Engineering Commons^™

Performance Of Four Near Zero Energy Homes: Lessons Learned, Florida Solar Energy Center, Carlos Colon

FSEC Energy Research Center®

While the idea of a zero or near zero energy home is well understood, the actual performance of the structure can be different than expected. High performance homes necessitate increasingly complex envelope, HVAC, water heating, and appliance systems, and successful designs rely on proper function and feedback from those systems to achieve low-energy goals. This paper presents measured data on four near zero energy homes located in Florida that are a part of the U.S. DOE Building America program. The monitored data are compared to both a benchmark model and the prototype computer simulations. By examining the submetered energy data, …

A Framework For Determining The Reliability Of Nanoscale Metallic Oxide Semiconductor (Mos) Devices, Wilkistar Otieno

USF Tampa Graduate Theses and Dissertations

An increase in worldwide investments during the past several decades has pro-pelled scienti c breakthroughs in nanoscience and technology research to new and exciting levels. To ensure that these discoveries lead to commercially viable prod-ucts, it is important to address some of the fundamental engineering and scientific challenges related to nanodevices. Due to the centrality of reliability to product integrity, nanoreliability requires critical analysis and understanding to ensure long-term sustainability of nanodevices and systems. In this study, we construct a relia-bility framework for nanoscale dielectric lms used in Metallic Oxide Semiconductor (MOS) devices. The successful fabrication and incorporation of metallic …

Advanced Signal Processing Techniques For Single Trial Electroencephalography Signal Classification For Brain Computer Interface Applications, Kun Li

USF Tampa Graduate Theses and Dissertations

Brain Computer Interface (BCI) is a direct communication channel between brain and computer. It allows the users to control the environment without the need to control muscle activity [1-2]. P300-Speller is a well known and widely used BCI system that was developed by Farwell and Donchin in 1988 [3]. The accuracy level of the P300-BCI Speller as measured by the percent of communicated characters correctly identified by the system depends on the ability to detect the P300 event related potential (ERP) component among the ongoing electroencephalography (EEG) signal. Different techniques have been tested to reduce the number of trials needed …

A Study On Prospects For The Evolution Of Maritime Traffic Management Systems Taking Into Account E-Navigation, Kwang An

World Maritime University Dissertations

No abstract provided.

Flotation Circuit Performance Determination Using Size By Size Recovery – Case Of Bulyanhulu Gold Mine, Savinus Maronga

Tanzania Journal of Engineering and Technology (TJET)

The Bulyanhulu rougher flotation circuit performance has been determined by establishing the performance of individual cells. Direct sampling was done on all the rougher cell input, output and size analysis was performed on the samples with material in each size fraction assayed for copper and gold to determine their recoveries. It was observed that the performance of rougher cell number 3 and 4 was poor compared to other cells especially for finer particles below 53 µm where the recoveries were below 60%. In the last two flotation cells recoveries of both metals was very good (above 90%) in all particle …

Universal Design Of Transportation Systems: A Case Study Of Access And Mobility Of People With Disabilities At Selected Intersections In Dar Es Salaam, Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

The pedestrian facilities at intersections must be usable by pedestrians of all ages and capabilities. Intersections in particular must be designed to safely accommodate pedestrians of all ages and physical and mental abilities. Often, however, intersection designs fail to accommodate people with visual and mobility disabilities. In this regard, for pedestrians with disabilities, intersections can prove to be a challenge. Some of those challenges include provision of insufficient pedestrian clearance time due to use of inappropriate design pedestrian speed. Most importantly, the required facilities to enable People With Disabilities (PWD) to use the intersection without hindrance may be missing. Obstacles …

Illicit Trafficking Of Radioactive Sources: Experiences With Fake Materials In Tanzania, Iddi Mkilaha

Tanzania Journal of Engineering and Technology (TJET)

Radioactive materials although are very useful, they are one of the catastrophic sources of mass destruction if misused. These materials have a number of positive uses which makes them very essential in our modern society. Incidences such as the bombings of the US Embassies in East Africa, the September 11, and many others had formed a basis for international responsive actions to control illicit trafficking of Radioactive and Nuclear Materials. The aim of this work is to track the movements and subsequently uses of these materials. Tanzania is one of the countries where International Nuclear Safeguards protocols are fully operational …

