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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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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Constraints on Mass, Spin and Magnetic Field of Microquasar H 1743-322 from Observations of QPOs

The study of quasi-periodic oscillations (QPOs) of X-ray flux observed in many microquasars can provide a powerful tool for testing of the phenomena occurring in strong gravity regime. QPOs phenomena can be well related to the oscillations of charged particles in accretion disks orbiting Kerr black holes immersed in external large-scalemagnetic fields. In the present paper we study the model ofmagnetic relativistic precession and provide estimations of the mass and spin of the central object of the microquasar H 1743-322 which is a candidate for a black hole. Moreover, we discuss the possible values of external magnetic field and study its influence on the motion of charged particles around rotating black hole.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

A complete low-energy polarized proton-deuteron breakup experiment

An experiment at low energy will be done at the COSY cooler synchrotron and storage ring in order to study the three-particle final states of proton-deuteron scattering reactions measuring a complete set of single and double spin observables over large areas of phase space. The physics objective is to test the predictive power of chiral effective field theory at an energy where convergence is guaranteed and few previous measurements exist. A direct comparison between theoretical predictions and experimental data will be enabled by the use of the so called sampling method.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2020

Impurity lattice Monte Carlo for hypernuclei

Abstract We consider the problem of including $$\varLambda $$ Λ hyperons into the ab initio framework of nuclear lattice effective field theory. In order to avoid large sign oscillations in Monte Carlo simulations, we make use of the fact that the number of hyperons is typically small compared to the number of nucleons in the hypernuclei of interest. This allows us to use the impurity lattice Monte Carlo method, where the minority species of fermions in the full nuclear Hamiltonian is integrated out and treated as a worldline in Euclidean projection time. The majority fermions (nucleons) are treated as explicit degrees of freedom, with their mutual interactions described by auxiliary fields. This is the first application of the impurity lattice Monte Carlo method to systems where the majority particles are interacting. Here, we show how the impurity Monte Carlo method can be applied to compute the binding energies of the light hypernuclei. In this exploratory work we use spin-independent nucleon–nucleon and hyperon–nucleon interactions to test the computational power of the method. We find that the computational effort scales approximately linearly in the number of nucleons. The results are very promising for future studies of larger hypernuclear systems using chiral effective field theory and realistic hyperon–nucleon interactions, as well as applications to other quantum many-body systems.

Frame, Dillon↗
DOE OSTI2015

Precipitation in pores: A geochemical frontier

This article's purpose is to review some of the recent research in which geochemists have examined precipitation of solid phases in porous media, particularly in pores a few nanometers in diameter (nanopores). While this is a “review,” it is actually more forward-looking in that the list of things about this phenomenon that we do not know or cannot control at this time is likely longer than what we do know and can control. For example, there are three directly contradictory theories on how to predict how precipitation proceeds in a medium of varying pore size, as will be discussed below. The confusion on this subject likely stems from the complexity of the phenomenon itself: One can easily clog a porous medium by inducing a rapid, homogeneous precipitation directly from solution, or have limited precipitation occur that does not affect permeability or even porosity substantially. It is more difficult to engineer mineral precipitation in order to obtain a specific outcome, such as filling all available pore space over a targeted area for the purposes of contaminant sequestration. However, breakthrough discoveries could occur in the next five to ten years that enhance our ability to predict robustly and finely control precipitation in porous media by understanding how porosity and permeability evolve in response to system perturbations. These discoveries will likely stem (at least in part) from advances in our ability to 1) perform and interpret X-ray/neutron scattering experiments that reveal the extent of precipitation and its locales within porous media (Anovitz and Cole 2015, this volume), and 2) utilize increasingly powerful simulations to test concepts and models about the evolution of porosity and permeability as precipitation occurs (Steefel et al. 2015, this volume). A further important technique to isolate specific phenomena and understand reactivity is also microfluidics cell experiments that allow specific control of flow paths and fluid velocities (Yoon et al. 2012). An improved ability to synthesize idealized porous media will allow for tailored control of pore distributions, mineralogy and will allow more reproducible results. This in turn may allow us to isolate specific processes without the competing and obfuscatory effects that hinder generalization of observations when working with solely natural samples. It is likely that no one single experiment, or simulation technique will provide the key discoveries: to make substantive progress will require a collaborative effort to understand the interplay between fluid transport and geochemistry. Finally, where rock fracturing and elevated pressures are of concern, an understanding and capability to model geomechanical properties are necessary (Scherer 1999).

