Physical Sciences and Mathematics Commons^™

The Dissociative Recombination Of The Helium Molecular Ion The Observed Final Products, Luminita Coman

FIU Electronic Theses and Dissertations

Dissociative recombination reaction has been studied theoretically and experimentally for about four decades. Because of the complexity of this process there is not yet a definite agreement between theory and experiment. In this work, dissociative recombination (DR) of helium molecular ion in thermal plasma was studied using Time of Flight (TOF) spectroscopy. This method allowed the identification of the final atom states products of DR. We found the following final products of the DR of the molecular ion: He(³S; 1s3s), He(¹S; 1s3s), He(³P; 1s3p), He(³D; 1s3d), He(¹D; 1s3d), He(^{1 …}

The Hall A Aerogel Čerenkov Detector, Marius Coman

FIU Electronic Theses and Dissertations

The efficiency of the Aerogel Čerenkov detector for detecting particles having velocities greater than the speed of light in the aerogel media and the yield for rejecting particles having subthreshold velocities - smaller than the speed of light in the interaction media - was studied and is presented. The efficiency/inefficiency determination of the Aerogel Čerenkov detector consists of calculating the probabilities that a particle having a velocity above/below threshold generates a photoelectron in the aerogel block. The efficiency is determined using the normalised pulse height distribution of the photoelectrons. The Aerogel Čerenkov detector will play a key role in particle …

Efficient Storage And Retrieval Of Georeferenced Objects In A Semantic Database For Web-Based Applications, Debra Lee Davis

FIU Electronic Theses and Dissertations

The use and dissemination of remotely-sensed data is an important resource that can be used for environmental, commercial and educational purposes. Because of this, the use and availability of remotely-sensed data has increased dramatically in recent years. This usefulness, however, is often overshadowed by the difficulty encountered with trying to deal with this type of data. The amount of data available is immense. Storing, searching and retrieving the data of interest is often difficult, time consuming and inefficient. This is particularly true when these types of data need to be rapidly and continually accessed via the Internet, or combined with …

Engineering Access Control For Distributed Enterprise Applications, Konstantin Beznosov

FIU Electronic Theses and Dissertations

Access control (AC) is a necessary defense against a large variety of security attacks on the resources of distributed enterprise applications. However, to be effective, AC in some application domains has to be fine-grain, support the use of application-specific factors in authorization decisions, as well as consistently and reliably enforce organization-wide authorization policies across enterprise applications. Because the existing middleware technologies do not provide a complete solution, application developers resort to embedding AC functionality in application systems. This coupling of AC functionality with application logic causes significant problems including tremendously difficult, costly and error prone development, integration, and overall ownership …

Ammonite Biostratigraphy, Lithofacies Variations, And Paleoceanographic Implications For Barremian-Aptian Sequences Of Northeastern Mexico, Ricardo Barragan

FIU Electronic Theses and Dissertations

Two Barremian-Aptian sequences studied in Durango and Nuevo Leon States, northeastern Mexico include three lithic units which have been described as the Cupido Formation of Barremian-early Early Aptian age, its lateral equivalent, the Lower Tamaulipas Formation, and the La Pena Formation extending through the early Albian.

The present work improves the existing ammonite Aptian biozonation by considering constraints associated with a discontinuous spatial and temporal record of the different taxa within the La Pena Formation.

Four ammonite biozones are established: 1) The Dufrenoyia justinae Zone for the late Early Aptian, 2) The Burckhardtites nazasensis/Rhytidoplites robertsi Zone for the middle Aptian, …

Integration And Querying Of Heterogeneous, Autonomous, Distributed Database Systems, Rukshan Indika Athauda

FIU Electronic Theses and Dissertations

Today, databases have become an integral part of information systems. In the past two decades, we have seen different database systems being developed independently and used in different applications domains. Today's interconnected networks and advanced applications, such as data warehousing, data mining & knowledge discovery and intelligent data access to information on the Web, have created a need for integrated access to such heterogeneous, autonomous, distributed database systems. Heterogeneous/multidatabase research has focused on this issue resulting in many different approaches. However, a single, generally accepted methodology in academia or industry has not emerged providing ubiquitous intelligent data access from heterogeneous, …