Digital Commons Network^™

Investigation Of Reflective Materials For The Solar Cooker, Florida Solar Energy Center, John Harrison

FSEC Energy Research Center®

A critical task in developing a solar cooker is to identify reflector materials that would be both suitable for this application as well as economical. FSEC has conducted an extensive search for available reflective materials. This has included contacting reflective materials manufacturers as well as national laboratories that are currently working with private industry in developing reflector that can be used primarily on large concentrating solar energy devices. This investigation used a variety of resources. These included the FSEC solar library, web search engines, solar industry catalogs and directories, personal contacts, aluminum industry sources, solar cooker discussion groups, and a …

Horses Damp The Spring In Their Step, Alan M. Wilson, M. Polly Mcguigan, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle–tendon units^{1, 2}.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints^{3, 4}. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle^{5 …}

A Fuzzy Autopilot Design Approach That Utilizes Non-Linear Consequent Terms, Robert Sutton, Paul J. Craven

Journal of Marine Science and Technology

This paper describes the development of a fuzzy autopilot for controlling the non-linear yaw dynamics of an autonomous underwater vehicle (AUV) model. The autopilot design is based on a new approach that uses a Gaussian fuzzy inference mechanism. For the design study, the AUV model is hosted in the MATLAB/Simulink environment. Simulation results are presented which illustrate the potential of this novel methodology.

On A Computational Algorithm To The Hje In Nnlinear H∞ Control, Shr-Shiung Hu, Pao-Hwa Yang, Jeng-Yih Juang

Journal of Marine Science and Technology

The Hamilton-Jacobi equation (HJE) plays an essential role in both classical mechanics and nonlinear H∞ control theory. In this paper, we propose a detailed successive algorithm for finding an approximate solution of the HJE by solving linear equations. A scalar example is given to compare the computational procedures and the accuracy for the proposed approach with some other methods. In addition, the nonlinear H∞ controller design for the inverted pendulum is also included to show the superiority of the nonlinear H∞ controller, as compared with the linear H∞ controller, in the aspect of the robust performance/stability.

Coulomb Friction Applied To Analyze The Cutting Vibration Of Tool On Workpiece, Chein-Shan Liu

Journal of Marine Science and Technology

In this paper we study a single-degree-of-freedom model with the parallel presence of a linear spring and a Coulomb's contact friction device, the mass slider of which is mounted on the belt which running forward at a constant speed. We prove that no matter what the parameters are, the mass upon starting to slide never comes to stick on the belt. The oscillating amplitude of the slider is proportional to the belt running speed υ, and is inverse proportional to the natural frequency ω. In order to depress the vibration amplitude we may either decrease the belt running speed, increase …

Hybrid Transient-Parametric Method And System To Distinguish And Analyze Sources Of Acoustic Emission For Nondestructive Inspection And Structural, Health Monitoring, Yuris Dzenis

Department of Mechanical and Materials Engineering: Faculty Publications

A nondestructive evaluation (NDE) technique for inspecting or health monitoring of Structures and/or Specimens by analyzing acoustic emission (AE) signals emitted by the Structures and/or specimens. The method and System ana lyzes acoustic emission (AE) signals emitted by structures and/or Specimens. AE Signals emitted by the Structures and/or Specimens are parametrically filtered as a function of parametric filters corresponding to characteristic waveforms of transient AE classes of predefined AE signals. In para metric analysis, the filtering may be pre- or post-recording. In transient AE analysis, the filtering may be prior to transient recording of the transient signals.

A Theory Of Volumetric Growth For Compressible Elastic Biological Materials, Stephen M. Klisch, Timothy J. Van Dyke, Anne Hoger

Mechanical Engineering

A general theory of volumetric growth for compressible elastic materials is presented. The authors derive a complete set of governing equations in the present configuration for an elastic material undergoing a continuous growth process. In particular, they obtain two constitutive restrictions from a work-energy principle. First, the authors show that a growing elastic material behaves as a Green-elastic material. Second, they obtain an expression that relates the stress power due to growth to the rate of energy change due to growth. Then, the governing equations for a small increment of growth are derived from the more general theory. The equations …

