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2015

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Articles 12031 - 12060 of 12617

Full-Text Articles in Physical Sciences and Mathematics

Spectrally Accurate Quadratures For Evaluation Of Layer Potentials Close To The Boundary For The 2d Stokes And Laplace Equations, Alex Barnett, Bowei Wu, Shravan Veerapaneni Jan 2015

Spectrally Accurate Quadratures For Evaluation Of Layer Potentials Close To The Boundary For The 2d Stokes And Laplace Equations, Alex Barnett, Bowei Wu, Shravan Veerapaneni

Dartmouth Scholarship

Dense particulate flow simulations using integral equation methods demand accurate evaluation of Stokes layer potentials on arbitrarily close interfaces. In this paper, we generalize techniques for close evaluation of Laplace double-layer potentials in [J. Helsing and R. Ojala, J. Comput. Phys., 227 (2008), pp. 2899--2921]. We create a “globally compensated” trapezoid rule quadrature for the Laplace single-layer potential on the interior and exterior of smooth curves. This exploits a complex representation, a product quadrature (in the style of Kress) for the sawtooth function, careful attention to branch cuts, and second-kind barycentric-type formulae for Cauchy integrals and their derivatives. Upon …


Some Multivariate Process Capability Indices, Rachel Lee Goodwin Jan 2015

Some Multivariate Process Capability Indices, Rachel Lee Goodwin

Mathematics Dissertations

Process capability indices (PCIs) play an important role in the field of Statistical Process Control. Prior to the last 25 years, PCIs had been formulated to assess the quality of a single product characteristic. Product quality, however, is typically dependent on several related variables. Therefore, there is a great need for multivariate process capability indices (MPCIs). The quality of a product is almost always determined from sample data. Thus, it is imperative that an MPCI has a corresponding confidence interval. In that way, conclusions may be drawn regarding the capability of the process that makes that product. Of the MPCIs …


Property D Cyclic Neofields, Scott Lacy Jan 2015

Property D Cyclic Neofields, Scott Lacy

Mathematics Dissertations

In 1948 L. J. Paige introduced the notion of a neofield (N,\oplus,\cdot) as a set N with two binary operations, generally referred to as addition (\oplus) and multiplication (\cdot) such that (N,\oplus) is a loop with identity 0 and (N-\{0\},\cdot) is a group, with both left and right distribution of multiplication over addition. The neofield was considered a generalization of a field and its application was for the coordinatizing of projective planes and related geometry problems. In 1967 A.D. Keedwell introduced the notion of property D cyclic neofields in relation to his study of latin squares and their application to …


The Influence Of Dynamic Visualization On Undergraduate Calculus Learning, Julie Marie Skinner Sutton Jan 2015

The Influence Of Dynamic Visualization On Undergraduate Calculus Learning, Julie Marie Skinner Sutton

Mathematics Dissertations

The urgent need in the United States to produce an additional one million graduates in the areas of science, technology, engineering and mathematics and previous research into why students choose to abandon their quest to earn such degrees motivates exploration of the appropriate use of technology that engages students in the first-year calculus classroom. Technology enhances our capacity to incorporate visualization into the teaching of mathematics, yet research suggests that high school mathematics students who prefer to visualize when solving mathematics tasks are not the “super stars” of their classrooms. In this qualitative study, nine students, five of whom prefer …


Advancements And Applications Of Nonstandard Finite Difference Methods, Daniel Wood Jan 2015

Advancements And Applications Of Nonstandard Finite Difference Methods, Daniel Wood

Mathematics Dissertations

A class of dynamically consistent numerical methods are analyzed for general n-dimensional productive-destructive systems (PDS). Using this analysis, a methodology for constructing positive and elementary stable nonstandard numerical methods is established. The nonstandard approach results in qualitatively superior numerical methods when compared to the standard ones. PDS model a wide range of dynamical systems, including ones with biological, chemical and physical interactions. Building upon this, a nonstandard finite difference method for solving autonomous dynamical systems with positive solutions is constructed. The proposed numerical methods are computationally efficient and easy to implement. Several examples are given which show that the numerical …


On M-Inverse Loops And Quasigroups Of Order N With A Long Inverse Cycle., Carl Edward Looney Jan 2015

