Physical Sciences and Mathematics Commons^™

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2005 Through December 31, 2005, Anthony Hechanova

Publications (NSTD)

• Liquid Salt Technical Working Group Meeting. The first meeting of the Liquid Salt Technical Working Group was held on October 28, 2005 at the Pratt Whitney Rocketdyne facility in Canoga Park, CA. 20 experts from academia, industry, and national laboratories participated to discuss current state of knowledge and research needs for high temperature liquid salt applications.
• Nuclear Hydrogen Initiative Semi-annual Review. Several participants from the UNLVRF University Consortium gave technical presentations at the NHI Semi-annual Review meeting in Rockville, MD, November 9-10, 2005.
• Quarterly Collaboration Meeting. The University of Nevada, Las Vegas hosted a UNLVRF HTHX Project quarterly meeting December …

Precision Top-Quark Mass Measurement In The Lepton+Jets Topology In Pp̅ Collisions At √S =1.96 Tev, A. Abulencia, Kenneth A. Bloom, Cdf Collaboration

Kenneth Bloom Publications

We report two measurements of the top-quark mass M_top using the CDF II detector at the Fermilab Tevatron in a 318 pb^-1 data sample of tt̅ events in the lepton + jets final state. One method uses an event-based likelihood technique resulting inM_top = 173.2_-2.4^+2.6(stat) ± 3.2(syst) GeV/c² or 173.2_-4.0^+4.1GeV/c². The second method reconstructs a top-quark mass in each event using the measured invariant mass of the hadronically decaying W boson to constrain the jet energy scale to obtain a value forM_top of …

Evolution Of Stellar Bars In Live Axisymmetric Halos: Recurrent Buckling And Secular Growth, Inma Martinez-Valpuesta, Isaac Shlosman, Clayton Heller

Department of Physics and Astronomy Faculty Publications

Evolution of stellar bars in disk galaxies is accompanied by dynamical instabilities and secular changes. Following the vertical buckling instability, the bars are known to weaken dramatically and develop a pronounced boxy/ peanut shape when observed edge-on. Using high-resolution N-body simulations of stellar disks embedded in live axisymmetric dark matter halos, we have investigated the long-term changes in the bar morphology, specifically the evolution of the bar size, its vertical structure, and the exchange of angular momentum. We find that following the initial buckling, the bar resumes its growth from deep inside the corotation radius and follows the ultraharmonic resonance …

Numerical Simulation Of Nonlinear Elastic Wave Propagation In Piecewise Homogeneous Media, Arkadi Berezovski, Mihhail Berezovski, Juri Engelbrecht

Publications

Systematic experimental work [S. Zhuang, G. Ravichandran, D. Grady, J. Mech. Phys. Solids 51 (2003) 245–265] on laminated composites subjected to high velocity impact loading exhibits the dispersed wave field and the oscillatory behavior of waves with respect to a mean value. Such a behavior is absent in homogeneous solids. An approximate solution to the plate impact in layered heterogeneous solids has been developed in [X. Chen, N. Chandra, A.M. Rajendran, Int. J. Solids Struct. 41 (2004) 4635–4659]. The influence of the particle velocity on many process characteristics was demonstrated. Based on earlier results [A. Berezovski, J. Engelbrecht, G.A. Maugin, …

Optical Dipole Traps For Cold Atoms Using Diffracted Laser Light, Glen D. Gillen, Shekhar Guha, Katharina Christandl

Physics

We theoretically investigate the feasibility of using intensity distributions of light of a single laser beam diffracted by a circular aperture as optical dipole traps for cold neutral atoms. Localized and cylindrically symmetric traps on the central axis of the circular aperture exist for both blue- and red-detuned laser light. Experimental mapping of the spots of interest using CO₂ laser light demonstrates the existence of these light distributions for laboratory conditions and their agreement with theoretical predictions.

