Engineering Commons^™

Synthesis And Experimental Testing Of A Nonlinear Optimal Tracking Controller, Timothy Mclain, Randal W. Beard, Christopher A. Bailey

Faculty Publications

This paper presents a novel approach for developing tracking controllers for nonlinear systems. The approach involves the numerical solution, by Galerkin approximation, of the time-varying Hamilton-Jacobi-Bellman (HJB) equation and results in a nonlinear controller approximating the optimal tracking control law for a specified desired trajectory and cost function. Experimental results are presented for a nonlinear pendulum system.

Installing Photovoltaic Systems: A Question And Answer Guide For Solar Electric Systems, Florida Solar Energy Center, Fsec Photovoltaic Division

FSEC Energy Research Center®

This Question and Answer Guide for Solar Electric Systems addresses general considerations about photovoltaics (PV) technology and requirements for installing photovoltaic power systems, including building-integrated applications. Contained in this guide are commonly asked questions about the technology, and responses based on current state-of-the-art equipment and industry design practice.

Recommendations For Maximizing Battery Life In Photovoltaic Systems: A Review Of The Lessons Learned, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report contains notes, observations and recommendations about the use of batteries in small stand-alone photovoltaic (PV) systems. The conclusions of this work are based on the results of more than a decade's worth of battery testing at the Florida Solar Energy Center and related work with Sandia National Laboratories, the PV industry and user groups. The most critical findings were the relationship between battery state-of-charge and battery life and the importance of an adequate PV array-to-load ratio.

Development Of Icejet Machining Technology, Dimitri V. Shishkin

Theses

This work was concerned with the application of ice powder for material processing. Material cutting and surface cleaning were also studied. As a result, innovative cleaning and etching technology was pioneered. The corresponding technology was designed and demonstrated.

The study involved investigation of water freezing, crushing of generated ice, ice transportation, formation of ice water and ice air streams and, finally, use of this stream for material cutting and cleaning. The theoretical work included investigation of the phase change in water and ice formation, effect of ice temperature on particles behavior and entrainment of ice particles by the water stream. …

Oxygen Permeation Through Composite Oxide-Ion And Electronic Conductors, Kevin Huang, Michael Schroeder, John B. Goodenough

Faculty Publications

Oxygen permeation through composites consisting of four well-known oxide-ion conductors and a noble metal, Pd or Ag, is reported. The oxides were Zr_0.9Y_0.1O_1.95 (YSZ), (Bi_1.75Y_0.25O₃)_0.95(CeO₂)_0.05 (BYC5), Ce_0.8Sm_0.2O_1.9 (SSC), and La_0.8Sr_0.2Ga_0.83Mg_0.17O_2.815 (LSGM). The results show that (BYC5 + Ag) yields the highest oxygen permeation flux, but the composite deteriorates with time. The composites (SSC + Pd), (LSGM + Pd), and (YSZ + Pd) give stable, but relatively lower oxygen permeation flux …

Directivity Patterns Of Acoustic Radiation From Bowed Violins, Lily M. Wang, Courtney B. Burroughs

Durham School of Architectural Engineering and Construction: Faculty Publications

Directivity patterns of acoustic radiation have been measured in the far-field of a violin, excited with an open-frame mechanical bowing machine. Analysis of the directivity patterns confirms that, at frequencies below 600 Hz, the violin radiates omnidirectionally, while above 600 Hz, certain trends are apparent as the patterns become increasingly complex. It is noted that when different strings are excited, the far-field radiation patterns observed at nearly the same frequency are similar, even in higher frequency ranges where modal overlap is high. When the difference in frequency between two directivity patterns exceeds some fraction of a semitone, though, the measured …

Variable Area Inlet For Vehicle Thermal Control, Thomas R. Layne, Milton E. Franke, Darrell B. Ridgedly

AFIT Patents

A variable area inlet structure for a vehicle utilizing ram air for coolant is described which comprises a variable area inlet device in the ram air inlet in the form of a butterfly valve, damper, shutter, or similar structure, a temperature sensor in thermal contact with a component within the vehicle to be cooled by ram air flow, a controller and actuator, responsive to the temperature sensor and operatively connected to the variable area device, for controlling the inlet area in response to the component temperature.

Pv Lighting Systems For Bcc - Evaluation Of Vrla Batteries And Pwm Controls, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report presents the initial seven-month performance summary for these 15 PV lighting systems, for the period February 13 through September 15, 1997. During this time, the systems were configured with three types of valve-regulated lead acid (VRLA) batteries (five systems using each type of battery), all operating with pulse-width-modulated (PWM) battery charge controllers. Details of the system configurations are presented in this report. Prior to initial operation, extensive baseline data was collected on the individual components installed in each system. This data included battery capacity and high-rate load measurements, battery weights, charge controller set points, PV array currents and …

Ole Miss Engineer 1999

Ole Miss Engineer

No abstract provided.

