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At least 325 records · Page 18

Seismoacoustic Data Fusion for Ground Coupled Airwaves: a FACT Case Study for Calibration and Array Processing

This report covers an inquiry into seismoacoustic array processing using infrasound arrivals combined with resulting Ground Coupled Airwaves (GCA) that are present on collocated seismic sensors. In preparation, data calibration and denoising is completed for a seismoacoustic sensor array that was deployed at the Facility for Acceptance, Calibration, and Testing on Kirtland Airforce Base from August through September of 2021. The events of interest for this study are small, local explosive sources that lead to short duration, impulsive signals on the instruments. The goal is to determine if combining infrasound signals with the corresponding GCAs on collocated seismic sensors can be used to improve the results returned by automated signal detection and characterization (e.g., back azimuth estimates). Preparation for seismic and infrasound data involves removing the instrument response so that sensors have flat power spectra over the frequency range 0.1-10 Hz, where signal from events of interest may be detected. After instrument response removal, deployment conditions specific to this array require a retrospective noise analysis to determine station emplacement characteristics. Once all data is calibrated, a manual search is performed for possible GCA arrivals across the seismoacoustic network. These arrivals are then processed through beamforming and subsequent event identification, resulting in a catalogue of seismoacoustic GCA arrivals with corresponding back azimuth and trace velocity estimations.

47 OTHER INSTRUMENTATION↗

Setup and Testing of the RS105 Wire Array Pulser

The report covers the RS105 Wire Array Pulser testbed. The setup of the wire array at Reapplication, building 996, is laid out. Setup instructions are provided. Details of the commissioning test are given. Measurement data from the commissioning test shows the field output of the array exceeds 50 kV/m and that tuning the pulser output with a peaking switch can provide a rise time of ~2.3 ns and a pulse width of ~23 ns. The field levels and timeframes shown are within the tolerance conditions of

42 ENGINEERING↗

High-Density, Actively Multiplexed µECoG Array on Reinforced Silicone Substrate

Simultaneous interrogation of electrical signals from wide areas of the brain is vital for neuroscience research and can aid in understanding the mechanisms of brain function and treatments for neurological disorders. There emerges a demand for development of devices with highly conformal interfaces that can span large cortical regions, have sufficient spatial resolution, and chronic recording capability while keeping a small implantation footprint. In this work, we have designed 61 channel and 48 channel high-density, cortical, micro-electrocorticographic electrode arrays with 400 µm pitch on an ultra-soft but durable substrate. We have also developed a custom multiplexing integrated circuit (IC), methods for packaging the IC in a water-tight liquid crystal polymer casing, and a micro-bonding method for attaching the electronics package to the electrode array. With the integrated multiplexer, the number of external wire connections can be reduced to 16 wires, thereby diminishing the invasive footprint of the device. Both the electrode array and IC were tested in vivo in a rat model to demonstrate the ability to sense finely-localized electrophysiological signals.

Rachinskiy, Iakov↗

The Synthesis of Manganese Hydroxide Nanowire Arrays for a High-Performance Zinc-Ion Battery

The morphology, microstructure as well as the orientation of cathodic materials are the key issues when preparing high-performance aqueous zinc-ion batteries (ZIBs). In this paper, binder-free electrode Mn(OH)2 nanowire arrays were facilely synthesized via electrodeposition. The nanowires were aligned vertically on a carbon cloth. The as-prepared Mn(OH)2 nanowire arrays were used as cathode to fabricate rechargeable ZIBs. The vertically aligned configuration is beneficial to electron transport and the free space between the nanowires can provide more ion-diffusion pathways. As a result, Mn(OH)2 nanowire arrays yield a high specific capacitance of 146.3 Ma h g−1 at a current density of 0.5 A g−1. They also demonstrates ultra-high diffusion coefficients of 4.5 × 10−8~1.0 × 10−9 cm2 s−1 during charging and 1.0 × 10−9~2.7 × 10−11 cm−2 s−1 during discharging processes, which are one or two orders of magnitude higher than what is reported in the studies. Furthermore, the rechargeable Zn//Mn(OH)2 battery presents a good capacity retention of 61.1% of the initial value after 400 cycles. This study opens a new avenue to boost the electrochemical kinetics for high-performance aqueous ZIBs.

