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Chemical And Electronic Structure Of Surfaces And Interfaces In Compound Semiconductors, Sujitra Pookpanratana

UNLV Theses, Dissertations, Professional Papers, and Capstones

The interface formation between two different materials is important in applications for optoelectronic devices. Often, the success or performance of these devices is dependent on the formation of these heterojunctions. In this work, the surface and interfaces in such materials for optoelectronic devices are investigated by a suite of X-ray analytical techniques including X-ray photoelectron (XPS), X-ray excited Auger electron (XAES), and X-ray emission (XES) spectroscopies to provide novel insight.

For the group III-nitrides (e.g., AlxGa1-xN) used in many light emitting devices, a significant challenge exists to form an Ohmic contact. The electron affinities and band gaps of GaN and …

Traffic Scene Understanding Using Sound-Based Localization, Svm Classification And Clustering, Shreyas Kodasara Rajagopal

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The thesis is about an embedded system application aimed at identifying the semantics of traffic based on acoustic data. Sound localization, classification and clustering are used for scene understanding. The report presents a set of experiments used to simulate different traffic scenarios. An alternative implementation for sound localization is also explored, where fixed point representation of rational numbers is used instead of floating point numbers. The results for both the implementations are compared in terms of execution speed and accuracy for a Programmable System-on-Chip (PSoC). | 43 pages

Correlation Between Structure And Thermoelectric Properties: Searching For Better Thermoelectric Materials, Qing Jie

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The wide-spread application of thermoelectric devices is important for effective utilization of energy and environment. The market share of thermoelectric devices could potentially reach billions of dollars per year and urgently needs new materials with high energy conversion efficiency, which depends primarily on the thermoelectric figure of merit (ZT). ZT = S2T/(ΡΚ), where S, Ρ, Κ, T are Seebeck coefficient, electrical resistivity, thermal conductivity and absolute temperature, respectively, and S2/Ρ is the power factor (P.F.). ZT could be enhanced by either decreasing the thermal conductivity or increasing the power factor of the material under study. In this work, the relationship …

Solid State Nmr And Pair Distribution Function Studies Of Silicon Electrodes For Lithium-Ion Batteries, Baris Key

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The universally used negative electrode material in a LIB is carbon, because of its moderate capacity (372 mAhg-1 for graphite), cyclability and high rate capability. However, new, low cost, safe electrode materials with higher capacities are still urgently required for both portable and transportation applications. Silicon anodes are particularly attractive alternatives to carbon with extremely high gravimetric energy densities (3572 mAhg-1). Compared to graphite, silicon has a massive volumetric capacity of 8322 mAhcm-3 (calculated based on the original volume of silicon) which is approximately ten times that graphite. At room temperature, upon electrochemical lithiation, silicon undergoes a crystalline to amorphous …

Kings, Evil Courtiers, And The Intended Audience Of The Historia Langobardorum, Edward Currie

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The Historia Langobardorum (History of the Langobards) was written by Paul the Deacon in the 780s-790s. It is an important work of historiography, but little attention has been paid to the power of the text as political propaganda. This study sets out to analyze how Paul promotes harmony between Carolingians and Langobards, uplifts the image of the old Langobardic king Grimoald I, and encourages an agreeable view of the contemporary prince of Benevento, Grimoald III, who rebelled against Charlemagne in 791.

Wiki Vandalysis. Wikipedia Vandalism Analysis, Manoj Harpalani

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Wikipedia describes itself as"The free encyclopedia that anyone canedit". Along with the helpful volunteers who contribute by improving the articles, a great number of malicious users abuse the open nature of Wikipedia by vandalizing articles. Wikipedia editors fight vandalism both manually and with automated bots that use regular expressions and other simple rules to recognize malicious edits[Carter]. Researchers have also proposed Machine Learning algorithms for vandalism detection[Smets et al. | 2008; Potthast et al. | 2008a], but these algorithms are still in their infancy and have much room for improvement. This paper presents an approach to fighting vandalism using natural …

