Engineering Commons^™

Best Practice For The Location Of The Air And Thermal Boundaries In Small Commercial Buildings, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Suspended t-bar ceilings are common in commercial buildings. Research has found that these ceilings are very leaky, and several problems arise from this. If the space above the ceiling is vented to outdoors, the entire building becomes leaky. Furthermore, if the insulation is located at the ceiling rather than the roof, then the ceiling space will be hot (summer), and if the ceiling space is also vented to outdoors, then the ceiling space will be hot and humid. The thermal and humidity conditions of the ceiling space have important implications for space conditioning loads, building ventilation rates, and indoor relative …

Factors Influencing Water Heating Energy Use And Peak Demand In A Large Scale Residential Monitoring Study, Florida Solar Energy Center, Matthew Bouchelle

FSEC Energy Research Center®

A load research project by the Florida Power Corporation (FPC) is monitoring 204 residences in Central Florida, collecting detailed end-use load data. The monitoring is being performed to better estimate the impact of FPC's load control program, as well as obtain improved appliance energy consumption indexes and load profiles. A portion of the monitoring measures water heater energy use and demand in each home on a 15-minute basis. The paper summarizes the various impacts identified on water heating energy use and demand.

On The Behavior Of A Class Of Patched Plates During Cooling, Anette M. Karlsson, W. J. Bottega

Mechanical Engineering Faculty Publications

The behavior of patched beam-plates during uniform cooling is considered. A non-linear formulation is adopted and the problems of interest are solved analytically yielding exact results within the context of the mathematical model employed. Three non-dimensional parameters corresponding to (i) a loading parameter, (ii) a critical temperature and (iii) a critical membrane force, are seen to characterize the response of the composite structure. Stability is considered and critical behavior includes bifurcation and asymptotic buckling, non-trivial “groundstates”, and demarcation and transition in deflection direction. Extensive numerical simulations based on analytical solutions are performed. Results are presented for various loading and support …

The Influence Of Foot Positioning On Ankle Sprains, I. C. Wright, R. R. Neptune, Antonie J. Van Den Bogert, B. M. Nigg

Mechanical Engineering Faculty Publications

The goal of this study was to examine the influence of changes in foot positioning at touch-down on ankle sprain occurrence. Muscle model driven computer simulations of 10 subjects performing the landing phase of a side-shuffle movement were performed. The relative subtalar joint and talocural joint angles at touchdown were varied, and each subject-specific simulation was exposed to a set of perturbed floor conditions. The touchdown subtalar joint angle was not found to have a considerable influence on sprain occurrence, while increased touchdown plantar flexion caused increased ankle sprain occurrences. Increased touchdown plantar flexion may be the mechanism which causes …

A Simulation Model For Scheduling And Analysis Of A Job Shop Manufacturing System Using Automated Guided Robots, Sherif Abdel Monem Barakat

Archived Theses and Dissertations

No abstract provided.

Solar Swimming Pool Heating In Florida: Collector Sizing And Economics, Florida Solar Energy Center, Charles Cromer

FSEC Energy Research Center®

There are over 300,000 swimming pools in Florida, and most of them must be heated during winter months to maintain comfortable swimming conditions. For the average user, temperatures ranging from 78 °F to 80° F for spring and fall and 76° for winter are usually considered comfortable. This publication presents a simple method that can be used to determine the solar collector area (within ± 20 percent) needed to heat a swimming pool to comfort conditions assuming average weather patterns.

Preliminary Design Of An Electrodynamic Balance For Single Particle Analysis, C. Bobcowski, J. Costa, S. Shaw, R. Zucal, J. Schmalzel, R. Ordonez, John Chen

Mechanical Engineering

An electrodynamic chamber (EDC) is a device that controls the electrodynamic field surrounding a single particle. By suspending the particle at a fixed point in space, various measurements can be made to determine thermodynamic properties of the particle. This paper describes the preliminary engineering development of an EDC for combustion research at Rowan University.

