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At least 37 records · Page 2

RadMAP: The Radiological Multi-sensor Analysis Platform

The variability of gamma-ray and neutron background during the operation of a mobile detector system greatly limits the ability of the system to detect weak radiological and nuclear threats. The natural radiation background measured by a mobile detector system is the result of many factors, including the radioactivity of nearby materials, the geometric configuration of those materials and the system, the presence of absorbing materials, and atmospheric conditions. Background variations tend to be highly non-Poissonian, making it difficult to set robust detection thresholds using knowledge of the mean background rate alone. The Radiological Multi-sensor Analysis Platform (RadMAP) system is designed to allow the systematic study of natural radiological background variations and to serve as a development platform for emerging concepts in mobile radiation detection and imaging. To do this, RadMAP has been used to acquire extensive, systematic background measurements and correlated contextual data that can be used to test algorithms and detector modalities at low false alarm rates. By combining gamma-ray and neutron detector systems with data from contextual sensors, the system enables the fusion of data from multiple sensors into novel data products. The data are curated in a common format that allows for rapid querying across all sensors, creating detailed multi-sensor datasets that are used to study correlations between radiological and contextual data, and develop and test novel techniques in mobile detection and imaging. Here we will describe the instruments that comprise the RadMAP system, the effort to curate and provide access to multi-sensor data, and some initial results on the fusion of contextual and radiological data.

47 OTHER INSTRUMENTATION↗

Roadside tree attenuation measurements at UHF for land mobile satellite systems

Tree attenuation results at 870 MHz are described for experiments conducted in October 1985 and March 1986 in Central Maryland. These experiments employed a helicopter as a source platform and a van with receiver and data acquisition instrumentation. Tree attenuation results were obtained for the cases in which the van was stationary and in motion. The experiments were performed for the purpose of providing the designers of planned land mobile satellite systems with important elements in the determination of link parameter requirements; namely, the expected fading statistics due to roadside trees for both mobile and stationary vehicles. Single tree attenuation results gave worst case median fades as high as 15 dB although roadside tree values were noted to produce fades in excess of 20 dB for small percentages of time. The cumulative fade distributions and their relative contributions as a function of path elevation angle, right side versus left side driving, and different road types are derived from the field measurements. Upon comparing the attenuations from bare deciduous trees (March 1986) with those due to trees in full foliage (October 1985), the increase in dB attenuations were, in general, less than 25 percent for the dynamic cases, and less than 40 percent for the worst case static configuration. This result demonstrates that the dominant fading is caused by the wooded tree branches as opposed to the leaves on these branches. The tail end of the observed fade distributions was observed to follow lognormal distributions with respect to dB attenuation.

Goldhirsh, Julius↗

Requirements for a mobile communications satellite system. Volume 3: Large space structures measurements study

This study report defines a set of tests and measurements required to characterize the performance of a Large Space System (LSS), and to scale this data to other LSS satellites. Requirements from the Mobile Communication Satellite (MSAT) configurations derived in the parent study were used. MSAT utilizes a large, mesh deployable antenna, and encompasses a significant range of LSS technology issues in the areas of structural/dynamics, control, and performance predictability. In this study, performance requirements were developed for the antenna. Special emphasis was placed on antenna surface accuracy, and pointing stability. Instrumentation and measurement systems, applicable to LSS, were selected from existing or on-going technology developments. Laser ranging and angulation systems, presently in breadboard status, form the backbone of the measurements. Following this, a set of ground, STS, and GEO-operational were investigated. A third scale (15 meter) antenna system as selected for ground characterization followed by STS flight technology development. This selection ensures analytical scaling from ground-to-orbit, and size scaling. Other benefits are cost and ability to perform reasonable ground tests. Detail costing of the various tests and measurement systems were derived and are included in the report.

Akle, W.↗

A Fast Load Control System Based on Mobile Distribution-Level Phasor Measurement Unit

The increase of renewable penetration in power grids calls for loads to participate in frequency regulation to avoid under-frequency load shedding after large resource contingencies. The motivation of our work is to fulfill a fast residential load control for frequency stability enhancement. For this purpose, a novel Mobile Distribution-level Phasor Measurement Unit (MDPMU) is developed for disturbance event detection, power mismatch estimation and fast load control. First, the systematic design of the MDPMU introduced. The proposed MDPMU has the major advantages of low cost and high frequency measurement accuracy. Second, the distribution-level measurement is utilized for the Rate Of Change Of Frequency (ROCOF) calculation. Upon detection of a power system frequency event, power mismatch is estimated at the early stage of the event. Details of a robust approach to calculate ROCOF and determine the event starting point are presented. Practical issues including the measurement reporting rate and estimation time are also examined. Finally, with the proposed control system, residential load responses can be controlled coordinately based on load availability and compensation prices offered by customers, providing adaptive frequency regulation service after large resource contingencies. The accuracy of frequency measurement and power mismatch estimation are evaluated via experimental analysis. The frequency stability improvement by load control is validated via PSS/E simulation.