58 GEOSCIENCES↗
DOE OSTI2011

LDRD final report on confinement of cluster fusion plasmas with magnetic fields.

Two versions of a current driver for single-turn, single-use 1-cm diameter magnetic field coils have been built and tested at the Sandia National Laboratories for use with cluster fusion experiments at the University of Texas in Austin. These coils are used to provide axial magnetic fields to slow radial loss of electrons from laser-produced deuterium plasmas. Typical peak field strength achievable for the two-capacitor system is 50 T, and 200 T for the ten-capacitor system. Current rise time for both systems is about 1.7 {mu}s, with peak current of 500 kA and 2 MA, respectively. Because the coil must be brought to the laser, the driver needs to be portable and drive currents in vacuum. The drivers are complete but laser-plasma experiments are still in progress. Therefore, in this report, we focus on system design, initial tests, and performance characteristics of the two-capacitor and ten-capacitors systems. The questions of whether a 200 T magnetic field can retard the breakup of a cluster-fusion plasma, and whether this field can enhance neutron production have not yet been answered. However, tools have been developed that will enable producing the magnetic fields needed to answer these questions. These are a two-capacitor, 400-kA system that was delivered to the University of Texas in 2010, and a 2-MA ten-capacitor system delivered this year. The first system allowed initial testing, and the second system will be able to produce the 200 T magnetic fields needed for cluster fusion experiments with a petawatt laser. The prototype 400-kA magnetic field driver system was designed and built to test the design concept for the system, and to verify that a portable driver system could be built that delivers current to a magnetic field coil in vacuum. This system was built copying a design from a fixed-facility, high-field machine at LANL, but made to be portable and to use a Z-machine-like vacuum insulator and vacuum transmission line. This system was sent to the University of Texas in Austin where magnetic fields up to 50 T have been produced in vacuum. Peak charge voltage and current for this system have been 100 kV and 490 kA. It was used this last year to verify injection of deuterium and surrogate clusters into these small, single-turn coils without shorting the coil. Initial test confirmed the need to insulate the inner surface of the coil, which requires that the clusters must be injected through small holes in an insulator. Tests with a low power laser confirmed that it is possible to inject clusters into the magnetic field coils through these holes without destroying the clusters. The university team also learned the necessity of maintaining good vacuum to avoid insulator, transmission line, and coil shorting. A 200-T, 2 MA system was also constructed using the experience from the first design to make the pulsed-power system more robust. This machine is a copy of the prototype design, but with ten 100-kV capacitors versus the two used in the prototype. It has additional inductance in the switch/capacitor unit to avoid breakdown seen in the prototype design. It also has slightly more inductance at the cable connection to the vacuum chamber. With this design we have been able to demonstrate 1 MA current into a 1 cm diameter coil with the vacuum chamber at air pressure. Circuit code simulations, including the additional inductance with the new design, agree well with the measured current at a charge voltage of 40 kV with a short circuit load, and at 50 kV with a coil. The code also predicts that with a charge voltage of 97 kV we will be able to get 2 MA into a 1 cm diameter coil, which will be sufficient for 200 T fields. Smaller diameter or multiple-turn coils will be able to achieve even higher fields, or be able to achieve 200-T fields with lower charge voltage. Work is now proceeding at the university under separate funding to verify operation at the 2-MA level, and to address issues of debris mitigation, measurement of the magnetic field, and operation in vacuum. We anticipate operation at full current with single-turn, magnetic field coils this fall, with 200 T experiments on the Texas Petawatt laser in the spring of 2012.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2013

Hot Isostatic Press Can Optimization for Aluminum Cladding of U-10Mo Reactor Fuel Plates: FY12 Final Report and FY13 Update

Currently, the proposed processing path for low enriched uranium – 10 wt. pct. molybdenum alloy (LEU-10Mo) monolithic fuel plates for high power research and test reactors includes hot isostatic pressing (HIP) to bond the aluminum cladding that encapsulates the fuel foil. Initial HIP experiments were performed at Idaho National Laboratory (INL) on approximately ¼ scale “mini” fuel plate samples using a HIP can design intended for these smaller experimental trials. These experiments showed that, with the addition of a co-rolled zirconium diffusion barrier on the LEU-10Mo alloy fuel foil, the HIP bonding process is a viable method for producing monolithic fuel plates. Further experimental trials at Los Alamos National Laboratory (LANL) effectively scaled-up the “mini” can design to produce full-size fuel prototypic plates. This report summarizes current efforts at LANL to produce a HIP can design that is further optimized for higher volume production runs. The production-optimized HIP can design goals were determined by LANL and Babcock & Wilcox (B&W) to include maintaining or improving the quality of the fuel plates produced with the baseline scaled-up mini can design, while minimizing material usage, improving dimensional stability, easing assembly and disassembly, eliminating machining, and significantly reducing welding. The initial small-scale experiments described in this report show that a formed-can approach can achieve the goals described above. Future work includes scaling the formed-can approach to full-size fuel plates, and current progress toward this goal is also summarized here.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2015

