A Powerful e ± Outflow Driven by a Proto-strange Quark Star

An electron–positron layer can cover the surface of a bare strange star (SS), the electric field in which can excite the vacuum and drive a pair wind by taking away the heat of the star. In order to investigate the pair-emission ability of a proto-SS, we establish a toy model to describe its early thermal evolution, where the initial trapping of neutrinos is specially taken into account. It is found that the early cooling of the SS is dominated by the neutrino diffusion rather than the conventional Urca processes, which leads to the appearance of an initial temperature plateau. During this plateau phase, the surface e ± pair emission can maintain a constant luminosity of 1048 − 1050erg s−1 for about a few to a few tens of seconds, which is dependent on the value of the initial temperature. The total energy released through this e ± wind can reach as high as ∼1051 erg. In principle, this pair wind could be responsible for the prompt emission or extended emission of some gamma-ray bursts.

Optical properties of high-pressure fluid hydrogen across molecular dissociation

Optical properties of compressed fluid hydrogen in the region where dissociation and metallization is observed are computed by ab initio methods and compared with recent experimental results. We confirm that at T > 3,000 K, both processes are continuous, while at T < 1,500 K, the first-order phase transition is accompanied by a discontinuity of the dc conductivity and the thermal conductivity, while both the reflectivity and absorption coefficient vary rapidly but continuously. Our results support the recent analysis of National Ignition Facility (NIF) experiments [Celliers PM, et al. (2018) Science 361:677–682], which assigned the inception of metallization to pressures where the reflectivity is ∼0.3. Our results also support the conclusion that the temperature plateau seen in laser-heated diamond-anvil cell (DAC) experiments at temperatures higher than 1,500 K corresponds to the onset of optical absorption, not to the phase transition.

Demonstration of temperature-plateau superheated liquid by photothermal conversion of plasmonic titanium nitride nanostructures

When photothermally superheated liquid is on a high thermal conductive substrate, the liquid temperature stays constant for a certain range of incident laser power before bubbles are formed.

Broad temperature plateau for high ZTs in heavily doped p-type SnSe single crystals

The increased number of carrier pockets near the Fermi level and the optimized carrier concentration in doped SnSe single crystal can lead to a high averageZTave∼ 1.2 from 300 K to 800 K and a peakZTmaxvalue in excess of 2.0 at 800 K along the crystallographicb-axis.

Analysis of Moisture Evaporation from Underwear Designed for Fire-Fighters

In this study we analysed the effect of moisture on the thermal protective performance of fire-fighter clothing in case of routine fire-fighting conditions. In the first stage of this research we investigated simultaneous heat and moisture transfer through a single-layer fabric, used as underwear for fire-fighters, at different moisture conditions. In the second stage of the study, the underwear in dry and wet state was tested together with protective clothing systems for fire-fighter consisting of three or four layers. It was found that during the evaporation of the moisture, a temperature plateau appeared during which temperatures hardly rose. The energy consumption used for the phase change of moisture located in the assembly dominated the heat transfer process as long as there was moisture present. As soon as all water had evaporated, the temperatures approached the temperatures measured for dry samples. The moisture within the clothing assembly did not lead to increased temperatures compared with the measurements with dry samples. This research has confirmed that moisture can positively affect the thermal protection of a clothing system.