Engineering Commons^™

Blazed Metasurface Grating With Handedness Preservation For Circularly Polarized Incident Wave, Xiaoqiang Li, Cheng Tao, Lijun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

A new blazed metasurface grating for circularly polarized (CP) incident wave operating at 10 GHz is proposed. Such a structure can provide strong auto-collimation for the CP incident wave. Unlike the conventional scatterer, which typically reverses the handedness of the incident CP wave upon reflection, the proposed grating can preserve the handedness. The auto-collimation blazing effect and handedness preservation are achieved by a specially designed reactive impedance surface, which allows independent response controls to transverse electric (TE) and transverse magnetic (TM) polarizations. The proposed idea is demonstrated by simulations and verified by experiments. Comparisons with conventional sawtooth grating are made …

Genetic Engineering In Agriculture Curricula For Grades 9-12, Tyson Sorensen, Olivia Horning, Kelsey Hall, David Francis, Joshua Dallin

Browse all Datasets

This is a curriculum package that was developed for teachers to be able to integrate genetic engineering and biotechnology concepts, skills, and career applications into their classrooms. This package was developed as part of the LEARN workshop entitled "Genetic Engineering: Workshop for Teachers." This curriculum package includes five full units of instructions with lesson plans, presentation resources, and other resources for teachers. This package is intended for students in grades 9-12.

Each unit is complete with the corresponding slides found in the main Genetic Engineering PowerPoint. Teachers have the liberty to cover the material on an as-needed bases based on …

Copper Complexation By Dissolved Organic Matter In Arid Soils: A Voltametric Study, Spencer M. Steinberg, Vernon F. Hodge

Chemistry and Biochemistry Faculty Research

A voltammetric method was used to estimate the complexing capacity of water extracts from both desert soils sampled at the root zone of creosote and salt cedar plants, and in soils from interspace or background regions where no vegetative influence was apparent. The copper complexing capacity of water extracts of these desert soils was influenced by contact time and pH. In soils from the root zones of creosote and salt cedar plant, copper complexation capacities at pH 8 were from 5 µM to 60 µM after five min contact periods, while 18 h contact periods yielded copper complexation capacities of …

Planar Resonator Embedded Substrate Integrated Waveguide (Siw) Cavity Filter, Kirti Dhwaj, Richard Hadi, Tao Yang, Li (Lijun) Jun Jiang, Joshu Kovitz, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

Two capacitor loaded planar resonators are introduced in a two-cavity substrate integrated waveguide (SIW) structure to obtain a fourth order filter. The planar resonators each produce a transmission zero by signal interference. Design methodology for a 5 % bandwidth bandpass filter operating at 2.35 GHz is presented in the paper. Two transmission zeroes are placed on either side of the filter passband to obtain a quasi-elliptic response with a mid-band inserion loss of 1.65 dB. Good agreement is obtained between measured and simulated responses of the single-layer printed circuit board (PCB) filter.

Intelligent Sensing And Decision Making In Smart Technologies, Wenbing Zhao, Jinsong Wu, Peng Shi, Hongqiao Wang

Electrical and Computer Engineering Faculty Publications

No abstract provided.

Crash Severity Analysis Of Rear-End Crashes In California Using Statistical And Machine Learning Classification Methods, Alidad Ahmadi, Arash Jahangiri, Vincent Berardi, Sahar Ghanipoor Machiani

Psychology Faculty Articles and Research

Investigating drivers’ injury level and detecting contributing factors that aggravate the damage level imposed on drivers and vehicles is a critical subject in the field of crash analysis. In this study, a comprehensive vehicle-by-vehicle crash data set is developed by integrating 5 years of data from California crash, vehicles involved, and road databases. The data set is used to model the severity of rear-end crashes for comparing three analytic techniques: multinomial logit, mixed multinomial logit, and support vector machine (SVM). The results of the crash severity models and the role of contributing factors to the severity outcome of rear-end crashes …

The Feasibility Of High Strength Stainless Steel In Prestressing Applications For Pile Design, Cara Morton

