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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 OSTI2015

The Resource Identification Initiative: A cultural shift in publishing

A central tenet in support of research reproducibility is the ability to uniquely identify research resources, i.e., reagents, tools, and materials that are used to perform experiments. However, current reporting practices for research resources are insufficient to allow humans and algorithms to identify the exact resources that are reported or answer basic questions such as “What other studies used resource X?” To address this issue, the Resource Identification Initiative was launched as a pilot project to improve the reporting standards for research resources in the methods sections of papers and thereby improve identifiability and reproducibility. The pilot engaged over 25 biomedical journal editors from most major publishers, as well as scientists and funding officials. Authors were asked to include Research Resource Identifiers (RRIDs) in their manuscripts prior to publication for three resource types: antibodies, model organisms, and tools (including software and databases). RRIDs represent accession numbers assigned by an authoritative database, e.g., the model organism databases, for each type of resource. To make it easier for authors to obtain RRIDs, resources were aggregated from the appropriate databases and their RRIDs made available in a central web portal (www.scicrunch.org/resources). RRIDs meet three key criteria: they are machine readable, free to generate and access, and are consistent across publishers and journals. The pilot was launched in February of 2014 and over 300 papers have appeared that report RRIDs. The number of journals participating has expanded from the original 25 to more than 40. Here, we present an overview of the pilot project and its outcomes to date. We show that authors are generally accurate in performing the task of identifying resources and supportive of the goals of the project. We also show that identifiability of the resources pre- and post-pilot showed a dramatic improvement for all three resource types, suggesting that the project has had a significant impact on reproducibility relating to research resources.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2016

A METHOD TO CONSTRAIN MASS AND SPIN OF GRB BLACK HOLES WITHIN THE NDAF MODEL

Black holes (BHs) hide themselves behind various astronomical phenomena and their properties, i.e., mass and spin, are usually difficult to constrain. One leading candidate for the central engine model of gamma-ray bursts (GRBs) invokes a stellar mass BH and a neutrino-dominated accretion flow (NDAF), with the relativistic jet launched due to neutrino-anti-neutrino annihilations. Such a model gives rise to a matter-dominated fireball, and is suitable to interpret GRBs with a dominant thermal component with a photospheric origin. We propose a method to constrain BH mass and spin within the framework of this model and apply the method to the thermally dominant GRB 101219B, whose initial jet launching radius, r {sub 0}, is constrained from the data. Using our numerical model of NDAF jets, we estimate the following constraints on the central BH: mass M {sub BH} ∼ 5–9 M {sub ⊙}, spin parameter a {sub *} ≳ 0.6, and disk mass 3 M {sub ⊙} ≲ M {sub disk} ≲ 4 M {sub ⊙}. Our results also suggest that the NDAF model is a competitive candidate for the central engine of GRBs with a strong thermal component.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

Lower hybrid current drive favoured by electron cyclotron radiofrequency heating

The important goal of adding to the bootstrap a fraction of non-inductive plasma current, which would be controlled for obtaining and optimizing steady-state profiles, can be reached by using the Current Drive produced by Lower Hybrid waves (LHCD). FTU (Frascati Tokamak Upgrade) experiments demonstrated, indeed, that LHCD is effective at reactor-graded high plasma density, and the LH spectral broadening is reduced, operating with higher electron temperature in the outer region of plasma column (T{sub e-periphery}). This method was obtained following the guidelines of theoretical predictions indicating that the broadening of launched spectrum produced by parametric instability (PI) should be reduced, and the LHCD effect at high density consequently enabled, under higher (T{sub e-periphery}). In FTU, the temperature increase in the outer plasma region was obtained by operating with reduced particle recycling, lithized walls and deep gas fuelling by means of fast pellet. Heating plasma periphery with electron cyclotron resonant waves (ECRH) will provide a further tool for achieving steady-state operations. New FTU experimental results are presented here, demonstrating that temperature effect at the plasma periphery, affecting LH penetration, occurs in a range of plasma parameters broader than in previous work. New information is also shown on the modelling assessing frequencies and growth rates of the PI coupled modes responsible of spectral broadening. Finally, we present the design of an experiment scheduled on FTU next campaign, where ECRH power is used to slightly increase the electron temperature in the outer plasma region of a high-density discharge aiming at restoring LHCD. Consequent to model results, by operating with a toroidal magnetic field of 6.3 T, useful for locating the electron cyclotron resonant layer at the periphery of the plasma column (r/a∼0.8, f{sub 0}=144 GHz), an increase of T{sub e} in the outer plasma (from 40 eV to 80 eV at r/a∼0.8) is expected by the JETTO code, sufficient for recovering LHCD. An ECRH power of 0.8 MW, and the standard FTU regime at high plasma density (n{sub eav}∼1.3×10{sup 20}m{sup −3} and plasma current of 0.5 MA) have been considered. The code has been set with transport modelling to reproduce the evolution of FTU kinetic profiles.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Fast ion generation and bulk plasma heating with three-ion ICRF scenarios

