Abstract:
Articles having surfaces with enhanced wetting properties are presented. One embodiment is an article having a surface configured for promoting a phase transformation from a liquid phase to a vapor phase. The article comprises an element comprising a surface disposed to be in contact with a liquid to be transformed to a vapor, and the surface comprises a plurality of surface features having a median feature size, a, and a median feature spacing, b, such that the ratio b/a is up to about 8. The surface comprises a material disposed to contact the liquid, and this material has a nominal wettability sufficient to generate a nominal contact angle of up to about 80 degrees with a drop of the liquid. Another embodiment is a fuel rod for a nuclear reactor comprising a surface configured as described above.
Abstract:
A method of removing impurities from heavy fuel includes providing a first stationary adsorption column. The method further includes packing adsorbent particles that have a particle size distribution wherein at least about 50% of the particles have a diameter greater than about 18 microns in the first column. The method further includes diluting heavy fuel with a solvent to form a solvent-fuel mixture, and supplying the solvent-fuel mixture through the first column to facilitate removing impurities from the mixture.
Abstract:
An optical article comprising a primary mark disposed on the optical article and a secondary mark disposed on the optical article in close proximity to the primary mark. The primary mark comprises a first optical-state change material and the secondary mark comprises a second optical-state change material. The optical article is transformed from a pre-activated state to an activated state when a localized authorized activation method is used that selectively activates the primary mark. The optical article is transformed from a pre-activated state to an deactivated state when a non-localized unauthorized activation method is used that activates the secondary mark along with the primary mark resulting in the second optical-state change material undergoing a reverse color change when compared to the first optical-state change material. An optical article with a single mark including multiple color change optical-state change material is also disclosed. Methods of covering and encapsulating the marks are also disclosed.
Abstract:
A method of preparing block copolymers by solid state polymerization is described. A mixture of a partially crystalline polycarbonate having activated terminal aryloxy groups, for example terminal methyl salicyl groups, when heated together with an oligomeric polyester having reactive terminal hydroxy groups under solid state polymerization conditions affords block copolymers. The activated terminal aryloxy groups play a key role in preserving the block lengths of the starting materials. A control sample in which the partially crystalline polycarbonate lacks activated terminal aryloxy groups, for example polycarbonates substituted by phenol, affords a much lower molecular weight, more highly randomized copolymer product. The product block copolymers are useful as “weatherable” plastic materials.