Engineering Commons^™

Bonding Of Polydimethylsiloxane Microfluidics To Silicon-Based Sensors, Long-Fang Tsai, William C. Dahlquist, Seunghyun Kim, Gregory P. Nordin

Faculty Publications

We investigate bonding polydimethylsiloxane (PDMS) to silicon using a thin (~2μm) intermediate adhesive layer stamped onto a PDMS piece prior to bonding. In particular, we compare as adhesive layers Sylgard 184 and 182 curing agents and a UV curable adhesive (NOA 75). We examine the effect of both curing temperature and duration on curing agent bond strength. Bond strengths for the different adhesives are determined by measuring the average burst pressure at a PDMS-silicon interface using a PDMS test design. We find that Sylgard 184 curing agent gives the highest bond strength with burst pressure of 700 kPa or more …

Circular And Near-Circular Polarization States Of Evanescent Monochromatic Light Fields In Total Internal Reflection, R. M. A Azzam

Electrical Engineering Faculty Publications

Conditions for the production of near-circular polarization states of the evanescent field present in the rarer medium in total internal reflection of incident monochromatic p-polarized light at a dielectric-dielectric planar interface are determined. Such conditions are satisfied if high-index (>3.2) transparent prism materials (e.g., GaP and Ge) are used at angles of incidence well above the critical angle but sufficiently below grazing incidence. Furthermore, elliptical polarization of incident light with nonzero p and s components can be tailored to cause circular polarization of the resultant tangential electric field in the plane of the interface or circular polarization of the …

Determination Of Isotherms Of Enantiomers On A Chiral Stationary Phase Using Supercritical Fluid Chromatography, Wade Newlin Mack Ii

USF Tampa Graduate Theses and Dissertations

Supercritical fluids provide a robust, tunable environment with favorable transport properties and enhanced solubility. Supercritical carbon dioxide is an environmentally friendly substance that has distinct advantages to traditional solvents used in large scale chemical processing. Ibuprofen is an enantiomeric drug that has been shown to fight prostate cancer and has been used as a mild Alzheimer's disease treatment in the S conformation. Purification of high value products with decreased hazardous material consumption is accomplished by employing supercritical fluid chromatography (SFC). Large scale, single enantiomer purification of pharmaceuticals is dependent on scale-up information. Equilibrium isotherms provide the necessary information to scale-up …

Session 1 Presentation: Ocean Testing Of A Power-Capturing Wave Buoy, Kathleen Edwards

Ocean Waves Workshop

No abstract provided.

Time To Make Renting A Long-Term Housing Choice, Lorcan Sirr

Media

No abstract provided.

Surface Modification Of Liposomes Containing Nanoemulsions, Jonathan Michael Hartley

Theses and Dissertations

Many attempts have been made to make cancer therapy more selective and less detrimental to the health of the patients. Nanoparticles have emerged as a way to solve some of the problems of traditional chemotherapy. Nanoparticles can provide protection for the therapeutic from degradation or clearance, as well as protection to healthy tissue from the damaging effects of chemotherapy drugs. Researchers are pursuing different strategies but all have the same goals of improving the outcomes of cancer patients. The field of controlled release of drugs has increased significantly in hopes of better treating diseases like cancer. Improved control of drug …

A Comparison Of Bss Algorithms In Harsh Environments, Christopher Osterwise, Steven Grant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper compares the performance of several blind source separation (BSS) algorithms in environments of varying reverberation, noise, microphone spacing, and sparsity. of particular interest are two frequency domain algorithms: one Cascaded ICA with Intervention Alignment (CICAIA), and one algorithm by Pham, Servire, and Boumaraf. the former is found to work exceptionally well in high noise, low microphone spacing environments. the latter proves to work exceptionally well in high SNR and moderate- to widely spaced arrays. in addition, while the literature on BSS algorithms is extensive, their performance under varying noise conditions has not been widely explored. Also, though usually …

