Hot dry rock geothermal energy as a separate state from that of the continuum of permeable rock—just as one would consider a completely closed faucet as distinct from one that is open to any degree, whether the flow be a trickle or a flood. In the same way, HDR technology should be regarded as totally distinct from EGS. A definitive book on HDR development, including a full account of the experiments at Fenton Hill, was published by Springer-Verlag in April 2012. Hot dry rock geothermal energy Hot dry rock (HDR) is an abundant source of geothermal energy available for use. A vast store of thermal
Notes from the Underground (Hollywood Undead album) much fun they had doing without the label telling them what to do, he explained this record will be more like "Swan Songs" than "American Tragedy". He also revealed the album will be released on January 8, 2013. On December 11, the band announced that they will embark on a headlining tour titled "The Underground Tour", to promote "Notes from the Underground". Tour dates range from January 8, 2013, to January 23, starting in Hollywood, California. A video was released in promotion of the upcoming tour. On October 29, 2012, the first official single from "Notes from the Underground", titled