145,706 research outputs found
The Coming Boom in Computer Loads
Computers and other electronic equipment now consume as much electricity as electric steel furnaces, and their growth shows no signs of slowing. Utilities are active participants in the computer revolution. Northeast Utilities, for example, reports that 20% of electricity use in a typical new office building in its service area goes to computers. Given the expected growth in computers and computer loads, this technology deserves greater attention from utility planners and other energy analysts. It is shown that the commercial sector has been the largest contributor to kilowatt-hour (kwh) sales growth and that new uses within the commercial sector have accounted for the biggest portion of this growth. Confirming this conclusion are a 4-year Department of Energy-funded study of the Park Plaza Building office tower and a 1985 study of 181 office buildings by Northwest Utilities. A prospective study suggests that computers could account for as much as 150 billion kwh by the early 1990s
A very important process of nucleosynthesis in stars
When some nuclei are free from strong gravitational field, they are unstable and will become stable nuclei by competitions of following processes: (1) neutron-evaporation; (2) spontaneous fission; and (3) beta prime 3-decay. At the initial stage, (1) and (2) are important and (3) can be ignored. The qualitative results are as follows: (1) it seems that nuclei with A 100 come from the spontaneous fission and beta prime decay of neutron-evaporated nuclei with A similiar to 140-440, which can replace the r-process; (2) the super-heavy elements with Z=114--126 (A similiar to 330--360) can be formed. They can be observed in cosmic rage if they have the halftime T 10 to the 7th poweer years; (3) the peak in the rare-earth elements comes from the symmetric fission of super-heavy elements; (4) there are more neutron-rich nuclei in the fragments; and (5) the abundances of a 83 elements in cosmic rays are one order of magnitude higher than that in the solar system
Nucleosynthesis in the terrestrial and solar atmospheres
Variations of Delta D, delta C-13, Delta C-14 and Delta O-18 with time were measured by a lot of experiments. Many abnormalities of isotope abundances in cosmic rays were found by balloons and satellites. It is suggested that these abnormalities are related to nuclearsynthesis in the terrestrial and solar atmospheres and are closely related to solar activities
Quantum orientational melting of mesoscopic clusters
By path integral Monte Carlo simulations we study the phase diagram of two -
dimensional mesoscopic clusters formed by electrons in a semiconductor quantum
dot or by indirect magnetoexcitons in double quantum dots. At zero (or
sufficiently small) temperature, as quantum fluctuations of particles increase,
two types of quantum disordering phenomena take place: first, at small values
of quantum de Boer parameter q < 0.01 one can observe a transition from a
completely ordered state to that in which different shells of the cluster,
being internally ordered, are orientationally disordered relative to each
other. At much greater strengths of quantum fluctuations, at q=0.1, the
transition to a disordered (superfluid for the boson system) state takes place.Comment: 4 pages, 6 Postscript figure
Entropic equation of state and scaling functions near the critical point in scale-free networks
We analyze the entropic equation of state for a many-particle interacting
system in a scale-free network. The analysis is performed in terms of scaling
functions which are of fundamental interest in the theory of critical phenomena
and have previously been theoretically and experimentally explored in the
context of various magnetic, fluid, and superconducting systems in two and
three dimensions. Here, we obtain general scaling functions for the entropy,
the constant-field heat capacity, and the isothermal magnetocaloric coefficient
near the critical point in scale-free networks, where the node-degree
distribution exponent appears to be a global variable and plays a
crucial role, similar to the dimensionality for systems on lattices. This
extends the principle of universality to systems on scale-free networks and
allows quantification of the impact of fluctuations in the network structure on
critical behavior.Comment: 8 pages, 4 figure
Topological phase transition in wire medium enables high Purcell factor at infrared frequencies
In this paper, we study topological phase transition in a wire medium
operating at infrared frequencies. This transition occurs in the reciprocal
space between the indefinite (open-surface) regime of the metamaterial to its
dielectric (closed-surface) regime. Due to the spatial dispersion inherent to
wire medium, a hybrid regime turns out to be possible at the transition
frequency. Both such surfaces exist at the same frequency and touch one
another. At this frequency, all values of the axial wavevector correspond to
propagating spatial harmonics. The implication of this regime is the
overwhelming radiation enhancement. We numerically investigated the gain in
radiated power for a sub-wavelength dipole source submerged into such the
medium. In contrast to all previous works, this gain (called the Purcell
factor) turns out to be higher for an axial dipole than for a transversal one
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