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

Digital Commons Network™

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

Brigham Young University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5191 - 5220 of 8053

Full-Text Articles in Entire DC Network

Development Of Biocompatible Polymer Monoliths For The Analysis Of Proteins And Peptides, Yun Li Aug 2009

Development Of Biocompatible Polymer Monoliths For The Analysis Of Proteins And Peptides, Yun Li

Theses and Dissertations

Biocompatibility is an important issue for the development of chromatographic stationary phases for the analysis of biomolecules (including proteins and peptides). A biocompatible stationary phase material is a material that resists nonspecific adsorption of biomolecules and does not interact with them in a way that would alter or destroy their structures or biochemical functions. The monolithic column format is a good alternative to typical spherical particle packed columns for capillary liquid chromatography of biomacromolecules. Several novel anion-exchange polymer monoliths for the analysis of proteins were synthesized for improved biocompatibility. Two novel polymeric monoliths were prepared in a single step by …

Go to article

Isogeometric Finite Element Analysis Using T-Splines, Jingang Li Aug 2009

Isogeometric Finite Element Analysis Using T-Splines, Jingang Li

Theses and Dissertations

Non-uniform rational B-splines (NURBS) methodology is presented, on which the isogeometric analysis is based. T-splines are also introduced as a surface design methodology, which are a generalization of NURBS and permit local refinement. Isogeometric analysis using NURBS and T-splines are applied separately to a structural mechanics problem. The results are compared with the closed-form solution. The desirable performance of isogeometric analysis using T-splines on engineering analysis is demonstrated.

Go to article

Real-Time Virus Analysis Via Image Charge Detection Surface Induced Dissociation Tandem Mass Spectrometry, Seth T. Call Aug 2009

Real-Time Virus Analysis Via Image Charge Detection Surface Induced Dissociation Tandem Mass Spectrometry, Seth T. Call

Theses and Dissertations

This thesis reports on the development of a novel mass spectrometer combining image charge detection with surface induced dissociation for real-time analysis of intact viruses. Protonated viruses produced using electrospray are accelerated and subsequently impact on a solid surface. Capsid peptides released during the impact are analyzed using time-of-flight mass spectrometry. Image charge detection is used to measure the mass and charge states of structurally intact, electrosprayed viruses prior to impact. Since virus capsids are composed of loosely-bound proteins, collision of viruses with surfaces at moderate impact energies could release intact proteins. The masses and numbers of different protein types …

Go to article

Design And Characterization Of A Human Exposure Chamber And Inversion Episodes In Salt Lake City, Utah In January/February Of 2009, Roman Yuri Kuprov Aug 2009

Design And Characterization Of A Human Exposure Chamber And Inversion Episodes In Salt Lake City, Utah In January/February Of 2009, Roman Yuri Kuprov

Theses and Dissertations

Research on health effects of particulate matter (PM) has been a very active area in the last two decades. One plausible mechanism by which exposure to PM affects human health includes modification of autonomic endothelium function. Decreased endothelium activity causes heightened risks of cardiovascular disease. A human exposure chamber designed to conduct experiments to quantify diminished function of endothelium from short term exposure to PM is described. The chamber consists of two stages for containment and pre-treatment of PM and exposure of human subjects. Concentrations of CO, CO2, NO, NO2, O3, and PM2.5, are monitored and controlled in the exposure …

Go to article

Supporting Remote Manipulation: An Ecological Approach, John A. Atherton Aug 2009

Supporting Remote Manipulation: An Ecological Approach, John A. Atherton

Theses and Dissertations

User interfaces for remote robotic manipulation widely lack sufficient support for situation awareness and, consequently, can induce high mental workload. With poor situation awareness, operators may fail to notice task-relevant features in the environment often leading the robot to collide with the environment. With high workload, operators may not perform well over long periods of time and may feel stressed. We present an ecological visualization that improves operator situation awareness. Our user study shows that operators using the ecological interface collided with the environment on average half as many times compared with a typical interface, even with a poorly calibrated …

