Designing A Cost Effective Microalgae Harvesting Strategy For Biodiesel Production With Electrocoagulation And Dissolved Air Flotation,
2013
Louisiana State University and Agricultural and Mechanical College
Designing A Cost Effective Microalgae Harvesting Strategy For Biodiesel Production With Electrocoagulation And Dissolved Air Flotation, Adam James Dassey
LSU Doctoral Dissertations
Microalgal harvesting strategies for biodiesel production have been a major setback in the industry with high energy estimates of $3400/ton biomass by centrifugation. The present study utilized effective mass and energy balances to reduce these large operating costs. The energy for Stage 1 centrifugation was reduced by 82% when harvesting 28.5% of biomass at 18 L/min as opposed to 95% harvesting at 1 L/min. This strategy was further confirmed using electrocoagulation (EC) with Nannochloris and Dunaliella algae with perforated aluminum and iron electrodes at low (< 6 mg/L) metal ion concentrations. Despite 20% lower harvesting efficiencies, the iron electrodes were more energy and cost efficient with operating costs less than $0.03/L oil when flocculating and settling Nannochloris and Dunaliella cultures. Furthermore, a continuous multistage algae harvester using EC and dissolved air flotation (DAF) for Stage 1 harvesting and centrifugation for Stage 2 dewatering was designed. It was determined throughout the testing that greater EC costs for improved harvesting efficiencies were necessary to offset the large energy requirements of the DAF. The multistage system dewatered a low density (100 mg/L) Nannochloris to 20% solids for a final energy requirement of 1.536 kWh/kg algae ($138/ton). Using the data collected from this research and existing literature, a life cycle analysis was assembled to judge the sustainability of microalgal biofuels in Louisiana. High and low energy estimates for culturing (mixing, CO2, nutrients), harvesting, lipid extraction and energy conversion were compared with the current research. Scaling the EC/DAF system for a full size facility was expected to reduce the harvesting costs to 1.133 kWh/kg algae, resulting as $0.44/L oil for a culture with 20% lipids. Despite this improvement in harvesting costs, the production of algal for the sole purpose of biodiesel was not economically viable. Considering a system with a growth rate of 15 g/m2/day and lipid content of 20%, the energy inputs exceeded the outputs from biodiesel production by 36% under the most ideal conditions. However, incorporating additional revenue through wastewater treatment and biogas production from residual biomass could improve sustainability and profitability of algal biodiesel to an 18.5% energy surplus at its current state.
Geodatabase-Assisted Storm Surge Modeling,
2013
Louisiana State University and Agricultural and Mechanical College
Geodatabase-Assisted Storm Surge Modeling, Sait Ahmet Binselam
LSU Doctoral Dissertations
Tropical cyclone-generated storm surge frequently causes catastrophic damage in communities along the Gulf of Mexico. The prediction of landfalling or hypothetical storm surge magnitudes in U.S. Gulf Coast regions remains problematic, in part, because of the dearth of historic event parameter data, including accurate records of storm surge magnitude (elevation) at locations along the coast from hurricanes. While detailed historical records exist that describe hurricane tracks, these data have rarely been correlated with the resulting storm surge, limiting our ability to make statistical inferences, which are needed to fully understand the vulnerability of the U.S. Gulf Coast to hurricane-induced storm …
A Metaheuristic-Based Simulation Optimization Framework For Supply Chain Inventory Management Under Uncertainty,
2013
Louisiana State University and Agricultural and Mechanical College
A Metaheuristic-Based Simulation Optimization Framework For Supply Chain Inventory Management Under Uncertainty, Qinglin Duan
LSU Doctoral Dissertations
The need for inventory control models for practical real-world applications is growing with the global expansion of supply chains. The widely used traditional optimization procedures usually require an explicit mathematical model formulated based on some assumptions. The validity of such models and approaches for real world applications depend greatly upon whether the assumptions made match closely with the reality. The use of meta-heuristics, as opposed to a traditional method, does not require such assumptions and has allowed more realistic modeling of the inventory control system and its solution. In this dissertation, a metaheuristic-based simulation optimization framework is developed for supply …
Roles Of Compressive Residual Stress In Enhancing The Corrosion Resistance Of Nano Nitride Composite Coatings On Steel,
