Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Organic LED”

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 919 records · Page 51
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Final Technical Report for project entitled Highly Active, Durable, and Ultra-Low PGM NSTF Thin Film ORR Catalysts and Support

In this project, the objective was to develop new oxygen reduction reaction (ORR) electrocatalysts for proton exchange membrane fuel cells (PEMFCs) which could exceed all of the Department of Energy (DOE) 2020 targets listed in DE-FOA-0001224, Subtopic 1b, Table I. The expected outcome was development of one or more electrocatalysts which are substantially improved over the current state-of-the-art in terms of overall activity, durability, and cost, and are suitable for automotive traction and stationary fuel cell applications. This report summarizes this project’s progress towards meeting the stated objectives and includes a summary of key findings and conclusions. The development activities towards new highly active and durable thin film electrocatalysts has led to the discovery of several electrocatalysts which approached or exceeded several DOE 2020 targets for activity, durability, and performance in proton exchange membrane fuel cell (membrane electrode assemblies (MEAs). In this project, electrocatalyst development focused on systematic physical and electrochemical characterization of electrocatalyst activity, durability, and performance in MEAs as a function of electrocatalyst fabrication, compositional and structural variables. The project approach was to develop relationships between the catalyst functional responses (activity, durability and performance) with catalyst physical properties and catalyst fabrication methods. Additionally, the thin film catalysts were integrated onto the unique and durable 3M Nanostructured Thin Film (NSTF) support, consisting of arrays of self-assembled organic crystalline whiskers. The catalysts were evaluated against the project targets via extensive electrochemical characterization in MEA format at 3M, advanced structural and compositional microscopy at Oak Ridge National Laboratory (ORNL), and atomic structure analysis via XAFS at Argonne National Laboratory (ANL). The extensive electrochemical and physical characterization resulted in development of several trends which correlate the catalysts’ electrochemical properties to their physical properties, including composition, structure, and method of fabrication. The development was guided by density functional theory (DFT) modeling at Purdue University and kinetic Monte Carlo (kMC) modeling at Johns Hopkins University. The catalyst simulations provided key insights into the observed experimental activity and durability trends, and additionally were utilized to assess new electrocatalyst concepts prior to or coincident with physical catalyst development. This development has led to several electrocatalyst candidates with activity and durability which approach or exceed DOE targets. One class of catalysts, based on nm-scale thin layers of Pt on Ir, met or exceeded 6 of the 6 DOE targets the project addressed.

08 HYDROGEN↗
DOE OSTI2024

Bench-Scale Electrolytic Dissolution of Quarter-Scale FCA Cans

In 2016, the Savannah River National Laboratory (SRNL) led, in support of and under sponsorship of the Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Office of Material Management and Minimization (M3), the removal and transfer of the plutonium based Fast Critical Assembly (FCA) fuel from the Japan Atomic Energy Agency (JAEA) Tokai facility to the Savannah River Site (SRS). The team also included JAEA, multiple organizations in Savannah River Nuclear Solutions (SRNS), International Nuclear Services, and many other entities. The FCA fuel removal project completion was a key deliverable for M3 to the 2016 Nuclear Security Summit and constituted the largest inventory of weapons-usable plutonium removed under the nonproliferation program. The FCA materials consist of thousands of stainless steel (SS) clad plates and hundreds of SS clad rods. The FCA fuel elements were packaged in a carrier can and stored at SRS pending disposition of the fuel. Following an assessment of candidate disposition options, SRNS identified electrolytic dissolution (ED) as the most promising disposition option for the FCA plates and their preferred option was endorsed by DOE. This option entails electrochemically dissolving the entire FCA carrier can with fuel elements and was based on bench-scale laboratory testing and historical work on processing SS-clad and zirconium-clad uranium-based fuel in the H-Canyon electrolytic dissolver (last operated in 1980). The FCA plate consists of a plutonium-aluminum metal alloy core hermitically sealed in SS cladding.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1991

Rendezvous, proximity operations and capture quality function deployment report

Rendezvous, Proximity Operations, and Capture (RPOC) is a missions operations area which is extremely important to present and future space initiatives and must be well planned and coordinated. To support this, a study team was formed to identify a specific plan of action using the Quality Function Deployment (QFD) process. This team was composed of members from a wide spectrum of engineering and operations organizations which are involved in the RPOC technology area. The key to this study's success is an understanding of the needs of potential programmatic customers and the technology base available for system implementation. To this end, the study team conducted interviews with a variety of near term and future programmatic customers and technology development sponsors. The QFD activity led to a thorough understanding of the needs of these customers in the RPOC area, as well as the relative importance of these needs.

