Release of man-made radionuclides into seawater from dumped and sunken nuclear- and radiation-hazardous objects

NASA Astrophysics Data System (ADS)

Vysotsky, V. L.; Sivintsev, Yu. V.; Sotnikov, V. A.; Khokhlov, V. N.

2014-12-01

The methodology and results of a weighted average evaluation of the release of man-made radio-nuclides into seawater out of nuclear- and radiation-hazardous objects located on the sea bottom over a long period of time (from dumping/sinking to complete destruction of their structural elements) are presented in the paper. The expected radio-ecological implications of environmental contamination are estimated for the main stages of destruction.

Survival and migration behavior of juvenile salmonids at McNary Dam, 2004, Final report of research

USGS Publications Warehouse

Perry, Russell W.; Braatz, Amy C.; Fielding, Scott D.; Lucchesi, Joel N.; Plumb, John M.; Adams, Noah S.; Rondorf, Dennis W.

2005-01-01

During 2004, the USGS Columbia River Research Laboratory conducted a study at McNary Dam using radio telemetry to estimate passage and survival parameters of juvenile salmonids. Our primary objective was to estimate these parameters under ambient environmental and operational conditions, and thus project-wide treatments were not implemented. The primary dam operation consisted of “biop” spill, where spill occurred at night between 1800 and 0600 hours, and no spill occurred between 0600 and 1800 hours for the majority of our study period. During the spring study period, we radio-tagged and released 1,896 yearling Chinook salmon and 1,888 juvenile steelhead. During the summer study period, we radio-tagged and released 1,919 subyearling Chinook salmon. All fish were tagged using gastric techniques to implant transmitters weighing 1.58 g for yearling Chinook salmon, 1.93 g for juvenile steelhead, and 0.96 g for subyearling Chinook salmon. Minimum fish sizes were based on a 6.5% tag:fish weight ratio, and the size of tagged fish represented about 91%, 100%, and 17% of the population, respectively for yearling Chinook salmon, juvenile steelhead, and subyearling Chinook salmon. About 60% of radio-tagged fish were released 10 km upstream of McNary Dam at Hat Rock State Park, Oregon, with the remainder released as control groups 400 m downstream of the dam.

Translocation and radio-telemetry monitoring of pygmy marmoset, Cebuella pygmaea (Spix, 1823), in the Brazilian Amazon.

PubMed

Dias, C A R; Queirogas, V L; Pedersoli, M A

2015-01-01

Two groups of pygmy marmoset (Cebuella pygmaea) were rescued along the left bank of the Madeira River during the formation of Santo Antônio Hydroelectric Dam reservoir in the state of Rondônia, Northern Brazil. Reintroduction of both groups occurred in areas of open Tropical rainforest located within the project´s Permanent Preservation Area. A post-release monitoring was conducted for three months using radio-telemetry. Individuals of each group remained together and settled in stable home ranges near their respective release sites. The mortality rate of translocated animals was about 7%. This seems to be the first report documenting the complete group translocation of C. pygmaea and the first to successfully employ radio-telemetry techniques in monitoring this species. This study demonstrated the feasibility of translocation and the use of radio-telemetry in monitoring C. pygmaea.

The theory of ionospheric focused heating

NASA Technical Reports Server (NTRS)

Bernhardt, P. A.; Duncan, L. M.

1987-01-01

Ionospheric modification by high power radio waves and by chemical releases are combined in a theoretical study of ionospheric focused heating. The release of materials which promote electron-ion recombination creates a hole in the bottomside ionosphere. The ionospheric hole focuses high power radio waves from a ground-based transmitter to give a 20 dB or greater enhancement in power density. The intense radio beam excites atomic oxygen by collisions with accelerated electrons. Airglow from the excited oxygen provides a visible trace of the focused beam. The large increase in the intensity of the radio beam stimulates new wave-plasma interactions. Numerical simulations show that the threshold for the two-plasmon decay instability is exceeded. The interaction of the pump electromagnetic wave with the backward plasmon produces a scattered electromagnetic wave at 3/2 the pump frequency. The scattered wave provides a unique signature of the two-plasmon decay process for ground-based detection.

Parachute deploy/Release mechanism

NASA Technical Reports Server (NTRS)

Robelen, D. B.

1979-01-01

Mechanism operated by signals from single radio-control channel deploy and releases small drogue parachute from flying aircraft. Technique has uses in industrial process control and in recreational hobby applications.

Radio emissions from pulsar companions: a refutable explanation for galactic transients and fast radio bursts

NASA Astrophysics Data System (ADS)

Mottez, F.; Zarka, P.

2014-09-01

Context. The six known highly dispersed fast radio bursts are attributed to extragalactic radio sources that are of unknown origin but extremely energetic. We propose here a new explanation that does not require an extreme release of energy and involves a body (planet, asteroid, white dwarf) orbiting an extragalactic pulsar. Aims: We investigate a theory of radio waves associated with such pulsar-orbiting bodies. We focus our analysis on the waves emitted from the magnetic wake of the body in the pulsar wind. After deriving their properties, we compare them with the observations of various transient radio signals to determine whether they could originate from pulsar-orbiting bodies. Methods: The analysis is based on the theory of Alfvén wings: for a body immersed in a pulsar wind, a system of two stationary Alfvén waves is attached to the body, provided that the wind is highly magnetised. When they are destabilised through plasma instabilities, Alfvén wings can be the locus of strong radio sources that are convected with the pulsar wind. By assuming a cyclotron maser instability operating in the Alfvén wings, we make predictions about the shape, frequencies, and brightness of the resulting radio emissions. Results: Because of the beaming by relativistic aberration, the signal is seen only when the companion is perfectly aligned between its parent pulsar and the observer, as is the case for occultations. For pulsar winds with a high Lorentz factor (≥104), the whole duration of the radio event does not exceed a few seconds, and it is composed of one to four peaks that last a few milliseconds each and are detectable up to distances of several Mpc. The Lorimer burst, the three isolated pulses of PSR J1928+15, and the recently detected fast radio bursts are all compatible with our model. According to it, these transient signals should repeat periodically with the companion's orbital period. Conclusions: The search of pulsar-orbiting bodies could be an exploration theme for new- or next-generation radio telescopes.

Topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on nonhormonal management of vasomotor symptoms.

PubMed

Carpenter, Janet S; Laine, Tei; Harrison, Blake; LePage, Meghan; Pierce, Taran; Hoteling, Nathan; Börner, Katy

2017-10-01

We sought to depict the topical, geospatial, and temporal diffusion of the 2015 North American Menopause Society position statement on the nonhormonal management of menopause-associated vasomotor symptoms released on September 21, 2015, and its associated press release from September 23, 2015. Three data sources were used: online news articles, National Public Radio, and Twitter. For topical diffusion, we compared keywords and their frequencies among the position statement, press release, and online news articles. We also created a network figure depicting relationships across key content categories or nodes. For geospatial diffusion within the United States, we compared locations of the 109 National Public Radio (NPR) stations covering the statement to 775 NPR stations not covering the statement. For temporal diffusion, we normalized and segmented Twitter data into periods before and after the press release (September 12, 2015 to September 22, 2015 vs September 23, 2015 to October 3, 2015) and conducted a burst analysis to identify changes in tweets from before to after. Topical information diffused across sources was similar with the exception of the more scientific terms "vasomotor symptoms" or "vms" versus the more colloquial term "hot flashes." Online news articles indicated media coverage of the statement was mainly concentrated in the United States. NPR station data showed similar proportions of stations airing the story across the four census regions (Northeast, Midwest, south, west; P = 0.649). Release of the statement coincided with bursts in the menopause conversation on Twitter. The findings of this study may be useful for directing the development and dissemination of future North American Menopause Society position statements and/or press releases.

Evaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014

USGS Publications Warehouse

Courter, Ian; Garrison, Tommy; Kock, Tobias J.; Perry, Russell W.

2015-01-01

The influence of stream flow on survival of emigrating juvenile (smolts) Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss is of key management interest. However, few studies have quantified flow effects on smolt migration survival, and available information does not indicate a consistent flow-survival relationship within the typical range of flows under management control. It is hypothesized that smolt migration and dam passage survival are positively correlated with stream flow because higher flows increase migration rates, potentially reducing exposure to predation, and reduce delays in reservoirs. However, available empirical data are somewhat equivocal concerning the influence of flow on smolt survival and the underlying mechanisms driving this relationship. Stream flow effects on survival of emigrating anadromous salmonids in the Yakima Basin have concerned water users and fisheries managers for over 20 years, and previous studies do not provide sufficient information at the resolution necessary to inform water operations, which typically occur on a small spatiotemporal scale. Using a series of controlled flow releases from 2012-2014, combined with radio telemetry, we quantified the relationship between flow and smolt survival from Roza Dam 208 km downstream to the Yakima River mouth, as well as for specific routes of passage at Roza Dam. A novel multistate mark-recapture model accounted for weekly variation in flow conditions experienced by radio-tagged fish. Groups of fish were captured and radio-tagged at Roza Dam and released at two locations, upstream at the Big Pines Campground (river kilometer [rkm] 211) and downstream in the Roza Dam tailrace (rkm 208). A total of 904 hatchery-origin yearling Chinook salmon O. tshawytscha were captured in the Roza Dam fish bypass, radio-tagged and released upstream of Roza Dam. Two hundred thirty seven fish were released in the tailrace of Roza Dam. Fish released in the tailrace of Roza Dam were tagged concurrently with fish released upstream of the dam using identical tagging methods. Tagging and release events were conducted to target a range of flow conditions indicative of flows observed during the typical migration period (March-May) for juvenile spring Chinook salmon in the Yakima River. Three, five and four separate upstream releases were conducted in 2012, 2013, and 2014 respectively, and at least 43 fish were released alive on each occasion. The release sample sizes in 2014 were much larger (~130) compared to previous years for the purpose of increasing precision of survival estimates across the range of flows tested. Migration movements of radio-tagged spring Chinook salmon smolts were monitored with an array of telemetry receiver stations (fixed sites) that extended 208 rkm downstream from the forebay of Roza Dam to the mouth of the Yakima River. Fixed monitoring sites included the forebay of Roza Dam (rkm 208), the tailrace of Roza Dam (rkm 207.9), the mouth of Wenas Creek (rkm 199.2), the mouth of the Naches River (two sites, rkm 189.4), Sunnyside Dam (two sites, rkm 169.1), Prosser Dam (rkm 77.2), and the mouth of the Yakima River (two sites, rkm2 3). This array segregated the study area into four discrete reaches in which survival of tagged fish was estimated. Aerial and underwater antennas were also used to monitor tagged fish at Roza Dam. Aerial antennas were located in the forebay, on the East gate, on the West gate, and in the tailrace of Roza Dam. Underwater antennas were located in the fish bypass, upstream of the East gate, and upstream of the West gate to collect route-specific passage data for tagged fish. Additional years of data collection and analysis could alter or improve our understanding of the influence of flow and other environmental factors on smolt survival in the Yakima River. Nevertheless, during 2012-2014, yearling hatchery Chinook salmon smolt emigration survival was significantly associated with stream flow in the

Ex vivo human skin evaluation of localized fat reduction and anti-aging effect by TriPollar radio frequency treatments.

PubMed

Boisnic, Sylvie; Branchet, Marie Christine

2010-02-01

A wide variety of radio frequency (RF) treatments for localized fat and cellulite reduction as well as anti-aging are available nowadays, but only a few have shown the biological mechanism responsible for the clinical results. To determine the biological mechanism of the TriPollar RF device for localized fat and cellulite reduction as well as the collagen remodeling effect. Human skin samples were collected from abdominoplasty surgery and facial lifts, in order to evaluate the lipolytic and anti-aging effects of the apollo device powered by TriPollar RF technology using an ex vivo human skin model. The anti-cellulite effect was evaluated by the dosage of released glycerol and histological analysis of the hypodermis. Skin tightening was evaluated by morphometric analysis of collagen fibers and the dosage of collagen synthesis. Following TriPollar treatment, a significant increase of glycerol release by skin samples was found. The structure of fat cells was altered in shape and a modification of the fibrous tract was also detected in the fat layer. Additional findings indicated stimulation of the dermal fibroblasts with increased collagen synthesis. The detected alteration in the hypodermal layer is manifested by fat and cellulite reduction accompanied by structural and biochemical improvement of dermal collagen, which result in overall skin tightening.

The GnRH analogue triptorelin confers ovarian radio-protection to adult female rats.

PubMed

Camats, N; García, F; Parrilla, J J; Calaf, J; Martín-Mateo, M; Caldés, M Garcia

2009-10-02

There is a controversy regarding the effects of the analogues of the gonadotrophin-releasing hormone (GnRH) in radiotherapy. This has led us to study the possible radio-protection of the ovarian function of a GnRH agonist analogue (GnRHa), triptorelin, in adult, female rats (Rattus norvegicus sp.). The effects of the X-irradiation on the oocytes of ovarian primordial follicles, with and without GnRHa treatment, were compared, directly in the female rats (F(0)) with reproductive parameters, and in the somatic cells of the resulting foetuses (F(1)) with cytogenetical parameters. In order to do this, the ovaries and uteri from 82 females were extracted for the reproductive analysis and 236 foetuses were obtained for cytogenetical analysis. The cytogenetical study was based on the data from 22,151 metaphases analysed. The cytogenetical parameters analysed to assess the existence of chromosomal instability were the number of aberrant metaphases (2234) and the number (2854) and type of structural chromosomal aberrations, including gaps and breaks. Concerning the reproductive analysis of the ovaries and the uteri, the parameters analysed were the number of corpora lutea, implantations, implantation losses and foetuses. Triptorelin confers radio-protection of the ovaries in front of chromosomal instability, which is different, with respect to the single and fractioned dose. The cytogenetical analysis shows a general decrease in most of the parameters of the triptorelin-treated groups, with respect to their controls, and some of these differences were considered to be statistically significant. The reproductive analysis indicates that there is also radio-protection by the agonist, although minor to the cytogenetical one. Only some of the analysed parameters show a statistically significant decrease in the triptorelin-treated groups.

Radio Bursts as Diagnostics of Relative Abundances in Solar Particles

NASA Astrophysics Data System (ADS)

Cane, H. V.; Richardson, I. G.; von Rosenvinge, T. T.

2008-05-01

Based solely on the presence of associated low frequency type III radio bursts with specific characteristics, Cane et al. (2002) suggested that large solar energetic particle events are likely to include contributions from particles accelerated in the associated flares. Studies using ACE/SIS observations of O and Fe intensity-time profiles have supported this suggestion. Nevertheless, some researchers have argued that particles cannot be flare accelerated if the relative abundances differ from those in the small particle events that are widely accepted to be composed of flare particles. However, based on the radio data, the flare particles in large events are not released at the time of the flare soft X-ray onset but are delayed, either because they are accelerated later or released later. These changed conditions are expected to alter the relative abundances (electrons to protons, heavy to light ions) compared to those associated with small flares. From a comprehensive analysis of the characteristics of the coronal mass ejections (CMEs), flares and radio bursts (at metric and longer wavelengths) associated with the ~340 proton events at >25 MeV that occurred during solar cycle 23, we confirm earlier results (Cane et al. 1986) that the timing of the type III bursts is a reasonable discriminator for the relative abundances at the start of solar particle events. In contrast, the speeds of the associated CMEs do not discriminate events, nor does the presence of meter wavelength type II bursts. Cane, H. V., R. E. McGuire, and T. T. von Rosenvinge (1986), Two classes of solar energetic particle events associated with impulsive and long-duration soft X-ray flares, Astrophys. J., 301, 448. Cane, H. V., W. C. Erickson, and N. P. Prestage (2002), Solar flares, type III radio bursts, coronal mass ejections, and energetic particles, J. Geophys. Res., 107(A10), 1315, doi:10.1029/2001JA000320.

Preliminary technical evaluation of an ARGOS-monitored radio tag for tracking manatees

NASA Astrophysics Data System (ADS)

Mate, B.; Rathbun, G.; Merrick, R.; Reed, J.

A radio tagged manatee was released into a river leading to subtropical waters and tracked by satellite. Up to 8 locations a day are reported. The manatee remained in the river system, but is expected to head for the Gulf of Mexico.

REVIEWS OF TOPICAL PROBLEMS: Millisecond solar radio spikes

NASA Astrophysics Data System (ADS)

Fleishman, G. D.; Mel'nikov, V. F.

1998-12-01

Currently available models of one of the most intriguing types of unsteady rf solar emission, millisecond solar radio spikes, are discussed. A comparative analysis of the models' implications and of the body of existing data yields an outline of the most realistic radio spike model possible. The spikes are produced by the cyclotron maser mechanism. The cyclotron cone instability is caused by fast electrons distributed over energies according to a (piecewise) power law. The angular part of the distribution function (whose exact form is, as yet, undetermined) suffers fluctuations due to the magnetic field inhomogeneities that arise in the burst loop as a consequence of the original energy release. In some portions of the loop the distribution is not anisotropic enough to secure the development of a cyclotron instability; it is in these 'microtraps' where individual spikes form. Key areas of future theoretical and experimental research are suggested with a view to verifying the adequacy and realizing the diagnostic potential of the model.

Radio Heating of Lunar Soil to Release Gases

NASA Technical Reports Server (NTRS)

Chui, Talso; Penanen, Konstantin

2006-01-01

A report proposes the development of a system to collect volatile elements and compounds from Lunar soil for use in supporting habitation and processing into rocket fuel. Prior exploratory missions revealed that H2, He, and N2 are present in Lunar soil and there are some indications that water ice may also be present. The proposed system would include a shroud that would be placed on the Lunar surface. Inside the shroud would be a radio antenna aimed downward. The antenna would be excited at a suitably high power and at a frequency chosen to optimize the depth of penetration of radio waves into the soil. The radio waves would heat the soil, thereby releasing volatiles bound to soil particles. The escaping volatiles would be retained by the shroud and collected by condensation in a radiatively cooled vessel connected to the shroud. It has been estimated that through radio-frequency heating at a power of 10 kW for one day, it should be possible to increase the temperature of a soil volume of about 1 cubic m by about 200 C -- an amount that should suffice for harvesting a significant quantity of volatile material.

Cognitive Radio Application for Evaluating Coexistence with Cognitive Radars: A Software User’s Guide

DTIC Science & Technology

2017-10-01

with both conventional wireless systems as well as other types of cognitive RF systems (e.g., cognitive radar). The radio hardware for this...WBX daughtercard. This technical report begins with a system -level overview in Section 1. Then, the remaining sections explain the configuration and...Approved for public release; distribution is unlimited. 1 1. Introduction and Theory of Operation The system model has 2 kinds of cognitive radio

Summary of Migration and Survival Data from Radio-Tagged Juvenile Coho Salmon in the Trinity River, Northern California, 2008

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal; Juhnke, Steve; Stutzer, Greg

2009-01-01

The survival of hatchery-origin juvenile coho salmon from the Trinity River Hatchery was estimated as they migrated seaward through the Trinity and Klamath Rivers. The purpose of the study was to collect data for comparison to a similar study in the Klamath River and provide data to the Trinity River Restoration Program. A total of 200 fish fitted with radio transmitters were released into the Trinity River near the hatchery (river kilometer 252 from the mouth of the Klamath River) biweekly from March 19 to May 28, 2008. Fish from the earliest release groups took longer to pass the first detection site 10 kilometers downstream of the hatchery than fish from the later release groups, but travel times between subsequent sites were often similar among the release groups. The travel times of individuals through the 239 kilometer study area ranged from 15.5 to 84.6 days with a median of 43.3 days. The data and models did not support differences in survival among release groups, but did support differences among river reaches. The probability of survival in the first 53 kilometers was lower than in the reaches farther downstream, which is similar to trends in juvenile coho salmon in the Klamath River. The lowest estimated survival in this study was in the first 10 kilometers from release in the Trinity River (0.676 SE 0.036) and the highest estimated survival was in the final 20 kilometer reach in the Klamath River (0.987 SE 0.013). Estimated survivals of radio-tagged juvenile coho salmon from release to Klamath River kilometer 33 were 0.639 per 100 kilometers for Trinity River fish and 0.721 per 100 kilometers for Klamath River fish.

Movements of translocated wolves in Minnesota

USGS Publications Warehouse

Fritts, S.H.; Paul, W.J.; Mech, L.D.

1984-01-01

From Feb. 1975-May 1978, 104 wolves (C. lupus) captured at or near Minnesota farms where depredations on livestock had been reported were translocated northward and eastward for 50-317 km into extensive forests; 3 others were released westward. Nine wolves were translocated twice, and 1 three times. Information on movements was obtained by radiotracking 17 wolves and by recovery of 16 others. All radio-tagged wolves left the release areas; adults left quickly, but pups generally remained longer, behaved less decisively, and settled nearby temporarily. Wolves released together did not remain together. Initial travel of most radio-tagged adults was between south and west, the general direction to their original location. Final directions were primarily to the west and northwest, due in part to physiographic barriers. Eight adults homed, 1 twice, to capture areas that were < 64 km from release sites. Nonhoming wolves were radiotracked and/or recovered 32-351 km from their capture sites and 23-302 km from their release sites. Translocation was largely unsuccessful at keeping problem wolves out of lifestock production areas. The problem of initial travel away from release sites in wolf reintroductions probably could be minimized by transport and release of 6-9 mo. old wolves.

High resolution monitoring system for IRE stack releases.

PubMed

Deconninck, B; De Lellis, C

2013-11-01

The main activity of IRE (Institute for Radio-Element) is radioisotope production of bulk (99)Mo and (131)I for medical application (diagnosis and therapy). Those isotopes are chemically extracted from HEU (High Enriched Uranium) targets activated in reactors. During this process, fission products are released from the targets, including noble gases isotopes (Xe and Kr). Like any nuclear plant, IRE has release limits which are given by the Belgium authority and moreover IRE is in the process of continuously reducing the level of its releases. To achieve this mission, the need of an accurate tool is necessary and IRE has developed a specific monitoring system using a high resolution detector in order to identify and accurately estimate its gaseous releases. This system has a continuous air sampling system in the plant main stack. The sampled gases cross charcoal cartridges where they are slowed down and concentrated for higher detection efficiency. In front of those cartridges is installed an HPGe detector with a detection chain connected to a specific analysis system allowing on-line spectrum analysis. Each isotope can be separately followed without interferences, especially during the production process where high activity can be released. Due to its conception, the system also allows to measure iodine isotopes by integration on the charcoal cartridges. This device is of great help for accurately estimate IRE releases and to help for understanding specific releases and their origin in the production or maintenance process. Copyright © 2013 Elsevier Ltd. All rights reserved.

X-ray Properties of Deep Radio-Selected Quasars

NASA Technical Reports Server (NTRS)

Becker, Robert

2002-01-01

This report summarizes the research supported by the ADP grant entitled 'X-ray Properties of Deep Radio-Selected Quasars'. The primary effort consisted of correlating the ROSAT All-Sky Survey catalog with the April 1997 release of the FIRST (Faint Images of the Radio Sky at Twenty centimeters) radio catalog. We found that a matching radius of 60 sec excluded most false matches while retaining most of the true radio-X-ray sources. The correlation of the approx. 80,000 source RASS and approx. 268,000 FIRST catalogs matched 2,588 FIRST sources with 1,649 RASS sources out of a possible 5,520 RASS sources residing in the FIRST survey area. This number is much higher than expected from our previous experience of correlating the RASS with radio surveys and indicates we detected new classes of objects not seen in the correlations with less sensitive radio surveys.

A tiny event producing an interplanetary type III burst

NASA Astrophysics Data System (ADS)

Alissandrakis, C. E.; Nindos, A.; Patsourakos, S.; Kontogeorgos, A.; Tsitsipis, P.

2015-10-01

Aims: We investigate the conditions under which small-scale energy release events in the low corona gave rise to strong interplanetary (IP) type III bursts. Methods: We analyzed observations of three tiny events, detected by the Nançay Radio Heliograph (NRH), two of which produced IP type III bursts. We took advantage of the NRH positioning information and of the high cadence of AIA/SDO data to identify the associated extreme-UV (EUV) emissions. We measured positions and time profiles of the metric and EUV sources. Results: We found that the EUV events that produced IP type III bursts were located near a coronal hole boundary, while the one that did not was located in a closed magnetic field region. In all three cases tiny flaring loops were involved, without any associated mass eruption. In the best observed case, the radio emission at the highest frequency (435 MHz) was displaced by ~55'' with respect to the small flaring loop. The metric type III emission shows a complex structure in space and in time, indicative of multiple electron beams, despite the low intensity of the events. From the combined analysis of dynamic spectra and NRH images, we derived the electron beam velocity as well as the height, ambient plasma temperature, and density at the level of formation of the 160 MHz emission. From the analysis of the differential emission measure derived from the AIA images, we found that the first evidence of energy release was at the footpoints, and this was followed by the development of flaring loops and subsequent cooling. Conclusions: Even small energy release events can accelerate enough electrons to give rise to powerful IP type III bursts. The proximity of the electron acceleration site to open magnetic field lines facilitates the escape of the electrons into the interplanetary space. The offset between the site of energy release and the metric type III location warrants further investigation. The movie is available in electronic form at http://www.aanda.org

Space Telecommunications Radio System (STRS) Architecture Standard. Release 1.02.1

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Kacpura, Thomas J.; Handler, Louis M.; Hall, C. Steve; Mortensen, Dale J.; Johnson, Sandra K.; Briones, Janette C.; Nappier, Jennifer M.; Downey, Joseph A.; Lux, James P.

2012-01-01

This document contains the NASA architecture standard for software defined radios used in space- and ground-based platforms to enable commonality among radio developments to enhance capability and services while reducing mission and programmatic risk. Transceivers (or transponders) with functionality primarily defined in software (e.g., firmware) have the ability to change their functional behavior through software alone. This radio architecture standard offers value by employing common waveform software interfaces, method of instantiation, operation, and testing among different compliant hardware and software products. These common interfaces within the architecture abstract application software from the underlying hardware to enable technology insertion independently at either the software or hardware layer.

Angiotensin II inhibits iron uptake and release in cultured neurons.

PubMed

Liu, Yong; Huang, Suna; Du, Fang; Yang, Guang; Jiang, Li Rong; Zhang, Chao; Qian, Zhong-ming

2014-05-01

Based on the well-confirmed roles of angiotensin II (ANGII) in iron transport of peripheral organs and cells, the causative link of excess brain iron with and the involvement of ANGII in neurodegenerative disorders, we speculated that ANGII might also have an effect on expression of iron transport proteins in the brain. In the present study, we investigated effects of ANGII on iron uptake and release using the radio-isotope methods as well as expression of cell iron transport proteins by Western blot analysis in cultured neurons. Our findings demonstrated for the first time that ANGII significantly reduced transferrin-bound iron and non-transferrin bound iron uptake and iron release as well as expression of two major iron uptake proteins transferrin receptor 1 and divalent metal transporter 1 and the key iron exporter ferroportin 1 in cultured neurons. The findings suggested that endogenous ANGII might have a physiological significance in brain iron metabolism.

The Right Tools for the Right Jobs.

ERIC Educational Resources Information Center

Barbalich, Andrea, Ed.

1995-01-01

A chart shows the best campus public relations uses for 17 communication techniques: face-to-face contact; phone call, regular mail; electronic mail; special events; a speech; press release; press kit; press conference; television and radio public service announcements; video news releases; promotions and posters; advertising; newsletter;…

Radiosensitizer-eluting nanocoatings on gold fiducials for biological in-situ image-guided radio therapy (BIS-IGRT)

NASA Astrophysics Data System (ADS)

Nagesha, D. K.; Tada, D. B.; Stambaugh, C. K. K.; Gultepe, E.; Jost, E.; Levy, C. O.; Cormack, R.; Makrigiorgos, G. M.; Sridhar, S.

2010-10-01

Image-guided radiation treatments (IGRT) routinely utilize radio-opaque implantable devices, such as fiducials or brachytherapy spacers, for improved spatial accuracy. The therapeutic efficiency of IGRT can be further enhanced by biological in situ dose painting (BIS-IGRT) of radiosensitizers through localized delivery within the tumor using gold fiducial markers that have been coated with nanoporous polymer matrices loaded with nanoparticles (NPs). In this work, two approaches were studied: (i) a free drug release system consisting of Doxorubicin (Dox), a hydrophilic drug, loaded into a non-degradable polymer poly(methyl methacrylate) (PMMA) coating and (ii) poly(d,l-lactic-co-glycolic acid) (PLGA) NPs loaded with fluorescent Coumarin-6, serving as a model for a hydrophobic drug, in a biodegradable chitosan matrix. Temporal release kinetics measurements in buffer were carried out using fluorescence spectroscopy. In the first case of free Dox release, an initial release within the first few hours was followed by a sustained release over the course of the next 3 months. In the second platform, release of NPs and the free drug was controlled by the degradation rate of the chitosan matrix and PLGA. The results show that dosage and rate of release of these radiosensitizers coated on gold fiducials for IGRT can be precisely tailored to achieve the desired release profile for radiation therapy of cancer.

Space Telecommunications Radio Systems (STRS) Hardware Architecture Standard: Release 1.0 Hardware Section

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Kacpura, Thomas J.; Smith, Carl R.; Liebetreu, John; Hill, Gary; Mortensen, Dale J.; Andro, Monty; Scardelletti, Maximilian C.; Farrington, Allen

2008-01-01

This report defines a hardware architecture approach for software-defined radios to enable commonality among NASA space missions. The architecture accommodates a range of reconfigurable processing technologies including general-purpose processors, digital signal processors, field programmable gate arrays, and application-specific integrated circuits (ASICs) in addition to flexible and tunable radiofrequency front ends to satisfy varying mission requirements. The hardware architecture consists of modules, radio functions, and interfaces. The modules are a logical division of common radio functions that compose a typical communication radio. This report describes the architecture details, the module definitions, the typical functions on each module, and the module interfaces. Tradeoffs between component-based, custom architecture and a functional-based, open architecture are described. The architecture does not specify a physical implementation internally on each module, nor does the architecture mandate the standards or ratings of the hardware used to construct the radios.

Cryptanalysis of the Sodark Family of Cipher Algorithms

DTIC Science & Technology

2017-09-01

software project for building three-bit LUT circuit representations of S- boxes is available as a GitHub repository [40]. It contains several improvements...DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release. Distribution is unlimited. 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The...second- and third-generation automatic link establishment (ALE) systems for high frequency radios. Radios utilizing ALE technology are in use by a

KSC-02pd1858

NASA Image and Video Library

2002-12-05

KENNEDY SPACE CENTER, FLA. - Stephen Ezell, meteorological systems operator at Weather Station A, Cape Canaveral Air Force Station, gets ready to release a weather balloon. Such balloons are released twice a day. The package in Ezell's hand is a radio sonde that collects temperature and humidity data as the balloon rises. The data is released to agencies nationwide, including the 45th Space Wing, which uses the data for its daily weather reports. The weather station provides additional data to NASA for launches -- releasing 12 balloons in eight hours prior to liftoff - and landings - releasing 5 balloons in six and a half hours before expected touchdown.

KSC-02pd1859

NASA Image and Video Library

2002-12-05

KENNEDY SPACE CENTER, FLA. -- Stephen Ezell, meteorological systems operator at Weather Station A, Cape Canaveral Air Force Station, releases a weather balloon. Such balloons are released twice a day. The package at the bottom is a radio sonde that collects temperature and humidity data as the balloon rises. The data is released to agencies nationwide, including the 45th Space Wing, which uses the data for its daily weather reports. The weather station provides additional data to NASA for launches -- releasing 12 balloons in eight hours prior to liftoff - and landings - releasing 5 balloons in six and a half hours before expected touchdown.

KSC-02pd1857

NASA Image and Video Library

2002-12-05

KENNEDY SPACE CENTER, FLA. - Stephen Ezell, meteorological systems operator at Weather Station A, Cape Canaveral Air Force Station, gets ready to release a weather balloon. Such balloons are released twice a day. The package in Ezell's hand is a radio sonde that collects temperature and humidity data as the balloon rises. The data is released to agencies nationwide, including the 45th Space Wing, which uses the data for its daily weather reports. The weather station provides additional data to NASA for launches -- releasing 12 balloons in eight hours prior to liftoff - and landings - releasing 5 balloons in six and a half hours before expected touchdown.

Sensitive microplate assay for the detection of proteolytic enzymes using radiolabeled gelatin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, B.D.; Kwan-Lim, G.E.; Maizels, R.M.

1988-07-01

A sensitive, microplate assay is described for the detection of a wide range of proteolytic enzymes, using radio-iodine-labeled gelatin as substrate. The technique uses the Bolton-Hunter reagent to label the substrate, which is then coated onto the wells of polyvinyl chloride microtiter plates. By measuring the radioactivity released the assay is able to detect elastase, trypsin, and collagenase in concentrations of 1 ng/ml or less, while the microtiter format permits multiple sample handling and minimizes sample volumes required for analysis.

Sun Radio Interferometer Space Experiment (SunRISE)

NASA Astrophysics Data System (ADS)

Kasper, Justin C.; SunRISE Team

2018-06-01

The Sun Radio Interferometer Space Experiment (SunRISE) is a NASA Heliophysics Explorer Mission of Opportunity currently in Phase A. SunRISE is a constellation of spacecraft flying in a 10-km diameter formation and operating as the first imaging radio interferometer in space. The purpose of SunRISE is to reveal critical aspects of solar energetic particle (SEP) acceleration at coronal mass ejections (CMEs) and transport into space by making the first spatially resolved observations of coherent Type II and III radio bursts produced by electrons accelerated at CMEs or released from flares. SunRISE will focus on solar Decametric-Hectometric (DH, 0.1 < f < 15 MHz) radio bursts that always are detected from space before major SEP events, but cannot be seen on Earth due to ionospheric absorption. This talk will describe SunRISE objectives and implementation. Presented on behalf of the entire SunRISE team.

Best-Ever Snapshot of a Black Hole's Jets

NASA Image and Video Library

2017-12-08

NASA image release May 20, 2011 To see a really cool video related to this image go here: www.flickr.com/photos/gsfc/5740451675/in/photostream The giant elliptical galaxy NGC 5128 is the radio source known as Centaurus A. Vast radio-emitting lobes (shown as orange in this optical/radio composite) extend nearly a million light-years from the galaxy. Credit: Capella Observatory (optical), with radio data from Ilana Feain, Tim Cornwell, and Ron Ekers (CSIRO/ATNF), R. Morganti (ASTRON), and N. Junkes (MPIfR). To read more go to: www.nasa.gov/topics/universe/features/radio-particle-jets... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

High Dynamic Range Cognitive Radio Front Ends: Architecture to Evaluation

NASA Astrophysics Data System (ADS)

Ashok, Arun; Subbiah, Iyappan; Varga, Gabor; Schrey, Moritz; Heinen, Stefan

2016-07-01

Advent of TV white space digitization has released frequencies from 470 MHz to 790 MHz to be utilized opportunistically. The secondary user can utilize these so called TV spaces in the absence of primary users. The most important challenge for this coexistence is mutual interference. While the strong TV stations can completely saturate the receiver of the cognitive radio (CR), the cognitive radio spurious tones can disturb other primary users and white space devices. The aim of this paper is to address the challenges for enabling cognitive radio applications in WLAN and LTE. In this process, architectural considerations for the design of cognitive radio front ends are discussed. With high-IF converters, faster and flexible implementation of CR enabled WLAN and LTE are shown. The effectiveness of the architecture is shown by evaluating the CR front ends for compliance of standards namely 802.11b/g (WLAN) and 3GPP TS 36.101 (LTE).

Wireless implantable chip with integrated nitinol-based pump for radio-controlled local drug delivery.

PubMed

Fong, Jeffrey; Xiao, Zhiming; Takahata, Kenichi

2015-02-21

We demonstrate an active, implantable drug delivery device embedded with a microfluidic pump that is driven by a radio-controlled actuator for temporal drug delivery. The polyimide-packaged 10 × 10 × 2 mm(3) chip contains a micromachined pump chamber and check valves of Parylene C to force the release of the drug from a 76 μL reservoir by wirelessly activating the actuator using external radio-frequency (RF) electromagnetic fields. The rectangular-shaped spiral-coil actuator based on nitinol, a biocompatible shape-memory alloy, is developed to perform cantilever-like actuation for pumping operation. The nitinol-coil actuator itself forms a passive 185 MHz resonant circuit that serves as a self-heat source activated via RF power transfer to enable frequency-selective actuation and pumping. Experimental wireless operation of fabricated prototypes shows successful release of test agents from the devices placed in liquid and excited by radiating tuned RF fields with an output power of 1.1 W. These tests reveal a single release volume of 219 nL, suggesting a device's capacity of ~350 individual ejections of drug from its reservoir. The thermal behavior of the activated device is also reported in detail. This proof-of-concept prototype validates the effectiveness of wireless RF pumping for fully controlled, long-lasting drug delivery, a key step towards enabling patient-tailored, targeted local drug delivery through highly miniaturized implants.

Implanting radio transmitters in wintering canvasbacks

USGS Publications Warehouse

Olsen, Glenn H.; Dein, F. Joshua; Haramis, G. Michael; Jorde, Dennis G.

1992-01-01

To conduct telemetry studies of wintering canvasbacks (Aythya valisineria) on Chesapeake Bay [Maryland, USA], we needed to devise a suitable method of radio transmitter attachment. We describe as aseptic, intraabdominal surgical technique, using the inhalation anesthetic isoflurane, to implant 20-g radio transmitters in free-ranging canvasbacks. We evaluated the technique over 3 winters (1987-89), when an annual average of 83 female canvasbacks received implant surgery during a 9-day period in mid-December. Of 253 ducks, 248 (98%) were implanted successfully, and 200 (80.65) completed the 70-day study until early March. No mortality or abnormal behavior from surgery was identified post-release.

Recruitment and accrual of women in a randomized controlled trial of spinal manipulation.

PubMed

Cambron, J A

2001-02-01

To report on recruitment efforts and accrual rates for a nonmusculoskeletal chiropractic clinical trial. Information regarding the method of recruitment was collected for each individual who responded to an advertisement and completed an interviewer-administered telephone screening. A suburban chiropractic teaching clinic with recruitment efforts extending throughout the larger metropolitan area. A total of 2312 women were screened for participation and the advertisement source was noted for each. Of these, 138 women were recruited and fulfilled all study requirements. The numbers of responses and accrual rates were determined for 8 different recruitment methods: newspaper advertisements, community referrals, radio advertisements, community colleges, press releases, a community electronic sign, public television, and local posters. The most effective recruitment methods were newspaper advertisements, community referrals, and radio advertisements; the least effective methods were public television and local posters. The effort required for the recruitment of subjects was underestimated in this study. Based on the information gained, future recruitment methods for study participants will primarily focus on low-effort, high-yield methods such as newspaper and radio advertising, followed by press releases, campus electronic signs, and public television.

KSC-02pd1856

NASA Image and Video Library

2002-12-05

KENNEDY SPACE CENTER, FLA. - Stephen Ezell, meteorological systems operator at Weather Station A, Cape Canaveral Air Force Station, walks out with a weather balloon that he will release. Such balloons are released twice a day. The package in Ezell's hand is a radio sonde that collects temperature and humidity data as the balloon rises. The data is released to agencies nationwide, including the 45th Space Wing which uses the data for its daily weather reports. The weather station provides additional data to NASA for launches - releasing 12 balloons in eight hours prior to liftoff - and landings - releasing 5 balloons in six and a half hours before expected touchdown.

KSC-02pd1860

NASA Image and Video Library

2002-12-05

KENNEDY SPACE CENTER, FLA. - At Weather Station A, Cape Canaveral Air Force Station, Judy Kelley, supervisor of Meteorology Operations, and Stephen Ezell, meteorological systems operator, get ready to release a weather balloon. Such balloons are released twice a day. The package at the bottom is a radio sonde that collects temperature and humidity data as the balloon rises. The data is released to agencies nationwide, including the 45th Space Wing, which uses the data for its daily weather reports. The weather station provides additional data to NASA for launches -- releasing 12 balloons in eight hours prior to liftoff - and landings - releasing 5 balloons in six and a half hours before expected touchdown.

Physics of the Solar Active Regions from Radio Observations

NASA Astrophysics Data System (ADS)

Gelfreikh, G. B.

1999-12-01

Localized increase of the magnetic field observed by routine methods on the photosphere result in the growth of a number of active processes in the solar atmosphere and the heliosphere. These localized regions of increased magnetic field are called active regions (AR). The main processes of transfer, accumulation and release of energy in an AR is, however, out of scope of photospheric observations being essentially a 3D-process and happening either under photosphere or up in the corona. So, to investigate these plasma structures and processes we are bound to use either extrapolation of optical observational methods or observations in EUV, X-rays and radio. In this review, we stress and illustrate the input to the problem gained from radio astronomical methods and discuss possible future development of their applicatications. Historically speaking each new step in developing radio technique of observations resulted in detecting some new physics of ARs. The most significant progress in the last few years in radio diagnostics of the plasma structures of magnetospheres of the solar ARs is connected with the developing of the 2D full disk analysis on regular basis made at Nobeyama and detailed multichannel spectral-polarization (but one-dimensional and one per day) solar observations at the RATAN-600. In this report the bulk of attention is paid to the new approach to the study of solar activity gained with the Nobeyama radioheliograph and analyzing the ways for future progress. The most important new features of the multicomponent radio sources of the ARs studied using Nobeyama radioheliograph are as follow: 1. The analysis of magnetic field structures in solar corona above sunspot with 2000 G. Their temporal evolution and fluctuations with the periods around 3 and 5 minutes, due to MHD-waves in sunspot magnetic tubes and surrounding plasma. These investigations are certainly based on an analysis of thermal cyclotron emission of lower corona and CCTR above sunspot umbra. 2. Magnetography of the solar active regions presenting the weak magnetic fields (with the sensitivity of several G) reflecting longitude component of the magnetic field in chromosphere and corona and solar faculae structure. The method is based on an analysis of the weak polarization (of the order of 1% or less). 3. An analysis of the structure, temperature, and density of arches seen above neutral magnetic field lines (seen in most ARs with spots and without ones). 4. Study of temporal and spatial behavior of inversion of the sign of the circular polarization with the result of magnetography of the solar corona. 5. An analysis of the solar activity at high heliographic latitudes, observed mostly as polar faculae (increased brightness structures having counterparts in optical white light observations). In modern study of the solar activity analysis of the activity of polar zones are of principal importance. Nobeyama probably presents the most reliable way to study this. The above points present not exactly completed results but rather the directions for future studies. These should use full time coverage of observations at different phases of the solar activity and combination of observations with other radio, optical, EUV and X-ray observations whenever possible.

USDA's Vick tells radio audience wind farms mean huge water savings

USDA-ARS?s Scientific Manuscript database

Since most of the electricity in the U.S. is generated using coal and natural gas as fuel, almost every wind farm announcement includes the estimated amount of carbon dioxide which was not released to the atmosphere. According to Wikipedia, 2.25 tons of CO2 and 1.14 tons of CO2 were released for eve...

The C2 Workstation and Data Replication over Disadvantaged Tactical Communication Links

DTIC Science & Technology

2007-09-01

person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number...SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 14 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b...PUBLIC RELEASE C2WS Physical Environment Zodiac Network Radio Network Combat Level Node (Vehicle) Radio Local Store Local Store Local Store To Other

Theoretical and experimental studies of atmospheric structure and dynamics, using high altitude chemical release, Radio meteor, and meteorological rocket network and other data

NASA Technical Reports Server (NTRS)

Edwards, H. D.

1976-01-01

Data collected by the Georgia Tech Radio Meteor Wind Facility during the fall and winter of 1975 are analyzed indicating a relationship between lower thermospheric circulation at mid latitudes and polar stratospheric dynamics. Techniques of measurement of mixing processes in the upper atmosphere and the interpretation of those measurements are described along with a diffusion simulation program based on the Global Reference Atmosphere program.

Juvenile Radio-Tag Study: Lower Granite Dam, 1985 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stuehrenberg, Lowell C.

The concept of using mass releases of juvenile radio tags represents a new and potentially powerful research tool that could be effectively applied to juvenile salmonid passage problems at dams on the Columbia and Snake Rivers. A system of detector antennas, strategically located, would automatically detect and record individually tagged juvenile salmonids as they pass through the spillway, powerhouse, bypass system, or tailrace areas below the dam. Accurate measurements of spill effectiveness, fish guiding efficiency (FGE), collection efficiency (CE), spillway survival, powerhouse survival, and bypass survival would be possible without handling large numbers of unmarked fish. A prototype juvenile radio-tagmore » system was developed and tested by the National Marine Fisheries Service (NMFS) and Bonneville Power Administration (BPA) at John Day Dam and at Lower Granite Dam. This report summarizes research to: (1) evaluate the effectiveness of the prototype juvenile radio-tag system in a field situation and (2) to test the basic assumptions inherent in using the juvenile radio tag as a research tool.« less

Celestial Reference Frames at Multiple Radio Wavelengths

NASA Technical Reports Server (NTRS)

Jacobs, Christopher S.

2012-01-01

In 1997 the IAU adopted the International Celestial Reference Frame (ICRF) built from S/X VLBI data. In response to IAU resolutions encouraging the extension of the ICRF to additional frequency bands, VLBI frames have been made at 24, 32, and 43 gigahertz. Meanwhile, the 8.4 gigahertz work has been greatly improved with the 2009 release of the ICRF-2. This paper discusses the motivations for extending the ICRF to these higher radio bands. Results to date will be summarized including evidence that the high frequency frames are rapidly approaching the accuracy of the 8.4 gigahertz ICRF-2. We discuss current limiting errors and prospects for the future accuracy of radio reference frames. We note that comparison of multiple radio frames is characterizing the frequency dependent systematic noise floor from extended source morphology and core shift. Finally, given Gaia's potential for high accuracy optical astrometry, we have simulated the precision of a radio-optical frame tie to be approximately10-15 microarcseconds ((1-sigma) (1-standard deviation), per component).

Installation of Radioskaf 11.2 Kit and batteries for Radioskaf (Suitsat-1) on Expedition 12

NASA Image and Video Library

2006-01-24

ISS012-E-15655 (24 Jan. 2006) --- In the Unity node of the International Space Station, cosmonaut Valery I. Tokarev, Expedition 12 flight engineer representing Russia's Federal Space Agency, puts finishing touches on an old Russian Orlan spacesuit that will be released by hand from the space station during a spacewalk Feb. 3, 2006. Outfitted with a special radio transmitter and other gear, the spacesuit comprises a Russian experiment called SuitSat. It will fly free from the station as a satellite in orbit for several weeks of scientific research and radio tracking, including communications by amateur radio operators. Eventually, it will enter the atmosphere and be destroyed.

Vulnerabilities in GSM technology and feasibility of selected attacks

NASA Astrophysics Data System (ADS)

Voznak, M.; Prokes, M.; Sevcik, L.; Frnda, J.; Toral-Cruz, Homer; Jakovlev, Sergej; Fazio, Peppino; Mehic, M.; Mikulec, M.

2015-05-01

Global System for Mobile communication (GSM) is the most widespread technology for mobile communications in the world and serving over 7 billion users. Since first publication of system documentation there has been notified a potential safety problem's occurrence. Selected types of attacks, based on the analysis of the technical feasibility and the degree of risk of these weaknesses, were implemented and demonstrated in laboratory of the VSB-Technical University of Ostrava, Czech Republic. These vulnerabilities were analyzed and afterwards possible attacks were described. These attacks were implemented using open-source tools, software programmable radio USRP (Universal Software RadioPeripheral) and DVB-T (Digital Video Broadcasting - Terrestrial) receiver. GSM security architecture is being scrutinized since first public releases of its specification mainly pointing out weaknesses in authentication and ciphering mechanisms. This contribution also summarizes practically proofed and used scenarios that are performed using opensource software tools and variety of scripts mostly written in Python. Main goal of this paper is in analyzing security issues in GSM network and practical demonstration of selected attacks.

Simple-1: Development stage of the data transmission system for a solid propellant mid-power rocket model

NASA Astrophysics Data System (ADS)

Yarce, Andrés; Sebastián Rodríguez, Juan; Galvez, Julián; Gómez, Alejandro; García, Manuel J.

2017-06-01

This paper presents the development stage of a communication module for a solid propellant mid-power rocket model. The communication module was named. Simple-1 and this work considers its design, construction and testing. A rocket model Estes Ventris Series Pro II® was modified to introduce, on the top of the payload, several sensors in a CanSat form factor. The Printed Circuit Board (PCB) was designed and fabricated from Commercial Off The Shelf (COTS) components and assembled in a cylindrical rack structure similar to this small format satellite concept. The sensors data was processed using one Arduino Mini and transmitted using a radio module to a Software Defined Radio (SDR) HackRF based platform on the ground station. The Simple-1 was tested using a drone in successive releases, reaching altitudes from 200 to 300 meters. Different kind of data, in terms of altitude, position, atmospheric pressure and vehicle temperature were successfully measured, making possible the progress to a next stage of launching and analysis.

Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources

NASA Technical Reports Server (NTRS)

Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.;

Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources

DOE PAGES

Aatrokoski, J.

2011-12-01

Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativisticmore » jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper, physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shock. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.« less

Radiological Society of North America

MedlinePlus

... Courses Electronic Education Exhibits RSNA Journals RSNA/AAPM Physics Modules RadioGraphics ABR Diagnostic Radiology Core Exam Study ... Brain Tumor Classification System In 2016, the World Health Organization (WHO) released an update to its brain ...

Postrelease movements and survival of adult and young black-footed ferrets

USGS Publications Warehouse

Biggins, Dean E.; Godbey, Jerry L.; Livieri, Travis M.; Matchett, Marc R.; Bibles, Brent D.

2006-01-01

A successful captive breeding program for highly endangered black-footed ferrets (Mustela nigripes) has resulted in surplus animals that have been released at multiple sites since 1991. Because reproductive output of captive ferrets declines after several years, many adult ferrets must be removed from captive breeding facilities annually to keep total production high. Adults are routinely released, with young-of-the-year, on prairie dog (Cynomys spp.) colonies. We evaluated postrelease movements and survival rates for 94 radio-tagged young and adult ferrets. Radio-tagged adult ferrets made longer movements than young ferrets during the night of release and had significantly lower survival rates for the first 14 days. Coyotes (Canis latrans) caused the largest number of ferret losses. A larger data set of 623 ferrets represented adults and young that were individually marked with passive integrated transponders but were not radio tagged. Minimum survival rates, calculated primarily from ferrets detected during spotlight searches and identified with tag readers, again were significantly lower for adults than for young ferrets at 30 days postrelease (10.1 percent and 45.5 percent survival, respectively) and at 150 days postrelease (5.7 percent and 25.9 percent). Assessment of known survival time by using linear modeling demonstrated a significant interaction between age and sex, with greater disparity between adults and kits for females than for males. Postrelease survival of adult ferrets might be increased if animals were given earlier and longer exposure to the quasinatural environments of preconditioning pens. 

Reading the Enemy’s Mail: Origins and Development of U.S. Army Tactical Radio Intelligence in World War II, European Theater of Operations

DTIC Science & Technology

1993-05-10

MASTER OF MILITARY ART AND SCIENCE E6LECTES 0V 171993 A 21 by JEFFREY S. HARLEY, MAJ, USA B.A., Old Dominion University, Norfolk, Virginia, 1980 Fort...HARLEY, MAJ, USA B.A., Old Dominion University, Norfolk, Virginia, 1980 Fort Leavenworth, Kansas 1993 Approved for public release; distribution is...were still active in their old locations.29 Beginning with unplanned, uncoordinated occasional radio intercepts at the Battle of Tannenberg, the

FAST's Discovery of a New Millisecond Pulsar (MSP) toward the Fermi-LAT unassociated source 3FGL J0318.1+0252

NASA Astrophysics Data System (ADS)

Wang, Pei; Li, Di; Zhu, Weiwei; Zhang, Chengmin; Yan, Jun; Hou, Xian; Clark, Colin J.; Saz Parkinson, Pablo M.; Michelson, Peter F.; Ferrara, Elizabeth C.; Thompson, David J.; Smith, David A.; Ray, Paul S.; Kerr, Matthew; Shen, Zhiqiang; Wang, Na; Fermi-LAT Collaboration

2018-04-01

The Five hundred-meter Aperture Spherical radio Telescope (FAST), operated by the National Astronomical Observatories, Chinese Academy of Sciences, has discovered a radio millisecond pulsar (MSP) coincident with the unassociated gamma-ray source 3FGL J0318.1+0252 (Acero et al. 2015 ApJS, 218, 23), also known as FL8Y J0318.2+0254 in the recently released Fermi Large Area Telescope (LAT) 8-year Point Source List (FL8Y).

LeMMINGs - I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores

NASA Astrophysics Data System (ADS)

Baldi, R. D.; Williams, D. R. A.; McHardy, I. M.; Beswick, R. J.; Argo, M. K.; Dullo, B. T.; Knapen, J. H.; Brinks, E.; Muxlow, T. W. B.; Aalto, S.; Alberdi, A.; Bendo, G. J.; Corbel, S.; Evans, R.; Fenech, D. M.; Green, D. A.; Klöckner, H.-R.; Körding, E.; Kharb, P.; Maccarone, T. J.; Martí-Vidal, I.; Mundell, C. G.; Panessa, F.; Peck, A. B.; Pérez-Torres, M. A.; Saikia, D. J.; Saikia, P.; Shankar, F.; Spencer, R. E.; Stevens, I. R.; Uttley, P.; Westcott, J.

2018-05-01

We present the first data release of high-resolution (≤0.2 arcsec) 1.5-GHz radio images of 103 nearby galaxies from the Palomar sample, observed with the eMERLIN array, as part of the LeMMINGs survey. This sample includes galaxies which are active (low-ionization nuclear emission-line regions [LINER] and Seyfert) and quiescent (H II galaxies and absorption line galaxies, ALGs), which are reclassified based upon revised emission-line diagrams. We detect radio emission ≳0.2 mJy for 47/103 galaxies (22/34 for LINERS, 4/4 for Seyferts, 16/51 for H II galaxies, and 5/14 for ALGs) with radio sizes typically of ≲100 pc. We identify the radio core position within the radio structures for 41 sources. Half of the sample shows jetted morphologies. The remaining half shows single radio cores or complex morphologies. LINERs show radio structures more core-brightened than Seyferts. Radio luminosities of the sample range from 1032 to 1040 erg s-1: LINERs and H II galaxies show the highest and lowest radio powers, respectively, while ALGs and Seyferts have intermediate luminosities. We find that radio core luminosities correlate with black hole (BH) mass down to ˜107 M⊙, but a break emerges at lower masses. Using [O III] line luminosity as a proxy for the accretion luminosity, active nuclei and jetted H II galaxies follow an optical Fundamental Plane of BH activity, suggesting a common disc-jet relationship. In conclusion, LINER nuclei are the scaled-down version of FR I radio galaxies; Seyferts show less collimated jets; H II galaxies may host weak active BHs and/or nuclear star-forming cores; and recurrent BH activity may account for ALG properties.

Behavior and movement of formerly landlocked juvenile coho salmon after release into the free-flowing Cowlitz River, Washington

USGS Publications Warehouse

Kock, Tobias J.; Henning, Julie A.; Liedtke, Theresa L.; Royer, Ida M.; Ekstrom, Brian K.; Rondorf, Dennis W.

2011-01-01

Formerly landlocked Coho Salmon (Oncorhynchus kisutch) juveniles (age 2) were monitored following release into the free-flowing Cowlitz River to determine if they remained in the river or resumed seaward migration. Juvenile Coho Salmon were tagged with a radio transmitter (30 fish) or Floy tag (1050 fish) and their behavior was monitored in the lower Cowlitz River. We found that 97% of the radio-tagged fish remained in the Cowlitz River beyond the juvenile outmigration period, and the number of fish dispersing downstream decreased with increasing distance from the release site. None of the tagged fish returned as spawning adults in the 2 y following release. We suspect that fish in our study failed to migrate because they exceeded a threshold in size, age, or physiological status. Tagged fish in our study primarily remained in the Cowlitz River, thus it is possible that these fish presented challenges to juvenile salmon migrating through the system either directly by predation or indirectly by competition for food or habitat. Given these findings, returning formerly landlocked Coho Salmon juveniles to the free-flowing river apparently provided no benefit to the anadromous population. These findings have management implications in locations where landlocked salmon have the potential to interact with anadromous species of concern.

A radio spectral index map and catalogue at 147-1400 MHz covering 80 per cent of the sky

NASA Astrophysics Data System (ADS)

de Gasperin, F.; Intema, H. T.; Frail, D. A.

2018-03-01

The radio spectral index is a powerful probe for classifying cosmic radio sources and understanding the origin of the radio emission. Combining data at 147 MHz and 1.4 GHz from the TIFR GMRT Sky Survey (TGSS) and the NRAO VLA Sky Survey (NVSS), we produced a large-area radio spectral index map of ˜80 per cent of the sky (Dec. > - 40 deg), as well as a radio spectral index catalogue containing 1396 515 sources, of which 503 647 are not upper or lower limits. Almost every TGSS source has a detected counterpart, while this is true only for 36 per cent of NVSS sources. We released both the map and the catalogue to the astronomical community. The catalogue is analysed to discover systematic behaviours in the cosmic radio population. We find a differential spectral behaviour between faint and bright sources as well as between compact and extended sources. These trends are explained in terms of radio galaxy evolution. We also confirm earlier reports of an excess of steep-spectrum sources along the galactic plane. This corresponds to 86 compact and steep-spectrum source in excess compared to expectations. The properties of this excess are consistent with normal non-recycled pulsars, which may have been missed by pulsation searches due to larger than average scattering along the line of sight.

Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory

NASA Astrophysics Data System (ADS)

Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Aramo, C.; Arganda, E.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Bäcker, T.; Balzer, M.; Barber, K. B.; Barbosa, A. F.; Bardenet, R.; Barroso, S. L. C.; Baughman, B.; Beatty, J. J.; Becker, B. R.; Becker, K. H.; Bellido, J. A.; Benzvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brogueira, P.; Brown, W. C.; Bruijn, R.; Buchholz, P.; Bueno, A.; Burton, R. E.; Caballero-Mora, K. S.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chauvin, J.; Chiavassa, A.; Chinellato, J. A.; Chou, A.; Chudoba, J.; Clay, R. W.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cook, H.; Cooper, M. J.; Coppens, J.; Cordier, A.; Cotti, U.; Coutu, S.; Covault, C. E.; Creusot, A.; Criss, A.; Cronin, J.; Curutiu, A.; Dagoret-Campagne, S.; Dallier, R.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; de Domenico, M.; de Donato, C.; de Jong, S. J.; de La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; de Mitri, I.; de Souza, V.; de Vries, K. D.; Decerprit, G.; Del Peral, L.; Deligny, O.; Dembinski, H.; Denkiewicz, A.; di Giulio, C.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Dobrigkeit, C.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dos Anjos, J. C.; Dova, M. T.; D'Urso, D.; Dutan, I.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Ferrero, A.; Fick, B.; Filevich, A.; Filipčič, A.; Fliescher, S.; Fracchiolla, C. E.; Fraenkel, E. D.; Fröhlich, U.; Fuchs, B.; Gamarra, R. F.; Gambetta, S.; García, B.; García Gámez, D.; Garcia-Pinto, D.; Gascon, A.; Gemmeke, H.; Gesterling, K.; Ghia, P. L.; Giaccari, U.; Giller, M.; Glass, H.; Gold, M. S.; Golup, G.; Gomez Albarracin, F.; Gómez Berisso, M.; Gonçalves, P.; Gonzalez, D.; Gonzalez, J. G.; Gookin, B.; Góra, D.; Gorgi, A.; Gouffon, P.; Gozzini, S. R.; Grashorn, E.; Grebe, S.; Griffith, N.; Grigat, M.; Grillo, A. F.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hague, J. D.; Hansen, P.; Harari, D.; Harmsma, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hojvat, C.; Holmes, V. C.; Homola, P.; Hörandel, J. R.; Horneffer, A.; Hrabovský, M.; Huege, T.; Insolia, A.; Ionita, F.; Italiano, A.; Jiraskova, S.; Kadija, K.; Kampert, K. H.; Karhan, P.; Karova, T.; Kasper, P.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kelley, J. L.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Koang, D.-H.; Kotera, K.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuehn, F.; Kuempel, D.; Kulbartz, J. K.; Kunka, N.; La Rosa, G.; Lachaud, C.; Lautridou, P.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Lemiere, A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lucero, A.; Ludwig, M.; Lyberis, H.; Macolino, C.; Maldera, S.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martínez Bravo, O.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurizio, D.; Mazur, P. O.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Mertsch, P.; Meurer, C.; Mićanović, S.; Micheletti, M. I.; Miller, W.; Miramonti, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, E.; Moreno, J. C.; Morris, C.; Mostafá, M.; Moura, C. A.; Mueller, S.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Nhung, P. T.; Nierstenhoefer, N.; Nitz, D.; Nosek, D.; Nožka, L.; Nyklicek, M.; Oehlschläger, J.; Olinto, A.; Oliva, P.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parizot, E.; Parra, A.; Parrisius, J.; Parsons, R. D.; Pastor, S.; Paul, T.; Pech, M.; PeĶala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrinca, P.; Petrolini, A.; Petrov, Y.; Petrovic, J.; Pfendner, C.; Phan, N.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Ponce, V. H.; Pontz, M.; Privitera, P.; Prouza, M.; Quel, E. J.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Risse, M.; Ristori, P.; Rivera, H.; Riviére, C.; Rizi, V.; Robledo, C.; Rodrigues de Carvalho, W.; Rodriguez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodriguez-Cabo, I.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-D'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Salamida, F.; Salazar, H.; Salina, G.; Sánchez, F.; Santander, M.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, S.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Schmidt, F.; Schmidt, T.; Scholten, O.; Schoorlemmer, H.; Schovancova, J.; Schovánek, P.; Schroeder, F.; Schulte, S.; Schuster, D.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Semikoz, D.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tamashiro, A.; Tapia, A.; Taşcău, O.; Tcaciuc, R.; Tegolo, D.; Thao, N. T.; Thomas, D.; Tiffenberg, J.; Timmermans, C.; Tiwari, D. K.; Tkaczyk, W.; Todero Peixoto, C. J.; Tomé, B.; Tonachini, A.; Travnicek, P.; Tridapalli, D. B.; Tristram, G.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van den Berg, A. M.; Vargas Cárdenas, B.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Warner, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Westerhoff, S.; Whelan, B. J.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Winders, L.; Winnick, M. G.; Wommer, M.; Wundheiler, B.; Yamamoto, T.; Younk, P.; Yuan, G.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Ziolkowski, M.

