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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 541 records · Page 30
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Simultaneous Discovery of Positive and Negative Interactions Among Rhizosphere Bacteria Using Microwell Recovery Arrays

Understanding microbe-microbe interactions is critical to predict microbiome function and to construct communities for desired outcomes. Investigation of these interactions poses a significant challenge due to the lack of suitable experimental tools available. Here we present the microwell recovery array (MRA), a new technology platform that screens interactions across a microbiome to uncover higher-order strain combinations that inhibit or promote the function of a focal species. One experimental trial generates 10 4 microbial communities that contain the focal species and a distinct random sample of uncharacterized cells from plant rhizosphere. Cells are sequentially recovered from individual wells that display highest or lowest levels of focal species growth using a high-resolution photopolymer extraction system. Interacting species are then identified and putative interactions are validated. Using this approach, we screen the poplar rhizosphere for strains affecting the growth of Pantoea sp. YR343, a plant growth promoting bacteria isolated from Populus deltoides rhizosphere. In one screen, we montiored 3,600 microwells within the array to uncover multiple antagonistic Stenotrophomonas strains and a set of Enterobacter strains that promoted YR343 growth. The later demonstrates the unique ability of the platform to discover multi-membered consortia that generate emergent outcomes, thereby expanding the range of phenotypes that can be characterized from microbiomes. This knowledge will aid in the development of consortia for Populus production, while the platform offers a new approach for screening and discovery of microbial interactions, applicable to any microbiome.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Ultra-Fast Laser Fabrication of Alumina Micro-Sample Array and High-Throughput Characterization of Microstructure and Hardness

In the light of recent advances in material informatics, there is a great demand for high-throughput approaches of sample fabrication and property characterization. Currently, no high-throughput approach has been demonstrated for the fast sampling of the microstructure and the correlated properties. In this paper, we demonstrate the ultra-fast fabrication of an alumina sample array and the high-throughput hardness characterization of these sample units. The alumina sample array was fabricated using picosecond (PS) laser micromachining and CO2 laser sintering within a short time (i.e., less than a few minutes). After laser sintering, the hardness of these sample units was characterized using micro-indentation, and the microstructure was observed using scanning electron microscopy (SEM). In each sample unit, the microstructure was uniform for the entire top surface and within about 20 µm depth from the top surface. The relative density (RD) and corresponding micro-hardness of the sample units was found to continuously vary over a wide range from 89% RD with 600 kgf/mm2 hardness to 99% RD with 1609 kgf/mm2 hardness. For these laser-sintered samples, the correlation of hardness and relative density of the alumina matched well with the literature reports on sintered alumina obtained using conventional low-throughput furnace sintering experiments.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Influence of Time and Frequency Domain Wave Forcing on the Power Estimation of a Wave Energy Converter Array

Industry-specific tools for analyzing and optimizing the design of wave energy converters (WECs) and associated power systems are essential to advancing marine renewable energy. This study aims to quantify the influence of phase information on the device power output of a virtual WEC array. We run the phase-resolving wave model FUNWAVE-TVD (Total Variation Diminishing) to generate directional waves at the PacWave South site offshore from Newport, Oregon, where future WECs are expected to be installed for testing. The two broad cases presented correspond to mean wave climates during warm months (March–August) and cold months (September–February). FUNWAVE-TVD time series of sea-surface elevation are then used in WEC-Sim, a time domain numerical model, to simulate the hydrodynamic response of each device in the array and estimate their power output. For comparison, WEC-Sim is also run with wave energy spectra calculated from the FUNWAVE-TVD simulations, which do not retain phase information, and with wave spectra computed using the phase-averaged model Simulating WAves Nearshore (SWAN). The use of spectral data in WEC-Sim requires a conversion from frequency to time domain by means of random superposition of wave components, which are not necessarily consistent because of the linear assumption implicit in this method. Thus, power response is characterized by multiple realizations of the wave climates.

