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Graduate School Of Engineering And Management 2010-2011 Catalog, Graduate School Of Engineering And Management, Air Force Institute Of Technology

AFIT Documents

The Graduate Catalog represents the offerings, programs, and requirements in effect at the time of publication.

Climate Change And Sea Level Rise Initiative (Ccslri), Larry P. Atkinson

CCSLRI Brochures

Brochure of the Old Dominion University Climate Change and Sea Level Rise Initiative (CCSLRI)

Evaluation Of A Web-Based Learning Tool For Teaching Gis Within The Context Of Transportation Engineering, Ashley Banaszek, Hong Sheng, Richard H. Hall, Ronaldo Luna, Ghulam Bham

Business and Information Technology Faculty Research & Creative Works

An Exploratory Study Was Conducted to Evaluate a Web-Based Learning Module for Teaching Geographic Information Systems to Civil Engineering Students within the Context of a Problem Related to Crash Data Analysis. This Module is One Part of a National Science Foundation Course, Curricula, and Laboratory Improvement Project in Which GIS Modules Are Being Developed for Several Areas of Civil Engineering. the Module Was Used as a Laboratory Assignment in a Transportation Engineering Course. Two Days Later Students Completed Both an Objective Multiple-Choice Quiz over the Material Covered in the Lab and a Subjective Questionnaire. Quantitative Analysis Was Carried Out on …

Discrete Coordinate Transformation For Designing All-Dielectric Flat Antennas, Wenxuan Tang, Christos Argyropoulos, Efthymios Kallos, Wei Song, Yang Hao

Department of Electrical and Computer Engineering: Faculty Publications

Transformation electromagnetics provides a practical approach to control electromagnetic fields at will. Based on this principle, novel devices such as the invisible cloak have been proposed. Here we examine the extension of this technique as applied to the design of flat devices in antenna systems. A method using discrete coordinate transformation is proposed, which allows the conversion of conventional devices with curved shapes into flat systems, while preserving their non-dispersive, isotropic, broadband, and lossless properties. Two specific design examples, a flat reflector and a flat lens embedded in free space, are presented. To avoid the loss and narrow bandwidth issues …

Clustering Of Protein Families Into Functional Subtypes Using Relative Complexity Measure With Reduced Amino Acid Alphabets, Aydin Albayrak, Hasan H. Otu, Ugur O. Sezerman

Department of Electrical and Computer Engineering: Faculty Publications

Background: Phylogenetic analysis can be used to divide a protein family into subfamilies in the absence of experimental information. Most phylogenetic analysis methods utilize multiple alignment of sequences and are based on an evolutionary model. However, multiple alignment is not an automated procedure and requires human intervention to maintain alignment integrity and to produce phylogenies consistent with the functional splits in underlying sequences. To address this problem, we propose to use the alignment-free Relative Complexity Measure (RCM) combined with reduced amino acid alphabets to cluster protein families into functional subtypes purely on sequence criteria. Comparison with an alignment-based approach was …

Bioinformatic Identification And Characterization Of Human Endothelial Cell-Restricted Genes, Manoj Bhasin, Lei Yuan, Derin B. Keskin, Hasan H. Otu, Towia A. Libermann, Peter Oettgen

Department of Electrical and Computer Engineering: Faculty Publications

Background: In this study, we used a systematic bioinformatics analysis approach to elucidate genes that exhibit an endothelial cell (EC) restricted expression pattern, and began to define their regulation, tissue distribution, and potential biological role.

Results:Using a high throughput microarray platform, a primary set of 1,191 transcripts that are enriched in different primary ECs compared to non-ECs was identified (LCB >3, FDR

Conclusion: The study provides an initial catalogue of EC-restricted genes most of which are ubiquitously expressed in different endothelial cells.

Numerical And Analytical Verification Of A Multiscale Computational Model For Impact Problems In Heterogeneous Viscoelastic Materials With Evolving Damage, Bruno Bachiega Araujo

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Composites are engineered materials that take advantage of the particular properties of each of its two or more constituents. They are designed to be stronger, lighter and to last longer which can lead to the creation of safer protection gear, more fuel efficient transportation methods and more affordable materials, among other examples.