Field Performance of Inverter-Driven Heat Pumps in Cold Climates

Traditionally, air-source heat pumps (ASHPs) have been used more often in warmer climates; however, some new ASHPs are gaining ground in colder areas. These systems operate at subzero (Fahrenheit) temperatures and many do not include backup electric resistance elements. There are still uncertainties, however, about capacity and efficiency in cold weather. Also, questions such as “how cold is too cold?” do not have clear answers. These uncertainties could lead to skepticism among homeowners; poor energy savings estimates; suboptimal system selection by heating, ventilating, and air-conditioning contractors; and inconsistent energy modeling. In an effort to better understand and characterize the heating performance of these units in cold climates, the U.S. Department of Energy Building America team, Consortium for Advanced Residential Buildings (CARB), monitored seven inverter-driven, ductless ASHPs across the Northeast. Operating data were collected for three Mitsubishi FE18 units, three Mitsubishi FE12 units, and one Fujitsu 15RLS2 unit. The intent of this research was to assess heat output, electricity consumption, and coefficients of performance (COPs) at various temperatures and load conditions. This assessment was accomplished with long- and short-term tests that measured power consumption; supply, return, and outdoor air temperatures; and airflow through the indoor fan coil.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Computational Bayesian Framework for Quantification and Reduction of Predictive Uncertainty in Subsurface Environmental Modeling

Subsurface environmental systems are open and complex, in which intricate hydrologic, microbiologic, and geochemical processes occur and interact at multiple scales. Understanding and predicting system responses to natural forces (e.g., climate changes) and human activities (e.g., contaminant remediation and CO 2 sequestration) is indispensable for managing water resources, cleaning subsurface contamination at many sites of the Department of Energy (DOE), and providing expert analysis to inform policy-making on long-term stewardship of nuclear waste disposal and CO 2 storage sites. Groundwater reactive transport modeling is necessary for understanding and predicting the complex subsurface environmental system. However, as complex systems are never completely predictable, model predictions of the subsurface system are inherently uncertain, and uncertainty is one of the greatest obstacles in simulating the subsurface environment. Quantifying predictive uncertainty of the complex system is critical to test model predictive power, support decision-making, and guide experimental design and data collection for uncertainty reduction. This project tackled two major obstacles to efficient and effective quantification and reduction of predictive uncertainty in simulating the complex subsurface environment. One obstacle is that existing methods of uncertainty quantification are too fragmented and incomplete for understanding and predicting the complex subsurface environment as a whole. The other obstacle is that existing methods of uncertainty quantification are computationally demanding and may not be applicable to groundwater reactive transport modeling that is always computationally expensive. The above two obstacles to uncertainty quantification directly affect the design of data collection schemes for uncertainty reduction. In this project, we developed a comprehensive Bayesian framework to remove the first obstacle. The second obstacle was tackled by using the sparse grid methods, which were originally developed and analyzed for numerical integration in the field of applied mathematics. We integrated the sparse grid methods into the Bayesian framework seamlessly, which led to a sparse-grid-based method of Bayesian uncertainty analysis. The developed computational Bayesian framework has been applied to a number of subsurface environmental problems through collaborating with scientists at the Pacific Northwest National Laboratory and Oak Ridge National Laboratory. The applications demonstrated that the computational Bayesian framework is general and compatible with any models and numerical codes of subsurface modeling. It is thus can be applied to gain insights for subsurface environmental modeling. This project helped the PI achieve his career goal to advance the state-of-the-art computational methods in uncertainty quantification for subsurface environmental modeling. This project supported two doctoral students, two master students, and one post-doc. The two doctoral students, after their graduation, worked as post-docs at the Pacific Northwest National Laboratory and the Oak Ridge National Laboratory. The project produced a total of 29 journal articles (four under review), one book chapter, and a number of conference proceedings and abstracts.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Comparison of Errors in Solar Power Plant Variability Simulation Methods

