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Articles 143401 - 143430 of 302598

Full-Text Articles in Physical Sciences and Mathematics

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard Apr 2015

Studies Of Arctic Halogen Chemistry From The Snowpack To The Gas Phase, Kyle D Custard

Open Access Dissertations

The temporary depletion of both tropospheric ozone and gaseous mercury during the Arctic springtime has been a focus of active research over the past several decades. Both of these phenomena have been linked to chemical reactions with halogen radicals. In particular, bromine atoms have been shown to act as the primary driver for these chemical depletions, although both chlorine and iodine atoms also contribute. Molecular bromine, along with its oxidation products, have been well studied in the Arctic, yet chlorine has not. Chlorine is known to impact the local oxidation capacity via its high reactivity with volatile organic compounds. Despite …


Visibility Computation Through Image Generalization, Jian Cui Apr 2015

Visibility Computation Through Image Generalization, Jian Cui

Open Access Dissertations

This dissertation introduces the image generalization paradigm for computing visibility. The paradigm is based on the observation that an image is a powerful tool for computing visibility. An image can be rendered efficiently with the support of graphics hardware and each of the millions of pixels in the image reports a visible geometric primitive. However, the visibility solution computed by a conventional image is far from complete. A conventional image has a uniform sampling rate which can miss visible geometric primitives with a small screen footprint. A conventional image can only find geometric primitives to which there is direct line …


Novel Methods For Manipulating Ion Types In The Solution And Gas Phases For The Structural Analysis Of Biomolecules Using Mass Spectrometry, Christine M Fisher Apr 2015

Novel Methods For Manipulating Ion Types In The Solution And Gas Phases For The Structural Analysis Of Biomolecules Using Mass Spectrometry, Christine M Fisher

Open Access Dissertations

Mass Spectrometry has become a valuable tool for the analysis of a variety of molecules, making it applicable to many fields. The advent of nanoelectrospray ionization (nESI) as a soft/low energy ionization technique has enabled the analysis of large, intact biomolecules. Most mass spectrometry experiments consist of three main steps: ionization, probe step(s), and mass analysis. The present work focuses on a variety of methods for altering ion types at various stages of the mass spectrometry experiment to affect ion fragmentation. Ion types can be manipulated in the solution/droplet phases using novel nESI emitters, generated from borosilicate theta capillaries. These …


Public Understanding Of Chemistry Research In Print News, Michael D. Hands Apr 2015

Public Understanding Of Chemistry Research In Print News, Michael D. Hands

Open Access Dissertations

Despite numerous calls for improving scientific literacy, many American adults show a lack of understanding of experiments, scientific study, and scientific inquiry. News media is one important avenue for science learning, but previous research investigating health and/or environmental science news has shown that it is inconsistent in the presentation of scientific research limitations, potentially impacting reader understanding. In the first phase of this dissertation, seventeen news articles reporting on a single chemistry research article, along with associated press releases and research articles, were analyzed using move analysis to determine the structure of each type of text. It was found that …


Uncertainty Quantification And Calibration Of Physical Models, Xian He Apr 2015

Uncertainty Quantification And Calibration Of Physical Models, Xian He

Open Access Dissertations

An ecosystem model is a representation of a real complex ecological system, and is usually described by sophisticated mathematical models. Terrestrial Ecosystem Model (TEM) is one of the ecosystem models, that describes the dynamics of car- bon, nitrogen, water and other vegetation related variables. There are uncertainties in the TEM which are attributed to inaccurate input data, insufficient knowledge of the parameters, inherent randomness and simplification of the physical model. Quantification of uncertainty of such an ecosystem model is computationally very heavy. Bayesian calibration method has been used as an efficient way to calibrate and quantify uncertainties of the computer …


Experimental Constraints On Exotic Spin-Dependent Interactions Using Specialized Materials, Rakshya Khatiwada Apr 2015

Experimental Constraints On Exotic Spin-Dependent Interactions Using Specialized Materials, Rakshya Khatiwada

Open Access Dissertations

Various theories predict the possible existence of symmetry violating forces with mesoscopic range interactions from mm-m [1]. These forces can arise from the coupling of a spin 0 boson to spin 1/2 fermions through scalar (gs) and pseudoscalar (gp) couplings. We discuss two experiments that can investigate these interactions using nucleon rich, impressively low magnetic susceptibility (5-100 times lower than pure water) test masses and electron-spin rich, polarized test masses (spin density: 10^20 h/cm3 ). The first experiment looks for a P-odd, T-odd interaction potential proportional to (S.r) where S is the spin of one particle and r is the …


