Engineering Commons^™

Understanding Performance--Limiting Mechanisms In Li-Ion Batteries For High-Rate Applications, Indrajeet Vilasrao Thorat

Theses and Dissertations

This work presents novel modeling and experimental techniques that provide insight into liquid-phase mass transport and electron transfer processes in lithium-ion batteries. These included liquid-phase ionic mass transport (conduction and diffusion), lithium diffuion in the solid phase and electronic transport in the solid phase. Fundamental understanding of these processes is necessary to efficiently design and optimize lithium-ion batteries for different applications. To understand the effect of electrode structure on the electronic resistance of the cathode, we tested power performance of cathodes with combinations of three different carbon conductivity additives: vapor-grown carbon fibers (CF), carbon black (CB) and graphite (GR). With …

Real-Time Optical Flow Sensor Design And Its Application On Obstacle Detection, Zhaoyi Wei

Theses and Dissertations

Motion is one of the most important features describing an image sequence. Motion estimation has been widely applied in structure from motion, vision-based navigation and many other fields. However, real-time motion estimation remains a challenge because of its high computational expense. The traditional CPU-based scheme cannot satisfy the power, size and computation requirements in many applications. With the availability of new parallel architectures such as FPGAs and GPUs, applying these new technologies to computer vision tasks such as motion estimation has been an active research field in recent years. In this dissertation, FPGAs have been applied to real-time motion estimation …

Cad Model For Co-Propagating Spatially Multiplexed Channels Of Same Wavelength Over Standard Multimode Fibers, Syed H. Murshid, Raka Biswas, Abhijit Chakravarty

Electrical Engineering and Computer Science Faculty Publications

Spatial Domain Multiplexing (SDM) is a novel technique that allows co-propagation of two or more optical communication channels of the same wavelengths over a single strand of optical fiber cable by maintaining spatial separation between the channels. Spatial multiplexer known as the beam combiner module (BCM) supports helical propagation of light to ensure spatial separation between the channels. It is inserted at the input end of the system. Spatial de-multiplexing is achieved by a unit named beam separator module (BSM). This unit is inserted at the receiving end of the system and it routes the optical energy from individual channels …

Efficient Unidirectional Ridge Excitation Of Surface Plasmons, I P. Radko, S I. Bozhevolnyi, G Brucoli, L Mart´In-Moreno, F J. Garc´Ia-Vidal, A Boltasseva

Birck and NCN Publications

Using leakage-radiation microscopy, we characterize the efficiency of unidirectional surface-plasmon excitation with periodic (800 nm) arrays of 130-nm-high and 330-nm-wide gold ridges on a thin gold film illuminated with a focused (5-mu m-wide) laser beam. We demonstrate that, at the resonant wavelength of 816 nm, the excitation efficiency of > 0.4 can be obtained with >= 5 ridges by adjusting the beam position. Conducting numerical simulations, we account for the experimental results and calculate the electric-field enhancement achieved near the gold surface.

Design Simulation Of Top Ito Gratings To Improve Light Transmission For Gallium Nitride Leds, Xiaomin Jin, Simeon Trieu, Fei Wang, Bei Zhang, Tao Dai, Xiangning Kang, Guoyi Zhang

Electrical Engineering

We present simulation results of the indium tin oxide (ITO) top diffraction grating using a rigorous couple wave analysis (RCWA) for GaN LEDs. We study three different nano-structure patterns: cylindrical pillar grating, conical pillar grating, and cylindrical nano-hole grating. We show the light transmission improvement with nano-grating designs and present design-charts for the nano-hole grating.

Ultrasonic Drug Delivery To Tumors Via Stealth Liposomes, Peter Jones, Ghaleb A. Husseini, William G. Pitt, Beverly L. Roeder

Faculty Publications

Our research develops ultrasonically-controlled drug delivery systems. Previous micellar drug carriers released the drug upon ultrasonication. We have developed a liposomal drug carrier that is even more effective upon insonation in reducing tumors.

