Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Recovery Act”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8

Recovery Act: Tennessee Energy Efficient Schools Initiative Ground Source Heat Pump Program

The Tennessee Energy Efficient Schools Initiative (EESI) Hybrid-Water Source Heat Pump (HY-GSHP) Program sought to provide installation costs and operation costs for different Hybrid water source heat pump systems’ configurations so that other State of Tennessee School Districts will have a resource for comparison purposes if considering a geothermal system.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Recovery Act – Integrated Pilot-Scale Biorefinery for Producing Ethanol from Hybrid Algae

As a scientific and engineering endeavor, the Algenol IBR Biorefinery project has been a success by almost any measure. The vision for the system evolved significantly over the course of the project, always due to recognized opportunities for improved performance, lower energy consumption, and reduced costs. Our commitment to thorough, realistic, techno-economic and life cycle assessments has been an essential element for system innovation, technology guidance, and change management of the overall facility. The biological tools developed during this program for cyanobacteria are second to none, and are the primary reason for the remarkable improvements in organism performance. The breakthrough was the successful transformation of our most robust wild type organism (AB1) early in 2012. That was followed by a series of improvements over the next several years that produced strains wherein over 80% of the fixed carbon was converted into ethanol. At the same time, our expertise in cultivation, physiology, process engineering, CO2 management, and photobioreactor design and manufacturing grew at a comparable pace. We learned enormous amounts from the various upsets, weather variations, contamination events, and new technology related disappointments. We overcame those challenges to produce fuel grade ethanol with a low carbon footprint, and are within striking distance of economic viability even with the challenges of low fossil fuel prices.

09 BIOMASS FUELS↗

The Post-Closure Inspection Report For Closed Non- Resource Conservation And Recovery Act (RCRA) Corrective Action Units (CAUs) On The Nevada National Security Site (NNSS), For Calendar Year 2018

This letter serves as the Calendar Year 2018 post-closure inspection letter report for the following Non-RCRA CAUs located on the NNSS, including CAUs located on the Nevada Test and Training Range (NTTR) that are accessed through the NNSS Main Gate. Use restriction issues that were identified in the 2017 inspections were addressed in 2018.

54 ENVIRONMENTAL SCIENCES↗

Non-Resource Conservation and Recovery Act Corrective Action Unit (CAU) Post-Closure Inspection Report, Nevada National Security Site, Nevada (CY2021, Revision 0)

This report includes visual inspection results, maintenance and repair activities, and recommendations for calendar year (CY) 2021 for use restrictions (URs) at corrective action sites (CASs) located on the Nevada National Security Site (NNSS) and on the Nevada Test and Training Range (NTTR) that are accessed through the NNSS Main Gate. This document is formatted by project activity (i.e., Industrial Sites, Soils, and Defense Threat Reduction Agency [DTRA]); then by corrective action unit (CAU); and then by CAS.

54 ENVIRONMENTAL SCIENCES↗

Post-Closure Inspection Letter Report for Closed Non-Resource Conservation and Recovery Act (RCRA) Corrective Action Units (CAUs) On the Nevada National Security Site (NNSS), For Calendar Year 2019, With Errata Sheet

Post-Closure inspection letter report for the following CAUs for calendar year 2019 including CAUs located on the Nevada Test and Training Range (NTTR) that are accessed through the NNSS Main Gate. Use restriction issues that were identified in 2018 inspections were addressed in 2019.

54 ENVIRONMENTAL SCIENCES↗

Post-Closure Inspection (PCI) Letter Report for Closed Non-Resource Conservation and Recovery Act (RCRA) Corrective Action Units (CAUs) on the Nevada National Security Site (NNSS), for Calendar Year (CY) 2020

This letter report is for the following CAUs for CY 2020, including CAUs located on the Nevada Test and Training Range (NTTR) that are accessed through the NNSS Main Gate. Use restriction (UR) issues that were identified in the 2019 inspections were addressed in 2020.

