8,996 research outputs found
Method and apparatus for varying thermal conductivity Patent
Method and apparatus for adjusting thermal conductance in electronic components for space us
Strong irradiation of protostellar cores in Corona Australis
The importance of the physical environment in the evolution of newly formed
low-mass stars remains an open question. In particular, radiation from nearby
more massive stars may affect both the physical and chemical structure of these
kinds of young stars. Aims: To constrain the physical characteristics of a
group of embedded low-mass protostars in Corona Australis in the vicinity of
the young luminous Herbig Be star R CrA. Methods: Millimetre wavelength maps of
molecular line and continuum emission towards the low-mass star forming region
IRS7 near R CrA from the SMA and APEX are presented. The maps show the
distribution of 18 lines from 7 species (H2CO, CH3OH, HC3N, c-C3H2, HCN, CN and
SiO) on scales from 3" to 60" (400-8000 AU). Using a set of H2CO lines, we
estimate the temperatures and column densities in the region using LTE and
non-LTE methods. The results are compared with 1-D radiative transfer modelling
of the protostellar cores. These models constrain which properties of the
central source, envelope, and environment can give rise to the observed line
and continuum emission. Results: Most of the H2CO emission from the regions
emerges from two elongated narrow ridges dominating the emission picked up in
both interferometric and single-dish measurements. The temperatures inferred
from the H2CO lines are no less than ~30 K and more likely 50-60 K, and the
line emission peaks are offset by ~2500 AU from the location of the embedded
protostars. The temperatures can not be explained by the heating from the young
stellar objects themselves. Irradiation by the nearby Herbig Be star R CrA
could, however, explain the high temperatures. The elevated temperatures can in
turn impact the physical and chemical characteristics of protostars and lead to
enhanced abundances of typical tracers of photon dominated regions seen in
single-dish line surveys of embedded protostars in the region.Comment: Accepted for publication in A&A; 21 pages, 28 figures; Added footnote
in Section 2.
Investigation of perognathus as an experi- mental organism for research in space biology progress report, 1 apr. - 30 jun. 1965
Reproduction of mice in confinemen
Investigation of perognathus as an experimen- tal organism for research in space biology fourth quarterly progress report, 1 jul. - 30 sep. 1964
Perognathus investigated as experimental organism for space biology researc
Investigation of Perognathus as an experimental organism for research in space biology Progress report, 1 Jul. - 30 Sep. 1965
Histopathology of pocket mouse intestine mucous after irradiation - growth and development data on laboratory pocket mous
Documentation for the spatial analysis system (SPAN) for resource use by animals
Nearest-neighbor analyses have been used with mapped data f or tests of spatial dispersion and association i n plant and animal ecology. This paper full describes a computer software package developed to use Monte
Carlo trials instead of chi-squared distributions for assigning probabilities to observed values of nearest neighbor statistics. The program can factor-out the unique geometry of resources in a sample plot,which can affect locations of animals, thus testing for direct patterns
among the animals independent of their resource patterns. The Kappa statistic for association is a1 o calculated a1though its application has met with limited success. A users manual and the Fortran program language
is included. (80pp.
Linear and angular momentum of electromagnetic fields generated by an arbitrary distribution of charge and current densities at rest
Starting from Stratton-Panofsky-Phillips-Jefimenko equations for the electric
and magnetic fields generated by completely arbitrary charge and current
density distributions at rest, we derive far-zone approximations for the
fields, containing all components, dominant as well as sub-dominant. Using
these approximate formulas, we derive general formulas for the total
electromagnetic linear momentum and angular momentum, valid at large distances
from arbitrary, non-moving charge and current sources.Comment: Six pages, one figure. Errors correcte
Improved head-controlled TV system produces high-quality remote image
Manipulator operator uses an improved resolution tv camera/monitor positioning system to view the remote handling and processing of reactive, flammable, explosive, or contaminated materials. The pan and tilt motions of the camera and monitor are slaved to follow the corresponding motions of the operators head
Analytical Data Report of Grab Samples Collected From BP-5 Operable Unit G Well (C5853)
This is an analytical data report for sediment samples received from CHPRC
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