Dynamic Routes for Arrivals in Weather: Concept Overview and Status
Concept overview and status for the ATD-3 (Air Traffic Management Technology Demonstration-3) Dynamic Routes for Arrivals in Weather (ATD-3 DRAW) project.
Isaacson, Douglas R.↗
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Airborne Spacing for Terminal Arrival Routes (ASTAR) Proof-of-Concept Flight Test
The Airborne Spacing for Terminal Arrival Routes (ASTAR) Flight Test was conducted by the NASA Air Traffic Management Technology Demonstration – 1 (ATD- 1) project to demonstrate the use of NASA’s ASTAR algorithm beyond a simulated environment and assess the operational risks of performing a multi-aircraft flight test of Flight-deck Interval Management (FIM). Utilizing contemporary tools of the Federal Aviation Administration’s Next Generation Air Transportation System (NextGen) such as ADS-B, the ASTAR algorithm calculated speeds that the flight crew flew to achieve a precise spacing interval behind another aircraft at the final approach fix. Airspeed commands issued by the algorithm were flown by the flight crew of the FIM-equipped aircraft to achieve or maintain an assigned spacing goal from a target vehicle. The ASTAR algorithm was integrated with the Boeing supplied B-787 ecoDemonstrator aircraft, and five flight trials were conducted as a joint effort between NASA and Boeing on December 12, 2014. Initial results indicated arrival times within several seconds of accuracy of the planned termination point between two aircraft performing FIM in a real world environment. This flight test opened the way for the much more expansive ATD-1 Avionics Phase II flight test which occurred in early 2017. The flight trials under Phase II preceded further testing by the community in preparation for inclusion of the Interval Management concept as a part of the NextGen environment.
Roper, Roy D.↗
The TASAR Project: Launching Aviation on an Optimized Route Toward Aircraft Autonomy
The Traffic Aware Strategic Aircrew Request (TASAR) concept applies onboard automation for the purpose of advising the pilot of route modifications that would be beneficial to the flight. Leveraging onboard computing platforms with connectivity to avionics and diverse data sources on and off the aircraft, TASAR introduces a new, powerful capability for in-flight trajectory management to the cockpit and its flight crew that is anticipated to induce a significant culture change in airspace operations. Flight crews empowered by TASAR and its derivative technologies could transform from today’s flight plan followers to proactive trajectory managers, taking an initial critical step towards increasing autonomy in the airspace system. TASAR was developed as a catalyst for operational autonomy, a future vision where the responsibilities and authorities of trajectory management reside with the aircraft operator and are distributed among participating aircraft, thus fulfilling a vision dating back decades and enabling a fully scalable airspace system. This NASA Technical Paper maps TASAR to its foundational vision and traces its research and development from initial concept generation to an operational evaluation by a U.S. airline in revenue service, the final stage before technology transfer and commercialization.
Wing, David J.↗
A Trajectory Algorithm to Support En Route and Terminal Area Self-Spacing Concepts: Fifth Revision
This document describes an algorithm for the generation of a four dimensional trajectory. Input data for this algorithm are similar to an augmented Standard Terminal Arrival (STAR) with the augmentation in the form of altitude or speed crossing restrictions at waypoints on the route. The algorithm calculates the altitude, speed, along path distance, and along path time for each of these waypoints. Wind data at each of these waypoints are also used for the calculation of ground speed and turn radius. This revision of the algorithm now accommodates linear decelerations between two speed-constrained waypoints. While this modification may appear trivial, the calculation of the deceleration rate cannot be accomplished using a closed-form solution. An iterative solution was developed that allowed for the variability of path distance due to speed influence on turn radii, Mach-CAS transition altitude, and the impact of wind on ground speed in calculating an accurate deceleration value.
Aircraft Operations↗
Increasingly minimal bias routing
A system and algorithm configured to generate diversity at the traffic source so that packets are uniformly distributed over all of the available paths, but to increase the likelihood of taking a minimal path with each hop the packet takes. This is achieved by configuring routing biases so as to prefer non-minimal paths at the injection point, but increasingly prefer minimal paths as the packet proceeds, referred to herein as Increasing Minimal Bias (IMB).
97 MATHEMATICS AND COMPUTING↗
Routing flits in a network-on-chip based on operating states of routers
A system is described that includes an integrated circuit chip having a network-on-chip. The network-on-chip includes multiple routers arranged in a topology and a separate communication link coupled between each router and each of one or more neighboring routers of that router among the multiple routers in the topology. The integrated circuit chip also includes multiple nodes, each node coupled to a router of the multiple routers. When operating, a given router of the multiple routers keeps a record of operating states of some or all of the multiple routers and corresponding communication links. The given router then routes flits to destination nodes via one or more other routers of the multiple routers based at least in part on the operating states of the some or all of the multiple routers and the corresponding communication links.
