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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.

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At least 19 records

Impact of different cleaning processes on the laser damage threshold of antireflection coatings for Z-Backlighter optics at Sandia National Laboratories

We have examined how different cleaning processes affect the laser-induced damage threshold of antireflection coatings for large dimension, Z-Backlighter laser optics at Sandia National Laboratories. Laser damage thresholds were measured after the coatings were created, and again 4 months later to determine which cleaning processes were most effective. There is a nearly twofold increase in laser-induced damage threshold between the antireflection coatings that were cleaned and those that were not cleaned. Aging of the coatings after 4 months resulted in even higher laser-induced damage thresholds. Also, the laser-induced damage threshold results revealed that every antireflection coating had a high defect density, despite the cleaning process used, which indicates that improvements to either the cleaning or deposition processes should provide even higher laser-induced damage thresholds.

36 MATERIALS SCIENCE↗

Clean Energy Policy Analysis: Impact Analysis of Potential Clean Energy Policy Options for the Hawaii Clean Energy Initiative (HCEI)

This report provides detailed analyses of 21 clean energy policy options considered by the Hawaii Clean Energy Initiative working groups for recommendation to the 2010 Hawaii State Legislature. The report considers the impact each policy may have on ratepayers, businesses, and the state in terms of energy saved, clean energy generated, and the financial costs and benefits. The analyses provideinsight into the possible impacts, both qualitative and quantitative, that these policies may have in Hawaii based on the experience with these policies elsewhere. As much as possible, the analyses incorporate Hawaii-specific context to reflect the many unique aspects of energy use in the State of Hawaii.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Leveraging State Clean Water Revolving Funds to Expand Clean Energy Financing

To meet clean energy goals, states will need significant capital. Federal funding from the Inflation Reduction Act and the Infrastructure Investment and Jobs Act will help, including by capitalizing clean energy state revolving loan funds (RLFs). States can leverage state clean water revolving funds to finance even more clean energy improvements. New York and Pennsylvania have used this innovative mechanism to extend the impact of their clean energy loan programs. For states looking to extend the reach of their clean energy financing programs, the brief: -Explains how each state leveraged their state revolving funds, -Identifies critical success factors for doing so, and -Offers key elements for replicating this model In New York, New York State Energy Research and Development Authority structured a sale of bonds secured by the repayments from a portfolio of residential energy efficiency loans from its Green Jobs – Green New York Program, with the additional support of a guarantee from the state’s clean water revolving fund. The Pennsylvania Treasury Department received a direct investment of funds from Pennsylvania’s clean water revolving fund to support the relaunch of the Keystone Home Energy Loan Program (HELP), which had previously been shuttered due to lack of support funding. From our review of these two case studies, when facilitating state clean water revolving fund transactions to support clean energy lending, the following critical success factors emerged: -Reference to preventing atmospheric deposition resulting from the combustion of fossil fuels in the state’s Clean Water Act Section 319 Nonpoint Source Pollution Management Plan, which sets out that state’s strategy for reducing pollution into state waterways. -Strong relationships and trust between the clean water revolving fund administrator and the state agency administering the clean energy loan program. -Limited funding exposure for the clean water revolving funds—which are generally large and well capitalized—to ensure that any losses experienced by clean water revolving funds would have a negligible impact on the fund’s ability to support core water and wastewater projects. -Willingness, on the part of the clean water revolving fund administrator, to innovate and engage in careful analysis to support transaction structuring, and support from state energy partner organizations. The brief provides case studies of these states’ experiences, critical success factors, and key elements for replicating the model.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

36 MATERIALS SCIENCE↗

Contamination control and assay results for the Majorana Demonstrator ultra clean components

The Majorana Demonstrator is a neutrinoless double beta decay experiment utilizing enriched Ge-76 detectors in 2 separate modules inside of a common solid shield at the Sanford Underground Research Facility. The Demonstrator has utilized world leading assay sensitivities to develop clean materials and processes for producing ultra-pure copper and plastic components. This experiment is now operating, and initial data provide new insights into the success of cleaning and processing. Post production copper assays after the completion of Module 1 showed an increase in U and Th contamination in finished parts compared to starting bulk material. A revised cleaning method and additional round of surface contamination studies prior to Module 2 construction have provided evidence that more rigorous process control can reduce surface contamination. In conclusion, this article describes the assay results and discuss further studies to take advantage of assay capabilities for the purpose of maintaining ultra clean fabrication and process design.