54 ENVIRONMENTAL SCIENCES↗

Non-Resource Conservation and Recovery Act Corrective Action Unit (CAU) Post-Closure Inspection Report, Nevada National Security Site, Nevada For Calendar Year 2022

This report includes visual inspection results, descriptions of maintenance and repair activities, and recommendations for calendar year (CY) 2022 for use restrictions (URs) at corrective action sites (CASs) located on the Nevada National Security Site (NNSS) and on the Nevada Test and Training Range (NTTR) that are accessed through the NNSS Main Gate. This document is formatted by project activity (i.e., Industrial Sites, Soils, and Defense Threat Reduction Agency [DTRA]); then by corrective action unit (CAU); and then by CAS.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Non-Resource Conservation and Recovery Act Corrective Action Unit (CAU) Post-Closure Inspection Report, Nevada National Security Site, Nevada: For Calendar Year 2023

This report includes visual inspection results, descriptions of maintenance and repair activities, and recommendations for CY 2023 for URs at CASs located on the NNSS and on the NTTR that are accessed through the NNSS Main Gate. This document is formatted by project activity (i.e., Industrial Sites, Soils, and DTRA]; then by CAU; and then by CAS.

54 ENVIRONMENTAL SCIENCES↗

Recovery Act: A Low Cost Spray Deposited Solar PV Anti-Reflection Coating Final Technical Report

PV module glass is typically low iron glass which exhibits extremely low absorption of light at solar wavelengths. However, reflection losses from typical high quality solar glass are about 4.5% of the input solar energy. By applying an antireflection coating to the cover glass of their modules, a PV module maker will gain at least a 3% increase in the light passing through the glass and being converted to electricity. Thus achieving an increase of >3% in electricity output from the modules. This Project focussed on developing a process that deposits a layer of porous silica (SiO2) on glass or plastic components, and testing the necessary subcomponents and subsystems required to demonstrate the commercial technology. This porous layer acts as a broadband single layer AR coating for glass and plastics, with the added benefit of being a hydrophilic surface for low surface soiling.

14 SOLAR ENERGY↗

Recovery Act - Nano-composite Structures for OPV Devices

Improved material for use in organic photovoltaics (OPV) devices, also called polymer-solar cells (PSC), has been developed. Increased ordering of the active layer of bulk heterojunction (BHJ) cells has been achieved by the use of inert silica spheres in conjunction with suitable fullerene derivatives. Silica spheres with average diameters between 10 and 15 nm, consistent with the exciton diffusion length in the active layer, have been added. The potential for significantly improved device performance due to a higher degree of photon absorption, enabled by increased light scattering, and a maximized interface between electron donor and acceptor, ensuring efficient exciton dissociation, has been demonstrated. A method allowing for the covalent attachment of fullerene derivatives to the silica sphere surface has been developed.

14 SOLAR ENERGY↗

Recovery Act: "Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates" (Final Report)

III-V photovoltaics have exhibited efficiencies above 40%, but have found only a limited use because of the high cost of single crystal substrates. At the other end of the spectrum, polycrystalline and amorphous thin film solar cells offer the advantage of low-cost fabrication, but have not yielded high efficiencies. Our program is based on single-crystalline-like thin film photovoltaics on polycrystalline substrates using biaxially-textured templates made by Ion Beam-Assisted Deposition (IBAD). MgO templates made by IBAD on flexible metal substrate have been successfully used for epitaxial growth of germanium films. In spite of a 4.5% lattice mismatch, heteroepitaxial growth of Ge was achieved on CeO 2 that was grown on IBAD MgO template. Room temperature optical bandgap of the Ge films was identified at 0.67 eV indicating minimal residual strain. Refraction index and extinction coefficient values of the Ge films were found to match well with that measured from a reference Ge single crystal. GaAs has been successfully grown epitaxially on Ge on metal substrate by molecular beam epitaxy. RHEED patterns indicate self annihilation of antiphase boundaries and the growth of a single domain GaAs. The GaAs is found to exhibit strong photoluminescence signal and, an existence of a relatively narrow (FWHM~20 meV) band-edge excitons measured in this film indicates a good optoelectronic quality of deposited GaAs. While excellent epitaxial growth has been achieved in GaAs on flexible metal substrates, the defect density of the films as measured by High Resolution X-ray Diffraction and etch pit experiments showed a high value of 5 x 10 8 per cm 2 . Cross sectional transmission electron microscopy of the multilayer architecture showed concentration of threading dislocations near the germanium-ceria interface. The defect density was found decrease as the Ge films were made thicker. The defects appear to originate from the MgO layer presumably because of large lattice mismatches between the various layers. The defect density in GaAs was reduced by a factor of five by adding a step of in-situ deposition of Ge by MBE on the sputtered Ge prior to GaAs growth. We have investigated device design strategies that would support development of high-efficiency devices in presence of dislocation densities of 10 8 cm -2 present in our epitaxial GaAs films. Results from modeling work show that with a proper emitter, base and doping selection, the modeled efficiency of a GaAs cells with dislocation densities of 10 9 and 10 8 cm -2 could be increased from 1% and 7% to 11% and 17% respectively. Under AM0, this single junction GaAs solar cell, has optimized value of emitter and base thickness of around 0.7 and 1.7 microns respectively, to give a maximum efficiency of 24.2%. We have fabricated complete GaAs solar cells using our Ge films on metal substrates. Pattern resolution of few microns with well-defined grid line of 30 microns has been realized on few cm square flexible templates. The ability to grow single-crystalline-like Ge films on flexible, polycrystalline substrates by reel-to-reel tape processing now provides an immense potential to fabricate high quality III-V photovoltaics on flexible, inexpensive substrates.

