The present invention provides nucleoside compounds and certain derivatives thereof which are inhibitors of RNA-dependent RNA viral polymerase. These compounds are inhibitors of RNA-dependent RNA viral replication and are usef ul for the treatment of RNA-dependent RNA viral infection. They are particularl y useful as inhibitors of hepatitis C virus (HCV) NS5B polymerase, as inhibito rs of HCV repl...

The bottom end of a second flue section is fitted to the top end of a first flue section, a spacer element is fitted to the flue sections, and flue section partition devices are used to fix the spacer elements in a given orientation along the flue sections. A cladding pipe section (4a, 4b) is threaded over the second flue section and spacer element. The space between the flue and pipe sections is ...