Polarization-Dependent Nonlinear Optical Microscopy Methods For The Analysis Of Crystals And Biological Tissues, Emma L. Kerian Apr 2015

Polarization-Dependent Nonlinear Optical Microscopy Methods For The Analysis Of Crystals And Biological Tissues, Emma L. Kerian

Open Access Dissertations

The ability to solve a high-resolution protein structure is largely dependent on the successful generation and identification of protein crystals prior to X-ray diffraction (XRD). For novel protein targets, high-throughput crystallography often involves generation of multiple targets and thousands of crystallization trials per target to generate diffraction-quality crystals. Second harmonic generation (SHG) imaging has been developed as a fast, non-destructive and sensitive method for the selective identification of protein crystals, even in highly scattering environments. Polarization-dependent SHG microscopy methods were developed to assess the presence of multidomain crystals to provide a handle on crystal quality. In addition, polarization-dependent two-photon excited …


Transport Studies In Graphene-Based Materials And Structures, Jiuning Hu Apr 2015

Transport Studies In Graphene-Based Materials And Structures, Jiuning Hu

Open Access Dissertations

Graphene, a single atomic layer of graphite, has emerged as one of the most attractive materials in recent years for its many unique and excellent properties, inviting a broad area of fundamental studies and applications. In this thesis, we present some theoretical/experimental studies about the thermal, electronic and thermoelectric transport properties in graphene-based systems. We employ the molecular dynamic simulations to study the thermal transport in graphene nanoribbons (GNRs) exhibiting various properties, including chirality dependent thermal conductivity, thermal rectification in asymmetric GNRs, defects and isotopic engineering of the thermal conductivity and negative differential thermal conductance (NDTC) at large temperature biases. …


Parallel Symmetric Eigenvalue Problem Solvers, Alicia Marie Klinvex Apr 2015

Parallel Symmetric Eigenvalue Problem Solvers, Alicia Marie Klinvex

Open Access Dissertations

Sparse symmetric eigenvalue problems arise in many computational science and engineering applications: in structural mechanics, nanoelectronics, and spectral reordering, for example. Often, the large size of these problems requires the development of eigensolvers that scale well on parallel computing platforms. In this dissertation, we describe two such eigensolvers, TraceMin and TraceMin-Davidson. These methods are different from many other eigensolvers in that they do not require accurate linear solves to be performed at each iteration in order to find the smallest eigenvalues and their associated eigenvectors. After introducing these closely related eigensolvers, we discuss alternative methods for solving the saddle point …


A Hydroclimatic Assessment Of The U.S. Corn Belt Across Spatial And Temporal Scales, Olivia B. Kellner Apr 2015

A Hydroclimatic Assessment Of The U.S. Corn Belt Across Spatial And Temporal Scales, Olivia B. Kellner

Open Access Dissertations

The term hydroclimate is used to describe the climate of a given location as determined by the incident radiant energy (temperature) and the existence of water in its various forms on Earth. Two types of climate comprise the science of hydroclimatology: the climate as established by general global circulation patterns at specific locations on Earth (large-scale climate) and the climate established at Earth's surface resulting from the daily fluxes of radiant energy and water in its various forms between the atmosphere, Earth's surface, and the subsurface (local-scale climate) (Shelton 2009). This dissertation investigates different spatial and temporal scales of the …


Computational Optical Imaging: Applications In Synthetic Aperture Imaging, Phase Retrieval, And Digital Holography, Dennis Joseph Lee Apr 2015

Computational Optical Imaging: Applications In Synthetic Aperture Imaging, Phase Retrieval, And Digital Holography, Dennis Joseph Lee

Open Access Dissertations

Computational imaging has become an important field, as a merger of both algorithms and physical experiments. In the realm of microscopy and optical imaging, an important application is the problem of improving resolution, which is bounded by wavelength and numerical aperture according to the classic diffraction limit. We will investigate the resolution enhancement of phase objects such as transparent biological cells. One key challenge is how to measure phase experimentally. Standard interferometric techniques have the drawback of being sensitive to environmental vibrations and temperature fluctuations, and they use a reference arm which requires more space and cost. Non-holographic methods provide …


Quantitative Mrna Detection With Advanced Nonlinear Microscopy, Jing Liu Apr 2015