24 POWER TRANSMISSION AND DISTRIBUTION↗

First ARM Mobile Facility (AMF1) Aerosol Observing System (AOS01) Instrument Handbook

The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility Mobile Aerosol Observing System – Aerosols (MAOS-A), designated AOS01, entered service in March of 2012 at the Los Alamos National Laboratory for the Pajarito Aerosol Coupling to Ecosystems (PACE) field campaign. The Aerosol Observing System is meant to be a standalone, completely autonomous, aerosol sampling system. It requires only power, 208VAC 1φ or 440 VAC 1φ, and an internet connection to be operational. The physical structure is a standard-sized shipping container, 20 feet long by 8 feet wide. Inside, the walls, ceiling, and floor are insulated using >3.5” of spray polyurethane foam with an R-value of 6.2/inch of insulation. The interior walls, floor and ceiling are lined with ¾” plywood for durability and have integrated unistrut for mounting equipment.

54 ENVIRONMENTAL SCIENCES↗

Radiation Measurement Systems and Experiences in Japan after the Fukushima Accident

In the approximately 4 years since the March 2011 earthquake and subsequent Tsunami damaged the three Dai-Ichi nuclear power plants, the AREVA and Canberra team have deployed a variety of different radiation measurement machines in Japan. These measurement projects or instruments include: - Dose-rate mapping of the close-in areas on the damaged reactor site using the stored output of dose rate meters carried by workers planning for the installing of a water processing unit; - Spectroscopic on-line measurements of the first water processing unit on the site, where these nuclide-specific measurements at multiple points allowed remote users to determine the optimum processing parameters - General purpose food measurement units, both high precision HPGe systems and low cost NaI systems, which were used throughout the country for food quality measurements; - In-vivo measurement systems, both fixed and mobile whole body counting units, that were used on at least 500,000 people, demonstrating to them that internal doses were very low; - In-vivo measurements with special high-sensitivity whole body counters on babies and children, demonstrating to the parents of these children that internal doses are very low; - Automatic systems for high throughput assay of bags of rice that are part of the consumer confidence plan to prove to customers that Fukushima Prefecture rice is safe; - High sensitivity automatic system to assay boxes of special semi-dry persimmons and to report the activity of each individual item within the box meets the regulatory limit; - System to assay soil on a conveyor belt and sort the output according to level of radioactivity, which would then reduce the volume of material that must be treated as radioactive; - System to assay a truck loaded with 1 cubic meter sacks of soil and vegetation, and report the results of each individual sack. - On-line water measurement system for SrY90 at levels that are suitable for release to the environment; - Mobile system to prove that rolls of grass harvested for animal feed meet the regulatory requirements. This document briefly describes the purpose of each measurement project, describes the instruments and assay method that used, and discusses some of the operational experiences from each of these projects. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗

2022 Through April 2023 Corrective Measures Implementation and Interim Measures Annual Status Report: Summary of Biosparge System Operation and Maintenance, Interim Measures and Monitoring Mobile Launch Platform Rehabilitation Sites / Vehicle Assembly Building Area (Swmu 056) Kennedy Space Center, Florida

This report presents a summary of the Corrective Measures Implementation (CMI) and Interim Measure (IM) implementation activities that occurred from January 2022 through April 2023 at the Mobile Launch Platform Rehabilitation Sites (MLP)/Vehicle Assembly Building (VAB) Area, Solid Waste Management Unit 056 (SWMU 056), located at the John F. Kennedy Space Center, Florida. The following summaries briefly describe areas within SWMU 056 identified by historical site investigation activities where groundwater monitoring and remedial actions have been implemented to date.

VOCs↗

PAGEMS

Glenn Research Center has extensive instrumentation developed for measuring particulate and gaseous emissions. The Particulate and Gaseous Emissions Measurement System (PAGEMS) is a mobile facility housing advanced instrumentation used for measuring combustion particulates and gaseous species. Particulates sizes ranging from 10 nm to 10 mm can be measured along with SO2, NO, NO2, CO, CO2, THC and O2 . Measurements can be made from subatmospheric up to 60 atm. Representative data from two engine tests will be discussed. In one test, the fuel sulfur content was changed, while the other test (T-63 engine) used various fuel additives. Probe design is essential to acquiring accurate particulate data. I will discuss the AEDC designed particulate probe, and the results of a University of Minnesota calibration study using the probe. Another suite of instrumentation, a tunable diode laser (TDL), enables in-situ real time gaseous species measurements. Representative TDL data from a T-38 aircraft will be presented. In conclusion, near term measurement opportunities will be discussed.

