1,850 research outputs found
The QUEST large area CCD camera
We have designed, constructed, and put into operation a very large area CCD camera that covers the field of view of the 1.2 m Samuel Oschin Schmidt Telescope at the Palomar Observatory. The camera consists of 112 CCDs arranged in a mosaic of four rows with 28 CCDs each. The CCDs are 600 x 2400 pixel Sarnoff thinned, back-illuminated devices with 13 µm x 13 µm pixels. The camera covers an area of 4.6° x 3.6° on the sky with an active area of 9.6 deg_2. This camera has been installed at the prime focus of the telescope and commissioned, and scientific-quality observations on the Palomar-QUEST Variability Sky Survey were started in 2003 September. The design considerations, construction features, and performance parameters of this camera are described in this paper
The NOνA simulation chain
The NOνA experiment is a two-detector, long-baseline neutrino experiment operating in the recently upgraded NuMI muon neutrino beam. Simulating neutrino interactions and backgrounds requires many steps including: the simulation of the neutrino beam flux using FLUKA and the FLUGG interface; cosmic ray generation using CRY; neutrino interaction modeling using GENIE; and a simulation of the energy deposited in the detector using GEANT4. To shorten generation time, the modeling of detector-specific aspects, such as photon transport, detector and electronics noise, and readout electronics, employs custom, parameterized simulation applications. We will describe the NOνA simulation chain, and present details on the techniques used in modeling photon transport near the ends of cells, and in developing a novel data-driven noise simulation. Due to the high intensity of the NuMI beam, the Near Detector samples a high rate of muons originating in the surrounding rock. In addition, due to its location on the surface at Ash River, MN, the Far Detector collects a large rate (˜ 140 kHz) of cosmic muons. We will discuss the methods used in NOνA for overlaying rock muons and cosmic ray muons with simulated neutrino interactions and show how realistically the final simulation reproduces the preliminary NOνA data
An experiment for the measurement of the bound-beta decay of the free neutron
The hyperfine-state population of hydrogen after the bound-beta decay of the
neutron directly yields the neutrino left-handedness or a possible right-handed
admixture and possible small scalar and tensor contributions to the weak force.
Using the through-going beam tube of a high-flux reactor, a background free
hydrogen rate of ca. 3 s can be obtained. The detection of the neutral
hydrogen atoms and the analysis of the hyperfine states is accomplished by Lamb
shift source type quenching and subsequent ionization. The constraints on the
neutrino helicity and the scalar and tensor coupling constants of weak
interaction can be improved by a factor of ten.Comment: 9 pages, 5 figures. Submitted to EPJ
Time Domain Explorations With Digital Sky Surveys
One of the new frontiers of astronomical research is the exploration of time
variability on the sky at different wavelengths and flux levels. We have
carried out a pilot project using DPOSS data to study strong variables and
transients, and are now extending it to the new Palomar-QUEST synoptic sky
survey. We report on our early findings and outline the methodology to be
implemented in preparation for a real-time transient detection pipeline. In
addition to large numbers of known types of highly variable sources (e.g., SNe,
CVs, OVV QSOs, etc.), we expect to find numerous transients whose nature may be
established by a rapid follow-up. Whereas we will make all detected variables
publicly available through the web, we anticipate that email alerts would be
issued in the real time for a subset of events deemed to be the most
interesting. This real-time process entails many challenges, in an effort to
maintain a high completeness while keeping the contamination low. We will
utilize distributed Grid services developed by the GRIST project, and implement
a variety of advanced statistical and machine learning techniques.Comment: 5 pages, 2 postscript figures, uses adassconf.sty. To be published
in: "ADASS XIV (2004)", Eds. Patrick Shopbell, Matthew Britton and Rick
Ebert, ASP Conference Serie
Feasibility and benefits of reclaiming a man-made lake: A case study of Lake Paradise Mattoon, Illinois
Man-made lakes in Illinois and other states are experiencing severe sedimentation problems, which reduce water-storage capacities and degrade water quality, as well as limit recreational opportunities. In a pilot project at Lake Paradise, Mattoon, Illinois, a number of studies have been conducted on the feasibility and benefits of lake reclamation. Included are studies on the feasibility of dredging Lake Paradise, on the importance of recreation planning to lake reclamation, and on the economics of lake reclamation. The Lake Paradise studies indicate that the sediment of Lake Paradise can be dredged to increase storage capacity and improve water quality and that the sediment can probably be restored as a soil amendment to the surrounding farmland. The studies also indicate that recreation should be an important consideration of lake reclamation planning and that lake reclamation may be cost-efficient compared to other alternatives such as constructing additional water-supply reservoirs. It is recommended that Illinois communities that are experiencing problems with their lakes due to sediment suspension and accumulation should consider lake reclamation as one possible element of a water resources management program. In evaluating the potential of lake reclamation, communities should conduct studies to determine the feasibility of dredging and the uses of the dredged sediments, the economic benefits of reclamation as compared to other alternatives, and the perceptions that local residents have of the benefits of reclaiming a lake. It is also recommended that further research studies of the economics and techniques of dredging and sediment disposal be conducted.U.S. Department of the InteriorU.S. Geological SurveyOpe
An evaluation of several diet acidifiers commonly utilized in pig starter diets to improve growth performance
Early-weaned pigs (weaned at 14 d of age) that are managed in a conventional one-site production system and fed a complex segregated early-weaning diet will benefit from the inclusion of a diet acidifier during the first week. However, the data indicate no benefit from including a diet acidifier in semicomplex diets fed during subsequent growth phases.; Swine Day, Manhattan, KS, November 21, 199
Effects of different specialty protein sources on growth performance of starter pigs
Two hundred and ten weanling pigs were fed diets containing either soybean meal, spray-dried blood meal, spray-dried red blood cells, select menhaden fish meal, or synthetic amino acids. From d 0 to 7 postweaning, pigs fed either spray-dried whole blood meal or red blood cells had greater ADG and ADFI than pigs fed select menhaden fish meal or added synthetic amino acids. However, from d °to 14 and 0 to 21, no differences in growth performance occurred among pigs fed the various protein sources. However, pigs fed added synthetic amino acids had poorer ADG compared with the mean for pigs fed the other protein sources.; Swine Day, Manhattan, KS, November 21, 199
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