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Articles 661 - 690 of 1816

Full-Text Articles in Physical Sciences and Mathematics

Determining Feasibility Resilience: Set Based Design Iteration Evaluation Through Permutation Stability Analysis, James E. Ross May 2017

Determining Feasibility Resilience: Set Based Design Iteration Evaluation Through Permutation Stability Analysis, James E. Ross

Dissertations

The goal of robust design is to select a design that will still perform satisfactorily even with unexpected variation in design parameters. A resilient design will accommodate unanticipated future system requirements. Through studying the variations of system parameters through the use of multi objective optimization, a designer hopes to locate a robustly resilient design, which performs current mission well even with varying system parameters and is able to be easily repurposed to new missions. This ability to withstand changes is critical because it is common for the product of a design to undergo changes throughout its life cycle. This subject …


Krylov Subspace Spectral Methods For Pdes In Polar And Cylindrical Geometries, Megan Richardson May 2017

Krylov Subspace Spectral Methods For Pdes In Polar And Cylindrical Geometries, Megan Richardson

Dissertations

As a result of stiff systems of ODEs, difficulties arise when using time stepping methods for PDEs. Krylov subspace spectral (KSS) methods get around the difficulties caused by stiffness by computing each component of the solution independently. In this dissertation, we extend the KSS method to a circular domain using polar coordinates. In addition to using these coordinates, we will approximate the solution using Legendre polynomials instead of Fourier basis functions. We will also compare KSS methods on a time-independent PDE to other iterative methods. Then we will shift our focus to three families of orthogonal polynomials on the interval …


Polyisobutylene Telechelic Prepolymers By In Situ End-Quenching And Post-Polymerization Modifications, Bin Yang May 2017

Polyisobutylene Telechelic Prepolymers By In Situ End-Quenching And Post-Polymerization Modifications, Bin Yang

Dissertations

This volume focuses on the development of telechelic polyisobutylene (PIB) prepolymers by combining end-capping of living carbocationic polymerization of isobutylene (IB) with suitable reactants and post-polymerization modifications. Alkylation kinetics of PIB tert-chloride with alkoxybenzenes using either TiCl4 or AlCl3 were investigated. Quantitative para-position end-capped products were only achieved if the alkoxybenzene/AlCl3 molar ratio was greater than unity; while no such molar ratio is required for TiCl4, but the alkylation rate was slower than AlCl3 under the same conditions. Photopolymerization kinetics analysis of PIB triphenol tri(meth)acrylates with low and high Mns, …


Syntheses, Structures And Magnetic Properties Of Cyano-Bridged Transition Metal Compounds, Uma Prasad Mallik Apr 2017

Syntheses, Structures And Magnetic Properties Of Cyano-Bridged Transition Metal Compounds, Uma Prasad Mallik

Dissertations

To investigate the hypotheses, that systematically changing the electronic and relative sizes of tricyanido building blocks will tune magnetic properties of their cluster derivatives, we prepared two new tricyanido pyrazolylborate complexes, [NEt4][(Tp*Me)­Fe(CN)3]­·H2O and [NEt4]­[(Tp*Bn)­FeIII(CN)3]­·H2O·MeOH, and investigated their self-assembly. The new building blocks were prepared, structurally characterized, and their coordination chemistry explored to prepare small molecule-based magnetic materials.

Three bent trinuclear ferromagnetic cluster derivatives of {[(Tp*Me)­FeIII(CN)3][NiII(L)2]}·n(solvent) [L = …


Correspondence Between Multiwavelet Shrinkage/Multiple Wavelet Frame Shrinkage And Nonlinear Diffusion, Hanan Ali Alkhidhr Apr 2017

Correspondence Between Multiwavelet Shrinkage/Multiple Wavelet Frame Shrinkage And Nonlinear Diffusion, Hanan Ali Alkhidhr

