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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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At least 847 records · Page 47
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Construction and Analysis of Electronic circuits

The Aviation Environmental Technical Branch produces many various types of aeronautical research that benefits the NASA mission for space exploration and in turn, produces new technology for our nation. One of the present goals of the Aviation Environmental Technical Branch is to create better engines for airplanes by testing supersonic jet propulsion and safe fuel combustion. During the summer of 2004, I was hired by Vincent Sattenvhite Chief executive of the Aviation Environmental Technical Branch to Assist Yves Lamothe with a fuel igniter circuit. Yves Lamothe is an electrical engineer who is currently working on safe fuel combustion testing. This testing is planned to determine the minimum ignition energy for fuel and air vapors of current and alternative fuels under simulated flight conditions. An air temperature bath will provide simulated flight profile temperatures and the heat fluxes to the test chamber. I was assigned with Yves to help complete the igniter circuit which consists of a 36k voltage supply an oscilloscope, and a high voltage transistor switch. During my tenure in the L.E.C.I.R.P. program I studied the basics of electricity and circuitry along with two other projects that I completed. In the beginning of my internship, I devote all of my time to research the aspects of circuitry so that I would be prepared for the projects that I was assigned to do. I read about lessons on; the basic physical concepts of electronics, Electrical units, Basic dc circuits, direct current circuit analysis, resistance and cell batteries, various types of magnetism , Alternating current basics, inductance, and power supplies. I received work sheets and math equations from my Mentor so that I could be able to apply these concepts into my work. After I complete my studies, I went on to construct a LED chaser circuit which displays a series of light patterns using a 555 timer. I incorporated a switch and motion detector into the circuit to create basic alarm system. This project challenged my ability to interpret a schematic and expand it. While I was still completing the LED chaser circuit I Also was given A Basic Stamp Toddler Robot to build and program. The Toddler robot can walk in 36 various styles using advanced robotics. I used many different programs to create movement and direction of the robot. Also the Toddler can use infrared vision to sense objects. This enables the robot to maneuver indefinitely without running into objects. During my tenure at the NASA Glen Research Center I definite utilized the NASA mission to educate. I learned valuable information to help in my up coming year as a freshman in college.

Thomas, Ashley N.↗
DOE OSTI2022

Fast-forwarding quantum simulation with real-time quantum Krylov subspace algorithms

Quantum subspace diagonalization (QSD) algorithms have emerged as a competitive family of algorithms that avoid many of the optimization pitfalls associated with parameterized quantum circuit algorithms. While the vast majority of the QSD algorithms have focused on solving the eigenpair problem for ground, excited-state, and thermal observable estimation, there has been a lot less work in considering QSD algorithms for the problem of quantum dynamical simulation. In this work, we propose several quantum Krylov fast-forwarding (QKFF) algorithms capable of predicting long-time dynamics well beyond the coherence time of current quantum hardware. Our algorithms use real-time evolved Krylov basis states prepared on the quantum computer and a multi-reference subspace method to ensure convergence towards high-fidelity, long-time dynamics. In particular, we show that the proposed multi-reference methodology provides a systematic way of trading off circuit depth with classical post-processing complexity. Further, we also demonstrate the efficacy of our approach through numerical implementations for several quantum chemistry problems including the calculation of the auto-correlation and dipole moment correlation functions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1990

Numerical simulation of a catastrophe model for coronal mass ejections

Van Tend and Kuperus (1978) proposed a simple catastrophe model for magnetically driving coronal mass ejections, prominence eruptions, and two-ribbon flares. Their model, which is based on simple circuit concepts, suggests that a stable configuration containing a current filament will lose equilibrium when the filament current exceeds a critical value. Here, a two-dimensional numerical simulation is used to test how the Van Tend-Kuperus model works in an ideal MHD fluid. The simulation exhibits the expected loss of mechanical equilibrium near the predicted critical value, but the current filament moves only a short distance upward before coming to rest at a new equilibrium. However, this new equilibrium contains a current sheet which is resistively unstable to magnetic reconnection, and if magnetic reconnection occurs rapidly, the filament can continue to move upward at Alfvenic speeds.