Quantitative Mrna Detection With Advanced Nonlinear Microscopy, Jing Liu

Open Access Dissertations

Cell-specific information on quantity and localization of key mRNA transcripts in single-cell level are critical to the assessment of cancer risk, therapy efficacy, and effective prevention strategies. While current techniques are not capable to visualize single mRNA transcript beyond the diffraction limit. In this thesis, two nonlinear technologies, second harmonic super-resolution microscopy (SHaSM) and transient absorption microscopy (TAM), are developed to detect and quantify single Human edimer receptor 2 (Her2) mRNA transcripts. The SHaSM is used to detect single mRNA transcript beyond the diffraction limit, while the TAM is employed to detect mRNA without the interference of fluorescence background. The …


A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li Apr 2015

A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li

Open Access Theses

Proton affinity (PA) is a fundamental property that is related to the structure and reactivity of a molecule. Currently, very few experimental PA values are available for organic radicals and none for biradicals. Equilibrium methods cannot be used for these measurements. The traditional bracketing method is based on monitoring reactions of different reference bases with known proton affinities with the protonated analyte for the occurrence of exothermic proton transfer to determine the upper and lower limits of proton affinity. However, the energy deposited into the precursor ions upon CAD when forming protonated radicals may cause endothermic proton transfer reactions occur …


Video Advertisement Mining For Predicting Revenue Using Random Forest, Yuan Hsin Huang Apr 2015

Video Advertisement Mining For Predicting Revenue Using Random Forest, Yuan Hsin Huang

Open Access Theses

Shaken by the threat of financial crisis in 2008, industries began to work on the topic of predictive analytics to efficiently control inventory levels and minimize revenue risks. In this third-generation age of web-connected data, organizations emphasized the importance of data science and leveraged the data mining techniques for gaining a competitive edge. Consider the features of Web 3.0, where semantic-oriented interaction between humans and computers can offer a tailored service or product to meet consumers' needs by means of learning their preferences. In this study, we concentrate on the area of marketing science to demonstrate the correlation between TV …


Downward Model Development Of The Soil Moisture Accounting Loss Method In Hec-Hms: Revelations Concerning The Soil Profile, Jessica Holberg Apr 2015

Downward Model Development Of The Soil Moisture Accounting Loss Method In Hec-Hms: Revelations Concerning The Soil Profile, Jessica Holberg

Open Access Theses

Despite the fact that the soil profile is known to impact streamflow, most Curve Number (CN)-based models ignore subsurface processes. This study explores the influence of soil storage on peak flows. Two watersheds in flat, humid west-central Indiana were modeled using both the Natural Resources Conservation Service (NRCS) Curve Number and four versions of the Soil Moisture Accounting (SMA) loss methods in the United States Army Core of Engineers-developed (USACE) Hydrologic Engineering Center Hydrologic Modeling System (HEC-HMS). One watershed encompasses the Wabash and Tippecanoe Rivers' confluence; the other contains an ephemeral stream, Plum Creek. The CN-based model was developed using …


Trajectory Generation For Lane-Change Maneuver Of Autonomous Vehicles, Ashesh Goswami Apr 2015

Trajectory Generation For Lane-Change Maneuver Of Autonomous Vehicles, Ashesh Goswami

Open Access Theses

Lane-change maneuver is one of the most thoroughly investigated automatic driving operations that can be used by an autonomous self-driving vehicle as a primitive for performing more complex operations like merging, entering/exiting highways or overtaking another vehicle. This thesis focuses on two coherent problems that are associated with the trajectory generation for lane-change maneuvers of autonomous vehicles in a highway scenario: (i) an effective velocity estimation of neighboring vehicles under different road scenarios involving linear and curvilinear motion of the vehicles, and (ii) trajectory generation based on the estimated velocities of neighboring vehicles for safe operation of self-driving cars during …


Impact Of Biogenic Volatile Organic Compounds On Peroxyacetyl Nitrate Production In The Southeast United States, Christopher John Groff Apr 2015

Impact Of Biogenic Volatile Organic Compounds On Peroxyacetyl Nitrate Production In The Southeast United States, Christopher John Groff

Open Access Theses

Our atmosphere is arguably the fundamental entity that has made life on Earth possible. Knowledge of the delicate nature of our atmosphere continues to spread as "green" initiatives promote awareness of human influence on the environment. However, many climate scientists fear that unless immediate mitigation occurs, the reversal of human impact on our planet will be impossible, leading to unknown consequence. Perturbations to natural processes are likely to cause drastic change to the planet as we know it and ultimately result in significant health issues. It is important to push the boundaries of our understanding of atmospheric processes with intent …