In Situ Stem Technique For Characterization Of Nanoscale Interconnects During Electromigration Testing, Ismail Gobulukoglu, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

A technique for observing microstructure and morphology changes during annealing or electromigration of 100 nm-scale and smaller interconnects is presented. The technique is based on dynamic in situ characterization using a UHV field-emission scanning transmission electron microscope (STEM) and can enable full microstructural characterization (images, diffraction patterns and compositions) during electromigration testing. Initial steps in the validation of the approach include in situ electron-beam OMCVD of Al-containing wires and observation of these wires. Although the deposition conditions were not optimized. Al-containing wires, with high edge acuity, thickness uniformity, and with minimum interconnect widths as small as 15 nm have successfully …

Finite Element Simulation Of Creep Buckling Of Cipp Liners Under External Pressure, Qiang Zhao

Doctoral Dissertations

The problem of long-term structural behavior of CIPP liners under external hydrostatic pressure has been characterized as a structural instability problem which is induced by time-dependent material deformation or creep. It is also a contact problem since the liner deflection is externally constrained by the host pipe. The intrinsically nonlinear problem is investigated by means of finite element simulation, with emphases on (a) the essential structural behaviors and mechanisms of buckling, and (b) the influences of inelastic material properties (i.e. yield strengths and creep rates) and geometrical parameters on liner's buckling resistance.

A liner first deforms as a free pipe …

On The Detachment Of Step-Tapered Doublers: Part 2—Evolution Of Pressure Loaded Structures, Anette M. Karlsson, W. J. Bottega

Mechanical Engineering Faculty Publications

One-dimensional edge debonding of layerwise step-tapered patches from both flat and cylindrical structures subjected to applied pressure is studied in the context of the general formulation presented in Part 1. Numerical simulations based on analytical solutions of the problems of interest are performed and intricate results presented in the form of threshold curves/delamination paths for various taper angles and support conditions. Configurations corresponding to full contact of the debonded segments, edge contact of the debonded segments and no contact of the debonded segments of the evolving composite structure are included in the model and found to significantly affect the predicted …

On The Detachment Of Step-Tapered Doublers : Part 1—Foundations, W. J. Bottega, Anette M. Karlsson

Mechanical Engineering Faculty Publications

One-dimensional edge debonding of layerwise step-tapered patches from both flat and cylindrical structures is examined. The problems are approach from a unified point of view, as propagating boundary problems in the calculus of variations, with the models for both flat and curved structures being formulated simultaneously. The effects of a contact zone adjacent to the bonded region are incorporated as is the phenomenon of edge-point contact. The formulation results in a selfconsistent representation of the various intact and debonded segments of the composite structure comprised of a multilayer patch and a base structure. It concurrently yields the conditions which establish …

Multifield Spectral Analysis Of Human Respiratory Sounds, John William Ray Jr.

Doctoral Dissertations

Computer analysis of human respiratory sounds (phonopneumography) has been attempted since the 1960s with poor results. Steady research efforts by numerous researchers have failed to yield a practical diagnostic tool to replace the physician and the stethoscope. This has been the result of the high degree of variability in proposed analysis parameters from subject to subject.

The purpose of this research is to examine a new approach to phonopneumography by comparing multiple lung fields of the same subject for the same breath in order to develop the diagnostic parameters. This approach has the advantage of allowing the subject to provide …

Graphical Display And Data Structure For Virtual Prototyping, David William Manry

Doctoral Dissertations

One of the goals of engineering firms is to bring better products to market faster. Although concurrent engineering can aid in this endeavor, it requires that all areas of an organization work simultaneously. Thus, current product data must be accessible to everyone.

Virtual prototyping allows this simultaneous exchange of information. Virtual prototyping not only replaces the physical model in product development with a virtual model, but also it goes further by allowing data associated with each part of the model to be accessed. This data is not limited to just geometric properties but could contain other quantifiable properties, such as …

On-Line Free Form Surface Measurement Via A Fuzzy-Logic Controlled Scanning Probe, Ming Chang, Paul P. Lin

Mechanical Engineering Faculty Publications

This paper presents a system and methodology for on-line free form surface measurement via a scanning contact probe installed on a CNC (computer numerical control) machine. The scanning probe provides more sampling points than any traditional touch trigger type of probes used on CNC machines, and better measuring accuracy than laser displacement sensing or structured lighting. The presented measuring system's main advantage is that the number of measured points can vary with the change of surface curvature. To improve the measuring stability and continuity, fuzzy logic control, in lieu of traditional PID control, is employed. As a result, the …

