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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Effects of defects in composite wind turbine blades – Part 2: Progressive damage modeling of fiberglass-reinforced epoxy composites with manufacturing-induced waves

Abstract. Composite wind turbine blades are typically reliable; however, premature failures are often in regions of manufacturing defects. While the use of damage modeling has increased with improved computational capabilities, they are often performed for worst-case scenarios in which damage or defects are replaced with notches or holes. To better understand and predict these effects, an effects-of-defects study has been undertaken. As a portion of this study, various progressive damage modeling approaches were investigated to determine if proven modeling capabilities could be adapted to predict damage progression of composite laminates with typical manufacturing flaws commonly found in wind turbine blades. Models were constructed to match the coupons from, and compare the results to, the characterization and material testing study presented as a companion. Modeling methods were chosen from established methodologies and included continuum damage models (linear elastic with Hashin failure criteria, user-defined failure criteria, nonlinear shear criteria), a discrete damage model (cohesive elements), and a combined damage model (nonlinear shear with cohesive elements). A systematic, combined qualitative–quantitative approach was used to compare consistency, accuracy, and predictive capability for each model to responses found experimentally. Results indicated that the Hashin and combined models were best able to predict material response to be within 10 % of the strain at peak stress and within 10 % of the peak stress. In both cases, the correlation was not as accurate as the wave shapes were changed in the model; correlation was still within 20 % in many cases. The other modeling approaches did not correlate well within the comparative framework. Overall, the results indicate that this combined approach may provide insight into blade performance with known defects when used in conjunction with a probabilistic flaw framework.

Nelson, Jared W. (ORCID:0000000207736091)↗
DOE OSTI2014

LARP7 suppresses P-TEFb activity to inhibit breast cancer progression and metastasis

Transcriptional elongation by RNA polymerase (Pol) II is essential for gene expression during cell growth and differentiation. The positive transcription elongation factor b (P-TEFb) stimulates transcriptional elongation by phosphorylating Pol II and antagonizing negative elongation factors. A reservoir of P-TEFb is sequestered in the inactive 7SK snRNP where 7SK snRNA and the La-related protein LARP7 are required for the integrity of this complex. Here, we show that P-TEFb activity is important for the epithelial–mesenchymal transition (EMT) and breast cancer progression. Decreased levels of LARP7 and 7SK snRNA redistribute P-TEFb to the transcriptionally active super elongation complex, resulting in P-TEFb activation and increased transcription of EMT transcription factors, including Slug, FOXC2, ZEB2, and Twist1, to promote breast cancer EMT, invasion, and metastasis. Our data provide the first demonstration that the transcription elongation machinery plays a key role in promoting breast cancer progression by directly controlling the expression of upstream EMT regulators.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

Overview of the TCV tokamak program: Scientific progress and facility upgrades

The TCV tokamak is augmenting its unique historical capabilities (strong shaping, strong electron heating) with ion heating, additional electron heating compatible with high densities, and variable divertor geometry, in a multifaceted upgrade program designed to broaden its operational range without sacrificing its fundamental flexibility. The TCV program is rooted in a three-pronged approach aimed at ITER support, explorations towards DEMO, and fundamental research. A 1 MW, tangential neutral beam injector (NBI) was recently installed and promptly extended the TCV parameter range, with record ion temperatures and toroidal rotation velocities and measurable neutral-beam current drive. ITER-relevant scenario development has received particular attention, with strategies aimed at maximizing performance through optimized discharge trajectories to avoid MHD instabilities, such as peeling-ballooning and neoclassical tearing modes. Experiments on exhaust physics have focused particularly on detachment, a necessary step to a DEMO reactor, in a comprehensive set of conventional and advanced divertor concepts. The specific theoretical prediction of an enhanced radiation region between the two X-points in the low-field-side snowflake-minus configuration was experimentally confirmed. Fundamental investigations of the power decay length in the scrape-off layer (SOL) are progressing rapidly, again in widely varying configurations and in both D and He plasmas; in particular, the double decay length in L-mode limited plasmas was found to be replaced by a single length at high SOL resistivity. Experiments on disruption mitigation by massive gas injection and electron-cyclotron resonance heating (ECRH) have begun in earnest, in parallel with studies of runaway electron generation and control, in both stable and disruptive conditions; a quiescent runaway beam carrying the entire electrical current appears to develop in some cases. Developments in plasma control have benefited from progress in individual controller design and have evolved steadily towards controller integration, mostly within an environment supervised by a tokamak profile control simulator. TCV has demonstrated effective wall conditioning with ECRH in He in support of the preparations for JT-60SA operation.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2013