Statistical Models For Snp Detection, Shengnan Cai

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Variations in DNA sequences of humans have a strong association with many diseases. Single Nucleotide Polymorphism (SNP) is the most common type of DNA variations. Our research is to detect SNPs from the data generated by Polymerase Chain Reaction (PCR) and next generation sequencing methods. In the first part of the study, we had a relatively small data set with fewer known SNPs as the training data. We developed a classification model based on the cross validation method. From the first part of the research, we gained knowledge of the properties of the data. In the next phase, we obtained …

Measurement Of Vertically Aligned Carbon Nanotube Array Compression Response, Changhong Cao

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The use of carbon nanotubes (CNTs) in the form of vertically aligned arrays or films has been of interest due to the super-compressible response and the ability to be used as electrical and thermal contacts. CNT arrays have shown the remarkable ability to react as foam-like structures and exhibit localized, coordinated buckling within specific regions. An understanding of the buckling region evolution and the resulting effects on the bulk CNT array response are important, unanswered fundamental questions necessary for the future application of CNT arrays. Here, we report on the low-cycle compression of bulk vertically aligned CNT arrays to observe …

Repression Of Meiotic Gene Expression By Regulated Rna Stability And By Antisense Transcription In Schizosaccharomyces Pombe, Huei-Mei Chen

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Meiosis produces haploid gametes from diploid germ cells. Many genes are used only for meiosis and cause harm if they are expressed in vegetative (non-meiotic) cells. My dissertation research focused on mechanisms that keep meiotic functions completely off in vegetative cells in a model organism, the fission yeast Schizosaccharomyces pombe. Early meiotic genes drive a specialized S-phase and meiotic recombination events. I found that at least 30 early meiotic genes in S. pombe are transcribed even in vegetative cells where they are kept off by degradation of their transcripts through a novel mechanism directed by Mmi1, an RNA binding protein. …

Thermal Spray Processing Of Ceramic Oxide Coatings: An Integrated Approach, Jose Rafael Colmenares Angulo

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Abstract of Dissertation: Thermal Spray Processing of Ceramic Oxide Coatings: An Integrated Approachby Jose Rafael Colmenares AnguloDoctor of Philosophy in Materials Science and EngineeringStony Brook University 2010Thermal spray represents a complex processing technology given the stochastic nature of rapid splat melting, impact and solidification. The present work represents a series of studies with the aim of improving the understanding of process-property relationships on ceramic oxides integrating recent work from the Center of Thermal Spray Research regarding particle and non-particle state issues intrinsic to thermal spray processing with material specific applicationsIssues regarding reliability of two-wavelength pyrometry and time-of-flight methods for thermal …

High Level Describable Attributes For Predicting Aesthetics And Interestingness, Sagnik Dhar

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

With the rise in popularity of digital cameras, the amount of visual data available on the web is growing exponentially. Some of these pictures are extremely beautiful and aesthetically pleasing. Unfortunately the vast majority are uninteresting or of low quality. This paper demonstrates a simple, yet powerful method to automatically select high aesthetic quality images from large image collections with performance significantly better than the state of the art. We also show significantly better results on predicting the interestingness of Flickr images, and on a novel problem of predicting query specific interestingness. Our aesthetic quality estimation method explicitly predicts some …

The Role Of The Hemopexin Domain Of Matrix Metalloproteinases In Cell Migration, Antoine Hugues-Olivier Dufour

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The biological functions of matrix metalloproteinases (MMPs) extend beyond extracellular matrix degradation. Non-proteolytic activities of MMPs are just beginning to become understood. The role of proMMPs in cell migration was herein evaluated using transfected COS-1 cells with various proMMP cDNAs employed in a Transwell chamber migration assay. Latent MMP-2 and MMP-9 enhanced cell migration to a greater extent than latent MMP-1,. 3,. 11 and. 28. To examine if proteolytic activity is required for MMP-enhanced cell migration, three experimental approaches including a fluorogenic substrate degradation assay, transfection of cells with catalytically inactive mutant of MMP cDNAs, and addition of MMP inhibitors …

