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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 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

DUST ATTENUATION OF THE NEBULAR REGIONS OF z ∼ 2 STAR-FORMING GALAXIES: INSIGHT FROM UV, IR, AND EMISSION LINES

We use a sample of 149 spectroscopically confirmed UV-selected galaxies at z ∼ 2 to investigate the relative dust attenuation of the stellar continuum and the nebular emission lines. For each galaxy in the sample, at least one rest-frame optical emission line (Hα/[N ii] λ6583 or [O iii] λ5007) measurement has been taken from the litterature, and 41 galaxies have additional Spitzer/MIPS 24 μm observations that are used to infer infrared luminosities. We use a spectral energy distribution (SED) fitting code that predicts nebular line strengths when fitting the stellar populations of galaxies in our sample, and we perform comparisons between the predictions of our models and the observed/derived physical quantities. We find that on average our code is able to reproduce all the physical quantities (e.g., UV β slopes, infrared luminosities, emission line fluxes), but we need to apply a higher dust correction to the nebular emission compared to the stellar emission for the largest star formation rate (SFR) (log SFR/M{sub ⊙} yr{sup −1} > 1.82, Salpeter initial mass function). We find a correlation between SFR and the difference in nebular and stellar color excesses, which could resolve the discrepant results regarding nebular dust correction at z ∼ 2 from previous studies.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2019

Geothermal Reservoir Simulation Results in support of Feasibility Study of Direct District Heating for the Cornell Campus Utilizing Deep Geothermal Energy

This dataset contains input data, code, ReadMe files, output data, and figures that summarize the results of a stochastic analysis of geothermal reservoir production from two potential geothermal reservoirs that were evaluated for the Cornell University Deep Direct-Use project. These potential reservoirs are the Trenton-Black River (TBR) from 2.27-2.3 km depth, and basement rocks from 3.0-3.5 km depth and 3.5-4.0 km depth. Several utilization scenarios consisting of different injection fluid temperatures and flow rates were evaluated for each reservoir. Uncertainty in geologic properties, thermal properties, economic costs, and utilization efficiencies were evaluated using a Monte Carlo analysis of the reservoir simulations. Some reservoir simulations of the TBR were completed using the TOUGH2 software, as implemented in PetraSIM. The PetraSIM run files and associated data are provided with this submission. All other reservoir simulations were completed using the GEOPHIRES software, with some modifications to complete the uncertainty analyses. ReadMe files that describe additions to GEOPHIRES, the GEOPHIRES input data, and the output data are all provided, and references are provided to the code repository. Figures that summarize the reservoir heat production, temperature drawdown, and the probability of meeting targeted building heating demands with the produced heat and fluid temperatures are provided.