Dissertations

There are numerous methodologies for signal and image denoising. Wavelet, wavelet frame shrinkage, and nonlinear diffusion are effective ways for signal and image denoising. Also, multiwavelet transforms and multiple wavelet frame transforms have been used for signal and image denoising. Multiwavelets have important property that they can possess the orthogonality, short support, good performance at the boundaries, and symmetry simultaneously. The advantage of multiwavelet transform for signal and image denoising was illustrated by Bui et al. in 1998. They showed that the evaluation of thresholding on a multiwavelet basis has produced good results. Further, Strela et al. have showed that …


Development And Evaluation Of Machine Learning Algorithms For Biomedical Applications, Turki Talal Turki Apr 2017

Development And Evaluation Of Machine Learning Algorithms For Biomedical Applications, Turki Talal Turki

Dissertations

Gene network inference and drug response prediction are two important problems in computational biomedicine. The former helps scientists better understand the functional elements and regulatory circuits of cells. The latter helps a physician gain full understanding of the effective treatment on patients. Both problems have been widely studied, though current solutions are far from perfect. More research is needed to improve the accuracy of existing approaches.

This dissertation develops machine learning and data mining algorithms, and applies these algorithms to solve the two important biomedical problems. Specifically, to tackle the gene network inference problem, the dissertation proposes (i) new techniques …


Big Data Analytics In Computational Biology And Bioinformatics, Kevin Byron Apr 2017

Big Data Analytics In Computational Biology And Bioinformatics, Kevin Byron

Dissertations

Big data analytics in computational biology and bioinformatics refers to an array of operations including biological pattern discovery, classification, prediction, inference, clustering as well as data mining in the cloud, among others. This dissertation addresses big data analytics by investigating two important operations, namely pattern discovery and network inference.

The dissertation starts by focusing on biological pattern discovery at a genomic scale. Research reveals that the secondary structure in non-coding RNA (ncRNA) is more conserved during evolution than its primary nucleotide sequence. Using a covariance model approach, the stems and loops of an ncRNA secondary structure are represented as a …


Mathematical Modeling Of Membrane Filtration, Pejman Sanaei Apr 2017

Mathematical Modeling Of Membrane Filtration, Pejman Sanaei

Dissertations

The purpose of this thesis is to formulate and investigate new mathematical models for membrane filtration. The work presented is divided into six chapters. In the first chapter the problem is introduced and motivated. In the second chapter, a new mathematical model for flow and fouling in a pleated membrane filter is presented. Pleated membrane filters are widely used in many applications, and offer significantly better surface area to volume ratios than equal area unpleated membrane filters. However, their filtration characteristics are markedly inferior to those of equivalent unpleated membrane filters in dead-end filtration. While several hypotheses have been advanced …


Protein Engineering Of Cota Laccase By Using Bacillus Subtilis Spore Display, Silu Sheng Apr 2017

Protein Engineering Of Cota Laccase By Using Bacillus Subtilis Spore Display, Silu Sheng

Dissertations

Spore display offers advantages over more commonly utilized microbe cell-surface display systems. For instance, protein-folding problems associated with the expressed recombinant polypeptide crossing membranes are avoided. Hence, a different region of protein space can be explored that previously was not accessible. In addition, spores tolerate many physical/chemical extremes. The aim is to improve pH stability using spore display. The maximum activity of CotA is between pH 4 and 5 for the substrate ABTS (ABTS = diammonium 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate)). However, the activity dramatically decreases at pH 4. The activity is not significantly altered at pH 5. CotA is used as a …


Viewability Prediction For Display Advertising, Chong Wang Apr 2017

Viewability Prediction For Display Advertising, Chong Wang

Dissertations

As a massive industry, display advertising delivers advertisers’ marketing messages to attract customers through graphic banners on webpages. Display advertising is also the most essential revenue source of online publishers. Currently, advertisers are charged by user response or ad serving. However, recent studies show that users barely click or convert display ads. Moreover, about half of the ads are actually never seen by users. In this case, advertisers cannot enhance their brand awareness and increase return on investment. Publishers also lose much revenue. Therefore, the ad pricing standards are shifting to a new model: ad impressions are paid if they …


