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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Tuning Metastability of Poly(3-hexyl thiophene) Solutions to Enable in Situ Atomic Force Microscopy Imaging of Surface Nucleation

Poly(3-hexyl thiophene) (P3HT), a workhorse material for the study of organic electronic devices, assembles into nanofibers (NFs) upon crystallization from solution, providing the means to tailor morphology and improve device performance. We investigate how P3HT regioregularity, molecular weight, and concentration influence the hysteresis between crystallization and melting temperatures of NFs. Hysteresis is found to increase with molecular weight and reach an asymptote for polymer chains above the chain folding threshold (Mn > 12 kg/mol). Regioregularity does not substantially affect the hysteresis above a level of 88%, while increasing polymer concentration is found to reduce hysteresis. This insight facilitates in situ high-resolution atomic force microscopy measurements that provide better understanding of the mechanism of NF crystallization on graphite. We find an interchain distance (along the a crystallographic axis) of 16.7 ± 0.7 Å, and a spacing of 7.7 ± 0.2 Å along the c axis, suggesting that the crystals on graphite are form I.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Sulfurization of α-MoO{sub 3} nanostructured thin film

In this report, the sulfurization of vertically aligned molybdenum trioxide (α- MoO{sub 3}) nanoflakes (NFs) with high aspect ratio (height/thickness >20) on the nickel coated glass substrates in a mixture of H{sub 2}S and argon gas at atmospheric pressure has been studied. The effect of sulfurization have been investigated to understand the basic reaction mechanism and the morphology, structural properties of grown nanoflakes. XPS and XRD indicate the formation of MoS{sub 2} along with the other intermediate phase such as MoO{sub 2} at temperature 200 °C. The surface morphology of samples have been studied systematically by using scanning electron microscope (SEM). The results demonstrate partial conversion of MoO{sub 3} NFs into MoS{sub 2} along with the change in the morphology of nanoflakes. All the observed results are well in consonance with each other.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Plasma assisted growth of MoO{sub 3} films on different substrate locations relative to sublimation source

In the present paper, we reported the role of substrate locations relative to source on the growth of MoO{sub 3} films deposited on Ni coated glass substrates using plasma assisted sublimation process (PASP). According to the XRD and SEM results, substrate location is very crucial factor to control the morphology of MoO{sub 3} films and the best nanostructure growth (in terms of alignments and features) is obtained in case of Sample B (in which substrate is placed on source). The structural results point out that all films exhibit only orthorhombic phase of molybdenum oxide (i.e. α-MoO{sub 3})but the most preferential growth is recorded in Sample B due to the presence of intense peaks crossponding to only (0 k 0) family of crystal planes (k = 2, 4,6..). The Raman analysis again confirms the orthorhombic nature of MoO{sub 3} NFs and details of vibrational bondsin Sample B have been given in the present report. The MoO{sub 3} NFs show intense PL emission in wavelength range of 300-700 nm with three peaks located at 415, 490, and 523 nm in accordance to the improved crystallinity in Sample B.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2016

Effect of plasma voltage on sulfurization of α-MoO{sub 3} nanostructured thin films

In this report, the effect of plasma voltage on plasma assisted sulfurization (PAS) of vertically aligned molybdenum trioxide (α- MoO{sub 3}) nanoflakes (NFs) on glass substrates has been studied systematically. MoO{sub 3} NFs were deposited using plasma assisted sublimation process. These nanoflakes were subjected to H{sub 2}S/Ar plasma at two different plasma voltages 600 and 1000 volts; to study the effect of plasma ionization on degree of sulfurization of MoO{sub 3} into MoS{sub 2}. XRD and Raman analysis show that film sulfurized at 1000 volts have relatively higher degree of conversion into MoS{sub 2}, as more intense peaks of MoS{sub 2} and MoO{sub 2} are obtained than that sulfurized at 600 volts. HRTEM of sulfurized film shows that outer surface of nanoflake has been converted into MoS{sub 2} (4-5 monolayers). Meanwhile, MoO{sub 3} was reduced into MoO{sub 2} as confirmed by XRD and Raman results. All the observed results are well in consonance with each other.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

