5,872 research outputs found
Giotto Extended Mission (GEM)
The primary objectives of the Giotto Extended Mission (GEM), are to determine the composition and physical state of the Grigg Skjellerup Comet's nucleus; to determine the processes that govern the composition and distribution of neutral and ionized species in the cometary atmosphere. Giotto consists of a single European Space Agency (ESA) spacecraft that was launched in 1985 from Center Spatial Guyanis in French Guiana on an Ariane launch vehicle. After a successful launch into geostationary orbit and a heliocentric transfer trajectory, the spacecraft successfully encountered Halley's Comet in 1986. One month after encountering Halley's Comet, Mar. 1986, the spacecraft was placed in hibernation in a heliocentric orbit slightly less than 1 AU. Between Feb. and Jul. 1990 the spacecraft was successfully reactivated, checked out, and placed on a trajectory course to intercept comet Grigg Skjellerup. The spacecraft has been in hibernation since Jul. 1990. Information is presented in tabular form in the following areas: coverage goals, Deep Space Network Support, frequency assignments, telemetry, command, and tracking support responsibility
Animals in Film and Television
People have always had a fascination for large, exotic types of animals and as a result many zoos were set up all over Europe and North America. For many years there was a great deal of money to be made from exhibiting animals, and very little regard was paid to their welfare.
With the advent of cinema and television we have come to appreciate these animals in their own environment. Some modern zoos have attempted, therefore, to reproduce a type of natural surrounding for the larger species of animal, but the compromise between providing an animal with its natural environment and still allowing it to be seen by the public is not easy to attain, and there has always been a tendency to err on the side of the public. This tendency to favor the viewing public rather than the animals has resulted in concern about the way in which animals are exploited for films and television. These are modern problems, and they come under two distinct headings
Achieving a Concensus on Dog Control Strategies: A Brief Primer
The author discusses challenges in developing effective policies for stray dog control. Stray dog symptoms vary from country to country. In Cyprus, the presence of echinococcus that stray dogs exacerbate is a problem across the Mediterranean. Rabies spread by stray dogs is a problem in many other countries, while anti-social dog behaviors (fouling, barking, biting) are an issue in large cities in developed countries. Considerable differences of opinion as to the best approaches to stray dog control exist among animal welfare organizations. One approach to developing effective and agreed stray dog control policies has been forming a national NGO umbrella organization. In the UK and Australia, this organization is the Joint Advisory Committee on Pets in Society (JACOPIS) and has already produced positive results
Achieving a Concensus on Dog Control Strategies: A Brief Primer
The welfare arguments surrounding dog ownership may not stimulate the same passionate fervor as those relating to the use of animals in experiments, factory farming, or the hunting of live animals with hounds, but nevertheless, they are matters of real concern to most welfare organizations. The most serious problems are caused through irresponsible ownership, which leads to overbreeding and the inevitable consequence of large number
Animals in Film and Television
Animals are entertaining. Human beings have exploited this undoubted fact for centuries and to the commercial advantage of many people. How we have exploited animals\u27 natural and unnatural behavior has varied. These variations include the straightforward exhibition of an animal in a zoo to the perversity of dogfighting, in which animals are allowed to fight until one or another is killed or badly injured. Entertainment implies both amusement and enjoyment, and it is incredible to realize that even within our so-called advanced Western civilization, there are still people who can gain enjoyment from either directly torturing and killing animals or by witnessing animals inflict pain and death upon each other. North America and most European countries have rightly condemned and outlawed bearbaiting,
cockfighting, and dogfighting. There is no doubt that these last two still have their followers and that organized events take place. Most people are appalled when they read stories of illegal dogfights taking place,
but is there any real difference in principle between that and bullfighting in Spain, foxhunting in Europe, or the use of the cinch strap on horses in rodeos in North America? Each of these is a form of entertainment or sport that depends to some degree on the infliction of pain and suffering on animals
Life inside black holes
We consider test planet and photon orbits of the third kind inside a black
hole, which are stable, periodic and neither come out of the black hole nor
terminate at the singularity. Interiors of supermassive black holes may be
inhabited by advanced civilizations living on planets with the third-kind
orbits. In principle, one can get information from the interiors of black holes
by observing their white hole counterparts.Comment: 4 pages, 2 figure
Determination of the Antiferroquadrupolar Order Parameters in UPd3
By combining accurate heat capacity and X-ray resonant scattering results we
have resolved the long standing question regarding the nature of the
quadrupolar ordered phases in UPd_3. The order parameter of the highest
temperature quadrupolar phase has been uniquely determined to be antiphase
Q_{zx} in contrast to the previous conjecture of Q_{x^2-y^2} . The azimuthal
dependence of the X-ray scattering intensity from the quadrupolar superlattice
reflections indicates that the lower temperature phases are described by a
superposition of order parameters. The heat capacity features associated with
each of the phase transitions characterize their order, which imposes
restrictions on the matrix elements of the quadrupolar operators.Comment: 4 pages, 5 figure
Resonant X-Ray Scattering on the M-Edge Spectra from Triple-k Structure Phase in U_{0.75}Np_{0.25}O_{2} and UO_{2}
We derive an expression for the scattering amplitude of resonant x-ray
scattering under the assumption that the Hamiltonian describing the
intermediate state preserves spherical symmetry. On the basis of this
expression, we demonstrate that the energy profile of the RXS spectra expected
near U and Np M_4 edges from the triple-k antiferromagnetic ordering phase in
UO_{2} and U_{0.75}Np_{0.25}O_{2} agree well with those from the experiments.
We demonstrate that the spectra in the \sigma-\sigma' and \sigma-\pi' channels
exhibit quadrupole and dipole natures, respectively.Comment: 3 pages, 3 figures, to be published in J. Phys. Soc. Jpn. Supp
Influence of static Jahn-Teller distortion on the magnetic excitation spectrum of PrO2: A synchrotron x-ray and neutron inelastic scattering study
A synchrotron x-ray diffraction study of the crystallographic structure of
PrO2 in the Jahn-Teller distorted phase is reported. The distortion of the
oxygen sublattice, which was previously ambiguous, is shown to be a chiral
structure in which neighbouring oxygen chains have opposite chiralities. A
temperature dependent study of the magnetic excitation spectrum, probed by
neutron inelastic scattering, is also reported. Changes in the energies and
relative intensities of the crystal field transitions provide an insight into
the interplay between the static and dynamic Jahn-Teller effects.Comment: 7 pages, 6 figure
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