5,509 research outputs found
Planning for the Sun to Come Up: How Nevada and California Explain the Future of Net Metering
This Article explores the growth of rooftop solar and the future of net metering through the debates and policies of Nevada and California. Part II details the recent, rapid growth and projected future growth of solar power in the United States. Part II also describes how Nevada and Californiaare leading the nation in utilization of solar power and are already addressing issues that are likely to emerge in other areas of the country. Part III begins with a brief introduction to net metering and the national scope of net metering program reviews. Part III concludes with a summary of the most recent changes to each states net metering laws. Part IV contains a comparative analysis of five key legislative and regulatory factors influencing how net metering will develop in the future. The elements are the interaction between renewable portfolio standards and net metering programs, solar photovoltaic (PV) incentive programs, time-of-use rates, electricity sector decoupling, and comprehensive electric grid planning. Part V summarizes key findings from our research and provides lessons learned for other states considering evolving their net metering programs. Part VI concludes this article with a forward-looking assessment of the challenges facing net metering
On the shopfloor: exploring the impact of teacher trade unions on school-based industrial relations
Teachers are highly unionised workers and their trade unions exert an important influence on the shaping and implementation of educational policy. Despite this importance there is relatively little analysis of the impact of teacher trade unions in educational management literature. Very little empirical research has sought to establish the impact of teacher unions at school level. In an era of devolved management and quasi-markets this omission is significant. New personnel issues continue to emerge at school level and this may well generate increased trade union activity at the workplace. This article explores the extent to which devolved management is drawing school-based union representation into a more prominent role. It argues that whilst there can be significant differences between individual schools, increased school autonomy is raising the profile of trade union activity in the workplace, and this needs to be better reflected in educational management research
Predicting remaining life of transmission tower steelwork components
Failures in transmission towerâs components usually result in extended disruption of power supply. Repair is very costly as it involves replacement of the transmission linesâ sections affected. Additionally, it might also entail litigation cost associated with power disruption. Maintenance decisions have to be taken in time to prevent a failure. At present, maintenance decisions are mainly based on expertâs judgement, who perform inspections every 10 to 12 years. On specific sites, towerâs components degrade much faster due to aggressive atmospheric conditions, with corrosion being the primary cause of deterioration. In this context, data indicating health state from an UK utility were used to create a Cox model that relates the time before a failure occurs to climatic and atmospheric conditions highly correlated with corrosion. The paper demonstrates the use of the model for predicting remaining tower life, and highlights how this can feed into maintenance planning
Preliminary archaeoentomological analyses of permafrost-preserved cultural layers from the pre-contact Yupâik Eskimo site of Nunalleq, Alaska : implications, potential and methodological considerations
Acknowledgements Site excavation and samples collection were conducted by archaeologists from the University of Aberdeen, with the help of archaeologists and student excavators from the University of Aberdeen University of Alaska Fairbanks and Bryn Mawr College, Kuskokwim Campus, College of Rural Alaska and residents of Quinhagak and Mekoryuk. This study is funded through AHRC grant to the project âUnderstanding Cultural Resilience and Climate Change on the Bering Sea through Yupâik Ecological Knowledge, Lifeways, Learning and Archaeologyâ to Rick Knecht, Kate Britton and Charlotta Hillderal (University of Aberdeen; AH/K006029/1). Thanks are due to Qanirtuuq Inc. and Quinhagak, Alaska for sampling permissions and to entomologists working at the CNC in Ottawa for allowing access to reference collections of beetles, lice and fleas. Yves Bousquet, Ales Smetana and Anthony E. Davies are specially acknowledged for their help with the identification of coleopteran specimens. Finally, we would also like to thank Scott Elias for useful comments on the original manuscript.Peer reviewedPublisher PD
Supergravity p-branes revisited: extra parameters, uniqueness, and topological censorship