Bulzan, Dan↗

Online elemental analysis of process gases with ICP-OES: A case study on waste wood combustion

Highlights: Black-Right-Pointing-Pointer Simultaneous measurements of 23 elements in process gases of a waste wood combustor. Black-Right-Pointing-Pointer Mobile ICP spectrometer allows measurements of high quality at industrial plants. Black-Right-Pointing-Pointer Continuous online measurements with high temporal resolution. Black-Right-Pointing-Pointer Linear correlations among element concentrations in the raw flue gas were detected. Black-Right-Pointing-Pointer Novel sampling and calibration methods for ICP-OES analysis of process gases. - Abstract: A mobile sampling and measurement system for the analysis of gaseous and liquid samples in the field was developed. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is built into a van, was used as detector. The analytical system was calibrated with liquid and/or gaseous standards. It was shown that identical mass flows of either gaseous or liquid standards resulted in identical ICP-OES signal intensities. In a field measurement campaign trace and minor elements in the raw flue gas of a waste wood combustor were monitored. Sampling was performed with a highly transport efficient liquid quench system, which allowed to observe temporal variations in the elemental process gas composition. After a change in feedstock an immediate change of the element concentrations in the flue gas was detected. A comparison of the average element concentrations during the combustion of the two feedstocks showed a high reproducibility for matrix elements that are expected to be present in similar concentrations. On the other hand elements that showed strong differences in their concentration in the feedstock were also represented by a higher concentration in the flue gas. Following the temporal variations of different elements revealed strong correlations between a number of elements, such as chlorine with sodium, potassium and zinc, as well as arsenic with lead, and calcium with strontium.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Utilization of Mobile VLBI for Geodetic Measurements

Three mobile very long base interferometry (VLBI) systems were fabricated for the NASA Crustal Dynamics Project. These systems include the 9-meter-diameter MV-3 telescope. Since 1980, mobile systems operated in conjunction with several fixed base stations in the western United States as part of a geodetic survey program to determine relative motions and regional strain fields near the tectonic plate boundaries in California and Alaska. A description is given of the three mobile systems and the environment in which they must function. The inherent accuracy of mobile VLBI measurements is assessed, based on a consideration of major sources of error. Some recent results are presented which serve to illustrate various aspects of the error model and are of geodetic interest as they span the broad region surrounding the surface trace of the San Andreas Fault. These results indicate that baseline measurements utilizing the current mobile VLBI systems attained an accuracy of 2 cm or better in the horizontal plane. It is likely that crustal motions will be detected within the next few years, provided they are presently occurring at the geological rates.

Davidson, J. M.↗

Utilization of mobile VLBI for geodetic measurements

Three mobile very long base interferometry (VLBI) systems were fabricated for the NASA Crustal Dynamics Project. These systems include the 9-meter-diameter MV-3 telescope. Since 1980, mobile systems operated in conjunction with several fixed base stations in the western United States as part of a geodetic survey program to determine relative motions and regional strain fields near the tectonic plate boundaries in California and Alaska. A description is given of the three mobile systems and the environment in which they must function. The inherent accuracy of mobile VLBI measurements is assessed, based on a consideration of major sources of error. Some recent results are presented which serve to illustrate various aspects of the error model and are of geodetic interest as they span the broad region surrounding the surface trace of the San Andreas Fault. These results indicate that baseline measurements utilizing the current mobile VLBI systems attained an accuracy of 2 cm or better in the horizontal plane. It is likely that crustal motions will be detected within the next few years, provided they are presently occurring at the geological rates.

Davidson, J. M.↗

Engine Test and Measurements

Although the importance of aerosols and their precursors are now well recognized, the characterization of current subsonic engines for these emissions is far from complete. Furthermore, since the relationship of engine operating parameters to aerosol emissions is not known, extrapolation to untested and unbuilt engines necessarily remains highly uncertain. 1997 NASA LaRC engine test, as well as the parallel 1997 NASA LaRC flight measurement, attempts to address both issues by expanding measurements of aerosols and aerosol precursors with fuels containing different levels of fuel sulfur content. The specific objective of the 1997 engine test is to obtain a database of sulfur oxides emissions as well as the non-volatile particulate emission properties as a function of fuel sulfur and engine operating conditions. Four diagnostic systems, extractive and non-intrusive (optical), will be assembled for the gaseous and particulate emissions characterization measurements study. NASA is responsible for the extractive gaseous emissions measurement system which contains an array of analyzers dedicated to examining the concentrations of specific gases (NO, NO(x), CO, CO2, O2, THC, SO2) and the smoke number. University of Missouri-Rolla uses the Mobile Aerosol Sampling System to measure aerosol/particulate total concentration, size distribution, volatility and hydration property. Air Force Research Laboratory uses the Chemical Ionization Mass Spectrometer to measure SO2, SO3/H2SO4, and HN03 Aerodyne Research, Inc. uses Infrared Tunable Diode Laser system to measure SO2, SO3, NO, H2O, and CO2.

