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2013

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Articles 121 - 150 of 1248

Full-Text Articles in Physics

Contributions To Pion Decay From Lorentz Violation In The Weak Sector, Brett David Altschul Oct 2013

Contributions To Pion Decay From Lorentz Violation In The Weak Sector, Brett David Altschul

Faculty Publications

Lorentz violation in the weak sector would affect the β-decay lifetimes of pions. The decay amplitude may be rendered anisotropic, but only an isotropic violation of boost invariance can affect the net lifetime in the center-of-mass frame. However, since the rest frames of the pions that produce the NuMI neutrino beam at Fermilab vary with the rotation of the Earth, it is possible to constrain anisotropic Lorentz violation using prior analyses of sidereal variations in the event rate at the MINOS near detector. The resulting bounds on weak-sector Lorentz violation are at the 10−4 level, a substantial improvement over …

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Imaging Molecular Structures With Atomic Force Microscopy, Unurbat Erdenemunkh, Tyler Flanagan Oct 2013

Imaging Molecular Structures With Atomic Force Microscopy, Unurbat Erdenemunkh, Tyler Flanagan

Student Works

As part of the LEEP project we repaired the Atomic Force Microscopy (AFM), and wrote a user manual on using AFM. Then we scanned Self Assembly of Copolymer Films collaboration with Prof. Sergio Granados –Focil and Copper Oxide Nanocubes with Professor Prof.Luis Smith.

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Using Open Datasets And Simulations In Laboratories, Jim Crumley Oct 2013

Using Open Datasets And Simulations In Laboratories, Jim Crumley

Physics Faculty Publications

While advances in instrumentation physics have made many areas more accessible to undergraduate physics laboratories, other areas are still beyond reach. Open data sets and simulations can open up some other frontiers of physics, such as Space Physics and Astronomy. In this talk, I will give an overview of some resources for open data and simulations, and then describe my experiences using these tools in both introductory and advanced labs in our curriculum.

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New Insights Into The Study Of Magnetic Field In The Clumpy Torus Of Agn Using Near-Infrared Polarimetry, Enrique Lopez-Rodriguez, Christopher C. Packham, Stuart Young, Moshe Elitzur, Nancy A. Levenson, Rachel E. Mason, Christina Ramos Almeida, Almudena Alonso-Herrero, Terry J. Jones, Eric S. Perlman Oct 2013

New Insights Into The Study Of Magnetic Field In The Clumpy Torus Of Agn Using Near-Infrared Polarimetry, Enrique Lopez-Rodriguez, Christopher C. Packham, Stuart Young, Moshe Elitzur, Nancy A. Levenson, Rachel E. Mason, Christina Ramos Almeida, Almudena Alonso-Herrero, Terry J. Jones, Eric S. Perlman

Aerospace, Physics, and Space Science Faculty Publications

We present J, H and K., imaging polarimetry of IC5063. N1R polarimetry observations may advance our understanding of the mechanisms of polarisation and hence magnetic field strength in the torus of AGN. In these proceedings we summarize the polarisation results of the central 1.2" aperture (̃263 pc) of IC5063. We present a simple polarising model to account for various mechanisms of polarisation in the central regions of IC5063. The model is consistent with dichroic absorption from diffuse stellar emission through dust in the nuclear bulge and electron scattering as dominant mechanisms of polarisation at J and H. Dichroic absorption from …

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Spalding To Receive National Physics Award, Kim Hill Oct 2013

Spalding To Receive National Physics Award, Kim Hill

News and Events (Discontinued Series)

No abstract provided.

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Physics 2710 – Example Exam Ii, David Peak Oct 2013

Physics 2710 – Example Exam Ii, David Peak

Exams

No abstract provided.