Bharadwaj, Srikant↗
C$^3$: A "Cool" Route to the Higgs Boson and Beyond
We present a proposal for a cold copper distributed coupling accelerator that can provide a rapid route to precision Higgs physics with a compact 8 km footprint. This proposal is based on recent advances that increase the efficiency and operating gradient of a normal conducting accelerator. This technology also provides an $e^{+}e^{-}$ collider path to physics at multi-TeV energies. In this article, we describe our vision for this technology and the near-term R&D program needed to pursue it.
43 PARTICLE ACCELERATORS↗
Flexible supply gas routing for gas compressors
Most multistage compressors specify a maximum inlet pressure that may be supplied to the compressor to stay within designed limits. If the supply gas to be compressed is at a higher pressure than the specified maximum inlet pressure, then its pressure must be reduced before connecting it to the compressor. This pressure reduction is inefficient. The present invention avoids reducing the inlet pressure by routing the supply gas directly to the appropriate compression stage depending on its inlet pressure such that the compressor loads are still within the specified limits of the equipment.
Echter, Nicholas Paul↗
C$^3$: A "Cool" Route to the Higgs Boson and Beyond
We present a proposal for a cold copper distributed coupling accelerator that can provide a rapid route to precision Higgs physics with a compact 8 km footprint. This proposal is based on recent advances that increase the efficiency and operating gradient of a normal conducting accelerator. This technology also provides an e + e - collider path to physics at multi-TeV energies. In this article, we describe our vision for this technology and the near-term R&D program needed to pursue it.
Caterina, Vernieri↗
Gasification of Coal and Biomass: The Route to Net-Negative-Carbon Power and Hydrogen
This is a summary of the progress at the end of BP1 for the project entitled "Gasification of Coal and Biomass: The Route to Net-Negative-Carbon Power and Hydrogen"
Hack, Horst↗
Hierarchical microstructures: a potential route to enhanced stability in structural materials for advanced nuclear reactors
The drive to increase efficiency in nuclear energy systems is leading to the need for materials that operate at higher temperatures and stress levels for extended periods, while maintaining stable microstructures to ensure their performance is not compromised. A novel route to producing materials that can perform well in such environments is the creation of hierarchical microstructures. A hierarchical microstructure is a microstructure in which features are present at multiple length scales simultaneously. In this work, a hierarchical microstructure is fabricated in a nickel-base superalloy, featuring nanometer-size gamma precipitates inside larger gamma-prime particles, which are in turn embedded in the gamma matrix phase. The hierarchical features of the microstructure lead to enhanced stability of the gamma-prime precipitates during annealing; the particle size does not follow the expected t^(1/3) growth law predicted by the classic LSW theory. Phase-field simulations are used to understand the unexpected stability of the gamma-prime precipitates.
36 MATERIALS SCIENCE↗
Hierarchical microstructures: a potential route to enhanced stability in structural materials for advanced nuclear reactors
The drive to increase efficiency in nuclear energy systems is leading to the need for materials that operate at higher temperatures and stress levels for extended periods, while maintaining stable microstructures to ensure their performance is not compromised. A novel route to producing materials that can perform well in such environments is the creation of hierarchical microstructures. A hierarchical microstructure is a microstructure in which features are present at multiple length scales simultaneously. In this work, a hierarchical microstructure is fabricated in a nickel-base superalloy, featuring nanometer-size gamma precipitates inside larger gamma-prime particles, which are in turn embedded in the gamma matrix phase. The hierarchical features of the microstructure lead to enhanced stability of the gamma-prime precipitates during annealing; the particle size does not follow the expected t^(1/3) growth law predicted by the classic LSW theory. Phase-field simulations are used to understand the unexpected stability of the gamma-prime precipitates.