36 MATERIALS SCIENCE↗

Cost-effectiveness and Economic Incidence of a Clean Energy Standard

A Clean Energy Standard (CES) is a flexible, market-based policy instrument that could be adopted to reduce greenhouse gas emissions from the U.S. electricity system over time. This paper uses several well-known energy system and electricity models to analyze a CES that reflects broad principles outlined in President Obama's January 2011 State of the Union Address and in the Administration's subsequent Blueprint for a Secure Energy Future. 1 In particular, it examines three different design options for a CES that would each lead to approximately 80% clean electricity by 2035. These different design options provide broadly similar economic incentives for clean energy deployment and yield similar overall welfare impacts, but they exhibit different distributional outcomes. The most inclusive CES crediting approach favors producers over consumers in competitive electricity markets as well as regions with larger initial endowments of clean energy. On the other hand, the most restrictive crediting approach favors consumers over producers and reduces preferences for regions with larger initial endowments of clean energy. While specific technology outcomes vary across the four models used in this study, key insights about cost-effectiveness and economic incidence are largely robust to the underlying modeling platform. These insights may be important considerations in future CES policy design efforts.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Heart of the Hearth: Making the Popular Clean, Not the Clean Popular - Technology Research, Development, and Tools for Clean Biomass Cookstoves

This technical report summarizes the work completed by BioLite in fulfilment of the US DOE EERE award. The work plan focused on three key objectives: developing an optimized combustion system that demonstrates high combustion efficiency and low PM 2.5 and CO emissions, integrate the system into popular stove phenotypes – side-fed rocket stove architecture like the BioLite HomeStove, and the Patsari chimney stove in Mexico such that they maintain their important phenotypical characteristics, independently evaluate quantitative fuel and emissions performance of the integrated ‘Turbo-Patsari’ in Mexican households. The project activities were organized into six major tasks: A. Develop, fabricate, and test proof-of-concept prototypes B. Develop field prototypes, assess user feedback and field performance C. Define revised stove design for pre-production model, Identify manufacturing requirements and estimated cost to build, Conduct reliability, emissions, and performance testing of pre-production Turbo-Patsari D. Build pre-production Turbo-Patsari stove combustion cores E. Conduct pre-production field trials F. Summarize field trial results and evaluate Turbo-Patsari for potential volume production. A two-pronged approach was adopted for the above tasks. The first involved building a modular test platform that allowed parametric variation of multiple stove design parameters that directly affect its performance – heat output, thermal efficiency, and emissions. The second part of the approach comprised of building a surrogate Patsari based on GIRA’s specifications that could then be modified or retrofitted for optimum performance based on the learnings from the modular test platform. The following sections of the report will describe the findings of tests on these platform, the subsequent development, design, and installation of the Turbo-Patsari, and finally the in-home field trial.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Adapted tube cleaning practices to reduce particulate contamination at hydrogen fueling stations

The higher rate of component failure and downtime during initial operation in hydrogen stations is not well understood. The National Renewable Energy Laboratory (NREL) has been collecting failed components from retail and research hydrogen fueling stations in California and Colorado and analyzing them using an optical zoom and scanning electron microscope. The results show stainless steel metal particulate contamination. While it is difficult to definitively know the origin of the contaminants, a possible source of the metal particulates is improper tube cleaning practices. To understand the impact of different cleaning procedures, NREL performed an experiment to quantify the particulates introduced from newly cut tubes. The process of tube cutting, threading and beveling, which is performed most often during station fabrication, is shown to introduce metal contaminants and thus is an area that could benefit from improved cleaning practices. This paper shows how these particulates can be reduced, which could prevent station downtime and costly repair. These results are from the initial phase of a project in which NREL intends to further investigate the sources of particulate contamination in hydrogen stations.

