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

Physical Sciences and Mathematics Commons

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

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 91 - 120 of 6924

Full-Text Articles in Physical Sciences and Mathematics

Sequence Stratigraphy Of The Lower Pennsylvanian (Bashkirian, Morrowan) Round Valley Limestone, Split Mountain Anticline (Dinosaur National Monument) And In The Eastern Uinta Mountains, Utah, Nathan Robert Davis Dec 2010

Sequence Stratigraphy Of The Lower Pennsylvanian (Bashkirian, Morrowan) Round Valley Limestone, Split Mountain Anticline (Dinosaur National Monument) And In The Eastern Uinta Mountains, Utah, Nathan Robert Davis

Theses and Dissertations

The Early Pennsylvanian (Bashkirian/Morrowan) Round Valley Limestone of northeastern Utah was deposited on the Wyoming shelf, a slowly subsiding depositional surface located between the Eagle and Oquirrh basins. The 311-foot-thick Round Valley Limestone displays a distinct cyclicity formed by stacked, meter-scale parasequences, comprised of a limited suite of open- to restricted-marine limestones with minor interbeds of siltstone and shale. Open-marine deposits are characterized by mudstone and heterozoan wackestone-packstone microfacies (MF1-4) and comprise the lower portions of parasequences. Rocks of these microfacies were deposited during maximum high-order transgression of the shelf. As sediment filled the limited accommodation, the shelf became restricted, …


Warped Product Einstein Metrics Over Spaces With Constant Scalar Curvature, Chenxu He, Peter Petersen, William Wylie Dec 2010

Warped Product Einstein Metrics Over Spaces With Constant Scalar Curvature, Chenxu He, Peter Petersen, William Wylie

Mathematics - All Scholarship

In this paper we study warped product Einstein metrics over spaces with constant scalar curvature. We call such a manifold rigid if the universal cover of the base is Einstein or is isometric to a product of Einstein manifolds. When the base is three dimensional and the dimension of the fiber is greater than one we show that the space is always rigid. We also exhibit examples of solvable four dimensional Lie groups that can be used as the base space of non-rigid warped product Einstein metrics showing that the result is not true in dimension greater than three. We …


Evaluation Real-Time Data Warehousing Challenges From A Theoretical And Practical Perspective, Dale Hargens Dec 2010

Evaluation Real-Time Data Warehousing Challenges From A Theoretical And Practical Perspective, Dale Hargens

Regis University Student Publications (comprehensive collection)

The concept of real-time data warehousing has grown in popularity in recent years as organizations demand access to critical pieces of data in real-time to produce analytics and make business decisions to gain competitive advantage. Real-time data warehousing systems differ substantially from traditional data warehousing systems, thus, presenting a unique set of organizational and operational challenges. The basis for the research was to investigate whether adequate information is available regarding the organizational and operational challenges of real-time data warehousing and whether that information is available to the database community. This exploration was done by gathering primary research, conducting a case …


Caesked: A Class Scheduler For Wmu Students, Chris Fruin, Jerry Grochowski Dec 2010

Caesked: A Class Scheduler For Wmu Students, Chris Fruin, Jerry Grochowski

Computer Science Senior Projects

Scheduling classes is a tedious process for WMU students. CAESked, a class scheduling web application, was created to ease this process. The programming languages PHP and JavaScript were used to build a solution which integrates WMU data for upcoming courses into a web application. With features including a weekly calendar, a campus map, and class information all in one place, CAESked provides students with an easy to use tool for adding classes to their schedule.


The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez Dec 2010

The Vinylguaiacol/Indole Or Vgi ("Veggie") Ratio: A Novel Molecular Parameter To Evaluate The Relative Contributions Of Terrestrial And Aquatic Organic Matter To Sediments., Michael A. Kruge, Kevin K. Olsen, Jaroslaw W. Slusarczyk, Elaine Gomez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The organic matter (OM) fraction of estuarine sediments is often distinctive and thus diagnostically useful in determinations of sedimentary provenance. Among the most fundamental distinctions to be made is that between terrestrial and aquatic OM. To supplement the parameters commonly used for this purpose (e.g., C/N and stable isotope ratios), we proposed the Vinylguaiacol/Indole or VGI ("Veggie") ratio, defined as [vinylguaiacol / (indole + vinylguaiacol)] using data produced by analytical pyrolysis-gas chromatography/mass spectrometry of dried, homogenized sediment samples. The ratio employs the peak areas of these two compounds on the mass chromatograms of their molecular ions (m/z 150 and 117). …