Use Of Unbiased Estimating Equations To Estimate Correlation In Generalized Estimating Equation Analysis Of Longitudinal Trials, Wenguang Sun, Justine Shults, Mary Leonard

UPenn Biostatistics Working Papers

In a recent publication, Wang and Carey (Journal of the American Statistical Association, 99, pp. 845-853, 2004) presented a new approach for estimation of the correlation parameters in the framework of generalized estimating equations (GEE). They considered correlated continuous, binary and count data with a generalized Markov correlation structure that includes the first-order autoregressive AR(1) and Markov structures as special cases. They made detailed comparisons with pseudo-likelihood (PL) and the first stage of quasi-least squares (QLS), a two-stage approach in the framework of generalized estimating equations (GEE). In this note we extend their comparisons for the second (bias corrected) stage …

Indiana Wildlife Disease News, Volume 1, Issue 1 -- January 2006

Indiana Wildlife Disease News

Special points of interest:
• Special Issue on Avian Influenza
• Understanding bird migration and how it could relate to the spread of AI
• A brief history of AI in the United States
• An update on wildlife disease in Indiana and surrounding states
• The purpose of Indiana Wildlife Disease News

Inside this issue:
Migratory Bird Flyways 2
History of AI in the United States 2
Winter mortality in birds 3
Mycoplasmal conjunctivitis 3
AI and Migratory Birds 4
Midwest Wildlife Disease Update 5
ASERT (Animal Surveillance and Emergency Response Teams) 5

Sudden Gravitational Transition, Robert R. Caldwell, William Komp, Leonard Parker, Daniel A. T. Vanzella

Dartmouth Scholarship

We investigate the properties of a cosmological scenario which undergoes a gravitational phase transition at late times. In this scenario, the Universe evolves according to general relativity in the standard, hot big bang picture until a redshift z≲1. Nonperturbative phenomena associated with a minimally-coupled scalar field catalyzes a transition, whereby an order parameter consisting of curvature quantities such as R2, RabRab, RabcdRabcd acquires a constant expectation value. The ensuing cosmic acceleration appears driven by a dark-energy component with an equation-of-state w<−1. We evaluate the constraints from type 1a supernovae, the cosmic microwave background, and other cosmological observations. We find that a range of models making a sharp transition to cosmic acceleration are consistent with observations.

Parity-Violating Electron Scattering From (4)He And The Strange Electric Form Factor Of The Nucleon, K. A. Aniol, Timothy Holmstrom, Happex Collaboration

Chemistry & Physics Faculty Publications

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from ⁴He at an average scattering angle ⟨θ_lab⟩=5.7° and a four-momentum transfer Q²=0.091  GeV². From these data, for the first time, the strange electric form factor of the nucleon G_E^s can be isolated. The measured asymmetry of A_PV=(6.72±0.84_(stat)±0.21_(syst))×10^-6 yields a value ofG_E^s=-0.038±0.042_(stat)±0.010_(syst), consistent with zero.

Liquid Chromatography-Electrospray Ionization Mass Spectrometry For Direct Identification And Quantification Of Iophenoxic Acid In Serum, Melinda C. Wiles, Tyler A. Campbell

United States Department of Agriculture Wildlife Services: Staff Publications

A liquid chromatographic electrospray ionization mass spectrometric technique was developed for direct quantitation of iophenoxic acid (IA) in serum. IA was spiked into canine, feline, bovine, equine, and porcine sera, extracted, and quantified using negative ion monitoring following chromatographic separation on a Luna C18(2) 3 μm (100mm×2.1 mm) reversed-phase column. The limit of detection was 25 ng/mL and the limit of quantification was 50 ng/mL. Inter- and intra-assay accuracy (86–113% and 87–115%, respectively) and precision (1.8–7.7%) were calculated. Analysis of serum collected from feral pigs, raccoons, and opossums following ingestion of IA-marked baits confirmed the appropriateness of this method for …

Correlating Factors Between Student Participation And Student Learning Via A Service Learning Project In Secondary Education: A Case Study, Shawn V. Jensen

Theses and Dissertations

In this study a service-learning project was conducted with secondary students in a construction technology based course. Three research questions were considered; (1) does service learning projects help to engage student participation, (2) can students learn the course curriculum while participating in a service learning project, and (3) is there a correlation between student participation and student learning as it pertains to service learning projects? The data was collected through surveys, observations, interviews, and evaluations. The researcher concluded the following from the study; 92% of the students were actively participating in the two week service project, 76% of the students …

Fluid-Solid Transition In A Hard-Core System, Lewis Bowen, Russell Lyons, Charles Radin, Peter Winkler

Dartmouth Scholarship

We prove that a system of particles in the plane, interacting only with a certain hard-core constraint, undergoes a fluid-solid phase transition.

