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At least 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Generative Adversarial Networks and Mixture Density Networks-Based Inverse Modeling for Microstructural Materials Design

Abstract There are two broad modeling paradigms in scientific applications: forward and inverse. While forward modeling estimates the observations based on known causes, inverse modeling attempts to infer the causes given the observations. Inverse problems are usually more critical as well as difficult in scientific applications as they seek to explore the causes that cannot be directly observed. Inverse problems are used extensively in various scientific fields, such as geophysics, health care and materials science. Exploring the relationships from properties to microstructures is one of the inverse problems in material science. It is challenging to solve the microstructure discovery inverse problem, because it usually needs to learn a one-to-many nonlinear mapping. Given a target property, there are multiple different microstructures that exhibit the target property, and their discovery also requires significant computing time. Further, microstructure discovery becomes even more difficult because the dimension of properties (input) is much lower than that of microstructures (output). In this work, we propose a framework consisting of generative adversarial networks and mixture density networks for inverse modeling of structure–property linkages in materials, i.e., microstructure discovery for a given property. The results demonstrate that compared to baseline methods, the proposed framework can overcome the above-mentioned challenges and discover multiple promising solutions in an efficient manner.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Land-based wind turbines with flexible rail-transportable blades – Part 1: Conceptual design and aeroservoelastic performance

This work investigates the conceptual design and the aeroservoelastic performance of land-based wind turbines whose blades can be transported on rail via controlled bending. The turbines have a nameplate power of 5 MW and a rotor diameter of 206 m, and they aim to represent the next generation of land-based machines. Three upwind designs and two downwind designs are presented, combining different design goals together with conventional glass and pultruded carbon fiber laminates in the spar caps. One of the five blade designs is segmented and serves as a benchmark to the state of the art in industry. The results show that controlled flexing requires a reduction in the flapwise stiffness of the blades, but it represents a promising pathway for increasing the size of land-based wind turbine rotors. Given the required stiffness, the rotor can be designed either downwind with standard rotor preconing and nacelle uptilt angles or upwind with higher-than-usual angles. A downwind-specific controller is also presented, featuring a cut-out wind speed reduced to 19 m s –1 and a pitch-to-stall shutdown strategy to minimize blade tip deflections toward the tower. The flexible upwind and downwind rotor designs equipped with pultruded carbon fiber spar caps are found to generate the lowest levelized cost of energy, 2.9 % and 1.3 %, respectively, less than the segmented design. The paper concludes with several recommendations for future work in the area of large flexible wind turbine rotors.

17 WIND ENERGY↗
DOE OSTI2022

Deep Learning and Natural Language Processing for Accelerated Inverse Design of Optical Metamaterials

Optical metamaterial device design has enjoyed a long track of success over the past 50 years leading to the manipulation of light over a wide range of wavelengths spanning the ultraviolet to the far infrared. The manipulation of light over such wavelengths has already led to many technological advancements such as the design of selective radiative absorbers for solar energy, daytime passive cooling using deep space, and optical invisibility cloaks for defense applications. Further disruptive advancements in energy, defense, computing, and biomedical fields could be enabled or enhanced by future optical metamaterial devices. These technologies could lead to increased energy efficiency and hence reduced national primary energy consumption, cheap long duration energy storage, and next generation solid-state heat engines. But historically the methods to invent and develop all of these devices have been time- consuming and based mostly on intuition and iteration. Finding an optimal design can take years. In this project we developed a machine learning-based algorithm capable of automatically generating device designs to produce desired optical properties, reducing the design cycle life in certain situations to be almost instantaneous.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Technologies to Reactors: Enabling Accelerated Deployment of Nuclear Energy Systems Workshop Report