Wey, Chown Chou↗

Propagation effects by roadside trees measured at UHF and L-band for mobile satellite systems

Propagation field tests were performed in Central Maryland and involved a helicopter and mobile van as the source and receiving platforms, respectively. Tests were implemented at both UHF (870 MHz) and L-band (1.5 GHz) during a period in which the trees were in full blossom and contained maximum moisture. Cumulative fade distributions were determined from the data for various fixed elevation angles, side of the road driving, and road types for both worst and best case path geometries and for overall average road conditions.

Goldhirsh, Julius↗

Particle Number Concentrations for HI-SCALE Field Campaign Report

In support of the Holistic Interactions of Shallow Clouds, Aerosols, and Ecosystems (HI-SCALE) project to study new particle formation in the atmosphere, a pair of custom water condensation particle counters were provided to the second intensive field campaign, from mid-August through mid-September 2017, at the U.S. Department of Energy Southern Great Plains Atmospheric Radiation Measurement (ARM) Climate Research Facility observatory. These custom instruments were developed by Aerosol Dynamics, Inc. (Hering et al. 2017) to detect particles into the nanometer size range. Referred to as “versatile water condensation particle counter (vWCPC)”, they are water-based, laminar-flow condensational growth instruments whose lower particle size threshold can be set based on user-selected operating temperatures. For HI-SCALE, the vWCPCs were configured to measure airborne particle number concentrations in the size range from approximately 2nm to 2μm. Both were installed in the particle sizing system operated by Chongai Kuang of Brookhaven National Laboratory (BNL). One of these was operated in parallel to a TSI Model 3776, upstream of the mobility particle sizing system, to measure total ambient particle concentrations. The airborne particle concentration data from this “total particle number vWCPC” (Ntot-vWCPC) system has been reported to the ARM database. The data are reported with one-second resolution. The second vWCPC was operated in parallel with the BNL diethylene glycol instrument to count particles downstream of a separate differential mobility size analyzer. Data from this “DMA-vWCPC” system was logged by BNL, and will eventually be provided by that laboratory.

HI-SCALE, aerosol particle number concentration, v↗

Measurement of multipath delay profile in land mobile satellite channels

Mobile satellite communication channel has been evaluated mainly with fading statistics of signal. When bandwidth of transmitting signal becomes wider, frequency selectivity of fading becomes a significant factor of the channel. Channel characteristics, not only signal variation but multipath delay spread should be evaluated. A multipath measurement system is proposed and developed for mobile satellite applications. With this system and ETS-V satellite, multipath delay profiles are measured in various environments including Tokyo metropolis and Sapporo city at 1.5 GHz. Results show that the maximum excess delay is within 1 microsec and the maximum delay spread is 0.2 microsecs at elevation angles of 40 to 47 degrees. In wideband signal transmission of about 1 MHz and more, designers should consider the effect of selective fading due to the multipath of land mobile satellite channel.

Ikegami, Tetsushi↗

L- and K-band LMSS propagation measurements using MARECS-B, OLYMPUS, and ACTS

L-band measurements of land mobile satellite systems (LMSS) propagation effects were last made at the end of 1988, but some voids were left in the database, making modeling of low elevation roadside tree shadowing and multipath reflections difficult for some path geometries. Transmission of a pilot tone from MARECS-B at 55 deg West during Sep. and Dec. 1991 gave an opportunity to fill the gaps in the experimental results. Two campaigns during which fade data were obtained at elevation angles from 7 deg to 40 deg are described. Below 15 deg, specular terrain reflections in a non-shadowing, hilly environment were observed to introduce significant fading. Although the reflecting surface was at a distance of up to several km, it is shown that the reflected signals are delayed by less than 1 microsec. Mobile measurements were also attempted receiving the 20 GHz Olympus beacon, but antenna pointing problems restricted first results to straight-line driving.

Vogel, W. J.↗

Sonic boom measurement test plan for Space Shuttle STS-2 reentry

Procedures and system specifications associated with the space shuttle STS-2 sonic boom measurement program are described. Specifically included are details such as mobile data acquisition station locations, measurement systems calibration levels, predicted sonic boom overpressure levels, overpressure level assignment for each data acquisition station, data recording times on and off, universal coordinate time, and measurement system descriptions.

Henderson, H. R.↗