Physical Sciences and Mathematics Commons^™

Reactions Of Singlet Oxygen And Singlet Oxygen Mimics With Dicyclopropylethylenes: Comparison Of Reactivity And Mechanisms, Gina Elizabeth Alume

FIU Electronic Theses and Dissertations

An extensive study of the reaction pathways of 1,1- dicyclopropyl ethylene, cis- and trans- 1,2-dicyclopropylethylenes has been undertaken with different electrophiles 4-methyl-1,2,4- triazoline-3,5-dione (MTAD), tetracyanoethylene (TCNE), and singlet oxygen (10₂). Comparison of reactivity and reaction mechanisms among the electrophiles is investigated. Singlet oxygen exhibits significantly lower reactivity compared to the other electrophiles. MTAD and TCNE react with dicyclopropylethylenes to produce predominantly "2+2" adducts and a small amount of the "ene" adducts. The "2+2" is the major product presumably because of the high activation energy leading to the highly strained "ene" products. Solvent trapping studies provide strong evidence of …

The Application Of A Multimedia System To The Tourist Guide Of The Miami International Airport, Ying-Yuang Chen

FIU Electronic Theses and Dissertations

This project is to present a multimedia system designed for Miami International Airport as a tourist guide for passengers and to demonstrate the functionalities and facilities of the airport.

The project is based on an inexpensive integrated and comprehensive multimedia environment. The major components of the environment consist of (1) a low cost PC 386/486 with only ISA bus and IDE hard drive, (2) a high quality and high performance add-on real-time video/audio codec board (30/25 fps for NTSC/PAL video and synchronized audio sampled at 22KHz), (3) software packages including interactive utility programs to record, playback and edit real-time video/audio …

Semantic Geographic Information System, Elma L. Alvarez

FIU Electronic Theses and Dissertations

This thesis research describes the design and implementation of a Semantic Geographic Information System (GIS) and the creation of its spatial database. The database schema is designed and created, and all textual and spatial data are loaded into the database with the help of the Semantic DBMS's Binary Database Interface currently being developed at the FIU's High Performance Database Research Center (HPDRC). A friendly graphical user interface is created together with the other main system's areas: displaying process, data animation, and data retrieval. All these components are tightly integrated to form a novel and practical semantic GIS that has facilitated …

Theoretical Analysis Of Cross Joint Geometries And Their Classification, Taixu Bai

FIU Electronic Theses and Dissertations

Joints as opening-mode fractures play important roles as indicators of tectonic stress fields and as pathways for underground fluid flow. This thesis analytically investigates the relationships among cross joint geometry, orientations and ratios of remote principal stresses, and fluid pressure. Results show that main trends of cross joints are perpendicular to the least far field stresses during cross joint formation, and cross joint paths can be used to determine relative magnitudes of remote principal stresses. Based on the theoretical derivation, cross joint geometries are grouped into five main categories: curving-parallel, curving-perpendicular, quasi-curving-parallel, quasi-curving-perpendicular and non-curving geometries. By introducing the concepts …

Hydrocarbon Speciation Studies In Ancient Sediments By High Temperature Supercritical Carbon Dioxide Extraction, Doraida Diaz

FIU Electronic Theses and Dissertations

Results on the application of high-temperature supercritical carbon dioxide extraction (HT-SFE) to the study of hydrocarbon (HC) speciation in geological samples are presented. Ancient sediments were treated by stepwise extractions, and by using a fresh sample each time. SFE temperatures ranged between 50 and 350°C. Individual analytes showed to be speciated in different ways throughout the solid matrix because different fractions are extracted under different energy conditions. Aromatic HCs appear to have a stronger association with the matrix than the aliphatics due to their higher polarity and molecular planarity. No evidence of geosynthesis of alkylaromatics during HT-SFE was obtained. Tri- …

Laser Cooling Of A Metastable Argon Atomic Beam, Carlos A. Avila

FIU Electronic Theses and Dissertations

A production of low velocity and monoenergetic atomic beams would increase the resolution in spectroscopic studies and many other experiments in atomic physics. Laser Cooling uses the radiation pressure to decelerate and cool atoms. The effusing from a glow discharge metastable argon atomic beam is affected by a counterpropagating laser light tuned to the cycling transition in argon. The Zeeman shift caused by a spatially varying magnetic field compensates for the changing Doppler shift that takes the atoms out of resonance as they decelerated. Deceleration and velocity bunching of atoms to a final velocity that depends on the detuning of …

Investigation Of Spatial Patterns Of Ground-Water Exchange With Lakes, Using A Three-Dimensional Numerical Model, Indranil Bandopadhyay

FIU Electronic Theses and Dissertations

Hydrogeologic variables controlling groundwater exchange with inflow and flow-through lakes were simulated using a three-dimensional numerical model (MODFLOW) to investigate and quantify spatial patterns of lake bed seepage and hydraulic head distributions in the porous medium surrounding the lakes. Also, the total annual inflow and outflow were calculated as a percentage of lake volume for flow-through lake simulations. The general exponential decline of seepage rates with distance offshore was best demonstrated at lower anisotropy ratio (i.e., Kh/Kv = 1, 10), with increasing deviation from the exponential pattern as anisotropy was increased to 100 and 1000. 2-D vertical section models constructed …

Speciation Of Uranium And Organic Compounds On Solid Matrix Studied By Supercritical Fluid Extraction, Li Chen

FIU Electronic Theses and Dissertations

The liquid extraction and spectrophotometric quantitation of uranium from different solid matrices is compared to supercritical fluid extraction (SFE) using various combinations of 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octadione (FOD), tri-n-butylphosphate (TBP), ethanol, and carbon dioxide measuring the UV absorption of the uranium-FOD complex. The matrix is shown to have a tremendous effect on the extractability of uranium from different solid matrices. Compared to liquid extraction, the SFE method yields higher recoveries, is significantly faster, is of equal or greater precision, and greatly reduces the amount of organic solvents used. In the second part of this work, the speciation of hydrophobic organic compounds (HOCs) in …

Automating Transformational Design For Distributed Programs, Champak Das

FIU Electronic Theses and Dissertations

We address the problem of designing concurrent, reactive, nonterminating programs. Our approach to developing concurrent programs involves the use of correctness-preserving transformations to realize each step of program development. The transformations we have designed automatically guarantee the preservation of the deadlock freedom property, and hence deadlock freedom does not have to be manually verified after each development step. Since our transformations are syntactic, they are easily mechanizable as well. This makes syntactic transformations particularly appealing for the development of large, complex, and correct distributed systems, where a manual approach would be prohibitively expensive. In this work we present a set …