Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physics (127)
- Condensed Matter Physics (55)
- Environmental Sciences (28)
- Earth Sciences (18)
- Chemistry (16)
-
- Mathematics (15)
- Life Sciences (11)
- Atmospheric Sciences (8)
- Oceanography and Atmospheric Sciences and Meteorology (8)
- Geology (6)
- Computer Sciences (5)
- Engineering (5)
- Astrophysics and Astronomy (4)
- Social and Behavioral Sciences (4)
- Soil Science (4)
- Statistics and Probability (4)
- Biology (3)
- Civil and Environmental Engineering (3)
- Geography (3)
- Nature and Society Relations (3)
- Water Resource Management (3)
- Cosmology, Relativity, and Gravity (2)
- Ecology and Evolutionary Biology (2)
- Geometry and Topology (2)
- Natural Resources and Conservation (2)
- Plant Sciences (2)
- Aerospace Engineering (1)
- Agricultural and Resource Economics (1)
- Agriculture (1)
- Keyword
-
- Physics (30)
- Problem set (11)
- Many-particle systems (10)
- Schrödinger (4)
- Centrocercus urophasianus (3)
-
- Electrostatic discharge (3)
- Foundations (3)
- Greater sage-grouse (3)
- Radiation (3)
- Scale (3)
- Space environment effects (3)
- 3D modeling (2)
- Arcing (2)
- Breakdown (2)
- British Columbia (2)
- Climate change (2)
- Conductivity (2)
- Dielectric breakdown (2)
- Effects (2)
- Electron emission (2)
- Energetic electron bombardment (2)
- Food availability (2)
- Functional response (2)
- Gene expression (2)
- Habitat monitoring (2)
- Halide receptors (2)
- Halogen (2)
- Hydrology (2)
- Ionosphere (2)
- LIDAR (2)
- Publication
-
- Presentations (19)
- All Physics Faculty Publications (17)
- Physics Capstone Projects (16)
- Posters (15)
- Funded Research Records (14)
-
- Wildland Resources Faculty Publications (13)
- Problems (12)
- Chemistry and Biochemistry Faculty Publications (11)
- Mathematics and Statistics Faculty Publications (11)
- Many Particles (10)
- Senior Theses and Projects (10)
- Journal Articles (8)
- Watershed Sciences Faculty Publications (8)
- Environment and Society Faculty Publications (6)
- Geosciences Faculty Publications (5)
- Plants, Soils, and Climate Faculty Publications (5)
- Schrodinger (5)
- Conference Proceedings (4)
- Browse all Datasets (3)
- Foundations (3)
- Computer Science Faculty and Staff Publications (2)
- Computer Science Student Research (2)
- Physics Student Research (2)
- Publications (2)
- Tutorials on... in 1 hour or less (2)
- All ECSTATIC Materials (1)
- All Physics Faculty Presentations (1)
- Bingham Research Center (1)
- Civil and Environmental Engineering Faculty Publications (1)
- Syllabus (1)
Articles 31 - 60 of 211
Full-Text Articles in Physical Sciences and Mathematics
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Characterizing The Effects Of Radiation On Muscle Cells, Lori Caldwell, Charles Harding, Jr Dennison, Elizabeth Vargis
Posters
As longer space missions become more desirable to public and private institutions, the physiological impact on astronauts must be considered. One of the primary concerns for those spending time in low gravity and high radiation environments is muscle atrophy. A major cause of muscular atrophy is oxidative stress which is amplified by increased levels of ionizing radiation during spaceflight. Additionally, high levels of radiation can damage DNA, increasing the risk of cancer. Utah State University’s Space Environment Test Facility was used to irradiate C2C12 myoblasts and human vascular endothelial cells with a dosage mimicking that on the International Space Station …
A Bivariate Hypothesis Testing Approach For Mapping The Trait-Influential Gene, Garrett Saunders, Matthew D. Meng, John R. Stevens
A Bivariate Hypothesis Testing Approach For Mapping The Trait-Influential Gene, Garrett Saunders, Matthew D. Meng, John R. Stevens
Mathematics and Statistics Faculty Publications
The linkage disequilibrium (LD) based quantitative trait loci (QTL) model involves two indispensable hypothesis tests: the test of whether or not a QTL exists, and the test of the LD strength between the QTaL and the observed marker. The advantage of this two-test framework is to test whether there is an influential QTL around the observed marker instead of just having a QTL by random chance. There exist unsolved, open statistical questions about the inaccurate asymptotic distributions of the test statistics. We propose a bivariate null kernel (BNK) hypothesis testing method, which characterizes the joint distribution of the two test …
Electron Yield Of Challenging Materials: Low Density Polyethylene And Carbon-Composite Nanodielectrics, Matthew Robertson, Jordan Lee, Jr Dennison
Electron Yield Of Challenging Materials: Low Density Polyethylene And Carbon-Composite Nanodielectrics, Matthew Robertson, Jordan Lee, Jr Dennison
