Peter L. Douglas

Learn More
Statistics-based experimental design was used to investigate the effect of medium components (starch, peptone, ammonium sulfate, yeast extract, and CaCl2.2H2O) on hen's egg white lysozyme production by Aspergillus niger HEWL WT-13-16. A 2(5-1) fractional factorial design augmented with center points revealed that peptone, starch, and ammonium sulfate were(More)
This paper considers the problem of reducing CO2 emissions from a power grid consisting of a variety of power-generating plants: coal, natural gas, nuclear, hydroelectric, and alternative energy. The problem is formulated as a mixed integer linear program (MILP) and implemented in GAMS (General Algebraic Modeling System). Preprocessing and variable(More)
Modified resolution and overall separation factors used to quantify the separation of complex chromatography systems are described. These factors were proven to be applicable to the optimization of amino acid resolution in reverse-phase (RP) HPLC chromatograms. To optimize precolumn derivatization with phenylisothiocyanate, a 2(5-1) fractional factorial(More)
This work proposes a hybrid of stochastic programming (SP) approaches for an optimal midterm refinery planning that addresses three sources f uncertainties: prices of crude oil and saleable products, demands, and yields. An SP technique that utilizes compensating slack variables is mployed to explicitly account for constraints’ violations to increase model(More)
The extraction of nimbin from neem seeds using supercritical carbon dioxide is investigated in this paper. A model that accounts for intraparticle diffusion (De) and external mass transfer of nimbin (kf) is presented for the supercritical extraction process. Mass transfer is based on local equilibrium adsorption between solute (nimbin) and solid (neem(More)
We report a novel dual-lumophore oxygen sensor incorporating two lumophores: (1) the platinum(II) cyclometalated complex of the N^C^N-coordinating ligand 1,3,5-tri-(2-pyridyl)benzene and (2) Platinum octaethylporphyrin, which differ in both their emission colours and oxygen sensitivities. Sensor response is given by a dramatic change in emission colour,(More)
A comprehensive metabolic network comprising three intracellular compartments (cytoplasm, mitochondrion and peroxisome) was developed for Aspergillus niger. The metabolic flux network includes carbohydrate and amino acid metabolism in both anabolic and catabolic reactions. Linear programming was used for the optimization of the specific growth rates in(More)
A stoichiometry-based model for the fed-batch culture of the recombinant bacterium Bacillus subtilis ATCC 6051a, producing extracellular alpha-amylase as a desirable product and proteases as undesirable products, was developed and verified. The model was then used for optimizing the feeding schedule in fed-batch culture. To handle higher-order model(More)
Plug-in hybrid electric vehicles (PHEVs) have a large potential to reduce greenhouse gases emissions and increase fuel economy and fuel flexibility. PHEVs are propelled by the energy from both gasoline and electric power sources. Penetration of PHEVs into the automobile market affects the electrical grid through an increase in electricity demand. This paper(More)
The search for ideal biomaterials is still on-going for tissue regeneration. In this study, blends of poly ε-caprolactone (PCL) with poly l-lactic acid (PLLA), nalidixic acid (NA) and polyethylene glycol (PEG) were prepared. Mechanical and thermal properties of the blends were investigated by tensile and flexural analysis, DSC, TGA, WXRD, MFI, BET, SEM and(More)