This thesis proposes a numerical and analytical verification of an in-house developed multiscale model for predicting the mechanical behavior of composite materials with various configurations subjected to impact loading. This verification is done by comparing the results obtained with analytical and numerical solutions with the results found when …

Magneto-Optical Properties Of Cobalt Slanted Columnar Thin Films, Daniel Schmidt, Tino Hofmann, Craig M. Herzinger, Eva Schubert, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

Magneto-optical properties of ferromagnetic slanted columnar thin films from cobalt made by electron-beam glancing angle deposition are reported. Magneto-optic ellipsometry in the polar Kerr effect configuration was employed to determine the field- and wavelength-dependent complex magneto-optic polarizability parameter within the spectral range from 0.74 to 3.0 eV. Kerr effect measurements and calculations reveal a strong azimuthal dependence for the incident linear polarization with peak Kerr rotation one order of magnitude larger than what has been reported for solid Co thin films.

Non-Destructiveapproachto Ellipsometric Monitoring Of A Film Coating On The Inner Surface Of A Tube Shaped Sample, Gregory K. Prilbil, John A. Woollam, Martin M. Liphardt, James D. Welch

Department of Electrical and Computer Engineering: Faculty Publications

Disclosed is the use of a focused electromagnetic beam which is caused to impinge on the top surface of a tube shaped sample, to investigate a film coating on inner surface during fabrication thereof and/or thereafter.

Influence Of Shear Key Performance On The Fatigue Life Of Adjacent Beam Bridges, Sara Roberts

All Theses

Adjacent beam bridges, such as box beams and hollow core bridges have been one of the most popular forms of precast prestressed bridges in the past. Recently, an awareness of major durability problems has led owners to make improvements to the old standards or move away from the system completely. These issues usually stem from the breakdown of the shear key which provides continuity between adjacent members. This research focuses on determining the best improvements that will reduce durability issues and increase the bridge's service life.
A review of previous research performed on adjacent beam bridges is performed, focusing on …

What About The Children? Benjamin And Arendt: On Education, Work, And The Political, Jules Simon

Departmental Papers (Philosophy)

This article is a rough draft of an article that I contributed to an edited volume of articles dealing with progressive education theory. I reflect on articles that Hannah Arendt and Walter Benjamin wrote that deal with educational reform and innovation, both political in nature.

Valence-Shell Photoionization Of The Chlorinelike Ca3+ Ion, Ghassan A. Alna’Washi, M. Lu, M. Habibi, R. A. Phaneuf, A. L. D. Kilcoyne, A. S. Schlachter, C. Cisneros, B. M. Mclaughlin

United States Department of Energy: Publications

Absolute photoionization measurements were performed for a mixture of ²P^o_3/2 ground-state and ²P^o_1/2 metastable-state Ca³⁺ ions over the photon energy range 65.7–104.6 eV by merging an ion beam with a beam of monochromatized synchrotron radiation. The ionization threshold energy of the ²P^o_3/2 ground state was measured to be 67.063 ± 0.015 eV, which is 0.207 eV lower than the value tabulated in the NIST database. Most of the observed resonances associated with multiple Rydberg series of autoionizing states have been assigned spectroscopically using the quantum defect form of the Rydberg …

Effects Of Canopy-Payload Relative Motion On Control Of Autonomous Parafoils, Nathan Slegers

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

An 8 degree-of-freedom model is developed that accurately models relative pitching and yawing motion of a payload with respect to a parafoil. Constraint forces and moments are found analytically rather than using artificial constraint stabilization. A turn rate controller common in precision placement algorithms is used to demonstrate that relative yawing motion of the payload can result in persistent oscillations of the system. A model neglecting relative payload yawing failed to predict the same oscillations. It is shown that persistent oscillations can be eliminated by reduction of feedback gains; however, resulting tracking performance is poor. A reduced order linear model …

Diapycnal Diffusivities In Homogeneous Stratified Turbulence, D. D. Stretch, S. K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Quantifying diapycnal mixing in stably stratified turbulence is fundamental to the understanding and modeling of geophysical flows. Data of diapycnal mixing from direct numerical simulations of homogeneous stratified turbulence and from grid turbulence experiments, are analyzed to investigate the scaling of the diapycnal diffusivity. In these homogeneous flows the instantaneous diapycnal diffusivity is given exactly by Kd= ∈ρ/ (∂ ρ /∂z)²where ∈ρ is the dissipation rate of density fluctuations, and ∂ ρ /∂z is the mean density gradient. The diffusivity Kd may be expressed in terms of the large-scale properties of the turbulence as K d = γLE …

Kitab Al-Hadaya Wa Al-Tuhaf: A Unique Window On Islamic Textiles, Wendy Landry

Textile Society of America: Symposium Proceedings

During the first millennium, a rare kind of literature evolved in the Islamic world that provides a fascinating window on the interest and importance of material objects. A unique example of this literature, entitled Kitab al-Hadaya wa al-Tuhaf [Book of Gifts and Rarities] was translated into English, annotated and published in 1996 by Kuwaiti curator and scholar Ghada al Hijjawi al-Qaddumi. It is an anthology of anecdotes referring to the period between the sixth century and the twelfth century, probably compiled in the late twelfth century by an official in the Islamic Egyptian government.

