4,935 research outputs found
Space Station Freedom Structural Characterization Experiment (SCE) node code
A method is described for naming the Space Station Freedom nodes and truss members that enhances the management, maintenance, and record keeping methods utilized by the space station
A Connection between Submillimeter Continuum Flux and Separation in Young Binaries
We have made sensitive 800-micron continuum observations of low-mass,
pre-main sequence (PMS) binary stars with projected separations less than 25 AU
in Taurus-Auriga to study disks in the young binary environment. We did not
detect any of the observed binaries, with typical 3-sigma upper limits of about
30 mJy. Combining our observations with previous 1300-micron observations of
PMS Taurus binaries by Beckwith et al. (1990) and others, we find that the
submillimeter fluxes from binaries with projected separations between 1 AU and
50 AU are significantly lower than fluxes from binaries with projected
separations > 50 AU. The submillimeter fluxes from the wider binaries are
consistent with those of PMS single stars. This may indicate lower disk surface
densities and masses in the close binaries. Alternatively, dynamical clearing
of gaps by close binaries is marginally sufficient to lower their submillimeter
fluxes to the observed levels, even without reduction of surface densities
elsewhere in the disks.Comment: 12 pages, uuencoded compressed postscript with figures; Wisconsin
Astrophysics 526; to appear in ApJ Letter
Young Binary Stars and Associated Disks
The typical product of the star formation process is a binary star. Binaries
have provided the first dynamical measures of the masses of pre-main-sequence
(PMS) stars, providing support for the calibrations of PMS evolutionary tracks.
Surprisingly, in some star-forming regions PMS binary frequencies are higher
than among main-sequence solar-type stars. The difference in PMS and
main-sequence binary frequencies is apparently not an evolutionary effect;
recent attention has focussed on correlations between binary frequency and
stellar density or cloud temperatures. Accretion disks are common among young
binary stars. Binaries with separations between 1 AU and 100 AU have
substantially less submillimeter emission than closer or wider binaries,
suggesting that they have truncated their disks. Evidence of dynamical clearing
has been seen in several binaries. Remarkably, PMS binaries of all separations
show evidence of circumstellar disks and continued accretion. This suggests
that the circumstellar disks are replenished from circumbinary disks or
envelopes. The frequent presence of disks suggests that planet formation can
occur in binary environments, and formation of planets in wide binaries is
already established by their discovery. Circumbinary disk masses around very
short period binaries are ample to form planetary systems such as our own. The
nature of planetary systems among the most common binaries, with separations
between 10 AU and 100 AU, is less clear given the observed reduction in disk
mass, though they may have disk masses adequate for the formation of
terrestrial-like planets.Comment: 32 pages, including 6 Postscript figures (TeX, uses psfig.sty); to
appear in "Protostars & Planets IV". Gif figures with captions and high-res
Postscript color figure available at
http://hven.swarthmore.edu/~jensen/preprints/ppiv.htm
Analysis of the evolution of research contributions by The Accounting Review, 1926-2005
In her presidential message to the American Accounting Association (AAA) in August 2005, Judy Rayburn discussed the issue of the relatively low citation rate for accounting research compared to finance, management, and marketing. Rayburn concluded that accounting\u27s low citation rate was due to a lack of diversity in topics and research methods. In this paper, we provide a review of the AAA\u27s flagship journal, The Accounting Review (TAR), following its 80 years of publication, and describe why some recent AAA leaders believe that significant changes should be made to the journal\u27s publication and editorial policies. At issue is whether scholarly accounting research is overly focused on mathematical analysis and empirical research, or accountics as it has sometimes been called, at the expense of research that benefits the general practice of accountancy and discovery research on more interesting topics. We conclude from our review of TAR that after mostly publishing research about accounting practices for the first 40 years, a sweeping change in editorial policy occurred in the 1960s and 1970s that narrowly defined scholarly research in accounting as that which employs accountics
Changes in infant segment inertias during the first three months of independent walking
BACKGROUND: During infancy, rapid changes in physical growth affect the size and shape of the body segments. To understand the effects of growth on movement, it is first necessary to quantify rates of development during the acquisition of important motor milestones. The goal of this longitudinal study was to quantify the physical growth of infant body segments during the initial stages of independent walking. METHODS: Ten infants (N = 10) aged between 28 and 55 weeks at the beginning of the study were tested biweekly (every two weeks) for three months. A 13-segment mathematical model of the human body was used to estimate the inertial parameters of the infant body segments at each session. An analysis of variance was used to test for significant differences in segment masses between biweekly measures. Polynomial contrasts were used to test for linear trends in the growth data. RESULTS: Significant differences between biweekly measures of segment mass were found only for the head/neck (F(5,45) = 3.42, p < 0.05), upper trunk (F(5,45) = 4.04, p < 0.01), and lower trunk (F(5,45) = 3.49, p < 0.01). The lower trunk demonstrated a linear increase in mass (F(1,9) = 4.56, p < 0.05). However, the upper trunk demonstrated a quadratic trend in growth (F(1,9) = 9.13, p < 0.01), while the head/neck segment showed a cubic trend in growth (F(1,9) = 3.80, p < 0.05). Significant differences in axial segment masses were also found between subjects (F(9,45) = 5.92, p < 0.001). CONCLUSION: Given that postural control proceeds in a cephalocaudal manner, the lower trunk segment would be brought under control last, in terms of the axial segments. Increases in the mass of this segment could constrain the system, thereby acting as a control parameter for the onset and development of motor patterns
Spin dynamics in the ordered spin ice TbSnO
Geometrical frustration is a central challenge in contemporary condensed
matter physics, a crucible favourable to the emergence of novel physics. The
pyrochlore magnets, with rare earth magnetic moments localized at the vertices
of corner-sharing tetrahedra, play a prominent role in this field, with a rich
variety of exotic ground states ranging from the "spin ices" \hoti\ and \dyti\
to the "spin liquid" and "ordered spin ice" ground states in \tbti\ and \tbsn.
Inelastic neutron scattering provides valuable information for understanding
the nature of these ground states, shedding light on the crystal electric field
(CEF) level scheme and on the interactions between magnetic moments. We have
performed such measurements with unprecedented neutron flux and energy
resolution, in the "ordered spin ice" \tbsn. We argue that a new interaction,
which involves the spin lattice coupling through a low temperature distortion
of the trigonal crystal field, is necessary to account for the data
UNLV New Horizons Band & UNLV Community Concert Band
Program listing performers and works performed
Accounting Hall of Fame 2000 induction: Shaun F. O\u27Malley
For the induction of Shaun f. O\u27Malley: Remarks by Robert L. Brown, PricewaterhouseCoopers; Citation prepared by Daniel L. Jensen, The Ohio State University, read by Robert L. Brown, PricewaterhouseCoopers; Response by Shaun f. O\u27Malley, PricewaterhouseCooper
Limiting absorption principle for the dissipative Helmholtz equation
Adapting Mourre's commutator method to the dissipative setting, we prove a
limiting absorption principle for a class of abstract dissipative operators. A
consequence is the resolvent estimates for the high frequency Helmholtz
equation when trapped trajectories meet the set where the imaginary part of the
potential is non-zero. We also give the resolvent estimates in Besov spaces
Accounting Hall of Fame 2000 induction: Ross M. Skinner
For the induction of Robert M. Skinner: Remarks by Robert T. Rutherford, The Canadian Institute of Chartered Accountants; Citation prepared by Daniel L. Jensen, The Ohio State University, Read by Robert T. Rutherford; Response by Ross M. Skinner, Clarkson Gordo
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