Password Strength Analysis: User Coping Mechanisms In Password Selection, Brian Thomas Curnett Apr 2015

Password Strength Analysis: User Coping Mechanisms In Password Selection, Brian Thomas Curnett

Open Access Theses

The security that passwords provide could be seriously flawed due to the way people cope with having to memorize and recall their passwords. The National Institute of Standards and Technology (NIST) standard that is used to measure the password strength, known as entropy, is designed for a single use and does not consider that users may choose to keep parts of their password across password changes. This study shows that a portion of users keep some information from previous passwords across changes. These habits which will be called coping mechanisms that over time serve to erode the protection provided by …


The Stability Of The Iris As A Biometric Modality, Benjamin Wright Petry Apr 2015

The Stability Of The Iris As A Biometric Modality, Benjamin Wright Petry

Open Access Theses

In this thesis, the question of the stability of a group of individual subjects' irises is examined and answered. This stability is examined in regards to the time scale of the month range. The covariate for this research was time. Images collected during one month of separation between captures were examined. The genuine and impostor scores for these images were calculated and then interpreted using the stability score index. This index produced a quantifiable value for the stability of iris match scores over the months of the examination. ^ Additionally, a new framework for collecting and analyzing time in biometrics …


How Effective Is Group Feedback In Encouraging Occupants Of An Office Building To Reduce Energy Consumption?, Ushik D. Shah Apr 2015

How Effective Is Group Feedback In Encouraging Occupants Of An Office Building To Reduce Energy Consumption?, Ushik D. Shah

Open Access Theses

Lighting contributes to a high percentage of the total energy use in office buildings. The lack of financial incentive often dissuades office workers from trying to save electricity at their work place. This thesis aims at reducing the total power consumed by an office building by using persuasive technologies on the occupants to promote environmentally conscious and energy saving behavior. ^ A three week field study was conducted by providing occupants of an office building feedback about their energy consumption along with messages to encourage them to save energy. Feedback was provided via television screens and flyers placed strategically at …


A Case Study Of Introductory Programming With Moocs, Miguel Angel Javier Ruiz Apr 2015

A Case Study Of Introductory Programming With Moocs, Miguel Angel Javier Ruiz

Open Access Theses

Computational thinking has become a crucial skill for the 21st Century learners in all disciplines. Research suggests that the best and fastest approach to understand the concepts of computational thinking is through developing programming skills. However, finding effective and affordable learning environments to introduce programming skills to a massive scale of students remains a challenge. Currently, the unprecedented utilization of MOOCs represent an opportunity to achieve this goal. But, existing introductory programming MOOCs have failed to provide instructionally-sound experience for learners. The purpose of this descriptive research is two-fold: (1) Identify the affordances of fifteen MOOC's platforms that are best …


Recursive Tree Traversal Dependence Analysis, Yusheng Weijiang Apr 2015

Recursive Tree Traversal Dependence Analysis, Yusheng Weijiang

Open Access Theses

While there has been much work done on analyzing and transforming regular programs that operate over linear arrays and dense matrices, comparatively little has been done to try to carry these optimizations over to programs that operate over heap-based data structures using pointers. Previous work has shown that point blocking, a technique similar to loop tiling in regular programs, can help increase the temporal locality of repeated tree traversals. Point blocking, however, has only been shown to work on tree traversals where each traversal is fully independent and would allow parallelization, greatly limiting the types of applications that this transformation …


A Characteristic-Based Visual Analytics Approach To Detect Subtle Attacks From Netflow Records, Weijie Wang Apr 2015

A Characteristic-Based Visual Analytics Approach To Detect Subtle Attacks From Netflow Records, Weijie Wang

Open Access Theses

Security is essentially important for any enterprise networks. Denial of service, port scanning, and data exfiltration are among of the most common network intrusions. It's urgent for network administrators to detect such attacks effectively and efficiently from network traffic. Though there are many intrusion detection systems (IDSs) and approaches, Visual Analytics (VA) provides a human-friendly approach to detect network intrusions with situational awareness functionality. Overview visualization is the first and most important step in a VA approach. However, many VA systems cannot effectively identify subtle attacks from massive traffic data because of the incapability of overview visualizations. In this work, …


Origin Of Enigmatic Rocks Located North Of The Stillwater Complex, Montana, M. Christopher Jenkins, Jennifer A. Thomson, Michael L. Zientek Apr 2015