Apr 2000

Lester F. Larsen Tractor Museum: Planning and Development Documents

State Museum Report Raffle Committee Book Sales Plans

Florida Homeowner's Manual For Energy Efficiency, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Most homeowners would like to save on their monthly expenses. One of these expenses - the utility bill - costs the average Florida homeowner five percent of his/her total annual after-tax income. Currently, Floridians are paying about eight cents per kilowatt hour (kWh) for electricity. Without close monitoring, electrical uses such as air conditioning can easily push utility costs over $150 per month. Effective conservation measures involve using household appliances less frequently and servicing them properly. These measures will improve their performance as well as their useful life - a real savings over the long run. Also, when you use …

A Hybrid Finite Element-Finite Difference Method For Thermal Analysis In A Double-Layered Thin Film, Teng Zhu

Doctoral Dissertations

Thin film technology is of vital importance in microtechnology applications. For instance, thin films of metals, of dielectrics such as SiO2, or Si semiconductors are important components of microelectronic devices. The reduction of the device size to the microscale has the advantage of enhancing the switching speed of the device. The reduction, on the other hand, increases the rate of heat generation that leads to a high thermal load on the microdevice. Heat transfer at the microscale with an ultrafast pulsed-laser is also a very important process for thin films. Hence, studying the thermal behavior of thin films or of …

Ole Miss Engineer 2000

Ole Miss Engineer

No abstract provided.

Orthogonal Grid Generation, Non-Reflecting Boundary Condition, And Parallel Computation For Fluid Flow, Shaopeng Sun

Doctoral Dissertations

The purpose of this study is to investigate one of the most interesting areas in computational fluid dynamics. The content of this paper is divided into three parts. The first part is the orthogonal grid generation. The second part is the non-reflecting boundary condition in curvilinear coordinates. The third part is parallel computation by Message Passing Interface.

The grid generation method is presented by solving elliptic partial difference equations. The elliptic grid generation method is based on the use of composite mapping, which consists of a non-linear algebraic transformation and an elliptic transformation. The elliptic transformation is based on the …

Kinetics Of Laser Chemical Vapor Deposition Of Carbon And Refractory Metals, Feng Gao

Doctoral Dissertations

Three-dimensional laser chemical vapor deposition (3D-LCVD) has been used to grow rods of carbon, tungsten, titanium, and hafnium from a variety of hydrocarbons and metal halide-based precursors. A novel computerized 3D-LCVD system was designed and successfully used in the experiments. A focused Nd:Yag laser beam (λ = 1.06 μm) was utilized to locally heat up a substrate to deposition temperature. The rods, which grew along the axis of the laser beam, had a typical diameter of 30–80 μm and a length of about 1 mm. The precursors for carbon deposition were the alkynes: propyne, butyne, pentyne, hexyne, and octyne. Propyne …

Quantification Of In Vivo Acl Elongation During Dynamic Joint Movements: A New Methodology, Scott G. Mclean, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Anterior cruciate ligament (ACL) injuries are common in movement tasks incorporating sudden changes in velocity, such as sidtestepping. Current techniques adopted to quantify ACL strain are invasive as well as limited to slow, quasi-static move- ments. This paper presents a method for non-invasive measurement of ACL elongation during dynamic movement tasks, validation of the method, and demonstrates its applicability to the analysis of sidestep movements

Curvilinear Interface Methodology For Finite-Element Applications, Ollie James Rose

Mechanical & Aerospace Engineering Theses & Dissertations

Recent trends in design and manufacturing suggest a tendency toward multiple centers of specialty which results in a need for improved integration methodology for dissimilar finite element or CFD meshes. Since a typical finite element or CFD analysis requires about 50% of an engineers effort to be devoted to modeling and input, there is a need to advance the state-of-the-art in modeling, methodology. These two trends indicate a need to for the capability to combine independently-modeled configurations in an automated and robust way without the need for global remodeling. One approach to addressing this need is the development of interfacing …

Fabrication Of Thermoplastic Composite Laminates Having Film Interleaves By Automated Fiber Placement, Anthony Bruce Hulcher

Mechanical & Aerospace Engineering Theses & Dissertations

Experiments were carried out at the NASA Langley Research Center automated fiber placement facility to determine an optimal process for the fabrication of composite materials having polymer film interleafs. A series of experiments was conducted to determine an optimal process for the composite prior to investigation of a process to fabricate laminates with polymer films. The results of the composite tests indicated that a well-consolidated, void-free laminate could be attained. Preliminary interleaf processing trials were then conducted to establish some broad guidelines for film processing. The primary finding of these initial studies was that a two-stage process was necessary in …

Improving Co-Generation Plant Performance Using Computer Modeling Software: A Parametric Study, Gerald R. Munyan

Mechanical & Aerospace Engineering Theses & Dissertations

The desire to optimize plant performance continues to direct the goals of design and plant engineers associated with larger thermal systems. With the increasing availability of software designed for modeling thermal systems, the task of improving plant performance continues to develop. The ability to model a facility using a commercially available software package allows the design engineer and plant engineer to investigate the effects of variations in plant conditions or components on overall plant operations.