Lamkin, Stephen L.↗
NASA NTRS2011

Developing Flexible Discrete Event Simulation Models in an Uncertain Policy Environment

On February 1st, 2010 U.S. President Barack Obama submitted to Congress his proposed budget request for Fiscal Year 2011. This budget included significant changes to the National Aeronautics and Space Administration (NASA), including the proposed cancellation of the Constellation Program. This change proved to be controversial and Congressional approval of the program's official cancellation would take many months to complete. During this same period an end-to-end discrete event simulation (DES) model of Constellation operations was being built through the joint efforts of Productivity Apex Inc. (PAl) and Science Applications International Corporation (SAIC) teams under the guidance of NASA. The uncertainty in regards to the Constellation program presented a major challenge to the DES team, as to: continue the development of this program-of-record simulation, while at the same time remain prepared for possible changes to the program. This required the team to rethink how it would develop it's model and make it flexible enough to support possible future vehicles while at the same time be specific enough to support the program-of-record. This challenge was compounded by the fact that this model was being developed through the traditional DES process-orientation which lacked the flexibility of object-oriented approaches. The team met this challenge through significant pre-planning that led to the "modularization" of the model's structure by identifying what was generic, finding natural logic break points, and the standardization of interlogic numbering system. The outcome of this work resulted in a model that not only was ready to be easily modified to support any future rocket programs, but also a model that was extremely structured and organized in a way that facilitated rapid verification. This paper discusses in detail the process the team followed to build this model and the many advantages this method provides builders of traditional process-oriented discrete event simulations.

Miranda, David J.↗
NASA NTRS2019

Systemic Alterations with Spaceflight Associated Health Risks Originating from Both Circulating miRNAs and Mitochondrial Biology

The many known health risks currently associated with space travel include increased risk of cardiovascular disease, cancer, central nervous system related diseases, muscle degeneration, and changes with host-gut microbiome interactions that can have profound impact with these and other health risks. The majority of the risk from space travel stem of the two components of the space environment which are microgravity and radiation. Two specific systemic effects have been uncovered by us to impact the body as a whole due to the space environment. One factor is related from our earlier work (Beheshti et al, PLOS One, 2018), we predicted that there is a systemic component of the host that causes general increased health risks due to spaceflight driven by a circulating microRNA (miRNA) signature consisting of 13 miRNAs that directly regulates both p53 and TGF1. MiRNAs are small non-coding RNA molecules with a negative and post-transcriptional regulation on gene expression) are increasingly recognized as major systemic regulators of responses to stressors, including microgravity, oxidative stress, and DNA damage. In addition, due to the size and stability of miRNAs, it is known that miRNAs can circulate throughout the body and have been found in the majority of the bodily fluids including blood, urine, saliva, and tears. Here, we start to dissect the actual impact of this miRNA signature on both the radiation and microgravity components and prove that this miRNA signature actually exists in the circulation of a host. The other systemic factor we uncovered was the impact the mitochondria on the whole body due to spaceflight. We hypothesize that spaceflight may promote a physiologic response driven by systemic mitochondria pathways leading to metabolic disorder stemming from the liver and directly impacting other organs and tissues. A systems biology method was implemented utilizing GeneLab datasets that involved in vitro experiments performed at the low Earth orbit, in vivo experiments involving mice flown to space, and finally human physiological data from astronauts. A comprehensive multi-omics approach was implemented which involved correlating transcriptomic analysis with proteomics, metabolomics, and methylation analysis. This approach led us to confirm our hypothesis that a systemic mitochondrial driven response is responsible for increasing potential health risk and is conserved from the in vitro studies, to the in vivo studies, and finally confirmed in astronauts.

