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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 tunable level, phase change material-based metasurface near IR optical filter on a transmissive doped silicon-on-insulator platform is demonstrated. This type of filter is non-volatile, non-mechanical, with switching being enabled by Joule heating via current pulses.
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Abstract not provided.
A PV system composed of sub-arrays, each having a group of PV cells that are electrically connected to each other. A power management circuit for each sub-array has a communications interface and serves to connect or disconnect the sub-array to a programmable power grid. The power grid has bus rows and bus columns. A bus management circuit is positioned at a respective junction of a bus column and a bus row and is programmable through its communication interface to connect or disconnect a power path in the grid. As a result, selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low system voltage, and, alternately in series so as to produce a high system voltage that is greater than the low voltage by at least a factor of ten.
Abstract not provided.
Abstract not provided.
A PV system composed of sub-arrays, each having a group of PV cells that are electrically connected to each other. A power management circuit for each sub-array has a communications interface and serves to connect or disconnect the sub-array to a programmable power grid. The power grid has bus rows and bus columns. A bus management circuit is positioned at a respective junction of a bus column and a bus row and is programmable through its communication interface to connect or disconnect a power path in the grid. As a result, selected sub-arrays are connected by selected power paths to be in parallel so as to produce a low system voltage, and, alternately in series so as to produce a high system voltage that is greater than the low voltage by at least a factor of ten.
Abstract not provided.
A photonic device is provided for impressing a modulation pattern on an optical carrier. The device includes a unit in which a photodetector and an optical microresonator are monolithically integrated. The device further includes an optical waveguide evanescently coupled to the optical microresonator and having at least an upstream portion configured to carry at least one optical carrier toward the microresonator. The optical microresonator is tunable so as to resonate with the optical carrier frequency. The optical microresonator and the photodetector are mutually coupled such that in operation, charge carriers photogenerated in the photodetector are injected into the microresonator, where the photocurrent changes the resonant conditions. In some embodiments the device is operable as an optical-to-optical frequency converter. In other embodiments the device is operable as an oscillator.
A device including a porous metal organic framework (MOF) disposed between two terminals, the device including a first state wherein the MOF is infiltrated by a guest species to form an electrical path between the terminals and a second state wherein the electrical conductivity of the MOF is less than the electrical conductivity in the first state. A method including switching a porous metal organic framework (MOF) between two terminals from a first state wherein a metal site in the MOF is infiltrated by a guest species that is capable of charge transfer to a second state wherein the MOF is less electrically conductive than in the first state.
Abstract not provided.
Existing development tools for early stage design and scoping of energy systems are often time consuming to use, proprietary, and do not contain the necessary function to model complete systems (i.e., controls, primary, and secondary systems) in a common platform. The Modelica programming language based TRANSFORM tool (1) provides a standardized, common simulation environment for early design of energy systems (i.e., power plants), (2) provides a library of baseline component modules to be assembled into full plant models using available geometry, design, and thermal-hydraulic data, (3) defines modeling conventions for interconnecting component models, and (4) establishes user interfaces and support tools to facilitate simulation development (i.e., configuration and parameterization), execution, and results display and capture.