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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 1,639 records · Page 91
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Coupling subsurface and above-surface models for optimizing the design of borefields and district heating and cooling systems in the presence of varying water-table depth. In: Proceedings, 46th Workshop on Geothermal Reservoir Engineering

Dynamic energy simulation is important for the design and sizing of district heating and cooling systems with geothermal heat exchange. Current modeling approaches in building and district energy simulation tools typically consider heat conduction through the ground between boreholes, without flow of groundwater. On the other hand, detailed simulation tools for subsurface heat and mass transfer exist, but these fall short in simulating above-surface energy systems. To support the design and operation of such systems, we have developed a coupled model including a software package for building and district energy simulation, and software for detailed heat and mass transfer in the ground. For the first, we use the open-source Modelica Buildings Library, which includes dynamic simulation models for building and district energy and control systems. For the heat and mass transfer in the soil, we use the TOUGH simulator. TOUGH can model heat and multi-phase, multi-component mass transport for a variety of fluid systems, as well as chemical reactions, in fractured porous media. In previous work, we described the coupling of these software packages, including how time-dependent boundary conditions for the borehole walls are synchronized for use in Modelica and TOUGH. We verified that the coupled Modelica/TOUGH code produced consistent results with the original Modelica code for an idealized problem in which heat transfer was purely by conduction in a uniform geologic medium. Here, we examine less idealized problems for which TOUGH’s advanced capabilities for modeling fluid flow are required. The first problem has a shallow vadose zone, and the second problem has a thicker vadose zone with a water-table depth that varies in time, which requires a fine vertical grid discretization for the TOUGH model.

Doughtry, Christine↗
DOE OSTI2022

Puerto Rico Grid and Recovery Post Hurricane Maria

This presentation discusses the impact of and recovery from Hurricanes Irma and Maria in Puerto Rico. The hurricanes hit two weeks apart in 2017, resulting in damage to all elements (generation, distribution, and transmission) of Puerto Rico's already fragile energy system.

demand response↗
DOE OSTI2022

Lessons Learned for Rapid Decarbonization of Power Sectors

This report covers key lessons learned for the rapid decarbonization of power sectors, emphasizing best practices in planning, building, and operating electricity systems. Decarbonization covers all greenhouse gases, including carbon dioxide and methane. The intended audience of this report consists of energy ministers and other high-level energy sector decisionmakers.

21CPP↗
DOE OSTI2022

Devices and methods for creating plasma channels for laser plasma acceleration

This disclosure provides systems, methods, and apparatus related to devices and methods for creating hollow, near-hollow, and parabolic plasma channels. In one aspect, a device includes a block of material and a cooling system. The block of material defines a channel having a cylindrical shape and having a first open end and a second open end. An axis of the channel lies along a straight line. The block of material further defines a first gas port and a second gas port. The first gas port and the second gas port are in fluid communication with channel. The cooling system is operable to cool the channel to below the freezing point of a gas.

Leemans, Wim↗
DOE OSTI2022

Bias control for a memory device

Methods, systems, and devices for bias control for a memory device are described. A memory system may store indication of whether data is coherent. In some examples, the indication may be stored as metadata, where a first value indicates that the data is not coherent and a second value or a third value indicate that the data is coherent. When a processing unit or other component of the memory system processes a command to access data, the memory system may operate according to a device bias mode when the indication is the first value, and according to a host bias mode when the indication is the second value or the third value.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Techno-Economic Analysis of an SOFC Hybrid Carbon Conversion Concept

This is a presentation prepared for the 2023 Hydrogen and Fuel Cell Seminar to take place in Long Beach, CA on February 7-9, 2023. The presentation highlights analysis recently conducted by NETL on the cost and performance associated with operating SOFC systems in a hybridized configuration with compressed air energy storage.