On M-Inverse Loops And Quasigroups Of Order N With A Long Inverse Cycle., Carl Edward Looney

Mathematics Dissertations

In 2002, A.D Keedwell and V.A Sherbacov introduced the concept of finite m-inverse quasigroups with long inverse cycles. Keedwell and Sherbacov observed that finite m-inverse loops and quasigroups with a long inverse cycle could be useful in the study of cryptology. Keedwell and Sherbacov studied the existence of these algebraic structures by determining if a Cayley table of the elements of such structures could be constructed. They showed that m-inverse loops of order 9 with a long inverse cycle do not exist for m = 2; 4 and 6; thus, there do not exist 2,4, or 6 inverse-quasigroups of order …


Numerical Methods For Spontaneous And Evoked Glutamate Release, Justin Shane Blackwell Jan 2015

Numerical Methods For Spontaneous And Evoked Glutamate Release, Justin Shane Blackwell

Mathematics Dissertations

As synapses are responsible for the majority of neuron communications in the brain, the events of evoked and spontaneous synaptic vesicle release/fusion are key features of all synaptic current. These release events typically activate receptors within a single postsynaptic site and give rise to miniature postsynaptic currents through activations of $N$-methyl-$D$-asparate (NMDA) and $\alpha$-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, and therefore, they have been extremely instrumental in neurotransmissions. In this paper we will use a mathematical model to simulate spontaneous and evoked neurotransmission resulted from glutamate release within a synapse. Among several issues that modeling can provide quantitative assessment, the issue of …


Nilpotent Lie Algebras And Nilmanifolds Constructed From Graphs, Allie Denise Ray Jan 2015

Nilpotent Lie Algebras And Nilmanifolds Constructed From Graphs, Allie Denise Ray

Mathematics Dissertations

The interaction between graph theory and differential geometry has been studied previously, but S. Dani and M. Mainkar brought a new approach to this study by associating a two-step nilpotent Lie algebra (and thereby a two-step nilmanifold) with a simple graph. We prsesent a new construction that associates a two-step nilpotent Lie algebra to an arbitrary (not necessarily simple) directed edge-labeled graph. We then use properties of a Schreier graph to determine necessary and sufficient conditions for this Lie algebra to extend to a three-step nilpotent Lie algebra.After considering the curvature of the two-step nilmanifolds associated with the graphs, we …


Understanding The Contractional History Of Surprise Canyon, California Through Digital Field Mapping, 3d Modeling, And U-Pb Zircon Geochronology, Joshua A. Cobb Jan 2015

Understanding The Contractional History Of Surprise Canyon, California Through Digital Field Mapping, 3d Modeling, And U-Pb Zircon Geochronology, Joshua A. Cobb

Open Access Theses & Dissertations

Detailed digital mapping of lower-middle Surprise Canyon has revealed a more complex structure than previously interpreted. Rock units derived from the metamorphosed equivalents of the Pahrump Group exposed in Surprise Canyon display juxtapositions inconsistent with stratigraphic variations suggested in previous studies. This study proposes a contractional history of the central Panamint Mountains defined by two kinematically distinct and geochronologically constrained deformation events. D1 is characterized by a shallow dipping, NNW striking L and LS tectonite fabric ubiquitously observed in all metasedimentary and basement units. F1 folds are mesoscopic in scale and isoclinal with an axial planar S1 foliation. A prominent …


Transition States And Modeling For Co9s8/Mos2 Catalysis, Gabriel Angel Gonzalez Jan 2015

Transition States And Modeling For Co9s8/Mos2 Catalysis, Gabriel Angel Gonzalez

Open Access Theses & Dissertations

Transition state computational studies of the sulfur removal from dibenzothiophene (DBT) molecule have herein been performed considering the Co9S8/MoS2 interface existing on unsupported Co/MoS2 catalysts. The linear synchronous transit (LST) and quadratic synchronous transit (QST) methods integrated in a density functional theory (DFT) program such as Dmol3 were used for the calculations of energy barriers of the transition states. Three different configurations present on the Co9S8/MoS2 interface have been envisaged as possible catalytic sites: sulfur-sulfur (S, S) sites, and molybdenum-sulfur (Mo, S) and molybdenum-molybdenum (Mo, Mo) edge sites. This study revealed that the (Mo, Mo) edge site is the most …


