Engineering Commons^™

Remote Experimental Station For Engineering Education, Muralidhar Doddapuneni

FIU Electronic Theses and Dissertations

This thesis provides a distance-learning laboratory for students of electrical and computer engineering department where the instructor can conduct experiments on a computer and send the results to the students at remote computers. The output of the experiment conducted by the instructor is sampled using a successive approximation Analog to Digital (A/D) converter. A microcontroller collects samples using high speed queued serial peripheral interface clock and transmits data to IBM-compatible personal computer over a serial port interface, where the samples are processed using Fast Fourier Transforms and graphed. The client/server application developed transfers the acquired samples over Transmission Control Protocol/Internet …

Characterization Of Engineered Human Lung Tissue, Benjamin Boytor

FIU Electronic Theses and Dissertations

Characterizing engineered human lung tissue is an important step in developing a functional tissue replacement for lung tissue repair and in vitro analysis. Small tissue constructs were grown by seeding IMR-90 fetal lung fibroblasts and adult microvascular endothelial cells onto a Polyglycolic acid (PGA) polymer template. Introducing the constructs to dynamic culture conditions inside a bioreactor facilitated three-dimensional growth seen in scanning electron microscopy images (SEM).

Characterization of the resultant tissue samples was done using SEM imagery, tensile tests, and biochemical assays to quantify extra-cellular matrix (ECM) composition. Tensile tests of the engineered samples indicated an increase in the mechanical …

Determination Of Whole-Body Specific Absorption Rate (Sar) And Characterization Of Ferris Wheel Radio Frequency (Rf) Exposure System Using Calorimetric Techniques, Subbarao V. Chebrolu

FIU Electronic Theses and Dissertations

The "Ferris Wheel" RE Exposure System was designed by Motorola Inc. to study the long-term biological effects due to RE exposure [3]. The main goal of this research project was to characterize the "Ferris Wheel" to know how efficient and symmetrical was the exposure system in distributing the RE power among its loads. The characterization of the system was done in terms of power efficiency, SAR, Whole-Body SAR and Localized SAR.

Exposure to RF sources is quantified in terms of SAR which defines the rate of electromagnetic deposition per unit mass. Determination of Whole-Body averaged SAR requires to have the …

Simulation And Analysis Of Network Traffic For Efficient And Reliable Information Transfer, Neelima Boppana

FIU Electronic Theses and Dissertations

With the growing commercial importance of the Internet and the development of new real-time, connection-oriented services like IP-telephony and electronic commerce resilience is becoming a key issue in the design of TP-based networks. Two emerging technologies, which can accomplish the task of efficient information transfer, are Multiprotocol Label Switching (MPLS) and Differentiated Services. A main benefit of MPLS is the ability to introduce traffic-engineering concepts due to its connection-oriented characteristic. With MPLS it is possible to assign different paths for packets through the network. Differentiated services divides traffic into different classes and treat them differently, especially when there is a …

Design Of A Fast And Resource-Efficient Fault Management System In Optical Networks To Suit Real-Time Multimedia Applications, Tirthankar Ghosh

FIU Electronic Theses and Dissertations

Today's telecommunications networks are relying more and more on optical fibers as their physical medium. Currently the Wavelength Division Multiplexing technology enables hundreds of wavelengths to be multiplexed on a single fiber. Using this technology capacity can be dramatically increased, even to the order of Terabits per second. While WDM technology has given a satisfactory answer to the ever-increasing demand for capacity, there is still a problem which needs to be handled efficiently: survivability.

Our proposed fault restoration system optimized between restoration cost and speed. We extended the concept of Forward Equivalence Class (FEC) in Multi Protocol Label switching (MPLS) …

Fault/Configuration Management For Wireless Ad-Hoc Network, Abhay Doshi

FIU Electronic Theses and Dissertations

An ad hoc network is maintained by the combined efforts of all the mobile nodes themselves, who often operate under severe constraints, such as limited battery power, variable link quality, and limited storage capacity. As a result, there is a growing need for enhanced fault and configuration management solutions to help in tracking problems as well as solving them.

