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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 1,297 records · Page 72
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Real-Time Wavelength Discrimination for Improved Neutron Discrimination in CLYC

We investigated the effects of optical filters on the pulse shape discrimination properties of Cs 2 LiYCl 6 :Ce (CLYC) scintillator crystals. By viewing the scintillation light through various optical filters, we attempted to better distinguish between neutron and gamma ray events in the crystal. We applied commercial interference and colored glass filters in addition to fabricating quantum dot (QD) filters by suspending QDs in plastic films and glass. QD filters ultimately failed because of instability of the QDs with respect to oxidation when exposed to ambient air, and the tendency of the QDs to aggregate in the plastic. Of the commercial filters, the best results were obtained with a bandpass interference filter covering the spectral region containing core-valence luminescence (CVL) light. However, the PSD response of filtered CLYC light was always poorer than the response exhibited by unfiltered light because filters always reduced the amount of light available for signal processing.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Evaluating System Parameters on a Dragonfly using Simulation and Visualization

The dragon y topology is becoming a popular choice for build- ing high-radix, low-diameter networks with high-bandwidth links. Even with a powerful network, preliminary experi- ments on Edison at NERSC have shown that for communica- tion heavy applications, job interference and thus presumably job placement remains an important factor. In this paper, we explore the e ects of job placement, job sizes, parallel workloads and network con gurations on network through- put to better understand inter-job interference. We use a simulation tool called Damsel y to model the network be- havior of Edison and study the impact of various system parameters on network throughput. Parallel workloads based on ve representative communication patters are used and the simulation studies on up to 131,072 cores are aided by a new visualization of the dragon y network.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2014

Report of the EMI Testing of the Johnson Noise Thermometry System

This report summarizes the Electromagnetic Interference (EMI) testing of the Johnson Noise Thermometry System developed at ORNL. The EMI performance is very important for Johnson Noise Thermometry because it requires accurate measurement of a very small noise signal that is amplified 10,000 times. Any interference in the form on pickup from external signal sources from such as fluorescent lighting ballasts, motors, etc. can skew the measurement. Testing is therefore very important in determining the effects of these external noise sources. Results from testing in several environments with various sources of EMI are presented here.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

Task 4 - EMI/RFI Issues Potentially Impacting Electromagnetic Compatibility of I&C Systems (NRCHQ6014D0015)

The U.S. Nuclear Regulatory Commission’s (NRC’s) regulations in Part 50, “Domestic Licensing of Production and Utilization Facilities,” of Title 10 of the Code of Federal Regulations (10 CFR Part 50) state that structures, systems, and components important to safety in a nuclear power plant are to be designed to accommodate the effects of environmental conditions (i.e., remain functional under all postulated service conditions) and that design control measures such as testing are to be used to check the adequacy of design. Regulatory Guide (RG) 1.180 was developed to provide guidance to licensees and applicants on methods acceptable to the NRC staff for complying with the NRC’s regulations on design, installation, and testing practices for addressing the effects of electromagnetic and radio-frequency interference (EMI/RFI) and power surges on safety-related instrumentation and control (I&C) systems. The first revision of RG 1.180 was issued in January 2000 and a second revision was issued in October 2003*. The second revision differed from the first revision in endorsing Military Standard (MIL-STD)-461E and the International Electrotechnical Commission (IEC) Standard (Std) 61000 series of EMI/RFI test methods, extending the guidance to cover signal line testing, incorporating frequency ranges where portable communications devices are experiencing increasing use, and relaxing the operating envelopes (test levels) when experience and confirmatory research warranted. It also offered exemptions from specific test criteria based on technical considerations such as plant conditions and the intended location of the safety-related I&C equipment. Since the last revision, new requirements have been identified, associated RGs have been created and updated, and additional industry guidance has been developed. Additionally, the operational environment has changed with the increase in wireless communication technology for both personal (smartphone) and industrial (remote I&C) purposes. Also, specific concerns and issues with testing methods and methodologies have been identified that must be addressed. Further, most of the standards that serve as the basis for the RG have been revised. Therefore, the NRC’s Office of Regulatory Research has contracted with Oak Ridge National Laboratory (ORNL) to incorporate new information and resolve the identified issues under NRC-HQ-60-14-D-0015, “Update to RG 1.180, Revision 2, Guidelines for Evaluating Electromagnetic and Radio-Frequency Interference in Safety-Related Instrumentation and Control Systems.” The ultimate goal of this project is to provide NRC the technical basis for developing and publishing a new revision of the RG. The focus of Task 4 was for ORNL to identify and address any new or additional EMI/RFI issues that could potentially impact the EMC of I&C systems. More specifically, ORNL was to evaluate the impact of any new issue on safety equipment in their local environments and then determine whether the issues should be included and discussed in the revision to RG 1.180 that is currently under way.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