The Meteorological Conditions Affecting The Propagation Of Respiratory Diseases, Rosette Maria Gonzalez Jan 2015

The Meteorological Conditions Affecting The Propagation Of Respiratory Diseases, Rosette Maria Gonzalez

Open Access Theses & Dissertations

Valley Fever, also known as Coccidioidomycosis, is endemic of the US Southwest. In 2012 this disease was the second most-reported disease in Arizona, according to the New Yorker January 2014 edition. The Paso Del Norte Region (PdN) is a semi-arid region with significant agricultural acreage and Valley Fever is known to be a threat in this region. It is our goal in this Thesis work to apply an existing PBL Height Program (e.g., Liu, et.al.) to the Paso Del Norte Region (PdN) to study the effect it has in the transmission of Valley Fever. Obtaining the PBLH as it evolves …


Multi-Expert Multi-Criteria Decision Making, Joel Henderson Jan 2015

Multi-Expert Multi-Criteria Decision Making, Joel Henderson

Open Access Theses & Dissertations

Expert analysis and decisions are highly valued assets in a wide variety of fields, from social services to grant funding committees. However, the use of experts can be prohibitive due to either lack of availability or cost. As such, it is desirable to be able to replicate such decisions. However, there are many obstacles that impede an accurate simulation of expert decisions. For example, despite looking at the same information, two experts may disagree on the decisions. In addition, a single expert may make inconsistent decisions across similar scenarios.

In this work, we focus on multi-criteria decision making and in …


Transition Metal Carbide (Tmc) Novel Materials For Novel Catalytic Applications, Svetlana Lagoykina Jan 2015

Transition Metal Carbide (Tmc) Novel Materials For Novel Catalytic Applications, Svetlana Lagoykina

Open Access Theses & Dissertations

Transition metal carbides (TMC) constitute a diverse class of materials and traditionally have many technological applications. TMC became a subject of extensive research since 1973, when their platinum -like properties were discovered. They demonstrated high catalytical activity and selectivity in a variety of chemical reaction and have potential for some novel catalytic application.

This research is an effort to design new high effective, selective and stable bimetal or alkali promoted TMC catalyst. After extensive theoretical research a wide range of TMC, including bimetal and alkali promoted carbides, were synthesized by different methods. All solids were characterized by XRD and microscopy. …


Ac-Susceptibility Investigations Of Superspin Blocking And Freezing In Interacting Magnetic Nanoparticle Ensembles, Joshua Logan Morris Jan 2015

Ac-Susceptibility Investigations Of Superspin Blocking And Freezing In Interacting Magnetic Nanoparticle Ensembles, Joshua Logan Morris

Open Access Theses & Dissertations

We have investigated the effect of dipolar interactions on the superspin blocking and freezing of 10 nm average size Fe3O4 magnetic nanoparticle ensembles. Our dynamic susceptibility data reveals a two-regime behavior of the blocking temperature, TB, upon diluting a Fe3O4/hexane magnetic nanoparticle fluid. As the nanoparticle volume ratio, Phi, is reduced from an as-prepared reference Phi = 1 to Phi = 1/96, the blocking temperature decreases from 46.1 K to 34.2 K, but higher values reenter upon further diluting the magnetic fluid to Phi = 1/384 (where TB = 42.5 K). We show that cooling below TB within the higher …


Ac-Susceptibility And Epr Investigations Of Superspin Dynamics In Magnetite Nanoparticles, Alex D. Price Jan 2015

Ac-Susceptibility And Epr Investigations Of Superspin Dynamics In Magnetite Nanoparticles, Alex D. Price

Open Access Theses & Dissertations

In this investigation we use two complementary techniques to distinguish between superparamagnetic blocking (SPB) and superspin-glass (SSG) freezing phenomena in magnetite nanoparticles. While these manifestations of the superspin dynamics are fundamentally different, they have similar "signatures", especially in dc-magnetization experiments. Even if ac-susceptibility measurements are employed, careful use of mathematical models to analyze the data are needed to uncover which type of phenomena (SPB or SSG freezing) occurs within the material. Yet, by utilizing electron paramagnetic resonance (EPR) on a 10 nm Fe3O4 nano-powder as well as on a ferrofluid (based on the same nanoparticle ensemble) we found a very …


