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[en] We investigate recent claims for a detection of "Hawking points" (positions on the sky with unusually large temperature gradients between rings) in the cosmic microwave background (CMB) temperature maps at the 99.98 % confidence level. We find that, after marginalization over the size of the rings, an excess is detected in Planck satellite maps at only an 87 % confidence level (i.e., little more than ). Therefore, we conclude that there is no statistically significant evidence for the presence of Hawking points in the CMB.
[en] The thermomechanical force acting on an asymmetrically heated body in He II is discussed. The force is produced by the normal component flow caused by the thermal inhomogeneity. The effect is calculated in terms of linearized dissipative two-liquid hydrodynamics for the case of a spherical body. For the 3-D geometry the force is essentially determined by the viscous contribution (while that for a plane body would be caused by the hydrostatical fountain pressure). This fact results in the sensitivity of the effect to the boundary conditions for vnperpendicular. Thus the experimental observation of the thermomechanical force can give an opportunity for measurement of the unknown kinetic coefficient
[en] Highlights: • Interfacial reaction in Cu/Sn-9Zn/Ni joint with thermal gradient was in situ studied. • Cu5Zn8 IMC layer effectively hindered Cu-Ni cross-interaction and thermomigration. • Ni3Sn4-type and Cu6Sn5-type IMCs had little effect on protecting Cu or Ni substrate. • Spalling mechanism of interfacial Cu5Zn8 layer was revealed.
[en] In this paper we have exploited the self-imaging or Talbot effect and Moire technique to measure the temperature distribution in the air enclosed between two paral led plates of different temperatures. This study shows that for the plates width of 60 cm a change of 1degC in 1 cm can be easily detected
[en] Thermal phase variations of short-period planets indicate that they are not spherical cows: day-to-night temperature contrasts range from hundreds to thousands of degrees, rivaling their vertical temperature contrasts. Nonetheless, the emergent spectra of short-period planets have typically been fit using one-dimensional (1D) spectral retrieval codes that only account for vertical temperature gradients. The popularity of 1D spectral retrieval codes is easy to understand: they are robust and have a rich legacy in solar system atmospheric studies. Exoplanet researchers have recently introduced multidimensional retrieval schemes to interpret the spectra of short-period planets, but these codes are necessarily more complex and computationally expensive than their 1D counterparts. In this paper we present an alternative: phase-dependent spectral observations are inverted to produce longitudinally resolved spectra that can then be fit using standard 1D spectral retrieval codes. We test this scheme on the iconic phase-resolved spectra of WASP-43b and on simulated observations for the James Webb Space Telescope (JWST) using the open-source Pyrat Bay 1D spectral retrieval framework. Notably, we take the model complexity of the simulations one step further from previous studies by allowing for longitudinal variations in composition in addition to temperature. We show that performing 1D spectral retrieval on longitudinally resolved spectra is more accurate than applying 1D spectral retrieval codes to disk-integrated emission spectra, even though this is identical in terms of computational load. We find that for the extant Hubble and Spitzer observations of WASP-43b, the difference between the two approaches is negligible, but JWST phase measurements should be treated with longitudinally resolved spectral retrieval (ReSpect).
[en] Attention is called to a simple theoretical kinematical study of the gradient of any cosmic scalar field in the universe, which might be used for an alternative interpretation for the very recent results obtained by COBE regarding the matter density gradient and in turn the temperature gradient in the universe. (author). 10 refs
[en] We give a summary of the presentations and discussions that took place in the High Gradient Structures Working Group at the 2006 Advanced Accelerator Concepts Workshop. Following the working group mission statement and charge, the talks are listed, with brief descriptions and highlights of the discussions that they generated
[en] We quantitatively investigate the behavior of momentum cumulants in the φ4 theory under thermal gradients, using stochastic thermostats. We relate this to the violations of local equilibrium. The non-equilibrium behavior is found to be quite well described by a dependence ∼(∇T)2, on the temperature gradient. Dependence of the quantities on the thermostat type is analyzed and its physical implications are discussed