Engineering Commons^™

Determination Of The Power Law Exponent For Southern Highlands Of Tanzania, H. H. Mwanyika, R. M. Kainkwa

Tanzania Journal of Science

The 1/7th power law is among the methods that have been used to extrapolate wind speed to the hub heights of wind turbines from the measuring levels. However, it tends to underestimate the actual long-term average wind speeds. In this paper, the power law exponent for Makambako, a site located in the southern highland zone of Tanzania, was established using wind speeds measured at heights Z1=2 m and Z2=7 m. The average power law exponent obtained at the test site was 0.47, a value that is substantially higher than the 1/7th power law exponent. It is low during the dry …

Video Stabilization And Target Localization Using Feature Tracking With Video From Small Uavs, David Linn Johansen

Theses and Dissertations

Unmanned Aerial Vehicles (UAVs) equipped with lightweight, inexpensive cameras have grown in popularity by enabling new uses of UAV technology. However, the video retrieved from small UAVs is often unwatchable due to high frequency jitter. Beginning with an investigation of previous stabilization work, this thesis discusses the challenges of stabilizing UAV based video. It then presents a software based computer vision framework and discusses its use to develop a real-time stabilization solution. A novel approach of estimating intended video motion is then presented. Next, the thesis proceeds to extend previous target localization work by allowing the operator to easily identify …

Numerical Modeling Of Concrete Masonry Walls Strengthened By Fiber Reinforced Polymers Under Lateral Loads, Mohamed Salama

Archived Theses and Dissertations

The use of fiber reinforced polymers (FRP) for the seismic retrofit of masonry walls is on the rise. Design formulae are available to estimate the lateral load capacity of the strengthened walls. However, recent experimental data from tests conducted on full scale concrete masonry walls under cyclic lateral loads have shown that these design capacities have not been reached because of the occurrence of other failure modes not accounted for in the design formulae. The limiting failure mode in all test samples referred to in this work was due to premature compression failure of the masonry units at the wall …

The Energy Policy Pyramid - A Hierarchal Tool For Decision Makers, Florida Solar Energy Center, Robin Vieira

FSEC Energy Research Center®

Policies of dealing with energy programs are often misdirected. Decision makers jump first to fuel substitution to either lower emissions or counter fuel price escalation. When it comes to both return on short-term economic investment and long-term sustainability for the economy and environment, there is a clear hierarchy. This paper presents the hierarchy as The Energy Policy Pyramid©.

Mid-Infrared Multiple Quantum Well Lasers Using Digitally-Grown Allnassb Barriers And Strained Inassb Wells, Leslie G. Vaughn

Electrical and Computer Engineering ETDs

Al_xln_(1-x)As_ySb_(1-y)quaternary alloys have been used in Type I midwave infrared (MWIR) laser structures as barrier materials with lnAs and InAsSb quantum wells. However, growth of these alJoys has limited the application because of a large miscibi lity gap. In this research, quaternary films with compositions well into the miscibility gap (0

Combining the quaternary bandgap equation with strain and quantum size effects. the wavelengths for strained lnAsSb wells in AllnAsSb quaternary barriers are predicted and compared to measured values generated from PL experiments. The reasonable agreement of these experimental results with the …

Cooling Performance Assessment Of Building America Homes, Florida Solar Energy Center, Dave Chasar

FSEC Energy Research Center®

Long-term monitoring of building energy use and environmental conditions has been a strong component of FSEC research since the 1980s. Fully-automated data collection, verification, archiving and management ensure accurate logging of large amounts of data simultaneously from numerous field sites prior to being made available for analysis and display via the internet. Homes are typically monitored using 15 to 50 channels of data to measure indoor and outdoor environmental conditions and energy use of heating, cooling, water heating, whole house, and other points (e.g. Solar PV or Solar DHW) if needed.