Heat Absorption Analysis By Falling Particles At High Temperatures For Concentrating Solar Power Systems, Arturo Sepulveda Fernandez Jan 2015

Heat Absorption Analysis By Falling Particles At High Temperatures For Concentrating Solar Power Systems, Arturo Sepulveda Fernandez

Open Access Theses & Dissertations

High temperature Heat Transfer Fluid (HTF) with Thermal Energy Storage (TES) for the Concentrated Solar Power (CSP) technology can provide a large and relatively cheaper storage option, as opposed to limited and expensive electrical battery storage with PV technology, and hence, it has potential to maintain a constant production when no sunlight is available. Research of material like aluminum, silicon, graphite could be potential candidates to work as thermal energy storage. Currently, nitrate and chloride molten salts are widely used as the TES medium for a CSP plant. However, molten salt, especially chlorides, must be handled carefully at high temperature …


Stochastic Differential Equation Applied To High Frequency Data Arising In Geophysics And Other Disciplines, Osei Kofi Tweneboah Jan 2015

Stochastic Differential Equation Applied To High Frequency Data Arising In Geophysics And Other Disciplines, Osei Kofi Tweneboah

Open Access Theses & Dissertations

Estimating future seismic hazards of a region constitutes an important study many scholars have shown a renewed interest in the past few decades. A good estimation of the seismic hazard in a region requires predicting the location and magnitude of future seismic events. As the knowledge of the geophysical mechanisms that drive seismic events have increased, so have the corresponding mathematical model representations.

This Thesis is devoted to the study of modeling geophysical data. We propose a stochastic differential equation arising on the superposition of independent Ornstein-Uhlenbeck processes driven by a Gamma process.

Superposition of independent Gamma Ornstein-Uhlenbeck processes offers …


Optimization Schemes For The Inversion Of Bouguer Gravity Anomalies, Azucena Zamora Jan 2015

Optimization Schemes For The Inversion Of Bouguer Gravity Anomalies, Azucena Zamora

Open Access Theses & Dissertations

Data sets obtained from measurable physical properties of the Earth structure have helped advance the understanding of its tectonic and structural processes and constitute key elements for resource prospecting. 2-Dimensional (2-D) and 3-D models obtained from the inversion of geophysical data sets are widely used to represent the structural composition of the Earth based on physical properties such as density, seismic wave velocities, magnetic susceptibility, conductivity, and resistivity. The inversion of each one of these data sets provides structural models whose consistency depends on the data collection process, methodology, and overall assumptions made in their individual mathematical processes. Although sampling …


Development Of 3-D Shear Wave Models Using A Multi-Objective Optimization Scheme, Lennox Emmanuel Thompson Jan 2015

Development Of 3-D Shear Wave Models Using A Multi-Objective Optimization Scheme, Lennox Emmanuel Thompson

Open Access Theses & Dissertations

Evidence of geologic activity still occurring in Rio Grande Rift (RGR) includes quaternary faulting, seismicity, and widening at a small rate. We map the crustal thickness and seismic velocity ratio to create crustal model cross sections that highlights the regional extension of the Southern Rio Grande Rift (SRGR). Specifically, we compute receiver functions and receiver function stacks for 147 USArray and previously collected data, and interpolate the crustal and velocity results using a kriging interpolation scheme. By incorporating gravity, magnetics, receiver functions, velocity models, and the interpretation of seismic reflection/refraction data, we produce a constrained crustal model that characterizes the …


The Role Of Collaborative Ontology Development In The Knowledge Negotiation Process, Norma Rivera Jan 2015

The Role Of Collaborative Ontology Development In The Knowledge Negotiation Process, Norma Rivera

Open Access Theses & Dissertations

Interdisciplinary research (IDR) collaboration can be defined as the process of integrating experts' knowledge, perspectives, and resources to advance scientific discovery. The flourishing of more complex research problems, together with the growth of scientific and technical knowledge has resulted in the need for researchers from diverse fields to provide different expertise and points of view to tackle these problems. These collaborations, however, introduce a new set of "culture" barriers as participating experts are trained to communicate in discipline-specific languages, theories, and research practices. We propose that building a common knowledge base for research using ontology development techniques can provide a …


