Engineering Commons^™

Imaging Of Buried Utilities By Ultra Wideband Sensory Systems, Arun Prakash Jaganathan

Doctoral Dissertations

Third-party damage to the buried infrastructure like natural gas pipelines, water distribution pipelines and fiber optic cables are estimated at $10 billion annually across the US. Also, the needed investment in upgrading our water and wastewater infrastructure over the next 20 years is estimated by Environmental Protection Agency (EPA) at $400 billion, however, non-destructive condition assessment technologies capable of providing quantifiable data regarding the structural integrity of our buried assets in a cost-effective manner are lacking. Both of these areas were recently identified several U.S. federal agencies as 'critical national need'. In this research ultra wideband (UWB) time-domain radar technology …

Nanoengineered Templates For Controlled Delivery Of Bioactive Compounds, Nalinkanth Ghone Veerabadran

Doctoral Dissertations

The significance of any drugs, therapeutic proteins, or any bioactive compounds, is based not only on their effects on diseases but also on how specifically, how readily, how controllable and how prolonged their effects on the disease without having any side effects. Thus the techniques involved in the drug encapsulation and its controlled release for a longer duration of time form one of the important processes of drug reformulation. In recent years nanoparticles have created overwhelming attention for delivering drugs by nanoencapsulation. The smaller size of nanoparticles has longer circulation time and higher cellular uptake when compared with larger size …

A Simulation Of The Neural Action Potential Under The Influence Of Acetylcholinesterase Inhibitors Modeled In The Neuromuscular Junction, Frank Jenkins

Doctoral Dissertations

The rise of terrorism has created an interest in better ways to detect when humans are exposed to neurotoxins, especially nerve gases developed for military use, most of which are acetylcholinesterase inhibitors. Many current methods of detection are based on mass spectrometry, a method that is cumbersome and not particularly robust when used as an early warning method. The detection of acetylcholinesterase inhibitors would benefit from a combined model of the processes occurring in the neuromuscular junction between the presynaptic action potential and the motor end-plate action potential that includes the kinetics of acetylcholine and acetylcholinesterase in the synaptic cleft. …

Tin Dioxide Nanoparticle Based Sensor Integrated With Microstrip Antenna For Passive Wireless Ethylene Sensing, Mercyma Deeba Balachandran

Doctoral Dissertations

In this dissertation, we present the development and integration of a passive ethylene gas sensor with triangular microstrip patch antenna for wireless monitoring of climacteric fruit freshness. The existing ethylene sensors are mostly SnO2 resistor based active sensors, fabricated on rigid substrates requiring high fabrication temperatures and cannot be used for wireless applications. The proposed passive ethylene gas sensor is a novel nanoparticle based SnO2 capacitive sensor which, unlike the other existing SnO2resistor based active thick film and thin film sensors, consists of 10 nm to 15 nm SnO2 nanoparticles coated as a thin dielectric film of 1300 nm thickness. …

Poly(Ethylenedioxythiophene) Based Electronic Devices For Sensor Applications, Jie Liu

Doctoral Dissertations

Organic electronic devices, based on Poly (3,4-ethylenedioxythiophene)-Poly (styrene sulfonic acid) (PEDOT-PSS) as the active layer for sensor applications, have been studied. Two sets of sensors have been developed. In one case, sensors consisting of PEDOT-PSS resistors have been realized and demonstrated for soil moisture monitoring. The resistor model for the soil moisture sensor enables the sensor device to be fabricated at low cost and easily tested with a simple structure. Unlike the large dimension device used in Time Domain Reflectometry (TDR), the sensors are small and are capable of capturing microscale behavior of moisture in soil which is useful for …

A Finite Difference Method For Studying Thermal Deformation In Three-Dimensional Thin Films Exposed To Ultrashort Pulsed Lasers, Suyang Zhang

Doctoral Dissertations

Thermal analysis related to ultrashort-pulsed lasers has been intensely studied in science and engineering communities in recent years, because the pulse duration of ultrashort-pulsed lasers is only the order of sub-picoseconds to femtoseconds, and the lasers have exclusive capabilities in limiting the undesirable spread of the thermal process zone in the heated sample. Studying the thermal deformation induced by ultrashort-pulsed lasers is essential for preventing thermal damage. For the ultrashort-pulsed laser, the thermal damage is different from that caused by the long pulsed lasers and cracks occur after heating.

This dissertation presents a new finite difference method for studying thermal …

Acquisition Of Cardiac Control Parameters From Whole Vagus Nerve Recordings, Marcia A. Pool

Doctoral Dissertations

Heart rate varies continuously depending on the amount of activity being performed or the emotional state of an individual. Both branches of the autonomic nervous system work to alter heart rate depending on the needs of the body. While healthy individuals are capable of altering their heart rate, individuals with certain types of heart disease do not have this ability. For these individuals, cardiac pacemakers are used to alter heart rate. Cardiac pacemakers use sensors to determine the pacing frequency for the heart; however, there is no current optimum sensor. In order to discover a better sensor, this study investigated …

Wireless Sensor Network Modeling Using Modified Recurrent Neural Network: Application To Fault Detection, Azzam Issam Moustapha

Doctoral Dissertations

Wireless Sensor Networks (WSNs) consist of a large number of sensors, which in turn have their own dynamics. They interact with each other and the base station, which controls the network. In multi-hop wireless sensor networks, information hops from one node to another and finally to the network gateway or base station. Dynamic Recurrent Neural Networks (RNNs) consist of a set of dynamic nodes that provide internal feedback to their own inputs. They can be used to simulate and model dynamic systems such as a network of sensors.

In this dissertation, a dynamic model of wireless sensor networks and its …

Fabrication Of Bioactive Osteogenic Controlled-Release Systems, Cellular Platforms, And Cellular Capsules Using Layer -By -Layer Nanoassembly, Skylar Stewart-Clark

Doctoral Dissertations

There is an ever-increasing awareness that the field of tissue engineering offers many potential solutions to clinical problems. While advances along these lines have been made, the design and implementation of an "off the shelf" tissue is yet to be realized. Thus, the objectives of this work were largely aimed at the design and fabrication of biocompatible, bioactive structures which could be integrated into existing biomaterial products.

The electrostatic layer-by-layer (LbL) self-assembly technique was used to incorporate biologically relevant molecules within controlled release systems, cell culture platforms, and 3-D cellular capsules. Two delivery systems were investigated to determine the release …