2011-04-01

The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs “radio-hybrid” measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluorescence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.

Space Telecommunications Radio Architecture (STRS)

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

2006-01-01

A software defined radio (SDR) architecture used in space-based platforms proposes to standardize certain aspects of radio development such as interface definitions, functional control and execution, and application software and firmware development. NASA has charted a team to develop an open software defined radio hardware and software architecture to support NASA missions and determine the viability of an Agency-wide Standard. A draft concept of the proposed standard has been released and discussed among organizations in the SDR community. Appropriate leveraging of the JTRS SCA, OMG's SWRadio Architecture and other aspects are considered. A standard radio architecture offers potential value by employing common waveform software instantiation, operation, testing and software maintenance. While software defined radios offer greater flexibility, they also poses challenges to the radio development for the space environment in terms of size, mass and power consumption and available technology. An SDR architecture for space must recognize and address the constraints of space flight hardware, and systems along with flight heritage and culture. NASA is actively participating in the development of technology and standards related to software defined radios. As NASA considers a standard radio architecture for space communications, input and coordination from government agencies, the industry, academia, and standards bodies is key to a successful architecture. The unique aspects of space require thorough investigation of relevant terrestrial technologies properly adapted to space. The talk will describe NASA s current effort to investigate SDR applications to space missions and a brief overview of a candidate architecture under consideration for space based platforms.

Space Telecommunications Radio Architecture (STRS): Technical Overview

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.

2006-01-01

A software defined radio (SDR) architecture used in space-based platforms proposes to standardize certain aspects of radio development such as interface definitions, functional control and execution, and application software and firmware development. NASA has charted a team to develop an open software defined radio hardware and software architecture to support NASA missions and determine the viability of an Agency-wide Standard. A draft concept of the proposed standard has been released and discussed among organizations in the SDR community. Appropriate leveraging of the JTRS SCA, OMG s SWRadio Architecture and other aspects are considered. A standard radio architecture offers potential value by employing common waveform software instantiation, operation, testing and software maintenance. While software defined radios offer greater flexibility, they also poses challenges to the radio development for the space environment in terms of size, mass and power consumption and available technology. An SDR architecture for space must recognize and address the constraints of space flight hardware, and systems along with flight heritage and culture. NASA is actively participating in the development of technology and standards related to software defined radios. As NASA considers a standard radio architecture for space communications, input and coordination from government agencies, the industry, academia, and standards bodies is key to a successful architecture. The unique aspects of space require thorough investigation of relevant terrestrial technologies properly adapted to space. The talk will describe NASA's current effort to investigate SDR applications to space missions and a brief overview of a candidate architecture under consideration for space based platforms.

NASA's SDR Standard: Space Telecommunications Radio System

NASA Technical Reports Server (NTRS)

Reinhart, Richard C.; Johnson, Sandra K.

2007-01-01

A software defined radio (SDR) architecture used in space-based platforms proposes to standardize certain aspects of radio development such as interface definitions, functional control and execution, and application software and firmware development. NASA has charted a team to develop an open software defined radio hardware and software architecture to support NASA missions and determine the viability of an Agency-wide Standard. A draft concept of the proposed standard has been released and discussed among organizations in the SDR community. Appropriate leveraging of the JTRS SCA, OMG s SWRadio Architecture and other aspects are considered. A standard radio architecture offers potential value by employing common waveform software instantiation, operation, testing and software maintenance. While software defined radios offer greater flexibility, they also poses challenges to the radio development for the space environment in terms of size, mass and power consumption and available technology. An SDR architecture for space must recognize and address the constraints of space flight hardware, and systems along with flight heritage and culture. NASA is actively participating in the development of technology and standards related to software defined radios. As NASA considers a standard radio architecture for space communications, input and coordination from government agencies, the industry, academia, and standards bodies is key to a successful architecture. The unique aspects of space require thorough investigation of relevant terrestrial technologies properly adapted to space. The talk will describe NASA s current effort to investigate SDR applications to space missions and a brief overview of a candidate architecture under consideration for space based platforms.

Quasi-periodic Reversals of Radio Polarization at 17 GHz Observed in the 2002 April 21 Solar Event

NASA Astrophysics Data System (ADS)

Huang, Guangli; Lin, Jun

2006-03-01

We investigate high spatial resolution radio polarization data obtained by the Nobeyama Radioheliograph (NoRH) and high time resolution data observed with the Nobeyama Radio Polarimeters (NoRP) during the well-studied flare/CME event of 2002 April 21. A 17 GHz radio source at the loop top was seen by NoRH to move upward together with the expanding flare loops at a speed of around 10 km s-1. In the 5 minutes before the source began its upward motion, the Stokes V of the radio signals at 17 GHz showed quasi-periodic reversals between left-circular polarization (LCP) and right-circular polarization (RCP). Following this interval, the polarizations gradually turned to LCP. During this period, the polarization of the corresponding footpoint source maintained the RCP sense. The reversal of Stokes V between RCP and LCP was also detected at lower frequencies (1-2 GHz) by NoRP, without spatial resolution. The observed reversals between RCP and LCP of the radio signals from the top of the flare loop system can be taken as evidence that magnetic energy is released or energetic particles are produced at the magnetic reconnection site in a quasi-periodic fashion.

First TV Image of Mars

NASA Image and Video Library

2011-04-12

This is an enhanced contrast version of the first Mars photograph released on July 15, 1965. This is man first close-up photograph of another planet, a photographic representation of digital data radioed from Mars by the Mariner 4 spacecraft.

78 FR 37474 - Radio Broadcasting Services; Dove Creek, Colorado

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-21

..., and released March 1, 2013. The full text of this Commission decision is available for inspection and... CY- A257, Washington, DC 20554. The complete text of this decision also may be purchased from the...

75 FR 80013 - Radio Broadcasting Services; Jewett, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-21

..., 2010, and released December 3, 2010. The full text of this Commission decision is available for... 12th Street, SW., Room CY-A257, Washington, DC 20554. The complete text of this decision also may be...

76 FR 43933 - Radio Broadcasting Services; Markham, TX

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-22

... released June 28, 2011. The full text of this Commission decision is available for inspection and copying...., Room CY-A257, Washington, DC 20554. The complete text of this decision also may be purchased from the...

Migration behavior and dispersal of adult spring Chinook salmon released into Lake Scanewa on the upper Cowlitz River during 2005

USGS Publications Warehouse

Perry, R.W.; Kock, Tobias J.; Kritter , M.A; Rondorf, Dennis W.

2007-01-01

During 2005, we conducted a radio-telemetry study to answer a number of basic questions about the migration behavior of adult Spring Chinook salmon (Oncorhynchus tshawytscha) released into the upper Cowlitz River watershed. We also conducted a pilot study of adult Coho salmon (Oncorhynchus kisutch) using radio-tags recovered from adult spring Chinook salmon. This data is included as an Appendix. Our study was designed to evaluate the dispersal of adult spring Chinook salmon to determine the proportion of the run 1) spawning in the Cispus River, 2) spawning in the Cowlitz River, 3) passing downstream through Cowlitz Falls Dam into Riffe Lake, and 4) remaining in Lake Scanewa. We also examined spatial patterns of movement in the study area and temporal patterns of fish movements. Last, we examined differences in migration behavior between hatchery and wild fish and male and female fish.

Radiocesium in the Savannah River Site environment.

PubMed

Carlton, W H; Murphy, C E; Evans, A G

1994-09-01

The Savannah River Site has produced plutonium, tritium, and other special nuclear materials for national defense, other government programs, and some civilian purposes. Radiocesium, a waste product, has been released to the environment during the operation of five reactors, two radio-chemical processing facilities, and a high-level waste storage system. During the period 1955-1989, 130 GBq of 137Cs was released to the atmosphere and 2.2 x 10(4) GBq was released to site streams and ponds. Approximately 65% of the latter remained on the site. The maximum individual effective dose equivalent at the site boundary was estimated to be 3.3 microSv from atmospheric releases and 600 microSv from liquid releases. The 80-km population dose was 1.6 person-Sv.

A search for long-time-scale, low-frequency radio transients

NASA Astrophysics Data System (ADS)

Murphy, Tara; Kaplan, David L.; Croft, Steve; Lynch, Christene; Callingham, J. R.; Bannister, Keith; Bell, Martin E.; Hurley-Walker, Natasha; Hancock, Paul; Line, Jack; Rowlinson, Antonia; Lenc, Emil; Intema, H. T.; Jagannathan, P.; Ekers, Ronald D.; Tingay, Steven; Yuan, Fang; Wolf, Christian; Onken, Christopher A.; Dwarakanath, K. S.; For, B.-Q.; Gaensler, B. M.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; McKinley, B.; Morgan, J.; Offringa, A. R.; Procopio, P.; Staveley-Smith, L.; Wayth, R.; Wu, C.; Zheng, Q.

2017-04-01

We present a search for transient and highly variable sources at low radio frequencies (150-200 MHz) that explores long time-scales of 1-3 yr. We conducted this search by comparing the TIFR GMRT Sky Survey Alternative Data Release 1 (TGSS ADR1) and the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey catalogues. To account for the different completeness thresholds in the individual surveys, we searched for compact GLEAM sources above a flux density limit of 100 mJy that were not present in the TGSS ADR1; and also for compact TGSS ADR1 sources above a flux density limit of 200 mJy that had no counterpart in GLEAM. From a total sample of 234 333 GLEAM sources and 275 612 TGSS ADR1 sources in the overlap region between the two surveys, there were 99 658 GLEAM sources and 38 978 TGSS ADR sources that passed our flux density cut-off and compactness criteria. Analysis of these sources resulted in three candidate transient sources. Further analysis ruled out two candidates as imaging artefacts. We analyse the third candidate and show it is likely to be real, with a flux density of 182 ± 26 mJy at 147.5 MHz. This gives a transient surface density of ρ = (6.2 ± 6) × 10-5 deg-2. We present initial follow-up observations and discuss possible causes for this candidate. The small number of spurious sources from this search demonstrates the high reliability of these two new low-frequency radio catalogues.

Investigating the Origins of Two Extreme Solar Particle Events: Proton Source Profile and Associated Electromagnetic Emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kocharov, Leon; Usoskin, Ilya; Pohjolainen, Silja

We analyze the high-energy particle emission from the Sun in two extreme solar particle events in which protons are accelerated to relativistic energies and can cause a significant signal even in the ground-based particle detectors. Analysis of a relativistic proton event is based on modeling of the particle transport and interaction, from a near-Sun source through the solar wind and the Earth’s magnetosphere and atmosphere to a detector on the ground. This allows us to deduce the time profile of the proton source at the Sun and compare it with observed electromagnetic emissions. The 1998 May 2 event is associatedmore » with a flare and a coronal mass ejection (CME), which were well observed by the Nançay Radioheliograph, thus the images of the radio sources are available. For the 2003 November 2 event, the low corona images of the CME liftoff obtained at the Mauna Loa Solar Observatory are available. Those complementary data sets are analyzed jointly with the broadband dynamic radio spectra, EUV images, and other data available for both events. We find a common scenario for both eruptions, including the flare’s dual impulsive phase, the CME-launch-associated decimetric-continuum burst, and the late, low-frequency type III radio bursts at the time of the relativistic proton injection into the interplanetary medium. The analysis supports the idea that the two considered events start with emission of relativistic protons previously accelerated during the flare and CME launch, then trapped in large-scale magnetic loops and later released by the expanding CME.« less

H{sub 2}O Megamasers toward Radio-bright Seyfert 2 Nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, J. S.; Liu, Z. W.; Henkel, C.

2017-02-20

Using the Effelsberg-100 m telescope, we perform a successful pilot survey on H{sub 2}O maser emission toward a small sample of radio-bright Seyfert 2 galaxies with a redshift larger than 0.04. The targets were selected from a large Seyfert 2 sample derived from the spectroscopic Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). One source, SDSS J102802.9+104630.4 ( z ∼ 0.0448), was detected four times during our observations, with a typical maser flux density of ∼30 mJy and a corresponding (very large) luminosity of ∼1135 L {sub ⊙}. The successful detection of this radio-bright Seyfert 2 and an additional tentativemore » detection support our previous statistical results that H{sub 2}O megamasers tend to arise from Seyfert 2 galaxies with large radio luminosity. The finding provides further motivation for an upcoming larger H{sub 2}O megamaser survey toward Seyfert 2s with particularly radio-bright nuclei with the basic goal to improve our understanding of the nuclear environment of active megamaser host galaxies.« less

Magnetar giant flares in multipolar magnetic fields. II. Flux rope eruptions with current sheets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Lei; Yu, Cong, E-mail: muduri@shao.ac.cn, E-mail: cyu@ynao.ac.cn

2014-11-20

We propose a physical mechanism to explain giant flares and radio afterglows in terms of a magnetospheric model containing both a helically twisted flux rope and a current sheet (CS). With the appearance of a CS, we solve a mixed boundary value problem to get the magnetospheric field based on a domain decomposition method. We investigate properties of the equilibrium curve of the flux rope when the CS is present in background multipolar fields. In response to the variations at the magnetar surface, it quasi-statically evolves in stable equilibrium states. The loss of equilibrium occurs at a critical point and,more » beyond that point, it erupts catastrophically. New features show up when the CS is considered. In particular, we find two kinds of physical behaviors, i.e., catastrophic state transition and catastrophic escape. Magnetic energy would be released during state transitions. This released magnetic energy is sufficient to drive giant flares, and the flux rope would, therefore, go away from the magnetar quasi-statically, which is inconsistent with the radio afterglow. Fortunately, in the latter case, i.e., the catastrophic escape, the flux rope could escape the magnetar and go to infinity in a dynamical way. This is more consistent with radio afterglow observations of giant flares. We find that the minor radius of the flux rope has important implications for its eruption. Flux ropes with larger minor radii are more prone to erupt. We stress that the CS provides an ideal place for magnetic reconnection, which would further enhance the energy release during eruptions.« less

New Books for Industrial Educators

ERIC Educational Resources Information Center

School Shop, 1975

1975-01-01

The most recent book releases in the field of industrial-technical education are listed alphabetically under: automotive/power mechanics; building trades; drafting; electricity/electronics; graphic arts, industrial arts, vocational, technical and career education; industrial mathematics; machine shop/metalworking; metrics; radio/television;…

75 FR 62690 - Radio Broadcasting Services; Grants Pass, Oregon

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-13

..., adopted September 24, 2010, and released September 27, 2010. The full text of this Commission decision is..., Portals II, 445 12th Street, SW., Room CY-A257, Washington, DC 20554. The complete text of this decision...

Estimation of peacock bass (Cichla spp.) mortality rate during catch-release fishing employing different post-capture procedures.

PubMed

Barroco, L S A; Freitas, C E C; Lima, Á C

2018-05-01

The effect of catch-and-release fishing on the survival of peacock bass (Cichla spp.) was evaluated by comparing two types of artificial bait (jig and shallow-diver plugs) and two types of post-catch confinement. Two experiments were conducted during the periods January-February and October-November 2012 in the Unini River, a right-bank tributary of the Negro River. In total, 191 peacock bass were captured. Both groups of fish were subjected to experimental confinement (collective and individual) for three days. Additionally, 11 fish were tagged with radio transmitters for telemetry monitoring. Mortality rate was estimated as the percentage of dead individuals for each type of bait and confinement. For peacock bass caught with jig baits, mortality was zero. The corresponding figure for shallow-diver bait was 1.66% for fish in collective containment, 18.18% for fish monitored by telemetry and 0% for individuals confined individually. Our results show low post-release mortality rates for peacock bass. Furthermore, neither the type of confinement nor the type of bait had a statistically significant influence on mortality rates. While future studies could include other factors in the analysis, our results show that catch-and-release fishing results in low mortality rates.

The GMRT 150 MHz all-sky radio survey. First alternative data release TGSS ADR1

NASA Astrophysics Data System (ADS)

Intema, H. T.; Jagannathan, P.; Mooley, K. P.; Frail, D. A.

2017-02-01

We present the first full release of a survey of the 150 MHz radio sky, observed with the Giant Metrewave Radio Telescope (GMRT) between April 2010 and March 2012 as part of the TIFR GMRT Sky Survey (TGSS) project. Aimed at producing a reliable compact source survey, our automated data reduction pipeline efficiently processed more than 2000 h of observations with minimal human interaction. Through application of innovative techniques such as image-based flagging, direction-dependent calibration of ionospheric phase errors, correcting for systematic offsets in antenna pointing, and improving the primary beam model, we created good quality images for over 95 percent of the 5336 pointings. Our data release covers 36 900 deg2 (or 3.6 π steradians) of the sky between -53° and +90° declination (Dec), which is 90 percent of the total sky. The majority of pointing images have a noise level below 5 mJy beam-1 with an approximate resolution of 25''×25'' (or 25''×25''/ cos(Dec-19°) for pointings south of 19° declination). We have produced a catalog of 0.62 Million radio sources derived from an initial, high reliability source extraction at the seven sigma level. For the bulk of the survey, the measured overall astrometric accuracy is better than two arcseconds in right ascension and declination, while the flux density accuracy is estimated at approximately ten percent. Within the scope of the TGSS alternative data release (TGSS ADR) project, the source catalog, as well as 5336 mosaic images (5°×5°) and an image cutout service, are made publicly available at the CDS as a service to the astronomical community. Next to enabling a wide range of different scientific investigations, we anticipate that these survey products will provide a solid reference for various new low-frequency radio aperture array telescopes (LOFAR, LWA, MWA, SKA-low), and can play an important role in characterizing the epoch-of-reionisation (EoR) foreground. The TGSS ADR project aims at continuously improving the quality of the survey data products. Near-future improvements include replacement of bright source snapshot images with archival targeted observations, using new observations to fill the holes in sky coverage and replace very poor quality observational data, and an improved flux calibration strategy for less severely affected observational data. Full Table 3 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A78

Software Defined Radio Standard Architecture and its Application to NASA Space Missions

NASA Technical Reports Server (NTRS)

Andro, Monty; Reinhart, Richard C.

2006-01-01

A software defined radio (SDR) architecture used in space-based platforms proposes to standardize certain aspects of radio development such as interface definitions, functional control and execution, and application software and firmware development. NASA has charted a team to develop an open software defined radio hardware and software architecture to support NASA missions and determine the viability of an Agency-wide Standard. A draft concept of the proposed standard has been released and discussed among organizations in the SDR community. Appropriate leveraging of the JTRS SCA, OMG's SWRadio Architecture and other aspects are considered. A standard radio architecture offers potential value by employing common waveform software instantiation, operation, testing and software maintenance. While software defined radios offer greater flexibility, they also poses challenges to the radio development for the space environment in terms of size, mass and power consumption and available technology. An SDR architecture for space must recognize and address the constraints of space flight hardware, and systems along with flight heritage and culture. NASA is actively participating in the development of technology and standards related to software defined radios. As NASA considers a standard radio architecture for space communications, input and coordination from government agencies, the industry, academia, and standards bodies is key to a successful architecture. The unique aspects of space require thorough investigation of relevant terrestrial technologies properly adapted to space. The talk will describe NASA's current effort to investigate SDR applications to space missions and a brief overview of a candidate architecture under consideration for space based platforms.

Radio stars observed in the LAMOST spectral survey

NASA Astrophysics Data System (ADS)

Zhang, Li-Yun; Yue, Qiang; Lu, Hong-Peng; Han, Xian-Ming L.; Zhang, Yong; Shi, Jian-Rong; Wang, Yue-Fei; Hou, Yong-Hui; Zi-Huang, Cao

2017-09-01

Radio stars have attracted astronomers’ attention for several decades. To better understand the physics behind stellar radio emissions, it is important to study their optical behaviors. The LAMOST survey provides a large database for researching stellar spectroscopic properties of radio stars. In this work, we concentrate on their spectroscopic properties and infer physical properties from their spectra, such as stellar activity and variability. We mined big data from the LAMOST spectral survey Data Release 2 (DR2), published on 2016 June 30, by cross-matching them with radio stars from FIRST and other surveys. We obtained 783 good stellar spectra with high signal to noise ratio for 659 stars. The criteria for selection were positional coincidence within 1.5‧‧ and LAMOST objects classified as stars. We calculated the equivalent widths (EWs) of the Ca ii H&K, Hδ, Hγ, Hβ, Hα and Ca ii IRT lines by integrating the line profiles. Using the EWs of the Hα line, we detected 147 active stellar spectra of 89 objects having emissions above the Hα continuum. There were also 36 objects with repeated spectra, 28 of which showed chromospheric activity variability. Furthermore, we found 14 radio stars emitting noticeably in the Ca ii IRT lines. The low value of the EW8542/EW8498 ratio for these 14 radio stars possibly alludes to chromospheric plage regions.

GASS: the Parkes Galactic all-sky survey. II. Stray-radiation correction and second data release

NASA Astrophysics Data System (ADS)

Kalberla, P. M. W.; McClure-Griffiths, N. M.; Pisano, D. J.; Calabretta, M. R.; Ford, H. Alyson; Lockman, F. J.; Staveley-Smith, L.; Kerp, J.; Winkel, B.; Murphy, T.; Newton-McGee, K.

2010-10-01

Context. The Parkes Galactic all-sky survey (GASS) is a survey of Galactic atomic hydrogen (H i) emission in the southern sky observed with the Parkes 64-m Radio Telescope. The first data release was published by McClure-Griffiths et al. (2009). Aims: We remove instrumental effects that affect the GASS and present the second data release. Methods: We calculate the stray-radiation by convolving the all-sky response of the Parkes antenna with the brightness temperature distribution from the Leiden/Argentine/Bonn (LAB) all sky 21-cm line survey, with major contributions from the 30-m dish of the Instituto Argentino de Radioastronomía (IAR) in the southern sky. Remaining instrumental baselines are corrected using the LAB data for a first guess of emission-free baseline regions. Radio frequency interference is removed by median filtering. Results: After applying these corrections to the GASS we find an excellent agreement with the Leiden/Argentine/Bonn (LAB) survey. The GASS is the highest spatial resolution, most sensitive, and is currently the most accurate H i survey of the Galactic H i emission in the southern sky. We provide a web interface for generation and download of FITS cubes.

78 FR 25861 - Radio Broadcasting Services; Peach Springs, Arizona

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

... Docket No. 12-374, adopted March 1, 2013, and released March 1, 2013. The full text of this Commission..., Portals II, 445 12th Street SW., Room CY- A257, Washington, DC 20554. The complete text of this decision...

An Analysis Framework for Understanding the Origin of Nuclear Activity in Low-power Radio Galaxies

NASA Astrophysics Data System (ADS)

Lin, Yen-Ting; Huang, Hung-Jin; Chen, Yen-Chi

2018-05-01

Using large samples containing nearly 2300 active galaxies of low radio luminosity (1.4 GHz luminosity between 2 × 1023 and 3 × 1025 W Hz‑1, essentially low-excitation radio galaxies) at z ≲ 0.3, we present a self-contained analysis of the dependence of the nuclear radio activity on both intrinsic and extrinsic properties of galaxies, with the goal of identifying the best predictors of the nuclear radio activity. While confirming the established result that stellar mass must play a key role on the triggering of radio activities, we point out that for the central, most massive galaxies, the radio activity also shows a strong dependence on halo mass, which is not likely due to enhanced interaction rates in denser regions in massive, cluster-scale halos. We thus further investigate the effects of various properties of the intracluster medium (ICM) in massive clusters on the radio activities, employing two standard statistical tools, principle component analysis and logistic regression. It is found that ICM entropy, local cooling time, and pressure are the most effective in predicting the radio activity, pointing to the accretion of gas cooling out of a hot atmosphere to be the likely origin in triggering such activities in galaxies residing in massive dark matter halos. Our analysis framework enables us to logically discern the mechanisms responsible for the radio activity separately for central and satellite galaxies.

Ionospheric Response to Solar Flares Using an Improved Version of SAMI2

DTIC Science & Technology

2008-03-01

THE AIR FORCE AIR UNIVERSITY AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio APPROVED FOR PUBLIC RELEASE; DISTRIBUTION ...Reich III, AAS, B.S. Captain, USAF March 2008 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED AFrT/GAP/ENP/0&M08 Approved: IoNospHERrc RpspoxsE To...This region plays a key role in the absorption of HF-radio signals, especially very low frequency (VLF) signals used in military communications

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paluch, Mark; Scholz, Allan; McLellan, Holly

2009-07-13

This study was designed to monitor movements of bull trout that were provided passage above Albeni Falls Dam, Pend Oreille River. Electrofishing and angling were used to collect bull trout below the dam. Tissue samples were collected from each bull trout and sent to the U. S. Fish and Wildlife Service Abernathy Fish Technology Center Conservation Genetics Lab, Washington. The DNA extracted from tissue samples were compared to a catalog of bull trout population DNA from the Priest River drainage, Lake Pend Oreille tributaries, and the Clark Fork drainage to determine the most probable tributary of origin. A combined acousticmore » radio or radio tag was implanted in each fish prior to being transported and released above the dam. Bull trout relocated above the dam were able to volitionally migrate into their natal tributary, drop back downstream, or migrate upstream to the next dam. A combination of stationary radio receiving stations and tracking via aircraft, boat, and vehicle were used to monitor the movement of tagged fish to determine if the spawning tributary it selected matched the tributary assigned from the genetic analysis. Seven bull trout were captured during electrofishing surveys in 2008. Of these seven, four were tagged and relocated above the dam. Two were tagged and left below the dam as part of a study monitoring movements below the dam. One was immature and too small at the time of capture to implant a tracking tag. All four fish released above the dam passed by stationary receivers stations leading into Lake Pend Oreille and no fish dropped back below the dam. One of the radio tags was recovered in the tributary corresponding with the results of the genetic test. Another fish was located in the vicinity of its assigned tributary, which was impassable due to low water discharge at its mouth. Two fish have not been located since entering the lake. Of these fish, one was immature and not expected to enter its natal tributary in the fall of 2008. The other fish was large enough to be mature, but at the time of capture its sex was unable to be determined, indicating it may not have been mature at the time of capture. These fish are expected to enter their natal tributaries in early summer or fall of 2009.« less

Radio data archiving system

NASA Astrophysics Data System (ADS)

Knapic, C.; Zanichelli, A.; Dovgan, E.; Nanni, M.; Stagni, M.; Righini, S.; Sponza, M.; Bedosti, F.; Orlati, A.; Smareglia, R.

2016-07-01

Radio Astronomical Data models are becoming very complex since the huge possible range of instrumental configurations available with the modern Radio Telescopes. What in the past was the last frontiers of data formats in terms of efficiency and flexibility is now evolving with new strategies and methodologies enabling the persistence of a very complex, hierarchical and multi-purpose information. Such an evolution of data models and data formats require new data archiving techniques in order to guarantee data preservation following the directives of Open Archival Information System and the International Virtual Observatory Alliance for data sharing and publication. Currently, various formats (FITS, MBFITS, VLBI's XML description files and ancillary files) of data acquired with the Medicina and Noto Radio Telescopes can be stored and handled by a common Radio Archive, that is planned to be released to the (inter)national community by the end of 2016. This state-of-the-art archiving system for radio astronomical data aims at delegating as much as possible to the software setting how and where the descriptors (metadata) are saved, while the users perform user-friendly queries translated by the web interface into complex interrogations on the database to retrieve data. In such a way, the Archive is ready to be Virtual Observatory compliant and as much as possible user-friendly.

FR II radio galaxies in the Sloan Digital Sky Survey: observational facts

NASA Astrophysics Data System (ADS)

Kozieł-Wierzbowska, D.; Stasińska, G.

2011-08-01

Starting from the Cambridge Catalogues of radio sources, we have created a sample of 401 Fanaroff-Riley type II (FR II) radio sources that have counterparts in the main galaxy sample of the seventh Data release of the Sloan Digital Sky Survey (SDSS) and analyse their radio and optical properties. We find that the luminosity in the Hα line - which we argue gives a better measure of the total emission-line flux than the widely used luminosity in [O III]- is strongly correlated with the radio luminosity P1.4 GHz. We show that the absence of emission lines in about one third of our sample is likely due to a detection threshold and not to a lack of optical activity. We also find a very strong correlation between the values of LHα and P1.4 GHz when scaled by ‘MBH’, an estimate of the black hole mass. We find that the properties of FR II galaxies are mainly driven by the Eddington parameter LHα/‘MBH’ or, equivalently, P1.4 GHz/‘MBH’. Radio galaxies with hotspots are found among the ones with the highest values of P1.4 GHz/‘MBH’. Compared to classical active galactic nuclei (AGN) hosts in the main galaxy sample of the SDSS, our FR II galaxies show a larger proportion of objects with very hard ionizing radiation field and large ionization parameter. A few objects are, on the contrary, ionized by a softer radiation field. Two of them have double-peaked emission lines and deserve more attention. We find that the black hole masses and stellar masses in FR II galaxies are very closely related: ‘MBH’∝M1.13* with very little scatter. A comparison sample of line-less galaxies in the SDSS follows exactly the same relation, although the masses are, on average, smaller. This suggests that the FR II radio phenomenon occurs in normal elliptical galaxies, preferentially in the most massive ones. Although most FR II galaxies are old, some contain traces of young stellar populations. Such young populations are not seen in normal line-less galaxies, suggesting that the radio (and optical) activity in some FR II galaxies may be triggered by recent star formation. The ‘MBH’-M* relation in a comparison sample of radio-quiet AGN hosts from the SDSS is very different, suggesting that galaxies which are still forming stars are also still building their central black holes. Globally, our study indicates that, while radio and optical activity are strongly related in FR II galaxies, the features of the optical activity in FR IIs are distinct from those of the bulk of radio-quiet active galaxies. An appendix (available as Supporting Information with the online version of the article) gives the radio maps of our FR II galaxies, superimposed on the SDSS images, and the parameters derived for our analysis that were not publicly available.

Comparison of the X-Ray and Radio Light Curves of Quasar PKS 1510--089

NASA Technical Reports Server (NTRS)

Aller, M. F.; Marscher, A. P.; Marchenko-Jorstad, S. G.; McHardy, I. M.; Aller, H. D.

1998-01-01

We present results for the X-ray-bright superluminal AGN PKS 1510-089 (z=0.36) monitored weekly with the Rossi X-Ray Timing Explorer for the past four years in order to study the origin of X-ray emission from this extremely variable blazer. These RXTE data are compared with weekly cm-band flux and polarization observations from the Michigan Diameter telescope, to identify correlated activity and associated frequency-dependent time delays for constraining X-ray emission models; and bimonthly 7mm VLBA total and linearly polarized intensity imaging to identify temporal associations between X-ray events and the ejection of superluminal components and disturbances in the magnetic field, to test if the X-ray energy release is related to changes in the inner jet flow. Both the X-ray (2-20 keV) and radio flux are highly variable on timescales of weeks. The VLBA mas structure is dominated by a bright core with a weak jet; both the ejection of very fast superluminal knots and changes in the fractional polarization and EVPA of the core on timescales of one to four months are identified. Two outbursts in 1997 are well-resolved in both the centimeter and X-ray bands. Both the strong temporal association and the similar outburst shape support a causal relation, and a discrete cross-correlation analysis identifies that the X-ray lags the radio by 16 days during the bursts. Starting in 1998 the behavior changes: the correlation is weaker with the X-ray possibly leading the radio by six days. During the full time window there is a correlation between bands as expected if the radio photons are upscattered to X-ray energies. The time correlations and difference between the flat X-ray spectral index (0.0 <= alpha <= 0.5 where F(sub v) is proportional to v(exp -alpha)), and the mm-wave synchrotron spectrum (alpha = 0.8) are discussed within the framework of viable SSC models.

Evaluation of the behavior and movement of adult summer steelhead in the lower Cowlitz River, Washington, following collection and release, 2013-2014

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Gleizes, Chris; Dammers, Wolf

2014-01-01

Summer steelhead (Oncorhynchus mykiss) produced by a hatchery on the lower Cowlitz River, Washington, support a popular sport fishery during June–September each year. Many of these fish return to the Cowlitz Salmon Hatchery and are held until they are spawned in December. In the past, fishery managers have released some of the steelhead that return to the hatchery at downstream release sites (hereafter referred to as “recycled steelhead”) to increase angling opportunity. The recycling of summer steelhead is a potential use of hatchery fish that can benefit anglers in the lower Cowlitz River, provided these fish are harvested or return to the hatchery. However, recycled steelhead that are not removed from the river could compete against or spawn with wild winter steelhead, which would be a negative consequence of recycling. The Washington Department of Fish and Wildlife (WDFW) conducted an evaluation during 1998 and recycled 632 summer steelhead. They determined that 55 percent of the recycled steelhead returned to the hatchery and 15 percent of the fish were harvested by anglers. The remaining 30 percent of recycled fish were not known to have been removed from the river. Recycling has not occurred in recent years because definitive studies have not been conducted to determine the fate of the fish that remain in the lower Cowlitz River after being recycled. The U.S. Geological Survey and WDFW conducted a 2-year study during 2012–2014 to quantify recycled steelhead that (1) returned to the hatchery, (2) were captured by anglers, or (3) remained in the river. All recycled steelhead were marked with a Floy® tag and opercle punch, and 20 percent of the recycled fish were radio-tagged to determine post-release behavior and movement patterns, and to describe locations of tagged fish that remained in the river during the spawning period. During 2012–2013, we recycled 549 steelhead and determined that 50 percent of the fish returned to the hatchery, 18 percent of the fish were harvested by anglers, and 32 percent of the fish were not known to have been removed from the river. During October–December 2012, only 9 percent of the radio-tagged steelhead remained in the lower Cowlitz River and none of these fish entered tributaries monitored by fixed-telemetry sites. The second year of the evaluation was conducted during 2013–2014. A total of 502 steelhead were recycled during June–August and releases were conducted weekly with group sizes that ranged from 30 to 76 fish. Results from 2013–2014 were similar to results from 2012–2013. Fifty percent (251 fish) of the recycled steelhead returned to the hatchery, 20 percent (100 fish) were harvested by anglers, and 30 percent (151 fish) were unaccounted for. The median elapsed time from release to hatchery return was 13 days, and the median elapsed time from release to capture by an angler was 11 days. The percentage of unaccounted-for steelhead in the general population was moderately high (30 percent), but detection records of radio-tagged fish suggest that few recycled steelhead were present in the lower Cowlitz River during the spawning period. A total of 109 steelhead were radio-tagged during 2013–2014, and most of these fish (88 percent) moved upstream following release and entered the Trout Hatchery–Salmon Hatchery reach (river miles 44–51). The median elapsed time from release to reach entry was 4.6 days (range of 0.5–65.5 days). After fish entered this reach, they spent a considerable amount of time near the Cowlitz Trout Hatchery (median residence time of 16.7 hours) or Cowlitz Salmon Hatchery (median residence time of 146.3 hours), or they moved back and forth between these two sites. Thirty radio-tagged steelhead made at least two trips between the sites and some fish made as many as seven trips. Detection records showed that 61 percent (66 fish) of the radio-tagged fish returned to the hatchery reach and 21 percent (23 fish) of the fish were captured by anglers. The remaining 18 percent (20 fish) of the radio-tagged fish had various fates. One fish (less than 1 percent) left the Cowlitz River and nine fish (8 percent) died, were harvested, or spit their transmitter near boat launches in the river. The remaining 10 fish (9 percent) had the potential to interact with winter steelhead. Four tagged steelhead (4 percent) entered lower Cowlitz River tributaries (two fish in the Toutle River; two fish in Salmon Creek) during October and November, and five tagged fish (5 percent) were last detected in the lower Cowlitz River in October. One fish (less than 1 percent) was never detected after being released. We measured the diameter of opercle punches in recycled steelhead to determine the temporal effectiveness of these marks. A total of 116 opercle punches were measured—36 were measured at the time of tagging and 80 were measured when fish returned to the hatchery. Opercle punches remained open for less than 1 month. None of the fish that returned to the hatchery more than 30 days after release had opercle punches that were open. All recycled steelhead were marked with a Floy® tag and opercle punch. However, if a steelhead lost its Floy® tag and was captured by an angler, or returned to the hatchery more than 30 days after being recycled, it likely would not have been accurately identified as having been recycled because of regrowth of the opercle punch. During 2013–2014, at least 70 percent of the recycled steelhead were removed from the lower Cowlitz River by anglers, returned to the hatchery, or left the river. Radiotelemetry data indicated that a maximum of 9 percent of the radio-tagged fish remained in the lower Cowlitz River during the spawning period and only 4 percent of the radio-tagged fish entered tributaries where wild steelhead are known to spawn. These results are consistent with findings from previous studies. Overall, results from these studies suggest that about one-third of the recycled steelhead were not known to have been removed from the river. However, the radiotelemetry data indicated that only about 10 percent of the recycled steelhead were present in the lower Cowlitz River during late autumn and early winter, and few of those fish (0 in 2012–2013 and 4 in 2013–2014) entered tributaries where winter steelhead spawn. These results have management implications in the lower Cowlitz River where the risks and rewards of steelhead recycling will be weighed to determine the future of the recycling program.

Using GPS radio occultation data in the study of tropical cyclogenesis

NASA Astrophysics Data System (ADS)

Didlake, A. C., Jr.; Kuo, Y. B.; Metcalfe, T.

2005-12-01

Numerous studies have examined atmospheric conditions and patterns in tropical cyclogenesis. Although much has been accomplished, a complete understanding of tropical cyclogenesis is hindered by the lack of data in the regions where formation occurs. The GPS (Global Positioning System) radio occultation technique can provide valuable data in key areas. In GPS radio occultation, GPS satellites emit radio signals through the atmosphere that are received by another satellite in a low Earth orbit. Various atmospheric properties are calculated based on the alteration of the signal. This study assessed the value of GPS radio occultation data in the study of tropical cyclogenesis by examining storms of the 2002 Western North Pacific typhoon season. The signature of precursor disturbances to tropical cyclogenesis was determined by analyzing composites of data from the NCEP Aviation (AVN) analysis over four days. Similar composites of GPS radio occultation data were produced. The AVN analysis showed strong signals of precursor disturbances in the low-level wind fields and atmospheric refractivity. The GPS radio occultation data detected similarly increased refractivity values in corresponding regions, but had sizeable measurement differences with the AVN analysis. These differences were attributed to AVN analysis error due to the lack of input observational data and the high accuracy of GPS radio occultation measurements. Further comparisons showed that with the limited quantity of data currently available, GPS radio occultation by itself was not sufficient to detect precursor disturbances. It can best be used in data assimilation to improve the analysis and forecasts of tropical storms.

Mississippi Magic: Summer Library Program, 1999.

ERIC Educational Resources Information Center

Hudspeth, Jean; Shurden, Lynn Fletcher

This manual for the 1999 Mississippi summer library program for preschool through elementary age children contains the following sections: (1) Introduction, including planning, promotional activities, sample radio spots and press releases, sample letters to parents, tips for including children with disabilities, a general bibliography, a…

Dependence of the Broad Absorption Line Quasar Fraction on Radio Luminosity

NASA Astrophysics Data System (ADS)

Shankar, Francesco; Dai, Xinyu; Sivakoff, Gregory R.

2008-11-01

We find that the fraction of classical broad absorption line quasars (BALQSOs) among the FIRST radio sources in the Sloan Data Release 3, is 20.5+ 7.3-5.9% at the faintest radio powers detected (L1.4 GHz ~ 1032 erg s-1), and rapidly drops to lesssim8% at L1.4 GHz ~ 3 × 1033 erg s-1. Similarly, adopting the broader absorption index (AI) definition of Trump et al., we find the fraction of radio BALQSOs to be 44+ 8.1-7.8%, reducing to 23.1+ 7.3-6.1% at high luminosities. While the high fraction at low radio power is consistent with the recent near-IR estimates by Dai et al., the lower fraction at high radio powers is intriguing and confirms previous claims based on smaller samples. The trend is independent of the redshift range, the optical and radio flux selection limits, or the exact definition of a radio match. We also find that at fixed optical magnitude, the highest bins of radio luminosity are preferentially populated by non-BALQSOs, consistent with the overall trend. We do find, however, that those quasars identified as AI-BALQSOs but not under the classical definition do not show a significant drop in their fraction as a function of radio power, further supporting independent claims that these sources, characterized by lower equivalent width, may represent an independent class from the classical BALQSOs. We find the balnicity index, a measure of the absorption trough in BALQSOs, and the mean maximum wind velocity to be roughly constant at all radio powers. We discuss several plausible physical models which may explain the observed fast drop in the fraction of the classical BALQSOs with increasing radio power, although none is entirely satisfactory. A strictly evolutionary model for the BALQSO and radio emission phases requires a strong fine-tuning to work, while a simple geometric model, although still not capable of explaining polar BALQSOs and the paucity of FRII BALQSOs, is statistically successful in matching the data if part of the apparent radio luminosity function is due to beamed, non-BALQSOs.

Tracing Fast Electron Beams Emanating from the Magnetic Reconnection Site in a Solar Jet

NASA Astrophysics Data System (ADS)

Chen, B.; Yu, S.; Battaglia, M.; Krucker, S.

2017-12-01

Fast electron beams propagating in the solar corona can emit radio waves commonly known as type III radio bursts. At decimetric wavelengths, these bursts are emitted from the low corona where flare energy release is thought to take place. As such, decimetric type III radio bursts can serve as an excellent tool to directly trace fast electron beams in the vicinity of the flare energy release site. Here we report observations of decimetric type III bursts during a jet event using the Jansky Very Large Array (VLA) in 1-2 GHz. Taking advantage of VLA's highly sensitive spectral imaging capability with an ultra-high cadence of 50 ms, we derive detailed trajectories of fast electron beams (with a bulk speed of at least 0.3-0.5c, or several tens of keV) and place them in the context of extreme ultraviolet and X-ray images obtained by SDO/AIA and RHESSI. Our results show that the electron beams originated in a region just below the jet and above the lower-lying small-scale flare loops, presumably where the magnetic energy release took place. We show that the electron beams appear in groups, each with a duration of only a few seconds. Each group, consisting of beams propagating along magnetic field lines at different angles, is seen to emanate from a single site trailing the jet, interpreted as the magnetic reconnection null point. Our results suggest, at least for the present case, that the fast electron beams were energized directly at the magnetic reconnection site which was highly inhomogeneous and fragmentary possibly down to kilometer scales.

Approach, passage, and survival of juvenile salmonids at Little Goose Dam, Washington: Post-construction evaluation of a temporary spillway weir, 2009

USGS Publications Warehouse

Beeman, J.W.; Braatz, A.C.; Hansel, H.C.; Fielding, S.D.; Haner, P.V.; Hansen, G.S.; Shurtleff, D.J.; Sprando, J.M.; Rondorf, D.W.

2010-01-01

This report describes a study of dam passage and survival of radio-tagged juvenile salmonids after installation of a temporary spillway weir (TSW) at Little Goose Dam, Washington, in 2009. The purpose of the study was to document fish passage and survival when the dam was operated with the TSW in place. Spillway weirs are one of several methods used to improve downstream passage of juvenile salmonids. Each spillway weir design is based on the concept of providing an overflow weir with a depth more similar to the natural migration depth of juvenile salmonids than conventional spill bays. Little Goose Dam was the last of the four lower Snake River dams to have a spillway weir installed. This was the first year that some form of surface passage device was operating at all Snake River and Columbia River dams between Lewiston, Idaho, and the Columbia River estuary. The study design stipulated that a total of 30 percent of the river discharge would continuously be passed over the TSW and the conventional spill bays, and this percentage was achieved. The TSW also was to be operated at the 'low crest' elevation during the spring and the 'high crest' elevation during the summer, but the TSW was only operated at the low crest elevation during this study. Behavior, passage, and survival of spring and summer juvenile salmonid migrants passing through Little Goose Dam were examined using radio telemetry. Survival was estimated using the Route Specific Survival Model (RSSM) by releasing tagged fish near Central Ferry State Park 21 kilometers upstream of the dam and in the tailrace approximately 0.5 kilometer downstream of the dam. From April 18 to May 21, 2009, 1,520 yearling Chinook salmon (Oncorhynchus tshawytscha) and 1,517 juvenile steelhead (O. mykiss) were radio tagged and released. From June 6 to July 5, 2009, 4,251 subyearling Chinook salmon (O. tshawytscha) were radio tagged and released. Release dates of subyearling Chinook salmon were selected to avoid 'reservoir-type' fish that cease to migrate around July. Detection sites were installed in the forebay 2 kilometers upstream of the dam, on the dam, and at several sites downstream. Detection equipment was operated from April 18 to June 5, 2009, and from June 6 to July 6, 2009, hereinafter referred to as the study periods. We describe passage behaviors through the forebay, main passage routes, and tailrace, survival probabilities through the pool (release to the forebay) and forebay and passage and survival probabilities through the main passage routes (TSW, conventional spill bays, turbines, juvenile bypass), and survival passing the concrete (the dam itself) and the dam (concrete plus the forebay).

Banging Galaxy Clusters: High Fidelity X-ray Temperature and Radio Maps to Probe the Physics of Merging Clusters

NASA Astrophysics Data System (ADS)

Burns, Jack O.; Hallman, Eric J.; Alden, Brian; Datta, Abhirup; Rapetti, David

2017-06-01

We present early results from an X-ray/Radio study of a sample of merging galaxy clusters. Using a novel X-ray pipeline, we have generated high-fidelity temperature maps from existing long-integration Chandra data for a set of clusters including Abell 115, A520, and MACSJ0717.5+3745. Our pipeline, written in python and operating on the NASA ARC high performance supercomputer Pleiades, generates temperature maps with minimal user interaction. This code will be released, with full documentation, on GitHub in beta to the community later this year. We have identified a population of observable shocks in the X-ray data that allow us to characterize the merging activity. In addition, we have compared the X-ray emission and properties to the radio data from observations with the JVLA and GMRT. These merging clusters contain radio relics and/or radio halos in each case. These data products illuminate the merger process, and how the energy of the merger is dissipated into thermal and non-thermal forms. This research was supported by NASA ADAP grant NNX15AE17G.

H2O Megamasers toward Radio-bright Seyfert 2 Nuclei

NASA Astrophysics Data System (ADS)

Zhang, J. S.; Liu, Z. W.; Henkel, C.; Wang, J. Z.; Coldwell, G. V.

2017-02-01

Using the Effelsberg-100 m telescope, we perform a successful pilot survey on H2O maser emission toward a small sample of radio-bright Seyfert 2 galaxies with a redshift larger than 0.04. The targets were selected from a large Seyfert 2 sample derived from the spectroscopic Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). One source, SDSS J102802.9+104630.4 (z ˜ 0.0448), was detected four times during our observations, with a typical maser flux density of ˜30 mJy and a corresponding (very large) luminosity of ˜1135 L ⊙. The successful detection of this radio-bright Seyfert 2 and an additional tentative detection support our previous statistical results that H2O megamasers tend to arise from Seyfert 2 galaxies with large radio luminosity. The finding provides further motivation for an upcoming larger H2O megamaser survey toward Seyfert 2s with particularly radio-bright nuclei with the basic goal to improve our understanding of the nuclear environment of active megamaser host galaxies. Based on observations with the 100 m telescope of the MPIfR (Max-Planck-Institut für Radioastronomie) at Effelsberg.

Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

NASA Technical Reports Server (NTRS)

Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

Cen A Radio Optical Gamma Composite

NASA Image and Video Library

2017-12-08

NASA release April 1, 2010 It takes the addition of radio data (orange) to fully appreciate the scale of Cen A's giant radio-emitting lobes, which stretch more than 1.4 million light-years. Gamma-rays from Fermi's Large Area Telescope (purple) and an image of the galaxy in visible light are also included in this composite. Credit: NASA/DOE/Fermi LAT Collaboration, Capella Observatory, and Ilana Feain, Tim Cornwell, and Ron Ekers (CSIRO/ATNF), R. Morganti (ASTRON), and N. Junkes (MPIfR) To learn more about these images go to: www.nasa.gov/mission_pages/GLAST/news/smokestack-plumes.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

FCC press release and consumer/retailer enforcement advisories regarding cell jammers, GPS jammers, and other jamming devices

DOT National Transportation Integrated Search

2011-02-09

FCC ENFORCEMENT BUREAU STEPS UP EDUCATION AND ENFORCEMENT EFFORTS AGAINST CELLPHONE AND GPS JAMMING. CONSUMERS BEWARE: It is Unlawful to Use Cell Jammers and Other Equipment : that Blocks, Jams, or Interferes with Authorized Radio Communication...

16 CFR 1115.26 - Guidelines and policies.

Code of Federal Regulations, 2014 CFR

2014-01-01

... SUBSTANTIAL PRODUCT HAZARD REPORTS Guidelines and Requirements for Mandatory Recall Notices § 1115.26... minimize the use of highly technical or legal terminology. (3) A recall notice should be targeted and...; (ii) Computer, radio, television, or other electronic transmission or medium; (iii) Video news release...

16 CFR 1115.26 - Guidelines and policies.

Code of Federal Regulations, 2012 CFR

2012-01-01

... SUBSTANTIAL PRODUCT HAZARD REPORTS Guidelines and Requirements for Mandatory Recall Notices § 1115.26... minimize the use of highly technical or legal terminology. (3) A recall notice should be targeted and...; (ii) Computer, radio, television, or other electronic transmission or medium; (iii) Video news release...

Preening behavior of adult gyrfalcons tagged with backpack transmitters

USGS Publications Warehouse

Booms, T.L.; Schempf, P.F.; Fuller, M.R.

2011-01-01

Radio transmitters provide data that enhance understanding of raptor biology (Walls and Kenward 2007) and are now used to answer a multitude of research questions (Meyburg and Fuller 2007). However, transmitters affect the birds that carry them (Barron et al. 2010), and it is important to document and evaluate such effects (Casper 2009). For example, decreased survival has been documented in Prairie Falcons (Falco mexicanus; Steenhof et al. 2006), Northern Goshawks (Accipiter gentilis; Reynolds et al. 2004), and Spotted Owls (Strix occidentalis; Paton et al. 1991) tagged with radio transmitters. However, no such effects were reported for Peregrine Falcons (Falco peregrinus; Fuller et al. 1998, McGrady et al. 2002) and a number of other species (Kenward 2001). White and Garrott (1990) noted that in general, animals tagged with radio transmitters often altered their behaviors for 1–14 d after release during an adjustment period that included increased preening and grooming frequencies. Although more than 90 Gyrfalcons (Falco rusticolus) have been tagged with radio transmitters (e.g., Burnham 2007, McIntyre et al. 2009, T. Booms unpubl. data), the effects of transmitters on this species are not well documented. Anecdotal information suggests some Gyrfalcons might be negatively affected by radio-tagging (Booms et al. 2008). As part of a study investigating Gyrfalcon breeding biology, we conducted opportunistic, focused observations on two radio-tagged adult female Gyrfalcons and their unmarked mates. We here describe and quantify preening behavior of Gyrfalcons shortly after radio-tagging.

United States Navy - Canadian forces solid state flight data recorder/crash position locator experiment on the B-720 controlled impact demonstration

NASA Technical Reports Server (NTRS)

Watters, D. M.

1986-01-01

The operation of a radio beacon position locator during and after the remotely controlled transport aircraft is discussed. The radio beacon transmission was actuated and was picked up by the Navy P-3A chase aircraft for a short time, after which reception was lost. The pilot reported that he received a signal on both 121.5 MHz and 243 MHz for a period of approximately 5 seconds. Five minutes after the crash a portable direction finding unit located on the roof of the NASA Dryden Flight Research Facility, 4 miles distant from the crash, was unable to pick up the beacon transmission. The fire crews started fighting the fires approximately 90 seconds after the time of impact. Navy personnel access to the crash site was allowed on the morning of December 2, 1984. Radio beacon locator was found resting top side up, 15 feet forward and 13 feet perpendicular from the tray location the starboard side of the aircraft. An immediate inspection indicated the airfoil suffered moderate fire damage with paint peeling but not intumescing. The visual marker strobe lamp housings were intact but extensively burned such that it was impossible to see if the lamps had survived. The airfoil suffered minor structural damage, with assorted dents, etc. The extended plunger on the ARU-21 release unit indicated that the pyrotechnic deployment system operated. The radio beacon base (tray) suffered some heat and fire damage, and was charred and blackened by smoke. The frangible switch in the nose survived and the switch in the belly was recovered and found to have actuated. It is assumed that this switch fired the ARU-21 squib. There were no other release switches installed in the normally open system in the aircraft.

Angler harvest, hatchery return, and tributary stray rates of recycled adult summer steelhead Oncorhynchus mykiss in the Cowlitz River, Washington

USGS Publications Warehouse

Kock, Tobias J.; Perry, Russell W.; Gleizes, Chris; Dammers, Wolf; Liedtke, Theresa L.

2016-01-01

Hatchery ‘recycling’ programs have been used to increase angling opportunities by re-releasing fish into a river after they returned to a hatchery or fish trap. Recycling is intended to increase opportunities for fishermen, but this strategy could affect wild fish populations if some recycled fish remain in the river and interact with wild fish populations. To quantify hatchery return and angler harvest rates of recycled steelhead, we conducted a 2-year study on the Cowlitz River, Washington. A total of 1051 steelhead were recycled, including 218 fish that were radio-tagged. Fates of recycled steelhead were similar between years: 48.4% returned to the hatchery, 19.2% were reported captured by anglers, and 32.4% remained in the river. A multistate model quantified the effects of covariates on hatchery return and angler harvest rates, which were positively affected by river discharge and negatively affected by time since release. However, hatchery return rates increased and angler harvest rates decreased during periods of increasing discharge. A total of 21.1% (46 fish) of the radio-tagged steelhead failed to return to the hatchery or be reported by anglers, but nearly half of those fish (20 fish) appeared to be harvested and not reported. The remaining tagged fish (11.9% of the radio-tagged population) were monitored into the spawning period, but only five fish (2.3% of the radio-tagged population) entered tributaries where wild steelhead spawning occurs. Future research focused on straying behaviour, and spawning success of recycled steelhead may further advance the understanding of the effects of recycling as a management strategy.

A physics-based model for the ionization of samarium by the MOSC chemical releases in the upper atmosphere

NASA Astrophysics Data System (ADS)

Bernhardt, Paul A.; Siefring, Carl L.; Briczinski, Stanley J.; Viggiano, Albert; Caton, Ronald G.; Pedersen, Todd R.; Holmes, Jeffrey M.; Ard, Shaun; Shuman, Nicholas; Groves, Keith M.

2017-05-01

Atomic samarium has been injected into the neutral atmosphere for production of electron clouds that modify the ionosphere. These electron clouds may be used as high-frequency radio wave reflectors or for control of the electrodynamics of the F region. A self-consistent model for the photochemical reactions of Samarium vapor cloud released into the upper atmosphere has been developed and compared with the Metal Oxide Space Cloud (MOSC) experimental observations. The release initially produces a dense plasma cloud that that is rapidly reduced by dissociative recombination and diffusive expansion. The spectral emissions from the release cover the ultraviolet to the near infrared band with contributions from solar fluorescence of the atomic, molecular, and ionized components of the artificial density cloud. Barium releases in sunlight are more efficient than Samarium releases in sunlight for production of dense ionization clouds. Samarium may be of interest for nighttime releases but the artificial electron cloud is limited by recombination with the samarium oxide ion.

75 FR 71411 - Radio Broadcasting Services; Silverpeak, NV

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-23

... rule; dismissal. SUMMARY: The Audio Division dismisses the petition for rule making filed by Shamrock... Division dismissed the petition for rule making and terminated the proceeding without adoption of a final..., and released November 5, 2010. The full text of this Commission decision is available for inspection...

16 CFR § 1115.26 - Guidelines and policies.

Code of Federal Regulations, 2013 CFR

2013-01-01

... REGULATIONS SUBSTANTIAL PRODUCT HAZARD REPORTS Guidelines and Requirements for Mandatory Recall Notices § 1115... minimize the use of highly technical or legal terminology. (3) A recall notice should be targeted and...; (ii) Computer, radio, television, or other electronic transmission or medium; (iii) Video news release...

Formulation and performance characterization of radio-sterilized "progestin-only" microparticles intended for contraception.

PubMed

Puthli, Shivanand; Vavia, Pradeep

2009-01-01

The aim of this study was to formulate and characterize a microparticulate system of progestin-only contraceptive. Another objective was to evaluate the effect of gamma radio-sterilization on in vitro and in vivo drug release characteristics. Levonorgestrel (LNG) microspheres were fabricated using poly(lactide-co-glycolide) (PLGA) by a novel solvent evaporation technique. The formulation was optimized for drug/polymer ratio, emulsifier concentration, and process variables like speed of agitation and evaporation method. The drug to polymer ratio of 1:5 gave the optimum encapsulation efficiency. Speed of agitation influenced the spherical shape of the microparticles, lower speeds yielding less spherical particles. The speed did not have a significant influence on the drug payloads. A combination of stabilizers viz. methyl cellulose and poly vinyl alcohol with in-water solvent evaporation technique yielded microparticles without any free drug crystals on the surface. This aspect significantly eliminated the in vitro dissolution "burst effect". The residual solvent content was well within the regulatory limits. The microparticles passed the test for sterility and absence of pyrogens. In vitro dissolution conducted on the product before and after gamma radiation sterilization at 2.5 Mrad indicated no significant difference in the drug release patterns. The drug release followed zero-order kinetics in both static and agitation conditions of dissolution testing. The in vivo studies conducted in rabbits exhibited LNG release up to 1 month duration with drug levels maintained within the effective therapeutic window.