25 ENERGY STORAGE↗

Quantum science with arrays of metastable helium-3 atoms

The motion of atoms in programmable optical tweezer arrays offers many new opportunities for neutral atom quantum science. These include inter- and intra-site atom motion for resource-efficient implementations of fermionic and bosonic modes, respectively, as well as tweezer transport for efficient compilation of arbitrary circuits. However, the exploitation of atomic motion for all three purposes and others is limited by the inertia of the atoms. We present a comprehensive architectural blueprint for the use of fermionic metastable helium-3 (He) atoms -- the lightest trappable atomic species -- in programmable optical tweezer arrays. This includes a concrete analysis of atomic structure considerations as well as Rydberg-mediated interactions. We show that inter-tweezer hopping of He atoms can be faster than previous demonstrations with lithium-6. We also demonstrate a new toolbox for encoding and manipulating qubits directly in the tweezer trap potential, uniquely enabled by the light mass of He. Finally, we provide several examples of new opportunities for fermionic quantum simulation and computation that leverage the transport and inter-tweezer hopping of He atom arrays. These tools present new methods to improve the resource efficiency of neutral atom quantum science that may also enable quantum simulations of lattice gauge theories and quantum chemistry outside the Born-Oppenheimer approximation

Li, Zheyuan↗

Microneedle arrays for biosensing and drug delivery

Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

47 OTHER INSTRUMENTATION↗

Encoding data within a crossbar memory array

In an example, in a method for encoding data within a crossbar memory array containing cells, bits of input data may be received. The received bits of data may be mapped to the cells in a row of the memory array, in which the cells are to be assigned to one of a low resistance state and a high resistance state. A subset of the mapped bits in the row may be grouped into a word pattern. The word pattern may be arranged such that more low resistance states are mapped to cells that are located closer to a voltage source of the row of the memory array than to cells that are located farther away from the voltage source.

Muralimanohar, Naveen↗

Solar panel field array support system and apparatus and method for construction use

A combined PV panel assembly jig and forklift transport pallet is used to assemble PV panels for transport to a field array from a protected manufacturing environment. The panels are assembled to have adhesively applied rails for transport by a robotic drone on a ground-support rack and are pre-wired. The PV panel assembly jig holds, protects, and aligns the PV panels in an upside down position, opposite to their operational position, for ease of wiring in order to decrease the manual labor required in the field. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.

14 SOLAR ENERGY↗

A Fluid Solver for Studying Torsional Galloping in Solar-Tracking PV Panel Arrays

Solar-tracking photovoltaic arrays are susceptible to aeroelastic fluttering during high-wind events. This dynamic fluttering behavior can grow in amplitude until the panels enter an unstable mode known as torsional galloping which can lead to panel failure or total array destruction. To better understand the physics of the torsional galloping phenomenon, and to inform the discussion around panel design and recommended panel stow positions during high wind events, a fluid-structure interaction solver composed of a simulated atmospheric boundary layer with simplified panel structural responses was designed. The simulation choices and features of this solver were informed by the geometry and physical properties of an experimental panel array known to exhibit torsional galloping behavior during hind-wind events. These simulations revealed that the torsional galloping instability is driven by a combination of cyclic vortex shedding from the sun-facing side of the panel and the elastic properties of the torque tube linking the panel assemblies. Testing different stow angles across a range of wind speeds indicates that panels are generally more stable when stowed at negative angles where the leading edge is closer to the ground, hypothesized to be due to ground-blocking effects.

41 EE - Solar Energy Technologies Office (EE-4S)↗

Shared aperture antenna array

A shared aperture antenna array including an array of antennas is disclosed. Elements of neighboring antennas are shared to create additional antennas. The shared elements include radiating patches and apertures. Each antenna shares an aperture with neighboring antennas. The array of antennas may be linear or two-dimensional. A phase shifting network with single-pole-single-throw reflective switches may be coupled to the antennas.

Tedeschi, Jeffrey R.↗

A Lunar Farside Low Radio Frequency Array for Dark Ages 21-cm Cosmology

An array of low-frequency dipole antennas on the lunar farside surface will probe a unique, unexplored epoch in the early Universe called the Dark Ages. It begins at Recombination when neutral hydrogen atoms formed, first revealed by the cosmic microwave background. This epoch is free of stars and astrophysics, so it is ideal to investigate high energy particle processes including dark matter, early Dark Energy, neutrinos, and cosmic strings. A NASA-funded study investigated the design of the instrument and the deployment strategy from a lander of 128 pairs of antenna dipoles across a 10 kmx10 km area on the lunar surface. The antenna nodes are tethered to the lander for central data processing, power, and data transmission to a relay satellite. The array, named FARSIDE, would provide the capability to image the entire sky in 1400 channels spanning frequencies from 100 kHz to 40 MHz, extending down two orders of magnitude below bands accessible to ground-based radio astronomy. The lunar farside can simultaneously provide isolation from terrestrial radio frequency interference, the Earth's auroral kilometric radiation, and plasma noise from the solar wind. It is thus the only location within the inner solar system from which sky noise limited observations can be carried out at sub-MHz frequencies. Through precision calibration via an orbiting beacon and exquisite foreground characterization, the farside array would measure the Dark Ages global 21-cm signal at redshifts z~35-200. It will also be a pathfinder for a larger 21-cm power spectrum instrument by carefully measuring the foreground with high dynamic range.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Beam-steering system based on a MEMS-actuated vertical-coupler array

An integrated-optics MEMS-actuated beam-steering system is disclosed, wherein the beam-steering system includes a lens and a programmable vertical coupler array having a switching network and an array of vertical couplers, where the switching network can energize of the vertical couplers such that it efficiently emits the light into free-space. The lens collimates the light received from the energized vertical coupler and directs the output beam along a propagation direction determined by the position of the energized vertical coupler within the vertical-coupler array. In some embodiments, the vertical coupler is configured to correct an aberration of the lens. In some embodiments, more than one vertical coupler can be energized to enable steering of multiple output beams. In some embodiments, the switching network is non-blocking.