USF Tampa Graduate Theses and Dissertations

Approximately 50% of the Nation’s infrastructure was built over 40 years ago for a 50 year service life according to the National Association of Corrosion Engineers [72]. To mitigate the cost of major repair or replacement at 50 years, AASHTO now requires all new bridge construction to have a 100 year service life. One of the main challenges in achieving this goal is avoiding corrosion, especially in warm, saltwater environments like those found in the Southeastern United States. Elements that cross the waterline (piles) are a weak link the infrastructure. Good quality concrete easily maintains a service life of 75+ …

Weir Family Collection (Mss 651), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid for Manuscripts Collection 651. Letters and papers of the Weir family of Muhlenberg County, Kentucky, and related members of the Rumsey and Miller families. Well-to-do merchants and farmers, the Weirs were leading supporters of the Union during the Civil War, providing advocacy, financial support, and military service. Includes full-text scans of a letter from the brother of steamboat pioneer James Rumsey defending his legacy as an innovator; James Weir's journal; James Weir's will; the annotated recollections of Edward Weir, Sr.; and two letters from former Weir slaves recolonized in Liberia (Click on "Additional files" below).

Silica Nanoparticle-Endothelial Interaction: Uptake And Effect On Platelet Adhesion Under Flow Conditions, Jiban Saikia, Raziye Mohammadpour, Mostafa Yazdimamaghani, Hannah Northrup, Vladimir Hlady, Hamidreza Ghandehari

Chemical and Biochemical Engineering Faculty Research & Creative Works

Silica nanoparticles are extensively used in biomedical applications and consumer products. Little is known about the interaction of these NPs with the endothelium and effect on platelet adhesion under flow conditions in circulation. In this study, we investigated the effect of silica nanoparticles on the endothelium and its inflammation, and subsequent adhesion of flowing platelets in vitro. Platelet counts adhered onto the surface of endothelial cells in the presence of nanoparticles increased at both low and high concentrations of nanoparticles. Preincubation of endothelial cells with nanoparticles also increased platelet adhesion. Interestingly, platelet adhesion onto TNF-α-treated endothelial cells decreased in the …

Linking Lignin Source With Structural And Electrochemical Properties Of Lignin-Derived Carbon Materials, Wenqi Li, Yan Zhang, Lalitendu Das, Yikai Wang, Mi Li, Namal Wanninayake, Yunqiao Pu, Doo Young Kim, Yang-Tse Cheng, Arthur J. Ragauskas, Jian Shi

Biosystems and Agricultural Engineering Faculty Publications

Valorization of lignin to high-value chemicals and products along with biofuel production is generally acknowledged as a technology platform that could significantly improve the economic viability of biorefinery operations. With a growing demand for electrical energy storage materials, lignin-derived activated carbon (AC) materials have received increasing attention in recent years. However, there is an apparent gap in our understanding of the impact of the lignin precursors (i.e., lignin structure, composition and inter-unit linkages) on the structural and electrochemical properties of the derived ACs. In the present study, lignin-derived ACs were prepared under identical conditions from two different lignin …

Big Data And Sensor Network For Construction Material Testing, Yao Shi

Theses and Dissertations

Engineers and contractors need to have a precise understanding of the development progress of concrete strength in the natural environment, which helps to save project time and cost. However, current practice of concrete construction depends on published data, charts and curves from laboratory tests. The data would not show frequently changing environmental conditions in the real world, which can affect concrete quality significantly. The objective of this research is to design a reliable and accurate method to validate test data of the strength developments of concrete specimens in early stages. The approach includes the following tasks: (1) arrange sensors to …

Geoflood: Large-Scale Flood Inundation Mapping Based On High-Resolution Terrain Analysis, Xing Zheng, David R. Maidment, David G. Tarboton, Yan Y. Liu, Paola Passalacqua

Civil and Environmental Engineering Faculty Publications

Recent floods from intense storms in the southern United States and the unusually active 2017 Atlantic hurricane season have highlighted the need for real‐time flood inundation mapping using high‐resolution topography. High‐resolution topographic data derived from lidar technology reveal unprecedented topographic details and are increasingly available, providing extremely valuable information for improving inundation mapping accuracy. The enrichment of terrain details from these data sets, however, also brings challenges to the application of many classic approaches designed for lower‐resolution data. Advanced methods need to be developed to better use lidar‐derived terrain data for inundation mapping. We present a new workflow, GeoFlood, for …