Energy performance in many Building America homes has been …

Energy Performance Aspects Of A Florida Green Roof, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Previous green roof studies have found that planted roofs significantly reduce roof temperatures and roof heat flux, and simulations indicate cooling load reductions of up to 25%. This monitored study evaluates summer and winter energy performance aspects of a green roof on a central Florida university building addition that was completed in 2005.

Analysis of 2005 summer data indicates significantly lower peak roof surface temperatures for the green roof compared with the conventional roof and a significant shift in when the peak temperature occurs compared to the conventional roof. Summer roof heat flux estimates show the green roof to have …

Measured Crawlspace Conditions In A Hud-Code Home, Florida Solar Energy Center, David Beal

FSEC Energy Research Center®

The Florida Solar Energy Center conducted research utilizing two unconditioned, old, singlewide side-by-side manufactured homes, one with a ground cover and one with exposed dirt under it. Three different skirting options were tested, open or no skirting, perforated skirting, and solid skirting.

Ambient and crawlspace dewpoints were recorded. The data is summarized in the table below. The skirting configurations tested are in Column 1, Column 2 lists the average ambient dewpoint, 3 the ground cover crawlspace, 4 the exposed dirt crawlspace dewpoint.

Successfully sealing HUD code home crawlspaces is the last piece of the puzzle of floor failures plaguing homes …

School Conditions Will Continue To Earn Failing Grades, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

This study addresses indoor air quality and general conditions problems in schools throughout the United States. Tools employed to investigate conditions include a nationwide, web-based survey, characterization of actual operating conditions in schools through field audits and diagnostic tests, and retrofits in problem schools.

Survey results found temperature to be by far the greatest comfort complaint in regular classrooms, with indoor air quality (IAQ) and then humidity being the next greatest areas of complaints. Ventilation problems were found at each of eight audited schools. These problems appear to be occurring due to a combination of factors including lack of maintenance, …

“Strategically Locating Soybean And Biodiesel Processing Facilities In Nebraska”, Lori Luebbe

Industrial Agricultural Products Center: Publications and Information

Is the production of biodiesel feasible in Nebraska? A standard answer depends on the business operating condition. More specifically, a statewide, as opposed to a site specific, study conducted by the Independent Biodiesel Feasibility Group (IBFG) in July 2005 for the Nebraska Soybean Association (NSA) concluded a positive return on equity could be expected. At that time, the return was estimated to be poor for the small scale, 5 million gallons per year (MGPY) scenario analyzed and only modest for the mid, 15 MGPY, and larger scale, 30 MGPY scenarios. For a complete copy of the feasibility study, contact the …

“Strategically Locating Soybean And Biodiesel Processing Facilities In Nebraska”, Lori Luebbe, Milford Hanna, Loren Isom, Robert Weber, Zach Schroeder, Richard Sanne, Mark Harris, Victor Bohuslavsky, Todd Sneller, Brian Wilcox

Industrial Agricultural Products Center: Publications and Information

Is the production of biodiesel feasible in Nebraska? A standard answer depends on the business operating condition. More specifically, a statewide, as opposed to a site specific, study conducted by the Independent Biodiesel Feasibility Group (IBFG) in July 2005 for the Nebraska Soybean Association (NSA) concluded a positive return on equity could be expected. At that time, the return was estimated to be poor for the small scale, 5 million gallons per year (MGPY) scenario analyzed and only modest for the mid, 15 MGPY, and larger scale, 30 MGPY scenarios. For a complete copy of the feasibility study, contact the …

48th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 48th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Breckenridge, Colorado, July 23-27, 2006.