Presentations
The electron yield—the ratio of the number of emitted electrons to incident electrons—is a key material property that characterizes how materials will charge due to exposure to electron fluxes. The USU Materials Physics Group has developed expertise in measuring this for a wide array of conductors, semiconductors and insulators, including many challenging materials. The basic definitions associated with electron yield and how they are measured will be discussed. We will highlight many critical applications investigated at USU, particularly those associated with spacecraft charging as materials interact with space plasma environments. Electron irradiation experiments conducted to investigate the electron transport, charging, …
Electron Yield Of Challenging Materials: Low Density Polyethylene And Carbon-Composite Nanodielectrics, Matthew Robertson, Jordan Lee, Jr Dennison
Electron Yield Of Challenging Materials: Low Density Polyethylene And Carbon-Composite Nanodielectrics, Matthew Robertson, Jordan Lee, Jr Dennison
Presentations
No abstract provided.
An Enhanced Operational Definition Of Dielectric Breakdown For Dc Voltage Step-Up Tests, Allen Andersen, Jr Dennison
An Enhanced Operational Definition Of Dielectric Breakdown For Dc Voltage Step-Up Tests, Allen Andersen, Jr Dennison
Journal Articles
The imprecise definition of breakdown in the ASTM D3755-14 standard can misidentify breakdown. If the recommended test circuit current sensing element threshold is set too high, breakdown may occur undetected. Conversely, false positives may result from designating a low current threshold. An operational definition of breakdown much less sensitive to these pitfalls is outlined herein. This enhanced definition of breakdown is based on the average rate of change of the leakage current with increasing voltage, rather than a simple current threshold, avoiding ambiguous association with anomalies in current traces. For tests that continuously monitor leakage current, breakdown can be detected …
Highly Accelerated Test Method For Characterizing Likelihood Of Breakdown In Hvdc Dielectric Materials, Allen Andersen, Jr Dennison
Highly Accelerated Test Method For Characterizing Likelihood Of Breakdown In Hvdc Dielectric Materials, Allen Andersen, Jr Dennison
Journal Articles
Increasing application and development of HVDC technologies emphasizes the need for improved characterization of candidate insulating materials. Accurately predicting the lifetime to breakdown of dielectric materials by means of accelerated voltage step-up to breakdown tests can be prohibitively time consuming. Step-up to breakdown tests with sufficiently slow voltage ramp rates that continuously monitor leakage current have detected a distribution of DC partial discharge (DCPD) events occurring prior to breakdown, which increase with increasing field. These DCPD distributions are shown to correlate strongly with the likelihood of breakdown for four common polymers. Given that hundreds of DCPD events are typically observed …
Halogen Bonds Formed Between Substituted Imidazoliums And N Bases Of Varying N-Hybridization, Steve Scheiner
Halogen Bonds Formed Between Substituted Imidazoliums And N Bases Of Varying N-Hybridization, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Heterodimers are constructed containing imidazolium and its halogen-substituted derivatives as Lewis acid. N in its sp3, sp2 and sp hybridizations is taken as the electron-donating base. The halogen bond is strengthened in the Cl < Br < I order, with the H-bond generally similar in magnitude to the Br-bond. Methyl substitution on the N electron donor enhances the binding energy. Very little perturbation arises if the imidazolium is attached to a phenyl ring. The energetics are not sensitive to the hybridization of the N atom. More regular patterns appear in the individual phenomena. Charge transfer diminishes uniformly on going from amine to imine to nitrile, a pattern that is echoed by the elongation of the C-Z (Z=H, Cl, Br, I) bond in the Lewis acid. These trends are also evident in the Atoms in Molecules topography of the electron density. Molecular electrostatic potentials are not entirely consistent with energetics. Although I of the Lewis acid engages in a stronger bond than does H, it is the potential of the latter which is much more positive. The minimum on the potential of the base is most negative for the nitrile even though acetonitrile does not form the strongest bonds. Placing the systems in dichloromethane solvent reduces the binding energies but leaves intact most of the trends observed in vacuo; the same can be said of ∆G in solution.