13 HYDRO ENERGY↗
DOE OSTI2023

Using Vertically Aligned Carbon Nanofiber Arrays on Rigid or Flexible Substrates for Delivery of Biomolecules and Dyes to Plants

The delivery of biomolecules and impermeable dyes to intact plants is a major challenge. Nanomaterials are up-and-coming tools for the delivery of DNA to plants. As exciting as these new tools are, they have yet to be widely applied. Nanomaterials fabricated on rigid substrate (backing) are particularly difficult to successfully apply to curved plant structures. This study describes the process for microfabricating vertically aligned carbon nanofiber arrays and transferring them from a rigid to a flexible substrate. We detail and demonstrate how these fibers (on either rigid or flexible substrates) can be used for transient transformation or dye (e.g., fluorescein) delivery to plants. We show how VACNFs can be transferred from rigid silicon substrate to a flexible SU-8 epoxy substrate to form flexible VACNF arrays. Further, to overcome the hydrophobic nature of SU-8, fibers in the flexible film were coated with a thin silicon oxide layer (2-3 nm). To use these fibers for delivery to curved plant organs, we deposit a 1 µL droplet of dye or DNA solution on the fiber side of VACNF films, wait 10 min, place the films on the plant organ and employ a swab with a rolling motion to drive fibers into plant cells. With this method, we have achieved dye and DNA delivery in plant organs with curved surfaces.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

MIRC-X: A Highly Sensitive Six-telescope Interferometric Imager at the CHARA Array

Michigan InfraRed Combiner-eXeter (MIRC-X) is a new highly sensitive six-telescope interferometric imager installed at the CHARA Array that provides an angular resolution equivalent of up to a 330 m diameter baseline telescope in J- and H-band wavelengths ((λ/(2B))∼0.6 mas). We upgraded the original Michigan InfraRed Combiner (MIRC) instrument to improve sensitivity and wavelength coverage in two phases. First, a revolutionary sub-electron noise and fast-frame-rate C-RED ONE camera based on an SAPHIRA detector was installed. Second, a new-generation beam combiner was designed and commissioned to (i) maximize sensitivity, (ii) extend the wavelength coverage to J band, and (iii) enable polarization observations. A low-latency and fast-frame-rate control software enables high-efficiency observations and fringe tracking for the forthcoming instruments of the CHARA Array. Since mid-2017, MIRC-X has been offered to the community and has demonstrated best-case H-band sensitivity down to 8.2 correlated magnitude. MIRC-X uses single-mode fibers to coherently combine the light from six telescopes simultaneously with an image-plane combination scheme and delivers a visibility precision better than 1%, and closure phase precision better than 1°. MIRC-X aims at (i) imaging protoplanetary disks, (ii) detecting exoplanets with precise astrometry, and (iii) imaging stellar surfaces and starspots at an unprecedented angular resolution in the near-infrared. In this paper, we present the instrument design, installation, operation, and on-sky results, and demonstrate the imaging capability of MIRC-X on the binary system ι Peg. The purpose of this paper is to provide a solid reference for studies based on MIRC-X data and to inspire future instruments in optical interferometry.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

Commissioning the H i Observing Mode of the Beam Former for the Cryogenically Cooled Focal L-band Array for the GBT (FLAG)

We present the results of commissioning observations for a new digital beam-forming back end for the Focal plane L-band Array for the Robert C. Byrd Green Bank Telescope (FLAG), a cryogenically cooled Phased Array Feed (PAF) with the lowest measured T {sub sys}/η of any PAF outfitted on a radio telescope to date. We describe the custom software used to apply beam-forming weights to the raw element covariances to create research-quality spectral-line images for the new fine-channel mode, study the stability of the beam weights over time, characterize FLAG’s sensitivity over a frequency range of 150 MHz, and compare the measured noise properties and observed distribution of neutral hydrogen emission from several extragalactic and Galactic sources with data obtained with the current single-pixel L-band receiver. These commissioning runs establish FLAG as the preeminent PAF receiver currently available for spectral-line observations on the world’s major radio telescopes.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2018

Deep Very Large Array Observations of the Merging Cluster CIZA J2242.8+5301: Continuum and Spectral Imaging