15 GEOTHERMAL ENERGY↗
DOE OSTI2012

Benchmarking ENDF/B-VII.1, JENDL-4.0 and JEFF-3.1.1 with MCNP6

Recent releases of three major world nuclear reaction data libraries, ENDF/B-VII.1, JENDL-4.0, and JEFF-3.1.1, have been tested extensively using benchmark calculations. The calculations were performed with the latest release of the continuous energy Monte Carlo neutronics code MCNP, i.e. MCNP6. Three types of benchmarks were used, viz. criticality safety benchmarks, (fusion) shielding benchmarks, and reference systems for which the effective delayed neutron fraction is reported. For criticality safety, more than 2000 benchmarks from the International Handbook of Criticality Safety Benchmark Experiments were used. Benchmarks from all categories were used, ranging from low-enriched uranium, compound fuel, thermal spectrum ones (LEU-COMP-THERM), to mixed uranium-plutonium, metallic fuel, fast spectrum ones (MIX-MET-FAST). For fusion shielding many benchmarks were based on IAEA specifications for the Oktavian experiments (for Al, Co, Cr, Cu, LiF, Mn, Mo, Si, Ti, W, Zr), Fusion Neutronics Source in Japan (for Be, C, N, O, Fe, Pb), and Pulsed Sphere experiments at Lawrence Livermore National Laboratory (for {sup 6}Li, {sup 7}Li, Be, C, N, O, Mg, Al, Ti, Fe, Pb, D2O, H2O, concrete, polyethylene and teflon). The new functionality in MCNP6 to calculate the effective delayed neutron fraction was tested by comparison with more than thirty measurements in widely varying systems. Among these were measurements in the Tank Critical Assembly (TCA in Japan) and IPEN/MB-01 (Brazil), both with a thermal spectrum, two cores in Masurca (France) and three cores in the Fast Critical Assembly (FCA, Japan), all with fast spectra. The performance of the three libraries, in combination with MCNP6, is shown to be good. The results for the LEU-COMP-THERM category are on average very close to the benchmark value. Also for most other categories the results are satisfactory. Deviations from the benchmark values do occur in certain benchmark series, or in isolated cases within benchmark series. Such instances can often be related to nuclear data for specific non-fissile elements, such as C, Fe, or Gd. Indications are that the intermediate and mixed spectrum cases are less well described. The results for the shielding benchmarks are generally good, with very similar results for the three libraries in the majority of cases. Nevertheless there are, in certain cases, strong deviations between calculated and benchmark values, such as for Co and Mg. Also, the results show discrepancies at certain energies or angles for e.g. C, N, O, Mo, and W. The functionality of MCNP6 to calculate the effective delayed neutron fraction yields very good results for all three libraries.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Design of and data reduction from compact Thomson parabola spectrometers

Thomson parabola spectrometers are used to characterize MeV ion beams produced in high intensity laser interactions. These spectrometers disperse multiple ion species according to their charge to mass ratio through the use of parallel electric and magnetic fields. Analytical solutions for ion deflection in electric and magnetic fields have been used to extract ion spectra with the assumption that fringing effects are negligible. Experimental space restrictions and dynamic range requirements necessitate designs that stress the analytical assumptions. Depending on design parameters, the error in the analytical assumption can be comparable to the energy resolution. Estimates are provided to approximate the error on the total ion deflection. A method for modeling ion trajectories including fringing effects is presented using software freely available or in common use. The magnetostatic fields are modeled in 3D, including material properties of nearby magnetic materials using RADIA. Electrostatic fields are modeled in 2D for a spectrometer implementing angled plates using the partial differential equation toolbox in MATLAB. Using these models to calculate the ion trajectory allows for analysis of a Thomson parabola spectrometer with an arbitrary field configuration.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

Deep Energy Retrofits - Eleven California Case Studies

This research documents and demonstrates viable approaches using existing materials, tools and technologies in owner-conducted deep energy retrofits (DERs). These retrofits are meant to reduce energy use by 70% or more, and include extensive upgrades to the building enclosure, heating, cooling and hot water equipment, and often incorporate appliance and lighting upgrades as well as the addition of renewable energy. In this report, 11 Northern California (IECC climate zone 3) DER case studies are described and analyzed in detail, including building diagnostic tests and end-use energy monitoring results. All projects recognized the need to improve the home and its systems approximately to current building code-levels, and then pursued deeper energy reductions through either enhanced technology/ building enclosure measures, or through occupant conservation efforts, both of which achieved impressive energy performance and reductions. The beyond-code incremental DER costs averaged $25,910 for the six homes where cost data were available. DERs were affordable when these incremental costs were financed as part of a remodel, averaging a $30 per month increase in the net-cost of home ownership.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Multiphysics analysis of fuel fragmentation, relocation, and dispersal susceptibility–Part 1: Overview and code coupling strategies

