Optimization of Algae Bioreactor Systems for Biofuel Production [Summer 2011]
Dr. Joanne M. Belovich: j.belovich@csuohio.edu (216) 687-3502

Biodiesel is one of the fastest growing renewable fuels in the U.S. It can be used in existing diesel equipment and vehicles and with existing distribution infrastructure. Biodiesel plants rely on feedstock sources such as recycled grease, meat fat, and soybean or canola oil. However, none of these can meet the long-term demand for transportation fuel. Algae has significant promise as a feedstock for biodiesel production, since up to 50% of the algae dry mass can be lipids, the precursor for biodiesel. The cells use CO2 as their carbon source and can be grown in large open ponds, or in photobioreactors, with power plant exhaust as the source of CO2. Algae growth can occur in non-arable lands with minimal freshwater required. One of the major limitations to the cost-effective use of algae for biofuel production is the low algae concentration in the production stream and the high cost of nutrients. We are investigating methods for optimizing biomass and oil productivity while minimizing raw material costs.

Computer-Aided Design of Gravitational Settlers for Bio-fuels Production from Microalgae [Summer 2011]
Dr. Jorge E. Gatica: j.gatica@csuohio.edu (216) 523-7274
and
Dr. Joanne M. Belovich: j.belovich@csuohio.edu (216) 687-3502

There are two major limitations that currently prevent algae from being a biodiesel feedstock. The capital costs associated with the algae cultivation systems, either open ponds or bioreactors, are high, relative to the price of diesel. Even in the best culturing systems, algae concentration will not surpass 20 g/L because of light limitation. The low biomass concentration results in a large amount of water that must be removed before the biomass can be processed into biodiesel. This process of removing the water and concentrating the cells, called the “dewatering” process, is both energy and equipment intensive. The purpose of this research is to optimize the design of gravity settlers for algae dewatering for large-scale biofuel production. The research activities will expose students to both computer simulations and hands-on laboratory work. Finite-Element (FEM) based Computational Fluid Dynamics (CFD) constitute modeling environments well suited to handle complex geometries such as those of gravity settlers. This project is aimed at formulating a FEM CFD model of cell-fluid interactions in the process equipment to simulate dynamic and steady-state particle settling scenarios. The model will be validated and refined using data collected from a laboratory-scale settler prototype. The CFD model is then anticipated to be used in design optimization of pilot-scale configurations and identification of [optimum] operating conditions to maximize equipment performance.

Measurement of Transport Parameters in Bone Tissue [Summer 2011]
Dr. Joanne M. Belovich: j.belovich@csuohio.edu (216) 687-3502

Bone tissue readily forms during skeletal development, juvenile growth, and most adult skeletal repair processes. However, more than one million annual bone injuries in the U.S. require bone grafts to assist in repair and this number is expected to increase as the population ages. The growth of bone tissue in vitro, which mimics in vivo bone in form and function, requires selection of the proper scaffold, cell source, loading environment, and culture conditions, among numerous other factors. Two important features of native bone to be mimicked in tissue-engineered bone are the spatial asymmetry of the tissue and the extracellular matrix (osteoid), and while these have not been replicated in vitro, it is well-known that mechanical loading is vital for osteoid generation. It has been hypothesized that the availability of growth factor molecules in the tissue contributes to the formation of the tissue, supported by observations that mechanical stimulation appears to enhance the transport rates of these molecules. We plan to measure the effective diffusion coefficients of key metabolites such as oxygen and glucose, as well as larger growth factor molecules, in bone tissue. The enhancement of transport of these components by mechanical loading will also be ascertained.

Attachment and Growth of Bone Forming Cells: Influence of Surface Texture [Summer 2011]
Dr. Surendra N. Tewari: s.tewari@csuohio.edu (216) 523-7342
and
Dr. Joanne M. Belovich: j.belovich@csuohio.edu (216) 687-3502

The purpose of this research is to examine the influence of surface textures of Ti-6Al-4V (wt pct.) alloy on the attachment and proliferation behavior of bone forming osteoblast cells. The optimum texture would be the one that demonstrates the highest cell adhesion and proliferation even when it is pre-coated with the non-adhesive proteins. The student will establish an experimental set-up to observe and record in-situ the attachment and proliferation behavior of cells, and carry out the associated experiments. The student should be highly motivated and have strong interest in hands-on bio-chemical experiments in a lab environment.