A novel integrated time-resolved array avalanche photodiode detection system for nuclear resonant scattering measurements

Here, the nuclear resonant scattering (NRS) experiment requires photon-counting detectors with high time resolution, short dead time, large dynamic range, low noise, and large detection area. An 8-channel avalanche photodiode (APD) array detector system with high integrity, flexibility, and reliability has been developed to adapt to the demands of NRS experiments. The detector system mainly consists of four key parts: (i) an array-APD sensor, (ii) 8-channel integrated fast preamplifiers, (iii) the time-to-digital converter readout electronics, and (iv) a data acquisition system and EPICS support software. Remarkably, the system exhibits a time resolution of better than 500 ps and has a sufficiently low noise level, allowing for the lowest detection energy threshold of 4 keV. The performance of the new array-APD system as well as its real application in nuclear forward scattering (NFS) and nuclear resonant inelastic x-ray scattering (NRIXS) experiments was tested in two synchrotron facilities. With the new system, the NFS signal very close to the prompt electronic scattering signal can be extracted. Thanks to the customized EPICS-areaDetector-based control software, NRIXS spectra can be readily measured with time and energy information of the NRIXS signal stored in the raw data, which is promising for developing NRIXS data analysis in the time domain. The array-APD detector can be deployed for nuclear resonant scattering experiments at various synchrotron radiation facilities.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Spin disorder in maghemite nanoparticles investigated using polarized neutrons and nuclear resonant scattering

The manuscript reports the investigation of spin disorder in maghemite nanoparticles of different shape by a combination of polarized small-angle neutron scattering (SANSPOL) and nuclear forward scattering (NFS) techniques. Both methods are sensitive to magnetization on the nanoscale. SANSPOL allows for investigation of the particle morphology and spatial magnetization distribution and NFS extends this nanoscale information to the atomic scale, namely the orientation of the hyperfine field experienced by the iron nuclei. The studied nanospheres and nanocubes with diameters of 7.4nm and 10.6 nm, respectively, exhibit a significant spin disorder. This effect leads to a reduction of the magnetization to 44% and 58% of the theoretical maghemite bulk value, observed consistently by both techniques.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2024

Pressure induced Invar effect in Fe 55 ⁢Ni 45 : An experimental study with nuclear resonant scattering

Pressure-dependent synchrotron x-ray diffraction (XRD), nuclear resonant inelastic x-ray scattering (NRIXS), and nuclear forward scattering (NFS) measurements were made on 57 Fe 55 Ni 45 . XRD measurements were at 298 and 392 K at pressures up to 20 GPa, confirming a pressure-induced Invar effect between 7 and 13 GPa. A decrease of the 57 Fe magnetic moment was found in NFS measurements under pressure, showing an increase in magnetic entropy. The 57 Fe phonon density of states (DOS) was obtained from NRIXS measurements. The low thermal expansion in the high-pressure Invar region originates from a competition between the thermal expansion from spins and phonons as calculated from Maxwell relations. Finally, the longitudinal phonon modes changed their pressure dependence near the Curie transition, which is evidence for a spin-phonon interaction.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2018

The Incredible Effect of Heat Load Increase Rate on the Specific Heat Flux at Boiling of Some Nanofluids

Boiling curves for different heat-load increase rates (HLIRs) are obtained for distilled water, tap water, and two nanofluids (NFs) based on a natural mixture of montmorillonite and attapulgite (AlSi-7) and titanium dioxide (NF-8). An unusually strong influence of the HLIR on the thermal parameters of NFs is detected upon boiling of AlSi-7 based on a mixture of highly anisometric nanoparticles of aluminosilicates of various morphologies capable of forming nanostructured openwork “architectures” on the heater surface. An explanation of the reasons for the observed effect is proposed. The data obtained indicate the existence of an optimal HLIR at which the structure of the deposit appearing on the heating surface during the boiling of an NF is most favorable for heat exchange.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2012

