Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2015

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 481 - 510 of 9578

Full-Text Articles in Physical Sciences and Mathematics

Fabrication, Characterization, And Application Of Carbon Nanoparticles For The Detection Of Heavy Metal Ions In Aqueous Media, Aaron Michael Simpson Dec 2015

Fabrication, Characterization, And Application Of Carbon Nanoparticles For The Detection Of Heavy Metal Ions In Aqueous Media, Aaron Michael Simpson

Graduate Theses/Dissertations

This research set out to develop a method for producing Carbon nanoparticles (CNPs) from glycerol and use them to detect Cu2+, Hg2+, and Pb2+ ions in aqueous solution. Three synthesis methods were developed using the following mixtures: (1) glycerol and silica, (2) glycerol, silica, and H3PO4, and (3) glycerol with H3PO4. The structure of the particles was characterized using a variety of spectroscopic techniques. Size distributions were obtained from scanning electron microscopy images. The particles were spherical with average diameters of 66, 58, and 89 nm respectively and believed to consist of a carbon core with carboxylic acid and alcohol …


An Enantiodivergent Synthesis Of CΑ-Methyl Nipecotic Acid Analogues From δ-Lactam Derivatives Obtained Through A Highly Stereoselective Cyclization Strategy, Souvik Banerjee, Emily R. Vogel, Daniel Hinton, Michael Sterling, Douglas S. Masterson Dec 2015

An Enantiodivergent Synthesis Of CΑ-Methyl Nipecotic Acid Analogues From δ-Lactam Derivatives Obtained Through A Highly Stereoselective Cyclization Strategy, Souvik Banerjee, Emily R. Vogel, Daniel Hinton, Michael Sterling, Douglas S. Masterson

Faculty Publications

A stereoselective and enantiodivergent strategy for the construction of δ-lactams is described. The strategy utilizes chiral malonic esters prepared from enantiomerically enriched mono esters of disubstituted malonic acid. A cyclization occurs with the selective displacement of a substituted benzyl alcohol as the leaving group. The resulting δ-lactams are then converted into nipecotic acid analogues using straightforward transformations. The resulting nipecotic acid analogues proved capable organocatalysts in Mannich reactions.


The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic Dec 2015

The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic

Biology Theses

Soil respiration, from plant roots and soil microbes, accounts for 60 – 80 percent of total ecosystem respiration, with the microbial component contributing approximately 54 percent. Global climate trends resulting from CO2 emissions include increased soil temperatures and changes in precipitation regimes resulting in less frequent, more intense rainfall events. Soil temperature and moisture availability drive soil respiration rates, but how they impact the microbial respiration is poorly qualified. I investigated how the soil microbial community responds to changes in temperature and moisture availability in a laboratory based experiment. Soils from a mixed hardwood forest under two thermal regimes …


Constructions And Isomorphism Types Of Images, Jessica Luna Ramirez Dec 2015

Constructions And Isomorphism Types Of Images, Jessica Luna Ramirez

Electronic Theses, Projects, and Dissertations

In this thesis, we have presented our discovery of true finite homomorphic images of various permutation and monomial progenitors, such as 2*7: D14, 2*7 : (7 : 2), 2*6 : S3 x 2, 2*8: S4, 2*72: (32:(2S4)), and 11*2 :m D10. We have given delightful symmetric presentations and very nice permutation representations of these images which include, the Mathieu groups M11, M12, the 4-fold cover of the Mathieu group M22, 2 x …


Synthesis Of Medicinally Relevant Thiazolyl Aryl Ketones Under Mild Conditions, Danielle M. Gardner Dec 2015

Synthesis Of Medicinally Relevant Thiazolyl Aryl Ketones Under Mild Conditions, Danielle M. Gardner

Health, Human Performance and Recreation Undergraduate Honors Theses

Purpose: The growing amount of clinical resistance observed in current antifungal drugs and in anti-HIV pharmaceuticals is a concern in the medical community. The purpose of this study is to develop a mild synthetic process for biomedically relevant thiazolyl aryl ketones that can be used to develop antifungal and anti-HIV drugs. We hypothesized that the proposed synthetic technique would be more efficient, produce fewer unwanted byproducts, and be more tolerant of functional groups than existing methods.