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Global Fossil Energy Markets And Climate Change Mitigation: An Analysis With Remind, Nico Bauer, Ioanna Mouratiadou, Gunnar Luderer, Lavinia Baumstark, Robert J. Brecha, Ottmar Edenhofer, Elmar Kriegler Oct 2013

Global Fossil Energy Markets And Climate Change Mitigation: An Analysis With Remind, Nico Bauer, Ioanna Mouratiadou, Gunnar Luderer, Lavinia Baumstark, Robert J. Brecha, Ottmar Edenhofer, Elmar Kriegler

Physics Faculty Publications

We analyze the dynamics of global fossil resource markets under different assumptions for the supply of fossil fuel resources, development pathways for energy demand, and climate policy settings. Resource markets, in particular the oil market, are characterized by a large discrepancy between costs of resource extraction and commodity prices on international markets. We explain this observation in terms of (a) the intertemporal scarcity rent, (b) regional price differentials arising from trade and transport costs, (c) heterogeneity and inertia in the extraction sector. These effects are captured by the REMIND model. We use the model to explore economic effects of changes …

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Formation Of Nanodiamonds At Near-Ambient Conditions Via Microplasma Dissociation Of Ethanol Vapour, Ajay Kumar, Pin Ann Lin, Albert Xue, Boyi Hao, Yoke Khin Yap, R. Mohan Sankaran Oct 2013

Formation Of Nanodiamonds At Near-Ambient Conditions Via Microplasma Dissociation Of Ethanol Vapour, Ajay Kumar, Pin Ann Lin, Albert Xue, Boyi Hao, Yoke Khin Yap, R. Mohan Sankaran

Department of Physics Publications

Clusters of diamond-phase carbon, known as nanodiamonds, exhibit novel mechanical, optical and biological properties that have elicited interest for a wide range of technological applications. Although diamond is predicted to be more stable than graphite at the nanoscale, extreme environments are typically used to produce nanodiamonds. Here we show that nanodiamonds can be stably formed in the gas phase at atmospheric pressure and neutral gas temperatures <100 °C by dissociation of ethanol vapour in a novel microplasma process. Addition of hydrogen gas to the process allows in flight purification by selective etching of the non-diamond carbon and stabilization of the nanodiamonds. The nanodiamond particles are predominantly between 2 and 5 nm in diameter, and exhibit cubic diamond, n-diamond and lonsdaleite crystal structures, similar to nanodiamonds recovered from meteoritic residues. These results may help explain the origin of nanodiamonds in the cosmos, and offer a simple and inexpensive route for the …

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Aggregation, Pretransitional Behavior, And Optical Properties In The Isotropic Phase Of Lyotropic Chromonic Liquid Crystals Studied In High Magnetic Fields, T. Ostapenko, Y. A. Nastishin, Peter J. Collings, S. N. Sprunt, O D. Lavrentovich, J. T. Gleeson Oct 2013

Aggregation, Pretransitional Behavior, And Optical Properties In The Isotropic Phase Of Lyotropic Chromonic Liquid Crystals Studied In High Magnetic Fields, T. Ostapenko, Y. A. Nastishin, Peter J. Collings, S. N. Sprunt, O D. Lavrentovich, J. T. Gleeson

Physics & Astronomy Faculty Works

We report results on the high-field magneto-optical response of four aqueous, lyotropic, chromonic liquid crystal formulations in the isotropic phase. Measurements of the field-induced birefringence at temperatures above the isotropic-nematic coexistence region at high magnetic fields reveal qualitative differences in different materials; these differences can be attributed to the nature of aggregation and are discussed within the context of competing aggregation models. Extending these measurements to very high fields and large optical phase differences reveals the presence of an unexpected optical phenomenon: magnetic field-induced circular birefringence, measured in the Voigt geometry, in a system containing no molecularly chiral species. Possible …

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Longitudinal Emittance Blowup In The Large Hadron Collider, P. Baudrenghien, T. Mastoridis Oct 2013

Longitudinal Emittance Blowup In The Large Hadron Collider, P. Baudrenghien, T. Mastoridis

