Engineering Commons^™

Trident: A Comprehensive Timing Error Resilient Technique Against Choke Points At Ntc., Aatreyi Bal, Sanghamitra Roy, Koushik Chakraborty

Electrical and Computer Engineering Faculty Publications

Near Threshold Computing (NTC) systems have been inherently plagued with heightened process variation (PV) sensitivity. Choke points are an intriguing manifestation of this PV sensitivity. In this paper, we explore the probability of minimum timing violations, caused by choke points, in an NTC system and, their non-Trivial impacts on the system reliability. We show that conventional timing error mitigation techniques are inefficient in tackling choke point induced minimum timing violations. Consequently, we propose a comprehensive error mitigation technique, Trident, to tackle choke points, at NTC. Trident offers a 1.37x performance improvement and a 1.1x energy efficiency gain over Razor at …

Complete Stress-Induced Depolarization Of Relaxor Ferroelectric Crystals Without Transition Through A Non-Polar Phase, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Wesley Hackenberger, Jun Luo, Shujun Zhang, Christopher S. Lynch, Jay B. Chase, Hwan R. Jo, Christopher C. Roberts

Mining Engineering Faculty Research & Creative Works

The development of relaxer ferroelectric single crystal technology is driven by the ability to tailor ferroelectric properties through domain engineering not achievable in polycrystalline materials. In this study, three types of domain-engineered rhombohedral Pb (In_1/2Nb_1/2) O₃-Pb (Mg_1/3Nb_2/3) O₃-PbTiO₃ crystals were subjected to transverse high strain rate loading. The experimental results indicate that the domain configuration has a significant effect on the stress-induced depolarization and the associated charge released. A complete depolarization of the single-domain crystals with 3m symmetry is observed, while multidomain crystals with 4mm and mm2 …

Nonlinear Control Of Underactuated And Constrained Systems, Derek Hoffman

Doctoral Dissertations and Master's Theses

It is the purpose of this document to elaborate on the control of systems that are underactuated or otherwise constrained. To do so, local- and global-coordinate formulations are implemented to generate well-defined system dynamics for a multitude of scenarios. These dynamics are shown to lie on manifolds defined by mathematical restrictions, allowing for singularity-free modeling for global considerations. Feed-back controllers by extension share these benefits, facilitating singularity-free control algorithms as a result. Further, unactuated degrees of freedom can be treated as additional constraints, resulting in an embedded manifold upon the original dynamics. A transformation between a provided set of dynamical …

The Effect Of Poly (Glycerol Sebacate) Incorporation Within Hybrid Chitin–Lignin Sol–Gel Nanofibrous Scaffolds, Tuerdimaimaiti Abudula, Lassaad Gzara, Giovanna Simonetti, Ahmed Alshahrie, Numan Salah, Pierfrancesco Morganti, Angelo Chianese, Afsoon Fallahi, Ali Tamayol, Sidi A. Bencherif, Adnan Memic

Department of Mechanical and Materials Engineering: Faculty Publications

Chitin and lignin primarily accumulate as bio-waste resulting from byproducts of crustacean crusts and plant biomass. Recently, their use has been proposed for diverse and unique bioengineering applications, amongst others. However, their weak mechanical properties need to be improved in order to facilitate their industrial utilization. In this paper, we fabricated hybrid fibers composed of a chitin–lignin (CL)-based sol–gel mixture and elastomeric poly (glycerol sebacate) (PGS) using a standard electrospinning approach. Obtained results showed that PGS could be coherently blended with the sol–gel mixture to form a nanofibrous scaffold exhibiting remarkable mechanical performance and improved antibacterial and antifungal activity. The …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Student Eagle Week

Visualizing Load Path In Perforated Shear Walls, Ying Chih Chen

USF Tampa Graduate Theses and Dissertations

Shear walls are the primary lateral load resisting elements in bearing wall systems used in masonry construction. Horizontal loads due to wind or earthquake are transferred to vertical walls by diaphragms that are rigid such as concrete floor slabs or flexible such as wood floors. With rigid diaphragms, loads are apportioned to the supporting walls based on their relative rigidity. Walls with openings accommodating doors and windows (“perforated walls”) have reduced rigidity that can be determined using available hand calculation methods. These methods primarily focus on analysis procedures, not on the visualization of the load path that is critically important …

Comparison Of Functional Porous Organic Polymers (Pops) And Natural Material Zeolite For Nitrogen Removal And Recovery From Synthetic Urine, Yan Zhang

