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Finite Difference Time Domain Analysis Of Fractal Antennas Used In Wireless Communications, Chritz Adenauer Duncan

FIU Electronic Theses and Dissertations

The advances in wireless technology and the ever-growing demand for multiband and smaller antennas in wireless communications has led to the field of mathematics known as fractal. The use of fractal geometry in antenna design has created a significant amount of interest within the wireless communications societies and most importantly, antenna design.

This thesis investigates the performance and optimization of fractal antennas used in wireless communications. The principle analytical tool utilized in the study is the Finite Difference Time Domain technique (FDTD). This numerical method was applied to calculate the electromagnetic propagation characteristics of the Sierpinski gasket and Koch snowflake …

A Study Of Gas Holdup Properties Of Selected Non-Newtonian Simulants, Milena Abarca

FIU Electronic Theses and Dissertations

The U.S. Department of Energy (DOE) needs a design basis to properly design a PJM and ventilation systems for the Waste Treatment Plant vessels. In order to meet DOE's needs for proper ventilation and PJM design technologies, Florida International University's Hemispheric Center for Environmental Technology (FIU-HCET) has studied the properties for gas holdup in selected non Newtonian fluids with physicochemical properties comparable to nuclear waste.

The primary purpose of this research was to study the holdup properties of selected non - Newtonian simulants and quantify the level of gas holdup in selected simulants using continuous argon injection in five gallons …

A Novel Neural Network Based System For Assessing Risks Associated With Information Technology Security Breaches, Monica Dezulueta

FIU Electronic Theses and Dissertations

Security remains a top priority for organizations as their information systems continue to be plagued by security breaches. This dissertation developed a unique approach to assess the security risks associated with information systems based on dynamic neural network architecture. The risks that are considered encompass the production computing environment and the client machine environment. The risks are established as metrics that define how susceptible each of the computing environments is to security breaches.

The merit of the approach developed in this dissertation is based on the design and implementation of Artificial Neural Networks to assess the risks in the computing …

Bme Stats Fall 2004, Department Of Biomedical Engineering, Florida International University

STATS

No abstract provided.

Bme Annual Report 2003-2004, Department Of Biomedical Engineering, Florida International University

Biomedical Engineering Department Annual Reports

No abstract provided.

Double Diffusive Convection During Solidification Of Ammonium Chloride - Water (Nh4cl-H20) Mixture In A Trapezoidal Cavity, Ravi Kumar Duggirala

FIU Electronic Theses and Dissertations

The effect of the initial concentration of ammonium chloride (sub eutectic: C < 19.8 wt. % and eutectic C_e= 19.8 wt. %) and boundary temperatures (T_cold = -30 ⁰C to -10 ⁰C) on the solidification process is examined. Particle Image Velocimetry (PIV) is used in this study to measure the velocity fields in the melt during the solidification process. The distributions of temperatures at discrete locations in the solution and the boundary walls were measured. This study focuses on the solidification of an ammonium chloride-water (NH₄Cl- H₂O) solution in a trapezoidal cavity with one and two inclined cooling …

Modification Of A Novel Polymer With Potential Use In Artificial Heart Valves : Effects On Hemocompatibility And Mechanical Properties, Tejas Dilipkumar Choksi

FIU Electronic Theses and Dissertations

Platelet mediated thrombosis has been a major source of mortality and morbidity in cardiovascular device patients as the device surface upon contact with blood induces surface thrombosis. Two specific objectives of this thesis are: 1) Identify the effect of phospholipid modification on Quatromer and 2) Identify the most effective modification technique that will inhibit the surface induced thrombosis and enhance the long-term blood compatibility of Quatromer. Six different phospholipids were grafted in the Quatromer and the role of each of the modified substrates was evaluated in terms of mechanical properties and hemocompatibility. The surface analysis studies showed a significant decrease …

Design And Analysis Of Micro-Channel Heat-Exchanger Embedded In Low Temperature Co-Fire Ceramic (Ltcc), Hari Kishore Adluru

FIU Electronic Theses and Dissertations

Increased device density, switching speeds of integrated circuits and decrease in package size is placing new demands for high power thermal-management. The convectional method of forced air cooling with passive heat sink can handle heat fluxes up-to 3-5W/cm²; however current microprocessors are operating at levels of 100W/cm², This demands the usage of novel thermal-management systems. In this work, water-cooling systems with active heat sink are embedded in the substrate.