36 - MATERIALS SCIENCE↗
Efficient Routing of Quantum LDPC Codes on Programmable 2D Toric Architectures
Quantum low-density parity-check codes are promising candidates towards scalable fault-tolerant quantum computation. Among these, bivariate bicycle (BB) codes offer superior encoding rates and large code distance compared to surface codes. However, their requirement on long-range stabilizer measurements poses significant challenges for implementation on realistic hardware with limited connectivity, such as superconducting circuit platforms. In this work, we introduce a novel hardware-software co-design that leverages a programmable communication network architecture to address these limitations. Our approach utilizes a 2D toric network of oscillators as a flexible communication fabric linking qubits at each site. Such architecture significantly reduces the number of long-range couplers required from O ( n ) to O (√ n ). Dual-rail qubits, along with native gates including Swap-Wait-Swap gates and beamsplitter SWAPs, ensure that long-range two-qubit gates can be executed with high fidelity and low latency. To further enhance performance, our qubit layout and routing algorithm utilize symmetries of the codes and enable maximum parallelism for long-range two-qubit gates, maintaining a low syndrome extraction cycle duration and scalability over the code length. We perform circuit-level simulation with realistic noise modeling based on experimental hardware parameters, observing an logical error rate per logical qubit per cycle of 3.06% for [[18,4,4]] BB code, 2.6× less than the existing experimental result. These findings provide a practical roadmap and identify key technological advancements needed to achieve low-overhead fault-tolerant quantum computing at scale.
Liu, Kun [Yale Univ., New Haven, CT (United States↗
Sn 0.24 WO 3 hexagonal tungsten bronze prepared via the metal chloride route
In this work, we report the synthesis of Sn 0.24 WO 3 single crystals via an alternative, less well-known, solid-state synthetic approach that involves the use of tin chloride as a starting material. The compound adopts an unusual variant of the hexagonal tungsten bronze structure in space group P6/mmm (a = 7.4264(7) Å and c = 3.7843(4) Å) with a previously unreported distribution of Sn cations, disordered over two distinct sites in the tunnels. Sn 0.24 WO 3 shows no signs of superconductivity down to 170 mK and exhibits weakly-metallic conducting behavior.
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
The hydrogen-containing bronzes H 0.23 WO 3 and H 0.10 ReO 3 synthesized via a polymer route
We report the synthesis of two hydrogen-containing perovskite-type bronzes H 0.23 WO 3 and H 0.10 ReO 3 utilizing an unconventional solid-state synthetic approach, involving the use of the polymer Poly(vinylidene fluoride) (CH 2 CF 2 ) n. Powder neutron diffraction at ambient temperature shows that H 0.23 WO 3 crystallizes in a tetragonal symmetry distortion of the simple perovskite structure (space group P4/nmm), with lattice parameters a = 5.2279(2) Å, and c =3.8763(1) Å. H 0.10 ReO 3 , in contrast, crystallizes in a monoclinic distortion of a simple cubic perovskite (space group P2/m), with lattice parameters a = 5.3125(1) Å, b = 5.3155(3) Å, c = 3.7045(3) Å, and γ = 90.43(1)°. Both H 0.23 WO 3 and H 0.10 ReO 3 exhibit intrinsically diamagnetic behavior, with low temperature paramagnetic upturns and no signs of bulk superconductivity down to 0.35 K.
36 MATERIALS SCIENCE↗
Refueling infrastructure planning in intercity networks considering route choice and travel time delay for mixed fleet of electric and conventional vehicles
The range anxiety has been a major factor that affects the market acceptance of electric vehicles. Even with the recent development of battery technologies, a lack of charging stations and range anxiety are still significant concerns, specifically for intercity trips. This calls for more investments in building charging stations and advancing battery technologies to increase the market share of electric vehicles and improve sustainability. This study suggests a configuration for plug-in electric vehicle charging infrastructure to support long-distance intercity trips of electric vehicles at the network level. A model is proposed to minimize the total system cost including infrastructure investment (building charging stations/spots) and travel time delays (charging time, waiting time in the queue, and detour time to access charging stations). This study fills existing gaps in the literature by capturing realistic patterns of travel demand and considering flow-dependent charging delays at charging stations. Furthermore, the proposed model, which is formulated as a mixed-integer program with nonlinear constraints, solves the optimization problem at the network level. At the network level, impacts of charging station locations on the traffic assignment problem with a mixed fleet of electric and conventional vehicles need to be considered. To this end, a traffic assignment module is integrated with a simulated annealing algorithm. The numerical experiments show a satisfactory application of the model for a full-scale case study (intercity network in Michigan). The solution quality and efficiency of the proposed solution algorithm are evaluated against those of an enumeration approach for a small case study. The results suggest that even for the current market share and charging stations’ setting, a significant investment is needed to support intercity trips without range anxiety issues and with acceptable delays. Additionally, through sensitivity analyses, the required infrastructure and battery investments to support intercity trips with acceptable delays are established for hypothetical increased market shares and battery size in the future.
42 ENGINEERING↗
Space Technology, Ancient Frankincese Trade Routes, and the Discovery of the Lost City of Ubar
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Space Technology Frankincense Trade Routes Lost Ci↗