Nuclear energy provides almost 20% of the electric power in the United States, producing power with high availability while accounting for 63% of our carbon-free energy production. While we have the capacity to expand this clean power source within the United States, we have not built any advanced reactor plant designs in our rapidly evolving electricity generation market, where cost is a major driver. With construction cost and plant safety being major elements of cost for new nuclear, advanced reactor technologies could provide lower cost, safer, carbon-free, grid-resilient energy sources for the US electricity grid. When the current fleet of nuclear reactors was originally designed, many of today’s science and technology (S&T) advances were not available. Today these advances show great promise for transforming our national approach to nuclear reactor design. Other industries are capitalizing on rapid innovations in materials, manufacturing, sensors and control systems, and high-fidelity modeling and simulation (M&S), along with data analytics to provide lower costs in manufacturing and extended ranges of operations. In the nuclear industry, these innovations can translate into similar benefits as well as rapid design and qualification of advanced nuclear fuels. Effectively implementing these types of innovations could position American expert leadership to compete more fully in the international nuclear energy market. In July of 2018, the US Department of Energy (DOE) Office of Nuclear Energy sponsored a workshop to address these possibilities: “Technologies to Reactors: Enabling Accelerated Deployment of Nuclear Energy Systems.” Workshop participants explored how modern and emerging S&T can be used to transform the approach to nuclear reactor design, licensing, and operation to accelerate deployment of advanced nuclear energy systems. More than 80 experts from federal agencies, academia, and industry participated in the workshop to develop consensus on priority technology directions (PTDs) and recommend technology and deployment initiatives to explore and demonstrate key benefits for the nuclear community.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2014

A Composite Modeling Analysis of the Deformation Behavior of Medium Manganese Steels

The deformation behavior of medium manganese steels was evaluated with uniaxial tensile testing and the results were correlated with predictions of a composite model shown previously to provide design insight into the development of multi-phase steels with third-generation advanced high strength steel (3GAHSS) properties. An equilibrium thermodynamic-based methodology to design microstructures containing systematic amounts of metastable austenite with controlled stability against transformation is presented. The analysis is based on Mn enrichment of austenite during intercritical annealing of medium Mn (7 and 10 wt pct.) low carbon (0.1 and 0.15 wt pct) steels. The steels were produced as laboratory heats that were hot and cold rolled prior to annealing. After annealing the microstructures consisted primarily of either a matrix of fine grained ferrite with austenite contents between 32.6 and 45.2 wt pct (7Mn, 0.1C steels) or a matrix of martensite with various amounts of austenite in the higher Mn steel. The different intercritical annealing conditions produced steels with wide variations in austenite contents and austenite compositions (Mn and C contents) resulting in steels with significant variations in austenite stability. Predictions based on the composite analysis with different assumed flow behaviors for the individual constituents and stability functions for the meta-stable austenite are presented and shown to accurately predict strength-ductility combinations over a range of austenite volume fractions for the 7Mn steel. Applicability of the composite analysis is extended to consider the deformation behavior of the 10Mn steel and evaluate other possible microstructural combinations leading to 3GAHSS properties.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Polarized {sup 3}He{sup −} ion source with hyperfine state selection

High beam polarization is essential to the scientific productivity of a collider. Polarized {sup 3}He ions are an essential part of the nuclear physics programs at existing and future ion-ion and electron-ion colliders such as BNL's RHIC and eRHIC and JLab's ELIC. Ion sources with performance exceeding that achieved today are a key requirement for the development of these next generation high-luminosity high-polarization colliders. The development of high-intensity high-brightness arc-discharge ion sources at the Budker Institute of Nuclear Physics (BINP) has opened up an opportunity for realization of a new type of a polarized {sup 3}He{sup −} ion source. This report discusses a polarized {sup 3}He{sup −} ion source based on the large difference of extra-electron auto-detachment lifetimes of the different {sup 3}He{sup −} ion hyperfine states. The highest momentum state of 5/2 has the largest lifetime of τ ∼ 350 µs while the lower momentum states have lifetimes of τ ~ 10 µs. By producing {sup 3}He{sup −} ion beam composed of only the |5/2, ±5/2> hyperfine states and then quenching one of the states by an RF resonant field, {sup 3}He{sup −} beam polarization of 90% can be achieved. Such a method of polarized {sup 3}He{sup −} production has been considered before; however, due to low intensities of the He{sup +} ion sources existing at that time, it was not possible to produce any interesting intensity of polarized {sup 3}He{sup −} ions. The high-brightness arc-discharge ion source developed at BINP can produce a high-brightness {sup 3}He{sup +} beam with an intensity of up to 2 A allowing for selection of up to ∼1-4 mA of {sup 3}He{sup −} ions with ∼90% polarization. The high gas efficiency of an arc-discharge source is important due to the high cost of {sup 3}He gas. Some features of such a PIS as well as prototype designs are considered. An integrated {sup 3}He{sup −} ion source design providing high beam polarization could be prepared using existing BNL equipment with incorporation of new designs of the 1) arc discharge plasma generator, 2) extraction system, 3) charge exchange jet, and 4) magnetic separation system.