Red Rock Desert Learning Center Core Group Meeting: January 17, 2006, Red Rock Desert Learning Center

Reports (RRLC)

1. Introductions & Announcements (5 min.)
2. Approval of Minutes from December 6, 2005 Meeting (5 min.)
3. Update on Project Schedule – Michael Reiland (10 min.)
   A. Utilities
   B. Parking
   C. Construction Estimates/Inflation
4. Statement of Work/Request for Information Update – Michael Reiland
   (10 min.)
5. Update on Water Line – Michael Reiland/Las Vegas Valley Water District
   (10 min.)
6. Update on Environmental Assessment – Michael Reiland (10 min.)
7. Update on Curriculum Development – Jeanne Klockow (5 min.)
8. Standing Reports (10 min.)
   A. Line and Space Architects
   B. BLM Capital Improvements – Michael Reiland
   C. Community Outreach – LaNelda Rolley
   --RRDLC Open House, January 26, …

Energetically Optimal Travel Across Terrain: Visualizations And A New Metric Of Geographic Distance With Archaeological Applications, Brian M. Wood, Zoë J. Wood

Computer Science and Software Engineering

We present a visualization and computation tool for modeling the caloric cost of pedestrian travel across three dimensional terrains. This tool is being used in ongoing archaeological research that analyzes how costs of locomotion affect the spatial distribution of trails and artifacts across archaeological landscapes. Throughout human history, traveling by foot has been the most common form of transportation, and therefore analyses of pedestrian travel costs are important for understanding prehistoric patterns of resource acquisition, migration, trade, and political interaction. Traditionally, archaeologists have measured geographic proximity based on "as the crow flies" distance. We propose new methods for terrain visualization …

Tsil: A Program For The Calculation Of Two-Loop Self-Energy Integrals, Steve P. Martin, David G. Robertson

Physics Faculty Scholarship

TSIL is a library of utilities for the numerical calculation of dimensionally regularized two-loop self-energy integrals. A convenient basis for these functions is given by the integrals obtained at the end of O.V. Tarasov's recurrence relation algorithm. The program computes the values of all of these basis functions, for arbitrary input masses and external momentum. When analytical expressions in terms of polylogarithms are available, they are used. Otherwise, the evaluation proceeds by a Runge–Kutta integration of the coupled first-order differential equations for the basis integrals, using the external momentum invariant as the independent variable. The starting point of the integration …

Factors Contributing To Dust Emissions In Clark County, Nevada Quarterly Progress Report: Period Ending January 15, 2006, Margaret N. Rees

Dust Emissions from Public Lands

• Task agreement formally executed November 1, 2005
• Search for post-doctoral scholar commenced November 17, 2005

Leadership In Technical Resources And Teams, Mike Bush

Regis University Student Publications (comprehensive collection)

In today's business environment, organizations look to technology to solve a myriad of issues. These issues range from 24 X 7 X 365 shopping hours via the internet to dashboards that indicate the health of the business to knowledge management implementations where timely, accurate access to organizational knowledge is available. In all cases, the technology enables the business functions. Because of this reliance, technical resources and technical teams are expected to display leadership in actions, in thinking and on an equal plane as their business person counterparts. Most Master of Business Administration programs require a "Ëœmanagement' or a "Ëœleadership' section …

Is Hollywood Good For Mathematics? (A Brief Discussion)., Christopher D. Goff

College of the Pacific Faculty Presentations

Mathematics has played a role in many recent films, such as Good Will Hunting, A Beautiful Mind, and Proof. But how exactly is mathematics being portrayed? What ramifications does this portrayal have on our ”students,” broadly defined? In Good Will Hunting, mathematics is Will’s ticket out of his lower-class life and into a prestigious existence. In A Beautiful Mind, mathematical talent and schizophrenia are identified, at least in part. In Proof, mathematics not only links a daughter to her late father, but it also provides a backdrop for much of the story’s conflict. In this discussion, we will begin by …

