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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Testing of PIP-II pre-production 650 MHz couplers in warm test stand and in cryomodule

650 MHz fundamental power couplers were developed for PIP-II project to deliver RF power for low-beta and high-beta elliptical cavities. Few prototypes were built and tested and after some modification we built 8 pre-production couplers (with few spares for vacuum side) for HB650 cryomodule. All couplers were successfully tested in pulse mode (up to 100kW) and in CW mode (up to 50kW) in test stand at full reflection at 8 phases. In baseline configuration with DC bias we do not see any multipactoring activity after short processing. We also tested power processing without bias for uncoated and TiN coated ceramic window. Results of these studies presented in this paper. One of the coupler was assembled on LB650 cavity and tested at cryogenic environment in STC cryostat at ~20kW power with full reflection at different reflection phase. We also demonstrated good result from power processing without bias for warm and cold cavity. Six couplers were assembled on HB650 cavities in pre-production cryomodule. Test results from cryomodule qualification is discussing in this paper.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

TPC Test-stands: An Overview & Future Prospects

The DUNE near detector design in Phase II will include a magnetized high-pressure gaseous-argon TPC (HPgTPC) surrounded by a calorimeter, called ND-GAr. ND-GAr is designed to provide fine-grained tracking, and due to its low detection threshold, it will be able to constrain one of the least-understood uncertainties for oscillation analysis: nuclear effects in argon at the neutrino interaction vertex. This talk will provide an overview of and an outlook about the ongoing R&D efforts in the context of the existing test stands that are evaluating the various readout system options for DUNE ND-GAr.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

TinyTPC - A test stand for photosensitive dopants

LArTPCs highly doped with Xenon could be interesting platforms for probing MeV- and sub-MeV physics including neutrinoless-double beta decay. A main hurdle is the small fraction of scintillation photons that are collected, which significantly impacts LArTPCs' energy resolution. One solution is the use of photosensitive dopants, which convert light to charge. A team from Rutgers University and FNAL have built a test stand (TinyTPC) with a LArPix pixelated anode plane and an active mass of 2.1 kg to study these charge enhancements. Our plan is to measure the TinyTPC’s energy resolution with and without dopants for radioactive gamma sources, which is crucial for accurate calorimetric energy reconstruction of low-energy physics signals. The doping agent that will be used is isobutylene and the radiation sources are Co-60, Y-88, and Th-228.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

TinyTPC - A Test Stand for Photosensitive Dopants

Liquid argon time projection chambers (LArTPCs) are widely used to study accelerator neutrinos. Since LArTPCs are sensitive down to 10– 100 keV, neutrino experiments' physics programs could be extended to lower energies. However, in this scale, LArTPCs' energy resolution is significantly degraded because only charge is collected efficiently. One solution is the introduction of photosensitive dopants, which convert scintillation light to ionization yield. We have built a test stand (TinyTPC) with a LArPix pixelated anode plane and an active mass of 2.1 kg to study these charge enhancements. Our plan is to measure TinyTPC’s energy resolution with and without dopants using radioactive sources. This poster presentation will discuss TinyTPC's status and goals.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Operational Experience of a Cryomodule Test Stand for LCLS-II Cryomodules

CMTS1 (cryomodule test stand 1) at Fermilab was built to test cryomodules built for the LCLS-II beamline at SLAC and is currently testing cryomodules for LCLS-II-HE, the high energy upgrade to LCLS-II. The first cryomodule test was in 2016 and to date over 30 cryomodules have been tested here. This talk will highlight operational experience of the vacuum systems including insulating, coupler, and a low particulate beamline vacuum system. It will focus on the problems that have come up over the years, their solutions, and mitigations put in place to prevent further issues.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Optimizing TinyTPC Test Stand for Low Energy Event Reconstruction

