Other Physics Commons^™

Beam-Induced Radiation Heating On The Superconducting Undulator At The Advanced Photon Source, Laura Elizabeth Boon

Open Access Dissertations

In January 2013 the Advanced Photon Source (APS), a 7 GeV synchrotron X-ray source, commissioned a Superconducting Undulator (SCU). The superconducting magnet is thermally isolated from the beam vacuum chamber, which absorbs the beam-induced heating. Previous beam induced heat load studies at other laboratories had not included a robust calculation of radiation heating from the upstream dipole magnet. The mitigation of the radiation heating mechanism, and production of photoelectrons to seed an electron cloud was studied for this thesis. ^ An analytical model was developed to predict the radiation heat load on the SCU chamber. This model was benchmarked with …

Quantum Crystallography Of Hydronium Cations, Sonjae Sycoria Wallace

Dissertations, Theses, and Capstone Projects

Cationic hydronium clusters of the form [HaOb]^c,(c>0), have been investigated. After investigating over 2000 crystal structures containing hydronium cations found in the Cambridge Structural Database. The hydronium cationic compounds that were most unusual, mischaracterized, or those of apparent aggregates, were investigated further by geometry optimization and in some cases with the Quantum Theory of Atoms in Molecules (QTAIM). The results of our investigations yielded the first reports of stable conformations of cyclic dihydronium cationic clusters. In a second investigation we reported the first theoretically confirmed transition state of a H7O3+conformer captured within a crystal. A third product from our …

Conservation Of The Spin And Orbital Angular Momenta In Electromagnetism, Konstantin Y. Bliokh, Justin Dressel, Franco Nori

Mathematics, Physics, and Computer Science Faculty Articles and Research

We review and re-examine the description and separation of the spin and orbital angular momenta (AM) of an electromagnetic field in free space. While the spin and orbital AM of light are not separately meaningful physical quantities in orthodox quantum mechanics or classical field theory, these quantities are routinely measured and used for applications in optics. A meaningful quantum description of the spin and orbital AM of light was recently provided by several authors, which describes separately conserved and measurable integral values of these quantities. However, the electromagnetic field theory still lacks corresponding locally conserved spin and orbital AM currents. …

Quantitative Assessment Of Blood Coagulation By Cold Atmospheric Plasma, Caitlin Heslin, Daniela Boehm, Vladimir Milosavljevic, Michelle Laycock, Patrick J. Cullen, Paula Bourke

Articles

Cold atmospheric plasma (CAP) is produced by ionizing a chosen gas, thereby creating charged and reactive species. The reactive species generated are capable of inducing a range of biomedically relevant interactions including blood coagulation. However, the underlying biochemical processes of plasma-assisted blood coagulation are largely unknown, and data quantifying blood clot formation or the impact of system parameters on the intensity of the blood clot are scarce. In this study, blood coagulation was quantified by measuring hemoglobin absorbance. System parameters of the kINPen plasma jet were investigated and compared, including treatment time, distance from the plasma source and gas flow …

Kinematic Effects In Large Transport Aircraft, Shem Malmquist, Dennis A. Vincenzi Ph.D., Dahai Liu Ph.D.

International Journal of Aviation, Aeronautics, and Aerospace

The control of an aircraft relies on sensory feedback. It follows that any aspect that could create a situation where that feedback is faulty can lead to unintended outcomes. The size of very large jet aircraft can result in kinematic effects that impact the perceptions of the flight crew. Due to the large amount of inertia involved, coupled with aerodynamic factors, when the aircraft pitch (θ) is initially changed, the short term actual motion of the aircraft, as viewed from the center of gravity, remains relatively unchanged. As a consequence of aircraft design, this results in the flight deck changing …

Quantitative Data Extraction Using Spatial Fourier Transform In Inversion Shear Interferometer, Yanzeng Li

Graduate Theses - Physics and Optical Engineering

Currently there are many interferometers used for testing wavefront, measuring the quality of optical elements, and detecting refractive index changes in a certain medium. Each interferometer has been constructed for a specific objective. Inversion shear interferometer is one of them. Compared to other interferometers, it has its own advantages, such as only being sensitive to coma aberration, but it has some limitations as well. It does not allow use of phase shifting technique. A novel inversion shear interferometer was invented using holographic lenses. By using the spatial carrier method, phase information of the wavefront was extracted. The breakthrough of the …

Volumetric Scintillation Dosimetry For Scanned Proton Beams, Daniel G. Robertson

Dissertations and Theses (Open Access)

