26,484 research outputs found
Saturn S-IB stage Final static test report, stage S-IB-2
Acceptance test firing of Saturn flight stage S-IB-
Central Exclusive Di-jet Production at the Tevatron
We perform a phenomenological analysis of dijet production in double pomeron
exchange at the Tevatron. We find that the CDF Run I results do not rule out
the presence of an exclusive dijet component, as predicted by Khoze, Martin and
Ryskin (KMR). With the high statistics CDF Run II data, we predict that an
exclusive component at the level predicted by KMR may be visible, although the
observation will depend on accurate modelling of the inclusive double pomeron
exchange process. We also compare to the predictions of the DPEMC Monte Carlo,
which contains a non-perturbative model for the central exclusive process. We
show that the perturbative model of KMR gives different predictions for the
di-jet ET dependence in the high di-jet mass fraction region than
non-perturbative models.Comment: 17 pages, 15 figure
Application of remote sensing technology to land evaluation, planning utilization of land resources, and assessment of westland habitat in eastern South Dakota, parts 1 and 2
The author has identified the following significant results. LANDSAT fulfilled the requirements for general soils and land use information. RB-57 imagery was required to provide the information and detail needed for mapping soils for land evaluation. Soils maps for land evaluation were provided on clear mylar at the scale of the county highway map to aid users in locating mapping units. Resulting mapped data were computer processed to provided a series of interpretive maps (land value, limitations to development, etc.) and area summaries for the users
Saturn S-IB stage Final static test report, stage S-IB-4
Acceptance static test firing data for Saturn flight stage S-IB-
The 24-Cell and Calabi-Yau Threefolds with Hodge Numbers (1,1)
Calabi-Yau threefolds with h^11(X)=h^21(X)=1 are constructed as free
quotients of a hypersurface in the ambient toric variety defined by the
24-cell. Their fundamental groups are SL(2,3), a semidirect product of Z_3 and
Z_8, and Z_3 x Q_8.Comment: 22 pages, 3 figures, 3 table
Assembly and analysis of fragmentation data for liquid propellant vessels
Fragmentation data was assembled and analyzed for exploding liquid propellant vessels. These data were to be retrieved from reports of tests and accidents, including measurements or estimates of blast yield, etc. A significant amount of data was retrieved from a series of tests conducted for measurement of blast and fireball effects of liquid propellant explosions (Project PYRO), a few well-documented accident reports, and a series of tests to determine auto-ignition properties of mixing liquid propellants. The data were reduced and fitted to various statistical functions. Comparisons were made with methods of prediction for blast yield, initial fragment velocities, and fragment range. Reasonably good correlation was achieved. Methods presented in the report allow prediction of fragment patterns, given type and quantity of propellant, type of accident, and time of propellant mixing
Large Interstellar Polarisation Survey II. UV/optical study of cloud-to-cloud variations of dust in the diffuse ISM
It is well known that the dust properties of the diffuse interstellar medium
exhibit variations towards different sight-lines on a large scale. We have
investigated the variability of the dust characteristics on a small scale, and
from cloud-to-cloud. We use low-resolution spectro-polarimetric data obtained
in the context of the Large Interstellar Polarisation Survey (LIPS) towards 59
sight-lines in the Southern Hemisphere, and we fit these data using a dust
model composed of silicate and carbon particles with sizes from the molecular
to the sub-micrometre domain. Large (> 6 nm) silicates of prolate shape account
for the observed polarisation. For 32 sight-lines we complement our data set
with UVES archive high-resolution spectra, which enable us to establish the
presence of single-cloud or multiple-clouds towards individual sight-lines. We
find that the majority of these 35 sight-lines intersect two or more clouds,
while eight of them are dominated by a single absorbing cloud. We confirm
several correlations between extinction and parameters of the Serkowski law
with dust parameters, but we also find previously undetected correlations
between these parameters that are valid only in single-cloud sight-lines. We
find that interstellar polarisation from multiple-clouds is smaller than from
single-cloud sight-lines, showing that the presence of a second or more clouds
depolarises the incoming radiation. We find large variations of the dust
characteristics from cloud-to-cloud. However, when we average a sufficiently
large number of clouds in single-cloud or multiple-cloud sight-lines, we always
retrieve similar mean dust parameters. The typical dust abundances of the
single-cloud cases are [C]/[H] = 92 ppm and [Si]/[H] = 20 ppm.Comment: A&A accepte
Picard group of hypersurfaces in toric 3-folds
We show that the usual sufficient criterion for a generic hypersurface in a
smooth projective manifold to have the same Picard number as the ambient
variety can be generalized to hypersurfaces in complete simplicial toric
varieties. This sufficient condition is always satisfied by generic K3 surfaces
embedded in Fano toric 3-folds.Comment: 14 pages. v2: some typos corrected. v3: Slightly changed title. Final
version to appear in Int. J. Math., incorporates many (mainly expository)
changes suggested by the refere
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