Winter 2010 E-Certi Newsletter, Center For Educational Research And Teaching Innovation

CAFE Faculty Newsletters

Hello S&T faculty and welcome to another edition of the CERTI newsletter, dedicated to celebrating excellence in the classroom. In this issue, you’ll find articles on a unique method for students to ask questions and how to make history a hands-on learning experience. Also, here are tips from the Curators’ Teaching Professors on working toward balance in your career.

Ceramic Nanomaterials For Energy, Gagan Jodhani

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

In this work we try to synthesize MoO3 and WO3 nanoceramics by understanding the effects of precursor parameters on the electrospinning process. We synthesized polymer based composites with molybdenum oxide and Tungsten oxide under straight polarity i.e. keeping needle charged and collector grounded; as well as reverse polarity i.e. keeping the needle grounded and collector charged. We observed MoO3 nanotubes after heat treatment of the composite mats spun in reverse polarity. The reason for formation of nanotubes is the presensce of molybdenum oxide particles as an outer shell surrounding the polymer fiber core in the spun mats, this core shell …

The Microstructure And Properties Of Plasma Sprayed Ceramic Composites, Kerry James Lapierre

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The microstructure and properties of plasma-sprayed ceramics and ceramic matrix composites (CMCs) have been investigated. Substrate-free deposits were fabricated by plasma spraying onto expendable graphite substrates. The deposits were evaluated in the as-sprayed and heat-treated conditions. X-ray diffractometry (XRD) was used in conjunction with differential scanning calorimetry (DSC) to examine the phase content and transformation temperatures of plasma-sprayed Al2O3. Mechanical properties were measured using three-point flexural testing and density measurements were made for both the as-sprayed and heat treated conditions. Significant increases in modulus and strength were achieved as a result of post. spray heat treatment.Having established baseline properties with …

Visual Game Tuning: Integrating Interactive Visualizations Into Game Development, Markus Elliot Lacay

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Game development is a rapidly evolving area of study that blends together a broad spectrum of technical and creative influences. Through their systematic use of rules, mechanics and multimedia assets, games can be thought of as an increasingly complex set of multivariate state data. Often, the interactions between these variable sets and their affect on game behavior are not readily apparent to the system architects at the time of development. These details can easily be overlooked until much later in the development cycle, when the refactoring of their implementations can result in significant overhead. To combat this problem project managers …

Determination Of The Monoclinic Properties Of Human Tooth Enamel Microstructure By A Periodic Three Dimensional Finite Element Model, Cunyou Lu

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Researchers have reported diverse mechanical properties (Young's modulus) of human tooth enamel from experiments and finite element simulations, because of the complicated microstructure, which contains variations in crystal orientations and non-homogeneous properties. Although past models have effectively considered the microstructural effects, appropriate conditions for introducing crystal orientations within enamel rods and the property variations between rods and the interrod enamel are still necessary.In this thesis, the micromechanical response of the enamel microstructure is investigated using a periodic finite element model to determine the effective monoclinic mechanical properties and determine localized effects of microstructure on the stress field. A spherical micro-indentation …

Evaluation Of The Effect Of Pprocessing Parameters On Adhesion Performance Of Polyetherbased Tpu Over Mold On To Polycarbonate Substrate, Mukund Purushottam Patankar

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The overmolding process involves the use of two separate materials to form one cohesive component. The final product is a single piece, made out of polymers with very different mechanical properties that must be safe and permanently bonded together throughout its useful life. The first shot is generally a hard plastic and is referred to as a substrate the second material is generally a soft thermoplastic elostomer (TPE) and referred as overmold. The rigid substrate is used for structural purposes, and the softer materials are expected to take care of the user comfort. Overmolding can add immeasurable value to product …