Physics

The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11 min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are …

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Multi-Level Surface Enhanced Raman Scattering Using AgoX Thin Film, Ming Lun Tseng, Chia Min Chang, Bo Han Cheng, Pin Chieh Wu, K. S. Chung, M. K. Hsiao, H. W. Huang, D. W. Huang, Hai-Pang Chiang, P.T. Leung, D. P. Tsai Oct 2013

Multi-Level Surface Enhanced Raman Scattering Using AgoX Thin Film, Ming Lun Tseng, Chia Min Chang, Bo Han Cheng, Pin Chieh Wu, K. S. Chung, M. K. Hsiao, H. W. Huang, D. W. Huang, Hai-Pang Chiang, P.T. Leung, D. P. Tsai

Physics Faculty Publications and Presentations

Ag nanostructures with surface-enhanced Raman scattering (SERS) activities have been fabricated by applying laser-direct writing (LDW) technique on silver oxide (AgOx) thin films. By controlling the laser powers, multi-level Raman imaging of organic molecules adsorbed on the nanostructures has been observed. This phenomenon is further investigated by atomic-force microscopy and electromagnetic calculation. The SERS-active nanostructure is also fabricated on transparent and flexible substrate to demonstrate our promising strategy for the development of novel and low-cost sensing chip.

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Investigation Of Time Varying Nuclear Decay Rates, Peter G. Barton, Rafael F. Lang Oct 2013

Investigation Of Time Varying Nuclear Decay Rates, Peter G. Barton, Rafael F. Lang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Since the discovery of radioactive decay, radioactive decay rates have consistently shown to be constant. Recently, groups of researchers around the world have noticed variation in the decay rates of different radioactive isotopes, while other groups have noticed no such effect. If the variation is truly varying decay rates, this would imply groundbreaking new physics and would have implications for practices such as carbon dating. More sophisticated experiments are required to determine if the variations are truly new physics or systematic effects inherent to nuclear decay experiments. We are building an experiment where activity data from various radioactive sources will …

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Elementary Studies Of Twisted Bilayer Graphene, Branden P. Burns, Yong P. Chen Oct 2013

Elementary Studies Of Twisted Bilayer Graphene, Branden P. Burns, Yong P. Chen

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the nanotechnology field, some existing materials and applications are harmful to the environment, not efficient for certain tasks, or too expensive to be fully utilized. Graphene is a strong and cheap material that can be used to improve current nanotechnologies for more practical uses in society. Twisted bilayer graphene (TBG) is an orientation of graphene layers that exhibit different properties than regular bilayer graphene. It is made by placing a single layer of graphene on top of another at an angle with respect to the other lattice orientation. Understanding the characteristics of TBG is important to uncover more physics …

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Investigation Of Major Intermolecular Interactions In 7,8-Dihydrobenzo(K)Phenanthridin-6(5h)-One Crystal Using Quantum Calculations And Crystallographic Visualization Programs, Zhiwei Liao, Tonglei Li, Mingtao Zhang Oct 2013

Investigation Of Major Intermolecular Interactions In 7,8-Dihydrobenzo(K)Phenanthridin-6(5h)-One Crystal Using Quantum Calculations And Crystallographic Visualization Programs, Zhiwei Liao, Tonglei Li, Mingtao Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, tablets and capsules are the most common ways of delivering drugs. The active pharmaceutical ingredients and excipients used to make those tablets and capsules are in their crystalline form generally. However, a single molecule can form multiple different crystal structures because of different packing arrangements of the molecules. These different crystal structures have identical chemical composition but different properties such as solubility, density, stability, etc. This phenomenon is called polymorphism. Occurrence of polymorphism could be a disaster for both patients and pharmaceutical companies, as the drug could lose its efficacy due to changes in properties. Studying intermolecular interactions in …

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Fabrication Of Multilayered Structure For Coherent Random Lasing, John Rauchenstein, Young L. Kim Oct 2013