Behavior and movement of adult summer steelhead following collection and release, lower Cowlitz River, Washington, 2012--2013

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Ekstrom, Brian K.; Rondorf, Dennis W.; Gleizes, Chris; Dammers, Wolf; Gibson, Scott; Murphy, Jamie

2013-01-01

Executive SummaryHistorically, adult summer steelhead Oncorhynchus mykiss returning to hatcheries on the lower Cowlitz River were sometimes transported and released in the river (recycled) to provide additional angling opportunity for the popular sport fishery in the basin. However, this practice has not been used in recent years because of concerns associated with interactions between hatchery fish and wild fish. Fishery managers were interested in resuming recycling but lacked information regarding effects of this practice on wild steelhead so we conducted a study during 2012–2013 to: (1) enumerate recycled steelhead that returned to the hatchery or were removed by anglers; and (2) determine if steelhead that were not removed from the river remained in the system where they could interact with wild fish.During June–August 2012, a total of 549 summer steelhead were captured at the Cowlitz Salmon Hatchery, tagged, and released downstream near the Interstate 5 Bridge. All recycled steelhead were tagged with a white Floy® tag and opercle-punched; 109 (20 percent) of these fish also were radio-tagged. All adult steelhead that return to the hatchery were handled by hatchery staff so recycled steelhead that returned to the hatchery were enumerated daily. A creel survey and voluntary angler reports were used to determine the number of recycled steelhead that were caught by anglers. We established three fixed telemetry monitoring sites on the mainstem Cowlitz River and eight additional sites were deployed on tributaries to the lower Cowlitz River where wild winter steelhead are known to spawn. We also conducted mobile tracking from a boat during October 2012, November 2012, and January 2013 to locate radio-tagged fish.A total of 10,722 summer steelhead were captured at the Cowlitz Salmon Hatchery in 2012, which was the largest return since 2008. River flows during much of the study period were similar to 2008–2011 average flows, however, high-flow periods in July and November 2012 were nearly twice as high as the 2008–2011 average flows. We determined that 50 percent (273 fish) of the recycled steelhead returned to the hatchery and 18 percent (102 fish) of the recycled steelhead were caught by anglers. Most (243 fish; 89 percent) of the recycled steelhead that returned to the hatchery were recollected during July–August. The average elapsed time from release to recapture at the hatchery was 9 days (d) and 72 percent (182 fish) of the fish returned to the hatchery within 14 d of release. These trends were similar for recycled steelhead that were caught by anglers. Most fish were caught during July–August and the median time from release to capture was 10 d. We determined that 65 percent (70 fish) of the angler-caught fish returned to the hatchery within 14 d of release. River flows appeared to affect both hatchery returns and angler catch. The daily number of recycled steelhead that were recollected at the hatchery were low during periods when river flows were decreasing and high during periods when river flows were increasing. Conversely, daily angler catch of recycled steelhead generally was low when flows were increasing and high when flows were decreasing.We determined that 32 percent of the recycled steelhead (174 fish) were not removed from the lower Cowlitz River, based on observations from hatchery returns and angler reports, but results from the radio-tagged fish were insightful for understanding what may have happened to these fish. By comparison, we determined that 24 percent of the radio-tagged fish were not known to have been removed from the river. We determined that 12 percent of these fish were actively moving in the lower Cowlitz River during October 2012–January 2013. None of the radio-tagged fish were detected in tributaries during the study period except for a single fish that spent approximately 7 d in the Toutle River during early September. During October 2012–January 2013, 10 percent of the radio-tags from recycled steelhead were detected near popular fishing areas, and 2 percent of the radio-tagged steelhead were never detected during the study period. We suspect that a large proportion of these fish may have been harvested and not reported, or died.Detection patterns of radio-tagged steelhead showed that most fish (82 percent) moved upstream from the release site and were detected at the Trout Hatchery and the Barrier Dam sites. The median time from release to detection at these sites was 3.7 d and many of these fish made multiple trips between the two sites. Nearly one-third (29 percent) of the recycled steelhead that were detected at the Trout Hatchery and the Barrier Dam made at least two trips between the sites and some fish made as many as six trips. Radio-tagged fish that remained in the lower Cowlitz River during the spawning period (December 2012–January 2013) were observed in the river reach between the mouth of Ostrander Creek (river mile 10) and the Trout Hatchery (river mile 44).During this study, we collected data on opercle punch regrowth rates to understand the temporal effectiveness of this marking technique. We took opercle measurements for a total of 190 fish during the study. Fresh opercle punches were measured for 63 fish at the time of marking, and the remaining 127 fish were measured when fish returned to the hatchery. We determined that opercle punches remained open for about 30 d. The holes appeared to regrow slowly in the first 20 d after marking, but regrowth accelerated during the 20–30 d post-marking period. After 30 d, all opercle punches that we observed had completely closed due to tissue regrowth.Our study showed that a large proportion (68 percent) of the recycled steelhead were removed from the lower Cowlitz River. These fish primarily entered the hatchery or were caught by anglers within 14 d of release, which suggests that they present minimal risk to wild fish in the system. However, the remaining fish (32 percent) could not be accounted for, which may complicate fisheries management decisions associated with recycling summer steelhead. Findings from the radiotelemetry study suggest that unreported harvest or mortality could explain a large proportion of those fish that were not reported as having been removed from the river. Furthermore, intensive monitoring of the key spawning tributaries failed to detect a single fish during the spawning period. These findings were supported by observations from weir traps operated by the Washington Department of Fish and Wildlife. Our findings indicate that additional research may be warranted to further examine the effects of recycling hatchery summer steelhead in the lower Cowlitz River.

Movements of adult chinook salmon during spawning migration in a metals-contaminated system, Coeur d'Alene River, Idaho

USGS Publications Warehouse

Goldstein, J.N.; Woodward, D.F.; Farag, A.M.

1999-01-01

Spawning migration of adult male chinook salmon Oncorhynchus tshawytscha was monitored by radio telemetry to determine their response to the presence of metals contamination in the South Fork of the Coeur d'Alene River, Idaho. The North Fork of the Coeur d'Alene River is relatively free of metals contamination and was used as a control. In all, 45 chinook salmon were transported from their natal stream, Wolf Lodge Creek, tagged with radio transmitters, and released in the Coeur d'Alene River 2 km downstream of the confluence of the South Fork and the North Fork of the Coeur d'Alene River. Fixed telemetry receivers were used to monitor the upstream movement of the tagged chinook salmon through the confluence area for 3 weeks after release. During this period, general water quality and metals concentrations were monitored in the study area. Of the 23 chinook salmon observed to move upstream from the release site and through the confluence area, the majority (16 fish, 70%) moved up the North Fork, and only 7 fish (30%) moved up the South Fork, where greater metals concentrations were observed. Our results agree with laboratory findings and suggest that natural fish populations will avoid tributaries with high metals contamination.

Search for Gamma-Ray Emission from the Coma Cluster with Six Years of Fermi-LAT Data

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.;

Under the Radar: The First Woman in Radio Astronomy, Ruby Payne-Scott

NASA Astrophysics Data System (ADS)

Miller Goss, W.

2012-05-01

Under the Radar, the First Woman in Radio Astronomy, Ruby Payne-Scott W. Miller Goss, NRAO Socorro NM Ruby Payne-Scott (1912-1981) was an eminent Australian scientist who made major contributions to the WWII radar effort (CSIR) from 1941 to 1945. In late 1945, she pioneered radio astronomy efforts at Dover Heights in Sydney, Australia at a beautiful cliff top overlooking the Tasman Sea. Again at Dover Heights, Payne-Scott carried out the first interferometry in radio astronomy using an Australian Army radar antenna as a radio telescope at sun-rise, 26 January 1946. She continued these ground breaking activities until 1951. Ruby Payne-Scott played a major role in discovering and elucidating the properties of Type III bursts from the sun, the most common of the five classes of transient phenomena from the solar corona. These bursts are one of the most intensively studied forms of radio emission in all of astronomy. She is also one of the inventors of aperture synthesis in radio astronomy. I examine her career at the University of Sydney and her conflicts with the CSIR hierarchy concerning the rights of women in the work place, specifically equal wages and the lack of permanent status for married women. I also explore her membership in the Communist Party of Australia as well as her partially released Australian Scientific Intelligence Organization file. Payne-Scott’s role as a major participant in the flourishing radio astronomy research of the post war era remains a remarkable story. She had a number of strong collaborations with the pioneers of early radio astronomy in Australia: Pawsey, Mills, Christiansen, Bolton and Little. I am currently working on a popular version of the Payne-Scott story; “Making Waves, The Story of Ruby Payne-Scott: Australian Pioneer Radio Astronomer” will be published in 2013 by Springer in the Astronomers’ Universe Series.

A search for faint high-redshift radio galaxy candidates at 150 MHz

NASA Astrophysics Data System (ADS)

Saxena, A.; Jagannathan, P.; Röttgering, H. J. A.; Best, P. N.; Intema, H. T.; Zhang, M.; Duncan, K. J.; Carilli, C. L.; Miley, G. K.

2018-04-01

Ultrasteep spectrum (USS) radio sources are good tracers of powerful radio galaxies at z > 2. Identification of even a single bright radio galaxy at z > 6 can be used to detect redshifted 21 cm absorption due to neutral hydrogen in the intervening intergalactic medium. Here we describe a new sample of high-redshift radio galaxy (HzRG) candidates constructed from the TIFR GMRT Sky Survey First Alternative Data Release survey at 150 MHz. We employ USS selection (α ≤ -1.3) in ˜10 000 deg2, in combination with strict size selection and non-detections in all-sky optical and infrared surveys. We apply flux density cuts that probe a unique parameter space in flux density (50 mJy < S150 < 200 mJy) to build a sample of 32 HzRG candidates. Follow-up Karl G. Jansky Very Large Array (VLA) observations at 1.4 GHz with an average beam size of 1.3 arcsec revealed ˜ 48 per cent of sources to have a single radio component. P-band (370 MHz) imaging of 17 of these sources revealed a flattening radio SED for 10 sources at low frequencies, which is expected from compact HzRGs. Two of our sources lie in fields where deeper multiwavelength photometry and ancillary radio data are available and for one of these we find a best-fitting photo-z of 4.8 ± 2.0. The other source has zphot = 1.4 ± 0.1 and a small angular size (3.7 arcsec), which could be associated with an obscured star-forming galaxy or with a `dead' elliptical. One USS radio source not part of the HzRG sample but observed with the VLA none the less is revealed to be a candidate giant radio galaxy with a host galaxy photo-z of 1.8 ± 0.5, indicating a size of 875 kpc.

Towards a cosmic-ray mass-composition study at Tunka Radio Extension

NASA Astrophysics Data System (ADS)

Kostunin, D.; Bezyazeekov, P. A.; Budnev, N. M.; Fedorov, O.; Gress, O. A.; Haungs, A.; Hiller, R.; Huege, T.; Kazarina, Y.; Kleifges, M.; Korosteleva, E. E.; Krömer, O.; Kungel, V.; Kuzmichev, L. A.; Lubsandorzhiev, N.; Mirgazov, R. R.; Monkhoev, R.; Osipova, E. A.; Pakhorukov, A.; Pankov, L.; Prosin, V. V.; Rubtsov, G. I.; Schröder, F. G.; Wischnewski, R.; Zagorodnikov, A.

2017-03-01

The Tunka Radio Extension (Tunka-Rex) is a radio detector at the TAIGA facility located in Siberia nearby the southern tip of Lake Baikal. Tunka-Rex measures air-showers induced by high-energy cosmic rays, in particular, the lateral distribution of the radio pulses. The depth of the air-shower maximum, statistically depends on the mass of the primary particle, is determined from the slope of the lateral distribution function (LDF). Using a model-independent approach, we have studied possible features of the one-dimensional slope method and tried to find improvements for the reconstruction of primary mass. To study the systematic uncertainties given by different primary particles, we have performed simulations using the CONEX and CoREAS software packages of the recently released CORSIKA v7.5 including the modern high-energy hadronic models QGSJet-II.04 and EPOS-LHC. The simulations have shown that the largest systematic uncertainty in the energy deposit is due to the unknown primary particle. Finally, we studied the relation between the polarization and the asymmetry of the LDF.

A solar radio dynamic spectrograph with flexible temporal-spectral resolution

NASA Astrophysics Data System (ADS)

Du, Qing-Fu; Chen, Lei; Zhao, Yue-Chang; Li, Xin; Zhou, Yan; Zhang, Jun-Rui; Yan, Fa-Bao; Feng, Shi-Wei; Li, Chuan-Yang; Chen, Yao

2017-09-01

Observation and research on solar radio emission have unique scientific values in solar and space physics and related space weather forecasting applications, since the observed spectral structures may carry important information about energetic electrons and underlying physical mechanisms. In this study, we present the design of a novel dynamic spectrograph that has been installed at the Chashan Solar Radio Observatory operated by the Laboratory for Radio Technologies, Institute of Space Sciences at Shandong University. The spectrograph is characterized by real-time storage of digitized radio intensity data in the time domain and its capability to perform off-line spectral analysis of the radio spectra. The analog signals received via antennas and amplified with a low-noise amplifier are converted into digital data at a speed reaching up to 32 k data points per millisecond. The digital data are then saved into a high-speed electronic disk for further off-line spectral analysis. Using different word lengths (1-32 k) and time cadences (5 ms-10 s) for off-line fast Fourier transform analysis, we can obtain the dynamic spectrum of a radio burst with different (user-defined) temporal (5 ms-10 s) and spectral (3 kHz˜320 kHz) resolutions. This enables great flexibility and convenience in data analysis of solar radio bursts, especially when some specific fine spectral structures are under study.

Harmonization based on regulatory science between scientific and commercial radio uses in a case of ultrawideband radio

NASA Astrophysics Data System (ADS)

Kohno, Ryuji; Iinatti, Jari; Sameshima, Keiko

2016-12-01

Harmonization for scientific and commercial radio uses is one of the unsolved problems in academia, industry, and regulatory bodies. The demands for commercial radio, mobile communications, and broadcasting have significantly increased over the past few decades; therefore, interference has become a major concern. There is an increasing need to prevent such interferences, for example, between commercial radio systems and other potentially sensitive radio systems such as those used for radio astronomy or studies. When discussing the fairness in resolving such conflicts, regulatory science may be a useful multidisciplinary approach as it scientifically investigates the advantages and disadvantages of a new application or technology for conflicts between different stakeholders through a mathematical analysis of risks versus benefits of the given technology. Such an analysis enables fair rules or regulations to be made. In this study, we apply the above-mentioned concept to harmonize the scientific and commercial uses of radio. After a brief introduction to regulatory science, a case study about the coexistence between ultrawideband commercial radio systems and radio astronomy is considered. Finally, a proposal by International Union of Radio Science, Japan, to the Science Council of Japan in the Cabinet Office to establish a "Center for Coexistence and Harmonization of Scientific and Commercial Uses of Radio Waves" is explained.

Fast Radio Bursts from the Collapse of Strange Star Crusts

NASA Astrophysics Data System (ADS)

Zhang, Yue; Geng, Jin-Jun; Huang, Yong-Feng

2018-05-01

Fast radio bursts (FRBs) are transient radio sources at cosmological distances. No counterparts in other bands have been observed for non-repeating FRBs. Here we suggest the collapse of strange star (SS) crusts as a possible origin for FRBs. SSs, which are composed of almost equal numbers of u, d, and s quarks, may be encapsulated by a thin crust of normal hadronic matter. When a SS accretes matter from its environment, the crust becomes heavier and heavier. It may finally collapse, leading to the release of a large amount of magnetic energy and plenty of electron/positron pairs on a very short timescale. Electron/positron pairs in the polar cap region of the SS can be accelerated to relativistic velocities, streaming along the magnetic field lines to form a thin shell. FRBs are produced by coherent emission from these electrons when the shell is expanding. Basic characteristics of observed FRBs can be explained in our model.

The versatile GBT astronomical spectrometer (VEGAS): Current status and future plans

NASA Astrophysics Data System (ADS)

Prestage, Richard M.; Bloss, Marty; Brandt, Joe; Chen, Hong; Creager, Ray; Demorest, Paul; Ford, John; Jones, Glenn; Kepley, Amanda; Kobelski, Adam; Marganian, Paul; Mello, Melinda; McMahon, David; McCullough, Randy; Ray, Jason; Roshi, D. Anish; Werthimer, Dan; Whitehead, Mark

2015-07-01

The VEGAS multi-beam spectrometer (VEGAS) was built for the Green Bank Telescope (GBT) through a partnership between the National Radio Astronomy Observatory (NRAO) and the University of California at Berkeley. VEGAS is based on a Field Programmable Gate Array (FPGA) frontend and a heterogeneous computing backend comprised of Graphical Processing Units (GPUs) and CPUs. This system provides processing power to analyze up to 8 dual-polarization or 16 single-polarization inputs at bandwidths of up to 1.25 GHz per input. VEGAS was released for "shared-risk" observing in March 2014 and it became the default GBT spectral line backend in August 2014. Some of the early VEGAS observations include the Radio Ammonia Mid-Plane Survey, mapping of HCN/HCO+ in nearby galaxies, and a variety of radio-recombination line and pulsar projects. We will present some of the latest VEGAS science highlights.

A model of fast radio bursts: collisions between episodic magnetic blobs

NASA Astrophysics Data System (ADS)

Li, Long-Biao; Huang, Yong-Feng; Geng, Jin-Jun; Li, Bing

2018-06-01

Fast radio bursts (FRBs) are bright radio pulses from the sky with millisecond durations and Jansky-level flux densities. Their origins are still largely uncertain. Here we suggest a new model for FRBs. We argue that the collision of a white dwarf with a black hole can generate a transient accretion disk, from which powerful episodicmagnetic blobs will be launched. The collision between two consecutive magnetic blobs can result in a catastrophic magnetic reconnection, which releases a large amount of free magnetic energy and forms a forward shock. The shock propagates through the cold magnetized plasma within the blob in the collision region, radiating through the synchrotron maser mechanism, which is responsible for a non-repeating FRB signal. Our calculations show that the theoretical energetics, radiation frequency, duration timescale and event rate can be very consistent with the observational characteristics of FRBs.

Radio Galaxy Zoo: Machine learning for radio source host galaxy cross-identification

NASA Astrophysics Data System (ADS)

Alger, M. J.; Banfield, J. K.; Ong, C. S.; Rudnick, L.; Wong, O. I.; Wolf, C.; Andernach, H.; Norris, R. P.; Shabala, S. S.

2018-05-01

We consider the problem of determining the host galaxies of radio sources by cross-identification. This has traditionally been done manually, which will be intractable for wide-area radio surveys like the Evolutionary Map of the Universe (EMU). Automated cross-identification will be critical for these future surveys, and machine learning may provide the tools to develop such methods. We apply a standard approach from computer vision to cross-identification, introducing one possible way of automating this problem, and explore the pros and cons of this approach. We apply our method to the 1.4 GHz Australian Telescope Large Area Survey (ATLAS) observations of the Chandra Deep Field South (CDFS) and the ESO Large Area ISO Survey South 1 (ELAIS-S1) fields by cross-identifying them with the Spitzer Wide-area Infrared Extragalactic (SWIRE) survey. We train our method with two sets of data: expert cross-identifications of CDFS from the initial ATLAS data release and crowdsourced cross-identifications of CDFS from Radio Galaxy Zoo. We found that a simple strategy of cross-identifying a radio component with the nearest galaxy performs comparably to our more complex methods, though our estimated best-case performance is near 100 per cent. ATLAS contains 87 complex radio sources that have been cross-identified by experts, so there are not enough complex examples to learn how to cross-identify them accurately. Much larger datasets are therefore required for training methods like ours. We also show that training our method on Radio Galaxy Zoo cross-identifications gives comparable results to training on expert cross-identifications, demonstrating the value of crowdsourced training data.

Valuing Flexibility Phase 2

DTIC Science & Technology

2012-10-29

longer by adding an additional mid section8.  Radio Frequency Identification (RFID): This established technology is being considered for use to...MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited...Introduction ............................................................................................ 11 3 A Taxonomy of Methods for Valuing

Valuing Flexibility. Phase 2

DTIC Science & Technology

2012-10-29

modules and their interfaces are designed such that the ship can be made longer by adding an additional mid section8.  Radio Frequency ...MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release, distribution... 11 3 A Taxonomy of Methods for Valuing Flexibility

Machine Learning-Aided, Robust Wideband Spectrum Sensing for Cognitive Radios

DTIC Science & Technology

2015-06-12

to even Approved for public release; distribution is unlimited. 2 on the order of a giga -Hertz (GHz). Due to wide bandwidth and noncontiguous...Frequency Band CS Compressive Sampling DFT Discrete Fourier Transform EMI Electro Magnetic Interference FFT Fast Fourier Transform GHz Giga Hertz Hz Hertz

78 FR 27342 - Radio Broadcasting Services; Moran, Texas

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-10

... instructions for submitting comments and additional information of the rulemaking process, see the..., adopted April 24, 2013, and released April 26, 2013. The full text of this Commission decision is... (Room CY-A257), 445 12th Street SW., Washington, DC 20554. The complete text of this decision may also...

Radio-Astronomical Instruments Observations (Selected Articles),

DTIC Science & Technology

1982-08-02

NL SIIDAUG 82 L I MATVEYENKO, G S MISEZHNIKOV UNCLASSIFIED FTO_ ID(RS) -0564-82 N FTD-ID(RS) T -0564-82 FOREIGN TECHNOLOGY DIVISION RADIO-ASTRONOMICAL...INSTR1ThMNTS OBSERVATIONS (Selected Articles) 3 71982 Approved for public release; LAJ distribuion~ urJA’nited. • I . FTD- ID(RS) T -0564-82 UNEDITED... T , t * r a yy y y 7, u F, f E # Ye, ye; E, e* X x X x Kh, kh X C Zh, zn .4 u L q Ts, ts - -. Z ,. 4 f 14 Ch ,ch U 7 H u I , i w Sh, sh 2 R ia Y, y

Specific Absorption Rate in a Sitting Rhesus Model at 225, 1290, and 5950 MHz for E, H, and K Polarizations.

DTIC Science & Technology

1984-04-23

Olsen SI• 23 April-198A ! Lf), i’-iApproved for public release; distribution unli~mited. S •~~i 4 0 9 .- 020 . Approved for public release... Houk , MC, USN Chief Scientific Advisor Commanding Officer 23 April 1984 NAVAL, AEROSPACE MEDICAL RESEARCH LABORATORY ,NVAL AIR STATION PENSACOLA, FLORIDA...Distrl ,oit i nti/ Avaiiab! itv Codes Avaw I !/or ii L- - - • - -•. . .. . T . . . . .. . . . v ’ - • q T ’ : • : ,-t INTRODUCTION Radio

78 FR 59844 - Operation in the 57-64 GHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-30

.... With regard to the radio astronomy service and National Radio Astronomy Observatory (NRAO) concerns... analysis of potential harmful interference from 60 GHz devices to radio astronomy service. 20. Consistent with this experience, the Commission finds that interference to Radio Astronomy Service (RAS) stations...

Array analysis of electromagnetic radiation from radio transmitters for submarine communication

NASA Astrophysics Data System (ADS)

Füllekrug, Martin; Mezentsev, Andrew; Watson, Robert; Gaffet, Stéphane; Astin, Ivan; Evans, Adrian

2014-12-01

The array analyses used for seismic and infrasound research are adapted and applied here to the electromagnetic radiation from radio transmitters for submarine communication. It is found that the array analysis enables a determination of the slowness and the arrival azimuth of the wave number vectors associated with the electromagnetic radiation. The array analysis is applied to measurements of ˜20-24 kHz radio waves from transmitters for submarine communication with an array of 10 radio receivers distributed over an area of ˜1 km ×1 km. The observed slowness of the observed wave number vectors range from ˜2.7 ns/m to ˜4.1 ns/m, and the deviations between the expected arrival azimuths and the observed arrival azimuths range from ˜-9.7° to ˜14.5°. The experimental results suggest that it is possible to determine the locations of radio sources from transient luminous events above thunderclouds with an array of radio receivers toward detailed investigations of the electromagnetic radiation from sprites.

Bayesian analysis of multi-state data with individual covariates for estimating genetic effects on demography

USGS Publications Warehouse

Converse, Sarah J.; Royle, J. Andrew; Urbanek, Richard P.

2012-01-01

Inbreeding depression is frequently a concern of managers interested in restoring endangered species. Decisions to reduce the potential for inbreeding depression by balancing genotypic contributions to reintroduced populations may exact a cost on long-term demographic performance of the population if those decisions result in reduced numbers of animals released and/or restriction of particularly successful genotypes (i.e., heritable traits of particular family lines). As part of an effort to restore a migratory flock of Whooping Cranes (Grus americana) to eastern North America using the offspring of captive breeders, we obtained a unique dataset which includes post-release mark-recapture data, as well as the pedigree of each released individual. We developed a Bayesian formulation of a multi-state model to analyze radio-telemetry, band-resight, and dead recovery data on reintroduced individuals, in order to track survival and breeding state transitions. We used studbook-based individual covariates to examine the comparative evidence for and degree of effects of inbreeding, genotype, and genotype quality on post-release survival of reintroduced individuals. We demonstrate implementation of the Bayesian multi-state model, which allows for the integration of imperfect detection, multiple data types, random effects, and individual- and time-dependent covariates. Our results provide only weak evidence for an effect of the quality of an individual's genotype in captivity on post-release survival as well as for an effect of inbreeding on post-release survival. We plan to integrate our results into a decision-analytic modeling framework that can explicitly examine tradeoffs between the effects of inbreeding and the effects of genotype and demographic stochasticity on population establishment.

Convenient and Efficient Method for Quality Control Analysis of 18F-Fluorocholine: For a Small Scale GMP-based Radiopharmaceuticals Laboratory Set-up.

PubMed

Hassan, Hishar; Abu Bakar, Suharzelim; Halim, Khairul Najah Che A; Idris, Jaleezah; Nordin, Abdul Jalil

2016-01-01

Prostate cancer continues to be the most prevalent cancer in men in Malaysia. As time progresses, the prospect of PET imaging modality in diagnosis of prostate cancer is promising, with on-going improvement on novel tracers. Among all tracers, 18F-Fluorocholine is reported to be a reputable tracer and reliable diagnostic technique for prostate imaging. Nonetheless, only 18F-Fluorodeoxyglucose (18F-FDG) is available and used in most oncology cases in Malaysia. With a small scale GMP-based radiopharmaceuticals laboratory set-up, initial efforts have been taken to put Malaysia on 18F-Fluorocholine map. This article presents a convenient, efficient and reliable method for quality control analysis of 18F-Fluorocholine. Besides, the aim of this research work is to assist local GMP radiopharmaceuticals laboratories and local authority in Malaysia for quality control analysis of 18F-Fluorocholine guideline. In this study, prior to synthesis, quality control analysis method for 18F-Fluorocholine was developed and validated, by adapting the equipment set-up used in 18F-Fluorodeoxyglucose (18FFDG) routine production. Quality control on the 18F-Fluorocholine was performed by means of pH, radionuclidic identity, radio-high performance liquid chromatography equipped with ultraviolet, radio- thin layer chromatography, gas chromatography and filter integrity test. Post-synthesis; the pH of 18F-Fluorocholine was 6.42 ± 0.04, with half-life of 109.5 minutes (n = 12). The radiochemical purity was consistently higher than 99%, both in radio-high performance liquid chromatography equipped with ultraviolet (r-HPLC; SCX column, 0.25 M NaH2PO4: acetonitrile) and radio-thin layer chromatography method (r-TLC). The calculated relative retention time (RRT) in r-HPLC was 1.02, whereas the retention factor (Rf) in r-TLC was 0.64. Potential impurities from 18F-Fluorocholine synthesis such as ethanol, acetonitrile, dimethylethanolamine and dibromomethane were determined in gas chromatography. Using our parameters, (capillary column: DB-200, 30 m x 0.53 mm x 1 um) and oven temperature of 35°C (isothermal), all compounds were well resolved and eluted within 3 minutes. Level of ethanol and acetonitrile in 18F-Fluorocholine were detected below threshold limit; less than 5 mg/ml and 0.41 mg/ml respectively. Meanwhile, dimethylethanolamine and dibromomethane were undetectable. A convenient, efficient and reliable quality control analysis work-up procedure for 18FFluorocholine has been established and validated to comply all the release criteria. The convenient method of quality control analysis may provide a guideline to local GMP radiopharmaceutical laboratories to start producing 18F-Fluorocholine as a tracer for prostate cancer imaging.

Search for possible relationship between volcanic ash particles and thunderstorm lightning activity

NASA Astrophysics Data System (ADS)

Várai, A.; Vincze, M.; Lichtenberger, J.; Jánosi, I. M.

2011-12-01

Explosive volcanic eruptions that eject columns of ash from the crater often generate lightning discharges strong enough to be remotely located by very low frequency radio waves. A fraction of volcanic ash particles can stay and disperse long enough to have an effect on weather phenomena days later such as thunderstorms and lightnings. In this work we report on lightning activity analysis over Europe following two recent series of volcanic eruptions in order to identify possible correlations between ash release and subsequent thunderstorm flash frequency. Our attempts gave negative results which can be related to the fact that we have limited information on local atmospheric variables of high enough resolution, however lightning frequency is apparently determined by very local circumstances.

Evaluation and Analysis of a Multi-Band Transceiver for Next Generation Telemetry Applications

DTIC Science & Technology

2014-06-01

DDC ) BAND SELECTION Kintex FPGA DIGITAL RADIO RECEIVER DIGITAL RADIO TRANSMITTER ADC Fs < 225 MSPS Fs = 400 MHz RF BW = 36 MHz FREQ TRANSLATION VIA...MANAGER (MMCM) DIGITAL DOWN CONVERSION ( DDC ) BAND SELECTIVE FILTER Kintex FPGA DIGITAL RADIO RECEIVER DIGITAL RADIO TRANSMITTER FIR FINE TRANSLATION

Probing Twisted Magnetic Field Using Microwave Observations in an M Class Solar Flare on 11 February, 2014

NASA Astrophysics Data System (ADS)

Sharykin, I. N.; Kuznetsov, A. A.; Myshyakov, I. I.

2018-02-01

This work demonstrates the possibility of magnetic-field topology investigations using microwave polarimetric observations. We study a solar flare of GOES M1.7 class that occurred on 11 February, 2014. This flare revealed a clear signature of spatial inversion of the radio-emission polarization sign. We show that the observed polarization pattern can be explained by nonthermal gyrosynchrotron emission from the twisted magnetic structure. Using observations of the Reuven Ramaty High Energy Solar Spectroscopic Imager, Nobeyama Radio Observatory, Radio Solar Telescope Network, and Solar Dynamics Observatory, we have determined the parameters of nonthermal electrons and thermal plasma and identified the magnetic structure where the flare energy release occurred. To reconstruct the coronal magnetic field, we use nonlinear force-free field (NLFFF) and potential magnetic-field approaches. Radio emission of nonthermal electrons is simulated by the GX Simulator code using the extrapolated magnetic field and the parameters of nonthermal electrons and thermal plasma inferred from the observations; the model radio maps and spectra are compared with observations. We have found that the potential-magnetic-field approach fails to explain the observed circular polarization pattern; on the other hand, the Stokes-V map is successfully explained by assuming nonthermal electrons to be distributed along the twisted magnetic structure determined by the NLFFF extrapolation approach. Thus, we show that the radio-polarization maps can be used for diagnosing the topology of the flare magnetic structures where nonthermal electrons are injected.

CHILES Con Pol: An ultra-deep JVLA survey probing galaxy evolution and cosmic magnetism

NASA Astrophysics Data System (ADS)

Hales, Christopher A.; Momjian, Emmanuel; van Gorkom, Jacqueline; Rupen, Michael P.; Greiner, Maksim; Ensslin, Torsten A.; Bonzini, Margherita; Padovani, Paolo; Harrison, Ian; Brown, Michael L.; Gim, Hansung; Yun, Min S.; Maddox, Natasha; Stewart, Adam; Fender, Rob P.; Tremou, Evangelia; Chomiuk, Laura; Peters, Charee; Wilcots, Eric M.; Lazio, Joseph

2015-08-01

We are undertaking a 1000 hour campaign with the Karl G. Jansky VLA to survey 0.2 square degrees of the COSMOS field in full polarization continuum at 1.4 GHz. Our observations are part of a joint program with the spectral line COSMOS HI Large Extragalactic Survey (CHILES). When complete, we expect our CHILES Continuum Polarization (CHILES Con Pol) survey to reach an SKA-era sensitivity of 500 nJy per 4 arcsecond resolving beam, the deepest view of the radio sky yet. CHILES Con Pol will open new and fertile parameter space, with sensitivity to star formation rates of 10 Msun per year out to an unprecedented redshift of z=2, and ultra-luminous infrared galaxies and sub-millimeter galaxies out to redshifts of z=8 and beyond. This rich resource will extend the utility of radio band studies beyond the usual radio quasar and radio galaxy populations, opening sensitivity to the starforming and radio-quiet AGN populations that form the bulk of extragalactic sources detected in the optical, X-ray, and infrared bands. In this talk I will outline the key science of CHILES Con Pol, including galaxy evolution and novel measurements of intergalactic magnetic fields. I will present initial results from the first 180 hours of the survey and describe our forthcoming Data Release 1. I invite the astronomical community to consider unique science that can be pursued with CHILES Con Pol radio data.

Do solar decimetric spikes originate in coronal X-ray sources?

NASA Astrophysics Data System (ADS)

Battaglia, M.; Benz, A. O.

2009-06-01

Context: In the standard solar flare scenario, a large number of particles are accelerated in the corona. Nonthermal electrons emit both X-rays and radio waves. Thus, correlated signatures of the acceleration process are predicted at both wavelengths, coinciding either close to the footpoints of a magnetic loop or near the coronal X-ray source. Aims: We attempt to study the spatial connection between coronal X-ray emission and decimetric radio spikes to determine the site and geometry of the acceleration process. Methods: The positions of radio-spike sources and coronal X-ray sources are determined and analyzed in a well-observed limb event. Radio spikes are identified in observations from the Phoenix-2 spectrometer. Data from the Nançay radioheliograph are used to determine the position of the radio spikes. RHESSI images in soft and hard X-ray wavelengths are used to determine the X-ray flare geometry. Those observations are complemented by images from GOES/SXI. Results: We find that the radio emission originates at altitudes much higher than the coronal X-ray source, having an offset from the coronal X-ray source amounting to 90´´ and to 113´´ and 131´´ from the two footpoints, averaged over time and frequency. Conclusions: Decimetric spikes do not originate from coronal X-ray flare sources contrary to previous expectations. However, the observations suggest a causal link between the coronal X-ray source, related to the major energy release site, and simultaneous activity in the higher corona.

Sky Survey Provides New Radio View of Universe

NASA Astrophysics Data System (ADS)

2004-10-01

Astronomers using the National Science Foundation's Very Large Array (VLA) have overcome longstanding technical hurdles to map the sky at little-explored radio frequencies that may provide a tantalizing look deep into the early Universe. The scientists have released images and data covering half of the sky visible from the VLA, and hope to complete their survey within a year. Radio Galaxies A "rogues' gallery" of radio galaxy types seen in the VLSS. CREDIT: NRAO/AUI/NSF (Click on Image for Graphics Page) The VLA Low-frequency Sky Survey (VLSS) is producing sky images made at an observing frequency of 74 MHz, a far lower frequency than used for most current radio-astronomy research. "Because of the Earth's ionosphere, such a low frequency has proven very difficult for high-quality imaging, and it is only in the past few years that we have developed the techniques that make a project like the VLSS possible," said Rick Perley, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. Because the high-quality VLSS images will give astronomers a look at the Universe through what essentially is a new "window," they expect the images to reveal some rare and important objects. "We expect to find very distant radio galaxies -- galaxies spewing jets of material at nearly light speed and powered by supermassive black holes," said Joseph Lazio of the Naval Research Laboratory in Washington, DC. "By determining just how distant these radio galaxies are, we will learn how early the black holes formed in the history of the Universe," he added. Another tantalizing possibility is that the low-frequency images may reveal "halos" and "relics" produced by collisions of galaxies in clusters. If the halos and relics are found in the distant, and thus early, Universe, it will give scientists important clues about the timetable for formation of large-scale structure. In addition, the astronomers hope that the VLSS images may show previously-undiscovered pulsars -- superdense, spinning neutron stars. Massive planets -- "super Jupiters" circling stars beyond the Sun -- also might reveal themselves through bursts of radio emission at the frequency of this survey, the astronomers speculated. Images from the survey are being made available to other scientists as soon as they are completed. The survey will use some 800 hours of VLA observing time. The newly-released images and data are available via the NRAO Web site. "By doing this survey and making the results available, we are bringing low-frequency radio data, previously quite difficult to produce, to all astronomers in a simple and easy manner," Perley said. "We also expect that this survey will spur additional research into objects that scientists find puzzling or interesting," Perley saidd. "We really will have to wait for years to know the full scientific benefit of this survey," he said. In addition to Perley and Lazio, the VLSS team includes James Condon and William Cotton of NRAO; Aaron Cohen and Wendy Lane of the National Research Council and the Naval Research Laboratory; Namir Kassim of the Naval Research Laboratory; and William Erickson of the University of Maryland and University of Tasmania. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Detection probability of an in-stream passive integrated transponder (PIT) tag detection system for juvenile salmonids in the Klamath River, northern California, 2011

USGS Publications Warehouse

Beeman, John W.; Hayes, Brian; Wright, Katrina

2012-01-01

A series of in-stream passive integrated transponder (PIT) detection antennas installed across the Klamath River in August 2010 were tested using tagged fish in the summer of 2011. Six pass-by antennas were constructed and anchored to the bottom of the Klamath River at a site between the Shasta and Scott Rivers. Two of the six antennas malfunctioned during the spring of 2011 and two pass-through antennas were installed near the opposite shoreline prior to system testing. The detection probability of the PIT tag detection system was evaluated using yearling coho salmon implanted with a PIT tag and a radio transmitter and then released into the Klamath River slightly downstream of Iron Gate Dam. Cormack-Jolly-Seber capture-recapture methods were used to estimate the detection probability of the PIT tag detection system based on detections of PIT tags there and detections of radio transmitters at radio-telemetry detection systems downstream. One of the 43 PIT- and radio-tagged fish released was detected by the PIT tag detection system and 23 were detected by the radio-telemetry detection systems. The estimated detection probability of the PIT tag detection system was 0.043 (standard error 0.042). Eight PIT-tagged fish from other studies also were detected. Detections at the PIT tag detection system were at the two pass-through antennas and the pass-by antenna adjacent to them. Above average river discharge likely was a factor in the low detection probability of the PIT tag detection system. High discharges dislodged two power cables leaving 12 meters of the river width unsampled for PIT detections and resulted in water depths greater than the read distance of the antennas, which allowed fish to pass over much of the system with little chance of being detected. Improvements in detection probability may be expected under river discharge conditions where water depth over the antennas is within maximum read distance of the antennas. Improvements also may be expected if additional arrays of antennas are used.

Catalog and Atlas from a Sensitive 1.5 GHz Radio Survey Around the North Ecliptic Pole

DTIC Science & Technology

1994-02-28

Physik D T 17(C Garching, Germany F ’, F P. REICH R. WIELEBINSKI Max-Planck-Institutfiir Radioastronomie Bonn, Germany 94-09976 February 28, 1994 11...lnstitut fur Radioastronomie , Bonn, Germany 12a. DISTRIBUTION/AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for public release; distribution

Oxygenation-Enhanced Radiation Therapy of Breast Tumors

DTIC Science & Technology

2011-11-01

development of stabilized perfluorocarbon emulsions as oxygen carriers, their characterization, and response to external triggers, including...elevated temperature, reduced pressure, and dwell time. Targeted oxygenation, perfluorocarbon emulsions, breast cancer 29 The University of Utah Salt...investigation of the proposed novel strategy of radio sensitization of hypoxic breast tumors by targeted oxygen release from perfluorocarbon oxygen

46 CFR 184.510 - Recommended emergency broadcast instructions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... NAME), (INSERT VESSEL'S NAME), (INSERT VESSEL'S CALL SIGN), OVER.” (5) Release the microphone button... VESSEL'S NAME & CALL SIGN).” (14) If your situation permits, stand by the radio to await further... 2182 kHz. (Channel 16 VHF and 2182 kHz on SSB are for emergency and calling purposes only.) (3) Press...

Fast radio bursts as pulsar lightning

NASA Astrophysics Data System (ADS)

Katz, J. I.

2017-07-01

There are striking phenomenological similarities between fast radio bursts (FRBs) and lightning in the Earth's and planetary atmospheres. Both have very low duty factors, ≲10-8-10-5 for FRBs and (very roughly) ˜10-4 for the main return strokes in an active thundercloud. Lightning occurs in an electrified insulating atmosphere when a conducting path is created by and permits current flow. FRBs may occur in neutron star magnetospheres whose plasma is believed to be divided by vacuum gaps. Vacuum is a perfect insulator unless electric fields are sufficient for electron-positron pair production by curvature radiation, a high-energy analogue of electrostatic breakdown in an insulating gas. FRB may be 'electrars' powered by the release of stored electrostatic energy, counterparts to soft gamma repeaters powered by the release of stored magnetostatic energy (magnetars). This frees pulsar FRB models from the constraint that their power not exceeds the instantaneous spin-down power. Energetic constraints imply that the sources of more energetic FRBs have shorter spin-down lifetimes, perhaps even less than the 3 yr over which FRB 121102 has been observed to repeat.

Detecting signatures of cosmological recombination and reionization in the cosmic radio background

NASA Astrophysics Data System (ADS)

Subrahmanyan, Ravi; Shankar Narayana Rao, Udaya; Sathyanarayana Rao, Mayuri; Singh, Saurabh

2015-08-01

Evolution of the baryons during the Epochs of cosmological Recombination and Reionization has left traces in the cosmic radio background in the form of spectral distortions (Sunyaev & Chluba 2008 Astron. Nachrichten, 330, 657; Pritchard & Loeb 2012 Rep Prog Phys 75(8):086901). The spectral signature depends on the evolution in the ionization state in hydrogen and helium and on the spin temperature of hydrogen. These probe the physics of energy release beyond the last scattering surface at redshifts exceeding 1090 and the nature of the first sources and gas evolution down to redshift about 6. The spectral distortions are sensitive to the nature of the first stars, ultra-dwarf galaxies, accreting compact objects, and the evolving ambient radiation field: X-rays and UV from the first sources. Detection of the all-sky or global spectral distortions in the radio background is hence a probe of cosmological recombination and reionization.We present new spectral radiometers that we have purpose designed for precision measurements of spectral distortions at radio wavelengths. New antenna elements include frequency independent and electrically small fat-dipole (Raghunathan et al. 2013 IEEE TAP, 61, 3411) and monopole designs. Receiver configurations have been devised that are self-calibratable (Patra et al. 2013 Expt Astron, 36, 319) so that switching of signal paths and of calibration noise sources provide real time calibration for systematics and receiver noise. Observing strategies (Patra et al. arXiv:1412.7762) and analysis methods (Satyanarayana Rao et al. arXiv:1501.07191) have been evolved that are capable of discriminating between the cosmological signals and the substantially brighter foregrounds. We have also demonstrated the value of system designs that exploit advantages of interferometer detection (Mahesh et al. arXiv:1406.2585) of global spectral distortions.Finally we discuss how the Square Kilometer Array stations may be outfitted with precision spectral radiometer outriggers (Subrahmanyan et al. arXiv:1501.04340) to provide the zero-spacing measurement sets, complement the interferometer visibilities and give the SKA a capability for measurements of cosmic radio background spectral distortions.

The BL LAC phenomenon: X-ray observations of transition objects and determination of the x-ray spectrum of a complete sample of flat-spectrum radio sources

NASA Technical Reports Server (NTRS)

Worrall, Diana M.

1994-01-01

This report summarizes the activities related to two ROSAT investigations: (1) x-ray properties of radio galaxies thought to contain BL Lac type nuclei; and (2) x-ray spectra of a complete sample of flat-spectrum radio sources. The following papers describing the research are provided as attachments: Multiple X-ray Emission Components in Low Power Radio Galaxies; New X-ray Results on Radio Galaxies; Analysis Techniques for a Multiwavelength Study of Radio Galaxies; Separation of X-ray Emission Components in Radio Galaxies; X-ray Emission in Powerful Radio Galaxies and Quasars; Extended and Compact X-ray Emission in Powerful Radio Galaxies; and X-ray Spectra of a Complete Sample of Extragalactic Core-dominated Radio Sources.

Effects of radio frequency magnetic fields on iron release from cage proteins.

PubMed

Céspedes, Oscar; Ueno, Shoogo

2009-07-01

Ferritin, the iron cage protein, contains a superparamagnetic ferrihydrite nanoparticle formed from the oxidation and absorption of Fe(2+) ions. This nanoparticle increases its internal energy when exposed to alternating magnetic fields due to magnetization lag. The energy is then dissipated to the surrounding proteic cage, affecting its functioning. In this article we show that the rates of iron chelation with ferrozine, an optical marker, are reduced by up to a factor of 3 in proteins previously exposed to radio frequency magnetic fields of 1 MHz and 30 microT for several hours. The effect is non-thermal and depends on the frequency-amplitude product of the magnetic field. (c) 2009 Wiley-Liss, Inc.

Radio wave heating of the corona and electron precipitation during flares

NASA Technical Reports Server (NTRS)

Melrose, D. B.; Dulk, G. A.

1982-01-01

Electron-cyclotron masers, excited while energy release is occurring in a flaring magnetic loop, are likely to generate extremely intense radiation at decimeter wavelengths. The energy in the radiation can be comparable with that in the electrons associated with hard X-ray bursts, i.e., a significant fraction of the total energy in the flare. Essentially all of the radio energy is likely to be reabsorbed by gyroresonance absorption, either near the emitting region or at some distance away in neighboring loops. Enhanced diffusion of fast electrons caused by the maser can lead to precipitation at the maximum possible rate, and hence account for hard X-ray emission from the footpoints of the magnetic loops.

FRESH ACTIVITY IN OLD SYSTEMS: RADIO AGNs IN FOSSIL GROUPS OF GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hess, Kelley M.; Wilcots, Eric M.; Hartwick, Victoria L., E-mail: hess@ast.uct.ac.za, E-mail: ewilcots@astro.wisc.edu, E-mail: vhartwick@wisc.edu

2012-08-15

We present the first systematic 1.4 GHz Very Large Array radio continuum survey of fossil galaxy group candidates. These are virialized systems believed to have assembled over a gigayear in the past through the merging of galaxy group members into a single, isolated, massive elliptical galaxy and featuring an extended hot X-ray halo. We use new photometric and spectroscopic data from Sloan Digital Sky Survey Data Release 7 to determine that three of the candidates are clearly not fossil groups. Of the remaining 30 candidates, 67% contain a radio-loud (L{sub 1.4GHz} > 10{sup 23} W Hz{sup -1}) active galactic nucleusmore » (AGN) at the center of their dominant elliptical galaxy. We find a weak correlation between the radio luminosity of the AGN and the X-ray luminosity of the halo suggesting that the AGN contributes to energy deposition into the intragroup medium. We only find a correlation between the radio and optical luminosity of the central elliptical galaxy when we include X-ray-selected, elliptically dominated non-fossil groups, indicating a weak relationship between AGN strength and the mass assembly history of the groups. The dominant elliptical galaxy of fossil groups is on average roughly an order of magnitude more luminous than normal group elliptical galaxies in optical, X-ray, and radio luminosities and our findings are consistent with previous results that the radio-loud fraction in elliptical galaxies is linked to the stellar mass of a population. The current level of activity in fossil groups suggests that AGN fueling continues long after the last major merger. We discuss several possibilities for fueling the AGN at the present epoch.« less

Prostaglandin release from in vitro guinea-pig gallbladder.

PubMed

Booker, M L; LaMorte, W W

1983-02-01

In order to study prostaglandin release from guinea pig gallbladder, full thickness tissue sections were incubated for one hour in Krebs solution. Extraction and two dimensional chromatography of incubation media obtained in the presence of radio-labelled arachidonic acid demonstrated the presence of PGE2, PGF2 alpha, 6-keto-PGF1 alpha and thromboxane B2. These results were supported by radioimmunoassay of incubations conducted in the absence of exogenous arachidonate and in the presence of varying concentrations of unlabelled exogenous arachidonate. The previously reported predominance of PGE2 was only seen at high concentrations of exogenous arachidonate.

Estimation of Electron Density profile Using the Propagation Characteristics of Radio Waves by S-520-29 Sounding Rocket

NASA Astrophysics Data System (ADS)

Itaya, K.; Ishisaka, K.; Ashihara, Y.; Abe, T.; Kumamoto, A.; Kurihara, J.

2015-12-01

S-520-29 sounding rocket experiment was carried out at Uchinoura Space Center (USC) at 19:10 JST on 17 August, 2014. The purpose of this sounding rocket experiments is observation of sporadic E layer that appears in the lower ionosphere at near 100km. Three methods were used in order to observe the sporadic E layer. The first method is an optical method that observe the light of metal ion emitted by the resonance scattering in sporadic E layer using the imager. The second method is observation of characteristic of radio wave propagation that the LF/MF band radio waves transmitted from the ground. The third method is measuring the electron density in the vicinity of sounding rocket using the fast Langmuir probe and the impedance probe. We analyze the propagation characteristics of radio wave in sporadic E layer appeared from the results of the second method observation. This rocket was equipped with LF/MF band radio receiver for observe the LF/MF band radio waves in rocket flight. Antenna of LF/MF band radio receiver is composed of three axis loop antenna. LF/MF band radio receiver receives three radio waves of 873kHz (JOGB), 666kHz (JOBK), 60kHz (JJY) from the ground. 873kHz and 60kHz radio waves are transmitting from north side, and 666kHz radio waves are transmitting from the east side to the trajectory of the rocket. In the sounding rocket experiment, LF/MF band radio receiver was working properly. We have completed the observation of radio wave intensity. We analyze the observation results using a Doppler shift calculations by frequency analysis. Radio waves received by the sounding rocket include the influences of Doppler shift by polarization and the direction of rocket spin and the magnetic field of the Earth. So received radio waves that are separate into characteristics waves using frequency analysis. Then we calculate the Doppler shift from the separated data. As a result, 873kHz, 666kHz radio waves are reflected by the ionosphere. 60kHz wave was able to propagate in ionosphere because wavelength of 60kHz was longer than the thickness of the sporadic E layer. In this study, we explain the result of LF/MF band radio receiver observations and the electron density of the ionosphere using frequency analysis by S-520-29 sounding rocket experiment.

Samara Probe For Remote Imaging

NASA Technical Reports Server (NTRS)

Burke, James D.

1989-01-01

Imaging probe descends through atmosphere of planet, obtaining images of ground surface as it travels. Released from aircraft over Earth or from spacecraft over another planet. Body and single wing shaped like samara - winged seed like those of maple trees. Rotates as descends, providing panoramic view of terrain below. Radio image obtained by video camera to aircraft or spacecraft overhead.

HF propagation results from the Metal Oxide Space Cloud (MOSC) experiment

NASA Astrophysics Data System (ADS)

Joshi, Dev; Groves, Keith M.; McNeil, William; Carrano, Charles; Caton, Ronald G.; Parris, Richard T.; Pederson, Todd R.; Cannon, Paul S.; Angling, Matthew; Jackson-Booth, Natasha

2017-06-01

With support from the NASA sounding rocket program, the Air Force Research Laboratory launched two sounding rockets in the Kwajalein Atoll, Marshall Islands in May 2013 known as the Metal Oxide Space Cloud experiment. The rockets released samarium metal vapor at preselected altitudes in the lower F region that ionized forming a plasma cloud. Data from Advanced Research Project Agency Long-range Tracking and Identification Radar incoherent scatter radar and high-frequency (HF) radio links have been analyzed to understand the impacts of the artificial ionization on radio wave propagation. The HF radio wave ray-tracing toolbox PHaRLAP along with ionospheric models constrained by electron density profiles measured with the ALTAIR radar have been used to successfully model the effects of the cloud on HF propagation. Up to three new propagation paths were created by the artificial plasma injections. Observations and modeling confirm that the small amounts of ionized material injected in the lower F region resulted in significant changes to the natural HF propagation environment.

Impulsiveness and energetics in solar flares with and without type II radio bursts - A comparison of hard X-ray characteristics for over 2500 solar flares

NASA Astrophysics Data System (ADS)

Pearson, Douglas H.; Nelson, Robert; Kojoian, Gabriel; Seal, James

1989-01-01

The hard X-ray characteristics of more than 2500 solar flares are used to study the relative size, impulsiveness, and energetics of flares with and without type II radio bursts. A quantitative definition of the hard X-ray impulsiveness is introduced, which may be applied to a large number of events unambiguously. It is found that the flares with type II bursts are generally not significantly larger, more impulsive, or more energetic than those without type II bursts. Also, no evidence is found to suggest a simple classification of the flares as either 'impulsive' or 'gradual'. Because type II bursts are present even in small flares with relatively unimpulsive energy releases, it is concluded that changes in the ambient conditions of the solar atmosphere causing an unusually low Alfven speed may be important in the generation of the shock wave that produces type II radio bursts.

X-ray studies of quasars with the Einstein Observatory. IV - X-ray dependence on radio emission

NASA Technical Reports Server (NTRS)

Worrall, D. M.; Tananbaum, H.; Giommi, P.; Zamorani, G.

1987-01-01

The X-ray properties of a sample of 114 radio-loud quasars observed with the Einstein Observatory are examined, and the results are compared with those obtained from a large sample of radio-quiet quasars. The results of statistical analysis of the dependence of X-ray luminosity on combined functions of optical and radio luminosity show that the dependence on both luminosities is important. However, statistically significant differences are found between subsamples of flat radio spectra quasars and steep radio spectra quasars with regard to dependence of X-ray luminosity on only radio luminosity. The data are consistent with radio-loud quasars having a physical component, not directly related to the optical luminosity, which produces the core radio luminosity plus 'extra' X-ray emission.

A technical review of cellular radio and analysis of a possible protocol

NASA Astrophysics Data System (ADS)

Reese, William D.

1992-09-01

Radio and television technology made the field of cellular radio possible. This thesis shows the development of radio and television technology from both a historical and technical aspect. A review of the important researchers and their contributions is followed by a technical explanation of the theories behind electromagnetic radiation of radio and television signals and the technology which was developed to implement such transmissions. The evolution of development which the paper outlines begins with some of the first theories about electricity and magnetism and the subsequent mathematical foundation developed to explain them. This is followed by a number of experimental and developmental researchers and their contributions. The bulk of the paper is concentrated on explaining the earliest generations of radio and all generations of television. The major components of both radio and television are described in detail along with an explanation of what they do and how they work. Such components, in many cases, found important uses in fields outside those for which they were developed. A brief overview of the regulatory environment of each technology and the U.S. and international standardization efforts is also included. Finally, the paper illustrates a modern-day application of radio technology--the cellular radio industry. A description of the components and their functions is followed by a possible cellular radio protocol and analysis.

The Relationship Between Solar Radio and Hard X-Ray Emission

NASA Technical Reports Server (NTRS)

White, S. M.; Benz, A. O.; Christe, S.; Farnik, F.; Kundu, M. R.; Mann, G.; Ning, Z.; Raulin, J.-P.; Silva-Valio, A. V. R.; Saint-Hilaire, P.;

Radio continuum properties of luminous infrared galaxies. Identifying the presence of an AGN in the radio

NASA Astrophysics Data System (ADS)

Vardoulaki, E.; Charmandaris, V.; Murphy, E. J.; Diaz-Santos, T.; Armus, L.; Evans, A. S.; Mazzarella, J. M.; Privon, G. C.; Stierwalt, S.; Barcos-Muñoz, L.

2015-02-01

Context. Luminous infrared galaxies (LIRGs) are systems enshrouded in dust, which absorbs most of their optical/UV emission and radiates it again in the mid- and far-infrared. Radio observations are largely unaffected by dust obscuration, enabling us to study the central regions of LIRGs in an unbiased manner. Aims: The main goal of this project is to examine how the radio properties of local LIRGs relate to their infrared spectral characteristics. Here we present an analysis of the radio continuum properties of a subset of the Great Observatories All-sky LIRG Survey (GOALS), which consists of 202 nearby systems (z< 0.088). Our radio sample consists of 35 systems, containing 46 individual galaxies, that were observed at both 1.49 and 8.44 GHz with the VLA with a resolution of about 1 arcsec (FWHM). The aim of the project is to use the radio imagery to probe the central kpc of these LIRGs in search of active galactic nuclei (AGN). Methods: We used the archival data at 1.49 and 8.44 GHz to create radio-spectral-index maps using the standard relation between flux density Sν and frequency ν, Sν ~ ν- α, where α is the radio spectral index. By studying the spatial variations in α, we classified the objects as radio-AGN, radio-SB, and AGN/SB (a mixture). We identified the presence of an active nucleus using the radio morphology, deviations from the radio/infrared correlation, and spatially resolved spectral index maps, and then correlated this to the usual mid-infrared ([NeV]/[NeII] and [OIV]/[NeII] line ratios and equivalent width of the 6.2 μm PAH feature) and optical (BPT diagram) AGN diagnostics. Results: We find that 21 out of the 46 objects in our sample (~45%) are radio-AGN, 9 out of the 46 (~20%) are classified as starbursts (SB) based on the radio analysis, and 16 (~35%) are AGN/SB. After comparing to other AGN diagnostics we find 3 objects out of the 46 (~7%) that are identified as AGN based on the radio analysis, but are not classified as such based on the mid-infrared and optical AGN diagnostics presented in this study. Appendix A is available in electronic form at http://www.aanda.orgVLA images as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/574/A4

NASA's Fermi Telescope Resolves Radio Galaxy Centaurus A

NASA Image and Video Library

2017-12-08

NASA release April 1, 2010 Fermi's Large Area Telescope resolved high-energy gamma rays from an extended region around the active galaxy Centaurus A. The emission corresponds to million-light-year-wide radio-emitting gas thrown out by the galaxy's supersized black hole. This inset shows an optical/gamma-ray composite of the galaxy and its location on the Fermi one-year sky map. Credit: NASA/DOE/Fermi LAT Collaboration, Capella Observatory To learn more about these images go to: www.nasa.gov/mission_pages/GLAST/news/smokestack-plumes.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Behavior of White Sturgeon near hydroprojects and fishways

USGS Publications Warehouse

Parsley, M.J.; Wright, C.D.; Van Der Leeuw, B. K.; Kofoot, E.E.; Perry, C.A.; Moser, M.L.

2006-01-01

During March 2004 through November 2005, white sturgeon movements were monitored at The Dalles Dam to characterize their distribution and movements in the immediate vicinity of the dam and to determine timing and routes of passage. A combination of radio and acoustic telemetry technologies were used to detect tagged fish within fishways and at strategic locations along the dam, the shorelines, and in the forebay. White sturgeon > 95 cm total length (TL) that were captured on baited setlines fished in the forebay and in the tailrace cul-de-sac received a surgically implanted transmitter that emitted radio and acoustic signals. During the course of this study, a total of 148 fish were tagged; 58 were captured and released in the forebay and 90 in the tailrace.

Long-Term Survival of an Urban Fruit Bat Seropositive for Ebola and Lagos Bat Viruses

PubMed Central

Hayman, David T. S.; Emmerich, Petra; Yu, Meng; Wang, Lin-Fa; Suu-Ire, Richard; Fooks, Anthony R.; Cunningham, Andrew A.; Wood, James L. N.

2010-01-01

Ebolaviruses (EBOV) (family Filoviridae) cause viral hemorrhagic fevers in humans and non-human primates when they spill over from their wildlife reservoir hosts with case fatality rates of up to 90%. Fruit bats may act as reservoirs of the Filoviridae. The migratory fruit bat, Eidolon helvum, is common across sub-Saharan Africa and lives in large colonies, often situated in cities. We screened sera from 262 E. helvum using indirect fluorescent tests for antibodies against EBOV subtype Zaire. We detected a seropositive bat from Accra, Ghana, and confirmed this using western blot analysis. The bat was also seropositive for Lagos bat virus, a Lyssavirus, by virus neutralization test. The bat was fitted with a radio transmitter and was last detected in Accra 13 months after release post-sampling, demonstrating long-term survival. Antibodies to filoviruses have not been previously demonstrated in E. helvum. Radio-telemetry data demonstrates long-term survival of an individual bat following exposure to viruses of families that can be highly pathogenic to other mammal species. Because E. helvum typically lives in large urban colonies and is a source of bushmeat in some regions, further studies should determine if this species forms a reservoir for EBOV from which spillover infections into the human population may occur. PMID:20694141

Long-term survival of an urban fruit bat seropositive for Ebola and Lagos bat viruses.

PubMed

Hayman, David T S; Emmerich, Petra; Yu, Meng; Wang, Lin-Fa; Suu-Ire, Richard; Fooks, Anthony R; Cunningham, Andrew A; Wood, James L N

2010-08-04

Ebolaviruses (EBOV) (family Filoviridae) cause viral hemorrhagic fevers in humans and non-human primates when they spill over from their wildlife reservoir hosts with case fatality rates of up to 90%. Fruit bats may act as reservoirs of the Filoviridae. The migratory fruit bat, Eidolon helvum, is common across sub-Saharan Africa and lives in large colonies, often situated in cities. We screened sera from 262 E. helvum using indirect fluorescent tests for antibodies against EBOV subtype Zaire. We detected a seropositive bat from Accra, Ghana, and confirmed this using western blot analysis. The bat was also seropositive for Lagos bat virus, a Lyssavirus, by virus neutralization test. The bat was fitted with a radio transmitter and was last detected in Accra 13 months after release post-sampling, demonstrating long-term survival. Antibodies to filoviruses have not been previously demonstrated in E. helvum. Radio-telemetry data demonstrates long-term survival of an individual bat following exposure to viruses of families that can be highly pathogenic to other mammal species. Because E. helvum typically lives in large urban colonies and is a source of bushmeat in some regions, further studies should determine if this species forms a reservoir for EBOV from which spillover infections into the human population may occur.

