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In this study, a new cubic hard sphere equation of state (EOS) was developed from standard classical thermodynamics. The new equation is applied to calculate properties of fluids and vapor-liquid phase equilibrium calculations. The derived equation is a simplified expression of the hard sphere equation which yields satisfactory agreement with the molecular simulation of hard molecule data. The EOS is written in a cubic form by combining the derived repulsive hard spheres with Redlich-Kwong (RK) empirical attractive term. Satisfactory calculated results for the saturated properties of pure fluids for temperature ranges from 303 to 523 K and pressure ranges from 50 to 5000 psi are obtained. Simplicity and generality of this equation combined with reasonable accuracy makes it a useable EOS for almost all areas of equipment design for separation processes and production operations including refinery and petroleum reservoir industries. The accuracy of the predicted properties from the developed EOS are greater than of other commonly used two parameter cubic equations of state, RK and Pang-Robinson (PR).

A simple, consistent, and self-contained error propagation algorithm was developed using the uncertainty information related to pure component physical properties, binary interaction parameters, and thermodynamic model parameters combined with Monte Carlo simulation along with the Latin Hypercube Sampling (LHS) method. This algorithm is generally applicable to simulate the error propagation in process flow sheets of arbitrary complexity as long as the thermodynamic model parameters encode uncertainty information. In this work, two significant problems related to hydrocarbon processing are studied under the light of uncertainty analysis. First, the injection of a valuable liquid hydrocarbon into an existing natural gas pipeline for transportation was studied in order to find the optimum injection rate of liquid n-butane that can be safely added to the flowing gas without undesired condensation. The main factors considered in this calculation are the hydrocarbon dew point, the natural gas physical properties, and conformity to pipeline specifications. Second, uncertainties on Reid vapor pressure (RVP) calculations were taken into account for the calculation of optimal rate of liquid n-butane blending into gasoline. Gasoline blending is an important operation in refineries where gasoline must be produced with enough volatility for the proper operation of engines in cold climates.

Kinetic and structural studies have been carried out on the effects of meso-tetrakis(4-sulfonatophenyl)-porphyrin (H 2 TPPS 4 ) as an anionic and meso-tetrakis(3-N-methyl-pyridyl)porphyrin (H 2 TMPYP) as a cationic porphyrin with adenosine deaminase (ADA) in 25 mM citrate/phosphate buffer, pH = 4-8, at 37 o C using UVvis spectrophotometry, circular dichroism (CD), fluorescence spectrophotometry as well as molecular dynamics (MD) and molecular docking. Kinetic results showed that the two porphyrins are non-competitive inhibitors. Increasing pH, increases K I and cationic porphyrin has a higher K I and lower binding constant (K b ) at all pH ranges. Analyzing the secondary structure revealed that both ligands decrease the secondary structure and that the anionic porphyrin is more effective.