Physics Commons^™

Volume Holographic Optical Elements, Ching-Cherng Sun, Partha P. Banerjee

Partha Banerjee

The final two papers are concerned with the analysis of novel holograms. Banerjee et al. investigate holographic recording and reconstruction for edge-lit holograms recorded in a 90-degree geometry. Various cases of recording and readout that incorporate propagational diffraction have been modeled. It is shown that the 90-degree geometry can result in beam shaping, as evidenced through preliminary experimental results with photorefractive lithium niobate. Nguyen et al. propose a new approach for designing computer-generated holograms. An artificial neural network is used to initiate the genetic algorithm so that the high computation cost of genetic algorithms for synthesizing holograms is significantly reduced …

Chemical Dynamics Of Aluminum Nanoparticles In Ammonium Nitrate And Ammonium Perchlorate Matrices: Enhanced Reactivity Of Organically Capped Aluminum, William K. Lewis, Barbara A. Harruff-Miller, Joseph R. Gord, Andrew T. Rosenberger, Thomas M. Sexton, Elena A. Guliants, Christopher E. Bunker

Elena A. Guliants

Aluminum nanoparticles have been a subject of active investigation in recent years because of their potential to enhance the energy content of energetic materials. The associated kinetics of the chemical reaction and energy release are, in many cases, governed by the properties of the passivation layer protecting the particle rather than those of the underlying metal core. The passivation layer of Al particles is typically an oxide shell several nanometers thick, but other possibilities are now available. We have previously developed synthesis routes to produce air-stable Al nanoparticles that are capped by oleic acid. In the present study, we examine …

Carbon Nanoparticles As Visible-Light Photocatalysts For Efficient Co2 Conversion And Beyond, Li Cao, Sushant Sahu, Parambath Anilkumar, Christopher E. Bunker, Juan Xu, K. A. Shiral Fernando, Ping Wang, Elena A. Guliants, Kenneth N. Tackett Ii, Ya-Ping Sun

Elena A. Guliants

Increasing atmospheric CO2 levels have generated much concern, driving the ongoing carbon sequestration effort. A compelling CO2 sequestration option is its photocatalytic conversion to hydrocarbons, for which the use of solar irradiation represents an ultimate solution. Here we report a new strategy of using surface-functionalized small carbon nanoparticles to harvest visible photons for subsequent charge separation on the particle surface in order to drive the efficient photocatalytic process. The aqueous solubility of the catalysts enables photoreduction under more desirable homogeneous reaction conditions. Beyond CO2 conversion, the nanoscale carbon-based photocatalysts are also useful for the photogeneration of H2 from water under …

Spatio-Spectral Sampling And Color Filter Array Design, Keigo Hirakawa, Patrick Wolfe

Keigo Hirakawa

Owing to the growing ubiquity of digital image acquisition and display, several factors must be considered when developing systems to meet future color image processing needs, including improved quality, increased throughput, and greater cost-effectiveness. In consumer still-camera and video applications, color images are typically obtained via a spatial subsampling procedure implemented as a color filter array (CFA), a physical construction whereby only a single component of the color space is measured at each pixel location. Substantial work in both industry and academia has been dedicated to post-processing this acquired raw image data as part of the so-called image processing pipeline, …

Bose-Einstein Condensation Of Potassium Atoms By Sympathetic Cooling, Giovanni Modugno, Gabriele Ferrari, Giacomo Roati, Robert Brecha, A. Simoni, Massimo Inguscio

Robert J. Brecha

We report on the Bose-Einstein condensation of potassium atoms, whereby quantum degeneracy is achieved by sympathetic cooling with evaporatively cooled rubidium. Because of the rapid thermalization of the two different atoms, the efficiency of the cooling process is high. The ability to achieve condensation by sympathetic cooling with a different species may provide a route to the production of degenerate systems with a larger choice of components.

