Gas clouds under the influence of gravitation in thermodynamic equilibrium cannot be isothermal due to the Dufour effect, the energy flux induced by density gradients. In galaxy clusters this effect may be responsible for most of the ”cooling flows” instead of radiative cooling of the gas. Observations from XMM-Newton and Chandra satellites agree well with model calculations, assuming equilibri...

In this and in accompanying reports, the topologies for cooling superconducting systems are investigated. The goal is to explore options that allow for flexibility of operation, low temperature rise in the superconductor and low refrigerator power consumption. A focus of this report is the study of means for cooling distribution systems with cryogenic loads dominated by current lead loss. Use o...

In this work we present an analysis of the influence of the thermodynamic regime on the monochromatic emissivity, the radiative power loss and the radiative cooling rate for optically thin carbon plasmas over a wide range of electron temperature and density assuming steady state situations. Furthermore, we propose analytical expressions depending on the electron density and temperature for the ...

We have developed an analytical model for evaporative cooling [1]. By simulating evaporation as a sequence of discrete steps, we could predict the time dependence of all important parameters such as temperature, density, elastic collision rate. By incorporating trap loss due to background gas collisions into our model we derived the threshold conditions for “run-away” evaporation. This is chara...

A novel solar-based combined system which is consisting of a concentrated PV, a double effect LiBr-H2O absorption chiller, and a Proton Exchange Membrane (PEM) is proposed for hydrogen production. A portion of the received energy is recovered to run a double effect absorption chiller and the rest is turned into electricity, being consumed in the PEM electrolyzer for hydrogen producti...

In power electronics systems the management of power loss and temperature of switching devices is indispensable for the reliability of the whole system. In this paper, a simple electro-thermal simulation model is presented. This simulation model is capable of predicting the power loss and estimating the junction temperature of power device in various environmental conditions. The electro-therma...

Radiative cooling, a unique and uncommon passive cooling method for devices operating outdoors, has recently been demonstrated to be effective for photovoltaic thermal management. In this work, we investigate the effect of radiative cooling as a complement to existing passive cooling methods like convective cooling in a related system with much higher heat loads: a high-concentration photovolta...

We derive self-similar solutions including cooling and heating in an Einstein de-Sitter universe, and investigate the effects of cooling and heating on the gas density and temperature distributions. We assume that the cooling rate has a power-law dependence on the gas density and temperature, Λ∝ρT, and the heating rate is Γ∝ρT . The values of A and B are chosen by requiring that the cooling tim...

A condensing device allows to avoid condensation on cooling ceilings in rooms with humid air. It uses thermoelectric modules in contact with the cooling panels. The pumped heat is transferred into the cooling ceiling to keep its temperature above the dew point. Tests have been performed in a full-scale chamber. A set of condensing units was mounted on a standard hydraulic cooling ceiling. The c...

In internal combustion engines, only about a third of the total fuel input energy is converted into useful work. If the energy rejected into the cooling system and the exhaust gases could be recovered instead and put into useful work, fuel economy would have been substantially improved. The main aim of this research paper was to evaluate the effects of the hybrid nano-catalyst containing ce...