Comparison Of Safety Performance By Design Types At Freeway Diverge Areas And Exit Ramp Sections, Hongyun Chen

USF Tampa Graduate Theses and Dissertations

The primary objective of the study is to evaluate the safety performance of different freeway exit types used in current practical designs. More specific, the research objectives include the following two parts: 1) to compare the safety performance of different design types at freeway diverge areas and exit ramp sections; and 2) to identify the impact factors contributing to the crashes happening at these two specific segments.

The study area includes four subjects, the freeway widely-spaced diverge areas; the freeway closely-spaced diverge areas; the left-side off-ramps and the exit ramp sections. For the freeway diverge areas, design types were defined …

Adaptive Routing Scheme For Emerging Wireless Ad Hoc Networks, Behdis Eslamnour, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Node mobility causes fading wireless channels, which in turn renders topology changes in emerging wireless ad hoc networks. in this paper, on-line estimators and Markov models are utilized to estimate fading channel conditions. using the estimated channel conditions as well as queue occupancy, available energy and link delay, approximate dynamic programming (ADP) techniques are utilized to find dynamic routes, while solving discrete-time Hamilton-Jacobi-Bellman (HJB) equation forward-in-time for route cost in multichannel multi-interface networks. the performance of the proposed load balancing method in the presence of fading channels and the performance of the optimal route selection approach for multichannel multi-interface wireless …

Time-Varying Harmonic Analyzer Prototype, Diego F. Fabri, Carlos H. N. Martins, Leandro R. M. Silva, Carlos A. Duque

University Faculty Publications and Creative Works

This paper presents a time-varying harmonic analyzer based on the Sliding Window DFT implemented on a DSP platform. The harmonic decomposition is carried out using the TMS320F28027 digital signal processor, and the samples of the decomposed signal are sent to a PC based computer using serial interface. Several real cases are analyzed, revealing the time-varying behavior of the harmonic component. Different from commercial harmonic analyzer, the prototype presented in this paper uses a different way to visualize the harmonic components, based on time decomposition approach. This new visualization of time-varying harmonics might help engineers and researchers to develop new insights …

Time-Varying Harmonic Analyzer Prototype, Diego F. Fabri, Carlos H. N. Martins, Leandro R. M. Silva, Carlos A. Duque

University Faculty Publications and Creative Works

This paper presents a time-varying harmonic analyzer based on the Sliding Window DFT implemented on a DSP platform. The harmonic decomposition is carried out using the TMS320F28027 digital signal processor, and the samples of the decomposed signal are sent to a PC based computer using serial interface. Several real cases are analyzed, revealing the time-varying behavior of the harmonic component. Different from commercial harmonic analyzer, the prototype presented in this paper uses a different way to visualize the harmonic components, based on time decomposition approach. This new visualization of time-varying harmonics might help engineers and researchers to develop new insights …

Analysis Of Factors Affecting Technological Innovativeness In Engineering Enterprises In Tanzania, Emanuel Mjema

Tanzania Journal of Engineering and Technology (TJET)

This paper discusses the technological innovativeness in engineering enterprises in Tanzania and analyses the factors affecting the innovativeness. It starts by analyzing various concepts regarding innovation, then analyzed from documentary review factors affecting innovativeness and then analyzed the innovativeness in Tanzanian enterprises. From the documentary review it was learnt that the following key factors influence technological innovativeness: Existence of innovation management; Existence of market to absorb the products of innovation; Existence of partnership between the universities and the firms; Existence of positive culture and politics towards innovation; The government playing its role to influence innovation; Existence of the right knowledge; …

A Multicriteria Based Quantitative Framework For Assessing Sustainability Of Pile Foundations, Aditi Misra