Synthesis And Detection Of Dna Damage, Xun Gao Apr 2017

Synthesis And Detection Of Dna Damage, Xun Gao

Dissertations

The biological effects of DNA alkyl adducts are difficult to evaluate at the cellular level due to their instability. Synthesis of oligonucleotides that contain a single N7-alkylguanine has become a vital tool to achieve the above goal. However, the instability of N7-alkyguanines is not compatible with the phosphoramidite chemistry used by solid-phase oligonucleotide synthesis either. Development of chemically stable analogues of unstable DNA lesions enables accurate study of polymerase bypass. The design and successful synthesis of N7-hydroxyethyl-9-deaza-2′-deoxyguanosine and N7-oxoethyl-9-deaza-2′-deoxyguanosine as the stable analogues of N7-hydroxyethyl- 2'-deoxyguanosine and N7-oxoethyl-2′-deoxyguanosine, respectively, are reported. The synthesis of these two nucleosides whose N7 side …


Qualitative Modeling Of Chaotic Logical Circuits And Walking Droplets: A Dynamical Systems Approach, Aminur Rahman Apr 2017

Qualitative Modeling Of Chaotic Logical Circuits And Walking Droplets: A Dynamical Systems Approach, Aminur Rahman

Dissertations

Logical circuits and wave-particle duality have been studied for most of the 20th century. During the current century scientists have been thinking differently about these well-studied systems. Specifically, there has been great interest in chaotic logical circuits and hydrodynamic quantum analogs.

Traditional logical circuits are designed with minimal uncertainty. While this is straightforward to achieve with electronic logic, other logic families such as fluidic, chemical, and biological, naturally exhibit uncertainties due to their inherent nonlinearity. In recent years, engineers have been designing electronic logical systems via chaotic circuits. While traditional boolean circuits have easily determined outputs, which renders dynamical models …


Investigation Of New Learning Methods For Visual Recognition, Qingfeng Liu Apr 2017

Investigation Of New Learning Methods For Visual Recognition, Qingfeng Liu

Dissertations

Visual recognition is one of the most difficult and prevailing problems in computer vision and pattern recognition due to the challenges in understanding the semantics and contents of digital images. Two major components of a visual recognition system are discriminatory feature representation and efficient and accurate pattern classification. This dissertation therefore focuses on developing new learning methods for visual recognition.

Based on the conventional sparse representation, which shows its robustness for visual recognition problems, a series of new methods is proposed. Specifically, first, a new locally linear K nearest neighbor method, or LLK method, is presented. The LLK method derives …


Statistical Learning Methods For Mining Marketing And Biological Data, Jie Zhang Apr 2017

Statistical Learning Methods For Mining Marketing And Biological Data, Jie Zhang

Dissertations

Nowadays, the value of data has been broadly recognized and emphasized. More and more decisions are made based on data and analysis rather than solely on experience and intuition. With the fast development of networking, data storage, and data collection capacity, data have increased dramatically in industry, science and engineering domains, which brings both great opportunities and challenges. To take advantage of the data flood, new computational methods are in demand to process, analyze and understand these datasets.

This dissertation focuses on the development of statistical learning methods for online advertising and bioinformatics to model real world data with temporal …


Protecting Sensitive Data In Clouds Using Active Data Bundles And Agent-Based Secure Multi-Party Computation, Akram Y. Sarhan Apr 2017

Protecting Sensitive Data In Clouds Using Active Data Bundles And Agent-Based Secure Multi-Party Computation, Akram Y. Sarhan

Dissertations

Protection of data in cloud computing including distributed environments is a critical concern for many enterprises. This study proposes a solution that protects sensitive data outsourced to a cloud throughout their entire life cycle—both in the cloud as well as outside of the cloud (e.g., during transmission to or from the cloud). The solution enhances the existing data protection approach known as Active Bundle scheme, which uses a Trusted Third Party (ABTTP).