Representation And Validation Of Domain And Range Restrictions In A Relational Database-Driven Ontology Maintenance System, Patrick G. Edgett, Leong Lee, Jennifer L. Leopold, Alton B. Coalter Dec 2010

Representation And Validation Of Domain And Range Restrictions In A Relational Database-Driven Ontology Maintenance System, Patrick G. Edgett, Leong Lee, Jennifer L. Leopold, Alton B. Coalter

Computer Science Faculty Research & Creative Works

An ontology can be used to represent and organize the objects, properties, events, processes, and relations that embody an area of reality [1]. These knowledge bases may be created manually (by individuals or groups), and/or automatically using software tools, such as those developed for information retrieval and data mining. Recently the National Science Foundation funded a large collaborative development project for the semi-automated construction of an ontology of amphibian anatomy (AmphibAnat [2]). to satisfy the extensive community curation requirements of that project, a generic, Web-Based, multi-user, relational database ontology management system (RDBOM [3]) was constructed, based upon a novel theoretical …


Fitting A Distribution To Catastrophic Event, Ebenezer Osei Dec 2010

Fitting A Distribution To Catastrophic Event, Ebenezer Osei

Theses and Dissertations

Statistics is a branch of mathematics which is heavily employed in the area of Actuarial Mathematics. This thesis first reviews the importance of statistical distributions in the analysis of insurance problems and the applications of Statistics in the area of risk and insurance. The Normal, Log-normal, Pareto, Gamma, standard Beta, Frechet, Gumbel, Weibull, Poisson, binomial, and negative binomial distributions are looked at and the importance of these distributions in general insurance is also emphasized. A careful review of literature is to provide practitioners in the general insurance industry with statistical tools which are of immediate application in the industry. These …


Chaos And Universality In Two-Dimensional Ising Spin Glasses, Alan Middleton, Creighton K. Thomas, David A. Huse Dec 2010

Chaos And Universality In Two-Dimensional Ising Spin Glasses, Alan Middleton, Creighton K. Thomas, David A. Huse

Physics - All Scholarship

Recently extended precise numerical methods and droplet scaling arguments allow for a coherent picture of the glassy states of two-dimensional Ising spin glasses to be assembled. The length scale at which entropy becomes important and produces "chaos", the extreme sensitivity of the state to temperature, is found to depend on the type of randomness. For the $\pm J$ model this length scale dominates the low-temperature specific heat. Although there is a type of universality, some critical exponents do depend on the distribution of disorder.


Chemical Vapor Deposition Of Silanes And Patterning On Silicon, Feng Zhang Dec 2010

Chemical Vapor Deposition Of Silanes And Patterning On Silicon, Feng Zhang

Theses and Dissertations

Self assembled monolayers (SAMs) are widely used for surface modification. Alkylsilane monolayers are one of the most widely deposited and studied SAMs. My work focuses on the preparation, patterning, and application of alkysilane monolayers. 3-aminopropyltriethoxysilane (APTES) is one of the most popular silanes used to make active surfaces for surface modification. To possibly improve the surface physical properties and increase options for processing this material, I prepared and studied a series of amino silane surfaces on silicon/silicon dioxide from APTES and two other related silanes by chemical vapor deposition (CVD). I also explored CVD of 3-mercaptopropyltrimethoxysilane on silicon and quartz. …


Testing Embedded System Applications, Tingting Yu Dec 2010

Testing Embedded System Applications, Tingting Yu

School of Computing: Dissertations, Theses, and Student Research

Embedded systems are becoming increasingly ubiquitous, controlling a wide variety of popular and safety-critical devices. Testing is the most commonly used method for validating software systems, and effective testing techniques could be helpful for improving the dependability of these systems. However, there are challenges involved in developing such techniques. Embedded systems consist of layers of software – application layers utilize services provided by underlying system service and hardware support layers. A typical embedded application consists of multiple user tasks. Interactions between application layers and lower layers, and interactions between the various user tasks that are initiated by the application layer, …


The Fierce Green Fire: Vol. 1 Issue 7, Wofford College Environmental Studies Program Dec 2010

The Fierce Green Fire: Vol. 1 Issue 7, Wofford College Environmental Studies Program

The Fierce Green Fire

No abstract provided.


