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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Integrated Biomass Refining Institute at North Carolina State University

The overall objective of the Integrated Biomass Refining Institute (IBRI) is to advance the fundamental understanding of novel biomass conversion technologies leading to the production of biofuels and bioproducts, expanding the range of feedstock that can be utilized and compounds produced from a biomass refinery. The outcomes of this project will be new analytical facilities for biofuels and bioproducts research at North Carolina State University (NCSU), establishment of the capabilities of a cellulosic ethanol screening pilot facility to monitor and control processes, and publications in the open literature and presentations at public conferences regarding novel crops and technologies for cost-effective biomass processing.

09 BIOMASS FUELS↗
DOE OSTI2017

Visible Quantum Nanophotonics.

The goal of this LDRD is to develop a quantum nanophotonics capability that will allow practical control over electron (hole) and photon confinement in more than one dimension. We plan to use quantum dots (QDs) to control electrons, and photonic crystals to control photons. InGaN QDs will be fabricated using quantum size control processes, and methods will be developed to add epitaxial layers for hole injection and surface passivation. We will also explore photonic crystal nanofabrication techniques using both additive and subtractive fabrication processes, which can tailor photonic crystal properties. These two efforts will be combined by incorporating the QDs into photonic crystal surface emitting lasers (PCSELs). Modeling will be performed using finite-different time-domain and gain analysis to optimize QD-PCSEL designs that balance laser performance with the ability to nano-fabricate structures. Finally, we will develop design rules for QD-PCSEL architectures, to understand their performance possibilities and limits.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2017

Integrated Predictive Tools for Customizing Microstructure and Material Properties of Additively Manufactured Aerospace Components

Additive Manufacturing (AM) refers to a process by which digital three-dimensional (3-D) design data is converted to build up a component by depositing material layer-by-layer. United Technologies Corporation (UTC) is currently involved in fabrication and certification of several AM aerospace structural components made from aerospace materials. This is accomplished by using optimized process parameters determined through numerous design-of-experiments (DOE)-based studies. Certification of these components is broadly recognized as a significant challenge, with long lead times, very expensive new product development cycles and very high energy consumption. Because of these challenges, United Technologies Research Center (UTRC), together with UTC business units have been developing and validating an advanced physics-based process model. The specific goal is to develop a physics-based framework of an AM process and reliably predict fatigue properties of built-up structures as based on detailed solidification microstructures. Microstructures are predicted using process control parameters including energy source power, scan velocity, deposition pattern, and powder properties. The multi-scale multi-physics model requires solution and coupling of governing physics that will allow prediction of the thermal field and enable solution at the microstructural scale. The state-of-the-art approach to solve these problems requires a huge computational framework and this kind of resource is only available within academia and national laboratories. The project utilized the parallel phase-fields codes at Oak Ridge National Laboratory (ORNL) and Lawrence Livermore National Laboratory (LLNL), along with the high-performance computing (HPC) capabilities existing at the two labs to demonstrate the simulation of multiple dendrite growth in threedimensions (3-D). The LLNL code AMPE was used to implement the UTRC phase field model that was previously developed for a model binary alloy, and the simulation results were compared against the UTRC simulation results, followed by extension of the UTRC model to simulate multiple dendrite growth in 3-D. The ORNL MEUMAPPS code was used to simulate dendritic growth in a model ternary alloy with the same equilibrium solidification range as the Ni-base alloy 718 using realistic model parameters, including thermodynamic integration with a Calphad based model for the ternary alloy. Implementation of the UTRC model in AMPE met with several numerical and parametric issues that were resolved and good comparison between the simulation results obtained by the two codes was demonstrated for two dimensional (2-D) dendrites. 3-D dendrite growth was then demonstrated with the AMPE code using nondimensional parameters obtained in 2-D simulations. Multiple dendrite growth in 2-D and 3-D were demonstrated using ORNL’s MEUMAPPS code using simple thermal boundary conditions. MEUMAPPS was then modified to incorporate the complex, time-dependent thermal boundary conditions obtained by UTRC’s thermal modeling of single track AM experiments to drive the phase field simulations. The results were in good agreement with UTRC’s experimental measurements.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Final Project Report CFA-14-6357: A New Paradigm for Understanding Multiphase Ceramic Waste Form Performance

This project fabricated model multiphase ceramic waste forms with processing-controlled microstructures followed by advanced characterization with synchrotron and electron microscopy-based 3D tomography to provide elemental and chemical state-specific information resulting in compositional phase maps of ceramic composites. Details of 3D microstructural features were incorporated into computer-based simulations using durability data for individual constituent phases as inputs in order to predict the performance of multiphase waste forms with varying microstructure and phase connectivity.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Identification of Promising Remediation Technologies for Iodine in the UP-1 Operable Unit

