Abstract: A system and method by which programming is delivered via the internet to an end-user. The delivered programming can be based on specified selection criteria. The programming can be supported by information generated by support tools, including, but not limited to: ebooks, articles, games, content summaries, links to websites, telephone numbers, learning confirmation sessions, recommended reading and resources, etc. The service can be provided through a variety of revenue models. If a subscriber revenue model is used, the user can elect to pay for this programming in a number of ways, including either as a time-based subscription or on a pay-per-view/pay-per-topic basis.

Abstract: The present invention is a material and method of making the material that exhibits improved radiation attenuation simulation of real lungs, i.e., an "authentic lung tissue" or ALT phantom.Specifically, the ALT phantom is a two-part polyurethane medium density foam mixed with calcium carbonate, potassium carbonate if needed for K-40 background, lanthanum nitrate, acetone, and a nitrate or chloride form of a radionuclide. This formulation is found to closely match chemical composition and linear attenuation of real lungs.The ALT phantom material is made according to established procedures but without adding foaming agents or preparing thixotropic concentrate and with a modification for ensuring uniformity of density of the ALT phantom that is necessary for accurate simulation. The modification is that the polyurethane chemicals are mixed at a low temperature prior to pouring the polyurethane mixture into the mold.