1,721,070 research outputs found
Fourier Transform Rheology: A New Tool to Characterize Material Properties, Fourier Transforms
No full textOn the choice of the optimal forcing waveform for a biochemical reactor using the pi-criterion
No full textDeterminazione del miglior modello per la descrizione di processi di degradazione biochimica
No full textFourier Transform Rheology as a universal non-linear mechanical characterization of droplet size and interfacial tension of dilute monodisperse emulsions
No full textA new protocol to gain interfacial tension and droplet size of dilute monodisperse emulsions from Fourier Transform Rheology (FTR), is proposed. Specifically, a universal dimensionless quantity E was found at small strain amplitudes to correlate with the droplet size of the emulsion where E is inversely related to the square of the capillary number Ca and directly proportional to the relative intensities of the fifth and third harmonics, I5/I3. The limiting value E0 at small strain deformations can be used as a universal
parameter to calculate different emulsion properties. Different morphological constitutive models for emulsions were used to establish the universality of the parameter E0. Preliminary analysis on experimental data confirms the validity of this approach for the characterization of emulsion properties, including
the estimation of interfacial tension and droplet radius
Fourier Transform Rheology to estimate the drop size distribution of dilute immiscible polymer blends
No full textA Stochastic Formulation for the Prediction of PSD in Crystallization Processes: Comparative Assessment of Alternative Model Formulations
No full textA stochastic formulation for the description of antisolvent mediated crystal growth processes is discussed. In the proposed approach the crystal size growth dynamics is driven by a deterministic growth factor coupled to a stochastic component. The evolution in time of the particle size distribution is then described in terms of a Fokker-Planck equation. In this formulation the specific form of the stochastic model leads to different shapes for the probability density function. I this work we investigate and assess comparatively the performance of the FPE approach to model the crystal size distribution based on different expressions for the stochastic component. In particular, we consider the Langevin equation with a multiplicative noise term that depends on the crystal size (time and space). It is shown and corroborated via experimentation that the best stochastic model is given by the Geometric Brownian Motion (GBM). Excellent quantitative agreement between experiments and the predictions from the FPE- GBM model were obtained for a range of conditions. Validations against experimental data are presented for the NaCl-water-ethanol anti-solvent crystallization system
On the prediction of PSD in antisolvent mediated crystallization processes based on Fokker-Planck equations
No full textA phenomenological model for the description of antisolvent mediated crystal growth processes is presented. The crystal size growth dynamics is supposed to be driven by a deterministic growth factor coupled to a stochastic component. Two different models for the stochastic component are investigated: a Linear and a Geometric Brownian motion terms. The evolution in time of the particle size distribution is then described in terms of the Fokker-Planck equation. Validations against experimental data are presented for the NaCl-water-ethanol anti-solvent crystallization system. It was found that a proper modeling of the stochastic component does have an impact on the model capabilities to fit the experimental data. In particular, the GBM assumption is better suited to describe the antisolvent crystal growth process under examination
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