Challenges In Assessing College Students' Conception Of Duality: The Case Of Infinity, Grace Olutayo Babarinsa-Ochiedike Jan 2015

Challenges In Assessing College Students' Conception Of Duality: The Case Of Infinity, Grace Olutayo Babarinsa-Ochiedike

Open Access Theses & Dissertations

Interpreting students' views of infinity posits a challenge for researchers due to the dynamic nature of the conception. There is diversity and variation among students' process-object perceptions. The fluctuations between studentsâ?? views however reveal an undeveloped duality conception. This study examined college students' conception of duality in understanding and representing infinity with the intent to design strategies that could guide researchers in categorizing students' views of infinity into different levels.

Data for the study were collected from N=238 college students enrolled in Calculus sequence courses (Pre-Calculus, Calculus I through Calculus III) at one of the southwestern universities in the U.S. …


Salt And Mineral Recovery From High Salinity Waters, Osvaldo Alejandro Broesicke Jan 2015

Salt And Mineral Recovery From High Salinity Waters, Osvaldo Alejandro Broesicke

Open Access Theses & Dissertations

Natural salt springs in the Salt Fork Basin in Crosby County, Texas, result in the natural salt pollution of the Brazos River, rendering it unusable for most potable purposes. Previous research indicates that by intercepting the source of the pollution, water quality of the Brazos River can be greatly improved. This paper investigates and assesses two strategies for salt and mineral recovery using natural brine collected from the Salt Fork Basin, the first of which is presented in a separate work.

The research described in this paper evaluates the potential of a desulfation, soda-caustic softening, acidification/decarbonation, and evaporation process to …


Study Of A Directly Heated Oxy-Fuel Supercritical Power Generation System, A S M Arifur Rahim Chowdhury Jan 2015

Study Of A Directly Heated Oxy-Fuel Supercritical Power Generation System, A S M Arifur Rahim Chowdhury

Open Access Theses & Dissertations

The Directly heated supercritical oxy-fuel gas turbines have the potential to become an important addition to current power generation systems. They provide a higher thermal efficiency and more effective carbon capture techniques than existing gas turbines. Due to the higher density of the working fluids, the turbomachinery size in these systems can be reduced significantly; this will facilitate to minimize the operational cost. To achieve supercritical working fluid at the turbine inlet combustion needs to be conducted under enormous amounts of pressure; these values are is about 10 times those found in the present gas turbines. Additionally, existing material operational …


Arizona Fissures: Unique And Possibly Dangerous?, Georgia Miller Jan 2015

Arizona Fissures: Unique And Possibly Dangerous?, Georgia Miller

A with Honors Projects

Fissures are cracks in the earth that form from stretching and pull-apart of geologic materials near earth’s surface. They generally form in areas that experience frequent earthquake and volcanic activity; areas with active tectonics. Recently discovered fissures in Arizona are different, as they form from pumping of subsurface gas and water resources. In the UK, similar but also slightly different processes are happening. In this region, instability causes more rapid and more frequent fissure formation due to more active tectonic processes. Therefore, fissures in the UK are a more common occurrence than those in Arizona. Fissures in both locations are …


Ieee Access Special Section Editorial: Recent Advances In Software Defined Networking For 5g Networks, Mugen Peng, Tao Huang, Y. Richard Yu, Jianli Pan Jan 2015

Ieee Access Special Section Editorial: Recent Advances In Software Defined Networking For 5g Networks, Mugen Peng, Tao Huang, Y. Richard Yu, Jianli Pan

Computer Science Faculty Works

No abstract provided.