Go to article

The Withdrawn And Sociable Behaviors Of Children With Specific And Nonspecific Language Impairment, Heather Haskin Aug 2009

The Withdrawn And Sociable Behaviors Of Children With Specific And Nonspecific Language Impairment, Heather Haskin

Theses and Dissertations

Recently researchers have identified a group of children with language impairment (LI) whose IQ scores are below the typical IQ cutoff of 85 for specific language impairment (SLI) but above the IQ cutoff of 70 for intellectual disability (Weismer et al., 2000). This group is referred to as having nonspecific language impairment (NLI). Eleven children with NLI, eleven same-age peers with SLI, and eleven same-age typical peers were compared on withdrawn and sociable behaviors demonstrated in the classroom setting using the Teacher Behavior Rating Scale (Hart & Robinson, 1996). Three subtypes of withdrawal (solitary-active, solitary-passive, reticent) and two subtypes of …

Go to article

Active Human Power Generation: As A New Portion Of The Energy Supply, Robert J. Mccleary Ii Aug 2009

Active Human Power Generation: As A New Portion Of The Energy Supply, Robert J. Mccleary Ii

Library Research Grants

The discovery and use of energy has revolutionized society for more then two hundred years. With it we have witnessed an explosion of knowledge and technology unparallel in history. Unfortunately our main sources of energy are in limited supply. In order to continue to enjoy the progress made during these last few centuries it is necessary to know both when our supply will run out and to find alternative sources.

The question of when the fossil fuels will run out has been on the minds of many scientists for more than fifty years. In 1956 Dr. M. King Hubbert developed …

Go to article

Reducing Source Load In Bittorrent, Brian Sanderson, Daniel Zappala Aug 2009

Reducing Source Load In Bittorrent, Brian Sanderson, Daniel Zappala

Faculty Publications

One of the main goals of BitTorrent is to reduce load on web servers by encouraging clients to share content between themselves. However, BitTorrent’s current design relies heavily on the original source to serve a disproportionate amount of the file. We modify standard BitTorrent software so that a source determines the current popularity of each of the blocks of a file and tries to serve only those blocks that are rare. Using extensive PlanetLab experiments, we show that this modification can save a significant amount of the source’s upload bandwidth, with the tradeoff of some increased peer download time. In …

Go to article

Generating Derivative Structures From Multilattices: Algorithm And Application To Hcp Alloys, Gus L. W. Hart, Rodney W. Forcade Jul 2009

Generating Derivative Structures From Multilattices: Algorithm And Application To Hcp Alloys, Gus L. W. Hart, Rodney W. Forcade

Faculty Publications

We present an algorithm for generating all derivative superstructures of a nonprimitive parent lattice. The algorithm has immediate application in important materials design problems such as modeling hexagonal-close-packed (hcp) alloys. Extending the work of Hart and Forcade [Phys. Rev. B 77, 224115 (2008)] (which applies only to Bravais lattices), this approach applies to arbitrary multilattices. The algorithm enumerates superlattices and atomic configurations using permutation groups rather than direct geometric comparisons. The key concept is to use the quotient group associated with each superlattice to determine all unique atomic configurations. The algorithm is very efficient; the run time scales linearly with …

Go to article

A Hop-By-Hop Architecture For Multicast Transport In Ad Hoc Wireless Networks, Manoj Kumar Pandey Jul 2009

A Hop-By-Hop Architecture For Multicast Transport In Ad Hoc Wireless Networks, Manoj Kumar Pandey

Theses and Dissertations

Ad hoc wireless networks are increasingly being used to provide connectivity where a wired networking infrastructure is either unavailable or inaccessible. Many deployments utilize group communication, where several senders communicate with several receivers; multicasting has long been seen as an efficient way to provide this service. While there has been a great deal of research on multicast routing in ad hoc networks, relatively little attention has been paid to the design of multicast transport protocols, which provide reliability and congestion control. In this dissertation we design and implement a complete multicast transport architecture that includes both routing and transport protocols. …