Effects Of Placement Conditions On Decomposition Of Municipal Solid Wastes In Cold Regions, James Hanson, Nazli Yeşiller, K. A. Howard, Wei-Lien Liu, S. P. Cooper

Civil and Environmental Engineering

The effects of placement practices on decomposition of wastes were investigated at Anchorage Regional Landfill (Anchorage, Alaska) since 2002. Temperatures and gas concentrations of wastes placed at various seasons were monitored. Wastes were placed at sub-freezing temperatures during cold seasons. Waste temperatures generally increased upon placement. High variation was observed in waste temperatures near the surface whereas steady temperatures were obtained at depth. High maximum stable temperatures resulted from warm placement conditions. Steady temperatures between approximately –1 to +35°C were observed. The central portion of a frozen waste band (with a total initial thickness of 7 m at placement, currently …

Determining The Value Of A Master's Degree In Construction Management, Benjamin K. Davis

Theses and Dissertations

The purpose of this study is to determine the value of a master's degree in construction management in southern Idaho. A telephone and Internet survey was employed to determine the value that members of the construction industry in southern Idaho place on construction management (CM) degrees, both graduate and undergraduate. The survey included 27 self-described general contractors who are members of The Associated General Contractors of America (AGC) in regions 3 and 4 in the state of Idaho. Regions three and four include Twin Falls, Idaho Falls, Pocatello, Ketchum, Burley and surrounding communities. Following the compilation of surveys, it was …

Melt Detection And Estimation In Greenland Using Tandem Quikscat And Seawinds Scatterometers, Brandon R. Hicks

Theses and Dissertations

Ku-band dual-polarization radar backscatter measurements from the SeaWinds on QuikScat (QuikScat) and SeaWinds on ADEOS-2 (SeaWinds) scatterometers are used to classify the melt state and estimate melt severity in Greenland. Backscatter measurements are organized into high temporal and high spatial resolution images created using the Scatterometer Image Reconstruction (SIR) algorithm and a new temporal data segmentation technique. Melt detection is performed using a layered electromagnetic model combined with a Markov chain model. The new melt detection method allows classification of the snow-pack into three states: melt, refreeze, and frozen. Melt severity and refreeze severity indexes are also developed. The melt …

Modeling The Mechanical Effects Of Liquid Mediated Adhesion Between The Human Vocal Folds, Gifford Zach Decker

Theses and Dissertations

The vocal folds are a complex self-oscillating biological system. In the current research, an equation was developed to model viscous adhesion forces that occur when the collision of the vocal folds results in the formation of a liquid bridge. The adhesion equation was validated using experimental data, and simplified to a one-dimensional approximation with an included correction factor that adjusted the predicted pressure in situations where the one-dimensional approximation was invalid. A non-oscillating vocal fold model with a modeled liquid bridge was used to study stress resulting from viscous adhesion. The vertical normal stress magnitude ranged from about 80 to …

Comparing Time And Accuracy Of Building Information Modeling To On-Screen Takeoff For A Quantity Takeoff Of A Conceptual Estimate, Morgan A. Alder

Theses and Dissertations

Estimating is a critical aspect of every construction project. The most tedious component of an estimate is the quantity takeoff. Different tools are available to improve an estimator's productivity for a quantity takeoff. Faster quantity takeoffs enable estimator to bid more jobs. This study analyzed the time and accuracy of performing quantity takeoffs when using building information modeling (BIM) through a comparison study using Revit (BIM software) and On-Center's OST. In preparation for the study the researcher conducted a pilot study. Participants of the study were asked to perform a quantity takeoff using both Revit and OST. Their resulting data …

Contractor Variability In Construction Of Cement Treated Base Layers, Maile Anne Rogers

Theses and Dissertations

The primary purposes of this research were to identify construction factors most correlated to specific mechanical properties of cement-treated base (CTB) layers and to determine which construction factors exhibit comparatively high variability within individual construction sections of the two pavement reconstruction projects included in this study. In addition, differences between construction sections tested in this research were evaluated. The research focused on the construction of CTB layers in two pavement reconstruction projects in northern Utah, one along Interstate 84 (I-84) near Morgan and one along U.S. Highway 91 (US-91) near Richmond. The significant predictor variables associated with California bearing ratio …

Development Of An End-Effector Sensory Suite For A Rehabilitation Robot, Stephanie A. Stiber

USF Tampa Graduate Theses and Dissertations

This research presents an approach in assisting the control and operation of a rehabilitation robot manipulator to execute simple grasping tasks for persons with severe disabilities. It outlines the development of an end-effector sensory suite that includes the BarrettHand end-effector, laser range finder, and a low cost camera.