Radiation↗
NASA NTRS2020

UAM Vision Concept of Operations (ConOps) UAM Maturity Level (UML) 4

This Vision ConOps is intended as a foundation to engage members of the UAM community and provide a consensus on the future vision of UAM operations. It provides a concept for more detailed discussion and a basis for the exploration of ideas using a common framework to inform the continued development and integration of UAM as part of the broader transportation system. Advanced Air Mobility (AAM) encompasses a range of innovative aviation technologies (small drones, electric aircraft, automated air traffic management, etc.) that are transforming aviation’s role in everyday life, including the movement of goods and people. Urban Air Mobility (UAM) represents one of the most exciting and complex AAM concepts with highly automated aircraft, providing commercial services to the public over densely populated cities. This concept has generated tremendous interest and industry investment. UAM envisages a future in which advanced technologies and new operational procedures enable practical, cost-effective air travel as an integral mode of transportation in metropolitan areas. It represents one of the most exciting and complex AAM concepts with highly automated aircraft providing commercial services to the public over densely populated cities. For this reason, the National Aeronautics and Space Administration (NASA) selected UAM as the initial goal of its AAM efforts and the focus of this Vision Concept of Operations (ConOps) document. UAM Community Vision ConOps: This Vision ConOps effort was led by experts from NASA’s Aeronautics Research Mission Directorate (ARMD) in collaboration with the Federal Aviation Administration (FAA) and Deloitte’s Ecosystem Advisory Group (a cohort of advisers with aviation, aerospace, and regulatory expertise). To develop this Vision ConOps, NASA, FAA, and Deloitte built upon the current body of aeronautical research and consulted with more than 100 stakeholder organizations. This UAM community includes entities ranging from legacy aviation leaders to innovators and new market entrants. Stakeholders consulted included the federal government, state and local government, aerospace original equipment manufacturers (OEMs), local transportation organizations, prospective UAM operators, academia, industry standards-setting bodies, airports, service suppliers, and others (as described in Appendix G). This input was captured through the following methods: • A series of more than two dozen interviews with industry experts, federal regulators, state and local governments, and industry trade groups provided insight into the challenges of UAM integration into the National Airspace System (NAS), as well as technology developments and a variety of perspectives as to how UAM systems will integrate. • A series of two-day community workshops enabling active, detailed engagement of nearly 100 industry, academic, federal, and state stakeholder individuals. These workshops, hosted by NASA and Deloitte, explored UAM concepts in detail, and stakeholders were invited to collaboratively analyze and propose solutions to some of the greatest conceptual challenges behind UAM at an intermediate state. • A review of more than 160 sources of UAM literature from across government, industry, and academia, which are listed in Appendix H. • The public sharing of workshop input and document drafts for review and input across the UAM community. Feedback in the form of more than 1,000 comments and inputs on the document was received from industry groups, individual companies, academia, and government (federal, state, and local), among others. Although effort was made to incorporate inputs from across the UAM stakeholder group, not all comments could ultimately be incorporated in this version. The team resolved conflicting comments or ideas while maintaining consistency with the known direction of regulators and ensuring the document was coherent and consistent. It is recognized that this is a rapidly evolving area and that concepts will likely change over time; as such, this Vision ConOps is a living document and is expected to evolve as concepts mature. The ConOps does, however, provide a vision of UAM concepts and solutions based on the broad insights from across the UAM stakeholder community at the time of its publication and is intended to serve as a UAM North Star for continued research and development of UAM. As a broad Vision ConOps, is not a detailed engineering document; rather, it focuses primarily on outlining a broad, high-level vision across all aspects of a UAM transportation system.

Urban Air Mobility↗
DOE OSTI2013

Fukushima Media Involvement: Lessons Learned and Challenges - 13261

Only days after the Fukushima nuclear reactor disaster on March 11, 2011, the DOE's Pacific Northwest National Laboratory, or PNNL, found itself in a maelstrom of media attention following its announcement of the detection of minute levels of radioactive material originating from the damaged reactors 4,500 miles away. Because PNNL develops state-of-the-art ultra-sensitive radionuclide detection and monitoring systems for national security applications, and has some of the equipment operating on its Richland campus, there was little surprise when one of these sophisticated systems led PNNL to be the first to detect measurable radionuclides in the United States. On Wednesday, March 16, 2011, that system detected minuscule levels of short-lived radioactive xenon, a telltale element derived from either weapons testing or a major reactor disruption. Immediately after the detection was announced, a flurry of inquiries nearly overwhelmed staff as governments, scientific organizations, the general public, and reporters struggled to understand and estimate what impacts this disaster might have on health and environment. Over the course of about three weeks, PNNL's News and Media Relations staff and its scientists and engineers responded to more than 100 requests for information, and engaged in dozens of personal interviews with international, national, regional, and local media. While many of the interviews and resulting stories were accurate and well done, not all communication went flawlessly. In the midst of chaos and confusion, which are part of any significant crisis, hiccoughs are sure to occur. Addressed here is 'the rest of the story'. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Systematically programmed adaptive evolution reveals potential role of carbon and nitrogen pathways during lipid accumulation in Chlamydomonas reinhardtii

