Physical Sciences and Mathematics Commons^™

Physics 2710 – Example Exam Iii, David Peak

Exams

No abstract provided.

Interferometric Swath Processing Of Cryosat Data For Glacial Ice Topography, L. Gray, D. Burgess, L. Copland, R. Cullen, N. Galin, R. Hawley, V. Helm

Dartmouth Scholarship

We have derived digital elevation models (DEMs) over the western part of the Devon Ice Cap in Nunavut, Canada, using "swath processing" of interferometric data collected by Cryosat between February 2011 and January 2012. With the standard ESA (European Space Agency) SARIn (synthetic aperture radar interferometry) level 2 (L2) data product, the interferometric mode is used to map the cross-track position and elevation of the "point-of-closest-approach" (POCA) in sloping glacial terrain. However, in this work we explore the extent to which the phase of the returns in the intermediate L1b product can also be used to map the heights of …

Titanium Oxide Nanotubes: Synthesis, Properties And Applications For Solar Energy Harvesting, Eugen Panaitescu

Eugen Panaitescu

Titanium oxide (titania) nanotubes, although relatively recently discovered (less than 15 years ago), have already shown great promise regarding solar energy harvesting applications, exhibiting very good photocatalytic and photovoltaic properties. An alternative anodization route for production of titania nanotubes at the surface of a titanium foil using chloride ions as catalyst instead of the routinely used highly toxic fluorides, is presented in this work. Moreover, the fabrication parameters are extensively studied, thus providing both an insight into the synthesis mechanism and hints towards possible process optimization routes. Although not forming uniformly over the sample surface and lacking long range ordering, …

Analysis, Prototyping, And Design Of An Ionization Profile Monitor For The Spallation Neutron Source Accumulator Ring, Dirk A. Bartkoski

Doctoral Dissertations

The Spallation Neutron Source (SNS) located in the Oak Ridge National Laboratory is comprised of a 1 GeV linear H^- [H^-] accelerator followed by an accumulator ring that delivers high intensity 1 μs [microsecond] long pulses of 1.5x10¹⁴ [1.5x10^14] protons to a liquid mercury target for neutron production by spallation reaction. With its strict 0.01% total beam loss condition, planned power upgrade, and proposed second target station, SNS ring beam-profile diagnostics capable of monitoring evolving beam conditions during high-power conditions are crucial for efficient operation and improvement. By subjecting ionized electrons created during beam interactions with the residual …

Measurement Of The Prompt Double J/Psi Production Cross Section In Pp Collisions At Sqrt(S) = 7 Tev, Andrew David York

Doctoral Dissertations

The simultaneous production of two J/psi mesons has been significantly observed in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector. The two J/psi mesons are fully reconstructed in their decay to muons. The signal yield is extracted with an extended maximum likelihood fit based on four event variables. A method was developed to correct for detector acceptances and efficiencies based on the measured momenta of the J/psi and their decay muons to maintain the least model dependence possible.

The measurement is performed in an acceptance region defined by the individual J/psi transverse momentum and rapidity. …

Identifying Productive Resources In Secondary School Students' Discourse About Energy, Benedikt Walter Harrer

Electronic Theses and Dissertations

A growing program of research in science education acknowledges the beginnings of disciplinary reasoning in students’ ideas and seeks to inform instruction that responds productively to these disciplinary progenitors in the moment to foster their development into sophisticated scientific practice. This dissertation examines secondary school students’ ideas about energy for progenitors of disciplinary knowledge and practice. Previously, researchers argued that students’ ideas about energy were constrained by stable and coherent conceptual structures that conflicted with an assumed unified scientific conception and therefore needed to be replaced. These researchers did not attend to the productive elements in students’ ideas about energy. …

Information-Entropic Stability Bound For Compact Objects: Application To Q-Balls And The Chandrasekhar Limit Of Polytropes, Marcelo Gleiser, Damian Sowinski