Master's Theses

ABSTRACT

Civil Engineering is the major instrument of anthropocentric development over centuries through ever expanding infrastructure, cities and facilities.  Civil engineering processes are both resource and fuel intensive.  The building industry alone, during the construction stage, uses about 30-40% of the total resources used in the industrialized countries.  There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project.  Geotechnical engineering is most resource intensive although this intensive consumption of energy goes unnoticed mainly because of the indirect nature of the energy used in the …

Design Concepts Of Terahertz Quantum Cascade Lasers: Proposal For Terahertz Laser Efficiency Improvements, Tillmann Kubis, Saumitra Raj Mehrotra, Gerhard Klimeck

Birck and NCN Publications

Conceptual disadvantages of typical resonant phonon terahertz quantum cascade lasers 􏰎THz-QCLs􏰍 are analyzed. Alternative designs and their combination within a concrete device proposal are discussed to improve the QCL performance. The improvements are 􏰎1􏰍 indirect pumping of the upper laser level, 􏰎2􏰍 diagonal optical transitions, 􏰎3􏰍 complete electron thermalization, and 􏰎4􏰍 materials with low effective electron masses. The nonequilibrium Green’s function method is applied to predict stationary electron transport and optical gain. The proposed THz-QCL shows a higher optical gain, a lower threshold current, and a higher operation temperature. Alloy disorder scattering can worsen the QCL performance.

An Fpga-Based System For Tracking Digital Information Transmitted Via Peer-To-Peer Protocols, Karl R. Schrader, Barry E. Mullins, Gilbert L. Peterson, Robert F. Mills

Faculty Publications

This paper presents a Field Programmable Gate Array (FPGA)-based tool designed to process file transfers using the BitTorrent Peer-to-Peer (P2P) protocol and VoIP phone calls made using the Session Initiation Protocol (SIP). The tool searches selected control messages in real time and compares the unique identifier of the shared file or phone number against a list of known contraband files or phone numbers. Results show the FPGA tool processes P2P packets of interest 92% faster than a software-only configuration and is 97.6% accurate at capturing and processing messages at a traffic load of 89.6 Mbps.

A Memory Saving Vector Fast Multipole Algorithm For Solving The Augmented Efie, Yang G. Liu, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

An augmented EFIE (A-EFIE)[9], [10] has been proposed to separate the contributions of the vector potential and the scalar potential for avoiding the imbalance at low frequencies. The corresponding low frequency fast multipole algorithm (LFFMA) [11] was also developed for solving the A-EFIE. Instead of the factorization of the scalar Green's function by using scalar addition theorem in the LF-FMA, we adopt the vector addition theorem for the factorization of the dyadic Green's function to realize memory savings. We are to develop a vector fast multipole algorithm for solving the A-EFIE. © 2010 IEEE.

An Integrated Approach For Phytate Degradation And Recovery Of Myo-Inositol And Phosphate As Valued-Added Products From The By-Products Of Corn Ethanol Industry, Jun Dang

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

An integrated process was developed to hydrolyze the phytates in light steep water (LSW) and to simultaneously isolate inorganic phosphate (Pi) and myo-inositol products. The proposed integrated process is helpful in resolving the environmental and nutritional concerns in the use of corn gluten feed (CGF) in the animal diets. This process comprised of partial and total hydrolysis of LSW and intermediate anion exchange separation technique. The phytates in LSW were initially degraded to negatively charged myo-inositol phosphates (InsP₂ - InsP₅). The optimized experimental parameters for the partial hydrolysis of LSW were determined to be 2 h hydrolysis …

A High-Quality Mach-Zehnder Interferometer Fiber Sensor By Femtosecond Laser One-Step Processing, Longjiang Zhao, Lan Jiang, Sumei Wang, Hai Xiao, Yongfeng Lu, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During new fiber sensor development experiments, an easy-to-fabricate simple sensing structure with a trench and partially ablated fiber core is fabricated by using an 800 nm 35 fs 1 kHz laser. It is demonstrated that the structure forms a Mach-Zehnder interferometer (MZI) with the interference between the laser light passing through the air in the trench cavity and that in the remained fiber core. The fringe visibilities are all more than 25 dB. The transmission spectra vary with the femtosecond (fs) laser ablation scanning cycle. The free spectral range (FSR) decreases as the trench length increases. The MZI structure is …

