Engineering Commons^™

Cerebellar Source Localization Using Event-Related Potentials In A Simple Motor Task, Efrain Torres, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Electroencephalography (EEG) is widely used to characterize the temporal patterns of electrical activity, primarily associated with neocortex. Traditionally, the sensitivity of EEG to cerebellar activity has been considered limited with the electrical potentials assumed to stem from cortical pyramidal cells. This study leverages recent work examining the structure, organization, and synchrony of purkinje neurons to promote local field potentials measured by EEG. In conjunction with high fidelity EEG recording and source imaging analysis we examined the feasibility of using current EEG systems to characterize cerebellar function in a series of simple motor tasks. Distributed source imaging analysis revealed consistent task-related …

Self-Assembly Of 3d Nanostructures In Electrospun Polycaprolactone-Polyaniline Fibers And Their Application As Scaffolds For Tissue Engineering, Samerender Nagam Hanumantharao, Carolynn Que, Smitha Rao

Department of Biomedical Engineering Publications

The fabrication of synthetic scaffolds that mimic the microenvironment of cells is a crucial challenge in materials science. The honeycomb morphology is one such bio-mimicking structure that possesses unique physical properties and high packing efficiency in a 3-dimensional space. Here, we present a novel method for electrospinning polycaprolactone-polyaniline with continuous, self-assembled, uniform, interwoven nanofibers forming patterns without the use of templates or porogens. By using the approach presented here, unique architectures mimicking the natural mechanical anisotropy of extracellular matrix were created by varying the electric field. Adult human dermal fibroblasts (HDFa) cells were successfully cultured on the nanofiber scaffolds without …

Process Parameter Development Of Additively Manufactured Af9628 Weapons Steel, Erin M. Hager

Theses and Dissertations

The manufacture of components in Additive Manufacturing processes is limited by the range of materials available. Qualification of materials for Additive Manufacturing is time intensive, and is often specific to a single type of machine. In this study, an approach to selecting power, speed, and hatch spacing values for a newly powderized material, AF9628 weapons steel, is described that results in highly dense (>99.9%) parts on an MLab 200R Cusing. Initial power and speed values used in a weld track study were selected based on a survey of parameters used on similar materials, with a focus on the energy …

Removal Of Synthetic Azo Dye Using Bimetallic Nickel-Iron Nanoparticles, Shelby L. Foster, Katie Estoque, Michael Voecks, Nikki Rentz, Lauren F. Greenlee

Chemical Engineering Faculty Publications and Presentations

Bimetallic nanoparticles comprised of iron (Fe) and nickel (Ni) were investigated for the removal of an azo dye contaminant in water. Morphology (core shell and alloy) and metal molar ratio (Ni2Fe10, Ni5Fe10, and Ni10Fe10) were tested as key nanoparticle properties. The shelf life of the nanoparticles was tested over a 3-week period, and the effect of initial nanoparticle concentration on dye removal was evaluated. The highest initial nanoparticle concentration (1000 mg/L) showed consistent Orange G removal and the greatest extent of dye removal, as compared to the other tested concentrations (i.e., 750 mg/L, 500 mg/L, and 250 mg/L) for the …

Investigating The Impact Of Taper And Aspect Ratio On A Stalling Wing Using A Corrected Vortex Lattice Method, Ryan Anderson

Undergraduate Honors Theses

The advent of new technologies such as eVTOL vehicles is exciting. The development of fast aerodynamics models incorporating stall is one small step on the road to realizing such concepts by improving the speed of design optimization algorithms. To this end, a modified vortex lattice model was developed based on one reported by dos Santos and Marques [4]. The model was validated against experimental data found in the literature. Making use of its stall capabilities, a sample study was performed to test for any coupling effect between aspect ratio and taper ratio. This was done by calculating the lift curve …

Simulation On Gas-Molten Salt Heat Transfer In Bubble Column For Solar Thermal Storage, Wenhao Pu, Ning Yang, Chen Yue, Dong Han, Weifeng He, Yitung Chen

Mechanical Engineering Faculty Research

The charging and discharging of molten salt thermal storage is of great importance to the operation and maintenance of the solar power plant. The molten salt bubble column is proposed for solar thermal storage, which is regarded as direct contact heat exchanger. The gas from the solar field is directly injected into the molten salt bubble column. High heat transfer rates can be achieved between the gas and the molten salt due to the direct contact. Numeric study on the hydrodynamics and heat transfer characteristic of the gas molten salt bubble column is carried out based on the two fluid …

Modeled Affinity Constants For Phosphorus Adsorption And Desorption Due To Saltwater Intrusion, Yasemin Taşcı