Special Session: The Future Of Iot Security, Sibin Mohan, Mikael Asplund, Gedare Bloom, Ahmad-Reza Sadeghi, Ahmad Ibrahim, Negin Salajageh, Paul Griffioen, Bruno Sinopoli

Faculty Work Comprehensive List

The Internet-of-Things (IoT) is a large and complex domain. These systems are often constructed using a very diverse set of hardware, software and protocols. This, combined with the ever increasing number of IoT solutions/services that are rushed to market means that most such systems are rife with security holes. Recent incidents (e.g., the Mirai botnet) further highlight such security issues. With emerging technologies such as blockchain and software-defined networks (SDNs), new security solutions are possible in the IoT domain. In this paper we will explore future trends in IoT security: (a) the use of blockchains in IoT security, (b) data …

Sdnet2018: An Annotated Image Dataset For Non-Contact Concrete Crack Detection Using Deep Convolutional Neural Networks, Sattar Dorafshan, Robert J. Thomas, Marc Maguire

Civil Engineering Faculty Publications

SDNET2018 is an annotated image dataset for training, validation, and benchmarking of artificial intelligence based crack detection algorithms for concrete. SDNET2018 contains over 56,000 images of cracked and non-cracked concrete bridge decks, walls, and pavements. The dataset includes cracks as narrow as 0.06 mm and as wide as 25 mm. The dataset also includes images with a variety of obstructions, including shadows, surface roughness, scaling, edges, holes, and background debris. SDNET2018 will be useful for the continued development of concrete crack detection algorithms based on deep convolutional neural networks (DCNNs), which are a subject of continued research in the field …

Characterization Of Nanomaterials For Thermal Management Of Electronics, Amit Rai

Doctoral Dissertations

Recently, there has been a growing interest in flexible electronic devices as they are light, highly flexible, robust, and use less expensive substrate materials. Such devices are affected by thermal management issues that can reduce the device’s performance and reliability. Therefore, this work is focused on the study of the thermal properties of nanomaterials and the methods to address such issues. The goal is to enhance the effective thermal conductivity by adding nanomaterials to the polymer matrix or by structural modification of nanomaterials. The thermal conductivity of copper nanowire/polydimethylsiloxane and copper nanowire/polyurethane composites were measured and showed more than threefold …

Metal Segregation During The Solidification Of Titanium-Aluminum Alloys For 3d Printing Applications, Jwala Parajuli

Master's Theses

Titanium-Aluminum alloys are one of the widely used alloys in multiple engineering applications. They are highly preferred in Selective Laser Melting (SLM) processes due to their low density, high melting temperature, and good strength. Segregation occurs during the solidification of most alloys and produces a non-uniform distribution of atoms. In SLM, segregation may depict the type of adhesion between the two deposited interfacial layers and the strength between the interphase between an already solidified layer and a new one, and overall, the quality of the printed part. In order to avoid segregation, the understanding of the segregation behavior at atomistic …

Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden

Doctoral Dissertations

The U.S. produces 5559.6 million metric tons of carbon dioxide annually, of which 21% is produced by industrial processes. Steam reforming, an industrial process that accounts for 95% of all hydrogen production in industry, produces 134.5 million metric tons of carbon dioxide or around 11% of the total carbon dioxide produced by industry. This carbon dioxide is then either emitted or goes through a sequestration process that accounts for 75% of the plant's operational costs. An alternative reaction to steam reforming is dry reforming, which utilizes carbon dioxide rather than emitting it and can be used in conjunction with current …

Electrical Characterization Of Graphene And Nanodiamond Nanostructures, A Z M Nowzesh Hasan

Doctoral Dissertations

The electrical characterization on two-dimensional carbon-based graphene and nanodiamond materials was performed to improve charge transport properties for the label-free electrical biosensors. The charge transport in solution-gated graphene devices is affected by the impurities and disorders of the underlying dielectric interface and its interaction with the electrolytes. Advancement in field-effect ion sensing by introducing a dielectric isomorph, hexagonal boron nitride between graphene and silicon dioxide of a solution-gated graphene field-effect transistor was investigated. Increased transconductance due to increased charge carrier mobility is accompanied with larger ionic sensitivity. These findings define a standard to construct future graphene devices for biosensing and …

Multidimensional Feature Engineering For Post-Translational Modification Prediction Problems, Norman Mapes Jr.