Progress on DCLL Blanket Concept

Under the US Fusion Nuclear Science and Technology Development program, we have selected the Dual Coolant Lead Lithium concept (DCLL) as a reference blanket, which has the potential to be a high performance DEMO blanket design with a projected thermal efficiency of >40%. Reduced activation ferritic/martensitic (RAF/M) steel is used as the structural material. The self-cooled breeder PbLi is circulated for power conversion and for tritium breeding. A SiC-based flow channel insert (FCI) is used as a means for magnetohydrodynamic pressure drop reduction from the circulating liquid PbLi and as a thermal insulator to separate the high-temperature PbLi (~700°C) from the helium-cooled RAF/M steel structure. We are making progress on related R&D needs to address critical Fusion Nuclear Science and Facility (FNSF) and DEMO blanket development issues. When performing the function as the Interface Coordinator for the DCLL blanket concept, we had been developing the mechanical design and performing neutronics, structural and thermal hydraulics analyses of the DCLL TBM module. We had estimated the necessary ancillary equipment that will be needed at the ITER site and a detailed safety impact report has been prepared. This provided additional understanding of the DCLL blanket concept in preparation for the FNSF and DEMO. This paper will be a summary report on the progress of the DCLL TBM design and R&Ds for the DCLL blanket concept.

Wong, Clement↗
DOE OSTI2013

One System Integrated Project Team Progress in Coordinating Hanford Tank Farms and the Waste Treatment Plant

The One System Integrated Project Team (IPT) was formed at the Hanford Site in late 2011 as a way to improve coordination and itegration between the Hanford Tank Waste Treatment and Immobilization Plant (WTP) and the Tank Operations Contractor (TOC) on interfaces between the two projects, and to eliminate duplication and exploit opportunities for synergy. The IPT is composed of jointly staffed groups that work on technical issues of mutal interest, front-end design and project definition, nuclear safety, plant engineering system integration, commissioning, planning and scheduling, and environmental, safety, health and quality (ESH&Q) areas. In the past year important progress has been made in a number of areas as the organization has matured and additional opportunities have been identified. Areas covered in this paper include: Support for development of the Office of Envirnmental Management (EM) framework document to progress the Office of River Protection's (ORP) River Protection Project (RPP) mission; Stewardship of the RPP flowsheet; Collaboration with Savannah River Site (SRS), Savannah River National Laboratory (SRNL), and Pacific Northwest National Laboratory (PNNL); Operations programs integration; and, Further development of the waste acceptance criteria.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Progress of MICE RFCC Module

Recent progress on the design and fabrication of the RFCC (RF and superconducting Coupling Coil) module for the international MICE (Muon Ionization Cooling Experiment) are reported. The MICE ionization cooling channel has two RFCC modules, each having four 201- MHz normal conducting RF cavities surrounded by one superconducting coupling coil (solenoid) magnet. The magnet is designed to be cooled by three cryocoolers. Fabrication of the RF cavities is complete; preparation for the cavity electro-polishing, low power RF measurements, and tuning are in progress at Lawrence Berkeley National Laboratory (LBNL). Fabrication of the cold mass of the first coupling coil magnet has been completed in China and the cold mass arrived at LBNL in late 2011. Preparations for testing the cold mass are currently under way at Fermilab. Plans for the RFCC module assembly and integration are being developed and are described.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Recent Progress in Producing Lignin-Based Carbon Fibers for Functional Applications