Characterization of Thermally Responsive Polypeptide Nanoparticles [Summer 2011]
Dr. Nolan B. Holland: n.holland1@csuohio.edu (216) 687-2572

Our lab is working with an interdisciplinary team to characterize a material system that reversibly forms nanoparticles in response to environmental changes. The system has potential for use in numerous practical applications, e.g. as biosensors, drug-delivery vehicles, or viscosity modifiers. The particles are prepared from materials inspired by elastin, a naturally occurring protein. They are biosynthesized in E. coli and can be made to respond to a wide variety of stimuli, including temperature, pH, salt concentration, light, and solvent. We are characterizing the size and shape of the particles and devising methods to control their behavior.

Protein Purification Using an Elastin-like Polypeptide Tag [Summer 2011]
Dr. Nolan B. Holland: n.holland1@csuohio.edu (216) 687-2572

Purification is a critical issue in the preparation of biologically active proteins for use as enzyme catalysts, pharmaceuticals, or biological reagents. Separation of proteins can be performed by utilizing chemical or physical properties of the proteins. An alternative approach tags the product with a fusion protein or polypeptide expressed as part of the protein. The tag can have a high affinity for a specific resin that can be used to bind the protein and after release by some method pure protein is obtained. To remove the tag after purification enzymatic cut sites can be introduced between the tag and the protein to cleave off the tag. We are developing a system that utilizes environmentally responsive polypeptide tags to purify proteins at low cost and under gentle conditions.

Making Responsive Hydrogels from Molecular-Scale Building Blocks
Dr. Nolan B. Holland: n.holland1@csuohio.edu (216) 687-2572

Responsive materials can exhibit drastic changes in their volume and generate force with small environmental changes. The stimulus can be temperature, pH, light, or other solution property. These materials have found applications as biomaterials, drug delivery devices, and in microfluidic devices. The most common materials currently used are randomly cross-linked polymer hydrogels. Their major limitation is their slow response time and limited volume change due to the process of chain aggregation and water transport. The objective of this project is to overcome these limitations by developing molecular scale responsive subunits. These molecular building blocks will be composed of only three polypeptide chains linked together, and will respond to their environment independent of being incorporated in a bulk gel. Because of their organized folded structure, these materials will respond much more quickly and exhibit a greater percent reduction in size than the traditional responsive hydrogels. These benefits should be retained when these building blocks are connected to form larger responsive networks.

Antifreeze Protein Design for More Effective Ice Crystal Growth Inhibition
Dr. Nolan B. Holland: n.holland1@csuohio.edu (216) 687-2572

Antifreeze proteins help organisms that live in cold climates survive freezing temperatures. They function by binding onto specific surfaces of ice crystals, which prevents the crystals from growing. This reduces the temperature at which ice can grow in antifreeze solutions. However, the proteins do not correspondingly reduce the melting temperature of ice, leaving a temperature gap between the melting and freezing point (termed thermal hysteresis) where the ice will neither freeze nor thaw. Within this temperature window, the proteins prevent ice recrystallization, i.e. the growth of large crystals at the expense of smaller ones. Because of this ability to stabilize ice solutions, antifreeze proteins have already found application as a frozen food additive. They also show promise as additives to help extend the storage life of transplant organs or for stabilizing ice slurries to improve efficiency of refrigeration and air conditioning systems. The primary research objective is to design new molecular constructs to increase the efficiency of the antifreeze proteins by as much as 100 times, so that the same activity can be achieved with only a fraction of the protein. This will be accomplished by producing constructs with multiple binding regions to increase the avidity for the ice surface.

Slurry Based Environmental Barrier Coating for Silicon carbide Components [Summer 2011]
Dr. Surendra N. Tewari: s.tewari@csuohio.edu (216) 523-7342

Silicon-based ceramics, such as SiC/SiC composites and monolithic Si 3 N 4 ceramics, are leading candidate materials for next generation gas turbine engine hot section structural components. However, they suffer from rapid surface recession in gas turbine combustion environments due to the volatilization of the silica scale by water vapor. Their use in gas turbine engine applications is not possible without the availability of effective environmental barrier coatings (EBC). Purpose of this research is to develop slurry coating formulations that will provide protection against water-vapor related environmental damage at high temperature.
The student will prepare several rare-earth silicate ceramic slurries and characterize them for the quality of surface coverage. The coated samples will then be sintered at several temperatures to determine an optimum combination of coating composition and heat-treatment that not only covers the silicon-carbide surface, but also adheres to the substrate and does not de-bond during thermal cycling. The ceramic slurry formulations will be sintered at a range of temperature to determine their extent of densification. The coated samples will then be cycled in a controlled environment furnace to determine their resistance to water-vapor corrosion. Microstructure of the coatings will be characterized by optical and scanning electron microscopy. This research will involve mostly hands-on experimental type of activity in the materials processing laboratory in the chemical and biomedical engineering department.