Collapse Of A Degenerate Fermi Gas, Giovanni Modugno, Giacomo Roati, Francesco Riboli, Francesca Ferlaino, Robert Brecha, Massimo Inguscio

Robert J. Brecha

A degenerate gas of identical fermions is brought to collapse by the interaction with a Bose-Einstein condensate. We used an atomic mixture of fermionic potassium-40 and bosonic rubidium-87, in which the strong interspecies attraction leads to an instability above a critical number of particles. The observed phenomenon suggests a direction for manipulating fermion-fermion interactions on the route to superfluidity.

Cost Optimization With Solar And Conventional Energy Production, Energy Storage, And Real Time Pricing, Ata Raziei, Kevin Hallinan, Robert Brecha

Robert J. Brecha

Research is presented that investigates the potential for solar power generation with battery energy storage for reducing the effective cost of energy delivered to residential customers if real time pricing is present. A linear optimization approach is developed based upon a two-step process. In step one, given a specified solar array area and battery capacity, the optimal means to meet loads based upon grid power, solar power, and/or battery power is determined. This analysis considers an expected lifespan of the solar panel. With these results established, in the next step, the capital costs for the solar arrays and batteries are …

Dipolar Oscillations In A Quantum Degenerate Fermi–Bose Atomic Mixture, Francesca Ferlaino, Robert Brecha, Peter Hannaford, Francesco Riboli, Giacomo Roati, Giovanni Modugno, Massimo Inguscio

Robert J. Brecha

We study the dynamics of coupled dipolar oscillations in a Fermi–Bose mixture of 40K and 87Rb atoms. This low-energy collective mode is strongly affected by the interspecies interactions. Measurements are performed in the classical and quantum degenerate regimes and reveal the crucial role of the statistical properties of the mixture. At the onset of quantum degeneracy, we investigate the role of Pauli blocking and superfluidity for K and Rb atoms, respectively, resulting in a change in the collisional interactions.

The Carbon Rent Economics Of Climate Policy, Matthias Kalkuhl, Robert Brecha

Robert J. Brecha

By reducing the demand for fossil fuels, climate policy can reduce scarcity rents for fossil resource owners. As mitigation policies ultimately aim to limit emissions, a new scarcity for “space” in the atmosphere to deposit emissions is created. The associated scarcity rent, or climate rent (that is, for example, directly visible in permit prices under an emission trading scheme) can be higher or lower than the original fossil resource rent. In this paper, we analyze analytically and numerically the impact of mitigation targets, resource availability, backstop costs, discount rates and demand parameters on fossil resource rents and the climate rent. …

Analyzing Major Challenges Of Wind And Solar Variability In Power Systems, Falko Ueckerdt, Robert Brecha, Gunnar Luderer

Robert J. Brecha

Ambitious policy targets together with current and projected high growth rates indicate that future power systems will likely show substantially increased generation from renewable energy sources. A large share will come from the variable renewable energy (VRE) sources wind and solar photovoltaics (PV); however, integrating wind and solar causes challenges for existing power systems. In this paper we analyze three major integration challenges related to the structural matching of demand with the supply of wind and solar power: low capacity credit, reduced utilization of dispatchable plants, and over-produced generation. Based on residual load duration curves we define corresponding challenge variables …

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

Robert J. Brecha

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 …

Logistic Curves, Extraction Costs And Peak Oil, Robert Brecha

Robert J. Brecha

Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the …

Economic And Environmental Impacts Of Community-Based Residential Building Energy Efficiency Investment, Jun-Ki Choi, Drew Morrison, Kevin Hallinan, Robert Brecha

Robert J. Brecha

A systematic framework for evaluating the local economic and environmental impacts of investment in building energy efficiency is developed. Historical residential building energy data, community-wide economic input-output data, and emission intensity data are utilized. The aim of this study is to show the comprehensive insights and connection among achieving variable target reductions for a residential building energy use, economic and environmental impacts. Central to this approach for the building energy reduction goal is the creation of individual energy models for each building based upon historical energy data and available building data. From these models, savings estimates and cost implications can …