Background: The concept of adaptive evolution implies underlying genetic mutations conferring a selective advantage to an organism under particular environmental conditions. Thus, a flow cytometry-based strategy was used to study the adaptive evolution in Chlamydomonas reinhardtii wild-type strain CC124 and starchless mutant sta6-1 cells, with respect to lipid metabolism under nitrogen-(N) depleted and -replete conditions. Results: The successive sorting and regeneration of the top 25,000 high-lipid content cells of CC124 and sta6-1, combined with nitrogen starvation, led to the generation of a new population with an improved lipid content when compared to the original populations (approximately 175% and 50% lipid increase in sta6-1 and CC124, respectively). During the adaptive evolution period, the major fatty acid components observed in cells were C16:0, C16:1, C18:0, and C18:1-3, and elemental analysis revealed that cellular carbon to nitrogen ratio increased at the end of adaptive evolution period In order to gain an insight into highly stimulated intracellular lipid accumulation in CC124 and sta6-1 resulting from the adaptive evolution, proteomics analyses of newly generated artificial high-lipid content populations were performed. Functional classifications showed the heightened regulation of the major chlorophyll enzymes, and the enzymes involved in carbon fixation and uptake, including chlorophyll-ab-binding proteins and Rubisco activase. The key control protein (periplasmic L-amino acid oxidase (LAO1)) of carbon-nitrogen integration was specifically overexpressed. Glutathione-S-transferases and esterase, the enzymes involved in lipid-metabolism and lipid-body associated proteins, were also induced during adaptive evolution. Conclusions: Adaptive evolution results demonstrate the potential role of photosynthesis in terms of carbon partitioning, flux, and fixation and carbon-nitrogen metabolism during lipid accumulation in microalgae. This strategy can be used as a new tool to develop C. reinhardtii strains and other microalgal strains with desired phenotypes such as high lipid accumulation.

09 BIOMASS FUELS↗
DOE OSTI2016

Facile synthesis of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts mat with the enhanced fluorescence and mechanical performance

Yellow-emitting phosphor mat consisting of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts was prepared by electrospinning and subsequent nitridation. The as-prepared fiber precursor is smooth and uniform with diameter of 800 to 900 nm. After removing organic templates and nitridation, the morphology of the fiber is well retained and thus a smooth microbelts phosphor mat was obtained. X-ray diffraction and the photoluminescence (PL) spectra reveals that a relatively pure Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16} phase and the highest spectral intensity could be obtained at a relatively low temperature of 1500 °C and Eu{sup 2+} doping molar concentration of 0.1. The excitation spectra exhibits a broad band, ranging from 300 to 550 nm, which could be excited by blue LED chip at room temperature. The emission spectra of all exhibits a single broad band in the 400 to 700 nm region, with the maximum intensity always being at 580 nm. The Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts phosphor mat has the bending strength about 4.5 MPa with a photoluminescence quantum yield as high as 65%. By employing it as yellow phosphor, a high-performance warm white LED could be fabricated with low correlated color temperature (2985 K), high-color-rendering index (Ra=86) and luminous efficacy of 129.5 lm W{sup −1}. Different color temperatures also could be tuned by employing microbelts phosphor mats with different thicknesses. - Graphical abstract: Yellow-emitting phosphor mat consisting of Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts fibers were prepared by electrospinning the fiber precursor and subsequent nitridation. Because the good mechanical strength it could be utilized to realize LEDs remote packaging. By employing it as yellow phosphor, a high-performance warm white LED could be fabricated. Different color temperatures also could be tuned by employing microbelts phosphor mats with different thicknesses. - Highlights: • Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} microbelts mats were synthesized by electrospinning method. • The optimum doping concentration of Eu{sup 2+} ion is 0.1 mole. • The microbelts mats show strong yellow emission at 580 nm. • The Ca{sub 0.68}Si{sub 9}Al{sub 3}(ON){sub 16}:Eu{sup 2+} mat had the bending strength about 4.5 Mp. • Different color temperatures could be turned with different thicknesses of the mats.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