Establishing a Scientific Basis for Optimizing Compositions, Process Paths and Fabrication Methods for Nanostructured Ferritic Alloys for Use in Advanced Fission Energy Systems

The broad objective of this NEUP was to further develop a class of 12-15Cr ferritic alloys that are dispersion strengthened and made radiation tolerant by an ultrahigh density of Y-Ti-O nanofeatures (NFs) in the size range of less than 5 nm. We call these potentially transformable materials nanostructured ferritic alloys (NFAs). NFAs are typically processed by ball milling pre-alloyed rapidly solidified powders and yttria (Y2O3) powders. Proper milling effectively dissolves the Ti, Y and O solutes that precipitate as NFs during hot consolidation.

36 MATERIALS SCIENCE↗
DOE OSTI2013

Comparison of results for quarter 5 surface water split samples collected at the nuclear fuel services site Erwin Tennessee

Oak Ridge Associated Universities (ORAU), under the Oak Ridge Institute for Science and Education (ORISE) contract, collected split surface water samples with Nuclear Fuel Services (NFS) representatives on August 21, 2013. Representatives from the U.S. Nuclear Regulatory Commission (NRC) and the Tennessee Department of Environment and Conservation were also in attendance. Samples were collected at four surface water stations, as required in the approved Request for Technical Assistance number 11-018. These stations included Nolichucky River upstream (NRU), Nolichucky River downstream (NRD), Martin Creek upstream (MCU), and Martin Creek downstream (MCD). Both ORAU and NFS performed gross alpha and gross beta analyses, and the comparison of results using the duplicate error ratio (DER), also known as the normalized absolute difference, are tabulated. All DER values were less than 3 and results are consistent with low (e.g., background) concentrations.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Analysis of Renewable Energy Potential on U. S. National Forest Lands

In 2005, the National Renewable Energy Laboratory (NREL) completed an assessment of the potential for solar and wind energy development on National Forest System (NFS) public lands managed by the US Department of Agriculture, U.S. Forest Service (USFS). This report provides an update of the analysis in the NREL report, and extends the analysis with additional siting factors for solar and wind energy. It also expands the scope to biomass and geothermal energy resources. Hydropower is acknowledged as another major renewable energy source on NFS lands; however, it was not analyzed in this project primarily because of the substantially different analysis that would be needed to identify suitable locations.

09 BIOMASS FUELS↗
DOE OSTI2014

A Preliminary Review of U.S. Forest Service Business Practices To Authorize Special Uses, Including Energy Infrastructure Projects, on National Forest System Lands

The U.S. Forest Service (USFS) Special Uses-Lands Program is in jeopardy. Although this program, authorized in Title 36, Part 251, of the U.S. Code of Federal Regulations (36 CFR Part 251), ranks among the top four revenue-generating programs for use of National Forest System (NFS) lands, along with the Timber, Minerals, and Special Uses-Recreation Programs, the Special Uses-Lands Program is in a state of neglect. Repeated cuts in funding (a decrease of 26% from fiscal years 2010 to 2014) are adversely affecting staffing and training, which in turn is affecting timely permit processing and ultimately the public’s ability to use and benefit from NFS lands. In addition, highly experienced staff with valuable institutional knowledge of the program have begun to retire. The ability of the program to function under these dire circumstances can be attributed to the dedication of Special Uses staff to the program and their commitment to the public. The initial focus of this report was to identify opportunities for improving performance of permitting and review for large energy infrastructure-related projects. However, it became clear during this analysis that these projects are generally adequately staffed and managed. This is due in large part to the availability of cost-recovery dollars and the high-profile nature of these projects. However, it also became apparent that larger issues affecting the bulk of the work of the Special Uses-Lands Program need to be addressed immediately. This report is a preliminary examination of the state of the Special Uses-Lands Program and focuses on a few key items requiring immediate attention. Further investigation through case studies is recommended to dig deeper into the Special Uses-Lands Program business process to determine the most costeffective strategies for streamlining the overall process and the metrics by which performance can be evaluated, including for the permitting and tracking of energy infrastructure projects.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2018