USF Tampa Graduate Theses and Dissertations

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface …

Evaluation And Modeling Of The Effect Of Tool Edge Radius On Machined Surface Roughness In Turning Uns A92024-T351 Aluminum Alloy, Ning Fang, P. Srinivasa Pai

Engineering Education Faculty Publications

Tool edge radius plays a significant role in affecting the surface integrity of machined products. The vast majority of existing research, however, takes no account of the effect of tool edge radius in the evaluation and modeling of machined surface roughness, an essential indicator of surface integrity. The present study fills this important research gap and has performed a total of 45 turning experiments on Unified Numbering System (UNS) A92024-T351 aluminum alloy with carefully selected cutting tools with three levels of tool edge radii. This article describes the experimental setup and measurements of tool edge radius and machined surface roughness. …

Temperature-Compensated Magnetic Field Sensing With A Dual-Ring Structure Consisting Of Microfiber Coupler-Sagnac Loop And Fiber Bragg Grating - Assisted Resonant Cavity, Fangfang Wei, Dejun Liu, Arun Kumar Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

A novel temperature-compensated magnetic field sensor based on a ring erbium-doped fiber laser combined with a fiber Bragg grating (FBG) and a Sagnac loop containing a microfiber coupler (MFC) and magnetic fluid is proposed and investigated. Thanks to the dual-ring structure of the MFC-Sagnac loop and the FBG-assisted resonant cavity, the output of the structure has two distinct laser peaks. In addition to the magnetic field sensing capability, the proposed structure can simultaneously provide temperature information. The maximum experimentally demonstrated sensitivity to a magnetic field determined from the spectral shift of one laser peak is 102 pm/mT in the magnetic …

Aerodynamic Flutter And Buffeting Of Long-Span Bridges Under Wind Load, Shuqian Liu

LSU Doctoral Dissertations

With the continuous increase of span lengths, the aerodynamic characteristics of long-span bridges under external wind excitation have become much more complex and wind-induced vibration has always been a problem of great concern. The present research targets on the aerodynamic performance of long-span bridges under wind load with an emphasis on bridge flutter and buffeting.

For the aerodynamic flutter analysis of long-span bridges, the present research investigated the effects of the wind turbulence on flutter stability. The characterizations of the self-excited forces are presented in both the frequency-domain and in the time-domain, and the flutter analysis is conducted under both …

Coastal Louisiana Landscape And Hurricane Storm Surge Evolution 1850 - 2110, Christopher George Siverd

LSU Doctoral Dissertations

The hurricane storm surge analysis presented in this dissertation examines surge response to changes in the Louisiana coastal landscape and Gulf of Mexico water level from 1850 to 2110. Land to water (L:W) isopleths, lines depicting areas of constant land to water ratio along the modern Louisiana coast, are utilized in the development of a simplified storm surge model that closely reproduces the surge output of a state-of-the-art detailed model. Eleven comparable storm surge models are constructed with each featuring a representation of the Louisiana coastal landscape circa 1850, 1890, 1930, 1970, 1990, 2010, 2030, 2050, 2070, 2090 and 2110. …

Microscale Metal Forming: Mesoscopic Size Effect, Extrusion And Molding, Bin Zhang

LSU Doctoral Dissertations

The continuing trend of metallic device and product miniaturization has motivated studies on microscale metal forming technologies. A better understanding of materials’ mechanical response and deformation behavior is of importance for the design and operation of micro metal forming processes. In this dissertation, uniaxial compression testing was conducted on Al ring and pillar specimens with characteristic dimensions at meso to micro scales. The experimental data reveal inadequacies of the existing surface layer model and provides a baseline for delineating deformation mechanisms in micro metal forming operations. Microscale reverse extrusion experiment was carried out on Cu and Al rod specimens with …

Quantitative Evaluation Of A Lightweight Sediment For A Physical Model Of The Lower Mississippi River, Mauricio Hooper

LSU Doctoral Dissertations

The Lower Mississippi River Physical Model (LMRPM), housed at the LSU Center for River Studies on the Baton Rouge, LA Water Campus, is a distorted, movable bed model comprising the lower 195 miles of the Mississippi River from Donaldsonville through the Head of Passes into the Gulf of Mexico. Since the LMRPM was designed to replicate the hydraulics (i.e., flow and river stages) and bulk non-cohesive sediment transport, the model lightweight sediment must replicate both the incipient motion and two-dimensional dune characteristics (height and length). In addition, the model scale and distortion require that the sediment time scale be determined …

Experimental And Numerical Study Of Dynamic Water Control In Naturally Fractured Reservoirs, Younes Ahmed Alblooshi

LSU Doctoral Dissertations

Excessive water production problem is more troubling in naturally fractured reservoirs (NFR) than matrix-only deposits. In NFR, fluid flow through fracture conduits substantially differs from that in the rock matrix. Development of fractured hydrocarbon reservoirs require good understanding of fluid flow in the network of fractures. In NFR with bottom-water drive, mitigation of excessive water is always a challenge.