The approach taken in this research differs greatly from the currently available rehabilitation robot arms in that it requires minimal user instruction, it is easy to operate and more effective for persons severely disabled. A thorough study of the currently available systems; Manus, Raptor and Kares II arm, is also presented.

In …

Preparation Of High-Strength Nanometer Scale Twinned Coating And Foil, Xinghang Zhang, Amit Misra, Michael Nastasi, Richard G. Hoagland

Department of Mechanical and Materials Engineering: Faculty Publications

Very high strength single phase stainless steel coating has been prepared by magnetron sputtering onto a substrate. The coating has a unique microstructure of nanometer spaced twins that are parallel to each other and to the substrate surface. For cases where the coating and substrate do not bind strongly, the coating can be peeled off to provide foil.

Iii-Nitride Transistors With Capacitively Coupled Contacts, Grigory Simin, Z.-J. Yang, A. Koudymov, V. Adivarahan, M. Asif Khan

Faculty Publications

AlGaN∕GaNheterostructure field-effect transistor design using capacitively coupled contacts (C³HFET) is presented. Insulated-gate [C³ metal-oxide-semiconductor HFET(C³MOSHFET)] has also been realized. The capacitively coupled source, gate, and drain of C3 device do not require annealedOhmic contacts and can be fabricated using gate alignment-free technology. For typical AlGaN∕GaNheterostructures, the equivalent contact resistance of C³ transistors is below 0.6Ωmm. In rf-control applications, the C³HFET and especially the C³MOSHFET have much higher operating rf powers as compared to HFETs.C³ design is instrumental for studying the two-dimensional electron gas transport in other wide band gap …

Innovative Schematic Concept Analysis For A Space Suit Portable Life Support Subsystem, M. Schuller, R. Kobrick, T. Lalk, L. Wiseman, F. Little, Et Al.

Publications

Conceptual designs for a space suit Personal Life Support Subsystem (PLSS) were developed and assessed to determine if upgrading the system using new, emerging, or projected technologies to fulfill basic functions would result in mass, volume, or performance improvements. Technologies were identified to satisfy each of the functions of the PLSS in three environments (zero-g, Lunar, and Martian) and in three time frames (2006, 2010, and 2020). The viability of candidate technologies was evaluated using evaluation criteria such as safety, technology readiness, and reliability. System concepts (schematics) were developed for combinations of time frame and environment by assigning specific technologies …

Microwave Remote Sensing Of Saharan Ergs And Amazon Vegetation, Haroon Stephen

Theses and Dissertations

This dissertation focuses on relating spaceborne microwave data to the geophysical characteristics of the Sahara desert and the Amazon vegetation. Radar and radiometric responses of the Saharan ergs are related to geophysical properties of sand formations and near surface winds. The spatial and temporal variability of the Amazon vegetation is studied using multi-frequency and multi-polarization data. The Sahara desert includes large expanses of sand dunes called ergs that are constantly reshaped by prevailing winds. Radar backscatter measurements observed at various incidence and azimuth angles from the NASA Scatterometer (NSCAT), the ERS scatterometer (ESCAT), the SeaWinds scatterometer aboard QuikScat (QSCAT), and …

Yield Response Of Corn To Deficit Irrigation In A Semiarid Climate, José O. Payero, Steven R. Melvin, Suat Irmak, David D. Tarkalson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigation water supplies are decreasing in many areas of the U.S. Great Plains, which is requiring many farmers to con¬sider deficit-irrigating corn (Zea mays L.) or growing crops like winter wheat (Triticum aestivum L.) that require less water, but that are less profitable. The objectives of this study were to: (1) quantify the yield response of corn to deficit irrigation, and (2) determine which of several seasonal water variables correlated best to corn yield in a semiarid climate. Eight (T1–T8) and nine (T1–T9) deficit-irrigated treatments (including dryland), were compared in 2003 and 2004 in North Platte, Nebraska. The …

Incorporating Wireless Power Transfer In An Led Lighting Application, Jonathan S. Shipley

Theses and Dissertations

There are various situations in which electrical energy is desired but cannot by conveniently supplied. Since the days of Hienrich Hertz and Nikola Tesla, scientists have tried to solve this problem using different methods of wireless power transfer. Today, wireless power transfer has only been commercially demonstrated at small distances through use of induction. This thesis demonstrated the transfer of wireless power at relatively large distances through radio frequencies in the development of a prototype for a commercial product - a wireless household lamp.