Lignin, a biopolymer, has been investigated as a renewable and low-cost carbon fiber precursor since the 1960s. Although successful lab-scale production of lignin-based carbon fibers has been reported, there are currently not any commercial producers. This paper will highlight some of the known challenges with converting lignin-based precursors into carbon fiber, and the reported methods for purifying and modifying lignin to improve it as a precursor. Several of the challenges with lignin are related to its diversity in chemical structure and purity, depending on its biomass source (e.g. hardwood, softwood, grasses) and extraction method (e.g. organosolv, kraft). In order to make progress in this field, GrafTech and Oak Ridge National Laboratory are collaborating to develop lignin-based carbon fiber technology and to demonstrate it in functional applications, as part of a cooperative agreement with the DOE Advanced Manufacturing Office. The progress made to date with producing lignin-based carbon fiber for functional applications, as well as developing and qualifying a supply chain and value proposition, are also highlighted.

Paul, Ryan↗
DOE OSTI2016

Progress on the three-particle quantization condition

We report progress on extending the relativistic model-independent quantization condition for three particles, derived previously by two of us, to a broader class of theories, as well as progress on checking the formalism. In particular, we discuss the extension to include the possibility of 2->3 and 3->2 transitions and the calculation of the finite-volume energy shift of an Efimov-like three-particle bound state. The latter agrees with the results obtained previously using non-relativistic quantum mechanics.

Briceno, Raul↗
DOE OSTI2016

R&D Progress on Recovery/Recycle of Zirconium from Used Fuel Cladding

There has been significant progress accomplished at Oak Ridge National Laboratory (ORNL) on the development of a dry chlorination process for recovery and purification of zirconium from used nuclear fuel (UNF) cladding by conversion to zirconium tetrachloride, which sublimes to a vapor and is then condensed as a dry salt product, essentially free of fuel and alloy components (impurities). We have accomplished significant progress on developing a chlorination process for removing the zirconium in UNF cladding and purifying the product salt for re-use—possibly in manufacture of new cladding, or at a minimum to meet specifications for disposal as low level waste.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2018

Transient Reactor Test Facility (TREAT) Low Enriched Uranium (LEU) Conversion Progress

The National Nuclear Security Administration Office of Material Management and Minimization (NNSA M3) is working towards converting the Transient Reactor Test Facility (TREAT) located at the Idaho National Laboratory (INL) from its original high-enriched uranium (HEU) core to a low-enriched uranium (LEU) core. TREAT reactor operations were restarted in November of 2017 and data obtained from the initial testing will be used to validate the existing ANL reactor modeling. Fuel block development has progressed with the completion of 2 and 4 inch crack free surrogate fuel blocks. Alternative fabrication methods for the fuel blocks continue to be explored and are showing promising results. Additionally, cladding oxidation studies have been performed and analyzed to initiate the down selection of cladding material to be used for the TREAT LEU fuel elements. This paper describes the current status of the above mentioned activities, and discusses the anticipated path forward for the conversion program as it progresses toward a final fuel design and fuel fabrication process.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Investigating YAP’s role in Human Mammary Epithelial Cell (HMEC) Immortalization and Cancer Stem Cell (CSC) Phenotype Acquisition during Early Breast Cancer Progression