Inadvertent Disposal of Chromium Waste at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nevada

Nuclear Fuel Services, Inc. (NFS), a waste generator approved to ship waste to the Nevada National Security Site (NNSS), made 49 waste shipments in the period 2009 to 2015 that were subsequently determined to contain chromium that exceeded the Toxicity Characteristic Leaching Procedure regulatory limit, which would require the waste to carry hazardous waste code D007. One of the 49 shipments contained bottles of liquid blowback solution and was returned to NFS for disposition. The remaining 48 shipments consisted of a total of 93 disposal packages of chromium-containing waste that were disposed in seven low-level waste (LLW) cells at the Area 5 Radioactive Waste Management Site (RWMS).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Corrective Action Decision Document/Corrective Action Plan for Corrective Action Unit 577: Area 5 Chromium Containing Waste Disposal Cells, Nevada National Security Site, Nevada

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) is for Corrective Action Unit (CAU) 577, “Area 5 Chromium Containing Waste Disposal Cells,” which is located in Area 5 of the Nevada National Security Site (NNSS). CAU 577 includes five low-level waste cells at the Area 5 Radioactive Waste Management Site (RWMS) where buried waste received from Nuclear Fuel Services, Inc. (NFS), was subsequently determined to contain chromium that exceeded the Toxicity Characteristic Leaching Procedure regulatory limit, which would require the waste to carry hazardous waste code D007. To resolve issues related to this alleged violation of hazardous waste regulations, a Settlement Agreement was executed between the Nevada Division of Environmental Protection (NDEP) and the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office on April 25, 2019, which identified agreed-upon mitigation measures. The Settlement Agreement required that the chromium-containing waste received from NFS would be addressed following the closure process laid out in the Federal Facility Agreement and Consent Order (FFACO).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Results from the First Field Test of a Ruggedized Continuous Holdup Monitor

A first field test of the inexpensive and ruggedized online holdup monitor under development at the US Department of Energy’s Oak Ridge National Laboratory (ORNL) was performed in September of 2023 with highly successful results. ORNL staff collaborated with personnel at the National Fuel Services (NFS) to place two battery-powered detector units at the facility, one on a fuel processing line and the other on a HEPA filter. Both units collected gamma-ray counts per second, temperature, humidity, and battery power data every 5 s seconds over the course of 19 days. Analyzed results from the measurements were discussed with NFS personnel after the units were removed. Vendor feedback on the units was overwhelmingly positive with an expressed desire to deploy finished units at the facility and an open invitation for testing future prototypes.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1989

Deceit: A flexible distributed file system

Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness.

Siegel, Alex↗
NASA NTRS1991

MultiNet TCP/P/IP for VAX/VMS update

Outlines of device support; DECnet interoperability; installation; MultiNet services; domain name server; Telnet; FTP; SMTP; DECwindows over TCP/IP; BSD r services; remote printing; RPC services and NFS server; NFS client; netcontrol; diagnostics; programming support; and MultiNet features are presented in viewgraph format.

Vance, L. Stuart↗
NASA NTRS1992

Network issues for large mass storage requirements

File Servers and Supercomputing environments need high performance networks to balance the I/O requirements seen in today's demanding computing scenarios. UltraNet is one solution which permits both high aggregate transfer rates and high task-to-task transfer rates as demonstrated in actual tests. UltraNet provides this capability as both a Server-to-Server and Server-to-Client access network giving the supercomputing center the following advantages highest performance Transport Level connections (to 40 MBytes/sec effective rates); matches the throughput of the emerging high performance disk technologies, such as RAID, parallel head transfer devices and software striping; supports standard network and file system applications using SOCKET's based application program interface such as FTP, rcp, rdump, etc.; supports access to the Network File System (NFS) and LARGE aggregate bandwidth for large NFS usage; provides access to a distributed, hierarchical data server capability using DISCOS UniTree product; supports file server solutions available from multiple vendors, including Cray, Convex, Alliant, FPS, IBM, and others.

Perdue, James↗