Dartmouth Scholarship

Spatially-bound objects across diverse length and energy scales are characterized by a binding energy. We propose that their spatial structure is mathematically encoded as information in their momentum modes and described by a measure known as configurational entropy (CE). Investigating solitonic Q-balls and stars with a polytropic equation of state P=Kργ, we show that objects with large binding energy have low CE, whereas those at the brink of instability (zero binding energy) have near maximal CE. In particular, we use the CE to find the critical charge allowing for classically stable Q-balls and the Chandrasekhar limit for white dwarfs (γ=4/3) …

Kinetic Fractionation Of Gases By Deep Air Convection In Polar Firn, K. Kawamura, J. P. Severinghaus, M. R. Albert, Z. R. Courville

Dartmouth Scholarship

A previously unrecognized type of gas fractiona- tion occurs in firn air columns subjected to intense convec- tion. It is a form of kinetic fractionation that depends on the fact that different gases have different molecular diffusivi- ties. Convective mixing continually disturbs diffusive equi- librium, and gases diffuse back toward diffusive equilibrium under the influence of gravity and thermal gradients. In near- surface firn where convection and diffusion compete as gas transport mechanisms, slow-diffusing gases such as krypton (Kr) and xenon (Xe) are more heavily impacted by convec- tion than fast diffusing gases such as nitrogen (N2) and ar- gon …

Physics 2710 – Example Exam Ii, David Peak

Exams

No abstract provided.

College Of Science And Mathematics Newsletter, Fall 2013, College Of Science And Mathematics, Wright State University

College of Science and Mathematics Newsletters

This 8 page newsletter discusses various happenings within the College of Science and Mathematics. It begins with a letter from the dean, and continues on with news, events, alumni news, and other community news.

On The Origin Of Mode- And Bond-Selectivity In Vibrationally Mediated Reactions On Surfaces, Daniel Killelea, Arthur L. Utz

Chemistry: Faculty Publications and Other Works

The experimental observations of vibrational mode- and bond-selective chemistry at the gas–surface interface indicate that energy redistribution within the reaction complex is not statistical on the timescale of reaction. Such behavior is a key prerequisite for efforts to use selective vibrational excitation to control chemistry at the technologically important gas–surface interface. This paper outlines a framework for understanding the origin of non-statistical reactivity on surfaces. The model focuses on the kinetic competition between intramolecular vibrational energy redistribution (IVR) within the reaction complex, which in the long-time limit leads to statistical behavior, and quenching, scattering, or desorption processes that restrict the …

Physics 2710 – Example Exam I, David Peak

Exams

No abstract provided.

Shadows In Time: A Study Of Temporal Metaphysics Through Hard Science Fiction And Its Restrictions On The Past And Future, Lindsey E. Mitchell

Oglethorpe Journal of Undergraduate Research

Through a series of essays, this body of work explores the varying theories concerning the nature of time and how each theory affects the possibility and outcome of time travel. Following these essays, a collection of short stories focuses on what the author considers the most probable theories concerning time and expands on how they might affect a time traveler's decisions and fate.

An Ethnographic Study: Becoming A Physics Expert In A Biophysics Research Group, Idaykis Rodriguez

FIU Electronic Theses and Dissertations

Expertise in physics has been traditionally studied in cognitive science, where physics expertise is understood through the difference between novice and expert problem solving skills. The cognitive perspective of physics experts only create a partial model of physics expertise and does not take into account the development of physics experts in the natural context of research. This dissertation takes a social and cultural perspective of learning through apprenticeship to model the development of physics expertise of physics graduate students in a research group. I use a qualitative methodological approach of an ethnographic case study to observe and video record the …

College Of Science And Mathematics Newsletter, Summer 2013, College Of Science And Mathematics, Wright State University

College of Science and Mathematics Newsletters

This 8 page newsletter discusses various happenings within the College of Science and Mathematics. It begins with a letter from the dean, and continues on with news, events, alumni news, and other community news.