Nanomechanical And Morphological Characterization Of Tungsten Trioxide (Wo3) Thin Films Grown By Atomic Layer Deposition, M. A. Mamun, K. Zhang, H. Baumgart, A. A. Elmustafa Jan 2015

Nanomechanical And Morphological Characterization Of Tungsten Trioxide (Wo3) Thin Films Grown By Atomic Layer Deposition, M. A. Mamun, K. Zhang, H. Baumgart, A. A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

This study investigates the nanomechanical properties and surface morphology of tungsten oxide WO3thin films deposited on p-type Si(100) substrates using atomic layer deposition (ALD) technology with 2000 ALD deposition cycles at a growth temperature of 300°C and annealed at different temperatures. The samples were further furnace annealed at 500, 600 and 700°C for 60 min. The influence of the deposition process on the structure and properties of the WO3 films is discussed, presented and correlated to the characteristic features of the ALD technique. The results depict significant difference in the hardness and modulus measurements between the as …


Romania's Participation To The European Assessment Project Titled Hyunder, Multi-Criterial Analyses Of Salt Cavern Locations, Ioan Iordache, Dorin Schitea, Adriana Marinoiu, Mihaela Buga, Mihai Balan, Ioan Stefanescu, Adrian Gheorghe, Mihaela Iordache, Viviana Cigolotti (Ed.), Chiara Barchiesi (Ed.), Michela Chianella (Ed.) Jan 2015

Romania's Participation To The European Assessment Project Titled Hyunder, Multi-Criterial Analyses Of Salt Cavern Locations, Ioan Iordache, Dorin Schitea, Adriana Marinoiu, Mihaela Buga, Mihai Balan, Ioan Stefanescu, Adrian Gheorghe, Mihaela Iordache, Viviana Cigolotti (Ed.), Chiara Barchiesi (Ed.), Michela Chianella (Ed.)

Engineering Management & Systems Engineering Faculty Publications

The scope of the work is to assess the potential, the actors and relevant business cases for large scale storage of renewable electricity by hydrogen underground storage in Romania. This presentation intends to provide a picture of the multi-criterial analyses of salt cavern locations in Romania.

The energy sector is facing with the necessity to store large energy quantities for short to long term in order to adapt to the increasingly intermittent renewable energy. The results of this presentation have originated from an ongoing European assessment project by the name of HyUnder (FCH JU, grant 303417) regarding utilization of salt …


Learning By Doing - Energy Systems Management, Nima Shahriari, Adrian V. Gheorghe Jan 2015

Learning By Doing - Energy Systems Management, Nima Shahriari, Adrian V. Gheorghe

Engineering Management & Systems Engineering Faculty Publications

Climate change concerns have confronted energy policy makers by unprecedented challenges in the 21st century. Revolution of renewable energy technologies, as well as more efficient energy systems, has been promising in the context of global warming. However, these technologies are not maturing and chaning. Consequently planning for development of these resources requires dealing with various multidisciplinary research questions such as financial feasibility of renewable energy projects. Nevertheless, there is considerable lack of education programs offering multidisciplinary approach for addressing the current energy challenges. Based on the 21st evolving energy landscape, an interdisciplinary graduate certificate course work was designed at Old …


Engineering Analytics: Research Into The Governance Structure Needed To Integrate The Dominant Design Methodologies, Teddy Steven Cotter Jan 2015

Engineering Analytics: Research Into The Governance Structure Needed To Integrate The Dominant Design Methodologies, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2014, Cotter (2014) explored the current state of engineering design, identified the dominate approaches to engineering design, discussed potential contributions from the new field of data analytics to engineering design, and proposed an Engineering Analytics framework that integrates the dominate engineering design approaches and data analytics within a human-intelligence/machine-intelligence (HI-MI) design architecture. This paper reports research applying ontological engineering to integrate the dominate engineering design methodologies into a systemic engineering design decision governance architecture.


Statistical Engineering: A Causal-Stochastic Modeling Research Update, Teddy Steven Cotter Jan 2015

Statistical Engineering: A Causal-Stochastic Modeling Research Update, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2012, Cotter (2012) summarized prior works that led to the proposal for statistical engineering, identified the gaps in knowledge that statistical engineering needs to address, explored additional gaps in knowledge not addressed in the prior works, set forth a working definition of and body of knowledge for statistical engineering, and set forth proposals of potential systems contributions the Engineering Management profession could make toward the development of statistical engineering. In 2014, the ASQ Statistics Division, DOT&E, NASA, and IDA co-sponsored a Statistical Engineering Agreement to jointly research development of the discipline of statistical engineering. The statistics community …