Introducing dopants into liquid argon offers a promising avenue to enhance the sensitivity and performance of LAr detectors such as DUNE. To explore this opportunity, we are optimizing and deploying the TinyTPC test stand, a compact time projection chamber with LArPix readout to study the effects of photosensitive dopants on the charge detected. TinyTPC enables comparative measurements of low-energy responses under various operational configurations and provides a platform to study the behavior of pixel readouts at low energy. We ensured system reliability through continuous current and voltage monitoring, modeling the detector's electrical behavior, and indirectly estimating total resistance under testing conditions. We ran the Blanche cryostat under various thresholds and gain configurations to evaluate their potential impact to low-energy event reconstruction and advancing R&D efforts for dopant integration in neutrino detectors

Van Loenen, Drew [Franciscan U. Steubenville]↗
DOE OSTI2026

Developing a GUI for the Robotic Test Stand

The introduction of this poster explains the technology behind DUNE’s far and near detectors and how passing neutrinos generate electrons that drift into a wire grid. I then explain how 3 ASICs manage signals received from electron interception. Next, the poster states how COLDATA chips are undergoing quality control by a Robotic Test Stand using a state machine. I further explained how earlier tests were done via a command line script and the necessity to implement a user-friendly Graphical User Interface with new features a command line can’t implement. For the implementation section, tools and methods for implementation are listed such as Python, tkinter, and GitHub as well as how multithreading and queue implementation was necessary for GUI functionality. Then, I elaborated on the GUIs new features. Finally, I explain how the GUI will be distributed across multiple institutions and future changes planned for the GUI. Photos of the RTS, far detector cave, diagram of anode assembly plane, COLDATA chips, set up tab, result tab, and legacy command line interface are shown.

Gutierrez Villanueva, Jaziel [DuPage Coll.]↗
DOE OSTI2025

ILAMBv2.7 benchmarking results comparing E3SMv2.1 land-atmosphere coupled (BGCv2LNDATM) and stand alone land (ELM) simulations with CMIP6 emission driven historical simulations

This dataset contains land model benchmarking results for the Energy Exascale Earth System Model version 2.1 (E3SMv2.1), including outputs from both coupled biogeochemistry simulations and stand-alone land model simulations. These results are compared against several emission-driven historical simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6). Benchmarking was conducted using the International Land Model Benchmarking (ILAMB) package, version 2.7 (ILAMBv2.7). CMIP6 model outputs were sourced from the Earth System Grid Federation (ESGF), while the E3SMv2.1 results were derived from raw model outputs. These outputs underwent processing steps such as time serialization, conservative regridding, and data standardization to ensure comparability. For spatial interpolation, the Earth System Modeling Framework (ESMF) tool, ESMF_RegridWeightGen, was employed to generate regridding weights, enabling the transformation of E3SM’s native cubed-sphere grid to a regular latitude-longitude grid.

Feng, Sha [PNNL]↗
DOE OSTI2024

Stand Age and Climate Change Effects on Carbon Increments and Stock Dynamics

Carbon assimilation and wood production are influenced by environmental conditions and endogenous factors, such as species auto-ecology, age, and hierarchical position within the forest structure. Disentangling the intricate relationships between those factors is more pressing than ever due to climate change’s pressure. We employed the 3D-CMCC-FEM model to simulate undisturbed forests of different ages under four climate change (plus one no climate change) Representative Concentration Pathways (RCP) scenarios from five Earth system models. In this context, carbon stocks and increment were simulated via total carbon woody stocks and mean annual increment, which depends mainly on climate trends. We find greater differences among different age cohorts under the same scenario than among different climate scenarios under the same age class. Increasing temperature and changes in precipitation patterns led to a decline in above-ground biomass in spruce stands, especially in the older age classes. On the contrary, the results show that beech forests will maintain and even increase C-storage rates under most RCP scenarios. Scots pine forests show an intermediate behavior with a stable stock capacity over time and in different scenarios but with decreasing mean volume annual increment. These results confirm current observations worldwide that indicate a stronger climate-related decline in conifers forests than in broadleaves.

