SEARCH · Engineering Papers
Results for “devices”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Highly-Tunable Nickel Cobalt Oxide as a Low-Temperature P-Type Contact in Organic Photovoltaic Devices
Abstract not provided
Renewable energy integration and system operation challenge: control and optimization of millions of devices
The electric power infrastructure, originally designed and built on large-scale power plants, is evolving into a more resilient power generation and delivery system in which millions of smaller units of distributed energy generation resources units will be installed in sub-transmission and distribution networks. In order to control, manage and optimize the future grid, a hierarchical design is presented in this chapter which enables the distributed control on grid edge while inheriting the existing centralized control structure. This layered design of large-scale power system operation and control uses the following principle: reactive power control is treated as a primary control for voltage stability, and the real power control is primarily a grid-level control but can also be a supplementary control for voltage support in the case of insufficient reactive power control capacity. For the purpose of active control and operation at the distribution level, a recursive power network model is derived from nodal injection and branch power flow models. Based on the model, the proposed algorithms of hierarchical control, grid-edge inference and dynamic hosting allowance are developed and presented for multi-level controlled operation. And, a co-simulation architecture of integrated T&D system is presented to validate and demonstrate the feasibility and scalability of proposed algorithms.
Nanocrystal Grain Growth and Device Architectures for High-Efficiency CdTe Ink-Based Photovoltaics
Explore the source record for details and available documents.
Capacitive energy storage in micro-scale devices: recent advances in design and fabrication of micro-supercapacitors
Explore the source record for details and available documents.
High-performance broadband optical coatings on InGaN/GaN solar cells for multijunction device integration
We demonstrate InGaN/GaN multiple quantum well solar cells grown by metalorganic chemical vapor deposition on a bulk (0001) substrate with high-performance broadband optical coatings to improve light absorption. A front-side anti-reflective coating and a back-side dichroic mirror were designed to minimize front surface reflections across a broad spectral range and maximize rear surface reflections only in the spectral range absorbed by the InGaN, making the cells suitable for multijunction solar cell integration. Application of optical coatings increased the peak external quantum efficiency by 56% (relative) and conversion efficiency by 37.5% (relative) under 1 sun AM0 equivalent illumination.
Wondering what to blame? Turn PV performance assessments into maintenance action items through the deployment of learning algorithms embedded in a Raspberry Pi device.
Abstract not provided.
A Novel Energy-Conversion Device for Wind and Hydrokinetic Applications.
Abstract not provided.
Similarities between Ionizing Radiation Effects and Negative-Bias Temperature Instability (NBTI) in MOSFET Devices.
Abstract not provided.
Design of Antireflective Nanostructures and Optical Coatings for Next-Generation Multijunction Photovoltaic Devices
Abstract not provided
Low-energy electro- and photo-emission spectroscopy of GaN materials and devices
In hot-electron semiconductor devices, carrier transport extends over a wide range of conduction states, which often includes multiple satellite valleys. Electrical measurements can hardly give access to the transport processes over such a wide range without resorting to models and simulations. An alternative experimental approach however exists which is based on low-energy electron spectroscopy and provides, in a number of cases, very direct and selective information on hot-electron transport mechanisms. Recent results obtained in GaN crystals and devices by electron emission spectroscopy are discussed. Using near-band-gap photoemission, the energy position of the first satellite valley in wurtzite GaN is directly determined. By electro-emission spectroscopy, we show that the measurement of the electron spectrum emitted from a GaN p-n junction and InGaN/GaN light-emitting diodes (LEDs) under electrical injection of carriers provides a direct observation of transport processes in these devices. In particular, at high injected current density, high-energy features appear in the electro-emission spectrum of the LEDs showing that Auger electrons are being generated in the active region. These measurements allow us identifying the microscopic mechanism responsible for droop which represents a major hurdle for widespread adoption of solid-state lighting.
Continuously tunable uniaxial strain control of van der Waals heterostructure devices
Uniaxial strain has been widely used as a powerful tool for investigating and controlling the properties of quantum materials. However, existing strain techniques have so far mostly been limited to use with bulk crystals. Although recent progress has been made in extending the application of strain to two-dimensional van der Waals (vdW) heterostructures, these techniques have been limited to optical characterization and extremely simple electrical device geometries. Here, we report a piezoelectric-based in situ uniaxial strain technique enabling simultaneous electrical transport and optical spectroscopy characterization of dual-gated vdW heterostructure devices. Critically, our technique remains compatible with vdW heterostructure devices of arbitrary complexity fabricated on conventional silicon/silicon dioxide wafer substrates. We demonstrate a large and continuously tunable strain of up to –0.15% at millikelvin temperatures, with larger strain values also likely achievable. We quantify the strain transmission from the silicon wafer to the vdW heterostructure, and further demonstrate the ability of strain to modify the electronic properties of twisted bilayer graphene. Our technique provides a highly versatile new method for exploring the effect of uniaxial strain on both the electrical and optical properties of vdW heterostructures and can be easily extended to include additional characterization techniques.
