Introduction: The thermal conductivity of powdered media is characteristically very low in vacuum, and is effectively dependent on many parameters of their constituent particles and packing structure. Understanding of the heat transfer mechanism within powder layers in vacuum and theoretical modeling of their thermal conductivity are of great importance for several scientific and engineering pr...

Thermal image is an image that shows the thermal or temperature properties of an object. Thermal image of an object is obtained from a thermal infrared camera. This camera works by employing radiative heat transfer principles and uses sensors to capture the radiated energy of an object. Thermal image of an object in the real world which is captured by a thermal camera is a real thermal image of...

Selective emittance materials show high technical potential for use as radiative cooling heat exchangers for buildings. This paper presents the thermal modeling of the photonic radiative cooler and the simulation of a system that integrats the photonic radiative cooler with radiant floor cooling in a medium office building. The system was simulated with EnergyPlus and the extensive use of its e...

Programmable thermal emissivity structures based on the bioinspired self-shape anisotropic materials were developed at macro-scale, and further studied theoretically at smaller scale. We study a novel concept, incorporating materials that are capable of transforming their shape via microstructural rearrangements under temperature stimuli, while avoiding the use of exotic shape memory materials ...

In this article, the temperature behavior of output power of superluminescent light-emitting diode (SLED) by considering the effect of non-radiative recombination coefficient, non-radiative spontaneous emission coefficient and Auger recombination coefficients has been investigated. For this aim, GaN pyramidal quantum dots were used as the active region. The numerical method has been used to sol...

The present study deals with the analysis of the effects of radiative heat transfer of micropolar fluid flow over a porous and stretching sheet in the presence of magnetic field. The dynamic viscosity and thermal conductivity coefficient have formulated by temperature-dependent relations to obtain more exact results. The flow is supposed two-dimensional, incompressible, steady and laminar and t...

We measure near-field radiative cooling of a thermally isolated nanostructure up to a few degrees and show that in principle this process can efficiently cool down localized hotspots by tens of degrees at submicrometer gaps. This process of cooling is achieved without any physical contact, in contrast to heat transfer through conduction, thus enabling novel cooling capabilities. We show that th...

The study of space debris is of critical importance to all space-faring nations. The characterization of debris objects through means of passive imaging techniques would allow for further studies into the origination, specifications, and future trajectory of debris objects. The long-wave infrared waveband is a potential candidate for the observation of space debris. However, in order to simulat...

The radiative and nonradiative components of the threshold current in 1.3 m, p-doped and undoped quantum-dot semiconductor lasers were studied between 20 and 370 K. The complex behavior can be explained by simply assuming that the radiative recombination and nonradiative Auger recombination rates are strongly modified by thermal redistribution of carriers between the dots. The large differences...

The non-linear fluid dynamics of a warped accretion disc was investigated in an earlier paper by developing a theory of fully non-linear bending waves in a thin, viscous disc. That analysis is here extended to take proper account of thermal and radiative effects by solving an energy equation that includes viscous dissipation and radiative transport. The problem is reduced to simple one-dimensio...