Forbes, T. G.↗
DOE OSTI2022

Quantum state preparation by adiabatic evolution with custom gates

Quantum state preparation by adiabatic evolution is currently rendered ineffective by the long implementation times of the underlying quantum circuits, comparable to the decoherence time of present and near-term quantum devices. These implementation times can be significantly reduced by realizing these circuits with custom gates. Using classical computing, we model the output of a realistic two-qubit processor implementing the adiabatic evolution of a two-spin system by means of custom gates. This modeled output is then compared with the results of quantum simulations solving the same problem on IBM Quantum (IBMQ) systems. Additionally, when used to emulate the behavior of the IBMQ quantum circuit, our realistic model yields state fidelities ranging from 65% to 85%, similar to the actual performance of a diverse set of IBMQ devices. When we reduced the implementation time by using custom gates, however, the loss of fidelity was reduced by at least a factor of 4, allowing us to accurately extract the energy of the target state. This improvement is enough to render adiabatic evolution useful for quantum state preparation for small systems or as a preconditioner for other state preparation methods.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Quantum tensor network algorithms for evaluation of spectral functions on quantum computers

We investigate quantum algorithms derived from tensor networks to simulate the static and dynamic properties of quantum many-body systems. Using a sequentially prepared quantum circuit representation of a matrix product state (MPS) that we call a quantum tensor network (QTN), we demonstrate algorithms to prepare ground and excited states on a quantum computer and apply them to molecular nanomagnets (MNMs) as a paradigmatic example. In this setting, we develop two approaches for extracting the spectral correlation functions measured in neutron-scattering experiments: (a) a generalization of the SWAP test for computing wave function overlaps and, (b) a generalization of the notion of matrix product operators to the QTN setting which generates a linear combination of unitaries. The latter method is discussed in detail for translationally invariant spin-half systems, where it is shown to reduce the qubit resource requirements compared with the SWAP method and may be generalized to other systems. We demonstrate the versatility of our approaches by simulating spin-1/2 and spin-3/2 MNMs, with the latter being an experimentally relevant model of a Cr$^{3+}_{8}$ ring. Here, our approach has qubit requirements that are independent of the number of constituents of the many-body system and scale only logarithmically with the bond dimension of the MPS representation, making them appealing for implementation on near-term quantum hardware with mid-circuit measurement and reset.

Neutron scattering↗
DOE OSTI2023

Degradation behavior of CIGS solar Cells: A parametric analysis

A parametric study of the effect of bulk and interface properties on device characteristics as a function of heat and light stress under open-circuit and short-circuit conditions is developed for Cu(In,Ga)(S,Se) 2 solar cells using SCAPS-1D simulator. The variables and interdependencies modeled include: (1) conduction band offset (CBO) between buffer and absorber; (2) buffer ionized donor density; (3) CIGS shallow acceptor density; (4) CIGS deep acceptor density; (5) CIGS shallow donor density; (6) ionized acceptor concentration in the ordered vacancy compound (OVC) CIGS/buffer interface; and (7) back contact work-function. An increase in absorber shallow acceptor or a decrease in shallow donor density results in an increase in net carrier density and open-circuit voltage (V OC ). Further, a decrease in V OC is observed with an increase in the deep acceptors or neutral midgap defects in the CIGS due to higher charge carrier recombination. A change of CBO from spike to cliff condition is a dominant mechanism of decreasing VOC with an interface defect density of 10 12 cm -2 . The minimum depletion width is found to be specifically sensitive to CBO and interface defect density. An inflection in the capacitance–voltage curves (in reverse bias) is observed with simultaneous increase in bulk deep acceptor density and shallow donor density near the back contact.

14 SOLAR ENERGY↗
DOE OSTI2024

Reduction of vanadium diffusivity within copper grain boundaries due to enhanced binding

We investigate permeation of vanadium (V) through copper (Cu) layers in V/Cu/niobium (Nb) and molybdenum (Mo)/Cu/V tri-layer composites and compare it with the permeation behavior of Nb. Despite their low solubility in single-crystal Cu, both V and Nb permeate readily due to short-circuit transport through Cu grain boundaries (GBs). However, Nb permeates preferentially to V. Atomistic simulations suggest that this difference is due to lower V diffusivity at general GBs in Cu, compared to Nb. Here, the lower V diffusivity, in turn, arises from stronger V binding to the boundary, which manifests as a greater equilibrium GB concentration as well as a higher activation energy for GB diffusion.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Deformed Fredkin model for the ν = 5 / 2 Moore-Read state on thin cylinders

