Engineering Commons^™

Nanomechanical And Nanotribological Characterization Of Sub-Micron Polymeric Spheres, Himanshu Kumar Verma

USF Tampa Graduate Theses and Dissertations

Friction between nanoscale objects has been a subject of great interest and intense research effort for the last two decades. However, the vast majority of the work done in this area has focused upon the sliding friction between two rigid, atomically smooth surfaces. Thus the parameter most explored has been the corrugation in the atomic potentials and how this affects the force required to slide one object across another. In truth, many nanoscale objects whose translation force is of practical interest are more spherical in nature. We hypothesize that the factors that determine the translation force will be related, not …

An Investigation On The Band Gap And Band Edge Of Semi-Conducting Lanthanum Transition Metal Perovskites For Photocatalytic Applications, Divya Suresh

USF Tampa Graduate Theses and Dissertations

For the past few decades, a frenzy of attention has been given towards the development of an assortment of photocatalysts as a solution for various environmental problems. TiO2 is the most widely used photocatalyst. TiO2 is biocompatible, chemically and thermally stable but TiO2 and a vast majority other photocatalysts have large band gaps, and hence they find applicability only in the UV region of the solar spectrum. These large band gap photocatalysts suffer a severe limitation with regard to their overall process efficiency as the UV region contributes to about 3 to 4 % of the solar spectrum in terms …

The Effect Of Urbanization On The Embodied Energy Of Drinking Water In Tampa, Florida, Mark Vincent Eli Santana

USF Tampa Graduate Theses and Dissertations

Increasing urbanization has serious implications for resource and energy use. One of these resources is drinking water. The increased amount of impervious surfaces associated with urban development is responsible for increased runoff during rain events, which may have a negative impact on the quality of nearby bodies of water, including drinking water sources. The growing populations associated with urbanization require a higher water demand. In addition, urban drinking water systems use energy to collect, treat, and distribute a safe reliable effluent to users. Therefore, this study focuses on the degree to which urbanization influences the embodied energy of drinking water …

Optimization And Control For Microgrid And Power Electronic Converters, Vahid Rasouli Disfani

USF Tampa Graduate Theses and Dissertations

The proposed dissertation research investigates Optimization and Control for Microgrid and Power Electronic Converters. The research has two major parts:

i- Microgrid Operation and Control,

ii- Power Electronic Converter Control and Optimization.

In the first part, three focuses are investigated. First, a completely distributed algorithm is developed for dc optimal power flow problem for power distribution systems as one of the necessary functions considered in unit-commitment problem in day-ahead markets. This method is derived based upon the partial primal-dual representation of the economic dispatch problem, which is finally translated to DC-OPF problem. Second, the optimal interaction between the utility and …

Applications Of Optical Properties From Nanomaterials For Enhanced Activity Of A Titania Photocatalyst Under Solar Radiation, Jon W. Pickering

USF Tampa Graduate Theses and Dissertations

In recent years, employing advanced oxidation processes (AOPs) as a means of wastewater remediation has emerged as a promising route towards maintaining a sustainable global water management program. The heterogeneous photocatalytic oxidation process has been of particular interest due to the prospective of utilizing solar radiation as the driving force behind the degradation of pollutants. Of the photocatalyst studied to date, TiO2 remains the most attractive material for environmental applications due to its affordability, stability, biocompatibility and high quantum yield. A key draw back however is roughly only 5% of solar radiation incident on earth can provide the energy required …

Topographical Enhancement Of Cell Adhesion On Poorly Adhesive Materials, Maritza Muniz Maisonet

USF Tampa Graduate Theses and Dissertations

The overall thrust of this dissertation is to gain a fundamental understanding of the synergistic effects between surface topography and chemical functionality of poorly adhesive materials on enhancing the adhesion of mouse embryonic fibroblasts. Cellular response to surface topography and chemical functionality have been extensively studied on their own providing valuable information that helps in the design of new and improved biomaterials for tissue engineering applications. However, there is a lack of understanding of the synergistic effect of microscale and nanoscale topography with chemical functionality and the relative impact and contribution of each in modulating cellular behavior. By understanding the …

Spatiotemporal Sensing And Informatics For Complex Systems Monitoring, Fault Identification And Root Cause Diagnostics, Gang Liu