The Active Data Bundle (ADB) was formerly called an Active Bundle (AB). It is a software construct that encapsulates data, metadata, and a virtual machine (VM). The metadata …


Biosorption Of Pharmaceuticals And Noble Metals Nanoparticles By Algal Turf Communities, Haider Abid Faraj Apr 2017

Biosorption Of Pharmaceuticals And Noble Metals Nanoparticles By Algal Turf Communities, Haider Abid Faraj

Dissertations

Pharmaceuticals and nanoparticles are increasingly released into the aquatic ecosystem, while removing these contaminants from waters can be challenging. This study explores the use of periphytic algal turf communities to remove these contaminants. Initially algal turfs from different locations and aquatic systems were analyzed for pharmaceuticals commonly observed in wastewater outflows. Lab-grown turfs were exposed to a mixture of six representative pharmaceuticals of different functionality (acid, base, neutral and steroidal). Analysis of water column and the algal biomass showed pharmaceutical removal rates varied, specific to each pharmaceutical. Caffeine and estradiol had the highest removal rates while carbamazepine was not removed. …


Artificial Immune Systems: Applications, Multi-Class Classification, Optimizations, And Analysis, Brian Haroldo Schmidt Apr 2017

Artificial Immune Systems: Applications, Multi-Class Classification, Optimizations, And Analysis, Brian Haroldo Schmidt

Dissertations

The focus of this research is the application of the Artificial Immune System (AIS) paradigm to a new research area along with the modifications necessary to adapt it to a new problem. In the past 10 years, there has been much research into the use of various Machine Learning (ML) algorithms in Network Flow Traffic Classification. AIS algorithms have thus far not been applied to this problem. Because AIS algorithms have been used extensively for Network Intrusion Detection applications, which is a similar area of research, the motivation to extend them to the network flow classification problem is clear.

This …


Subgroup Analysis And Growth Curve Models For Longitudinal Data, Nichole Andrews Apr 2017

Subgroup Analysis And Growth Curve Models For Longitudinal Data, Nichole Andrews

Dissertations

In clinical trials and biomedical studies, treatments are compared to determine which one is effective against illness. Growth curve analysis can be beneficial in longitudinal biomedical studies, as we can evaluate the treatment effect on the response over time. The generalized growth curve model using polynomial regression is proposed for longitudinal data. An optimal degree for the polynomial is obtained using the BIQIF, an adaptation of the Bayesian information criterion. Quadratic inference functions are used to estimate the parameters of the model, which takes into account the fact that repeated measurements from the same subject are more likely to be …


Dft Investigations Of Hygrogen Storage Materials, Gang Wang Jan 2017

Dft Investigations Of Hygrogen Storage Materials, Gang Wang

Dissertations

Hydrogen serves as a promising new energy source having no pollution and abundant on earth. However the most difficult problem of applying hydrogen is to store it effectively and safely, which is smartly resolved by attempting to keep hydrogen in some metal hydrides to reach a high hydrogen density in a safe way. There are several promising metal hydrides, the thermodynamic and chemical properties of which are to be investigated in this dissertation. Sodium alanate (NaAlH4) is one of the promising metal hydrides with high hydrogen storage capacity around 7.4 wt. % and relatively low decomposition temperature of around 100 …


Detection Of Unknown Emerging Contaminants In Natural Water Using Tandem Mass Spectrometry, Qian Wang Jan 2017

Detection Of Unknown Emerging Contaminants In Natural Water Using Tandem Mass Spectrometry, Qian Wang

Dissertations

Recently, a great deal of concern has been given to the quality of drinking water. Lake Michigan is the drinking water source of Chicago area. It is very important that the quality of drinking water meets the standard setup by the EPA. However, there is a group of chemicals that are not being monitored regularly or are unknown to researchers and are the so-called emerging contaminants.