Development Without Energy? Assessing Future Scenarios Of Energy Consumption In Developing Countries, Jan Steckel, Robert Brecha, Michael Jakob, Jessica Strefler, Gunnar Luderer

Robert J. Brecha

We analyze the relationship between economic development and energy consumption in the context of greenhouse gas mitigation. The main contribution of this work is to compare estimates of energy thresholds in the form of minimum energy requirements to reach high levels of development with output projections of per capita final energy supply from a group of integrated assessment models (IAMs). Scenarios project that reductions of carbon emissions in developing countries will be achieved not only by means of decreasing the carbon intensity, but also by making a significant break with the historically observed relationship between energy use and economic growth. …

Partition-Based Weighted Sum Filters For Image Restoration, Kenneth Barner, Ahmad Sarhan, Russell Hardie

Russell C. Hardie

We develop the concept of partitioning the observation space to build a general class of filters referred to as partition-based weighted sum (PWS) filters. In the general framework, each observation vector is mapped to one of M partitions comprising the observation space, and each partition has an associatedfiltering function. We focus on partitioning the observation space utilizing vector quantization and restrict the filtering function within each partition to be linear. In this formulation, a weighted sum of the observation samples forms the estimate, where the weights are allowed to be unique within eachpartition. The partitions are selected and weights tuned …

Video Feature — Banned Books And The Stuart Rose Collection, Robert Brecha, Una Cadegan, John Inglis, Paul Morman

Robert J. Brecha

A faculty panel discussion in two sessions:

Session 1:
The Index: Una Cadegan (history) looks at the current scholarship on the Index of Forbidden Books.
Galileo: Robert Brecha (physics) highlights the banning of Galileo and observational science.

Session 2:
Thomas Aquinas: John Inglis (philosophy) speaks on the banning of Thomas Aquinas's Summa Theologica, the most important book in Catholic intellectual tradition.
Descartes and the Index of Forbidden Books: Paul Morman (history, Distinguished Service Professor) highlights the book by Descartes that he was not allowed to study while a student at UD in the 1960s.

Ultrashort Pulse Propagation And Multi-Chromatic Ionization In Dielectrics, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.

Nonlinear Ultrashort Pulse Propagation And Multi-Chromatic Ionization In Bulk Dielectrics, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.

Microwave Optics Research, Allen Andersen, Todd Lines

Allen Andersen

The BYU-Idaho Physics Department x-band microwave optics equipment was originally intended for use in classroom demonstrations. I evaluated this equipment for use in research. I designed and built additional equipment needed in order to perform attenuation and other experiments then used it to conduct research on the transmission properties of paper and other substances. The new equipment allowed me to create a standard experimental procedure, take reasonably accurate measurements, and reduce undesired standing wave effects. Mathematical and experimental analysis was done to determine the necessary parameters of the new equipment. The new apparatus is comparable to setups featured in published …

Material Damage From Ultrashort Bursts Of Light, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.

Simulation Of Ultrashort Laser Pulses In Nonlinear Media, Jeremy Gulley

Jeremy R. Gulley

No abstract is currently available.

Real-Time Measurements On Electron Plasma Response In Dielectrics Under Influence Of Ultrafast Laser Radiation, Sebastian Winkler, Jeremy Gulley, Igor Burakov, Razvan Stoian, Nadezhda Bulgakova, Anton Husakou, Alexandre Mermillod-Blondin, Arkadi Rosenfeld, David Ashkenasi, Ingolf Hertel, William Dennis

Jeremy R. Gulley

No abstract is currently available.

Simulation Of Ultrashort Laser Pulse Propagation With High-Order Dispersion, Raman Scattering, And Shock Formation, Jeremy Gulley, Erik Zeek, William Dennis

Jeremy R. Gulley

No abstract is currently available.

Simulation Of High Intensity Laser Pulse Propagation Through Optical Systems, Jeremy Gulley, Erik Zeek, William Dennis

Jeremy R. Gulley

No abstract is currently available.

Ionic Polishing Of Fused Silica And Glass, Raymond Wilson

Raymond Wilson