5,283 research outputs found
Siting Issues for Solar Thermal Power Plants with Small Community Applications
Technologies for solar thermal plants are being developed to provide energy alternatives for the future. Implementation of these plants requires consideration of siting issues as well as power system technology. While many conventional siting considerations are applicable, there is also a set of unique siting issues for solar thermal plants. Early experimental plants will have special siting considerations. The siting issues associated with small, dispersed solar thermal power plants in the 1 to 10 MWe power range for utility/small community applications are considered. Some specific requirements refer to the first 1 MWe engineering experiment for the Small Power Systems Applications (SPSA) Project. The siting issues themselves are discussed in three categories: (1) system resource requirements, (2) environmental effects on the system, and (3) potential impact of the plant on the environment. Within these categories, specific issues are discussed in a qualitative manner. Examples of limiting factors for some issues are taken from studies of other solar systems
Thermal power systems small power systems application project: Siting issues for solar thermal power plants with small community applications
The siting issues associated with small, dispersed solar thermal power plants for utility/small community applications of less than 10 MWe are reported. Some specific requirements are refered to the first engineering experiment for the Small Power Systems Applications (SPSA) Project. The background for the subsequent issue discussions is provided. The SPSA Project and the requirements for the first engineering experiment are described, and the objectives and scope for the report as a whole. A overview of solar thermal technologies and some technology options are discussed
Integrated photonic building blocks for next-generation astronomical instrumentation II: the multimode to single mode transition
There are numerous advantages to exploiting diffraction-limited
instrumentation at astronomical observatories, which include smaller
footprints, less mechanical and thermal instabilities and high levels of
performance. To realize such instrumentation it is imperative to convert the
atmospheric seeing-limited signal that is captured by the telescope into a
diffraction-limited signal. This process can be achieved photonically by using
a mode reformatting device known as a photonic lantern that performs a
multimode to single-mode transition. With the aim of developing an optimized
integrated photonic lantern, we undertook a systematic parameter scan of
devices fabricated by the femtosecond laser direct-write technique. The devices
were designed for operation around 1.55 {\mu}m. The devices showed (coupling
and transition) losses of less than 5% for F/# 12 injection and the
total device throughput (including substrate absorption) as high as 75-80%.
Such devices show great promise for future use in astronomy.Comment: 12 pages, 9 figure
Entanglement of arbitrary superpositions of modes within two-dimensional orbital angular momentum state spaces
We use spatial light modulators (SLMs) to measure correlations between arbitrary superpositions of orbital angular momentum (OAM) states generated by spontaneous parametric down-conversion. Our technique allows us to fully access a two-dimensional OAM subspace described by a Bloch sphere, within the higher-dimensional OAM Hilbert space. We quantify the entanglement through violations of a Bell-type inequality for pairs of modal superpositions that lie on equatorial, polar, and arbitrary great circles of the Bloch sphere. Our work shows that SLMs can be used to measure arbitrary spatial states with a fidelity sufficient for appropriate quantum information processing systems
Multiband processing of multimode light: combining 3D photonic lanterns with waveguide Bragg gratings
The first demonstration of narrowband spectral filtering of multimode light
on a 3D integrated photonic chip using photonic lanterns and waveguide Bragg
gratings is reported. The photonic lanterns with multi-notch waveguide Bragg
gratings were fabricated using the femtosecond direct-write technique in
boro-aluminosilicate glass (Corning, Eagle 2000). Transmission dips of up to 5
dB were measured in both photonic lanterns and reference single-mode waveguides
with 10.4-mm-long gratings. The result demonstrates efficient and symmetrical
performance of each of the gratings in the photonic lantern. Such devices will
be beneficial to space-division multiplexed communication systems as well as
for units for astronomical instrumentation for suppression of the atmospheric
telluric emission from OH lines.Comment: 5 pages, 4 figures, accepted to Laser & Photonics Review
Economic integration and human capital investment
In this paper we seek to characterise a market for heterogeneous managers created by heterogeneous firms and the decisions on investment in both sector-specific and firm-specific human capital when those decisions are made prior to the realisation of firms' profitability and the degree of markets’ integration may vary. We consider the (Nash) equilibrium and relate this to a first-best allocation. The rent-seeking motives of managers and firms will generally make sector- and firm-specific investment decisions not socially optimum, both with respect to the number of investors and the level of each investment. The effect on welfare of markets’ integration varies with the nature of the skills considered. With more general, sector-specific, skills more integration, by increasing the matching ability of the market, reduces the distortion caused by rent-seeking, and increases social welfare. However, with more specific skills the increased matching ability of a more integrated market, by making managers more mobile, destroys some firm-specific human capital and so reduces welfare
Comparison of nonlinear dynamic inversion and inverse simulation
No abstract available
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