A Parallel Molecular Dynamics Program For Simulation Of Water In Ion Channels, Laxmi Mullapudi

Theses and Dissertations

With a modest beginning from developing a model of dynamics of hard liquid spheres (Alder et al., 1957), molecular dynamics (MD) simulations have come to a point where complex biomolecules can be simulated with precision close to reality (Noskov et al., 2007). In this context, a parallel molecular dynamics program for simulation of ion channels associated with cellular membranes has been developed. The parallel MD code developed is simple, efficient, and easily coupled to other codes such as the hybrid molecular dynamics/ brownian dynamics (MD/BD) code developed for the study of protein interactions (Ying et al., 2005). The Atom Decomposition …

Modeling Subprime Mortgage Delinquency, Default, Prepayment And Loss, Olgay Cangur

Dissertations and Theses

The current financial environment presents significant challenges for the mortgage industry. Declining house prices have surfaced the importance of delinquency, loan default and loss predictions. Simple models of prepayment behavior are no longer applicable. Investors, originators, servicers and regulators are in need of more accurate predictions for their portfolios of interest.

This dissertation focuses on two topics relevant to modeling residential mortgages. The first topic provides a framework for modeling delinquencies, prepayments, defaults and losses that represents an enhancement over previous studies. A total of nine loan payment statuses are used (current, thirty-days delinquent, sixty-days delinquent, ninety-days delinquent, early foreclosure, …

Ceas E-News 04.23.2009, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Team earns third place in concrete canoe competition

Structural And Functional Considerations In The Design Of Collagen-Based Electrospun Scaffolds, Chantal Ayres

Theses and Dissertations

Electrospinning can be used to selectively process a variety of natural and synthetic polymers into highly porous scaffolds composed of nano-to-micron diameter fibers. This process shows great potential as a gateway to the development of physiologically relevant tissue engineering scaffolds. In this study we examine the structural and functional considerations regarding electrospun scaffolds for dermal template applications using novel quantification techniques. In order to characterize scaffold structure, a technique utilizing the fast Fourier transform was developed to systematically quantify fiber alignment and evaluate how different electrospinning parameters impact the structure and material properties of an electrospun scaffold. Gelatin was suspended …

Barriers To Mitigation: A Pilot Study, James Lee, Crystal Paul, Guna Selvaduray

Faculty Publications

This pilot research was undertaken to discover barriers that prevent homeowners from mitigating earthquake hazards in their homes. There is a relatively significant body of literature on disaster mitigation, which is reviewed and summarized in this report. However, no studies address how these barriers may be overcome so that homeowners would be more proactive in mitigation. If the barriers can be identified, then future communications and policy actions that address these barriers can be taken, resulting in more widespread mitigation implementation that reduces the injury and damage potential that communities face, leading to a reduction in the post-disaster response requirement, …

Agent-Based Infrastructure For Data And Transaction Management In Mobile Heterogeneous Environment, Machigar Ongtang, Ali R. Hurson, Yu Jiao

Electrical and Computer Engineering Faculty Research & Creative Works

Mobile technology and advances in databases have allowed users to access and manipulate data across multiple heterogeneous and autonomous data sources via wireless connection, namely mobile multidata base system. Transaction management in this environment is nontrivial due to heterogeneity and autonomy of the participating data sources, frequent disconnections, and technological constraints of the access devices. Agent based Transaction Management scheme for Mobile Multidata base (AT3M) systems uses autonomous agents to enable a fully distributed transaction management, accommodates users' mobility, allows parallel execution of the global sub transactions, and responds to some of the limitations of the technology. the framework is …

Dynamics Simulation And Malfunction Diagnosis Of Heavy Machinery Using Msc Adams, Dewen Kong, Jim M. Meagher, Xi Wu

Mechanical Engineering

No abstract provided.