Innovative signal processing for Johnson Noise thermometry

This report summarizes the newly developed algorithm that subtracted the Electromagnetic Interference (EMI). The EMI performance is very important to this measurement because any interference in the form on pickup from external signal sources from such as fluorescent lighting ballasts, motors, etc. can skew the measurement. Two methods of removing EMI were developed and tested at various locations. This report also summarizes the testing performed at different facilities outside Oak Ridge National Laboratory using both EMI removal techniques. The first EMI removal technique reviewed in previous milestone reports and therefore this report will detail the second method.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2017

Tethered Aerostat Effects on Nearby Seismometers

This report assesses seismic interference generated by a tethered aerostat. The study was motivated by a planned aerostat deployment within the footprint of the Dry Alluvium Geology seismic network. No evidence was found for seismic interference generated by the aerostat, and thus the e ects on the Dry Alluvium Geology sensors will be negligible.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Analyzing Solutions High in Total Dissolved Solids for Rare Earth Elements (REEs) Using Cation Exchange and Online Pre-Concentration with the seaFAST2 Unit; NETL-TRS-7-2017; NETL Technical Report Series; U.S. Department of Energy, National Energy Technology Laboratory: Albany, OR, 2017; p 32

The accurate quantification of the rare earth element (REE) dissolved concentrations in natural waters are often inhibited by their low abundances in relation to other dissolved constituents such as alkali, alkaline earth elements, and dissolved solids. The high abundance of these constituents can suppress the overall analytical signal as well as create isobaric interferences on the REEs during analysis. Waters associated with natural gas operations on black shale plays are characterized by high salinities and high total dissolved solids (TDS) contents >150,000 mg/L. Methods used to isolate and quantify dissolved REEs in seawater were adapted in order to develop the capability of analyzing REEs in waters that are high in TDS. First, a synthetic fluid based on geochemical modelling of natural brine formation fluids was created within the Marcellus black shale with a TDS loading of 153,000 mg/L. To this solution, 1,000 ng/mL of REE standards was added based on preliminary analyses of experimental fluids reacted at high pressure and temperature with Marcellus black shale. These synthetic fluids were then run at three different dilution levels of 10, 100, and 1,000–fold dilutions through cation exchange columns using AG50-X8 exchange resin from Eichrom Industries. The eluent from the cation columns were then sent through a seaFAST2 unit directly connected to an inductively coupled plasma mass spectrometer (ICP-MS) to analyze the REEs. Percent recoveries of the REEs ranged from 80–110% and fell within error for the external reference standard used and no signal suppression or isobaric interferences on the REEs were observed. These results demonstrate that a combined use of cation exchange columns and seaFAST2 instrumentation are effective in accurately quantifying the dissolved REEs in fluids that are >150,000 mg/L in TDS and have Ba:Eu ratios in excess of 380,000.

03 NATURAL GAS↗
DOE OSTI2017

Analysis of Environmental Swipes Using Fluorescence Microscopy - Summary Report

This report summarizes efforts as part of a collaboration between Oak Ridge National Laboratory (ORNL) and the University of Kansas (KU) during fiscal year 2016 for the purpose of screening environmental swipes (ESs) using fluorescence microscopy. The overall goal of this work is to image actinide-bearing species by exploiting the fluorescence properties of the uranyl moiety. If successfully developed, this capability would permit automated screening of actinide species in environmental swipes to prioritize samples for destructive analysis. The evaluation of efforts to date has shown that uranyl fluoride can be imaged using fluorescence microscopy and the vibronic structure can be resolved; however, difficulties arise when attempting to image these materials on ESs because of spectral interference. Due to the fluorescence decay differences between cellulosic fibers and uranyl-containing materials, time-gating approaches were investigated to minimize this interference. This approach shows promise; however, the technique requires additional developmental work before it can be transitioned to a robust method for laboratory use.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Decoupled Modulation Control

