Experiments have demonstrated the feasibility of heat exchangers with flow channels containing open-cell metallic foams. Nonmetallic foams could also be used. One proposed design calls for an open-cell foam in the annular region between an inner and an outer tube, with a heat-transfer fluid flowing along the annular region...

A Luneberg lens is a microwave lens consisting of a series of concentric shells of differing dielectric constants. The highest dielectric constant, or refractive index, resides at the core and the lowest, at the outer shell. Microwaves passing through this arrangement of shells are focused in the...

An accelerated-testing method has been developed for evaluating the effectiveness of various measures taken to prevent the corrosion of steel reinforcing bars ("rebars") cast into concrete. Such measures can include chemical admixtures incorporated into the concrete, coatings, penetrants,...