Scanned beam proton therapy is a promising cancer treatment modality which is becoming more widely available with the increasing number of proton radiotherapy centers. Scanned proton beams can produce complex 3D dose distributions, presenting a challenge for adequate quality assurance testing. Because each scanned beam dose measurement requires the delivery of the entire field, multiple measurements can be time consuming. These quality assurance challenges limit the number of patients who can be treated with this modality. The overall objective of this project is to increase the safety and availability of complex proton therapy treatments by developing a fast volumetric scintillation …

Development Of A New Independent Monte Carlo Dose Calculation Quality Assurance Audit To Ol For Clinical Trials, Austin M. Faught

Dissertations and Theses (Open Access)

Introduction: Commercially available treatment planning systems (TPS) may use a number of different radiation dose calculation algorithms during the planning process. The Radiological Physics Center (RPC), tasked with ensuring clinically comparable and consistent dose delivery amongst institutions participating in NCI funded multi-institutional clinical trials, has traditionally relied upon measurements to achieve this objective. As a supplement to the tools used by the RPC, an independent dose calculation tool is needed to determine patient dose distributions in three dimensions so as to act as a quality assurance tool for the dose calculations.

Methods: Multiple source models representing the output of Elekta …

Investigating The Proposed Affordances And Limitations Of The Substance Metaphor For Energy, Lisa Goodhew

Honors Projects

This study explores the instructional advantages and disadvantages of representing energy as a material substance; this is done in the context of a computer simulation that illustrates processes of energy transfer and transformation. These affordances and limitations have been proposed in science education literature as extensions of the substance metaphor itself, but there is little empirical evidence to support them. This study is intended to provide preliminary empirical evidence for these affordances and limitations. We examine data from eight interviews conducted with students from Seattle Pacific University’s introductory physics classes as they used the simulation. We explore the hypotheses that …

Looking For Cosmic Neutrino Background, Chiaki Yanagisawa

Publications and Research

Since the discovery of neutrino oscillation in atmospheric neutrinos by the Super-Kamiokande experiment in 1998, study of neutrinos has been one of exciting fields in high-energy physics. All the mixing angles were measured. Quests for (1) measurements of the remaining parameters, the lightest neutrino mass, the CP violating phase(s), and the sign of mass splitting between the mass eigenstates m₃ and m₁, and (2) better measurements to determine whether the mixing angle θ₂₃ is less than π/4, are in progress in a well-controlled manner. Determining the nature of neutrinos, whether they are Dirac or Majorana particles …

Dynamics And Manipulation Of Nanomagnets, Liufei Cai

Dissertations, Theses, and Capstone Projects

This thesis presents my work on the spin dynamics of nanomagnets and investigates the possibility of manipulating nanomagnets by various means. Most of the work has been published\cite{LC-PRB2010, LC-PRB2012, LC-PRB2013, LC-EPL2014}. Some has been submitted for publication\cite{LC-arxiv2014}. The structure of this thesis is as follows.

In Chapter 1, I present the theory of manipulation of a nanomagnet by rotating ac fields whose frequency is time dependent. Theory has been developed that maps the problem onto Landau-Zener problem. For the linear frequency sweep the switching phase diagrams are obtained on the amplitude of the ac field and the frequency sweep rate. …

Yang-Mills Theories As Deformations Of Massive Integrable Models, Axel Cortes Cubero

Dissertations, Theses, and Capstone Projects

Yang Mills theory in 2+1 dimensions can be expressed as an array of coupled (1+1)-dimensional principal chiral sigma models. The SU(N) principal chiral sigma model in 1+1 dimensions is integrable, asymptotically free and has massive excitations. We calculate all the form factors and two- point correlation functions of the Noether current and energy-momentum tensor, in

't Hooft's large-N limit (some form factors can be found even at finite N). We use these new form factors to calculate physical quantities in (2+1)-dimensional Yang-Mills theory, generalizing previous SU(2) by P. Orland to SU(N). The anisotropic gauge theory is related to standard isotropic …

Design And Implementation Of Anti-Ballistic Missile System Using Video Motion Detection And A Nerf Gun, Steven Bowman

Physics

The goal of this senior project was to use a video camera and a dart gun to create an antiballistic missile dart launcher. I created a motion detecting and trajectory calculating program with a webcam and linked it to a Nerf dart gun to fire Nerf darts at airborne projectiles. Despite the creation of successful trajectory calculating and dart launching systems, my best efforts have resulted in an inconsistent anti-ballistic system where a very small number of projectiles are actually hit.