Four PV power plant variability simulation methods - no-smoothing, time average, Marcos, and the wavelet variability model (WVM) - were compared to measured data from a 19MW PV power plant to test the relative accuracy of each method. Errors (simulated vs. measured) were quantified using five application-specific metrics: the largest down ramps, the largest up ramps, the mean absolute error in matching the cumulative distribution of large ramps, the total energy contained in down ramps over the entire period considered, total energy in down ramps on the worst day. These errors we evaluated over timescales ranging from 1-second to 1-hour and over plant sizes of 1 to 14MW and the total plant size of 19MWs to determine trends in model errors as a function of timescale and plant size. Overall, the WVM was found to most often have the smallest errors. The Marcos method also often had small errors, including having the smallest errors of all methods at small PV plant sizes (1 to 7MWs). The no-smoothing method had large errors and should not be used. The time average method was an improvement over the no-smoothing method, but generally has larger errors than the WVM and Marcos methods.

14 SOLAR ENERGY↗
DOE OSTI2021

First atomic weapons following WWII were detonated 75 years ago Operation Crossroads kicks off era of testing Los Alamos-created weapons [Slides]

It was time to test. After the Los Alamos-created atomic bombs helped end World War II, the no-longer-secret Lab transitioned into an era of weapons testing, starting 75 years ago with Operation Crossroads with the goal of studying nuclear weapons’ effects on warships. In August 1945, U.S. Senator Brien McMahon, who later authored the Atomic Energy Act of 1946, said: “In order to test the destructive powers of the atomic bomb against naval vessels, I would like to see these (Japanese naval) ships taken to sea and an atomic bomb dropped on them. The resulting explosion should prove to us just how effective the atomic bomb is when used against the giant naval ships.”

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
DOE OSTI2022

Fully Integrated High Speed Megawatt Class Motor and High Frequency Variable Speed Drive System

This project involved developing a fully integrated high speed megawatt class motor and high frequency variable speed drive system that serve as a commercially viable and technically sound methodology for high speed industrial system applications. The project team organizations consist of Clemson University and TECO Westinghouse Motor Company (TWMC) formed an academic and industrial collaboration that combines the design, analysis, manufacturing and testing experience required for a large research project of this magnitude. The project resulted in an integrated high speed megawatt class medium voltage motor drive system that is at a TRL 6 with a clear path for commercialization. The fully integrated prototype system has been manufactured by TWMC in its Round Rock, Texas facility and tested at full power on a dynamometer at the Clemson University’s eGRID Center in North Charleston, South Carolina.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Coupling between collective modes in the deformed 98 Zr nucleus: Insights from consistent HFB+QRPA calculations with the Gogny interaction

The Zirconium isotopes exhibit structural properties that present multiple challenges to nuclear theory. Investigations of the coupling present within isoscalar modes and within isovector modes are scarce but important for advancing our understanding of the microscopic picture of nuclei. To explore some of these underlying coupling features, and to test the predictive power of a state-of the-art nuclear structure approach, we provide a detailed analysis of the properties of 90,96,98Zr. This region includes a benchmarking case and offers insights into nuclear deformation phenomena. To investigate the coupling between collective modes in deformed nuclei, we focused our analysis on the ground and excited-state properties of these isotopes, employing a consistent approach with the axially-symmetric deformed Hartree-Fock-Bogoliubov (HFB) and the Quasiparticle Random Phase Approximation (QRPA) framework, both using the Gogny D1M force. This approach effectively describes both low-lying and giant-resonance states. We devoted special attention to the deformed 98Zr nucleus, where we confirm the existence of coupling between monopole and quadrupole excitations through the K π = 0 + QRPA components and demonstrate an analogous dipole-octupole coupling through the K π = 0 − and K π = 1 − components. Intrinsic transition densities and associ ated radial projections illustrate the coupling. Our work complements and extends earlier studies carried out using density-functional-based methods and notably, we included the complete Coulomb interaction also in the pairing fields, i.e. we treat terms exactly that are approximated in typical calculations that use the Gogny D1 and D2 interaction families.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Model-Free Primal-Dual Methods for Network Optimization with Application to Real-Time Optimal Power Flow