Although the historical veracity of the …

Figured Velvets From Simple Looms: Velvet Pick-Up And Related Techniques For Handweavers, Wendy Landry

Textile Society of America: Symposium Proceedings

Much historical velvet was designed to be figural, often in elaborate curvilinear floral motifs, and multiple colours. These complex patterns could be efficiently designed for and executed on the available drawlooms and their successors, the jacquard looms. Faced with such complexity, and the unavailability of jacquard looms and drawlooms, few handweavers have attempted to add velvet technique to their repertoire. However, the basic principles and weave structures of velvet are relatively simple and can be executed on simpler handlooms. Pick-up techniques and simple loom modifications make figured velvet accessible for weavers without access to complex jacquard velvet looms, allowing them …

Supercritical Carbon Dioxide Processing Of Nano - Clays And Polymer/Clay Nanocomposites, Mihai Manitiu

Wayne State University Dissertations

Effective dispersion of the fillers in a polymer matrix and improvement of polymer-clay interactions are two key challenges in the field of nanocomposites. A novel processing method that utilizes the unique properties of supercritical carbon dioxide (scCO2) to disperse nano-clay and prepare a series of polymer/clay nanocomposites with enhanced properties was explored.

Significant dispersion was achieved using the scCO2 process with Cloisite 10A without the presence of an organic phase as evident by the absence of the diffraction peak in WAXD and the presence of individual tactoids that lost their parallel registry. The expanded flexible structure of the scCO2 processed …

A Study Of Diamond Nanoparticles, Rajarshi Chakraborty

Material Science and Engineering Theses - Archive

Diamond nanoparticles grown previously by Hot Filament Assisted Chemical Vapor Deposition have been characterized by utilizing Atomic Force Microscopy, Scanning Electron Microscopy, Raman Spectroscopy and X Ray Diffraction. AFM and SEM data shows increase in nanoparticle size with growth period ranging from about 20 nm for 15 minutes to 200 nm for 105 minutes growth. Raman spectra have been analyzed by using optical phonon confinement in nanometer size crystals. Based on the SEM, Raman spectroscopy and XRD data, we present clear evidence for nanometer size (10-200 nm) diamond particles in CVD-grown diamond thin films.

Aircraft Conceptual Design - An Adaptable Parametric Sizing Methodology, Gary John Coleman

Mechanical and Aerospace Engineering Dissertations - Archive

Aerospace is a maturing industry with successful and refined baselines which work well for traditional baseline missions, markets and technologies. However, when new markets (space tourism) or new constrains (environmental) or new technologies (composite, natural laminar flow) emerge, the conventional solution is not necessarily best for the new situation. Which begs the question "how does a design team quickly screen and compare novel solutions to conventional solutions for new aerospace challenges?" The answer is rapid and flexible conceptual design Parametric Sizing. In the product design life-cycle, parametric sizing is the first step in screening the total vehicle in terms of …

Constrained Dynamics Approach For Motion Synchronization And Consensus, Divya Bhatia

Mechanical and Aerospace Engineering Theses - Archive

In this research we propose to develop constrained dynamical systems based stable attitude synchronization, consensus and tracking (SCT) control laws for the formation of rigid bodies. The generalized constrained dynamics Equations of Motion (EOM) are developed utilizing constraint potential energy functions that enforce communication constraints. Euler-Lagrange equations are employed to develop the non-linear constrained dynamics of multiple vehicle systems. The constraint potential energy is synthesized based on a graph theoretic formulation of the vehicle-vehicle communication. Constraint stabilization is achieved via Baumgarte's method. The performance of these constrained dynamics based formations is evaluated for bounded control authority.The above method has been …

Ideal Cycle Analysis Of A Regenerative Pulse Detonation Engine For Power Production, Rafaela Bellini

Mechanical and Aerospace Engineering Dissertations - Archive

Over the last few decades, considerable research has been focused on pulse detonation engines (PDEs) as a promising replacement for existing propulsion systems with potential applications in aircraft ranging from the subsonic to the lower hypersonic regimes. On the other hand, very little attention has been given to applying detonation for electric power production. One method for assessing the performance of a PDE is through thermodynamic cycle analysis. Earlier works have adopted a thermodynamic cycle for the PDE that was based on the assumption that the detonation process could be approximated by a constant volume process, called the Humphrey cycle. …