Forestry↗
DOE OSTI2023

Coordination of rooting, xylem, and stomatal strategies explains the response of conifer forest stands to multi-year drought in the southern Sierra Nevada of California

Abstract. Extreme droughts are a major determinant of ecosystem disturbance that impacts plant communities and feeds back into climate change through changes in plant functioning. However, the complex relationships between aboveground and belowground plant hydraulic traits and their role in governing plant responses to drought are not fully understood. In this study, we use a model, the Functionally Assembled Terrestrial Ecosystem Simulator in a configuration that includes plant hydraulics (FATES-Hydro), to investigate ecosystem responses to the 2012–2015 California drought in comparison with observations at a site in the southern Sierra Nevada that experienced widespread tree mortality during this drought. We conduct a sensitivity analysis to explore how different plant water sourcing and hydraulic strategies lead to differential responses during normal and drought conditions. The analysis shows the following. Deep roots that sustain productivity through the dry season are needed for the model to capture observed seasonal cycles of evapotranspiration (ET) and gross primary productivity (GPP) in normal years, and deep-rooted strategies are nonetheless subject to large reductions in ET and GPP when the deep soil reservoir is depleted during extreme droughts, in agreement with observations. Risky stomatal strategies lead to greater productivity during normal years as compared to safer stomatal control, but they also lead to a high risk of xylem embolism during the 2012–2015 drought. For a given stand density, stomatal and xylem traits have a stronger impact on plant water status than on ecosystem-level fluxes. Our study highlights the significance of resolving plant water sourcing strategies to represent drought impacts on plants and consequent feedbacks in models.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

Low Carbon Technology Strategies: Stand-Alone Retail and Strip Mall

This document includes steps that building owners and operators can implement to achieve smart, healthy, and low-carbon retail buildings within their existing building portfolios. Stand-alone retail and strip malls often use packaged rooftop units for heating, cooling, and ventilation.

analytics↗
DOE OSTI2023

Thin free-standing oxide membranes

This disclosure provides systems, methods, and apparatus related to thin free-standing oxide membranes. In one aspect, a method includes providing a substrate. The substrate defines a hole having a diameter of about 500 nanometers to 5000 nanometers. A layer of metal is deposited on the substrate. A supporting layer is deposited on the layer of metal. A first side of the supporting layer is the side that is disposed on the layer of metal. A metal oxide layer is deposited on the first side of the supporting layer and on the substrate. In some implementations, the method further includes removing the supporting layer.

Lu, Yi-Hsien↗
DOE OSTI2023

Free‐Standing α‐MoO 3 / Ti 3 C 2 MXene Hybrid Electrode in Water‐in‐Salt Electrolytes

While transition‐metal oxides such as α‐MoO 3 provide high capacity, their use is limited by modest electronic conductivity and electrochemical instability in aqueous electrolytes. Two‐dimensional (2D) MXenes, offer metallic conductivity, but their capacitance is limited in aqueous electrolytes. Insertion of partially solvated cations into Ti 3 C 2 MXene from lithium‐based water‐in‐salt (WIS) electrolytes enables charge storage at positive potentials, allowing a wider potential window and higher capacitance. Herein, we demonstrate that α‐MoO 3 /Ti 3 C 2 hybrids combine the high capacity of α‐MoO 3 and conductivity of Ti 3 C 2 in WIS (19.8 m LiCl) electrolyte in a wide 1.8 V voltage window. Cyclic voltammograms reveal multiple redox peaks from α‐MoO 3 in addition to the well‐separated peaks of Ti 3 C 2 in the hybrid electrode. This leads to a higher specific charge and a higher rate capability compared to a carbon and binder containing α‐MoO 3 electrode. These results demonstrate that the addition of MXene to less conductive oxides eliminates the need for conductive carbon additives and binders, leads to a larger amount of charge stored, and increases redox capacity at higher rates. In addition, MXene encapsulated α‐MoO 3 showed improved electrochemical stability, which was attributed to the suppressed dissolution of α‐MoO 3 . The work suggests that oxide/MXene hybrids are promising for energy storage.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Performance Evaluation of Liquid-Cooled Open Stand-Alone Refrigerated Cases