So the objective of this study is to using tandem-mass spectrometry to detect and identify emerging contaminants. Water samples were obtained along a few locations along the Chicago River and Lake Michigan. By using …


Mild Hydrofunctionalizations Of Olefins Using More Cost-Effective Metal Catalysts, Alexander James Villani-Gale Jan 2017

Mild Hydrofunctionalizations Of Olefins Using More Cost-Effective Metal Catalysts, Alexander James Villani-Gale

Dissertations

The focus of this dissertation is the study of alkene hydroaylation reactions. In the first chapter, a review of the relevant literature concerning zinc- and iron-catalyzed hydroarylation of unsaturated bonds is presented. In chapter two, the development of a zinc-catalyzed hydroarylation of alkenes is presented, which is quickly followed by a detailed investigation into the probable mechanism. Chapter three discusses the development of an iron/silver-catalyzed arene prenylation reaction, followed by the development of an iron/zinc-catalyzed arene prenylation reaction. The final section of chapter three discusses the adaptation of the iron/zinc-catalyzed arene prenylation into an undergraduate organic teaching laboratory.


Heterocycles Via The Pd-Catalyzed Heterofunctionalization Of Alkylidenecyclopropanes, Phillip Roman Lazzara Jan 2017

Heterocycles Via The Pd-Catalyzed Heterofunctionalization Of Alkylidenecyclopropanes, Phillip Roman Lazzara

Dissertations

Natural compounds are often used as inspiration for novel chemical structures that provide medicinal benefits to human health. The unique 3-dimentional structures of these molecules make the majority of them synthetic challenges for organic chemists. While there is great diversity among these molecules, many of these carbon-based compounds exhibit similar key structural features. One of the most common features amongst biologically active molecules is a rigid carbon ring bearing nitrogen or oxygen atoms, which are known as heterocycles. The structural rigidity of heterocycles helps properly align key interactions of the molecule with those of a specific protein, which causes the …


Spectroscopic And Spectro-Astrometric Analysis Of T Tauri Stars, Logan Ryan Brown Dec 2016

Spectroscopic And Spectro-Astrometric Analysis Of T Tauri Stars, Logan Ryan Brown

Dissertations

To understand our own solar origins, we must investigate the composition of the protoplanetary disk from which the solar system formed. To infer this, we study analogs to the early solar system called T Tauri stars. These objects are low-mass, pre-main sequence stars surrounded by circumstellar disks of material from which planets are believed to form. We present high-resolution, near-infrared spectroscopic data for the T Tauri stars DR Tau and AA Tau using NIRSPEC at the Keck II telescope. For DR Tau, a spectro-astrometric analysis was performed, obtaining sub-seeing spatial information on water emission. Alongside a disk model, we constrained …


The Synthesis And Characterization Of Photoluminescent Conjugated Frameworks Containing Silicon And Germanium, Douglas William Hammerstroem Dec 2016

The Synthesis And Characterization Of Photoluminescent Conjugated Frameworks Containing Silicon And Germanium, Douglas William Hammerstroem

Dissertations

Siloles and 9-heterofluorenes (Si, Ge) are conjugated π-electron systems containing Group 14 atoms which demonstrate unique properties such as high electron affinity, mobility, and bathochromically shifted optical spectra relative to their all-carbon analogs. This is due to their low-lying lowest-unoccupied molecular orbital (LUMO) which is resultant of the σ*-π* conjugation between the exocyclic groups at the Group 14 center and the butadiene unit of the ring. As a consequence, they have received considerable attention for their use as components for a wide variety of optical and electronic applications such as organic light emitting diodes (OLEDs), photovoltaic devices, field-effect transistors (FETs), …


Development Of An Hplc-Based Oligosaccharide Synthesizer, Salvatore Pistorio Dec 2016

