6,461 research outputs found
Paravertebral blocks and enhanced recovery after surgery protocols in breast reconstructive surgery: Patient selection and perspectives
Emissivity measurements of reflective surfaces at near-millimeter wavelengths
We have developed an instrument for directly measuring the emissivity of reflective surfaces at near-millimeter wavelengths. The thermal emission of a test sample is compared with that of a reference surface, allowing the emissivity of the sample to be determined without heating. The emissivity of the reference surface is determined by one’s heating the reference surface and measuring the increase in emission. The instrument has an absolute accuracy of Δe = 5 x 10^-4 and can reproducibly measure a difference in emissivity as small as Δe = 10^-4 between flat reflective samples. We have used the instrument to measure the emissivity of metal films evaporated on glass and carbon fiber-reinforced plastic composite surfaces. We measure an emissivity of (2.15 ± 0.4) x 10^-3 for gold evaporated on glass and (2.65 ± 0.5) x 10^-3 for aluminum evaporated on carbon fiber-reinforced plastic composite
The Volume of 2D Black Holes
It is shown that the definition for the volume of stationary black holes
advocated in hep-th/0508108 readily generalizes to the case of dilaton gravity
in D=2. The dilaton field is included as part of the measure. A feature
observed in D=3 and 4 has been the impossibility to obtain infinite volume
while retaining finite area without encountering some kind of pathology. It is
demonstrated that this also holds in D=2. Consistency with spherically reduced
gravity is shown. For the Witten black hole it is found that the area is
proportional to the volume.Comment: 9 pages, 3 figures, uses iopart_mod.cl
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