DIRECT DETECTION OF COMPLEX ORGANIC PRODUCTS IN ULTRAVIOLET (Lyα) AND ELECTRON-IRRADIATED ASTROPHYSICAL AND COMETARY ICE ANALOGS USING TWO-STEP LASER ABLATION AND IONIZATION MASS SPECTROMETRY

As discovery of complex molecules and ions in our solar system and the interstellar medium has proliferated, several groups have turned to laboratory experiments in an effort to simulate and understand these chemical processes. So far only infrared (IR) and ultraviolet (UV) spectroscopy has been able to directly probe these reactions in ices in their native, low-temperature states. Here we report for the first time results using a complementary technique that harnesses two-step two-color laser ablation and ionization to measure mass spectra of energetically processed astrophysical and cometary ice analogs directly without warming the ices—a method for hands-off in situ ice analysis. Electron bombardment and UV irradiation of H{sub 2}O, CH{sub 3}OH, and NH{sub 3} ices at 5 K and 70 K led to complex irradiation products, including HCO, CH{sub 3}CO, formamide, acetamide, methyl formate, and HCN. Many of these species, whose assignment was also strengthened by isotope labeling studies and correlate with IR-based spectroscopic studies of similar irradiated ices, are important ingredients for the building blocks of life. Some of them have been detected previously via astronomical observations in the interstellar medium and in cometary comae. Other species such as CH{sub 3}CO (acetyl) are yet to be detected in astrophysical ices or interstellar medium. Our studies suggest that electron and UV photon processing of astrophysical ice analogs leads to extensive chemistry even in the coldest reaches of space, and lend support to the theory of comet-impact-induced delivery of complex organics to the inner solar system.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2016

Two-Column Aerosol Project (TCAP) Field Campaign Report

This study included the deployment of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Mobile Facility (AMF), ARM Mobile Aerosol Observing System (MAOS) and the ARM Aerial Facility (AAF). The study was a collaborative effort involving scientists from DOE national laboratories, NOAA, NASA, and universities. The AAF and MAOS were deployed for two approximately month-long Intensive Operational Periods (IOPs) conducted in June 2012 and February 2013. Seasonal differences in the aerosol chemical and optical properties observed using the AMF, AAF, and MAOS are presented in this report. The total mass loading of aerosol is found to be much greater in the summer than in the winter, with the difference associated with greater amounts of organic aerosol. The mass fraction of organic aerosol is much reduced in the winter, when sulfate is the dominant aerosol type. Surprisingly, very little sea-salt aerosol was observed in the summer. In contrast, much more sea salt aerosol was observed in the winter. The mass loading of black carbon is nearly the same in both seasons. These differences lead to a relative increase in the aerosol light absorption in the winter and an associated decrease in observed single-scattering albedo. Measurements of aerosol mixing state were made using a single-particle mass spectrometer, which showed that the majority of the summertime aerosol consisted of organic compounds mixed with various amounts of sulfate. A number of other findings are also summarized in the report, including: impact of aerosol layers aloft on the column aerosol optical depth; documentation of the aerosol properties at the AMF; differences in the aerosol properties associated with both columns, which are not systematic but reflect the complicated meteorological and chemical processes that impact aerosol as it is advected away from North America; and new instruments and data-processing techniques for measuring both aerosol and cloud properties that were deployed for the first time during the TCAP. Key lessons learned during TCAP include the need for closer coordination between the AMF, MAOS, and the AAF so that all AMF instruments can be online and functioning during the AAF IOPs. Based on experiences from TCAP, it is also important for instrument mentors, or other relevant individuals, to review data on a regular basis to ensure that data quality remains high during the entire deployment. TCAP was marked by two important meteorological events including the passage of Hurricane Sandy at the end of October 2012 and the occurrence of one of the largest New England blizzards in recorded history. During Sandy the AMF received some, generally minor, damage and was largely functional a short time after the storm. The blizzard led to extensive power outages on Cape Cod and a multi-day interruption of measurements by the AMF, MAOS, and AAF. In each case, however, the ARM Facilities were returned to service and functioning as soon as was reasonably possible.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Mini-Review: Oxidative stress, redox stress or redox success?