Iodine-129 (129I) generated at the U.S. Department of Energy (DOE) Hanford Site during plutonium production was released to the subsurface, resulting in several large, though dilute, plumes in the groundwater, including the plume in the 200-UP-1 operable unit (OU). Because 129I is an uncommon contaminant, relevant remediation experience and scientific literature are limited, though work is under way to better understand the fate and transport of 129I in the environment and the effectiveness of potential remediation technologies. The recent UP-1 Evaluation Plan for Iodine and report on the Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site provide information on the history of contamination in the 200-UP-1 OU, relevant controlling processes (biological and geochemical), risk, the conceptual site model, and potential remedial options, which provided a foundation for this study. In this study, available information was compiled and used to categorize potential remediation technologies, culminating in a recommendation of promising technologies for further evaluation. Approaches to improve the technical information about promising technologies are also recommended in this study so that a subsequent evaluation of potential remediation alternatives can assess these technologies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Developing quantitative capabilities for a scanning microwave impedance microscope

Currently no instrument exists to quantitatively measure electrical properties (dielectric constant and conductivity) on sub-micron regions, a capability of extreme importance to measure the functioning of sub-micron structures and devices. In particular, such electrical measurements could support the development and manufacture of advanced energy related materials used in technologies such as photovoltaic cells, fuel cells and advanced batteries, thereby increasing performance and/or lowering production costs. The goal of this project is to develop microwave imaging add-on modules and probes capable of quantitatively measuring the electrical properties of small regions of a material using microwaves. These modules for scanning probe microscopes, such as atomic force microscopes, make use of the near-field interaction between the exciting microwaves and a material and can resolve regions 10 nanometers in size (less than a million atoms) with little perturbation of the material. In Phase 1 commercial probes and modified hardware were used to establish the feasibility of using microwave imaging systems to quantify local permittivity and conductivity. Repeatable measurements that vary in a systematic way with electrical parameters were obtained from a variety of samples. In Phase 2 research prototypes of the needed hardware and probes were developed and their performance against test structures and real-world samples was demonstrated. Result of this research project include demonstration of quantification of both permittivity and doping level at precisions up to 10% using multiple technical approaches. The level of performance and ease of use meets market expectations and the technology and protocols researched under this grant are currently being commercialized. Quantitative capabilities of this sort will provide a key capability to energy related technologies, and to a wide variety of semiconductor, biological, and materials science applications. Applications include both materials research in academic and industrial labs, as well as manufacturing applications. In a manufacturing environment the quantitative measurement and imaging capabilities could be used both as metrology for process control and as a tool for failure analysis and yield improvement.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Fundamental Corrosion Studies in High-Temperature Molten Salt Systems for Next Generation Concentrated Solar Power Systems

The objective of this project is to increase Concentrated Solar Power (CSP) system lifetime through characterization of corrosion mechanisms in heat transfer systems and identification of materials and corrosion resistance methods applicable at temperatures above 850°C. Coupling of experimental methods with thermodynamic and kinetic modeling has given greater insight into the corrosion phenomena and enabled modeling of the corrosion in molten chloride heat transfer systems. The project has been identified the selective oxidation of Cr along the grain boundaries of high Cr content alloys as the principle corrosion mechanisms occurring in CSP systems. The corrosion rate was also found to be mass transfer limited by diffusion of chromium chlorides along the grain boundaries. It was shown that the corrosion could be increased by adding naturally convective flow to mechanism using a thermosiphon. A reaction mechanism has been proposed for selective oxidation of Cr that is driven by the electrochemical potential difference between the Ni crucible for immersion testing and the alloy coupon. This driving force will be similar to the differences caused by having varying Ni content or Cr content throughout a heat transfer system. It could also mimic the differences in electrochemical potential between various parts of the system that are at different temperatures. The reaction mechanism consists of an initiation step due to system impurities and a set of propagation steps that results in formation of a NiCr alloy at the crucible that drives corrosion and selective oxidation of Cr from the alloy. The presences of chromium chlorides in the salt are also essential to the corrosion mechanism to transport the Cr. The formation of a NiCr alloy on the crucible surface with no contact between the alloy coupons and the crucible provides support to this mechanism of having corrosion reactions occurring at both the alloy and the crucible. The thermodynamics of this reaction mechanism have been modeled and were shown to be galvanic. A corrosion model has been developed based on this mechanism and has been implemented in CFD so that it can be used to predict corrosion in a wide variety of system geometries. The model was validated using the thermosiphon data and dimensionless analysis. The corrosion rates of the samples were modeled to within 10% percent of the experimental values. The model has been extended to include the effect of Mg corrosion inhibitor on the corrosion rate in the system. The use of Mg as a metallic corrosion inhibitor has been demonstrated as a method to reduce the corrosion rate of alloys in molten chlorides to below 15 microns per year. Mg is an effective corrosion inhibitor at concentrations as low as 0.3 mol%. Corrosion potential monitoring experiments have shown that the Mg lowers the corrosion potential for the alloy below the equilibrium potential for Cr oxidation and thus prevents corrosion. Experiments have been performed on the ability of Mg to inhibit corrosion in realistic environments that include lower purity salts and welded and stressed alloys. The results have shown that for all these scenarios the corrosion can be reduced to meet the DOE targets. The electrochemical monitoring of Mg for process control has also been demonstrated.