Zeolite Membrane Permeation: Modeling and Validation
Dr. D.B.Shah: d.shah@csuohio.edu (216) 687-3569

Zeolites are crystalline aluminosilicate absorbents that have a distinctly defined pore structure. In comparison to other absorbents in its class (i.e. silica, alumina, or activated carbon), zeolites have pores that are of uniform size and thus show no pore size distribution. As a result of this unique feature, they can be used to separate chemical species based on size, shape, and configuration. In this work, we will investigate the conditions under which a hydrocarbon separation based on molecular size, shape, and adsorptive and diffusive properties can be accomplished.
In the analysis of zeolite diffusion and permeation, a mathematical transport model is required to simulate and fully understand the overall separation process. In this study, a mixture of different components is used as a feed stream. These components diffuse and permeate across a zeolite membrane at different rates. A mathematical model will be used to predict the rates of transport of individual components. The model will require the adsorptive and diffusive properties of these components in the zeolite. The model to be used in this study is based on the Maxwell-Stefan equations and was developed by Krishna [1]. It will be used to simulate the permeation behavior of mixtures. Two separate scenarios associated with weak and strong interactions will be investigated. The simulated results obtained from the solution of the model equations will be compared with those derived from more rigorous calculations. Such calculations will illustrate whether a simplified transport model can be used to simulate permeation of individual components of a hydrocarbon mixture.
References
R. Krishna, R. Baur, Analytic solution of the Maxwell-Stefan equations for multicomponent permeation across a zeolite membrane, Chemical Engineering Journal, 97 (2004) 37-45

Adsorption and Diffusion in Zeolites
Dr. Orhan Talu: o.talu@csuohio.edu (216) 687-3539
and
Dr. D.B.Shah: d.shah@csuohio.edu (216) 687-3569

Zeolites occupy a pre-eminent position as adsorbents and catalysts. To determine the potential of any zeolitic material for an industrial application, its adsorptive and diffusive behavior must be well characterized. Our laboratories possess a number of such systems that allow us to characterize these zeolites in terms of their adsorption capacities and the rate of adsorption. Students participating in this project will gain hands-on experience in measuring adsorption isotherms and diffusivities in zeolites. Appropriate adsorbent-adsorbate systems will be identified and measurements will be performed on such systems.

Reaction Engineering Principles in Thin Film Applications
Characterization of Precursors leading to Protective and Conversion Coatings in Metallic and Ceramic Substrates [Summer 2011]
Dr. Jorge E. Gatica: j.gatica@csuohio.edu (216) 523-7274

Corrosion resistance and energy efficiency have long been driving forces to substitute low-carbon steels by advanced materials in the manufacture of car body parts. Chromate-based coating processes have been used by industry for many years as a means to generate protective coatings on metal surfaces. In order to meet EPA mandates, chromate-based technologies need to be phased out.
In this research we are investigating new approaches in coating technology that could provide alternative practical options to chromate-based coatings. Preliminary research conducted at Cleveland State University has identified metal-working fluids that can provide effective high-temperature wear and friction control as potential precursors for producing thin films in non-ferrous alloys and ceramics. The purpose of this research is to investigate the effect of different intermetallics as additives that can promote the chemical interaction of these precursors with metallic and non-metallic substrates.
Current research activities complement this long-term research project aiming at elucidating the effect of transition metals on mechanisms leading to protective coatings. At present we are focusing our attention on deposition experiments complemented by spectroscopic and calorimetric characterization of precursor solutions and the coatings these solutions yield on aluminum alloys.