This project is part of a joint effort between Commonwealth Edison Company (ComEd) and the National Renewable Energy Laboratory (NREL) to evaluate the energy and demand savings potential of emerging efficient buildings technologies. This project quantifies the energy efficiency benefits from retrofitting an air-cooled, constant-speed compression, self-contained medium-temperature open-vertical display case with a high efficiency water-cooled condensing unit. In addition to a water-cooled heat rejection mechanism, the high-efficiency condensing unit utilizes a variable-speed compressor, electronic expansion valve and advanced controls system. The focus of this project, however, was mainly on capturing the energy savings potentials of the water-cooled condenser, variable-speed compression and electronic expansion valve, and not on the advanced controls. The results of this evaluation will be considered by ComEd and CLEAResult for future energy efficiency rebate offerings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2026

Integrated Test Stand

Explore the source record for details and available documents.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Self‐Standing Carbon Nanofibers@Carbon Felt Electrodes to Boost Electrolyzer Productivity: Application to the Electro‐Manufacturing of trans ‐3‐Hexenedioic Acid and Adipic Acid

The industrial implementation of electrosynthesis for chemical manufacturing remains constrained by the limited surface area of conventional electrodes. Herein, this challenge is addressed by designing a carbon nanofiber@carbon felt (CNF@CF) electrode platform that combines the high conductivity, flexibility, and ease of handling of commercial carbon felts (CF) with the large surface area and tunable surface chemistry of carbon nanofibers (CNFs). CNFs are deliberately grown onto the CF scaffold to form a sword-in-sheath structure, where entangled nanofibers wrap the felt macrofibers to provide excellent mechanical stability and electrical conductivity without binders. CNF@CF is evaluated both as an electrode and as a catalyst support for the electrochemical hydrogenation of cis,cis-muconic acid (ccMA), a biobased platform molecule key to the production of performance polyamides and renewable Nylon 6,6. As a noncatalytic electrode for the partial hydrogenation to trans-3-hexenedioic acid, CNF@CF achieves a threefold increase in both cumulative productivity and Faradaic efficiency (FE) compared to bare CF. A similar boost in catalytic activity and energy efficiency is observed using Pd/CNF@CF for the hydrogenation of ccMA to adipic acid. These results highlight the opportunities of the CNF@CF platform for electro-organic synthesis and sustainable chemical manufacturing.

electrochemical hydrogenation↗
DOE OSTI2023

Evapotranspiration Partitioning of Eucalyptus benthamii and Pinus taeda During Early Stand Development

Increasing demand for bioenergy from intensively managed woody crops raises concerns of increased evapotranspiration and potential decreases in water yield. Pinus taeda (loblolly pine) is currently the most cultivated species in the southeastern USA, the country’s wood basket. However, Eucalyptus species could achieve greater productivity but with unknown ramifications for water budgets. To address the knowledge gap, we determined annual water budgets of loblolly pine and Eucalyptus benthamii (eucalypt) from growing years 3 through 5 in a replicated (n = 3) two-factor design comparing species and groundwater depth. Paired plots were established across a depth-to-groundwater gradient from shallow (~ 2 m) to deep (~ 8 m). Hydrologic budgets were constructed by measuring precipitation, interception, soil evaporation, and transpiration. Eucalypt evapotranspiration and above-ground biomass production for growing years 3 through 5 were on average 25 and 14% greater than pine, respectively; however, evapotranspiration did not differ across groundwater depths. At the end of growing year 5, eucalypt had higher transpiration and evapotranspiration per unit area than pine. Soil evaporation was substantial in young plantations (nearly 500 mm) in growing year 3 but declined as the canopy closed. Partitioning of evapotranspiration components in developing bioenergy plantations was dynamic due to canopy development driven decreases in soil evaporation and increases in transpiration and interception; total evapotranspiration was less variable from year to year. Water use efficiency (WUE, kg biomass/m 3 H 2 O) per unit evapotranspiration was similar between species, but WUE per unit transpiration was higher in pine. As a result, considering total evapotranspiration in young plantations can affect WUE interpretations.

59 BASIC BIOLOGICAL SCIENCES↗