The US nuclear energy industry is investigating strategies to increase the reactor operating cycle to 24 months, resulting in peak rod average burnups exceeding the current limit of 62 GWd/tU. This increase will in turn increase the probability of fuel fragmentation, relocation, and dispersal (FFRD) in the event of a loss-of-coolant accident (LOCA). This effort couples multiple codes to (1) evaluate full-core power histories for high-burnup fuel operated in a Westinghouse 4-loop pressurized water reactor, (2) model a postulated large-break LOCA, and (3) calculate the mass of fuel susceptible to FFRD. This paper, the first of three describing the work, focuses on code coupling strategies and FFRD susceptibility calculations. The other two companion papers focus on code-specific designs and analyses. Three codes were used in this work. VERA was used to calculate steady-state power histories, TRACE was used to model the transient thermal hydraulics, and BISON was used to model steady-state and transient fuel performance and cladding failure. Herein, several fuel pulverization models were used to calculate FFRD susceptibility in failed rods. Depending on the cladding failure/fuel pulverization model combination, the core-wide FFRD susceptibility during the postulated LOCA range from 0 to over 5,000 kg.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

An LCA model for waste incineration enhanced with new technologies for metal recovery and application to the case of Switzerland

Highlights: • An enhanced process-based LCA model for MSWI is featured and applied in case study. • LCA modeling of recent technological developments for metal recovery from fly ash. • Net release from Swiss MSWI 133 kg CO{sub 2}-eq/tonne waste from attributional LCA perspective. • Net savings from a consequential LCA perspective reach up to 303 kg CO{sub 2}-eq/tonne waste. • Impacts according to ReCiPe and CExD show similar pattern to climate change. - Abstract: A process model of municipal solid waste incinerators (MSWIs) and new technologies for metal recovery from combustion residues was developed. The environmental impact is modeled as a function of waste composition as well as waste treatment and material recovery technologies. The model includes combustion with a grate incinerator, several flue gas treatment technologies, electricity and steam production from waste heat recovery, metal recovery from slag and fly ash, and landfilling of residues and can be tailored to specific plants and sites (software tools can be downloaded free of charge). Application of the model to Switzerland shows that the treatment of one tonne of municipal solid waste results on average in 425 kg CO{sub 2}-eq. generated in the incineration process, and 54 kg CO{sub 2}-eq. accrue in upstream processes such as waste transport and the production of operating materials. Downstream processes, i.e. residue disposal, generates 5 kg CO{sub 2}-eq. Savings from energy recovery are in the range of 67 to 752 kg CO{sub 2}-eq. depending on the assumptions regarding the substituted energy production, while the recovery of metals from slag and fly ash currently results in a net saving of approximately 35 kg CO{sub 2}-eq. A similar impact pattern is observed when assessing the MSWI model for aggregated environmental impacts (ReCiPe) and for non-renewable resource consumption (cumulative exergy demand), except that direct emissions have less and no relevance, respectively, on the total score. The study illustrates that MSWI plants can be an important element of industrial ecology as they provide waste disposal services and can help to close material and energetic cycles.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

HERO WEC V1.0 - WEC-Sim Model

This zip file contains the files that are needed to simulate NREL's HERO WEC (hydraulic and electric reverse osmosis wave energy converter). This requires the user to have already installed WEC-Sim. In addition to the standard toolboxes that are required to run WEC-Sim the user will also need the Simscape Fluids and Simscape Driveline packages. In the zip file you will find the following: - HEROV1_HPTO.slx: Simulink-based WEC Sim model of the first gen (V1.0) Hydraulic PTO (power take-off) that was designed for the HERO WEC - wecSimInputFile.m: Input file needed to run the model - userDefinedFunctionsMCR.m: MCR (multi condition run) script that is needed if a use wants to simulate multiple wave conditions. - geometry (folder): Includes the geometry file that is needed for visualization - hydroData (folder): Includes the required WAMIT data to run WEC-Sim