Highlights: • Reactive oxygen species were major drivers of evolution. • Reductive stress may not be a very useful concept. • Major antioxidant defences include restriction of O{sub 2} levels and sequestration of iron ions into non-redox active forms. • These defences allowed aerobic life to evolve but led to a battle between host and pathogens for iron. The first life forms evolved in a highly reducing environment. This reduced state is still carried by cells today, which makes the concept of “reductive stress” somewhat redundant. When oxygen became abundant on the Earth, due to the evolution of photosynthesis, life forms had to adapt or become extinct. Living organisms did adapt, proliferated and an explosion of new life forms resulted, using reactive oxygen species (ROS) to drive their evolution. Adaptation to oxygen and its reduction intermediates necessitated the simultaneous evolution of select antioxidant defences, carefully regulated to allow ROS to perform their major roles. Clearly this “oxidative stress” did not cause a major problem to the evolution of complex life forms. Why not? Iron and oxygen share a close relationship in aerobic evolution. Iron is used in proteins to transport oxygen, promote electron transfers, and catalyse chemical reactions. In all of these functions, iron is carefully sequestered within proteins and restricted from reacting with ROS, this sequestration being one of our major antioxidant defences. Iron was abundant to life forms before the appearance of oxygen. However, oxygen caused its oxidative precipitation from solution and thereby decreased its bioavailability and thus the risk of iron-dependent oxidative damage. Micro-organisms had to adapt and develop strategies involving siderophores to acquire iron from the environment and eventually their host. This battle for iron between bacteria and animal hosts continues today, and is a much greater daily threat to our survival than “oxidative stress” and “redox stress”.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2012

Manganese valence and coordination structure in Mn,Mg-codoped {gamma}-AlON green phosphor

The valence and coordination structure of manganese in a Mn,Mg-codoped {gamma}-AlON spinel-type oxynitride green phosphor were studied by synchrotron X-ray diffraction and absorption fine structure measurements. The absorption edge position of the XANES revealed the bivalency of Mn. Two cation sites are available in the spinel structure for cation doping: a tetrahedral site and an octahedral site. The pre-edge of the XANES and the distance to the nearest neighbor atoms obtained from the EXAFS measurement showed that Mn was situated at the tetrahedral site. Rietveld analysis showed that the vacancy occupied the octahedral site. The preferential occupation of the tetrahedral site by Mn and the roles of N and Mg are discussed in relation to the spinel crystal structure. - Graphical Abstract: Fourier transform of EXAFS of Mn K-edge for Mn,Mg-codoped green phosphor and Mn coordination structure. Highlights: Black-Right-Pointing-Pointer Mn, Mg-codoped {gamma}-AlON green phosphor for white LED. Black-Right-Pointing-Pointer The valence of Mn is divalent. Black-Right-Pointing-Pointer Mn occupies the tetrahedral site in the spinel structure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Solid State Ionics - the key to the discovery, introduction and domination of lithium batteries for portable energy storage

2017 is the 50th anniversary of the discovery of fast ion transport in β-alumina. This discovery led to a revolution in the study of solid materials that might exhibit ionic motion as fast as that found in liquids. The need for materials with both fast ionic and electronic conductivity and a wide stoichiometry range to measure the ionic conductivity of beta alumina led to the intercalation concept for rechargeable alkali metal batteries. These discoveries and the resulting development of the lithium battery are described in this paper.