Go to article

A Top-Down Proteomic Approach For The Discovery Of Novel Serum Biomarkers Of Pregnancy-Related Disease, Karen Merrell Jul 2009

A Top-Down Proteomic Approach For The Discovery Of Novel Serum Biomarkers Of Pregnancy-Related Disease, Karen Merrell

Theses and Dissertations

The serum fraction of blood is an ideal material in which to search for novel biomarkers for disease. It is easily obtained through relatively non-invasive means, routinely collected, and a rich treasure-trove of information about the health of an individual. Cells react to signal molecules, take up nutrients, and release waste products, fragments that are the result of proteolysis, and other molecules out into the bloodstream. If these components are unique to the cells in question, that part of the complex mixture that is the blood stream can potentially characterize the health of the tissue or organ those cells are …

Go to article

Massively Parallel Indirect Dielectrophoresis Controlled Placement Of Carbon Nanotubes, Hiram Jacob Conley Jul 2009

Massively Parallel Indirect Dielectrophoresis Controlled Placement Of Carbon Nanotubes, Hiram Jacob Conley

Theses and Dissertations

Placement of single walled carbon nanotubes is demonstrated through massively parallel indirect dielectrophoresis (MPID). MPID is shown to be able to control the placement of carbon tubes as well as the number of tubes placed. Lumped element analysis for AC circuits is used to model MPID. This model allows for predictions of the number of tubes that will be captured in a trap. This model has been consistent with experimental data of numbers of nanotube placed in a junction. Carbon nanotubes placed with MPID are shown to be electrically active.

Go to article

Extreme Ultraviolet Polarimetry With Laser-Generated High-Order Harmonics: Characterization Of Uranium, Nicole Brimhall Jul 2009

Extreme Ultraviolet Polarimetry With Laser-Generated High-Order Harmonics: Characterization Of Uranium, Nicole Brimhall

Theses and Dissertations

We developed an extreme ultraviolet (EUV) polarimeter, which employs laser-generated high-order harmonics as the light source. This relatively high-flux, directional EUV source has available wavelengths between 10 nm and 47 nm with easily rotatable linear polarization. The polarimeter has allowed us to characterize the optical constants of materials that may be useful for EUV optics. The instrument has a versatile positioning system and a spectral resolution of about 180, and we have demonstrated that reflectance as low as 0.1% can be measured repeatably at EUV wavelengths. We investigate the high harmonic source used for polarimetry measurements by documenting the spatial …

Go to article

Four-Body Problem With Collision Singularity, Duokui Yan Jul 2009

Four-Body Problem With Collision Singularity, Duokui Yan

Theses and Dissertations

In this dissertation, regularization of simultaneous binary collision, existence of a Schubart-like periodic orbit, existence of a planar symmetric periodic orbit with multiple simultaneous binary collisions, and their linear stabilities are studied. The detailed background of those problems is introduced in chapter 1. The singularities of simultaneous binary collision in the collinear four-body problem is regularized in chapter 2. We use canonical transformations to collectively analytically continue the singularities of the simultaneous binary collision solutions in both the decoupled case and the coupled case. All the solutions are found and more importantly, we find a crucial first integral which describes …

Go to article

An Investigation Of The Support For Literacy Instruction In Elementary Mathematics Textbooks, Wendy Ann Williams Jul 2009

An Investigation Of The Support For Literacy Instruction In Elementary Mathematics Textbooks, Wendy Ann Williams

Theses and Dissertations

The purpose of this study was to investigate the kinds of support offered for integrating literacy strategies into mathematics instruction in elementary mathematics textbooks so that students are given opportunity to achieve the vision NCTM (2000) has for mathematical power for all. The research methodology for this was a qualitative content analysis using a priori codes. Two textbook series were chosen for this study. In each series examples of literacy integration ideas based on Trabasso's and Bouchard's (2002) effective comprehension strategies to teach comprehension were cited and analyzed. The results show that there is support for teachers to integrate literacy …