Methods: Prior to each of the ketone reactions, the necessary salt was synthesized by mixing thiazole and 9-bromofluorene neat in a reaction tube heated …


Alkali-~Activated Fly Ash Binders: Feasibility As A Sustainable Alternative To Ordinary Portland Cement For Pre-~Cast Systems, Kimberly Sierra Dec 2015

Alkali-~Activated Fly Ash Binders: Feasibility As A Sustainable Alternative To Ordinary Portland Cement For Pre-~Cast Systems, Kimberly Sierra

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fresh, load-dependent, transport, and durability properties of alkali-activated fly ash mortars were studied. The influences of activator concentration, solution-to-binder ratio, curing condition, activator type, and sodium silicate-to-total solution ratio on the properties of the studied alkali-activated mortars were examined. This study was divided in two phases. The first phase dealt with the use of sodium hydroxide as the sole activator. The second phase of the study was divided into two parts, both of which used a combination of sodium hydroxide and sodium silicate as the activator solution. Part I of phase II used elevated temperature curing conditions, whereas part II …


The Visual Framing Of The Three Cycles Of Climate Control In The New York Times 1851 To Present, Jason Lee Thompson Dec 2015

The Visual Framing Of The Three Cycles Of Climate Control In The New York Times 1851 To Present, Jason Lee Thompson

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research explored the visual framing of climate control in The New York Times through three cycles of media history. Although no peer-reviewed study has explored this specific topic, a wealth of prior communication articles on both the visual and textual aspects of climate change and geoengineering in the media was mined in order to discover the frames present. Once the visual frames of climate control (war, fix, people, and impacts) were revealed a content analysis was conducted in order to see which frame elements were most and least frequent considering the images of climate control. When combining all three …


Architectural Form, Orientation, And Energy For Residential Design In The Southern Nevada Region., Ludwing Vaca Dec 2015

Architectural Form, Orientation, And Energy For Residential Design In The Southern Nevada Region., Ludwing Vaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the population increase, the high demand of energy from the residential sector, as well as the harsh weather conditions of the Las Vegas region, there needs to be careful consideration in the design of new homes. Energy efficiency in a single family residential building can be augmented early in the design process by careful consideration of the building form and orientation. A systematic investigation and analysis was taken to study the effects of five building forms and different orientations along the cardinal points using the software BEopt version 2.4.0.1. To connect the study to real world circumstances, a residential …


The Classical Theory Of Rearrangements, Monica Josue Agana Dec 2015

The Classical Theory Of Rearrangements, Monica Josue Agana

Boise State University Theses and Dissertations

One type of conditionally convergent series that has long been considered by mathematicians is the Alternating Harmonic Series and its sum under various types of rearrangements. The purpose of this thesis is to introduce results from the classical theory of rearrangements dating back to the 19th and early 20th century. We will look at results by mathematicians such as Ohm, Riemann, Schlömilch, Pringsheim, and Sierpiński. In addition, we show examples of each classical result by applying the Alternating Harmonic Series under the different types of rearrangements, and also introducing theorems by Lévy and Steinitz, and Wilczyński which are modern extensions …


Poisson Versus Negative Binomial Regression In The Analysis Of Count Data, Barbie Ann L. Bugna Dec 2015

Poisson Versus Negative Binomial Regression In The Analysis Of Count Data, Barbie Ann L. Bugna

Dissertations

Commonly used tests for treatment effect in kx2 frequency data are Poisson regression, negative binomial regression, and Cochran-Mantel-Haentzel. In practice, Poisson regression or CMH is used as default, and NB regression is used only when there is reason to believe the data has overdispersion beyond what is expected of Poisson counts.