43 PARTICLE ACCELERATORS↗
DOE OSTI2016

Evaluation of Solid Sorbents as a Retrofit Technology for CO 2 Capture

ADA completed a DOE-sponsored program titled Evaluation of Solid Sorbents as a Retrofit Technology for CO 2 Capture under program DE-FE0004343. During this program, sorbents were analyzed for use in a post-combustion CO 2 capture process. A supported amine sorbent was selected based upon superior performance to adsorb a greater amount of CO 2 than the activated carbon sorbents tested. When the most ideal sorbent at the time was selected, it was characterized and used to create a preliminary techno-economic analysis (TEA). A preliminary 550 MW coal-fired power plant using Illinois #6 bituminous coal was designed with a solid sorbent CO 2 capture system using the selected supported amine sorbent to both facilitate the TEA and to create the necessary framework to scale down the design to a 1 MWe equivalent slipstream pilot facility. The preliminary techno-economic analysis showed promising results and potential for improved performance for CO 2 capture compared to conventional MEA systems. As a result, a 1 MWe equivalent solid sorbent system was designed, constructed, and then installed at a coal-fired power plant in Alabama. The pilot was designed to capture 90% of the CO 2 from the incoming flue gas at 1 MWe net electrical generating equivalent. Testing was not possible at the design conditions due to changes in sorbent handling characteristics at post-regenerator temperatures that were not properly incorporated into the pilot design. Thus, severe pluggage occurred at nominally 60% of the design sorbent circulation rate with heated sorbent, although no handling issues were noted when the system was operated prior to bringing the regenerator to operating temperature. Testing within the constraints of the pilot plant resulted in 90% capture of the incoming CO 2 at a flow rate equivalent of 0.2 to 0.25 MWe net electrical generating equivalent. The reduction in equivalent flow rate at 90% capture was primarily the result of sorbent circulation limitations at operating temperatures combined with pre-loading of the sorbent with CO 2 prior to entering the adsorber. Specifically, CO 2 -rich gas was utilized to convey sorbent from the regenerator to the adsorber. This gas was nominally 45°C below the regenerator temperature during testing. ADA’s post-combustion capture system with modifications to overcome pilot constraints, in conjunction with incorporating a sorbent with CO 2 working capacity of 15 g CO 2 /100 g sorbent and a contact time of 10 to 15 minutes or less with flue gas could provide significant cost and performance benefits when compared to an MEA system.

36 MATERIALS SCIENCE↗
DOE OSTI2015

CRISTAL V2.0: A New-generation criticality package - 14597

A new release of the CRISTAL French criticality calculation package, named CRISTAL V2.0, has been developed and intensively validated by IRSN and CEA, in collaboration with AREVA. This package was designed to cover the needs of criticality practitioners in the fields of nuclear fuel cycle facilities and transportation of fissile materials. Based on an optimized modular architecture in an updated software development environment, the design of CRISTAL package V2.0 integrates new generation of cross section libraries, new calculation schemes consistent with new applications, and up-to-date calculation codes capabilities. Four calculation routes are currently available allowing multi-group and continuous energy calculations. The validation database is composed of more than 3000 critical experiments, in order to cover a wide range of configurations. The CRISTAL V2.0 package also comprises customer services covering a range of areas of activity like documentation, hotline, maintenance and training courses. A wide promotion and an increased recognition referred both nationally and internationally are foreseen, including the provision of the CRISTAL V2.0 package to the OECD / NEA Data Bank. (authors)

42 ENGINEERING↗
DOE OSTI2014

Sci—Fri PM: Topics — 08: The Role and Benefits of Electromagnetic Needle-Tracking Technologies in Brachytherapy

