in this experimental work the pressure induced phase transformation of silicon and germaniumhas been studied. it was shown that at a particular value of applied pressure, (pt), depending on the sampletemperature, the electrical resistance of the specimen falls off to a metallic state. the main goal of this studywas to find out how the phase transformation pressure, pt, for a p-type silicon vari...

in our current study, supercritical water impregnation (scwi) was introduced as a unique catalyst preparation method by employing the high diffusivity property of supercritical water. the method allows nano-particles to place on support surfaces in extremely dispersed conditions. the silica-based nanocatalyst granules for this purpose were prepared by initial impregnation of highly porous silic...

In this study, it was evaluated the capability to generate HYAFF membranes by phase inversion assisted by supercritical fluids. HYAFF is a biopolymer, hyaluronic acid ester, much used in the pharmaceutical and biomedical applications. Several techniques have been tested to generate structures (membranes and scaffolds) for biomedical applications; but, all of them present several limitations. Fo...

Project Goals: We are developing Bacillus megaterium as a host for continuous biofuel production coupled with in situ product extraction by supercritical CO2 (scCO2) stripping. We employ a cross-disciplinary collaborative approach to achieve the following: (1) Develop a supercritical CO2 tolerant strain of B. megaterium into a bioproduction host for biofuels (2) Engineer de novo pathways for bi...

We present here phase equilibria calculations of polyethylene solutions in different solvents as obtained with two versions of the SAFT equation of state, soft-SAFT and PC-SAFT. The objective of this work is twofold: to check the accuracy of the soft-SAFT equation in providing reliable polymer solutions behavior and to propose a methodology from which systematic studies on polymer solutions can...

High pressure vapor-liquid equilibrium (VLE) of CO2-expanded organic solvents is investigated using Peng-Robinson-LCVM-UNIFAC equation of state. Bubble pressure of ten ternary mixtures is predicted using this mixing rule and correlations are developed based only on binary experimental data. Due to the lack of experimental data for liquid phase density in the literature, it was necessary to perf...

We calculate the thermal conductivity of supercritical and liquid carbon dioxide using a recently developed nonequilibrium molecular dynamics (NEMD) algorithm for molecular fluids. We evaluate the translational, rotational, potential energy and force contributions to the heat flux separately. We find that at high density both the rotational contribution for a nonspherical molecule and the contr...

We describe a method, called affinity partitioning, for the purification of proteins containing specific ligand binding receptor sites. This method adds specificity to the procedures for protein purification with aqueous polymer two-phase systems by introduction of a polymer derivative, coupled to an appropriate ligand. The addition of a polymer-ligand that partitions predominantly into one pha...

We synthesized polyethylene (PE), poly(ethylene-co-1-decene), poly(ethyleneco-p-methylstyrene) and poly(ethylene-ter-1-decene-ter-p-methystyrene) using a rac-Et(Ind)2ZrCl2 metallocene catalyst and a methylaluminoxane cocatalyst system. The materials were characterized using nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. We compared and studied the kinetics,...