Integrated Freestanding Single-Crystal Silicon Nanowires: Conductivity And Surface Treatment, Chung-Hoon Lee, Clark Ritz, Minghuang Huang, Michael Ziwisky, Robert Blise, Max Lagally

Electrical and Computer Engineering Faculty Research and Publications

Integrated freestanding single-crystal silicon nanowires with typical dimension of 100 nm × 100 nm × 5 µm are fabricated by conventional 1:1 optical lithography and wet chemical silicon etching. The fabrication procedure can lead to wafer-scale integration of silicon nanowires in arrays. The measured electrical transport characteristics of the silicon nanowires covered with/without SiO₂ support a model of Fermi level pinning near the conduction band. The I–V curves of the nanowires reveal a current carrier polarity reversal depending on Si–SiO₂ and Si–H bonds on the nanowire surfaces

Purification Of Solar Grade Silicon Using Electromagnetic Field, Anping Dong, Lucas N.W. Damoah, Lifeng Zhang, Hui Zhu

Materials Science and Engineering Faculty Research & Creative Works

Non-metallic particles and the metallic impurity elements in the solar cell silicon have a strong detrimental effect on the conversion efficiency of the solar cell. Removing these impurities is one of the important tasks for silicon refining. the current paper proposed a new approach to purify silicon - electromagnetic (EM) separation. Since the non-metallic particles and the metallic impurity elements are non- or less conductive while the molten silicon is well conductive, under EM field, the Lorenz force will push the particles to the boundary layer, thus separate these inclusions. in the current study, a high frequency EM field was …

Extraction Of Contact Resistance In Carbon Nanofiber Via Interconnects With Varying Lengths, Ken Li, Patrick Wilhite, Vinit Khera, Shoba Krishnan, Xuhui Sun, Cary Y. Yang

Electrical and Computer Engineering

A method to extract the contact resistance and bulk resistivity of vertically grown carbon nanofibers (CNFs) or similar one-dimensional nanostructures is described. Using a silicon-compatible process to fabricate a terrace test structure needed for the CNF length variation, the contact resistance is extracted by measuring in situ the resistances of individual CNFs with different lengths and within a small range of diameters using a nanoprober inside a scanning electron microscope. Accurate determination of contact resistances for various combinations of catalysts and underlayer metals can lead to eventual optimization of materials’ growth and device fabrication processes for CNF via interconnects.

Florida Weatherization Training - Quarterly Report (October 2010-December 2010), Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The weatherization training for the State of Florida Dept of Community Affairs continues at the Florida Solar Energy Center's Training Facility. Progress for the sixth three months of the contract included a five day classroom training on October 18-22 (17 students) and in-field evaluations (16 students).

Non-Metallic Particles In Solar Grade Silicon (Sog-Si), Lucas Nana Wiredu Damoah, Anping Dong, Lifeng Zhang, Hui Zhu

Materials Science and Engineering Faculty Research & Creative Works

This study investigated the non-metallic inclusions in Solar 2rade Silicon (SoG-Si), especially the distribution of inclusions in the top 15mm layer of multicrystalline silicon ingot. the SoG-Si ingot produced from directional solidification process usually pushes the impurities to the top and finally cut off and discarded, which leads to material loss. the hard inclusions lead to wire breakages during the cutting of the ingot into wafers. the main kinds of inclusions found in top-cut silicon scraps from two manufacturers have been investigated using acid extraction, automated feature analysis techniques and SEM-EDS and optical Microscope: They are needle-like Si3N4 and lumpy …

Indirect Adaptive Control Of An Active Filter Using Echo State Networks, Jing Dai, Ganesh K. Venayagamoorthy, Ronald G. Harley, Keith A. Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

