The Problem of Feral Hogs and the Challenges of Providing a Weak‐Link Public Good

Author(s):  
Sean F. Ellis ◽  
Mark Masters ◽  
Kent D. Messer ◽  
Collin Weigel ◽  
Paul J. Ferraro
Keyword(s):  
Author(s):  
J.-Y. Wang ◽  
Y. Zhu ◽  
A.H. King ◽  
M. Suenaga

One outstanding problem in YBa2Cu3O7−δ superconductors is the weak link behavior of grain boundaries, especially boundaries with a large-angle misorientation. Increasing evidence shows that lattice mismatch at the boundaries contributes to variations in oxygen and cation concentrations at the boundaries, while the strain field surrounding a dislocation core at the boundary suppresses the superconducting order parameter. Thus, understanding the structure of the grain boundary and the grain boundary dislocations (which describe the topology of the boundary) is essential in elucidating the superconducting characteristics of boundaries. Here, we discuss our study of the structure of a Σ5 grain boundary by transmission electron microscopy. The characterization of the structure of the boundary was based on the coincidence site lattice (CSL) model.Fig.l shows two-beam images of the grain boundary near the projection. An array of grain boundary dislocations, with spacings of about 30nm, is clearly visible in Fig. 1(a), but invisible in Fig. 1(b).


Author(s):  
Z. L. Wang ◽  
C. L. Briant ◽  
J. DeLuca ◽  
A. Goyal ◽  
D. M. Kroeger ◽  
...  

Recent studies have shown that spray-pyrolyzed films of the Tl-1223 compound (TlxBa2Ca2Cu3Oy, with 0.7 < × < 0.95) on polycrystalline yttrium stabilized zirconia substrates can be prepared which have critical current density Jc near 105 A/cm2 at 77 K, in zero field. The films are polycrystalline, have excellent c-axis alignment, and show little evidence of weak-link behavior. Transmission electron microscopy (TEM) studies have shown that most grain boundaries have small misorientation angles. It has been found that the films have a nigh degree of local texture indicative of colonies of similarly oriented grains. It is believed that inter-colony conduction is enhanced by a percolative network of small angle boundaries at colony interfaces. It has also been found that Jc is increased by a factor of 4 - 5 after the films were annealed at 600 °C in oxygen. This study is thus carried out to determine the effect on grain boundary chemistry of the heat treatment.


1999 ◽  
Author(s):  
Mark E. Sibicky ◽  
Cortney B. Richardson ◽  
Anna M. Gruntz ◽  
Timothy J. Binegar ◽  
David A. Schroeder ◽  
...  
Keyword(s):  

2005 ◽  
pp. 131-141
Author(s):  
V. Mortikov

The basic properties of international public goods are analyzed in the paper. Special attention is paid to the typology of international public goods: pure and impure, excludable and nonexcludable, club goods, regional public goods, joint products. The author argues that social construction of international public good depends on many factors, for example, government economic policy. Aggregation technologies in the supply of global public goods are examined.


2017 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Andrew R. Kear

Natural gas is an increasingly vital U.S. energy source that is presently being tapped and transported across state and international boundaries. Controversy engulfs natural gas, from the hydraulic fracturing process used to liberate it from massive, gas-laden Appalachian shale deposits, to the permitting and construction of new interstate pipelines bringing it to markets. This case explores the controversy flowing from the proposed 256-mile-long interstate Nexus pipeline transecting northern Ohio, southeastern Michigan and terminating at the Dawn Hub in Ontario, Canada. As the lead agency regulating and permitting interstate pipelines, the Federal Energy Regulatory Commission is also tasked with mitigating environmental risks through the 1969 National Environmental Policy Act's Environmental Impact Statement process. Pipeline opponents assert that a captured federal agency ignores public and scientific input, inadequately addresses public health and safety risks, preempts local control, and wields eminent domain powers at the expense of landowners, cities, and everyone in the pipeline path. Proponents counter that pipelines are the safest means of transporting domestically abundant, cleaner burning, affordable gas to markets that will boost local and regional economies and serve the public good. Debates over what constitutes the public good are only one set in a long list of contentious issues including pipeline safety, proposed routes, property rights, public voice, and questions over the scientific and democratic validity of the Environmental Impact Statement process. The Nexus pipeline provides a sobering example that simple energy policy solutions and compromise are elusive—effectively fueling greater conflict as the natural gas industry booms.


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