System for simultaneously loading program to master computer memory devices and corresponding slave computer memory devices
A bus programmable slave module card for use in a computer control system is disclosed which comprises a master computer and one or more slave computer modules interfacing by means of a bus. Each slave module includes its own microprocessor, memory, and control program for acting as a single loop controller. The slave card includes a plurality of memory means (S1, S2...) corresponding to a like plurality of memory devices (C1, C2...) in the master computer, for each slave memory means its own communication lines connectable through the bus with memory communication lines of an associated memory device in the master computer, and a one-way electronic door which is switchable to either a closed condition or a one-way open condition. With the door closed, communication lines between master computer memory (C1, C2...) and slave memory (S1, S2...) are blocked. In the one-way open condition invention, the memory communication lines or each slave memory means (S1, S2...) connect with the memory communication lines of its associated memory device (C1, C2...) in the master computer, and the memory devices (C1, C2...) of the master computer and slave card are electrically parallel such that information seen by the master's memory is also seen by the slave's memory. The slave card is also connectable to a switch for electronically removing the slave microprocessor from the system. With the master computer and the slave card in programming mode relationship, and the slave microprocessor electronically removed from the system, loading a program in the memory devices (C1, C2...) of the master accomplishes a parallel loading into the memory devices (S1, S2...) of the slave.
Wireless device monitoring systems and monitoring devices, and associated methods
Wireless device monitoring systems and monitoring devices include a communications module for receiving wireless communications of a wireless device. Processing circuitry is coupled with the communications module and configured to process the wireless communications to determine whether the wireless device is authorized or unauthorized to be present at the monitored area based on identification information of the wireless device. Methods of monitoring for the presence and identity of wireless devices are also provided.
Separating semiconductor devices from substrate by etching graded composition release layer disposed between semiconductor devices and substrate including forming protuberances that reduce stiction
A method includes etching a release layer that is coupled between a plurality of semiconductor devices and a substrate with an etch. The etching includes etching the release layer between the semiconductor devices and the substrate until the semiconductor devices are at least substantially released from the substrate. The etching also includes etching a protuberance in the release layer between each of the semiconductor devices and the substrate. The etch is stopped while the protuberances remain between each of the semiconductor devices and the substrate. The method also includes separating the semiconductor devices from the substrate. Other methods and apparatus are also disclosed.
Bio-assessment device and method of making the device
Disclosed herein are embodiments of a device that can be used to mimic the biochemical and physiological actions of a lung organ. Also disclosed herein are embodiments of components that are included in the device as well as methods of making and using the device. Further disclosed are platform device embodiments and various components used therein that can be used in combination with the lung organ devices disclosed herein. In some embodiments, the disclosed devices can be used to determine drug toxicity and also can be used with one or more disease models to determine methods of treating disease.
Systems, methods, and devices for failure detection of one or more energy storage devices
An energy storage device management system can include a management portion for charging/discharging an energy storage device and an ultrasound interrogation portion for passing ultrasound energy through the energy storage device during charge/discharge cycles. A memory stores a stream of capture data instances derived from ultrasound energy exiting the energy storage device and baseline ultrasound data instances corresponding with the energy storage device during normal charging/discharging thereof. A processor can compare each capture data instance with the baseline ultrasound data and detect abnormal operating states of the energy storage device. A warning system can issue a notification when abnormal operating states are detected.
Systems, devices, and methods for authenticating millimeter wave devices
Systems, devices, and methods are described for millimeter wave device authentication. A system may include one or more access points. Each access point of the one or more access points is configured to extract, from one or more beam patterns generated via a client device, a beam feature associated with the client device. Each access point may also be configured to transmit the beam feature. The system may also include a server communicatively coupled to the one or more access points and including a database for storing known beam features. The server may be configured to receive the beam feature associated with the client device from at least one access point of the one or more access points. Also, the server may be configured to authenticate the client device in response to the received beam feature matching a known beam feature stored in the at least one database.