An active filter is a power electronic device used in a power system to decrease "harmonic current pollution" caused by nonlinear loads. the Echo State Network (ESN) has been widely used as an effective system identifier with much faster training speed than the other Recurrent Neural Networks (RNNs). However, only a few attempts have been made to use an ESN as a system controller. as the first attempt to use an ESN in indirect NeuroControl, this paper proposes an indirect adaptive NeuroControl scheme using two ESNs to control an active filter in a multiple-reference frame. as the first step in …

Citizen Satellites: Tiny, Standardized Spacecraft Are Making Orbital Experiments Affordable To Even The Smallest Research Groups, Robert J. Twiggs, Alex Soojung-Kim Pang

Robert "Bob" Twiggs STEM Education Collection

An article written by Bob Twiggs and Alex Soojung-Kim Pang and published in the Scientific American titled "Citizen Satellites: Tiny, standardized spacecraft are making orbital experiments affordable to even the smallest research groups" from 2010.

Studies On The Preparation And Luminescence Properties Of Cadmium Selenide Quantum Dots, Their Immobilization, And Applications., Travis Justin Heath

Electronic Theses and Dissertations

Quantum dots are semiconductive particles whose properties are highly influenced by the presence of at least one electron. Cadmium selenide quantum dots were synthesized via colloidal synthesis. Contrary to previous preparations, more focus was placed on the temperature rather than the duration of time at which they form. A series of colored solutions were obtained because the excited quantum dots of various sizes emitted specific wavelengths of light. The emission spectra showed that the temperature-dependent quantum dots were successfully synthesized. The quantum dots were also immobilized on various surfaces, and the luminescence properties were examined. The quantum dots that were …

High Impedance Arc Fault Detection In A Manhole Environment., Thomas Arthur Cooke

Electronic Theses and Dissertations

The scope of this thesis was to develop a prototype high-impedance arc detection system that a utility worker could use as an early warning system while working in a manhole environment. As part of this system sensors and algorithms were developed to increase the sensitivity of detecting an arc while ignoring loads that can give false positive signatures for arcing. The latest technology was used to repeat measurements performed in previous research from decades ago that lacked in sampling speed and amplitude resolution. Several types of arcs were produced and analyzed so to establish a library of various waveform and …

New Handheld Emissions Detector For Pinpointing The Location Of Inadvertently Energized Objects In Urban Environments., Kermit O. Phipps

Electronic Theses and Dissertations

The power distribution infrastructure in the United States is deteriorating at a rapid rate exposing infrastructure wiring and creating potential shock hazards. Periodic road and sidewalk maintenance projects can also expose wiring and create energized objects. In urban settings inadvertently energized objects include: lamp posts, bus shelters, metal street curbs, sign posts, transformer vaults, and manhole covers as well as concrete and asphalt pavement. Every year electric shocks occur when people and domestic animals (such as dogs and cats) make incidental contact with these energized objects. In very rare cases the shocks from these contacts are lethal. Through current personal …

2010 Fall Engr333 Project Final Report, 2010 Fall Engr333

ENGR 333

Calvin College dorms have a chronic issue with wasting energy. The dorms have little insulation, high infiltration rates, and are heated by low efficiency boilers. These existing characteristics combine for a larger required heating load and increased energy usage. The excess heat, due to poor temperature control, is often vented out through the windows whenever students deem necessary. This project will attempt to reduce wasted energy and efficiently distribute heat as needed.

The Thermal Systems Design class of 2010 was challenged with retrofitting the Bolt-Heyns-Timmer (BHT) dorm to decrease energy consumption and improve efficiency. The class was presented with the …

Active Noise Control Of A Two-Fan Exhaust-Mounted Array Using Near-Field Control Sources And Error Sensors, Ryan Leonard Rust

Theses and Dissertations

Multiple fans are sometimes used in an array configuration to cool various types of electronic equipment. In addition to adding another noise source, using two fans with closely spaced blade passage frequencies (BPF) can create an annoying beat frequency. A two fan array with each fan having a different BPF was considered. The fans were theoretically modeled at the BPF and first harmonics. Each fan has two acoustic paths to the far field. Thus, each fan was modeled as a two source array. The first control configuration consisted of one control filter using six control sources and six error sensors …