Modeling, Fabrication, And Optimization Of Niobium Cavities – Phase I: Quarterly Progress Report August 20, 2001 - November 20, 2001, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Multipacting is one of the major loss mechanisms in rf superconductivity cavities for accelerators. This loss mechanism limits the maximum amount of energy/power supported by the cavities. Optimal designs have been identified in others’ studies. In practice, these designs are not easily manufactured. Chemical etching processes used to polish the cavity walls result in a nonuniform surface etch. A nonuniform surface etch will leave some unclean areas with contaminants and micron size particles. These significantly affect mutipacting. Further, a nonuniform etch will leave areas with damaged grain structure, which is not good for superconducting properties. Typically, the depth of chemical …

Industry Guide To Selecting The Best Residential Window Options For The Florida Climate (Revised), Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

It used to be said that windows are little more than holes in the insulation. It is true to some extent that poorly insulated and drafty windows in certain climates defeat the purpose of wall insulation. However, modern high performance windows are almost as good as opaque insulated wall sections, at least in terms of total energy savings over long periods of time. In some cases, they can be shown to actually out-perform insulated walls. Of course, they have the priceless additional benefits of providing views to the outdoors and natural daylight illumination indoors important issues of quality and comfort. …

A Study Of Muscle Activation In A Mathematical Model Of The Human Head And Neck, Janet Brelin-Fornari, A. Arabyan

Mechanical Engineering Presentations And Conference Materials

A model of the human head and neck that incorporates active and passive muscles is utilized in the analysis of non-impact loading in high “g” environments. The active muscles have the capability to be activated partially and in different combinations.The model is implemented in MADYMO using lumped parameters and Hill muscles. A comparison of simulation results with experimental data, generated by the Naval Biodynamics Laboratory (NBDL) for neck flexion and rebound, shows excellent agreement for a 15g impulsive load.

Moisture Problems In Manufactured Housing: Probable Causes And Cures, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

A significant number of new manufactured houses built to HUD code and located in the hot, humid Southeast are experiencing moisture problems. Soft wallboards, buckled floors, damaged wood molding and extensive mold growth are the most common symptoms. These problems do not respond to the standard service and repair strategies for water intrusion

At the request of four manufacturers, over twenty-five such moisture damaged homes were investigated in 1999 and 2000 to determine likely causes. One time blower door, duct tightness and pressure differential measurements were performed on all homes. Field data on ambient, crawlspace, belly and house temperatures and …

Implementation Of The Compressible Flow Solution Methodology For Solving 2d Shallow-Water Flow Problems, Joaquin Moran, Jose A. Rincon

Publications and Scholarship

This paper concerns with the implementation of the compressible flow solution methodology for solving 2D shallow water flow problems. It is well known that in both cases, the continuity and momentum conservation equations look quite similar, but depth replaces density of compressible flow, and the Froude number will replace the Maeh number. Thus, any mass imbalance produces a change in depth equivalent to the density change for compressible flow. It is possible to combine momentum and continuity equations to obtain a predictor-corrector algorithm for establishing the depth field. However, as the Froude number increases, the governing equations change their character …

Ortho-Planar Linear-Motion Springs, John J. Parise, Larry L. Howell, Spencer P. Magleby

Faculty Publications

This paper presents an ortho-planar spring design that operates by raising or lowering its platform relative to the base with no rotation. The compact nature of the design, and its non-rotating motion, eliminates the problem of rotation against adjoining surfaces and is less sensitive to variation in assemblies than many current compact springs. Nomenclature is presented to identify different configurations, mathematical equations are provided that accurately model the force-defection relationships, and a pneumatic valve positioner application is demonstrated.

Crash Attenuation System, John D. Reid, John R. Rohde, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A crash attenuation system having an impact head, and energy absorption mechanism. The energy absorbing mechanism has a mandrel for rupturing thin-walled tubes in a controlled rupture to absorb impact forces from a colliding vehicle. A frame may be used to mount the system to a truck, trailer, guardrail, median barrier end treatment, or a crash cushion. Stress concentrators may be incorporated into the tubes and the mandrels to selectively control rupturing and energy dissipation.