Stress Analysis Of Laminated Composite Beam With I-Section, Jitesh Cherukkadu Parambil

Mechanical and Aerospace Engineering Theses - Archive

The advantage of material properties and flexibility of choosing material have made composite materials a primary preference for structural application. Unlike isotropic materials, the parametric study of composite beams for optimized design is complicated due to high number of parameters involved in designing like lay-up sequence, and layer configuration. Moreover, the limitations of FEA techniques in designing have created a need for an analytical closed-form solution for stress analysis of laminated composite beams. The objective of this study focuses on the development of an analytical method for stress analysis of composite I-beam. This method includes the structural response due to …

Development Of Amphiphilic Biodegradable Photoluminescent Polymers, Shengyuan Zhou

Material Science and Engineering Theses - Archive

The development of amphiphilc block copolymers have been attracted much attention due to their potential use in drug delivery and targeting. Less research work focused on their prospective application as fluorescent imaging probes. Although some research reported fluorescent materials encapsulated in amphiphilc micelles has provided significant opportunities for biological labeling and imaging in biomedical fields, these fluorescent materials, such as organic dyes and quantum dots, suffer from photobleaching, cytotoxicity and lack of biodegradability. A novel and ideal amphiphilic biodegradable photoluminescent polymeric micelle was developed, which will open new avenues for biomedical filed. The objective of this reseach was to develop …

Synthesis And Characterization Of Platinum And Carbon Nanoparticle In Benzene By Electric Plasma Discharge In Ultrasonic Cavitation, Rakesh Pratapbhai Chaudhary

Material Science and Engineering Theses - Archive

Nanoparticles are of interest due to the high number of atoms located on the surface. This high surface area is conductive to higher catalytic efficiency than normal seen in bulk metals. Of numerous Nanoparticles catalysts studied, Platinum (Pt) nanoparticles have attracted particular interest due to their superior catalysis for many chemical reactions, especially for fuel cell reactions including hydrogen oxidation and oxygen reduction. Carbon supported Pt nanoparticles are active anode catalysts for fuel cells. In this thesis nano-sized Pt particles have been synthesized by an advanced and cost effective method. Pt nanoparticles embedded in carbon matrix were synthesized by an …

Solution To Multi Term Boltzmann Equation For Plasma Assisted Combustion, Antriksh Luthra

Mechanical and Aerospace Engineering Theses - Archive

Plasma assisted ignition and combustion (PAIC) is a technology where plasma is generated by high voltage, nano second pulse duration and high repetitive rate pulses. The high reduced electric field during the pulse allows efficient electronic excitation and molecular dissociation, thereby generating a pool of chemically active radical species. This speeds up the reaction process needed to generate a high speed flame a very high energy is liberated though the mode of excited electrons to the neutral molecules of the fuel in such a way that the energy sent should not go in momentum transfer but it should be so …

