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Concentrating solar power (CSP) technologies use large mirrors to collect sunlight to convert thermal energy to electricity. The viability of CSP systems requires the development of advanced reflector materials that are low in cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. The long-standing goals for a solar reflector are specular reflectance above 90% into a 4 mrad half-cone angle for at least 10 years outdoors with a cost of less than $13.8/[m.sup.2] (the 1992 $10.8/[m.sup.2] goal corrected for inflation to 2002 dollars) when manufactured in large volumes. Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the CSP Program at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Test results to date for several candidate solar reflector materials will be presented. These include the optical durability of thin glass, thick glass, aluminized reflectors, front-surface mirrors, and silvered polymer mirrors. The development, performance, and durability of these materials will be discussed. Based on accelerated exposure testing the glass, silvered polymer, and front-surface mirrors may meet the 10 year lifetime goals, but at this time because of significant process changes none of the commercially available solar reflectors and advanced solar reflectors have demonstrated the 10 year or more aggressive 20 year lifetime goal. Keywords: Glass Mirrors, Aluminized Mirrors, Silvered Polymer Mirrors, Front Surface Reflector, Optical Durability

Commercialization of concentrating solar power (CSP) technologies require the development of advanced reflector materials that are low cost and maintain high specular reflectance for extended lifetimes under severe outdoor environments. During the past nine years, the National Renewable Energy Laboratory (NREL) has funded Science Applications International Corporation (SAIC) in McLean, Virginia, to develop a promising low-cost advanced solar reflective material (ASRM) combining the best of both thin-glass and silvered-polymer reflectors. The alumina ([Al.sup.2][O.sub.3]) coating is deposited by ion-beam-assisted physical vapor deposition (IBAD). Materials undergoing testing demonstrate excellent durability under accelerated and outdoor weathering. To help commercialize the technology, NREL had a cost analysis performed incorporating realistic web coating assumptions and the technical improvements made in the ASRM. The biggest process cost items are the alumina and machine burden (which collects the cost of the building and office staff). The switch from a polyethylene terethaphalate (PET) to a steel substrate for the ASRM is a significant contributor to the cost. The cost of high-purity alumina should drop from $400 to $200/kg when purchased in 20 kg quantities. Alumina deposition rate then becomes the critical cost driver. In a previous study, deposition rates above 100 nm/s were not examined, but deposition rates greater than 100 nm/s are being used routinely for thin alumina coatings deposited on commercial web-coaters as barrier coatings. In addition, multiple (2-3) [Al.sub.2][O.sub.3] IBAD zones can be used in one roll-coating machine to deposit thicker alumina at a lower web speed. This means that with increasing deposition rate and/or multiple zones, the total production cost of the SAIC ASRM with 1 [micro]m thick [Al.sub.2][O.sub.3] on PET will meet both the 1992 cost goal of $10.76/[m.sup.2] ($1/[ft.sup.2]) and the equivalent cost goal of $13.79/[m.sup.2] ($1.31/[ft.sup.2]) when the 1992 cost goal is corrected for inflation. There is a minimum deposition rate needed to reach the cost goal and a maximum deposition rate related to the number of zones after which no significant cost gains are observed. These asymptotic total production costs are $8.06/[m.sup.2] ($7.39/[m.sup.2] excluding substrate) for a large commercial web-coating company and $7.62/[m.sup.2] ($6.94/[m.sup.2] excluding substrate) for a smaller company. As can be seen by these numbers, the $10.76/[m.sup.2] cost goal can be reached, but the cost of the substrate is still a major consideration. In addition, the width of the web was increased from 600 to 1200 mm, which decreased the asymptotic total production costs. The results of the cost analysis will be described. Keywords: Alumina, [Al.sup.2][O.sub.3], Cost Analysis, Front Surface Reflector, IBAD, Roll Coater

The quality of grandparent/grandchild relationships and the activities that grandchildren and their most-close grandparents have in common were explored. The child probably develops a more intimate association with at least one grandparent, after divorce. This association becomes more significant with the child's transition to stepfamily life from single-parent family life.

This paper elaborates a program of cooperative involvement of the state mental health centers directors association, university residential instruction and university extension in strengthening family life education resources. It suggests a model for integrating interests of agency personnel advanced students on campus and state extension staff. [ABSTRACT FROM AUTHOR]