Frequency Driven Phasic Shifting And Elastic-Hysteretic Partitioning Properties Of Fractional Mechanical System Representation Schemes, Jerzy T. Sawicki, Joe Padovan

Mechanical Engineering Faculty Publications

Based on the Louiville–Riemann fractional formulation of lumped hysteretic mechanical system simulations, asymptotic-type relationships are derived. These are employed to determine how such operators, which act as viscoelastic elements, partition system energy into conservative and nonconservative components. Special emphasis is given to: (a) determine how operator order serves to weigh such a splitting, (b) determine how partitioning affects system phasing and amplitude response, and (c) to establish how conservative and nonconservative effects modulate during a given system cycle. The generality of the undertaken approach is such that multi-element fractional Kelvin Voigt formulations subject to spectrally rich inputs can be handled, …

Relationship Between Cost Of Technical Training And Cost Reduction Of Internal Defects At John Deere Waterloo Foundry, John Brackin

Graduate Research Papers

Can the cost of technical training at John Deere Waterloo Foundry pay for itself in the reduction of internal defects? This research compared training costs to the savings from reduced internal defects on Molding Unit 801 located in the John Deere Waterloo Foundry. Training was the independent variable of this research. The results of this research identified a correlation between training costs ( operational definition on page 10) and defect reduction costs. A correlation between these two established a break even point for training dollars spent.

The dependent variable was the dollar savings based on reduction of internal defects. There …

Stratal Architecture In A Prograding Shoreface Deposit, Eastern Shore, Va: Relationship To Grain Size, Permeability, And Facies Distribution, Andrew C. Miller

OES Theses and Dissertations

A fundamental concern of the stratigrapher is to develop predictive models of stratigraphic organization. In sedimentology one of the most significant problems that has yet to be resolved is the fact that there is a lack of quantitative information regarding the relationship between geometry of beds, thickness of beds, grain size and sedimentary structures in sandy environments, especially shallow marine deposits. Scientists have also realized the need to correlate quantitative permeability to sedimentary structures and scales of stratigraphic organization. The purpose of the study is to investigate the scales of stratigraphic organization that control the variation of grain size and …

An Experimental Investigation Into The Effect Of Clearance And Torque On Load Sharing In A Bolted Joint, Jerry B. Robertson

Mechanical & Aerospace Engineering Theses & Dissertations

The shear load experienced by each bolt in a multi-fastener bolted butt joint is a percentage of the total load applied to the joint. Joint failure can be premature when one fastener is subjected to a disproportional amount of the total load. Conversely, the ultimate load the joint can endure may be increased if the distribution of loads can be equalized by some means. In this investigation, two and four fastener butt joints were studied. An instrumented bolt was constructed that could measure the bending stresses in the bolt associated with the bearing load. That data was converted into force …

1999 (Spring) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the spring of 1999.

Mar 1999, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Additional Funds Donation to Camp Creek Threshers Renovation Status

Energygauge Usa: A Residential Building Energy Simulation Design Tool, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) is developing a new software (EnergyGauge USA) which allows simple calculation and rating of energy use of residential buildings around the United States. In the past, most residential analysis and rating software have used simplified methods for calculation of residential building energy performance due to limitations on computing speed. However, EnergyGauge USA, takes advantage of current generation personal computers that perform an hourly annual computer simulation in less than 30 seconds. A simplified user interface allows buildings to be quickly defined while bringing the computing power and accuracy of an hourly computer simulation to …

Observations Of Lattice Curvature Near The Interface Of A Deformed Aluminium Bicrystal, Brent L. Adams, W. E. King, S. Sun

Faculty Publications

This work was partially supported by MRSEC Program of the National Science Foundation (DMR-9632556), and under the auspices of the US Department of Energy and Lawrence Livermore National Laboratory under contract W-7405- Eng-48. S. Sun gratefully acknowledges the comments of Professor E. T. Onat, Professor B. T. Chu and Professor W. Tong of the Mechanical Engineering Department at Yale University, and their valuable guidance in the process of completing this project as a doctoral dissertation. The assistance of B. El-Dasher of Carnegie-Mellon University is also gratefully acknowledged. Reported here is a study of the pattern of lattice curvature near the …

Activated Carbon Produced From Agricultural Residues, Daniel W. Armstrong, V. J. Flanigan, William Joseph James, Jui-Lung Li, Kimber L. Rundlett

Chemistry Faculty Research & Creative Works

A process for producing activated carbon from agricultural residues by heating the residues to a temperature in the range of about 250° C. to about 550° C. to volatilize organic compounds in the residues and to carbonize the residues and further heating to activate the carbonized residues. Activated carbon produced from agricultural residues.