We propose a frustration-free model for the Moore-Read quantum Hall state on sufficiently thin cylinders with circumferences ≲ 7 magnetic lengths. While the Moore-Read Hamiltonian involves complicated long-range interactions between triplets of electrons in a Landau level, our effective model is a simpler one-dimensional chain of qubits with deformed Fredkin gates. We show that the ground state of the Fredkin model has high overlap with the Moore-Read wave function and accurately reproduces the latter's entanglement properties. Moreover, we demonstrate that the model captures the dynamical response of the Moore-Read state to a geometric quench, induced by suddenly changing the anisotropy of the system. We elucidate the underlying mechanism of the quench dynamics and show that it coincides with the linearized bimetric field theory. The minimal model introduced here can be directly implemented as a first step towards quantum simulation of the Moore-Read state, as we demonstrate by deriving an efficient circuit approximation to the ground state and implementing it on an IBM quantum processor. Published by the American Physical Society 2024

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
NASA NTRS1970

Two techniques for digital filter design

Digital controllers, one using a special-purpose computer and the other using a combination of digital and analog techniques, are designed around /1/ computers that simulate the transfer function and interface with the system, and /2/ analog and digital circuits, converters, amplifiers, constant multipliers, and delay lines that form a digital filter.

Carroll, C. C.↗
NASA NTRS1975

An interactive driving simulation for driver control and decision-making research

Display techniques and equations of motion for a relatively simple fixed base car simulation are described. The vehicle dynamics include simplified lateral (steering) and longitudinal (speed) degrees of freedom. Several simulator tasks are described which require a combination of operator control and decision making, including response to wind gust inputs, curved roads, traffic signal lights, and obstacles. Logic circuits are used to detect speeding, running red lights, and crashes. A variety of visual and auditory cues are used to give the driver appropriate performance feedback. The simulated equations of motion are reviewed and the technique for generating the line drawing CRT roadway display is discussed. On-line measurement capabilities and experimenter control features are presented, along with previous and current research results demonstrating simulation capabilities and applications.

Allen, R. W.↗
NASA NTRS1976

High altitude calibration of thirty-three silicon and gallium arsenide solar cells on a sounding rocket

Twenty-nine n/p silicon and four p/n gallium arsenide solar cells were calibrated on board a high-altitude sounding rocket which provided a stable platform outside the earth's atmosphere. Approximately 75 characteristic current-voltage curves were obtained for each of thirty-two of the cells; the calibration accuracy for both current and voltage was 0.1%. For comparison, the short circuit current, open circuit voltage, and maximum power of the solar cells were also measured under solar simulators (air mass = 0) and on the ground (air mass = 1.2).

Thomas, N. L.↗
NASA NTRS1985

Burnwire Simulator

Fuse-containing device simulates pyrotechnic firing circuitry. Simulator includes housing receptacle connector at one end, and fuse at opposite end. Fuse circuit useful in any system having complex built-in wiring for current pulse applications.

Bummer, G. L.↗
NASA NTRS1990

Serial multiplier arrays for parallel computation

Arrays of systolic serial-parallel multiplier elements are proposed as an alternative to conventional SIMD mesh serial adder arrays for applications that are multiplication intensive and require few stored operands. The design and operation of a number of multiplier and array configurations featuring locality of connection, modularity, and regularity of structure are discussed. A design methodology combining top-down and bottom-up techniques is described to facilitate development of custom high-performance CMOS multiplier element arrays as well as rapid synthesis of simulation models and semicustom prototype CMOS components. Finally, a differential version of NORA dynamic circuits requiring a single-phase uncomplemented clock signal introduced for this application.

Winters, Kel↗
NASA NTRS2001

Experimental Verification of the Use of Metal Filled Via Hole Fences for Crosstalk Control of Microstrip Lines in LTCC Packages

Coupling between microstrip lines in dense RF packages is a common problem that degrades circuit performance. Prior three-dimensional-finite element method (3-D-FEM) electromagnetic simulations have shown that metal filled via hole fences between two adjacent microstrip lines actually Increases coupling between the lines: however, if the top of the via posts are connected by a metal strip, coupling is reduced. In this paper, experimental verification of the 3-D-FEM simulations is demonstrated for commercially fabricated low temperature cofired ceramic (LTCC) packages. In addition, measured attenuation of microstrip lines surrounded by the shielding structures is presented and shows that shielding structures do not change the attenuation characteristics of the line.