Fabrication Of Multilayered Structure For Coherent Random Lasing, John Rauchenstein, Young L. Kim

The Summer Undergraduate Research Fellowship (SURF) Symposium

High powered lasers have many applications, including medical treatment and surgery. However, these lasers are extremely expensive and are therefore not widely available. The aim of this study was to demonstrate a method to create such a laser with significantly decreased overall cost and increased efficiency. In order to do this, we explored a phenomenon called random lasing which is a light amplification process. To start with, a low-cost pumping laser is directed at normal incidence toward a multi-layered sample with two alternating layers. At first pearl, a naturally found material that has many organic nano-scale layers (similar to the …

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Time Dependent Conductivity Of Low Density Polyethylene, Phil Lundgreen, Justin Dekany, Jr Dennison Oct 2013

Time Dependent Conductivity Of Low Density Polyethylene, Phil Lundgreen, Justin Dekany, Jr Dennison

Presentations

No abstract provided.

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Diverse Light Emissions From Epoxy Due To Energetic Electron Bombardment, Justin Christensen, Justin Dekany, Jr Dennison Oct 2013

Diverse Light Emissions From Epoxy Due To Energetic Electron Bombardment, Justin Christensen, Justin Dekany, Jr Dennison

Presentations

No abstract provided.

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Extensions Of The Walden-Wintle Model Of Charge Transport In Disordered Materials For Charge Injection With Electron Beams, Jr Dennison, Greg Wilson, Alec Sim, Jodie C. Gillespie Oct 2013

Extensions Of The Walden-Wintle Model Of Charge Transport In Disordered Materials For Charge Injection With Electron Beams, Jr Dennison, Greg Wilson, Alec Sim, Jodie C. Gillespie

Presentations

No abstract provided.

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Time Dependent Conductivity Of Low Density Polyethylene, Phillip Lundgreen, Justin Dekany, Jr Dennison Oct 2013

Time Dependent Conductivity Of Low Density Polyethylene, Phillip Lundgreen, Justin Dekany, Jr Dennison

Posters

The time independent conductivity of Low Density Polyethylene (LDPE) is useful in determining rates of conductivity based on intrinsic properties of a material. A simple, yet elegant, parallel plate capacitor setup allowed for data collection which extended beyond 97 hours. Through precise measurements the different stages of charge distribution were determined to the level of 3 10-16 A. Through the use of data analysis programs, the dielectric constant and dispersion constant were both determined for LDPE and then compared with a simple, macroscopic, first-principles model to determine the quality of the fit.

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Functionalizing Carbon Nanotube Forests With 1,5-Diaminoaphthalene, Ben Pound, T. -C. Shen Oct 2013

Functionalizing Carbon Nanotube Forests With 1,5-Diaminoaphthalene, Ben Pound, T. -C. Shen

Browse All Undergraduate research

No abstract provided.

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Pre-Breakdown Arcing In Dielectrics Under Electric Field Stress, Allen Andersen, Jr Dennison Oct 2013

Pre-Breakdown Arcing In Dielectrics Under Electric Field Stress, Allen Andersen, Jr Dennison

Graduate Student Presentations

No abstract provided.

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Satellite And Ground-Based Measurements Of Mesospheric Temperature Variability Over Cerro Pachon, Chile (30.3° S), Jonathan Pugmire, Michael J. Taylor, Yucheng Zhao, P. D. Pautet, J. M. Russell Oct 2013

Satellite And Ground-Based Measurements Of Mesospheric Temperature Variability Over Cerro Pachon, Chile (30.3° S), Jonathan Pugmire, Michael J. Taylor, Yucheng Zhao, P. D. Pautet, J. M. Russell

Graduate Student Posters

— Observations of mesospheric OH (6,2) rotational temperatures by the Utah State University Mesospheric Temperature Mapper (MTM) located at the Andes Lidar Observatory, Cerro Pachon, Chile (30.3◦ S, 70.7◦ W) reveal a large range of nightly variations induced by atmospheric gravity waves and tides, as well as strong seasonal oscillations. This study investigates MTM temperature variability over the past 4 years comprising over 800 nights of high-quality data and compares the results with MTM measurements from Maui, Hawaii (2001-2005) and coincident mesospheric temperature measurement by the SABER instrument on the NASA TIMED satellite.