Despite the progress that has been made in understanding radio relics, there are still open questions regarding the underlying particle acceleration mechanisms. In this paper, we present deep 1–4 GHz Very Large Array (VLA) observations of CIZA J2242.8+5301 ( z = 0.1921), a double radio relic cluster characterized by small projection on the plane of the sky. Our VLA observations reveal, for the first time, the complex morphology of the diffuse sources and the filamentary structure of the northern relic. Additionally, we discover new, faint, diffuse radio emission extending north of the main northern relic. Our Mach number estimates for the northern and southern relics, based on the radio spectral index map obtained using the VLA observations and existing LOw Frequency ARray (LOFAR) and Giant Metrewave Radio Telescope data, are consistent with previous radio and X-ray studies ( and ). However, color–color diagrams and models suggest a flatter injection spectral index than the one obtained from the spectral index map, indicating that projection effects might be not entirely negligible. The southern relic consists of five "arms." Embedded in it, we find a tailed radio galaxy that seems to be connected to the relic. A spectral index flattening, where the radio tail connects to the relic, is also measured. We propose that the southern relic may trace AGN fossil electrons that are reaccelerated by a shock, with an estimated strength of . High-resolution mapping of other tailed radio galaxies also supports a scenario where AGN fossil electrons are revived by the merger event and could be related to the formation of some diffuse cluster radio emission.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2019

BICEP2/Keck Array XI: Beam Characterization and Temperature-to-Polarization Leakage in the BK15 Data Set

Precision measurements of cosmic microwave background (CMB) polarization require extreme control of instrumental systematics. In a companion paper we have presented cosmological constraints from observations with the BICEP2 and Keck Array experiments up to and including the 2015 observing season (BK15), resulting in the deepest CMB polarization maps to date and a statistical sensitivity to the tensor-to-scalar ratio of σ ( r ) = 0.020. In this work we characterize the beams and constrain potential systematic contamination from main beam shape mismatch at the three BK15 frequencies (95, 150, and 220 GHz). Herein far-field maps of 7360 distinct beam patterns taken from 2010–2015 are used to measure differential beam parameters and predict the contribution of temperature-to-polarization leakage to the BK15 B -mode maps. In the multifrequency, multicomponent likelihood analysis that uses BK15, Planck , and Wilkinson Microwave Anisotropy Probe maps to separate sky components, we find that adding this predicted leakage to simulations induces a bias of Δ r = 0.0027 ± 0.0019. Future results using higher-quality beam maps and improved techniques to detect such leakage in CMB data will substantially reduce this uncertainty, enabling the levels of systematics control needed for BICEP Array and other experiments that plan to definitively probe large-field inflation.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2021

Acoustic MEMS Sensor Array for Quench Detection of CICC Superconducting Cables

A novel quench detection method using microelectro- mechanical system (MEMS) sensor technology has been investigated in use for high temperature superconducting (HTS) conductors such REBCO tape cables. The sensor array along a superconducting cable, such as a cable-in-conduit-conductor (CICC), is installed in a cooling channel. It will allow sensitive and quick detection for a local quench of a superconducting cable. This work has confirmed that a quench of a single REBCO tape can be detected in liquid nitrogen by a MEMS piezoelectric microphone sensor. The quench detection design utilizing a MEMS sensor array method is discussed for the case of a toroidal field (TF) magnets of a fusion Tokamak device.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2018

Thin film photovoltaic devices with microlens arrays

Textured transparent layers are formed on the incident light receiving surface of thin film solar cells to increase their efficiency by altering the incident light path and capturing a portion of the light reflected at the MLA. The textured transparent layer is an array of lenses of micrometer proportions such as hemispheres, hemi-ellipsoids, partial-spheres, partial-ellipsoids, cones, pyramids, prisms, half cylinders, or combinations thereof. A method of forming the textured transparent layer to the light incident surface of the solar cell is by forming an array of lenses from a photocurable resin and its subsequent curing. The photocurable resin can be applied by inkjet printing or can be applied by roll to roll imprinting or stamping with a mold.

14 SOLAR ENERGY↗
DOE OSTI2019

Fuel nozzle having respective arrays of pre-mixing conduits with respective vortex generators

A fuel nozzle including vortex generating features for use in a combustion turbine engine is provided. An array of inner pre-mixing conduits (20) extends between an inlet end (14) and an outlet end (16) of the nozzle. An array of outer pre-mixing conduits (22) may be disposed radially outwardly relative to the inner pre-mixing conduits (20). A fuel-directing tube (24) includes fuel-directing arms (26) structured to direct fuel flow into the outer pre-mixing conduits (22) to be mixed with a flow of air. The fuel-directing arms include a bluff structural arrangement (30) that may be disposed upstream of fuel injection locations (32, 32') into the outer pre-mixing conduits (22). The proposed nozzle is believed to provide superior micro-mixing capability, such as by increasing the depth of penetration of jets of fuel in a cross-flow of air, and/or formation of vortices in a wake zone downstream from the vortex generating features.