Launching electromagnetic waves in the ion cyclotron range of frequencies (ICRF) is an efficient method of plasma heating, actively employed in most of fusion machines. ICRF has a number of important supplementary applications, including the generation of high-energy ions. In this paper, we discuss a new set of three-ion ICRF scenarios and the prospect of their use as a dedicated tool for fast ion generation in tokamaks and stellarators. A distinct feature of these scenarios is a strong absorption efficiency possible at very low concentrations of resonant minority ions (∼ 1% or even below). Such concentration levels are typical for impurities contaminating fusion plasmas. An alternative ICRF scenario for maximizing the efficiency of bulk D-T ion heating is suggested for JET and ITER tokamaks, which is based on three-ion ICRF heating of intrinsic Beryllium impurities.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2012

Exotic nuclei in astrophysics

Recently the academic community has marked several anniversaries connected with discoveries that played a significant role in the development of astrophysical investigations. The year 2009 was proclaimed by the United Nations the International Year of Astronomy. This was associated with the 400th anniversary of Galileo Galilei’s discovery of the optical telescope, which marked the beginning of regular research in the field of astronomy. An important contribution to not only the development of physics of the microcosm, but also to the understanding of processes occurring in the Universe, was the discovery of the atomic nucleus made by E. Rutherford 100 years ago. Since then the investigations in the fields of physics of particles and atomic nuclei have helped to understand many processes in the microcosm. Exactly 80 years ago, K. Yanski used a radio-telescope in order to receive the radiation from cosmic objects for the first time, and at the present time this research area of physics is the most efficient method for studying the properties of the Universe. Finally, the April 12, 1961 (50 years ago) launching of the first sputnik into space with a human being onboard, the Russian cosmonaut Yuri Gagarin, marked the beginning of exploration of the Universe with the direct participation of man. All these achievements considerably extended our ideas about the Universe. This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclear-physics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Superplastic Forming of Duplex Stainless Steel for Aerospace Part

In this study, the high temperature forming behavior of duplex stainless steel has been characterized and the outer shell of a combustion chamber was fabricated with pressure difference of hot gas. It consists of two parts which are the outer skin made of stainless steel to sustain the internal pressure and the inner shell made of copper alloy for regenerative cooling channels. Two outer skins partitioned to half with respect to the symmetric axis was prepared by hot gas forming process with a maximum pressure of 7 MPa following to FEM analysis. For inner layer, copper alloy was machined for cooling channels and then placed in the gas pressure welding fixture. It is shown that the optimum condition of gas pressure welding is 7 MPa at 890 deg. C, for one hour. EDX analysis and scanning electron microscope micrograph confirm the atomic diffusion process is observed at the interface and copper atoms diffuse into steel, while iron and chrome atoms diffuse into copper. The result shows that the manufacturing method with superplastic forming and gas pressure welding of steel and copper alloy has been successful for near net shape manufacturing of scaled combustion chamber of launch vehicle.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Modeling and observations of an elevated, moving infrasonic source: Eigenray methods

In this paper, the acoustic ray tracing relations are extended by the inclusion of auxiliary parameters describing variations in the spatial ray coordinates and eikonal vector due to changes in the initial conditions. Computation of these parameters allows one to define the geometric spreading factor along individual ray paths and assists in identification of caustic surfaces so that phase shifts can be easily identified. A method is developed leveraging the auxiliary parameters to identify propagation paths connecting specific source-receiver geometries, termed eigenrays. The newly introduced method is found to be highly efficient in cases where propagation is non-planar due to horizontal variations in the propagation medium or the presence of cross winds. Finally, the eigenray method is utilized in analysis of infrasonic signals produced by a multi-stage sounding rocket launch with promising results for applications of tracking aeroacoustic sources in the atmosphere and specifically to analysis of motor performance during dynamic tests.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