14 SOLAR ENERGY↗

Recovery Act : Near-Single-Crystalline Photovoltaic Thin Films on Polycrystalline, Flexible Substrates

III-V photovoltaics have exhibited efficiencies above 40%, but have found only a limited use because of the high cost of single crystal substrates. At the other end of the spectrum, polycrystalline and amorphous thin film solar cells offer the advantage of low-cost fabrication, but have not yielded high efficiencies. Our program is based on single-crystalline-like thin film photovoltaics on polycrystalline substrates using biaxially-textured templates made by Ion Beam-Assisted Deposition (IBAD). MgO templates made by IBAD on flexible metal substrate have been successfully used for epitaxial growth of germanium films. In spite of a 4.5% lattice mismatch, heteroepitaxial growth of Ge was achieved on CeO2 that was grown on IBAD MgO template. Room temperature optical bandgap of the Ge films was identified at 0.67 eV indicating minimal residual strain. Refraction index and extinction coefficient values of the Ge films were found to match well with that measured from a reference Ge single crystal. GaAs has been successfully grown epitaxially on Ge on metal substrate by molecular beam epitaxy. RHEED patterns indicate self annihilation of antiphase boundaries and the growth of a single domain GaAs. The GaAs is found to exhibit strong photoluminescence signal and, an existence of a relatively narrow (FWHM~20 meV) band-edge excitons measured in this film indicates a good optoelectronic quality of deposited GaAs. While excellent epitaxial growth has been achieved in GaAs on flexible metal substrates, the defect density of the films as measured by High Resolution X-ray Diffraction and etch pit experiments showed a high value of 5 * 10^8 per cm^2. Cross sectional transmission electron microscopy of the multilayer architecture showed concentration of threading dislocations near the germanium-ceria interface. The defect density was found decrease as the Ge films were made thicker. The defects appear to originate from the MgO layer presumably because of large lattice mismatches between the various layers. The defect density in GaAs was reduced by a factor of five by adding a step of in-situ deposition of Ge by MBE on the sputtered Ge prior to GaAs growth. We have investigated device design strategies that would support development of high-efficiency devices in presence of dislocation densities of 10^8 cm^-2 present in our epitaxial GaAs films. Results from modeling work show that with a proper emitter, base and doping selection, the modeled efficiency of a GaAs cells with dislocation densities of 10^9 and 10^8 cm^-2 could be increased from 1% and 7% to 11% and 17% respectively. Under AM0, this single junction GaAs solar cell, has optimized value of emitter and base thickness of around 0.7 and 1.7 microns respectively, to give a maximum efficiency of 24.2%. We have fabricated complete GaAs solar cells using our Ge films on metal substrates. Pattern resolution of few microns with well-defined grid line of 30 microns has been realized on few cm square flexible templates. The ability to grow single-crystalline-like Ge films on flexible, polycrystalline substrates by reel-to-reel tape processing now provides an immense potential to fabricate high quality III-V photovoltaics on flexible, inexpensive substrates.

14 SOLAR ENERGY↗