Engineering Commons^™

Energy Efficient Office Building Design For A Hot And Humid Climate: Florida's New Energy Center, Florida Solar Energy Center, Philip Fairey

FSEC Energy Research Center®

Hot and humid climates, such as those in Florida, pose unique challenges to architects and engineers seeking energy efficient office building designs. The severe impact of internal loads on cooling, the intense solar conditions and the need for increased ventilation set against high relative humidities, all serve to limit the success of many conventional methods of reducing building energy use. To provide a high-visibility demonstration of potential energy design solutions, the Florida Solar Energy Center (FSEC) is building a state-of-the-art office complex for its new facility in Cocoa, Florida.

Surface-Related Breakdown In Silicon: Imaging Of Current Filaments In Long P+-N--N+ Structures, B. J. Hankla, P. F. Williams, G. A. Frecks, F. E. Peterkin

P. F. (Paul Frazer) Williams Publications

We present Schlieren images which show the existence and evolution of current filaments during the very early stages of surface-related breakdown inside 1 cm silicon p⁺-n^--n⁺ structures. These images confirm our previous finding that breakdown occurs in the silicon rather than in the ambient, and suggest that a streamerlike mechanism may be responsible.

Methodology Evaluation For Remotely Estimating Water Quality Parameters In Estuarine Waters, Charles R. Bostater, Manuel Gimond

Ocean Engineering and Marine Sciences Faculty Publications

Water absorption signatures were measured from water samples placed in a 50 cm pathlength cylindrical cuvette. Quantitative analysis of chlorophyll-a and dissolved organic matter (DOM- humic acid, fulvic acid, or tannic acid) was conducted using second derivative spectra followed by computation of double inflection ratio (DIR) spectra for all possible combinations of bands (from 362-1 1 15 nm with 252 channels). A specially designed instrument system is described which allows measurements of absorption of particulate and dissolved organic matter (chlorophyll-a and DOM) in a water sample. The ability of the system to allow measurement of absorption signatures and relating the …

Response Function Of A Two-Dimensional Electron Gas In A Unidirectional Periodic Potential , S. M. Stewart, C. Zhang

Faculty of Engineering - Papers (Archive)

The dynamical density-response function of a periodically modulated two-dimensional electron gas under a perpendicular magnetic field is calculated within the random-phase approximation. It is found that the response function is not only broadened by the periodic potential, it also contains a series of subsingularities at the band edges. The maximum number of subsingularities is 2nmax, where nmax is the number of occupied Landau leveles (the last level may be partially filled). It is further proposed that light-scattering or electromagnetic absorption experiments can be performed to study these predicted structures.

The Measured Summer Performance Of Tile Roof Systems And Attic Ventilation Strategies In Hot, Humid Climates, Florida Solar Energy Center, David Beal

FSEC Energy Research Center®

During 1994, simultaneous full-scale testing of residential plywood-decked roofing system was conducted using a flexible roof facility (FRF). The facility consists of a 24-ft by 48ft rectangular building with one large conditioned space under an attic that is partitioned into six separate test cells. Throughout the test protocol one cell was configured as a residential black-shingle roof system, employed as the baseline for comparison of the alternative roofing systems.

Two identical cells were employed during the summer of 1994 to investigate soffit and ridge venting. Tests of two different configurations best illustrate the results. A comparison of a sealed attic …

Structural Characterization Of Aluminum Films Deposited On Sputtered-Titanium Nitride/ Silicon Substrate By Metalorganic Chemical Vapor Deposition From Dimethylethylamine Alane, Xiaodong Li, Byoung-Youp Kim, Shi-Woo Rhee

Faculty Publications

Alfilmsdeposited on sputtered‐TiN/Si substrate by metalorganic chemical vapor deposition(MOCVD) from dimethylethylamine alane (DMEAA) were characterized using x‐ray diffraction(XRD),Auger electron spectroscopy(AES),atomic force microscopy(AFM), and transmission electron microscopy (TEM). The TiN filmsputtered on the Si has a preferred orientation along the growth direction with the 〈111〉 of the film parallel to the Si〈111〉. Sputtering of the TiN film on the Si induced strains at the interface. The TiN/Si interface is flat while the Al/TiN interface is rough. There exist many dislocations at the Al/TiN interface. The Al₂O₃ phase was formed at the Al/TiN interface during the early stages of …