A test on reactive force fields for the study of silica dimerization reactions

We studied silica dimerization reactions in the gas and aqueous phase by density functional theory (DFT) and reactive force fields based on two parameterizations of ReaxFF. For each method (both ReaxFF force fields and DFT), we performed constrained geometry optimizations, which were subsequently evaluated in single point energy calculations using the other two methods. Standard fitting procedures typically compare the force field energies and geometries with those from quantum mechanical data after a geometry optimization. The initial configurations for the force field optimization are usually the minimum energy structures of the ab initio database. Hence, the ab initio method dictates which structures are being examined and force field parameters are being adjusted in order to minimize the differences with the ab initio data. As a result, this approach will not exclude the possibility that the force field predicts stable geometries or low transition states which are realistically very high in energy and, therefore, never considered by the ab initio method. Our analysis reveals the existence of such unphysical geometries even at unreactive conditions where the distance between the reactants is large. To test the effect of these discrepancies, we launched molecular dynamics simulations using DFT and ReaxFF and observed spurious reactions for both ReaxFF force fields. Our results suggest that the standard procedures for parameter fitting need to be improved by a mutual comparative method.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

MO-DE-BRA-01: Enhancing Radiation Physics Instruction Through Gamification and E-Learning

Purpose: This project sought to “gamify” the instruction of radiation interaction physics concepts for technology students. Gamification applies game mechanics and user interactions in active learning contexts. In one part of this project, a self-guided eModule was developed for conceptual radiation interaction instruction. In a second part, a web-based game, Particle Launch (http://particle-launcher.ist.unomaha.edu), was created to challenge students to quickly apply radiation interaction concepts in a way that is stimulating and motivating. Methods: The eModule, focused on conceptual interaction physics, was designed in Adobe Captivate and incorporates animation, web videos, and assessment questions in order to generate student interest. Navigating the whole module takes 40 minutes for beginners. Assessments after three main sections are comprised of 3–4 questions randomly selected from a question pool. In collaboration with the University of Nebraska at Omaha’s College of Information Science and Technology, the Particle Launch game was created with the Unity gaming engine and designed with a game-play look and feel. The object of the game is to utilize different particles, energies, and directions to destroy a target given a limited number of resources and time to complete the task. A rewards system encourages accurate shots. Results: The eModule part of the project encourages a flipped classroom model in which class time is devoted to application of concepts rather than information-based lectures. Currently, eModule assessments are not tracked but this feature could be incorporated to encourage participation. Furthermore, in a class of five technology students, the game was found to be fun and engaging and had the effect of reinforcing basic concepts from the eModule. Conclusion: Gamification has significant potential to alter medical physics instruction. Game-play feedback is an important part of the learning process. Students found Particle Launch inviting and challenging and further research could help game design. This project was generously supported by the Office of the Vice-Chancellor for Academic Affairs and the University of Nebraska Medical Center.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2020

A Free‐Radical Prompted Barrierless Gas‐Phase Synthesis of Pentacene

Abstract A representative, low‐temperature gas‐phase reaction mechanism synthesizing polyacenes via ring annulation exemplified by the formation of pentacene (C 22 H 14 ) along with its benzo[ a ]tetracene isomer (C 22 H 14 ) is unraveled by probing the elementary reaction of the 2‐tetracenyl radical (C 18 H 11 . ) with vinylacetylene (C 4 H 4 ). The pathway to pentacene—a prototype polyacene and a fundamental molecular building block in graphenes, fullerenes, and carbon nanotubes—is facilitated by a barrierless, vinylacetylene mediated gas‐phase process thus disputing conventional hypotheses that synthesis of polycyclic aromatic hydrocarbons (PAHs) solely proceeds at elevated temperatures. This low‐temperature pathway can launch isomer‐selective routes to aromatic structures through submerged reaction barriers, resonantly stabilized free‐radical intermediates, and methodical ring annulation in deep space eventually changing our perception about the chemistry of carbon in our universe.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Malware forensics on mobile devices for DOE-EM applications - 15708