25 ENERGY STORAGE↗
DOE OSTI2015

Stereoselective Ring-Opening Metathesis Polymerization (ROMP) of Methyl- N -(1-phenylethyl)-2-azabicyclo[2.2.1]hept-5-ene-3-carboxylate by Molybdenum and Tungsten Initiators

Ring-opening metathesis polymerization (ROMP) of methyl- N -(1-phenylethyl)-2-azabicyclo[2.2.1]hept-5-ene-3-carboxylate (PhEtNNBE; ( S ) and racemic) was researched employing six molybdenum and tungsten imido alkylidene initiators and two tungsten oxo alkylidene initiators. Of the six initiators that we introduced should yield cis,syndiotactic -poly[( S )-PhEtNNBE], two molybdenum OHMT alkylidene initiators, Mo(NR)(CHMe 2 Ph)(pyr)(OHMT) (R = 1-adamantyl (Ad) or 2,6-Me 2 C 6 H 3 (Ar'); OHMT = O -2,6-mesityl 2 C 6 H 3 ; pyr = pyrrolide), and two tungsten oxo alkylidene initiators, W(O)(CHMe 2 Ph)(2,5-dimethylpyrrolide)(PMe 2 Ph)(OR) (OR = OHMT or ( R )-OBr 2 Bitet where ( R )-Br 2 BitetOH = ( R )-3,3'-dibromo-2'-( tert -butyldimethylsilyloxy)-5,5',6,6',7,7',8,8'-octahydro-1,1'-binaphthyl-2-ol), produced essentially pure cis,syndiotactic -poly[(S)-PhEtNNBE]. Essentially pure cis,isotactic -poly[( S )-PhEtNNBE] was formed when ( S )-PhEtNNBE was polymerized by Mo(NAr')(CHCMe 2 Ph)(OBiphen CF3 )(thf) or W(NAr')(CHCMe 2 Ph)(( S )-OBiphen Me ) (OBiphen CF3 = 3,3'-di- tert -butyl-5,5'-bistrifluoromethyl-6,6'-dimethyl-1,1'-biphenyl-2,2'-diolate; ( S )-OBiphen Me = 3,3'-di- tert -butyl-5,5',6,6'-tetramethyl-1,1'-biphenyl-2,2'-diolate). The best initiator for ROMP of rac -PhEtNNBE was Mo(NAd)(CHMe 2 Ph)(pyr)(OHMT) at 0 °C, which led to a polymer that is biased (~80%) toward a cis,syndiotactic structure and that contains alternating enantiomers in the chain ( cis,syndio,alt -poly[( rac )-PhEtNNBE]).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Highly active atomically dispersed CoN 4 fuel cell cathode catalysts derived from surfactant-assisted MOFs: carbon-shell confinement strategy

Development of platinum group metal (PGM)-free catalysts for oxygen reduction reaction (ORR) is essential for affordable proton exchange membrane fuel cells. Herein, a new type of atomically dispersed Co doped carbon catalyst with a core–shell structure has been developed via a surfactant-assisted metal–organic framework approach. The cohesive interactions between the selected surfactant and the Co-doped zeolitic imidazolate framework (ZIF-8) nanocrystals lead to a unique confinement effect. During the thermal activation, this confinement effect suppressed the agglomeration of Co atomic sites and mitigated the collapse of internal microporous structures of ZIF-8. Among the studied surfactants, Pluronic F127 block copolymer led to the greatest performance gains with a doubling of the active site density relative to that of the surfactant-free catalyst. According to density functional theory calculations, unlike other Co catalysts, this new atomically dispersed Co–N–C@F127 catalyst is believed to contain substantial CoN 2+2 sites, which are active and thermodynamically favorable for the four-electron ORR pathway. The Co–N–C@F127 catalyst exhibits an unprecedented ORR activity with a half-wave potential (E 1/2 ) of 0.84 V (vs. RHE) as well as enhanced stability in the corrosive acidic media. It also demonstrated high initial performance with a power density of 0.87 W cm–2 along with encouraging durability in H 2 –O 2 fuel cells. The atomically dispersed Co site catalyst approaches that of the Fe–N–C catalyst and represents the highest reported PGM-free and Fe-free catalyst performance.