We show that the Poisson regression is sensitive to the Poisson assumption, and does not maintain its size in the presence of overdispersion. In particular, it tends to interpret overdispersion as significant treatment effect. Thus there is a need for a reliable pretest for the Poisson assumption. A commonly …


Design And Synthesis Of New Non-Steroidal Anti-Inflammatory Drugs With Anti-Cancer Activity On Colon Rectal Cancer Cell Lines Hct-116 And Caco-2, Wanda Ivette Rodríguez Rivera Dec 2015

Design And Synthesis Of New Non-Steroidal Anti-Inflammatory Drugs With Anti-Cancer Activity On Colon Rectal Cancer Cell Lines Hct-116 And Caco-2, Wanda Ivette Rodríguez Rivera

Dissertations

Colon rectal cancer is one of the most common types of cancer and is the third leading cause of cancer related deaths among western countries. Current chemotherapy treatments are highly toxic and mostly result in only a low percentage of tumor reduction; therefore an effective treatment with low toxicity is needed.

In this study, different innovative new COX-2 inhibitors were synthesized using the frame of biologically active chalcones to which active COX-2 pharmacophores SO2CH3, SO2NH2, SO2NHCOCH3 were added. Additionally, the effect of different alkyl chain lengths and the effect …


Nonlinear Partial Differential Equations, Their Solutions, And Properties, Prasanna Bandara Dec 2015

Nonlinear Partial Differential Equations, Their Solutions, And Properties, Prasanna Bandara

Boise State University Theses and Dissertations

Although valuable understanding of real-world phenomena can be gained experimentally, it is often the case that experimental investigations can be found to be limited by financial, ethical or other constraints making such an approach impractical or, in some cases, even impossible. To nevertheless understand and make predictions of the natural world around us, countless processes encountered in the physical and biological sciences, engineering, economics and medicine can be efficiently described by means of mathematical models written in terms of ordinary or/and partial differential equations or their systems. Fundamental questions that arise in the modeling process need care that relies on …


F–Geometric Mean Graphs, A. D. Baskar, S. Arockiaraj Dec 2015

F–Geometric Mean Graphs, A. D. Baskar, S. Arockiaraj

Applications and Applied Mathematics: An International Journal (AAM)

In a study of traffic, the labelling problems in graph theory can be used by considering the crowd at every junction as the weights of a vertex and expected average traffic in each street as the weight of the corresponding edge. If we assume the expected traffic at each street as the arithmetic mean of the weight of the end vertices, that causes mean labelling of the graph. When we consider a geometric mean instead of arithmetic mean in a large population of a city, the rate of growth of traffic in each street will be more accurate. The geometric …


On Calculation Of Failure Probability For Structures Designed Based On Magnitudes Of Historical Event, Farzad Noubary, Reza Noubary Dec 2015

On Calculation Of Failure Probability For Structures Designed Based On Magnitudes Of Historical Event, Farzad Noubary, Reza Noubary

Applications and Applied Mathematics: An International Journal (AAM)

During their operational life, structures may be subject to various types of live load caused by events such as earthquakes, high speed winds, etc. Given the design life of a structure, the probability for a specific live load to cause a failure depends on the magnitude of the load structure it is designed to withstand (designed load). In this article, methods are developed for calculation of the failure probability for structures designed to withstand loads comparable to historical loads at the site of interest.


Asymptotically Double Lacunary Equivalent Sequences In Topological Groups, Ayhan Esi, M. K. Ozdemir Dec 2015

Asymptotically Double Lacunary Equivalent Sequences In Topological Groups, Ayhan Esi, M. K. Ozdemir

Applications and Applied Mathematics: An International Journal (AAM)

In this paper we study the concept of asymptotically double lacunary statistical convergent sequences in topological groups and prove some inclusion theorems.