Space Science

NASA Image and Video Library

2001-04-02

The largest solar flare ever recorded occurred at 4:51 p.m. EDT, on Monday, April 2, 2001. as Observed by the Solar and Heliospheric Observatory (SOHO) satellite. Solar flares, among the solar systems mightiest eruptions, are tremendous explosions in the atmosphere of the Sun capable of releasing as much energy as a billion megatons of TNT. Caused by the sudden release of magnetic energy, in just a few seconds, solar flares can accelerate solar particles to very high velocities, almost to the speed of light, and heat solar material to tens of millions of degrees. The recent explosion from the active region near the sun's northwest limb hurled a coronal mass ejection into space at a whopping speed of roughly 7.2 million kilometers per hour. Luckily, the flare was not aimed directly towards Earth. Second to the most severe R5 classification of radio blackout, this flare produced an R4 blackout as rated by the NOAA SEC. This classification measures the disruption in radio communications. Launched December 2, 1995 atop an ATLAS-IIAS expendable launch vehicle, the SOHO is a cooperative effort involving NASA and the European Space Agency (ESA). (Image courtesy NASA Goddard SOHO Project office)

Largest Solar Flare on Record

NASA Technical Reports Server (NTRS)

2001-01-01

The largest solar flare ever recorded occurred at 4:51 p.m. EDT, on Monday, April 2, 2001. as Observed by the Solar and Heliospheric Observatory (SOHO) satellite. Solar flares, among the solar systems mightiest eruptions, are tremendous explosions in the atmosphere of the Sun capable of releasing as much energy as a billion megatons of TNT. Caused by the sudden release of magnetic energy, in just a few seconds, solar flares can accelerate solar particles to very high velocities, almost to the speed of light, and heat solar material to tens of millions of degrees. The recent explosion from the active region near the sun's northwest limb hurled a coronal mass ejection into space at a whopping speed of roughly 7.2 million kilometers per hour. Luckily, the flare was not aimed directly towards Earth. Second to the most severe R5 classification of radio blackout, this flare produced an R4 blackout as rated by the NOAA SEC. This classification measures the disruption in radio communications. Launched December 2, 1995 atop an ATLAS-IIAS expendable launch vehicle, the SOHO is a cooperative effort involving NASA and the European Space Agency (ESA). (Image courtesy NASA Goddard SOHO Project office)

On-Orbit Ephemeris Determination with Radio Doppler Validation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dallmann, Nicholas; Proicou, Michael Chris; Seitz, Daniel Nathan

2016-02-09

Multiple CubeSats are often released from the same host spacecraft into virtually the same orbit at nearly the same time. A satellite team needs the ability to identify and track its own satellites as soon as possible. However, this can be a difficult and confusing task with a large number of satellites. Los Alamos National Laboratory encountered this issue during a launch of LANL-designed CubeSats that were released with more than 20 other objects. A simple radio Doppler method used shortly after launch by the Los Alamos team to select its satellites of interest from the list of available trackedmore » ephemerides is described. This method can also be used for automated real time ephemeris validation. For future efforts, each LANL-designed CubeSat will automatically perform orbit determination from the position, velocity, and covariance estimates provided by an added on-board GPS receiver. This self-determined ephemeris will be automatically downlinked by ground stations for mission planning, antenna tracking, Doppler-pre-correction, etc. A simple algorithm based on established theory and well suited for embedded on-board processing is presented. The trades examined in selecting the algorithm components and data formats are briefly discussed, as is the expected performance.« less

Classifying bent radio galaxies from a mixture of point-like/extended images with Machine Learning.

NASA Astrophysics Data System (ADS)

Bastien, David; Oozeer, Nadeem; Somanah, Radhakrishna

2017-05-01

The hypothesis that bent radio sources are supposed to be found in rich, massive galaxy clusters and the avalibility of huge amount of data from radio surveys have fueled our motivation to use Machine Learning (ML) to identify bent radio sources and as such use them as tracers for galaxy clusters. The shapelet analysis allowed us to decompose radio images into 256 features that could be fed into the ML algorithm. Additionally, ideas from the field of neuro-psychology helped us to consider training the machine to identify bent galaxies at different orientations. From our analysis, we found that the Random Forest algorithm was the most effective with an accuracy rate of 92% for a classification of point and extended sources as well as an accuracy of 80% for bent and unbent classification.

Planck intermediate results. VII. Statistical properties of infrared and radio extragalactic sources from the Planck Early Release Compact Source Catalogue at frequencies between 100 and 857 GHz

NASA Astrophysics Data System (ADS)

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Argüeso, F.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Balbi, A.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Bernard, J.-P.; Bersanelli, M.; Bethermin, M.; Bhatia, R.; Bonaldi, A.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Cabella, P.; Cardoso, J.-F.; Catalano, A.; Cayón, L.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, L.-Y.; Christensen, P. R.; Clements, D. L.; Colafrancesco, S.; Colombi, S.; Colombo, L. P. L.; Coulais, A.; Crill, B. P.; Cuttaia, F.; Danese, L.; Davis, R. J.; de Bernardis, P.; de Gasperis, G.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Dörl, U.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Forni, O.; Fosalba, P.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Harrison, D.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Jaffe, T. R.; Jaffe, A. H.; Jagemann, T.; Jones, W. C.; Juvela, M.; Keihänen, E.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurinsky, N.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lawrence, C. R.; Leonardi, R.; Lilje, P. B.; López-Caniego, M.; Macías-Pérez, J. F.; Maino, D.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Mazzotta, P.; Melchiorri, A.; Mendes, L.; Mennella, A.; Mitra, S.; Miville-Deschènes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sajina, A.; Sandri, M.; Savini, G.; Scott, D.; Smoot, G. F.; Starck, J.-L.; Sudiwala, R.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Türler, M.; Valenziano, L.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; White, M.; Yvon, D.; Zacchei, A.; Zonca, A.

2013-02-01

We make use of the Planck all-sky survey to derive number counts and spectral indices of extragalactic sources - infrared and radio sources - from the Planck Early Release Compact Source Catalogue (ERCSC) at 100 to 857 GHz (3 mm to 350 μm). Three zones (deep, medium and shallow) of approximately homogeneous coverage are used to permit a clean and controlled correction for incompleteness, which was explicitly not done for the ERCSC, as it was aimed at providing lists of sources to be followed up. Our sample, prior to the 80% completeness cut, contains between 217 sources at 100 GHz and 1058 sources at 857 GHz over about 12 800 to 16 550 deg2 (31 to 40% of the sky). After the 80% completeness cut, between 122 and 452 and sources remain, with flux densities above 0.3 and 1.9 Jy at 100 and 857 GHz. The sample so defined can be used for statistical analysis. Using the multi-frequency coverage of the Planck High Frequency Instrument, all the sources have been classified as either dust-dominated (infrared galaxies) or synchrotron-dominated (radio galaxies) on the basis of their spectral energy distributions (SED). Our sample is thus complete, flux-limited and color-selected to differentiate between the two populations. We find an approximately equal number of synchrotron and dusty sources between 217 and 353 GHz; at 353 GHz or higher (or 217 GHz and lower) frequencies, the number is dominated by dusty (synchrotron) sources, as expected. For most of the sources, the spectral indices are also derived. We provide for the first time counts of bright sources from 353 to 857 GHz and the contributions from dusty and synchrotron sources at all HFI frequencies in the key spectral range where these spectra are crossing. The observed counts are in the Euclidean regime. The number counts are compared to previously published data (from earlier Planck results, Herschel, BLAST, SCUBA, LABOCA, SPT, and ACT) and models taking into account both radio or infrared galaxies, and covering a large range of flux densities. We derive the multi-frequency Euclidean level - the plateau in the normalised differential counts at high flux-density - and compare it to WMAP, Spitzer and IRAS results. The submillimetre number counts are not well reproduced by current evolution models of dusty galaxies, whereas the millimetre part appears reasonably well fitted by the most recent model for synchrotron-dominated sources. Finally we provide estimates of the local luminosity density of dusty galaxies, providing the first such measurements at 545 and 857 GHz. Appendices are available in electronic form at http://www.aanda.orgCorresponding author: herve.dole@ias.u-psud.fr

A hydrodynamics-informed, radiation model for HESS J0632+057 from radio to gamma rays

NASA Astrophysics Data System (ADS)

Barkov, Maxim V.; Bosch-Ramon, Valenti

2018-06-01

Relativistic hydrodynamical simulations of the eccentric gamma-ray binary HESS J0632+057 show that the energy of a putative pulsar wind should accumulate in the binary surroundings between periastron and apastron, being released by fast advection close to apastron. To assess whether this could lead to a maximum of the non-thermal emission before apastron, we derive simple prescriptions for the non-thermal energy content, the radiation efficiency, and the impact of energy losses on non-thermal particles, in the simulated hydrodynamical flow. These prescriptions are used to estimate the non-thermal emission in radio, X-rays, GeV, and TeV, from the shocked pulsar wind in a binary system simulated using a simplified 3-dimensional scheme for several orbital cycles. Lightcurves at different wavelengths are derived, together with synthetic radio images for different orbital phases. The dominant peak in the computed lightcurves is broad and appears close to, but before, apastron. This peak is followed by a quasi-plateau shape, and a minor peak only in gamma rays right after periastron. The radio maps show ejection of radio blobs before apastron in the periastron-apastron direction. The results show that a scenario with a highly eccentric high-mass binary hosting a young pulsar can explain the general phenomenology of HESS J0632+057: despite its simplicity, the adopted approach yields predictions that are robust at a semi-quantitative level and consistent with multiwavelength observations.

Plasma and radio waves from Neptune: Source mechamisms and propagation

NASA Technical Reports Server (NTRS)

Menietti, J. Douglas

1994-01-01

The purpose of this project was to conduct a comprehensive investigation of the radio wave emission observed by the planetary radio astronomy (PRA) instrument on board Voyager 2 as it flew by Neptune. The study has included data analysis, theoretical and numerical calculations, and ray tracing to determine the possible source mechanisms and locations of the radiation, including the narrowband bursty and smooth components of the Neptune radio emission.

Analysis and Modeling of Jovian Radio Emissions Observed by Galileo

NASA Technical Reports Server (NTRS)

Menietti, J. D.

2003-01-01

Our studies of Jovian radio emission have resulted in the publication of five papers in refereed journals, with three additional papers in progress. The topics of these papers include the study of narrow-band kilometric radio emission; the apparent control of radio emission by Callisto; quasi-periodic radio emission; hectometric attenuation lanes and their relationship to Io volcanic activity; and modeling of HOM attenuation lanes using ray tracing. A further study of the control of radio emission by Jovian satellites is currently in progress. Abstracts of each of these papers are contained in the Appendix. A list of the publication titles are also included.

Quantification of scaling exponents and dynamical complexity of microwave refractivity in a tropical climate

NASA Astrophysics Data System (ADS)

Fuwape, Ibiyinka A.; Ogunjo, Samuel T.

2016-12-01

Radio refractivity index is used to quantify the effect of atmospheric parameters in communication systems. Scaling and dynamical complexities of radio refractivity across different climatic zones of Nigeria have been studied. Scaling property of the radio refractivity across Nigeria was estimated from the Hurst Exponent obtained using two different scaling methods namely: The Rescaled Range (R/S) and the detrended fluctuation analysis(DFA). The delay vector variance (DVV), Largest Lyapunov Exponent (λ1) and Correlation Dimension (D2) methods were used to investigate nonlinearity and the results confirm the presence of deterministic nonlinear profile in the radio refractivity time series. The recurrence quantification analysis (RQA) was used to quantify the degree of chaoticity in the radio refractivity across the different climatic zones. RQA was found to be a good measure for identifying unique fingerprint and signature of chaotic time series data. Microwave radio refractivity was found to be persistent and chaotic in all the study locations. The dynamics of radio refractivity increases in complexity and chaoticity from the Coastal region towards the Sahelian climate. The design, development and deployment of robust and reliable microwave communication link in the region will be greatly affected by the chaotic nature of radio refractivity in the region.

VLBI Phase-Referenced Observations on Southern Hemisphere HIPPARCOS Radio Start

NASA Technical Reports Server (NTRS)

Guirado, J. C.; Preston, R. A.; Jones, D. L.; Lestrade, J. F.; Reynolds, J. E.; Jauncey, D. L.; Tzioumis, A. K.; Ferris, R. H.; King, E. A.; Lovell, J. E. J.;

Honduran-U.S. Relations

DTIC Science & Technology

2008-09-25

Analysis, September 11, 2008. 10 “Head of Radio Cadenas Voces Flees the Country in Fear for His Life,” Reporters Without Borders, November 2, 2007. 11...2007, a popular radio commentator at Radio Cadenas Voces (RCV), a station highly critical of the Zelaya government, was shot and killed. In early

SBS 0846+513: a New Gamma-ray Emitting Narrow-line Seyfert 1 Galaxy

NASA Technical Reports Server (NTRS)

D'Ammando, F.; Orienti, M.; Finke, J.; Raiteri, C. M.; Angelakis, E.; Fuhrmann, L.; Giroletti, M.; Hovatta, T.; Max-Moerbeck, W.; Perkins, J. S.;

Army 86 Cost Sensitivity Analysis.

DTIC Science & Technology

1980-05-01

NI VI AN/PVS-4 W/IMG 5 Q15414 RADAR ST AN/MPQ-4A LP 25 Q16110 RADAR SET AN/PPS- SALP 773 Q34308 RADIO SET AN/GRC-160 191 Q45779 RADIO SET AN/VRC-12 654...VI AN/PVS-4 W/ING 5 Q15414 RADAR ST AN/MPQ-4A LP 25 Q16110 RADAR SET AN/PPS- SALP 592 Q34308 RADIO SET AN/GRC-160 555 Q38299 RADIO SET AN/PRC-25 474...PVS-4 W/IMG Q15414 RADAR ST AN/MPQ-4A LP Q16110 RADAR SET AN/PPS- SALP Q34308 RADIO SET AN/GRC-160 Q38299 RADIO SET AN/PRC-25 Q45779 RADIO SET AN/VRC-12

Hubble Sees Stars and a Stripe in Celestial Fireworks

NASA Image and Video Library

2017-12-08

Release date: July 1, 2008 This image is a composite of visible (or optical), radio, and X-ray data of the full shell of the supernova remnant from SN 1006. The radio data show much of the extent that the X-ray image shows. In contrast, only a small linear filament in the northwest corner of the shell is visible in the optical data. The object has an angular size of roughly 30 arcminutes (0.5 degree, or about the size of the full moon), and a physical size of 60 light-years (18 parsecs) based on its distance of nearly 7,000 light-years. The small green box along the bright filament at the top of the image corresponds to the dimensions of the Hubble release image. The optical data was obtained at the University of Michigan's 0.9-meter Curtis Schmidt telescope at the National Science Foundation's Cerro Tololo Inter-American Observatory (CTIO) near La Serena, Chile. H-alpha, continuum-subtracted data were provided by F. Winkler (Middlebury COllege) et al. The X-ray data were acquired from the Chandra X-ray Observatory's AXAF CCD Imaging Spectrometer (ACIS) at 0.5-3keV, and were provided by J. Hughes (Rutgers University) et al. The radio data, supplied by K. Dyer (NRAO, Socorro) et al., were a composite from the National Radio Astronomy Observatory's Very Large Array (NRAO/VLA) in Socorro, New Mexico, along with the Green Bank Telescope (GBT) in Green Bank, West Virginia. Data of the supernova remnant were blended on a visible-light stellar background created using the Digitized Sky Survey's Anglo-Australian Observatory (AAO2) blue and red plates. Photo Credit: NASA, ESA, and Z. Levay (STScI) Science Credit: Radio: NRAO/AUI/NSF GBT+VLA 1.4 GHz mosaic (Dyer, Maddalena and Cornwell, NRAO); X-ray: NASA/CXC/Rutgers/G. Cassam-Chenai and J. Hughes et al.; Optical: F.Winkler/Middlebury College and NOAO/AURA/NSF; and DSS To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Radio Observations of the Type IIP Supernova 20017eaw

NASA Astrophysics Data System (ADS)

Stockdale, Christopher; Perez-Torres, Miguel; Argo, Megan; Ryder, Stuart D.; Panagia, Nino; Van Dyk, Schuyler; Bauer, Franz Erik; Roming, Peter; Marcaide, Jon; Pooley, Dave; Lien, Amy; Sramek, Richard A.

2018-01-01

We present the results of radio observations of the type IIP Supernova 2017eaw using the Very Large Array and the eMERLIN radio telescopes at centimeter wavelengths. SN 2017eaw is a rare type IIP that did not show prompt radio emission after initial explosion. We will present our analysis of the current data and discuss the implications for the pre-explosion evolution of the progenitor star of SN 20017eaw. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities.

Radio detection of extensive air showers

NASA Astrophysics Data System (ADS)

Huege, Tim

2017-12-01

Radio detection of extensive air showers initiated in the Earth's atmosphere has made tremendous progress in the last decade. Today, radio detection is routinely used in several cosmic-ray observatories. The physics of the radio emission in air showers is well-understood, and analysis techniques have been developed to determine the arrival direction, the energy and an estimate for the mass of the primary particle from the radio measurements. The achieved resolutions are competitive with those of more traditional techniques. In this article, I shortly review the most important achievements and discuss the potential for future applications.

Postflight analysis of the EVCS-LM communications link for the Apollo 15 mission

NASA Technical Reports Server (NTRS)

Royston, C. L., Jr.; Eggers, D. S.

1972-01-01

Data from the Apollo 15 mission were used to compare the actual performance of the EVCS to LM communications link with the preflight performance predictions. Based on the results of the analysis, the following conclusions were made: (1) The radio transmission loss data show good correlation with predictions during periods when the radio line of sight was obscured. (2) The technique of predicting shadow losses due to obstacles in the radio line of sight provides a good estimate of the actual shadowing loss. (3) When the transmitter was on an upslope, the radio transmission loss approached the free space loss values as the line of sight to the LM was regained.

Subcutaneous anchor attachment increases retention of radio transmitters on Xantus' and marbled murrelets

USGS Publications Warehouse

Newman, Scott H.; Takekawa, John Y.; Whitworth, Darrell L.; Burkett, Esther E.

1999-01-01

We modified a subcutaneous anchor attachment and achieved transmitter reten- tion times that exceeded those reported previously for other attachments used on alcids. Traditional suture and epoxy attachment methods were used on Xantus' Murrelets in 1995 and 1996, while the modified attachment was used for Xantus' Murrelets in 1996 and 1997 and Marbled Murrelets in 1997. Modifications included use of an inhalant anesthetic, placing the anchor in a more cranial position on the back, application of marine epoxy, and place- ment of a single subcutaneous non-absorbable suture at the caudal end of the radio to hold the radio in place initially. We located 22 of 56 (39%) Xantus' Murrelets radio-marked using suture and epoxy during aerial surveys in 1995 and 1996. Of birds radio-marked using the subcutaneous anchor attachment, we located 92 of 113 (81%) Xantus' Murrelets marked in 1996 and 1997 and all 28 (100%) Marbled Murrelets marked in 1997 during aerial surveys. The maximum confirmed duration for the subcutaneous anchor transmitter attachment was 51 d for Xantus' Murrelets and 78 d for Marbled Murrelets versus 41 d for the suture and epoxy attachment used on Xantus' Murrelets. Recapture rates of radio-marked Xantus' Mur- relets were similar to recapture rates of unmarked Xantus' Murrelets. Our post-release ob- servations indicated negligible short-term physical effects from the attachment procedure, while telemetry data and examination of recaptured murrelets indicated no evidence of infection or other long-term physical effects. Breeding behavior of some murrelets was not disrupted; however, further evaluation of potential effects of this attachment technique on breeding and behavior is needed.

Radar investigation of barium releases over Arecibo Observatory, Puerto Rico

NASA Technical Reports Server (NTRS)

Djuth, Frank T.

1995-01-01

The NASA Combined Release and Radiation Effects Satellite (CRRES) El Coqui rocket campaign was successfully carried out in Puerto Rico during the period 18 May through 12 July 1992. This report describes five chemical release experiments in the upper ionosphere supported by Geospace Research, Inc. during the El Coqui campaign. Additional spin-off science is also discussed. The El Coqui releases are designated AA-1 (rocket 36-082), AA-2 (rocket 36-081), AA-3b (rocket 36-064), AA-4 (rocket 36-065), and AA-7 (rocket 36-083). Particular attention is paid to releases AA-2 and AA-4. These two experiments involved the illumination of ionospheric release regions with powerful high-frequency (HF) radio waves transmitted from the Arecibo HF facility. In the AA-2 experiment, microinstabilities excited by the HF wave in a Ba(+) plasma were examined. This release yielded a smooth plasma cloud that helped clarify several fundamental issues regarding the physics of wave plasma instabilities. During AA-2 extremely strong HF-induced Langmuir turbulence was detected with the Arecibo 430 MHz radar. CF3Br was released in the AA-4 study to create an ionospheric hole that focused the HF beam. This experiment successfully explored wave-plasma coupling in an O(+) ionosphere under conditions of very high HF electric field strengths.

Galactic synchrotron radiation from radio to microwaves, and its relation to cosmic-ray propagation models: past, present and future

NASA Astrophysics Data System (ADS)

Orlando, Elena

2016-04-01

Galactic synchrotron radiation observed from radio to microwaves is produced by cosmic-ray (CR) electrons propagating in magnetic fields (B-fields). The low-frequency foreground component separated maps by WMAP and Planck depend on the assumed synchrotron spectrum. The synchrotron spectrum varies for different line of sights as a result of changes on the CR spectrum due to propagation effects and source distributions. Our present knowledge of the CR spectrum at different locations in the Galaxy is not sufficient to distinguish various possibilities in the modeling. As a consequence uncertainties on synchrotron emission models complicate the foreground component separation analysis with Planck and future microwave telescopes. Hence, any advancement in synchrotron modeling is important for separating the different foreground components.The first step towards a more comprehensive understanding of degeneracy and correlation among the synchrotron model parameters is outlined in our Strong et al. 2011 and Orlando et al. 2013 papers. In the latter the conclusion was that CR spectrum, propagation models, B-fields, and foreground component separation analysis need to be studied simultaneously in order to properly obtain and interpret the synchrotron foreground. Indeed for the officially released Planck maps, we use only the best spectral model from our above paper for the component separation analysis.Here we present a collections of our latest results on synchrotron, CRs and B-fields in the context of CR propagation, showing also our recent work on B-fields within the Planck Collaboration. We underline also the importance of using the constraints on CRs that we obtain from gamma ray observations. Methods and perspectives for further studies on the synchrotron foreground will be addressed.

rfpipe: Radio interferometric transient search pipeline

NASA Astrophysics Data System (ADS)

Law, Casey J.

2017-10-01

rfpipe supports Python-based analysis of radio interferometric data (especially from the Very Large Array) and searches for fast radio transients. This extends on the rtpipe library (ascl:1706.002) with new approaches to parallelization, acceleration, and more portable data products. rfpipe can run in standalone mode or be in a cluster environment.

Fermi Large Area Telescope Observations Of Misaligned Active Galactic Nuclei

DOE PAGES

Abdo, A. A.

2010-08-13

Analysis is presented for 15 months of data taken with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope for 11 non-blazar active galactic nuclei (AGNs), including seven FRI radio galaxies and four FRII radio sources consisting of two FRII radio galaxies and two steep spectrum radio quasars. The broad line FRI radio galaxy 3C 120 is reported here as a γ-ray source for the first time. The analysis is based on directional associations of LAT sources with radio sources in the 3CR, 3CRR, and MS4 (collectively referred to as 3C-MS) catalogs. Seven of the eleven LAT sourcesmore » associated with 3C-MS radio sources have spectral indices larger than 2.3 and, except for the FRI radio galaxy NGC 1275 that shows possible spectral curvature, are well described by a power law. No evidence for time variability is found for any sources other than NGC 1275. The γ-ray luminosities of FRI radio galaxies are significantly smaller than those of the BL Lac objects detected by the LAT, whereas the γ-ray luminosities of the FRII sources are quite similar to those of FSRQs, which could reflect different beaming factors for the γ-ray emission. A core dominance (CD) study of the 3CRR sample indicates that sources closer to the jet axis are preferentially detected with the Fermi LAT, insofar as the γ-ray-detected misaligned AGNs have larger CD at a given average radio flux. The results are discussed in view of the AGN unification scenario.« less

Fermi Large Area Telescope Observations of Misaligned Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Cannon, A.; Caraveo, P. A.; Carrigan, S.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Celotti, A.; Charles, E.; Chekhtman, A.; Chen, A. W.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Colafrancesco, S.; Conrad, J.; Davis, D. S.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grandi, P.; Grenier, I. A.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Kamae, T.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Latronico, L.; Lee, S.-H.; Lemoine-Goumard, M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Malaguti, G.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Michelson, P. F.; Migliori, G.; Mitthumsiri, W.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nestoras, I.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Parent, D.; Pelassa, V.; Pepe, M.; Persic, M.; Pesce-Rollins, M.; Piron, F.; Porter, T. A.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reyes, L. C.; Roth, M.; Sadrozinski, H. F.-W.; Sanchez, D.; Sander, A.; Scargle, J. D.; Sgrò, C.; Siskind, E. J.; Smith, P. D.; Spandre, G.; Spinelli, P.; Stawarz, Ł.; Stecker, F. W.; Strickman, M. S.; Suson, D. J.; Takahashi, H.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Torresi, E.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vilchez, N.; Villata, M.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Yang, Z.; Ylinen, T.; Ziegler, M.

2010-09-01

Analysis is presented for 15 months of data taken with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope for 11 non-blazar active galactic nuclei (AGNs), including seven FRI radio galaxies and four FRII radio sources consisting of two FRII radio galaxies and two steep spectrum radio quasars. The broad line FRI radio galaxy 3C 120 is reported here as a γ-ray source for the first time. The analysis is based on directional associations of LAT sources with radio sources in the 3CR, 3CRR, and MS4 (collectively referred to as 3C-MS) catalogs. Seven of the eleven LAT sources associated with 3C-MS radio sources have spectral indices larger than 2.3 and, except for the FRI radio galaxy NGC 1275 that shows possible spectral curvature, are well described by a power law. No evidence for time variability is found for any sources other than NGC 1275. The γ-ray luminosities of FRI radio galaxies are significantly smaller than those of the BL Lac objects detected by the LAT, whereas the γ-ray luminosities of the FRII sources are quite similar to those of FSRQs, which could reflect different beaming factors for the γ-ray emission. A core dominance (CD) study of the 3CRR sample indicates that sources closer to the jet axis are preferentially detected with the Fermi LAT, insofar as the γ-ray-detected misaligned AGNs have larger CD at a given average radio flux. The results are discussed in view of the AGN unification scenario.

Deuterium trapping in the carbon-silicon co-deposition layers prepared by RF sputtering in D2 atmosphere

NASA Astrophysics Data System (ADS)

Zhang, Hongliang; Zhang, Weiyuan; Su, Ranran; Tu, Hanjun; Shi, Liqun; Hu, Jiansheng

2018-04-01

Deuterated carbon-silicon layers co-deposited on graphite and silicon substrates by radio frequency magnetron sputtering in pure D2 plasma were produced to study deuterium trapping and characteristics of the C-Si layers. The C-Si co-deposited layers were examined by ion beam analysis (IBA), Raman spectroscopy (RS), infrared absorption (IR) spectroscopy, thermal desorption spectroscopy (TDS) and scanning electron microscopy (SEM). It was found that the growth rate of the C-Si co-deposition layer decreased with increasing temperature from 350 K to 800 K, the D concentration and C/Si ratios increased differently on graphite and silicon substrates. TDS shows that D desorption is mainly as D2, HD, HDO, CD4, and C2D4 and release peaks occurred at temperatures of less than 900 K. RS and IR analysis reveal that the structure of the C-Si layers became more disordered with increasing temperatures. Rounded areas of peeling with 1-2 μm diameters were observed on the surface.

The First Data from Gaia

NASA Astrophysics Data System (ADS)

Fabricius, C.; Torra, J.

2018-01-01

The Gaia astrometric satellite is in its science operational phase since July 2014. At an average rate of 50 million observations per day, Gaia scans the full sky once every six months. The first data release (Gaia DR1), issued in September 2016, contains astrometric and photometric results for more than 1 billion stars brighter than magnitude 21 based on observations acquired during the first 14 months of operations. For more than two million stars brighter than 11.5 mag, positions, parallaxes, and proper motions have been obtained to HIPPARCOS-type precision through a combination with the earlier HIPPARCOS and Tycho-2 positions. For the remaining stars, positions at epoch J2015.0 have been obtained by essentially neglecting their proper motions and parallaxes. Positions and proper motions are in the ICRF radio/ VLBI frame. We give an overview of the current status of the mission, the astrometric challenges, the Data Processing and Analysis Consortium operations, the validation processes, the contents of Gaia DR1, and the prospects for the coming releases. We emphasise that although Gaia DR1 data are based on provisional and incomplete calibrations of the instrument, the results represent a huge improvement in the available fundamental stellar data, and discuss some of the first results.

Tuning model drug release and soft-tissue bioadhesion of polyester films by plasma post-treatment.

PubMed

Mogal, Vishal T; Yin, Chaw Su; O'Rorke, Richard; Boujday, Souhir; Méthivier, Christophe; Venkatraman, Subbu S; Steele, Terry W J

2014-04-23

Plasma treatments are investigated as a post-production method of tuning drug release and bioadhesion of poly(lactic-co-glycolic acid) (PLGA) thin films. PLGA films were treated under varying conditions by controlling gas flow rate, composition, treatment time, and radio frequency (RF) power. In vitro release of the drug-like molecule fluorescein diacetate (FDAc) from plasma-treated PLGA was tunable by controlling RF power; an increase of 65% cumulative release is reported compared to controls. Bioadhesion was sensitive to RF power and treatment time, assessed using ex vivo shear-stress tests with wetted swine aorta. We report a maximum bioadhesion ∼6-fold that of controls and 5-fold that of DOPA-based mussel adhesives tested to swine skin.1 The novelty of this post-treatment is the activation of a hydrophobic polyester film for bioadhesion, which can be quenched, while simultaneously tuning drug-release kinetics. This exemplifies the promise of plasma post-treatment for in-clinic bioadhesive activation, along with technological advancements, i.e., atmospheric plasma and hand-held "plasma pencils".

Type II Radio Bursts Observed by STEREO/Waves and Wind/Waves instruments

NASA Astrophysics Data System (ADS)

Krupar, V.; Magdalenic, J.; Zhukov, A.; Rodriguez, L.; Mierla, M.; Maksimovic, M.; Cecconi, B.; Santolik, O.

2013-12-01

Type II radio bursts are slow-drift emissions triggered by suprathermal electrons accelerated on shock fronts of propagating CMEs. We present several events at kilometric wavelengths observed by radio instruments onboard the STEREO and Wind spacecraft. The STEREO/Waves and Wind/Waves have goniopolarimetric (GP, also referred to as direction finding) capabilities that allow us to triangulate radio sources when an emission is observed by two or more spacecraft. As the GP inversion has high requirements on the signal-to-noise ratio we only have a few type II radio bursts with sufficient intensity for this analysis. We have compared obtained radio sources with white-light observations of STEREO/COR and STEREO/HI instruments. Our preliminary results indicate that radio sources are located at flanks of propagating CMEs.

Fine scale habitat use by age-1 stocked muskellunge and wild northern pike in an upper St. Lawrence River bay

USGS Publications Warehouse

Farrell, John M.; Kapuscinski, Kevin L.; Underwood, Harold

2014-01-01

Radio telemetry of stocked muskellunge (n = 6) and wild northern pike (n = 6) was used to track late summer and fall movements from a common release point in a known shared nursery bay to test the hypothesis that age-1 northern pike and stocked muskellunge segregate and have different habitat affinities. Water depth, temperature, substrate and aquatic vegetation variables were estimated for each muskellunge (n = 103) and northern pike (n = 131) position and nested ANOVA comparisons by species indicated differences in habitat use. Muskellunge exhibited a greater displacement from the release point and used habitat in shallower water depths (mean = 0.85 m, SE = 0.10) than northern pike (mean = 1.45 m, SE = 0.08). Both principal components analysis (PCA) and principal components ordination (PCO) were used to interpret underlying gradients relative to fish positions in two-dimensional space. Our analysis indicated that a separation of age-1 northern pike and muskellunge occurred 7 d post-release. This first principal component explained 48% of the variation in habitat use. Northern pike locations were associated with deeper habitats that generally had softer silt substrates and dense submersed vegetation. Muskellunge locations post-acclimation showed greater association with shallower habitats containing firmer sandy and clay substrates and emergent vegetation. The observed differences in habitat use suggest that fine-scale ecological separation occurred between these stocked muskellunge and wild northern pike, but small sample sizes and potential for individual variation limit extension of these conclusions. Further research is needed to determine if these patterns exist between larger samples of fishes over a greater range of habitats.

Application of the HARDMAN methodology to the single channel ground-airborne radio system (SINCGARS)

NASA Astrophysics Data System (ADS)

Balcom, J.; Park, J.; Toomer, L.; Feng, T.

1984-12-01

The HARDMAN methodology is designed to assess the human resource requirements early in the weapon system acquisition process. In this case, the methodology was applied to the family of radios known as SINCGARS (Single Channel Ground-Airborne Radio System). At the time of the study, SINCGARS was approaching the Full-Scale Development phase, with 2 contractors in competition. Their proposed systems were compared with a composite baseline comparison (reference) system. The systems' manpower, personnel and training requirements were compared. Based on RAM data, the contractors' MPT figures showed a significant reduction from the figures derived for the baseline comparison system. Differences between the two contractors were relatively small. Impact and some tradeoff analyses were hindered by data access problems. Tactical radios, manpower and personnel requirements analysis, impact and tradeoff analysis, human resource sensitivity, training requirements analysis, human resources in LCSMM, and logistics analyses are discussed.

Radio Signal Augmentation for Improved Training of a Convolutional Neural Network

DTIC Science & Technology

2016-09-01

official government endorsement or approval of commercial products or services referenced in this report. Bluetooth ® is a registered...trademark of Bluetooth SIG, Inc.. Nuand™ and blade RF™ are trademarks of Nurand, LLC. Released by E. R. Buckland, Head IO Support to National... Bluetooth ® computer mouse, and Bluetooth ® search from a mobile cellular phone. Qualitatively, model Moffset dramatically outperformed model Mclean in

Investigating the Department of Defense’s Implementation of Passive Radio Frequency Identification (RFID)

DTIC Science & Technology

2005-12-01

Logistics Support Activity MIT Massachusetts Institution of Technology MRE Meals -Ready-to-Eat MRO Material Release Order MSC Military Sealift... increase once item tagging becomes mandated. Reader, middleware, specialized hardware, and physical infrastructure costs can add up too. Reader’s...that system integration revenues could surpass hardware by 2007 (Asif & Mandviwalla, 2005, p. 26). (4) Training. Training is another challenge

The Effect of Radiation "Memory" in Alkali-Halide Crystals

NASA Astrophysics Data System (ADS)

Korovkin, M. V.; Sal'nikov, V. N.

2017-01-01

The exposure of the alkali-halide crystals to ionizing radiation leads to the destruction of their structure, the emergence of radiation defects, and the formation of the electron and hole color centers. Destruction of the color centers upon heating is accompanied by the crystal bleaching, luminescence, and radio-frequency electromagnetic emission (REME). After complete thermal bleaching of the crystal, radiation defects are not completely annealed, as the electrons and holes released from the color centers by heating leave charged and locally uncompensated defects. Clusters of these "pre centers" lead to electric microheterogeneity of the crystal, the formation of a quasi-electret state, and the emergence of micro-discharges accompanied by radio emission. The generation of REME associated with residual defectiveness, is a manifestation of the effect of radiation "memory" in dielectrics.

Post-release survival of surf scoters following an oil spill: an experimental approach to evaluating rehabilitation success.

PubMed

De la Cruz, Susan E W; Takekawa, John Y; Spragens, Kyle A; Yee, Julie; Golightly, Richard T; Massey, Greg; Henkel, Laird A; Scott Larsen, R; Ziccardi, Michael

2013-02-15

Birds are often the most numerous vertebrates damaged and rehabilitated in marine oil spills; however, the efficacy of avian rehabilitation is frequently debated and rarely examined experimentally. We compared survival of three radio-marked treatment groups, oiled, rehabilitated (ORHB), un-oiled, rehabilitated (RHB), and un-oiled, non-rehabilitated (CON), in an experimental approach to examine post-release survival of surf scoters (Melanitta perspicillata) following the 2007 M/V Cosco Busan spill in San Francisco Bay. Live encounter-dead recovery modeling indicated that survival differed among treatment groups and over time since release. The survival estimate (±SE) for ORHB was 0.143±0.107 compared to CON (0.498±0.168) and RHB groups (0.772±0.229), suggesting scoters tolerated the rehabilitation process itself well, but oiling resulted in markedly lower survival. Future efforts to understand the physiological effects of oil type and severity on scoters are needed to improve post-release survival of this species. Published by Elsevier Ltd.

Post-release survival of surf scoters following an oil spill: an experimental approach to evaluating rehabilitation success

USGS Publications Warehouse

De La Cruz, Susan E. W.; Takekawa, John Y.; Spragens, Kyle A.; Yee, Julie; Golightly, Richard T.; Massey, Greg; Henkel, Laird A.; Larsen, Scott; Ziccardi, Michael

2013-01-01

Birds are often the most numerous vertebrates damaged and rehabilitated in marine oil spills; however, the efficacy of avian rehabilitation is frequently debated and rarely examined experimentally. We compared survival of three radio-marked treatment groups, oiled, rehabilitated (ORHB), un-oiled, rehabilitated (RHB), and un-oiled, non-rehabilitated (CON), in an experimental approach to examine post-release survival of surf scoters (Melanitta perspicillata) following the 2007 M/V Cosco Busan spill in San Francisco Bay. Live encounter-dead recovery modeling indicated that survival differed among treatment groups and over time since release. The survival estimate (±SE) for ORHB was 0.143 ± 0.107 compared to CON (0.498 ± 0.168) and RHB groups (0.772 ± 0.229), suggesting scoters tolerated the rehabilitation process itself well, but oiling resulted in markedly lower survival. Future efforts to understand the physiological effects of oil type and severity on scoters are needed to improve post-release survival of this species.

CoNNeCT Antenna Positioning System Dynamic Simulator Modal Model Correlation

NASA Technical Reports Server (NTRS)

Jones, Tevor M.; McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Suarez, Vicente

2012-01-01

The National Aeronautics and Space Administration (NASA) developed an on-orbit, adaptable, Software Defined Radios (SDR)/Space Telecommunications Radio System (STRS)-based testbed facility to conduct a suite of experiments to advance technologies, reduce risk, and enable future mission capabilities on the International Space Station (ISS). The Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) Project will provide NASA, industry, other Government agencies, and academic partners the opportunity to develop and field communications, navigation, and networking technologies in both the laboratory and space environment based on reconfigurable, software-defined radio platforms and the STRS Architecture. The CoNNeCT Payload Operations Nomenclature is "SCAN Testbed," and this nomenclature will be used in all ISS integration, safety, verification, and operations documentation. The SCAN Testbed (payload) is a Flight Releasable Attachment Mechanism (FRAM) based payload that will launch aboard the Japanese H-II Transfer Vehicle (HTV) Multipurpose Exposed Pallet (EP-MP) to the International Space Station (ISS), and will be transferred to the Express Logistics Carrier 3 (ELC3) via Extravehicular Robotics (EVR). The SCAN Testbed will operate on-orbit for a minimum of two years.

CoNNeCT Antenna Positioning System Dynamic Simulator Modal Model Correlation

NASA Technical Reports Server (NTRS)

Jones, Trevor M.; McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Suarez, Vicente J.

2012-01-01

The National Aeronautics and Space Administration (NASA) developed an on-orbit, adaptable, Software Defined Radios (SDR)/Space Telecommunications Radio System (STRS)-based testbed facility to conduct a suite of experiments to advance technologies, reduce risk, and enable future mission capabilities on the International Space Station (ISS). The Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) Project will provide NASA, industry, other Government agencies, and academic partners the opportunity to develop and field communications, navigation, and networking technologies in both the laboratory and space environment based on reconfigurable, software-defined radio platforms and the STRS Architecture. The CoNNeCT Payload Operations Nomenclature is SCAN Testbed, and this nomenclature will be used in all ISS integration, safety, verification, and operations documentation. The SCAN Testbed (payload) is a Flight Releasable Attachment Mechanism (FRAM) based payload that will launch aboard the Japanese H-II Transfer Vehicle (HTV) Multipurpose Exposed Pallet (EP-MP) to the International Space Station (ISS), and will be transferred to the Express Logistics Carrier 3 (ELC3) via Extravehicular Robotics (EVR). The SCAN Testbed will operate on-orbit for a minimum of two years.

Magnetic field activated lipid-polymer hybrid nanoparticles for stimuli-responsive drug release.

PubMed

Kong, Seong Deok; Sartor, Marta; Hu, Che-Ming Jack; Zhang, Weizhou; Zhang, Liangfang; Jin, Sungho

2013-03-01

Stimuli-responsive nanoparticles (SRNPs) offer the potential of enhancing the therapeutic efficacy and minimizing the side-effects of chemotherapeutics by controllably releasing the encapsulated drug at the target site. Currently controlled drug release through external activation remains a major challenge during the delivery of therapeutic agents. Here we report a lipid-polymer hybrid nanoparticle system containing magnetic beads for stimuli-responsive drug release using a remote radio frequency (RF) magnetic field. These hybrid nanoparticles show long-term stability in terms of particle size and polydispersity index in phosphate-buffered saline (PBS). Controllable loading of camptothecin (CPT) and Fe(3)O(4) in the hybrid nanoparticles was demonstrated. RF-controlled drug release from these nanoparticles was observed. In addition, cellular uptake of the SRNPs into MT2 mouse breast cancer cells was examined. Using CPT as a model anticancer drug the nanoparticles showed a significant reduction in MT2 mouse breast cancer cell growth in vitro in the presence of a remote RF field. The ease of preparation, stability, and controllable drug release are the strengths of the platform and provide the opportunity to improve cancer chemotherapy. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Survival of captive-reared Puerto Rican Parrots released in the Caribbean National Forest

USGS Publications Warehouse

White, T.H.; Collazo, J.A.; Vilella, F.J.

2005-01-01

We report first-year survival for 34 captive-reared Puerto Rican Parrots (Amazona vittata) released in the Caribbean National Forest, Puerto Rico between 2000 and 2002. The purpose of the releases were to increase population size and the potential number of breeding individuals of the sole extant wild population, and to refine release protocols for eventual reintroduction of a second wild population elsewhere on the island. After extensive prerelease training, we released 10 parrots in 2000, 16 parrots in 2001, and eight parrots in 2002 ranging in age from 1-4 years old. All birds were equipped with radio-transmitters to monitor survival. The overall first-year survival estimate for the 34 parrots was 41% (CI = 22%-61%). Only one parrot died within the first week postrelease, with most (94%) surviving for at least eight weeks after release. Most (54%) documented mortalities were due to raptor predation, which claimed 21% of all released parrots. A captive-reared bird (male, age one), released in 2001, paired with a wild female and fledged two young in 2004. We also calculated survival based on 0% and 50% of observed predation losses and found hypothetical survival rates of 72% and 54%, respectively. Rigorous prerelease training and acclimation was believed to have improved initial postrelease parrot survival, and releasing mixed age-class groups suggests the potential for shortening the time to recruitment. ?? The Cooper Ornithological Society 2005.

Jamaican Call-In Radio: A Uses and Gratification Analysis.

ERIC Educational Resources Information Center

Surlin, Stuart H.

Noting that radio call-in programs seem to contain the elements for active audience involvement and participation, a study was conducted to examine the hypothesis that information gain and surveillance are the primary gratifications sought through call-in radio programs, especially in a culture that has a strong oral tradition and relatively few…

BLAZAR SPECTRAL PROPERTIES AT 74 MHz

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; Funk, S.; Giroletti, M.

2013-10-01

Blazars are the most extreme class of active galactic nuclei. Despite a previous investigation at 102 MHz for a small sample of BL Lac objects and our recent analysis of blazars detected in the Westerbork Northern Sky Survey, a systematic study of the blazar spectral properties at frequencies below 100 MHz has been never carried out. In this paper, we present the first analysis of the radio spectral behavior of blazars based on the recent Very Large Array Low-frequency Sky Survey (VLSS) at 74 MHz. We search for blazar counterparts in the VLSS catalog, confirming that they are detected atmore » 74 MHz. We then show that blazars present radio-flat spectra (i.e., radio spectral indices of ∼0.5) when evaluated, which also about an order of magnitude in frequency lower than previous analyses. Finally, we discuss the implications of our findings in the context of the blazars-radio galaxies connection since the low-frequency radio data provide a new diagnostic tool to verify the expectations of the unification scenario for radio-loud active galaxies.« less

SPECTRAL ANALYSIS IN ORBITAL/SUPERORBITAL PHASE SPACE AND HINTS OF SUPERORBITAL VARIABILITY IN THE HARD X-RAYS OF LS I +61°303

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jian; Torres, Diego F.; Zhang, Shu

2014-04-10

We present an INTEGRAL spectral analysis in the orbital/superorbital phase space of LS I +61°303. A hard X-ray spectrum with no cutoff is observed at all orbital/superorbital phases. The hard X-ray index is found to be uncorrelated with the radio index (non-simultaneously) measured at the same orbital and superorbital phases. In particular, the absence of an X-ray spectrum softening during periods of negative radio index does not favor a simple interpretation of the radio index variations in terms of a microquasar's changes of state. We uncover hints of superorbital variability in the hard X-ray flux, in phase with the superorbitalmore » modulation in soft X-rays. An orbital phase drift of the radio peak flux and index along the superorbital period is observed in the radio data. We explore its influence on a previously reported double-peak structure of a radio orbital light curve, and present it as a plausible explanation.« less

Air shower measurements with the LOPES radio antenna array

NASA Astrophysics Data System (ADS)

Lopes Collaboration; Haungs, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

2009-06-01

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from extensive air showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte-Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPESSTAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2003-11-25

A method of performing a magnetic resonance analysis of a biological object that includes placing the biological object in a main magnetic field and in a radio frequency field, the main magnetic field having a static field direction; rotating the biological object at a rotational frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. According to another embodiment, the radio frequency is pulsed to provide a sequence capable of producing a spectrum that is substantially free of spinning sideband peaks.

THE VLA-COSMOS PERSPECTIVE ON THE INFRARED-RADIO RELATION. I. NEW CONSTRAINTS ON SELECTION BIASES AND THE NON-EVOLUTION OF THE INFRARED/RADIO PROPERTIES OF STAR-FORMING AND ACTIVE GALACTIC NUCLEUS GALAXIES AT INTERMEDIATE AND HIGH REDSHIFT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sargent, M. T.; Schinnerer, E.; MartInez-Sansigre, A.

2010-02-01

VLA 1.4 GHz ({sigma}{approx} 0.012 mJy) and MIPS 24 and 70 {mu}m ({sigma}{approx} 0.02 and 1.7 mJy, respectively) observations covering the 2 deg{sup 2} COSMOS field are combined with an extensive multiwavelength data set to study the evolution of the infrared (IR)-radio relation at intermediate and high redshift. With {approx}4500 sources-of which {approx}30% have spectroscopic redshifts-the current sample is significantly larger than previous ones used for the same purpose. Both monochromatic IR/radio flux ratios (q {sub 24} and q {sub 70}), as well as the ratio of the total IR and the 1.4 GHz luminosity (q {sub TIR}), are usedmore » as indicators for the IR/radio properties of star-forming galaxies and active galactic nuclei (AGNs). Using a sample jointly selected at IR and radio wavelengths in order to reduce selection biases, we provide firm support for previous findings that the IR-radio relation remains unchanged out to at least z{approx} 1.4. Moreover, based on data from {approx}150 objects we also find that the local relation likely still holds at zin [2.5, 5]. At redshift z< 1.4, we observe that radio-quiet AGNs populate the locus of the IR-radio relation in similar numbers as star-forming sources. In our analysis, we employ the methods of survival analysis in order to ensure a statistically sound treatment of flux limits arising from non-detections. We determine the observed shift in average IR/radio properties of IR- and radio-selected populations and show that it can reconcile apparently discrepant measurements presented in the literature. Finally, we also investigate variations of the IR/radio ratio with IR and radio luminosity and find that it hardly varies with IR luminosity but is a decreasing function of radio luminosity.« less

Using the media.

PubMed

1994-01-01

To use the mass media (newspaper, radio, and TV) to reach a large audience with information about AIDS, it is important to choose the media outlets carefully, since they use information that satisfies their audience in content and style. For example, radio, TV, or videos are best to reach illiterate groups. Ways to approach each sector of the written and electronic media include press releases, news conferences, information kits, and personal contacts. Letters to the editor and offers of submitting articles for publication are additional ways to approach newspapers. Audio- or videocassettes with interviews or images conveying HIV/AIDS prevention messages can be submitted to TV and radio stations. It is important to present the information attractively to gain the journalists' attention. News releases should include sources of information and a contact name. It is important to inform the mass media of successes revolving around AIDS prevention, emphasizing local successes. One should identify what media slots have the most influence. For example, a medical officer in Chiang Mai, Thailand, notes that popular disc jockeys have more influence than do government information broadcasts. It is best to promote facts that probably will increase support for AIDS prevention campaigns. If possible, groups should seek free space or air time for AIDS prevention messages. AIDS prevention messages should not use fear because it does not promote safer sexual behavior. Instead, they should link condom use with a sense of independence, responsibility, and being fashionable. Leaflets, posters, videotapes, slides, displays, slogans, audiocassettes, T-shirts, stickers, and other activities or products reinforce the effectiveness of media campaigns. Interviews with or feature articles and programs about people infected or affected by HIV/AIDS chip away at the belief that "AIDS could never happen to me."

An overview and guide: planning instructional radio.

PubMed

Imhoof, M

1984-03-01

Successful instructional radio projects require both comprehensive and complex planning. The instructional radio planning team needs to have knowledge and capabilities in several technical, social, and educational areas. Among other skills, the team must understand radio, curriculum design, the subject matter being taught, research and evaluation, and the environment in which the project operates. Once a basic approach to educational planning has been selected and broad educational goals set, radio may be selected as a cost effective means of achieving some of the goals. Assuming radio is a wise choice, there are still several factors which must be analyzed by a team member who is a radio specialist. The most obvious consideration is the inventory and evaluation of the facilities: studios; broadcast, recording, and transmission equipment; classroom radios; and so on. Capabilities of broadcast personnel are another consideration. Initial radio lessons need to teach the learners how to listen to the radio if they have no previous experience with institutional radio broadcasts. A captive, inschool audience ready to listen to radio instructions requires a different use of the medium than a noncaptive audience. With the noncaptive audience, the educational broadcaster must compete with entertaining choices from other media and popular activities and pastimes of the community. The most complex knowledge and analysis required in planning instructional radio concerns the relationship of the content to the medium. Environmental factors are important in planning educational programs. The physical environment may present several constraints on the learning experience and the use of radio. The most obvious is the effect of climate and terrain on the quality of radio reception. The physical environment is easily studied through experience in the target area, but this knowledge plays a significant role in designing effective learning materials for specific learners. Social activities utilized in broadcasts which are contrary to the learners' experience will at best seem strange and at worst be incomprehensible. Curriculum development in an instructional radio project adds more complexity to the planner's task. The most important information needed is whether a new curriculum is to be developed or whether the existing curriculum is to be adapted for radio. Another major analysis task is relating the curriculum to the medium. The project planning team needs to understand the research aims and evaluation methods in instructional radio projects. Sometimes an outside evaluation specialist or team is employed, but in many projects the planning team is responsible for implementing the research design, carrying out the development activities, gathering data, and evaluating the project. Subject matter testing is another technical area of expertise needed by the project team.

Carriers for the Tunable Release of Therapeutics: Etymological Classification and Examples

PubMed Central

Uskoković, Vuk; Ghosh, Shreya

2016-01-01

Introduction Physiological processes at the molecular level take place at precise spatiotemporal scales, which vary from tissue to tissue and from one patient to another, implying the need for the carriers that enable tunable release of therapeutics. Areas Covered Classification of all drug release to intrinsic and extrinsic is proposed, followed by the etymological clarification of the term “tunable” and its distinction from the term “tailorable”. Tunability is defined as analogous to tuning a guitar string or a radio receiver to the right frequency using a single knob. It implies changing a structural parameter along a continuous quantitative scale and correlating it numerically with the release kinetics. Examples of tunable, tailorable and environmentally responsive carriers are given, along with the parameters used to achieve these levels of control. Expert Opinion Interdependence of multiple variables defining the carrier microstructure obstructs the attempts to elucidate parameters that allow for the independent tuning of release kinetics. Learning from the tunability of nanostructured materials and superstructured metamaterials can be a fruitful source of inspiration in the quest for the new generation of tunable release carriers. The greater intersection of traditional materials sciences and pharmacokinetic perspectives could foster the development of more sophisticated mechanisms for tunable release. PMID:27322661

Interference coupling analysis based on a hybrid method: application to a radio telescope system

NASA Astrophysics Data System (ADS)

Xu, Qing-Lin; Qiu, Yang; Tian, Jin; Liu, Qi

2018-02-01

Working in a way that passively receives electromagnetic radiation from a celestial body, a radio telescope can be easily disturbed by external radio frequency interference as well as electromagnetic interference generated by electric and electronic components operating at the telescope site. A quantitative analysis of these interferences must be taken into account carefully for further electromagnetic protection of the radio telescope. In this paper, based on electromagnetic topology theory, a hybrid method that combines the Baum-Liu-Tesche (BLT) equation and transfer function is proposed. In this method, the coupling path of the radio telescope is divided into strong coupling and weak coupling sub-paths, and the coupling intensity criterion is proposed by analyzing the conditions in which the BLT equation simplifies to a transfer function. According to the coupling intensity criterion, the topological model of a typical radio telescope system is established. The proposed method is used to solve the interference response of the radio telescope system by analyzing subsystems with different coupling modes separately and then integrating the responses of the subsystems as the response of the entire system. The validity of the proposed method is verified numerically. The results indicate that the proposed method, compared with the direct solving method, reduces the difficulty and improves the efficiency of interference prediction.

Disaster Radio for Communication of Vital Messages and Health-Related Information: Experiences From the Haiyan Typhoon, the Philippines.

PubMed

Hugelius, Karin; Gifford, Mervyn; Örtenwall, Per; Adolfsson, Annsofie

2016-08-01

Crisis communication is seen as an integrated and essential part of disaster management measures. After Typhoon Haiyan (Yolanda) in the Philippines 2013, radio was used to broadcast information to the affected community. The aim of this study was to describe how disaster radio was used to communicate vital messages and health-related information to the public in one affected region after Typhoon Haiyan. Mixed-methods analysis using qualitative content analysis and descriptive statistics was used to analyze 2587 logged radio log files. Radio was used to give general information and to demonstrate the capability of officials to manage the situation, to encourage, to promote recovery and foster a sense of hope, and to give practical advice and encourage self-activity. The content and focus of the messages changed over time. Encouraging messages were the most frequently broadcast messages. Health-related messages were a minor part of all information broadcast and gaps in the broadcast over time were found. Disaster radio can serve as a transmitter of vital messages including health-related information and psychological support in disaster areas. The present study indicated the potential for increased use. The perception, impact, and use of disaster radio need to be further evaluated. (Disaster Med Public Health Preparedness. 2016;10:591-597).

Radio Galaxy Zoo: A Search for Hybrid Morphology Radio Galaxies

NASA Astrophysics Data System (ADS)

Kapińska, A. D.; Terentev, I.; Wong, O. I.; Shabala, S. S.; Andernach, H.; Rudnick, L.; Storer, L.; Banfield, J. K.; Willett, K. W.; de Gasperin, F.; Lintott, C. J.; López-Sánchez, Á. R.; Middelberg, E.; Norris, R. P.; Schawinski, K.; Seymour, N.; Simmons, B.

2017-12-01

Hybrid morphology radio sources (HyMoRS) are a rare type of radio galaxy that display different Fanaroff-Riley classes on opposite sides of their nuclei. To enhance the statistical analysis of HyMoRS, we embarked on a large-scale search of these sources within the international citizen science project, Radio Galaxy Zoo (RGZ). Here, we present 25 new candidate hybrid morphology radio galaxies. Our selected candidates are moderate power radio galaxies ({L}{median}=4.7× {10}24 W Hz-1 sr-1) at redshifts 0.14< z< 1.0. Hosts of nine candidates have spectroscopic observations, of which six are classified as quasars, one as high- and two as low-excitation galaxies. Two candidate HyMoRS are giant (> 1 Mpc) radio galaxies, one resides at the center of a galaxy cluster, and one is hosted by a rare green bean galaxy. Although the origin of the hybrid morphology radio galaxies is still unclear, this type of radio source starts depicting itself as a rather diverse class. We discuss hybrid radio morphology formation in terms of the radio source environment (nurture) and intrinsically occurring phenomena (nature; activity cessation and amplification), showing that these peculiar radio galaxies can be formed by both mechanisms. While high angular resolution follow-up observations are still necessary to confirm our candidates, we demonstrate the efficacy of the RGZ in the pre-selection of these sources from all-sky radio surveys, and report the reliability of citizen scientists in identifying and classifying complex radio sources.

Analysis of satellite measurements of terrestrial radio noise

NASA Technical Reports Server (NTRS)

Bakalyar, G.; Caruso, J. A.; Vargas-Vila, R.; Ziemba, E.

1974-01-01

Worldwide distributions of terrestrial radio noise as monitored by Radio Astronomy Explorer 1 (RAE 1) generated and compared with CCIR predictions. These contour maps show the global morphology of radio noise at 6.55 and 9.18 MHz for fall, winter, spring and summer during the local time blocks of 00-08 LT and 16-24 LT. These computer produced maps show general agreement with CCIR predictions over large land masses. The RAE and CCIR maps diverge at high latitudes over Asia and frequently over ocean regions. Higher noise levels observed by RAE at high latitudes are attributed to magnetospheric emission while higher noise levels observed by RAE over Asia are attributable to high power transmitters. Analysis of RAE noise observations in conjunction with various geophysical phenomena showed no obvious correlation.

Radar investigation of barium releases over Arecibo Observatory, Puerto Rico. Final report, 12 August 1991-30 June 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Djuth, F.T.

1995-07-01

The NASA Combined Release and Radiation Effects Satellite (CRRES) El Coqui rocket campaign was successfully carried out in Puerto Rico during the period 18 May through 12 July 1992. This report describes five chemical release experiments in the upper ionosphere supported by Geospace Research, Inc. during the El Coqui campaign. Additional spin-off science is also discussed. The El Coqui releases are designated AA-1 (rocket 36-082), AA-2 (rocket 36-081), AA-3b (rocket 36-064), AA-4 (rocket 36-065), and AA-7 (rocket 36-083). Particular attention is paid to releases AA-2 and AA-4. These two experiments involved the illumination of ionospheric release regions with powerful high-frequencymore » (HF) radio waves transmitted from the Arecibo HF facility. In the AA-2 experiment, microinstabilities excited by the HF wave in a Ba(+) plasma were examined. This release yielded a smooth plasma cloud that helped clarify several fundamental issues regarding the physics of wave plasma instabilities. During AA-2 extremely strong HF-induced Langmuir turbulence was detected with the Arecibo 430 MHz radar. CF3Br was released in the AA-4 study to create an ionospheric hole that focused the HF beam. This experiment successfully explored wave-plasma coupling in an O(+) ionosphere under conditions of very high HF electric field strengths.« less

Surgical and immediate postrelease mortality of harlequin ducks (Histrionicus histrionicus) implanted with abdominal radio transmitters with percutaneous antennae

USGS Publications Warehouse

Mulcahy, Daniel M.; Esler, Daniel N.

1999-01-01

Radiotelemetry is an essential tool in the study of free-ranging bird populations, and a variety of transmitter-attachment methods have been developed. A promising new method is abdominal implantation of a transmitter with a percutaneous antenna. Researchers using this technique should be concerned about and aware of mortality during surgery and during the immediate postrelease period (the 14-day period following surgery). Of 307 radio-implant surgeries performed between 1995 and 1997 in harlequin ducks (Histrionicus histrionicus), 7 (2.3%) deaths were documented during surgery or anesthetic recovery. Of 295 birds released with implanted radios, 10 (3.4%) died during the immediate postrelease period. Modifications to anesthetic procedures used in the 204 surgeries performed in 1996 and 1997 reduced mortality to 1.5% during surgery and 1.5% during the immediate postrelease period. Anesthetic modifications included intubation of all birds, placement of birds on an elevated platform that allowed the head to rest at a level lower than the body during surgery, placement of a heated water blanket under the birds during surgery, monitoring of body temperature, and use of electrocardiogram and Doppler ultrasound to monitor heart rates and arrhythmias. Low levels of mortality associated with abdominal implantation of radio transmitters may be unavoidable, but mortality can be minimized with adjustments to anesthetic technique.

The influence of the energy emitted by solar flare soft X-ray bursts on the propagation of their associated interplanetary shock waves

NASA Technical Reports Server (NTRS)

Pinter, S.; Dryer, M.

1985-01-01

The relationship between the thermal energy released from 29 solar flares and the propagation features of their associated interplanetary shock waves that were detected at 1 AU is investigated. The 29 interplanetary shock waves were identified unambiguously and their tracking from each solar flare was deduced by tracking their associated interplanetary type-II radio emission. The thermal energy released in the solar flares was estimated from the time-intensity profiles of 1-8 A soft X-ray bursts from each flare. A good relationship is found between the flares' thermal energy with the IP shock-waves' transient velocity and arrival time at the earth - that is, the largest flare energy released is associated with the faster shock waves. Finally, a possible scenario of formation of a shock wave during the early phase of the flare and its propagation features is discussed.

Improving Warehouse Inventory Management Through Rfid, Barcoding and Robotics Technologies

DTIC Science & Technology

2014-12-01

as a spider merge. This was designed and installed to speed up the conveyors . In their original design , conveyors traveled throughout the warehouse...lifts LCL lower confidence level xiv MRO material release order NPV net present value PMT positive material transfer POM Program Objective...depots. Active Radio Frequency Identification (aRFID ) Migration A program designed to move the active RFID enterprise from a proprietarily air interface

Blood pressure responses of wild giraffes studied by radio telemetry.