Go to article

The Design And Development Of A Statistics Performance Support System: An Application Of Behavioral Modeling And Case Based Reasoning, Isaku Tateishi Jul 2009

The Design And Development Of A Statistics Performance Support System: An Application Of Behavioral Modeling And Case Based Reasoning, Isaku Tateishi

Theses and Dissertations

The following report is a description of the design, development, and evaluation of an online statistics performance support system. The target audience for the support system is students of Instructional Psychology and Technology (IP&T), especially those who have taken the IP&T 550 "Empirical Inquiry and Statistics" course. The product is designed to be used as a supplemental reference tool. The main purpose of the online performance support system is to help IP&T students select appropriate statistical procedures for their research and learn how to perform the necessary calculations using a statistics analysis software package called SPSS. This report summarizes the …

Go to article

Effects Of After School Programs On Elementary School Students' Language Arts And Mathematics Achievement, Jennifer Lynn Presnell Jul 2009

Effects Of After School Programs On Elementary School Students' Language Arts And Mathematics Achievement, Jennifer Lynn Presnell

Theses and Dissertations

This study evaluated after school program participation on student academic achievement as a way of helping schools meet Adequate Yearly Progress (AYP) standards set by the No Child Left Behind Act. After school programs were divided into academic after school programs and traditional after school programs. Student achievement was measured through Criterion Referenced Tests in Language Arts and Mathematics. This study took place in a small urban school district located in the Intermountain West. Students in after school programs were matched with students not participating in the programs on several background characteristics including socioeconomic status, English language proficiency status, school …

Go to article

High-Stakes Testing Under The No Child Left Behind Act: How Has It Impacted School Culture?, Rashel Anderson Tingey Jul 2009

High-Stakes Testing Under The No Child Left Behind Act: How Has It Impacted School Culture?, Rashel Anderson Tingey

Theses and Dissertations

The purpose of this study was to investigate the impact of high-stakes testing under the No Child Left Behind (NCLB) Act on school culture. Individual interviews and focus groups were conducted with first grade through sixth grade teachers and principals from two of Nebo School District's schools located in Utah. Their responses were categorized into twelve themes. Most of the teachers and principals reported that high-stakes testing negatively impacted student and teacher motivation, teaching and learning, and curriculum. They also discussed negative effects of the application questioned the accuracy of high-stakes testing. Fewer teachers and principals communicated positive effects of …

Go to article

Energy Current Imaging Method For Time Reversal In Elastic Media, Brian E. Anderson, Michele Griffa, Robert A. Guyer, Paul A. Johnson, Carene Larmat, Pierre-Yves Le Bas, Timothy J. Ulrich Jul 2009

Energy Current Imaging Method For Time Reversal In Elastic Media, Brian E. Anderson, Michele Griffa, Robert A. Guyer, Paul A. Johnson, Carene Larmat, Pierre-Yves Le Bas, Timothy J. Ulrich

Faculty Publications

An energy current imaging method is presented for use in locating sources of wave energy during the back propagation stage of the time reversal process. During the back propagation phase of an ideal time reversal experiment, wave energy coalesces from all angles of incidence to recreate the source event; after the recreation, wave energy diverges in every direction. An energy current imaging method based on this convergence/divergence behavior has been developed. The energy current imaging method yields a smaller spatial distribution for source reconstruction than is possible with traditional energy imaging methods.