Biomarkers Of Mild Cognitive Impairment And Alzheimer's Disease, Mark A. Lovell, Bert C. Lynn Dec 2010

Biomarkers Of Mild Cognitive Impairment And Alzheimer's Disease, Mark A. Lovell, Bert C. Lynn

Chemistry Faculty Patents

A method for quantifying a neurodegenerative disorder in a patient that includes obtaining a fluid sample from the subject; measuring a protein biomarker complex in said fluid sample and correlating the measurement with mild cognitive impairment or Alzheimer's disease status. The biomarkers include those that comprise at least one of a transthyretin protein and/or a prostaglandin-H2 D-isomerase protein, and at least one second, different protein selected from a transthyretin, prostaglandin-H2 D-isomerase, beta-2-microglobulin, cystatin C, superoxide dismutase [Cu—Zn], plasma retinol-binding protein, phosphatidylethanolamine-binding protein, carbonic anhydrase 2, prostaglandin-H2 D-isomerase, and/or serotransferrin protein.


Transit Spectrophotometry Of The Exoplanet Hd 189733b Ii. New Spitzer Observations At 3.6 Μm, Jean-Michel Désert, David K. Sing, Alfred Vidal-Madjar, Guillaume Hébrard, David Ehrenreich, Alain Lecavelier Des Etangs, Vivien Parmentier, Roger Ferlet, Gregory W. Henry Dec 2010

Transit Spectrophotometry Of The Exoplanet Hd 189733b Ii. New Spitzer Observations At 3.6 Μm, Jean-Michel Désert, David K. Sing, Alfred Vidal-Madjar, Guillaume Hébrard, David Ehrenreich, Alain Lecavelier Des Etangs, Vivien Parmentier, Roger Ferlet, Gregory W. Henry

Information Systems and Engineering Management Research Publications

Context. We present a new primary transit observation of the hot-jupiter HD 189733b, obtained at 3.6 μm with the Infrared Array Camera (IRAC) onboard the Spitzer Space Telescope. Previous measurements at 3.6 microns suffered from strong systematics, and conclusions could hardly be obtained with confidence on the water detection by comparison of the 3.6 and 5.8 microns observations.

Aims. We aim at constraining the atmospheric structure and composition of the planet and improving previously derived parameters.

Methods. We use a high-S/NSpitzer photometric transit light curve to improve the precision of the near infrared radius of …


Precatalysts Useful In Polyolefin Polymerization Reactions, Omofolami Tesileem Ladipo, Richard Eaves, Alexey Zazybin, Sean Parkin Dec 2010

Precatalysts Useful In Polyolefin Polymerization Reactions, Omofolami Tesileem Ladipo, Richard Eaves, Alexey Zazybin, Sean Parkin

Chemistry Faculty Patents

Compounds are provided that are useful as precatlysts in the polymerization of olefins such as ethylene and propylene. Other compounds are useful as intermediates in the production of such precatalysts.


On A Generalized Time-Varying Seir Epidemic Model With Mixed Point And Distributed Time-Varying Delays And Combined Regular And Impulsive Vaccination Controls, Ravi P. Agarwal, Manuel De La Sen, Asier Ibeas, Santiago Alonso-Quesada Dec 2010

On A Generalized Time-Varying Seir Epidemic Model With Mixed Point And Distributed Time-Varying Delays And Combined Regular And Impulsive Vaccination Controls, Ravi P. Agarwal, Manuel De La Sen, Asier Ibeas, Santiago Alonso-Quesada

Mathematics and System Engineering Faculty Publications

This paper discusses a generalized time-varying SEIR propagation disease model subject to delays which potentially involves mixed regular and impulsive vaccination rules. The model takes also into account the natural population growing and the mortality associated to the disease, and the potential presence of disease endemic thresholds for both the infected and infectious population dynamics as well as the lost of immunity of newborns. The presence of outsider infectious is also considered. It is assumed that there is a finite number of time-varying distributed delays in the susceptible-infected coupling dynamics influencing the susceptible and infected differential equations. It is also …


Superhydrophobic Thin Films Fabricated By Reactive Layer-By-Layer Assembly Of Azlactone-Functionalized Polymers, Maren E. Buck, Sarina C. Schwartz, David M. Lynn Dec 2010