42 ENGINEERING↗

Photovoltaic array for a power-by-light system

A hybrid-integrated series/parallel-connected photovoltaic diode array employs 10s-to-100s of single-wavelength III-V compound semiconductor photodiodes in an array bonded onto a transparent optical plate through which the array is illuminated by monochromatic light. The power-by-light system receiver enables high-voltage, up to 1000s of volts, optical transmission of power to remote electrical systems in harsh environments.

Vawter, Gregory A.↗

Method for micromolding a polymeric membrane having a pore array

A method for micro-molding a polymeric membrane and including pouring a predetermined volume of curable polymer unto a micro-fabricated mold having a post array with pillars, and overlaying the polymer with a support substrate. A spacer, such as a rubber spacer, is placed in contact with the support substrate and a force is applied to an exposed side of the spacer to compress the support substrate and the polymer together. While applying the force, the polymer is cured on the mold for a predetermined time period and at a predetermined temperature to form a polymeric membrane having a pore array with a plurality of pores corresponding to the plurality of pillars of the post array. The polymeric membrane is removed from the support substrate.

36 MATERIALS SCIENCE↗

A 4 x 4 SiPM Sensor Array with Fast Preamplified Output Engineered for the PWO Detectors of the EIC EEEMCAL

The PbWO4 scintillation detectors for the Electron-Ion Collider Electron Endcap Electromagnetic Calorimeter (EEEMCAL) cannot use vacuum photomultipler tubes due to the high magnetic field environment. We are presenting a readout solution with a 4 x 4 SiPM array directly coupled to a preamplification and summing stage. A second amplification stage with variable gain and offset adjustments is also included in the compact electronics module. The integrated power supply feeds the signal processing chain and the adjustable bias control. The parameter settings are saved locally on a EEPROM and are adjustable via the integrated communication interface through USB or RS485. The design was optimized to maximize signal collection energy resolution, for fast timing and wide dynamic range while keeping a small footprint with low power consumption and heat dissipation. The output response is fast enough to meet the 100 ? 200 ns digitization gate requirements for the detector. The electronics assembly requires no active cooling and includes a temperature sensor and a gain compensation of thermal variations which are important features for stable operation in large scale detector structures. A detector prototype was constructed with 20 mm x 20 mm x 200 mm PWO crystals affixed with individual SiPM array readouts and arranged in a 3 x 3 array. This detector was tested at the Thomas Jefferson National Accelerator Facility with 5GeV positrons. We will present the results of these detector characterization measurements.

Philip, O.↗

Beam-steering system based on a MEMS-actuated vertical-coupler array

An integrated-optics MEMS-actuated beam-steering system is disclosed, wherein the beam-steering system includes a lens and a programmable vertical coupler array having a switching network and an array of vertical couplers, where the switching network can energize of the vertical couplers such that it efficiently emits the light into free-space. The lens collimates the light received from the energized vertical coupler and directs the output beam along a propagation direction determined by the position of the energized vertical coupler within the vertical-coupler array. In some embodiments, the vertical coupler is configured to correct an aberration of the lens. In some embodiments, more than one vertical coupler can be energized to enable steering of multiple output beams. In some embodiments, the switching network is non-blocking.

Zhang, Xiaosheng↗

Photolithography system including selective light array

A system, device, and method for imparting or transferring a geometric pattern on the surface of a substrate. The device comprises, a housing forming at least a partially enclosed space, a light source body comprising an array of light emitters, a base disposed below the light source body and configured for supporting the substrate having a photoresist layer thereon, and a controller for activating a predetermined number of individual light emitters corresponding to the predetermined geometric pattern. Each individual light emitter within the array of light emitters is selectively activatable to emit a light. The array of light emitters comprises a plurality of light-emitting diodes, a plurality of quantum dots, or both.

Young, Barbara Diane↗

Shared aperture antenna array

A shared aperture antenna array including an array of antennas is disclosed. Elements of neighboring antennas are shared to create additional antennas. The shared elements include radiating patches and apertures. Each antenna shares an aperture with neighboring antennas. The array of antennas may be linear or two-dimensional. A phase shifting network with single-pole-single-throw reflective switches may be coupled to the antennas.

Tedeschi, Jonathan R.↗