20,226 research outputs found
Analog voicing detector responds to pitch
Modified electronic voice encoder /Vocoder/ includes an independent analog mode of operation in addition to the conventional digital mode. The Vocoder is a bandwidth compression equipment that permits voice transmission over channels, having only a fraction of the bandwidth required for conventional telephone-quality speech transmission
Metastable Cosmic Strings in Realistic Models
We investigate the stability of the electroweak Z-string at high
temperatures. Our results show that while finite temperature corrections can
improve the stability of the Z-string, their effect is not strong enough to
stabilize the Z-string in the standard electroweak model. Consequently, the
Z-string will be unstable even under the conditions present during the
electroweak phase transition. We then consider phenomenologically viable models
based on the gauge group and show
that metastable strings exist and are stable to small perturbations for a large
region of the parameter space for these models. We also show that these strings
are superconducting with bosonic charge carriers. The string superconductivity
may be able to stabilize segments and loops against dynamical contraction.
Possible implications of these strings for cosmology are discussed.Comment: 24 pages, 2 figures (available on request); HUTP-92/A032,
Fermilab-Pub-92/228-
Losing by Degrees: Rising Costs and Public Disinvestment in Higher Education
Washington's public colleges and universities are a critical resource for building a prosperous future for our state and fulfilling the promise of opportunity for all. Without strong public institutions of higher education, our youth will be stymied in striving to reach their full potential, and our state will not remain competitive in the global economy. Yet over the past two decades, the state's financial support for higher education has not kept pace with population growth and rising costs. Public institutions differ from private colleges and universities in their commitment to providing access to higher education and improving the well-being of all state residents. The University of Washington, in its statement of values, describes "Being Public" as follows: "As a public university we are deeply committed to serving all our citizens. We collaborate with partners from around the world to bring knowledge and discovery home to elevate the quality of lives of Washingtonians." As centers of education, research, and innovation, public colleges and universities spur economic development throughout the state. Washington's business leaders have long expressed the need for a more highly trained workforce, with more public investment in every level of education, from preschool through graduate study. Governor Christine Gregoire said in her 2009-11 Budget Proposal, "Washington's public colleges and universities are the economic engine that drives the state's economy and will drive our recovery." To build a strong foundation for Washington's future, we must increase public investment in higher education as a part of upgrading our whole public education system. Doing so will require identifying new sources of public revenue
The Performance of Natural Ventilation In A Dance Studio – Lessons From Tracer Gas Measurements And Control Integration
The naturally ventilated, three storey School of Arts Jarman Building provides two dance studios, an exhibition gallery, teaching rooms, video editing suites and offices. The main dance studio is double-height, has underfloor heating and accommodates sixty people. Fresh air enters from low level perimeter louvres and exits at high level through a stack that rises through the third storey to a stack terminal with motorized louvres. Tracer gas (CO2) measurements were used to measure the ventilation rate in conjunction with hot-wire anemometry in the stack tower. The results showed that when all air inlet and exit louvres were set to closed, the residual air flow up the stack was 0.33m3/s representing a potential heat loss of 9kW in winter at 0°C outside. When the louvres were all open, the air flow increased to between 0.49 and 0.62m3/s, a level consistent with the studio’s design occupancy. It was found that the studio’s 4m high perimeter curtains represent a barrier to fresh air entering the main room space and cause the incoming air to migrate upwards towards the stack exit and effectively bypass the central part of the studio. Tracer gas decay rates showed that the main space experienced an air exchange rate 50% less than that for the overall studio. An investigation of the controls also revealed that the underfloor heating system operated independently of the control of the stack ventilation system, leading to simultaneous heating and venting. The research shows the vital importance of prescribing contractually that key controls are integrated, that fresh air dampers are well-sealed when closed, and the importance of designing a fresh air supply that matches the way a space is used
Proto-Brown Dwarf Disks as Products of Protostellar Disk Encounters
The formation of brown dwarfs via encounters between proto-stars has been
confirmed with high-resolution numerical simulations with a restricted
treatment of the thermal conditions. The new results indicate that young brown
dwarfs (BDs) formed this way are disk-like and often reside in multiple
systems. The newly-formed proto-BDs disks are up to 18 AU in size and spin
rapidly making small-scale bipolar outflows, fragmentation and the possible
formation of planetary companions likely as have recently been observed for
BDs. The object masses range from 2 to 73 Jupiter masses, distributed in a
manner consistent with the observed sub-stellar initial mass function. The
simulations usually form multiple BDs on eccentric orbits about a star. One
such system was hierarchical, a BD binary in orbit around a star, which may
explain recently observed hierarchical systems. One third of the BDs were
unbound after a few thousand years and interactions among orbiting BDs may
eject more or add to the number of binaries. Improvements over prior work
include resolution down to a Jupiter mass, self-consistent models of the
vertical structure of the initial disks and careful attention to avoid
artificial fragmentation.Comment: 4 pages, 3 figures, accepted for publication in ApJ Letter
Flows on scales of 150 Mpc?
We investigate the reality of large-scale streaming on scales of up to 150
Mpc using the peculiar motions of galaxies in three directions. New R-band CCD
photometry and spectroscopy for elliptical galaxies is used. The Fundamental
Plane distance indicator is calibrated using the Coma cluster and an
inhomogeneous Malmquist bias correction is applied. A linear bulk-flow model is
fitted to the peculiar velocities in the sample regions and the results do not
reflect the bulk flow observed by Lauer and Postman (LP). Accounting for the
difference in geometry between the galaxy distribution in the three regions and
the LP clustersconfirms the disagreement; assuming a low-density CDM power
spectrum, we find that the observed bulk flow of the galaxies in our sample
excludes the LP bulk flow at the 99.8% confidence level.Comment: 16 pages, 1 figur
Constructive and Unconstructive Repetitive Thought
The author reviews research showing that repetitive thought (RT) can have
constructive or unconstructive consequences. The main unconstructive
consequences of RT are (a) depression, (b) anxiety, and (c) difficulties in
physical health. The main constructive consequences of RT are (a) recovery from
upsetting and traumatic events, (b) adaptive preparation and anticipatory
planning, (c) recovery from depression, and (d) uptake of health-promoting
behaviors. Several potential principles accounting for these distinct
consequences of RT are identified within this review: (a) the valence of thought
content, (b) the intrapersonal and situational context in which RT occurs, and
(c) the level of construal (abstract vs. concrete processing) adopted during RT.
Of the existing models of RT, it is proposed that an elaborated version of the
control theory account provides the best theoretical framework to account for
its distinct consequences
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