Tissue Engineering An Acellular Bioresorbable Vascular Graft To Promote Regeneration, Patricia Wolfe

Theses and Dissertations

Tissue engineering is an interdisciplinary field that aims to restore, maintain, or improve diseased or damaged tissues. Electrospinning has become one of the most popular means to fabricate a scaffold for various tissue engineering applications as the process is extremely versatile and inexpensive. The ability for electrospinning to consistently create nanofibrous structures capable of mimicking the native extracellular matrix (ECM) is the basis behind why this technique is so successful in tissue engineering. Cardiovascular disease has been the leading cause of death in the United States for over 100 years, and because of this, the need for coronary artery replacements …

Thermodynamic Limit To Photonic-Plasmonic Light-Trapping In Thin Films On Metals, Eric A. Schiff

Physics - All Scholarship

We calculate the maximum optical absorptance enhancements in thin semiconductor films on metals due to structures that diffuse light and couple it to surface plasmon polaritons. The calculations can be used to estimate plasmonic effects on light-trapping in solar cells. The calculations are based on the statistical distribution of energy in the electromagnetic modes of the structure, which include surface plasmon polariton modes at the metal interface as well as the trapped waveguide modes in the film. The enhancement has the form 4n²+nλ/h (n – film refractive index, λ – optical wavelength, h …

Bearing-Only Cooperative-Localization And Path-Planning Of Ground And Aerial Robots, Rajnikant Sharma

Theses and Dissertations

In this dissertation, we focus on two fundamental problems related to the navigation of ground robots and small Unmanned Aerial Vehicle (UAVs): cooperative localization and path planning. The theme running through in all of the work is the use of bearing only sensors, with a focus on monocular video cameras mounted on ground robots and UAVs. To begin with, we derive the conditions for the complete observability of the bearing-only cooperative localization problem. The key element of this analysis is the Relative Position Measurement Graph (RPMG). The nodes of an RPMG represent vehicle states and the edges represent bearing measurements …

Investigation Of Biomolecular Interactions For Development Of Sensors And Diagnostics, Xiaojuan Zhang

Theses and Dissertations

The highly specific recognition processes between biomolecules mediate various crucial biological processes. Uncovering the molecular basis of these interactions is of great fundamental and applied importance. This research work focuses on understanding the interactions of several biomolecular recognition systems and processes that can provide fundamental information to aid in the rational design of sensing and molecular recognition tools. Initially, a reliable and versatile platform was developed to investigate biomolecular interactions at a molecular level. This involved several techniques, including biomolecule functionalization to enable attachment to self-assembled monolayers as well as atomic force microscopy (AFM) based force spectroscopy to uncover the …

Solid Oxide Fuel Cell Process And Apparatus, Mathew Ellis Cooper, David J. Bayless, Jason P. Trembly

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H₂S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H₂S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, …

Investigations On The Corrosion Resistance Of Metallic Bipolar Plates (Bpp) In Proton Exchange Membrane Fuel Cells (Pemfc) - Understanding Of The Effects Of Material, Coating And Manufacturing, Ender Dur

Theses and Dissertations

Polymer Electrolyte Membrane Fuel Cell (PEMFC) systems are promising technology for contributing to meet the deficiency of world`s clean and sustainable energy requirements in the near future. Metallic bipolar plate (BPP) as one of the most significant components of PEMFC device accounts for the largest part of the fuel cell`s stack. Corrosion for metallic bipolar plates is a critical issue, which influences the performance and durability of PEMFC. Corrosion causes adverse impacts on the PEMFC`s performance jeopardizing commercialization. This research is aimed at determining the corrosion resistance of metallic BPPs, particularly stainless steels, used in PEMFC from different aspects. Material …

On The Effect Of Functionally Graded Materials On Resonances Of Rotating Beams, Arnaldo J. Mazzei Jr.