2013
Edith Cowan University
Roles Of Compressive Residual Stress In Enhancing The Corrosion Resistance Of Nano Nitride Composite Coatings On Steel, Xiaoli Zhao, Paul Munroe, Daryoush Habibi, Zonghan Xie
Research outputs 2013
Nanocomposite coatings were synthesized, and subsequently annealed, in an attempt to understand the influence of residual stress upon their resistance to corrosion under acidic attack. Pitting corrosion, originating from microscopic coating defects, was commonly identified in the coatings subject to annealing. Finite element analysis was used to map the residual stress distribution adjacent to these defects and quantify resulting geometrical changes. The results show that with the presence of compressive residual stress in the coatings, corrosion-initiated cracking along weak interfaces was suppressed, and structural integrity maintained. Moreover, compressive residual stress helped constrict pre-existing structural defects in columnar-structured coatings and, in …
Use Of Comsol Simulation For Undergraduate Fluid Dynamics Course,
2013
Andrews University
Use Of Comsol Simulation For Undergraduate Fluid Dynamics Course, Hyun J. Kwon
Faculty Publications
The COMSOL software was used to introduce CFD and teach fluid dynamics more effectively. Introduction of CFD has become an important part of fluid dynamics in recent years; however, undergraduate students have less access to practical exposure to it, unless they take additional elective courses which are seldom offered in undergrad predominant institutes. Simulation has become an essential step in designing and optimizing process in many engineering problems. Therefore, the COMSOL simulation project was assigned to undergraduate CFD as a part of their term project to enhance their exposure to simulation software and help understanding the use of simulation on …
Optimizing Light Requirements And Dilution Rates For Maximizing Algal Cell Growth And Lipid Content For Biofuel Feedstock Production,
2013
Louisiana State University and Agricultural and Mechanical College
Optimizing Light Requirements And Dilution Rates For Maximizing Algal Cell Growth And Lipid Content For Biofuel Feedstock Production, Beatrice Gabriela Terigar
LSU Doctoral Dissertations
There is a rapidly growing interest in the potential of microalgae as feedstock for the next generation of biofuels. The current study was designed to meet the following objectives: (1) Investigate the interdependence among cell density, biomass and lipid productivity to maximize feedstock production from outdoor cultures; (2) Investigate the effect of cycling high-intensity lights to identify optimum Dark:Light (D/L) ratios, which can be effectively used by researchers to maximize aerial biomass productivities; (3) Develop a deterministic model to simulate the biomass productivity in an continuous-flow bioreactor at various hydraulic retention times. Results indicated that variation in HRTs has a …
Variability And Characteristics Of Recycled Asphalt Shingles Sampled From Different Sources,
2013
Louisiana State University and Agricultural and Mechanical College
Variability And Characteristics Of Recycled Asphalt Shingles Sampled From Different Sources, Aaron Lodge
LSU Master's Theses
Recent literature studies have demonstrated depletion in natural resources; therefore, making resources needed for the pavement industry is more costly. There is a need to minimize cost and to try to reduce the depletion of natural resources. While the recycling of asphalt shingles is beneficial in reducing the consumption of virgin materials, pavement performance should not be compromised. One major concern with recycled asphalt shingles (RAS) relates to the variability in the properties of the recycled materials originating from different sources. In addition, the rheological properties of RAS have not been evaluated as well as its influence on the virgin …
Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst,
2012
Shanghai Advanced Research Institute, Chinese Academy of Sciences (CAS), Shanghai 201210, China;Graduate School of the CAS, Beijing 100039, China;
Electrocatalytic Oxidation Of Formic Acid On Pd/Ni Heterostructured Catalyst, Mingjun Ren, Liangliang Zou, Ju Chen, Ting Yuan, Qinghong Huang, Haifeng Zhang, Hui Yang, Songlin Feng
Journal of Electrochemistry
A Pd/Ni bimetallic nanostructured electrocatalyst was fabricated via a two-step reduction route. Owing to an epitaxial growth of Pd atoms on the surface of Ni nanoparticles, heterostructured Pd/Ni nanocomposites were formed and verified by high resolution transmission electron microscopy combined with energy-dispersion X-ray spectroscopy. X-ray diffraction confirmed that the as-prepared Pd/Ni nanocomposites possessed a single face-centered-cubic (fcc) Pd structure, probably due to a weaker diffraction intensity of metallic Ni and/or overlapping by that of Pd. The intrinsic catalytic activity on the Pd/Ni is higher than that on the Pd. Moreover, the durability of formic acid oxidation on the Pd/Ni was …
Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors,
2012
Department of Chemical and Environmental Engineering, and Energy and Sustainability Research Division, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK;
Electrochemical Performance Of Screen-Printed Composite Coatings Of Conducting Polymers And Carbon Nanotubes On Titanium Bipolar Plates In Aqueous Asymmetrical Supercapacitors, Xiaohang Zhou, George Z. Chen
Journal of Electrochemistry
Composites of conducting polymers (polypyrrole and polyaniline) with acid treated multi-walled carbon nanotubes were formulated into printable aqueous inks, with the aid of functional additives (benzethonium chloride as a surfactant with or without polyvinyl alcohol as a binder). The inks were screen-printed as fairly uniform coatings of various mass loading densities and areas (up to 75 mg cm-2 and 100 cm2) on thin titanium plates (0.1 mm in thickness). These screen-printed plates were used to fabricate both unit cell and multi-cell stack of asymmetrical supercapacitors with screen-printed negative electrodes of activated carbon (pigment black) in aqueous electrolytes …
Advances And Challenges Of Intermediate Temperature Solid Oxide Fuel Cells: A Concise Review,
2012
Fuels and Energy Technology Institute and Department of Chemical Engineering Curtin University, Perth, WA 6102, Australia;
Advances And Challenges Of Intermediate Temperature Solid Oxide Fuel Cells: A Concise Review, Sanping Jiang
Journal of Electrochemistry
Fuel cell is an electrochemical energy conversion device to directly convert the chemical energy of fuels to electricity. Among all types of fuel cells, solid oxide fuel cells (SOFCs) operating at intermediate temperatures of 600~800 oC offer an attractive option that is much more fuel flexible than low temperature fuel cells such as proton exchange membrane fuel cells, and is suitable for a wide range of applications. However, two main challenges remain towards the commercial viability and acceptance of the SOFC technologies: the cost and durability. Both are critically dependent on the process, fabrication, performance, chemical and microstructural stability …
Electrocatalytic Activity Of Palladium Nanocatalysts Supported On Carbon Nanoparticles In Formic Acid Oxidation,
2012
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States;State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China;
Electrocatalytic Activity Of Palladium Nanocatalysts Supported On Carbon Nanoparticles In Formic Acid Oxidation, Jie Huang, Zhiyou Zhou, Yang Song, Xiongwu Kang, Ke Liu, Wancheng Zhou, Shaowei Chen
Journal of Electrochemistry
Palladium nanostructures were deposited onto carbon nanoparticle surface by a chemical reduction method. Transmission electron microscopic studies showed that whereas the resulting metal-carbon (Pd-CNP) nanocomposites exhibited a diameter of 20 to 30 nm, the metal components actually showed a cauliflower-like surface morphology that consisted of numerous smaller Pd nanoparticles (3 to 8 nm). Electrochemical studies showed that the effective surface area of the Pd-CNP nanoparticles was about 40% less than that of Pd black, possibly because the Pd nanoparticles were coated with a layer of carbon nanoparticles; yet, the Pd-CNP nanocomposites exhibited marked enhancement of the electrocatalytic activity in formic …
Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur,
2012
Department of Chemistry & Biochemistry, Miami University, Oxford, OH 45056, USA;
Adsorption And Electrooxidation Of Carbon Monoxide On Platinum Surfaces Modified With Sulfur, A. Mattox Mathew, W. Henney Matthew, Johnson Adam, Zou Shouzhong
Journal of Electrochemistry
Adsorbed sulfur is commonly considered as a reaction poison. However, small amounts of sulfur on platinum significantly increase the surface reactivity toward carbon monoxide (CO) electrooxidation. For the solution CO oxidation, the onset potential was shifted up to over 300 mV negative to that on S-free surface, and the extent of the negative potential shift increases with the sulfur coverage (Xs) up to about 0.6. The enhanced CO oxidation also depends on the solution pH. For the adsorbed CO, at low sulfur coverages (Xs < 0.3), the oxidation peak potential is about 40 mV negative to that of the corresponding clean Pt. However, at higher coverages, the peak potential is about 30 mV more positive. Surface-enhanced Raman spectra show that the adsorption of sulfur significantly redshifts the Pt-CO stretching frequency. These observations are explained by the weakening of the Pt-CO bond and the hindrance of CO diffusion by Sads.
