Search results for "cooling rate"
showing 6 items of 26 documents
Comment on "Ecological importance of the thermal emissivity of avian eggshells".
2012
Eggshell emissivity must be known to determine accurately the cooling rate of avian eggs when the parent, after heating by conduction during the incubation, is temporarily absent. We estimate possible values of eggshell emissivities from in-situ measurements and spectral libraries. Emissivity is near to 1 (probably higher than 0.95) and therefore its effect on cooling rate may be negligible, with differences between the temperature of the egg assuming a value of e=0.95 and that of a blackbody (e=1) below 0.2 °C.
Monte Carlo simulation of the glass transition in polymeric systems: Recent developments
1995
Abstract The bond fluctuation model on square and s.c. lattices is used as a coarse-grained model for flexible polymers in dense melts. Using an energy that favours long bonds, a conflict is created between the tendency of the bonds to stretch at low temperatures and packing constraints. This simple concept of ‘geometric frustration’ leads to glass transition. Both static and dynamic properties of this model are investigated by Monte Carlo simulations, paying attention to effects found by varying the cooling rate and the chain length N of the polymers. In two and three spatial dimensions an effective (cooling-rate dependent) glass transition temperature T g can be defined, where the system …
Crystallization Behaviour at High Cooling Rates of Two Polypropylenes
1993
Phase distribution of quenched samples of two isotactic polypropylenes, having different molecular weight distributions, was evaluated by a deconvolution procedure of WAXD spectra. The dependence on cooling rate of the two resins shows the low molecular weights rich polymer is characterized by a faster kinetics with an α-monoclinic to mesomorphic transition taking place at higher cooling rates.
Effect of cooling rate on the viscoelastic properties in the plastic zone of solid polymers
1979
PMMA and PC samples were subjected to several cooling rates from the glass transition temperature.
Crystallization kinetics in relation to polymer processing
1993
Phase distribution of quenched samples has been determined by a deconvolution procedure of WAXS spectra in a wide range of cooling rates. The informations collected together with isothermal and DSC results provide a very wide set of data on the crystallization kinetics of polymers relevant which covers conditions encountered in most polymer processing operations. They have been compared with predictions of a non-isothermal crystallization model assuming two independent and parallel crystallization processes competing during solidification.
Influence of“controlled processing conditions” on the solidification of iPP, PET and PA6
2002
In this work reliable experimental data for three semicrystalline polymers (iPP, PA6, PET) crystallised under pressure and high cooling rates are supplied. These results were achieved on the basis of a model experiment where drastic controlled solidification conditions are applied. The final objective was to quantify the effect of two typical operating conditions (pressure and cooling rate) on the final properties and morphology of the obtained product. The influence of processing conditions on some macroscopically relevant properties, such as density and micro hardness is stressed, together with the influence of processing conditions on the product morphology, investigated by means of Wide…