Nanoparticle Bridge Dna Biosensor, Hong-Wen Huang

Material Science and Engineering Dissertations - Archive

A new DNA sensing method is demonstrated in which DNA hybridization events lead to the formation of nanoparticle satellites that bridge two electrodes and are detected electrically. The hybridization events are exclusively carried out only on specific locations, the surfaces of C-ssDNA modified 50 nm GNPs. The uniqueness of this work is that only a small number of T-ccDNA molecules (<10) is required to form the nanoparticle satellites, allowing ultra-sensitive DNA sensing. The principle of this new DNA sensing technique has been demonstrated using target DNA and three-base-pair-mismatched DNA in 20nM concentrations. Three single-stranded DNA (ssDNA) system is used in our experiment which includes Capture-ssDNA (C-ssDNA), Target-ssDNA (T-ssDNA) and Probe-ssDNA (P-ssDNA). Both C-ssDNA and P-ssDNA are modified by a thiol group and can hybridize with different portions of T-ssDNA. T-ssDNA requires no modification in three ssDNA system, which is beneficial in many applications. C-ssDNA modified 50nm gold nanoparticle (C-50au) and P-ssDNA modified 30nm gold nanoparticle (P-30au) are prepared through the reaction of thiol-gold chemical bonding between thiolated ssDNA and gold nanoparticle (GNP) (C-ssDNA with 50nm GNP, P-ssDNA with 30nm GNP). We controllably place the C-50au only on the SiO2 band surface (~ 90nm width) between two gold electrodes (source and drain electrodes) by forming positively- and negatively-charged self-assembled monolayers (SAMs) on SiO2 and gold surface, respectively. DNA modified GNP is negatively charged due to ionization of phosphate group on DNA back bone. C-50au therefore is negatively charged and can only be attracted toward SiO2 area (repelled by negatively charged gold electrode surface). The amine group of positively-charged SAMs on SiO2 surface is then passivated by converting to non-polar methyl functional group after C-50au placement. P-30au is first hybridized with T-ssDNA in the solution phase (T-P-30au formed) and is introduced into DNA detection device in which C-50au are immobilized on ~90nm width SiO2 band (between two gold electrodes). The passivation step ensures every T-P-30au are attached only to C-50au through hybridization (T-P-30au will not be attracted toward SiO2 surface or gold electrodes). GNP bridges are formed across the electrodes and provide an electrical path between two gold electrodes.We ensure that every T-P-30au only hybridizes on the surface of C-50au by (1) accurately controlling C-50au placement between two gold electrodes, (2) passivating positively-charged SAMs on SiO2 surface after C-50au immobilization. When T-P-30au hybridize with C-50au on ~90nm wide SiO2 surface, GNP bridges form and provide an electrical path between two gold electrodes even with only a few hybridization events. Experimental results show that even a few GNP bridges formed on SiO2 band can provide a significant conductance change from an open circuit to a conductive circuit (current = 0.5 uA at voltage = 0.1 V with four GNP bridge). We also used 3-base-pair-mismatched ssDNA (3mm-ssDNA) as a control experiment, which always resulted in an open circuit (no GNP bridge formed). Our detection device is compatible with current CMOS fabrication technology and can be manufactured on a wafer scale. The direct electrical output of this DNA detection technique provides a promising basis for high-throughput screening (can be fabricated on a wafer scale) with no expensive equipment required.

Measurement Of The Spectral Distribution Of Low Energy Electrons Emitted As A Result Of Nvv Auger Transitions In Ag (100), Sushant Kalaskar

Material Science and Engineering Theses - Archive

Auger Photoelectron Coincidence Spectroscopy (APECS) was used to investigate the physics of the Low Energy Tail (LET) of the Auger spectrum of Ag (100) at the National Synchrotron Light Source, Brookhaven National Lab, New York. The incident photon energy was set at 180eV. The spectrum shows a peak due to the NVV Auger transition accompanied by a substantial low energy region. The APECS spectrum contains the contributions from electrons excited by the NVV Auger transition plus a background due to true coincidences between photoemitted valence band electrons that undergo inelastic scattering and transfer part of their energy with other valence …

Kinematic Analysis Of A Quadruped Robot Capable Of Working As A Machining Tool, Raghu Mandayam Anand

Mechanical and Aerospace Engineering Theses - Archive

Parallel robots have been proposed for some time now due to their potential advantages over serial robots in high load bearing, acceleration, stiffness and with lower moving mass. Mobile parallel configurations, i.e. multi-legged walking vehicles have been and are the focus of a great deal of current research. This thesis attempts to provide insights into the kinematic analysis of a quadruped robot capable of both walking and more importantly functioning as a machining tool. The gait analysis of quadruped robots has been extensively investigated and is not the focus of this research; however the gait ability is considered in the …

Effects Of Freezing On The Mechanical Properties Of Engineered Tissues, Lacey Mlcak

Mechanical and Aerospace Engineering Theses - Archive

Cryopreservation is used to preserve cells and tissues at low temperatures for short and long term uses. Some examples of where cryopreservation is used include the storage of organs, blood, embryos, and artificial tissues. A current challenge of cryopreservation is being able to understand and quantify the effects of freezing/thawing on the functional properties of tissues such as mechanical properties. This study investigated the changes in viscoelastic parameters of engineered tissues before and after freezing by performing creep-relaxation tests using a dynamic mechanical analyzer. Three types of engineered tissues were studied with varying cell and collagen concentrations for two different …

Experimental Study Of The Effects Of Thermally Conductive Microporous Coatings On Low Heat Flux Pool And Flow Boiling, Matthew Mlcak

Mechanical and Aerospace Engineering Theses - Archive

This study examines the effect of the Thermally Conductive Micro-porous Coating (TCMC) developed at the University of Texas at Arlington, on an extended length heater in flow boiling. The study was performed with application to heat transfer in a tankless hot water heater in mind. The coating is composed of copper particles of micron size soldered to each other and to the substrate. The optimal TCMC (75µm particles with a thickness of 425µm±25µm) was first determined from pool boiling tests. The coating was then tested in flow boiling utilizing tap water as the working fluid at two different levels of …