The power supply must be able to deliver large currents, sustained and controlled over a useful amount of time.

Complete access is by subscription, but useful amounts are made available free.

Building a useful amount of energy destroys the planet up front.

She had a useful amount of empathy that made her a good secretary.

In practice, capsules do create a significant and useful amount of lift.

This built-in feature provided a useful amount of flexibility in exchanging data with other systems.

The low temperature difference means that water volumes must be very large to extract useful amounts of heat.

If the charges are large ions, the bulk will likely need to be a liquid to let it move a useful amount.

Laser driven systems were initially believed to be able to generate commercially useful amounts of energy.

He called the company's $10 million budget "a useful amount of money, enough to get them on radar screens."