Superhydrophobic Thin Films Fabricated By Reactive Layer-By-Layer Assembly Of Azlactone-Functionalized Polymers, Maren E. Buck, Sarina C. Schwartz, David M. Lynn

Chemistry: Faculty Publications

We report an approach to the fabrication of superhydrophobic thin films that is based on the "reactive" layer-by-layer assembly of azlactone-containing polymer multilayers. We demonstrate that films fabricated from alternating layers of the azlactone functionalized polymer poly(2-vinyl- 4,4-dimethylazlactone) (PVDMA) and poly(ethyleneimine) (PEI) exhibit micro- and nanoscale surface features that result in water contact angles in excess of 150°. Our results reveal that the formation of these surface features is (i) dependent upon film thickness (i.e., the number of layers of PEI and PVDMA deposited) and (ii) that it is influenced strongly by the presence (or absence) of cyclic azlactone-functionalized oligomers …


Pauli Spin Blockade And Lifetime-Enhanced Transport In A Si/Sige Double Quantum Dot, C. B. Simmons, Teck Seng Koh, Nakul Shaji, Madhu Thalakulam, L. J. Klein, Hua Qin, H. Luo, D. E. Savage, M. G. Lagally, A. J. Rimberg Dec 2010

Pauli Spin Blockade And Lifetime-Enhanced Transport In A Si/Sige Double Quantum Dot, C. B. Simmons, Teck Seng Koh, Nakul Shaji, Madhu Thalakulam, L. J. Klein, Hua Qin, H. Luo, D. E. Savage, M. G. Lagally, A. J. Rimberg

Dartmouth Scholarship

We analyze electron-transport data through a Si/SiGe double quantum dot in terms of spin blockade and lifetime-enhanced transport (LET), which is transport through excited states that is enabled by long spin-relaxation times. We present a series of low-bias voltage measurements showing the sudden appearance of a strong tail of current that we argue is an unambiguous signature of LET appearing when the bias voltage becomes greater than the singlet-triplet splitting for the (2,0) electron state. We present eight independent data sets, four in the forward-bias (spin-blockade) regime and four in the reverse-bias (lifetime-enhanced transport) regime and show that all eight …


Rapid Landscape Transformation In South Island, New Zealand, Following Initial Polynesian Settlement, David B. Mcwethy, Cathy Whitlock, Janet M. Wilmshurst, Matt S. Mcglone, Mairie Fromont, Xun Li, Ann Dieffenbacher-Krall, William O. Hobbs, Sherilyn C. Fritz, Edward R. Cook Dec 2010

Rapid Landscape Transformation In South Island, New Zealand, Following Initial Polynesian Settlement, David B. Mcwethy, Cathy Whitlock, Janet M. Wilmshurst, Matt S. Mcglone, Mairie Fromont, Xun Li, Ann Dieffenbacher-Krall, William O. Hobbs, Sherilyn C. Fritz, Edward R. Cook

Department of Earth and Atmospheric Sciences: Faculty Publications

Humans have altered natural patterns of fire for millennia, but the impact of human-set fires is thought to have been slight in wet closed-canopy forests. In the South Island of New Zealand, Polynesians (Māori), who arrived 700–800 calibrated years (cal y) ago, and then Europeans, who settled ∼150 cal y ago, used fire as a tool for forest clearance, but the structure and environmental consequences of these fires are poorly understood. High-resolution charcoal and pollen records from 16 lakes were analyzed to reconstruct the fire and vegetation history of the last 1,000 y. Diatom, chironomid, and element concentration data were …


Do Cosmological Perturbations Have Zero Mean?, Christian Armendariz-Picon Dec 2010

Do Cosmological Perturbations Have Zero Mean?, Christian Armendariz-Picon

Physics - All Scholarship

A central assumption in our analysis of cosmic structure is that cosmological perturbations have zero ensemble mean. This property is one of the consequences of statistically homogeneity, the invariance of correlation functions under spatial translations. In this article we explore whether cosmological perturbations indeed have zero mean, and thus test one aspect of statistical homogeneity. We carry out a classical test of the zero mean hypothesis against a class of alternatives in which perturbations have non-vanishing means, but homogeneous and isotropic covariances. Apart from Gaussianity, our test does not make any additional assumptions about the nature of the perturbations and …


Paranets: A Parallel Network Architecture For The Future Internet, Khaled Harras, Abderrahmen Mtibaa Dec 2010