16 TIDAL AND WAVE POWER↗
DOE OSTI2018

Properties of the Fundamental Optical Functions of Magnesium Silicide

The spectra of 16 optical Mg{sub 2}Si functions in the range from 0 to 11 eV at 77 K are determined. They contain five maxima and shoulders due to interband transitions and metastable excitons, as well as the maxima of bulk and surface plasmons at ~9.56 and ~7.30 eV. Their peculiarities and general patterns of behavior are established. Calculations were performed based on a well-known experimental reflection spectrum in the range from 0 to 11 eV at 77 K. The integral spectra of the imaginary parts of the permittivity ε{sub 2}(E), characteristic bulk (–Im ε{sup –1}), and surface (–Im (1 + ε){sup –1}) energy losses of electrons are expanded into elementary components in the region from 2 to 5 eV. The main parameters of the transition components were determined, including the energies of their maxima and oscillator strengths. Calculations were carried out using computer programs based on the Kramers–Kronig relations and known analytical formulas for the correlation between optical functions, as well as an improved nonparametric method of combined Argand diagrams taking into account the effective number of valence electrons participating in the formation of individual bands. Instead of five maxima and shoulders of the integral spectra, 17 elementary bands with oscillator strengths in the range from 0.0003 to 1.92 were established. They are due to transverse and longitudinal type excitonic and interband transitions. Based on known theoretical calculations, we propose herein the localization and assumed nature of the optical transition bands.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2014

Simulating the spectral response of quantum dot-in-well infrared photodetectors from eight band k.p method

Conduction band energy levels in quantum-dot-in-a-well structures are computed by eight band k.p method (Burt-Foreman Hamiltonian) using finite element software. Optical absorption spectrum due to intersubband transitions is simulated using Fermi golden rule. The use of contact pair boundary condition in strain calculation and criteria for choosing band mixing parameter (E{sub p}) to avoid the spurious solutions are examined in this paper. The simulated intersubband optical absorption spectrum of different structures reported in the literature is in close agreement with the experimentally measured photoconductive absorption region and shows that the method can be used as an effective modeling for quick design of the heterostructures based infrared photodetectors for various wavelengths.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2010

SURVEYING THE DYNAMIC RADIO SKY WITH THE LONG WAVELENGTH DEMONSTRATOR ARRAY

This paper presents a search for radio transients at a frequency of 73.8 MHz (4 m wavelength) using the all-sky imaging capabilities of the Long Wavelength Demonstrator Array (LWDA). The LWDA was a 16-dipole phased array telescope, located on the site of the Very Large Array in New Mexico. The field of view of the individual dipoles was essentially the entire sky, and the number of dipoles was sufficiently small that a simple software correlator could be used to make all-sky images. From 2006 October to 2007 February, we conducted an all-sky transient search program, acquiring a total of 106 hr of data; the time sampling varied, being 5 minutes at the start of the program and improving to 2 minutes by the end of the program. We were able to detect solar flares, and in a special-purpose mode, radio reflections from ionized meteor trails during the 2006 Leonid meteor shower. We detected no transients originating outside of the solar system above a flux density limit of 500 Jy, equivalent to a limit of no more than about 10{sup -2} events yr{sup -1} deg{sup -2}, having a pulse energy density {approx}>1.5 x 10{sup -20} J m{sup -2} Hz{sup -1} at 73.8 MHz for pulse widths of about 300 s. This event rate is comparable to that determined from previous all-sky transient searches, but at a lower frequency than most previous all-sky searches. We believe that the LWDA illustrates how an all-sky imaging mode could be a useful operational model for low-frequency instruments such as the Low Frequency Array, the Long Wavelength Array station, the low-frequency component of the Square Kilometre Array, and potentially the Lunar Radio Array.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

Generalized Uncertainty Quantification for Linear Inverse Problems in X-ray Imaging