Collaborative Research: Mathematics Of Doing, Understanding, Learning And Educating For Secondary Schools, Brynja R. Kohler
Collaborative Research: Mathematics Of Doing, Understanding, Learning And Educating For Secondary Schools, Brynja R. Kohler
Funded Research Records
No abstract provided.
Toward Earthquake System Science: Western U.S. Lithospheric Stress/Strain Partitioning Of Mantle Dynamics, Anthony Lowry
Toward Earthquake System Science: Western U.S. Lithospheric Stress/Strain Partitioning Of Mantle Dynamics, Anthony Lowry
Funded Research Records
No abstract provided.
Collaborative Research: Synergistic Merging Of Traditional Aeronomy With Targeted High-Frequency (Hf) Heating Diagnostics, Herbert C. Carlson
Collaborative Research: Synergistic Merging Of Traditional Aeronomy With Targeted High-Frequency (Hf) Heating Diagnostics, Herbert C. Carlson
Funded Research Records
No abstract provided.
Special Issue: Intramolecular Hydrogen Bonding 2017, Steve Scheiner
Special Issue: Intramolecular Hydrogen Bonding 2017, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Even after more than a century of study [1–6], scrutiny, and detailed examination, the H-bond continues [7–12] to evoke a level of fascination that surpasses many other phenomena. Perhaps it is the ability of the simple H atom, with but a single electron, to act as a glue that maintains contact between much more complicated species. Or it might be its geometry, which prefers to hold the bridging proton on a direct line between the two heavy atoms. Not to be ignored are the spectral features of the H-bond: the large red shift of the stretching frequency of the covalent …
Cubesat Space Environments Effects Studied In The Space Survivability Test Chamber, Alexander Souvall, Gregory Wilson, Ben Russon, Katie Gamaunt, Jr Dennison
Cubesat Space Environments Effects Studied In The Space Survivability Test Chamber, Alexander Souvall, Gregory Wilson, Ben Russon, Katie Gamaunt, Jr Dennison
Posters
No abstract provided.
Fundamental Coupling Processes In The Mesosphere, Lower Thermosphere (Mlt) Using Enhanced Na Wind-Temperature Lidar Measurements At The Atmospheric Lidar Observatory, Titus Yuan
Funded Research Records
No abstract provided.
Collaborative Research: Facet: Quantifying The Topographic Response To Tectonic Processes In Southern Taiwan, Tammy M. Rittenour
Collaborative Research: Facet: Quantifying The Topographic Response To Tectonic Processes In Southern Taiwan, Tammy M. Rittenour
Funded Research Records
No abstract provided.