The objective of this research work is to develop decoupled modulation control methods for damping inter-area oscillations with low frequencies, so the damping control can be more effective and easier to design with less interference among different oscillation modes in the power system. A signal-decoupling algorithm was developed that can enable separation of multiple oscillation frequency contents and extraction of a “pure” oscillation frequency mode that are fed into Power System Stabilizers (PSSs) as the modulation input signals. As a result, instead of introducing interferences between different oscillation modes from the traditional approaches, the output of the new PSS modulation control signal mainly affects only one oscillation mode of interest. The new decoupled modulation damping control algorithm has been successfully developed and tested on the standard IEEE 4-machine 2-area test system and a minniWECC system. The results are compared against traditional modulation controls, which demonstrates the validity and effectiveness of the newly-developed decoupled modulation damping control algorithm.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2018

Examination of Shipping Package 9975-04194

In December 2017, K-Area personnel attempted to open package 9975-04194 to remove its contents. The upper fiberboard assembly could not be initially removed due to an interference fit that had developed against the lead shield. Corrosion of the shield created two specific conditions that caused this interference. First, there was widespread heavy blisters over the shield surface. Corrosion of the lead under the surface (associated with porosity in the as-cast shield which is open to the surface) appears to have caused the blisters to form. Second, corrosion also formed in a gap between the lead shield and the internal stainless steel liner, pushing the top edge of the shield outward into the upper fiberboard assembly. In both cases, portions of the shield are pushed outward since the corrosion product occupies a greater volume than the metallic lead it replaced.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Visualization of Multi-Dimensional Imaging Data for the DIII-D National Fusion Facility

With funding provided from the Office of Fusion Energy Science’s program on Diagnostic Systems for Magnetic Fusion Energy Sciences, the PI and his team have pioneered the development of microwave imaging systems for magnetic fusion plasma diagnostics. Specifically, electron cyclotron emission (ECE) imaging [1], a passive radiometric technique, measures electron temperature fluctuations; and microwave imaging reflectometry (MIR) [2], an active radar imaging technique, measures electron density fluctuations. These microwave imaging diagnostic instruments developed by UC Davis have made important contributions to fusion science in a relatively short period of time from their original installation on DIII-D. The microwave imaging diagnostic technique has matured considerably since the beginning of a fruitful collaboration with DIII-D and PPPL, and has also been adopted at preeminent tokamak facilities worldwide. As discussed in detail in the following, this has continued with the development of revolutionary microwave diagnostic instruments employing monolithic millimeter wave integrated circuit (MMIC) system-on-chip (SoC) technology. Specifically, “chip” receivers mounted in liquid crystal polymer (LCP) modules have been demonstrated to dramatically improve the performance of the electron cyclotron emission imaging (ECEI) system including: 30x improvement in noise temperature thereby permitting absolute 2-D electron temperature images, outstanding shielding against out-of-band interference including microwave bursting which had plagued previous ELM studies using the old quasi-optical mini-lens ECEI system, and independent modules facilitating flexible repair and replacement. Under the “Visualization of multi-dimensional imaging data for the DIII-D National Fusion Facility” program, funding was provided for a research scientist postdoc and a Ph.D. student to support physics studies at DIII-D employing these instruments. This endeavor is synergistic with our current grant under the DOE Fusion Energy Sciences (FES) program on Diagnostic Systems for Magnetic Fusion Energy Sciences. This support considerably increased the scientific output of the diagnostics. The activities were strongly focused in the areas of pedestal and ELM stability, energetic particle confinement, and the early detection and avoidance of tokamak disruptions employing the microwave imaging diagnostic instruments developed under the advanced diagnostics program where imaging of the ELM crash was made possible by the elimination of the interference from the associated microwave “bursts”