Kinetic Study Of Photoelectrochemical Oxidation Of Lignin Model Compounds On Tio2 Nanotubes,
2012
Department of Chemistry, Lakehead University, 955 Oliver Road, Thunder Bay, Ontario P7B 5E1, Canada;
Kinetic Study Of Photoelectrochemical Oxidation Of Lignin Model Compounds On Tio2 Nanotubes, Min Tian, Daniel Liba, Aicheng Chen
Journal of Electrochemistry
In this study, TiO2 nanotubes were prepared via the electrochemical oxidation of titanium substrates in a non-aqueous electrolyte and their morphology and microstructures were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The photoelectrochemical oxidation of two lignin model compounds, 1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanediol (DMP) and 3-hydroxy-1-(3,4-dimethoxyphenoxy)-2-(2-methoxyphenoxy)-1,3-propanone (HDM), was investigated. A new band appeared at ~304 nm during the photoelectrochemical oxidation of DMP. The rate of DMP intermediate formation was amplified with the increase of initial concentrations, while it was diminished with increased temperature. Despite the similarity in structure between HDM and DMP, there are only small increases in absorbance …
Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction,
2012
Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902, USA;
Ternary Alloy Electrocatalysts For Oxygen Reduction Reaction, Jin Luo, Lefu Yang, Binghui Chen, Chuanjian Zhong
Journal of Electrochemistry
Proton exchange membrane fuel cell represents an important electrochemical energy conversion device with many attractive features in terms of efficiency of energy conversion and minimization of environmental pollution. However, the large overpotential for oxygen reduction reaction at the cathode and the low activity, poor durability and high cost of platinum-based catalysts in the fuel cells constitute a focal point of major barriers to the commercialization of fuel cells. The development of nanostructured catalysts shows promises to addresses some of the challenging problems. The ability to engineer the composition and nanostructure of nanoalloy catalysts is important for developing active, robust and …
Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell,
2012
California Polytechnic State University, San Luis Obispo
Quantum Dot Deposition Into Pdms And Application Onto A Solar Cell, Christopher Marcus Botros, Richard N. Savage
Master's Theses
Research to increase the efficiency of conventional solar cells is constantly underway. The goal of this work is to increase the efficiency of conventional solar cells by incorporating quantum dot (QD) nanoparticles in the absorption mechanism. The strategy is to have the QDs absorb UV and fluoresce photons in the visible region that are more readily absorbed by the cells. The outcome is that the cells have more visible photons to absorb and have increased power output. The QDs, having a CdSe core and a ZnS shell, were applied to the solar cells as follows. First, the QDs were synthesized …
An Experimental Investigation On The Trailing Edge Cooling Of Turbine Blades,
2012
Wright State University - Main Campus
An Experimental Investigation On The Trailing Edge Cooling Of Turbine Blades, Zifeng Yang, Hui Hu
Mechanical and Materials Engineering Faculty Publications
An experimental study was conducted to quantify the flow characteristics of the wall jets pertinent to trailing edge cooling of turbine blades. A high-resolution stereoscopic particle image velocimetry (PIV) system was used to conduct detailed flow field measurements to quantitatively visualize the evolution of the unsteady vortices and turbulent flow structures in the cooling wall jet streams and to quantify the dynamic mixing process between the cooling jet stream and the mainstream flows. The detailed flow field measurements were correlated with the adiabatic cooling effectiveness maps measured by using pressure sensitive paint (PSP) technique to elucidate underlying physics in order …
Product Display Versus Graphical Representation On Packaging,
2012
Clemson University
Product Display Versus Graphical Representation On Packaging, Joshua Galvarino
All Theses
ABSTRACT
Previous research conducted (Hurley, et al., 2012) concerning physical and graphical product visibility from the primary display panel (PDP) is limited to one product category. This research expands previous peer-reviewed research, which indicates that there is a significant difference between consumer preferences of graphical display vs. physical product display on packaging.
The shelf presence of packages showing actual product visibility versus packages showing only a graphical representation of the product was evaluated. Both shopping results and quantitative data using eye-tracking technology were collected and cross-referenced with a qualitative, post-experiment survey.
Specifically, variables of packaging within pasta, snacks, prepared frozen …
Energy Trapping Of Thickness-Shear And Thickness-Twist Modes In A Partially Electroded At-Cut Quartz Resonator,
2012
University of Nebraska-Lincoln
Energy Trapping Of Thickness-Shear And Thickness-Twist Modes In A Partially Electroded At-Cut Quartz Resonator, Huijing He, Guoquan Nie, Jinxi Liu, Jiashi Yang
Department of Mechanical and Materials Engineering: Faculty Publications
The thickness-shear and thickness-twist vibrations of a finite and partially electroded AT-cut quartz resonator are investigated. The equations of anisotropic elasticity are used with the omission of the small elastic constant c56 . An analytical solution is obtained using Fourier series from which the free vibration resonant frequencies, mode shapes, and energy trapping are calculated and examined.
Me-Em Enewsbrief, December 2012,
2012
Michigan Technological University
Me-Em Enewsbrief, December 2012, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University
Department of Mechanical and Aerospace Engineering eNewsBrief
No abstract provided.
Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries,
2012
University of Nebraska-Lincoln
Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet
Department of Engineering Mechanics: Dissertations, Theses, and Student Research
Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on …