PubMed

Van Citters, R L; Kemper, W S; Franklin, D L

1966-04-15

Blood pressure was telemetered from transducers chronically implanted in the carotid arteries of two adult, wild, male giraffes captured and released near Kiboko, Kenya. Cerebral perfusion pressure ranged from 280/180 mm-Hg while the animal was lying with its head on the ground to 125/75 mm-Hg when it was standing erect; it varied between these levels during spontaneous activity such as walking, grazing, and running.

Experimental evidence of spatial memory and home range affinity in White-tailed Deer (Odocoileus virginianus)

USGS Publications Warehouse

Nelson, Michael E.

2015-01-01

The role of spatial memory in the movement of animals through landscapes remains elusive. To examine spatial memory and home range affinity of White-tailed Deer (Odocoileus virginianus) in northeastern Minnesota during 1995–2007, I translocated 17 adult does with known home ranges to unfamiliar sites and radio-tracked them after their release. Twelve does wearing transmitting radio-collars returned to their home ranges. Death and collar expiration precluded determination of whether the remaining five does would have returned to home ranges. Three of five does wearing global positioning system collars traveled throughout hundreds of square kilometres, circling, backtracking, and returning to release sites, while two others exhibited directional movement for tens of kilometres. Four does that survived to parturition stopped traveling and moved at hourly rates similar to those of control does during the first three weeks of the typical fawn-rearing period, but continued traveling later. Their aberrant extensive travel before and after interruption by parturition suggests that they recognized they were in unfamiliar areas, demonstrating both their capacity and propensity to search for and occupy the familiar space of their individual home ranges. Their successful return to home ranges provided experimental evidence of spatial memory and further elucidated its pervasive role in White-tailed Deer spatial ecology.

Extended Attribute Constructions in German Radio Newscasts: Analysis and Implications

ERIC Educational Resources Information Center

Wipf, Joseph

2004-01-01

Although a number of word-frequency lists exist in German, there is an absence of studies investigating the relative frequency with which various grammatical structures are used. Traditionally, extended modifiers have been most prevalent in written German. Based on an analysis of authentic radio news broadcasts, this article makes the case that…

A Statistical Analysis of the Solar Phenomena Associated with Global EUV Waves

NASA Astrophysics Data System (ADS)

Long, D. M.; Murphy, P.; Graham, G.; Carley, E. P.; Pérez-Suárez, D.

2017-12-01

Solar eruptions are the most spectacular events in our solar system and are associated with many different signatures of energy release including solar flares, coronal mass ejections, global waves, radio emission and accelerated particles. Here, we apply the Coronal Pulse Identification and Tracking Algorithm (CorPITA) to the high-cadence synoptic data provided by the Solar Dynamics Observatory (SDO) to identify and track global waves observed by SDO. 164 of the 362 solar flare events studied (45%) were found to have associated global waves with no waves found for the remaining 198 (55%). A clear linear relationship was found between the median initial velocity and the acceleration of the waves, with faster waves exhibiting a stronger deceleration (consistent with previous results). No clear relationship was found between global waves and type II radio bursts, electrons or protons detected in situ near Earth. While no relationship was found between the wave properties and the associated flare size (with waves produced by flares from B to X-class), more than a quarter of the active regions studied were found to produce more than one wave event. These results suggest that the presence of a global wave in a solar eruption is most likely determined by the structure and connectivity of the erupting active region and the surrounding quiet solar corona rather than by the amount of free energy available within the active region.

A model for the release, dispersion and environmental impact of a postulated reactor accident from a submerged commercial nuclear power plant

NASA Astrophysics Data System (ADS)

Bertch, Timothy Creston

1998-12-01

Nuclear power plants are inherently suitable for submerged applications and could provide power to the shore power grid or support future underwater applications. The technology exists today and the construction of a submerged commercial nuclear power plant may become desirable. A submerged reactor is safer to humans because the infinite supply of water for heat removal, particulate retention in the water column, sedimentation to the ocean floor and inherent shielding of the aquatic environment would significantly mitigate the effects of a reactor accident. A better understanding of reactor operation in this new environment is required to quantify the radioecological impact and to determine the suitability of this concept. The impact of release to the environment from a severe reactor accident is a new aspect of the field of marine radioecology. Current efforts have been centered on radioecological impacts of nuclear waste disposal, nuclear weapons testing fallout and shore nuclear plant discharges. This dissertation examines the environmental impact of a severe reactor accident in a submerged commercial nuclear power plant, modeling a postulated site on the Atlantic continental shelf adjacent to the United States. This effort models the effects of geography, decay, particle transport/dispersion, bioaccumulation and elimination with associated dose commitment. The use of a source term equivalent to the release from Chernobyl allows comparison between the impacts of that accident and the postulated submerged commercial reactor plant accident. All input parameters are evaluated using sensitivity analysis. The effect of the release on marine biota is determined. Study of the pathways to humans from gaseous radionuclides, consumption of contaminated marine biota and direct exposure as contaminated water reaches the shoreline is conducted. The model developed by this effort predicts a significant mitigation of the radioecological impact of the reactor accident release with a submerged commercial nuclear power plant. The two box models predict the most of the radio-ecological impact occurs during the first eight days after release. The most significant risk to humans is from consumption of biota. The reduction in impact to humans from a large radioactive release makes the concept worthy of further study.

Technique to determine location of radio sources from measurements taken on spinning spacecraft

NASA Technical Reports Server (NTRS)

Fainberg, J.

1979-01-01

The procedure developed to extract average source direction and average source size from spin-modulated radio astronomy data measured on the IMP-6 spacecraft is described. Because all measurements are used, rather than just finding maxima or minima in the data, the method is very sensitive, even in the presence of large amounts of noise. The technique is applicable to all experiments with directivity characteristics. It is suitable for onboard processing on satellites to reduce the data flow to Earth. The application to spin-modulated nonpolarized radio astronomy data is made and includes the effects of noise, background, and second source interference. The analysis was tested with computer simulated data and the results agree with analytic predictions. Applications of this method with IMP-6 radio data have led to: (1) determination of source positions of traveling solar radio bursts at large distances from the Sun; (2) mapping of magnetospheric radio emissions by radio triangulation; and (3) detection of low frequency radio emissions from Jupiter and Saturn.

Radio Measurements of Air Showers with LOPES

NASA Astrophysics Data System (ADS)

Schröder, F. G.; Apel, W. D.; Arteaga-Velazquez, J. C.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Fuchs, B.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Zabierowski, J.; Zensus, J. A.

2013-02-01

LOPES is a digital antenna array for the radio measurement of cosmic-ray air showers at energies around 1017 eV. It is triggered by the KASCADE-Grande air-shower array at the Karlsruhe Institute of Technology (KIT), Germany. Because of an absolute amplitude calibration and a sophisticated data analysis, LOPES can test models for the radio emission to an up-to-now unachieved level, thus improving our understanding of the radio emission mechanisms. Recent REAS simulations of the air-shower radio emission come closer to the measurements than any previously tested simulations. We have determined the radio-reconstruction precision of interesting air-shower parameters by comparing LOPES reconstructions to both REAS simulations and KASCADE-Grande measurements, and present our latest results for the angular resolution, the energy and the Xmax reconstruction based on the radio measurement of about 500 air showers. Although the precision of LOPES is limited by the high level of anthropogenic noise at KIT, it opens a promising perspective for next-generation radio arrays in regions with a lower ambient noise level.

Discovery of a Giant Radio Halo in a New Planck Galaxy Cluster PLCKG171.9-40.7

NASA Technical Reports Server (NTRS)

Giacintucci, Simona; Kale, Ruta; Wik, Daniel R.; Venturi, Tiziana; Markevitch, Maxim

2013-01-01

We report the discovery of a giant radio halo in a new, hot, X-ray luminous galaxy cluster recently found by Planck, PLCKG171.9-40.7. The radio halo was found using Giant Metrewave Radio Telescope observations at 235 MHz and 610 MHz, and in the 1.4 GHz data from a NRAO Very Large Array Sky Survey pointing that we have reanalyzed. The diffuse radio emission is coincident with the cluster X-ray emission, has an extent of approx.1 Mpc and a radio power of approx. 5×10(exp 24)W/Hz at 1.4 GHz. Its integrated radio spectrum has a slope of alpha approx. = 1.8 between 235 MHz and 1.4 GHz, steeper than that of a typical giant halo. The analysis of the archival XMMNewton X-ray data shows that the cluster is hot (approx. 10 keV) and disturbed, consistent with X-ray selected clusters hosting radio halos. This is the first giant radio halo discovered in one of the new clusters found by Planck.

Radio emission in the directions of cD and related galaxies in poor clusters. III. VLA observations at 20 cm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, J.O.; White, R.A.; Hough, D.H.

1981-01-01

VLA radio maps and optical identifications of a sample of sources in the directions of 21 Yerkes poor cluster fields are presented. The majority of the cluster radio sources are associated with the dominant D or cD galaxies (approx.70%). Our analysis of dominant galaxies in rich and poor clusters indicates that these giant galaxies are much more often radio emitters (approx.25% of cD's are radio active in the poor clusters), have steeper radio spectra, and have simpler radio morphologies (i.e., double or other linear structure) than other less bright ellipticals. A strong continuum of radio properties in cD galaxies ismore » seen from rich to poor clusters. We speculate that the location of these dominant galaxies at the cluster centers (i.e., at the bottom of a deep, isolated gravitational potential well) is the crucial factor in explaining their multifrequency activity. We briefly discuss galaxy cannibalism and gas infall models as fueling mechanisms for the observed radio and x-ray emission.« less

Radio emission in the directions of cD and related galaxies in poor clusters. III - VLA observations at 20 cm

NASA Technical Reports Server (NTRS)

Burns, J. O.; White, R. A.; Hough, D. H.

1981-01-01

VLA radio maps and optical identifications of a sample of sources in the directions of 21 Yerkes poor cluster fields are presented. The majority of the cluster radio sources are associated with the dominant D or cD galaxies (approximately 70 percent). Our analysis of dominant galaxies in rich and poor clusters indicates that these giant galaxies are much more often radio emitters (approximately 25 percent of cD's are radio active in the poor clusters), have steeper radio spectra, and have simpler radio morphologies (i.e., double or other linear structure) than other less bright ellipticals. A strong continuum of radio properties in cD galaxies is seen from rich to poor clusters. It is speculated that the location of these dominant galaxies at the cluster centers (i.e., at the bottom of a deep, isolated gravitational potential well) is the crucial factor in explaining their multifrequency activity. Galaxy cannibalism and gas infall models as fueling mechanisms for the observed radio and X-ray emission are discussed

A Technical Review of Cellular Radio and Analysis of a Possible Protocol

DTIC Science & Technology

1992-09-01

9 1. The Pioneers ............. ................................... 9 2. Time line of Radio Evolution...cellular telephone. Advances in low-power radio transmission and the speed with which modern computers can aid in frequency management and signal...lecturer at the Royal Institution in London. He subsequently worked his way up to lecturer and devoted ever increasing amounts of time to experiments

Radio Detection of Cosmic Rays-Achievements and Future Potential

NASA Astrophysics Data System (ADS)

Huege, Tim

When modern efforts for radio detection of cosmic rays started about a decade ago, hopes were high but the true potential was unknown. Since then, we have achieved a detailed understanding of the radio emission physics and have consequently succeeded in developing sophisticated detection schemes and analysis approaches. In particular, we have demonstrated that the important air-shower parameters arrival direction, particle energy and depth of shower maximum can be reconstructed reliably from radio measurements, with a precision that is comparable with that of other detection techniques. At the same time, limitations inherent to the radio-emission mechanisms have become apparent. In this article, I shortly review the capabilities of radio detection in the very high-frequency band, and discuss the potential for future application in existing and new experiments for cosmic-ray detection.

An optical imaging study of 0.4 ≤ z ≤ 0.8 quasar host galaxies . II. Analysis and interpretation

NASA Astrophysics Data System (ADS)

Örndahl, E.; Rönnback, J.

2005-11-01

We performed optical imaging of 102 radio-loud and radio-quiet quasars at z=0.4{-}0.8, of which 91 fields were found suitable for host galaxy analysis after the deselection of saturated and otherwise flawed images. The data sets were obtained mainly in the R band, but also in the V and I or Gunn i band, and were presented in Rönnback et al.(1996, MNRAS, 283, 282) and Örndahl et al. (2003, A&A, 404, 883). In this paper we combine the two above-mentioned samples and also separately discuss additional hosts, extracted from data taken by Wold et al. (2000, MNRAS, 316, 267; 2001, MNRAS, 323, 231). The joint sample forms a sizeable fraction of the to-date total number of observed sources at intermediate redshifts and increases the number of resolved radio-quiet hosts at z>0.4 considerably. Equal numbers of radio-loud and radio-quiet objects were observed, resulting in a detection rate of 79% for the radio-loud hosts and 66% for the radio-quiet hosts. Profile fitting could only be carried out for a minority of the sample, but it results in predominantly elliptical morphologies. This is consistent with the mean values of the axial ratios, for which we find b/a⪆0.8 for both radio-quiet and radio-loud hosts, just as in the case of normal elliptical galaxies. The mean absolute magnitudes of the radio-loud and radio-quiet hosts is M_R=-23.5 in both cases. This similarity between the mean magnitudes of the two types of host galaxy is also seen in the other imaged bands. While the radio-loud host absolute R magnitudes are correlated with redshift, only a weak trend of the same sort is seen for the radio-quiet host magnitudes. Note, however, that the sample is not fully resolved and that the detection limit, in combination with the relationship between host and nuclear luminosity, may conspire in creating the illusion of an upturn in magnitude. The average nucleus-to-host galaxy luminosity ratios of the radio-loud and radio-quiet objects do not differ significantly in any band, nor is the difference between the average luminosity ratios of flat spectrum and steep spectrum radio-loud quasars larger than 1.5σ. Thus, no effect of beaming (as expected in the unifying scheme) is seen. The colours of both radio-loud and radio-quiet host galaxies are found to be as blue as present-day late-type spirals and starburst galaxies. These blue colours are most likely due neither to galaxy evolution over the range, which only gives rise to a colour shift of 0.2 mag, nor to scattered nuclear light, since colours determined from annular apertures yield very similar results. Since close companions in projection are not uncommon (and a few sources even exhibit tidal tail-like features and other signs of interaction), ongoing star formation is a reasonable explanation of the blue host colours. As multiple-band imaging primarily was carried out for quasars showing indications of the presence of a host galaxy, the colour analysis results are valid for host galaxies which are large, bright, have low nucleus-to-host luminosity ratios, and/or display large scale disturbances, but cannot however safely be generalised to hold for the quasar host galaxy population at intermediate redshift as a whole.

Radio-science performance analysis software

NASA Astrophysics Data System (ADS)

Morabito, D. D.; Asmar, S. W.

1995-02-01

The Radio Science Systems Group (RSSG) provides various support functions for several flight project radio-science teams. Among these support functions are uplink and sequence planning, real-time operations monitoring and support, data validation, archiving and distribution functions, and data processing and analysis. This article describes the support functions that encompass radio-science data performance analysis. The primary tool used by the RSSG to fulfill this support function is the STBLTY program set. STBLTY is used to reconstruct observable frequencies and calculate model frequencies, frequency residuals, frequency stability in terms of Allan deviation, reconstructed phase, frequency and phase power spectral density, and frequency drift rates. In the case of one-way data, using an ultrastable oscillator (USO) as a frequency reference, the program set computes the spacecraft transmitted frequency and maintains a database containing the in-flight history of the USO measurements. The program set also produces graphical displays. Some examples and discussions on operating the program set on Galileo and Ulysses data will be presented.

Radio-Science Performance Analysis Software

NASA Astrophysics Data System (ADS)

Morabito, D. D.; Asmar, S. W.

1994-10-01

The Radio Science Systems Group (RSSG) provides various support functions for several flight project radio-science teams. Among these support functions are uplink and sequence planning, real-time operations monitoring and support, data validation, archiving and distribution functions, and data processing and analysis. This article describes the support functions that encompass radio science data performance analysis. The primary tool used by the RSSG to fulfill this support function is the STBLTY program set. STBLTY is used to reconstruct observable frequencies and calculate model frequencies, frequency residuals, frequency stability in terms of Allan deviation, reconstructed phase, frequency and phase power spectral density, and frequency drift rates. In the case of one-way data, using an ultrastable oscillator (USO) as a frequency reference, the program set computes the spacecraft transmitted frequency and maintains a database containing the in-flight history of the USO measurements. The program set also produces graphical displays. Some examples and discussion on operating the program set on Galileo and Ulysses data will be presented.

Radio-science performance analysis software

NASA Technical Reports Server (NTRS)

Morabito, D. D.; Asmar, S. W.

1995-01-01

The Radio Science Systems Group (RSSG) provides various support functions for several flight project radio-science teams. Among these support functions are uplink and sequence planning, real-time operations monitoring and support, data validation, archiving and distribution functions, and data processing and analysis. This article describes the support functions that encompass radio-science data performance analysis. The primary tool used by the RSSG to fulfill this support function is the STBLTY program set. STBLTY is used to reconstruct observable frequencies and calculate model frequencies, frequency residuals, frequency stability in terms of Allan deviation, reconstructed phase, frequency and phase power spectral density, and frequency drift rates. In the case of one-way data, using an ultrastable oscillator (USO) as a frequency reference, the program set computes the spacecraft transmitted frequency and maintains a database containing the in-flight history of the USO measurements. The program set also produces graphical displays. Some examples and discussions on operating the program set on Galileo and Ulysses data will be presented.

Temporal frequency of radio emissions for the April 25, 1984 flare

NASA Technical Reports Server (NTRS)

Wells, G. D.; Hausman, B. A.; Kroehl, H. W.

1986-01-01

The National Geophysical Data Center archives data of the solar-terrestrial environment. The USAF Radio Solar Telescope Network (RSTN) data allow performance of time series analysis to determine temporal oscillations as low as three seconds. The X13/3B flare which erupted in region 4474 (S12E43) on the 24 to 25 of April 1984, was selected. The soft X-rays, 1 to 8 A, remained above X-levels for 50 minutes and the radio emissions measured at Learmonth Solar Observatory reached a maximum of 3.15 x 10 to the 5th power SFUs at 410 MHz at 0000UT. A power spectral analysis of the fixed frequency RSTN data from Learmonth shows possible quasi-periodic fluctuations in the range two to ten seconds. Repetition rates or quasi-periodicities, in the case of the power spectral analysis, generally showed the same trends as the average solar radio flux at 245 and 8800 MHz. The quasi-periodicities at 1415 MHz showed no such trends.

Nanoparticle radio-enhancement: principles, progress and application to cancer treatment

NASA Astrophysics Data System (ADS)

Kuncic, Zdenka; Lacombe, Sandrine

2018-01-01

Enhancement of radiation effects by high-atomic number nanoparticles (NPs) has been increasingly studied for its potential to improve radiotherapeutic efficacy. The underlying principle of NP radio-enhancement is the potential to release copious electrons into a nanoscale volume, thereby amplifying radiation-induced biological damage. While the vast majority of studies to date have focused on gold nanoparticles with photon radiation, an increasing number of experimental, theoretical and simulation studies have explored opportunities offered by other NPs (e.g. gadolinium, platinum, iron oxide, hafnium) and other therapeutic radiation sources such as ion beams. It is thus of interest to the research community to consolidate findings from the different studies and summarise progress to date, as well as to identify strategies that offer promising opportunities for clinical translation. This is the purpose of this Topical Review.

Best-Ever Snapshot of a Black Hole's Jets

NASA Image and Video Library

2011-05-20

NASA image release May 20, 2011 To see a really cool video related to this image go here: www.flickr.com/photos/gsfc/5740451675/in/photostream This composite of visible, microwave (orange) and X-ray (blue) data reveals the jets and radio-emitting lobes emanating from Centaurus A's central black hole. Credit: ESO/WFI (visible); MPIfR/ESO/APEX/A.Weiss et al. (microwave); NASA/CXC/CfA/R.Kraft et al. (X-ray) To read more go to: www.nasa.gov/topics/universe/features/radio-particle-jets... NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Introduction to the Special Issue on Digital Signal Processing in Radio Astronomy

NASA Astrophysics Data System (ADS)

Price, D. C.; Kocz, J.; Bailes, M.; Greenhill, L. J.

2016-03-01

Advances in astronomy are intimately linked to advances in digital signal processing (DSP). This special issue is focused upon advances in DSP within radio astronomy. The trend within that community is to use off-the-shelf digital hardware where possible and leverage advances in high performance computing. In particular, graphics processing units (GPUs) and field programmable gate arrays (FPGAs) are being used in place of application-specific circuits (ASICs); high-speed Ethernet and Infiniband are being used for interconnect in place of custom backplanes. Further, to lower hurdles in digital engineering, communities have designed and released general-purpose FPGA-based DSP systems, such as the CASPER ROACH board, ASTRON Uniboard, and CSIRO Redback board. In this introductory paper, we give a brief historical overview, a summary of recent trends, and provide an outlook on future directions.

FPGA Based Wavelet Trigger in Radio Detection of Cosmic Rays

NASA Astrophysics Data System (ADS)

Szadkowski, Zbigniew; Szadkowska, Anna

2014-12-01

Experiments which show coherent radio emission from extensive air showers induced by ultra-high-energy cosmic rays are designed for a detailed study of the development of the electromagnetic part of air showers. Radio detectors can operate with 100 % up time as, e.g., surface detectors based on water-Cherenkov tanks. They are being developed for ground-based experiments (e.g., the Pierre Auger Observatory) as another type of air-shower detector in addition to fluorescence detectors, which operate with only ˜10 % of duty on dark nights. The radio signals from air showers are caused by coherent emission from geomagnetic radiation and charge-excess processes. The self-triggers in radio detectors currently in use often generate a dense stream of data, which is analyzed afterwards. Huge amounts of registered data require significant manpower for off-line analysis. Improvement of trigger efficiency is a relevant factor. The wavelet trigger, which investigates on-line the power of radio signals (˜ V2/ R), is promising; however, it requires some improvements with respect to current designs. In this work, Morlet wavelets with various scaling factors were used for an analysis of real data from the Auger Engineering Radio Array and for optimization of the utilization of the resources in an FPGA. The wavelet analysis showed that the power of events is concentrated mostly in a limited range of the frequency spectrum (consistent with a range imposed by the input analog band-pass filter). However, we found several events with suspicious spectral characteristics, where the signal power is spread over the full band-width sampled by a 200 MHz digitizer with significant contribution of very high and very low frequencies. These events may not originate from cosmic ray showers but could be the result of human contamination. The engine of the wavelet analysis can be implemented in the modern powerful FPGAs and can remove suspicious events on-line to reduce the trigger rate.

NRAO Makes Available VLA Sky Survey Maps

NASA Astrophysics Data System (ADS)

1994-06-01

An original and comprehensive data set potentially full of scientific surprises now is available to astronomers, students and the public through the information superhighway. Radio images of the sky produced by the Very Large Array radio telescope -- one of the premier astronomical instruments in the world -- as part of a massive survey now are stored in an electronic repository avail- able over the Internet computer communications network. "Each of these sensitive new sky maps shows about a thou- sand radio-emitting objects, most of which have never been seen before," said Dr. J. J. Condon, leader of the National Radio As- tronomy Observatory (NRAO) survey team. "We are releasing them as soon as they are completed because they contain more data than we could possibly analyze by ourselves." "By using electronic distribution, we can open this tre- mendous resource of information for computer analysis by all as- tronomers immediately, without waiting for traditional publication," Condon added. The radio images are copyright NRAO/ AUI. Permission is granted for use of the material without charge for scholarly, educational and private non-commercial purposes. "It is entirely conceivable -- even probable -- that valuable discoveries will be made by students or amateur astrono- mers who devote the time to study these maps carefully," said team member Dr. W. D. Cotton. "Making this new information available electronically means that more people can participate in adding to its scientific value." The maps are a product of the NRAO VLA Sky Survey (NVSS), which began its observational phase in September of 1993 and will cover 82 percent of the sky when completed by the end of 1996. The NVSS is expected to produce a catalog of more than two million ra- dio-emitting objects in the sky, and it is the first sky survey sensitive to linearly polarized emission from radio sources beyond our own Milky Way galaxy. "The NVSS is being made as a service to the entire astronomical community," Condon said. The survey will require about 2,500 hours of VLA observing time to complete. The data from the NVSS will become available in several forms, including complete processed maps, lists of the radio-emit- ting objects found, and data from which astronomers may produce maps tailored to their own interests. The data products are being placed in the public electronic repository as soon as NRAO scien- tists have verified their accuracy. Those interested should contact Condon at Internet address jcondon@nrao.edu for more information about accessing the data. The Very Large Array, in west-central New Mexico, is a radio telescope consisting of 27 dish antennas, each 82 feet in diameter, arranged in the shape of a Y. The arms of the Y are 13 miles long, and the 230-ton antennas are routinely moved into dif- ferent positions along the arms to provide a "zoom lens" capability for the telescope. Dedicated in 1980, the VLA is used annually by more than 600 astronomers from around the world. One of the most versatile instruments available to astronomers, it can observe ob- jects ranging from planets, comets and asteroids in our own solar system out to distant radio galaxies and quasars near the edge of the observable universe. In addition to the NVSS, the VLA also is making another, more detailed, survey of a smaller region of the sky. This survey, called FIRST (Faint Images of the Radio Sky at Twenty centimeters), will yield very accurate positions of radio-emitting objects in the same area of the sky to be surveyed in visible light by the Sloan Digital Sky Survey. The FIRST survey is headed by Dr. Robert H. Becker of the University of California at Davis and Lawrence Liv- ermore National Laboratory.

Radio continuum survey of the Coma/A1367 supercluster. I - 610 MHz observations of CGCG galaxies in four groups

NASA Astrophysics Data System (ADS)

Jaffe, W.; Gavazzi, G.; Valentijn, E.

1986-02-01

Radio continuum observations obtained with the Westerbork Radio Synthesis Telescope at 0.6 GHz of four groups of galaxies in the Coma/A1367 supercluster area are presented. Ninety-nine CGCG galaxies were surveyed, yielding the detection of 21 objects. A wide-angle-tail radio galaxy, NGC 4061, is found in the NGC 4065 group. Analysis of this source suggests a relatively low value (neT ≡ 1000 cm-3K) for the intracluster gas pressure in this group.

Voices of disability on the radio.

PubMed

O'Malley, Mary Pat

2008-01-01

While much commentary exists in relation to the portrayal of disabled people in the media, very little research examines the talk itself in any detail. This paper examines the how people with communication disabilities and disabled people are dealt with in the talk of a radio programme about disability. To show how the voices of disabled people, and in particular people with communication difficulties, are dealt with on a radio programme titled For and About People with Disability (http://www.rte.ie). Analysis of 15 episodes of an Irish radio programme for and about people with disability called Outside the Box to identify frames governing the discourse. Three frames are identified: radio programme frame; presenter frame; and interview frame. Communication disability never appears as a topic in the radio programme frame. In the presenter and interview frames the presenter foregrounds medical aspects of experiences, asks questions that only seek factual information, and fails to respond to subjective aspects of disabled people's experiences. Analysis of the interviewees' responses show how they hold the floor and introduce subjective accounts of living with disability. Frame analysis reveals how disability (including communication disability) is dealt with in the talk of a radio programme for and about people with disability. There is an overemphasis on medical aspects of disability and a view of disability as a primarily physical phenomenon is broadcast. In spite of mainly medical/factual questions, interviewees manage to include rich accounts of their experience. People with communication disability are not included, possibly due to issues of intelligibility or lack of awareness. Speech and language therapists have a valuable role to play in terms of 'learning to listen' and 'helping to tell'.

An Analysis of the Television and Radio Service Occupation.

ERIC Educational Resources Information Center

Pomeroy, James W.; And Others

The general purpose of the occupational analysis is to provide workable, basic information dealing with the many and varied duties performed in the television and radio service occupation. The document opens with a brief introduction followed by a job description. The bulk of the document is presented in table form. Eight duties are broken down…

MC2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

NASA Astrophysics Data System (ADS)

Finner, Kyle; Jee, M. James; Golovich, Nathan; Wittman, David; Dawson, William; Gruen, Daniel; Koekemoer, Anton M.; Lemaux, Brian C.; Seitz, Stella

2017-12-01

The second most significant detection of the Planck Sunyaev‑Zel’dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is located ∼ 400 {kpc} NW of the X-ray peak and the other ∼ 2.8 Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. We present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass {M}200{{c}}={1.59}-0.22+0.25× {10}15 {h}70-1 {M}ȯ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass {M}200{{c}}={1.16}-0.13+0.15× {10}14 {h}70-1 {M}ȯ located ∼ 400 {kpc} to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected ∼ 2 Mpc to the SE of the X-ray peak with mass {M}200{{c}}={1.68}-0.20+0.22× {10}14 {h}70-1 {M}ȯ . This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, {M}200{{c}}={1.87}-0.22+0.24× {10}14 {h}70-1 {M}ȯ , is NW of the X-ray peak and beyond the NW radio relic.

Likelihood of Incomplete Kidney Tumor Ablation with Radio Frequency Energy: Degree of Enhancement Matters.

PubMed

Lay, Aaron H; Stewart, Jeremy; Canvasser, Noah E; Cadeddu, Jeffrey A; Gahan, Jeffrey C

2016-07-01

Larger size and clear cell histopathology are associated with worse outcomes for malignant renal tumors treated with radio frequency ablation. We hypothesize that greater tumor enhancement may be a risk factor for radio frequency ablation failure due to increased vascularity. A retrospective review of patients who underwent radio frequency ablation for renal tumors with contrast enhanced imaging available was performed. The change in Hounsfield units (HU) of the tumor from the noncontrast phase to the contrast enhanced arterial phase was calculated. Radio frequency ablation failure rates for biopsy confirmed malignant tumors were compared using the chi-squared test. Multivariate logistic analysis was performed to assess predictive variables for radio frequency ablation failure. Disease-free survival was calculated using Kaplan-Meier analysis. A total of 99 patients with biopsy confirmed malignant renal tumors and contrast enhanced imaging were identified. The incomplete ablation rate was significantly lower for tumors with enhancement less than 60 vs 60 HU or greater (0.0% vs 14.6%, p=0.005). On multivariate logistic regression analysis tumor enhancement 60 HU or greater (OR 1.14, p=0.008) remained a significant predictor of incomplete initial ablation. The 5-year disease-free survival for size less than 3 cm was 100% vs 69.2% for size 3 cm or greater (p <0.01), while 5-year disease-free survival for HU change less than 60 was 100% vs 92.4% for HU change 60 or greater (p=0.24). Biopsy confirmed malignant renal tumors, which exhibit a change in enhancement of 60 HU or greater, experience a higher rate of incomplete initial tumor ablation than tumors with enhancement less than 60 HU. Size 3 cm or greater portends worse 5-year disease-free survival after radio frequency ablation. The degree of enhancement should be considered when counseling patients before radio frequency ablation. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Closed-Loop Analysis of Soft Decisions for Serial Links

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin A.; Steele, Glen F.; Zucha, Joan P.; Schlesinger, Adam M.

2013-01-01

We describe the benefit of using closed-loop measurements for a radio receiver paired with a counterpart transmitter. We show that real-time analysis of the soft decision output of a receiver can provide rich and relevant insight far beyond the traditional hard-decision bit error rate (BER) test statistic. We describe a Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in live-time during the development of software defined radios. This test technique gains importance as modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more protocol overhead through noisier channels, and software-defined radios (SDRs) use error-correction codes that approach Shannon's theoretical limit of performance.

The X-Ray Core of the Low-Luminosity Radio Galaxy 3C346 and ASCA Spectroscopy to Test BL LAC/Radio Galaxy Unification

NASA Technical Reports Server (NTRS)

Worrall, Diana

2000-01-01

Radio galaxies are relatively faint sources for Advanced Spacecraft for Cosmology Astrophysics (ASCA), and so in order to get the best possible results from the observations two things have been necessary, both of which delayed the fast preparation of papers. Firstly, the best possible data screening and background subtraction were necessary to improve the signal-to-noise, and all our several initial analysis trials were discarded in favor of using FTOOLS versions 4.1 and above. Secondly, we found that the ASCA spectra were statistically too poor to discriminate well between non-thermal and thermal models, never mind the mixture of the two which we expected on the basis of our ROSAT spatial separation of components in radio galaxies. This means that in each case we have needed to combine the ASCA spectroscopy with analysis of data from other X-ray or radio observations in order to exploit the ASCA data to the full. Our analysis for 3C 346 has yielded the cleanest final result. This powerful radio galaxy at a redshift of 0.161, lies in a poor cluster, which we have separated well from the dominant X-ray component of unresolved emission using a spatial analysis of archival ROSAT data. We were then able to fix the thermal component in our ASCA spectral analysis, and have found evidence that the unresolved emission varied by 32 +/- 13% over the 18 months between the ROSAT and ASCA observations. The unresolved X-ray emission does not suffer from intrinsic absorption, and we have related it to radio structures on both milliarcsecond scales and the arcsecond scales which Chandra can resolve. The source is a target of a Chandra AO2 proposal which we have recently submitted to follow up on our ASCA (and ROSAT) work. 3C 346's orientation to the line of sight is uncertain. However, the absence of X-ray absorption, and the radio/optical/X-ray colors, when combined with with previous radio evidence that the source is a foreshortened radio galaxy of the FRII class, suggest that the radio jets are seen at an angle to the line of sight of about 30 deg, intermediate between the radio-galaxy and quasar classes. The relatively hard ASCA response has allowed us to place an upper limit of 5.6 x 10(exp 43) ergs/ s on the 2-10 keV luminosity of any central X-ray component absorbed bN, gas which might be obscuring the broad-line emission region. Attached to this report is an almost final draft of a paper which we have prepared for submission to the Astrophysical Journal. Our combined ASCA and ROSAT results for NGC 6251 rule out our previously preferred flat-spectrum model and inverse-Compton interpretation for the source based on ROSAT data alone, but a softer X-ray spectrum and moderate absorption bring all the available data (including our early VLA HI measurements) into consistency, and we are reasonably confident that we understand the processes responsible for the X-ray emission. We have made some more sensitive HI absorption measurements which are currently being analyzed, and our plans are to publish our ASCA analysis in conjunction with the new HI results. The ASCA data for NGC 4261 have been difficult to interpret. A re-analysis of our ROSAT data with a wider range of physical parameters brings the ROSAT and ASCA results into reasonable agreement only if the emission from hot gas dominates more than suggested by our earlier work, which is itself unexpected since the radio core is bright and a large jet-related X-ray component would bring the source into agreement with results for others of its type. However, we have recently received our Chandra A01 data for this source, with the spatial resolution which allows us to separate thermal and non-thermal emission components. Our ASCA results will be re-interpreted once the analysis of our Chandra data is complete. The interpretation of the ASCA data for BL Lac object 3C 371 is ongoing, in conjunction with analysis of archival multifrequency data. Radio galaxies are complex in their X-ray properties, and hindsight has shown that the spatial resolution of ASCA is too poor for a reliable interpretation of the data without drawing on other observations. However, the ASCA spectra have made a useful contribution to the interpretation of these sources, and the groundwork is now there for more sensitive work using Chandra and XMM-Newton.

An Analysis of the Defense Acquisition Strategy for Unmanned Systems

DTIC Science & Technology

2013-11-20

Product Service Code RAA Rapid Acquisition Authority RCS Radar Cross Section REF Rapid Equipping Force RFID Radio Frequency Identification RDT...the radio frequency identification (RFID) chip also provides a useful basis for comparison. WWII served as the proving ground for RFID technology...enabling miniaturized Free Space Optical Communications systems capable of scaling across data rates, distances, and platforms and integrating with radio

Gas kinematics in powerful radio galaxies at z 2: Energy supply from star formation, AGN, and radio jets⋆

NASA Astrophysics Data System (ADS)

Nesvadba, N. P. H.; Drouart, G.; De Breuck, C.; Best, P.; Seymour, N.; Vernet, J.

2017-04-01

We compare the kinetic energy and momentum injection rates from intense star formation, bolometric AGN radiation, and radio jets with the kinetic energy and momentum observed in the warm ionized gas in 24 powerful radio galaxies at z 2. These galaxies are among our best candidates for being massive galaxies near the end of their active formation period, when intense star formation, quasar activity, and powerful radio jets all co-exist. All galaxies have VLT/SINFONI imaging spectroscopy of the rest-frame optical line emission, showing extended emission-line regions with large velocity offsets (up to 1500 km s-1) and line widths (typically 800-1000 km s-1) consistent with very turbulent, often outflowing gas. As part of the HeRGÉ sample, they also have FIR estimates of the star formation and quasar activity obtained with Herschel/PACS and SPIRE, which enables us to measure the relative energy and momentum release from each of the three main sources of feedback in massive, star-forming AGN host galaxies during their most rapid formation phase. We find that star formation falls short by factors 10-1000 of providing the energy and momentum necessary to power the observed gas kinematics. The obscured quasars in the nuclei of these galaxies provide enough energy and momentum in about half of the sample, however, only if both are transferred to the gas relatively efficiently. We compare with theoretical and observational constraints on the efficiency of the energy and momentum transfer from jet and AGN radiation, which favors the radio jets as main drivers of the gas kinematics. Based on observations carried out with the Very Large Telescope of ESO under Program IDs 079.A-0617, 084.A-0324, 085.A-0897, and 090.A-0614.Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

The effectiveness of mass media in changing HIV/AIDS-related behaviour among young people in developing countries.

PubMed

Bertrand, Jane T; Anhang, Rebecca

2006-01-01

To review the strength of the evidence for the effects of three types of mass media interventions (radio only, radio with supporting media, or radio and television with supporting media) on HIV/AIDS-related behaviour among young people in developing countries and to assess whether these interventions reach the threshold of evidence needed to recommend widespread implementation. We conducted a systematic review of studies that evaluated mass media interventions and were published or released between 1990 and 2004. Studies were included if they evaluated a mass media campaign that had the main objective of providing information about HIV/AIDS or sexual health. To be eligible for inclusion studies had to use a pre-intervention versus post-intervention design or an intervention versus control design or analyse cross-sectional data comparing those who had been exposed to the campaign with those who had not been exposed. Studies also had to comprehensively report quantitative data for most outcomes. Of the 15 programmes identified, 11 were from Africa, 2 from Latin America, 1 from Asia, and 1 from multiple countries. One programme used radio only, six used radio with supporting media, and eight others used television and radio with supporting media. The data support the effectiveness of mass media interventions to increase the knowledge of HIV transmission, to improve self-efficacy in condom use, to influence some social norms, to increase the amount of interpersonal communication, to increase condom use and to boost awareness of health providers. Fewer significant effects were found for improving self-efficacy in terms of abstinence, delaying the age of first sexual experience or decreasing the number of sexual partners. We found that mass media programmes can influence HIV-related outcomes among young people, although not on every variable or in every campaign. Campaigns that include television require the highest threshold of evidence, yet they also yield the strongest evidence of effects. This suggests that comprehensive mass media programmes are valuable.

X-RAYS FROM A RADIO-LOUD COMPACT BROAD ABSORPTION LINE QUASAR 1045+352 AND THE NATURE OF OUTFLOWS IN RADIO-LOUD BROAD ABSORPTION LINE QUASARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunert-Bajraszewska, Magdalena; Katarzynski, Krzysztof; Siemiginowska, Aneta

2009-11-10

We present new results on X-ray properties of radio-loud broad absorption line (BAL) quasars and focus on broadband spectral properties of a high-ionization BAL (HiBAL) compact steep spectrum (CSS) radio-loud quasar 1045+352. This HiBAL quasar has a very complex radio morphology indicating either strong interactions between a radio jet and the surrounding interstellar medium or a possible re-start of the jet activity. We detected 1045+352 quasar in a short 5 ksec Chandra ACIS-S observation. We applied theoretical models to explain spectral energy distribution of 1045+352 and argue that non-thermal, inverse-Compton (IC) emission from the innermost parts of the radio jetmore » can account for a large fraction of the observed X-ray emission. In our analysis, we also consider a scenario in which the observed X-ray emission from radio-loud BAL quasars can be a sum of IC jet X-ray emission and optically thin corona X-ray emission. We compiled a sample of radio-loud BAL quasars that were observed in X-rays to date and report no correlation between their X-ray and radio luminosity. However, the radio-loud BAL quasars show a large range of X-ray luminosities and absorption columns. This is consistent with the results obtained earlier for radio-quiet BAL quasars and may indicate an orientation effect in BAL quasars or more complex dependence between X-ray emission, radio emission, and an orientation based on the radio morphology.« less

Standard/Handbook for RF Ionization Breakdown Prevention in Spacecraft Components

DTIC Science & Technology

2015-06-19

localized glow discharge of the plasma ( corona ) while RF power is being applied. 8.4.3 RF Performance Changes If a breakdown occurs and damages the...in spacecraft components and systems. Ionization breakdown is a high-energy radio frequency (RF) discharge that can occur when the insulating media...energy can be discharged in a small volume, releasing large amounts of heat, melting local surfaces, and generating debris, all of which will likely

Standard/Handbook for RF Ionization Breakdown Prevention in Spacecraft Components

DTIC Science & Technology

2015-06-19

localized glow discharge of the plasma ( corona ) while RF power is being applied. 8.4.3 RF Performance Changes If a breakdown occurs and damages the part...in spacecraft components and systems. Ionization breakdown is a high-energy radio frequency (RF) discharge that can occur when the insulating media...energy can be discharged in a small volume, releasing large amounts of heat, melting local surfaces, and generating debris, all of which will likely

Environmental Assessment for the National Museum of the United States Air Force Addition, Wright-Patterson Air Force Base, Ohio

DTIC Science & Technology

2013-02-01

telephone, local computer systems, long-haul communications , and land mobile radio systems (WPAFB 2001). There are over 100 miles of communication cable...10. SPONSOR/MONITOR’S ACRONYM(S) 11 . SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release...Air Force technologies and would include unique characteristics in design, propulsion, payload capacity, buman factors, communication , range, speed

A simple mercury vapor detector for geochemical prospecting

USGS Publications Warehouse

Vaughn, William W.

1967-01-01

The detector utilizes a large-volume atomic-absorption technique for quantitative determinations of mercury vapor thermally released from crushed rock. A quartz-enclosed noble-metal amalgamative stage, which is temperature controlled and is actuated by a radio-frequency induction heater, selectively traps the mercury and eliminates low-level contamination. As little as 1 part per billion of mercury can be detected in a 1-gram sample in a 1-minute analytical period.

Solar radio continuum storms

NASA Technical Reports Server (NTRS)

1974-01-01

Radio noise continuum emission observed in metric and decametric wave frequencies is discussed. The radio noise is associated with actively varying sunspot groups accompanied by the S-component of microwave radio emissions. It is shown that the S-component emission in microwave frequencies generally occurs several days before the emission of the noise continuum storms of lower frequencies. It is likely that energetic electrons, 10 to 100 Kev, accelerated in association with the variation of sunspot magnetic fields, are the sources of the radio emissions. A model is considered to explain the relation of burst storms on radio noise. An analysis of the role of energetic electrons on the emissions of both noise continuum and type III burst storms is presented. It is shown that instabilities associated with the electrons and their relation to their own stabilizing effects are important in interpreting both of these storms.

The effect of solar radio bursts on the GNSS radio occultation signals

NASA Astrophysics Data System (ADS)

Yue, Xinan; Schreiner, William S.; Kuo, Ying-Hwa; Zhao, Biqiang; Wan, Weixing; Ren, Zhipeng; Liu, Libo; Wei, Yong; Lei, Jiuhou; Solomon, Stan; Rocken, Christian

2013-09-01

radio burst (SRB) is the radio wave emission after a solar flare, covering a broad frequency range, originated from the Sun's atmosphere. During the SRB occurrence, some specific frequency radio wave could interfere with the Global Navigation Satellite System (GNSS) signals and therefore disturb the received signals. In this study, the low Earth orbit- (LEO-) based high-resolution GNSS radio occultation (RO) signals from multiple satellites (COSMIC, CHAMP, GRACE, SAC-C, Metop-A, and TerraSAR-X) processed in University Corporation for Atmospheric Research (UCAR) were first used to evaluate the effect of SRB on the RO technique. The radio solar telescope network (RSTN) observed radio flux was used to represent SRB occurrence. An extreme case during 6 December 2006 and statistical analysis during April 2006 to September 2012 were studied. The LEO RO signals show frequent loss of lock (LOL), simultaneous decrease on L1 and L2 signal-to-noise ratio (SNR) globally during daytime, small-scale perturbations of SNR, and decreased successful retrieval percentage (SRP) for both ionospheric and atmospheric occultations during SRB occurrence. A potential harmonic band interference was identified. Either decreased data volume or data quality will influence weather prediction, climate study, and space weather monitoring by using RO data during SRB time. Statistically, the SRP of ionospheric and atmospheric occultation retrieval shows ~4% and ~13% decrease, respectively, while the SNR of L1 and L2 show ~5.7% and ~11.7% decrease, respectively. A threshold value of ~1807 SFU of 1415 MHz frequency, which can result in observable GNSS SNR decrease, was derived based on our statistical analysis.

The nature of radio emission from distant galaxies

NASA Astrophysics Data System (ADS)

Richards, Eric A.

I describe an observational program aimed at understanding the radio emission from distant, rapidly evolving galaxy populations. These observations were carried out at 1.4 and 8.5 GHz with the VLA centered on the Hubble Deep Field. Further MERLIN observations of the HDF region at 1.4 GHz provided an angular resolution of 0.2'' and when combined with the VLA data produced an image with an unprecedented rms noise of 4 μJy. All radio sources detected in the VLA complete sample are resolved with a median angular size of 1-2''. The differential count of the radio sources is marginally sub-Euclidean (γ = -2.4 +/- 0.1) and fluctuation analysis suggests nearly 60 sources per armin2 are present at the 1 μJy level. A correlation analysis indicates spatial clustering among the 371 radio sources on angular scales of 1-40 arcmin. Optical identifications are made primarily with bright (I = 22) disk systems composed of irregulars, peculiars, interacting/merging galaxies, and a few isolated field spirals. Available redshifts span the range 0.2-3. These clues coupled with the steep spectral index of the 1.4 GHz selected sample are indicative of diffuse synchrotron radiation in distant galactic disks. Thus the evolution in the microjansky radio population is driven principally by star-formation. I have isolated a number of optically faint radio sources (about 25% of the overall sample) which remain unidentified to I = 26-28 in the HDF and flanking optical fields. Several of these objects have extremely red counterparts and constitute a new class of radio sources which are candidate high redshift dusty protogalaxies.

Chimenea and other tools: Automated imaging of multi-epoch radio-synthesis data with CASA

NASA Astrophysics Data System (ADS)

Staley, T. D.; Anderson, G. E.

2015-11-01

In preparing the way for the Square Kilometre Array and its pathfinders, there is a pressing need to begin probing the transient sky in a fully robotic fashion using the current generation of radio telescopes. Effective exploitation of such surveys requires a largely automated data-reduction process. This paper introduces an end-to-end automated reduction pipeline, AMIsurvey, used for calibrating and imaging data from the Arcminute Microkelvin Imager Large Array. AMIsurvey makes use of several component libraries which have been packaged separately for open-source release. The most scientifically significant of these is chimenea, which implements a telescope-agnostic algorithm for automated imaging of pre-calibrated multi-epoch radio-synthesis data, of the sort typically acquired for transient surveys or follow-up. The algorithm aims to improve upon standard imaging pipelines by utilizing iterative RMS-estimation and automated source-detection to avoid so called 'Clean-bias', and makes use of CASA subroutines for the underlying image-synthesis operations. At a lower level, AMIsurvey relies upon two libraries, drive-ami and drive-casa, built to allow use of mature radio-astronomy software packages from within Python scripts. While targeted at automated imaging, the drive-casa interface can also be used to automate interaction with any of the CASA subroutines from a generic Python process. Additionally, these packages may be of wider technical interest beyond radio-astronomy, since they demonstrate use of the Python library pexpect to emulate terminal interaction with an external process. This approach allows for rapid development of a Python interface to any legacy or externally-maintained pipeline which accepts command-line input, without requiring alterations to the original code.

Short-term evaluation of arthroscopic management of tennis elbow; including resection of radio-capitellar capsular complex.

PubMed

Babaqi, AbdulRahman A; Kotb, Mohammed M; Said, Hatem G; AbdelHamid, Mohamed M; ElKady, Hesham A; ElAssal, Maher A

2014-06-01

There has been controversy regarding the pathogenesis and treatment of lateral epicondylitis. Different surgical techniques for the treatment of lateral epicondylitis prescribed. The purpose of this study was to evaluate the short-term outcomes of arthroscopic management including resection of the radio-capitellar capsular complex, using different validated scores. In this study, arthroscopic resection of a capsular fringe complex was done beside debridement of the undersurface of Extensor Carpi Radialis Brevis (ECRB). Thirty-one patients with recalcitrant lateral epicondylitis for a minimum of 6 months had surgery. In all patients, a collar-like band of radio-capitellar capsular complex was found to impinge on the radial head and subluxate into the radio-capitellar joint with manipulation under direct vision. Outcomes were assessed using Mayo Elbow Performance Index (MEPI), the Patient-Rated Tennis Elbow Evaluation (PRTEE), and the Disability of the Arm, Shoulder, and Hand (DASH), beside visual analog scale (VAS) for pain and satisfaction criteria. After arthroscopic surgery, overall satisfaction was extremely positive, over the 31 patients, 93.5% of the patients are satisfied. The mean score for pain improved from 8.64 to 1.48 points. The total PRTEE improved from 55.53 to 10.39 points. The mean MEPI score was improved from 61.82 to 94.10 points. DASH score also improved from 24.46 to 4.81 points. All improvements are statistically significant (P < 0.05). Arthroscopic release of ECRB in patients with chronic lateral epicondylitis is a reproducible method with a marked improvement in function within a short period, with special consideration for resection of radio-capitellar capsular complex.

Simultaneous use of mark-recapture and radiotelemetry to estimate survival, movement, and capture rates

USGS Publications Warehouse

Powell, L.A.; Conroy, M.J.; Hines, J.E.; Nichols, J.D.; Krementz, D.G.

2000-01-01

Biologists often estimate separate survival and movement rates from radio-telemetry and mark-recapture data from the same study population. We describe a method for combining these data types in a single model to obtain joint, potentially less biased estimates of survival and movement that use all available data. We furnish an example using wood thrushes (Hylocichla mustelina) captured at the Piedmont National Wildlife Refuge in central Georgia in 1996. The model structure allows estimation of survival and capture probabilities, as well as estimation of movements away from and into the study area. In addition, the model structure provides many possibilities for hypothesis testing. Using the combined model structure, we estimated that wood thrush weekly survival was 0.989 ? 0.007 ( ?SE). Survival rates of banded and radio-marked individuals were not different (alpha hat [S_radioed, ~ S_banded]=log [S hat _radioed/ S hat _banded]=0.0239 ? 0.0435). Fidelity rates (weekly probability of remaining in a stratum) did not differ between geographic strata (psi hat=0.911 ? 0.020; alpha hat [psi11, psi22]=0.0161 ? 0.047), and recapture rates ( = 0.097 ? 0.016) banded and radio-marked individuals were not different (alpha hat [p_radioed, p_banded]=0.145 ? 0.655). Combining these data types in a common model resulted in more precise estimates of movement and recapture rates than separate estimation, but ability to detect stratum or mark-specific differences in parameters was week. We conducted simulation trials to investigate the effects of varying study designs on parameter accuracy and statistical power to detect important differences. Parameter accuracy was high (relative bias [RBIAS] <2 %) and confidence interval coverage close to nominal, except for survival estimates of banded birds for the 'off study area' stratum, which were negatively biased (RBIAS -7 to -15%) when sample sizes were small (5-10 banded or radioed animals 'released' per time interval). To provide adequate data for useful inference from this model, study designs should seek a minimum of 25 animals of each marking type observed (marked or observed via telemetry) in each time period and geographic stratum.

Optimization of porous microchannel heat exchanger

NASA Astrophysics Data System (ADS)

Kozhukhov, N. N.; Konovalov, D. A.

2017-11-01

The technical progress in information and communication sphere leads to a sharp increase in the use of radio electronic devices. Functioning of radio electronics is accompanied by release of thermal energy, which must be diverted from the heat-stressed element. Moreover, using of electronics at negative temperatures, on the contrary, requires supply of a certain amount of heat to start the system. There arises the task of creating a system that allows both to supply and to divert the necessary amount of thermal energy. The development of complex thermostabilization systems for radio electronic equipment is due to increasing the efficiency of each of its elements separately. For more efficient operation of a heat exchanger, which directly affects the temperature of the heat-stressed element, it is necessary to calculate the mode characteristics and to take into account the effect of its design parameters. The results of optimizing the microchannel heat exchanger are presented in the article. The target optimization functions are the mass, pressure drop and temperature. The parameters of optimization are the layout of porous fins, their geometric dimensions and coolant flow. For the given conditions, the optimum variant of porous microchannel heat exchanger is selected.

Ultrawideband Electromagnetic Interference to Aircraft Radios: Results of Limited Functional Testing With United Airlines and Eagles Wings Incorporated, in Victorville, California

NASA Technical Reports Server (NTRS)

Ely, Jay J.; Shaver, Timothy W.; Fuller, Gerald L.

2002-01-01

On February 14, 2002, the FCC adopted a FIRST REPORT AND ORDER, released it on April 22, 2002, and on May 16, 2002 published in the Federal Register a Final Rule, permitting marketing and operation of new products incorporating UWB technology. Wireless product developers are working to rapidly bring this versatile, powerful and expectedly inexpensive technology into numerous consumer wireless devices. Past studies addressing the potential for passenger-carried portable electronic devices (PEDs) to interfere with aircraft electronic systems suggest that UWB transmitters may pose a significant threat to aircraft communication and navigation radio receivers. NASA, United Airlines and Eagles Wings Incorporated have performed preliminary testing that clearly shows the potential for handheld UWB transmitters to cause cockpit failure indications for the air traffic control radio beacon system (ATCRBS), blanking of aircraft on the traffic alert and collision avoidance system (TCAS) displays, and cause erratic motion and failure of instrument landing system (ILS) localizer and glideslope pointers on the pilot horizontal situation and attitude director displays. This report provides details of the preliminary testing and recommends further assessment of aircraft systems for susceptibility to UWB electromagnetic interference.

Placement of intracoelomic radio transmitters and silicone passive sampling devices in northern leopard frogs (Lithobates pipiens)

USGS Publications Warehouse

Yaw, Taylor; Swanson, Jennifer E; Pierce, Clay; Muths, Erin L.; Smalling, Kelly; Vandever, Mark; Zaffarano, Bianca Anne

2017-01-01

Historically, wetland toxin exposure studies have relied on single time point samples from stationary sampling devices. Development of passive sampling devices (PSDs) that can be attached to individual animals within wetland habitats has greatly improved in recent years, presenting an innovative sampling technology that can potentially yield individual-specific, quantifiable data about chemical exposure. In this study, silicone based PSDs were attached to the ventral skin of 20 northern leopard frogs (Lithobates pipiens) with polypropylene sutures after radio transmitters had been surgically implanted into the coleomic cavity. After a recovery period frogs were released back into the wetland habitat where they were acquired. The animals were located daily using radio telemetry to assess how long PSDs would remain attached in the frogs' natural habitat. After one week, PSDs remained on 18 of the original 20 frogs. At 2 weeks 17 frogs were recovered and no PSDs remained attached. Although valuable data can be obtained over a short time period, more research will be necessary to demonstrate effectiveness of externally attaching silicone PSDs to northern leopard frogs for time periods longer than 1-2 weeks.

Analysis of type II and type III solar radio bursts

NASA Astrophysics Data System (ADS)

Wijesekera, J. V.; Jayaratne, K. P. S. C.; Adassuriya, J.

2018-04-01

Solar radio burst is an arrangement of a frequency space that variation with time. Most of radio burst can be identified in low frequency range such as below 200 MHz and depending on frequencies. Solar radio bursts were the first phenomenon identified in the field of radio astronomy field. Solar radio frequency range is from 70 MHz to 2.2 GHz. Most of the radio burst can be identified in a low frequency range such as below 200 MHz. Properties of low-frequency radio were analyzed this research. There are two types of solar radio bursts were analyzed, named as type II and type III radio bursts. Exponential decay type could be seen in type II, and a linear could be indicated in type III solar radio bursts. The results of the drift rate graphs show the values of each chosen solar radio burst. High drift rate values can be seen in type III solar flares whereas low to medium drift rate values can be seen in type II solar flares. In the second part of the research the Newkirk model electron density model was used to estimate the drift velocities of the solar radio bursts. Although the special origin of the solar radio burst is not known clearly we assumed. The chosen solar radio bursts were originated within the solar radius of 0.9 - 1.3 range from the photosphere. We used power low in the form of (x) = A × 10‑bx were that the electron density related to the height of the solar atmosphere. The calculation of the plasma velocity of each solar radio burst was done using the electron density model and drift rates. Therefore velocity of chosen type II solar radio bursts indicates low velocities. The values are 233.2499 Km s‑1, 815.9522 Km s‑1 and 369.5425 Km s‑1. Velocity of chosen type III solar radio bursts were 1443.058 Km s‑1and 1205.05Km s ‑1.

Influence of prerelease experience on reintroduced black-footed ferrets (Mustela nigripes)

USGS Publications Warehouse

Biggins, D.E.; Vargas, A.; Godbey, J.L.; Anderson, S.H.

1999-01-01

Captive breeding is increasingly being used to create supplies of endangered animals for release into natural habitats, but rearing strategies vary and debates arise over which methods are most efficient. We assessed postrelease behaviors and survival of three groups of black-footed ferrets, each with different prerelease experience. Eighteen ferret kits ???60 days of age were moved with their dams from cages to 80-m2 outdoor pens with prairie dog burrows. These animals were compared to animals reared in standard cages (n = 72), some of which were given experience killing prairie dogs (n = 32). Ferrets were released onto white-tailed prairie dog (Cynomys leucurus) colonies in Wyoming, USA, in fall, 1992. Radio-tagged cage-reared ferrets made longer nightly moves and dispersed further from release sites than their pen-reared counterparts. The band return rate was 4-fold higher for pen-reared animals than for cage-reared animals during surveys conducted about 1 month after release. We recommend routine use of quasi-natural outdoor pens for prerelease conditioning of black-footed ferrets.

Reusable electrochemical cell for rapid separation of [18F]fluoride from [18O]water for flow-through synthesis of 18F-labeled tracers

PubMed Central

Sadeghi, Saman; Liang, Vincent; Cheung, Shilin; Woo, Suh; Wu, Curtis; Ly, Jimmy; Deng, Yuliang; Eddings, Mark; van Dam, R. Michael

2015-01-01

A brass-platinum electrochemical micro flow cell was developed to extract [18F]fluoride from an aqueous solution and release it into an organic based solution, suitable for subsequent radio-synthesis, in a fast and reliable manner. This cell does not suffer electrode erosion and is thus reusable while operating faster by enabling increased voltages. By optimizing temperature, trapping and release potentials, flow rates, and electrode materials, an overall [18F]fluoride trapping and release efficiency of 84±5% (n=7) was achieved. X-ray photoelectron spectroscopy (XPS) was used to analyze electrode surfaces of various metal-metal systems and the findings were correlated with the performance of the electrochemical cell. To demonstrate the reactivity of the released [18F]fluoride, the cell was coupled to a flow-through reactor and automated synthesis of [18F]FDG with a repeatable decay-corrected yield of 56±4% (n=4) was completed in <15 min. A multi-human dose of 5.92 GBq [18F]FDG was also demonstrated. PMID:23474380

THE LOW-FREQUENCY RADIO CATALOG OF FLAT-SPECTRUM SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; Giroletti, M.; D'Abrusco, R.

A well known property of the γ-ray sources detected by Cos-B in the 1970s, by the Compton Gamma-Ray Observatory in the 1990s, and recently by the Fermi observations is the presence of radio counterparts, particularly for those associated with extragalactic objects. This observational evidence is the basis of the radio-γ-ray connection established for the class of active galactic nuclei known as blazars. In particular, the main spectral property of the radio counterparts associated with γ-ray blazars is that they show a flat spectrum in the GHz frequency range. Our recent analysis dedicated to search blazar-like candidates as potential counterparts formore » the unidentified γ-ray sources allowed us to extend the radio-γ-ray connection in the MHz regime. We also showed that blazars below 1 GHz maintain flat radio spectra. Thus, on the basis of these new results, we assembled a low-frequency radio catalog of flat-spectrum sources built by combining the radio observations of the Westerbork Northern Sky Survey and of the Westerbork in the southern hemisphere catalog with those of the NRAO Very Large Array Sky survey (NVSS). This could be used in the future to search for new, unknown blazar-like counterparts of γ-ray sources. First, we found NVSS counterparts of Westerbork Synthesis Radio Telescope radio sources, and then we selected flat-spectrum radio sources according to a new spectral criterion, specifically defined for radio observations performed below 1 GHz. We also described the main properties of the catalog listing 28,358 radio sources and their logN-logS distributions. Finally, a comparison with the Green Bank 6 cm radio source catalog was performed to investigate the spectral shape of the low-frequency flat-spectrum radio sources at higher frequencies.« less

An initial evaluation of stable isotopic characterisation of post-blast plastic debris from improvised explosive devices.