USF Tampa Graduate Theses and Dissertations

In order to cope with system complexity and dynamic environments, modern industries are investing in a variety of sensor networks and data acquisition systems to increase information visibility. Multi-sensor systems bring the proliferation of high-dimensional functional Big Data that capture rich information on the evolving dynamics of natural and engineered processes. With spatially and temporally dense data readily available, there is an urgent need to develop advanced methodologies and associated tools that will enable and assist (i) the handling of the big data communicated by the contemporary complex systems, (ii) the extraction and identification of pertinent knowledge about the environmental …

Energy Production And Effluent Quality In Tubular Digesters Treating Livestock Waste In Rural Costa Rica, Maureen Njoki Kinyua

USF Tampa Graduate Theses and Dissertations

Use of tubular anaerobic digesters to treat livestock waste in developing countries has energy, agricultural, health, social and environmental benefits. However, careful use of digester effluent as a soil amendment is required due to the potential presence of protozoan parasites Cryptosporidium parvum and Giardia lamblia. This research investigated the performance of four tubular digesters in the Monteverde region of Costa Rica. High (>75%) volatile solids and BOD5 removal efficiencies were observed, which was attributed to the formation of a biologically active floccular sludge layer. Computational fluid dynamics (CFD) and bioprocess models were developed to evaluate the transport and transformation …

Environmental Sustainability Of Wastewater Treatment Plants Integrated With Resource Recovery: The Impact Of Context And Scale, Pablo K. Cornejo

USF Tampa Graduate Theses and Dissertations

There is an urgent need for wastewater treatment plants (WWTPs) to adapt to a rise in water and energy demands, prolonged periods of drought, climate variability, and resource scarcity. As population increases, minimizing the carbon and energy footprints of wastewater treatment, while properly managing nutrients is crucial to improving the sustainability WWTPs. Integrated resource recovery can mitigate the environmental impact of wastewater treatment systems; however, the mitigation potential depends on various factors such as treatment technology, resource recovery strategy, and system size.

Amidst these challenges, this research seeks to investigate the environmental sustainability of wastewater treatment plants (WWTPs) integrating resource …

A Study On 2.45 Ghz Bandpass Filters Fabricated With Additive Manufacturing, Nicholas Christian Arnal

USF Tampa Graduate Theses and Dissertations

Square open loop resonator (SOLR) bandpass filters fabricated with additive manufacturing techniques are presented and studied. One filter contains novel 3D capacitive plates used to enhance resonator coupling. The filters are centered at 2.45 GHz and loaded with capacitors for miniaturization as low as 21% that of a conventional SOLR bandpass filter. The pass-band insertion loss of the filters ranges from 3.8 dB to 5.5 dB and the 3 dB bandwidth ranges from 180 MHz to 250 MHz. Also, degradation in the effective conductivity of printed ink as a function of substrate roughness is analyzed. Finally, a study of dielectric …

Secure Wearable Systems With Wireless Phy-Layer Information, Lu Shi

Theses and Dissertations

In wireless wearable system such as body area network (BAN), device authentication and secret key extraction are essential for trustworthy and reliable gathering and delivery of user’s critical health information. Traditional authentication solutions depend on prior trust among nodes whose establishment would require either key pre-distribution or non-intuitive participation by inexperienced users. Most existing non-cryptographic authentication schemes require advanced hardware or significant modifications to the system software, which are impractical for BANs. Recently, most wireless network security schemes merely based on physical layer characteristics tackle device authentication and secret key extraction, but separately. It remains an open problem to simultaneously …

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• 2015 CEIT Faculty Research Seed Grants
• 2015 CEIT Undergraduate Research Awards

Performance Evaluation And Qos Enhancement Of Sip-Based Protocols For Ims Services, Rania Nazar Saleem

Theses and Dissertations

Of the various types of VoIP handling protocols, the Session Initiation Protocol (SIP) is an application layer protocol considered to be the most commonly used signaling protocol in the VoIP services industry. It is used for the purpose of creation, modification, and termination of sessions that contain multimedia streams at the endpoints known as User Agents (UA). SIP was standardized by the Internet Engineering Task Force (IETF) and is designed to work with other IETF Internet protocols to establish a full multimedia session. SIP is also the basis for the operation of IP Multimedia Subsystem (IMS), which forms the essential …

Rigidly Foldable Origami Gadgets And Tessellations, Thomas A. Evans, Robert J. Lang, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Rigidly foldable origami allows for motion where all deflection occurs at the crease lines and facilitates the application of origami in materials other than paper. In this paper, we use a recently discovered method for determining rigid foldability to identify existing flat-foldable rigidly foldable tessellations, which are also categorized. We introduce rigidly foldable origami gadgets which may be used to modify existing tessellations or to create new tessellations. Several modified and new rigidly foldable tessellations are presented.

