46,179 research outputs found
One-step dual purpose joining technique
This fastener used in induction heating is a wire screen basically of an eddy current carrying material such as carbon steel. Selected wires in the screen are copper, sheathed in an insulating material. The screen is placed between two sheets of thermoplastics. When inductively heated, the composite softens and flows around the apertures of the screen. After this heating and joining, the copper wires may be used to conduct electricity
Integrating Out Astrophysical Uncertainties
Underground searches for dark matter involve a complicated interplay of
particle physics, nuclear physics, atomic physics and astrophysics. We attempt
to remove the uncertainties associated with astrophysics by developing the
means to map the observed signal in one experiment directly into a predicted
rate at another. We argue that it is possible to make experimental comparisons
that are completely free of astrophysical uncertainties by focusing on {\em
integral} quantities, such as and
. Direct comparisons are possible when the
space probed by different experiments overlap. As examples, we
consider the possible dark matter signals at CoGeNT, DAMA and CRESST-Oxygen. We
find that expected rate from CoGeNT in the XENON10 experiment is higher than
observed, unless scintillation light output is low. Moreover, we determine that
S2-only analyses are constraining, unless the charge yield . For DAMA to be consistent with XENON10, we find for
that the modulation rate must be extremely high (\gsim 70% for
m_\chi = 7\, \gev), while for higher quenching factors, it makes an explicit
prediction (0.8 - 0.9 cpd/kg) for the modulation to be observed at CoGeNT.
Finally, we find CDMS-Si, even with a 10 keV threshold, as well as XENON10,
even with low scintillation, would have seen significant rates if the excess
events at CRESST arise from elastic WIMP scattering, making it very unlikely to
be the explanation of this anomaly.Comment: 25 pages, 7 figures; v2 replaced with published versio
Space Shuttle interactive meteorological data system study
Although focused toward the operational meteorological support review and definition of an operational meteorological interactive data display systems (MIDDS) requirements for the Space Meteorology Support Group at NASA/Johnson Space Center, the total operational meteorological support requirements and a systems concept for the MIDDS network integration of NASA and Air Force elements to support the National Space Transportation System are also addressed
TiB_2 and ZrB_2 diffusion barriers in GaAs Ohmic contact technology
The transition metal diboride compounds, ZrB_2 and TiB_2, interposed between Ni/Ge/Au Ohmic contact metallization on n‐type GaAs wafers and an overlying thick Au contact layer, have been investigated to evaluate their effectiveness in stabilizing the Ohmic contact by limiting the in‐diffusion of Au. All of the metal layers were e‐beam deposited except the ZrB_2 which was rf‐diode sputtered. The barrier layer thicknesses were 50 and 100 nm for the TiB_2 and the ZrB_2, respectively. Postdeposition alloying of the contacts was performed at 400, 425, or 450 °C. Auger electron spectroscopy depth profiling of the resultant Ohmic contacts demonstrates that the barrier layers effectively preclude penetration of Au to the Ohmic contact structure. Specific contact resistivities for such contacts are in the low 10^(−7) Ω cm^2 range; although some degradation of the contact resistivity is observed after long term annealing, the values of resistivities do not exceed 1.5×10^(−6) Ω cm^2 after 92 h at 350 °C
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