The research involved fabricating LTCC substrates of various configurations - an open-duct substrate, the second with thermal vias and the third with thermal vias and free-standing metal …

Information Model For Engineering Change Management, Clifford L. Panokarren

FIU Electronic Theses and Dissertations

Managing engineering changes is a critical task for organizations to remain competitive. In a manufacturing organization there are innumerable engineering change requests. This thesis is focused on the development of an information model that defines the engineering change process.

This research developed an activity model in IDEF0, an object model in IDEF1X and a dynamic model using state diagrams. The activity model captures the business process for executing an engineering change in terms of its constituting activities and sub-activities. The object model defines each object and its attributes identified in the activity model. The dynamic model captures the status change …

Improving Performance Of A Permeable Reactive Barrier In The Degradation Of Trichloroethylene Using Ultrasound, Jonathan A. Bulley

FIU Electronic Theses and Dissertations

The impact of ultrasound on improving the performance of a granular iron Permeable Reactive Barrier (PRB) in the degradation of Trichloroethylene (TCE) was evaluated.

Two treatment columns made of clear Plexiglas with a height of 1ft and a diameter of 2 inches and filled with granular iron were used. One was fitted with 25Khz ultrasound probes. A solution of TCE was run through at constant flow rate. Samples obtained from the column at different residence times before and after sonication were analyzed for concentrations of TCE and used to generate concentration profiles to obtain rate constants, which were compared.

An …

Energy-Aware Ad Hoc On-Demand Distance Vector Routing Protocol And Optimizing The Blocking Problem Induced In Wireless Ad Hoc Networks, Abdallah El Moutia

FIU Electronic Theses and Dissertations

The purpose of this thesis was to investigate some of the issues related to routing and medium access control protocol in ad hoc networks. In routing protocol, the goal is to tackle the power consumption problem and to present a case for using new cost energy-aware metric for Ad Hoc On-Demand Distance Vector (AODV). The idea of the new cost metric is to be able to avoid routes with a low energy capacity. By using this approach, high efficiency in energy consumption can be achieved in Ad-Hoc networks.

The second goal of this thesis was to investigate the blocking problem …

A Study Of Hydraulic Properties Of High Level Waste Simulant, Sudhakar N. Chodavarapu

FIU Electronic Theses and Dissertations

The purpose of this study was to determine the unsaturated hydraulic properties of High Level Waste simulant by applying inverse modeling and parameter estimation methods and data obtained by experiments.

Saltcake simulant was placed in column equipped with tensiometers and flow meters. Variable pressure boundary conditions ranging from 100 to 500 cm were applied along the column, outflow and the pressure head were measured with respect to time. The experimental data was analyzed using an inverse modeling software and the van Genuchten's hydraulic parameters for unsaturated porous media were determined. In addition, the unsaturated hydraulic conductivities were obtained as a …

Using Neural Networks For Goal Driven Simulation, Maria F. Clavijo

FIU Electronic Theses and Dissertations

An integration framework for Neural Networks (NN) and Goal Driven Simulation (GDS) has been designed. It offers no constraints regarding number of variables (n>3) and it does not have domain restrictions. The effectiveness of the framework was tested by observing the computational time required for obtaining responses and for training, and by assessing its accuracy for different scenarios. This framework has achieved the automation objective set by GDS under a shorter time frame, as it reduces the time from more than 42 hours to less than 14. A trained NN generates responses to queries almost instantaneously. However, it requires …