Novel Nonparametric Approaches To Stock Assessment And Regime Shift Prediction, Charles Thomas Perretti

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Ecosystem dynamics are often complex, nonlinear, and characterized by criticalthresholds or regime changes. Despite these difficulties, resource managers mustaccurately forecast species abundance and anticipate impending regime shifts in order toimplement sustainable management plans. In the first part of this thesis I explicitly describe a nonparametric method formultivariate forecasting which I call the MS-Map and evaluate its performance relative toa suite of parametric models. I found that, in the presence of noise, it is often possible toobtain more accurate forecasts from the MS-Map than from the model that was used togenerate the data. The inclusion of additional species yielded a large …

Analysis Of Supercomputers And Development Of A Novel Network, Reid Powell

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

As supercomputers have reached nearly 300,000 cores with 2 petaflops in Linpack performance in June 2010, energy consumption and temperature control are posing a developmental bottleneck. We retrospectively and comparatively examine all of the available data contained in the Green500 list that launched in November 2007, and the Top500 list, and propose a novel representation and analysis of the data, highlighting major evolutionary trends.With these new insights, we introduce a new technique for generating more efficient networks by systematically interlacing bypass rings to torus networks (iBT networks). The resulting network can improve the original torus network by reducing the network …

Shear-Induced Platelet Sensitization And The Development Of An Activation Model, Jawaad Sheriff

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Increased shear stresses are a hallmark of flow conditions in blood recirculating devices, and patients implanted with such devices require lifelong anticoagulation to counteract the high risk of thromboembolism. Despite this limitation, manufacturers only test for hemolysis in order to optimize device design. This is primarily due to the paucity of data regarding platelet damage, a major precursor of thromboembolism. Several studies have shown that platelets exposed to constant shear stress for a specified duration become activated. However, post high-shear stress activation behavior of platelets, which is critical to understanding increased thrombotic risk associated with blood recirculating devices, is poorly …

Carbon Dioxide Multiphase Flows In Microfluidic Devices, Ruopeng Sun

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

In this thesis, we experimentally studied the mass transfer during CO₂ absorption into water, ethanol, methanol and silicone oil under slug flow in microchannels. We showed that the initial bubble size is determined by the liquid fraction and channel geometry, while the CO₂ diffusion rate is determined by the gas pressure and liquid properties, such as the Henry's constant and the diffusion coefficient. The reduction of the gas void fractionΑ_G along the flow direction and the transformation of segmented flows into dilute bubbly flows was observed and predicted. In high viscosity liquids, we showed the liquid film …

Reading Into Race: Unsettled Reading And The Performance Of"Race", Julie Burton Swift

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Reading, race, and the primary productive link between the two--performativity--are the subject of this dissertation. By reading the formative discourse of phrenology and Ethnology, as well as nineteenth-century textbooks which teach reading, I suggest a context in which reading operates as an expressive framework for the problematics of race. In considering selected works of Edgar Allan Poe, Frederick Douglass, Harriet Jacobs, and Herman Melville, I examine the uses to which reading is put, not only to elaborate, but to perform race. By looking at unsettled reading--breakdowns of reading, failures to read, readings that prove unaccountable to the text--I emphasize the …

Nonlinear Modeling On Viscoelastic Contact Interface: Theoretical Study And Experimental Validation, Chia-Hung Dylan Tsai

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Viscoelasticity is a phenomenon of time-dependent strain and/or stress in elastic solids. Various contact interfaces with anthropomorphic end-effectors and polymeric solids found in robots and manipulators are intrinsically viscoelastic. It is therefore important to model such behavior and to study the effects of such time-dependent strain and stress on the stability and sustainability of grasping and manipulation. Both theoretical modeling and experimental study are presented in this dissertation. In theoretical modeling, a new nonlinear latency model is proposed for the application of contact interface involving viscoelasticity in robotics. Latency model can describe well various features of viscoelastic materials, such as …