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Winter Climatology Of Short-Period Polar Mesospheric Gravity Waves Observed Over Poker Flat Research Range, Alaska (65 O N, 147 O W), Michael Negale, Kim Nielsen, Michael J. Taylor, Dominique Pautet Oct 2013

Winter Climatology Of Short-Period Polar Mesospheric Gravity Waves Observed Over Poker Flat Research Range, Alaska (65 O N, 147 O W), Michael Negale, Kim Nielsen, Michael J. Taylor, Dominique Pautet

Physics Student Research

Short-period gravity wave observations over the Arctic region are few and their impact on the Arctic mesosphere lower thermosphere region via momentum deposition is of high interest. The Mesospheric Airglow Imaging and Dynamics project was initiated in January 2011 to investigate the presence and dynamics of these waves over the interior of Alaska. Observations were made from Poker Flat Research Range (PFRR) using an all-sky imager. This site provides an exceptional opportunity to establish a long-term climatology of short-period gravity waves in the Arctic Region. We present summary measurements of prominent gravity waves over two consecutive winters and compare their …

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Atomic Oxygen Modification Of The Nanodielectric Surface Composition Of Carbon-Loaded Polyimide Composites, Kelby T. Peterson, Jr Dennison Oct 2013

Atomic Oxygen Modification Of The Nanodielectric Surface Composition Of Carbon-Loaded Polyimide Composites, Kelby T. Peterson, Jr Dennison

Presentations

No abstract provided.

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Diverse Light Emissions From Epoxy Due To Energetic Electron Bombardment, Justin Christensen, Jr Dennison, Justin Dekaney Oct 2013

Diverse Light Emissions From Epoxy Due To Energetic Electron Bombardment, Justin Christensen, Jr Dennison, Justin Dekaney

Posters

Dielectric materials subjected to energetic electron fluxes can emit light in several forms. We have observed three distinct types of emissions: (i) short-duration (<1 ms), high-intensity electrostatic discharge (ESD) or “arc” events; (ii) intermediate-duration, high-intensity events which begin with a bright arc followed by an exponential decay of intensity (~10 to 100 sec decay constant), termed “flares”; and (iii) long-duration, low-intensity emission, or cathodoluminescence, that continues as long as the electron flux is on. These events were studied for bulk samples of bisphenol/amine epoxy, using an electron gun with varying current densities (0.3 to 5 nA-cm-2) and energies (12 to 40 keV) in a high vacuum chamber. Light emitted from the sample was measured with high-sensitivity visible and near-infrared video cameras. We present results of the spatial and temporal extent for each type of event. We also discuss how absolute spectral radiance and rates for each type of these events are dependent on incident electron current density, energy, and power density and on material type, temperature, and thickness. Applications of …

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Atomic Oxygen Modification Of The Nanodielectric Surface Composition Of Carbon-Loaded Polyimide Composites, Kelby T. Peterson, Jr Dennison Oct 2013

Atomic Oxygen Modification Of The Nanodielectric Surface Composition Of Carbon-Loaded Polyimide Composites, Kelby T. Peterson, Jr Dennison

Posters

Black Kapton is a nanodielectric composite of carbon particles (100-500 nm) embedded in an insulating polyimide polymer matrix (100-5000 nm depth). Analysis of this nanodielectric composite has been done via optical imaging, scanning electron microscopy, and energy- dispersive x-ray analysis in order to gain insight into its nanodielectric properties. The insulating polyimide is known to be inert and impervious to strong bases and acids, but is affected by atomic oxygen exposure. We have observed changes in the surface structure and relative carbon- polymer concentrations in MISSE-6 samples that were exposed to the low earth orbit environment for 18 months outside …