Case-Cohort Methods For Survival Data On Families From Routine Registers, Tron Anders Moger, Yudi Pawitan, Ørnulf Borgan

UW Biostatistics Working Paper Series

In the Nordic countries, there exist several registers containing information on diseases and risk factors for millions of individuals. This information can be linked into families by use of personal identification numbers, and represent a great opportunity for studying diseases that show familial aggregation. Due to the size of the registers, it is difficult to analyze the data by using traditional methods for multivariate survival analysis, such as frailty or copula models. Since the size of the cohort is known, case-cohort methods based on pseudo-likelihoods are suitable for analyzing the data. We present methods for sampling control families both with …

Comparison Of Haplotype-Based And Tree-Based Snp Imputation In Association Studies, James Y. Dai, Ingo Ruczinski, Michael Leblanc, Charles Kooperberg

UW Biostatistics Working Paper Series

Missing single nucleotide polymorphisms (SNPs) are quite common in genetic association studies. Subjects with missing SNPs are often discarded in analyses, which may seriously undermine the inference of SNP-disease association. In this article, we compare two haplotype-based imputation approaches and one regression tree-based imputation approach for association studies. The goal is to assess the imputation accuracy, and to evaluate the impact of imputation on parameter estimation. Haplotype-based approaches build on haplotype reconstruction by the expectation-maximization (EM) algorithm or a weighted EM (WEM) algorithm, depending on whether case-control status is taken into account. The tree-based approach uses a Gibbs sampler to …

Search For Neutral Higgs Bosons Of The Minimal Supersymmetric Standard Model Decaying To Τ Pairs In Pp̅ Collisions At √S = 1:96 Tev, A. Abulencia, Kenneth A. Bloom, Cdf Collaboration

Kenneth Bloom Publications

We present a search for neutral supersymmetric Higgs bosons decaying to τ pairs produced in pp̅ collisions at √s =1:96 TeV. The data, corresponding to 310 pb^-1 integrated luminosity, were collected with the Collider Detector at Fermilab in run II of the Tevatron. No significant excess above the standard model backgrounds is observed. We set exclusion limits on the production cross section times branching fraction to τ pairs for Higgs boson masses in the range from 90 to 250 GeV/c².

Domain Architecture Of Protein-Disulfide Isomerase Facilitates Its Dual Role As An Oxidase And An Isomerase In Ero1p-Mediated Disulfide Formation, Mohini Kulp, Eva Maria Frickel, Lars Ellgaard, Jonathan S. Weissman

Chemistry: Faculty Publications

Native disulfide bond formation in eukaryotes is dependent on protein-disulfide isomerase (PDI) and its homologs, which contain varying combinations of catalytically active and inactive thioredoxin domains. However, the specific contribution of PDI to the formation of new disulfides versus reduction/rearrangement of non-native disulfides is poorly understood. We analyzed the role of individual PDI domains in disulfide bond formation in a reaction driven by their natural oxidant, Ero1p. We found that Ero1p oxidizes the isolated PDI catalytic thioredoxin domains, A and A′ at the same rate. In contrast, we found that in the context of full-length PDI, there is an asymmetry …

Semidefinite Programming And Stability Of Dynamical System, Kazumi Niki Stovall

Mathematics Theses

In the first part of the thesis we present several interior point algorithms for solving certain positive definite programming problems. One of the algorithms is adapted for finding out whether there exists or not a positive definite matrix which is a real linear combination of some given symmetric matrices A1,A2, . . . ,Am. In the second part of the thesis we discuss stability of nonlinear dynamical systems. We search using algorithms described in the first part, for Lyapunov functions of a few forms. A suitable Lyapunov function implies the existence of a hyperellipsoidal attraction region for the dynamical system, …

Topology Control, Routing Protocols And Performance Evaluation For Mobile Wireless Ad Hoc Networks, Hui Liu

Computer Science Dissertations

A mobile ad-hoc network (MANET) is a collection of wireless mobile nodes forming a temporary network without the support of any established infrastructure or centralized administration. There are many potential applications based the techniques of MANETs, such as disaster rescue, personal area networking, wireless conference, military applications, etc. MANETs face a number of challenges for designing a scalable routing protocol due to their natural characteristics. Guaranteeing delivery and the capability to handle dynamic connectivity are the most important issues for routing protocols in MANETs. In this dissertation, we will propose four algorithms that address different aspects of routing problems in …

