There are facets to these systems that present some labor investment in large-scale applications.

But it is seen as holding promise for large-scale application.

One questioner asked whether the need for such elements would limit the kind of large-scale applications that scientists are beginning to envision.

And they say that, at best, many years will be needed to perfect large-scale applications.

For large-scale applications of type client-server, a server should be used.

"Broad and large-scale application is probably three to five years away," he said recently.

This process is technically feasible for large-scale commercial applications.

But, scientists said, this approach proved impractical for large-scale application because it required more water than was readily available in many dry African areas.

The most optimistic predictions suggest that large-scale applications of the new materials will take years to develop.

Indeed, the committee said, "immediate large-scale commercial applications on the earth's surface cannot be identified today."