The kinetics of melt crystallization of binary eutectic forming organic mixtures in non-flow systems with cooling from below for the preferential crystallization of one component alone have been studied experimentally. The effect of subcooling, superheating and the initial concentration of the melt on the crystallization kinetics have been studied. Based on the experimental data, a correlation ...

Using the phenol-terminated polycarbonate blend as an example, we demonstrate that the hydrodynamic boundary conditions for a flow of an adsorbing polymer melt are extremely sensitive to the structure of the epitaxial layer. Under shear, the adsorbed parts (chain ends) of the polymer melt move along the equipotential lines of the surface potential whereas the adsorbed additives serve as the sur...

We employ a continuous theory of two-phase flow to investigate the influence of grain boundary tension on distribution and migration of melts through a viscous matrix. The ‘disaggregation melt fraction’, the volume fraction of partial melt at which grain boundaries are completely wetted, is crucial in determining the total interfacial force per unit volume. In partially molten aggregates with s...

In a previous paper we have shown how small-angle neutron and x-ray scattering (SANS, SAXS) can be used to determine the melt compatibility of different polyolefins, including high-density (HD), low-density (LD), and linear low density (LLD) polyethylene. Such blends have attained widespread commercial applications, though the understanding of the mechanical and melt-flow properties of such ble...

[1] Seismic studies repeatedly image a low‐velocity layer overlying the mantle transition zone in tectonic settings ranging from subduction zones to continental cratons. This layer has been hypothesized to result from the presence of a dense partial melt formed by dehydration melting as relatively wet transition zone material is advected by convection currents into the low‐water‐solubility uppe...

Abstract: This paper deals with the control of the melt index and density of polymers produced. Nonlinear Model predictive control (NLMPC) is used for this purpose. A nonlinear reactor model combined with correlations for predicting polymer melt index and density are used to simulate the process. The simulations revealed the effectiveness of NLMPC to drive the polymer properties to follow a ser...

We describe the design and testing of a neural network for chemical process prediction and its use for process optimization. Our objective is to design an improved, robust, accurate, and adaptive model for Resin Melt Index prediction, leading to a better prediction of addition of chain stopper during polymerization. We synthesize a neural network to predict the melt index and optimize the chain...

When a binary alloy is directionally solidified, a two-phase mushy dendritic zone is often formed. Interdendritic convection of the melt may occur, and is coupled with compositional convection of the residual melt. If fluid flow velocities are high enough, local melt-back of the dendrites may occur, leading to channel formation, and thus preferred flow paths. In order to predict the onset of co...

Rates of ice mass loss at the calving margins of tidewater glaciers (frontal ablation rates) are a key uncertainty in sea level rise projections. Measurements are difficult because mass lost is replaced by ice flow at variable rates, and frontal ablation incorporates sub-aerial calving, and submarine melt and calving. Here we derive frontal ablation rates for three dynamically contrasting glaci...

[1] We derived the extent, onset date, end date, and duration of snowmelt in Antarctica from 1978 to 2004 using satellite passive microwave scanning multichannel microwave radiometer (SMMR) and Special Sensor Microwave Imager (SSM/I) data. A wavelettransform-based method was developed to determine and characterize melt occurrences. About 9–12% of the Antarctic surface experiences melt annually....