This dissertation presents an experimental and numerical study of dynamic water control in fractured basements using downhole water sink (DWS) well technology. A DWS well is a dual-completed well with the top completion used for oil production from payzone and a …

Effective Geometric Modeling For Scientific Computing And Forensic Reconstruction, Celong Liu

LSU Doctoral Dissertations

Geometric modeling is a fundamental and critical problem for many computer graphic and computer vision problems. We usually want to build a parameterization which establishes a low-distortion one-to-one map between geometric data and canonical parametric domain, and it is a fundamental tool to support many visual data processing tasks such as mesh generation, finite element simulations, visual analytics, geometric reconstruction, etc. In this dissertation, I studied two problems. The first is to construct low- distortion canonical (polycube) parameterization of large-scale geometric regions, with which high-quality semi-structured quad meshes can be generated and used to facilitate more efficient scientific computing. The …

Unified Strength Model Of Asphalt Mixture Under Various Loading Modes, Chengdong Xia, Songtao Lv, Lingyun You, Dong Chen, Yipeng Li, Jianlong Zheng

Department of Civil, Environmental, and Geospatial Engineering Publications

Although the rutting resistance, fatigue cracking, and the resistance to water and frost are important for the asphalt pavement, the strength of asphalt mixture is also an important factor for the asphalt mixture design. The strength of asphalt mixture is directly associated with the overall performance of asphalt mixture. As a top layer material of asphalt pavement, the strength of asphalt mixture plays an indispensable role in the top structural bearing layer. In the present design system, the strength of asphalt pavement is usually achieved via the laboratory tests. The stress states are usually different for the different laboratory approaches. …

An Extensive Game-Based Resource Allocation For Securing D2d Underlay Communications, Oleksii Rudenko, Yuhong Liu, Chenwei Wang, Susanto Rahardja

Computer Science and Engineering

Device-to-device (D2D) communication has been increasingly attractive due to its great potential to improve cellular communication performance. While resource allocation optimization for improving the spectrum efficiency is of interest in the D2D-related work, communication security, as a key issue in the system design, has not been well investigated yet. Recently, a few studies have shown that D2D users can actually serve as friendly jammers to help enhance the security of cellular user communication against eavesdropping attacks. However, only a few studies considered the security of D2D communications. In this paper, we consider the secure resource allocation problem, particularly, how to …

High-Resolution Dynamic Strain Sensor Using A Polarization-Maintaining Fiber Bragg Grating, Dipen Barot, Gang Wang, Lingze Duan

PRC-Affiliated Research

Dynamic strain sensing based on fiber Bragg gratings (FBG) has found a wide range of applications in structural health monitoring and industrial process control. Conventional approaches to enhance strain resolution upon the standard configuration have shown challenges in scaling up due to much increased system complexity. In this report, we demonstrate a new scheme based on an FBG sensor fabricated in a polarization-maintaining fiber. By using balanced detection to suppress laser intensity noise and enhance strain signal, we have demonstrated an improvement of 28 dB in signal level, 18 dB in signal-to-noise ratio, and 20× in strain resolution when compared …

High-Resolution Dynamic Strain Sensor Using A Polarization-Maintaining Fiber Bragg Grating, Dipen Barot, Gang Wang, Lingze Duan

PRC-Affiliated Research

Dynamic strain sensing based on fiber Bragg gratings (FBG) has found a wide range of applications in structural health monitoring and industrial process control. Conventional approaches to enhance strain resolution upon the standard configuration have shown challenges in scaling up due to much increased system complexity. In this report, we demonstrate a new scheme based on an FBG sensor fabricated in a polarization-maintaining fiber. By using balanced detection to suppress laser intensity noise and enhance strain signal, we have demonstrated an improvement of 28 dB in signal level, 18 dB in signal-to-noise ratio, and 20× in strain resolution when compared …

High-Resolution Dynamic Strain Sensor Using A Polarization-Maintaining Fiber Bragg Grating, Dipen Barot, Gang Wang, Lingze Duan

PRC-Affiliated Research

Dynamic strain sensing based on fiber Bragg gratings (FBG) has found a wide range of applications in structural health monitoring and industrial process control. Conventional approaches to enhance strain resolution upon the standard configuration have shown challenges in scaling up due to much increased system complexity. In this report, we demonstrate a new scheme based on an FBG sensor fabricated in a polarization-maintaining fiber. By using balanced detection to suppress laser intensity noise and enhance strain signal, we have demonstrated an improvement of 28 dB in signal level, 18 dB in signal-to-noise ratio, and 20× in strain resolution when compared …