Node Caching Enhancement Of Reactive Ad Hoc Routing Protocol, Sunsook Jung

Computer Science Theses

Enhancing route request broadcasting protocols constitutes a substantial part of research in mobile ad hoc network routing. In the thesis, enhancements of ad hoc routing protocols, energy efficiency metrics and clustered topology generators are discussed. The contributions include the followings. First, a node caching enhancement of Ad-hoc On-demand Distance Vector (AODV) routing protocol is introduced. Extensive simulation studies of the enhanced AODV in NS2 shows up to 9-fold reduction in the routing overhead, up to 20% improvement in the packet delivery ratio and up to 60% reduction in the end-to-end delay. The largest improvement happens to highly stressed situations. Secondly, …

A Survey, Taxonomy, And Analysis Of Network Security Visualization Techniques, Rawiroj Robert Kasemsri

Computer Science Theses

Network security visualization is a relatively new field and is quickly gaining momentum. Network security visualization allows the display and projection of the network or system data, in hope to efficiently monitor and protect the system from any intrusions or possible attacks. Intrusions and attacks are constantly continuing to increase in number, size, and complexity. Textually reading through log files or other textual sources is currently insufficient to secure a network or system. Using graphical visualization, security information is presented visually, and not only by text. Without network security visualization, reading through log files or other textual sources is an …

Web Shopping Expert Systems Using New Interval Type-2 Fuzzy Reasoning, Ling Gu

Computer Science Theses

Finding a product with high quality and reasonable price online is a difficult task due to the fuzzy nature of data and queries. In order to handle the fuzzy problem, a new type-2 fuzzy reasoning based decision support system, the Web Shopping Expert for online users is proposed. In the Web Shopping Expert, an interval type-2 fuzzy logic system is used and a fuzzy output can be obtained using the up-low limit technique, which offers an opportunity to directly employ all the rules and methods of the type-1 fuzzy sets onto the type-2 fuzzy sets. To achieve the best performance …

A Prototype Visible To Near-Infrared Spectrograph For The Chara Array, A Long-Baseline Stellar Interferometer, Chad Elliott Ogden

Physics and Astronomy Dissertations

This work is a description of the Visible to near Infrared Spectrograph system for the CHARA array. The CHARA Array is a 6-telescope interferometer at the Mount Wilson Observatory in the mountains north of Pasadena, California. It combines the light from the 1-meter telescopes, and measures the visibility of the resulting interference fringes, which gives information about the source intensity distribution on the sky. The resolution of the instrument is proportional to the telescope separation, or baseline, divided by the wavelength. The VIS system operates in the 600-1000~nm wavelength range, a factor of 3 to 4 shorter than the standard …

Simulating A Pipelined Reconfigurable Mesh On A Linear Array With A Reconfigurable Pipelined Bus System, Mathura Gopalan

Computer Science Theses

Due to the unidirectional nature of propagation and predictable delays, optically pipelined buses have been gaining more attention. There have been many models proposed over time that use reconfigurable optically pipelined buses. The reconfigurable nature of the models makes them capable of changing their component’s functionalities and structure that connects the components at every step of computation. There are both one dimensional as well as k –dimensional models that have been proposed in the literature. Though equivalence between various one dimensional models and equivalence between different two dimensional models had been established, so far there has not been any attempt …

A System For Rapid Configuration Of Distributed Workflows Over Web Services And Their Handheld-Based Coordination, Jaimini Joshi

Computer Science Theses

Web services technology has lately stirred tremendous interest in industry as well as the academia. Web services are self-contained, platform independent functionality which is available over the internet. Web services are defined, discovered & accessed using a standard protocols like WSDL, UDDI & SOAP. With the advent of Service-Oriented Architecture and need for more complex application, it became eminent to have a way in which these independent entities could collaborate in a coherent manner to provide a high level functionality. But the problem of service composition is not an easy one. One reason being the self-contained and loosely coupled interaction …