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

Measurement of Hard Exclusive Electroproduction of π 0 Meson Cross Section in Hall A of JLab with CEBAF at 12 GeV

A complete description of nucleon structure requires the simultaneous knowledge of both the spatial and momentum information of the ultimate constituents of the nucleon, the quarks and gluons. Generalized Parton Distributions (GPDs) provide such tools to describe nucleon structure. GPDs are measurable through hard exclusive processes like Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). GPDs can describe hard exclusive processes only if Bjorken factorization is achieved during the hard scattering process. While DVCS data have given hints of the factorization regime being attained, such hints have not been observed for DVMP data. Testing for factorization in DVMP processes is the topic of this thesis. Exclusive π 0 electroproduction has been measured by experiment E12-06-114 in Hall A of JLab. Cross sections have been measured at three fixed Bjorken- x ( x B ): 0.35, 0.48 and 0.6 in the Q 2 range 3 to 9 GeV 2 . In this document we present an analysis of a subset of the data: x B = 0.35 in the Q 2 range 3.1 to 4.5 GeV 2 . The different structure functions: unseparated cross section (σ T + ϵσ L ), longitudinal-transverse interference (σ LT ), transverse-transverse interference (σ TT ), and the polarized response (σ LT' ) terms were extracted. The data was compared to a transversity GPD model. The model fails to reproduce the data even though the order of magnitude is in agreement for both model and data. We observe a strong disagreement between the data and the model for σ LT in terms of both magnitude and the cross section sign. Our results are in a larger and wider Q 2 domain but they are in agreement with existing measurements.

Dlamini, Mongi↗
DOE OSTI2020

Glycolate Analysis in Tank 22: Developing and Testing Analytical Methods for the Savannah River Site Liquid Waste System

Researchers developed and tested a range of techniques to support a low mg/L Limit of Quantitation (LOQ) of glycolate in radioactive Tank 22 waste solution by Ion Chromatography (IC) and by proton NMR. For the IC method, Dionex OnGuard II cartridges were tested as a means of removing alkali earth and transition metals that can interfere during ion chromatography applications especially when analyzing for low-concentration, chelating analytes. Additionally, concentrations of nitrate in the raw Tank 22 sample (5,000 to 10,000 mg/L) were managed by using reasonable levels of sample dilution. The resulting IC performance quality was enhanced by improving the baseline, increasing sensitivity [Limit of Quantitation (LOQ) of 12 mg/L and Limit of Detection (LOD) of 4.0 mg/L], and resolving analytes into well-defined Gaussian peaks when using the Dionex OnGuard II H⁺ cartridges to remove matrix interferences. High concentrations of nitrate limited the performance of the IC method. To achieve an acceptable baseline, samples with high nitrate content require more dilution, resulting in higher detection limits. Tests on samples with higher concentrations of nitrate (Tank 30 and 32 supernate with approximately 150000 mg/L nitrate) suggested that IC detection limits for glycolate in these samples would be > 500 mg/L. Thus, an LOQ of 12 mg/L is not feasible by this IC method on evaporator feed samples. An alternative method of glycolate analysis, using proton nuclear magnetic resonance (H NMR), was developed by the research team. In initial tests, the H NMR technique provided reasonable quantitation of glycolate in Tank 22 conditions by direct observation of the liquid. The H NMR method may provide improved detection limits for solutions with higher nitrate concentrations. We recommend further development of this analysis for high nitrate LWS samples such as evaporator feed and evaporator drop tank content. A method for pretreatment of samples using crystalline silicotitanate (CST) was developed and tested. The objective of the pretreatment was to facilitate analysis of samples with higher levels of radioactivity. The pretreatment did not influence the glycolate concentration in solution, and the pretreatment is projected to reduce Cs 137 activity in a sample by a factor of 16,200. The double strike CST pretreatment was demonstrated and would allow milliliters of higher activity samples to be transferred from the Shielded Cells and handled in a containment unit for glycolate analysis. The various studies validated IC and H NMR methods for glycolate analysis, defined the range of applicability, and demonstrated key supporting analytical protocols. Based on the results, high quality glycolate analysis of Tank 22 is feasible down to approximately 12 mg/L, with the potential for broader applicability of the methods to other conditions in the Savannah River Site Liquid Waste System (LWS).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Wind Turbine Lightning Mitigation System Radar Cross Section Reduction