25 ENERGY STORAGE↗
DOE OSTI2016

Improving cyanobacterail O 2 -tolerance using CBS hydrogenase for hydrogen production

Cyanobacterial H 2 production is a viable path to renewable H 2 with water serving as the electron donor and sunlight the energy source. A grand challenge is the sensitivity of the underlying hydrogenase to O 2 , the latter an inherent byproduct of oxygenic photosynthesis. This challenge has been identified as a technical barrier in the Fuel Cell Technologies Office (FCTO) Multi-year Research, Development and Deployment Plan. One solution is to express in cyanobacterium an O 2 -tolerant hydrogenase to circumvent this barrier. We have uncovered an O 2 -tolerant hydrogenase from a photosynthetic bacterium Rubrivivax gelatinosus CBS (Casa Bonita Strain; hereafter “CBS”) with a half-life near 21 h when exposed to ambient O 2 . We sequenced the CBS genome and identified two sets of maturation machineries hyp1 and hyp2. Transcripts expression analysis and mutagenesis revealed that hyp1 is responsible for the assembly of the O 2 -tolerant CO-oxidation (Coo) hydrogenase and hyp2 is involved in the maturation of a H 2 -uptake hydrogenase. The structural genes encoding the O 2 -tolerant hydrogenase (cooLXUH) and maturation genes hyp1FABCDE were therefore cloned and expressed in the model cyanobacterium Synechocystis sp. PCC 6803. We obtained several recombinants displaying hydrogenase activity in a Synechocystis host lacking background activity, suggesting that the CBS hydrogenase is active in Synechocystis. Yet the activity is extremely low. To ensure balanced protein expression, we systematically optimized heterologous expression of 10 CBS genes by using stronger promoters and better ribosome binding site. Moreover we attempted the expression of cooM and cooK genes, verified to be important in CBS to afford activity. CooM is a very large protein and both CooM and CooK are membrane-associated. These properties limited our success in expressing both genes in Synechocystis, although they were both expressed in E. coli yet with no activity. This project was terminated in FY2016 due to the inability to generate a Synechocystis strain with consistent and active H 2 production activity. Nevertheless the research has led to a few high-impact publications and numerous conference presentations to increase global visibility of the DOE-funded research.

08 HYDROGEN↗
DOE OSTI2023

Quick Talk: Resilient Communities, Maryland

Groundswell, Inc., in partnership with the Maryland Energy Administration (MEA), Ayika Solutions, the National Renewable Energy Lab (NREL), and the Baltimore Office of Sustainability, is advancing a vision for resilient, community-centered energy systems in Maryland. This effort aligns with Groundswell's commitment to a clean energy economy that equitably benefits all communities, closing gaps in representation, wages, and access to wealth generation, savings, and local jobs within a diverse energy supply chain. Project Vision and Objectives The project emphasizes "energy resilience," defined as a community’s capacity to anticipate, adapt to, and swiftly recover from power disruptions through inclusive planning and technical solutions. The approach centers on Resilience Hubs—designated community facilities equipped to support residents before, during, and after power-related disruptions. These hubs offer emergency resources, coordinate communications, and deliver essential services while reducing carbon emissions, ultimately enhancing residents' quality of life. Additionally, Resilience Hubs foster social connections, support disaster preparedness, and provide spaces for community programming and everyday use. The goals of Resilient Communities Maryland include: Developing a replicable framework for community energy resilience, applicable beyond Maryland. Defining community-led indicators of social impact and resilience. Establishing equitable decision-making processes in project design and implementation. Informing MEA of practical, community-based resilience strategies to shape future state initiatives. Approach Groundswell and its partners prioritize collaborative engagement with local stakeholders, ensuring that solutions are responsive to each community's unique needs. By integrating feedback from residents, local organizations, and government entities, the team has developed a holistic model for resilience that balances immediate benefits, such as improved emergency response, with long-term gains in social equity and environmental sustainability. Key Outcomes This initiative has produced valuable resources and insights, including: A Community Energy Resilience Framework: Designed to guide other communities in establishing energy resilience strategies tailored to their specific needs. Case Studies: Documenting best practices and lessons learned from pilot projects to serve as models for future resilience efforts. Community-Driven Impact Metrics: Highlighting the positive social impacts that resilience initiatives can bring, such as improved social connectedness and local decision-making power. Recommendations for MEA: Offering evidence-based insights to inform policies and funding opportunities that support resilient energy infrastructure in vulnerable communities. Next Steps Groundswell's final report will detail findings, including the potential for scaling resilience hubs across Maryland and other regions, with a focus on equitable access and community-driven outcomes. This project underscores the importance of aligning energy resilience with social equity, reinforcing community agency, and building systems that withstand and recover from future challenges effectively and sustainably.

14 SOLAR ENERGY↗