2,893 research outputs found
An evolutionary approach for a compact-split-core reactor
An economical approach for advanced reactor power development is presented, and systems that result from the several stages of this plan are described. The development starts with a highly modularized heat pipe, radioisotopic design and evolves into a low specific weight high performance reactor system
A design study of a 350 kWe out-of-core nuclear thermionic converter system
Out-of-core nuclear thermionic converter system for high power level
Economic Development Benefits from Wind Power in Nebraska: A Report for the Nebraska Energy Office
Wind power constituted more than 35% of new U.S. electric generating capacity in 2007. Common drivers of wind power include Renewable Portfolio Standards (RPS), the federal production tax credit (PTC), and rural economic development benefits. Continued expansion of the wind industry into Nebraska would bring new employment and economic development to Nebraska and the country. This report by the National Renewable Energy Laboratory (NREL) focuses on the economic development impacts that would result in Nebraska from development and operation of wind power in the state as envisioned in the U.S. Department of Energy’s (DOE’s) report 20% Wind Energy by 2030. Under the national 20% wind scenario, 7,800 megawatts (MW) of new wind power is added in Nebraska. A practical first step to building 7,800 MW of wind is completing 1,000 MW. We also include the estimated economic impacts to Nebraska from building 1,000 MW of wind power. Economic impacts are estimated with NREL’s Jobs and Economic Development (JEDI) Wind model and include direct, indirect, and induced impacts. Direct impacts accrue from expenditures in the wind industry. Indirect impacts accrue in supporting industries as a result of increased demand for basic goods and services. Induced impacts result from reinvestment and spending by direct and indirect beneficiaries. In some cases, depending on the structure of the local economy, indirect and induced impacts may be greater than direct wind industry impacts. Jobs values are defined as construction-period jobs, operations-period jobs, and average employment impacts. All jobs totals include direct, indirect, and induced jobs. Construction-period jobs are defined as short-term, 1-year jobs, and include those jobs resulting from Nebraska-based construction and manufacturing. Operations-period jobs are full-time jobs that exist for the operating lifetime of the wind power facility; typically this is 20 years. Average employment is defined as the average jobs — direct, indirect, and induced — supported by wind development and operations over the full construction and operations period. This period is defined as 40 years for the 7,800 MW built in accord with the national 20% wind scenario and 22 years for the 1,000-MW analysis. All results are expressed as ranges and are based on the four possible development scenarios foreseen for Nebraska. Primary variables contributing to the range of impacts are the role of Nebraska manufacturing, the prevalence of Nebraska project ownership, and the availability and utilization of Nebraska labor
Development concept for a small, split-core, heat-pipe-cooled nuclear reactor
There have been two main deterrents to the development of semiportable nuclear reactors. One is the high development costs; the other is the inability to satisfy with assurance the questions of operational safety. This report shows how a split-core, heat-pipe cooled reactor could conceptually eliminate these deterrents, and examines and summarizes recent work on split-core, heat-pipe reactors. A concept for a small reactor that could be developed at a comparatively low cost is presented. The concept would extend the technology of subcritical radioisotope thermoelectric generators using 238 PuO2 to the evolution of critical space power reactors using 239 PuO2
Individual responsibility for environmental degradation:The moral and practical route to change
In environmental ethics a debate has arisen over the extent to which the individual should make changes in personal lifestyle in a long-term program of ameliorating environmental degradation, as opposed to directing energies toward public-policy change. In opposition are the facts that an individual's contribution to environmental degradation can only have a negligible effect. Public policy offers the only real hope for such massive coordinated effort, and environmental degradation is only one of many global problems to which ethically oriented people must focus their attentions and energies. So far, the pro-personal responsibility side has urged that personal lifestyle changes are necessary for moral coherence, thus in turn for integrity of character, and lifestyle changes can affect others in a kind of chain reaction because humans are socially submerged beings. The stalemate here can only stymies the needed coordinated effort toward ameliorating environmental degradation. Further, moral concerns need to be brought into this issue; namely, the ramifications of pursuing a policy-only approach, emphasizing policy as the sole (or even primary) means of ameliorating environmental degradation, implicitly undercuts the role of individual agents in morality in general, in terms of (1) individual responsibility, (2) autonomy, and (3) creativity in solving problems. All these problems not only bear on the program to reverse environmental degradation, but undermine other widely held moral values. Emphasizing personal lifestyle responsibility is not only the most moral alternative but is also the most assured way to affect long-term changes and the better way to make policy changes credible and sufficiently substantive for change
NiO Exchange Bias Layers Grown by Direct Ion Beam Sputtering of a Nickel Oxide Target
A new process for fabricating NiO exchange bias layers has been developed.
The process involves the direct ion beam sputtering (IBS) of a NiO target. The
process is simpler than other deposition techniques for producing NiO buffer
layers, and facilitates the deposition of an entire spin-valve layered
structure using IBS without breaking vacuum. The layer thickness and
temperature dependence of the exchange field for NiO/NiFe films produced using
IBS are presented and are similar to those reported for similar films deposited
using reactive magnetron sputtering. The magnetic properties of highly textured
exchange couples deposited on single crystal substrates are compared to those
of simultaneously deposited polycrystalline films, and both show comparable
exchange fields. These results are compared to current theories describing the
exchange coupling at the NiO/NiFe interface.Comment: 9 pages, Latex 2.09, 3 postscript figures. You can also this
manuscript at http://www.wsrcc.com/alison/fixed-nio/manuscript.html To be
published in _IEEE Trans. Magn._, Nov. 199
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Opportunities for and challenges to further reductions in the “specific power” rating of wind turbines installed in the United States
A wind turbine’s “specific power” rating relates its capacity to the swept area of its rotor in terms of Watt per square meter. For a given generator capacity, specific power declines as rotor size increases. In land-rich but capacity-constrained wind power markets, such as the United States, developers have an economic incentive to maximize megawatt-hours per constrained megawatt, and so have favored turbines with ever-lower specific power. To date, this trend toward lower specific power has pushed capacity factors higher while reducing the levelized cost of energy. We employ geospatial levelized cost of energy analysis across the United States to explore whether this trend is likely to continue. We find that under reasonable cost scenarios (i.e. presuming that logistical challenges from very large blades are surmountable), low-specific-power turbines could continue to be in demand going forward. Beyond levelized cost of energy, the boost in market value that low-specific-power turbines provide could become increasingly important as wind penetration grows
Small high-temperature nuclear reactors for space power
Criticality calculations for small, cylindrical, lithium cooled reactors for space power system
Andreev Level Qubit
We investigate the dynamics of a two-level Andreev bound state system in a
transmissive quantum point contact embedded in an rf-SQUID. Coherent coupling
of the Andreev levels to the circulating supercurrent allows manipulation and
read out of the level states. The two-level Hamiltonian for the Andreev levels
is derived, and the effect of interaction with the quantum fluctuations of the
induced flux is studied. We also consider an inductive coupling of qubits, and
discuss the relevant SQUID parameters for qubit operation and read out.Comment: 4 pages, 1 figur
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