Characteristics Of Mesospheric Gravity Waves Over Antarctica Observed By Angwin (Antarctic Gravity Wave Instrument Network) Imagers Using 3-D Spectral Analyses, Takashi S. Matsuda, Takuji Nakamura, Mitsumu K. Ejiri, Masaki Tsutsumi, Yoshihiro Tomikawa, Michael J. Taylor, Yucheng Zhao, Pierre-Dominique Pautet, Damian J. Murphy, Tracy Moffat-Griffin
Characteristics Of Mesospheric Gravity Waves Over Antarctica Observed By Angwin (Antarctic Gravity Wave Instrument Network) Imagers Using 3-D Spectral Analyses, Takashi S. Matsuda, Takuji Nakamura, Mitsumu K. Ejiri, Masaki Tsutsumi, Yoshihiro Tomikawa, Michael J. Taylor, Yucheng Zhao, Pierre-Dominique Pautet, Damian J. Murphy, Tracy Moffat-Griffin
Publications
We have obtained horizontal phase velocity distributions of the gravity waves around 90 km from four Antarctic airglow imagers, which belong to an international airglow imager/instrument network known as ANGWIN (Antarctic Gravity Wave Instrument Network). Results from the airglow imagers at Syowa (69°S, 40°E), Halley (76°S, 27°W), Davis (69°S, 78°E), and McMurdo (78°S, 167°E) were compared, using a new statistical analysis method based on 3-D Fourier transform (Matsuda et al., 2014) for the observation period between 7 April and 21 May 2013. Significant day-to-day and site-to-site differences were found. The averaged phase velocity spectrum during the observation period showed preferential …
Relational Values Resonate Broadly And Differently Than Intrinsic Or Instrumental Values, Or The New Ecological Paradigm, Sarah Klain, Paige Olmsted, Kai M. A. Chan, Terre Satterfield
Relational Values Resonate Broadly And Differently Than Intrinsic Or Instrumental Values, Or The New Ecological Paradigm, Sarah Klain, Paige Olmsted, Kai M. A. Chan, Terre Satterfield
Environment and Society Faculty Publications
Value orientations used to explain or justify conservation have been rooted in arguments about how much and in what context to emphasize the intrinsic versus instrumental value of nature. Equally prominent are characterizations of beliefs known as the New Ecological Paradigm (NEP), often used to help explain pro-environmental behaviour. A recent alternative to these positions has been identified as ‘relational value’—broadly, values linking people and ecosystems via tangible and intangible relationships to nature as well as the principles, virtues and notions of a good life that may accompany these. This paper examines whether relational values are distinct from other value …
Problem Set #8, David Peak
Problem Set #8, David Peak
Problems
A bit of stat mech
Problems 1-3 refer to: N identical, noninteracting, and distinguishable spin-1/2 particles (i.e., their separation is much greater than their de Broglie wavelength) are placed in an external magnetic field. Assume the ground state energy of one such particle is 0 and the excited state energy is ε , and the system is in thermal equilibrium at temperature T.
Schrödinger, 1, David Peak
Schrödinger, 1, David Peak
Schrodinger
The Schrödinger equation: the quantum description of one massive, slow-moving particle
To establish a probability wave equation for one photon, it was useful to note that probability density and electromagnetic energy density were proportional. The governing equation for EM radiation fields is the Maxwell wave equation, which is also the governing equation for photon probability wave functions. Converting from EM radiation to photon information is made plausible by identifying energy and momentum operators with time- and space-derivatives, respectively. Thus, the Maxwell wave equation can be interpreted as being equivalent to the energy-momentum relation for photons. Though we don’t have a …
Schrödinger, 5, David Peak
Schrödinger, 4, David Peak
Schrödinger, 4, David Peak
Schrodinger
The sanitized hydrogen atom: separating the variables
Separation of variables in the Schrödinger Equation for the hydrogen problem requires expressing Ψ as a product, Ψ(r,θ,φ,t) = R(r)Θ(θ )Φ(φ)T(t) , substituting into the partial differential equation [(5) in Sc3], and then dividing by Ψ. As in the square well problems, the separation constant for the t part of the separation is the particle’s eigen-energy, E.
Many-Particle Systems, 1, David Peak
Many-Particle Systems, 1, David Peak
Many Particles
Wavefunctions for more than one particle: Different kinds of particles
Introductory examples of quantum mechanical wavefunction calculations involve a single particle moving about in a “magic” potential energy—e.g., a particle trapped inside a square well or an electron in a hydrogen atom. But, potential energy arises from interaction, so these situations must inevitably include more than one particle. Even the simplest atom—hydrogen— consists of two particles: the electron and the proton. So, how should the Schrödinger Equation be generalized to account for multiple particles?
