Tank 241-AY-102 Leak Assessment Supporting Documentation: Miscellaneous Reports, Letters, Memoranda, And Data (open access)

Tank 241-AY-102 Leak Assessment Supporting Documentation: Miscellaneous Reports, Letters, Memoranda, And Data

This report contains reference materials cited in RPP-ASMT -53793, Tank 241-AY-102 Leak Assessment Report, that were obtained from the National Archives Federal Records Repository in Seattle, Washington, or from other sources including the Hanford Site's Integrated Data Management System database (IDMS).
Date: December 20, 2012
Creator: Engeman, J. K.; Girardot, C. L.; Harlow, D. G. & Rosenkrance, C. L.
System: The UNT Digital Library
Solar Grade Silicon from Agricultural By-products (open access)

Solar Grade Silicon from Agricultural By-products

In this project, Mayaterials developed a low cost, low energy and low temperature method of purifying rice hull ash to high purity (5-6Ns) and converting it by carbothermal reduction to solar grade quality silicon (Sipv) using a self-designed and built electric arc furnace (EAF). Outside evaluation of our process by an independent engineering firm confirms that our technology greatly lowers estimated operating expenses (OPEX) to $5/kg and capital expenses (CAPEX) to $24/kg for Sipv production, which is well below best-in-class plants using a Siemens process approach (OPEX of 14/kg and CAPEX of $87/kg, respectively). The primary limiting factor in the widespread use of photovoltaic (PV) cells is the high cost of manufacturing, compared to more traditional sources to reach 6 g Sipv/watt (with averages closer to 8+g/watt). In 2008, the spot price of Sipv rose to $450/kg. While prices have since dropped to a more reasonable $25/kg; this low price level is not sustainable, meaning the longer-term price will likely return to $35/kg. The 6-8 g Si/watt implies that the Sipv used in a module will cost $0.21-0.28/watt for the best producers (45% of the cost of a traditional solar panel), a major improvement from the cost/wafer driven by the …
Date: August 20, 2012
Creator: Laine, Richard M.
System: The UNT Digital Library
Laboratory Directed Research and Development Annual Report for 2010 (open access)

Laboratory Directed Research and Development Annual Report for 2010

This report documents progress made on all LDRD-funded projects during fiscal year 2010.
Date: June 20, 2011
Creator: Hughes, Pamela J.
System: The UNT Digital Library
Impact of elevated CO2 and O3 on insect-mediated ecosystem processes in a northern deciduous forest (open access)

Impact of elevated CO2 and O3 on insect-mediated ecosystem processes in a northern deciduous forest

Rising concentrations of atmospheric CO{sub 2} and O{sub 3} are altering the structure and function of forest ecosystems. Herbivorous insects are the major consumers in temperate deciduous forests, with the capacity to dramatically alter tree growth (via outbreaks), forest community composition and ecosystem dynamics (e.g., nutrient cycling). Until recently, however, experimental quantification of the impacts of CO{sub 2} and O{sub 3} on canopy herbivore communities and rates of defoliation and nutrient flux has not been addressed. This research, conducted at the Aspen FACE (Free Air CO{sub 2} Enrichment) facility in northern Wisconsin, U.S.A., evaluated the independent and interactive effects of CO{sub 2} and O{sub 3} on (1) the abundance and diversity of forest canopy insect communities, and (2) rates of insect herbivory and transfer of material (leaf greenfall and insect frass) from the canopy to the forest floor. Results of studies of individual insects revealed that elevated CO{sub 2} and O{sub 3} influence the performance of individual species of damaging insect pests, but the magnitude of impact is influenced by both insect species and their host tree species. Censuses of canopy insects showed that some species were positively affected, some negatively affected, and some not affected by elevated CO{sub 2} …
Date: November 20, 2011
Creator: Lindroth, Richard L.
System: The UNT Digital Library