Growing Algae In Produced Water | College Of Engineering, Usu College Of Engineering

College of Engineering News

LOGAN, Utah, Sept. 15, 2015 – The wastewater evaporation ponds that support the oil and natural gas extraction industries in the Uintah Basin may soon help spur the development of alternative bio-based fuels.

Uintah Basin’S Wastewater Evaporation Ponds Could Yield Bioenergy | Biological Engineering, Usu College Of Engineering

College of Engineering News

LOGAN, Utah, Sept. 15, 2015 – The wastewater evaporation ponds that support the oil and natural gas extraction industries in the Uintah Basin may soon help spur the development of alternative bio-based fuels.

Bugg, Becky (Fa 815), Manuscripts & Folklife Archives

Folklife Archives Finding Aids

Finding aid only for Folklife Archives Project 815. Paper titled “ Process of Milling: Case Studies,” prepared by Becky Bugg a folk studies student at Western Kentucky University. Bugg documents flour mills in Mercer County and Meade County, Kentucky.

Physiological Roles Of Pyruvate Ferredoxin Oxidoreductase And Pyruvate Formate-Lyase In Thermoanaerobacterium Saccharolyticum Jw/Sl-Ys485, Jilai Zhou, Daniel G. Olson, Anthony A. Lanahan, Liang Tian, Sean Jean-Loup Murphy, Jonathan Lo, Lee R. Lynd

Dartmouth Scholarship

Background:

Thermoanaerobacter saccharolyticum is a thermophilic microorganism that has been engineered to produce ethanol at high titer (30–70 g/L) and greater than 90 % theoretical yield. However, few genes involved in pyruvate to ethanol production pathway have been unambiguously identified. In T. saccharolyticum, the products of six putative pfor gene clusters and one pfl gene may be responsible for the conversion of pyruvate to acetyl-CoA. To gain insights into the physiological roles of PFOR and PFL, we studied the effect of deletions of several genes thought to encode these activities.

Results:

It was found that pyruvate ferredoxin oxidoreductase enzyme …

Morphology Of Nanoporous Carbon-Binder Domains In Li-Ion Batteries—A Fib-Sem Study, Severin Vierrath, Lukas Zielke, Riko Moroni, Andrew Mordon, Dean R. Wheeler, Roland Zengerle, Simon Thiele

Faculty Publications

FIB-SEM tomography is used to reconstruct the carbon-binder domain (CBD) of a LiCoO2 battery cathode (3.9 × 5 × 2.3 μm3) with contrast enhancement by ZnO infiltration via atomic layer deposition. We calculate the porosity inside the CBD (57.6%), the cluster-size distribution with a peak at 54 nm, and the pore-size distribution with a peak at 64 nm. The tortuosities of the pore space (1.6–2.0) and the CBD (2.3–3.5) show a mild anisotropy, which is attributed to the fabrication process. A comparison to a modeled homogenous CBD reveals that clustering in the CBD decreases its electronic conductivity while increasing …

The Effects Of Simplifications On Isolated Wheel Aerodynamics, Sammy Diasinos, Tracie Barber, Graham Doig

Aerospace Engineering

In order to study the aerodynamic forces and flow features of rotating wheels, compromises and simplifications are often made in wind tunnel testing, and more frequently so in numerical modelling. A CFD approach similar to that commonly used in industry was utilised to investigate common assumptions involving; the influence of geometric fidelity in wheel hub regions, ground representation, the modelling of the contact patch, and the effects of rotation on separation. It was found that the separation and wake characteristics were strongly influenced by the rotation of the wheel; the separation point changed by as much as 90% compared to …

B.E. Club Lab Tour | Biological Engineering, Usu College Of Engineering

College of Engineering News

Happy September 14th, 2015 (Monday) everyone! A reminder that tomorrow, September 15th, we are doing a lab tour of Dr. Miller’s lab. You can meet us at either the lab (SER 117) or in the ENGR building’s atrium 10 to 15 minutes before 5 pm so we can walk over as a group. The lab tour should last about 20 minutes, give or take. If you have not paid the membership fee ($5) and would still like to, we will be able sign you up either before or after the lab tour. Hope to see you there!