In modern brachytherapy, application of large doses of ionizing radiation in a limited number of fractions is frequent. Furthermore, as with any surgical procedures, brachytherapy is subject to learning curve effects. In this context, there could be advantages of integrating real-time tracking of needles/catheters to existing protocols given the recent prominent advances in tracking technologies. In this work, we review the use of an electromagnetic tracking system (EMTS) based on the second generation Aurora® Planar Field Generator (Northern Digital Inc) and custom design needles (Philips Healthcare) for brachytherapy applications. The position and orientation information is obtained from 5 degrees of freedom sensors. Basic system performance characterization is performed in well-controlled conditions to establish accuracy and reproducibility as well as potential interference from standard brachytherapy equipment. The results show that sensor locations can be tracked to within 0.04mm (la) when located within 26cm of the generator. Orientation accuracy of the needle remained within ±1° in the same region, but rose quickly at larger distances. The errors on position and orientation strongly dependent the sensor position in the characterization volume (500×500×500mm{sup 3}). The presence of an ultrasound probe was shown to have negligible effects on tracking accuracy. The use of EMTS for automatic catheter/applicator reconstruction was also explored. Reconstruction time was less than 10 sec/channel and tips identification was within 0.69±0.29mm of the reference values. Finally, we demonstrate that hollow needle designs with special EM adaptation also allow for real-time seed drop position estimation. In phantom experiments showed that drop positions were on average within 1.6±0.9mm of the reference position measured from μCT. Altogether, EMTS offer promising benefits in a wide range of brachytherapy applications.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Genetic Algorithm Design of a 3D Printed Heat Sink

In this paper, a genetic algorithm- (GA-) based approach is discussed for designing heat sinks based on total heat generation and dissipation for a pre-specified size andshape. This approach combines random iteration processesand genetic algorithms with finite element analysis (FEA) to design the optimized heat sink. With an approach that prefers survival of the fittest , a more powerful heat sink can bedesigned which can cool power electronics more efficiently. Some of the resulting designs can only be 3D printed due totheir complexity. In addition to describing the methodology, this paper also includes comparisons of different cases to evaluate the performance of the newly designed heat sinkcompared to commercially available heat sinks.

3D Printing↗
DOE OSTI2017

Transforming Wind Turbine Blade Mold Manufacturing with 3D Printing

Innovation in the design and manufacturing of wind power generation components continues to be critical. As a result of this challenge, DOE’s Wind Energy Technologies Office (WETO) and Advanced Manufacturing Office (AMO), both within EERE, are partnering with public and private organizations to apply additive manufacturing, commonly known as 3D printing, to the production of wind turbine blade molds. The traditional method of blade design requires the creation of a plug, or a full-size representation of the final blade, which is then used to make the mold. Creating the plug is one of the most time-intensive and labor-intensive processes in wind blade construction, saving time and money.

3D printing↗
DOE OSTI2017

Energy ideals, visions, narratives, and rhetoric: Examining sociotechnical imaginaries theory and methodology in energy research

Sociotechnical imaginaries emerged in the last decade as a potentially fruitful approach to understanding how collective social values inflect on the production of scientific knowledge and the design of technological systems. Yet insights generated to date have focused on the categories experts use to define a society’s idealized organization, either as the direct subject of analysis by documentary analysis or through the ways such categories circumscribe the field of authorized “values” open for adjudication in public engagement events. We argue that sociotechnical imaginaries require a new methodological framework for designing research in order to examine the collective values of citizens as they live their daily lives, rather than focusing on experts and the state in order to understand the shared moral, material, and scientific goals of a society. Drawing inspiration from rhetoric, corpus linguistics, and dialectology, we present the Social Energy Atlas, a new and burgeoning research project that employs such methods for studying emergent narrative patterns and variation at the local level. Furthermore, advancing the theory and practice of studying sociotechnical imaginaries is of tremendous benefit to Energy and Social Science researchers, and it is our intent this commentary encourages further careful development and use of the concept.