Study On Passive And/Or Active Vibration Control For Flexible Structures, Qinghua Chen

FIU Electronic Theses and Dissertations

The purpose of this research is to present new methods of active and passive vibration control for flexible structures. The study includes: 1) passive viscoelastic damping treatment; 2 ) active vibration control using layered shape memory alloy (SMA); 3) combined application of viscoelastic damping treatment and SMA; 4) experiments.

In order to maximize damping and save weight of the structure and cost, a partially covered double sandwich cantilever beam model has been presented. It is shown that the double sandwich beam is better than single sandwich beam for some conditions. To take into account of end loads effect of elastic …

Croatian Symposium Of Chemistry And Macromolecular Chemistry, Otto Vogl, Zvonimir Janovic

Emeritus Faculty Author Gallery

No abstract provided.

Polymer Science In Australia Iv. Universities In Victoria And Southern Australia, Otto Vogl, David Solomon, Ezio Rizzardo, Robert A. Shanks, David Williams

Emeritus Faculty Author Gallery

No abstract provided.

52. Bengt Ranby, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.

Design Guide For Cold-Formed Steel Trusses, Steel In Residential Construction Advisory Group

CCFSS Library (1939 - present)

No abstract provided.

Ultrasonic Nondestructive Testing Method For Evaluation Of Annular Seals, Nazli Yesiller

Civil and Environmental Engineering

No abstract provided.

Using Mathematica To Aid Simulation Analysis, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

As computer power has increased, so has the capability of software developers to write programs that assist people with time-consuming tasks. Mathematica is such a program. The objective of this paper is to demonstrate how Mathematica, a symbolic programming environment, can be used to aid simulation analysis. In addition to a general discussion of Mathematica’s uses, advantages, and disadvantages, several examples will be presented. The examples include using Mathematica for distribution fitting, queueing analysis, random number generation, and creating a surface plot for optimization.

Acuta Enews December 1995, Vol. 24, No. 12

ACUTA Newsletters

In This Issue

From the President

Cabling for the life of your network

Planning today

FRED fights fraud

From ACUTA Headquarters

17th Conference On Senior Engineering Design Projects, College Of Engineering And Applied Sciences

Senior Engineering Design Conference

The 17th Conference on Senior Engineering Design Projects was held on December 5, 1995 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Transients In Power Systems, M. Belkhayat, J. Edwards, N. Hoonchareon, O. Marte, D. Stenberg, E. Walters

Department of Electrical and Computer Engineering Technical Reports

Power system engineering largely focuses on steady state analysis. The main areas of power system engineering are power flow studies and fault studies - both steady state technologies. But the world is largely transient, and power systems are always subject to time varying and short lived signals. This technical report concerns several important topics in transient analyses of power systems. The leading chapter deals with a new analytical tool-wavelets-for power system transients. Flicker and electric are furnace transients are discussed in Chapters I1 and IV. Chapter 111 deals with transients from shunt capacitor switching. The concluding chapters deal with transformer …

Measured Cooling Energy Savings From Reflective Roofing Systems In Florida: Field And Laboratory Research Results, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

A series of field experiments in Florida have examined the impact of reflective roof coatings on air conditioning energy use in occupied homes. The tests were conducted on nine residential buildings from 1991 to 1994 using a before and after protocol where the roofs were whitened at mid-summer. Measured AC electrical savings in the buildings during similar pre- and post-retrofit periods averaged 19%, ranging from a low of 2% to a high of 43%. Utility peak coincident peak savings averaged 22%. Cooling energy reductions appear to depend on ceiling insulation level and roof solar reflectance, air duct system location and …

Energy Efficiency Technology Demonstration Project For Florida Educational Facilities: Occupancy Sensors, Florida Solar Energy Center, David Floyd

FSEC Energy Research Center®

In 1995 the Florida Department of Education and the Florida Solar Energy Center jointly sponsored a test of occupancy sensors used to control lighting in a Florida school. Occupancy sensors replace conventional light switches and use passive infrared or ultrasonic sensing to control lighting in classroom and other spaces. The test was intended to demonstrate the performance of such controls in saving energy in Florida educational facilities.

