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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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In this project, Lumileds has developed a high-power LED emitter with increased efficacy to improve luminaire performance in directional lighting applications. The efficacy gain was realized by an integrated development effort with improvements in each of the LED technology elements: epitaxy, die, phosphor and package.
Cree, Inc. conducted a narrow-band downconverter (NBD) materials development and implementation program which will lead to warm-white LED light engines with enhanced efficacy via improved spectral efficiency with respect to the human eye response. New red (600-630nm) NBD materials could result in as much as a 20% improvement in warm-white efficacy at high color quality relative to conventional phosphor-based light sources. Key program innovations included: high quantum yield; narrow peak width; minimized component-level losses due to “cross-talk” and light scattering among red and yellow-green downconverters; and improved reliability to reach parity with conventional phosphors. NBD-enabled downconversion efficiency gains relative to conventional phosphors yielded an end-of-project LED light engine efficacy of >160 lm/W at room temperature and 35 A/cm2, with a correlated color temperature (CCT) of ~3500K and >90 CRI (Color Rending Index). NBD-LED light engines exhibited equivalent luminous flux and color point maintenance at >1,000 hrs. of highly accelerated reliability testing as conventional phosphor LEDs. A demonstration luminaire utilizing an NBD-based LED light engine had a steady-state system efficacy of >150 lm/W at ~3500K and >90 CRI, which exceeded the 2014 DOE R&D Plan luminaire milestone for FY17 of >150 lm/W at just 80 CRI.
In this project, OLEDWorks developed a high efficacy and cost-effective flexible OLED lighting system which could reduce the cost of OLED light by introducing a combination of printable and scalable scattering type internal light extraction (ILE) and transparent conductive silver nanowire technologies that are compatible with roll-to-roll (R2R) processing methods. High efficacy was achieved by co-optimization of the internal light extraction, silver nanowire and ITO anodes, and stacked white OLED structure to reduce unwanted absorption, increase the outcoupling efficiency, and lower the OLED voltage. At the end of Phase I of this project a power efficacy of 90 lm/W was demonstrated in a flexible OLED lighting device based on ultrathin bendable glass. Without much additional work, the milestone of 100 lm/W is certainly within reach, and with further work on light extraction and white OLED materials, we believe 120 lm/W or higher is achievable within the next few years.
The High Efficacy Validation of Hydride Mega Tanks at ARIES Lab (HEVHY METAL) project will advance materials-based hydrogen storage technologies by large-scale demonstration and identification of deployment pathways. This includes demonstrating how two metal hydride HY2MEGA subsystems are installed with megawatt-scale green hydrogen infrastructure; validating its performance via rates, capacities, and efficiencies; and investigating supply and demand side techno-economics.
The High Efficacy Validation of Hydride Mega Tanks at ARIES Lab (HEVHY METAL) project will advance materials-based hydrogen storage technologies by large-scale demonstration and identification of deployment pathways. This includes demonstrating how two metal hydride HY2MEGA subsystems are installed with megawatt-scale green hydrogen infrastructure; validating its performance via rates, capacities, and efficiencies; and investigating supply and demand side techno-economics.
We present a novel graphical user interface (GUI) that facilitates high-efficacy collection of perceptual similarity opinions of a user in an effective and intuitive manner. The GUI is based on a hybrid mechanism that combines ranking and rating. Namely, it presents a base image for rating its similarity to seven peripheral images that are displayed simultaneously following a circular layout. The user is asked to report the base image s pairwise similarity to each peripheral image on a fixed scale while preserving the relative ranking among all peripheral images. The collected data are then used to predict the user s subjective opinions regarding the perceptual similarity of images. We tested this new approach against two methods commonly used in perceptual similarity studies: (1) a ranking method that presents triplets of images for selecting the image pair with the highest internal similarity and (2) a rating method that presents pairs of images for rating their relative similarity on a fixed scale. We aimed to determine which data collection method was the most time efficient and effective for predicting a user s perceptual opinions regarding the similarity of mammographic masses. Our study was conducted with eight individuals. By using the proposed GUI, we were able to derive individual user profiles that were 41.4% to 46.9% more accurate than those derived with the other two data collection GUIs. The accuracy improvement was statistically significant.
Zymomonas mobilis is a promising biofuel producer due to its high alcohol tolerance and streamlined metabolism that efficiently converts sugar to ethanol. Z. mobilis genes are poorly characterized relative to those of model bacteria, hampering our ability to rationally engineer the genome with pathways capable of converting sugars from plant hydrolysates into valuable biofuels and bioproducts. Many of the unique properties that make Z. mobilis an attractive biofuel producer are controlled by essential genes; however, these genes cannot be manipulated using traditional genetic approaches (e.g., deletion or transposon insertion) because they are required for viability. CRISPR interference (CRISPRi) is a programmable gene knockdown system that can precisely control the timing and extent of gene repression, thus enabling targeting of essential genes. Here, we establish a stable, high-efficacy CRISPRi system in Z. mobilis that is capable of perturbing all genes—including essential genes. We show that Z. mobilis CRISPRi causes either strong knockdowns (>100-fold) using single guide RNA (sgRNA) spacers that perfectly match target genes or partial knockdowns using spacers with mismatches. We demonstrate the efficacy of Z. mobilis CRISPRi by targeting essential genes that are universally conserved in bacteria, are key to the efficient metabolism of Z. mobilis, or underlie alcohol tolerance. Our Z. mobilis CRISPRi system will enable comprehensive gene function discovery, opening a path to rational design of biofuel production strains with improved yields.