Many-Particle Systems, 5, David Peak
Many-Particle Systems, 5, David Peak
Many Particles
Photons as T → 0 K
Photons are massless bosons. Because they are massless, any number of them can be added or subtracted without changing the photon system energy. (For example, a 1 eV photon can be exchanged for one hundred 0.01 eV photons, without changing system energy.) As a result, the chemical potential for photons is zero.
Many-Particle Systems, 2, David Peak
Many-Particle Systems, 2, David Peak
Many Particles
Multi-electron atoms
The rich diversity of chemical processes and structures is directly related to the diversity of electronic states of multi-electron atoms that, in turn, is dictated by the Pauli Exclusion Principle. To see how the Pauli Exclusion Principle produces atomic diversity, it is useful to begin simply, in particular, by considering the most elementary multi-electron “atom”: the hydrogen anion, H–.
Many-Particle Systems, 7, David Peak
Many-Particle Systems, 7, David Peak
Many Particles
Electronic energy bands in crystalline solids: The finite well model
Previously, we have considered the “conduction electrons” in a metal as if they were an ideal gas in a 3D infinite well. What allows us to do that? A crystalline solid consists of a periodic array of atoms, packed so close to one another that “flow” (long range relative motion of groups of atoms) is essentially impossible. It is useful to think of a solid as a giant (rigid) molecule. The periodic structure of the atoms has profound consequences for the behavior of the solid’s electrons. While, in detail, the …
Many-Particle Systems, 9, David Peak
Many-Particle Systems, 9, David Peak
Many Particles
Superconductivity phenomenology
Superconductors are materials that exhibit zero (or close to zero) resistance to electrical currents as well as perfect diamagnetism (the Meissner Effect). When a current is started in a superconducting loop, it persists for a very long time without an applied potential difference. The resistivity of a superconductor is measured to be less than 4x10–25 Ω-m (for comparison, the resistivity of an ordinary good conductor is about 10–8 Ω-m), and the associated decay time for the current is estimated to be greater than 100,000 years (as opposed to about 1 µs for an ordinary good …
Foundations, 1, David Peak
Foundations, 1, David Peak
Foundations
Quantum mechanics is money
Text message and take a picture with your smart phone; watch a movie on your Blu-ray player; get the bar code on your bag of chips scanned; obtain an MRI image of your aching shoulder; take a ride on a maglev train. None of these—and countless other—things would be possible without quantum mechanics! Leon Lederman, Nobel Prize winning physicist, is widely quoted as saying that 1/3 of the world’s economy is due to quantum mechanics. Lederman’s estimate is actually probably too low, but what surely is the case is that computers, lasers, and superconducting magnets (to …
Physics 2710: Introductory Modern Physics, David Peak
Foundations, 3, David Peak
Foundations, 3, David Peak
Foundations
Our goal is to try to reconcile classical EM with the existence of photons. The electric and magnetic fields associated with EM radiation, propagating in the x -direction, obey the Maxwell wave equation: ∂2E/∂t2 = c2(∂2E/∂x2).
Many-Particle Systems, 4, David Peak
Many-Particle Systems, 4, David Peak
Many Particles
Absolute temperature
When a system is in statistical equilibrium it can usefully be characterized by a few macroscopic variables. Temperature is one of the most important of these. The absolute temperature scale (measured in kelvins, K) has the following properties. (1) T = 0 K is the temperature of a macroscopic system found permanently in its ground state. Such a system has no excitations; it has its lowest possible energy and is completely isolated from the rest of the universe.
Many-Particle Systems, 8, David Peak
Many-Particle Systems, 8, David Peak
Many Particles
The classical picture of how electrons migrate through a resistor driven by an applied potential difference draws an analogy with a kind of pinball machine. In a pinball machine, gravity accelerates the pinball down the table, but the ball’s progress is impeded by collisions with bumpers, as depicted to the right. (θ is the angle the table makes with the horizontal direction.) When averaged over many collisions the ball’s average equation of motion is ma = mg sinθ − mv/τ , where a and v are directed down the table, and τ is the average time between collisions. If the …