16,821 research outputs found
Three-body forces and proton-rich nuclei
We present the first study of three-nucleon (3N) forces for proton-rich
nuclei along the N=8 and N=20 isotones. Our results for the ground-state
energies and proton separation energies are in very good agreement with
experiment where available, and with the empirical isobaric multiplet mass
equation. We predict the spectra for all N=8 and N=20 isotones to the proton
dripline, which agree well with experiment for 18Ne, 19Na, 20Mg and 42Ti. In
all other cases, we provide first predictions based on nuclear forces. Our
results are also very promising for studying isospin symmetry breaking in
medium-mass nuclei based on chiral effective field theory.Comment: 5 pages, 4 figures, minor changes, published versio
Experimental economics: Methods, problems and promise
The purpose of this paper is to discuss the growing importance of experimentation in economic analysis. We present a variety of economic issues that have been explored with laboratory techniques. We also address some common objections to experimentation, as well as some of the principal lessons that have been learned.
Transport phenomena in ionized gases as an initial value problem
Transport phenomena in ionized gases as initial value proble
Plasma diffusion as an initial value problem
Plasma diffusion as initial value proble
Experimental Economics
This is the first comprehensive treatment of laboratory experiments designed to evaluate economic propositions under carefully controlled conditions. While it acknowledges that laboratory experiments are no panacea, it argues cogently for their effectiveness in selected situations. Covering methodological and procedural issues as well as theory, Experimental Economics is not only a textbook but also a useful introduction to laboratory methods for professional economists. The emphasis is on organizing and evaluating existing results. The book can be used as an anchoring device for a course at either the graduate or advanced undergraduate level. Applications include financial market experiments, oligopoly price competition, auctions, bargaining, provision of public goods, experimental games, and decision making under uncertainty. The book also contains instructions for a variety of laboratory experiments.laboratory experiments, financial markets, price competition, auctions, bargaining, games, decision making, uncertainty
Nuclear forces and their impact on neutron-rich nuclei and neutron-rich matter
We review the impact of nuclear forces on matter at neutron-rich extremes.
Recent results have shown that neutron-rich nuclei become increasingly
sensitive to three-nucleon forces, which are at the forefront of theoretical
developments based on effective field theories of quantum chromodynamics. This
includes the formation of shell structure, the spectroscopy of exotic nuclei,
and the location of the neutron dripline. Nuclear forces also constrain the
properties of neutron-rich matter, including the neutron skin, the symmetry
energy, and the structure of neutron stars. We first review our understanding
of three-nucleon forces and show how chiral effective field theory makes unique
predictions for many-body forces. Then, we survey results with three-nucleon
forces in neutron-rich oxygen and calcium isotopes and neutron-rich matter,
which have been explored with a range of many-body methods. Three-nucleon
forces therefore provide an exciting link between theoretical, experimental and
observational nuclear physics frontiers.Comment: 28 pages, 13 figures, 1 tabl
Three-nucleon forces and spectroscopy of neutron-rich calcium isotopes
We study excited-state properties of neutron-rich calcium isotopes based on
chiral two- and three-nucleon interactions. We first discuss the details of our
many-body framework, investigate convergence properties, and for two-nucleon
interactions benchmark against coupled-cluster calculations. We then focus on
the spectroscopy of 47-56Ca, finding that with both 3N forces and an extended
pfg9/2 valence space, we obtain a good level of agreement with experiment. We
also study electromagnetic transitions and find that experimental data are well
described by our calculations. In addition, we provide predictions for
unexplored properties of neutron-rich calcium isotopes.Comment: 15 pages, 22 figures, published versio
Scene simulation for passive IR systems
The development of large mosaic detector arrays will allow for the construction of staring long wave infrared (LWIR) sensors which can observe large fields of view instantaneously and continuously. In order to evaluate and exercise these new systems, it will be necessary to provide simulated scenes of many moving targets against an infrared clutter background. Researchers are currently developing a projector/screen system. This system is comprised of a mechanical scanner, a diffuse screen, and a miniature blackbody. A prototype of the mechanical scanner, which is comprised of four independently driven scanners, has been designed, fabricated, and evaluated under room and cryogenic vacuum conditions. A large diffuse screen has been constructed and tested for structural integrity under cryogenic/vacuum thermal cycling. Construction techniques have been developed for the fabrication of miniature high-temperature blackbody sources. Finally, a concept has been developed to use this miniature blackbody to produce a spectrally tailorable source
The InDeVal insertion/deletion evaluation tool: a program for finding target regions in DNA sequences and for aiding in sequence comparison
BACKGROUND: The program InDeVal was originally developed to help researchers find known regions of insertion/deletion activity (with the exception of isolated single-base indels) in newly determined Poaceae trnL-F sequences and compare them with 533 previously determined sequences. It is supplied with input files designed for this purpose. More broadly, the program is applicable for finding specific target regions (referred to as "variable regions") in DNA sequence. A variable region is any specific sequence fragment of interest, such as an indel region, a codon or codons, or sequence coding for a particular RNA secondary structure. RESULTS: InDeVal input is DNA sequence and a template file (sequence flanking each variable region). Additional files contain the variable regions and user-defined messages about the sequence found within them (e.g., taxa sharing each of the different indel patterns). Variable regions are found by determining the position of flanking sequence (referred to as "conserved regions") using the LPAM (Length-Preserving Alignment Method) algorithm. This algorithm was designed for InDeVal and is described here for the first time. InDeVal output is an interactive display of the analyzed sequence, broken into user-defined units. Once the user is satisfied with the organization of the display, the information can be exported to an annotated text file. CONCLUSIONS: InDeVal can find multiple variable regions simultaneously (28 indel regions in the Poaceae trnL-F files) and display user-selected messages specific to the sequence variants found. InDeVal output is designed to facilitate comparison between the analyzed sequence and previously evaluated sequence. The program's sensitivity to different levels of nucleotide and/or length variation in conserved regions can be adjusted. InDeVal is currently available for Windows in Additional file 1 or from
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