Laser Disdrometer / Daily Standardized Files
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
SEARCH · Engineering Papers
Results for “hail”
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.
Laser Disdrometer / Daily Standardized Files
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Daily Standardized Files
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Daily Standardized Files
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Daily Standardized Files
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Standardized Data
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Standardized Data
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Standardized Data
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Standardized Data
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Laser Disdrometer / Standardized Data
The Parsivel2 Laser Disdrometers provide accurate measurements of precipitation, hail and snow. They also provide droplet size distributions.
17 WIND ENERGY↗
Development and Validation of Low-Cost, High-Reflectance Composite CSP Facets: SIPS Final Report
This work investigates the various challenges associated with developing heliostat structural composite facets using 1 mm glass mirrors. Such facets are desirable for Concentrating Solar Power because 1 mm glass mirrors provide an absolute increase in reflectivity of 2-3 % over the industry standard of 4 mm glass mirrors. Prototypes of paraboloid composite facets with 1 mm glass mirrors were constructed that have a root mean square slope error on the order of 2 mrad while achieving greater than 96% reflectivity. These facets were constructed using a low-quality aluminum mold and a bill of materials that show potential to achieve cost parity with existing 4 mm glass mirrors supported by structural steel. The facets produced were able to survive up to 50 mm hail ball impacts and were robust against accelerated environmental cycling designed to expose durability concerns. Further work is needed to develop a scalable and cost-effective manufacturing process with a similar bill of materials.
14 SOLAR ENERGY↗
On-Demand Transit: Features, Benefits, Challenges, Costs, and Evaluation
The U.S. Department of Energy's National Laboratory of the Rockies works in partnership with communities and transit agencies across North America to support and evaluate customized on-demand transit (ODT) systems. ODT, also known as on-demand mobility or microtransit, is a flexible form of public mobility. Unlike traditional fixed-route transit, ODT adjusts where and when service is provided rather than following predetermined schedules and routes. Having evolved from commercial ride-hailing business models, ODT leverages smartphone connectivity and real-time route optimization to provide highly responsive and dynamic service. ODT trips, which are usually shared, can function as a standalone service or as a first-/last-mile service connecting riders to other types of transit.
24 POWER TRANSMISSION AND DISTRIBUTION↗
From Fundamental Interfacial Reaction Kinetics to Macroscopic Current–Voltage Characteristics: Case Study of Solid Acid Fuel Cell Limitations and Possibilities
The unique properties of solid acid electrolytes, in particular CsH 2 PO 4 , are in many ways ideal for fuel cell operation. However, the technology is constrained by high cathode overpotentials. Here a simplified cathode geometry is employed to obtain the fundamental electrochemical parameters (exchange current density and charge transfer coefficient) describing the oxygen reduction reaction (ORR) at the CsH 2 PO 4 -Pt-gas interface. The parameters are incorporated into a 1D model of the voltage–current characteristics of realistic SAFC cathodes, which reproduced the measured polarization behavior of such cathodes without recourse to fitting adjustable parameters. Following this validation, the model is utilized to evaluate the impact of changes to cathode properties, microstructure, and operating conditions. Of these, the charge transfer coefficient, measured to have a value of ≈0.6 for ORR on Pt in the SAFC cathode environment, is found to have the greatest impact on power output. Nevertheless, even without material modifications, a combination of microstructural and operational modifications are identified with projected performance metrics meeting Department of Energy targets (0.8 V at 300 mA cm –2 , and peak power density of 1 W cm –2 ), albeit at high Pt loadings. However, the analysis indicates that truly meaningful advances will likely necessitate the discovery of alternative ORR catalysts.
36 MATERIALS SCIENCE↗
Pristine Interface between Lithium Lanthanum Zirconate and Lithium Manganese Oxide by Pulsed Laser Deposition
Solid state lithium-ion batteries have garnered increasing interest in recent years due to several potential advantages over liquid-electrolyte based systems. The possibility of integrating the lithium garnet oxide, Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (LLZTO), with the high voltage cathode, spinel Li x Mn 2 O 4 (LMO), is evaluated here. Thin film bilayer structures are prepared by pulsed laser deposition on MgO (001) substrates and characterized by x-ray diffraction and transmission electron microscopy. The LLZTO is grown by an alternating layer-by-layer deposition of LLZTO and Li 3 N and subsequently annealed for several hours at 575 °C to promote crystallinity. Growth of crystalline LMO with a pristine interface to LLZTO is achieved by gentle heat treatment (500 °C) to remove surface carbonate from the electrolyte and by cathode growth at a low temperature of 250 °C. Higher temperature depositions (330 – 450 °C) result in reaction between the two materials and the appearance of Li 2 MnO 3 , which may be in part due to the presence of excess lithium in the electrolyte layer. Because fully lithiated LiMn 2 O 4 has a voltage of ≈3.7 V versus Li+/Li, the observation of a well-defined interface, free of impurity phases and with no interdiffusion of elements, indicates LLZTO is stable to at least 3.7 V.
