Engineering Commons^™

Long Term Monitoring Of Trichloroethylene Degradation Indicator Parameters Using Sensors, Ravi Krishna Prasanth Gudavalli

FIU Electronic Theses and Dissertations

Past operations at Savannah River Site (SRS) have resulted in significant amount of groundwater contamination with trichloroethylene. Natural attenuation of chlorinated solvents via reductive dechlorination is one of the most important processes occurring at SRS, which requires monitoring. Many traditional monitoring techniques require manual sampling and analysis at an onsite or offsite laboratory, which is costly and time consuming. Therefore the need for a system, which can accurately and cost-effectively conduct real-time analysis using automated sensors, is important. There are several characteristics of groundwater like pH, ORP, conductivity and chloride that may be monitored to assess the TCE degradation. To …

Effect Of Blood Flow Patterns On Localized Platelet Adhesion Under Physiologic Flow Conditions Using Two-Dimensional And Three-Dimensional Stent Models - An Experimental And Computational Approach, Nandini Duraiswamy

FIU Electronic Theses and Dissertations

This dissertation presents dynamic flow experiments with fluorescently labeled platelets to allow for spatial observation of wall attachrent in inter-strut spacings, to investigate their relationship to flow patterns. Human blood with fluorescently labeled platelets was circulated through an in vitro system that produced physiologic pulsatile flow in (1) a parallel plate flow chamber that contained two-dimensional (2D) stents that feature completely recirculating flow, partially recirculating flow, and completely reattached flow, and (2) a three-dimensional (3D) cylindrical tube that contained stents of various geometric designs.

Flow detachment and reattachment points exhibited very low platelet deposition. Platelet deposition was very low in …

Optimal Image Deconvolution By Range And Noise Moment Constraints, Angelica Maria Diaz

FIU Electronic Theses and Dissertations

Image deconvolution, also known as image restoration, is concerned with the estimation of an uncorrupted image from a noisy, degraded one. The degradation of this image may be caused by defects of optical lenses, nonlinearity of the electro-optical sensor, relative motion between an object and camera, wrong focus, etc. By assuming a degradation model, one can formulate and develop a restoration algorithm. In this thesis, the developed algorithms are iterative deconvolution methods based on noise moment and pixel range constraints. The moments were used to ensure that noise associated with the deconvolution solution satisfies predetermined statistics. The pixel range constraints …

Optimization Of Waiting Time At Toll Plazas, Arvind Kumar Busam

FIU Electronic Theses and Dissertations

Toll plazas have several toll payment types such as manual, automatic coin machines, electronic and mixed lanes. In places with high traffic flow, the presence of toll plaza causes a lot of traffic congestion; this creates a bottleneck for the traffic flow, unless the correct mix of payment types is in operation. The objective of this research is to determine the optimal lane configuration for the mix of the methods of payment so that the waiting time in the queue at the toll plaza is minimized. A queuing model representing the toll plaza system and a nonlinear integer program have …

Secure Routing And Trust Computation In Multihop Infrastructureless Networks, Tirthankar Ghosh

FIU Electronic Theses and Dissertations

Today's wireless networks rely mostly on infrastructural support for their operation. With the concept of ubiquitous computing growing more popular, research on infrastructureless networks have been rapidly growing. However, such types of networks face serious security challenges when deployed. This dissertation focuses on designing a secure routing solution and trust modeling for these infrastructureless networks.

The dissertation presents a trusted routing protocol that is capable of finding a secure end-to-end route in the presence of malicious nodes acting either independently or in collusion, The solution protects the network from active internal attacks, known to be the most severe types of …

A Definition And Measure Of Workflow Modularity, Dawn-Marie Chin

FIU Electronic Theses and Dissertations

The purpose of this study is to define and measure workflow modularity. There is an increasing need for organizations to implement processes that can be easily configured to offer distinctive capabilities compared to the competition. The concept of modularity provides the foundation for organizations to design flexible processes.

The Event-Driven Process Chain (EPC) approach is used to model an example workflow to illustrate. Based on the model of atomic tasks, rules are developed to guide the creation of modules with high cohesion between tasks in a module and loose-coupling between modules. Matrices of atomic tasks interdependencies are developed and tasks …

Characterization Of Cerebral Blood Flow Response To Traumatic Brain Injury In An Animal Model Using Spect., Michael Capille

FIU Electronic Theses and Dissertations

In this study the focal effects of moderate traumatic brain injury (TBI) on cerebral blood flow (CBF) as reported by SPECT cerebral brain perfusion (CBP) imaging in an animal model were investigated by parallelized statistical techniques. Subjects were randomly assigned to either a control group or test group receiving fluid percussion injury directly to the left parietal lobe.

Qualitative SPECT CBP accuracy was assessed against reference radioactive microsphere technique (RMT) regional CBF measurements by map reconstruction, registration and smoothing. Cerebral hypoperfusion in the test group was then identified at the voxel level using a statistical parametric mapping (SPM) model.

Using …