The evaluation was performed at Northwest Elementary School in Pasco County on Florida's west central coast. A before and after monitoring protocol was utilized for the study which saw lighting circuits for 33 …

Florida Exterior Wall Insulation Field Test: Final Report, Florida Solar Energy Center, Stephen Barkaszi

FSEC Energy Research Center®

The Florida Solar Energy Center (FSEC) and Oak Ridge National Laboratory (ORNL) have conducted a field test of exterior insulation applied to Florida masonry residences. Approximately 50% of Florida's six million existing residences are of concrete block construction. Many of these homes, particularly those 15 years or older, have uninsulated walls.

Within the project, two single-family homes in Central Florida were extensively monitored to measure the energy savings of the technology. The primary objective was to examine the effect exterior insulation has on air conditioning (AC) energy use and peak electrical demand for two typical residences. A secondary objective was …

Smarts2, A Simple Model Of The Atmospheric Radiative Transfer Of Sunshine, Florida Solar Energy Center, Christian Gueymard

FSEC Energy Research Center®

An upgraded spectral radiation model called SMARTS2 is introduced. The solar shortwave direct beam irradiance is calculated from spectral transmittance functions for the main extinction processes in the cloudless atmosphere: Rayleigh scattering, aerosol extinction, and absorption by ozone, uniformly mixed gases, water vapor, and nitrogen dioxide. Temperature-dependent or pressure-dependent extinction coefficients have been developed for all these absorbing gases, based on recent spectroscopic data obtained either directly from the experimental literature or, in a preprocessed form, from MODTRAN2, a state-of-the-art rigorous code. The NO2 extinction effect, in both the UV and visible, is introduced for the first time in a …

The Effect Of Excitation Limits On Voltage Stability, Jyothi Ayyagari, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Voltage collapse has been commonly associated with insufficient reactive power support. Steady state studies have related reactive power generation limitations to the sudden onset of voltage instability. This paper extends this approach to the dynamic case. The relationship between the dynamic models and steady state behavior is established. The dynamic model is then used to investigate the sudden change in system stability when the maximum excitation limit is reached. Several illustrative examples are analyzed. Corrective actions are proposed which will move the physical system away from the region of instability.

Calibration And Measurement Of Dielectric Properties Of Finite Thickness Composite Sheets With Open-Ended Coaxial Sensors, Stoyan I. Ganchev, Nasser N. Qaddoumi, Sasan Bakhtiari, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The application of open-ended coaxial sensors for dielectric measurement of finite thickness composite sheets is studied. Expressions for calculation of the complex aperture admittance for two geometries are presented. These expressions are used to calculate the dielectric constant of infinite half-space as well as finite thickness slabs. A more efficient method of such calculations, using a personal computer, for low to medium loss dielectrics is demonstrated. The question of when a dielectric layer may be considered as infinitely thick is also addressed, and examples are presented. A different calibration technique (compared to the conventional ones) is described and successfully implemented. …

An Interferometric Technique For B/A Measurement, E. Carr Everbach, R. E. Apfel

Engineering Faculty Works

An isentropic phase method is described for measuringin vitro the acoustic nonlinearity parameterB/A of several aqueous buffers, protein solutions, lipid oils, and emulsions. The technique relies upon the use of an acoustic interferometer to measure the small changes in sound speed that accompany a rapid hydrostaticpressure change of between one and two atmospheres. Average accuracies of 0.85% are attainable with this method.