Meadows, Joseph↗
DOE OSTI2019

Ultrafast all-optical modulation of the visible and infrared spectrum with nanorod arrays

Disclosed herein is a method of optical modulation, the method comprising irradiating an optical switch with a control beam at a first control time and irradiating the optical switch with a signal beam at a signal time. The transmitted intensity of the signal beam in a direction depends on the delay time between the first control time and the signal time and the transmitted intensity of the signal beam in the direction is detectably different than a static signal. The optical switch comprises a nanorod array, the nanorod array comprising a plurality of nanorods extending outwardly from a substrate.

Chang, Robert P. H.↗
DOE OSTI2019

Infinite Array Comparison for Fast and Slow Systems in KENO V.a for SCALE 6.1.3

The purpose of this study is to quantitatively calculate the difference between reflective boundary condition (mirror) and large finite arrays in SCALE 6.1.3. The conclusions reached during this project are based on analysis of data calculated for the modeled base unit. These conclusions can be expanded to other systems; however, each unique system must be analyzed to determine the precise effectively infinite array size for that system.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Flexure-based, tip-tilt-piston actuation micro-array

A flexure-based micro-array having a plurality of micro-assemblies, each comprising: an object; and at least three electrostatic actuation modules for tipping, tilting, and/or piston-actuating the object, each actuation module comprising: a base with first and second electrodes electrically isolated from each other; an electrically conductive lever arm; a first flexure bearing suspending the lever arm adjacent the first and second electrodes so that electrical activation of at least one of the first and second electrodes produces an electrostatic moment of force on the lever arm to resiliently bias the first flexure bearing and pivot the lever arm about a fulcrum; and a second flexure bearing connecting the lever arm to the object at a connection location that is different from other connection locations of the other actuation modules so that pivoting the lever arm about the fulcrum induces the second flexure bearing to pivot the object about an object pivot axis defined between two of the other connection locations while the second flexure bearing decouples the lever arm from object displacements induced by two of the other actuation modules connected to the two other connection locations defining the object pivot axis, wherein the plurality of micro-assemblies are arranged with the objects juxtaposed in a substantially 2D array.

42 ENGINEERING↗
DOE OSTI2019

Driver circuitry and systems for high current laser diode arrays

Apparatuses, methods, and systems are disclosed to drive pumping laser diode arrays. In implementations, an integrated system can be constructed to in a compact, efficient and cost-effective manner and to meet the needs of driving laser diode arrays in various diode pumped solid state laser applications. The disclosed implementations include individual laser diode drivers or pulsers, methods of communicating with laser diode drivers, and methods of controlling the pulse shape of each laser diode driver.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

Tailored nanopost arrays (NAPA) for laser desorption ionization in mass spectrometry

The production and use of semiconducting nanopost arrays made by nanofabrication is described herein. These nanopost arrays (NAPA) provide improved laser ionization yields and controllable fragmentation with switching or modulation capabilities for mass spectrometric detection and identification of samples deposited on them.

36 MATERIALS SCIENCE↗
DOE OSTI2020

High-power ultraviolet (UV) and vacuum ultraviolet (VUV) lamps with micro-cavity plasma arrays

A plasma lamp includes plates that are approximately parallel, with at least one array of microcavities formed in a surface of at least one plate. When desirable, the plates are separated a fixed distance by spacers with at least one spacer being placed near the plate's edge to form a hermetic seal therewith. A gas makes contact with the microcavity array. Electrodes capable of delivering a time-varying voltage are located on the surface of each plate. At least one electrode is located on an exterior surface of at least one interior plate. Optionally, protective windows may be placed over the electrodes. The application of the time-varying voltage interacts with the gas to form a glow discharge plasma in the microcavities and the fixed volume between the plates (when present). The glow discharge plasma efficiently and uniformly emits UV/VUV radiation over the entire surface of the lamp.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Droplet array for single-cell analysis

Techniques, systems, and devices are described for implementing a droplet array for single-cell analysis. A method of conducting single-cell analysis comprises generating a plurality of droplets, wherein each of the plurality of droplets contains a core material surrounded by a protective shell; loading the plurality of droplets, via a carrying fluid, onto an array including a plurality of trap structures, wherein the plurality of droplets are held by the plurality of trap structures; selecting a target droplet, held by a trap structure, from the plurality of droplets; and releasing the target droplet from the trap structure.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