Engineering Commons^™

Balloon Borne Mars Research Platforms, Sean Michael Hancock

Mechanical & Aerospace Engineering Theses & Dissertations

Aerial platforms can fill a measurement gap between orbiters and rovers, providing planetary scale high resolution in situ measurements, access to scientifically interesting terrain that is either inaccessible or hazardous to rovers, and serve as a planet-wide delivery platforms to deploy surface probes and rovers to areas inaccessible given existing entry, descent, and landing systems. A permanent robotic outpost on the Martian surface can utilize locally-derived hydrogen as a lifting gas for balloon systems deployed from Mars. That approach can simplify the inflation and launch of aerial vehicles while allowing for a long duration deployment campaign that is not constrained …

A Microfluidic Device For Impedance Spectroscopy, Ahmet Can Sabuncu

Mechanical & Aerospace Engineering Theses & Dissertations

Recently, microfluidics has become a versatile tool to investigate cellular biology and to build novel biomedical devices. Dielectric spectroscopy, on the other hand, allows non-invasive probing of biological cells. Information on the cell membrane, cytoplasm, and nucleus can be obtained by dielectric spectroscopy provided that appropriate tools are used in specific frequency ranges. This dissertation includes fabrication, characterization, and testing of a simple microfluidic device to measure cell dielectric properties. The dielectric measurements are performed on human T-cell leukemia (Jurkat), mouse melanoma (B16), mouse hepatoma (Hepa), and human costal chondrocyte cells. Dielectric measurements consist of measuring the complex impedance of …

Hybrid Inorganic/Organic Nanostructured Tandem Solar Cells: Simulation And Fabrication Methods, Patrick Michael Boland Jr.

Electrical & Computer Engineering Theses & Dissertations

Organic solar cell technologies continue to be an extremely active area of scientific research. With their promise of providing low-cost, easily-processable, multi-application photovoltaics, these devices could very possibly be the most viable and practical form of renewable energy among many being explored. However, significant technological obstacles remain that must be overcome if this technology is to successfully realize the goal of providing abundant energy while simultaneously reducing dependence on fossil fuel-based sources. Compared with inorganic solar photovoltaics, power conversion efficiencies in organics are still too low to compete economically.

Much research has been accomplished over the past three decades in …

Spectrum Adaptation In Cognitive Radio Systems With Operating Constraints, Deepak R. Joshi

Electrical & Computer Engineering Theses & Dissertations

The explosion of high-data-rate-demanding wireless applications such as smart-phones and wireless Internet access devices, together with growth of existing wireless services, are creating a shortage of the scarce Radio Frequency (RF) spectrum. However, several spectrum measurement campaigns revealed that current spectrum usage across time and frequency is inefficient, creating the artificial shortage of the spectrum because of the traditional exclusive "command-and-control" model of using the spectrum. Therefore, a new concept of Cognitive Radio (CR) has been emerging recently in which unlicensed users temporarily borrow spectrum from the licensed Primary Users (PU) based on the Dynamic Spectrum Access (DSA) technique that …

Design Of Multi Agent Based Crowd Injury Model, Emin Kugu

Electrical & Computer Engineering Theses & Dissertations

A major concern of many government agencies is to predict and control the behavior of crowds in different situations. Many times such gatherings are legal, legitimate, and peaceful. But there are times when they can turn violent, run out of control, result in material damages and even casualties. It then becomes the duty of governments to bring them under control using a variety of techniques, including non-lethal and lethal weapons, if necessary.

In order to aid decision makers on the course of action in crowd control, there are modeling and simulation tools that can provide guidelines by giving programmed rules …

A Database For Estimating Scanner-Specific Ct Dose, Taly Gilat-Schmidt

Biomedical Engineering Faculty Research and Publications

Purpose: To develop a database for estimating scanner-specific organ dose in a voxelized patient model for any spectral shape and angular tube current modulation setting. The database enables the estimation of organ dose for both existing and novel acquisition techniques without requiring Monte Carlo simulations.