Static And Dynamic Responsive Behavior Of Polyelectrolyte Brushes Under External Electrical Field, Hui Ouyang, Zhenhai Xia, Jiang Zhe

Mechanical Engineering Faculty Research

The static and dynamic behaviors of partially charged and end-grafted polyelectrolyte brushes in response to electric fields were investigated by means of molecular dynamics simulation. The results show that the polymer brushes can be partially or fully stretched by applying an external electric field. Moreover, the brushes can switch reversibly from collapsed to stretched states, fully responding to the AC electric stimuli, and the gating response frequency can reach a few hundred MHz. The effects of the grafting density, the charge fraction of the brushes and the strength of the electric field on the average height of the polymer brushes …

Integrating Adams Software Into An Upper Division Mechanical Design And Analysis Course, Xi Wu, Dewen Kong, Jim Meagher

Mechanical Engineering

No abstract provided.

Contact Resistance In Carbon Nanostructure Via Interconnects, Wen Wu, Shoba Krishnan, Toshishige Yamada, Xuhui Sun, Patrick Wilhite, Raymond Wu, Ke Li, Cary Y. Yang

Electrical and Computer Engineering

We present an in-depth electrical characterization of contact resistance in carbon nanostructure via interconnects. Test structures designed and fabricated for via applications contain vertically aligned arrays of carbon nanofibers (CNFs) grown on a thin titanium film on silicon substrate and embedded in silicon dioxide. Current-voltage measurements are performed on single CNFs using atomic force microscope current-sensing technique. By analyzing the dependence of measured resistance on CNF diameter, we extract the CNF resistivity and the metal-CNF contact resistance.

Unified Theory Of Gas Damping Of Flexible Microcantilevers At Low Ambient Pressures, Rahul Bidkar, Ryan Tung, Alina Alexeenko, Sumali Hartono, Arvind Raman

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

Predicting the gas damping of microcantilevers oscillating in different vibration modes in unbounded gas at low pressures is relevant for increasing the sensitivity of microcantilever-based sensors. While existing free-molecular theories are valid only at very high Knudsen numbers, continuum models are valid only at very low Knudsen numbers. We solve the quasisteady Boltzmann equation and compute a closed-form fit for gas damping of rectangular microcantilevers that is valid over four orders of magnitude of Knudsen numbers spanning the free-molecular, the transition, and the low pressure slip flow regimes. Experiments are performed using silicon microcantilevers under controlled pressures to validate the …

Adding Escience Assets To The Data Web, Herbert H. Van De Sompel, Carl Lagoze, Michael L. Nelson, Simeon Warner, Robert Sanderson, Pete Johnston

Computer Science Faculty Publications

Aggregations of Web resources are increasingly important in scholarship as it adopts new methods that are data-centric, collaborative, and networked-based. The same notion of aggregations of resources is common to the mashed-up, socially networked information environment of Web 2.0. We present a mechanism to identify and describe aggregations of Web resources that has resulted from the Open Archives Initiative - Object Reuse and Exchange (OAI-ORE) project. The OAI-ORE specifications are based on the principles of the Architecture of the World Wide Web, the Semantic Web, and the Linked Data effort. Therefore, their incorporation into the cyberinfrastructure that supports eScholarship will …

Cad-Centric Dynamic Workflow Generation, Travis L. Kenworthy

Theses and Dissertations

CAD systems are important design tools that enable the designer to conceptualize, visualize, analyze, and manufacture a design (Shahin 2008). Although high-end CAD systems provide several built-in design applications, the users of CAD often select various custom or proprietary non-CAD analyses that constrain, optimize, or evaluate their designs. An efficient method is needed to perform trade studies from within the CAD environment. Methods have been developed to meet the challenges associated with this need. The methods have been implemented in a program, called the Process Integrator, which resides in a CAD system and allows the user to perform trade studies …

A Video Manager, Nicholas Omann

Honors Capstones

Capstone submitted as a graduate requirement for the BSU Honors Program.

A Numerical Approach For Predicting The Impact Of Vascular Architecture On Blood Flow During Ischemic Repair, Stephanie Ann Wood, Shilpi Ghosh, Kevin Jones, Gabriel Gruionu, Trevor R. Cardinals

Biomedical Engineering

Abstract of conference presentation.

Functional Vasodilation Following Murine Chronic Hindlimb Ischemia, Matthew David Yocum, Trevor R. Cardinal

Biomedical Engineering

Abstract of conference presentation.