Doctoral Dissertations

Protein sequence data has been produced at an astounding speed. This creates an opportunity to characterize these proteins for the treatment of illness. A crucial characterization of proteins is their post translational modifications (PTM). There are 20 amino acids coded by DNA after coding (translation) nearly every protein is modified at an amino acid level. We focus on three specific PTMs. First is the bonding formed between two cysteine amino acids, thus introducing a loop to the straight chain of a protein. Second, we predict which cysteines can generally be modified (oxidized). Finally, we predict which lysine amino acids are …

Electromagnetic Wave-Matter Interactions In Complex Opto-Electronic Materials And Devices, Raj Kumar Vinnakota

Doctoral Dissertations

This dissertation explores the fundamentals of light-matter interaction towards applications in the field of Opto-electronic and plasmonic devices. In its core, this dissertation attempts and succeeds in the the modeling of light-matter interactions, which is of high importance for better understanding the rich physics underlying the dynamics of electromagnetic field interactions with charged particles. Here, we have developed a self-consistent multi-physics model of electromagnetism, semiconductor physics and thermal effects which can be readily applied to the field of plasmotronics and Selective Laser Melting (SLM). Plasmotronics; a sub-field of photonics has experienced a renaissance in recent years by providing a large …

Engineered Coating Of Natural Fibers And Oil-Water Interfaces With Self-Assembly Of Clay Nanotubes, Abhishek Panchal

Doctoral Dissertations

Taking into consideration two different types of surfaces, this dissertation proposes techniques to coat the surface of natural fibers and oil-water interfaces by spontaneous self-assembly of halloysite clay nanotubes. The material of choice, halloysite clay, is a widely available natural resource and can be used after minimal processing. In regards to chemical composition, halloysite clay resembles aluminosilicate mineral kaolin; physically, a defect in the crystal structure ordering causes the sheets of kaolinite to roll into halloysite nanotubes. The dimensions of halloysite nanotubes are dependent on the source, but generally vary from 200 nm to 3 µm in length, 100-150 nm …

Effective Magnetic And Electric Response Of Composite Materials, Mona Hassan Alsaleh

Doctoral Dissertations

Metamaterials (MMs) are nanocomposite materials consisting of metal-dielectric resonators much smaller in size than the wavelength of the incident light. Common examples of metamaterials are based on split ring resonators (SRRs), parallel wires or strips and fishnet structures. These types of materials are designed and fabricated in order to provide unique optical responses to the incident electromagnetic radiation that are not available in naturally existing materials. The MMs can exhibit unusual properties such as strong magnetism at terahertz (THz) and optical frequencies. Additionally, negative index materials (NIMs) can provide negative index of refraction which can be used in many applications …

Mechanical Characterization Of Expanded Polystyrene Spheres Embed Sandwich Composites For Packaging Applications, Maheswaran R, Arockia Reemas S

Journal of Applied Packaging Research

This paper addresses on study of development of new packaging material comprising Expanded Polystyrene Spheres (EPS) embedded epoxy polymer based sandwich composites with aluminium skin. The density of the packing material is controlled by varying the volume of embedded spheres. In this study, the Flexural and Compression performance of Expanded Polystyrene Spheres (EPS) embedded polymer based sandwich composites with aluminium skin are investigated. The EPS volume percent in the core is 25% with epoxy matrix which makes the the density less than 1 g/cm3 for the composite. The fabricated Sandwich Composite are very light weight, the density is less than …

Hidden Curriculum Awareness: A Comparison Of Engineering Faculty, Graduate Students, And Undergraduates, Idalis Villanueva, Marialuisa Di Stefano, Laura Gelles, Katherine Youmans

Engineering Education Faculty Publications

In order for an engineering academic body (e.g., facultyand students) to navigate their surroundings, they must first become aware of the hidden curriculum around them. Hidden curriculum represents how particular assumptions, values, attitudes, and beliefs about schooling manifests in practice. When understood, these types of lessons or messages allow students, faculty, and staff to more easily navigate the academic and socio-political customs needed for success.