Malware attacks are deployed in order to achieve one of the following goals: To disrupt system functionality; To gather sensitive information; To gain access to private data. The top areas that become primary targets for malware to attack are: Availability, Integrity, Confidentiality. Malware forensics is a particular field where the execution and methods of a malware are studied. Malware activity has increased on unprotected mobile devices. Establishing an accurate and ethical approach is critical when assessing security issues. Knowing the method of execution leads to fewer security risks and prevention of future attacks. Our intentions are not to create a new wave of malware attacks, but to study them and point to possible vulnerabilities that can occur. To create a work-flow for desktop computers, the following benchmarks are used: Using an isolated environment, tracing the host processes, using dynamic analysis to isolate the malware and destroy it. The isolated environment will prevent any malignant code from activating and risking the rest of the computers in the vicinity and/or network. Tracing the host processes, will allow us to read the host and user processes, giving us valuable information on the activities of the device. Using dynamic analysis will allow us to manipulate the malware in a number of ways, such as using a debugger to try and change it. We used a virus and a Trojan to infiltrate a desktop computer for the following reasons: A - The virus will inject itself to force data to connect using a port. B - The Trojan will unlock and grant access to an unauthorized port. With the desktop work-flow in place as a systematic approach for mobile applications, we will investigate how to apply the same methods to the mobile devices. We are currently looking into different ways to develop 'friendly' malware to launch on the Android. We will then try to use malignant Windows malware to infect an Android, and using the work-flow try to come to the same conclusion as with the Android and Desktop, separately.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

Study on criticality control of fuel debris by Japan atomic energy agency to support regulation authority of Japan - 14571

From the viewpoint of safety regulation, criticality control of the fuel debris in the Fukushima Daiichi Nuclear Power Station would be a risk-informed control to mitigate consequences of criticality events, instead of a deterministic control to prevent such events. The Nuclear Regulation Authority of Japan has set up a research and development program to tackle this challenge. The Nuclear Safety Research Center of Japan Atomic Energy Agency, commissioned by the authority, has launched activities such as computations of criticality characteristics of the fuel debris, development of criticality risk assessment method, and preparation of criticality experiments to support them. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2011

Dynamic characterization of satellite components through non-invasive methods

The rapid deployment of satellites is hindered by the need to flight-qualify their components and the resulting mechanical assembly. Conventional methods for qualification testing of satellite components are costly and time consuming. Furthermore, full-scale vehicles must be subjected to launch loads during testing. The harsh testing environment increases the risk of component damage during qualification. The focus of this research effort was to assess the performance of Structural Health Monitoring (SHM) techniques as replacement for traditional vibration testing. SHM techniques were applied on a small-scale structure representative of a responsive satellite. The test structure consisted of an extruded aluminum space-frame covered with aluminum shear plates, which was assembled using bolted joints. Multiple piezoelectric patches were bonded to the test structure and acted as combined actuators and sensors. Various methods of SHM were explored including impedance-based health monitoring, wave propagation, and conventional frequency response functions. Using these methods in conjunction with finite element modeling, the dynamic properties of the test structure were established and areas of potential damage were identified and localized. The adequacy of the results from each SHM method was validated by comparison to results from conventional vibration testing.

42 ENGINEERING↗
DOE OSTI2011

UNDERFLIGHT CALIBRATION OF SOHO/CDS AND HINODE/EIS WITH EUNIS-07

Flights of Goddard Space Flight Center's Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket in 2006 and 2007 provided updated radiometric calibrations for Solar and Heliospheric Observatory/Coronal Diagnostic Spectrometer (SOHO/CDS) and Hinode/Extreme Ultraviolet Imaging Spectrometer (Hinode/EIS). EUNIS carried two independent imaging spectrographs covering wavebands of 300-370 A in first order and 170-205 A in second order. After each flight, end-to-end radiometric calibrations of the rocket payload were carried out in the same facility used for pre-launch calibrations of CDS and EIS. During the 2007 flight, EUNIS, SOHO/CDS, and Hinode/EIS observed the same solar locations, allowing the EUNIS calibrations to be directly applied to both CDS and EIS. The measured CDS NIS 1 line intensities calibrated with the standard (version 4) responsivities with the standard long-term corrections are found to be too low by a factor of 1.5 due to the decrease in responsivity. The EIS calibration update is performed in two ways. One uses the direct calibration transfer of the calibrated EUNIS-07 short wavelength (SW) channel. The other uses the insensitive line pairs, in which one member was observed by the EUNIS-07 long wavelength (LW) channel and the other by EIS in either the LW or SW waveband. Measurements from both methods are in good agreement, and confirm (within the measurement uncertainties) the EIS responsivity measured directly before the instrument's launch. The measurements also suggest that the EIS responsivity decreased by a factor of about 1.2 after the first year of operation (although the size of the measurement uncertainties is comparable to this decrease). The shape of the EIS SW response curve obtained by EUNIS-07 is consistent with the one measured in laboratory prior to launch. The absolute value of the quiet-Sun He II 304 A intensity measured by EUNIS-07 is consistent with the radiance measured by CDS NIS in quiet regions near the disk center and the solar minimum irradiance recently obtained by CDS NIS and the Solar Dynamics Observatory/Extreme Ultraviolet Variability Experiment.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2012