Efficient Datalog Queries With Time And Space Complexity Guarantees, Tuncay Tekle

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Many complex analysis problems can be most clearly and easily specified as logic rules and queries, where rules specify how given facts can be combined to infer new facts, and queries select facts of interest to the analysis problem at hand. However, it has been extremely challenging to obtain efficient implementations from logic rules and understand their time and space complexities, particularly for answering queries of interest without inferring all facts.This dissertation focuses on Datalog---an important class of rules for applications in databases, program analysis, security, semantic web, and many other areas. We describe a systematic method for precisely analyzing …

Classification Problems For Mdps And Optimal Customer Admission To M/M/K/N Queues, Fenghsu Yang

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

My dissertation addresses the unichain classification problem for any finite Markov decision process (MDP) with a recurrent or stopping state and the optimal admission problem for an M/M/k/N controlled queue with holding costs. In the first chapter, we study the unichain classification problem for MDPs. The unichain classification problem is to detect whether an MDP with finite states and actions is unichain or not. This problem has been proven to be NP-hard. We study this problem while an MDP contains a state which is either recurrent under all deterministic policies or absorbing under some action. We introduce the definitions of …

Characteristics Of Coherent Fiber Optics Imaging Bundle After High Power Transmission, Shih Hsi Yen

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

This thesis presents a comparative experimental characterization of a coherent fiber optics imaging bundle or coherent fiber bundle (CFB) before and after exposure to high energy density pulses (> 1k J/cm2). A Fujikura FIGH-30-850N ultra-thin imaging fiber with 30,000 individual optical fiber filaments, packed into a 780 um spot, was tested. Two fiber-coupled laser diodes, operating at a wavelength of 818 nm and 830nm respectively, provided the high power excitation source for the experiments. Analysis done using visual inspection and modulation transfer function techniques revealed that the laser induced fiber damage threshold (LIFDT) of the CFB is greater than 11k …

Studies Of Auxetic Foam And Bridge Deformation Using Digital Speckle Photography, Jiandong Yu

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The mechanical properties of auxetic (negative Poisson's ratio) foam are studied and reviewed with different experimental methods. Developments in design, manufacture, test and analysis of auxetic foam and related composites are presented. Auxetic foam can be made by open-cell conventional PVC foam, through volumetric compressing and heating process successively. When cooling down to room temperature, the cellular micro structure of PVC foam has been turned out to be re-entranted, which means the ribs of each cell of the foam are protrude inward permanently due to the external mechanical and thermal effects. The new re-entranted structure opens out many interesting and …

Design And Optimization On Mobile Data Gathering In Wireless Sensor Networks, Miao Zhao

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

Wireless sensor networks (WSNs) have emerged as a new information-gathering paradigm for taking spatial and temporal measurements of a given set of real-word parameters. In these applications, sensors monitor the environment and route their sensing data back to a static data sink. As the routing task depends purely on sensors themselves, the sensors near the sink need to relay much more packets than the sensors far away from the sink. As the result, it would incur substantial and non-uniform energy consumption among sensors. Therefore, how to efficiently aggregate the information from scattered sensors, generally referred to as data gathering, is …

The Specific Interactions Between Dendritic Cells And Porphyromonas Gingivalis, Amir Emanuel Zeituni

Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions)

The broad objective of this dissertation is to elucidate the specific interactions between Porphyromonas gingivalis (P. gingivalis) and dendritic cells (DCs). P. gingivalis is a black pigmented, anaerobic, Gram-negative bacterium that is associated with most cases of chronic periodontitis. P. gingivalis expresses a myriad of virulence factors, most notably, fimbrial adhesins that enable it to bind to and invade host epithelial cells, endothelial cells, macrophages and DCs. While much is known about the 41 kDa major fimbria adhesins of P. gingivalis, the minor fimbriae have received little attention. The results presented here suggest that the minor fimbriae may serve as …