Introduction To Ligo And An Experiment Regarding The Quality Factor Of Crystalline Silicon, Edward Taylor

Physics

Third generation LIGO detectors will be limited by thermal noise at a low frequency band where gravitational wave signals are expected to exist. A large contribution to thermal noise is caused by internal friction of the mirror and suspension elements. In order to meet the quantum mechanical sensitivity limits of the detector, it will be necessary to further push down the contribution of thermal noise. Future detectors will require new materials with extremely high mechanical quality. Silicon at cryogenic temperatures shows the promise to provide the required mechanical quality due to its vanishing expansion coefficient at 120 K. The fluctuation …

Effects Of Radiation Absorption And Mass Transfer On The Free Convective Flow Passed A Vertical Flat Plate Through A Porous Medium In An Aligned Magnetic Field, V. Manjulatha, S. V. K. Varma, V. C. C Raju

Applications and Applied Mathematics: An International Journal (AAM)

This article analyses the effects of radiation absorption and mass transfer on the steady free convective flow of a viscous, incompressible and electrically conducting fluid past an infinite vertical flat plate through a porous medium with an aligned magnetic field. Analytical solutions for concentration, temperature, and velocity are obtained by solving the governing equations in two cases namely (i) when the plate is at uniform temperature and concentration and (ii) when the plate is at constant heat and mass flux. Further the rate of mass transfer in terms of the Sherwood number, rate of heat transfer in terms of Nusselt …

Evaluation Of Schwarz Child’S Exterior And Interior Solutions In Bimetric Theory Of Gravitation, M. S. Borkar, P. V. Gayakwad

Applications and Applied Mathematics: An International Journal (AAM)

In this note, we have investigated Schwarz child’s exterior and interior solutions in bimetric theory of gravitation by solving Rosen’s field equations and concluded that the physical singularities at r = 0 and at r =2M do not appear in our solution. We have ruled out the discrepancies between physical singularity and mathematical singularity at r = 2M and proved that the Schwarzschild exterior solution is always regular and does not break-down at r = 2M. Further, we observe that the red shift of light in our model is much stronger than that of Schwarz child’s solution in general relativity …

Finite Thermal Wave Propagation In A Half-Space Due To Variable Thermal Loading, Abhik Sur, M. Kanoria

Applications and Applied Mathematics: An International Journal (AAM)

The thermoelastic interaction for the dual-phase-lag (DP) heat conduction in a thermoelastic half space is studied in the light of two-temperature generalized thermoelasticity theory (2TT). The medium is assumed to be initially quiescent. Using Laplace transform, the fundamental equations are expressed in the form of a vector-matrix differential equation which is then solved by statespace approach. The obtained general solution is then applied to the mechanical loading and various types of thermal loading (the thermal shock and the ramp-type heating). The numerical inversion of the Laplace transforms are carried out by the method of Fourier series expansion technique. The numerical …

String Fluid Cosmological Model With Magnetic Field In Bimetric Theory Of Gravitation, M. S. Borkar, N. P. Gaikwad

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, LRS Bianchi type I string fluid cosmological model with magnetic field in bimetric theory of gravitation is investigated by assuming barotropic equation of state for pressure and density and assuming the bulk viscosity to be inversely proportional to the scalar expansion. The source of energy momentum tensor is a bulk viscous fluid containing one dimensional string with electromagnetic field. The physical and geometrical properties of the model are discussed. The bulk viscosity affected the whole properties of the model.

Exploring The Relationship Between A Fluid Container's Geometry And When It Will Balance On Edge, Ryan J. Moriarty

Physics

At some point while consuming a beverage, many people will idly try to balance its container on edge. The act itself is physically straightforward, merely involving the system's center of mass and achieving a static equilibrium between the opposing torques caused by gravity and the normal force between the container and the surface on which it balances. Further analysis of the act, however, illuminates the richness of the exercise.

These nuances are apparent even in simplified two-dimensional models because of the depth of the relationship between a container's geometry and achieving balance. The purpose of such analysis is threefold: first, …

Analysis Of Far-Infrared Optical Spectra Of Multiferroics, Eric C. Standard

Dissertations

The optical spectra of multiferroic crystals Dy₃Fe₅O₁₂, Tb₃Fe₅O₁₂, and four hexagonal RMnO₃ (5D= Er, Tm, Yb, Lu) are studied using intense bright synchrotonic light in the infrared spectral range. In regards to the materials analyzed, two rare earth iron garnets and four rare earth manganites in total are examined. These materials have attracted much attention due to their interesting magnetoelectric properties. They could serve as the basis for the next generation of faster and more energy efficient memory and logic devices. To examine these materials, two …