Viable network architecture for a wireless ad-hoc environment, which takes advantages of both hierarchical and distributed architectures, has been investigated. A complete design solution is proposed which makes ad-hoc environments less susceptible to faults. Results shows that by applying the proposed …

Analysis Of Coaxial Fed U-Slot Patch Antennas Using Finite Difference Time Domain Method, Chandrasekhar Cherukuri

FIU Electronic Theses and Dissertations

The objective of this thesis was to analyze a Coaxial-Fed U-slot Rectangular Patch Antenna using Finite Difference Time Domain (FDTD) method. Important parameters such as S-parameters and Input Impedance of the antenna were simulated using XFDTD software and were analyzed. An important goal of this thesis was to provide design information about the U-slot antenna. For this purpose the effects of antenna layout on the resonant frequency and the bandwidth of the antenna were investigated. First the effect of varying slot width on the S-parameters, Voltage Standing Wave Ratio (VSWR) and Input Impedance were studied. Next the length of the …

Development Of An Open Architecture Motion Control System, Peng Chen

FIU Electronic Theses and Dissertations

A multipurpose open architecture motion control system was developed with three platforms for control and monitoring. The Visual Basic user interface communicated with the operator and gave instructions to the electronic components. The first platform had a BASIC Stamp based controller and three stepping motors. The second platform had a controller, amplifiers and two DC servomotors. The third platform had a DSP module. In this study, each platform was used on machine tools either to move the table or to evaluate the incoming signal. The study indicated that by using advanced microcontrollers, which use high-level languages, motor controllers, DSPs (Digital …

Lumps And Balls In High-Slump Concrete: Reasons And Remedy, Ivan R. Canino-Vazquez

FIU Electronic Theses and Dissertations

The objective of this research was to investigate the reason lumps occur in high-slump concrete and develop adequate batching procedures for a lumps-free high-slump ready-mix concrete mix used by the Florida Department of Transportation. Cement balls are round lumps of cement, sand, and coarse aggregate, typically about the size of a baseball that frequently occur in high-slump concrete. Such lumps or balls jeopardize the structural integrity of structural members.

Experiments were conducted at the CSR Rinker concrete plant in Miami, Florida, based on a protocol developed by a team of Florida Department of Transportation (FDOT) concrete engineers, Rinker personnel, and …

Embedded Heat Speaders In Low Temperature Cofired Ceramic Substrates, Guangnan Deng

FIU Electronic Theses and Dissertations

A new heat spreader that operates on a principle similar to heat pipes has been developed in Low Temperature Cofired Ceramic (LTCC) substrate. The heat spreader use sintered metal powder as the wick structure and water as the working fluid. Key topics related to the fabrication of embedded heat spreaders in LTCC substrate were studied. The conventional LTCC procedure has been improved to suit the requirement of heat spreader. A novel sintered porous silver powder has been developed to provide high capillary pressure and permeability for the wick structure. The maximum mass transport rate of the wick was about 0.692 …

Damage Assessment Of Various Structures By Hurricane Andrew Using Aerial Photographs, Sondwip Dhar

FIU Electronic Theses and Dissertations

The objective of this research was to assess the damage of various structures that were affected during Hurricane Andrew using aerial photographs. Different damage mechanisms were demonstrated. Quantitative damage assessment data was obtained by interpretation of aerial photographs. The damage data have been statistically analyzed. Various types of structures were studied and their typical damages were examined using the statistical analysis with respect to wind speed and zip codes. Illustrations of damages in different communities, damages to different roofs, and their possible failure mechanisms were also discussed. The damage data generated in this study can be used to predict damage …

Environmental Quality Monitoring At Five Golf Courses In Miami-Dade County, Lorna Bucknor

FIU Electronic Theses and Dissertations

Five golf courses in Miami-Dade County, Florida participated in a one year monitoring study to investigate the environmental impact of agrichemical turf management activities.

Groundwater, soil, surface water, and sediments were sampled quarterly at the golf courses in 1997. Ground and surface water were sampled for 51 pesticide residues (including arsenic), nitrates, and phosphates. Soil and sediments were sampled for arsenic.

Arsenic was the main contaminant of interest. Seventy-five percent of soil samples exceeded the Florida residential soil cleanup target level (CTL) while thirty-two percent of shallow groundwater samples exceeded the maximum contaminant level (MCL). Five other pesticide residues were …

Fabrication Considerations Of A Superconducting Transmission Line Microelectromechanical Switch, Alfredo Arturo Corrales

FIU Electronic Theses and Dissertations

Developing technologies have always faced the same problems. New applications require smaller systems, must consume less power, and provide greater sensitivity than what is currently available. This thesis provides crucial data for the manufacturing of a microelectromechanical (MEM) switch on a superconducting transmission line. New applications of front-end antennas require small, low-loss switches. MEM switches have shown insertion losses less than 0.1 dB and isolation of 50 dB at RF frequencies. Superconducting transmission lines can provide circuits with extremely low attenuation. The combination of the two can provide the best system for the need of these new applications. This thesis …