Garnet LLZO↗
Microstructural Underpinnings of Giant Intrinsic Exchange Bias in Epitaxial NiCo 2 O 4 Thin Films
Understanding intrinsic exchange bias in nominally single-component ferromagnetic or ferrimagnetic materials is crucial for simplifying related device architectures. However, the mechanisms behind this phenomenon and its tunability remain elusive, which hinders the efforts to achieve unidirectional magnetization for widespread applications. Inspired by the high tunability of ferrimagnetic inverse spinel NiCo 2 O 4 , the origin of intrinsic exchange bias in NiCo 2 O 4 (111) films deposited on Al 2 O 3 (0001) substrates are investigated. The comprehensive characterizations, including electron diffraction, X-ray reflectometry and spectroscopy, and polarized neutron reflectometry, reveal that intrinsic exchange bias in NiCo 2 O 4 (111)/Al 2 O 3 (0001) arises from a reconstructed antiferromagnetic rock-salt Ni x Co 1-x O layer at the interface between the film and the substrate due to a significant structural mismatch. Remarkably, by engineering the interfacial structure under optimal growth conditions, it can achieve exchange bias larger than coercivity, leading to unidirectional magnetization. Such giant intrinsic exchange bias can be utilized for realistic device applications. This work establishes a new material platform based on NiCo 2 O 4 , an emergent spintronics material, to study tunable interfacial magnetic and spintronic properties.
36 MATERIALS SCIENCE↗
pH‐Mediated Strong Metal‐Support Interaction Construction Through Dynamic Fermi Level Tuning
The metal–support interface is central to governing catalytic transformations. While strong metal–support interaction (SMSI) is an established strategy to tailor the morphology and electronic properties of supported metal catalysts, the role of interfacial charge redistribution in SMSI formation remains poorly understood and rarely leveraged. Here, in this study, we report a dual-stimuli approach that combines pH modulation with ultrasonication to mediate SMSI construction in aqueous solution through dynamic Fermi level tuning. By leveraging in situ pH-driven charge redistribution at the metal–support interface, we achieve controllable SMSI encapsulation of metal nanoparticles, as verified by electrochemical analysis, work function measurements, and x-ray-based techniques. The resulting catalysts exhibit tunable SMSI features and deliver enhanced activity and selectivity in hydrogenation reactions. This work establishes a facile strategy to modulate catalyst structure and electronic properties by exploiting Fermi level variation as a driving force, thereby advancing rational SMSI design and catalytic performance across diverse environments.
77 NANOSCIENCE AND NANOTECHNOLOGY↗
Controlling Exsolution Dynamics in High‐Entropy Oxides for Highly Active and Selective Acetylene Semi‐Hydrogenation
Exsolution-derived catalysts feature robust metal–support interactions that enhance catalytic performance; yet achieving precise control over exsolution dynamics in multicomponent oxides remains challenging. In this study, we demonstrate that exsolution behavior in high-entropy oxides (HEOs) can be rationally tuned through coupled lattice- and valence-engineering to create a highly active and selective catalyst for acetylene semi-hydrogenation. Incorporation of Li + into a rock salt-structured HEO (LiNiMgCuZnCoO x and LiHEO) induces local lattice distortion, generates oxygen vacancies, and partially oxidizes Co sites from Co 2+ to Co 3+ , collectively modulating local charge redistribution. This strategy enables facilitated Cu nanoparticle exsolution and alters the exsolution sequence from Cu 0 > Ni 0 > Co 0 in pristine HEO to Cu 0 > Co 0 > Ni 0 in the LiHEO. The resulting catalyst via controlled exsolution exhibits superior activity and ethylene selectivity, outperforming state-of-the-art transition metal systems. This work establishes entropy-enabled lattice and valence engineering as a facile route to programmable exsolution for enhanced catalysis.
36 MATERIALS SCIENCE↗
Interfacial magnetization enhancement and the perpendicularly magnetized component in Fe16N2 thin films
A detailed study of depth-resolved magnetization and microstructure of Fe16N2 thin films on MgO (001) and MgAl2O4 (001) substrates and Fe and Cr seed layers is presented. Two aspects of the magnetic properties of Fe16N2 thin films are discussed. First, magnetization enhancement at the interface is observed. Strain and nitrogen deficiency are discussed as possible interfacial mechanisms contributing to this enhancement. Second, the perpendicularly magnetized component (PMC) is identified in Fe16N2 thin films. Correlation with microstructural observations suggests that the PMC is associated with V-shaped grains that are not fully confined within the continuous Fe16N2 layer.
Hang, Xudong [University of Minnesota]↗