The computer code relates to human nature studies and more specifically to a novel graphical user interface (GUI) that facilitates high-efficacy collection of perceptual similarity opinions of a user in an effective and intuitive manner. The GUI presents a base image for rating its similarity to seven peripheral images that are displayed simultaneously following a circular layout. The user is asked to report the base image's pairwise similarity to each peripheral image on a fixed scale while preserving the relative ranking among all peripheral images. The collected data are then used to predict the user's subjective opinions regarding the perceptual similarity of images.
Cree successfully executed an 18-month Product Development research program which yielded significant advancements in solid-state luminaire efficacy, optics design, color tunability, and light utilization. The synergistic development of these technologies was intended to result in ultra-high efficacy luminaires with superior beam definition over conventional fixtures, leading to higher spatial light utilization based on application needs. In addition, program-derived technologies are expected to directly benefit automated dimming which reduces time-averaged lighting energy consumption. Program innovations were made in the areas of: light engines; low-profile modular optical designs; ultra-compact color sensors; and low-cost scene sensors for accurate occupancy detection in challenging application settings. Cree’s DOE-supported work in these technology focus areas will set the stage for further development toward productization at Cree.
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In this project, OLEDWorks and partners made significant progress in advancing OLED light extraction technology. Improving light extraction efficiency remains one of the most important research topics for OLEDs. Current state-of-the-art white OLED products extract only about 50% of the photons that are generated within the device. Promising new light extraction concepts, such as those based on sub electrode micro lens arrays (SEMLAs), were explored in this project with the potential to achieve extraction efficiency of 60% or higher. Flexible thin glass substrates with integrated SEMLAs were successfully fabricated and scaled to large area. When combined with optimized high efficiency stacked white OLED structures, we achieved the program goals of 120 LPW efficacy and long lifetime more than 100,000 hours.
ABSTRACT Shiga toxin-producingEscherichia coliinfections are difficult to treat due to the risk of antibiotic-induced stress upregulating the production of toxins, medical treatment is consequently limited to supportive care to prevent the development of hemolytic uremic syndrome (HUS). Here, we introduce a potentially therapeutic humanized mouse monoclonal antibody (Hu-mAb 2-5) targeting Stx2a, the most common Shiga toxin subtype identified from outbreaks. We demonstrate that Hu-mAb 2-5 has low immunogenicity in healthy adultsex vivoand high neutralizing efficacyin vivo, protecting mice from mortality and HUS-related tissue damage.
The separation of Radium (Ra) from interfering chemical analogues is of major importance for both the accurate measurement of Ra-226 in environmental samples and the preparation of radium targets destined for medical isotope production. The adsorption behavior of Ra, Barium (Ba), and Strontium (Sr) was investigated on multiple crown-ether-based proprietary extraction chromatographic resins developed by TrisKem Int. Among these, the TK101 resin, characterized by a novel room-temperature ionic liquid (RTIL) dual extractant–solvent system, demonstrated enhanced affinity and selectivity, particularly at low acid concentrations, achieving a D w of 3477 ± 73 for Ra in 0.04 M HNO₃, whereas the maximum Ra D w obtained with the traditional Sr resin in 8 M HNO 3 was only 12.33 ± 0.4. In 0.04 M HNO 3 , a Ra distribution ratio (D w ) of 776 was achieved within 1 min, indicating rapid uptake kinetics. The adsorption capacities were estimated at 19.6 ± 0.1 mg/g for Ba and 12.0 ± 0.2 mg/g for Sr. However, competing alkali metals significantly reduced alkaline earth metal uptake, indicating that the TK101 resin is best suited for radium purification following a preconcentration step to minimize matrix effects in high salinity samples. Dynamic column studies confirmed the strong chromatographic performance of the TK101 resin, with no significant Ba or Sr breakthrough in the Ra fraction and a Ra recovery of 87 ± 2.8%. These results demonstrate the potential of the TK101 resin for selective radium separation in analytical and radiochemical applications.
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Amazing performance in GaInN/GaN based LEDs has become possible by advanced epitaxial growth on a wide variety of substrates over the last decade. An immediate push towards product development and worldwide competition for market share have effectively reduced production cost and generated substantial primary energy savings on a worldwide scale. At all times of the development, this economic pressure forced very fundamental decisions that would shape huge industrial investment. One of those major aspects is the choice of epitaxial growth substrate. The natural questions are to what extend a decision for a certain substrate will limit the ultimate performance and to what extent, the choice of a currently more expensive substrate such as native GaN could overcome any of the remaining performance limitations. Therefore, this project has set out to explore what performance characteristic could be achieved under the utilization of bulk GaN substrate. Our work was guided by the hypotheses that line defects such as threading dislocations in the active region should be avoided and the huge piezoelectric polarization needs to be attenuated – if not turned off – for higher performing LEDs, particularly in the longer wavelength green and deep green portions of the visible spectrum. At their relatively lower performance level, deep green LEDs are a stronger indicator of relative performance improvements and seem particular sensitive to the challenges at hand.
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A hydrogen-based long duration storage technology will be demonstrated with ARIES-Flatirons assets for the GKN Hydrogen, a division of GKN Powder Metallurgy, HY2MEGA metal hydride storage subsystem. The project will design and execute experiments that emulate commercial use cases for load management, backup power, and grid resiliency in remote, underserved communities.