12,204 research outputs found
Evaluating Dam Relicensing and River Herring Habitat Restoration from a Broad, Multi-Ecosystem Perspective
This study investigates the potential benefits of using a broad, multi-ecosystem analysis in the licensing and relicensing of hydropower facilities. Specifically, it considers the impact of river herring restoration on coastal food webs and cod and other groundfish populations in the Gulf of Maine. The past two decades of research on fisheries management, ecosystem connectivity, and the connection between river herring and groundfish in the Gulf of Maine have resulted in a better understanding of the ways in which human activities, such as dam building, influence ecological processes. The paper analyzes two case studies of six Maine dams currently engaged in the Federal Energy Regulatory Commission’s (FERC) hydroelectric dam relicensing process. The analysis illustrates the shortcomings of the Federal Power Act’s provisions that address the balancing of ecological and power generation concerns. Following the case studies, a series of policy recommendations are presented to encourage a more transparent and predictable relicensing process that adequately values both ecological and power generation goals. Changes are suggested for both the FERC process itself and the process by which state and federal resource agencies may provide comments regarding how a proposed dam licensing or relicensing affects natural resources under their jurisdiction. The proposed policy recommendations will increase the resilience of natural systems as they adapt to climate impacts
Atypical energy eigenstates in the Hubbard chain and quantum disentangled liquids
We investigate the implications of integrability for the existence of quantum
disentangled liquid (QDL) states in the half-filled one-dimensional Hubbard
model. We argue that there exist finite energy-density eigenstates that exhibit
QDL behaviour in the sense of J. Stat. Mech. P10010 (2014). These states are
atypical in the sense that their entropy density is smaller than that of
thermal states at the same energy density. Furthermore, we show that thermal
states in a particular temperature window exhibit a weaker form of the QDL
property, in agreement with recent results obtained by strong-coupling
expansion methods in arXiv:1611.02075. This article is part of the themed issue
`Breakdown of ergodicity in quantum systems: from solids to synthetics matter'.Comment: 11 pages, 3 figures. arXiv admin note: text overlap with
arXiv:1611.0207
Rhodium/phospholane-phosphite catalysts give unusually high regioselectivity in the enantioselective hydroformylation of vinyl arenes
Using the phospholane-phosphite ligand, BOBPHOS, almost perfect regioselectivities and high enantioselectivities (up to 92% ee) are observed in Rh catalysed enantioselective hydroformylation of vinyl arenes. This can be achieved under solvent-free conditions.PostprintPeer reviewe
Surveys for the Diamond Darter (Crystallaria cincotta), an Endangered Species Known Historically from the Green River in Kentucky
More Energy, More Searches, but the pMSSM Lives On
We further examine the capability of the 7 and 8 TeV LHC to explore the
parameter space of the p(henomenological)MSSM with neutralino LSPs. Here we
present an updated study employing all of the relevant ATLAS SUSY analyses, as
well as all relevant LHC non-MET searches, whose data were publically available
as of mid-September 2012. We find that roughly 1/3 of our pMSSM model points
are excluded at present with an important role being played by both the heavy
flavor and multi-lepton searches, as well as those for heavy stable charged
particles. Nonetheless, we find that light gluinos, 1st/2nd generation squarks,
and stop/sbottoms (\lsim 400-700 GeV), as well as models with 1% fine-tuning or
better, are still viable in the pMSSM. In addition, we see that increased
luminosity at 8 TeV is unlikely to significantly improve the reach of the
"vanilla" searches. The impact of these null searches on the SUSY sparticle
spectrum is discussed in detail and the implications of these results for
models with low fine-tuning, a future lepton collider and dark matter searches
are examined.Comment: 33 pages, 9 figure
Algebraic properties of generalized Rijndael-like ciphers
We provide conditions under which the set of Rijndael functions considered as
permutations of the state space and based on operations of the finite field
\GF (p^k) ( a prime number) is not closed under functional
composition. These conditions justify using a sequential multiple encryption to
strengthen the AES (Rijndael block cipher with specific block sizes) in case
AES became practically insecure. In Sparr and Wernsdorf (2008), R. Sparr and R.
Wernsdorf provided conditions under which the group generated by the
Rijndael-like round functions based on operations of the finite field \GF
(2^k) is equal to the alternating group on the state space. In this paper we
provide conditions under which the group generated by the Rijndael-like round
functions based on operations of the finite field \GF (p^k) () is
equal to the symmetric group or the alternating group on the state space.Comment: 22 pages; Prelim0
Soil amendment effects of crop-weed interactions
The used bedding from hooped hog production structures can be composted and spread on farm fields as a soil amendment. Researchers studied how this composted material affects crop yields, weed growth, and soil components
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