A Massively Parallel Computation Strategy For Fdtd: Time And Space Parallelism Applied To Electromagnetics Problems, Michael A. Jensen, Amir Fijany, Yahya Rahmat-Samii, Jacob Barhen

Faculty Publications

We present a novel strategy for incorporating massive parallelism into the solution of Maxwell's equations using finite-difference time-domain methods. In a departure from previous techniques wherein spatial parallelism is used, our approach exploits massive temporal parallelism by computing all of the time steps in parallel. Furthermore, in contrast to other methods which appear to concentrate on explicit schemes such as Yee's (1966) algorithm, our strategy uses the implicit Crank-Nicolson technique which provides superior numerical properties. We show that the use of temporal parallelism results in algorithms which offer a massive degree of coarse grain parallelism with minimum communication and synchronization …

Guidelines For The Installation Of Left-Turn Phasing, Kenneth R. Agent, Nikiforos Stamatiadis, Bryan Dyer

Kentucky Transportation Center Research Report

The objective of this study was to update the guidelines to be considered when determining whether left-turn phasing should be used and the appropriate type at phasing to use. Emphasis was placed on high speed areas.

There were 264 intersections included in the study with data obtained tor 518 approaches at these intersections. The data included accidents and characteristics at the intersection. Traffic conflict data were collected. Simulation models were used to estimate delays.

Recommendations were made concerning guidelines to consider when deciding whether to install left turn phasing and whether to use protected-only or protected/permitted phasing. Variables considered included …

Impacts Of The Extended-Weight Coal Haul Road System, Jerry G. Pigman, Joseph D. Crabtree, Kenneth R. Agent, R. Clark Graves, John A. Deacon

Kentucky Transportation Center Research Report

The Extended-Weight Coal Haul Road System, created by the Kentucky Legislature in 1986, consists of all roads which carry over 50,000 tons of coal in a calendar year. Trucks hauling coal on this system are authorized to exceed normal weight limits through the payment of an annual decal fee. A research study was initiated in July of 1992 to analyze the impacts of the extended-weight system.

Analyses in this report are based on the following: historical data on coal production and transportation: data from coal decal applications; interviews of legislators. transportation officials. coal company representatives. and coal trucking representatives: newspaper …

Adaptive Methods For Distributed Video Presentation, Crispin Cowan, Shanwei Cen, Jonathan Walpole, Carlton Pu

Computer Science Faculty Publications and Presentations

This paper describes problems and solutions for delivering real-time, multi-media presentations across the Internet. A key characteristic of presentations of continuous media datatypes, such as digital video and audio, is their need for predictable real-time data delivery. For example, an NTSC quality video presentation requires video frames to be displayed every 1/30th of a second. Variations in this display rate can be observable as stalls or glitches in the video stream and reduce the quality of the presentation [6]. Delivering such presentations across the Internet is difficult because highly variable band- width and latency make it difficult to predict the …

1995 Strategic Plan For Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Check from Mr. Gerst Letter from Dr. Omtvedt Plan for Renovation Decision to Replace Roof Estimate from Landscaping

Magnetoplasmon Emission Versus Landau-Level Scattering In Resonant Tunneling Through Double-Barrier Structures , C. Zhang, D. J. Fisher

Faculty of Engineering - Papers (Archive)

We consider electron tunneling in a parallel magnetic field taking into account the electron-electron interaction. It is shown that a self-consistent treatment of the dynamical electron-electron interaction in resonant tunneling can lead to the proposed plasmon assisted resonant tunneling. Such magnetoplasmon assisted resonant tunneling gives rise to satellite peaks or shoulders in the tunneling current. At low temperatures, only magnetoplasmon emission processes contribute and satellites only appear on the high bias side of the main resonance. The mechanism proposed here may be used to study the magnetotunneling in high-mobility systems where disorder is at minimum.

Flash Memory Boot Block Architecture For Safe Firmware Updates, Hsiang Chi

FIU Electronic Theses and Dissertations

The most significant risk of updating embedded system code is the possible loss of system firmware during the update process. If the firmware is lost, the system will cease to operate, which can be very costly to the end user. This thesis is concerned with exploring alternate architectures which exploit the integration of flash memory technology in order to overcome this problem. Three design models and associated software techniques will be presented. These design models are described in detail in terms of the strategies they employ in order to prevent system lockup and the loss of firmware. The most important …