This paper examines the problem of real-time optimization of networked systems and develops online algorithms that steer the system towards the optimal trajectory without explicit knowledge of the system model. The problem is modeled as a dynamic optimization problem with time-varying performance objectives and engineering constraints. The design of the algorithms leverages the online zero-order primal-dual projected-gradient method. In particular, the primal step that involves the gradient of the objective function (and hence requires a networked systems model) is replaced by its zero-order approximation with two function evaluations using a deterministic perturbation signal. The evaluations are performed using the measurements of the system output, hence giving rise to a feedback interconnection, with the optimization algorithm serving as a feedback controller. The paper provides some insights on the stability and tracking properties of this interconnection. Finally, the paper applies this methodology to a real-time optimal power flow problem in power systems, and shows its efficacy on the IEEE 37-node distribution test feeder for reference power tracking and voltage regulation.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2015

Preliminary Results of the CASCADE Hidden Sector Photon Search

Light shining through a wall experiments can be used to make measurements of photon-WISP couplings. The first stage of the CASCADE experiment at the Cockcroft Institute of Accelerator Science and Technology is intended to be a proof-of-principle experiment utilising standard microwave technologies to make a modular, cryogenic HSP detector to take advantage of future high-power superconducting cavity tests. In these proceedings we will be presenting the preliminary results of the CASCADE LSW experiment showing a peak expected exclusion of $1.10\times10^{-8}$ in the mass range from 1.96\,$\mu$eV to 5.38\,$\mu$eV, exceeding current limits.

Woollett, Nathan↗
DOE OSTI2020

Ectomycorrhizal Plant-Fungal Co-invasions as Natural Experiments for Connecting Plant and Fungal Traits to Their Ecosystem Consequences

Introductions and invasions by fungi, especially pathogens and mycorrhizal fungi, are widespread and potentially highly consequential for native ecosystems, but may also offer opportunities for linking microbial traits to their ecosystem functions. In particular, treating ectomycorrhizal (EM) invasions, i.e., co-invasions by EM fungi and their EM host plants, as natural experiments may offer a powerful approach for testing how microbial traits influence ecosystem functions. Forests dominated by EM symbiosis have unique biogeochemistry whereby the secretions of EM plants and fungi affect carbon (C) and nutrient cycling; moreover, particular lineages of EM fungi have unique functional traits. EM invasions may therefore alter the biogeochemistry of the native ecosystems they invade, especially nitrogen (N) and C cycling. By identifying “response traits” that favor the success of fungi in introductions and invasions (e.g., spore dispersal and germination) and their correlations with “effect traits” (e.g., nutrient-cycling enzymes) that can alter N and C cycling (and affect other coupled elemental cycles), one may be able to predict the functional consequences for ecosystems of fungal invasions using biogeochemistry models that incorporate fungal traits. Here, we review what is already known about how EM fungal community composition, traits, and ecosystem functions differ between native and exotic populations, focusing on the example of EM fungi associated with species of Pinus introduced from the Northern into the Southern Hemisphere. We develop hypotheses on how effects of introduced and invasive EM fungi may depend on interactions between soil N availability in the exotic range and EM fungal traits. We discuss how such hypotheses could be tested by utilizing Pinus introductions and invasions as a model system, especially when combined with controlled laboratory experiments. Finally, we illustrate how ecosystem modeling can be used to link fungal traits to their consequences for ecosystem N and C cycling in the context of biological invasions, and we highlight exciting avenues for future directions in understanding EM invasion.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Myosin Head Configurations in Resting and Contracting Murine Skeletal Muscle

Transgenic mouse models have been important tools for studying the relationship of genotype to phenotype for human diseases, including those of skeletal muscle. We show that mouse skeletal muscle can produce high quality X-ray diffraction patterns establishing the mouse intact skeletal muscle X-ray preparation as a potentially powerful tool to test structural hypotheses in health and disease. A notable feature of the mouse model system is the presence of residual myosin layer line intensities in contracting mouse muscle patterns. This provides an additional tool, along with the I1,1/I1,0 intensity ratio, for estimating the proportions of active versus relaxed myosin heads under a given set of conditions that can be used to characterize a given physiological condition or mutant muscle type. We also show that analysis of the myosin layer line intensity distribution, including derivation of the myosin head radius, Rm, may be used to study the role of the super-relaxed state in myosin regulation. When the myosin inhibitor blebbistatin is used to inhibit force production, there is a shift towards a highly quasi-helically ordered configuration that is distinct from the normal resting state, indicating there are more than one helically ordered configuration for resting crossbridges.

Ma, Weikang↗