Abstract: Systems and method presented herein enable the estimation of porosity using neutron-induced gamma ray spectroscopy. For example, the systems and methods presented herein include receiving, via a control and data acquisition system, data relating to energy spectra of gamma rays captured by one or more gamma ray detectors of a neutron-induced gamma ray spectroscopy logging tool. The method also includes deriving, via the control and data acquisition system, one or more spectral yields relating to one or more elemental components from the data relating to the energy spectra of the gamma rays. The method further includes estimating, via the control and data acquisition system, a measurement of porosity based on the one or more spectral yields relating to the one or more elemental components.

Abstract: A wheel with a self-contained drive mechanism is provided to propel (or assist in propulsion of) bicycles, tricycles, and similar vehicles. The wheel preferably takes the form of a shock absorbing detachable wheel, which is readily received within the dropouts of a bicycle frame or fork to be attached therein by a standard quick-release mechanism. Thus, the wheel may be added to (or removed from) preexisting standard bicycles and the like.

Abstract: A wheel with a self-contained drive mechanism is provided to propel (or assist in propulsion of) bicycles, tricycles, and similar vehicles. The wheel preferably takes the form of a detachable wheel which is readily received within the dropouts of a bicycle frame or fork to be attached therein by a standard quick-release mechanism. Thus, the wheel may be added to (or removed from) preexisting standard bicycles and the like.