The malignant aspect of tumorigenesis in breast cancer is initiated when human mammary epithelial cells (HMEC) first immortalize (gain the ability to proliferate indefinitely) and subsequently undergo oncogenic activation. Our laboratory has developed a two-step HMEC immortalization process that we believe accurately models early breast cancer progression. Normal finite pre-stasis HMEC must overcome two distinct senescence barriers to achieve full immortality: stasis (stress-associated senescence) and replicative senescence, respectively. HMEC bypass stasis, and become post-stasis, when errors in the retinoblastoma pathway are present. Replicative senescence, a product of continuously shortening telomeres producing telomere dysfunction, is overcome by the reactivation of telomerase. Our lab has called HMEC that acquire the error allowing telomerase expression conditionally immortal (CI); CI cells may still have low telomerase expression. Full immortality is achieved when sufficient telomerase expression exists to maintain short stable telomeres following a process we have called conversion. The transcriptional coactivator YAP, upregulated in several human cancers, is closely correlated with a variety of oncogenic effects including proliferation and induction of cancer stem cell (CSC) properties. Our preliminary data have shown that YAP-transduced post-stasis HMEC expressed properties of CI cells. Growth curves indicated that some cell lines achieved full immortality; however, these cells had acquired an additional error – amplified expression of c-Myc, an oncogene known to induce telomerase in post-stasis or CI cells. The absence of uniform immortalization in the YAP-transduced cells suggests that YAP causes post-stasis HMEC to become conditionally immortal. This is further supported given that YAP-transduced post-stasis HMEC have decreased levels of the lncRNA MORT and rapidly go through conversion when p53 function is abrogated, well-documented attributes of CI HMEC. Previous studies have also reported that YAP controls the differentiation of breast progenitor cells; as a result, it is likely that YAP plays a role in inducing CSC phenotypes. In this study, we attempt to gain a greater understanding of YAP’s role in HMEC immortalization and induction of CSC properties in early breast cancer progression. We measured gene expression levels and attempted to identify proteins indicative of a CSC phenotype in YAP-transduced post-stasis HMEC. Our initial results did not reveal an association between YAP and HMEC conditional immortality or induction of CSC attributes in the cultures examined. However, using a YAP construct that promotes nuclear localization (where YAP is most active) has led to a potentially promising YAP-derived cell line that we presume to be immortal. We go on to demonstrate that YAP may be acting via non-transcriptional oncogenic roles in our HMEC specimens. Thus, we recommend future studies into YAP and the HMEC immortalization process given that they are promising targets for breast cancer prevention therapies.

Shah, Manav↗
DOE OSTI2015

Progress With Multi-Cell Nb3Sn Cavity Development Linked With Sample Materials Characterization

Exploiting both the new Nb3Sn coating system and the materials characterization tools nearby, we report our progress in low-loss Nb3Sn films development. Nb3Sn films a few micrometers thick were grown on Nb coupons as well as single- and multi-cell cavities by the Sn-diffusion technique. Films structure and composition were investigated on coated samples and cavity cutouts with characterization tools including SEM/EDS/EBSD, AFM, XPS, SIMS towards correlating film growth and RF loss to material properties and deposition parameters. Cavity coating efforts focused on establishing techniques for coating progressively more complicated RF structures, and understanding limiting mechanisms in coated cavities. Nb3Sn coated 1.5 GHz 1-cell and 1.3 GHz 2-cell cavities have shown quality factors of 1010 at 4.3 K, with several cavities reaching above Eacc = 10 MV/m. The dominant limiting mechanisms were low field quenches and quality factor degradation above 8 MV/m. The surface data indicates a near-stoichiometric Nb3Sn consistent with the transition temperature and gap measurements. The Nb3Sn layer is covered with Nb2O5 and SnO2 native oxides and has little memory of the pre-coating surface.

Eremeev, Grigory V.↗
DOE OSTI2022

Progress on Machine Learning for the SNS High Voltage Converter Modulators

The High-Voltage Converter Modulators (HVCM) used to power the klystrons in the Spallation Neutron Source (SNS) linac were selected as one area to explore machine learning due to reliability issues in the past and the availability of large sets of archived waveforms. Progress in the past two years has resulted in generating a significant amount of simulated and measured data for training neural network models such as recurrent neural networks, convolutional neural networks, and variational autoencoders. Applications in anomaly detection, fault classification, and prognostics of capacitor degradation were pursued in collaboration with the Jefferson Laboratory, and early promising results were achieved. This paper will discuss the progress to date and present results from these efforts.