14 SOLAR ENERGY↗
DOE OSTI2019

Exploratory Research: Transport and Transformation of Particulate Organic Matter in Permeable River Sediments

The hyporheic zone (HZ) is the volume of streambed sediments where surface water and groundwater mix. The mixing of ground and surface water geochemical constituents including organic matter and the presence of large microbial populations create an important location for biogeochemical activity. Large and periodic fluctuations in river stage such as those associated with operation of hydroelectric dams, may enhance downstream hyporheic exchange by reversing the direction of flow to/from the stream on a regular basis. Solute transport in hyporheic zones is affected by river regulation; however, little is known about the transport of particulate organic matter (POM) under these conditions. We performed a laboratory experiment to simulate the transport and retention of POM under conditions simulating flow reversal in the hyporheic zone. Here, POM is created by inoculating artificial river water with algae obtained from the Hanford Reach of the Columbia River. POM transport experiments are then conducted in columns packed with sandy sediments; these data are then used to calibrate a model describing fundamental processes controlling its transport in saturated sediments. Models results reveal that filtration, sorption to sediment, and sorption to previously retained POM are important mechanisms of POM retention in sandy, saturated sediments. Additionally, upon flow direction reversal, POM is readily mobilized leading to effluents concentrations above the initial input concentrations. These findings indicate that river stage changes may change POM storage in the hyporheic zone depending on the type and magnitude of flow variation.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

LLNL SFA OBER–SBR FY19 Program Management and Performance Report: Biogeochemistry of Actinides

Over 2,600 metric tons of plutonium (Pu) are estimated to have been produced worldwide, with approximately 70-90 metric tons added to this inventory each year from spent nuclear fuel. A subset of this Pu inventory has been released into the environment as a result of nuclear weapons production, weapons testing, poor waste management practices, and nuclear accidents. The migration of low levels of Pu released in the environment has been documented on the scale of kilometers. Due to its long half-life, toxicity, and its ability to migrate, Pu represents a potentially significant risk to humankind and the environment. Their fate depends on the nature of the release, the biogeochemical processes controlling mobilization, and the eventual exposure pathways. Understanding their behavior in the environment is critical for managing environmental contamination and planning for the safe, long-term isolation of nuclear waste from the biosphere.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Commercialization of Big Area Additive Manufacturing (CRADA NFE-16-06083 Final Report)

Oak Ridge National Laboratory (ORNL) first partnered with Cincinnati Incorporated (CI) through a Cooperative Research and Development Agreement (CRADA) (NFE-14-04957) in 2014 to demonstrate the feasibility and viability of Big Area Additive Manufacturing (BAAM). The first CRADA was a success and paved the way for large format additive manufacturing (LFAM). ORNL and CI partnered again for this second CRADA (NFE-16-06083) to improve process control, enhance printing capabilities, and shift towards production capability.

42 ENGINEERING↗
DOE OSTI2019

Demonstration of a Desktop Liquid Direct Metal Write Additive Manufacturing System (CRADA NFE-17-06531 Final Report)

ORNL worked with PrintSpace 3D to demonstrate cost effective electromagnetic induction melting of aluminum alloys on their desktop Altair 3D printer. An electromagnetic coil design and susceptor have been optimized and paired with a high frequency power supply to melt Al-Ce alloys. The manufacturing feasibility of Al-Ce wire was also proven to be successful and precise process control of electro-magnetic heating was demonstrated. The system was found to have inherent safety benefits, requiring no powder handling and with very localized heating. Further research will demonstrate the ability to use DMW technology to print high temperature engine components for the transportation industry.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Design Requirements for Ultrasonic Deformation Sensor for TREAT Experiments