Buchheit, Kyle L.↗
DOE OSTI2020

Overview of ARIES Research Projects Involving Inverter-Based Resources

NREL's Power Electronic Grid Interface (PEGI) Workshop, held October 13, 2020, focused on the research challenges of operating power systems with ever-higher levels of inverter-based generation and power-electronic-based load. This presentation provides an overview of ARIES research projects involving inverter-based resources.

grid↗
DOE OSTI2020

Grid-Forming Inverters - Enabling the Next Generation Grid

NREL's Power Electronic Grid Interface (PEGI) Workshop, held October 13, 2020, focused on the research challenges of operating power systems with ever-higher levels of inverter-based generation and power-electronic-based load. This presentation discusses grid-forming inverters and enabling the next generation grid.

grid↗
DOE OSTI2020

ARIES and PEGI Platform - Overview and Background

NREL's Power Electronic Grid Interface (PEGI) Workshop, held October 13, 2020, focused on the research challenges of operating power systems with ever-higher levels of inverter-based generation and power-electronic-based load. This presentation shares an overview of ARIES and the PEGI Platform.

ARIES↗
DOE OSTI2023

Key Takeaways: First Cohort of Action Plans for Rapid Power Sector Decarbonization

The purpose of this synthesis report is to extract key takeaways from the first cohort of CEM Action Plans for rapid power sector decarbonization, developed by Australia, Chile, the European Union, India, and the United Kingdom. These Action Plans differ in their approach to power sector decarbonization based on the domestic resources available, governance structure, and regional context, among other factors. However, they also share common themes that were emphasized in the collaborative report released at CEM13. This report is not intended to be inclusive of all components in each Action Plan. Rather, this report highlights how select best practices for planning, building, and operating power systems are being implemented differently in these Action Plans, with equal focus given to each jurisdiction. Ministers and stakeholders from other governments with similar decarbonization goals can consider these examples within their own unique context.

Australia↗
DOE OSTI2023

Continuous toolpaths for additive manufacturing

Toolpath generation for additive manufacturing systems involves operations on polygonal contours derived from a model for additively manufacturing a structure. One aspect involves modifying or creating a model to allow parts to be printed without starting and stopping the printing equipment by generating continuous toolpaths or toolpaths having a reduced number of isolated paths. Another aspect involves modifying a slicing engine to generate a continuous toolpath or toolpath having a reduced number of isolated paths based on a representation of an object to be additively manufactured. Another aspect involves selectively placing the gaps at alternating positions among the sliced layers to create a zippering effect.

Borish, Michael C.↗
DOE OSTI2023

Delay-locked-loop timing error mitigation

Systems, methods, and circuits provide delay-locked loop (DLL) timing error mitigation. A DLL false-lock detection system can include DLL circuitry configured to receive a reference clock signal having a time period. The system can include shift register circuitry and latched comparison circuitry which can determine a time period of a locked condition of the DLL delay line with respect to the reference clock signal time period. The system can determine whether the system is correctly locked to the base time period or incorrectly locked to a multiple of the base time period. A further system can operate to cause a phase detector circuitry in a DLL to ignore the first edge of a reference clock signal presented to the phase detector circuitry and thereby avoid stuck-lock conditions.

Filippini, Leo↗
DOE OSTI2023

Bias control for a memory device

Methods, systems, and devices for bias control for a memory device are described. A memory system may store indication of whether data is coherent. In some examples, the indication may be stored as metadata, where a first value indicates that the data is not coherent and a second value or a third value indicate that the data is coherent. When a processing unit or other component of the memory system processes a command to access data, the memory system may operate according to a device bias mode when the indication is the first value, and according to a host bias mode when the indication is the second value or the third value.

Walker, Dean↗
DOE OSTI2023

Development of Advanced Radionuclide Gamma spectrOmeter-2 (ARGO-2) for Low-level Radionuclide Measurements

A low-level multidimensional gamma spectrometer was recently installed at Pacific Northwest National Laboratory, USA. The spectrometer utilizes a dual-detector design and advanced detection techniques, demonstrating superior detection efficiency/sensitivity. This work details integral components of the system, including the dual-detector design, its shielding, and cosmic veto panels for background reduction. Results from system’s operation in singles and coincidence mode are highlighted.

