SEARCH · Search NASA

Results for “dat”

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.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11

All sources NASA NTRS DOE OSTI

DOE OSTI2022

Reconfigurable perovskite nickelate electronics for artificial intelligence

Reconfigurable devices offer the ability to program electronic circuits on demand. Here, in this work, we demonstrated on-demand creation of artificial neurons, synapses, and memory capacitors in post-fabricated perovskite NdNiO 3 devices that can be simply reconfigured for a specific purpose by single-shot electric pulses. The sensitivity of electronic properties of perovskite nickelates to the local distribution of hydrogen ions enabled these results. With experimental data from our memory capacitors, simulation results of a reservoir computing framework showed excellent performance for tasks such as digit recognition and classification of electrocardiogram heartbeat activity. Using our reconfigurable artificial neurons and synapses, simulated dynamic networks outperformed static networks for incremental learning scenarios. The ability to fashion the building blocks of brain-inspired computers on demand opens up new directions in adaptive networks.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2013

The Majorana Double Beta Decay Experiment: Present Status

The Majorana collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay experiment, an R&D effort that will field approximately 40 kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the Demonstrator

Aguayo, Estanislao↗

DOE OSTI2023

Physically-based control-oriented modeling for turbocharged stoichiometric spark-ignited engine with cooled EGR and flexible VVT systems

Accurate estimation and prediction of engine gas exchange system and in-cylinder conditions are critical for spark-ignited engine control and diagnostic algorithm development. In this paper, a physically-based, control-oriented model for a 2.8 l turbocharged, variable valve timing (VVT) and low pressure (LP) exhaust gas recirculation (EGR)-utilizing SI engine was developed. The model includes the impact of modulation to any combination of 10 actuators, including the throttle valve, compressor bypass valve, fueling rate, waste-gate, LP EGR valve, number of deactivated cylinders, intake valve open (IVO) timing, intake valve close (IVC) timing, exhaust valve open (EVO) timing and exhaust valve close (EVC) timing. The accuracy of the model in capturing engine dynamics was demonstrated by validating it against high-fidelity engine GT-Power simulation results for various drive cycles, particularly emphasizing elevated loads. In comparison to the open literature, novel contributions of the effort described in this paper includes in-cylinder gas composition modeling and turbine-out pressure estimation.

Zhang, Xu↗

DOE OSTI2019

Path-seq identifies an essential mycolate remodeling program for mycobacterial host adaptation

The success of Mycobacterium tuberculosis (MTB) stems from its ability to remain hidden from the immune system within macrophages. Here, we report a new technology (Path-seq) to sequence miniscule amounts of MTB transcripts within up to million-fold excess host RNA. Using Path-seq and regulatory network analyses, we have discovered a novel transcriptional program for in vivo mycobacterial cell wall remodeling when the pathogen infects alveolar macrophages in mice. We have discovered that MadR transcriptionally modulates two mycolic acid desaturases desA1/desA2 to initially promote cell wall remodeling upon in vitro macrophage infection and, subsequently, reduces mycolate biosynthesis upon entering dormancy. We demonstrate that disrupting MadR program is lethal to diverse mycobacteria making this evolutionarily conserved regulator a prime antitubercular target for both early and late stages of infection

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2018

Coordinating Distributed Energy Resources for Grid Services: A Case Study of Pacific Gas and Electric

Pacific Gas & Electric (PG&E) hosts more distributed solar photovoltaic (PV) systems than any other utility in the United States. Further, PG&E expects hundreds of thousands of new PV systems and electric vehicles and more than 400 MW of behind-the-meter distributed energy storage by 2030. To prepare for the grid of the future, PG&E is exploring ways to coordinate distributed energy resources.

14 SOLAR ENERGY↗

DOE OSTI2018

Check the Stack: An Enabling Framework for Resilient Microgrids

Highly destructive natural disasters have illustrated the fragility of critical infrastructure including emergency services, healthcare, and water treatment during long-term electricity outages. One pathway to increase the resilience of critical infrastructure amidst disruptions to grid systems is developing microgrids, particularly those that incorporate solar photovoltaics (PV) and energy storage. This document defines a resilient microgrid as a set of interconnected load that includes critical infrastructure and distributed energy resources with the ability to island from the grid during an outage. Research is limited with respect to how much critical infrastructure could benefit from microgrids, how many states have pursued this prioritization approach, and what policies need to be in place to support more widespread deployment. This report explores each of these questions to offer the industry and policymakers a clearer understanding of the opportunity for resilient microgrids and how policy can be designed to support this market.