Go to article

Verifying Predictions Of The L13 Crystal Structure In Cd-Pt And Pd-Pt By Exhaustive Enumeration, Gus L. W. Hart Jul 2009

Verifying Predictions Of The L13 Crystal Structure In Cd-Pt And Pd-Pt By Exhaustive Enumeration, Gus L. W. Hart

Faculty Publications

In 2001, S. Müller and A. Zunger [Phys. Rev. Lett. 87, 165502 (2001)] predicted a never-before-observed crystal structure in Ag-Pd. Recently, Curtarolo predicted the same structure to be stable in Pt-Cd and Pt-Pd [S. Curtarolo et. Al., CALPHAD: Comput. Coupling Phase Diagrams Thermochem. 29, 163 (2005)]. The predicted structure is unique in several ways. though never seen in any other face-centered-cubic-based intermetallic binary compound or ordered alloy, it is relatively simple—it contains only four atoms per unit cell. Furthermore, the structure is the only one of this small size, except the L12 structure, that cannot be characterized as a simple …

Go to article

Deepening Understanding Of Science Content Through Text Structure Instruction, Karen Thomas Jul 2009

Deepening Understanding Of Science Content Through Text Structure Instruction, Karen Thomas

Theses and Dissertations

The purpose of this study was to examine the effectiveness of an instructional program designed to explicitly teach text structure awareness to fourth grade students to assist in their understanding of science content in a unit of study on weather. The changes that occurred in teacher thinking and practice were also examined throughout the process of developing and implementing the instructional program. A quantitative analysis was performed to reveal any differences in mean posttest scores between a control group and a treatment group. Results indicated that the treatment group students' science content knowledge was increased significantly more than the students …

Go to article

Teacher Perspectives On Behaviors Exhibited By Students At Risk For Ebd And The Implications Of These Behaviors For The Development Of An Ebd Screener In Middle And Junior High Schools, Brittany Linn Schilling Jul 2009

Teacher Perspectives On Behaviors Exhibited By Students At Risk For Ebd And The Implications Of These Behaviors For The Development Of An Ebd Screener In Middle And Junior High Schools, Brittany Linn Schilling

Theses and Dissertations

Universal screening is an emerging practice in the field of education to provide at-risk students with early intervention services. Currently there is not a universal screener specifically designed for the middle school population. Therefore, the purpose of this study was to obtain junior high and middle school teachers' perspectives on behaviors exhibited by students at risk for emotional and behavioral disorders in order to develop preliminary test items. Several themes were identified from the teachers' perspectives. Teacher perspectives noted that at-risk students displayed a variety of internalizing and externalizing behaviors. These issues included difficulty maintaining peer and teacher relationships, difficulty …

Go to article

Radiation And Convection Heat Transfer In Wildland Fire Environments, David J. Frankman Jul 2009

Radiation And Convection Heat Transfer In Wildland Fire Environments, David J. Frankman

Theses and Dissertations

Wildland fire research has been extensive and on going since before 1950. The motivation behind this research is to prevent loss of property and lives. In spite of this research, the heat transfer of fuel ignition and flame spread is not well understood. This dissertation seeks to fill gaps in this understanding through modeling and also by experimentation. The effect of water vapor on the transmission of thermal radiation from the flame to the fuel was investigated. The Spectral Line Weighted-sum-of-gray-gases approach was adopted for treating the spectral nature of the radiation. The study reveals that water vapor has only …

Go to article

Phytogeography And Floristics Of Pinyon-Juniper Woodlands In Northern Arizona, Kyle Christie Jul 2009

Phytogeography And Floristics Of Pinyon-Juniper Woodlands In Northern Arizona, Kyle Christie

Western North American Naturalist

This study assesses the floristic diversity and affinities of pinyon-juniper (PJ) woodlands in northern Arizona at 2 different scales: regionally within the context of North American floristic patterns and locally within the 2500-m elevation gradient of the San Francisco Volcanic Field (SFVF). An analysis based upon 245 North American floras indicates that the PJ woodlands of the SFVF share strong affinities with the adjacent Colorado Plateau and Apachian floristic elements but also show high floristic similarity to the Great Plains. Data suggest that mid-elevation woodlands of the Colorado Plateau share floristic affinities with the Great Plains that are as strong …

Go to article

Front Matter, Vol. 69 No. 2 Jul 2009

Front Matter, Vol. 69 No. 2

Western North American Naturalist

No abstract provided.