Ultrasonic measurements of deformation can provide nondestructive measurements of dimensional changes rapidly (within tens to hundreds of microseconds). Further these methods are sensitive to both microstructural changes due to damage (from thermal, mechanical, and irradiation environments) and gross structural changes (such as swelling). As a result, ultrasonic methods have been applied to address needs in the nondestructive evaluation of structural components in nuclear power plants (including fuel cladding) during periodic pre-service and in-service inspection inspections. Ultrasonic measurements have been successfully used for nondestructive materials characterization, including nondestructive evaluation (NDE) of degradation and damage, microstructure characterization, and process control. Ultrasonic NDE is a critical element of the nuclear power industry’s in-service inspection program for maintaining the integrity of the pressure boundary, and is being actively investigated for post-irradiation examination of fuels. Ultrasonic measurements, typically performed at 10 MHz or higher, performed post irradiation show that fuel microstructural parameters, such as porosity and grain size, can be correlated to ultrasonic velocity. Ultrasonic methods historically have seen limited applicability to environments with high temperatures and irradiation. Though some environmental factors (such as temperature) affect the measurement (sound speed, for instance), the limitation is primarily due to the probes themselves. Most commonly, lead-zirconate-titanate (PZT) is used as the piezoelectric sensor material for ultrasonic nondestructive measurements. PZT is limited in its applicability at elevated temperatures (approximately above 300C). However, recent tests (through DOE-NE’s NEET-ASI program) have identified a number of alternatives that can operate at elevated temperatures (in excess of 400C) and can survive irradiation. Certain grades of PZT have also been demonstrated for use in imaging under-sodium in sodium fast reactors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2020

Investigating Scientific Data Change with User Research Methods

Scientific datasets are continually expanding and changing due to fluctuations with instruments, quality assessment and quality control processes, and modifications to software pipelines. Datasets include minimal information about these changes or their effects requiring scientists manually assess modifications through a number of labor intensive and ad-hoc steps. The Deduce project is investigating data change to develop metrics, methods, and tools that will help scientists systematically identify and make decisions around data changes. Currently, there is a lack of understanding, and common practices, for identifying and evaluating changes in datasets since systematically measuring and managing data change is under explored in scientific work. We are conducting user research to address this need by exploring scientist's conceptualizations, behaviors, needs, and motivations when dealing with changing datasets. Our user research utilizes multiple methods to produce foundational, generative insights and evaluate research products produced by our team. In this paper, we detail our user research process and outline our findings about data change that emerge from our studies. Our work illustrates how scientific software teams can push beyond just usability testing user interfaces or tools to better probe the underlying ideas they are developing solutions to address.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2020

bifiPV2020 Bifacial Workshop: A Technology Overview

The virtual bifiPV Workshop was held in July 2020 to provide the solar industry with a forum for sharing and discussing research into bifacial photovoltaic (PV) technology. This report outlines major insights from the workshop to give the reader an overview of the latest developments in bifacial PV technology worldwide, from the lab to the field. Citations are drawn from this workshop unless otherwise noted, with all proceedings available online at bifipvworkshop. com. Presentations for the bifiPV2020 Workshop focused on the following areas: bifacial power plant modeling and simulation, albedo improvements, the development of encapsulants, the durability and reliability of current bifacial technologies, performance comparisons between glass-glass and glass-transparent backsheet configurations, the future of passivated emitter and rear contact (PERC) solar cells, and the growing adoption of n-type solar cells. With 650 GW total PV installed worldwide and 1 TW to come very soon, PERC is now the standard PV cell type produced en masse. However, it is already reaching 23% efficiency, the upper limit for this type of technology. PV modules breaking the 0.5-kW barrier are starting to appear, and the costs of standard PERC technology are already below 0.2 USD/Wp. In 2019, five GW of bifacial PV were installed worldwide. In 2020, the majority of bifacial installations are expected to be located in the United States, China, and Middle East and North Africa (MENA) states. N-type bifacial technologies are becoming increasingly viable and have huge potential to dominate the market in the coming years. With bifacial technology mounted on horizontal single-axis trackers (HSAT), bids below 10 USD/MWh will soon be observed in the MENA region, and later in Chile and the United States. Factory audits and reliability testing can reduce field failures by helping buyers to select producers that follow rigorous quality assurance and quality control processes.

