Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Astrophysics and Astronomy (4)
- Cosmology, Relativity, and Gravity (2)
- Environmental Sciences (2)
- External Galaxies (2)
- Business (1)
-
- Business Administration, Management, and Operations (1)
- E-Commerce (1)
- Engineering (1)
- Environmental Monitoring (1)
- Life Sciences (1)
- Management Information Systems (1)
- Natural Resources and Conservation (1)
- Oil, Gas, and Energy (1)
- Operations Research, Systems Engineering and Industrial Engineering (1)
- Physical Processes (1)
- Physics (1)
- Plant Sciences (1)
- Stars, Interstellar Medium and the Galaxy (1)
- Sustainability (1)
- The Sun and the Solar System (1)
- Institution
Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Empirical Geographic Modeling Of Switchgrass Yields In The United States, Henriette I. Jager, Latha M. Baskaran, Craig C. Brandt, Ethan B. Davis
Empirical Geographic Modeling Of Switchgrass Yields In The United States, Henriette I. Jager, Latha M. Baskaran, Craig C. Brandt, Ethan B. Davis
Dartmouth Scholarship
Switchgrass (Panicum virgatum L.) is a perennial grass native to the United States that has been studied as a sustainable source of biomass fuel. Although many field‐scale studies have examined the potential of this grass as a bioenergy crop, these studies have not been integrated. In this study, we present an empirical model for switchgrass yield and use this model to predict yield for the conterminous United States. We added environmental covariates to assembled yield data from field trials based on geographic location. We developed empirical models based on these data. The resulting empirical models, which account for spatial …
Long-Lived Time-Dependent Remnants During Cosmological Symmetry Breaking: From Inflation To The Electroweak Scale, Marcelo Gleiser, Noah Graham, Nikitas Stamatopoulos
Long-Lived Time-Dependent Remnants During Cosmological Symmetry Breaking: From Inflation To The Electroweak Scale, Marcelo Gleiser, Noah Graham, Nikitas Stamatopoulos
Dartmouth Scholarship
Through a detailed numerical investigation in three spatial dimensions, we demonstrate that long-lived time-dependent field configurations emerge dynamically during symmetry breaking in an expanding de Sitter spacetime. We investigate two situations: a single scalar field with a double-well potential and an SU(2) non-Abelian Higgs model. For the single scalar, we show that large-amplitude oscillon configurations emerge spontaneously and persist to contribute about 1.2% of the energy density of the Universe. We also show that for a range of parameters, oscillon lifetimes are enhanced by the expansion and that this effect is a result of parametric resonance. For the SU(2) case, …
Perpendicular Ion Heating By Low-Frequency Alfvén-Wave Turbulence In The Solar Wind, Benjamin D. G. Chandran, Bo Li, Barrett N. Rogers, Eliot Quataert, Kai Germaschewski
Perpendicular Ion Heating By Low-Frequency Alfvén-Wave Turbulence In The Solar Wind, Benjamin D. G. Chandran, Bo Li, Barrett N. Rogers, Eliot Quataert, Kai Germaschewski
Dartmouth Scholarship
We consider ion heating by turbulent Alfvén waves (AWs) and kinetic Alfvén waves (KAWs) with wavelengths (measured perpendicular to the magnetic field) that are comparable to the ion gyroradius and frequencies ω smaller than the ion cyclotron frequency Ω. We focus on plasmas in which β < 1, where β is the ratio of plasma pressure to magnetic pressure. As in previous studies, we find that when the turbulence amplitude exceeds a certain threshold, an ion's orbit becomes chaotic. The ion then interacts stochastically with the time-varying electrostatic potential, and the ion's energy undergoes a random walk. Using phenomenological arguments, we derive an analytic expression for the rates at which different ion species are heated, which we test by simulating test particles interacting with a spectrum of randomly phased AWs and KAWs. We find that the stochastic heating rate depends sensitively on the quantity ε = δv ρ/v ⊥, where v ⊥ (v ∥) is the component of the ion velocity perpendicular (parallel) to the background magnetic field B 0, and δv ρ (δB ρ) is the rms amplitude of the velocity (magnetic-field) fluctuations at the gyroradius scale. In the case …