An analysis of the Kirk Lumber Company's co-generating facility was performed using the modeling program PROSIM written by the consulting engineering firm Endat Oy, of …

Process Flow Optimization Studies Through Discrete Event Simulation, Milind Chokshi

Electrical & Computer Engineering Theses & Dissertations

Computer-aided simulation has begun to emerge as a powerful tool for numerical analysis of the behavior and anticipated performance of industrial systems and their optimization. Applications include materials handling, storage and controls systems, prediction of manufacturing efficiencies, and production optimization. Simulations are used to test baseline models and subsequently analyze new production concepts, operating strategies, and planned procedures prior to costly implementation.

The study of process flows in a manufacturing environment is difficult due to its inherent stochastic nature. Breakdown of the sub-systems and failures of machines is a random process and needs to be solved based on concepts of …

Compressible Flow Modeling In A Low Pressure Natural Gas Fuel Injector, Eugene D. White Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

In 1997, Siemens Automotive in Newport News, Virginia, conducted mass flow experiments on their DEKA IV natural gas fuel injector using nitrogen gas as the test fluid. The mass flow rates measured from the steady state flow experiments increased linearly with increasing upstream reservoir pressure. This relationship in the experimental data suggested that a choked flow condition must exist somewhere inside the injector.

To test this hypothesis, nitrogen gas flow through the internal passages of a fuel injector at steady state was simulated using computational fluid dynamics software. Several numerical models were constructed. Axisymmetric two-dimensional models were constructed of the …

An Integrated Engineering-Computation Framework For Collaborative Engineering: An Application In Project Management, Hisham Mohamed El-Sayed Abdelsalam

Mechanical & Aerospace Engineering Theses & Dissertations

Today's engineering applications suffer from a severe integration problem. Engineering, the entire process, consists of a myriad of individual, often complex, tasks. Most computer tools support particular tasks in engineering, but the output of one tool is different from the others'. Thus, the users must re-enter the relevant information in the format required by another tool. Moreover, usually in the development process of a new product/process, several teams of engineers with different backgrounds/responsibilities are involved, for example mechanical engineers, cost estimators, manufacturing engineers, quality engineers, and project manager. Engineers need a tool(s) to share technical and managerial information and to …

Diffusion Problems In Wound Healing And A Scattering Approach To Immune System Interactions, Julia Suzanne Arnold

Mathematics & Statistics Theses & Dissertations

A theoretical model for the existence of a Critical Size Defect (CSD) in certain animals is the focus of the majority of this dissertation. Adam [1] recently developed a one-dimensional model of this phenomenon, and chapters I–V address the exist the CSD in a two-dimensional model and a three-dimensional model. The two dimensional (or 1-d circular) model is the more appropriate for a study of CSD's. In that model we assume a circular wound of uniform depth and develop a time-independent form of the diffusion equation relevant to the study of the CSD phenomenon. It transpires that the range of …

Pulsed Optoacoustics In Solids, Zibiao Wei

Electrical & Computer Engineering Theses & Dissertations

Optoacoustic techniques are widely used to probe and characterize target materials including solids, liquids and gases. Included in such applications are diagnoses of thin films and semiconductor materials. The need to obtain greater spatial resolution requires the generation of shorter optoacoustic pulses. For such pulses, non-thermal effects may be quite important. On the other hand, even when an optoacoustic pulse is generated by an initially non-thermal technique, the thermal aspects become important in its evolution and propagation. The research undertaken in this Ph.D. dissertation included the generation and detection of optoacoustic signals through the thermal elastic mechanism. Several applications in …

A Comparison Of Quasi-Static Indentation Testing To Low Velocity Impact Testing, Michael J. Douglas

Mechanical & Aerospace Engineering Theses & Dissertations

A static test method for modeling low-velocity foreign object impact events to composites would prove to be very beneficial to researchers since much more data can be obtained from a static test than from an impact test. In order to examine if this is feasible, a series of static indentation and low velocity impact tests were carried out and compared. Square specimens of many sizes and thicknesses were utilized to cover the array of types of low velocity impact events. Laminates with a rt/4 stacking sequence were employed since this is by far the most common type of engineering laminate. …