PubMed

Quirk, Anthony T; Bellerby, John M; Carter, James F; Thomas, Fay A; Hill, Jenny C

2009-06-01

A number of two-way radios, similar to those which have been employed to initiate Improvised Explosive Devices (IEDs), were acquired from a commercial supplier and grouped into four pairs. Samples of plastic material were collected from five distinct regions of each radio and analysed by Infrared and Raman spectroscopy to identify the nature of the material. One radio of each pair was then subjected to detonation with a commercially available plastic explosive. The combination of radio and explosive was considered to be representative of the components of an IED. Following detonation, fragments were recovered and, where possible, identified as specific sampling points of the radio. A combination of delta2H and delta13C stable isotopic analysis of material from each of the five sampling points was found to provide a pattern which was characteristic of a given radio and provided a means to associate pairs of radios. When few fragments were recovered, no positive association could be made between the fragments and the paired, undamaged radio. This was attributed, in part, to manufacturing variation in the radios. However, when three or more post-blast fragments were recovered it was possible to associate these with the paired, undamaged radio with a high degree of certainty.

Cross Matching as Strategy to Find Radio Stars

NASA Astrophysics Data System (ADS)

Christian, Tiffany; Kimball, Amy

2018-01-01

Using cross-matching between the FIRST (20cm) and GPS1 (optical) catalogs, we identified possible radio star candidates. This is an extension of earlier work by Kimball et al. (2009), who sought to identify radiostar candidates by cross-matching the FIRST (radio)and SDSS (optical) catalogs, but did not include the consideration of stellar proper motions. We used proper motions from GPS1 to match with FIRST radio sources; the region of sky where they overlap contains ~900,000 FIRST sources and several million GPS1 sources. We used WISE near-infrared and PanSTARRS optical information to identify matches that have stellar colors. Our selection constraints identified 6 stars (spectroscopically confirmed) as radio star candidates. They are faint in the radio (<1 mJy) indicating we may be searching at the limits of the radio survey. Other candidates had no spectral confirmation or object type identification in SIMBAD, which would make them ideal for follow up radio observations. However, random analysis indicated that many other possible candidates were random associations, which may also be true for these 6 stars.

Analysis of the Metal Oxide Space Clouds (MOSC) HF Propagation Environment

NASA Astrophysics Data System (ADS)

Jackson-Booth, N.; Selzer, L.

2015-12-01

Artificial Ionospheric Modification (AIM) attempts to modify the ionosphere in order to alter the high frequency (HF) propagation environment. It can be achieved through injections of aerosols, chemicals or radio (RF) signals into the ionosphere. The Metal Oxide Space Clouds (MOSC) experiment was undertaken in April/May 2013 to investigate chemical AIM. Two sounding rockets were launched from the Kwajalein Atoll (part of the Marshall Islands) and each released a cloud of vaporized samarium (Sm). The samarium created a localized plasma cloud, with increased electron density, which formed an additional ionospheric layer. The ionospheric effects were measured by a wide range of ground based instrumentation which included a network of high frequency (HF) sounders. Chirp transmissions were made from three atolls and received at five sites within the Marshall Islands. One of the receive sites consisted of an 18 antenna phased array, which was used for direction finding. The ionograms have shown that as well as generating a new layer the clouds created anomalous RF propagation paths, which interact with both the cloud and the F-layer, resulting in 'ghost traces'. To fully understand the propagation environment a 3D numerical ray trace has been undertaken, using a variety of background ionospheric and cloud models, to find the paths through the electron density grid for a given fan of elevation and azimuth firing angles. Synthetic ionograms were then produced using the ratio of ray path length to speed of light as an estimation of the delay between transmission and observation for a given frequency of radio wave. This paper reports on the latest analysis of the MOSC propagation environment, comparing theory with observations, to further understanding of AIM.

The Mobile Laboratory for Radio-Frequency Interference Monitoring at the Sardinia Radio Telescope

NASA Astrophysics Data System (ADS)

Bolli, Pietro; Gaudiomonte, Francesco; Ambrosini, Roberto; Bortolotti, Claudio; Roma, Mauro; Barberi, Carlo; Piccoli, Fabrizio

2013-10-01

In this paper, a quite unique mobile laboratory for monitoring radio-frequency interference with a radio-astronomical observatory is described. The unit is fully operational at the new Sardinia Radio Telescope, a 64-m antenna now in the commissioning phase in Italy. The mobile laboratory is mainly used to identify the source of interference with the radio astronomy service using iterative triangulations in the azimuth directions. Both the design and realization of this prototype were handled with outstanding care to limit the emission of self-interference as much as possible. The laboratory was equipped with excellent microwave instruments in terms of sensitivity, frequency coverage, dynamic range, and various demodulation and signal-analysis facilities. The unit can be quickly switched to different RF and power-supply configurations, while offering operators a safe and efficient workplace, even in adverse meteorological and driving conditions. In the past months, the mobile laboratory has proven to be successful in detecting and identifying many radio interferers. Two examples of measurement campaigns are described.

Interplanetary radio storms. II - Emission levels and solar wind speed in the range 0.05-0.8 AU

NASA Technical Reports Server (NTRS)

Bougeret, J.-L.; Fainberg, J.; Stone, R. G.

1984-01-01

Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetary medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the sun. Using a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the III storm burst radio emission at the harmonic of the local plasma frequency.

Spectral Indices of Faint Radio Sources

NASA Astrophysics Data System (ADS)

Gim, Hansung B.; Hales, Christopher A.; Momjian, Emmanuel; Yun, Min Su

2015-01-01

The significant improvement in bandwidth and the resultant sensitivity offered by the Karl G. Jansky Very Large Array (VLA) allows us to explore the faint radio source population. Through the study of the radio continuum we can explore the spectral indices of these radio sources. Robust radio spectral indices are needed for accurate k-corrections, for example in the study of the radio - far-infrared (FIR) correlation. We present an analysis of measuring spectral indices using two different approaches. In the first, we use the standard wideband imaging algorithm in the data reduction package CASA. In the second, we use a traditional approach of imaging narrower bandwidths to derive the spectral indices. For these, we simulated data to match the observing parameter space of the CHILES Con Pol survey (Hales et al. 2014). We investigate the accuracy and precision of spectral index measurements as a function of signal-to noise, and explore the requirements to reliably probe possible evolution of the radio-FIR correlation in CHILES Con Pol.

Hour time-scale QPOs in the X-ray and radio emission of LS I +61°303

NASA Astrophysics Data System (ADS)

Nösel, S.; Sharma, R.; Massi, M.; Cimò, G.; Chernyakova, M.

2018-05-01

LS I +61°303 is an X-ray binary with a radio outburst every ˜27 d. Previous studies of the stellar system revealed radio microflares superimposed on the large radio outburst. We present here new radio observations of LS I +61°303 at 2.2 GHz with the Westerbork Synthesis Radio Telescope (WSRT). Using various timing analysis methods, we find significant quasi-periodic oscillations (QPOs) of 55 min stable over the duration of 4 d. We also use archival data obtained from the Suzaku satellite at X-ray wavelengths. We report here for the first time significant X-ray QPOs of about 2 h present over the time span of 21 h. We compare our results with the previously reported QPO observations and we conclude that the QPOs seem to be associated with the radio outburst, independent of the amplitude of the outburst. Finally, the different QPO time-scales are discussed in the context of magnetic reconnection.

Performance Analysis on the Coexistence of Multiple Cognitive Radio Networks

DTIC Science & Technology

2015-05-28

the scarce spectrum resources. Cognitive radio is a key in minimizing the spectral congestion through its adaptability, where the radio parameters...static allocation of spectrum results in congestion in some parts of the spectrum and non use in some others, therefore, spectra utilization is...well as the secondary user (SU) activities in multiple CR networks. It is shown that the scheduler provided much needed gain during congestions . However

Architecture Analysis of Wireless Power Transmission for Lunar Outposts

DTIC Science & Technology

2015-09-01

through his work on wireless communication using radio wave propagation for both transmitting and receiving high frequency electricity using a focusing...Administration nm nanometers NRC National Research Council PGT platform generic technologies PMAD power management and distribution RF radio frequency xiv...GHz (Marzwell 2008). While the slot antenna can handle frequencies between 70 GHz and 150 GHz, it has been optimized for 94 GHz and has a radio

Spacecraft VHF Radio Propagation Analysis in Ocean Environments Including Atmospheric Effects

NASA Technical Reports Server (NTRS)

Hwu, Shian; Moreno, Gerardo; Desilva, Kanishka; Jih, CIndy

2010-01-01

The Communication Systems Simulation Laboratory (CSSL) at the National Aeronautics and Space Administration (NASA)/Johnson Space Center (JSC) is tasked to perform spacecraft and ground network communication system simulations. The CSSL has developed simulation tools that model spacecraft communication systems and the space/ground environment in which they operate. This paper is to analyze a spacecraft's very high frequency (VHF) radio signal propagation and the impact to performance when landing in an ocean. Very little research work has been done for VHF radio systems in a maritime environment. Rigorous Radio Frequency (RF) modeling/simulation techniques were employed for various environmental effects. The simulation results illustrate the significance of the environmental effects on the VHF radio system performance.

A statistical analysis of the Einstein normal galaxy sample. III - Radio and X-ray properties of elliptical and S0 galaxies

NASA Technical Reports Server (NTRS)

Fabbiano, G.; Klein, U.; Trinchieri, G.; Wielebinski, R.

1987-01-01

Radioastronomy, optical and X-ray data were used to probe the cause of high X-ray luminosities of 28 radio-quiet elliptical galaxies (RQE) and S0 galaxies previously scanned by the Einstein Observatory. Comparisons were made with similar data on double-lobed 3CR galaxies. Radio luminosities were highly correlated with the X-ray luminosities, agreeing with models of radio nuclear sources in early-type galaxies as accreting compact objects. Additionally, 3CR galaxies seemed to be large-scale versions of normal RQE. The significance of interstellar medium/intracluster medium interactions for high correlations between the core and total radio power from X-ray emitting galaxies is discussed.

Crowd-Sourced Radio Science at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Fry, C. D.; McTernan, J. K.; Suggs, R. M.; Rawlins, L.; Krause, L. H.; Gallagher, D. L.; Adams, M. L.

2018-01-01

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged citizen scientists and students in an investigation of the effects of an eclipse on the mid-latitude ionosphere. Activities included fieldwork and station-based data collection of HF Amateur Radio frequency bands and VLF radio waves before, during, and after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse.

Methods for magnetic resonance analysis using magic angle technique

DOEpatents

Hu, Jian Zhi [Richland, WA; Wind, Robert A [Kennewick, WA; Minard, Kevin R [Kennewick, WA; Majors, Paul D [Kennewick, WA

2011-11-22

Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

Observations and Modeling of Merging Galaxy Clusters

NASA Astrophysics Data System (ADS)

Golovich, Nathan Ryan

Context: Galaxy clusters grow hierarchically with continuous accretion bookended by major merging events that release immense gravitational potential energy (as much as ˜1065 erg). This energy creates an environment for rich astrophysics. Precise measurements of the dark matter halo, intracluster medium, and galaxy population have resulted in a number of important results including dark matter constraints and explanations of the generation of cosmic rays. However, since the timescale of major mergers (˜several Gyr) relegates observations of individual systems to mere snapshots, these results are difficult to understand under a consistent dynamical framework. While computationally expensive simulations are vital in this regard, the vastness of parameter space has necessitated simulations of idealized mergers that are unlikely to capture the full richness. Merger speeds, geometries, and timescales each have a profound consequential effect, but even these simple dynamical properties of the mergers are often poorly understood. A method to identify and constrain the best systems for probing the rich astrophysics of merging clusters is needed. Such a method could then be utilized to prioritize observational follow up and best inform proper exploration of dynamical phase space. Task: In order to identify and model a large number of systems, in this dissertation, we compile an ensemble of major mergers each containing radio relics. We then complete a pan-chromatic study of these 29 systems including wide field optical photometry, targeted optical spectroscopy of member galaxies, radio, and X-ray observations. We use the optical observations to model the galaxy substructure and estimate line of sight motion. In conjunction with the radio and X-ray data, these substructure models helped elucidate the most likely merger scenario for each system and further constrain the dynamical properties of each system. We demonstrate the power of this technique through detailed analyses of two individual merging clusters. Each are largely bimodal mergers occurring in the plane of the sky. We build on the dynamical analyses of Dawson (2013b) and Ng et al. (2015) in order to constrain the merger speeds, timescales, and geometry for these two systems, which are among a gold sample earmarked for further follow up. Findings: MACS J1149.5+2223 has a previously unidentified southern subcluster involved in a major merger with the well-studied northern subcluster. We confirm the system to be among the most massive clusters known, and we study the dynamics of the merger. MACS J1149.5+2223 appears to be a more evolved system than the Bullet Cluster observed near apocenter. ZwCl 0008.8+5215 is a less massive but a bimodal system with two radio relics and a cool-core "bullet" analogous to the namesake of the Bullet Cluster. These two systems occupy different regions of merger phase space with the pericentric relative velocities of ˜2800 km s-1 and ˜1800 km s-1 for MACS J1149.5+2223 and ZwCl 0008.8+5215, respectively. The time since pericenter for the observed states are ˜1.2 Gyr and ˜0.8 Gyr, respectivel. In the ensemble analysis, we confirm that radio relic selection is an efficient trigger for the identification of major mergers. In particular, 28 of the 29 systems exhibit galaxy substructure aligned with the radio relics and the disturbed intra-cluster medium. Radio relics are typically aligned within 20° of the axis connecting the two galaxy subclusters. Furthermore, when radio relics are aligned with substructure, the line of sight velocity difference between the two subclusters is small compared with the infall velocity. This strongly implies radio relic selection is an efficient selector of systems merging in the plane of the sky. While many of the systems are complex with several simultaneous merging subclusters, these systems generally only contain one radio relic. Systems with double radio relics uniformly suggest major mergers with two dominant substructures well aligned between the radio relics. Conclusions: Radio relics are efficient triggers for identifying major mergers occurring within the plane of the sky. This is ideal for observing offsets between galaxies and dark matter distributions as well as cluster shocks. Double radio relic systems, in particular, have the simplest geometries, which allow for accurate dynamical models and inferred astrophysics. Comparing and contrasting the dynamical models of MACS J1149.5+2223 and ZwCl 0008.8+5215 with similar studies in the literature (Dawson, 2013b; Ng et al., 2015; van Weeren et al., 2017), a wide range of dynamical phase space (˜ 1500 - 3000 km -1 at pericenter and ˜ 500 - 1500 Myr after pericenter) may be sampled with radio relic mergers. With sufficient samples of bimodal systems, velocity dependence of underlying astrophysics may be uncovered. (Abstract shortened by ProQuest.).

SBS 0846+513: a new γ-ray-emitting narrow-line Seyfert 1 galaxy

DOE PAGES

D'Ammando, F.; Orienti, M.; Finke, J.; ...

2012-10-11

In this paper, we report Fermi Large Area Telescope (LAT) observations of the radio-loud active galactic nucleus SBS 0846+513 (z = 0.5835), optically classified as a narrow-line Seyfert 1 galaxy, together with new and archival radio-to-X-ray data. The source was not active at γ-ray energies during the first two years of Fermi operation. A significant increase in activity was observed during 2010 October–2011 August. In particular, a strong γ-ray flare was observed in 2011 June reaching an isotropic γ-ray luminosity (0.1–300 GeV) of 1.0 × 10 48 erg s -1, comparable to that of the brightest flat spectrum radio quasars,more » and showing spectral evolution in γ rays. An apparent superluminal velocity of (8.2 ± 1.5)c in the jet was inferred from 2011 to 2012 Very Long Baseline Array (VLBA) images, suggesting the presence of a highly relativistic jet. Finally, both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indications of the presence of a relativistic jet as powerful as those of blazars. In addition, variability and spectral properties in radio and γ-ray bands indicate blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.« less

High-frequency (13.56-MHz) and ultrahigh-frequency (915-MHz) radio identification systems do not affect platelet activation and functions.

PubMed

Rogowska, Anna; Chabowska, Anna Małgorzata; Lipska, Alina; Boczkowska-Radziwon, Barbara; Bujno, Magdalena; Rusak, Tomasz; Dziemianczuk, Mateusz; Radziwon, Piotr

2016-05-01

In radiofrequency identification (RFID) systems used in labeling of blood components, blood cells are subjected to the direct influence of electromagnetic waves throughout the storage period. The aim of this study was to prove the safety of storage of platelet concentrates (PCs) in containers labeled with RFID tags. Ten pooled PCs obtained from 12 buffy coats each suspended in additive solution were divided into three separate containers that were assigned to three groups: control, PCs labeled with ultrahigh frequency (UHF) range tags and exposed to 915-MHz radio waves, and PCs labeled with high-frequency (HF) range tags and exposed to 13.56-MHz radio waves. PCs were stored at 20 to 24°C for 7 days. In vitro tests of platelet (PLT) function were performed on the first, fifth, and seventh days of storage. There were no significant differences in pH; hypotonic shock resistance; surface expression of CD62P, CD42a, or CD63; release of PLT-derived microparticles; PLT aggregation; and number of PLTs between PCs stored at a constant exposure to radio waves of two different frequencies and the control group on the first, fifth, and seventh days of storage. The results of the study indicate no impact of electromagnetic radiation generated in HF and UHF RFID systems and constant contact with the tags on the quality of stored PCs. © 2016 AABB.

The HI/OH/Recombination line survey of the inner Milky Way (THOR). Survey overview and data release 1

NASA Astrophysics Data System (ADS)

Beuther, H.; Bihr, S.; Rugel, M.; Johnston, K.; Wang, Y.; Walter, F.; Brunthaler, A.; Walsh, A. J.; Ott, J.; Stil, J.; Henning, Th.; Schierhuber, T.; Kainulainen, J.; Heyer, M.; Goldsmith, P. F.; Anderson, L. D.; Longmore, S. N.; Klessen, R. S.; Glover, S. C. O.; Urquhart, J. S.; Plume, R.; Ragan, S. E.; Schneider, N.; McClure-Griffiths, N. M.; Menten, K. M.; Smith, R.; Roy, N.; Shanahan, R.; Nguyen-Luong, Q.; Bigiel, F.

2016-10-01

Context. The past decade has witnessed a large number of Galactic plane surveys at angular resolutions below 20''. However, no comparable high-resolution survey exists at long radio wavelengths around 21 cm in line and continuum emission. Aims: We remedy this situation by studying the northern Galactic plane at 20'' resolution in emission of atomic, molecular, and ionized gas. Methods: Employing the Karl G. Jansky Very Large Array (VLA) in the C-array configuration and a large program, we observe the HI 21 cm line, four OH lines, nineteen Hnα radio recombination lines as well as the continuum emission from 1 to 2 GHz in full polarization over a large part of the first Galactic quadrant. Results: Covering Galactic longitudes from 14.5 to 67.4 deg and latitudes between ± 1.25 deg, we image all of these lines and the continuum at 20'' resolution. These data allow us to study the various components of the interstellar medium (ISM): from the atomic phase, traced by the HI line, to the molecular phase, observed by the OH transitions, to the ionized medium, revealed by the cm continuum and the Hnα radio recombination lines. Furthermore, the polarized continuum emission enables magnetic field studies. In this overview paper, we discuss the survey outline and present the first data release as well as early results from the different datasets. We now release the first half of the survey; the second half will follow later after the ongoing data processing has been completed. The data in fits format (continuum images and line data cubes) can be accessed through the project web-page. Conclusions: The HI/OH/Recombination line survey of the Milky Way (THOR) opens a new window to the different parts of the ISM. It enables detailed studies of molecular cloud formation, conversion of atomic to molecular gas, and feedback from Hii regions as well as the magnetic field in the Milky Way. It is highly complementary to other surveys of our Galaxy, and comparing the different datasets will allow us to address many open questions. Based on observations carried out with the Karl Jansky Very Large Array (VLA). http://www.mpia.de/thor

THE SUZAKU VIEW OF THE DISK-JET CONNECTION IN THE LOW-EXCITATION RADIO GALAXY NGC 6251

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, D. A.; Kraft, R. P.; Lee, J. C.

We present results from an 87 ks Suzaku observation of the canonical low-excitation radio galaxy (LERG) NGC 6251. We have previously suggested that LERGs violate conventional active galactic nucleus unification schemes: they may lack an obscuring torus and are likely to accrete in a radiatively inefficient manner, with almost all of the energy released by the accretion process being channeled into powerful jets. We model the 0.5-20 keV Suzaku spectrum with a single power law of photon index {Gamma} = 1.82{sup +0.04} {sub -0.05}, together with two collisionally ionized plasma models whose parameters are consistent with the known galaxy- andmore » group-scale thermal emission. Our observations confirm that there are no signatures of obscured, accretion-related X-ray emission in NGC 6251, and we show that the luminosity of any such component must be substantially sub-Eddington in nature.« less

Effects of a spring flushing flow on the distribution of radio-tagged juvenile rainbow trout in a Wyoming tailwater

USGS Publications Warehouse

Simpkins, D.G.; Hubert, W.A.; Wesche, T.A.

2000-01-01

The controlled release of dammed water, designed to produce a flushing flow that would remove fine sediments from spawning habitat in a flow-regulated river, did not displace juvenile rainbow trout Oncorhynchus mykiss (20-25 cm total length) downstream. Of eight naturally spawned (wild) and nine hatchery fish that were radio-tagged, only one wild fish and two hatchery fish were found in different locations after an eight-fold increase in flow. These three fish moved upstream and the greatest movement was 96 m. Cobble and boulder substrates in main-channel pools were thought to provide slow-water-velocity refuges during the flushing flow. Our findings and the findings of other researchers suggest that flushing flows can be conducted to enhance spawning habitat for rainbow trout without causing extensive downstream movements or habitat displacement of small fish in regulated rivers.

DIFFERENCES BETWEEN RADIO-LOUD AND RADIO-QUIET γ -RAY PULSARS AS REVEALED BY FERMI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hui, C. Y.; Lee, Jongsu; Takata, J.

By comparing the properties of non-recycled radio-loud γ -ray pulsars and radio-quiet γ -ray pulsars, we have searched for the differences between these two populations. We found that the γ -ray spectral curvature of radio-quiet pulsars can be larger than that of radio-loud pulsars. Based on the full sample of non-recycled γ -ray pulsars, their distributions of the magnetic field strength at the light cylinder are also found to be different. We note that this might result from an observational bias. By reexamining the previously reported difference of γ -ray-to-X-ray flux ratios, we found that the significance can be hamperedmore » by their statistical uncertainties. In the context of the outer gap model, we discuss the expected properties of these two populations and compare with the possible differences that are identified in our analysis.« less

The SUrvey for Pulsars and Extragalactic Radio Bursts - I. Survey description and overview

NASA Astrophysics Data System (ADS)

Keane, E. F.; Barr, E. D.; Jameson, A.; Morello, V.; Caleb, M.; Bhandari, S.; Petroff, E.; Possenti, A.; Burgay, M.; Tiburzi, C.; Bailes, M.; Bhat, N. D. R.; Burke-Spolaor, S.; Eatough, R. P.; Flynn, C.; Jankowski, F.; Johnston, S.; Kramer, M.; Levin, L.; Ng, C.; van Straten, W.; Krishnan, V. Venkatraman

2018-01-01

We describe the Survey for Pulsars and Extragalactic Radio Bursts (SUPERB), an ongoing pulsar and fast transient survey using the Parkes radio telescope. SUPERB involves real-time acceleration searches for pulsars and single-pulse searches for pulsars and fast radio bursts. We report on the observational set-up, data analysis, multiwavelength/messenger connections, survey sensitivities to pulsars and fast radio bursts and the impact of radio frequency interference. We further report on the first 10 pulsars discovered in the project. Among these is PSR J1306-40, a millisecond pulsar in a binary system where it appears to be eclipsed for a large fraction of the orbit. PSR J1421-4407 is another binary millisecond pulsar; its orbital period is 30.7 d. This orbital period is in a range where only highly eccentric binaries are known, and expected by theory; despite this its orbit has an eccentricity of 10-5.

ULF radio monitoring network in a seismic area

NASA Astrophysics Data System (ADS)

Toader, Victorin; Moldovan, Iren-Adelina; Ionescu, Constantin; Marmureanu, Alexandru

2017-04-01

ULF monitoring is a part of a multidisciplinary network (AeroSolSys) located in Vrancea (Curvature Carpathian Mountains). Four radio receivers (100 kHz - microwave) placed on faults in a high seismic area characterized by deep earthquakes detect fairly weak radio waves. The radio power is recorded in correlation with many other parameters related to near surface low atmosphere phenomena (seismicity, solar radiation, air ionization, electromagnetic activity, radon, CO2 concentration, atmospheric pressure, telluric currents, infrasound, seismo-acoustic emission, meteorological information). We follow variations in the earth's surface propagate radio waves avoiding reflection on ionosphere. For this reason the distance between stations is less than 60 km and the main source of emission is near (Bod broadcasting transmitter for long- and medium-wave radio, next to Brasov city). In the same time tectonic stress affects the radio propagation in air and it could generates ULF waves in ground (LAI coupling). To reduce the uncertainty is necessary to monitor a location for extended periods of time to outline local and seasonal fluctuations. Solar flares do not affect seismic activity but they produce disturbances in telecommunications networks and power grids. Our ULF monitoring correlated with two local magnetometers does not indicate this so far with our receivers. Our analysis was made during magnetic storms with Kp 7 and 8 according to NOAA satellites. To correlate the results we implemented an application that monitors the satellite EUTELSAT latency compared to WiMAX land communication in the same place. ULF band radio monitoring showed that our receiver is dependent on temperature and that it is necessary to introduce a band pass filter in data analysis. ULF data acquisition is performed by Kinemetrics and National Instruments digitizers with a sampling rate of 100 Hz in Miniseed format and then converted into text files with 1 Hz rate for analysis in very low frequency. In both cases we use spectrum analysis in three bands of frequency with different filters. More results showed that tectonic stress generated by seismicity is more important than effects of solar flares. This work was partially supported by the Partnership in Priority Areas Program - PNII, under MEN-UEFISCDI, DARING Project no. 69/2014 and the Nucleu Program - PN 16-35, Project no. 03 01.

The 3CR Chandra Snapshot Survey: Extragalactic Radio Sources with Redshifts between 1 and 1.5

NASA Astrophysics Data System (ADS)

Stuardi, C.; Missaglia, V.; Massaro, F.; Ricci, F.; Liuzzo, E.; Paggi, A.; Kraft, R. P.; Tremblay, G. R.; Baum, S. A.; O’Dea, C. P.; Wilkes, B. J.; Kuraszkiewicz, J.; Forman, W. R.; Harris, D. E.

2018-04-01

The aim of this paper is to present an analysis of newly acquired X-ray observations of 16 extragalactic radio sources listed in the Third Cambridge Revised (3CR) catalog and not previously observed by Chandra. Observations were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR extragalactic catalog up to z = 1.5. Among the 16 targets, two lie at z < 0.5 (3CR 27 at z = 0.184 and 3CR 69 at z = 0.458) all of the remaining 14 have redshifts between 1.0 and 1.5. In the current sample, there are three compact steep spectrum (CSS) sources, three quasars, and an FR I radio galaxy, while the other nine are FR II radio galaxies. All radio sources have an X-ray counterpart. We measured nuclear X-ray fluxes as well as X-ray emission associated with radio jet knots, hotspots, or lobes in three energy bands: soft (0.5–1 keV), medium (1–2 keV), and hard (2–7 keV). We also performed standard X-ray spectral analysis for the four brightest nuclei. We discovered X-ray emission associated with the radio lobe of 3CR 124, a hotspot of the quasar 3CR 220.2, another hotspot of the radio galaxy 3CR 238, and the jet knot of 3CR 297. We also detected extended X-ray emission around the nuclear region of 3CR 124 and 3CR 297 on scales of several tens of kiloparsecs. Finally, we present an update on the X-ray observations performed with Chandra and XMM-Newton on the entire 3CR extragalactic catalog.

Temporally Adjusted Complex Ambiguity Function Mapping Algorithm for Geolocating Radio Frequency Signals

DTIC Science & Technology

2014-12-01

Introduction 1.1 Background In today’s world of high -tech warfare, we have developed the ability to deploy virtually any type of ordnance quickly and... ANSI Std. 239–18 i THIS PAGE INTENTIONALLY LEFT BLANK ii Approved for public release; distribution is unlimited TEMPORALLY ADJUSTED COMPLEX AMBIGUITY...this time due to time constraints and the high computational complexity involved in the current implementation of the Moss algorithm. Full maps, with

Status of Mars Global Surveyor Science Data Archives

NASA Technical Reports Server (NTRS)

Slavney, S.; Arvidson, R. E.; Guinness, E. A.; Springer, R. J.

2001-01-01

The Mars Global Surveyor has been in orbit around Mars since September 1997, completing its primary mission on January 31, 2001. As of that date the spacecraft had completed more than 8000 mapping orbits. Data from its science instruments, radio science experiment, and SPICE files have been released regularly to the NASA Planetary Data System (PDS) as described in the MGS Archive Plan and Addendum and are available online. Additional information is contained in the original extended abstract.

It's Not What They Play, It's What They Say: A Content Analysis of DJ Chatter.

ERIC Educational Resources Information Center

Lont, Cynthia M.

Focusing on the sex roles portrayed over commercial radio targeting adolescents, a study conducted a content analysis of two radio stations in the Washington, D.C. market (the two stations held an average share of 30 to 35 percent of the adolescent audience in that area). The content analyzed included the advertisements, disc jockey (DJ) chatter,…

Chapter 27: Deja vu All Over Again: Using NVO Tools to Re-Investigate a Complete Sample of Texas Radio Survey Sources

NASA Astrophysics Data System (ADS)

Lucas, Ray A.; Rohde, David; Tamura, Takayuki; van Dyne, Jeffrey

At the first NVO Summer School in September 2004, a complete sample of Texas Radio Survey sources, first derived in 1989 and subsequently observed with the VLA in A-array snapshot mode in 1990, was revisited. The original investigators had never had the occasion to reduce the A-array 5-minute snapshot data, nor to do any other significant follow-up, though the sample still seemed a possibly useful but relatively small study of radio galaxies, AGN, quasars, extragalactic sources, and galaxy clusters, etc. At the time of the original sample definition in late 1989, the best optical material available for the region was the SRC-J plate from the UK Schmidt Telescope in Australia. In much more recent times, the Sloan Digital Sky Survey has included the region in its DR2 data release, so good multicolor optical imaging in a number of standard bandpasses has finally become available. These data, along with other material in the radio, infrared, and (where available) were used to get a better preliminary idea of the nature of the objects in the 1989 sample. We also investigated one of the original questions: whether these radio sources with steeper (or at least non-flat) radio spectra were associated with galaxy clusters, and in some cases higher-redshift galaxy clusters and AGN. A rudimentary web service was created which allowed the user to perform simple cone searches and SIAP image extractions of specified field sizes for multiwavelength data across the electromagnetic spectrum, and a prototype web page was set up which would display the resulting images in wavelength order across the page for sources in the sample. Finally, as an additional investigation, using radio and X-ray IDs as a proxy for AGN which might be associated with large, central cluster galaxies, positional matches of radio and X-ray sources from two much larger catalogs were done using the tool TOPCAT in order to search for the degree of correlation between ID positions, radio luminosity, and cluster ID positions. It was hoped that cross-correlated matches could possibly give some clue to the relationship of these radio sources to galaxy clusters. These preliminary results need more in-depth investigation and are currently being pursued via a NVO grant to the first author. The original VLA 5-minute A-array snapshots have also now been reduced and are complementary in nature to the VLA FIRST data. It is planned to eventually make these reduced VLA A-array data publicas part of a web service via the NVO facilities along with a table of multiwavelength properties for the sources in VOTable format.

The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field

NASA Astrophysics Data System (ADS)

Hale, C. L.; Jarvis, M. J.; Delvecchio, I.; Hatfield, P. W.; Novak, M.; Smolčić, V.; Zamorani, G.

2018-03-01

Dark matter haloes in which galaxies reside are likely to have a significant impact on their evolution. We investigate the link between dark matter haloes and their constituent galaxies by measuring the angular two-point correlation function of radio sources, using recently released 3 GHz imaging over ˜2 deg2 of the Cosmological Evolution Survey (COSMOS) field. We split the radio source population into star-forming galaxies (SFGs) and active galactic nuclei (AGN), and further separate the AGN into radiatively efficient and inefficient accreters. Restricting our analysis to z < 1, we find SFGs have a bias, b = 1.5 ^{+0.1}_{-0.2}, at a median redshift of z = 0.62. On the other hand, AGN are significantly more strongly clustered with b = 2.1 ± 0.2 at a median redshift of 0.7. This supports the idea that AGN are hosted by more massive haloes than SFGs. We also find low accretion rate AGN are more clustered (b = 2.9 ± 0.3) than high accretion rate AGN (b = 1.8^{+0.4}_{-0.5}) at the same redshift (z ˜ 0.7), suggesting that low accretion rate AGN reside in higher mass haloes. This supports previous evidence that the relatively hot gas that inhabits the most massive haloes is unable to be easily accreted by the central AGN, causing them to be inefficient. We also find evidence that low accretion rate AGN appear to reside in halo masses of Mh ˜ 3-4 × 1013 h-1 M⊙ at all redshifts. On the other hand, the efficient accreters reside in haloes of Mh ˜ 1-2 × 1013 h-1 M⊙ at low redshift but can reside in relatively lower mass haloes at higher redshifts. This could be due to the increased prevalence of cold gas in lower mass haloes at z ≥ 1 compared to z < 1.

Mpc-scale diffuse radio emission in two massive cool-core clusters of galaxies

NASA Astrophysics Data System (ADS)

Sommer, Martin W.; Basu, Kaustuv; Intema, Huib; Pacaud, Florian; Bonafede, Annalisa; Babul, Arif; Bertoldi, Frank

2017-04-01

Radio haloes are diffuse synchrotron sources on scales of ˜1 Mpc that are found in merging clusters of galaxies, and are believed to be powered by electrons re-accelerated by merger-driven turbulence. We present measurements of extended radio emission on similarly large scales in two clusters of galaxies hosting cool cores: Abell 2390 and Abell 2261. The analysis is based on interferometric imaging with the Karl G. Jansky Very Large Array, Very Large Array and Giant Metrewave Radio Telescope. We present detailed radio images of the targets, subtract the compact emission components and measure the spectral indices for the diffuse components. The radio emission in A2390 extends beyond a known sloshing-like brightness discontinuity, and has a very steep in-band spectral slope at 1.5 GHz that is similar to some known ultrasteep spectrum radio haloes. The diffuse signal in A2261 is more extended than in A2390 but has lower luminosity. X-ray morphological indicators, derived from XMM-Newton X-ray data, place these clusters in the category of relaxed or regular systems, although some asymmetric features that can indicate past minor mergers are seen in the X-ray brightness images. If these two Mpc-scale radio sources are categorized as giant radio haloes, they question the common assumption of radio haloes occurring exclusively in clusters undergoing violent merging activity, in addition to commonly used criteria for distinguishing between radio haloes and minihaloes.

Radio-Optical Alignments in a Low Radio Luminosity Sample

NASA Technical Reports Server (NTRS)

Lacy, Mark; Ridgway, Susan E.; Wold, Margrethe; Lilje, Per B.; Rawlings, Steve

1999-01-01

We present an optically-based study of the alignment between the radio axes and the optical major axes of eight z approximately 0.7 radio galaxies in a 7C sample. The radio galaxies in this sample are approximately 20-times less radio luminous than 3C galaxies at the same redshift, and are significantly less radio-luminous than any other well-defined samples studied to date. Using Nordic Optical Telescope images taken in good seeing conditions at rest-frame wavelengths just longward of the 4000A break, we find a statistically significant alignment effect in the 7C sample. Furthermore, in two cases where the aligned components are well separated from the host we have been able to confirm spectroscopically that they are indeed at the same redshift as the radio galaxy. However, a quantitative analysis of the alignment in this sample and in a corresponding 3C sample from HST (Hubble Space Telescope) archival data indicates that the percentage of aligned flux may be lower and of smaller spatial scale in the 7C sample. Our study suggests that alignments on the 50-kpc scale are probably closely related to the radio luminosity, whereas those on the 15 kpc scale are not. We discuss these results in the context of popular models for the alignment effect.

Waves in Space Plasmas (WISP)

NASA Technical Reports Server (NTRS)

Calvert, Wynne

1994-01-01

Activities under this project have included participation in the Waves in Space Plasmas (WISP) program, a study of the data processing requirements for WISP, and theoretical studies of radio sounding, ducting, and magnetoionic theory. An analysis of radio sounding in the magnetosphere was prepared.

Complex Signal Kurtosis and Independent Component Analysis for Wideband Radio Frequency Interference Detection

NASA Technical Reports Server (NTRS)

Schoenwald, Adam; Mohammed, Priscilla; Bradley, Damon; Piepmeier, Jeffrey; Wong, Englin; Gholian, Armen

2016-01-01

Radio-frequency interference (RFI) has negatively implicated scientific measurements across a wide variation passive remote sensing satellites. This has been observed in the L-band radiometers SMOS, Aquarius and more recently, SMAP [1, 2]. RFI has also been observed at higher frequencies such as K band [3]. Improvements in technology have allowed wider bandwidth digital back ends for passive microwave radiometry. A complex signal kurtosis radio frequency interference detector was developed to help identify corrupted measurements [4]. This work explores the use of ICA (Independent Component Analysis) as a blind source separation technique to pre-process radiometric signals for use with the previously developed real and complex signal kurtosis detectors.

Radio Astronomy Tools in Python: Spectral-cube, pvextractor, and more

NASA Astrophysics Data System (ADS)

Ginsburg, A.; Robitaille, T.; Beaumont, C.; Rosolowsky, E.; Leroy, A.; Brogan, C.; Hunter, T.; Teuben, P.; Brisbin, D.

2015-12-01

The radio-astro-tools organization has been established to facilitate development of radio and millimeter analysis tools by the scientific community. The first packages developed under its umbrella are: • The spectral-cube package, for reading, writing, and analyzing spectral data cubes • The pvextractor package for extracting position-velocity slices from position-position-velocity cubes along aribitrary paths • The radio-beam package to handle gaussian beams in the context of the astropy quantity and unit framework • casa-python to enable installation of these packages - and any other - into users' CASA environments without conflicting with the underlying CASA package. Community input in the form of code contributions, suggestions, questions and commments is welcome on all of these tools. They can all be found at http://radio-astro-tools.github.io.

Simultaneous long-term monitoring of LS I +61°303 by OVRO and Fermi-LAT

NASA Astrophysics Data System (ADS)

Jaron, Frédéric; Massi, Maria; Kiehlmann, Sebastian; Hovatta, Talvikki

2018-07-01

Previous long-term monitorings of the γ-ray-loud X-ray binary LS I +61°303 have revealed the presence of a long-term modulation of ˜4.5 yr. After 9 yr of simultaneous monitoring of LS I +61°303 by the Owens Valley Radio Observatory and the Fermi-LAT, two cycles of the long-term period are now available. Here we perform timing analysis on the radio and the γ-ray light curves. We confirm the presence of previously detected periodicities at both radio and GeV γ-ray wavelengths. Moreover, we discover an offset of the long-term modulation between radio and γ-ray data which could imply different locations of the radio (15 GHz) and GeV emission along the precessing jet.

Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation

NASA Astrophysics Data System (ADS)

Fry, C. D.; Adams, M.; Gallagher, D. L.; Habash Krause, L.; Rawlins, L.; Suggs, R. M.; Anderson, S. C.

2017-12-01

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. The Amateur Radio community has developed several automated receiving and reporting networks that draw from widely-distributed, automated and manual radio stations to build a near-real time, global picture of changing radio propagation conditions. We used these networks and employed HF radio propagation modeling in our investigation. A Ham Radio Science Citizen Investigation (HamSCI) collaboration with the American Radio Relay League (ARRL) ensured that many thousands of amateur radio operators would be "on the air" communicating on eclipse day, promising an extremely large quantity of data would be collected. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Our expectations were the D-Region ionosphere would be most impacted by the eclipse, enabling over-the-horizon radio propagation on lower HF frequencies (3.5 and 7 MHz) that are typically closed during the middle of the day. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

Downstream migration and multiple dam passage by Atlantic Salmon smolts

USGS Publications Warehouse

Nyqvist, D.; McCormick, Stephen; Greenberg, L.; Ardren, W.R.; Bergman, E.; Calles, O.; Castro-Santos, Theodore R.

2017-01-01

The purpose of this study was to investigate behavior and survival of radio-tagged wild and hatchery-reared landlocked Atlantic Salmon Salmo salar smolts as they migrated past three hydropower dams equipped with fish bypass solutions in the Winooski River, Vermont. Among hatchery-reared smolts, those released early were more likely to initiate migration and did so after less delay than those released late. Once migration was initiated, however, the late-released hatchery smolts migrated at greater speeds. Throughout the river system, hatchery-reared fish performed similarly to wild fish. Dam passage rates varied between the three dams and was highest at the dam where unusually high spill levels occurred throughout the study period. Of the 50 fish that did migrate downstream, only 10% managed to reach the lake. Migration success was low despite the presence of bypass solutions, underscoring the need for evaluations of remedial measures; simply constructing a fishway is not synonymous with providing fish passage.

Source Regions of the Type II Radio Burst Observed During a CME-CME Interaction on 2013 May 22

NASA Technical Reports Server (NTRS)

Makela, P.; Gopalswamy, N.; Reiner, M. J.; Akiyama, S.; Krupar, V.

2016-01-01

We report on our study of radio source regions during the type II radio burst on 2013 May 22 based on direction finding analysis of the Wind/WAVES and STEREO/WAVES (SWAVES) radio observations at decameter-hectometric wavelengths. The type II emission showed an enhancement that coincided with the interaction of two coronal mass ejections (CMEs) launched in sequence along closely spaced trajectories. The triangulation of the SWAVES source directions posited the ecliptic projections of the radio sources near the line connecting the Sun and the STEREO-A spacecraft. The WAVES and SWAVES source directions revealed shifts in the latitude of the radio source, indicating that the spatial location of the dominant source of the type II emission varies during the CME-CME interaction. The WAVES source directions close to 1MHz frequencies matched the location of the leading edge of the primary CME seen in the images of the LASCO/C3 coronagraph. This correspondence of spatial locations at both wavelengths confirms that the CME-CME interaction region is the source of the type II enhancement. Comparison of radio and white-light observations also showed that at lower frequencies scattering significantly affects radio wave propagation.

Current Measures on Radioactive Contamination in Japan: A Policy Situation Analysis.

PubMed

Gilmour, Stuart; Miyagawa, Shoji; Kasuga, Fumiko; Shibuya, Kenji

2016-01-01

The Great East Japan Earthquake on 11th March 2011 and the subsequent Fukushima Dai-ichi nuclear power plant disaster caused radioactive contamination in the surrounding environment. In the immediate aftermath of the accident the Government of Japan placed strict measures on radio-contamination of food, and enhanced radio-contamination monitoring activities. Japan is a pilot country in the WHO Foodborne Disease Burden Epidemiology Reference Group (FERG), and through this initiative has an opportunity to report on policy affecting chemicals and toxins in the food distribution network. Nuclear accidents are extremely rare, and a policy situation analysis of the Japanese government's response to the Fukushima Dai-ichi nuclear accident is a responsibility of Japanese scientists. This study aims to assess Japan government policies to reduce radio-contamination risk and to identify strategies to strengthen food policies to ensure the best possible response to possible future radiation accidents. We conducted a hand search of all publicly available policy documents issued by the Cabinet Office, the Food Safety Commission, the Ministry of Health, Labor and Welfare (MHLW), the Ministry of Agriculture, Forestry and Fishery (MAFF) and prefectural governments concerning food safety standards and changes to radiation and contamination standards since March 11th, 2011. We extracted information on food shipment and sales restrictions, allowable radio-contamination limits, monitoring activities and monitoring results. The standard for allowable radioactive cesium (Cs-134 and Cs-137) of 100 Bq/Kg in general food, 50 Bq/Kg in infant formula and all milk products, and 10 Bq/Kg in drinking water was enforced from April 2012 under the Food Sanitation Law, although a provisional standard on radio-contamination had been applied since the nuclear accident. Restrictions on the commercial sale and distribution of specific meat, vegetable and fish products were released for areas at risk of radioactive contamination. Monitoring of radioactive materials in food products in the prefectures has been mainly conducted before shipment to restrict the distribution of radio-contaminated foods. Between March 2011 and March 2012, 133,832 tests of non-commercial and commercial products were conducted, and 1,204 tests (0.9%) were found to violate the provisional standards. Since April 2012, 278,275 tests were conducted, and 2,372 tests (0.9%) were found to violate the revised standards. MHLW assessment of representative market baskets of foodstuffs at 15 locations throughout Japan between February and March 2014 found very low estimated dietary intake of radioactive cesium (0.0007-0.019 mSv/year), as did assessments of the contents of an average day's food. Monitoring of fisheries products in coastal areas affected by the nuclear accident found very limited and declining radio-contamination of live fish outside of Fukushima prefecture. Fisheries monitoring is of limited geographical scope and covers only certain fishes. Area-specific bans on production and distribution have been effective in preventing radioactive contamination in the Japanese food market. Currently there is no major concern about radioactive cesium concentrations in retail foodstuffs in Japan, and very low levels of contamination at the production and wholesale stage. However, because the residue limits and food safety policies were revised on an ad hoc, emergency basis after the nuclear accident, the monitoring procedure needs to be reviewed based on objective and scientifically rational criteria. A transparent and objective scientific framework is needed for prioritizing foodstuffs for inspection and revising Prefecture-specific restrictions. Monitoring of fishes and other seafood products in the wild should be regularized and the information made more publicly accessible, and monitoring activities expanded to identify foodstuffs that are no longer a food safety risk. Consultation with producers and consumers should be more formalized to ensure their concerns are incorporated into regular policy reviews in an appropriate and transparent manner. However, despite the limited available knowledge on best practice in food control and enforcement of provisional radio-contamination limits after the accident, current Japanese policy is sufficient to protect the Japanese public from major risk of radio-contamination from the commercial food market.

Current Measures on Radioactive Contamination in Japan: A Policy Situation Analysis

PubMed Central

Gilmour, Stuart; Miyagawa, Shoji; Kasuga, Fumiko; Shibuya, Kenji

2016-01-01

Background The Great East Japan Earthquake on 11th March 2011 and the subsequent Fukushima Dai-ichi nuclear power plant disaster caused radioactive contamination in the surrounding environment. In the immediate aftermath of the accident the Government of Japan placed strict measures on radio-contamination of food, and enhanced radio-contamination monitoring activities. Japan is a pilot country in the WHO Foodborne Disease Burden Epidemiology Reference Group (FERG), and through this initiative has an opportunity to report on policy affecting chemicals and toxins in the food distribution network. Nuclear accidents are extremely rare, and a policy situation analysis of the Japanese government’s response to the Fukushima Dai-ichi nuclear accident is a responsibility of Japanese scientists. This study aims to assess Japan government policies to reduce radio-contamination risk and to identify strategies to strengthen food policies to ensure the best possible response to possible future radiation accidents. Methods and Findings We conducted a hand search of all publicly available policy documents issued by the Cabinet Office, the Food Safety Commission, the Ministry of Health, Labor and Welfare (MHLW), the Ministry of Agriculture, Forestry and Fishery (MAFF) and prefectural governments concerning food safety standards and changes to radiation and contamination standards since March 11th, 2011. We extracted information on food shipment and sales restrictions, allowable radio-contamination limits, monitoring activities and monitoring results. The standard for allowable radioactive cesium (Cs-134 and Cs-137) of 100 Bq/Kg in general food, 50 Bq/Kg in infant formula and all milk products, and 10 Bq/Kg in drinking water was enforced from April 2012 under the Food Sanitation Law, although a provisional standard on radio-contamination had been applied since the nuclear accident. Restrictions on the commercial sale and distribution of specific meat, vegetable and fish products were released for areas at risk of radioactive contamination. Monitoring of radioactive materials in food products in the prefectures has been mainly conducted before shipment to restrict the distribution of radio-contaminated foods. Between March 2011 and March 2012, 133,832 tests of non-commercial and commercial products were conducted, and 1,204 tests (0.9%) were found to violate the provisional standards. Since April 2012, 278,275 tests were conducted, and 2,372 tests (0.9%) were found to violate the revised standards. MHLW assessment of representative market baskets of foodstuffs at 15 locations throughout Japan between February and March 2014 found very low estimated dietary intake of radioactive cesium (0.0007–0.019 mSv/year), as did assessments of the contents of an average day’s food. Monitoring of fisheries products in coastal areas affected by the nuclear accident found very limited and declining radio-contamination of live fish outside of Fukushima prefecture. Fisheries monitoring is of limited geographical scope and covers only certain fishes. Conclusions Area-specific bans on production and distribution have been effective in preventing radioactive contamination in the Japanese food market. Currently there is no major concern about radioactive cesium concentrations in retail foodstuffs in Japan, and very low levels of contamination at the production and wholesale stage. However, because the residue limits and food safety policies were revised on an ad hoc, emergency basis after the nuclear accident, the monitoring procedure needs to be reviewed based on objective and scientifically rational criteria. A transparent and objective scientific framework is needed for prioritizing foodstuffs for inspection and revising Prefecture-specific restrictions. Monitoring of fishes and other seafood products in the wild should be regularized and the information made more publicly accessible, and monitoring activities expanded to identify foodstuffs that are no longer a food safety risk. Consultation with producers and consumers should be more formalized to ensure their concerns are incorporated into regular policy reviews in an appropriate and transparent manner. However, despite the limited available knowledge on best practice in food control and enforcement of provisional radio-contamination limits after the accident, current Japanese policy is sufficient to protect the Japanese public from major risk of radio-contamination from the commercial food market. PMID:27007509

MC 2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finner, Kyle; Jee, M. James; Golovich, Nathan

The second most significant detection of the Planck Sunyaev-Zel'dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is locatedmore » $$\\sim 400\\,\\mathrm{kpc}$$ NW of the X-ray peak and the other $$\\sim 2.8$$ Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. Here, we present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass $${M}_{200{\\rm{c}}}={1.59}_{-0.22}^{+0.25}\\times {10}^{15}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass $${M}_{200{\\rm{c}}}={1.16}_{-0.13}^{+0.15}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ located $$\\sim 400\\,\\mathrm{kpc}$$ to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected $$\\sim 2$$ Mpc to the SE of the X-ray peak with mass $${M}_{200{\\rm{c}}}={1.68}_{-0.20}^{+0.22}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$. This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, $${M}_{200{\\rm{c}}}={1.87}_{-0.22}^{+0.24}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$, is NW of the X-ray peak and beyond the NW radio relic.« less

MC 2: Subaru and Hubble Space Telescope Weak-lensing Analysis of the Double Radio Relic Galaxy Cluster PLCK G287.0+32.9

DOE PAGES

Finner, Kyle; Jee, M. James; Golovich, Nathan; ...

2017-12-11

The second most significant detection of the Planck Sunyaev-Zel'dovich survey, PLCK G287.0+32.9 (z = 0.385), boasts two similarly bright radio relics and a radio halo. One radio relic is locatedmore » $$\\sim 400\\,\\mathrm{kpc}$$ NW of the X-ray peak and the other $$\\sim 2.8$$ Mpc to the SE. This large difference suggests that a complex merging scenario is required. A key missing puzzle for the merging scenario reconstruction is the underlying dark matter distribution in high resolution. Here, we present a joint Subaru Telescope and Hubble Space Telescope weak-lensing analysis of the cluster. Our analysis shows that the mass distribution features four significant substructures. Of the substructures, a primary cluster of mass $${M}_{200{\\rm{c}}}={1.59}_{-0.22}^{+0.25}\\times {10}^{15}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ dominates the weak-lensing signal. This cluster is likely to be undergoing a merger with one (or more) subcluster whose mass is approximately a factor of 10 lower. One candidate is the subcluster of mass $${M}_{200{\\rm{c}}}={1.16}_{-0.13}^{+0.15}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$ located $$\\sim 400\\,\\mathrm{kpc}$$ to the SE. The location of this subcluster suggests that its interaction with the primary cluster could be the source of the NW radio relic. Another subcluster is detected $$\\sim 2$$ Mpc to the SE of the X-ray peak with mass $${M}_{200{\\rm{c}}}={1.68}_{-0.20}^{+0.22}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$. This SE subcluster is in the vicinity of the SE radio relic and may have created the SE radio relic during a past merger with the primary cluster. The fourth subcluster, $${M}_{200{\\rm{c}}}={1.87}_{-0.22}^{+0.24}\\times {10}^{14}\\ {h}_{70}^{-1}\\ {M}_{\\odot }$$, is NW of the X-ray peak and beyond the NW radio relic.« less

The Metal Oxide Space Clouds (MOSC) Experiment: High Frequency (HF) Signatures and Interactions with the Ambient Ionosphere

NASA Astrophysics Data System (ADS)

Groves, K. M.; Caton, R. G.; Pedersen, T. R.; Parris, R. T.; Su, Y.; Cannon, P. S.; Jackson-booth, N. K.; Angling, M. J.; Retterer, J. M.

2013-12-01

With support from the NASA sounding rocket team, AFRL performed two separate 5 kg releases of samarium metal vapor in the lower F-region near Kwajalein Atoll in May 2013. A fraction of the samarium subsequently ionized forming a plasma cloud that persisted for tens of minutes to hours in the post-sunset period. Numerous sensors were used to characterize the clouds including the ALTAIR incoherent scatter radar, multiple GPS and optical instruments, satellite radio beacons, and a dedicated network of high frequency (HF) radio links. The primary objectives of the experiments were to understand the dynamics, evolution and chemistry of Sm atoms in the earth's upper atmosphere. Sm is predicted to both photo-ionize and chemi-ionize through charge exchange with neutral oxygen (O). Ionization rates and loss reactions are not well known. A secondary objective was to understand the interaction of an artificial plasma cloud with the low latitude ionosphere during the pre-reversal enhancement period leading up to the post-sunset development of large-scale Rayleigh-Taylor instability. It was initially hoped that the introduction of the artificial plasma might be sufficient to quench the development of the instability by maintaining high conductivity within the affected flux tubes. Modeling results showed that this result was unlikely due to the relatively small amount of material being released. However, it appeared possible that the presence of SmO+ near the bottomside of the F-region might be capable of reducing the formation of short-scale irregularities within the larger Rayleigh-Taylor 'bubbles'. Indeed, preliminary results indicate that the artificial layers, positioned at 170 and 180 km respectively, did interact with the overlying F region and in at least one case, cause a decrease in the short-scale component of the natural irregularity spectrum. The results suggest that it may be possible to mitigate the formation of low-latitude irregularities responsible for radio wave scintillation with a MOSC-based approach.

Concept and Analysis of a Satellite for Space-Based Radio Detection of Ultra-High Energy Cosmic Rays

NASA Astrophysics Data System (ADS)

Romero-Wolf, Andrew; Gorham, P.; Booth, J.; Chen, P.; Duren, R. M.; Liewer, K.; Nam, J.; Saltzberg, D.; Schoorlemmer, H.; Wissel, S.; Zairfian, P.

2014-01-01

We present a concept for on-orbit radio detection of ultra-high energy cosmic rays (UHECRs) that has the potential to provide collection rates of ~100 events per year for energies above 10^20 eV. The synoptic wideband orbiting radio detector (SWORD) mission's high event statistics at these energies combined with the pointing capabilities of a space-borne antenna array could enable charged particle astronomy. The detector concept is based on ANITA's successful detection UHECRs where the geosynchrotron radio signal produced by the extended air shower is reflected off the Earth's surface and detected in flight.

Bayesian analysis of X-ray jet features of the high redshift quasar jets observed with Chandra

NASA Astrophysics Data System (ADS)

McKeough, Kathryn; Siemiginowska, Aneta; Kashyap, Vinay; Stein, Nathan; Cheung, Chi C.

2015-01-01

X-ray emission of powerful quasar jets may be a result of the inverse Compton (IC) process in which the Cosmic Microwave Background (CMB) photons gain energy by interactions with the jet's relativistic electrons. However, there is no definite evidence that IC/CMB process is responsible for the observed X-ray emission of large scale jets. A step toward understanding the X-ray emission process is to study the Radio and X-ray morphologies of the jet. Results from Chandra X-ray and multi-frequency VLA imaging observations of a sample of 11 high- redshift (z > 2) quasars with kilo-parsec scale radio jets are reported. The sample consists of a set of four z ≥ 3.6 flat-spectrum radio quasars, and seven intermediate redshift (z = 2.1 - 2.9) quasars comprised of four sources with integrated steep radio spectra and three with flat radio spectra.We implement a Bayesian image analysis program, Low-count Image Reconstruction and Analysis (LIRA) , to analyze jet features in the X-ray images of the high redshift quasars. Out of the 36 regions where knots are visible in the radio jets, nine showed detectable X-ray emission. Significant detections are based on the upper bound p-value test based on LIRA simulations. The X-ray and radio properties of this sample combined are examined and compared to lower-redshift samples.This work is supported in part by the National Science Foundation REU and the Department of Defense ASSURE programs under NSF Grant no.1262851 and by the Smithsonian Institution, and by NASA Contract NAS8-39073 to the Chandra X-ray Center (CXC). This research has made use of data obtained from the Chandra Data Archive and Chandra Source Catalog, and software provided by the CXC in the application packages CIAO, ChIPS, and Sherpa. Work is also supported by the Chandra grant GO4-15099X.

Recent results of the LOPES experiment

NASA Astrophysics Data System (ADS)

Haungs, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Ender, M.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Link, K.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Mayer, H. J.; Melissas, M.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Toma, G.; Trinchero, G.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; Lopes Collaboration

2009-12-01

LOPES measures radio pulses from extensive air showers and aims to calibrate the emitted signal in the primary energy range of 10 16-10 18 eV. LOPES, a digital radio interferometer using high bandwidths and fast data processing, is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and profits from the reconstructed air shower observables of KASCADE-Grande. We report about recent analysis results of the radio signals measured by LOPES.

Spatial and temporal characteristics of flare energy release determined from X-ray and radio imaging observations

NASA Technical Reports Server (NTRS)

Hernandez, A. M.; Machado, M. E.; Vilmer, N.; Trottet, G.

1986-01-01

Using the Hard X-ray Imaging Spectrometer (HXIS) from the Solar Maximum Mission Satellite, the morphological aspects and temporal evolution of three major flares which occurred on June 29, 1980 are studied. One of these events, observed at 10:40 UT, is analyzed in particular detail, including Hard X-ray Burst Spectrometer (HXRBS) data and metric wavelength data from the Nancay radioheliograph. The flares occurred during the interaction of two distinct magnetic structures. There is an early onset phase during which there is a weak level of particle acceleration, perhaps accompanied by strong heating within the magnetic interaction region. The impulsive phase of high power energy release is associated with a major interaction between the two structures and accompanied by strong acceleration and heating.

ARTS, the Atmospheric Radiative Transfer Simulator - version 2.2, the planetary toolbox edition

NASA Astrophysics Data System (ADS)

Buehler, Stefan A.; Mendrok, Jana; Eriksson, Patrick; Perrin, Agnès; Larsson, Richard; Lemke, Oliver

2018-04-01

This article describes the latest stable release (version 2.2) of the Atmospheric Radiative Transfer Simulator (ARTS), a public domain software for radiative transfer simulations in the thermal spectral range (microwave to infrared). The main feature of this release is a planetary toolbox that allows simulations for the planets Venus, Mars, and Jupiter, in addition to Earth. This required considerable model adaptations, most notably in the area of gaseous absorption calculations. Other new features are also described, notably radio link budgets (including the effect of Faraday rotation that changes the polarization state) and the treatment of Zeeman splitting for oxygen spectral lines. The latter is relevant, for example, for the various operational microwave satellite temperature sensors of the Advanced Microwave Sounding Unit (AMSU) family.

An orbital angular momentum radio communication system optimized by intensity controlled masks effectively: Theoretical design and experimental verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Xinlu; Applied Optics Beijing Area Major Laboratory, Department of Physics, Beijing Normal University, Beijing 100875; Huang, Shanguo, E-mail: shghuang@bupt.edu.cn

A system of generating and receiving orbital angular momentum (OAM) radio beams, which are collectively formed by two circular array antennas (CAAs) and effectively optimized by two intensity controlled masks, is proposed and experimentally investigated. The scheme is effective in blocking of the unwanted OAM modes and enhancing the power of received radio signals, which results in the capacity gain of system and extended transmission distance of the OAM radio beams. The operation principle of the intensity controlled masks, which can be regarded as both collimator and filter, is feasible and simple to realize. Numerical simulations of intensity and phasemore » distributions at each key cross-sectional plane of the radio beams demonstrate the collimated results. The experimental results match well with the theoretical analysis and the receive distance of the OAM radio beam at radio frequency (RF) 20 GHz is extended up to 200 times of the wavelength of the RF signals, the measured distance is 5 times of the original measured distance. The presented proof-of-concept experiment demonstrates the feasibility of the system.« less

Interplanetary radio storms. 2: Emission levels and solar wind speed in the range 0.05-0.8 AU

NASA Technical Reports Server (NTRS)

Bougeret, J. L.; Fainberg, J.; Stone, R. G.