In industrial and engineering applications, X-ray radiography has attained wide use as a data collection protocol for the assessment of material properties in cases where direct observation is not possible. The direct measurement of nuclear materials, particularly when they are under explosive or implosive loading, is not feasible, and radiography can serve as a useful tool for obtaining indirect measurements. In such experiments, high energy X-rays are pulsed through a scene containing material of interest, and a detector records a radiograph by measuring the radiation that is not attenuated in the scene. One approach to the analysis of these radiographs is to model the imaging system as an operator that acts upon the object being imaged to produce a radiograph. In this model, the goal is to solve an inverse problem to reconstruct the values of interest in the object, which are typically material properties such as density or areal density. The primary objective in this work is to provide quantitative solutions with uncertainty estimates for three separate applications in X-ray radiography: deconvolution, Abel inversion, and radiation spot shape reconstruction. For each problem, we introduce a new hierarchical Bayesian model for determining a posterior distribution on the unknowns and develop efficient Markov chain Monte Carlo (MCMC) methods for sampling from the posterior. A Poisson likelihood, based on a noise model for photon counts at the detector, is combined with a prior tailored to each application: an edge-localizing prior for deconvolution; a smoothing prior with non-negativity constraints for spot reconstruction; and a full covariance sampling prior based on a Wishart hyperprior for Abel inversion. After developing our methods in a general setting, we demonstrate each model on both synthetically generated datasets, including those from a well known radiation transport code, and real high energy radiographs taken at two U. S. Department of Energy laboratories.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

HERO WEC V1.0 - WEC-Sim Model (July 2024)

**This submission supersedes submission MHKDR-483** This submission file contains the files that are needed to simulate NREL's HERO WEC (hydraulic and electric reverse osmosis wave energy converter). This requires the user to have already installed WEC-Sim. In addition to the standard toolboxes that are required to run WEC-Sim the user will also need the Simscape Fluids and Simscape Driveline packages. The zip file (HERO_V1_WECSim_2024.zip) contains the following: - HERO_HPTO_2024.slx: Simulink-based WEC Sim model of the first gen (V1.0) Hydraulic PTO (power take-off) that was designed for the HERO WEC. This model has been updated since submission #483 based on in-laboratory experimental results. - wecSimInputFile.m: Input file needed to run the model - userDefinedFunctionsMCR.m: MCR (multi condition run) script that is needed if a use wants to simulate multiple wave conditions. - geometry (folder): Includes the geometry file that is needed for visualization - hydroData (folder): Includes the required WAMIT data to run WEC-Sim -HydVisualization.mlx: Visualization script to plot simulation results (not needed to run)

16 TIDAL AND WAVE POWER↗
DOE OSTI2015

Recent Additions in the Modeling Capabilities of an Open-Source Wave Energy Converter Design Tool: Preprint

WEC-Sim is a midfidelity numerical tool for modeling wave energy conversion devices. The code uses the MATLAB SimMechanics package to solve multibody dynamics and models wave interactions using hydrodynamic coefficients derived from frequency-domain boundary-element methods. This paper presents the new modeling features introduced in the latest release of WEC-Sim. The first feature discussed conversion of the fluid memory kernel to a state-space form. This enhancement offers a substantial computational benefit after the hydrodynamic body-to-body coefficients are introduced and the number of interactions increases exponentially with each additional body. Additional features include the ability to calculate the wave-excitation forces based on the instantaneous incident wave angle, allowing the device to weathervane, as well as import a user-defined wave elevation time series. A review of the hydrodynamic theory for each feature is provided and the successful implementation is verified using test cases.