Paranets: A Parallel Network Architecture For The Future Internet, Khaled Harras, Abderrahmen Mtibaa

Computer Science Faculty Works

The evolution of networking technologies and portable devices has led users to expect connectivity anytime and everywhere. We have reached the point of seeing networking occur underwater, via aerial devices, and across space. While researchers push the true boundaries of networking to serve a wide range of environments, there is the challenge of providing robust network connectivity beyond the boundaries of the core internet, defined by fiber optics and well-organized backbones. As the internet edges expand, the expectation is that connectivity will be as good, in terms of high bandwidth and minimal interruption, as anywhere in the core. Such an …


Uncertainty Associated With Modeling The Global Ionosphere, Janelle V. Jenniges, Ariel O. Acebal, Larry Gardner, Robert W. Schunk, Lie Zhu Dec 2010

Uncertainty Associated With Modeling The Global Ionosphere, Janelle V. Jenniges, Ariel O. Acebal, Larry Gardner, Robert W. Schunk, Lie Zhu

Physics Student Research

A study has been conducted of the effect that different physical assumptions have on global models of the electron density distribution. The study was conducted with the Ionosphere Forecast Model (IFM) and the Ionosphere Plasmasphere Model (IPM) developed by Utah State University. Both physics-based, time-dependent, global models use the same empirical models for the neutral atmosphere (MSIS) and neutral wind (Horizontal Wind Model, HWM), but the altitude range, thermal structure, number of ion species, and magnetic 2ield are different. The IFM covers the altitude range from 90-1400 km, calculates the densities for four ions (NO+, O2+, N2+, O+), has a …


Dihomotopic Deadlock Detection Via Progress Shell Decomposition, David A. Cape, Stephen C. Jackson, Bruce M. Mcmillin Dec 2010

Dihomotopic Deadlock Detection Via Progress Shell Decomposition, David A. Cape, Stephen C. Jackson, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

The classical problem of deadlock detection for concurrent programs has traditionally been accomplished by symbolic methods or by search of a state transition system. This work examines an approach that uses geometric semantics involving the topological notion of dihomotopy to partition the state space into components, followed by search of a reduced state space. Prior work partitioned the state-space inductively. in this work, a decomposition technique motivated by recursion coupled with a search guided by the decomposition is shown to effectively reduce the size of state transition systems. the reduced state space yields asymptotic improvement in overall runtime for verification. …


Isomer-Dependent Adsorption And Release Of Cis- And Trans-Platin Anticancer Drugs By Mesopomus Silica Nanoparticles, Zhimin Tao, Youwei Xie, Jerry Goodisman, Tewodros Asefa Dec 2010

Isomer-Dependent Adsorption And Release Of Cis- And Trans-Platin Anticancer Drugs By Mesopomus Silica Nanoparticles, Zhimin Tao, Youwei Xie, Jerry Goodisman, Tewodros Asefa

Chemistry - All Scholarship

We report on adsorption and release of the anticancer drugs cisplatin and transplatin from mesoporous silica nanomaterials, emphasizing the differences between cisplatin and its much less toxic isomer. Two types of particles, M.CM-41 and SBA-IS, were used, either as just synthesized or after calcination to remove the templates. The particles were characterized by TEM, nitrogen physisorption, and elemental analysis. The UV-vis spectra of cisplatin and transplatin were obtained and the intensities of several bands (205-210 nm, 210-220 nm, 220-235 nm, and 300-330 nm) were found proportional to drug concentrations, allowing their use for measuring drug concentration. To evaluate drug adsorption …


Activation Of Propargylic Alcohols By Piano-Stool Ruthenium Complexes Bearing Phosphoramidite Ligands, Stephen Andrew Costin Dec 2010

Activation Of Propargylic Alcohols By Piano-Stool Ruthenium Complexes Bearing Phosphoramidite Ligands, Stephen Andrew Costin

Dissertations

Various piano-stool ruthenium complexes bearing phosphoramidite ligands have been synthesized and characterized spectroscopically and in some cases structurally. Reaction of phosphoramidite ligands with an appropriate metal precursor gives new piano-stool ruthenium complexes [RuCl(L)(arene)(phosphoramidite)], where L = Cl, PPh3, or others. The novel complexes are tested for their ability to activate propargylic alcohols catalytically as well as stoichiometrically. Specifically, catalytic substitution of propargylic alcohols via allenylidene intermediates is envisioned. Stoichiometric reactions designed to form stable, isolable allenylidenes are sought as well. h6-p-cymene complexes of the type [RuCl2(h6-p-cymene)(phosphoramidite)] activate propargylic alcohols in the reaction with carboxylic acids to form b-oxo esters. The …


