We investigate the properties of mean-variance efficient portfolios when the number of assets is large. We show analytically and empirically that the proportion of assets held short converges to 50% as the number of assets grows, and the investment proportions are extreme, with several assets...

Allowing patients to take part in the initial investment for the development of cures for their illnesses can, under certain conditions, lead to the development of drugs that would have otherwise not been developed and to a dramatic welfare increase. We theoretically analyze these conditions....

Rhodium metal deposited on a cordierite support, in the form of a honeycomb or foam, was placed in a quartz reactor in the focal zone of the Schaeffer Solar Furnace at the Weizmann Institute of Science. It was used as a catalyst for the CO2 reforming of methane. The concentrated direct radiation...

A detailed computer model that incorporates the principal optical and thermal parameters of the system used in the gasification of oil shale by concentrated solar flux has been developed. The results of the calculations agree reasonably well with the experimental data. This model can serve as a...

Gasification of oil shales followed by catalytic reforming can yield synthesis gas, which is easily transportable and may also be used for producing liquid fuels. We report here on experiments performed at the Weizmann Institute's Solar Central Receiver involving the use of concentrated solar...