A Special Theory Of Biphasic Mixtures And Experimental Results For Human Annulus Fibrosus Tested In Confined Compression, Stephen M. Klisch, Jeffrey C. Lotz

Mechanical Engineering

A finite deformation mixture theory is used to quantify the mechanical properties of the annulus fibrosus using experimental data obtained from a confined compression protocol. Certain constitutive assumptions are introduced to derive a special mixture of an elastic solid and an inviscid fluid, and the constraint of intrinsic incompressibility is introduced in a manner that is consistent with results obtained for the special theory. Thirty-two annulus fibrosus specimens oriented in axial (n = 16) and radial (n = 16) directions were obtained from the middle-lateral portion of intact intervertebral discs from human lumbar spines and tested in a stress-relaxation protocol. …

Fuel Optimization For Constrained Rotation Of Satellite Formations, Timothy Mclain, Randal W. Beard, Fred Y. Hadaegh

Faculty Publications

This paper considers the problem of reorienting a constellation of spacecraft such that the fuel distributed across the constellation is both conserved and expended uniformly. Results are derived for constellations with an arbitrary number of spacecraft, assuming that the constellation is in free space, that the spacecraft mass is time invariant, and that the thrusters can produce thrust in any direction. An open-loop control algorithm is derived by minimizing a cost function that trades off total fuel minimization and fuel equalization. The associated optimization problem is shown to be amenable to standard algorithms. Simulation results using a four-spacecraft constellation are …

Florida Photovoltaic Buildings Program: Status Report, Observations And Lessons Learned, Florida Solar Energy Center, Jennifer Szaro

FSEC Energy Research Center®

The Florida PV Buildings Program is a collaborative effort among the Florida Energy Office of the Department of Community Affairs (FEO/DCA), Sandia National Laboratories, the photovoltaic industry, nine end-user groups, and the Florida Solar Energy Center. It complements the federal government's Million Solar Roofs Initiative (MSRI), which calls for one million solar installations in the U.S. by 2010. Based on the present level of activity and assuming a relatively small growth rate, it is estimated that approximately 140,000 solar pool and domestic water heating systems will be installed in Florida by 2010, as well as 20,000 utility-interactive rooftop photovoltaic systems.

Emergency Power Systems With Photovoltaics: Course Manual, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

This workshop training manual provides information for disaster relief and emergency management organization on using photovoltaic systems to supply electrical power for their every day operation in a disaster. The general public and the PV industry will also benefit from this information. Topics presented in the workshop manual will include emergency management operations, energy needs analysis, photovoltaic technology, system performance, reliability, maintenance, selection criteria, applications, and equipment specifications.

Movement Coupling At The Ankle During The Stance Phase Of Running, Alex Stacoff, Benno M. Nigg, Christoph Reinschmidt, Antonie J. Van Den Bogert, Arne Lundberg, Edgar Stüssi, Jachen Denoth

Mechanical Engineering Faculty Publications

The purpose of this study was to quantify movement coupling at the ankle during the stance phase of running using bone-mounted markers. Intracortical bone pins with reflective marker triads were inserted under standard local anaesthesia into the calcaneus and the tibia of five healthy male subjects. The three-dimensional rotations were determined using a joint coordinate system approach. Movement coupling was observed in all test subjects and occurred in phases with considerable individual differences. Between the shoe and the calcaneus coupling increased after midstance which suggested that the test shoes provided more coupling for inversion than for eversion. Movement coupling between …

The Air Force Institute Of Technology (Afit) Micro Electro-Mechanical Systems (Mems) Interferometric Gyroscope (Mig), Jeremy P. Stringer

Theses and Dissertations

With the invention of Micro Electro-Mechanical Systems (MEMS) it has become possible to fabricate micro-inertial sensors. These new sensors have application in creating autonomous guided weapons systems. New technologies like Micro Unmanned Aerial Vehicles (UAVs), which cannot use conventional inertial sensors, rely on technologies like micro-inertial sensors to operate. Also, such sensors have the capability to reduce both power and space consumption on conventional aircraft. This technology is not yet mature, and current micro-inertial sensors do not have the accuracy required for highly precise navigation. To try to increase the accuracy of micro-inertial sensors, researchers are turning toward micro-optical gyroscopes. …

Feb 2000, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

M.H. Pony Raffle Promotional Brochere Inventory and Displays