14 SOLAR ENERGY↗
DOE OSTI2020

bifiPV2020 Bifacial Workshop: A Technology Overview

The virtual bifiPV Workshop was held in July 2020 to provide the solar industry with a forum for sharing and discussing research into bifacial photovoltaic (PV) technology. This report outlines major insights from the workshop to give the reader an overview of the latest developments in bifacial PV technology worldwide, from the lab to the field. Citations are drawn from this workshop unless otherwise noted. Presentations for the bifiPV2020 Workshop focused on the following areas: bifacial power plant modeling and simulation, albedo improvements, the development of encapsulants, the durability and reliability of current bifacial technologies, performance comparisons between glass-glass and glass-transparent backsheet configurations, the future of passivated emitter and rear contact (PERC) solar cells, and the growing adoption of n-type solar cells. With 650 GW total PV installed worldwide and 1 TW to come very soon, PERC is now the standard PV cell type produced en masse. However, it is already reaching 23% efficiency, the upper limit for this type of technology. PV modules breaking the 0.5-kW barrier are starting to appear, and the costs of standard PERC technology are already below 0.2 USD/Wp. In 2019, five GW of bifacial PV were installed worldwide. In 2020, the majority of bifacial installations are expected to be located in the United States, China, and Middle East and North Africa (MENA) states. N-type bifacial technologies are becoming increasingly viable and have huge potential to dominate the market in the coming years. With bifacial technology mounted on horizontal single-axis trackers (HSAT), bids below 10 USD/MWh will soon be observed in the MENA region, and later in Chile and the United States. Factory audits and reliability testing can reduce field failures by helping buyers to select producers that follow rigorous quality assurance and quality control processes.

14 SOLAR ENERGY↗
DOE OSTI2021

ManiPIO - Manipulate Process I/O for Industrial Control Systems

The Manipulate Process Input/Output (IO) (ManiPIO) program allows users to develop custom scripts to execute Industrial Control System (ICS) manipulations. The driving development principles of ManiPIO are modularity and ease of use. Currently the program can utilize the Modbus TCP communication protocol, but its modular programming structure allows other protocols to be quickly and easily implemented. Additional functionality can be added to fit specific user needs, due to the usage of Python classes. The input configuration instructions are human readable and allow the user to create a complex series of control system manipulations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2021

Microstructural-Level Fuel Performance Modeling of U-Mo Monolithic Fuel

As the physics that governs the microstructural evolution of nuclear fuel span various time and spatial scales, to fully understand the fuel behavior inevitably involves atomic to mesoscale resolution that can be difficult to determine experimentally. Microstructural-level modeling and simulations can be used to develop physics-based materials models that can provide physical understanding to inform fabrication process control, as well as a valuable feedback mechanism between post-irradiation examination (PIE) results and fabrication parameters. In accordance with the program schedule, the primary goals of the microstructure modeling effort are to: 1. Address critical microstructural questions and provide practical guidance to the fabricator via the fuel product specification; 2. Provide mechanistic inputs for the existing fuel performance code to improve its descriptive and predictive capability at the macroscopic scale. In fiscal year (FY)-21, the work scope consisted of six main facets: (1) the effect of carbides on fuel performance; (2) gas diffusivity in different phases; (3) integration of microstructural fuel performance modeling; (4) property degradation; (5) irradiation creep; and (6) historical analysis of microstructure data. Brief summaries of each are included below.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2023

Arctic Aerosol Sources and Mixing States Field Campaign Report

The Arctic is warming at a faster rate than anywhere else on Earth, with rapidly shrinking sea ice extent transforming the region. Depending on chemical and physical properties, atmospheric aerosols directly scatter and/or absorb radiation, serve as cloud droplet and/or ice crystal nuclei, and/or reduce the reflectiveness of the snow surface, thereby altering the atmospheric energy budget. There is a wide spread in the magnitude of simulated arctic aerosol radiative forcing, and significant differences in aerosol concentration levels and seasonal cycles often exist between models and observations. Increasing local natural and anthropogenic emissions are significant, with uncertain climate impacts due to complex feedbacks. Model evaluations, however, are limited by the dearth of arctic aerosol observations available and an inadequate understanding of arctic aerosol processes. The majority of previous arctic aerosol observations have been made through intensive spring/summer field campaigns, with few intensive measurement studies focused on the fall-winter transition, a period when freeze-up is occurring later and thinning sea ice is resulting in wintertime ice fracturing. Aerosol monitoring at arctic coastal stations has provided knowledge of long-term seasonal trends in aerosol concentrations. The completed ARM field campaign addresses observational and knowledge gaps through detailed aerosol size and chemical composition measurements during the fall-winter transition in the coastal Arctic and through the entire annual cycle in the central Arctic. The observations are improving our understanding of the sources and processes controlling the aerosol population in the rapidly changing Arctic.

54 ENVIRONMENTAL SCIENCES↗