Go to article

A Methodology For Designing Product Components With Built-In Barriers To Reverse Engineering, Stephen P. Harston Jul 2009

A Methodology For Designing Product Components With Built-In Barriers To Reverse Engineering, Stephen P. Harston

Theses and Dissertations

Reverse engineering, defined as extracting information about a product from the product itself, is a common industry practice for gaining insight into innovative products. Both the original designer and those reverse engineering the original design can benefit from estimating the time and barrier to reverse engineer a product. This thesis presents a set of metrics and parameters that can be used to calculate the barrier to reverse engineer any product as well as the time required to do so. To the original designer, these numerical representations of the barrier and time can be used to strategically identify and improve product …

Go to article

Ant Assemblages In Intact Big Sagebrush And Converted Cheatgrass-Dominated Habitats In Tooele County, Utah, Steven M. Ostoja, Eugene W. Schupp, Kelly Sivy Jul 2009

Ant Assemblages In Intact Big Sagebrush And Converted Cheatgrass-Dominated Habitats In Tooele County, Utah, Steven M. Ostoja, Eugene W. Schupp, Kelly Sivy

Western North American Naturalist

Biological invasions are one of the greatest threats to native species in natural ecological systems. One of the most successful invasive species is Bromus tectorum L. (cheatgrass), which is having marked impacts on native plant communities and ecosystem processes. However, we know little about the effects of this invasion on native animal species in the Intermountain West. Because ants have been used to detect ecological change associated with anthropogenic land use, they seem well suited for a preliminary evaluation of the consequences of cheatgrass-driven habitat conversion. In our study, we used pitfall traps to assess ant community assemblages in intact …

Go to article

American Totalitarianism In Norman Mailer's The Naked And The Dead And The Armies Of The Night, Benjamin E. Onofrio Jul 2009

American Totalitarianism In Norman Mailer's The Naked And The Dead And The Armies Of The Night, Benjamin E. Onofrio

Theses and Dissertations

Norman Mailer's seminal works The Naked and the Dead and The Armies of the Night both outline Mailers distaste for oppression. The Naked and the Dead's bleak reprisal of oppressive leadership tactics offers little in the way of a solution to fight this power. However, twenty years later, The Armies of the Night names personal expression of political views as the answer to oppressive force within the American government. Mailer met the hypocrisy of fighting for freedom abroad while oppressing one's own citizens by encouraging personal expression and flaunting the "rules" of the novel. In the end, Mailer surmises …

Go to article

Visualizing And Modeling Mining-Induced Surface Subsidence, Marcor Gibbons Platt Jul 2009

Visualizing And Modeling Mining-Induced Surface Subsidence, Marcor Gibbons Platt

Theses and Dissertations

Ground subsidence due to underground coal mining is a complex, narrowly-understood phenomenon. Due to the complicated physical processes involved and the lack of a complete knowledge of the characteristics of overlying strata, the reliability of current prediction techniques varies widely. Furthermore, the accuracy of any given prediction technique is largely dependent upon the accuracy of field measurements and surveys which provide input data for the technique. A valuable resource available for predicting and modeling subsidence is aerial survey technology. This technology produces yearly datasets with a high density of survey points. The following study introduces a method wherein these survey …

Go to article

Characterizing Material Property Tradeoffs Of Polycrystalline Diamond For Design Evaluation And Selection, Neil David Haddock Jul 2009

Characterizing Material Property Tradeoffs Of Polycrystalline Diamond For Design Evaluation And Selection, Neil David Haddock

Theses and Dissertations

Polycrystalline diamond (PCD) is used as a cutting tool in many industries because of its superior wear resistance compared to single crystal diamond. Engineers who design new PCD materials must have an understanding of the tradeoffs between material properties in order to tailor a product for different applications. Two competing material properties that are often encountered in PCD are transverse rupture strength and thermal-resistance. Thermal-resistance is directly related to the cobalt content of PCD, and is the ability of the material to withstand thermally induced degradation. In this thesis, we characterize the tradeoff boundary between transverse rupture strength and cobalt …

Go to article

First Prev Next Last