14 SOLAR ENERGY↗
DOE OSTI2025

Cost analysis of alternative large-scale high-temperature solid oxide electrolysis hydrogen production facilities

We extend our past cost analysis of gigawatt-scale solid oxide electrolysis (SOE) facilities that produce high purity hydrogen gas from water by estimating construction and operating costs for three new alternative design cases: (1) offsite feed steam generation; (2) near-atmospheric pressure (NAP) stack; and (3) onsite electric boiler feed steam generation. Pressure effects on hydrogen electrode-(cathode-)supported SOE cell (SOEC) stack performance are estimated for the same assumed cell and stack construction and used to determine facility-wide stack capital costs for achieving a fixed H2 production at different pressures. Modular balance of plant (BOP) process equipment capital costs are estimated for each new alternative design case using our past equipment sizing, design, and cost data and scaling relationships. Furthermore, we update BOP equipment sizing and design for the NAP case using Aspen®. Vendor quotes for electric boilers are used to estimate costs for the electric boiler design case. Factory and onsite assembly and installation costs for SOEC stacks and BOP equipment are calculated using our past simplified first-principles approach. First-of-a-kind (FOAK) and N th -of-a-kind (NOAK) production maturity cost estimates are included for all results. The case with NAP stacks offers the lowest facility total capital cost (TCC, ~23% lower than base) while use of small electric boilers requires the highest TCC (~3% higher than base). H 2 production prices decrease from the base of ~$\$2.17$ /kgH 2 to ~$\$1.92$/kgH 2 for 1 GW e DC SIP facilities utilizing NAP stacks supplied by offsites steam situated in large modules and blocks for $\$0.030$/kWh e and $0.009/kWh t prices for electricity and thermal energy, respectively. We report all costs in 2021 US dollars.

Balance of plant (BOP) process equipment↗
DOE OSTI2022

Snowmass Early Career

The Snowmass 2021 strategic planning process provided an essential opportunity for the United States high energy physics and astroparticle (HEPA) community to come together and discuss upcoming physics goals and experiments. As this forward-looking perspective on the field often reaches far enough into the future to surpass the timescale of a single career, consideration of the next generation of physicists is crucial. The 2021 Snowmass Early Career (SEC) organization aimed to unite this group, with the purpose of both educating the newest generation of physicists while informing the senior generation of their interests and opinions. SEC is the latest in a series of the previously dubbed "Snowmass Young" organizations, from 2013 and 2001. This iteration has expanded on these efforts to significantly increase involvement and broaden the representation of the early career community in the process. Early career physicists are the future of the field. They will design, build, and operate next-generation experiments, and put in the work to usher in new discoveries. They are also disproportionately involved in work to improve the climate within HEPA. This document summarizes the work of SEC in consolidating a huge variety of physics perspectives and community opinions towards a bright, strategic future.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Generating synthetic signaling networks for in silico modeling studies

Predictive models of signaling pathways have proven to be difficult to develop. Reasons include the uncertainty in the number of species, the complexity in species’ interactions, and the sparseness and uncertainty in experimental data. Traditional approaches to developing mechanistic models rely on collecting experimental data and fitting a single model to that data. This approach works for simple systems but has proven unreliable for complex systems such as biological signaling networks. For example, uncertainty and sparseness of the data often result in overfitted models that have little predictive value beyond recapitulating the experimental data itself. Thus, there is a need to develop new approaches to create predictive mechanistic models of complex systems. However, to determine the effectiveness of any new algorithm, a baseline model is needed to test its performance. To meet this need, we developed a method for generating artificial synthetic networks that are reasonably realistic and thus can be treated as ground truth models. These synthetic models can then be used to generate synthetic data for developing and testing algorithms designed to recover the underlying network topology and associated parameters. Here, we describe a simple approach for generating synthetic signaling networks that can be used for this purpose.