USF Tampa Graduate Theses and Dissertations

Urine comprises around 1% of domestic sewage volume but holds 80% of total nitrogen. Source separation is a sustainable way to wastewater management than traditional way due to low energy cost and preventing certain pollutants into wastewater treatment plants. Currently, removing and recovering nitrogen from source-separated urine has attracted more and more interests. Of them, ion exchange was used for removal and recovery of nitrogen in the form of ammonia from synthetic urine for potential application as a fertilizer in agriculture. No previous research studies were conducted to investigate the removal and recovery of nitrogen from hydrolyzed urine by ion …

Conversion Of Biomass To Liquid Hydrocarbon Fuels Via Anaerobic Digestion: A Feasibility Study, Ahmad Naqi

USF Tampa Graduate Theses and Dissertations

The use of biomass as a potential feedstock for the production of liquid hydrocarbon fuels has been under investigation in the last few decades. This paper discusses a preliminary design and a feasibility study of producing liquid hydrocarbon fuels from biomass through a combined biochemical and thermochemical route. The process involves anaerobic digestion (AD) of the biodegradable portion of the biomass to produce methane rich gas. The methane rich biogas stream is purified by removing contaminants and upgraded to liquid hydrocarbon fuel in a gas to liquid facility (GTL) via thermochemical conversion route. The biogas conversion involves two major steps: …

Synthesis And Characterization Of Polymer-Silica Composite Hydrogel Particles And Influence Of Hydrogel Composition On Cement Paste Microstructure, Matthew J. Krafcik, B Bose, Kendra Erk

School of Materials Engineering Faculty Publications

The objective of this research is to define the fundamental structure-property relationships of water-swollen polymer hydrogel particles that are employed as internal curing agents in cementitious mixtures, in addition to reporting a novel synthesis procedure for combining pozzolanic materials with hydrogel particles. Solution polymerization was performed to incorporate amorphous nanosilica particles within acrylic-based polymer hydrogel particles of varying chemical compositions (i.e., monomer ratio of acrylic acid (AA) to acrylamide (AM)). Experiments were designed to measure the absorption capacity and kinetics of hydrogel particles immersed in pure water and cementitious pore solution, as well as determine the impact of particles on …

Environmental Engineering At Cal Poly-San Luis Obispo, Harold M. Cota

Civil and Environmental Engineering

The story recorded here began with a timeline prepared by Professor Rod Keif outlining some of the important events in the formation of the Environmental Engineering Department at Cal Poly-San Luis Obispo. He expanded the timeline and added some comments in a 5-page History of Environmental Engineering at Cal Poly in 1998 (1).

Rod Keif was a key player in the Air Conditioning and Refrigeration Engineering Department that eventually became the Environmental Engineering Department. He prepared his students to be leaders in the industry, received the Distinguished Teachers Award in 1967, and was chairman of the Academic Senate in 1969. …

Estimation Of 3d Orientation From Inertial Sensors With Different/Nonuniform Sampling, Soulaimane Berkane

Western Research Forum

No abstract provided.

Adsorption Of Dyes On New Synthesised Layered Double Hydroxide Materials, Intissar Harizi

Western Research Forum

No abstract provided.

Experimental Examination Of Vorticity Stripping From A Wing-Tip Vortex In Free-Stream Turbulence, Hari C. Ghimire, Sean C. C. Bailey

Mechanical Engineering Faculty Publications

Time-resolved stereoscopic particle image velocimetry measurements were conducted of a wing-tip vortex decaying in free-stream turbulence. The objective of the research was to experimentally investigate the mechanism causing the increased rate of decay of the vortex in the presence of turbulence. It was observed that the circulation of the vortex core experienced periods of rapid loss and recovery when immersed in free-stream turbulence. These events were not observed when the vortex was in a laminar free stream. A connection was made between these events and distortion of the vortex, coinciding with stripping of core fluid from the vortex core. Specifically, …

Preparation, Modification, Characterization, And Biosensing Application Of Nanoporous Gold Using Electrochemical Techniques, Jay Bhattarai, Dharmendra Neupane, Bishal Nepal, Vasilii Mikhaylov, Alexei Demchenko, Keith Stine

Chemistry & Biochemistry Faculty Works

Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning …

A Study Of The Hexakis Icosahedron Vacuum Lighter Than Air Vehicle And The Effects Of Air Evacuation On The Structural Integrity, Anthony A. Castello