Pappas, Chris↗
DOE OSTI2023

PR100 One-Year Progress Update: Preliminary Modeling Results and High-Resolution Solar and Wind Data Sets

The Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy Study (PR100) is a 2-year study by the U.S. Department of Energy's (DOE's) Grid Deployment Office and six national laboratories to comprehensively analyze stakeholder-driven pathways to Puerto Rico's clean energy future. In Year 1 of the study, the PR100 team rigorously modeled and analyzed scenarios that meet Puerto Rico's renewable energy targets and achieve short-term recovery goals and long-term energy resilience. This presentation will be showcased in the form of a public webinar, which summarizes PR100 progress in Year 1, provides considerations that can inform potential funding and implementation decisions by key federal and local agencies and stakeholders. The presentation follows the publication in July 2022 of a PR100 Six-Month Progress Update (in English and Spanish), as well as public webinars in February 2022 to kick off the study and in July 2022 to present the 6-month update. A final written report and web-based visuals will be published in late 2023. All publications and public events associated with the study will be available in Spanish and English. This report is also available in Spanish: https://www.nrel.gov/docs/fy23osti/85201.pdf.

100%↗
DOE OSTI2023

Summary Analysis of Different Offshore Wind Capacity Density Drivers in Proposed U.S. Projects and Impacts on Progress Towards State and Federal Deployment Targets

Understanding the density of offshore wind development - or the "capacity density" - is important for state and federal offshore wind planning efforts and to track progress towards policy goals. NREL has traditionally assumed a capacity density of 3 megawatts per square kilometer (MW/km2) when estimating the U.S. project pipeline (Musial et al. 2022), but capacity densities for existing European offshore wind farms ranged from 2-19 MW/km2 (Borrmann et al. 2018). We track the expected capacity densities of the proposed U.S. projects in the East Coast and make an analysis by state and by developer to identify what are the capacity density norms in the industry and whether the state in which the development efforts are taking place has some impact on capacity density. We also analyze the effects of the area occupied by station keeping systems on capacity density for lease areas dedicated to floating projects and provide a list of main capacity density drivers. This summary analysis sets a baseline to study how different capacity density drivers could impact the progress towards state and federal deployment targets. Given the currently delineated Renewable Energy Areas in the Outer Continental Shelf (OCS) and the basis from the summary analysis, we estimate the expected offshore wind deployment over time federally and by state and compare it to the state and federal deployment targets. The proposed analysis helps identify gaps and needs to meet state and federal targets, which provides sufficient information to propose strategic supply chain and policy planning with the objective of meeting deployment goals.

capacity density↗
DOE OSTI2013

A logical progression of steps for implementation and testing of the 7-equation, two-phase model into a computational framework

A seven-step progression is given for the implementation of the seven-equation model, employed in the new RELAP-7 thermal hydraulics system analysis code, within the MOOSE-compatible framework. The model is well-posed and treats both phases as compressible flow in a one-dimensional, variable cross-sectional area duct/pipe/component. Some appropriate tests are also outlined to benchmark the model/implementation for each step of the progression. (authors)

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

Radioactive Waste Management and Nuclear Facility Decommissioning Progress in Iraq - 13216