Web-Based Ide To Create Model And Controller Components For Mvc-Based Web Applications On Cakephp, Sugiharto Widjaja Dec 2010

Web-Based Ide To Create Model And Controller Components For Mvc-Based Web Applications On Cakephp, Sugiharto Widjaja

Master's Projects

A Web-based IDE that allows users to easily manage Model and Controller components of a CakePHP web application was developed. With this IDE, users are able to manage the model and controller components without having to write very much PHP code. They are able to create new model components without having to worry about creating the database tables for the models as the IDE creates them automatically. The IDE offers a simple interface for users to edit the schema of their models. Users can add or delete data from their models without dealing with the SQL insert/delete statements. The IDE …


Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean Dec 2010

Volcanic Stratigraphy And A Kinematic Analysis Of Ne-Trending Faults Of Allens Ranch 7.5' Quadrangle, Utah County, Utah, Adam Paul Mckean

Theses and Dissertations

The mineral resources of the Tintic Mining District are influenced by three major events in its geologic history; the Mesozoic Sevier Orogeny, Paleogene volcanism and Late Neogene Basin and Range extension. In this paper a detailed analysis of each these geologic events is presented to help us understand the structural host, mineralization and exhumation of the Tintic Mining District ore. A kinematic analysis of the faults was completed to determine the origin of NE-trending faults, Sevier Orogeny or Basin and Range extension, in the northern part of the East Tintic Mountains in Allens Ranch 7.5' quadrangle, near the eastern margin …


Trusted Mobile Overlays, Robert Scott Robertson Dec 2010

Trusted Mobile Overlays, Robert Scott Robertson

Theses and Dissertations

Sensitive information is increasingly moving online and as data moves further from the control of its owner, there are increased opportunities for it to fall into malicious hands. The Web is comprised of three untrusted components where there is a risk of information compromise: networks, service providers, and clients. This thesis presents Trusted Mobile Overlays: a system that leverages trusted mobile devices to protect users from these untrusted components of the Web, while minimizing deployment difficulties. It presents a high-level design of the system as well as a prototype that implements the design.


Preventing Computer Identity Theft, Donald R. Mcdaniel Dec 2010

Preventing Computer Identity Theft, Donald R. Mcdaniel

Regis University Student Publications (comprehensive collection)

The arrival of the information age has created new challenges to the ability of individuals to protect the security and privacy of their personal information. One such challenge is that of identity theft, which has caused a number of hardships upon its victims. Perpetrators of this fraud may use identities of others to obtain loans, steal money, and violate the law. This paper will discuss the characteristics of the offenders and victims of identity theft. A systematic approach for preventing identity theft will also be presented with the hopes of curtailing this epidemic.


Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal Dec 2010

Nanoparticle Doped Photopolymer With Reduced Shrinkage For Holographic Recording, Mohesh Moothanchery, Svetlana Mintova, Izabela Naydenova, Vincent Toal

Conference Papers

We demonstrate holographic recording with Si-MFI zeolite doped acrylamide based photopolymerfilm. The influence of silicate nanoparticles on photopolymer shrinkage has been studied and compared withshrinkage in undoped photopolymer layers The shrinkage of the material (1.03%) is significantly lower forrecording in Si-MFI zeolite nanoparticle doped samples than for undoped layers (1.77%).


Sources Of The Radio Background Considered, Jack Singal, L. Stawarz, A. Lawrence, V. Petrosian Dec 2010

Sources Of The Radio Background Considered, Jack Singal, L. Stawarz, A. Lawrence, V. Petrosian

Physics Faculty Publications

We investigate different scenarios for the origin of the extragalactic radio background. The surface brightness of the background, as reported by the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission 2 (ARCADE 2) collaboration, is several times higher than that which would result from currently observed radio sources. We consider contributions to the background from diffuse synchrotron emission from clusters and the intergalactic medium, previously unrecognized flux from low-surface-brightness regions of radio sources and faint point sources below the flux limit of existing surveys. By examining radio source counts available in the literature, we conclude that most of the radio …