Theses and Dissertations

The research this paper focuses on is comparing the structural differences between the icosahedron and hexakis icosahedron frame and skin for use as a vacuum lighter than air vehicle (VLTAV), analyzing the stress concentrations in the hexakis icosahedron both with and without the skin, and finding the optimal location and size of the air evacuation method for creating the internal vacuum. Previous research to date has identified dynamic loading on the structure and optimization of the structure, but this will be the first research to analyze the manufacturing of the structure through the development of the air evacuation design. Findings …

Geometric Construction-Based Realization Of Spatial Elastic Behaviors In Parallel And Serial Manipulators, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

This paper addresses the realization of spatial elastic behavior with a parallel or a serial manipulator. Necessary and sufficient conditions for a manipulator (either parallel or serial) to realize a specific elastic behavior are presented and interpreted in terms of the manipulator geometry. These conditions completely decouple the requirements on component elastic properties from the requirements on mechanism kinematics. New construction-based synthesis procedures for spatial elastic behaviors are developed. With these synthesis procedures, one can select each elastic component of a parallel (or serial) mechanism based on the geometry of a restricted space of allowable candidates. With each elastic component …

Microwave Materials Characterization And Imaging For Structural Health Monitoring, Reza Zoughi

INSPIRE Archived Webinars

The relatively small wavelengths and large bandwidths associated with microwave signals make them great candidates for inspection of construction materials and structures, and for materials characterization and imaging. Signals at these frequencies readily penetrate inside of dielectric materials and composites and interact with their materials characteristics and inner structures. Water molecule is dipolar and possesses a relatively large complex dielectric constant, which is also highly sensitive to the presence of ions that increase its electrical conductivity. Consequently, chemical and physical changes in construction materials affect their complex dielectric constant. This can be measured, and through analytical and empirical dielectric mixing …

Congratulation A-Pin Recipients | College Of Engineering, Usu College Of Engineering

College of Engineering News

Interim College of Engineering Dean Dr. Jagath Kaluarachchi and department heads from across the College of Engineering on Thursday recognized sixteen students for receiving the prestigious A-Pin award.

Electrically Tunable Polarizer Based On Graphene-Loaded Plasmonic Cross Antenna, Yuwei Qin, Xiaoyan Y.Z. Xiong, Wei E.I. Sha, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

The unique gate-voltage dependent optical properties of graphene make it a promising electrically tunable plasmonic material. In this work, we proposed in situ control of the polarization of nanoantennas by combining plasmonic structures with an electrostatically tunable graphene monolayer. The tunable polarizer is designed based on an asymmetric cross nanoantenna comprising two orthogonal metallic dipoles sharing the same feed gap. Graphene monolayer is deposited on a Si/SiO2 substrate and inserted beneath the nanoantenna. Our modelling demonstrates that as the chemical potential is incremented up to 1 eV by electrostatic doping, resonant wavelength for the longer graphene-loaded dipole is blue shifted …

Bio-Inspired Hybrid Vibration Control Methodology For Intelligent Isolated Bridge Structures, Mariantonieta Gutierrez Soto

Civil Engineering Faculty Publications

Inspired by evolutionary game theory, the biological game of replicator dynamics is investigated for vibration control of bridge structures subjected to earthquake excitations. Replicator dynamics can be interpreted economically as a model of imitation of successful individuals. This paper uses replicator dynamics to reduce vibrations while optimally allocating the control device forces. The control algorithm proposed is integrated with a patented neural dynamic optimization algorithm to find optimal growth rate values with the goal of achieving satisfactory structural performance with minimum energy consumption. A model is described for hybrid vibration control of smart highway bridge structures subjected to earthquake loading.

Education Institutions Creation Of Partnerships, Iwasan D. Kejawa Ed.D

Department of Educational Administration: Faculty Publications

This issue is embracing the creation of partnerships with establishments worldwide for the provisions of life embodiments to graduates. At moment, there may be lack of friendship or partnership with establishments to create incentives for newly graduates of so many colleges and universities (Hirsh & Weber, 1999). Partnership with external companies will surely bring enormous grants to the colleges and universities and it will also encourage friendly establishments to provide incentives and perks to colleges, universities and alumni. It may be concluded that the advantages of creating rapport with external congruences is the comraderies and also compromises that will be …

Charpy Impact Test Methods For Cementitious Composites: Review And Commentary, Robert J. Thomas, Andrew D. Sorensen

Civil and Environmental Engineering Faculty Publications

Several researchers have recently employed the Charpy method to characterize the high strain rate mechanical strength of cementitious composites. This paper provides a critical review of existing applications of the Charpy method for impact testing of cementitious composites. Studies have employed various specimen sizes and geometries. Additionally, some studies have tested notched specimens while others have tested plain. Furthermore, varying methods of normalization result in results reported in a variety of incompatible units. The lack of consistency between studies limits the basis for comparison and the ability to validate results, which demonstrates a clear need for a standardized method for …

