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Full-Text Articles in Membrane Science

Optimizing Membrane Distillation With Solar Thermal Collectors, Andrew Mason, Ben Shulders, Siamak Nejati Sep 2020

Optimizing Membrane Distillation With Solar Thermal Collectors, Andrew Mason, Ben Shulders, Siamak Nejati

UCARE Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination including 100% rejection of solute (salt, heavy metals, etc.) and mergeability with other affordable energy sources (solar heat, electric resistance, etc.) However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar‐assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits the low cost of water production in comparison …


Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani Oct 2017

Hybrid Polymer Electrolyte For Lithium-Oxygen Battery Application, Amir Chamaani

FIU Electronic Theses and Dissertations

The transition from fossil fuels to renewable resources has created more demand for energy storage devices. Lithium-oxygen (Li-O2) batteries have attracted much attention due to their high theoretical energy densities. They, however, are still in their infancy and several fundamental challenges remain to be addressed. Advanced analytical techniques have revealed that all components of a Li-O2 battery undergo undesirable degradation during discharge/charge cycling, contributing to reduced cyclability. Despite many attempts to minimize the anode and cathode degradation, the electrolyte remains as the leading cause for rapid capacity fading and poor cyclability in Li-O2 batteries. In this …


Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, Ruichang Xiong, Rebecca L. Empting, Ian C. Morris, David J. Keffer Nov 2009

Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, Ruichang Xiong, Rebecca L. Empting, Ian C. Morris, David J. Keffer

Faculty Publications and Other Works -- Chemical and Biomolecular Engineering

Molecular dynamics (MD) simulations of a Lennard–Jones fluid in an inhomogeneous external field generate steady-state profiles of density and pressure with nanoscopic heterogeneities. The continuum level of mass, momentum, and energy transport balances is capable of reproducing the MD profiles only when the equation of state for pressure as a function of density is extracted directly from the molecular level of description. We show that the density profile resulting from simulation is consistent with both a molecular-level theoretical prediction from statistical mechanics as well as the solution of the continuum-level set of differential equations describing the conservation of mass and …


Energetic And Entropic Elasticity Of Nonisothermal Flowing Polymers: Experiment, Theory, And Simulation, T. C. Ionescu, B. J. Edwards, David Keffer, V. G. Mavrantzas Jan 2008

Energetic And Entropic Elasticity Of Nonisothermal Flowing Polymers: Experiment, Theory, And Simulation, T. C. Ionescu, B. J. Edwards, David Keffer, V. G. Mavrantzas

Faculty Publications and Other Works -- Chemical and Biomolecular Engineering

The thermodynamical aspects of polymeric liquids subjected to nonisothermal flow are examined from the complementary perspectives of theory, experiment, and simulation. In particular, attention is paid to the energetic effects, in addition to the entropic ones, that occur under conditions of extreme deformation. Comparisons of experimental measurements of the temperature rise generated under elongational flow at high strain rates with macroscopic finite element simulations offer clear evidence of the persistence and importance of energetic effects under severe deformation. The performance of various forms of the temperature equation are evaluated with regard to experiment, and it is concluded that the standard …


Transport Analysis And Model For The Performance Of An Ultrasonically Enhanced Filtration Process, Michael T. Grossner, Joanne M. Belovich, Donald L. Feke Jun 2005

Transport Analysis And Model For The Performance Of An Ultrasonically Enhanced Filtration Process, Michael T. Grossner, Joanne M. Belovich, Donald L. Feke

Chemical & Biomedical Engineering Faculty Publications

This paper presents an analysis of a filtration technique that uses ultrasound to aid the collection of small particles (tens of microns in diameter) from suspension. In this method, particles are retained within a porous mesh that is subjected to a resonant ultrasonic field, even though the pore size of the mesh is two orders of magnitude greater than the particle diameter. The role of acoustic forces in driving the retention phenomena has previously been studied on a micro-scale, which included modeling and experimental verification of particle motion and trapping near a single element of the mesh. Here, we build …


Diffusivities Of N-Alkanes In Silicalite By Steady-State Single-Crystal Membrane Technique, Orhan Talu, Matthew S. Sun, Dhananjai B. Shah Mar 1998

Diffusivities Of N-Alkanes In Silicalite By Steady-State Single-Crystal Membrane Technique, Orhan Talu, Matthew S. Sun, Dhananjai B. Shah

Chemical & Biomedical Engineering Faculty Publications

A novel experimental technique that measures the diffusive flux through a single-crystal membrane (SCM) was developed and tested. Unlike all other macroscopic techniques that depend on a transient response, SCM is used under steady-state conditions, which results in a wide range of applicability from 10−2 to 10−11 cm2/s. Phenomenological equations for the steady-state data analysis were developed. The variation of driving force over the diffusion path is included in the model. As required by thermodynamics, the micropore concentration is given as a function of surface-excess amount adsorbed and gas density. The membrane configuration measures diffusivity in …