ARGO, Coincidence measurements, Multidimensional g↗
DOE OSTI2023

Biomethanation to Upgrade Biogas to Pipeline Grade Methane

NREL is working closely with DOE, Electrochaea GmbH, and Southern California Gas Company (SoCalGas) to reduce costs of a biomethanation process capable of megawatt-scale deployment that upgrades organic biogas waste streams to produce pipeline quality renewable natural gas (RNG). Biomethanation is a two-step process using a single-celled methanogenic archaea that converts low-carbon low-cost hydrogen (H2) and waste carbon dioxide (CO2) to produce renewable methane (CH4). The process upgrades the biogenic CO2 - while allowing the CH4 to pass through - from biogas sources like dairies, wastewater treatment plants, and landfills. The CH4 produced is a drop-in direct replacement fuel and producers can participate in the growing number of carbon markets; like California's Low Carbon Fuel Standard and the Federal Renewable Fuel Standard. NREL and Argonne National Laboratory have completed a life cycle analysis using the GREET model to show that the biomethanation process produces RNG that is carbon negative even when H2 production via low-temperature water electrolysis is driven by the existing carbon intensity of California's electricity grid. And of course, even further carbon negative (-233 kg CO2e/kWh) when the electricity is produced from low-carbon sources like wind and solar. Leveraging lessons learned from operating SoCalGas' 700L 18-bar bioreactor system, NREL is designing and building a flexible RD&D platform that will enable field trials at biogas and other CO2 sources. A custom 16' long trailer will house a 20L 18-bar bioreactor, 3 - 25 kW proton exchange membrane electrolyzer, and dosing, thermal, and controls systems to support operations with only power, biogas, and water feedstocks required by the field locations. The end-of-project goal is to demonstrate pipeline quality RNG production (> 95% CH4, < 4% H2, <1% CO2, < 0.2% O2 and < 4 parts per million H2 sulfide) using real biogas feedstocks - thereby recycling both greenhouse gases for injection into the natural gas network or to be used onsite.

biogas upgrading↗
DOE OSTI2020

D and D Research on KM-IT Platform - 20494

The Knowledge Management Information Tool (KM-IT) is a web-based system developed to maintain and preserve the Department of Energy's (DoE's) knowledge base. The system was developed by Florida International University's Applied Research Center (FIU-ARC) with the support of the D and D community including the DOE Office of Environmental Management, and with the collaboration and support of the DoE's Energy Facility Contractors Group (EFCOG) and the former ALARA Centers at Hanford and Savannah. The KM-IT system is a community driven system tailored to serve the technical issues faced by the workforce across the DOE Complex. This KM-IT web-based interactive system is operational and available for use at www.dndkm.org and is currently comprised of the following modules: Web Crawler, Hotline, Technology, Hanford's ALARA Center Reports, Specialist Directory, Lessons Learned, Best Practices, Video/Picture Library, Vendors and Industry News. The Web Crawler dynamically searches through the KM-IT repository as well as the web and displays search results based on the search criteria. The Hotline allows registered users to post questions/problems related to D and D and to receive solutions from a subject-matter specialist. The Technology module serves as repository of D and D technologies and contains technology/ demonstration fact sheets and vendor information. D and D community members can add Lessons Learned, Best Practices, and Pictures/Videos to the D and D repository, after a formal approval process. The Vendor module provides a directory of commercial vendors who provide D and D related technologies, supplies, and services. KM-IT makes an excellent use of the knowledge that exists within the D and D community by allowing D and D project managers around the DOE complex to collaborate by sharing innovative ideas, past experiences, and practices and by maintaining a directory of subject matter specialists. FIU has developed the dedicated module on KM-IT platform to publish D and D research being performed at FIU. This module highlights current EM research efforts and activities in support of D and D being performed at FIU/SRNL associated with fixatives and intumescent products. FIU will expand this module to include the recent and current D and D research being performed across multiple DOE EM sites, national labs and universities. FIU will collaborate with SRNL, INL, ANL and other universities to explore and publish D and D research activities on KM-IT. As a result, the user community will have a centralized location to review new D and D related research across the DOE EM complex. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