Development Of An Hplc-Based Oligosaccharide Synthesizer, Salvatore Pistorio

Dissertations

Carbohydrates are the most abundant molecules on Earth. They are involved in a wide range of fundamental biological processes: anti-inflammation, immune response, joint lubrication, cell growth, antigenic determination. Carbohydrates are also held responsible for many damaging cellular processes, such as bacterial and viral infections, development of tumors, etc.. Therefore, the development of effective methods for the synthesis of complex carbohydrates has become a critical area of glycosciences. One challenge that stands out is the stereocontrol in the synthesis of glycosidic bonds, the linkage that serves as the only means to connect simple monosaccharides into complex oligomeric networks. Beyond this, the …


Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff Dec 2016

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …


Pedagogical Moves As Characteristics Of One Instructor’S Instrumental Orchestrations With Tinkerplots And The Ti-73 Explorer: A Case Study, James L. Kratky Dec 2016

Pedagogical Moves As Characteristics Of One Instructor’S Instrumental Orchestrations With Tinkerplots And The Ti-73 Explorer: A Case Study, James L. Kratky

Dissertations

Those supporting contemporary reform efforts for mathematics education in the United States have called for increased use of technologies to support student-centered learning of mathematical concepts and skills. There is a need for more research and professional development to support teachers in transitioning their instruction to better meet the goals of such reform efforts.

Instrumental approaches to conceptualizing technology use in mathematics education, arising out of the theoretical and empirical work in France and other European nations, show promise for use to frame studies on school mathematics in the United States. Instrumental genesis is used to describe the bidirectional and …


Crystallography And Magnetism Of Magnetocalorically Important Ni-Mn-X Based Heusler Alloys, Amila S. B. Madiligama Dec 2016

Crystallography And Magnetism Of Magnetocalorically Important Ni-Mn-X Based Heusler Alloys, Amila S. B. Madiligama

Dissertations

Ni-Mn-X Heusler alloys, demonstrating strong coupling between crystalline structure and magnetic state, were studied. They undergo field-induced, first-order transformations from a low symmetry martensite to a high-symmetry austenitic phase around room temperature. The substantial difference between the entropies of the two phases results in a large adiabatic temperature change, called “Giant Magnetocaloric Effect (GMCE)”. Consequently, these alloys are promising refrigerants for near-room temperature cooling systems. This magnetic cooling is an energy-efficient and eco-friendly technology.

Crystalline structures and magnetic states of these alloys, which determine their magnetocaloric performances, highly depend on their composition. To examine new paths to optimize their magnetocaloric …


Fast Method Of Particular Solutions For Solving Partial Differential Equations, Anup Raja Lamichhane Dec 2016

Fast Method Of Particular Solutions For Solving Partial Differential Equations, Anup Raja Lamichhane

Dissertations

Method of particular solutions (MPS) has been implemented in many science and engineering problems but obtaining the closed-form particular solutions, the selection of the good shape parameter for various radial basis functions (RBFs) and simulation of the large-scale problems are some of the challenges which need to overcome. In this dissertation, we have used several techniques to overcome such challenges.

The closed-form particular solutions for the Matérn and Gaussian RBFs were not known yet. With the help of the symbolic computational tools, we have derived the closed-form particular solutions of the Matérn and Gaussian RBFs for the Laplace and biharmonic …


Preparation Of Aminoalcohols And Their Application For The Synthesis Of Heterocycles And As Potential Sensors For Nerve Agents, David L. Sellers Dec 2016

Preparation Of Aminoalcohols And Their Application For The Synthesis Of Heterocycles And As Potential Sensors For Nerve Agents, David L. Sellers

Dissertations

Oxazoles and oxazolines are important heterocyclic scaffolds commonly used in pharmaceuticals and optoelectronic materials. Traditionally these heterocyclic compounds are prepared by condensation methodology that suffers from poor reactivity when using electron deficient or sterically crowded reaction partners. Condensation methods also exhibit low tolerance of many functional groups as the reactions typically use strong acids and high temperatures. This dissertation describes an alternate strategy for the formation of these compounds by employing an epoxide opening followed by oxidation to form these heterocyclic compounds.

Epoxide opening reactions with primary aliphatic, allylic, and benzylic amines, aminolysis reactions, often achieve high yields regardless of …