Developing Motion Platform Dynamics For Studying Biomechanical Responses During Exercise For Human Spaceflight Applications, Kaitlin Lostroscio

USF Tampa Graduate Theses and Dissertations

In future human spaceflight missions, with prolonged exposure to microgravity, resistive and aerobic exercises will be countermeasures for bone loss, muscle loss, and decreased aerobic capacity. Two of the exercises of interest are squats and rowing. The cyclic forces produced during these exercises are at relatively low frequencies which are likely to excite structural resonances of space vehicles. Vibration Isolation Systems (VIS) are being designed to be paired with future exploration exercise devices in order to prevent these cyclic exercise forces from impacting the space vehicle. The VIS may be configured such that a platform supports the human and exercise …

Application Of Cross-Linked Polyborosiloxanes And Organically Modified Boron Silicate Binders In Silicon-Containing Anodes For Lithium-Ion Batteries, Darius A. Shariaty, Dali Qian, Yang-Tse Cheng, Susan A. Odom

Chemistry Faculty Publications

To determine the effect of cross-linking in polymer binders on gravimetric capacity and retention in charge/discharge cycling of lithium-ion batteries containing silicon anodes, polymers with a varied chemiophysical characters have been studied as electrode binders. Here we report the utilization of cross-linked polyborosiloxanes and a boron-modified organosilicate as binders for nanoparticulate silicon-containing anodes for lithium-ion batteries. We show that highly cross-linked binders enable a large degree of capacity to be accessed and that capacity retention is greater when the electrodes are cycled in half cells. More extensive analysis of the boron-modified organosilicate is further explored.

Combining Thermo-Plasmonics With Microfluidics For Biological Applications, Sharad Ambardar

USF Tampa Graduate Theses and Dissertations

In this project we, for the first time, integrated microfluidics with thermo-plasmonics. While microfluidics is a popular platform allowing experiments with small volumes of fluid, thermo-plasmonics can be used for powerful particle manipulation including capturing, mixing, filtering and projection. Combined, these two techniques give us an opportunity to work with numerous complex fluids containing particles, cells, and micro-beads. Here we designed, developed and tested several devices demonstrating various aspects of this exciting hybrid technology. This required use of soft lithography, metal deposition, 3D printing, oxygen plasma treatment and several other surface modification techniques. Additional challenges were in the fabrication of …

Applications Of Open Source Gmaw-Based Metal 3-D Printing, Yuenyong Nilsiam, Paul G. Sanders, Joshua M. Pearce

Department of Materials Science and Engineering Publications

The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width …

Atomic Layer Deposition On Porous Materials: Problems With Conventional Approaches To Catalyst And Fuel Cell Electrode Preparation, Tzia Ming Onn, Rainer Küngas, Paolo Fornasiero, Kevin Huang, Raymond J. Gorte

Faculty Publications

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker …

Engineering Women’S Attitudes And Goals In Choosing Disciplines With Above And Below Average Female Representation, Dina Verdín, Allison Godwin, Adam Kirn, Lisa Benson, Geoff Potvin

School of Engineering Education Graduate Student Series

Women’s participation in engineering remains well below that of men at all degree levels. However, despite the low enrollment of women in engineering as a whole, some engineering disciplines report above average female enrollment. We used multiple linear regression to examine the attitudes, beliefs, career outcome expectations, and career choice of first-year female engineering students enrolled in below average, average, and above average female representation disciplines in engineering. Our work begins to understand how the socially constructed masculine cultural norms of engineering may attract women differentially into specific engineering disciplines. This study used future time perspective, psychological personality traits, grit, …

1931 - Rainfall And Stream Run-Off In Southern California Since 1769

Miscellaneous Documents and Reports

This report consists of a compilation and study of the varied information available for the purpose of determining and reconstructing the record of rainfall and runoff fluctuations in Southern California since the arrival of the Spanish Mission Fathers in 1769. By 1931, data regarding rainfall and stream runoff in Southern California had only been collected by rain gauges for approximately 50 years. Beginning in 1769 with the establishment of the first Spanish Mission in Alta California substantial amount of data existed in the form of the letters and reports from Mission Padres who related in detail information regarding the rain …

College Of Engineering News, Georgia Southern University

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

• IT Students win SE Decision sciences Institute 2018 Best paper award.