An Analysis Of Greenhouse Cookpot Design Considerations For Low-Cost Solar Cookers., Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

This analysis is prepared as part of a research project on low-cost solar cookers conducted by the Florida Solar Energy Center for the Dorothy Ann Foundation on behalf of Solar Household Energy, Inc. The overall purpose of the research project is to improve the performance, reliability and cost-effectiveness of low-cost solar cookers for use in developing nations. The analysis reported here concentrates solely on the cookpot and "greenhouse" design considerations for such systems.

Lightweight Cigs2 Thin-Film Solar Cells On Stainless Steel Foil, Florida Solar Energy Center, Neelkanth Dhere

FSEC Energy Research Center®

AM 0 PV parameters of large-grain, {112} orientated chalcopyrite CIGS2 thin films solar cells on 127µm thick SS flexible foil for space power were: V_oc = 802.9 mV, J_sc = 25.07 mA/cm², FF = 60.06%, and efficiency 0 = 8.84%. Detailed current versus voltage analysis gave values of series resistance Rs, shunt resistance Rp, diodefactor A, and reverse saturation current Jo of ~0.1 Ω cm2, ~600 Ω cm2, ~2.2 and ~1.85x10^-8 A cm^-2 respectively. Asharp QE cutoff was observed at CIGS2 bandgap of ~1.50 eV. Higher foil roughness resulted in a preliminary low 4.06% …

Oct 2001, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Software Program Storage Space Needed 16 new members

Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler

Mechanical Engineering

The purpose of this project was to design, build and test a low cost prototype that transfers compact discs (CDs) from a spindle to a computer based testing station. This will speed up the CD production/testing interface and eliminate the need for manual operation. Along with a heavy product design technical component, the project included a real life educational experience for the four students who got credit for a one year advanced senior project. Various designs were considered and the optimal design (based on cost and performance) was prototyped.

Fabrication Of 2- And 3-Dimensional Nanostructures, Hong Jiang, Camelia N. Borca, Bo Xu, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

Amongst tools for fabricating periodic and aperiodic nanostructures and nanodevices, electron beam-induced organometallic chemical vapor deposition (E-OMCVD) offers a highly flexible and controllable one-step deposition process. E-OMCVD enables maskless fabrication of nanoscale research and custom structures that have least dimensions near or below 10 nm–a scale at which other methods prove difficult or costly. Using the focused electron beam in a modified HB501 field-emission scanning transmission electron microscope (STEM), pads and wires with uniform thickness and well-defined shapes have been defined and deposited. Although conditions for fabricating the smallest deposits have not yet been optimized, the edge acuity (sharpness) of …

Study Of Delamination In Acceleration Tested Pv Modules, Florida Solar Energy Center, Neelkanth Dhere

FSEC Energy Research Center®

The average adhesional shear strength at silicon cell/EVA interface in damp-heat, acceleration-tested modules was ~27% of that measured in new modules. The average carbon concentration at the surface of samples extracted from acceleration tested modules was 15 atomic % or ~30% of that measured in new modules. Surface concentrations of sodium on Si-cell samples from the acceleration tested modules ranged from 4.9 to 22.0 atomic %while those of phosphorous ranged from 4.3 to 7.1 at. %. These are very high impurity concentrations. Often small concentrations of phosphorous were detected at the interface between titanium oxide antireflection coating and silicon cell. …

The Uiuc Virtual Spectrometer: A Java-Based Collaborative Learning Environment, Michael C. Dorneich, Patricia M. Jones

Michael C. Dorneich

The development of the UIUC Virtual Spectrometer (UIUC-VS), an interactive, Java-based simulation and tutoring system, is discussed. The apprenticeship model oflearning is utilized to create a learning environment for the study of a one-dimensional proton nuclear magnetic resonance (NMR) experiment, with the goal of linking theoretical knowledge with practical operational experience. Active, exploratory, apprentice-style learning is supported via modes of operation within the system. Students can flexibly choose to "observe the expert" perform and explain operational steps, or "act as an apprentice" and carry out the steps autonomously. Students can switch between modes at their discretion, giving them control of …

Ole Miss Engineer 2001

Ole Miss Engineer

No abstract provided.

2001 (Fall) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the fall of 2001.