1982-01-01

Storms of interplanetary type III radio bursts (IP storms) are commonly observed in the interplanetry medium by the ISEE-3 radio instrument. This instrument has the capability of accurately determining the arrival direction of the radio emission. At each observing frequency, the storm radio sources are tracked as they cross the line-of-sight to the Sun. Usng a simple model, the emission levels are determined at a number of radio frequencies for four separate storms. The IP storm radiation is found to occur in regions of enhanced density at levels of 0.05 to 0.8 AU. The density in these enhancements falls off faster than R(-2). The solar wind speed in the storm region is also measured. The analysis is consistent with steady conditions in the storm region during a few days around the central meridian passage of the storm. The comparison with average in situ density measurements compiled from the HELIOS 1-2 observations favors type III storm burst radio emission at the harmonic of the local plasma frequency.

Long-Term Stability of Radio Sources in VLBI Analysis

NASA Technical Reports Server (NTRS)

Engelhardt, Gerald; Thorandt, Volkmar

2010-01-01

Positional stability of radio sources is an important requirement for modeling of only one source position for the complete length of VLBI data of presently more than 20 years. The stability of radio sources can be verified by analyzing time series of radio source coordinates. One approach is a statistical test for normal distribution of residuals to the weighted mean for each radio source component of the time series. Systematic phenomena in the time series can thus be detected. Nevertheless, an inspection of rate estimation and weighted root-mean-square (WRMS) variations about the mean is also necessary. On the basis of the time series computed by the BKG group in the frame of the ICRF2 working group, 226 stable radio sources with an axis stability of 10 as could be identified. They include 100 ICRF2 axes-defining sources which are determined independently of the method applied in the ICRF2 working group. 29 stable radio sources with a source structure index of less than 3.0 can also be used to increase the number of 295 ICRF2 defining sources.

20-Year Status Report on the Human Systems Integration (HSI)/Manpower and Personnel Integration (MANPRINT) Soldier Survivability Domain

DTIC Science & Technology

2015-05-01

ARL/SLAD Electromagnetic Vulnerability Analysis Facility: provides the results of radio frequency detection and jamming susceptibility analysis of the...Lecture 10: Environment/Weather*  Lecture 11 : Habitability*  Lecture 12: Air Composition and Pressure*  Lecture 14: Communications ...Lecture 15: Radio Frequency /Microwave/E3I  Lecture 16: Vibration/Acoustic Noise  Lecture 17: Acceleration/Stabilization  Lecture 18

The Einstein@Home Gamma-ray Pulsar Survey. II. Source Selection, Spectral Analysis, and Multiwavelength Follow-up

NASA Astrophysics Data System (ADS)

Wu, J.; Clark, C. J.; Pletsch, H. J.; Guillemot, L.; Johnson, T. J.; Torne, P.; Champion, D. J.; Deneva, J.; Ray, P. S.; Salvetti, D.; Kramer, M.; Aulbert, C.; Beer, C.; Bhattacharyya, B.; Bock, O.; Camilo, F.; Cognard, I.; Cuéllar, A.; Eggenstein, H. B.; Fehrmann, H.; Ferrara, E. C.; Kerr, M.; Machenschalk, B.; Ransom, S. M.; Sanpa-Arsa, S.; Wood, K.

2018-02-01

We report on the analysis of 13 gamma-ray pulsars discovered in the Einstein@Home blind search survey using Fermi Large Area Telescope (LAT) Pass 8 data. The 13 new gamma-ray pulsars were discovered by searching 118 unassociated LAT sources from the third LAT source catalog (3FGL), selected using the Gaussian Mixture Model machine-learning algorithm on the basis of their gamma-ray emission properties being suggestive of pulsar magnetospheric emission. The new gamma-ray pulsars have pulse profiles and spectral properties similar to those of previously detected young gamma-ray pulsars. Follow-up radio observations have revealed faint radio pulsations from two of the newly discovered pulsars and enabled us to derive upper limits on the radio emission from the others, demonstrating that they are likely radio-quiet gamma-ray pulsars. We also present results from modeling the gamma-ray pulse profiles and radio profiles, if available, using different geometric emission models of pulsars. The high discovery rate of this survey, despite the increasing difficulty of blind pulsar searches in gamma rays, suggests that new systematic surveys such as presented in this article should be continued when new LAT source catalogs become available.

Construction of a Radio-Telescope Prototype in the 12 GHz Band

NASA Astrophysics Data System (ADS)

Ordóñez, J.; Quijano, A.; Luna, A.

2017-07-01

Radio astronomy is important in the branch of the Astronomy that studies the celestial bodies through their emissions in the domain of the radio waves, to obtain information of these bodies, astronomers must design new types of telescopes that can capture radiation at different wavelengths, including radio telescopes. This paper presents the construction of a prototype of an educational radio telescope, which is made using materials that are easily accessible and inexpensive. The construction of a radio telescope, will allow to carry out research in the field of radio astronomy, since at present it has not been possible to penetrate this branch due to the lack of an adequate equipment in the University of Nariño. The issues that are addressed in the construction of this instrument, its use and the analysis of the data, are very varied and with a high content of multidiciplinariety, gathering basic topics in areas such as astrophysics, physics, electronics, computing, mechanics, which are necessary for Concrete the efficient use of this instrument. For the development of the project, it counts with the advice of the director and researcher of the astronomical observatory of the University of Nariño MSc. Alberto Quijano Vodniza and Dr. Abraham Luna Castellanos of the National Institute of Astrophysics, Optics and Electronics INAOE. In addition to the construction of radiotelescope the final phase consists of the storage and analysis of data obtained with the observation of some celestial bodies that comply with The range in the 12 GHz band for study.

The Pearson-Readhead Survey of Compact Extragalactic Radio Sources from Space. II. Analysis of Source Properties

NASA Astrophysics Data System (ADS)

Lister, M. L.; Tingay, S. J.; Preston, R. A.

2001-06-01

We have performed a multidimensional correlation analysis on the observed properties of a statistically complete core-selected sample of compact radio-loud active galactic nuclei based on data from the VLBI Space Observing Programme (Paper I) and previously published studies. Our sample is drawn from the well-studied Pearson-Readhead (PR) survey and is ideally suited for investigating the general effects of relativistic beaming in compact radio sources. In addition to confirming many previously known correlations, we have discovered several new trends that lend additional support to the beaming model. These trends suggest that the most highly beamed sources in core-selected samples tend to have (1) high optical polarizations; (2) large parsec- kiloparsec-scale jet misalignments; (3) prominent VLBI core components; (4) one-sided, core, or halo radio morphology on kiloparsec scales; (5) narrow emission line equivalent widths; and (6) a strong tendency for intraday variability at radio wavelengths. We have used higher resolution space and ground-based VLBI maps to confirm the bimodality of the jet misalignment distribution for the PR survey and find that the sources with aligned parsec- and kiloparsec-scale jets generally have arcsecond-scale radio emission on both sides of the core. The aligned sources also have broader emission line widths. We find evidence that the BL Lacertae objects in the PR survey are all highly beamed and have very similar properties to the high optically polarized quasars, with the exception of smaller redshifts. A cluster analysis on our data shows that after partialing out the effects of redshift, the luminosities of our sample objects in various wave bands are generally well correlated with each other but not with other source properties.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Richard S.; Carlson, Thomas J.; Welch, Abigail E.

A multifactor study was conducted by Battelle for the US Army Corps of Engineers to assess the significance of the presence of a radio telemetry transmitter on the effects of rapid decompression from simulated hydro turbine passage on depth acclimated juvenile run-of-the-river Chinook salmon. Study factors were: (1) juvenile chinook salmon age;, subyearling or yearling, (2) radio transmitter present or absent, (3) three transmitter implantation factors: gastric, surgical, and no transmitter, and (4) four acclimation depth factors: 1, 10, 20, and 40 foot submergence equivalent absolute pressure, for a total of 48 unique treatments. Exposed fish were examined for changesmore » in behavior, presence or absence of barotrauma injuries, and immediate or delayed mortality. Logistic models were used to test hypotheses that addressed study objectives. The presence of a radio transmitter was found to significantly increase the risk of barotrauma injury and mortality at exposure to rapid decompression. Gastric implantation was found to present a higher risk than surgical implantation. Fish were exposed within 48 hours of transmitter implantation so surgical incisions were not completely healed. The difference in results obtained for gastric and surgical implantation methods may be the result of study design and the results may have been different if tested fish had completely healed surgical wounds. However, the test did simulate the typical surgical-release time frame for in-river telemetry studies of fish survival so the results are probably representative for fish passing through a turbine shortly following release into the river. The finding of a significant difference in response to rapid decompression between fish bearing radio transmitters and those not implies a bias may exist in estimates of turbine passage survival obtained using radio telemetry. However, the rapid decompression (simulated turbine passage) conditions used for the study represented near worst case exposure for fish passing through turbines. At this time, insufficient data exist about the distribution of river-run fish entering turbines, and particularly, the distribution of fish passing through turbine runners, to extrapolate study findings to the population of fish passing through FCRPS turbines. This study is the first study examining rapid decompression study to include acclimation depth as an experimental factor for physostomous fish. We found that fish acclimated to deeper depth were significantly more vulnerable to barotrauma injury and death. Insufficient information about the distribution of fish entering turbines and their depth acclimation currently exists to extrapolate these findings to the population of fish passing through turbines. However, the risk of barotrauma for turbine-passed fish could be particularly high for subyearling Chinook salmon that migrate downstream at deeper depths late in the early summer portion of the outmigration. Barotrauma injuries led to immediate mortality delayed mortality and potential mortality due to increased susceptibility to predation resulting from loss of equilibrium or swim bladder rupture.« less

Survival of captive-reared Hispaniolan Parrots released in Parque Nacional del Este, Dominican Republic

USGS Publications Warehouse

Collazo, J.A.; White, T.H.; Vilella, F.J.; Guerrero, S.A.

2003-01-01

We report first-year survival rates of 49 captive-reared Hispaniolan Parrots (Amazona ventralis) released in Parque Nacional del Este, Dominican Republic. Our goal was to learn about factors affecting postrelease survival. Specifically, we tested if survival was related to movements and whether modifying prerelease protocols influenced survival rates. We also estimated survival in the aftermath of Hurricane Georges (22 September 1998). Twenty-four parrots, fitted with radio-transmitters, were released between 14 September and 12 December 1997. Twenty-five more were released between 29 June and 16 September 1998. First-year survival rates were 30% in 1997 and 29% in 1998. Survival probability was related to bird mobility. In contrast to birds released in 1997, none of the 25 parrots released in 1998 suffered early postrelease mortality (i.e., 3-5 days after release). Two adjustments to prerelease protocols (increased exercise and reduced blood sampling) made in 1998 may have contributed to differences in mobility and survival between years. The reduction of early postrelease mortality in 1998 was encouraging, as was the prospect for higher first-year survival (e.g., 30% to 65%). Only one death was attributed to the immediate impact of the hurricane. Loss of foraging resources was likely a major contributor to ensuing mortality. Birds increased their mobility, presumably in search of food. Survival rates dropped 23% in only eight weeks posthurricane. This study underscores the value of standardized prerelease protocols, and of estimating survival and testing for factors that might influence it. Inferences from such tests will provide the best basis to make adjustments to a release program.

Multiverso: Rock'n'Astronomy

NASA Astrophysics Data System (ADS)

Caballero, J. A.

2012-05-01

In the last few years, there have been several projects involving astronomy and classical music. But have a rock band ever appeared at a science conference or an astronomer at a rock concert? We present a project, Multiverso, in which we mix rock and astronomy, together with poetry and video art (Caballero, 2010). The project started in late 2009 and has already reached tens of thousands people in Spain through the release of an album, several concert-talks, television, radio, newspapers and the internet.

Recent progress on improving ICRF coupling and reducing RF-specific impurities in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Zhang, Wei; Bobkov, Volodymyr; Noterdaeme, Jean-Marie; Tierens, Wouter; Aguiam, Diogo; Bilato, Roberto; Coster, David; Colas, Laurent; Crombé, Kristel; Fuenfgelder, Helmut; Faugel, Helmut; Feng, Yuhe; Jacquot, Jonathan; Jacquet, Philippe; Kallenbach, Arne; Kostic, Ana; Lunt, Tilmann; Maggiora, Riccardo; Ochoukov, Roman; Silva, Antonio; Suárez, Guillermo; Tuccilo, Angelo A.; Tudisco, Onofrio; Usoltceva, Mariia; Van Eester, Dirk; Wang, Yongsheng; Yang, Qingxi

2017-10-01

The recent scientific research on ASDEX Upgrade (AUG) has greatly advanced solutions to two issues of Radio Frequency (RF) heating in the Ion Cyclotron Range of Frequencies (ICRF): (a) the coupling of ICRF power to the plasma is significantly improved by density tailoring with local gas puffing; (b) the release of RF-specific impurities is significantly reduced by minimizing the RF near field with 3-strap antennas. This paper summarizes the applied methods and reviews the associated achievements.

Armed Drones and Targeted Killing: Policy Implications for Their Use in Deterring Violent Extremism

DTIC Science & Technology

2017-04-17

launched some 200 pilotless balloons mounted with bombs against the city of Venice.”6 It was not until World War I, with the advent of radio...into World War II, weapons manufacturers began fitting them with bombs and explosives to give them a strike capability. Bombers, like the B-17...would release these “flying bombs ”, which were more akin to guided missiles, near a target area, and then a pilot would remotely guide the drone to its

Protein Oxidation Implicated as the Primary Determinant of Bacterial Radioresistance

DTIC Science & Technology

2007-04-01

the facultative anaerobic, radio- resistant bacterium Lactobacillus plantarum [1,22] accumulates 20–25 mM Mn(II) [23]. For an irradiated cell...in dH2O at 0 8C and pre-conditioned to be anaerobic, H2O2 was released by D. radiodurans (;23 105 M) and L. plantarum (;6 3 105 M), in which the...non-irradiated D. radiodurans or L. plantarum control samples, nor by irradiated S. oneidensis (Figure 5A), which accumulates substantially more Fe

Peak-Flux-Density Spectra of Large Solar Radio Bursts and Proton Emission from Flares.

DTIC Science & Technology

1985-08-19

of the microwave peak (Z 1000 sfu in U-bursts) served as an indicator that the energy release during the impulsive phase was sufficient to produce a... energy or wave- length tends to be prominent in all, and cautions about over-interpreting associa- tions/correlations observed in samples of big flares...Sung, L. S., and McDonald, F. B. (1975) The variation of solar proton energy spectra and size distribution with helio- longitude, Sol. Phys. 41: 189. 28

Optical Positions of ICRF Sources from CTIO 1.0M Data

DTIC Science & Technology

2015-01-01

proyecto del USNO para enlazar los sistemas de referencia en radio y óptico, se tomaron datos con el telescopio CTIO de 1.0 m in 2009. Los primeros...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE...AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES RevMexAA (Serie de Conferencias), 46, 83â\\ග (2015) 14

GREEN BANK TELESCOPE AND SWIFT X-RAY TELESCOPE OBSERVATIONS OF THE GALACTIC CENTER RADIO MAGNETAR SGR J1745–2900

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynch, Ryan S.; Archibald, Robert F.; Kaspi, Victoria M.

We present results from eight months of Green Bank Telescope 8.7 GHz observations and nearly 18 months of Swift X-ray telescope observations of the radio magnetar SGR J1745–2900. We tracked the radio and X-ray flux density, polarization properties, profile evolution, rotation, and single-pulse behavior. We identified two main periods of activity. The first is characterized by approximately 5.5 months of relatively stable evolution in radio flux density, rotation, and profile shape, while in the second these properties varied substantially. Specifically, a third profile component emerged and the radio flux also became more variable. The single pulse properties also changed, mostmore » notably with a larger fraction of pulses with pulse widths ∼5–20 ms in the erratic state. Bright single pulses are well described by a log-normal energy distribution at low energies, but with an excess at high energies. The 2–10 keV flux decayed steadily since the initial X-ray outburst, while the radio flux remained stable to within ∼20% during the stable state. A joint pulsar timing analysis of the radio and X-ray data shows a level of timing noise unprecedented in a radio magnetar, though during the time covered by the radio data alone the timing noise was at a level similar to that observed in other radio magnetars. While SGR J1745–2900 is similar to other radio magnetars in many regards, it differs by having experienced a period of relative stability in the radio that now appears to have ended, while the X-ray properties evolved independently.« less

Analysis of type 3 solar radio bursts observed at kilometric wavelengths from the OGO-5 satellite

NASA Technical Reports Server (NTRS)

Alvarez, H.

1971-01-01

Research was conducted to analyze the data on solar radio bursts obtained by the OGO-5 satellite. Since the wavelengths corresponding to the three lowest frequencies of observations exceeded one kilometer, the bursts detected in those channels were designated as kilometer-waves. The data search covered approximately 9200 hours between March 1968 and February 1970, and included the maximum of solar cycle No. 20. The study concentrated on 64 Type 3 solar radio events reaching frequencies equal or lower than 0.35 MHz. This selection criteria led to the choice of the most intense radio events. Measurements included: times of start, times of decay, and amplitudes of the 64 events. The consistency of the results, within the accuracy of the measurements, lends support to some of the assumptions made for the analysis, notably, the validity of the local plasma hypothesis, the constancy of the exciter particles velocity, and spiral shape of their trajectory.

Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1988-01-01

In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

Mean and extreme radio properties of quasars and the origin of radio emission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kratzer, Rachael M.; Richards, Gordon T.

2015-02-01

We investigate the evolution of both the radio-loud fraction (RLF) and (using stacking analysis) the mean radio loudness of quasars. We consider how these properties evolve as a function of redshift and luminosity, black hole (BH) mass and accretion rate, and parameters related to the dominance of a wind in the broad emission-line region. We match the FIRST source catalog to samples of luminous quasars (both spectroscopic and photometric), primarily from the Sloan Digital Sky Survey. After accounting for catastrophic errors in BH mass estimates at high redshift, we find that both the RLF and the mean radio luminosity increasemore » for increasing BH mass and decreasing accretion rate. Similarly, both the RLF and mean radio loudness increase for quasars that are argued to have weaker radiation line driven wind components of the broad emission-line region. In agreement with past work, we find that the RLF increases with increasing optical/UV luminosity and decreasing redshift, while the mean radio loudness evolves in the exact opposite manner. This difference in behavior between the mean radio loudness and the RLF in L−z may indicate selection effects that bias our understanding of the evolution of the RLF; deeper surveys in the optical and radio are needed to resolve this discrepancy. Finally, we argue that radio-loud (RL) and radio-quiet (RQ) quasars may be parallel sequences, but where only RQ quasars at one extreme of the distribution are likely to become RL, possibly through slight differences in spin and/or merger history.« less

Fish-Eye Observing with Phased Array Radio Telescopes

NASA Astrophysics Data System (ADS)

Wijnholds, S. J.

The radio astronomical community is currently developing and building several new radio telescopes based on phased array technology. These telescopes provide a large field-of-view, that may in principle span a full hemisphere. This makes calibration and imaging very challenging tasks due to the complex source structures and direction dependent radio wave propagation effects. In this thesis, calibration and imaging methods are developed based on least squares estimation of instrument and source parameters. Monte Carlo simulations and actual observations with several prototype show that this model based approach provides statistically and computationally efficient solutions. The error analysis provides a rigorous mathematical framework to assess the imaging performance of current and future radio telescopes in terms of the effective noise, which is the combined effect of propagated calibration errors, noise in the data and source confusion.

Determining Thunderstorm Electric Fields using Radio Emission from Cosmic-Ray Air Showers

NASA Astrophysics Data System (ADS)

Hare, B.; Scholten, O.; Trinh, G. T. N.; Ebert, U.; Rutjes, C.

2017-12-01

We report on a novel non-intrusive way to investigate electric fields in thunderclouds.Energetic cosmic rays penetrating the atmosphere create a particle avalanche called an extensive air shower. The front of the shower is a plasma cloud that contains 10^6 or more free electrons and positrons moving towards the Earth's surface at the speed of light. The electric fields that exists in thunderclouds induces electric currents in the plasma cloud that emit radio waves. The radio footprint for intensity, linear and circular polarization thus contains the finger print of the atmospheric electric fields along the path of the air shower.Here we report on the analysis of many cosmic-ray radio footprints as have been measured at LOFAR, a dense array of simple radio antennas (several thousands of dual-polarized antennas) primarily developed for radio-astronomy observations. We show that this method can be used to determine the charge structure in thunderclouds and discuss the accuracy of the method. We have observed seasonal dependencies.

Satellite observations of type III solar radio bursts at low frequencies

NASA Technical Reports Server (NTRS)

Fainberg, J.; Stone, R. G.

1974-01-01

Type III solar radio bursts have been observed from 10 MHz to 10 kHz by satellite experiments above the terrestrial plasmasphere. Solar radio emission in this frequency range results from excitation of the interplanetary plasma by energetic particles propagating outward along open field lines over distances from 5 earth radii to at least 1 AU from the sun. This review summarizes the morphology, characteristics, and analysis of individual as well as storms of bursts. Substantial evidence is available to show that the radio emission is observed at the second harmonic instead of the fundamental of the plasma frequency. This brings the density scale derived by radio observations into better agreement with direct solar wind density measurements at 1 AU and relaxes the requirement for type III propagation along large density-enhanced regions. This density scale with the measured direction of arrival of the radio burst allows the trajectory of the exciter path to be determined from 10 earth radii to 1 AU.

Multi-messenger astronomy of gravitational-wave sources with flexible wide-area radio transient surveys

NASA Astrophysics Data System (ADS)

Kavic, Michael; Cregg C. Yancey, Brandon E. Bear, Bernadine Akukwe, Kevin Chen, Jayce Dowell, Jonathan D. Gough, Jonah Kanner, Kenneth Obenberger, Peter Shawhan, John H. Simonetti , Gregory B. Taylor , Jr-Wei Tsai

2016-01-01

We explore opportunities for multi-messenger astronomy using gravitational waves (GWs) and prompt, transient low-frequency radio emission to study highly energetic astrophysical events. We review the literature on possible sources of correlated emission of GWs and radio transients, highlighting proposed mechanisms that lead to a short-duration, high-flux radio pulse originating from the merger of two neutron stars or from a superconducting cosmic string cusp. We discuss the detection prospects for each of these mechanisms by low-frequency dipole array instruments such as LWA1, the Low Frequency Array and the Murchison Widefield Array. We find that a broad range of models may be tested by searching for radio pulses that, when de-dispersed, are temporally and spatially coincident with a LIGO/Virgo GW trigger within a ˜30 s time window and ˜200-500 deg(2) sky region. We consider various possible observing strategies and discuss their advantages and disadvantages. Uniquely, for low-frequency radio arrays, dispersion can delay the radio pulse until after low-latency GW data analysis has identified and reported an event candidate, enabling a prompt radio signal to be captured by a deliberately targeted beam. If neutron star mergers do have detectable prompt radio emissions, a coincident search with the GW detector network and low-frequency radio arrays could increase the LIGO/Virgo effective search volume by up to a factor of ˜2. For some models, we also map the parameter space that may be constrained by non-detections.

Portable Wireless LAN Device and Two-way Radio Threat Assessment for Aircraft Navigation Radios

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

2003-01-01

Measurement processes, data and analysis are provided to address the concern for Wireless Local Area Network devices and two-way radios to cause electromagnetic interference to aircraft navigation radio systems. A radiated emission measurement process is developed and spurious radiated emissions from various devices are characterized using reverberation chambers. Spurious radiated emissions in aircraft radio frequency bands from several wireless network devices are compared with baseline emissions from standard computer laptops and personal digital assistants. In addition, spurious radiated emission data in aircraft radio frequency bands from seven pairs of two-way radios are provided, A description of the measurement process, device modes of operation and the measurement results are reported. Aircraft interference path loss measurements were conducted on four Boeing 747 and Boeing 737 aircraft for several aircraft radio systems. The measurement approach is described and the path loss results are compared with existing data from reference documents, standards, and NASA partnerships. In-band on-channel interference thresholds are compiled from an existing reference document. Using these data, a risk assessment is provided for interference from wireless network devices and two-way radios to aircraft systems, including Localizer, Glideslope, Very High Frequency Omnidirectional Range, Microwave Landing System and Global Positioning System. The report compares the interference risks associated with emissions from wireless network devices and two-way radios against standard laptops and personal digital assistants. Existing receiver interference threshold references are identified as to require more data for better interference risk assessments.

Multi-messenger Astronomy of Gravitational-wave Sources with Flexible Wide-area Radio Transient Surveys

NASA Astrophysics Data System (ADS)

Yancey, Cregg C.; Bear, Brandon E.; Akukwe, Bernadine; Chen, Kevin; Dowell, Jayce; Gough, Jonathan D.; Kanner, Jonah; Kavic, Michael; Obenberger, Kenneth; Shawhan, Peter; Simonetti, John H.; -Wei Tsai, Gregory B. Taylor, Jr.

2015-10-01

We explore opportunities for multi-messenger astronomy using gravitational waves (GWs) and prompt, transient low-frequency radio emission to study highly energetic astrophysical events. We review the literature on possible sources of correlated emission of GWs and radio transients, highlighting proposed mechanisms that lead to a short-duration, high-flux radio pulse originating from the merger of two neutron stars or from a superconducting cosmic string cusp. We discuss the detection prospects for each of these mechanisms by low-frequency dipole array instruments such as LWA1, the Low Frequency Array and the Murchison Widefield Array. We find that a broad range of models may be tested by searching for radio pulses that, when de-dispersed, are temporally and spatially coincident with a LIGO/Virgo GW trigger within a ˜30 s time window and ˜200-500 deg2 sky region. We consider various possible observing strategies and discuss their advantages and disadvantages. Uniquely, for low-frequency radio arrays, dispersion can delay the radio pulse until after low-latency GW data analysis has identified and reported an event candidate, enabling a prompt radio signal to be captured by a deliberately targeted beam. If neutron star mergers do have detectable prompt radio emissions, a coincident search with the GW detector network and low-frequency radio arrays could increase the LIGO/Virgo effective search volume by up to a factor of ˜2. For some models, we also map the parameter space that may be constrained by non-detections.

JET TRAILS AND MACH CONES: THE INTERACTION OF MICROQUASARS WITH THE INTERSTELLAR MEDIUM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, D.; Morsony, B.; Heinz, S.

2011-11-20

A subset of microquasars exhibits high peculiar velocity with respect to the local standard of rest due to the kicks they receive when being born in supernovae. The interaction between the radio plasma released by microquasar jets from such high-velocity binaries with the interstellar medium must lead to the production of trails and bow shocks similar to what is observed in narrow-angle tailed radio galaxies and pulsar wind nebulae. We present a set of numerical simulations of this interaction that illuminate the long-term dynamical evolution and the observational properties of these microquasar bow-shock nebulae and trails. We find that thismore » interaction always produces a structure that consists of a bow shock, a trailing neck, and an expanding bubble. Using our simulations to model emission, we predict that the shock surrounding the bubble and the neck should be visible in H{sub {alpha}} emission, the interior of the bubble should be visible in synchrotron radio emission, and only the bow shock is likely to be detectable in X-ray emission. We construct an analytic model for the evolution of the neck and bubble shape and compare this model with observations of the X-ray binary SAX J1712.6-3739.« less

The influence of polarization on millimeter wave propagation through rain. [radio signals

NASA Technical Reports Server (NTRS)

Bostian, C. W.; Stutzman, W. L.; Wiley, P. H.; Marshall, R. E.

1973-01-01

The measurement and analysis of the depolarization and attenuation that occur when millimeter wave radio signals propagate through rain are described. Progress was made in three major areas: the processing of recorded 1972 data, acquisition and processing of a large amount of 1973 data, and the development of a new theoretical model to predict rain cross polarization and attenuation. Each of these topics is described in detail along with radio frequency system design for cross polarization measurements.

Ionospheric Caustics in Solar Radio Observations

NASA Astrophysics Data System (ADS)

Koval, A.; Chen, Y.; Stanislavsky, A.

2016-12-01

The Earth ionosphere possesses by natural focusing and defocusing effects on radio waves due to presence of variable ionospheric irregularities which could act like convergent and divergent lenses on incident radiation. In particular, the focusing of emission from the Sun was firstly detected on the Nançay Decameter Array dynamic spectra in the 1980s. On time-frequency spectrograms the intensity variations form specific structures different from well-known solar radio bursts and clearly distinguishing on a background of solar radiation. Such structures have been identified as ionospheric caustics (ICs) and considered to be the result of radio waves refraction on medium scale travelling ionospheric disturbances (MSTIDs). Although nowadays the ICs are registered by different radio observatories due to augmentation of low-frequency radio telescopes, the most recent papers devoted to ICs in solar radio records date back to the 1980s. In this study, we revisit the ICs issue with some new results by conducting a statistical analysis of occurrence rate of ICs in solar dynamic spectra in meter-decameter wavelength range for long continuous period (15 years). The seasonal variations in ICs appearance have been found for the first time. Besides, we report the possible solar cycle dependence of ICs emergence. The radio waves propagation in the ionosphere comprising MSTIDs will be considered. The present research renews the subject of ICs in the low-frequency solar radio astronomy after about 35-year letup.

Radio Galaxy Zoo: compact and extended radio source classification with deep learning

NASA Astrophysics Data System (ADS)

Lukic, V.; Brüggen, M.; Banfield, J. K.; Wong, O. I.; Rudnick, L.; Norris, R. P.; Simmons, B.

2018-05-01

Machine learning techniques have been increasingly useful in astronomical applications over the last few years, for example in the morphological classification of galaxies. Convolutional neural networks have proven to be highly effective in classifying objects in image data. In the context of radio-interferometric imaging in astronomy, we looked for ways to identify multiple components of individual sources. To this effect, we design a convolutional neural network to differentiate between different morphology classes using sources from the Radio Galaxy Zoo (RGZ) citizen science project. In this first step, we focus on exploring the factors that affect the performance of such neural networks, such as the amount of training data, number and nature of layers, and the hyperparameters. We begin with a simple experiment in which we only differentiate between two extreme morphologies, using compact and multiple-component extended sources. We found that a three-convolutional layer architecture yielded very good results, achieving a classification accuracy of 97.4 per cent on a test data set. The same architecture was then tested on a four-class problem where we let the network classify sources into compact and three classes of extended sources, achieving a test accuracy of 93.5 per cent. The best-performing convolutional neural network set-up has been verified against RGZ Data Release 1 where a final test accuracy of 94.8 per cent was obtained, using both original and augmented images. The use of sigma clipping does not offer a significant benefit overall, except in cases with a small number of training images.

Ionization and Corona Discharges from Stressed Rocks

NASA Astrophysics Data System (ADS)

Winnick, M. J.; Kulahci, I.; Cyr, G.; Tregloan-Reed, J.; Freund, F. T.

2008-12-01

Pre-earthquake signals have long been observed and documented, though they have not been adequately explained scientifically. These signals include air ionization, occasional flashes of light from the ground, radio frequency emissions, and effects on the ionosphere that occur hours or even days before large earthquakes. The theory that rocks function as p-type semiconductors when deviatoric stresses are applied offers a mechanism for this group of earthquake precursors. When an igneous or high-grade metamorphic rock is subjected to deviatoric stresses, peroxy bonds that exist in the rock's minerals as point defects dissociate, releasing positive hole charge carriers. The positive holes travel by phonon-assisted electron hopping from the stressed into and through the unstressed rock volume and build up a positive surface charge. At sufficiently large electric fields, especially along edges and sharp points of the rock, air molecules become field-ionized, loosing an electron to the rock surface and turning into airborne positive ions. This in turn can lead to corona discharges, which manifest themselves by flashes of light and radio frequency emissions. We applied concentrated stresses to one end of a block of gabbro, 30 x 15 x 10 cm3, inside a shielded Faraday cage and observed positive ion currents through an air gap about 25 cm from the place where the stresses were applied, punctuated by short bursts, accompanied by flashes of light and radio frequency emissions characteristic of a corona discharge. These observations may serve to explain a range of pre-earthquake signals, in particular changes in air conductivity, luminous phenomena, radio frequency noise, and ionospheric perturbations.

Design, fabrication, and measurement of reflective metasurface for orbital angular momentum vortex wave in radio frequency domain

NASA Astrophysics Data System (ADS)

Yu, Shixing; Li, Long; Shi, Guangming; Zhu, Cheng; Zhou, Xiaoxiao; Shi, Yan

2016-03-01

In this paper, a reflective metasurface is designed, fabricated, and experimentally demonstrated to generate an orbital angular momentum (OAM) vortex wave in radio frequency domain. Theoretical formula of phase-shift distribution is deduced and used to design the metasurface producing vortex radio waves. The prototype of a practical configuration is designed, fabricated, and measured to validate the theoretical analysis at 5.8 GHz. The simulated and experimental results verify that the vortex waves with different OAM mode numbers can be flexibly generated by using sub-wavelength reflective metasurfaces. The proposed method and metasurface pave a way to generate the OAM vortex waves for radio and microwave wireless communication applications.

Ultra-Fast Outflows in Radio-Loud AGN: New Constraints on Jet-Disk Connection

NASA Astrophysics Data System (ADS)

Sambruna, Rita

There is strong observational and theoretical evidence that outflows/jets are coupled to accretion disks in black hole accreting systems, from Galactic to extragalactic sizes. While in radio-quiet AGN there is ample evidence for the presence of Ultra-Fast Outflows (UFOs) from the presence of blue-shifted absorption features in their 4-10~keV spectra, sub-relativistic winds are expected on theoretical basis in radio-loud AGN but have not been observed until now. Our recent Suzaku observations of 5 bright Broad- Line Radio Galaxies (BLRGs, the radio-loud counterparts of Seyferts) has started to change this picture. We found strong evidence for UFOs in 3 out of 5 BLRGs, with ionization parameters, column densities, and velocities of the absorber similar to Seyferts. Moreover, the outflows in BLRGs are likely to be energetically very significant: from the Suzaku data of the three sources, outflow masses similar to the accretion masses and kinetic energies of the wind similar to the X-ray luminosity and radio power of the jet are inferred. Clearly, UFOs in radio-loud AGN represent a new key ingredient to understand their central engines and in particular, the jet-disk linkage. Our discovery of UFOs in a handful of BLRGs raises the questions of how common disk winds are in radio-loud AGN, what the absorber physical and dynamical characteristics are, and what is the outflow role in broader picture of galaxy-black hole connection for radio sources, i.e., for large-scale feedback models. To address these and other issues, we propose to use archival XMM-Newton and Suzaku spectra to search for Ultra-Fast Outflows in a large number of radio sources. Over a period of two years, we will conduct a systematic, uniform analysis of the archival X-ray data, building on our extensive experience with a similar previous project for Seyferts, and using robust analysis and statistical methodologies. As an important side product, we will also obtain accurate, self- consistent measurements of the broad-band X-ray spectra of radio-loud AGN for comparison to radio-quiet, addressing the origin of the division between the two classes. In addition, the upcoming Astro-H mission will greatly benefit from the outcomes of this project, which will provide templates for realistic simulations to define the scientific requirements of the calorimeter, and a list of targets to design a sample for the core AGN projects of the team.

Marshall Amateur Radio Club experiment (MARCE) post flight data analysis

NASA Technical Reports Server (NTRS)

Rupp, Charles C.

1987-01-01

The Marshall Amateur Radio Club Experiment (MARCE) data system, the data recorded during the flight of STS-61C, the manner in which the data was reduced to engineering units, and the performance of the student experiments determined from the data are briefly described.

77 FR 64792 - Radio Broadcasting Services; Pike Road, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

...] Radio Broadcasting Services; Pike Road, AL AGENCY: Federal Communications Commission. ACTION: Proposed... Corporation, Inc., proposing the allotment of Channel 228A at Pike Road, Alabama, as the community's second local service. A staff engineering analysis indicates that Channel 228A can be allotted to Pike Road...

77 FR 2242 - Radio Broadcasting Services; Pike Road, AL

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

...] Radio Broadcasting Services; Pike Road, AL AGENCY: Federal Communications Commission. ACTION: Proposed... Corporation, Inc., proposing the allotment of Channel 228A at Pike Road, Alabama, as its second local service. A staff engineering analysis indicates that Channel 228A can be allotted to Pike Road consistent...

78 FR 266 - Radio Broadcasting Services; Maysville, GA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-03

...] Radio Broadcasting Services; Maysville, GA AGENCY: Federal Communications Commission. ACTION: Final rule... at Maysville, Georgia, as the community's second local service. A staff engineering analysis confirms... reference coordinates for Channel 265A at Maysville are 34-20-16 NL and 83-39-52 WL. DATES: Effective...

On the Interaction of the PKS B1358-113 Radio Galaxy with the A1836 Cluster

DOE PAGES

Stawarz, L.; Szostek, A.; Cheung, C. C.; ...

2014-10-07

In this study, we present the analysis of multifrequency data gathered for the Fanaroff-Riley type-II (FR II) radio galaxy PKS B1358-113, hosted in the brightest cluster galaxy in the center of A1836. The galaxy harbors one of the most massive black holes known to date, and our analysis of the acquired optical data reveals that this black hole is only weakly active, with a mass accretion ratemore » $$\\dot{M}_{\\rm acc} \\sim 2 \\times 10^{-4} \\, \\dot{M}_{\\rm Edd} \\sim 0.02 \\, M_{\\odot }$$ yr –1. Based on analysis of new Chandra and XMM-Newton X-ray observations and archival radio data, and assuming the well-established model for the evolution of FR II radio galaxies, we derive the preferred range for the jet kinetic luminosity L j ~ (1-6) × 10 –3 L Edd ~ (0.5-3) × 10 45 erg s –1. This is above the values implied by various scaling relations proposed for radio sources in galaxy clusters, being instead very close to the maximum jet power allowed for the given accretion rate. We also constrain the radio source lifetime as τ j ~ 40-70 Myr, meaning the total amount of deposited jet energy E tot ~ (2-8) × 10 60 erg. We argue that approximately half of this energy goes into shock heating of the surrounding thermal gas, and the remaining 50% is deposited into the internal energy of the jet cavity. The detailed analysis of the X-ray data provides indication for the presence of a bow shock driven by the expanding radio lobes into the A1836 cluster environment. We derive the corresponding shock Mach number in the range $$\\mathcal {M}_{\\rm sh} \\sim 2\\hbox{--}4$$, which is one of the highest claimed for clusters or groups of galaxies. This, together with the recently growing evidence that powerful FR II radio galaxies may not be uncommon in the centers of clusters at higher redshifts, supports the idea that jet-induced shock heating may indeed play an important role in shaping the properties of clusters, galaxy groups, and galaxies in formation. In this context, we speculate on a possible bias against detecting stronger jet-driven shocks in poorer environments, resulting from inefficient electron heating at the shock front, combined with a relatively long electron-ion temperature equilibration timescale.« less

Key technologies and concepts for beyond-3G networks

NASA Astrophysics Data System (ADS)

Pehkonen, Kari; Uskela, Sami; Kalliojarvi, Kari; Oksanen, Lauri; Rikkinen, Kari

2001-10-01

Standardization of 3rd Generation (3G) mobile communication systems has produced the first specification releases and the commercial deployment of the 3G systems has started. Whereas 1G and 2G focused on efficiently providing voice services, in 3G a lot of attention has been devoted to solutions that support both Circuit Switched (CS) and Packet Switched (PS) communication. That has called for very flexible air interface and network solutions. 3G will continue to evolve and there are already on-going standardization activities that will, for example, boost the peak data rates up to 5-10 Mbps and improve spectral efficiency by 2-4 times. In the future, 3G evolution will be going towards 10/100 Mbps peak data rates in wide/local are coverage, respectively. This will take place partly because of technical improvements of 3G radio interface solutions, but also due to network evolution which will allow the integration other radio access methods like radio LANs into the 3G system. In longer term the 3G network evolution will be going towards ALL-IP networks. As 3G evolution seems to be going towards 10 Mbps/100 Mbps peak data rates and ALL-IP networks any beyond 3G air interface or network solution should be clearly better in order to justify its technical and commercial feasibility. Given the long evolution time of 3G and integration of other radio access schemes with 3G radio we may not even see a new, complete beyond 3G system being developed. Maybe we will just witness the emergence of a new, more advanced radio access solution which will then be connected to the evolving 3G network. As 3G evolution will continue for several years to come the research targets for any beyond 3G solutions must be set very high. When it comes to air interface, we should aim at 100 Mbps peak data rates for wide area access with high mobility, and at 1 Gbps for local area access with low mobility. Regarding possible commercial launches of any beyond 3G systems or solutions they could then take place around year 2010 or even later.

Probing the non-thermal emission in Abell 2146 and the Perseus cluster with the JVLA

NASA Astrophysics Data System (ADS)

Gendron-Marsolais, Marie-Lou; Hlavacek-Larrondo, Julie; van Weeren, Reinout; Clarke, Tracy; Intema, Huib; Russell, Helen; Edge, Alastair; Fabian, Andy; Olamaie, Malak; Rumsey, Clare; King, Lindsay; McNamara, Brian; Fecteau-Beaucage, David; Hogan, Michael; Mezcua, Mar; Taylor, Gregory; Blundell, Katherine; Sanders, Jeremy

2018-01-01

Jets created from accretion onto supermassive black holes release relativistic particles on large distances. These strongly affect the intracluster medium when located in the center of a brightest cluster galaxy. The hierarchical merging of subclusters and groups, from which cluster originate, also generates perturbations into the intracluster medium through shocks and turbulence, constituting a potential source of reacceleration for these particles. I will present deep multi-configuration low radio frequency observations from the Karl G. Jansky Very Large Array of two unique clusters, probing the non-thermal emission from the old particle population of the AGN outflows.Recently awarded of 550 hours of Chandra observations, Abell 2146 is one of the rare clusters undergoing a spectacular merger in the plane of the sky. Our recent deep multi-configuration JVLA 1.4 GHz observations have revealed the presence of a structure extending to 850 kpc in size, consisting of one component associated with the upstream shock and classified as a radio relic, and one associated with the subcluster core, consistent with a radio halo bounded by the bow shock. Theses structures have some of the lowest radio powers detected thus far in any cluster. The flux measurements of the halo, its morphology and measurements of the dynamical state of the cluster suggest that the halo was recently created (~ 0.3 Gyr after core passage). This makes A2146 extremely interesting to study, allowing us to probe the complete evolutionary stages of halos.I will also present results on 230-470 MHz JVLA observations of the Perseus cluster. Our observations of this nearby relaxed cool core cluster have revealed a multitude of new structures associated with the mini-halo, extending to hundreds of kpc in size. Its irregular morphology seems to be have been influenced both by the AGN activity and by the sloshing motion of the cluster’ gas. In addition, it has a filamentary structure similar to that seen in radio relics found in merging clusters.These results both illustrate the high-quality images that can be obtained with the new JVLA at low radio-frequencies.

The New Horizons Radio Science Experiment: Expected Performance in Measurements of Pluto's Atmospheric Structure, Surface Pressure, and Surface Temperature

NASA Astrophysics Data System (ADS)

Hinson, D. P.; Linscott, I.; Woods, W. W.; Tyler, G. L.; Bird, M. K.; Paetzold, M.; Strobel, D. F.

2014-12-01

The New Horizons (NH) payload includes a Radio Science Experiment (REX) for investigating key characteristics of Pluto and Charon during the upcoming flyby in July 2015. REX flight equipment augments the NH radio transceiver used for spacecraft communications and tracking. The REX hardware implementation requires 1.6 W and 160 g. This presentation will focus on the final design and the predicted performance of two high-priority observations. First, REX will receive signals from a pair of 70-m antennas on Earth - each transmitting 20 kW at 4.2-cm wavelength - during a diametric radio occultation by Pluto. The data recorded by REX will reveal the surface pressure, the temperature structure of the lower atmosphere, and the surface radius. Second, REX will measure the thermal emission from Pluto at 4.2-cm wavelength during two linear scans across the disk at close range when both the dayside and the nightside are visible, allowing the surface temperature and its spatial variations to be determined. Both scans extend from limb to limb with a resolution of about 10 pixels; one bisects Pluto whereas the second crosses the winter pole. We will illustrate the capabilities of REX by reviewing the method of analysis and the precision achieved in a lunar occultation observed by New Horizons in May 2011. Re-analysis of radio occultation measurements by Voyager 2 at Triton is also under way. More generally, REX objectives include a radio occultation search for Pluto's ionosphere; examination of Charon through both radio occultation and radiometry; a search for a radar echo from Pluto's surface; and improved knowledge of the Pluto system mass and the Pluto-Charon mass ratio from a combination of two-way and one-way Doppler frequency measurements.

Zebra pattern in decametric radio emission of Jupiter

NASA Astrophysics Data System (ADS)

Panchenko, M.; Rošker, S.; Rucker, H. O.; Brazhenko, A.; Zarka, P.; Litvinenko, G.; Shaposhnikov, V. E.; Konovalenko, A. A.; Melnik, V.; Franzuzenko, A. V.; Schiemel, J.

2018-03-01

We report the systematic analysis of zebra-like fine spectral structures in decametric frequency range of Jovian radio emission. Observations were performed by the large ground-based radio telescope URAN-2 during three observation campaigns between, Sep., 2012, and May, 2015. In total, 51 zebra pattern (ZP) events were detected. These rare fine radio features are observed in frequency range from 12.5 to 29.7 MHz as quasi-harmonically related bands of enhanced brightness. ZPs are strongly polarized radio emission with a duration from 20 s to 290 s and flux densities 105-106 Jy (normalized to 1 AU), that is, 1-2 orders lower than for Io-decametric radio emission (DAM). Occurrence of the events does not depend on the position of Io satellite but is strongly controlled by the Jovian central meridian longitude (CML). ZPs are mainly detected in two active sectors of Jovian CMLs: 100∘ to 160∘ for Northern sources (right-handed polarized) and 300∘ and 60∘ (via 360∘) for the Southern sources (left-handed). The frequency interval between neighboring stripes is from 0.26 to 1.5 MHz and in most cases this interval increases with frequency. We discussed the double plasma resonance with electrons or ions as a possible source of the ZPs. The performed analysis of the observations allows us to conclude that the observed ZPs are a new type of narrow band spectral structures in the Jovian DAM.

Initial Results Obtained with the First TWIN VLBI Radio Telescope at the Geodetic Observatory Wettzell

PubMed Central

Schüler, Torben; Kronschnabl, Gerhard; Plötz, Christian; Neidhardt, Alexander; Bertarini, Alessandra; Bernhart, Simone; la Porta, Laura; Halsig, Sebastian; Nothnagel, Axel

2015-01-01

Geodetic Very Long Baseline Interferometry (VLBI) uses radio telescopes as sensor networks to determine Earth orientation parameters and baseline vectors between the telescopes. The TWIN Telescope Wettzell 1 (TTW1), the first of the new 13.2 m diameter telescope pair at the Geodetic Observatory Wettzell, Germany, is currently in its commissioning phase. The technology behind this radio telescope including the receiving system and the tri-band feed horn is depicted. Since VLBI telescopes must operate at least in pairs, the existing 20 m diameter Radio Telescope Wettzell (RTW) is used together with TTW1 for practical tests. In addition, selected long baseline setups are investigated. Correlation results portraying the data quality achieved during first initial experiments are discussed. Finally, the local 123 m baseline between the old RTW telescope and the new TTW1 is analyzed and compared with an existing high-precision local survey. Our initial results are very satisfactory for X-band group delays featuring a 3D distance agreement between VLBI data analysis and local ties of 1 to 2 mm in the majority of the experiments. However, S-band data, which suffer much from local radio interference due to WiFi and mobile communications, are about 10 times less precise than X-band data and require further analysis, but evidence is provided that S-band data are well-usable over long baselines where local radio interference patterns decorrelate. PMID:26263991

Managing Awkward, Sensitive, or Delicate Topics in (Chinese) Radio Medical Consultations

ERIC Educational Resources Information Center

Yu, Guodong; Wu, Yaxin

2015-01-01

This study, using conversation analysis as the research methodology, probes into the use of "nage" (literally "that") as a practice of managing awkward, sensitive, or delicate issues in radio phone-in medical consultations about sex-related problems. Through sequential manipulation and turn manipulation, the caller uses…

Signal Identification and Isolation Utilizing Radio Frequency Photonics

DTIC Science & Technology

2017-09-01

analyzers can measure the frequency of signals and filters can be used to separate the signals apart from one another. This report will review...different techniques for spectrum analysis and isolation. 15. SUBJECT TERMS radio frequency, photonics, spectrum analyzer, filters 16. SECURITY CLASSIFICATION...Analyzers .......................................................................................... 3 3.2 Frequency Identification using Filters

Estimation of a coronal mass ejection magnetic field strength using radio observations of gyrosynchrotron radiation

NASA Astrophysics Data System (ADS)

Carley, Eoin P.; Vilmer, Nicole; Simões, Paulo J. A.; Ó Fearraigh, Brían

2017-12-01

Coronal mass ejections (CMEs) are large eruptions of plasma and magnetic field from the low solar corona into interplanetary space. These eruptions are often associated with the acceleration of energetic electrons which produce various sources of high intensity plasma emission. In relatively rare cases, the energetic electrons may also produce gyrosynchrotron emission from within the CME itself, allowing for a diagnostic of the CME magnetic field strength. Such a magnetic field diagnostic is important for evaluating the total magnetic energy content of the CME, which is ultimately what drives the eruption. Here, we report on an unusually large source of gyrosynchrotron radiation in the form of a type IV radio burst associated with a CME occurring on 2014-September-01, observed using instrumentation from the Nançay Radio Astronomy Facility. A combination of spectral flux density measurements from the Nançay instruments and the Radio Solar Telescope Network (RSTN) from 300 MHz to 5 GHz reveals a gyrosynchrotron spectrum with a peak flux density at 1 GHz. Using this radio analysis, a model for gyrosynchrotron radiation, a non-thermal electron density diagnostic using the Fermi Gamma Ray Burst Monitor (GBM) and images of the eruption from the GOES Soft X-ray Imager (SXI), we were able to calculate both the magnetic field strength and the properties of the X-ray and radio emitting energetic electrons within the CME. We find the radio emission is produced by non-thermal electrons of energies >1 MeV with a spectral index of δ 3 in a CME magnetic field of 4.4 G at a height of 1.3 R⊙, while the X-ray emission is produced from a similar distribution of electrons but with much lower energies on the order of 10 keV. We conclude by comparing the electron distribution characteristics derived from both X-ray and radio and show how such an analysis can be used to define the plasma and bulk properties of a CME.

HIDE & SEEK: End-to-end packages to simulate and process radio survey data

NASA Astrophysics Data System (ADS)

Akeret, J.; Seehars, S.; Chang, C.; Monstein, C.; Amara, A.; Refregier, A.

2017-01-01

As several large single-dish radio surveys begin operation within the coming decade, a wealth of radio data will become available and provide a new window to the Universe. In order to fully exploit the potential of these datasets, it is important to understand the systematic effects associated with the instrument and the analysis pipeline. A common approach to tackle this is to forward-model the entire system-from the hardware to the analysis of the data products. For this purpose, we introduce two newly developed, open-source Python packages: the HI Data Emulator (HIDE) and the Signal Extraction and Emission Kartographer (SEEK) for simulating and processing single-dish radio survey data. HIDE forward-models the process of collecting astronomical radio signals in a single-dish radio telescope instrument and outputs pixel-level time-ordered-data. SEEK processes the time-ordered-data, removes artifacts from Radio Frequency Interference (RFI), automatically applies flux calibration, and aims to recover the astronomical radio signal. The two packages can be used separately or together depending on the application. Their modular and flexible nature allows easy adaptation to other instruments and datasets. We describe the basic architecture of the two packages and examine in detail the noise and RFI modeling in HIDE, as well as the implementation of gain calibration and RFI mitigation in SEEK. We then apply HIDE &SEEK to forward-model a Galactic survey in the frequency range 990-1260 MHz based on data taken at the Bleien Observatory. For this survey, we expect to cover 70% of the full sky and achieve a median signal-to-noise ratio of approximately 5-6 in the cleanest channels including systematic uncertainties. However, we also point out the potential challenges of high RFI contamination and baseline removal when examining the early data from the Bleien Observatory. The fully documented HIDE &SEEK packages are available at http://hideseek.phys.ethz.ch/ and are published under the GPLv3 license on GitHub.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horesh, Assaf; Kulkarni, Shrinivas R.; Corsi, Alessandra

Only a few cases of Type Ic supernovae (SNe) with high-velocity ejecta (≥0.2 c) have been discovered and studied. Here, we present our analysis of radio and X-ray observations of the Type Ic SN PTF 12gzk. The radio emission declined less than 10 days after explosion, suggesting SN ejecta expanding at high velocity (∼0.3 c). The radio data also indicate that the density of the circumstellar material (CSM) around the supernova is lower by a factor of ∼10 than the CSM around normal Type Ic SNe. PTF 12gzk may therefore be an intermediate event between a 'normal' SN Ic andmore » a gamma-ray-burst-SN-like event. Our observations of this rapidly declining radio SN at a distance of 58 Mpc demonstrates the potential to detect many additional radio SNe, given the new capabilities of the Very Large Array (improved sensitivity and dynamic scheduling), which are currently missed, leading to a biased view of radio SNe Ic. Early optical discovery followed by rapid radio observations would provide a full description of the ejecta velocity distribution and CSM densities around stripped massive star explosions as well as strong clues about the nature of their progenitor stars.« less

Effects of honey use on the management of radio/chemotherapy-induced mucositis: a meta-analysis of randomized controlled trials.

PubMed

Xu, J-L; Xia, R; Sun, Z-H; Sun, L; Min, X; Liu, C; Zhang, H; Zhu, Y-M

2016-12-01

This meta-analysis aimed to assess the prophylactic effects of honey use on the management of radio/chemotherapy-induced mucositis. PubMed, Cochrane Library, Science Direct, China National Knowledge Infrastructure (CNKI), VIP (Chinese scientific journal database), and China Biology Medicine (CBM) were searched for relevant articles without language restriction. Two reviewers searched and evaluated the related studies independently. Statistical analyses were performed using Stata 11.0, calculating the pooled risk ratio (RR) with the corresponding 95% confidence interval (CI). Begg's funnel plot was used together with Egger's test to detect publication bias. A total of seven randomized controlled trials were finally included. Quality assessment showed one article to have a low risk of bias, two to have a moderate risk, and four to have a high risk. Meta-analysis showed that, compared with blank control, honey treatment could reduce the incidence of oral mucositis after radio/chemotherapy (RR 0.35, 95% CI 0.18-0.70, P=0.003). No meta-analysis was applied for honey vs. lidocaine or honey vs. golden syrup. The sensitivity analysis showed no significant change when any one study was excluded. No obvious publication bias (honey vs. blank control) was detected. In conclusion, honey can effectively reduce the incidence of radio/chemotherapy-induced oral mucositis; however, further multi-centre randomized controlled trials are needed to support the current evidence. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Effects of the 2017 Solar Eclipse on HF Radio Propagation and the D-Region Ionosphere: Citizen Science Investigation

NASA Technical Reports Server (NTRS)

Fry, C. D.; Rawlins, L.; Krause, L. H.; Suggs, R. M.; McTernan, J. K.; Adams, M. L.; Gallagher, D. L.; Anderson, Scott; Allsbrooks, Robert IV

2017-01-01

August 21, 2017 provided a unique opportunity to investigate the effects of the total solar eclipse on high frequency (HF) radio propagation and ionospheric variability. In Marshall Space Flight Center's partnership with the US Space and Rocket Center (USSRC) and Austin Peay State University (APSU), we engaged students and citizen scientists in an investigation of the eclipse effects on the mid-latitude ionosphere. Activities included implementing and configuring software, monitoring the HF Amateur Radio frequency bands and collecting radio transmission data on days before, the day of, and days after the eclipse to build a continuous record of changing propagation conditions as the moon's shadow marched across the United States. Post-eclipse radio propagation analysis provided insights into ionospheric variability due to the eclipse. We report on results, interpretation, and conclusions of these investigations.

Releasing captive-reared masked bobwhite for population recovery: A review

USGS Publications Warehouse

Gall, S.A.; Kuvlesky, W.P.; Gee, G.; Brennan, L.A.; Palmer, W.E.; Burger, L.W.; Pruden, T.L.

2000-01-01

Efforts to re-establish the endangered masked bobwhite (Colinus virginianus ridgwayi) to it's former southern Arizona range have been ongoing since establishment of the Buenos Aires National Wildlife Refuge in 1986. Pre-release conditioning techniques developed prior to Refuge establishment continued to be utilized in an effort to improve post-release survival of captive-reared masked bobwhite chicks. Foremost among these techniques was the use of wild Texas bobwhite (C. v. texanus) males as foster parents which were paired with all broods released on the Refuge. The efficacy of this technique was evaluated using radio telemetry in 1994, and the results indicated that the use of foster Texas males was not as effective as had been presumed because post-release chick survival was poor. Therefore, in 1995 pre-release conditioning protocol were modified in an effort to improve post-release survival. The primary intent of these modifications was to emphasize wild behavior among chicks prior to release. Modifications to established protocol included imprinting chicks to adult bobwhites immediately after eggs hatched and exposing 1-to-2 day old chicks to natural foods (insects and seeds) while they were in brooder units. Foster parents and their respective broods were then placed in flight pens that mimicked the natural conditions that would confront broods upon release. Family groups were held in flight pens for several weeks for acclimatization purposes and then transported to temporary enclosures erected at release sites where they were held for a week and then released. Finally all releases were conducted during fall after covey formation was apparent to ensure that foster parents and released chicks remained with a group of birds. Preliminary results indicated that post-release chick survival was higher than what was observed in 1994. Pre-conditioning research will continue in an effort to further quantify post-release survival of masked bobwhite chicks. Although the results of this research project are preliminary, it is possible that pre-release conditioning techniques developed for masked bobwhites will prove useful to quail reestablishment efforts throughout North America.

Artificial ionospheric modification: The Metal Oxide Space Cloud experiment

NASA Astrophysics Data System (ADS)

Caton, Ronald G.; Pedersen, Todd R.; Groves, Keith M.; Hines, Jack; Cannon, Paul S.; Jackson-Booth, Natasha; Parris, Richard T.; Holmes, Jeffrey M.; Su, Yi-Jiun; Mishin, Evgeny V.; Roddy, Patrick A.; Viggiano, Albert A.; Shuman, Nicholas S.; Ard, Shaun G.; Bernhardt, Paul A.; Siefring, Carl L.; Retterer, John; Kudeki, Erhan; Reyes, Pablo M.

2017-05-01

Clouds of vaporized samarium (Sm) were released during sounding rocket flights from the Reagan Test Site, Kwajalein Atoll in May 2013 as part of the Metal Oxide Space Cloud (MOSC) experiment. A network of ground-based sensors observed the resulting clouds from five locations in the Republic of the Marshall Islands. Of primary interest was an examination of the extent to which a tailored radio frequency (RF) propagation environment could be generated through artificial ionospheric modification. The MOSC experiment consisted of launches near dusk on two separate evenings each releasing 6 kg of Sm vapor at altitudes near 170 km and 180 km. Localized plasma clouds were generated through a combination of photoionization and chemi-ionization (Sm + O → SmO+ + e-) processes producing signatures visible in optical sensors, incoherent scatter radar, and in high-frequency (HF) diagnostics. Here we present an overview of the experiment payloads, document the flight characteristics, and describe the experimental measurements conducted throughout the 2 week launch window. Multi-instrument analysis including incoherent scatter observations, HF soundings, RF beacon measurements, and optical data provided the opportunity for a comprehensive characterization of the physical, spectral, and plasma density composition of the artificial plasma clouds as a function of space and time. A series of companion papers submitted along with this experimental overview provide more detail on the individual elements for interested readers.

Comparison Between Path Lengths Traveled by Solar Electrons and Ions in Ground-Level Enhancement Events

NASA Technical Reports Server (NTRS)

Tan, Lun C.; Malandraki, Olga E.; Reames, Donald; NG, Chee K.; Wang, Linghua; Patsou, Ioanna; Papaioannou, Athanasios

2013-01-01

We have examined the Wind/3DP/SST electron and Wind/EPACT/LEMT ion data to investigate the path length difference between solar electrons and ions in the ground-level enhancement (GLE) events in solar cycle 23. Assuming that the onset time of metric type II or decameter-hectometric (DH) type III radio bursts is the solar release time of non-relativistic electrons, we have found that within an error range of plus or minus 10% the deduced path length of low-energy (approximately 27 keV) electrons from their release site near the Sun to the 1 AU observer is consistent with the ion path length deduced by Reames from the onset time analysis. In addition, the solar longitude distribution and IMF topology of the GLE events examined are in favor of the coronal mass ejection-driven shock acceleration origin of observed non-relativistic electrons.We have also found an increase of electron path lengths with increasing electron energies. The increasing rate of path lengths is correlated with the pitch angle distribution (PAD) of peak electron intensities locally measured, with a higher rate corresponding to a broader PAD. The correlation indicates that the path length enhancement is due to the interplanetary scattering experienced by first arriving electrons. The observed path length consistency implies that the maximum stable time of magnetic flux tubes, along which particles transport, could reach 4.8 hr.