Methods: The transport of monoenergetic photons through three phantoms was simulated with the PENELOPE Monte Carlo radiation transport routines at 5 – 150 keV in 1 keV increments at 1000 projections in 0.36 degree increments. The source-to-detector distance for each simulation was 100 cm, with a source-to-isocenter distance of 50 cm. The lateral and axial …

Effect Of Particle Size And Trench Configuration On Deposition From Fine Coal Flyash Near Film Cooling Holes, Weiguo Ai, Robert G. Laycock, Devin Rappleye, Thomas H. Fletcher

Faculty Publications

Particulate deposition experiments were performed in a turbine accelerated deposition facility to examine the effects of flyash particle size and trench configuration on deposits near film cooling holes. Deposition on two bare metal Inconel coupons was studied, with hole spacings (s/d) of 3.4 and 4.5. Two sizes of sub-bituminous coal ash particles were used, with mass mean diameter of 4 and 13 μm, respectively. The effect of a cooling trench at the exit of the cooling holes was also examined in this deposition facility. Experiments were performed at different angles of impaction. Particles were accelerated to a combustor exit flow …

Coal Swelling Model For High Heating Rate Pyrolysis Applications, Randy C. Shurtz, Kolbein K. Kolste, Thomas H. Fletcher

Faculty Publications

Thermal swelling of coal during pyrolysis strongly influences combustion and gasification rates. Coal swelling is known to vary strongly with coal rank, heating rate, and total pressure. New experiments confirm and clarify previous observations that maximum swelling occurs for high-rank bituminous coals at heating rates slightly below 10⁴ K/s. Advanced swelling models based on bubble physics yield good qualitative trends at low heating rates, but they fail to predict observed decreases in coal swelling as particle heating rates increase beyond 10⁴ K/s. An empirical swelling correlation for computational fluid dynamics (CFD) applications that correctly describes experimentally observed trends …

Self Assembly In Additive Manufacturing: Opportunities And Obstacles, Nathan B. Crane, J. Tuckerman, G. N. Nielson

Faculty Publications

Purpose

Additive manufacturing offers substantial flexibility in shape, but much less flexibility in materials and functionality—particularly at small size scales. A system for automatically incorporating microscale components would enable the fabrication of objects with more functionality. This paper considers the potential of self assembly to serve as an automated programmable integration method. In particular, it addresses the ability of random self assembly processes to successfully assemble objects with high performance despite the possibility of assembly errors.

Methodology

A self-assembled thermoelectric system is taken as a sample system. The performance expectations for these systems are then predicted using modified one-dimensional models …

Impact Of Project Based Learning In Introduction To Engineering/Technology Class, Alok K. Verma

Engineering Technology Faculty Publications

Project based learning (PBL) has a proven record as a teaching tool. Concepts that are often hard to grasp are made easy by the use of project based activities. The constructivism learning theory suggests that people learn better by actively participating in the process of learning. The Introduction to Engineering and Engineering Technology class has been modified to include project based learning kits to engage freshmen early on in the program. The goal is to demonstrate students the link between the scientific principles and their engineering applications. The course is team taught by faculty from various engineering and technology disciplines …

Design And Implement A Cost-Effective Wireless Communication Project On A Pic Training System, Steve Hsiung, Walter F. Deal, Lacides Agustin Osorio, Mathew Henderson

Engineering Technology Faculty Publications

Wireless communication becomes popular and widely used in almost every electronic product in our daily life. The RF communication is one of the major wireless applications in consumer products. Usually, it is integrated with an embedded system (microcontroller) to control various applications such as temperature sensing, data logging, data exchange, actuator activation, and user interaction wirelessly. A project based model can be used as an effective instructional strategy to enhance learning about complex RF concepts and technologies. The project method can lead to improved understanding and create interest by actively engaging the student with hands-on and problem solving and critical …