Solution To Some Open Problems On E-Super Vertex Magic Total Labeling Of Graphs, G. Marimuthu, M. S. Raja Durga, G. D. Devi Dec 2015

Solution To Some Open Problems On E-Super Vertex Magic Total Labeling Of Graphs, G. Marimuthu, M. S. Raja Durga, G. D. Devi

Applications and Applied Mathematics: An International Journal (AAM)

Let G be a finite graph with p vertices and q edges. A vertex magic total labeling is a bijection f from V(G)∪E(G) to the consecutive integers 1, 2, ..., p+q with the property that for every u∈V(G) , f( u)+ ∑f(uv)=K for some constant k. Such a labeling is E-super if f :E(G)→{1, 2,..., q}. A graph G is called E-super vertex magic if it admits an E-super vertex magic labeling. In this paper, we solve two open problems given by Marimuthu, Suganya, Kalaivani and Balakrishnan (Marimuthu et al., 2015).


Silicon Carbon Nanotube Lithium Ion Batteries, Lawrence Kent Barrett Dec 2015

Silicon Carbon Nanotube Lithium Ion Batteries, Lawrence Kent Barrett

Theses and Dissertations

Silicon has the highest theoretical capacity of any known anode material, and silicon coated carbon nanotubes (Si-CNTs) have shown promise of dramatically increasing battery capacity. However, capacity fading with cycling and low rate capability prevent widespread use. Here, three studies on differing aspects of these batteries are presented. Here, three studies on differing aspects of these batteries are presented. The first examines the rate capability of these batteries. It compares the cycling of electrodes hundreds of microns thick with and without ten micron access holes to facilitate diffusion. The holes do not improve rate capability, but thinner coatings of silicon …


Construction Of A 408 Nm Laser System For Use In Ion Interferometry, Lawrence Archibald Dec 2015

Construction Of A 408 Nm Laser System For Use In Ion Interferometry, Lawrence Archibald

Theses and Dissertations

This work reports on the construction of a 408 nm laser system designed to drive stimulated Raman transitions between the F = 4 and F = 5 2 S 1/2 states of 87 Sr + using the 2 P 3/2 state as the intermediate state. This laser system will be used as part of a 87 Sr + ion interferometer. This work also includes a discussion of relevant theory describing the interaction of the ions and laser, along with a calculation of the transition rates as a function of laser power and detuning.


Superimposed And Auxiliary Dunes Of The Northern Namib Sand Sea: A Ground-Penetrating Radar Study, Clayton K. Chandler Dec 2015

Superimposed And Auxiliary Dunes Of The Northern Namib Sand Sea: A Ground-Penetrating Radar Study, Clayton K. Chandler

Theses and Dissertations

Understanding modern features allows for their use as analogues for understanding the environments of the past and even environments on other planetary bodies. This study uses Ground-Penetrating Radar (GPR) to image the near surface sedimentary structures on a large linear dune in the northern Namib Sand Sea and image the sedimentary structure of an auxiliary dune. GPR data was collected using a 200 MHz antenna with a continuous scan method and was processed by removing direct arrival, gain balancing, migration and more which produced the highest resolution imagery from this region to date. Large dune data was analyzed to determine …


The Solenoid And Warsawanoid Are Sharkovskii Spaces, Tyler Willes Hills Dec 2015

The Solenoid And Warsawanoid Are Sharkovskii Spaces, Tyler Willes Hills

Theses and Dissertations

We extend Sharkovskii's theorem concerning orbit lengths of endomorphisms of the real line to endomorphisms of a path component of the solenoid and certain subspaces of the Warsawanoid. In particular, Sharkovskii showed that if there exists an orbit of length 3 then there exist orbits of all lengths. The solenoid is the inverse limit of double covers over the circle, and the Warsawanoid is the inverse limit of double covers over the Warsaw circle. We show Sharkovskii's result is true for path components of the solenoid and certain subspaces of the Warsawanoid.


Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski Dec 2015

Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski

Wildland Resources Faculty Publications

Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize …


Generalized Cokähler Geometry And An Application To Generalized Kähler Structures, Ralph R. Gomez, Janet Talvacchia Dec 2015

Generalized Cokähler Geometry And An Application To Generalized Kähler Structures, Ralph R. Gomez, Janet Talvacchia

Mathematics & Statistics Faculty Works

In this paper, we propose a generalization of classical coKähler geometry from the point of view of generalized contact metric geometry. This allows us to generalize a theorem of Capursi (1984), Goldberg (1968) and show that the product M1×M2M1×M2 of generalized contact metric manifolds (Mi,Φi,E±,i,Gi)(Mi,Φi,E±,i,Gi), i=1,2i=1,2, where M1×M2M1×M2 is endowed with the product (twisted) generalized complex structure induced from Φ1Φ1 and Φ2Φ2, is (twisted) generalized Kähler if and only if View the MathML source(Mi,Φi,E±,i,Gi),i=1,2 are (twisted) generalized coKähler structures. As an application of our theorem we construct new examples of twisted generalized Kähler structures on manifolds that do not admit …


Low-Rank Network Decomposition Reveals Structural Characteristics Of Small-World Networks, Victor J. Barranca, D. Zhou, D. Cai Dec 2015

Low-Rank Network Decomposition Reveals Structural Characteristics Of Small-World Networks, Victor J. Barranca, D. Zhou, D. Cai

Mathematics & Statistics Faculty Works

Small-world networks occur naturally throughout biological, technological, and social systems. With their prevalence, it is particularly important to prudently identify small-world networks and further characterize their unique connection structure with respect to network function. In this work we develop a formalism for classifying networks and identifying small-world structure using a decomposition of network connectivity matrices into low-rank and sparse components, corresponding to connections within clusters of highly connected nodes and sparse interconnections between clusters, respectively. We show that the network decomposition is independent of node indexing and define associated bounded measures of connectivity structure, which provide insight into the clustering …


Correcting For Measurement Error In Latent Variables Used As Predictors, Lynne Steuerle Schofield Dec 2015

Correcting For Measurement Error In Latent Variables Used As Predictors, Lynne Steuerle Schofield

Mathematics & Statistics Faculty Works

This paper represents a methodological-substantive synergy. A new model, the Mixed Effects Structural Equations (MESE) model which combines structural equations modeling and item response theory, is introduced to attend to measurement error bias when using several latent variables as predictors in generalized linear models. The paper investigates racial and gender disparities in STEM retention in higher education. Using the MESE model with 1997 National Longitudinal Survey of Youth data, I find prior mathematics proficiency and personality have been previously underestimated in the STEM retention literature. Pre-college mathematics proficiency and personality explain large portions of the racial and gender gaps. The …


Objective Bayesian Analysis On The Quantile Regression, Shiyi Tu Dec 2015

Objective Bayesian Analysis On The Quantile Regression, Shiyi Tu

All Dissertations

The dissertation consists of two distinct but related research projects. First of all, we study the Bayesian analysis on the two-piece location-scale models, which contain several well-known sub-distributions, such as the asymmetric Laplace distribution, the skewed normal distribution, and the skewed Student-t distribution. The use of two-piece location-scale models is an attractive method to model non-symmetric data. From a practical point of view, a prior with some objective information may be more reasonable due to the lack of prior information in many applied situations. It has been shown that several common used objective priors, such as the Jeffreys prior, result …


An Investigation Of At-Risk College Students Through Data Mining And Implementation Of Predictive Analysis, Nicole Alaine Cresse Dec 2015

An Investigation Of At-Risk College Students Through Data Mining And Implementation Of Predictive Analysis, Nicole Alaine Cresse

Kutztown University Masters Theses

This project will encompass an in-depth study of at-risk college students that implements both predictive analysis and data mining techniques. At-risk students are students with a specific set of demographics, study habits, and historical academic performance. Using predictive analysis, factors that directly correlate with student performance will be used to create a detection algorithm for particular student characteristics. From this data, it will be determined if a student is deemed “at-risk” academically, and if action needs to be taken by faculty or the student themselves.

