3,332 research outputs found
Not Here, Not There, Not Anywhere: Politics, Social Movements, and the Disposal of Low‐Level Radioactive Waste . London : Earthscan/RFF Press . 240 pages. ISBN 9781933115924, $39.95 paperback. by Daniel J. Sherman . 2011 .
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96335/1/ropr12007.pd
Radioactive Waste Disposal at Sea: Public Ideas, Transnational Policy Entrepreneurs, and Environmental Regimes by Lasse Ringius
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96666/1/798175.pd
Relative phase stability and lattice dynamics of NaNbO from first-principles calculations
We report total energy calculations for different crystal structures of
NaNbO over a range of unit cell volumes using the all-electron
full-potential (L)APW method. We employed both the local-density approximation
(LDA) and the Wu-Cohen form of the generalized gradient approximation (GGA-WC)
to test the accuracy of these functionals for the description of the complex
structural behavior of NaNbO. We found that LDA not only underestimates the
equilibrium volume of the system but also predicts an incorrect ground state
for this oxide. The GGA-WC functional, on the other hand, significantly
improves the equilibrium volume and provides relative phase stability in better
agreement with experiments. We then use the GGA-WC functional for the
calculation of the phonon dispersion curves of cubic NaNbO to identify the
presence of structural instabilities in the whole Brillouin zone. Finally, we
report comparative calculations of structural instabilities as a function of
volume in NaNbO and KNbO to provide insights for the understanding of
the structural behavior of KNaNbO solid solutions.Comment: Accepted for publication in Physical Review
Conventional Politics for Unconventional Drilling? Lessons from Pennsylvania's Early Move into Fracking Policy Development
The emergence of hydraulic fracturing techniques is generating a dramatic expansion of the development of domestic natural gas resources in the U nited S tates and abroad. Fracking also poses a series of environmental protection challenges that cut across traditional medium and program boundaries. Formal constraints on federal government engagement thus far devolve considerable latitude to individual states for policy development. This provides an important test of whether recent scholarly emphasis on highly innovative state environmental and energy policies can be extended to this burgeoning area. P ennsylvania has moved to the epicenter of the fracking revolution, reflecting its vast Marcellus Shale resource and far‐reaching 2012 legislation. This article examines the P ennsylvania case and notes that the state's emerging policy appears designed to maximize resource extraction while downplaying environmental considerations. The case analysis generates questions as to whether this experience constitutes an influential state early mover that is likely to diffuse widely or is instead an aberration in a rapidly diversifying state policy development process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98279/1/ropr12018.pd
Enhancement of piezoelectricity in a mixed ferroelectric
We use first-principles density-functional total energy and polarization
calculations to calculate the piezoelectric tensor at zero temperature for both
cubic and simple tetragonal ordered supercells of Pb_3GeTe_4. The largest
piezoelectric coefficient for the tetragonal configuration is enhanced by a
factor of about three with respect to that of the cubic configuration. This can
be attributed to both the larger strain-induced motion of cations relative to
anions and higher Born effective charges in the tetragonal case. A normal mode
decomposition shows that both cation ordering and local relaxation weaken the
ferroelectric instability, enhancing piezoelectricity.Comment: 5 pages, revtex, 2 eps figure
Carbon Taxation and Policy Labeling: Experience from American States and Canadian Provinces
A vast economics literature embraces taxation of the carbon content of fossil fuels as the superior policy approach for reducing greenhouse gas emissions. However, experience around the world suggests that carbon taxes face exceedingly difficult political hurdles. Federal experience in the United States and in Canada confirms this pattern. This article reviews sub‐federal policy development among American states and Canadian provinces, a great many of which have pursued climate policy development. With one major exception, explicit carbon taxation appears to remain a political nonstarter. At the same time, states and provinces have been placing indirect carbon prices on fossil fuel use through a wide range of policies. These tend to strategically alter labeling, avoiding the terms of “tax” and “carbon” in imposing costs. The article offers a framework for considering such strategies and examines common design features, including direct linkage between cost imposition and fund usage to build political support.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91109/1/j.1541-1338.2012.00564.x.pd
The ferroelectric transition in YMnO from first principles
We have studied the structural phase transition of multiferroic YMnO from
first principles. Using group-theoretical analysis and first-principles density
functional calculations of the total energy and phonons, we perform a
systematic study of the energy surface around the prototypic phase. We find a
single instability at the zone-boundary which couples strongly to the
polarization. This coupling is the mechanism that allows multiferroicity in
this class of materials. Our results imply that YMnO is an improper
ferroelectric. We suggest further experiments to clarify this point.Comment: published version, PRB (rapid comm), slight change in presentatio
Taxing Fracking: The Politics of State Severance Taxes in the Shale Era
States producing gas and oil have long levied severance taxes at the point of extraction, commonly placing most revenues into general funds. These taxes have assumed new meaning in many states amid the expansion of gas and oil production accompanying the advent of hydraulic fracturing. We reviewed all major statutes and constitutional amendments related to severance taxes that were enacted at the state level during the first decade of the “shale era” (2005–14). There have been only modest adjustments in statutory tax rates and some evidence that states have attempted to reduce these rates, possibly in response to growing national production. In turn, there is also evidence that states have begun to pursue more targeted strategies for revenue use, including some expanded focus on responding to the negative externalities linked to drilling, expanded revenue sharing with localities, and increased long‐term protection of resources through state trust funds.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112282/1/ropr12127.pd
Random local strain effects in homovalent-substituted relaxor ferroelectrics: a first-principles study of BaTi0.74Zr0.26O3
We present first-principles supercell calculations on BaTi0.74Zr0.26O3, a
prototype material for relaxors with a homovalent substitution. From a
statistical analysis of relaxed structures, we give evidence for four types of
Ti-atom polar displacements: along the , , or
directions of the cubic unit cell, or almost cancelled. The type of a Ti
displacement is entirely determined by the Ti/Zr distribution in the adjacent
unit cells. The underlying mechanism involves local strain effects that ensue
from the difference in size between the Ti4+ and Zr4+ cations. These results
shed light on the structural mechanisms that lead to disordered Ti
displacements in BaTi(1-x)Zr(x)O3 relaxors, and probably in other BaTiO3-based
relaxors with homovalent substitution.Comment: 5 pages, 4 figure
- …