Stirring Up The Pot: Can Cooling Flows In Galaxy Clusters Be Quenched By Gas Sloshing?, J. A. A. Zuhone, M. Markevitch, R. E. Johnson
Stirring Up The Pot: Can Cooling Flows In Galaxy Clusters Be Quenched By Gas Sloshing?, J. A. A. Zuhone, M. Markevitch, R. E. Johnson
Dartmouth Scholarship
X-ray observations of clusters of galaxies reveal the presence of edges in surface brightness and temperature, known as "cold fronts." In relaxed clusters with cool cores, these commonly observed edges have been interpreted as evidence for the "sloshing" of the core gas in the cluster's gravitational potential. Such sloshing may provide a source of heat to the cluster core by mixing hot gas from the cluster outskirts with the cool-core gas. Using high-resolution N-body/Eulerian hydrodynamic simulations, we model gas sloshing in galaxy clusters initiated by mergers with subclusters. The simulations include merger scenarios with gas-filled and gasless subclusters. The …
Low-Frequency Turbulence In A Linear Magnetized Plasma, B. N. Rogers, Paolo Ricci
Low-Frequency Turbulence In A Linear Magnetized Plasma, B. N. Rogers, Paolo Ricci
Dartmouth Scholarship
Plasma turbulence in a linear device is explored for the first time with three-dimensional global two-fluid simulations, focusing on the plasma parameters of the Large Plasma Device. Three instabilities are present in the simulations: the Kelvin-Helmholtz instability, a sheath-driven instability, and a resistive drift wave instability. The Kelvin-Helmholtz mode is shown to dominate the transport of plasma across the magnetic field. Simple scaling laws are obtained for the plasma profiles.
Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman
Core Gas Sloshing In Abell 1644, Ryan E. Johnson, Maxim Markevitch, Gary A. Wegner, Christine Jones, William R. Forman
Dartmouth Scholarship
We present an analysis of a 72 ks Chandra observation of the double cluster Abell 1644 (z = 0.047). The X-ray temperatures indicate that the masses are M 500 = (2.6 ± 0.4) × 1014 h –1 M ☉ for the northern sub-cluster and M 500 = (3.1 ± 0.4) × 1014 h –1 M ☉ for the southern, main cluster. We identify a sharp edge in the radial X-ray surface brightness of the main cluster, which we find to be a cold front, with a jump in temperature of a factor of ~3. This edge possesses …
Rfid-Enabled Inventory Control Optimization: A Proof Of Concept In A Small-To-Medium Retailer, H. Dane, Katina Michael, S. F. Wamba
Rfid-Enabled Inventory Control Optimization: A Proof Of Concept In A Small-To-Medium Retailer, H. Dane, Katina Michael, S. F. Wamba
Faculty of Informatics - Papers (Archive)
This study examines the impact of radio-frequency identification (RFID) technology on the inventory control practices of a small-to-medium retailer using a proof of concept (PoC) approach. The exploratory study was conducted using a single case study of a hardware retailer stocking 5000 product lines provided by 110 active suppliers. To analyze the present mode of operation, procedural documents, semi-structured interviews and a participant observation was conducted. The basis for the proof of concept was a future mode of operation using a quasi-experimental design. Results indicate that in a small-to-medium retail environment, RFID technology could act as a loss prevention mechanism, …
Tools For Sustainable Development: A Comparison Of Building Performance Simulation Packages, Simi Hoque, Akanksha Sharma
Tools For Sustainable Development: A Comparison Of Building Performance Simulation Packages, Simi Hoque, Akanksha Sharma
Environmental Conservation Faculty Publication Series
The paper evaluates the energy performance of a test case (a single family home) using three different simulation software packages – REM Design, Energy Gauge and Treat. It will discuss the results of each simulation run and the reasons for variations in the results. The inputs for each of the three different simulation tools are heating, cooling, and water heating loads, building shell (exterior walls, roof, foundation, windows, doors) features, air leakage and electric consumption (lighting and appliances). The paper will also highlight the differences in data input for all three software and will underscore areas where improvements to the …