A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method

A wide variety of plasma waves play an important role in the energization and loss of particles in the inner magnetosphere. Our ability to understand and model wave-particle interactions in this region requires improved knowledge of the spatial distribution and properties of these waves as well as improved understanding of how the waves depend on changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a two-dimensional, finite element code that solves the full wave equations in global magnetospheric geometry. The code describes three-dimensional wave structure including mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional axisymmetric background plasma with general magnetic field topology. We illustrate the capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from external, solar wind compressions; and wave structure and mode conversion of electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which propagate along the magnetic field lines toward the ionosphere. We also discuss advantages of the finite element method for resolving resonant structures, and how the model may be adapted to include nonlocal kinetic effects.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

IRSN working program status on tools for evaluation of SFR cores static neutronics safety parameters

As technical support of the French Nuclear Safety Authority, IRSN will be in charge of safety assessment of any future project of Sodium Fast Reactor (SFR) that could be built in France. One of the main safety topics will deal with reactivity control. Since the design and safety assessment of the last two SFR plants in France (Phenix and Superphenix, more than thirty years ago), methods, codes and safety objectives have evolved. That is why a working program on core neutronic simulations has been launched in order to be able to evaluate accuracy of future core characteristics computations. The first step consists in getting experienced with the ERANOS well-known deterministic code used in the past for Phenix and Superphenix. Then Monte-Carlo codes have been tested to help in the interpretation of ERANOS results and to define what place this kind of codes can have in a new SFR safety demonstration. This experience is based on open benchmark computations. Different cases are chosen to cover a wide range of configurations. The paper shows, as an example, criticality results obtained with ERANOS, SCALE and MORET, and the first conclusions based on these results. In the future, this work will be extended to other safety parameters such as sodium void and Doppler effects, kinetic parameters or flux distributions. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2017

Substrate-Coated Illumination Droplet Spray Ionization: Real-Time Monitoring of Photocatalytic Reactions

Real-time monitoring of photocatalytic reactions facilitates the elucidation of the mechanisms of the reactions. However, suitable tools for real-time monitoring are lacking. Herein, a novel method based on droplet spray ionization named substrate-coated illumination droplet spray ionization (SCI-DSI) for direct analysis of photocatalytic reaction solution is reported. SCI-DSI addresses many of the analytical limitations of electrospray ionization (ESI) for analysis of photocatalytic-reaction intermediates, and has potential for both in situ analysis and real-time monitoring of photocatalytic reactions. In SCI-DSI-mass spectrometry (MS), a photocatalytic reaction occurs by loading sample solutions onto the substrate-coated cover slip and by applying UV light above the modified slip; one corner of this slip adjacent to the inlet of a mass spectrometer is the high-electric-field location for launching a charged-droplet spray. After both testing and optimizing the performance of SCI-DSI, the value of this method for in situ analysis and real-time monitoring of photocatalytic reactions was demonstrated by the removal of cyclophosphamide (CP) in TiO{sub 2}/UV. Reaction times ranged from seconds to minutes, and the proposed reaction intermediates were captured and identified by tandem mass spectrometry. Moreover, the free hydroxyl radical (·OH) was identified as the main radicals for CP removal. These results show that SCI-DSI is suitable for in situ analysis and real-time monitoring of CP removal under TiO{sub 2}-based photocatalytic reactions. SCI-DSI is also a potential tool for in situ analysis and real-time assessment of the roles of radicals during CP removal under TiO{sub 2}-based photocatalytic reactions.Graphical Abstract .

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

IAEA CONNECT: Connecting the network of networks for enhanced communication and training - 15143

To further support the exchange of information and cooperation in the management of radioactive waste, decommissioning and environmental remediation, a new tool has been developed and was officially launched in October 2014: The IAEA CONNECT platform. This paper describes the platform, including its objectives, principles, participation/audience, methods of work, Governance document, current available networks and features, and explains the context it was developed in, as well as the reasons behind its creation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