Computational Fluid Dynamics of Chemical Vapor Deposition
Analysis and Optimization of Thin Film Deposition Processes by Mathematical Modeling [Summer 2011]
Dr. Jorge E. Gatica: j.gatica@csuohio.edu (216) 523-7274

Chemical Vapor Deposition (CVD) has become an efficient technology for the production of thin films. The analysis of this technology, typically characterized by the potential for high throughput and minimal effluent generation, involves the complex interaction of transport phenomena, fluid dynamics, and chemical kinetics. Moreover, deposition environments often consist of complex assemblies in intricate flow geometries.
Proof-of-concept experiments are currently carried out in laboratory scale in a radiation furnace. Our goal is to design and optimize deposition experiments with the aid of a multi-physics mathematical modeling. With that purpose, a finite-element-based multi-physics modeling environment has been licensed by the Chemical Reaction Engineering (CRE) Group at CSU.
The immediate goal is to integrate this modeling environment with SolidWorks(TM), a CAD software that allows the design of complex three-dimensional structures, such as the deposition stage used in thin films experiments.

Sugar Cane Bio-ethanol Dehydration Assessment including Environmental Issues
Dr. Jorge E. Gatica: j.gatica@csuohio.edu (216) 523-7274

Environmental effects and health hazards posed by fossil-fuel based technologies complemented by changes in the global economy have further demanded the need for developing “cleaner” and more efficient technologies that rely on renewable or synthetic resources. An alternative, commonly referred to as bio-fuels, has significantly matured and today’s economy recognizes the significance of being able to produce ethanol from renewable resources such as biomass. Moreover, the potential of ethanol to be further converted to hydrogen makes it a very attractive alternative to replace or complement fossil fuels as sources of energy.
Though many techniques for ethanol dehydration are known; adsorption, distillation, hybrid processes, and pervaporation, are the most common technologies in practice. Two alternatives ethanol dehydration technologies are considered in this project. The first is based on the combination of distillation and azeotropic distillation, while the second relies on hybrid distillation and pervaporation processes.
Currently we are developing a simulation model (a user-defined module) and the interface that would enable to integrate this module with two popular Porcess Simulators: ASPEN Plus(TM) and ASPEN HYSYS(TM)
The immediate goal is to simulate both alternatives aiming to identify optimal design and operating parameters by means of rigorous simulation. Plans for a second phase include formulating an approach that would account for environmental issues in explicit form. The approach is to be based on Life Cycle Assessment (LCA) as described by the ISO 14000 series. Unlike most common approaches that consider environmental impact by focusing on reducing effluents, this methodology also considers the impact associated with all the involved processes in the FPD. One could consider the addition of environmental aspects within energy systems optimization as a promising contribution to the energetic optimization and LCA.

Remote Access and Control Kits (RACKs) for Laboratory Experiences in Chemical Engineering
Dr. Sridhar Ungarala: s.ungarala@csuohio.edu (216) 687-9368
and
Dr. Jorge E. Gatica:j.gatica@csuohio.edu (216) 523-7274

This project proposes to enhance student learning by means of an approach that combines interactive computer modules, experimental equipment accessed through the Internet, and process design using modern analysis tools. The project is focused on the recommendation by ABET that promotes exposure of engineering majors to laboratory practices, planning of experiments, experimental data acquisition and statistical analysis. The project aims to develop a set of interactive modules that enable remote access of laboratory settings for experiment monitoring, control, and analysis. These modules will be developed using high-end graphics, point-and-click graphical user interfaces and context-sensitive online help.

Formulation and Development of Metabolic Pathways using Parametric Sensitivity Analysis and Thermodynamic Constraints
Dr. Jorge E. Gatica: j.gatica@csuohio.edu (216) 523-7274

In order to understand quantitatively how metabolic processes work, a mechanistic model is often formulated through biochemical mass balances and reaction kinetics. Modeling dynamic phenomena in theses systems typically involve a large number of metabolites and models with several unknown parameters. Due to the difficulty in physically obtaining reaction rate constants for individual biochemical reactions, flux balances and thermodynamic constraints are often employed to reduce the number of unknown parameters. However, for most cases only limited experimental data and physiological trends are available. As a result, the degree of uncertainty in the system parameters will remain too high for a reliable model to be developed. In this research we intend to formulate a systematic parametric sensitivity analysis to identify critical parameters and experiments for modeling metabolic processes. The modeling of a recognized, although not fully characterized yet, metabolic pathway: the astrocyte-neuron lactate shuttle in mammalian brain metabolism, is selected as a case study for this project.