Electrical & Computer Engineering News, Georgia Southern University

Electrical & Computer Engineering: News & Publications (2014-2023)

• GS Electrical Engineering Graduate Student Receives Prestigious IEEE Travel Award

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

• EE Graduate Student Receives Prestigious IEEE Travel Grant

Root Causes Of Premature Pavement Failures Of Arkansas Interstate System, Nazmul Huda Chowdhury

Student Theses and Dissertations

As part of a major rehabilitation program during 1999-2004, several sections of the Arkansas Interstate Systems were overlayed. Some of these sections experienced severe distresses (rutting and cracking), while the others were performing well. The objective of the study is to evaluate the root causes of the poor performing pavements. Consequently, historical data were analyzed and mechanistic tests were performed on collected core samples from existing pavements in order to establish correlations with parameters influencing the aforementioned distresses. The initial high roughness value and high asphalt binder- aggregate ratio in poor performing sections indicate a stiffer mixture susceptible to premature …

Enhancing Wifi-Based Localization With Visual Clues, Han Xu, Zheng Yang, Zimu Zhou, Longfei Shangguan, Yunhao Liu, Ke Yi

Research Collection School Of Computing and Information Systems

Indoor localization is of great importance to a wide range of applications in the era of mobile computing. Current mainstream solutions rely on Received Signal Strength (RSS) of wireless signals as fingerprints to distinguish and infer locations. However, those methods suffer from fingerprint ambiguity that roots in multipath fading and temporal dynamics of wireless signals. Though pioneer efforts have resorted to motion-assisted or peer-assisted localization, they neither work in real time nor work without the help of peer users, which introduces extra costs and constraints, and thus degrades their practicality. To get over these limitations, we propose Argus, an image-assisted …

Molexpl: A Tool For Ab Initio Data Exploration And Visualization, Xueying Wang, Nicolas Onofrio, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Density functional theory (DFT) based on ab initio theory, is a powerful method to resolve the electronic structure of atoms, molecules and solids. However, in practical, DFT is limited to few hundreds of atoms. To overcome this limitation, researchers have developed empirical interatomic potentials implemented in molecular dynamics (MD) simulations. MD ignores the movements of electrons and describes bonding and non-bonding interaction as a function of the distance between atoms called force fields (FF) or interatomic potentials. These empirical potentials are optimized against large datasets of DFT calculations relevant to describe the interactions between the atoms included in the training …

Particle Filtering For Eeg Source Localization And Constrained State Spaces, Bradley Ebinger

Theses and Dissertations

Particle Filters (PFs) have a unique ability to perform asymptotically optimal estimation for non-linear and non-Gaussian state-space models. However, the numerical nature of PFs cause them to have major weakness in two important areas: (1) handling constraints on the state, and (2) dealing with high-dimensional states. In the first area, handling constraints within the PF framework is crucial in dynamical systems, which are often required to satisfy constraints that arise from basic physical laws or other considerations. The current trend in constrained particle filtering is to enforce the constraints on all particles of the PF. We show that this approach …

Using Simulation & Joint Time/Frequency Domain Analysis To Evaluate Absorber/Lossy Material Performance In Resonant Cavities, Bruce Archambeault, Michael Varner, Jiawei Zhang, Sam Connor, Edward Wheeler

Electrical and Computer Engineering Faculty Research & Creative Works

Comparing the effectiveness of different absorber/lossy materials as a function of frequency can be difficult and prone to misunderstanding when the reduction in field strength is observed directly. Often these materials are used in highly resonant cavities, therefore a better measure of the reduction of field strength is the resonant quality factor (Q-factor). The Joint Time-Frequency domain analysis technique allows simulation data from time domain simulations to be easily converted to Q-factor and allows quick and straightforward analysis of the improvement gained by using various absorber/lossy materials. Measurements are made to validate the simulation results.

Information Technology News, Georgia Southern University

Information Technology: News & Publications (2012-2023)

• IT student wins prestigious CSX scholarship

Brief Look At The Environment Of Space, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Brief Look at the Environment of Space" from September 10, 2015.