42 ENGINEERING↗
DOE OSTI2024

Non-Refrigerated Warehouse Design Guide [Slides]

Warehouses typically have a low energy use relative to their floor area. This make warehouses ideal to install solar panels and offset on-site energy use and have a surplus of energy if roof area is maximized. This surplus can be used to provide things like grid services or charge electric vehicle fleets. This document is intended to provide owners and operators of warehouse information on designing efficient/decarbonized warehouses and maximize on-site generation. The information here references outside publications to provide specific guidance, such as the ASHRAE Advanced Energy Design Guides, but tailors the information specifically to warehouses. This guide provides owners a better understanding of warehouse design as well as more specific information for themselves or outside designers to reference.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Underwater thermomagnetic generator for remote marine thermal energy harvesting and sensing

Thermomagnetic generators offer a promising approach for sustainable power generation in remote marine environments. Here, this study presents the design, thermal modeling, and experimental validation of a passively driven underwater thermomagnetic generator developed for powering ocean observation and monitoring sensors. The generator was evaluated under varying working fluids, thermal boundary conditions, and extended operation to assess real-world applicability. Two fluids, deionized water and silicone-based Thermal C5, were tested under simulated shallow- and deep-ocean conditions. Deionized water outperformed Thermal C5, especially in colder environments (~5°C), achieving a peak output of 2.7 mW due to larger temperature gradients and enhanced convective-evaporative heat transfer. Long-duration tests revealed a transient evaporation-condensation cycle that temporarily reduced rotor immersion and performance before stabilizing. The generator powered commercial marine sensors for over 6 h without external batteries, demonstrating the viability of compact, passively cooled thermomagnetic systems for autonomous, off-grid marine sensing.

13 HYDRO ENERGY↗
DOE OSTI2019

Light-Driven Charge Transfer in Face-to-Face Donor-Spacer-Acceptor Supramolecular Systems

The efficient conversion of sunlight to a useful form of energy both in green plants and in manmade dye-sensitized solar cells requires the efficient separation of a positive and negative charge. The charge separation process begins with the absorption of visible or ultraviolet light by a pigment such as chlorophyll or a dye such as a transition metal complex followed by fast electron transfer to a neighboring molecule to form a pair of ionized molecules with opposite charges. At that point, one of the two opposite charges must rapidly move away from the other one by the process of charge separation. Once the migrating charge reaches its destination, it can be converted to electrical or chemical energy. The overall efficiency of charge separation in these systems is determined by the competition between charge separation and charge recombination at each stage in the process. Whereas most investigations of photoinduced charge separation have employed synthetic polymers or covalent linkages to separate the photoactive molecular and charge acceptor, we have employed the natural biopolymer DNA for this purpose. DNA possesses a unique structure consisting of a hydrophobic core of hydrogen-bonded base pairs which form a one-dimensional π-stacked array. The possibility that the π-stacked base pairs of DNA might function as a one-dimensional conductor or molecular wire was first advanced over 50 years ago. However, systematic measurements of the dynamics and efficiency of charge separation in DNA-based systems were not undertaken prior to the initiation of our studies 22 years ago. A variety of organic chromophores can be attached to one or both ends of the base pair domain of DNA or at any location within the domain. The length and base sequence of the base pair domain can also be varied. The structures of these synthetic derivatives of DNA have been determined using a combination of X-ray diffraction, NMR spectroscopy, and molecular modeling. Selective excitation with UV or visible light of the appropriate chromophore can effect injection of either positive charge (holes) or negative charge (electrons) into the base pair domain. The dynamics of hole or electron injection can be studied by a combination of fluorescence quenching and transient absorption measurements. Moreover, the simple design of our systems is amenable to theoretical modeling, allowing the development and testing of models which may prove applicable to more complex systems. Our initial studies of hole transport in short synthetic DNA with either repeating or alternating base sequences showed it to be strongly distance dependent, seemingly contradicting claims that DNA might serve as a wire in molecular electron devices. Further research on the base-sequence dependence of hole transport dynamics showed that significant enhancement in hole transport dynamics could be achieved by the used of special sequences designed to prevent the photo-generated charges from recombining. More recent experimental research and theoretical modelling has served to define each stage of the charge-separation process: electronic excitation, hole injection, hole transport, hole transport, and charge recombination. DNA is less effective as a carrier for electron transport; however, many of these details have also been determined for this process. In summary, a combination of molecular design and synthesis, spectroscopy, and theory have made possible the most complete study of photoinduced charge separation on any complex donor-bridge-acceptor system studied to date. These results serve as a benchmark to which related studies can be compared.

14 SOLAR ENERGY↗