierung der Raumtemperaturen bei und der optimale Schmelzbereich des PCM-Speichers liegt in dieser Untersuchung bei 19 bis 22 °C. Thermo-active building systems using phase-change materials , a simulation study. The objective of this study aims at analyzing and evaluating thermo-active building systems as well as a night ventilation concept with respect to thermal interior comfort by means of a simulation study. Preliminary experiments in a low-energy office building facilitate the calibration of the simulation model in ESP-r. In particular, the analysis was carried out for (i) concrete core conditioning, (ii) grid conditioning without and (iii) with 20% of micro-encapsulated latent heat storage materials (PCM) applied to the ceiling. The central conclusions of this study are: (1) Grid conditioning provides a satisfactory room condition comparable with concrete core conditioning, (2) the application of PCM contributes to a reduced operative room temperature, and (3) in this study PCM with a melting range of 19 to 22 °C is most favorable. [source] | ||||||||||