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Conformational Response To Solvent Interaction And Temperature Of A Protein (Histone H3.1) By A Multi-Grained Monte Carlo Simulation, Ras B. Pandey, Barry L. Farmer Oct 2013

Conformational Response To Solvent Interaction And Temperature Of A Protein (Histone H3.1) By A Multi-Grained Monte Carlo Simulation, Ras B. Pandey, Barry L. Farmer

Faculty Publications

Interaction with the solvent plays a critical role in modulating the structure and dynamics of a protein. Because of the heterogeneity of the interaction strength, it is difficult to identify multi-scale structural response. Using a coarse-grained Monte Carlo approach, we study the structure and dynamics of a protein (H3.1) in effective solvent media. The structural response is examined as a function of the solvent-residue interaction strength (based on hydropathy index) in a range of temperatures (spanning low to high) involving a knowledge-based (Miyazawa-Jernigan(MJ)) residue-residue interaction. The protein relaxes rapidly from an initial random configuration into a quasi-static structure at low …

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Progress Towards Real-Time Radiation Measurements On Aircraft, L. Duane Bell, W. Kent Tobiska, Robert W. Schunk Oct 2013

Progress Towards Real-Time Radiation Measurements On Aircraft, L. Duane Bell, W. Kent Tobiska, Robert W. Schunk

Physics Student Research

The Space Weather Center (SWC) at Utah State University has created a team to deploy and obtain radiation effective dose rate data from dosimeters flown on commercial aircraft. The objective is to improve the accuracy of radiation dose and dose rate estimates for commercial aviation flight crews. There are two general sources of radiation exposure for flight crews: (1) the ever-present, background galactic cosmic rays (GCR), which originate outside the solar system, and (2) the solar energetic particle (SEP) events (or solar cosmic rays), which are associated with solar flares and coronal mass ejections lasting for several hours to days …

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Characterization Of Polylactic Acid Films For Food Packaging As Affected By Dielectric Barrier Discharge Atmospheric Plasma, Shashi Pankaj, Luke O'Neill, N. Misra, Paula Bourke Oct 2013

Characterization Of Polylactic Acid Films For Food Packaging As Affected By Dielectric Barrier Discharge Atmospheric Plasma, Shashi Pankaj, Luke O'Neill, N. Misra, Paula Bourke

Articles

Dielectric barrier discharge (DBD) air plasma is a novel technique for in-package decontamination of food, but it has not been yet applied to the packaging material. Characterization of commercial polylactic acid (PLA) films was done after in-package DBD plasma treatment at different voltage and treatment time to evaluate its suitability as food packaging material. DBD plasma increased the roughness of PLA film mainly at the site in contact with high voltage electrode at both the voltage levels of 70 and 80 kV. DBD plasma treatments did not induce any change in the glass transition temperature, but significant increase in the …

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Humidity And Temperature Effect On Properties Of Transmission Gratings Recorded In Pva/Aa-Based Photopolymer Layers, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova Oct 2013

Humidity And Temperature Effect On Properties Of Transmission Gratings Recorded In Pva/Aa-Based Photopolymer Layers, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova

Articles

This paper explores the effects of humidity on gratings recorded in a polyvinylalcohol–acrylamide photopolymer medium. Investigation of the behaviour of transmission gratings exposed to high humidity is of significant interest for two reasons, firstly because the grating's sensitivity to humidity can be exploited for the development of irreversible humidity indicators, secondly because too much sensitivity to humidity can limit the use of these materials in applications where an environmentally stable hologram is needed. In this paper we focus on the effect of high humidity on the properties of volume phase transmission gratings recorded in PVA/AA photopolymer layers in the temperature …

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