30 DIRECT ENERGY CONVERSION↗

Clean Energy Policy Analyses: Analysis of the Status and Impact of Clean Energy Policies at the Local Level

This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climatechange initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Clean Energy Policy Analyses: Analysis of the Status and Impact of Clean Energy Policies at the Local Level

This report takes a broad look at the status of local clean energy policies in the United States to develop a better understanding of local clean energy policy development and the interaction between state and local policies. To date, the majority of clean energy policy research focuses on the state and federal levels. While there has been a substantial amount of research on local level climate change initiatives, this is one of the first analyses of clean energy policies separate from climate change initiatives. This report is one in a suite of reports analyzing clean energy and climate policy development at the local, state, and regional levels.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Clean Cities and Communities: Advancing Affordable, Efficient, and Clean Transportation

Clean Cities and Communities is a U.S. Department of Energy (DOE) partnership to advance clean transportation nationwide. More than 75 DOE-designated Clean Cities and Communities coalitions work locally in urban, suburban, and rural communities to strengthen the nation's environment, energy security, and economic prosperity. As partners with DOE's Vehicle Technologies Office (VTO), coalitions work to deploy affordable, efficient, and clean transportation; energy efficient mobility systems; and fuel-saving technologies and practices.

ADVANCED PROPULSION SYSTEMS↗

Photocatalytic Nanofiltration Membranes with Self‐Cleaning Property for Wastewater Treatment

Membrane fouling is one of the most severe problems restricting membrane separation technology for wastewater treatment. This work reports a photocatalytic nanofiltration membrane (NFM) with self‐cleaning property fabricated using a facile biomimetic mineralization process. In this strategy, a polydopamine (PDA)/polyethyleneimine (PEI) intermediate layer is fabricated on an ultrafiltration membrane via a co‐deposition method followed by mineralization of a photocatalytic layer consisting of β‐FeOOH nanorods. The PDA–PEI layer acts both as a nanofiltration selective layer and an intermediate layer for anchoring the β‐FeOOH nanorods via strong coordination complexes between Fe 3+ and catechol groups. In visible light, the β‐FeOOH layer exhibits efficient photocatalytic activity for degrading dyes through the photo‐Fenton reaction in the presence of hydrogen peroxide, endowing the NFM concurrently with effective nanofiltration performance and self‐cleaning capability. Moreover, the mineralized NFMs exhibit satisfactory stability under simultaneous filtration and photocatalysis processing, showing great potential in advanced wastewater treatment.

Lv, Yan↗

The partial reduction of clean and doped alpha-Fe2O3(0001) from first principles

Fe surfaces have a wide range of applications due to the ability of Fe to be present in a number of different oxidation states, which can be further influenced by the presence of dopants that change the energetic and electronic surface properties. Thus, having an understanding of the elementary reduction processes of clean Fe oxide surfaces, and how dopants affect the energetics and electronics of such processes, is crucial to the science-guided design and optimization of said surfaces. In this work, we use density functional theory (DFT) to investigate the partial reduction of a-Fe2O3(0001) in the absence and presence of Pd and Pt dopants. In order to account for the strong on-site Coulombic interactions present in transition metal oxides, we used both the DFT?+?U method and 2006 Heyd-Scuseria-Ernzerhof functional and compare the results obtained from the different methods. We find that oxygen vacancies created in the clean a-Fe2O3(0001) surface prefer to diffuse into a subsurface layer, with the charge left behind from the first surface oxygen vacancy distributing between all of the near surface Fe atoms. The addition of Pd or Pt to the a-Fe2O3(0001) surface significantly decreases the energy required to create the first surface oxygen vacancy, suggesting the dopants intrinsically promote the reduction of a-Fe2O3(0001). Additionally, the presence of the dopants caused the charge left behind by the creation of the first surface oxygen vacancy to be localized on the dopant itself as well as the highest Fe atom. Overall, this work provides insight into the elementary energetic and electronic properties of the fully oxidized and partially reduced a-Fe2O3(0001) surface in the absence and presence of Pd and Pt dopants, which has potential implications for the design and optimization of doped Fe oxide surfaces.

Hensley, Alyssa↗

The Clean Energy Manufacturing Analysis Center (CEMAC): Providing Analysis and Insights on Clean Technology Manufacturing

The U.S. Department of Energy's Clean Energy Manufacturing Analysis Center (CEMAC) provides objective analysis and up-to-date data on global supply chains and manufacturing of clean energy technologies. Policymakers and industry leaders seek CEMAC insights to inform choices to promote economic growth and the transition to a clean energy economy.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