8,795 research outputs found
Project Explorer: Get Away Special #007
Tentatively scheduled to fly on STS-17 (41G), this get away special aims to demonstrate amateur radio transmissions to global ground stations in the English language. Experiments No. 1, 2, and 3 use the micro-gravity of space flight to study the solidification of lead-antimony and aluminum-copper alloys, the germination of radish seeds, and the growth of potassium-tetracyanoplatinate hydrate crystals in an aqueous solution. Flight results are to be compared with Earth-based data. Experiment No. 4 (the Marshall Amateur Radio Club Experiment - MARCE) features radio transmissions and also provides timing for the start of all other experiments. A microprocessor obtains real-time data from all experiments as well as temperature and pressure measurements within the GAS canister. These data are to be transmitted on previously announced amateur radio frequencies after they are converted into the English language by a digitalker for general reception. The support structure for the G #007 experiments consists of two primary plates and four bumper assemblies
Exploration of the solar system
A sourcebook of information on the solar system and the technology used for its exploration is presented. An outline of the potential achievements of solar system exploration is given along with a course of action which maximizes the rewards to mankind
Product-Related Risk and Cognitive Biases: The Shortcomings of Enterprise Liability
Products liability law has witnessed a long debate over whether manufacturers should be held strictly liable for the injuries that products cause. Recently, some have argued that psychological research on human judgment supports adopting a regime of strict enterprise liability for injuries caused by product design. These new proponents of enterprise liability argue that the current system, in which manufacturer liability for product design turns on the manufacturer\u27s negligence, allows manufacturers to induce consumers into undertaking inefficiently dangerous levels or types of consumption. In this paper we argue that the new proponents of enterprise liability have: (1) not provided any more than anecdotal evidence for their thesis; (2) failed to account for the mechanisms the law already has available to counter manufacturer manipulation of consumers; and (3) made no effort to address the well-known problems enterprise liability creates. Furthermore, even on its own terms, the new arguments for enterprise liability fail to consider the tendency of some manufacturers to exacerbate the risks that some products pose - a tendency that enterprise liability would exacerbate. In short, the insights gleaned from psychological research on human judgment do not support adopting a system of strict enterprise liability for products
Wind-tunnel Studies at Subsonic and Transonic Speeds of a Multiple-mission Variable-wing-sweep Airplane Configuration
Wind tunnel studies at supersonic and transonic speeds to determine aerodynamic characteristics of variable sweep wing aircraft - configuratio
The Paper Industry: Strategic Alliances, Joint Ventures, and Electronic Commerce Are Reshaping Our Business Models
J. Ben Reeves, MBA, is a wood and fiber procurement manager, Georgia-Pacific Corperation, Lynchburg, VA 24503.
Deanna S. Stepp, MBA, CRP, is a marketing director, Lawrence Transportation, Roanoke, VA 24012.
Lewis E. Wertz, Jr., MBA, MSCE, P.E., is an engineer-planner, R & K Engineering Inc., Roanoke, VA 24012.
Dale A. Henderson, Ph.D., is assistant professor of management, Department of Management, Radford University, Radford, VA 24142
Developing an Onboard Traffic-Aware Flight Optimization Capability for Near-Term Low-Cost Implementation
The concept of Traffic Aware Strategic Aircrew Requests (TASAR) combines Automatic Dependent Surveillance Broadcast (ADS-B) IN and airborne automation to enable user-optimal in-flight trajectory replanning and to increase the likelihood of Air Traffic Control (ATC) approval for the resulting trajectory change request. TASAR is designed as a near-term application to improve flight efficiency or other user-desired attributes of the flight while not impacting and potentially benefiting ATC. Previous work has indicated the potential for significant benefits for each TASAR-equipped aircraft. This paper will discuss the approach to minimizing TASAR's cost for implementation and accelerating readiness for near-term implementation
New Outlook on the Possible Existence of Superheavy Elements in Nature
A consistent interpretation is given to some previously unexplained phenomena
seen in nature in terms of the recently discovered long-lived high spin super-
and hyper-deformed isomeric states. The Po halos seen in mica are interpreted
as due to the existence of such isomeric states in corresponding Po or nearby
nuclei which eventually decay by gamma- or beta-decay to the ground states of
210Po, 214Po and 218Po nuclei. The low-energy 4.5 MeV alpha-particle group
observed in several minerals is interpreted as due to a very enhanced alpha
transition from the third minimum of the potential-energy surface in a
superheavy nucleus with atomic number Z=108 (Hs) and atomic mass number around
271 to the corresponding minimum in the daughter.Comment: 8 pages, 8 figures, 5 tables. Paper presented at VII Int.
School-Seminar on Heavy Ion Physics, May 27 - June 1, 2002, Dubna, Russi
Robust Digital Holography For Ultracold Atom Trapping
We have formulated and experimentally demonstrated an improved algorithm for
design of arbitrary two-dimensional holographic traps for ultracold atoms. Our
method builds on the best previously available algorithm, MRAF, and improves on
it in two ways. First, it allows for creation of holographic atom traps with a
well defined background potential. Second, we experimentally show that for
creating trapping potentials free of fringing artifacts it is important to go
beyond the Fourier approximation in modelling light propagation. To this end,
we incorporate full Helmholtz propagation into our calculations.Comment: 7 pages, 4 figure
Ising Expansion for the Hubbard Model
We develop series expansions for the ground state properties of the Hubbard
model, by introducing an Ising anisotropy into the Hamiltonian. For the
two-dimensional (2D) square lattice half-filled Hubbard model, the ground state
energy, local moment, sublattice magnetization, uniform magnetic susceptibility
and spin stiffness are calculated as a function of , where is the
Coulomb constant and is the hopping parameter. Magnetic susceptibility data
indicate a crossover around between spin density wave
antiferromagnetism and Heisenberg antiferromagnetism. Comparisons with Monte
Carlo simulations, RPA result and mean field solutions are also made.Comment: 22 pages, 6 Postscript figures, Revte
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