Mechanical Engineering Publications

Radially rotating beams attached to a rigid stem occur in several important engineering applications. Some examples include helicopter blades, turbine blades and certain aerospace applications. In most studies the beams have been treated as homogeneous. Here, with a goal of system improvement, non-homogeneous beams made of functionally graded materials are explored. The effects on the natural frequencies of the system are investigated. Euler-Bernoulli theory, including an axial stiffening effect and variations of both Young's modulus and density, is employed. An assumed mode approach is utilized, with the modes taken to be beam characteristic orthogonal polynomials. Results are obtained via Rayleigh-Ritz …

Engaging New Partners In Transportation Research: Integrating Publishing, Archiving, And Indexing Of Technical Literature Into The Research Process, Mark P. Newton, Darcy M. Bullock, Charles Watkinson, Paul J. Bracke, Deborah K. Horton

Libraries Research Publications

transportation research. The United States Department of Transportation (USDOT) annually invests approximately $180 million in State Planning and Research (SPR) and University Transportation Centers (UTC). This investment generates an extensive portfolio of “grey literature” that is not yet uniformly cataloged or accessible, despite the best efforts of the National Technical Information Service, the Transportation Research Board, and the National Transportation Library. This paper reports on a review of publishing and archiving practices for transportation research technical reports, summarizes best practices, and recommends that UTC and SPR research programs seek and strengthen partnerships with libraries to facilitate improved production, stewardship and …

Field-Effect Amperometric Immuno-Detection Of Protein Biomarker, Jiapeng Wang, Siu-Tung Yau

Electrical and Computer Engineering Faculty Publications

The field-effect enzymatic detection technique has been applied to the amperometric immunoassay of the cancer biomarker, carcinoma antigen 125 (CA 125). The detection adopted a reagentless approach, in which the analyte, CA 125, was immobilized on the detecting electrode, which was modified using carbon nanotubes, and the detection signal was obtained by measuring the reduction peak current of the enzyme that was used to label the antibody. A gating voltage was applied to the detecting electrode, inducing increase in the signal current and therefore providing amplification of the detection signal. The voltage-controlled signal amplification of the detection …

Towards Trustworthy Coordination For Web Services Business Activities, Hua Chai, Hongle Zhang, Wenbing Zhao, P. M. Melliar-Smith, L. E. Moser

Electrical and Computer Engineering Faculty Publications

We present a lightweight Byzantine fault tolerance (BFT) algorithm, which can be used to render the coordination of web services business activities (WS-BA) more trustworthy. The lightweight design of the BFT algorithm is the result of a comprehensive study of the threats to the WS-BA coordination services and a careful analysis of the state model of WS-BA. The lightweight BFT algorithm uses source ordering, rather than total ordering, of incoming requests to achieve Byzantine fault tolerant, state-machine replication of the WS-BA coordination services. We have implemented the lightweight BFT algorithm, and incorporated it into the open-source Kandula framework, which implements …

Bayesian Sediment Transport Model For Unisize Bed Load, Mark L. Schmelter, Mevin B. Hooten, David King Stevens

Civil and Environmental Engineering Faculty Publications

Fluvial sediment transport studies have long underscored the difficulty in reliablyestimating transport model parameters, collecting accurate observations, and makingpredictions because of measurement error, natural variability, and conceptual modeluncertainty. Thus, there is a need to identify modeling frameworks that accommodate theserealities while incorporating functional relationships, providing probability-basedpredictions, and accommodating for conceptual model discrimination. Bayesian statisticalapproaches have been widely used in a number of disciplines to accomplish just this, yetapplications in sediment transport are few. In this paper we propose and demonstrate aBayesian statistical approach to a simple sediment transport problem as a means toovercome some of these challenges. This approach provides …

Exploring The Barriers To Independent Study And Learning In First Year Undergraduate Engineering Students?, Robert Martin Morris

Papers, presentations and other resources

This mixed method case study was carried out in the Technological University Dublin, Ireland and was conducted with the co-operation of four experienced lecturers of engineering and three groups of first year undergraduate engineering students.