Ponchak, George E.↗
DOE OSTI2025

Power Quality and Load Capacity Evaluations of an Electric Vehicle for Multi-Robot System Applications

This paper evaluates the capability of a fully electric pickup truck, using the Ford F-150 Lightning as an example, to provide power to the circuit of a multi-robot system. The case study was conducted on a simulated INL Autonomous Pit Exploration System (APES) designed for the inspection of nuclear waste tank pits. Through a series of controlled tests, the vehicle’s power delivery consistency, load-handling capability, and battery performance were assessed under various conditions. First of all, the load test demonstrated that the vehicle provided stable power with low distortion and no unexpected interruptions. Second, during the operational limit test, the 240V system sustained loads up to 7.4 kW before tripping, providing insights into its operational limits. Last but not least, during a simulated full-scale APES operation, the vehicle’s battery depleted by only 6% over an hour, indicating sufficient capacity for extended use while retaining reserve power for transportation needs. This study highlights the potential of electric vehicles as reliable power sources for field operations, contributing to the advancement of sustainable technologies by reducing reliance on traditional fossil fuel generators and promoting the integration of clean energy solutions in remote and challenging environments.

Electric vehicle↗
DOE OSTI2025

IEEE SusTech 2025 Presentation

This paper evaluates the capability of a fully electric pickup truck, using the Ford F-150 Lightning as an example, to provide power to the circuit of a multi-robot system. The case study was conducted on a simulated INL Autonomous Pit Exploration System (APES) designed for the inspection of nuclear waste tank pits. Through a series of controlled tests, the vehicle’s power delivery consistency, load-handling capability, and battery performance were assessed under various conditions. First of all, the load test demonstrated that the vehicle provided stable power with low distortion and no unexpected interruptions. Second, during the operational limit test, the 240V system sustained loads up to 7.4 kW before tripping, providing insights into its operational limits. Last but not least, during a simulated full-scale APES operation, the vehicle’s battery depleted by only 6\% over an hour, indicating sufficient capacity for extended use while retaining reserve power for transportation needs. This study highlights the potential of electric vehicles as reliable power sources for field operations, contributing to the advancement of sustainable technologies by reducing reliance on traditional fossil fuel generators and promoting the integration of clean energy solutions in remote and challenging environments.

42 - ENGINEERING↗
DOE OSTI2022

Impact of battery cell imbalance on electric vehicle range

Due to manufacturing variation, battery cells often possess heterogeneous characteristics, leading to battery state-of-charge variation in real-time. Since the lowest cell state-of-charge determines the useful life of battery pack, such variation can negatively impact the battery performance and electric vehicles range. Existing research has been focused on control design to mitigate cell imbalance. However, it is yet unclear how much impacts the cell imbalance can have on electric vehicle range. This paper closes this knowledge gap by using a simulation environment consisting of real-world driving speed data, vehicle longitudinal control, propulsion and vehicle dynamics, and cell level battery modeling. In particular, each battery cell is modeled as an equivalent circuit model, and variations among cell parameters are introduced to assess their impact on electric vehicles range and to identify the most influential parameter variations. Simulation results and analysis can be used to assist balancing control design and to benchmark control performance.

25 ENERGY STORAGE↗
NASA NTRS1994

Versatile Dual-Channel Waveform Generator

Programmable waveform generator synthesizes two independent waveforms simultaneously at frequencies up to 250 MHz. Can be in phase or out of phase with each other. Use of commercial integrated circuits helps keep cost low. Operation governed by BASIC source code enabling any user equipped with suitable personal computer to specify waveforms. User can modify source code to satisfy special needs. Other applications include simulation of Doppler waveforms for radar, and of video signals for testing color displays and computer monitors. With eventual substitution of gallium arsenide integrated circuits for its present silicon integrated circuits, instrument able to generate waveforms with 14-bit precision and sample rates as high as 2 GHz.

Staples, Edward J.↗