Computational Renormalization Scheme For Quantum Field Theories, Rainer Grobe, Qichang Su, R E. Wagner

Faculty publications – Physics

We propose an alternative technique for numerically renormalizing quantum field theories based on their Hamiltonian formulation. This method is nonperturbative in nature and, therefore, exact to all orders. It does not require any correlation functions or Feynman diagrams. We illustrate this method for a model Yukawa-like theory describing the interaction of electrons and positrons with model photons in one spatial dimension. We show that, after mass renormalization of the fermionic and bosonic single-particle states, all other states in the Fock space have finite energies, which are independent of the momentum cutoff.

Gravity Evolved, Clark Duvall

Computer Science and Software Engineering

Gravity Evolved is a galactic physics game, created for mobile devices. In the game, you make your own solar system by creating planets, and then placing weapons on the planets. The physics of these planets and projectiles shot by the weapons are then simulated. Gravity Evolved has a Battle mode, where your solar system is pitted against an opposing solar system. In Battle mode, you earn money to unlock, create, and upgrade items in your solar system. Gravity Evolved will be on the Apple App Store and Google Play Store in the summer of 2013.

Meter-Sized Moonlet Population In Saturn's C Ring And Cassini Division, K. Baillié, J. E. Colwell, L. W. Esposito, Mark C. Lewis

Computer Science Faculty Research

Stellar occultations observed by the Cassini Ultraviolet Imaging Spectrograph reveal the presence of transparent holes a few meters to a few tens of meters in radial extent in otherwise optically thick regions of the C ring and the Cassini Division. We attribute the holes to gravitational disturbances generated by a population of ~10 m boulders in the rings that is intermediate in size between the background ring particle size distribution and the previously observed ~100 m propeller moonlets in the A ring. The size distribution of these boulders is described by a shallower power-law than the one that describes the …

Discontinuities And Alfvenic Fluctuations In The Solar Wind, G. Paschmann, S. Haaland, B. Sonnerup, T. Knetter

Dartmouth Scholarship

We examine the Alfvenicity of a set of 188 solar wind directional discontinuities (DDs) identified in the Cluster data from 2003 by Knetter (2005), with the objective of separating rotational discontinuities (RDs) from tangential ones (TDs). The DDs occurred over the full range of solar wind velocities and magnetic shear angles. By performing the Walen test in the de Hoffmann–Teller (HT) frame, we show that 77 of the 127 crossings for which a good HT frame was found had plasma flow speeds exceeding 80 % of the Alfven speed at an average angular deviation of 7.7◦; 33 cases had speeds …

Physics 3710 – Exam Iii, David Peak

Exams

No abstract provided.

Michael's Awesome Italian Adventure (With A Bit Of Science, Too), Michael W. Haskin

Physics

This senior project will provide the reader with a brief background about neutrinos, neutrinoless double beta decay, and the CUORE experiment being constructed in the Gran Sasso National Laboratory in Assergi, Italy. The remainder of the paper will follow my experience working as an undergraduate researcher at the laboratory during the summer of 2012. It will discuss the process of performing a cool down with the CUORE-0 cryostat as well as quality assurance testing of Teflon spacers to be used in the CUORE towers.

Investigating The Potential Applications Of A Raman Tweezer System, John Wray

Theses and Dissertations

This thesis describes the construction of an Optical Tweezer apparatus to be used in conjunction with a confocal Raman spectrometer. The tweezer utilizes an infrared (λ=1064 nm) laser directed into an inverted microscope with NA=1.4 oil immersion 100x objective lens that strongly focuses the laser light into a sample to function as a single-beam gradient force trap. The long term goal of this research program is to develop a single molecule Raman tweezers apparatus that allows one to control the position of a Raman nanoplasmonic amplifier. This thesis describes the construction of the Raman tweezer apparatus along with several Raman …

Neutron Interferometric Method To Provide Improved Constraints On Non-Newtonian Gravity At The Nanometer Scale, Geoffrey Greene, Vladimir Gudkov

Geoffrey Greene

In recent years, an energetic experimental program has set quite stringent limits on a possible “non-1/r2” dependence on gravity at short length scales. This effort has been largely driven by the predictions of theories based on compactification of extra spatial dimensions. It is characteristic of many such theories that the strength and length scales of such anomalous gravity are not clearly determined from first principles. As a result, it is productive to extend the current limits the range and strength of such hypothetical interactions. As a heavy, neutral, and (almost) stable particle, the neutron provides an ideal probe for the …