Modern wind turbines employ Lightning Mitigation Systems (LMSs) in order to reduce costly damages caused by lightning strikes. Lightning strikes on wind turbines occur frequently making LMS configurations a necessity. An LMS for a single turbine includes, among other equipment, cables running inside each blade, along the entire blade length. These cables are connected to various metallic receptors on the outside surface of the blades. The LMS cables can act as significant electromagnetic scatterers which may cause interference to radar systems. This interference may be mitigated by reducing the Radar Cross-Section (RCS) of the wind turbine's LMS. This report investigates proposed modifications to LMS cables in order to reduce the RCS when illuminated by Re locatable Over the Horizon Radar (ROTHR) systems which operate in the HF band (3 - 30 MHz). The proposed modifications include breaking up the LMS cables using spark gap connections, and changing the orientation of the LMS cable within the turbine blade. Both simulated analyses of such RCS mitigation techniques is provided as well as recommendations on further research.

17 WIND ENERGY↗
DOE OSTI2020

Assessing the Vulnerability of Unmanned Aircraft Systems to Directed Acoustic Energy

The increasingly large payloads of Unmanned Aircraft Systems (UASs) are exponentially increasing the threat to the nuclear enterprise. Current mitigation using RF interference is effective, but not feasible for fully autonomous systems and is prohibited in many areas. A new approach to UAS threat mitigation is needed that does not create radio interference but is effective against any type of vehicle. At the present time there is no commercial counter-UAS system that directly assaults the mems gyros and accelerometers in the Inertial Measurement Unit on the aircraft. But lab testing has revealed resonances in some IMUs that make them susceptible to moderate amplitude acoustic monotones. Sandia's energetic materials facility has enabled a quick and thorough exploration of UAS vulnerability to directed acoustic energy by using intense acoustic impulses to destabilize or down a UAS. We have: 1) detonated/deflagrated explosive charges of various sizes; 2) accurately measured impulse pressure and pulse duration; 3) determined what magnitude of acoustic insult to the IMU disrupts flight and for how long and; 4) determined if the air blast/shock wave on aircraft/propellers disrupts flight.

42 ENGINEERING↗
DOE OSTI2021

Applications of seismic threshold monitoring at an Antarctic glacier [Slides]

Geophysical waveforms collected from Arctic regions provides data required for monitoring global security targets. Some seismic instruments deployed on Scandinavian and Greenlandic sites provide waveform data, but these installations include specific challenges: Sea ice and glacial ice generates waveform interference; Meltwater generates narrowband interference, resembling tonal noise.

58 GEOSCIENCES↗
DOE OSTI2021

Requirements Documents for the Large Mechanical Parts Precision Cleaner (LMPPC) in the Optics Assembly Building (OAB)

The National Ignition Facility (NIF) is the world's largest energetic laser whose missions include sresearch in inertial confinement fusion, experiments for the Stockpile Stewardship, and other high fluence laser research. Due to the high fluence of lasers, extreme environmental conditions, and radiation presence, all mechanical parts (metal, plastic, etc.) installed on NIF must be precision cleaned. Precision cleaned parts are also required in supporting facilities like the Optics Processing Facility (OPF). Small debris inside the laser beams or on optics can cause optic damage, interfere with diagnostics, and interfere with experiments.

42 ENGINEERING↗
DOE OSTI2022

Responses to Nonconformances, AIHA Onsite Assessment August 29-31, 2022

A nonconformance report (NCR) was not generated to document the original Beryllium (Be) positive result being changed to negative due to an oversight by the lab. The sample was re-analyzed on the Agilent ICP-OES which includes software to deal with interferences and resulted in a negative for Be. In order to determine the cause of the false positive, which was originally thought to be due to the Titanium interference in the sample, the laboratory analyzed a blank and a reporting limit standard with 5 ppm and 10 ppm of Titanium added in. These were analyzed on the Perkin Elmer ICP 5 instrument to see if the positive Be was reproducible.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