Model Of A Sulfur-Based Cyclic Denitrification Filter For Marine Recirculating Aquaculture Systems, Zhang Cheng

USF Tampa Graduate Theses and Dissertations

Recirculating aquaculture systems (RAS) are a type of near zero-discharge fish production system that is used to treat and recirculate aquaculture wastewater and increase the biomass stocking density in the fish tank. The RAS presented in this thesis was a marine system which was operated with two temporally independent cycles, Loop 1, a continuous loop, and Loop 2, an intermittent loop. Flow in the RAS was switched between the two loops by a solenoid valve. During the operation of Loop 1, components involved in the cycle were successively the fish tank for fish production, solids filters for solids removal and …

Estimation Of Number Of People Living In Developing Countries That Received Water From A Spring Source, Prapti Shinde

USF Tampa Graduate Theses and Dissertations

In the year 2000, 170 countries decided to stand together and solve some primary and common global problems like poor health, water, and sanitation. Obtaining access to safe drinking water is every individual’s right. The UN defines safe drinking water as “the water required for each personal or domestic use must be safe, therefore free from micro-organisms, chemical substances and radiological hazards that constitute a threat to a person's health” (UNDESA, 2014). This thesis focuses on identifying the number of people who potentially receive spring water from a piped source in rural mountainous areas. There are three significant steps and …

A Comprehensive Techno-Economic Framework For Shale Gas Exploitation And Distribution In The United States, Jorge Asis Charbel Chebeir

LSU Doctoral Dissertations

Over the past years, shale gas has turned into one of the most significant sources of energy in the United States. Technological advancements have provided the energy industry with the necessary tools to allow the economic exploitation of an enormous volume of natural gas trapped in shale formations. This has boosted the domestic gas production and generated a boom in other sectors of the economy in the country. However, major challenges are involved in the development of shale gas resources. A drastic decline of wells’ productivity, the costs involved in the gas production and distribution facets, and the volatile behavior …

Steering System For Sae Baja, Dallin Colgrove

Undergraduate Honors Theses

This thesis is to study the different types of steering geometry for the BYU Baja vehicle. The main steering geometries of study are Ackermann and parallel steering geometries. Ackermann steering geometry is ideal for low speed turns. During low speed turns Ackermann steering performs better than parallel steering due to a smaller radius of turn. Parallel steering ideally is better for high speed turns, because with parallel steering the slip angle is smaller than that of Ackermann geometry. A recommendation is made to the BYU Baja team to use Ackermann steering, but still do some more analysis of parallel steering …

Graph Formalisms And Technologies To Support To Systems Engineering Modeling And Analysis, Mil'yonta Williams

Research Horizons Day Posters

No abstract provided.

Effect Of Low Temperature Heat Treatments On The Resulting Void Analysis Of Blown Power Deposition Inconel 625 Specimens, Noah Naden, An Nguyen

Research Horizons Day Posters

No abstract provided.

Nuclear Thermal Propulsion Reactor Shutdown And Residual Heating, Samantha B. Rawlins

Research Horizons Day Posters

No abstract provided.

Effects Of Additives On Sol Gel Synthesis Of Lithium Ion Battery Cathode Material, Gabrielle Andrew

Research Horizons Day Posters

No abstract provided.

A 3d Finite Difference Thermal Model Tailored For Additive Manufacturing, Tom Stockman, Judith A. Schneider, Bryant Walker, John S. Carpenter

PRC-Affiliated Research

Physics-based modeling of metal additive manufacturing (AM) processes is computationally challenging due to the very fine meshing required in both time and space. State-of-the-art numerical models that offer great insight into the process have been developed, but they require powerful computational resources and weeks of processing time. Thus, it is often more time-effective to fabricate multiple builds within the time it takes to complete one simulation prediction, further reinforcing the current trial-and-error approach to optimizing the build parameters. This study presents a simplified approach to the transient thermal modeling of the AM process. The numerical model is designed to run …

A 3d Finite Difference Thermal Model Tailored For Additive Manufacturing, Tom Stockman, Judith A. Schneider, Bryant Walker, John S. Carpenter

PRC-Affiliated Research

Physics-based modeling of metal additive manufacturing (AM) processes is computationally challenging due to the very fine meshing required in both time and space. State-of-the-art numerical models that offer great insight into the process have been developed, but they require powerful computational resources and weeks of processing time. Thus, it is often more time-effective to fabricate multiple builds within the time it takes to complete one simulation prediction, further reinforcing the current trial-and-error approach to optimizing the build parameters. This study presents a simplified approach to the transient thermal modeling of the AM process. The numerical model is designed to run …