14 SOLAR ENERGY↗

DOE OSTI2018

Expanding PV Value: Lessons Learned from Utility-led Distributed Energy Resource Aggregation in the United States

Distributed PV capacity in the United States has increased from about 0.4 Gigawatts (GW) in 2010 to 10.5 GW in 2017 (GTM Research and SEIA 2018). When distributed PV is coupled with other emerging distributed energy resources (DERs) like battery storage and electric vehicles (EVs) they can provide demand response, voltage regulation, and other grid services. When many DERs are aggregated and called upon to provide these services simultaneously they may offer the same or more value than large, centralized power producers. In the United States, utility efforts to aggregate DERs are in the nascent stage. If initial DER aggregation programs prove successful, it could open new value streams for PV and other emerging DERs, thereby expanding deployment and transforming the energy market. The literature on the scope, performance, and lessons learned from utility-led DER aggregation programs is limited. This report fills this research gap, first by surveying utility-led DER aggregation programs nationwide, and then providing a deeper analysis of five utility pilots. We compare lessons learned across the five cases to develop a list of common challenges and related solutions that other utilities might consider when developing next generation programs.

14 SOLAR ENERGY↗

DOE OSTI2018

2018 U.S. Utility-Scale Photovoltaics-Plus-Energy Storage System Costs Benchmark

Market growth for utility-scale photovoltaic (PV) systems has been rapid for several years. Today, with the cost reductions of energy storage technologies, the combining PV and energy storage has become feasible and beneficial, especially for the areas that have only PV standalone systems and need to shift the peak load to meet electricity demand in the evening. Overall, utility-scale PV plus energy storage systems can provide dispatchable energy and reliable capacity. This study details cost factors, including labor costs, material costs, overhead, and permitting costs using a system-level bottom-up cost modeling approach. We use this model to benchmark PV-plus-storage installation system cost and identify the cost difference for AC- and DC-coupled systems and duration variation. Finally, we assess the cost reduction opportunities of colocating PV systems with energy storage systems in order to indicate the possible economic impacts of the PV-plus-storage configuration and help future research and development (R&D) effects in the context of U.S. energy storage policymaking.

14 SOLAR ENERGY↗

DOE OSTI2018

2018 U.S. Utility-Scale Photovoltaics-Plus-Energy Storage System Costs Benchmark

14 SOLAR ENERGY↗

DOE OSTI2018

Best Practices for Operation and Maintenance of Photovoltaic and Energy Storage Systems; 3rd Edition

The goal of this guide is to reduce the cost and improve the effectiveness of operations and maintenance (O&M) for photovoltaic (PV) systems and combined PV and energy storage systems. Reported O&M costs vary widely based on the requirements of the system and the nature of the O&M contract, but a more standardized approach to planning and delivering O&M has the potential to both decrease costs and make those costs more predictable over time. This guide encourages adoption of best practices to reduce the cost of O&M and improve the performance of fielded systems, but it also enhances financing of new projects by making cost more predictable and mitigating performance risk. This guide also includes technical improvement opportunities in the design of systems and in specification of equipment because high-quality system deployment improves lifetime project performance and energy production while reducing, or at least optimizing, costs to deliver an O&M program. This guide provides recommendations that increase the effectiveness of O&M services; reduce O&M costs, improve solar asset transparency for investors and rating agencies; provide an industry framework for quality management; and reduce transaction costs.

14 SOLAR ENERGY↗

DOE OSTI2019

State and Local Policy Impacts on the Residential Solar PV Installation Industry

This study explores the effects of state and local policies on local residential solar PV installation industries. The results show that state and local policies affect the number of installers that compete in local PV markets, the relative sizes of those installers, and the market shares of high-volume national-scale installers. Understanding these effects could improve PV policy analysis and yield insights into how to achieve multiple PV policy objectives.

14 SOLAR ENERGY↗

DOE OSTI2019

Existing and Potential Corporate Off-Site Renewable Procurement in the Southeast

This project assesses the market for off-site PV in the Southeast, based on projected corporate load, corporate renewable goals for load in the Southeast, solar economics relative to utility rates, presence of a viable PV purchasing method, and other factors. This project gathered data directly and indirectly from corporations, high education institutions, and cities and counties with renewable energy targets. The result is a guide for utilities, state policymakers, and corporates trying to meet their corporate RE targets in the Southeast.

14 SOLAR ENERGY↗

DOE OSTI2019

Value Accrual to Customers, Installers, and Financiers in Third-Party Owned Solar PV Markets

Beyond the Federal Investment Tax Credit, the two primary financial incentives provided by residential solar photovoltaic (PV) systems are electricity bill savings and state and local government incentives. Using transaction-level data on third-party owned systems from 2012-2015, we estimate how value associated with these incentives are passed along the installer-financier-consumer supply chain in the third-party owned market. Our analysis finds evidence of financial incentive pass-through to system prices and customer payments with respect to both types of incentives. Moreover, we document differences in the levels of pass-through for different contract types: total pass-through to customer payments for both types of incentives is greater for PPAs than for UFOs. We find some evidence that pass-through rates to customer payments for PPAs change with market concentration. Finally, we illustrate that the magnitude of estimated pass-through changes for PPAs if we account for simultaneity between system prices and customer payments.