A Statistical Analysis Of Electromagnetic Ion Cyclotron (Emic) Waves And Their Correlation To The 11-Year Solar Cycle, Erik A. Lindgren

Honors Theses and Capstones

This thesis presents a statistical analysis of EMIC waves measured at Halley Research Station from 2008 through 2012. An introduction covering the origin of and theory behind EMIC waves is provided, along with a background covering previous statistical research regarding EMIC waves. Guidelines regarding EMIC wave definition and analysis are described along with examples of how they were used. The data shows an increase in the total number of EMIC waves as well as the number and percentage of EMIC waves with maximum frequency above 1 Hz during the 5-year period. The results suggest that the total number of EMIC …

College Of Science And Mathematics Newsletter, Spring 2013, College Of Science And Mathematics, Wright State University

College of Science and Mathematics Newsletters

This 8 page newsletter discusses various happenings within the College of Science and Mathematics. It begins with a letter from the dean, and continues on with news, events, alumni news, and other community news.

Enhancement Of Electron-Positron Pair Creation Due To Transient Excitation Of Field-Induced Bound States, M Jiang, Q Z. Lv, Z M. Sheng, Rainer Grobe, Qichang Su

Faculty publications – Physics

We study the creation of electron-positron pairs induced by two spatially separated electric fields that vary periodically in time. The results are based on large-scale computer simulations of the time-dependent Dirac equation in reduced spatial dimensions. When the separation of the fields is very large, the pair creation is caused by multiphoton transitions and mainly determined by the frequency of the fields. However, for small spatial separations a coherence effect can be observed that can enhance or reduce the particle yield compared to the case of two infinitely separated fields. If the travel time for a created electron or positron …

Determination Of Average Loss Lifetimes For Near‐Earth Electrons In Solar Storms, John Blears

Undergraduate Theses—Unrestricted

The rate of electron wave‐particle scattering in the near‐Earth magnetosphere is investigated using multiple simulations of solar storms from solar cycle 23 (1996‐2005). Simulations are created using the Hot Electron and Ion Drift Integrator (HEIDI) model, which analyzes the drifts of keV‐energy electrons through the inner magnetosphere and identifies the precipitation of these particles into the upper atmosphere. The loss lifetime formulation used by HEIDI, which represents the rate at which the keV‐energy of the electrons is extinguished, predicts unreasonably large loss lifetimes deep in the inner magnetosphere. This discrepancy between the values used by the HEIDI model and those …

Physics 3710 – Exam Ii, David Peak

Exams

No abstract provided.

Superfluidity In Neutron Stars, Samuel J. Witte

Undergraduate Theses—Unrestricted

Nucleon pairing is studied with specific considerations directed toward the possible influence on neutron star cooling. We present an in-depth analysis of BCS theory using realistic nuclear potentials and consider the impact short-range correlations can have on the gap. Gap calculations are incorporated into neutron star cooling simulations and the significance of the 3P2 −3F2 channel in various hadronic cooling models is closely examined. An analysis of the 1S0 gap in neutron matter suggests short-range correlations can drastically alter the magnitude, density range, and temperature dependence of the gap. While the newly constructed 1S0 gap does not significantly alter the …

Bottled Sky, Ioannis Michalou(Di)S

The STEAM Journal

Cloud-hunter Ioannis ΜICHALOU(di)S, lies in wait of air streams, grapping pieces of sky, shaping them, molding them, and baptizing them as ‘aerosculptures’. MICHALOU(di)S is the first visual artist worldwide to use art and science in a unique way. His latest Art-Science achievement is ‘Bottled Sky’. He states:

“In October 2001, while I was trying to create a cubic nephele, in the Visual Arts Research Centre of Massachusetts Institute of Technology (MIT), I came upon the silica aerogel for the first time... It is a space technology material, intangible -consisting of 99.9% air and 0.1% glass - which has been recently …