The main aim of the research was to identify factors which represent barriers to the independent study and learning of first year engineering students.

Many first year engineering students do not return to college for the second year of their programmes. Many reasons for this are identified in the research, including the failure of students to pass assessments and exams as a result of the …

Electronic Structure Of Realistically Extended Atomistically Resolved Disordered Si:P Delta-Doped Layers, Sunhee Lee, Hoon Ryu, Lloyd Hollenberg, Michelle Simmons, Gerhard Klimeck

Birck and NCN Publications

The emergence of scanning tunneling microscope (STM) lithography and low temperature molecular beam epitaxy (MBE) opens the possibility of creating scalable donor based quantum computing architectures. In particular, atomically precise Si:P monolayer structures (delta-doped layers) serve as crucial contact regions and in-plane gates in single impurity devices. In this paper we study highly confined delta-doped layers to explain the disorder in the P dopant placements in realistically extended systems. The band structure is computed using the tight-binding formalism and charge-potential self-consistency. The exchange-correlation corrected impurity potential pulls down subbands below the silicon valley minima to create impurity bands. Our methodology …

Differential Gene Expression To Investigate The Effects Of Low-Level Electrochemical Currents On Bacillus Subtilis., Robert Szkotak, Tagbo H R Niepa, Nikhil Jawrani, Jeremy L. Gilbert, Marcus B. Jones, Dacheng Ren

Biomedical and Chemical Engineering - All Scholarship

With the emergence and spread of multidrug resistant bacteria, effective methods to eliminate both planktonic bacteria and those embedded in surface-attached biofilms are needed. Electric currents at uA-mA/cm2 range are known to reduce the viability of bacteria. However, the mechanism of such effects is still not well understood. In this study, Bacillus subtilis was used as the model Gram-positive species to systematically investigate the effects of electrochemical currents on bacteria including the morphology, viability, and gene expression of planktonic cells, and viability of biofilm cells. The data suggest that weak electrochemical currents can effectively eliminate B. subtilis both as planktonic …

Comparative Life Cycle Assessments Of Lignocellulosic And Algae Biomass Conversion To Various Energy Products Through Different Pathways, Maria Juliana Pinilla

USF Tampa Graduate Theses and Dissertations

Bioenergy has the potential to reduce the world's dependence on fossil fuels, and to decrease the CO2 emissions due to fossil combustion. Lignocellulosic and algae biomass have been presented as promising feedstocks for bioenergy production.

In this study, a comparative Life Cycle Assessment (LCA) has been developed to evaluate the environmental impacts associated with different energy products via different routes across the whole life of algal and lignocellulosic bioenergy. Results were compared per energy basis, the production of 1 million BTU of energy products.

For the development of the comparative algae biomass conversion LCA, algal biomass was converted to liquid …

Looking After The Best Interests Of Dublin Must Be Top Priority, Lorcan Sirr, Conor Skehan

Media

No abstract provided.

Public Perception Of Unmanned Aerial Vehicles, Alice Tam

Aviation Technology Graduate Student Publications

This study explored public risk perception of unmanned aerial vehicles (UAV) for civilian commercial operations, including cargo and passenger transportation. Civilian operators are considering the use of UAVs to increase safety while reducing labor costs, but negative perceptions may delay the advancement of these aircraft. To document perception of UAV or UAS aircraft for commercial operations, a questionnaire was distributed to adults (ages 18+) who use commercial air travel. The survey classified age group, gender, and UAV familiarity as demographic variables. This study assessed risk perception of UAVs and its correlation to the variables through statistical analysis to identify whether …

Model-Free H∞ Stochastic Optimal Design For Unknown Linear Networked Control System Zero-Sum Games Via Q-Learning, Hao Xu, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, stochastic optimal strategy for unknown linear networked control system (NCS) quadratic zero-sum games related to H∞ optimal control in the presence of random delays and packet losses is solved in forward-in-time manner. This approach does not require the knowledge of the system matrices since it uses Q-learning. the proposed stochastic optimal control approach, referred as adaptive dynamic programming (ADP), involves solving the action dependent Q-function Q (z, u, d) of the zero-sum game instead of solving the state dependent value function J (z) which satisfies a corresponding Game Theoretic Riccati equation (GRE). an adaptive estimator (AE) is …