As part of a larger study, a total of 224 participants across 57 engineering programs in the United States and Latin America were asked to comment on a survey that asked respondents about the expectations …

Tuning The Magnetic Ground State Of Ce1−Xybxrhin5 By Yb Valence Fluctuations, S. Jang, N. Pouse, T. Keiber, Benjamin White, S. M. Dissler, J. W. Lynn, J. C. Collini, M. Janoschek, F. Bridges, M. Brian Maple

All Faculty Scholarship for the College of the Sciences

We characterize the properties of Ce_1−xYb_xRhIn₅ single crystals with 0 ⩽ x ⩽ 1 using measurements of powder x-ray diffraction, energy dispersive x-ray spectroscopy, electrical resistivity, magnetic susceptibility, specific heat, x-ray absorption near edge structure (XANES), and neutron diffraction. The Yb valence v_Yb, calculated from the magnetic susceptibility and measured using XANES, decreases from 3+ at x = 0 to ∼2.1+ at x_act = 0.2, where x_act is the measured Yb concentration. A transition from incommensurate to commensurate antiferromagnetism is observed in neutron diffraction measurements …

Metal Factory Opening | College Of Engineering, Usu College Of Engineering

College of Engineering News

The Metal Factory opened Thursday, Nov. 15 with a tour of its facilities.

Physical Electronic Properties Of Self-Assembled 2d And 3d Surface Mounted Metal-Organic Frameworks, Radwan Elzein

USF Tampa Graduate Theses and Dissertations

Metal-organic frameworks stand at the frontiers of molecular electronic research because they combine desirable physical properties of organic and inorganic components. They are crystalline porous solids constructed by inorganic nodes coordinated to organic ligands to form 1D, 2D, or 3D structures. They possess unique characteristics such as ultrahigh surface area crystal lattices up to 10000 m² g^-1, and tunable nanoporous sizes ranging from 0.2 to 50 nm. Their unprecedented structural diversity and flexibility beyond solid state materials can lead to unique properties such as tailorable electronic and ionic conductivity which can serve as interesting platforms for a …

High Performance Distributed On-Chip Voltage Regulation For Modern Integrated Systems, Longfei Wang

USF Tampa Graduate Theses and Dissertations

Distributed on-chip voltage regulation where multiple voltage regulators are distributed among different locations of the chip demonstrates advantages as compared to on-chip voltage regulation utilizing a single voltage regulator. Better on-chip voltage noise performance and faster transient response can be realized due to localized voltage regulation. Despite the advantages of distributed on-chip voltage regulation, unbalanced current sharing issue can occur among each voltage regulator, which has been demonstrated to deteriorate power conversion efficiency, stability, and reliability of the power delivery network. An effective balanced current sharing scheme that can be applied to most voltage regulator types is proposed to balance …

Duty-Cycle Based Physical Unclonable Functions (Pufs) For Hardware Security Applications, Mahmood Javed Azhar

USF Tampa Graduate Theses and Dissertations

Duty cycle and frequency are important characteristics of periodic signals that are exploited to develop a variety of application circuits in IC design. Controlling the duty cycle and frequency provides a method to develop adaptable circuits for a variety of applications. These applications range from stable on-chip clock generation circuits, on-chip voltage regulation circuits, and Physical unclonable functions for hardware security applications. Ring oscillator circuits that are developed with CMOS inverter circuits provide a simple, versatile flexible method to generated periodic signals on an IC chip. A digitally controlled ring oscillator circuit can be adapted to control its duty cycle …

Laboratory Self-Weight Consolidation Testing Of Dredged Material Analyzed Using A One-Dimensional Finite Strain Consolidation Method, Artine Azimi

Master of Science in Civil Engineering Theses

Research has shown that the properties which govern the consolidation of dredged material are best determined using a one-dimensional finite strain consolidation theory. This method requires a complete relationship between void ratio and effective stress for all expected void ratios in a dredged layer, which can be determined from laboratory testing. The United States Army Corps of Engineers (USACE) suggests using a self-weight consolidation test apparatus to obtain void ratio/effective stress conditions for very low effective stresses. In this paper a modified laboratory testing method of a self-weight consolidation test is developed to obtain a range of void ratios and …