3,579 research outputs found
The Impact of Long-Term Generation Contracts on Valuation of Electricity Generating Assets under the Regional Greenhouse Gas Initiative
The Regional Greenhouse Gas Initiative is an effort by nine states to constrain carbon dioxide emissions from the electric power sector using a cap-and-trade program. This paper assesses the importance of long-term electricity contracts under the program. We find that 12.2% of generation will be accounted for by long-term contracts in 2010, affecting select nuclear, hydroelectric, and cogeneration units. The contracts will have a negligible effect on the wholesale marginal cost of electricity and a small effect on retail price. States may want to consider contracts on a case-by-case basis when making decisions about the initial distribution of emission allowances, but they should account for effects on the portfolio of plants owned at the firm level, not the effects on individual facilities. Because of their relatively small effect, it seems unnecessary to allow the existence of long-term contracts to dictate the design of the overall program.climate, state policy, Regional Greenhouse Gas Initiative, long-term contracts, electricity
The Sociological Imagination in Challenging Times
This critical essay argues the events of the last few years have made sociology more relevant to students’ lives and increased their need for and the utility of a well-developed sociological imagination. To meet the opportunities created by this moment, sociology educators need well-designed and highly effective pedagogical interventions that develop their students\u27 sociological imaginations. Unfortunately, much of the available scholarship on developing students\u27 sociological imaginations lacks the conceptual clarity and empirical rigor needed to discern which pedagogical interventions are most effective. After a detailed review of the scholarly problems surrounding the sociological imagination, recommendations for expanding the field are provided
School Zone Flashers in Indianapolis, Indiana
Starting in 2013, the City of Indianapolis embarked on a phased effort to install school zone flashing beacons throughout the city. Through three phases of design and construction, nearly 600 flashers were installed, including 516 speed zone flashers and 76 rectangular rapid-flashing beacons. As part of the third phase, upgraded hardware was installed in the speed zone flashers to facilitate calendar updates and maintenance tracking. Construction cost $4.2 million utilizing HSIP funds. Join us to learn about this project
Positive co-degree density of hypergraphs
The minimum positive co-degree of a non-empty -graph , denoted
, is the maximum such that if is an -set
contained in a hyperedge of , then is contained in at least
distinct hyperedges of . Given a family of -graphs, we introduce
the {\it positive co-degree Tur\'an number} as the
maximum positive co-degree over all -vertex -graphs
that do not contain as a subhypergraph.
In this paper we concentrate on the behavior of for
-graphs . In particular, we determine asymptotics and bounds for several
well-known concrete -graphs (e.g.\ and the Fano plane).
We also show that, for -graphs, the limit ``jumps'' from to
, i.e., it never takes on values in the interval , and we
characterize which -graphs have . Our motivation comes
primarily from the study of (ordinary) co-degree Tur\'an numbers where a number
of results have been proved that inspire our results
Fall armyworm (Spodoptera frugiperda Smith) feeding elicits differential defense responses in upland and lowland switchgrass
Switchgrass (Panicum virgatum L.) is a low input, high biomass perennial grass being developed for the bioenergy sector. Upland and lowland cultivars can differ in their responses to insect herbivory. Fall armyworm [FAW; Spodoptera frugiperda JE Smith (Lepidoptera: Noctuidae)] is a generalist pest of many plant species and can feed on switchgrass as well. Here, in two different trials, FAW larval mass were significantly reduced when fed on lowland cultivar Kanlow relative to larvae fed on upland cultivar Summer plants after 10 days. Hormone content of plants indicated elevated levels of the plant defense hormone jasmonic acid (JA) and its bioactive conjugate JA-Ile although significant differences were not observed. Conversely, the precursor to JA, 12-oxo-phytodienoic acid (OPDA) levels were significantly different between FAW fed Summer and Kanlow plants raising the possibility of differential signaling by OPDA in the two cultivars. Global transcriptome analysis revealed a stronger response in Kanlow plant relative to Summer plants. Among these changes were a preferential upregulation of several branches of terpenoid and phenylpropanoid biosynthesis in Kanlow plants suggesting that enhanced biosynthesis or accumulation of antifeedants could have negatively impacted FAW larval mass gain on Kanlow plants relative to Summer plants. A comparison of the switchgrass-FAW RNA-Seq dataset to those from maize-FAW and switchgrass-aphid interactions revealed that key components of plant responses to herbivory, including induction of JA biosynthesis, key transcription factors and JA-inducible genes were apparently conserved in switchgrass and maize. In addition, these data affirm earlier studies with FAW and aphids that the cultivar Kanlow can provide useful genetics for the breeding of switchgrass germplasm with improved insect resistance
A matrix-free approach to geostatistical filtering
In this paper, we present a novel approach to geostatistical filtering which
tackles two challenges encountered when applying this method to complex spatial
datasets: modeling the non-stationarity of the data while still being able to
work with large datasets. The approach is based on a finite element
approximation of Gaussian random fields expressed as an expansion of the
eigenfunctions of a Laplace--Beltrami operator defined to account for local
anisotropies. The numerical approximation of the resulting random fields using
a finite element approach is then leveraged to solve the scalability issue
through a matrix-free approach. Finally, two cases of application of this
approach, on simulated and real seismic data are presented.Comment: 25 pages, 8 figure
- …