14 SOLAR ENERGY↗

DOE OSTI2019

Recent results from the Majorana Demonstrator

The MAJORANA DEMONSTRATOR is an experiment constructed to search for Neutrinoless double-beta decay in 76Ge and to demonstrate the feasibility to deploy a large-scale experiment in a phased and modular fashion. It consists of two modular arrays of natural and 76Ge-enriched germanium detectors totalling 44.1 kg, operating on the 4850’ level of the Sanford Underground Research Facility in Lead, South Dakota, USA. Data acquisition in the commissioning phase began in June 2015, followed by data acquisition with the full detector array in August 2016. The ultralow background and record energy resolution achieved by the MAJORANA DEMONSTRATOR enable a sensitive neutrinoless double-beta decay search, as well as additional searches for physics beyond the Standard Model. I will discuss the design elements that enable these searches, along with our latest results, focusing on the neutrinoless double-beta decay search. I will also discuss the current status and the future plans of the MAJORANA DEMONSTRATOR, as well as the plans for a future tonne-scale 76Ge experiment.

Myslik, Jordan W.↗

DOE OSTI2014

NREL RSF Measured Data 2011

Modern buildings are complex energy systems that must be controlled for energy efficiency. The Research Support Facility (RSF) at the National Renewable Energy Laboratory (NREL) has hundreds of controllers -- computers that communicate with the building's various control systems -- to control the building based on tens of thousands of variables and sensor points. These control strategies were designed for the RSF's systems to efficiently support research activities. Many events that affect energy use cannot be reliably predicted, but certain decisions (such as control strategies) must be made ahead of time. NREL researchers modeled the RSF systems to predict how they might perform. They then monitor these systems to understand how they are actually performing and reacting to the dynamic conditions of weather, occupancy, and maintenance. This submission includes the Measured Energy Data from the RSF Systems Model. The data includes a csv with measured data from NREL's Research and Support Facility (RSF) for 2011. The dataset contains hourly data for: Total Cooling (kW)- Total Heating (kW)- Total Mechanical (kW)- Total Lighting (kW)- Total Plug Loads (kW)- Total Data Center (kW)- Total Building (kW)- PV (kW)- Building Net (kW). Energy Model data and Weather data related to the RSF Systems Model can be found in the "Related Datasets" section of this submission.

2011↗

DOE OSTI2021

Sensor System and Observer Algorithm Co-Design For Modern Internal Combustion Engine Air Management Based on H2 Optimization

This paper outlines a novel sensor selection and observer design algorithm for linear time-invariant systems with both process and measurement noise based on H 2 optimization to optimize the tradeoff between the observer error and the number of required sensors. The optimization problem is relaxed to a sequence of convex optimization problems that minimize the cost function consisting of the H 2 norm of the observer error and the weighted l 1 norm of the observer gain. An LMI formulation allows for efficient solution via semi-definite programing. The approach is applied here, for the first time, to a turbo-charged spark-ignited engine using exhaust gas circulation to determine the optimal sensor sets for real-time intake manifold burnt gas mass fraction estimation. Simulation with the candidate estimator embedded in a high fidelity engine GT-Power model demonstrates that the optimal sensor sets selected using this algorithm have the best H 2 estimation performance. Sensor redundancy is also analyzed based on the algorithm results. This algorithm is applicable for any type of modern internal combustion engines to reduce system design time and experimental efforts typically required for selecting optimal sensor sets.

Zhang, Xu↗

NASA NTRS1986

The 60 GHz IMPATT diode development

The objective is to develop 60 GHz IMPATT diodes suitable for communications applications. The performance goals of the 60 GHz IMPATT is 1W CW output power with a conversion efficiency of 15 percent and 10-year lifetime. The final design of the 60 GHz IMPATT structure evolved from computer simulations performed at the University of Michigan. The initial doping profile, involving a hybrid double-drift (HDD) design, was derived from a drift-diffusion model that used the static velocity-field characteristics for GaAs. Unfortunately, the model did not consider the effects of velocity undershoot and delay of the avalanche process due to energy relaxation. Consequently, the initial devices were oscillating at a much lower frequency than anticipated. With a revised simulation program that included the two effects given above, a second HDD profile was generated and was used as a basis for fabrication efforts. In the area of device fabrication, significant progress was made in epitaxial growth and characterization, wafer processing, and die assembly. The organo-metallic chemical vapor deposition (OMCVD) was used. Starting with a baseline X-Band IMPATT technology, appropriate processing steps were modified to satisfy the device requirements at V-Band. In terms of efficiency and reliability, the device requirements dictate a reduction in its series resistance and thermal resistance values. Qualitatively, researchers were able to reduce the diodes' series resistance by reducing the thickness of the N+ GaAs substrate used in its fabrication.

Dat, Rovindra↗

NASA NTRS1999

Adaptive Filtering and Edge Detection Using Range Data

It is typical in edge and corner detection applications to examine a single scale or to consider some space of scales in the image without knowing which scale is appropriate for each location in the image.

Image smoothing edge detection stereoscopy filteri↗