We perform a complete integration of the Einstein-dilaton-antisymmetric form
action describing black p-branes in arbitrary dimensions assuming the
transverse space to be homogeneous and possessing spherical, toroidal or
hyperbolic topology. The generic solution contains eight parameters satisfying
one constraint. Asymptotically flat solutions form a five-parametric subspace,
while conditions of regularity of the non-degenerate event horizon further
restrict this number to three, which can be related to the mass and the charge
densities and the asymptotic value of the dilaton. In the case of a degenerate
horizon, this number is reduced by one. Our derivation constitutes a
constructive proof of the uniqueness theorem for -branes with the
homogeneous transverse space. No asymptotically flat solutions with toroidal or
hyperbolic transverse space within the considered class are shown to exist,
which result can be viewed as a demonstration of the topological censorship for
p-branes. From our considerations it follows, in particular, that some
previously discussed p-brane-like solutions with extra parameters do not
satisfy the standard conditions of asymptotic flatness and absence of naked
singularities. We also explore the same system in presence of a cosmological
constant, and derive a complete analytic solution for higher-dimensional
charged topological black holes, thus proving their uniqueness.Comment: Revtex4, no figure
Branes in the plane wave background with gauge field condensates
Supersymmetric branes in the plane wave background with additional constant
magnetic fields are studied from the world-sheet point of view. It is found
that in contradistinction to flat space, boundary condensates on some maximally
supersymmetric branes necessarily break at least some supersymmetries. The
maximally supersymmetric cases with condensates are shown to be in one to one
correspondence with the previously classified class II branes.Comment: LaTeX, 31 pages, no figures; v2: references added, some typos
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Effect of magnetic state on the transition in iron: First-principle calculations of the Bain transformation path
Energetics of the fcc () - bcc () lattice transformation by
the Bain tetragonal deformation is calculated for both magnetically ordered and
paramagnetic (disordered local moment) states of iron. The first-principle
computational results manifest a relevance of the magnetic order in a scenario
of the - transition and reveal a special role of the Curie
temperature of -Fe, , where a character of the transformation is
changed. At a cooling down to the temperatures one can expect that
the transformation is developed as a lattice instability whereas for
it follows a standard mechanism of creation and growth of an embryo of the new
phase. It explains a closeness of to the temperature of start of the
martensitic transformation, .Comment: 4 pages, 3 figures, submitted in Phys. Rev. Letter
The structure of causal sets
More often than not, recently popular structuralist interpretations of
physical theories leave the central concept of a structure insufficiently
precisified. The incipient causal sets approach to quantum gravity offers a
paradigmatic case of a physical theory predestined to be interpreted in
structuralist terms. It is shown how employing structuralism lends itself to a
natural interpretation of the physical meaning of causal sets theory.
Conversely, the conceptually exceptionally clear case of causal sets is used as
a foil to illustrate how a mathematically informed rigorous conceptualization
of structure serves to identify structures in physical theories. Furthermore, a
number of technical issues infesting structuralist interpretations of physical
theories such as difficulties with grounding the identity of the places of
highly symmetrical physical structures in their relational profile and what may
resolve these difficulties can be vividly illustrated with causal sets.Comment: 19 pages, 4 figure
Radiative association and inverse predissociation of oxygen atoms
The formation of \mbox{O}_2 by radiative association and by inverse
predissociation of ground state oxygen atoms is studied using
quantum-mechanical methods. Cross sections, emission spectra, and rate
coefficients are presented and compared with prior experimental and theoretical
results. At temperatures below 1000~K radiative association occurs by approach
along the state of \mbox{O}_2 and above 1000~K inverse
predissociation through the \mbox{B}\,{}^3\Sigma_u^- state is the dominant
mechanism. This conclusion is supported by a quantitative comparison between
the calculations and data obtained from hot oxygen plasma spectroscopy.Comment: submitted to Phys. Rev. A (Sept. 7., 1994), 19 pages, 4 figures,
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