Origin Of Enigmatic Rocks Located North Of The Stillwater Complex, Montana, M. Christopher Jenkins, Jennifer A. Thomson, Michael L. Zientek

Geology Student Works

The Stillwater Complex is an Archean layered mafic-ultramafic intrusion located in southwestern

Montana. The complex hosts a platinum-group element ore deposit — the J-M Reef. Recent geophysical data collected by the USGS from an area to the north of the Stillwater complex suggests that the complex continues at depth under cover. The northern exposure of Precambrian rock is not the complex but some enigmatic amphibolites. During the 2013 and 2014 field seasons, eight samples were collected from this Precambrian (?) lower-amphibolite to greenschist-facies metamorphic rock unit located approximately 2 kilometers north of the complex. Vail (1955) described the unit as …


Should Nuclear Energy Be More Heavily Incorporated By The United States?, Matthew Romer Apr 2015

Should Nuclear Energy Be More Heavily Incorporated By The United States?, Matthew Romer

Nebraska College Preparatory Academy: Senior Capstone Projects

America is involved in one of the biggest races towards electrical efficiency, cleanliness, and productivity. Nuclear energy is a major part of the U.S.’s non-­‐carbon emitting electricity, and has strict regulations for management. However, this form of energy has been on the decline in the past couple decades due to cost and competition with cheaper, less clean methods. Is nuclear energy feasible enough to continue?


Comprehensive Organic Synthesis Ii (Book Review), Jeffrey H. Glans Apr 2015

Comprehensive Organic Synthesis Ii (Book Review), Jeffrey H. Glans

Chemistry & Physics Faculty Publications

Jeffrey Glans' review focuses on the online version available through ScienceDirect.

Knochel, Paul and Gary A. Molander, eds. Comprehensive Organic Synthesis II. 2nd ed. Amsterdam; Waltham, MA: Elsevier, 2014. Web.

http://www.sciencedirect.com/science/referenceworks/9780080977430

ISBN: 9780080977430 (e-book)


The Planet, 2015, Spring, Beth Carlson, Huxley College Of The Environment, Western Washington University Apr 2015

The Planet, 2015, Spring, Beth Carlson, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.


Quantitative Analysis Of Single-Molecule Force Spectroscopy On Folded Chromatin Fibers, He Meng, Kurt Andresen, John Van Noort Apr 2015

Quantitative Analysis Of Single-Molecule Force Spectroscopy On Folded Chromatin Fibers, He Meng, Kurt Andresen, John Van Noort

Physics and Astronomy Faculty Publications

Single-molecule techniques allow for picoNewton manipulation and nanometer accuracy measurements of single chromatin fibers. However, the complexity of the data, the heterogeneity of the composition of individual fibers and the relatively large fluctuations in extension of the fibers complicate a structural interpretation of such force-extension curves. Here we introduce a statistical mechanics model that quantitatively describes the extension of individual fibers in response to force on a per nucleosome basis. Four nucleosome conformations can be distinguished when pulling a chromatin fiber apart. A novel, transient conformation is introduced that coexists with single wrapped nucleosomes between 3 and 7 pN. Comparison …


Local Well-Posedness Of Periodic Fifth Order Kdv-Type Equations, Yi Hu, Xiaochun Li Apr 2015

Local Well-Posedness Of Periodic Fifth Order Kdv-Type Equations, Yi Hu, Xiaochun Li

Department of Mathematical Sciences Faculty Publications

In this paper, the local well-posedness of periodic fifth order dispersive equation with nonlinear term P1(u)∂xu + P2(u)∂xu∂xu. Here P1(u) and P2(u) are polynomials of u. We also get some new Strichartz estimates.


Examining The Transitional Impact Of Icd-10 On Healthcare Fraud Detection, Tyler Olson Apr 2015

Examining The Transitional Impact Of Icd-10 On Healthcare Fraud Detection, Tyler Olson

Honors Theses, 1963-2015

On October 1st, 2015, the tenth revision of the International Classification of Diseases (ICD-10) will be mandatorily implemented in the United States. Although this medical classification system will allow healthcare professionals to code with greater accuracy, specificity, and detail, these codes will have a significant impact on the flavor of healthcare insurance claims. While the overall benefit of ICD-10 throughout the healthcare industry is unquestionable, some experts believe healthcare fraud detection and prevention could experience an initial drop in performance due to the implementation of ICD-10. We aim to quantitatively test the validity of this concern regarding an adverse transitional …