Rotational Doppler cooling and heating

An extra-heating mechanism in Doppler-cooling experiments

Doppler cooling a microsphere.

Doppler cooling the center-of-mass motion of an optically levitated microsphere via the velocity-dependent scattering force from narrow whispering gallery mode resonances is described. Light that is red detuned from the whispering gallery mode resonance can be used to damp the center-of-mass motion in a process analogous to the Doppler cooling of atoms. The scattering force is not limited by sa...

Cooling Flows or Heating Flows?

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only fo...

Cooling and Heating with Ground Source Energy

In the recent attempts to stimulate alternative energy sources for heating and cooling of buildings, emphasis has been put on utilisation of the ambient energy from ground source and other renewable energy sources. Exploitation of renewable energy sources and particularly ground heat in buildings can significantly contribute towards reducing dependency on fossil fuels. This paper highlights the...

Sustainable heating and cooling for cities

Over the past decades, Stockholm and Sweden have reduced CO2 emissions and increased resource efficiency, while maintaining high and sustainable economic growth. A major part of the recipe for success has been the development of the infrastructure for district heating and cooling. The district heating and cooling networks cover the Greater Stockholm Area. A set of large production plants, where...