2,284 research outputs found
Infrared testing of electronic components Final report, 5 Apr. 1965 - 5 Jun. 1966
Infrared radiation nondestructive test technique for electrical/electronic equipmen
Evaluation of performance impairment by spacecraft contaminants
The environmental contaminants (isolated as off-gases in Skylab and Apollo missions) were evaluated. Specifically, six contaminants were evaluated for their effects on the behavior of juvenile baboons. The concentrations of contaminants were determined through preliminary range-finding studies with laboratory rats. The contaminants evaluated were acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), trichloroethylene (TCE), heptane and Freon 21. When the studies of the individual gases were completed, the baboons were also exposed to a mixture of MEK and TCE. The data obtained revealed alterations in the behavior of baboons exposed to relatively low levels of the contaminants. These findings were presented at the First International Symposium on Voluntary Inhalation of Industrial Solvents in Mexico City, June 21-24, 1976. A preprint of the proceedings is included
A Strong Szego Theorem for Jacobi Matrices
We use a classical result of Gollinski and Ibragimov to prove an analog of
the strong Szego theorem for Jacobi matrices on . In particular, we
consider the class of Jacobi matrices with conditionally summable parameter
sequences and find necessary and sufficient conditions on the spectral measure
such that and lie in
, the linearly-weighted space.Comment: 26 page
Conceptual mechanization studies for a horizon definition spacecraft attitude control subsystem, phase A, part II, 10 October 1966 - 29 May 1967
Attitude control subsystem for spin stabilized spacecraft for mapping earths infrared horizon radiance profiles in 15 micron carbon dioxide absorption ban
High Energy Gamma-Ray Emission From Blazars: EGRET Observations
We will present a summary of the observations of blazars by the Energetic
Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory
(CGRO). EGRET has detected high energy gamma-ray emission at energies greater
than 100 MeV from more that 50 blazars. These sources show inferred isotropic
luminosities as large as ergs s. One of the most
remarkable characteristics of the EGRET observations is that the gamma-ray
luminosity often dominates the bolometric power of the blazar. A few of the
blazars are seen to exhibit variability on very short time-scales of one day or
less. The combination of high luminosities and time variations seen in the
gamma-ray data indicate that gamma-rays are an important component of the
relativistic jet thought to characterize blazars. Currently most models for
blazars involve a beaming scenario. In leptonic models, where electrons are the
primary accelerated particles, gamma-ray emission is believed to be due to
inverse Compton scattering of low energy photons, although opinions differ as
to the source of the soft photons. Hardronic models involve secondary
production or photomeson production followed by pair cascades, and predict
associated neutrino production.Comment: 16 pages, 7 figures, style files included. Invited review paper in
"Observational Evidence for Black Holes in the Universe," 1999, ed. S. K.
Chakrabarti (Dordrecht: Kluwer), 215-23
Satellite navigation in the U.S. Coast Guard.
This thesis investigates many of the issues surrounding
the civil maritime navigation dilemma facing the USCG. At
present, LORAN-C and OMEGA, which are hyperbolic radionavigation
systems and TRANSIT, a Doppler shift satellite-based
system, are the main systems employed in the civil maritime
field. NAVSTAR GPS, a passive ranging satellite navigation
system is, in the meantime, showing great promise as the
replacement system for primary radionavigation in the U.S.
There are several key questions, one involving national
security, which must be answered, however, before NAVSTAR
becomes operational. What positional accuracy will be made
available to the civil community? What are the economics
of the user equipments? Will NAVSTAR be accepted as a
successful replacement for LORAN by the civil community?
To aid in answering some of these questions, the results of
an informal survey of the civil maritime industry are presented.
The final outcome remains to be seen. These issues
will require careful thought by this country's top leaders
before any final committment to NAVSTAR can be made or prior
to any decision to discontinue LORAN-C or OMEGA.http://archive.org/details/satellitenavigat00hartLieutenant, United States Coast GuardApproved for public release; distribution is unlimited
Identified research directions for using manufacturing knowledge earlier in the product lifecycle
Design for manufacturing (DFM), especially the use of manufacturing knowledge to support design decisions, has received attention in the academic domain. However, industry practice has not been studied enough to provide solutions that are mature for industry. The current state of the art for DFM is often rule-based functionality within computer-aided design (CAD) systems that enforce specific design requirements. That rule-based functionality may or may not dynamically affect geometry definition. And, if rule-based functionality exists in the CAD system, it is typically a customisation on a case-by-case basis. Manufacturing knowledge is a phrase with vast meanings, which may include knowledge on the effects of material properties decisions, machine and process capabilities or understanding the unintended consequences of design decisions on manufacturing. One of the DFM questions to answer is: How can manufacturing knowledge, depending on its definition, be used earlier in the product life cycle to enable a more collaborative development environment? This paper will discuss the results of a workshop on manufacturing knowledge that highlights several research questions needing more study. This paper proposes recommendations for investigating the relationship of manufacturing knowledge with shape, behaviour and context characteristics of a product to produce a better understanding of what knowledge is most important. In addition, the proposal includes recommendations for investigating the system-level barriers to reusing manufacturing knowledge and how model-based manufacturing may ease the burden of knowledge sharing. Lastly, the proposal addresses the direction of future research for holistic solutions of using manufacturing knowledge earlier in the product life cycle
The Ursinus Weekly, April 4, 1938
Weekly board selects Dunn editor to succeed Groff • Concert by musical groups planned for Thursday • Peace conference play to be Aria de capo • Socialism is path around barriers, Holmes implies • Women to elect governing heads Wednesday • Weekly men at INA hear LaFollette • Co-ed vocation talks after Easter • Nominate Wimer, Bartholomew for YMCA presidency • Meistersingers take Garner up, offer to speed up Congress by singing sweet music at nation\u27s capital • Curtain Club accepts 15 at spring tryouts • Dr. Brownback plans trip • Sheeder lauds acting in junior play • Regional alumni groups plan get-togethers • Committees chosen for May Day pageant • Mr. Michael reveals alumni cooperate in getting jobs for graduates • Ex-Weekly editor runs for state legislature • Gigantic bill ready for third annual scraps carnival Wed. • Lineup uncertain in opener with \u27Cats this Thursday • Elect Jing Johnson to presidency of diamond loop • Politics and verse gain at expense of fiction in second Lantern of year • Berks County mathematical club to banquet here tomorrow • Vespers speaker urges students to follow Christ\u27s teachings • TKA meet to have four from Ursinus • Ruby photographers namedhttps://digitalcommons.ursinus.edu/weekly/1896/thumbnail.jp
Satellites of the largest Kuiper Belt objects
We have searched the four brightest objects in the Kuiper Belt for the presence of satellites using the newly commissioned Keck Observatory Laser Guide Star Adaptive Optics system. Satellites are seen around three of the four objects: Pluto (whose satellite Charon is well-known and whose recently discovered smaller satellites are too faint to be detected), 2003 EL61 (where a second satellite is seen in addition to the previously known satellite), and 2003 UB313 (where a satellite is seen for the first time). The object 2005 FY9, the brightest Kuiper Belt object (KBO) after Pluto, does not have a satellite detectable within 0".4 with a brightness of more than 1% of the primary. The presence of satellites around three of the four brightest KBOs is inconsistent with the fraction of satellites in the Kuiper Belt at large at the 99.2% confidence level, suggesting a different formation mechanism for these largest KBO satellites. The two satellites of 2003 EL61, and the one satellite of 2003 UB313, with fractional brightnesses of 5% and 1.5%, and 2%, of their primaries, respectively, are significantly fainter relative to their primaries than other known KBO satellites, again pointing to possible differences in their origin
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