The goal of this study is to determine the optimal algorithm that identifies at-risk students …


Design Of Oppnet Virtual Machine For Opportunistic Resource Utilization Networks: A Universal Standard For Application-Level Resource Sharing, Mai A. Alduailij Dec 2015

Design Of Oppnet Virtual Machine For Opportunistic Resource Utilization Networks: A Universal Standard For Application-Level Resource Sharing, Mai A. Alduailij

Dissertations

Opportunistic resource utilization networks or oppnets are a paradigm for specialized ad hoc networks. The Oppnet Virtual Machine (OVM) is a collection of primitives designed to create a middleware for application-level resource acquisition by oppnets and oppnet-enabled systems and devices (where the latter are defined as the computational entities able to communicate with other oppnets or oppnet-enabled entities). Acquisition of communication resources is the foundation for acquisition of other resources.

The OVM primitives can be downloaded by any computational entity—making entity oppnet-enabled. OVM ensures that oppnet-enabled entities can communicate and acquire resources in an opportunistic and ad hoc manner. This …


Assessment And Comparison Of The Electronic Properties Of Group 10 Bimetallic Nanoparticles Relative To Their Monometallic Counterparts, Ali Bolandi Dec 2015

Assessment And Comparison Of The Electronic Properties Of Group 10 Bimetallic Nanoparticles Relative To Their Monometallic Counterparts, Ali Bolandi

Dissertations

Group 10 transition metals with nanoscale dimensions offer significant advantages over their bulk counterparts. Significant work has been devoted toward studying the benefits of their catalytic efficiencies, however, less has been dedicated toward understanding their electronic properties and how such changes influence charge storage and sensor efficiency. The dissertation work focuses on designing metallic and bimetallic nanoparticles consisting of nanoscale Group 10 transition metals with welldefined structures, prepared using a facile synthetic procedure. The nanoparticles were characterized by electron microscopy, spectroscopic and x-ray techniques. The efficiency of monometallic and bimetallic nanoparticles toward electron storage was investigated electrochemically and by optical …


Novel Software Defined Radio Architecture With Graphics Processor Acceleration, Lalith Narasimhan Dec 2015

Novel Software Defined Radio Architecture With Graphics Processor Acceleration, Lalith Narasimhan

Dissertations

Wireless has become one of the most pervasive core technologies in the modern world. Demand for faster data rates, improved spectrum efficiency, higher system access capacity, seamless protocol integration, improved security and robustness under varying channel environments has led to the resurgence of programmable software defined radio (SDR) as an alternative to traditional ASIC based radios. Future SDR implementations will need support for multiple standards on platforms with multi-Gb/s connectivity, parallel processing and spectrum sensing capabilities. This dissertation implemented key technologies of importance in addressing these issues namely development of cost effective multi-mode reconfigurable SDR and providing a framework to …


Exact Implicit Solution Of Nonlinear Heat Transfer In Rectangular Straight Fin Using Symmetry Reduction Methods, M. S. Abdel Latif, A. H. Abdel Kader, H. M. Nour Dec 2015

Exact Implicit Solution Of Nonlinear Heat Transfer In Rectangular Straight Fin Using Symmetry Reduction Methods, M. S. Abdel Latif, A. H. Abdel Kader, H. M. Nour

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, the exact implicit solution of the second order nonlinear ordinary differential equation which governing heat transfer in rectangular fin is obtained using symmetry reduction methods. General relationship among the temperature at the fin tip, the temperature gradient at the fin base, the mode of heat transfer, 𝑛 and the fin parameters 𝑁 and ℰ is obtained. Some numerical examples are discussed and it is shown that the temperature of fin increases when approaching from the heat source. The relationship between the fin efficiency and the temperature of fin tip is obtained for any value of the mode …