16 TIDAL AND WAVE POWER↗
DOE OSTI2013

Building America Guidance for Identifying and Overcoming Code, Standard, and Rating Method Barriers

The U.S. Department of Energy’s (DOE) Building America program implemented a new Codes and Standards Innovation (CSI) Team in 2013. The Team’s mission is to assist Building America (BA) research teams and partners in identifying and resolving conflicts between Building America innovations and the various codes and standards that govern the construction of residences. A CSI Roadmap was completed in September, 2013. This guidance document was prepared using the information in the CSI Roadmap to provide BA research teams and partners with specific information and approaches to identifying and overcoming potential barriers to Building America (BA) innovations arising in and/or stemming from codes, standards, and rating methods. For more information on the BA CSI team, please email: CSITeam@pnnl.gov

Cole, Pamala C.↗
DOE OSTI2014

Achieving 50% Energy Savings in Office Buildings, Advanced Energy Design Guides: Office Buildings (Brochure)

This fact sheet summarizes recommendations for designing new office buildings that result in 50% less energy use than conventional designs meeting minimum code requirements. The recommendations are drawn from the Advanced Energy Design Guide for Small to Medium Office Buildings, an ASHRAE publication that provides comprehensive recommendations for designing low-energy-use office buildings with gross floor areas up to 100,000 ft2 (see sidebar). Designed as a stand-alone document, this fact sheet provides key principles and a set of prescriptive design recommendations appropriate for smaller office buildings with insufficient budgets to fully implement best practices for integrated design and optimized performance. The recommendations have undergone a thorough analysis and review process through ASHRAE, and have been deemed the best combination of measures to achieve 50% savings in the greatest number of office buildings.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2020

The MFiX Particle-in-Cell Method (MFiX-PIC) Theory Guide

MFiX (Multiphase Flow with Interphase eXchanges) is an open-source multiphase flow solver developed at the National Energy Technology Laboratory. Within the code, users have access to a single phase or interpenetrating continua-based multiphase two-fluid model (TFM), a discrete element model (DEM), and a particle-in-cell model (PIC). TFM, DEM, and PIC can all be used to create multiphase simulations that include hydrodynamics, chemical reactions, and heat transfer.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2018

A Portable Quantitative High-Resolution Gamma System for In-Situ Waste, D and D, and Emergency Measurements - 18573

The Canberra ISOCS system has been a highly successful and technologically innovative product since its introduction about 22 years ago. The combination of field-portable HPGe detectors, flexible shield/collimator set, and accurate mathematical efficiency calibration software made in-situ gamma spectroscopy measurements very practical. Good quality in-situ measurements are economically beneficial for items that are either large or complex, in comparison to the cost, time and impracticality of extracting a sample for laboratory measurements or producing representative calibration standards. And where the item is not homogeneous [most of the time for in-situ measurement situations] an assay of a large part of the item has been shown to be more accurate than a few widely dispersed extracted samples [the normal case]. However the size, weight, cost and complexity of the full-size ISOCS system limit its usefulness in some situations. A companion device was recently introduced, and is the subject of this document. The gamma sensor is a 1 cm{sup 3} CZT detector. It is surrounded by an optional tungsten shield/collimator set with a tripod for support. The detector is powered solely by a USB connection from a laptop PC. The full power of the ISOCS efficiency calibration software can be used with this detector. This entire package is less than 15 kg, needs no cooling, and is quite rugged, in comparison to the 120 kg for ISOCS with sensitive HPGe detectors which need Liquid Nitrogen or electro-mechanical cooling. Furthermore this CZT package is about 1/3 the cost. This is a very complementary device for the many current ISOCS users, especially for quick initial evaluations or simple situations where the full energy resolution and sensitivity of the HPGe ISOCS are not needed. Operating nuclear power plants or those in the initial phases of decommissioning are prime examples. Their complex layout often precludes the deployment of the full-sized ISOCS system, whereas the CZT system can be hand-carried there and very quickly setup for a measurement. The small detector size, and therefore low efficiency, is not a disadvantage, and in many cases is an advantage due to the elevated radioactivity of the items. This can be used to assay items in tanks, spills on floors, activity on filters, waste or items in small containers, and waste in drums. In the event of an emergency, it can be quickly deployed to measure gas or liquid effluent streams, air particulate and iodine filters in the field, or even in-vivo thyroid activity. Examples of measurements at nuclear facilities are shown and discussed in further detail, along with estimated detection limits. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