Sliding Mode Measurement Feedback Control For Antilock Braking Systems, Cem Unsal, Pushkin Kachroo

Electrical & Computer Engineering Faculty Research

We describe a nonlinear observer-based design for control of vehicle traction that is important in providing safety and obtaining desired longitudinal vehicle motion. First, a robust sliding mode controller is designed to maintain the wheel slip at any given value. Simulations show that longitudinal traction controller is capable of controlling the vehicle with parameter deviations and disturbances. The direct state feedback is then replaced with nonlinear observers to estimate the vehicle velocity from the output of the system (i.e., wheel velocity). The nonlinear model of the system is shown locally observable. The effects and drawbacks of the extended Kalman filters …

Electro-Hydrodynamic Pumped Hydraulic Actuation With Application To Active Vibration Control, Ahmad Reza Kashani, Sung Kang, Kevin P. Hallinan

Mechanical and Aerospace Engineering Faculty Publications

A new type of actuation device has been conceptualized that meets the needs of both large displacement, force and bandwidth within a package more compact than currently available magnetostrictive and stack-type piezoelectric actuators of similar rating. This concept relies on micro-scale electrohydrodynamic (EHD) pumping of a dielectric liquid within small channels. Configured as an actuator, the EHD pump(s) would be used to move fluid between two reservoirs—each having a compliant membrane that interfaces to the world to provide the means to achieve vibration cancellation or micro actuation.

Ordinarily limited to generating flow in macroscale applications, the EHD pump, when operating …

Heat Transfer To The Inclined Trailing Wall Of An Open Cavity, Orval A. Powell

Theses and Dissertations

Experimental and computational heat transfer investigations were performed on a cavity with an inclined trailing wall (20-degrees to the horizontal), simulating one under investigation for use in a scramjet engine. Heat transfer data are reported in the form of Stanton number obtained using a curve fit to the recorded transient surface temperature history under cold flow conditions. Ascending from the reattachment point, the Stanton number increased by nearly 50% due to flow compression. This effect of flow compression was also evident at the junction of the cavity floor and inclined trailing wall, where the Stanton number also increased by 50%. …

Energy And Resource Assessment Of The Caribbean Marine Research Center, Lee Stocking Island, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

A project is being coordinated by the Florida Solar Energy Center (FSEC) with the Perry Foundation and the Caribbean Marine Research Center (CMRC) on Lee Stocking Island in the Bahamas. The purpose of the research is to demonstrate energy and water savings associated with efficient technologies in an isolated sub-tropical climate. The project is being used as a test case to examine how energy and resource independent eco-tourism projects might be successfully accomplished in Florida and other Caribbean locations.

FSEC plans to monitor energy and water consumption in two buildings at the center. The VIP (Scientists' quarters) building has been …

Crop Updates 1999 - Lupins, Greg Shea, Geoff Thomas, Mark Sweetingham, Bill O'Neill, Wallace Cowling, Bevan Buirchell, Hua'an Yang, David Luckett, Allan Brown, John Hamblin, Joanne E. Barton, Kedar Adhikari, Nick Galwey, Miles Dracup, Bob French, Debbie Thackray, Roger Jones, Brenda Coutts, Narelle Reeve, Y. Cheng, R. A.C. Jones, Francoise Berlandier, Linnet Cartwright, James Fisher, Art Diggle, Bill Bowden, Chris Gazey, Luigi Morsechi, Terry Piper, Peter Newman, Dave Nicholsen, Mohammad Amjad, Glen Riethmuller, Ron Javis, Paul Blackwell, C. L. White

Crop Updates

This article contains twenty three papers

1998 LUPIN HIGHLIGHTS

LUPIN ANTHRACNOSE

1. Anthracnose overview, Greg Shea, Geoff Thomas and Mark Sweetingham, Agriculture Western Australia

2. Anthracnose – Critical seed infection levels for resistant and susceptible varieties, Geoff Thomas, Mark Sweetingham, Bill O'Neill and Greg Shea, Agriculture

Western Australia

3. Fungicide seed treatment for anthracnose and brown spot control in lupin, G. Thomas and M. Sweetingham, Agriculture Western Australia

LUPIN BREEDING AND AGRONOMY

4. Anthracnose resistance in lupins – an innovative Australian research effort 1996-1998, Wallace Cowling1'2, Bevan Buirchell_1,2 Mark Sweetinqham_1,2, Hua'an Yang₂, …