Management of Iraq's radioactive wastes and decommissioning of Iraq's former nuclear facilities are the responsibility of Iraq's Ministry of Science and Technology (MoST). The majority of Iraq's former nuclear facilities are in the Al-Tuwaitha Nuclear Research Center located a few kilometers from the edge of Baghdad. These facilities include bombed and partially destroyed research reactors, a fuel fabrication facility and radioisotope production facilities. Within these facilities are large numbers of silos, approximately 30 process or waste storage tanks and thousands of drums of uncharacterised radioactive waste. There are also former nuclear facilities/sites that are outside of Al-Tuwaitha and these include the former uranium processing and waste storage facility at Jesira, the dump site near Adaya, the former centrifuge facility at Rashdiya and the former enrichment plant at Tarmiya. In 2005, Iraq lacked the infrastructure needed to decommission its nuclear facilities and manage its radioactive wastes. The lack of infrastructure included: (1) the lack of an organization responsible for decommissioning and radioactive waste management, (2) the lack of a storage facility for radioactive wastes, (3) the lack of professionals with experience in decommissioning and modern waste management practices, (4) the lack of laws and regulations governing decommissioning or radioactive waste management, (5) ongoing security concerns, and (6) limited availability of electricity and internet. Since its creation eight years ago, the MoST has worked with the international community and developed an organizational structure, trained staff, and made great progress in managing radioactive wastes and decommissioning Iraq's former nuclear facilities. This progress has been made, despite the very difficult implementing conditions in Iraq. Within MoST, the Radioactive Waste Treatment and Management Directorate (RWTMD) is responsible for waste management and the Iraqi Decommissioning Directorate (IDD) is responsible for decommissioning activities. The IDD and the RWTMD work together on decommissioning projects. The IDD has developed plans and has completed decommissioning of the GeoPilot Facility in Baghdad and the Active Metallurgical Testing Laboratory (LAMA) in Al-Tuwaitha. Given this experience, the IDD has initiated work on more dangerous facilities. Plans are being developed to characterize, decontaminate and decommission the Tamuz II Research Reactor. The Tammuz Reactor was destroyed by an Israeli air-strike in 1981 and the Tammuz II Reactor was destroyed during the First Gulf War in 1991. In addition to being responsible for managing the decommissioning wastes, the RWTMD is responsible for more than 950 disused sealed radioactive sources, contaminated debris from the first Gulf War and (approximately 900 tons) of naturally-occurring radioactive materials wastes from oil production in Iraq. The RWTMD has trained staff, rehabilitated the Building 39 Radioactive Waste Storage building, rehabilitated portions of the French-built Radioactive Waste Treatment Station, organized and secured thousands of drums of radioactive waste organized and secured the stores of disused sealed radioactive sources. Currently, the IDD and the RWTMD are finalizing plans for the decommissioning of the Tammuz II Research Reactor. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Progress updates for the Hanford waste treatment and immobilization plant project - 15593

The Waste Treatment and Immobilization Plant (WTP) Project is vital to the U.S. Department of Energy's (DOE) mission to clean up radioactive waste at the Hanford Site in southeastern Washington State. The overall WTP Project objective is to design, build, and commission the facilities and systems that will treat and immobilize approximately 211 983 m{sup 3} (56 million gallons) of radioactive waste stored in 177 underground storage tanks. The combination of technologies in the WTP makes it a first-of-a-kind facility at a scale larger than ever built for radioactive waste processing. In recent years, the project has encountered issues that affected project design completion, especially in the Pretreatment and High-Level Waste Facilities. These included technical issues, changes in requirements, changes in funding, weaknesses in the nuclear supply chain, identification of new hazards, and new information about the tank waste. The combination of these issues led to a suspension of construction of the Pretreatment Facility and a partial suspension of construction of the High-Level Waste Facility in mid-2012. Since then, the WTP Project has made significant progress in establishing and implementing a strategy for resolving these issues. This strategy focuses on resuming full production work in a sequence that fully supports the DOE plan for a phased approach for starting treatment of the Hanford tank waste, beginning with the low-activity waste streams. Concurrent with the technical and programmatic issues, the DOE Office of River Protection has made numerous changes in the processes it uses to manage and oversee the WTP Project. These changes have had a beneficial impact on the progress the project has made in establishing a path forward for resuming production activities, and on planning for the necessary contract and baseline changes needed to complete the project. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