We analyze the solar reflectance of asphalt roofing shingles that are covered with pigmented mineral roofing granules. The reflecting surface is rough, with a total area approximately twice the nominal area. We introduce a simple analytical model that relates the 'micro-reflectance' of a small surface region to the 'macro-reflectance' of the shingle. This model uses a mean field approximation to account for multiple scattering effects. The model is then used to compute the reflectance of shingles with a mixture of different colored granules, when the reflectances of the corresponding mono-color shingles are known. Simple linear averaging works well, with small corrections to linear averaging derived for highly reflective materials. Reflective base granules and reflective surface coatings aid achievement of high solar reflectance. Other factors that influence the solar reflectance are the size distribution of the granules, coverage of the asphalt substrate, and orientation of the granules as affected by rollers during fabrication.

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

Newsletter of Congregation Beth Yeshurun in Houston, including news and events, upcoming services, member announcements, editorials, and other information of interest to congregants.

Morphological control of nanocrystals has becomeincreasingly important, as many of their physical and chemical propertiesare highly shape-dependent. Nanocrystal shape control for both single andmultiple material systems, however, remains fairly empirical andchallenging. New methods need to be explored for the rational syntheticdesign of heterostructures with controlled morphology. Overgrowth of adifferent material on well-faceted seeds, for example, allows for the useof the defined seed morphology to control nucleation and growth of thesecondary structure. Here, we have used highly faceted cubic Pt seeds todirect the epitaxial overgrowth of a secondary metal. We demonstrate thisconcept with lattice matched Pd to produce conformal shape-controlledcore-shell particles, and then extend it to lattice mismatched Au to giveanisotropic growth. Seeding with faceted nanocrystals may havesignificant potential towards the development of shape-controlledheterostructures with defined interfaces.

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.

Semiweekly newspaper from Burleson, Texas that includes local, state, and national news along with advertising.

Semi-weekly newspaper from Livingston, Texas that includes local, state and national news along with advertising.

Recital presented at the UNT College of Music Recital Hall in partial fulfillment of the Master of Music (MM) degree.

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.

Tri-weekly student newspaper from Abilene Christian University in Abilene, Texas that includes local, state and campus news along with advertising.

Semiweekly newspaper from Carthage, Texas that includes local, state, and national news along with advertising.