Impedance Spectroscopy Of Zebrafish Sperm, Robert Egnatchik

Honors Capstones

No abstract provided.

A Numerical Model Of The Friction Stir Plunge, Stanford Wayne Mcbride

Theses and Dissertations

A Lagrangian finite-element model of the plunge phase of the friction stir welding process was developed to better understand the plunge. The effects of both modeling and experimental parameters were explored. Experimental friction stir plunges were made in AA 7075-T6 at a plunge rate of 0.724 mm/s with spindle speeds ranging from 400 to 800 rpm. Comparable plunges were modeled in Forge2005. Various simulation parameters were explored to assess the effect on temperature prediction. These included the heat transfer coefficient between the tool and workpiece (from 0 to 2000 W/m-K), mesh size (node counts from 1,200 to 8,000), and material …

Fatigue Strength Of Common Tibial Intramedullary Nail Distal Locking Screws, Lanny V. Griffin, Robert M. Harris, Joseph J. Zubak

Biomedical Engineering

Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative …

Housing Market Outlook: San Luis Obispo, Ca And Surrounding Area, Gabe Randall, Scott D. Kelting

Construction Management

Starting between 1999 and 2000, national home prices began a period of unprecedented growth, increasing at a pace more than 8 times their annual average until peaking in early 2006. National home prices appreciated over 100% on average during the 6 year period before declining 27% from 2006 through Q4 2008. Markets across the sunbelt, namely Florida, Southern California, and Arizona saw prices appreciate as much as 180 % from 2000 to their peak in 2006; these areas have also declined the fastest and hardest, falling as much as 50% and boasting the highest foreclosure rates in the country.

Freeze-Spray Deposition Of Layered Alumina/Zirconia Composites, Qiang Fu, Oratai Jongprateep, Ashlee Abbott, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Freeze-spray deposition (FSD) method is described for rapid fabrication of layered composites with controlled layer thickness and uniform microstructure. The graded alumina/zirconia composites are fabricated by FSD of ceramic slurries followed by freeze drying. Aqueous slurries with glycerol addition are sprayed on a cooled substrate using an automated 3D gantry system. Processing parameters such as viscosity of the ceramic slurries, composition and thickness of deposited layers as well as sintering conditions are investigated to optimize the fabrication process. Microstructural analysis of the fabricated composites revealed uniform and crack-free transitional layers indicating a strong interfacial bonding between the layers.

2009 - The Fourteenth Annual Symposium Of Student Scholars

Symposium of Student Scholars Program Books

The full program book from the Fourteenth Annual Symposium of Student Scholars, held on April 13, 2009. Includes abstracts from the presentations and posters.

Vesicles In Poiseuille Flow, Gerrit Danker, Petia M. Vlahovska, Chaouqi Misbah

Dartmouth Scholarship

Blood microcirculation critically depends on the migration of red cells towards the flow centerline. We identify theoretically the ratio of the inner over the outer fluid viscosities λ as a key parameter. At low λ, the vesicle deforms into a tank-treading ellipsoid shape far away from the flow centerline. The migration is always towards the flow centerline, unlike drops. Above a critical λ, the vesicle tumbles or breaths and migration is suppressed. A surprising coexistence of two types of shapes at the centerline, a bulletlike and a parachutelike shape, is predicted.

Botulinum Toxin For Non-Surgical Lateral Release In Subjects With Patellofemoral Pain, Laura Maple

Theses and Dissertations

Previous studies for treating Patellofemoral Pain Syndrome (PFPS) are controversial regarding the effectiveness in alleviating anterior knee pain (AKP). The muscular imbalance between the vastus medialis oblique/vastus lateralis (VMO/VL) may be the underlying mechanical issue causing PFPS. It is hypothesized that Botox can decrease the force production capability of the lateral musculature mechanically similar to surgery. Strengthening the VMO while using Botox treatment can alleviating the muscular imbalance that occurs with subjects with PFPS. A double blind study, having all participants blinded and uninformed of the injection contents, was implemented to test this hypothesis testing three female subjects. Four knees …