Ballisticity Of Nanotube Field-Effect Transistors: Role Of Phonon Energy And Gate Bias, Siyuranga O. Koswatta, Sayed Hasan, Mark S. Lundstrom, M. P. Anantram, Dmitri E. Nikonov

Other Nanotechnology Publications

We investigate the role of electron-phonon scattering and gate bias in degrading the drive current of nanotube field-effect transistors (FETs). Optical phonon scattering significantly decreases the drive current only when gate voltage is higher than a well-defined threshold. For comparable electron-phonon coupling, a lower phonon energy leads to a larger degradation of drive current. Thus in semiconductor nanowire FETs, the drive current will be more sensitive than in carbon nanotube FETs because of the smaller phonon energies in semiconductors. Acoustic phonons and other elastic scattering mechanisms are most detrimental to nanotube FETs irrespective of biasing conditions.

A Solution For Commodity Field Hauling With Self-Unloading Semi-Trailers, Lee Pagens Wilkerson

Theses and Dissertations

Commodity hauling of bulk goods is a growing enterprise that has expanded from hauling agricultural products to hauling many other bulk products. Commodity trailers are used to haul agricultural products from storage facilities to processing plants. These trailers are designed for highway use but are frequently required to work in field conditions as well. In many cases this environment overstresses these trailers and results in permanent irreparable damage. In addition to the structural problems of these trailers, the current systems for unloading the bulk produce from these trailers have serious inadequacies. While functional, the currently used chain and non-chain driven …

Development Of An Index For Concrete Bridge Deck Management In Utah, Ellen T. White

Theses and Dissertations

The purpose of this research was to develop a new index for concrete bridge deck management in Utah. Data were collected in the summer of 2005 from 15 concrete bridge decks in the vicinity of Salt Lake City. The decks ranged from 2 to 21 years in age and were all constructed using epoxy-coated rebar. Visual inspection, sounding, Schmidt hammer testing, half-cell potential testing, and chloride concentration testing were performed on six 6-ft by 6-ft test areas randomly distributed within the single lane closed to traffic on each deck, and testing protocols followed American Society for Testing and Materials standards …

Numerical Modeling Of Blast-Induced Liquefaction, Wayne Yeung Lee

Theses and Dissertations

A research study has been conducted to simulate liquefaction in saturated sandy soil induced by nearby controlled blasts. The purpose of the study is to help quantify soil characteristics under multiple and consecutive high-magnitude shock environments similar to those produced by large earthquakes. The simulation procedure involved the modeling of a three-dimensional half-space soil region with pre-defined, embedded, and strategically located explosive charges to be detonated at specific time intervals. LS-DYNA, a commercially available finite element hydrocode, was the solver used to simulate the event. A new geo-material model developed under the direction of the U.S. Federal Highway Administration was …

Design Of A Linear Ultrasonic Piezoelectric Motor, Scott L. Sharp

Theses and Dissertations

A new geometrically unique ultrasonic motor (USM) was designed using finite element modeling (FEM). A USM operates by vibrating a drive tip in an elliptical motion while it is in periodic contact with a driven surface. Piezoelectric elements are used to create the elliptical motions and are driven near a resonant frequency to create the needed displacements for the motor to operate. An idea for a motor frame was conceived that consisted of an arch, a center ground, and two piezoelectric elements connected to the center ground. End caps were added between the frame and the piezoelectric elements to reduce …