Preliminary Evaluation Of Energy-Efficiency Improvements To Modular Classrooms, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The objective of our investigation is to evaluate innovations that would enable modular classroom builders to improve the energy performance of their classrooms. We investigate improved insulation, better windows, daylighting, cross-ventilation, sensible and latent heat recovery of ventilation air and light colored surfaces and radiant barriers for cooling dominated climates. The tasks associated with this work are as follows:

• Create a simulation software.
• Establish a baseline reference building using a standard modular classroom building.
• Parametric evaluation of the impact of ventilation and school schedule on energy use.
• Determine the feasibility of improving insulation and envelope systems.
• Determine the feasibility of …

A Nonlinear Motion Cueing Algorithm With A Human Perception Model, Robert J. Telban

Link Foundation Modeling, Simulation and Training Fellowship Reports

The objective of a motion system, when used in conjunction with a visual system, is to stimulate the pilot so that he can perceive the required motion cues necessary to fly the simulator within the same performance and control activity as the aircraft. An example of a motion system is the six-degree-of-freedom hexapod shown in Figure E.l. Platform motion allows the pilot to react more quickly to simulated aircraft motion as compared to visual stimuli alone, thus enabling him to co1Tect (and reduce the magnitude) of any deviation sooner than having to wait for the information visually. Without motion cues …

Buckling Of Composite Conical Shells Under Combined Axial Compression, External Pressure, And Bending, Youngjin Chung

Dissertations

Conical shells are extensively used in space crafts, robots, shelters, domes, tanks, and in machinery or devices (e.g. as Belleville washers). Thus, the design of minimum weight, maximum strength, stiffened conical (and cylindrical) shells under combined loads has long been of interest to designers. The objective of this study is to improve the strength of conical shells and reduce the weight of the structure. Buckling of composite conical shells subjected to combined axial loading, external pressure, and bending is investigated using energy and finite element methods. The conical shells have single and multiple layers, different cone angle, length, and radius. …

Integration Of E-Business Strategy For Multi-Lifecycle Production Systems, Yanchun Luo

Dissertations

Internet use has grown exponentially on the last few years becoming a global communication and business resource. Internet-based business, or e-Business will truly affect every sector of the economy in ways that today we can only imagine. The manufacturing sector will be at the forefront of this change. This doctoral dissertation provides a scientific framework and a set of novel decision support tools for evaluating, modeling, and optimizing the overall performance of e-Business integrated multi-lifecycle production systems. The characteristics of this framework include environmental lifecycle study, environmental performance metrics, hyper-network model of integrated e-supply chain networks, fuzzy multi-objective optimization method, …

Dynamic Friction Of Uhmwpe Angular Compliant Bearing For Joint Implants And Machinery, Max Roman

Theses

The feasibility of a unique design of orthopedic- joint implant is investigated. The work focuses on the dynamic friction characteristics of a new joint. This unique design can be also useful in machinery involving oscillating motion similar to that of the hip joint during walking. An elastomeric layer bonded behind the rigid acetubular cup can be beneficial in improving the durability of prosthetic implants. Angular compliance offered by the elastomeric layer reduces relative sliding between the surfaces, lowers contact stresses by distributing pressure more evenly, and reduces the possibility of incongruent loading conditions caused by misalignment. The application of a …

Mechanical Design Of The Heater Used In Near Infrared Filter, Jun Ma

Theses

This thesis presents a design and analytical process in the application of the heater used in a near infrared filter working in Big Bear Solar Observatory, CA. The objective of the project is to achieve the physics parameters for the filter, which will be used in the observation of the solar activity.

The most important part of this design is to keep a relatively fixed temperature inside the oven-like heater. The reason is that optical properties of calcite (kind of filter in telescope) are pretty sensitive to a tiny disturbance on inside temperature. This was the biggest issue in this …

Evaluate Deployment Of Photovoltaic Systems For Disasters, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

In 1996, the U.S. Department of Energy (DOE), developed a program with the Federal Emergency Management Agency (FEMA) to provide photovoltaic electrical power in disasters. In support of this effort, DOE purchased eight PV-generator trailers which were constructed in 1998 and supplied to FEMA for deployment in disaster response efforts. This report describes past and present use of the trailers, their depot location, list maintenance data, and the viability of the trailers in a disaster.