Calibration And 3-D Sound Reproduction In The Immersive Audio Environment, Pratik Shah, Steven Grant, William Chapin

Electrical and Computer Engineering Faculty Research & Creative Works

The effectiveness of virtual environments depends largely on how efficiently they recreate the real world. in the case of auditory virtual environments, the importance of accurate recreation is enhanced since there are no visual cues to assist perception, as in the case of audio-visual virtual environments. in this paper, we present the Immersive Audio Environment (IAE), an easily constructible and portable structure, which is capable of 3-D sound auralization with very high spatial resolution. a novel method for acoustically positioning loudspeakers in space, which is required by the IAE for simulation of sound sources, is presented in this paper. Our …

Nn/Rise-Based Asymptotic Tracking Control Of Uncertain Nonlinear Systems, Qinmin Yang, Sarangapani Jagannathan, Youxian Sun

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel control methodology for the tracking control of a high-order continuous time nonlinear systems with unknown dynamics and external disturbance. the control signal consists of the robust integral of the sign of the error (RISE) feedback signal multiplied with an adaptive gain plus neural network (NN) output. the two-layer NN learns the system dynamics in an online manner while residual reconstruction errors and the external bounded system disturbances are overcome by the RISE signal. Semi-global asymptotic tracking performance is theoretically guaranteed by using the Lyapunov standard method, while the NN weights and all other signals are …

Artificial Immune System-Based Diagnostics And Prognostics Scheme And Its Experimental Verification, Gary R. Halligan, Balaje T. Thumati, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel fault diagnostics and prediction (FDP) scheme is introduced by using artificial immune system (AIS) as an online approximator for a class of nonlinear discrete-time systems. Traditionally, AIS is considered as an offline tool for fault detection (FD). However, in this paper, AIS is utilized as an online approximator in discrete time (OLAD) along with a robust adaptive term in the proposed fault diagnostics observer. using the fact that the system outputs are alone measurable, an output residual is determined by comparing the observer and system outputs and a fault is detected if this output residual …

An Online Model-Based Fault Diagnosis Scheme For Hvac Systems, Balaje T. Thumati, Miles A. Feinstein, James W. Fonda, Alfred Turnbull, Fay J. Weaver, Mark E. Calkins, S. Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a model-based fault detection and isolation (FDI) scheme with online fault learning capabilities is proposed for HVAC systems. an observer comprising of an online approximator in discrete-time (OLAD) and a robust term is used for detection. a fault is detected if the generated detection residual, which is defined as the error between the observer outputs and HVAC system states, exceeds an apriori chosen threshold. the OLAD term in the FD observer learns the fault dynamics online while the robust term guarantees asymptotic estimation of the system states. Subsequent to detection, a fault isolation observer, which comprises of …

Analysis Of Coal By Static Time-Of-Flight Secondary Ion Mass Spectrometry (Tof-Sims), Lei Pei, Guilin Jiang, Larry Lin Baxter, Matthew R. Linford

Faculty Publications

Coal remains a primary fuel for power generation. Herein we present time-of-flight secondary ion mass spectra (ToF-SIMS data) taken with a Ga primary ion beam from ca. 30 coal specimens. These commercially different coal specimens were obtained from coal mining companies and/or power plants. They represent all major coal types used in power generation (bituminous coals, subbituminous coals, and lignites), and include low-rank materials (lignites and subbituminouscoals), which are represented as a minor portion of the data. Often, inorganic ions (Na, Al, Si,and K) are pronounced in the spectra, overshadowing peaks from organic moieties. This reflectsthe high sensitivity of SIMS …