30,864 research outputs found
Geothermal research and development program of the US Atomic Energy Commission
Within the overall federal geothermal program, the Atomic Energy Commission has chosen to concentrate on development of resource utilization and advanced research and technology as the areas most suitable to the expertise of its staff and that of the National Laboratories. The Commission's work in geothermal energy is coordinated with that of other agencies by the National Science Foundation, which has been assigned lead agency by the Office of Management and Budget. The objective of the Commission's program, consistent with the goals of the total federal program is to facilitate, through technological advancement and pilot plant operations, achievement of substantial commercial production of electrical power and utilization of geothermal heat by the year 1985. This will hopefully be accomplished by providing, in conjunction with industry, credible information on the economic operation and technological reliability of geothermal power and use of geothermal heat
A deterministic model for the occurrence and dynamics of multiple mutations in hierarchically organized tissues
We model a general, hierarchically organized tissue by a multi compartment
approach, allowing any number of mutations within a cell. We derive closed
solutions for the deterministic clonal dynamics and the reproductive capacity
of single clones. Our results hold for the average dynamics in a hierarchical
tissue characterized by an arbitrary combination of proliferation parameters.Comment: 4 figures, to appear in Royal Society Interfac
The Elements of the Neutrino Mass Matrix: Allowed Ranges and Implications of Texture Zeros
We study the range of the elements of the neutrino mass matrix m_nu in the
charged lepton basis. Neutrino-less double beta decay is sensitive to the ee
element of m_nu. We then analyze the phenomenological implications of single
texture zeros. In particular, interesting predictions for the effective mass
can be obtained, in the sense that typically only little cancellation due to
the Majorana phases is expected. Some cases imply constraints on the
atmospheric neutrino mixing angle.Comment: 21 pages, 7 figures. Minor corrections, matches version in PR
Numerical studies of planar closed random walks
Lattice numerical simulations for planar closed random walks and their
winding sectors are presented. The frontiers of the random walks and of their
winding sectors have a Hausdorff dimension . However, when properly
defined by taking into account the inner 0-winding sectors, the frontiers of
the random walks have a Hausdorff dimension .Comment: 15 pages, 15 figure
The Vacuum Structure of Light-Front -Theory
We discuss the vacuum structure of -theory in 1+1 dimensions
quantised on the light-front . To this end, one has to solve a
non-linear, operator-valued constraint equation. It expresses that mode of the
field operator having longitudinal light-front momentum equal to zero, as a
function of all the other modes in the theory. We analyse whether this zero
mode can lead to a non-vanishing vacuum expectation value of the field
and thus to spontaneous symmetry breaking. In perturbation theory, we get no
symmetry breaking. If we solve the constraint, however, non-perturbatively,
within a mean-field type Fock ansatz, the situation changes: while the vacuum
state itself remains trivial, we find a non-vanishing vacuum expectation value
above a critical coupling. Exactly the same result is obtained within a
light-front Tamm-Dancoff approximation, if the renormalisation is done in the
correct way.Comment: 28 pages LaTeX, 1 Postscript figur
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