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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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A Microwave Time Reversal Algorithm for Imaging Extended Defects in Dielectric Composites
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Microwave Catalysis for Process Intensified Modular Production of Carbon Nanomaterials from Natural Gas
The objective of this project was to develop a novel, low-cost process intensified modular process to directly convert flare gas or stranded gas to carbon nanomaterials and co-product hydrogen (H 2 ) with high conversion, selectivity, and stability. The proposed project was based on our exciting exploratory research on a patent pending technology for one-step conversion of natural gas to carbon nanotubes (CNTs) and carbon fibers (CNFs) without emitting CO 2 : CH 4 → H 2 + C (CNT, Carbon Fibers).
Development of the Ultra-Low Loss SuperconductingResonators Integrated with Detectors for Frequency-Domain Multiplexing Readout of Future Cosmic Microwave Background Experiments (Final Report)
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Microwave-Fluidized Catalytic Reactor for the Direct Conversion of Methane to Higher Hydrocarbons (Final Report)
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Phase I Final Technical Report Award Number: DE-SC0017227 Microwave-Fluidized Catalytic Reactor for the Direct Conversion of Methane to Higher Hydrocarbons
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Variable Orientation of Biomass/Fast Microwave Pyrolysis Yield
Biomass that is considered “unusable” can be reused through the pyrolysis or extreme heating of mass with no oxygen. Pyrolysis can be an extremely beneficial practice for the fuel industry; however, the physical process of pyrolysis can be difficult to obtain consistent results. The goal to my research is to find a more physically efficient process to obtain an equal or greater amount of biofuel in comparison to the original process that is currently used. This will be obtained by pyrolyzing biomass pellets in different volumes and orientations and observation the results/yields.
Up‐And‐Coming Advances in Optical and Microwave Nonreciprocity: From Classical to Quantum Realm
Reciprocity is a fundamental physical principle that roots in the time‐reversal symmetry of physical laws. It allows making predictions on any arbitrary complex system's response and operation and hence simplifies the analysis. However, there are many practical situations in which it is advantageous to break reciprocity, e.g., isolators preventing wave scattering back to lasers and generators, full‐duplex systems for multiplexing transmission and receiving in the same channel, nonreciprocal cavity excitation, and protection of fragile states of superconductor quantum computers from thermal noise. The most widespread approach to time‐reversal symmetry breaking and nonreciprocity based on magnetic field biasing suffers from bulkiness, cost ineffectiveness, and loss, motivating researchers and engineers to search for more practical approaches. Herein, the up‐and‐coming advances in optical nonreciprocity, including new materials (Weyl semimetals, topological insulators, metasurfaces), active structures, time‐modulation, parity‐time (PT)‐symmetry breaking, nonlinearity combined with a structural asymmetry, quantum nonlinearity, unidirectional gain and loss, chiral quantum states and valley polarization are overviewed. A general description of nonreciprocal systems is provided and the pros and cons of the mentioned approaches to nonreciprocity are discussed.
Application of hybrid laser powder bed fusion additive manufacturing to microwave radio frequency quarter wave cavity resonators
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Optical leakage mitigation in ortho-mode transducer detectors for microwave applications
Ortho-mode transducers (OMT) are a commonly used method of coupling opti-cal signals between waveguides and on-chip circuitry and detectors. While the ideal OMT-waveguide coupling requires minimal disturbance to the waveguide, when used for mm-wave applications the waveguide is often slide though and the OMT probes inserted on a thin support membrane. This interface is a potential source of signal leakage and can lead to signal loss and experimental systematics (e.g. in CMB polarization experiments where lost signal can result in temperature to polarization leakage). Here we report on the development of new OMT- waveguide coupling structures with the goal of reducing leakage at the horn-to-detector-wafer interface. The pixel to pixel optical leakage due to the gap be-tween the coupling waveguide and the backshort is reduced by means of a protrusion that passes through the OMT membrane and connects the waveguide sections on each side of the wafer. High frequency electromagnetic simulations indicate that these protrusions can reduce optical leakage in the gap by ~80% percent, with a ~60% filling factor, respect to an ordinary OMT coupling without protrusion, using designs that are compatible with current fabrication processes. We describe the design of the new coupling structure including the impact of varying two key parameters: wafer to optical coupling gap and protrusion fill factor. Prototype devices have been designed that will characterize the performance of the new design using a relative measurement with varying filling factors. We describe the simulation setup and results, and present a chip layout and sample box designed to perform an initial measurement.
Towards microwave volumetric additive manufacturing: Generation of a computational multi-physics model for localized curing
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Microwave enhancement of extractions and reactions in Liquid-Liquid biphasic systems
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Temperature stable (1-x)NaCa4V5O17-xBaV2O6 microwave dielectric ceramics for ULTCC applications
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