3,428 research outputs found
Local water markets for irrigation in southern Spain: A multicriteria approach
Spanish authorities have recently approved a new legislative framework for the creation of local water markets to improve allocative efficiency for this scarce resource. This paper analyses the potential impacts of the policy. A utility function for three groups of farmers was elicited, using a method that does not require interaction with the decision‐makers. Utility was measured as a function of the first two moments of the distribution of total gross margin. The utility functions were then used to simulate farmers' responses to changes in the price of water.Resource /Energy Economics and Policy,
Optimization Techniques for the Power Beaming Analysis of Microwave Transmissions from a Space-Based Solar Power Satellite
In the 21st century, the development of technologies to produce carbon free power sources remains paramount. In this paper, we study an optimal power transmission strategy from a space-based satellite generation station to Earth using scalar diffraction theory. The resulting model is then solved via a spectral method that guarantees a compactly supposed profile from the transmitting antenna. Finally, the problem is then solved via a more general pseudo-spectral method using control theory
Prototype 9.7 m Schwarzschild-Couder telescope for the Cherenkov Telescope Array: status of the optical system
The Cherenkov Telescope Array (CTA) is an international project for a
next-generation ground-based gamma ray observatory, aiming to improve on the
sensitivity of current-generation experiments by an order of magnitude and
provide energy coverage from 30 GeV to more than 300 TeV. The 9.7m
Schwarzschild-Couder (SC) candidate medium-size telescope for CTA exploits a
novel aplanatic two-mirror optical design that provides a large field of view
of 8 degrees and substantially improves the off-axis performance giving better
angular resolution across all of the field of view with respect to
single-mirror telescopes. The realization of the SC optical design implies the
challenging production of large aspherical mirrors accompanied by a
submillimeter-precision custom alignment system. In this contribution we report
on the status of the implementation of the optical system on a prototype 9.7 m
SC telescope located at the Fred Lawrence Whipple Observatory in southern
Arizona.Comment: Proceedings of the 35th International Cosmic Ray Conference (ICRC
2017), Busan, Korea. All CTA contributions at arXiv:1709.0348
Robust Feedback Control based on Low Order Models with Uncertainty Estimation for a class of Biomedical Problems
Can hyperbolic phase of Brans-Dicke field account for Dark Matter?
We show that the introduction of a hyperbolic phase for Brans-Dicke (BD)
field results in a flat vacuum cosmological solution of Hubble parameter H and
fractional rate of change of BD scalar field, F which asymptotically approach
constant values. At late stages, hyperbolic phase of BD field behaves like dark
matter
Horn-Coupled, Commercially-Fabricated Aluminum Lumped-Element Kinetic Inductance Detectors for Millimeter Wavelengths
We discuss the design, fabrication, and testing of prototype horn-coupled,
lumped-element kinetic inductance detectors (LEKIDs) designed for cosmic
microwave background (CMB) studies. The LEKIDs are made from a thin aluminum
film deposited on a silicon wafer and patterned using standard
photolithographic techniques at STAR Cryoelectronics, a commercial device
foundry. We fabricated twenty-element arrays, optimized for a spectral band
centered on 150 GHz, to test the sensitivity and yield of the devices as well
as the multiplexing scheme. We characterized the detectors in two
configurations. First, the detectors were tested in a dark environment with the
horn apertures covered, and second, the horn apertures were pointed towards a
beam-filling cryogenic blackbody load. These tests show that the multiplexing
scheme is robust and scalable, the yield across multiple LEKID arrays is 91%,
and the noise-equivalent temperatures (NET) for a 4 K optical load are in the
range 26\thinspace\pm6 \thinspace \mu \mbox{K} \sqrt{\mbox{s}}
PAPPA: Primordial Anisotropy Polarization Pathfinder Array
The Primordial Anisotropy Polarization Pathfinder Array (PAPPA) is a
balloon-based instrument to measure the polarization of the cosmic microwave
background and search for the signal from gravity waves excited during an
inflationary epoch in the early universe. PAPPA will survey a 20 x 20 deg patch
at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212,
and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip
transmission line to combine the phase modulation techniques used in radio
astronomy with the sensitivity of transition-edge superconducting bolometers.
Each switched circuit modulates the incident polarization on a single detector,
allowing nearly instantaneous characterization of the Stokes I, Q, and U
parameters. We describe the instrument design and status.Comment: 12 pages, 9 figures. Proceedings of the Fundamental Physics With CMB
workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy
Review
- …