Teaching radio astronomy with Affordable Small Radio Telescope (ASRT)

NASA Astrophysics Data System (ADS)

Joshi, Bhal Chandra

A simple, easy to build and portable radio telescope, called Affordable Small Radio Telescope (ASRT), has been developed by the Radio Physics Laboratory (RPL), a radio astronomy teaching unit associated with the National Centre for Radio Astrophysics (TIFR) and Inter-University Centre for Astronomy and Astrophysics (IUCAA), which are two premier astronomy institutes in India. ASRT consists of off-the-shelf available Direct to Home television dishes and is easy to assemble. Our design is scalable from simple very low cost telescope to more complex yet moderately costing instrument. ASRT provides a platform for demonstrating radio physics concepts through simple hands-on experiment as well as for carrying out solar monitoring by college/University students. The presentation will highlight the concept of ASRT and the different experiments that can be carried out using it. The solar monitoring observations will be discussed along-with details of methods for calibrating these measurements. The pedagogical usefulness of ASRT in introducing undergraduatephysics students to astrophysics, measurements and analysis methods used in radio astronomy will also be discussed. Use of ASRT in the last three years in the programs of RPL, namely the annual Radio Astronomy Winter School for College students (RAWSC) and Pulsar Observing for Students (POS) is also presented. This year a new program was initiated to form a virtual group of an ASRT community, which will not only share their measurements, but also think of improving the pedagogical usefulness of ASRT by innovative experiments. This initiative is presented with the best practices drawn from our experience in using ASRT as a tool for student training in space sciences. The talk will also point out future ideas in involving a larger body of students in simple radio astronomy experiments with the ASRT, which RPL is likely to nucleate as part of its mandate.

Overview of Solar Radio Bursts and their Sources

NASA Astrophysics Data System (ADS)

Golla, Thejappa; MacDowall, Robert J.

2018-06-01

Properties of radio bursts emitted by the Sun at frequencies below tens of MHz are reviewed. In this frequency range, the most prominent radio emissions are those of solar type II, complex type III and solar type IV radio bursts, excited probably by the energetic electron populations accelerated in completely different environments: (1) type II bursts are due to non-relativistic electrons accelerated by the CME driven interplanetary shocks, (2) complex type III bursts are due to near-relativistic electrons accelerated either by the solar flare reconnection process or by the SEP shocks, and (3) type IV bursts are due to relativistic electrons, trapped in the post-eruption arcades behind CMEs; these relativistic electrons probably are accelerated by the continued reconnection processes occurring beneath the CME. These radio bursts, which can serve as the natural plasma probes traversing the heliosphere by providing information about various crucial space plasma parameters, are also an ideal instrument for investigating acceleration mechanisms responsible for the high energy particles. The rich collection of valuable high quality radio and high time resolution in situ wave data from the WAVES experiments of the STEREO A, STEREO B and WIND spacecraft has provided an unique opportunity to study these different radio phenomena and understand the complex physics behind their excitation. We have developed Monte Carlo simulation techniques to estimate the propagation effects on the observed characteristics of these low frequency radio bursts. We will present some of the new results and describe how one can use these radio burst observations for space weather studies. We will also describe some of the non-linear plasma processes detected in the source regions of both solar type III and type II radio bursts. The analysis and simulation techniques used in these studies will be of immense use for future space based radio observations.

FR-type radio sources in COSMOS: relation of radio structure to size, accretion modes and large-scale environment

NASA Astrophysics Data System (ADS)

Vardoulaki, Eleni; Faustino Jimenez Andrade, Eric; Delvecchio, Ivan; Karim, Alexander; Smolčić, Vernesa; Magnelli, Benjamin; Bertoldi, Frank; Schinnener, Eva; Sargent, Mark; Finoguenov, Alexis; VLA COSMOS Team

2018-01-01

The radio sources associated with active galactic nuclei (AGN) can exhibit a variety of radio structures, from simple to more complex, giving rise to a variety of classification schemes. The question which still remains open, given deeper surveys revealing new populations of radio sources, is whether this plethora of radio structures can be attributed to the physical properties of the host or to the environment. Here we present an analysis on the radio structure of radio-selected AGN from the VLA-COSMOS Large Project at 3 GHz (JVLA-COSMOS; Smolčić et al.) in relation to: 1) their linear projected size, 2) the Eddington ratio, and 3) the environment their hosts lie within. We classify these as FRI (jet-like) and FRII (lobe-like) based on the FR-type classification scheme, and compare them to a sample of jet-less radio AGN in JVLA-COSMOS. We measure their linear projected sizes using a semi-automatic machine learning technique. Their Eddington ratios are calculated from X-ray data available for COSMOS. As environmental probes we take the X-ray groups (hundreds kpc) and the density fields (~Mpc-scale) in COSMOS. We find that FRII radio sources are on average larger than FRIs, which agrees with literature. But contrary to past studies, we find no dichotomy in FR objects in JVLA-COSMOS given their Eddington ratios, as on average they exhibit similar values. Furthermore our results show that the large-scale environment does not explain the observed dichotomy in lobe- and jet-like FR-type objects as both types are found on similar environments, but it does affect the shape of the radio structure introducing bents for objects closer to the centre of an X-ray group.

Passage and survival probabilities of juvenile Chinook salmon at Cougar Dam, Oregon, 2012

USGS Publications Warehouse

Beeman, John W.; Evans, Scott D.; Haner, Philip V.; Hansel, Hal C.; Hansen, Amy C.; Smith, Collin D.; Sprando, Jamie M.

2014-01-01

This report describes studies of juvenile-salmon dam passage and apparent survival at Cougar Dam, Oregon, during two operating conditions in 2012. Cougar Dam is a 158-meter tall rock-fill dam used primarily for flood control, and passes water through a temperature control tower to either a powerhouse penstock or to a regulating outlet (RO). The temperature control tower has moveable weir gates to enable water of different elevations and temperatures to be drawn through the dam to control water temperatures downstream. A series of studies of downstream dam passage of juvenile salmonids were begun after the National Oceanic and Atmospheric Administration determined that Cougar Dam was impacting the viability of anadromous fish stocks. The primary objectives of the studies described in this report were to estimate the route-specific fish passage probabilities at the dam and to estimate the survival probabilities of fish passing through the RO. The first set of dam operating conditions, studied in November, consisted of (1) a mean reservoir elevation of 1,589 feet, (2) water entering the temperature control tower through the weir gates, (3) most water routed through the turbines during the day and through the RO during the night, and (4) mean RO gate openings of 1.2 feet during the day and 3.2 feet during the night. The second set of dam operating conditions, studied in December, consisted of (1) a mean reservoir elevation of 1,507 ft, (2) water entering the temperature control tower through the RO bypass, (3) all water passing through the RO, and (4) mean RO gate openings of 7.3 feet during the day and 7.5 feet during the night. The studies were based on juvenile Chinook salmon (Oncorhynchus tshawytscha) surgically implanted with radio transmitters and passive integrated transponder (PIT) tags. Inferences about general dam passage percentage and timing of volitional migrants were based on surface-acclimated fish released in the reservoir. Dam passage and apparent survival probabilities were estimated using the Route-Specific-Survival Model with data from surface-acclimated fish released near the water surface directly upstream of the temperature control tower (treatment group) and slightly downstream of the dam (control group). In this study, apparent survival is the joint probability of surviving and migrating through the study area during the life of the transmitters. Two rearing groups were used to enable sufficient sample sizes for the studies. The groups differed in feed type, and for the December study only, the rearing location. Fish from each group were divided nearly equally among all combinations of release sites, release times, and surgeons. The sizes, travel times, and survivals of the two rearing groups were similar. There were statistical differences in fish lengths and travel times of the two groups, but they were small and likely were not biologically meaningful. There also was evidence of a difference in single-release estimates of survival between the rearing groups during the December study, but the differences had little effect on the relative survival estimates so the analyses of passage and survival were based on data from the rearing groups pooled. Conditions during the December study were more conducive to passing volitionally migrating fish than conditions during the November study. The passage percentage of the fish released in the reservoir was similar between studies (about 70 percent), but the passage occurred in a median of 1.0 day during the December study and a median of 9.3 days during the November study. More than 93 percent of the dam passage of volitionally migrating fish occurred at night during each study. This finding corroborates results of previous studies at Cougar Dam and suggests that the operating conditions at night are most important to volitionally migrating fish, given the current configuration of the dam. Most fish released near the temperature control tower passed through the RO. A total of 92.2 percent of the treatment group passed through the RO during the November study and the RO was the only route open during the December study. The assumptions of the survival model were either met or adjusted for during each study. There was little evidence that tagger skill or premature failure of radio transmitters had an effect on survival estimates. There were statistically significant differences in travel times between treatment and control groups through several of the river reaches they had in common, but the differences were typically only a few hours, and the two groups likely experienced the same in-river conditions. There was direct evidence of bias due to detection of euthanized fish with live transmitters released as part of the study design. The bias was ameliorated by adjusting the survival estimates for the probability of detecting dead fish with live transmitters, which reduced the estimated survival probabilities by about 0.02. The data and models indicated that the treatment effect was not fully expressed until the study reach terminating with Marshall Island Park on the Willamette River, a distance of 105.8 kilometers downstream of Cougar Dam. This was the first reach in which the 95-percent confidence interval of the estimated reach-specific relative survival overlapped 1.0, indicating similar survival of treatment and control groups. The median travel time of the treatment group from release to Marshall Island Park was 1.64 days during the November study and 1.36 days during the December study. The survival probability of fish that passed into the RO was greater during the December study than during the November study. The relative survival probability of fish passing through the RO was 0.4594 (standard error [SE] 0.0543) during the November study and 0.7389 (SE 0.1160) during the December study. These estimates represent relative survival probabilities from release near Cougar Dam to the Marshall Island site. The estimated survival probability of RO passage was lower than previous studies based on balloon and PIT tags, but higher than a similar study based on radio transmitters. We suggest that, apart from dam operations, the differences in survival primarily are due to the release location. We hypothesize that the balloon- and PIT-tagged fish released through a hose at a point near the RO gate opening experienced more benign conditions than the radio-tagged fish passing the RO volitionally. This hypothesis could be tested with further study. An alternative hypothesis is that some live fish remained within the study area beyond the life of their radio transmitter. The results from these and previous studies indicate that entrainment and survival of juvenile salmonids passing Cougar Dam varies with dam operating conditions. The condition most conducive to dam passage has been the discharge and low pool elevation condition tested during December 2012. That condition included large RO gate openings and was the condition with the highest dam passage survival.

Cognitive Radio Low-Energy Signal Analysis Sensor Integrated Circuits (CLASIC): A Broadband Mixed-Signal Iterative Down Conversion Spectrum Analyzer for Signal Recognition Applications

DTIC Science & Technology

2015-12-01

AFRL-RY-WP-TR-2015-0144 COGNITIVE RADIO LOW-ENERGY SIGNAL ANALYSIS SENSOR INTEGRATED CIRCUITS (CLASIC) A Broadband Mixed-Signal Iterative Down...See additional restrictions described on inside pages STINFO COPY AIR FORCE RESEARCH LABORATORY SENSORS DIRECTORATE WRIGHT-PATTERSON AIR FORCE...Signature// TODD KASTLE, Chief Spectrum Warfare Division Sensors Directorate This report is published in the interest of scientific and technical

Simulating 3D Spacecraft Constellations for Low Frequency Radio Imaging

NASA Astrophysics Data System (ADS)

Hegedus, A. M.; Amiri, N.; Lazio, J.; Belov, K.; Kasper, J. C.

2016-12-01

Constellations of small spacecraft could be used to realize a low-frequency phased array for either heliophysics or astrophysics observations. However, there are issues that arise with an orbiting array that do not occur on the ground, thus rendering much of the existing radio astronomy software inadequate for data analysis and simulation. In this work we address these issues and consider the performance of two constellation concepts. The first is a 32-spacecraft constellation for astrophysical observations, and the second is a 5-element concept for pointing to the location of radio emission from coronal mass ejections (CMEs). For the first, we fill the software gap by extending the APSYNSIM software to simulate the aperture synthesis for a radio interferometer in orbit. This involves using the dynamic baselines from the relative motion of the individual spacecraft as well as the capability to add galactic noise. The ability to simulate phase errors corresponding to positional uncertainty of the antennas was also added. The upgraded software was then used to model the imaging of a 32 spacecraft constellation that would orbit the moon to image radio galaxies like Cygnus A at .3-30 MHz. Animated images showing the improvement of the dirty image as the orbits progressed were made. RMSE plots that show how well the dirty image matches the input image as a function of integration time were made. For the second concept we performed radio interferometric simulations of the Sun Radio Interferometer Space Experiment (SunRISE) using the Common Astronomy Software Applications (CASA) package. SunRISE is a five spacecraft phased array that would orbit Earth to localize the low frequency radio emission from CMEs. This involved simulating the array in CASA, creating truth images for the CMEs over the entire frequency band of SunRISE, and observing them with the simulated array to see how well it could localize the true position of the CME. The results of our analysis show that we can localize the radio emission originating from the head or flanks of the CMEs in spite of the phase errors introduced by uncertainties in orbit and clock estimation.

LOFAR discovery of a 700-kpc remnant radio galaxy at low redshift

NASA Astrophysics Data System (ADS)

Brienza, M.; Godfrey, L.; Morganti, R.; Vilchez, N.; Maddox, N.; Murgia, M.; Orru, E.; Shulevski, A.; Best, P. N.; Brüggen, M.; Harwood, J. J.; Jamrozy, M.; Jarvis, M. J.; Mahony, E. K.; McKean, J.; Röttgering, H. J. A.

2016-01-01

Context. Remnant radio galaxies represent the final dying phase of radio galaxy evolution in which the jets are no longer active. Remnants are rare in flux-limited samples, comprising at most a few percent. As a result of their rarity and because they are difficult to identify, this dying phase remains poorly understood and the luminosity evolution is largely unconstrained. Aims: Here we present the discovery and detailed analysis of a large (700 kpc) remnant radio galaxy with a low surface brightness that has been identified in LOFAR images at 150 MHz. Methods: By combining LOFAR data with new follow-up Westerbork observations and archival data at higher frequencies, we investigated the source morphology and spectral properties from 116 to 4850 MHz. By modelling the radio spectrum, we probed characteristic timescales of the radio activity. Results: The source has a relatively smooth, diffuse, amorphous appearance together with a very weak central compact core that is associated with the host galaxy located at z = 0.051. From our ageing and morphological analysis it is clear that the nuclear engine is currently switched off or, at most, active at a very low power state. We find that the source has remained visible in the remnant phase for about 60 Myr, significantly longer than its active phase of 15 Myr, despite being located outside a cluster. The host galaxy is currently interacting with another galaxy located at a projected separation of 15 kpc and a radial velocity offset of ~ 300 km s-1. This interaction may have played a role in the triggering and/or shut-down of the radio jets. Conclusions: The spectral shape of this remnant radio galaxy differs from most of the previously identified remnant sources, which show steep or curved spectra at low to intermediate frequencies. Our results demonstrate that remnant radio galaxies can show a wide range of evolutionary paths and spectral properties. In light of this finding and in preparation for new-generation deep low-frequency surveys, we discuss the selection criteria to be used to select representative samples of these sources.

I. S. Shklovsky and Low-Frequency Radio Astronomy

NASA Astrophysics Data System (ADS)

Konovalenko, A. A.

2017-03-01

Purpose: Proving of the high astrophysical significance of the low-frequency radio astronomy (decameter and adjacent hectometer and meter wavelengths), demonstration of the priority results of the Ukrainian low-frequency radio astronomy as well as significant contribution of I. S. Shklovsky to its development. Design/methodology/approach: The requirements to characteristics of high efficiency radio telescopes UTR-2, URAN, GURT and to sensitive and interference immune observational methods at low frequencies are formulated by using the theoretical analysis and astrophysical predictions including those I. S. Shklovsky’s. Findings: New generation radio telescopes UTR-2, URAN, GURT are created and modernized. New observational methods at low frequencies are introduced. Large-scale investigations of the Solar system, Galaxy and Methagalaxy are carried out. They have allowed to detect new objects and phenomena for the continuum, monochromatic, pulse and sporadic cosmic radio emission. The role of I. S. Shklovsky in the development of many low-frequency radio astronomy directions is noted, too. Conclusions: The unique possibilities of the low-frequency radio astronomy which gives new information about the Universe, inaccessible with the other astrophysical methods, are shown. The progress of the low-frequency radio astronomy opens the impressive possibilities for the future. It includes modernization of the largest radio telescopes UTR-2, URAN, NDA and creation of new instruments GURT, NenuFAR, LOFAR, LWA, MWA, SKA as well as making multi-antenna and ground-space experiments. The contribution of outstanding astrophysicist of the XX century I. S. Shklovsky to this part of actual astronomical science is evident, claiming for attention and will never be forgotten.

MULTI-MESSENGER ASTRONOMY OF GRAVITATIONAL-WAVE SOURCES WITH FLEXIBLE WIDE-AREA RADIO TRANSIENT SURVEYS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yancey, Cregg C.; Shawhan, Peter; Bear, Brandon E.

We explore opportunities for multi-messenger astronomy using gravitational waves (GWs) and prompt, transient low-frequency radio emission to study highly energetic astrophysical events. We review the literature on possible sources of correlated emission of GWs and radio transients, highlighting proposed mechanisms that lead to a short-duration, high-flux radio pulse originating from the merger of two neutron stars or from a superconducting cosmic string cusp. We discuss the detection prospects for each of these mechanisms by low-frequency dipole array instruments such as LWA1, the Low Frequency Array and the Murchison Widefield Array. We find that a broad range of models may bemore » tested by searching for radio pulses that, when de-dispersed, are temporally and spatially coincident with a LIGO/Virgo GW trigger within a ∼30 s time window and ∼200–500 deg{sup 2} sky region. We consider various possible observing strategies and discuss their advantages and disadvantages. Uniquely, for low-frequency radio arrays, dispersion can delay the radio pulse until after low-latency GW data analysis has identified and reported an event candidate, enabling a prompt radio signal to be captured by a deliberately targeted beam. If neutron star mergers do have detectable prompt radio emissions, a coincident search with the GW detector network and low-frequency radio arrays could increase the LIGO/Virgo effective search volume by up to a factor of ∼2. For some models, we also map the parameter space that may be constrained by non-detections.« less

Accretion States of the Galactic Micro Quasar GRS 1758-258

NASA Technical Reports Server (NTRS)

Soria, Roberto; Mehdipour, Missagh; Broderick, Jess W.; Hao, JingFang; Hannikainen, Diana C.; Pottschmidt, Katja; Zhang, Shuang-Nan

2011-01-01

We present the results of a radio and X-ray study of the Galactic micro quasar GRS 1758-258, using unpublished archival data and new observations. We focus in particular on the 2000-2002 state transitions, and on its more quiet behaviour in 2008-2009. Our spectral and timing analysis of the XMM-Newton data shows that the source was in the canonical intermediate, soft and hard states in 2000 September 19,2001 March 22 and 2002 September 28, respectively. We estimate the disk size, luminosity and temperature, which are consistent with a black hole mass approx.10 Solar Mass, There is much overlap between the range of total X-ray luminosities (on average approx. 0.02L(sub Edd)) in the hard and soft states, and probably between the corresponding mass accretion rates; in fact, the hard state is often more luminous. The extended radio lobes seen in 1992 and 1997 are still present in 2008-2009. The 5-GHz radio core flux density has shown variability between approx. 0.1-0.5 mJy over the last two decades. This firmly places GRS 1758-258 in the radio-quiet sequence of Galactic black holes, in the radio/X-ray plane. We note that this dichotomy is similar to the dichotomy between the radio/X-ray sequences of Seyfert and radio galaxies. We propose that the different radio efficiency of the two sequences is due to relativistic electron/positron jets in radio-loud black holes, and sub-relativistic, thermally dominated outflows in radio-quiet sources.

REVIEWS OF TOPICAL PROBLEMS: Coronal magnetic loops

NASA Astrophysics Data System (ADS)

Zaitsev, Valerii V.; Stepanov, Alexander V.

2008-11-01

The goal of this review is to outline some new ideas in the physics of coronal magnetic loops, the fundamental structural elements of the atmospheres of the Sun and flaring stars, which are involved in phenomena such as stellar coronal heating, flare energy release, charged particle acceleration, and the modulation of optical, radio, and X-ray emissions. The Alfvén-Carlqvist view of a coronal loop as an equivalent electric circuit allows a good physical understanding of loop processes. Describing coronal loops as MHD-resonators explains various ways in which flaring emissions from the Sun and stars are modulated, whereas modeling them by magnetic mirror traps allows one to describe the dynamics and emission of high-energy particles. Based on these approaches, loop plasma and fast particle parameters are obtained and models for flare energy release and stellar corona heating are developed.

Perceptual and Acoustic Analyses of Good Voice Quality in Male Radio Performers.

PubMed

Warhurst, Samantha; Madill, Catherine; McCabe, Patricia; Ternström, Sten; Yiu, Edwin; Heard, Robert

2017-03-01

Good voice quality is an asset to professional voice users, including radio performers. We examined whether (1) voices could be reliably categorized as good for the radio and (2) these categories could be predicted using acoustic measures. Male radio performers (n = 24) and age-matched male controls performed "The Rainbow Passage" as if presenting on the radio. Voice samples were rated using a three-stage paired-comparison paradigm by 51 naive listeners and perceptual categories were identified (Study 1), and then analyzed for fundamental frequency, long-term average spectrum, cepstral peak prominence, and pause or spoken-phrase duration (Study 2). Study 1: Good inter-judge reliability was found for perceptual judgments of the best 15 voices (good for radio category, 14/15 = radio performers), but agreement on the remaining 33 voices (unranked category) was poor. Study 2: Discriminant function analyses showed that the SD standard deviation of sounded portion duration, equivalent sound level, and smoothed cepstral peak prominence predicted membership of categories with moderate accuracy (R 2  = 0.328). Radio performers are heterogeneous for voice quality; good voice quality was judged reliably in only 14 out of 24 radio performers. Current acoustic analyses detected some of the relevant signal properties that were salient in these judgments. More refined perceptual analysis and the use of other perceptual methods might provide more information on the complex nature of judging good voices. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Survival of mountain quail translocated from two distinct source populations

USGS Publications Warehouse

Troy, Ronald J.; Coates, Peter S.; Connelly, John W.; Gillette, Gifford; Delehanty, David J.

2013-01-01

Translocation of mountain quail (Oreortyx pictus) to restore viable populations to their former range has become a common practice. Because differences in post-release vital rates between animals from multiple source populations has not been well studied, wildlife and land managers may arbitrarily choose the source population or base the source population on immediate availability when planning translocation projects. Similarly, an understanding of the optimal proportion of individuals from different age and sex classes for translocation would benefit translocation planning. During 2006 and 2007, we captured and translocated 125 mountain quail from 2 ecologically distinct areas: 38 from southern California and 87 from southwestern Oregon. We released mountain quail in the Bennett Hills of south-central Idaho. We radio-marked and monitored a subsample of 58 quail and used them for a 2-part survival analysis. Cumulative survival probability was 0.23 ± 0.05 (SE) at 150 days post-release. We first examined an a priori hypothesis (model) that survival varied between the 2 distinct source populations. We found that source population did not explain variation in survival. This result suggests that wildlife managers have flexibility in selecting source populations for mountain quail translocation efforts. In a post hoc examination, we pooled the quail across source populations and evaluated differences in survival probabilities between sex and age classes. The most parsimonious model indicated that adult male survival was substantially less than survival rates of other mountain quail age and sex classes (i.e., interaction between sex and age). This result suggests that translocation success could benefit by translocating yearling males rather than adult males, perhaps because adult male breeding behavior results in vulnerability to predators

Structural Variability of 3C 111 on Parsec Scales

NASA Technical Reports Server (NTRS)

Grossberger, C.; Kadler, M.; Wilms, J.; Muller, C.; Beuchert, T.; Ros, E.; Ojha, R.; Aller, M.; Aller, H.; Angelakis, E.;

Taking the Radio Blinders Off of M83: A Wide Spectrum Analysis of the Historical Point Source Population

NASA Astrophysics Data System (ADS)

Stockdale, Christopher; Keefe, Clayton; Nichols, Michael; Rujevcan, Colton; Blair, William P.; Cowan, John J.; Godfrey, Leith; Miller-Jones, James; Kuntz, K. D.; Long, Knox S.; Maddox, Larry A.; Plucinsky, Paul P.; Pritchard, Tyler A.; Soria, Roberto; Whitmore, Bradley C.; Winkler, P. Frank

2015-01-01

We present low frequency observations of the grand design spiral galaxy, M83, using the C and L bands of the Karl G. Jansky Very Large Array (VLA). With recent optical (HST) and X-ray (Chandra) observations and utilizing the newly expanded bandwidth of the VLA, we are exploring the radio spectral properties of the historical radio point sources in M83. These observations allow us to probe the evolution of supernova remnants (SNRs) and to find previously undiscovered SNRs. These observations represent the fourth epoch of deep VLA observations of M83. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities.

Radio frequency spectrum management

NASA Astrophysics Data System (ADS)

Sujdak, E. J., Jr.

1980-03-01

This thesis is a study of radio frequency spectrum management as practiced by agencies and departments of the Federal Government. After a brief introduction to the international agency involved in radio frequency spectrum management, the author concentrates on Federal agencies engaged in frequency management. These agencies include the National Telecommunications and Information Administration (NTIA), the Interdepartment Radio Advisory Committee (IRAC), and the Department of Defense (DoD). Based on an analysis of Department of Defense frequency assignment procedures, recommendations are given concerning decentralizing military frequency assignment by delegating broader authority to unified commanders. This proposal includes a recommendation to colocate the individual Service frequency management offices at the Washington level. This would result in reduced travel costs, lower manpower requirements, and a common tri-Service frequency management data base.

Generating multiple orbital angular momentum vortex beams using a metasurface in radio frequency domain

NASA Astrophysics Data System (ADS)

Yu, Shixing; Li, Long; Shi, Guangming; Zhu, Cheng; Shi, Yan

2016-06-01

In this paper, an electromagnetic metasurface is designed, fabricated, and experimentally demonstrated to generate multiple orbital angular momentum (OAM) vortex beams in radio frequency domain. Theoretical formula of compensated phase-shift distribution is deduced and used to design the metasurface to produce multiple vortex radio waves in different directions with different OAM modes. The prototype of a practical configuration of square-patch metasurface is designed, fabricated, and measured to validate the theoretical analysis at 5.8 GHz. The simulated and experimental results verify that multiple OAM vortex waves can be simultaneously generated by using a single electromagnetic metasurface. The proposed method paves an effective way to generate multiple OAM vortex waves in radio and microwave wireless communication applications.

Baseline-dependent averaging in radio interferometry

NASA Astrophysics Data System (ADS)

Wijnholds, S. J.; Willis, A. G.; Salvini, S.

2018-05-01

This paper presents a detailed analysis of the applicability and benefits of baseline-dependent averaging (BDA) in modern radio interferometers and in particular the Square Kilometre Array. We demonstrate that BDA does not affect the information content of the data other than a well-defined decorrelation loss for which closed form expressions are readily available. We verify these theoretical findings using simulations. We therefore conclude that BDA can be used reliably in modern radio interferometry allowing a reduction of visibility data volume (and hence processing costs for handling visibility data) by more than 80 per cent.

VLA observations of radio sources in interacting galaxy pairs in poor clusters

NASA Technical Reports Server (NTRS)

Batuski, David J.; Hanisch, Robert J.; Burns, Jack O.

1992-01-01

Observations of 16 radio sources in interacting galaxies in 14 poor clusters were made using the Very Large Array in the B configuration at lambda of 6 and 2 cm. These sources had been unresolved in earlier observations at lambda of 21 cm, and were chosen as a sample to determine which of three models for radio source formation actually pertains in interacting galaxies. From the analysis of this sample, the starburst model appears most successful, but the 'central monster' model could pertain in some cases.

Vertical motions in the Uranian atmosphere - An analysis of radio observations

NASA Technical Reports Server (NTRS)

Hofstadter, Mark D.; Berge, Glenn L.; Muhleman, Duane O.

1990-01-01

The present, 6-cm radio map of Uranus indicates latitudinal features which may be due to vertical motions of the atmosphere. It appears in light of Voyager IR measurements as well as previously obtained radio data that these large-scale vertical motions, which have not undergone significant changes over the course of 8 years, extend from the 0.1- to the 45-bar levels; this span corresponds to a height of the order of 250 km. The latitudinal structures are believed to be primarily caused by horizontal variations of absorber abundances.

ECN-2301

NASA Image and Video Library

1969-09-10

The Hyper III was a low-cost test vehicle for an advanced lifting-body shape. Like the earlier M2-F1, it was a "homebuilt" research aircraft, i.e., built at the Flight Research Center (FRC), later redesignated the Dryden Flight Research Center. It had a steel-tube frame covered with Dacron, a fiberglass nose, sheet aluminum fins, and a wing from an HP-11 sailplane. Construction was by volunteers at the FRC. Although the Hyper III was to be flown remotely in its initial tests, it was fitted with a cockpit for a pilot. On the Hyper III's only flight, it was towed aloft attached to a Navy SH-3 helicopter by a 400-foot cable. NASA research pilot Bruce Peterson flew the SH-3. After he released the Hyper III from the cable, NASA research pilot Milt Thompson flew the vehicle by radio control until the final approach when Dick Fischer took over control using a model-airplane radio-control box. The Hyper III flared, then landed and slid to a stop on Rogers Dry Lakebed.

Manufacture of radio frequency micromachined switches with annealing.

PubMed

Lin, Cheng-Yang; Dai, Ching-Liang

2014-01-17

The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V.

Manufacture of Radio Frequency Micromachined Switches with Annealing

PubMed Central

Lin, Cheng-Yang; Dai, Ching-Liang

2014-01-01

The fabrication and characterization of a radio frequency (RF) micromachined switch with annealing were presented. The structure of the RF switch consists of a membrane, coplanar waveguide (CPW) lines, and eight springs. The RF switch is manufactured using the complementary metal oxide semiconductor (CMOS) process. The switch requires a post-process to release the membrane and springs. The post-process uses a wet etching to remove the sacrificial silicon dioxide layer, and to obtain the suspended structures of the switch. In order to improve the residual stress of the switch, an annealing process is applied to the switch, and the membrane obtains an excellent flatness. The finite element method (FEM) software CoventorWare is utilized to simulate the stress and displacement of the RF switch. Experimental results show that the RF switch has an insertion loss of 0.9 dB at 35 GHz and an isolation of 21 dB at 39 GHz. The actuation voltage of the switch is 14 V. PMID:24445415

The search for reference sources for delta VLBI navigation of the Galileo spacecraft

NASA Technical Reports Server (NTRS)

Ulvestad, J. S.; Linfield, R. P.

1986-01-01

A comprehensive search was made in order to identify celestial radio sources that can be used as references for navigation of the Galileo spacecraft by means of VLBI observations. The astronomical literature was seached for potential navigation sources, and several VLBI experiments were performed to determine the suitability of those sources for navigation. The results of such work performed since mid-1983 is reported. A summary is presented of the source properties required, the procedures used to identify candidate sources, and the results of the observations of these sources. The lists of souces presented are not meant to be taken directly and used for VLBI navigation, but they do provide a means of identifying the radio sources that could be used at various positions along the Galileo trajectory. Since the reference sources nearest the critical points of Jupiter encounter and probe release are rather weak, it would be extremely beneficial to use a pair of 70-m antennas for the VLBI measurements.

Ionospheric Variability as Observed by the CTECS and CORISS Sensors

NASA Astrophysics Data System (ADS)

Bishop, R. L.; Redding, M.; Straus, P. R.

2013-12-01

The Compact Total Electron Content Sensor (CTECS) is a GPS radio occultation instrument designed for cubesat platforms that utilizes a COTS receiver, modified firmware, and a custom designed antenna. CTECS was placed on the Pico Satellite Solar Cell Testbed 2 (PSSC2) nanosat that was installed on the Space Shuttle Atlantis (STS-135). PSSC2 was successfully released from the shuttle on 20 July 2011 near 380 km altitude. Because of attitude control and power issues, only 13.5 hours of data was collected during its approximately 5-month mission life. The C/NOFS Occultation Receiver for Ionospheric Sensing and Specification (CORISS) GPS radio occultation sensor on the C/NOFS satellite has collected data nearly continuously from May 2008 to June 2013. Both CTECS and CORISS obtain Total Electron Content and scintillation data. In this presentation the CTECS data is first validated against CORISS and available ground-based observations. Then combining the CTECS and CORISS data, low and mid latitude ionospheric variability including scintillation events is presented.

Radio Frequencies Emitted by Mobile Granular Materials: A Basis for Remote Sensing of Sand and Dust Activity on Mars and Earth

NASA Technical Reports Server (NTRS)

Marshall, J.; Farrell, W.; Houser, G.; Bratton, C.

1999-01-01

In recent laboratory experiments, measurements were made of microsecond radio-wave (RF) bursts emitted by grains of sand as they energetically circulated in a closed, electrically ungrounded chamber. The bursts appeared to result from nanoscale electrical discharging from grain surfaces. Both the magnitude and wave form of the RF pulses varied with the type of material undergoing motion. The release of RF from electrical discharging is a well-known phenomenon, but it is generally measured on much larger energy scales (e.g., in association with lightning or electrical motors). This phenomenon might be used to detect, on planetary surfaces, the motion and composition of sand moving over dunes, the turbulent motion of fine particles in dust storms, highly-energetic grain and rock collisions in volcanic eruptions, and frictional grinding of granular materials in dry debris flows, landslides, and avalanches. The occurrence of these discharges has been predicted from theoretical considerations Additional information is contained in the original.

Home range and movements of juvenile Puerto Rican parrots

USGS Publications Warehouse

Lindsey, G.D.; Arendt, W.J.; Kalina, J.; Pendleton, G.W.

1991-01-01

We studied home range and movements of 15 radio-marked, juvenile Puerto Rican parrots (Amazona vittata) fledging from wild nests during summer and fall, 1985-87. When juvenile parrots remained in the nest valley, home ranges during 1986 (.hivin.x = 32 .+-. 10 [SE] ha, n = 4) were larger (P = 0.0079) than during 1987 (.hivin.x = 13 .+-. 6 ha, n = 5). After radio-marked parrots integrated into adult flocks, home ranges during 1986 (.hivin.x = 1,075 .+-. 135 ha, n = 3) were similar (P = 0.10) to 1987 (.hivin.x = 416 .+-. 62 ha, n = 2). Juvenile parrots restricted their movements to nest valleys an average of 58 .+-. 29 days following fledging. After joining adult flocks, juvenile parrots routinely flew between the east and west slopes of the Luquillo Mountains but did not exhibit a seaonal pattern of movement. We recommend that captive-raised, juvenile parrots used in release programs be .gtoreq. 5 months old to ensure they are mature enough to integrate into wild flocks.

Investigating passage of ESA-listed juvenile fall Chinook salmon at Lower Granite Dam during winter when the fish bypass system is not operated

USGS Publications Warehouse

Kock, Tobias J.; Tiffan, Kenneth F.; Connor, William P.

2007-01-01

During the winter of 2006-07, we radio and passive integrated transponder (PIT) tagged, and released 99 juvenile fall Chinook salmon to evaluate over-wintering behavior and dam passage in the lower Snake River, Washington. All fish were released 10 km upstream of Lower Granite Dam at Granite Point in early November, 2006. Fixed radio telemetry detection sites located in the forebay and tailrace areas of Lower Granite, Little Goose, Lower Monumental, Ice Harbor, Bonneville dams, and at Lyle, Washington were used to monitor fish movements and dam passage through early-May 2007. Of the 99 fish released during our study, 80 passed Lower Granite Dam and were detected at downstream detection sites, 37 passed Little Goose Dam, 41 passed Lower Monumental Dam, 31 passed Ice Harbor Dam, 18 passed Lyle, WA, and 13 passed Bonneville Dam. Of the fish that passed Lower Granite Dam in the fall, 63 fish did so during the extended bypass period from November 1 through December 16. Of these fish, 53 were also detected by the PIT-tag interrogation system. Fifteen of the fish that passed Lower Granite Dam in the fall continued to pass lower Snake River dams and exit the system by the end of January. The remaining fish either died, their tags failed, or they resided in Little Goose Reservoir until spring when relatively few continued their seaward migration. Passage of tagged fish past lower Snake River dams generally declined during the winter as temperatures decreased, but increased again in the spring as temperatures and flows increased. Fish residence times in reservoirs and forebays was lengthy during the winter (up to 160 d), and varied by reservoir and time of year. We observed no diel trends in fish passage. Very few fish were detected at PIT-tag interrogation sites in the spring compared to detection by radio telemetry detection sites indicating that fish may have passed via spill. We believe that passage of overwintering juvenile fall Chinook salmon during winter is due more to chance than directed downstream movement. Since the primary route of passage during the winter is through powerhouse turbines, the potential exists for increased mortality for over-wintering juvenile fall Chinook salmon in the Snake River. Our findings that some fish can pass undetected during the winter likely bias traditional smolt-to-adult return rate calculations that are typically used to measure the success of juvenile transportation studies.

Measurement of horizontal air showers with the Auger Engineering Radio Array

NASA Astrophysics Data System (ADS)

Kambeitz, Olga

2017-03-01

The Auger Engineering Radio Array (AERA), at the Pierre Auger Observatory in Argentina, measures the radio emission of extensive air showers in the 30-80 MHz frequency range. AERA consists of more than 150 antenna stations distributed over 17 km2. Together with the Auger surface detector, the fluorescence detector and the underground muon detector (AMIGA), AERA is able to measure cosmic rays with energies above 1017 eV in a hybrid detection mode. AERA is optimized for the detection of air showers up to 60° zenith angle, however, using the reconstruction of horizontal air showers with the Auger surface array, very inclined showers can also be measured. In this contribution an analysis of the AERA data in the zenith angle range from 62° to 80° will be presented. CoREAS simulations predict radio emission footprints of several km2 for horizontal air showers, which are now confirmed by AERA measurements. This can lead to radio-based composition measurements and energy determination of horizontal showers in the future and the radio detection of neutrino induced showers is possible.

The second FERMI large area telescope catalog of gamma-ray pulsars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A. A.; Ajello, M.; Allafort, A.

2013-09-19

This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emissionmore » for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.« less

Average radio spectral energy distribution of highly star-forming galaxies

NASA Astrophysics Data System (ADS)

Tisanić, K.; Smolčić, V.; Delhaize, J.; Novak, M.; Intema, H.; Delvecchio, I.; Schinnerer, E.; Zamorani, G.

2018-05-01

The infrared-radio correlation (IRRC) offers a way to assess star formation from radio emission. Multiple studies found the IRRC to decrease with increasing redshift. This may in part be due to the lack of knowledge about the possible radio spectral energy distributions (SEDs) of star-forming galaxies. We constrain the radio SED of a complete sample of highly star-forming galaxies (SFR > 100 M⊙/ yr) based on the VLA-COSMOS 1.4 GHz Joint and 3 GHz Large Project catalogs. We reduce archival GMRT 325 MHz and 610 MHz observations, broadening the rest-frame frequency range to 0.3-15 GHz. Employing survival analysis and fitting a double power law SED, we find that the slope steepens from a spectral index of α1 = 0.51+/-0.04 below 4.5 GHz to α2 = 0.98+/-0.07 above 4.5 GHz. Our results suggest that the use of a K-correction assuming a single power-law radio SED for star forming galaxies is likely not the root cause of the IRRC trend.

From Radio with Love: An Overview of the Role of Radio Observations in Understanding High-Energy Emission from Active Galaxies

NASA Technical Reports Server (NTRS)

Ojha, Roopesh

2012-01-01

The gamma-ray satellite Fermi and the ground based TeV facilities MAGIC, VERITAS and HESS have ushered in a new era in the observation of high-energy emission from active galaxies. The energy budgets of these objects have a major contribution from gamma-rays and it is simply not possible to understand their physics without high-energy observations. Though the exact mechanisms for high-energy production in galaxies remains an open question, gamma-rays typically result from interactions between high-energy particles. Via different interactions these same particles can produce radio emission. Thus the non-thermal nature of gamma-ray emission practically guarantees that high-energy emitters are also radio loud. Aside from their obvious role as a component of multiwavelength analysis, radio observations provide two crucial elements essential to understanding the source structure and physical processes of high-energy emitters: very high timing resolution and very high spatial resolution. A brief overview of the unique role played by radio observations in unraveling the mysteries of the high energy Universe as presented here.

The second fermi large area telescope catalog of gamma-ray pulsars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdo, A. A.; Ajello, M.; Allafort, A.

2013-09-19

This catalog summarizes 117 high-confidence ≥0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emissionmore » for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions.« less

First evidence of diffuse ultra-steep-spectrum radio emission surrounding the cool core of a cluster

NASA Astrophysics Data System (ADS)

Savini, F.; Bonafede, A.; Brüggen, M.; van Weeren, R.; Brunetti, G.; Intema, H.; Botteon, A.; Shimwell, T.; Wilber, A.; Rafferty, D.; Giacintucci, S.; Cassano, R.; Cuciti, V.; de Gasperin, F.; Röttgering, H.; Hoeft, M.; White, G.

2018-05-01

Diffuse synchrotron radio emission from cosmic-ray electrons is observed at the center of a number of galaxy clusters. These sources can be classified either as giant radio halos, which occur in merging clusters, or as mini halos, which are found only in cool-core clusters. In this paper, we present the first discovery of a cool-core cluster with an associated mini halo that also shows ultra-steep-spectrum emission extending well beyond the core that resembles radio halo emission. The large-scale component is discovered thanks to LOFAR observations at 144 MHz. We also analyse GMRT observations at 610 MHz to characterise the spectrum of the radio emission. An X-ray analysis reveals that the cluster is slightly disturbed, and we suggest that the steep-spectrum radio emission outside the core could be produced by a minor merger that powers electron re-acceleration without disrupting the cool core. This discovery suggests that, under particular circumstances, both a mini and giant halo could co-exist in a single cluster, opening new perspectives for particle acceleration mechanisms in galaxy clusters.

Fermi LAT Observation of Centaurus a Radio Galaxy

NASA Astrophysics Data System (ADS)

Sahakyan, N. V.

2013-01-01

The results of analysis of approximately 3 year gamma-ray observations (August 2008-July 2011) of the core of radio galaxy Centaurus A with the Fermi Large Area Telescope (Fermi LAT) are presented. Binned likelihood analysis method applying to the data shows that below several GeV the spectrum can be described by a single power-law with photon index Γ = 2.73 ± 0.06. However, at higher energies the new data show significant excess above the extrapolation of the energy spectrum from low energies. The comparison of the corresponding Spectral Energy Distribution (SED) at GeV energies with the SED in the TeV energy band reported by the H.E.S.S. collaboration shows that we deal with two or perhaps even three components of gamma-radiation originating from different regions located within the central 10 kpc of Centaurus A. The analysis of gamma-ray data of Centaurus A lobe accumulated from the beginning of the operation until November 14, 2011 show extension of the HE gamma-ray emission beyond the WMAP radio image in the case of the Northern lobe [9]. The possible origins of gamma-rays from giant radio lobes of Centaurus A are discussed in the context of hadronic and leptonic scenarios.

Complex Dynamics of Equatorial Scintillation

NASA Astrophysics Data System (ADS)

Piersanti, Mirko; Materassi, Massimo; Forte, Biagio; Cicone, Antonio

2017-04-01

Radio power scintillation, namely highly irregular fluctuations of the power of trans-ionospheric GNSS signals, is the effect of ionospheric plasma turbulence. The scintillation patterns on radio signals crossing the medium inherit the ionospheric turbulence characteristics of inter-scale coupling, local randomness and large time variability. On this basis, the remote sensing of local features of the turbulent plasma is feasible by studying radio scintillation induced by the ionosphere. The distinctive character of intermittent turbulent media depends on the fluctuations on the space- and time-scale statistical properties of the medium. Hence, assessing how the signal fluctuation properties vary under different Helio-Geophysical conditions will help to understand the corresponding dynamics of the turbulent medium crossed by the signal. Data analysis tools, provided by complex system science, appear to be best fitting to study the response of a turbulent medium, as the Earth's equatorial ionosphere, to the non-linear forcing exerted by the Solar Wind (SW). In particular we used the Adaptive Local Iterative Filtering, the Wavelet analysis and the Information theory data analysis tool. We have analysed the radio scintillation and ionospheric fluctuation data at low latitude focusing on the time and space multi-scale variability and on the causal relationship between forcing factors from the SW environment and the ionospheric response.

Plasma and radio waves from Neptune: Source mechanisms and propagation

NASA Astrophysics Data System (ADS)

Wong, H. K.

1994-03-01

This report summarizes results obtained through the support of NASA Grant NAGW-2412. The objective of this project is to conduct a comprehensive investigation of the radio wave emission observed by the planetary radio astronomy (PRA) instrument on board Voyager 2 as if flew by Neptune. This study has included data analysis, theoretical and numerical calculations, ray tracing, and modeling to determine the possible source mechanism(s) and locations of the Neptune radio emissions. We have completed four papers, which are included in the appendix. The paper 'Modeling of Whistler Ray Paths in the Magnetosphere of Neptune' investigated the propagation and dispersion of lighting-generated whistler in the magnetosphere of Neptune by using three dimensional ray tracing. The two papers 'Numerical Simulations of Bursty Radio Emissions from Planetary Magnetospheres' and 'Numerical Simulations of Bursty Planetary Radio Emissions' employed numerical simulations to investigate an alternate source mechanism of bursty radio emissions in addition to the cyclotron maser instability. We have also studied the possible generation of Z and whistler mode waves by the temperature anisotropic beam instability and the result was published in 'Electron Cyclotron Wave Generation by Relativistic Electrons.' Besides the aforementioned studies, we have also collaborated with members of the PRA team to investigate various aspects of the radio wave data. Two papers have been submitted for publication and the abstracts of these papers are also listed in the appendix.

Continuum radiation from active galactic nuclei: A statistical study

NASA Technical Reports Server (NTRS)

Isobe, T.; Feigelson, E. D.; Singh, K. P.; Kembhavi, A.

1986-01-01

The physics of the continuum spectrum of active galactic nuclei (AGNs) was examined using a large data set and rigorous statistical methods. A data base was constructed for 469 objects which include radio selected quasars, optically selected quasars, X-ray selected AGNs, BL Lac objects, and optically unidentified compact radio sources. Each object has measurements of its radio, optical, X-ray core continuum luminosity, though many of them are upper limits. Since many radio sources have extended components, the core component were carefully selected out from the total radio luminosity. With survival analysis statistical methods, which can treat upper limits correctly, these data can yield better statistical results than those previously obtained. A variety of statistical tests are performed, such as the comparison of the luminosity functions in different subsamples, and linear regressions of luminosities in different bands. Interpretation of the results leads to the following tentative conclusions: the main emission mechanism of optically selected quasars and X-ray selected AGNs is thermal, while that of BL Lac objects is synchrotron; radio selected quasars may have two different emission mechanisms in the X-ray band; BL Lac objects appear to be special cases of the radio selected quasars; some compact radio sources show the possibility of synchrotron self-Compton (SSC) in the optical band; and the spectral index between the optical and the X-ray bands depends on the optical luminosity.

Effectiveness and cost effectiveness of television, radio and print advertisements in promoting the New York smokers' quitline.

PubMed

Farrelly, Matthew C; Hussin, Altijani; Bauer, Ursula E

2007-12-01

This study assessed the relative effectiveness and cost effectiveness of television, radio and print advertisements to generate calls to the New York smokers' quitline. Regression analysis was used to link total county level monthly quitline calls to television, radio and print advertising expenditures. Based on regression results, standardised measures of the relative effectiveness and cost effectiveness of expenditures were computed. There was a positive and statistically significant relation between call volume and expenditures for television (p<0.01) and radio (p<0.001) advertisements and a marginally significant effect for expenditures on newspaper advertisements (p<0.065). The largest effect was for television advertising. However, because of differences in advertising costs, for every $1000 increase in television, radio and newspaper expenditures, call volume increased by 0.1%, 5.7% and 2.8%, respectively. Television, radio and print media all effectively increased calls to the New York smokers' quitline. Although increases in expenditures for television were the most effective, their relatively high costs suggest they are not currently the most cost effective means to promote a quitline. This implies that a more efficient mix of media would place greater emphasis on radio than television. However, because the current study does not adequately assess the extent to which radio expenditures would sustain their effectiveness with substantial expenditure increases, it is not feasible to determine a more optimal mix of expenditures.

Plasma and radio waves from Neptune: Source mechanisms and propagation

NASA Technical Reports Server (NTRS)

Wong, H. K.

1994-01-01

This report summarizes results obtained through the support of NASA Grant NAGW-2412. The objective of this project is to conduct a comprehensive investigation of the radio wave emission observed by the planetary radio astronomy (PRA) instrument on board Voyager 2 as if flew by Neptune. This study has included data analysis, theoretical and numerical calculations, ray tracing, and modeling to determine the possible source mechanism(s) and locations of the Neptune radio emissions. We have completed four papers, which are included in the appendix. The paper 'Modeling of Whistler Ray Paths in the Magnetosphere of Neptune' investigated the propagation and dispersion of lighting-generated whistler in the magnetosphere of Neptune by using three dimensional ray tracing. The two papers 'Numerical Simulations of Bursty Radio Emissions from Planetary Magnetospheres' and 'Numerical Simulations of Bursty Planetary Radio Emissions' employed numerical simulations to investigate an alternate source mechanism of bursty radio emissions in addition to the cyclotron maser instability. We have also studied the possible generation of Z and whistler mode waves by the temperature anisotropic beam instability and the result was published in 'Electron Cyclotron Wave Generation by Relativistic Electrons.' Besides the aforementioned studies, we have also collaborated with members of the PRA team to investigate various aspects of the radio wave data. Two papers have been submitted for publication and the abstracts of these papers are also listed in the appendix.

draco: Analysis and simulation of drift scan radio data

NASA Astrophysics Data System (ADS)

Shaw, J. Richard

2017-12-01

draco analyzes transit radio data with the m-mode formalism. It is telescope agnostic, and is used as part of the analysis and simulation pipeline for the CHIME (Canadian Hydrogen Intensity Mapping Experiment) telescope. It can simulate time stream data from maps of the sky (using the m-mode formalism) and add gain fluctuations and correctly correlated instrumental noise (i.e. Wishart distributed). Further, it can perform various cuts on the data and make maps of the sky from data using the m-mode formalism.

Hybrid Mobile Communication Networks for Planetary Exploration

NASA Technical Reports Server (NTRS)

Alena, Richard; Lee, Charles; Walker, Edward; Osenfort, John; Stone, Thom

2007-01-01

A paper discusses the continuing work of the Mobile Exploration System Project, which has been performing studies toward the design of hybrid communication networks for future exploratory missions to remote planets. A typical network could include stationary radio transceivers on a remote planet, mobile radio transceivers carried by humans and robots on the planet, terrestrial units connected via the Internet to an interplanetary communication system, and radio relay transceivers aboard spacecraft in orbit about the planet. Prior studies have included tests on prototypes of these networks deployed in Arctic and desert regions chosen to approximate environmental conditions on Mars. Starting from the findings of the prior studies, the paper discusses methods of analysis, design, and testing of the hybrid communication networks. It identifies key radio-frequency (RF) and network engineering issues. Notable among these issues is the study of wireless LAN throughput loss due to repeater use, RF signal strength, and network latency variations. Another major issue is that of using RF-link analysis to ensure adequate link margin in the face of statistical variations in signal strengths.

Temporary Restoration of Bull Trout Passage at Albeni Falls Dam, 2008 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellgraph, Brian J.

2009-03-31

The goal of this project is to provide temporary upstream passage of bull trout around Albeni Falls Dam on the Pend Oreille River, Idaho. Our specific objectives are to capture fish downstream of Albeni Falls Dam, tag them with combination acoustic and radio transmitters, release them upstream of Albeni Falls Dam, and determine if genetic information on tagged fish can be used to accurately establish where fish are located during the spawning season. In 2007, radio receiving stations were installed at several locations throughout the Pend Oreille River watershed to detect movements of adult bull trout; however, no bull troutmore » were tagged during that year. In 2008, four bull trout were captured downstream of Albeni Falls Dam, implanted with transmitters, and released upstream of the dam at Priest River, Idaho. The most-likely natal tributaries of bull trout assigned using genetic analyses were Grouse Creek (N = 2); a tributary of the Pack River, Lightning Creek (N = 1); and Rattle Creek (N = 1), a tributary of Lightning Creek. All four bull trout migrated upstream from the release site in Priest River, Idaho, were detected at monitoring stations near Dover, Idaho, and were presumed to reside in Lake Pend Oreille from spring until fall 2008. The transmitter of one bull trout with a genetic assignment to Grouse Creek was found in Grouse Creek in October 2008; however, the fish was not found. The bull trout assigned to Rattle Creek was detected in the Clark Fork River downstream from Cabinet Gorge Dam (approximately 13 km from the mouth of Lightning Creek) in September but was not detected entering Lightning Creek. The remaining two bull trout were not detected in 2008 after detection at the Dover receiving stations. This report details the progress by work element in the 2008 statement of work, including data analyses of fish movements, and expands on the information reported in the quarterly Pisces status reports.« less

The Relationship between Media Consumption and Health-Related Anxieties after the Fukushima Daiichi Nuclear Disaster

PubMed Central

Sugimoto, Amina; Nomura, Shuhei; Tsubokura, Masaharu; Matsumura, Tomoko; Muto, Kaori; Sato, Mikiko; Gilmour, Stuart

2013-01-01

Background The Fukushima Daiichi nuclear disaster caused a global panic by a release of harmful radionuclides. In a disaster setting, misusage of contemporary media sources available today can lead to disseminated incorrect information and panic. The study aims to build a scale which examines associations between media and individual anxieties, and to propose effective media usages for future disaster management. Methods The University of Tokyo collaborated with the Fukushima local government to conduct a radiation-health-seminar for a total of 1560 residents, at 12 different locations in Fukushima. A 13 item questionnaire collected once before and after a radiation-seminar was used on factor analysis to develop sub-scales for multiple regression models, to determine relationships between the sub-scales and media type consumed. A paired t–test was used to examine any changes in sub-scale of pre- and post-seminar scores. Results Three sub-scales were revealed and were associated with different media types: was with rumors, while concern for the future was positively associated with regional-newspapers and negatively with national-newspapers. Anxiety about social-disruption was associated with radio. The seminar had a significant effect on anxiety reduction for all the three sub-scales. Conclusion Different media types were associated with various heightened concerns, and that a radiation seminar was helpful to reduce anxieties in the post-disaster setting. By tailoring post-disaster messages via specific media types, i.e., radio, it may be possible to effectively convey important information, as well as to calm fears about particular elements of post-disaster recovery and to combat rumors. PMID:23967046

The relationship between media consumption and health-related anxieties after the Fukushima Daiichi nuclear disaster.

PubMed

Sugimoto, Amina; Nomura, Shuhei; Tsubokura, Masaharu; Matsumura, Tomoko; Muto, Kaori; Sato, Mikiko; Gilmour, Stuart

2013-01-01

The Fukushima Daiichi nuclear disaster caused a global panic by a release of harmful radionuclides. In a disaster setting, misusage of contemporary media sources available today can lead to disseminated incorrect information and panic. The study aims to build a scale which examines associations between media and individual anxieties, and to propose effective media usages for future disaster management. The University of Tokyo collaborated with the Fukushima local government to conduct a radiation-health-seminar for a total of 1560 residents, at 12 different locations in Fukushima. A 13 item questionnaire collected once before and after a radiation-seminar was used on factor analysis to develop sub-scales for multiple regression models, to determine relationships between the sub-scales and media type consumed. A paired t-test was used to examine any changes in sub-scale of pre- and post-seminar scores. Three sub-scales were revealed and were associated with different media types: was with rumors, while concern for the future was positively associated with regional-newspapers and negatively with national-newspapers. Anxiety about social-disruption was associated with radio. The seminar had a significant effect on anxiety reduction for all the three sub-scales. Different media types were associated with various heightened concerns, and that a radiation seminar was helpful to reduce anxieties in the post-disaster setting. By tailoring post-disaster messages via specific media types, i.e., radio, it may be possible to effectively convey important information, as well as to calm fears about particular elements of post-disaster recovery and to combat rumors.

Expanded Owens Valley Solar Array Science and Data Products

NASA Astrophysics Data System (ADS)

Gary, Dale E.; Hurford, G. J.; Nita, G. M.; Fleishman, G. D.; McTiernan, J. M.

2010-05-01

The Owens Valley Solar Array (OVSA) has been funded for major expansion, to create a university-based facility serving a broad scientific community, to keep the U.S. competitive in the field of solar radio physics. The project, funded by the National Science Foundation through the MRI-Recovery and Reinvestment program, will result in a world-class facility for scientific research at microwave radio frequencies (1-18 GHz) in solar and space weather physics. The project also includes an exciting program of targeted astronomical science. The solar science to be addressed focuses on the magnetic structure of the solar corona, on transient phenomena resulting from magnetic interactions, including the sudden release of energy and subsequent particle acceleration and heating, and on space weather phenomena. The project will support the scientific community by providing open data access and software tools for analysis of the data, to exploit synergies with on-going solar research in other wavelength bands. The New Jersey Institute of Technology (NJIT) will upgrade OVSA from its current complement of 7 antennas to a total of 15 by adding 8 new antennas, and will reinvest in the existing infrastructure by replacing the existing control systems, signal transmission, and signal processing with modern, far more capable and reliable systems based on new technology developed for the Frequency Agile Solar Radiotelescope (FASR). The project will be completed in time to provide solar-dedicated observations during the upcoming solar maximum in 2013 and beyond. We will detail the new science addressed by the expanded array, and provide an overview of the expected data products.

Survival of captive and free-ranging Harlequin Ducks (Histrionicus histrionicus) following surgical liver biopsy

USGS Publications Warehouse

Mulcahy, Daniel M.; Esler, Daniel N.

2010-01-01

We measured intra- and postoperative mortality rates of captive and free-ranging Harlequin Ducks (Histrionicus histrionicus) undergoing surgical liver biopsy sampling for determination of the induction of cytochrome P4501A, a biomarker of oil exposure. Liver biopsies were taken from and radio transmitters were implanted into 157 free-ranging Harlequin Ducks over three winters (55 in 2000, 55 in 2001, and 47 in 2002). No birds died during surgery, but seven (4.5%) died during recovery from anesthesia (three in 2001 and four in 2002). None of the deaths could be attributed directly to the liver biopsy. Four of the 150 (2.7%) birds that were released died in the 2 wk period after surgery. All post-release deaths occurred in 2001; no birds died after release in 2000 or 2002. No mortalities of 36 captive birds occurred during surgery or recovery or in the 2 wk period following surgery. Hemorrhage was a minor problem with one captive bird. Surgical liver biopsies appear to be a safe procedure, but anesthetic complications may occur with overwintering ducks.

UNVEILING THE NATURE OF THE UNIDENTIFIED GAMMA-RAY SOURCES. V. ANALYSIS OF THE RADIO CANDIDATES WITH THE KERNEL DENSITY ESTIMATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massaro, F.; Funk, S.; D'Abrusco, R.

2013-11-01

Nearly one-third of the γ-ray sources detected by Fermi are still unidentified, despite significant recent progress in this area. However, all of the γ-ray extragalactic sources associated in the second Fermi-LAT catalog have a radio counterpart. Motivated by this observational evidence, we investigate all the radio sources of the major radio surveys that lie within the positional uncertainty region of the unidentified γ-ray sources (UGSs) at a 95% level of confidence. First, we search for their infrared counterparts in the all-sky survey performed by the Wide-field Infrared Survey Explorer (WISE) and then we analyze their IR colors in comparison withmore » those of the known γ-ray blazars. We propose a new approach, on the basis of a two-dimensional kernel density estimation technique in the single [3.4] – [4.6] – [12] μm WISE color-color plot, replacing the constraint imposed in our previous investigations on the detection at 22 μm of each potential IR counterpart of the UGSs with associated radio emission. The main goal of this analysis is to find distant γ-ray blazar candidates that, being too faint at 22 μm, are not detected by WISE and thus are not selected by our purely IR-based methods. We find 55 UGSs that likely correspond to radio sources with blazar-like IR signatures. An additional 11 UGSs that have blazar-like IR colors have been found within the sample of sources found with deep recent Australia Telescope Compact Array observations.« less

Different Effects of Human Umbilical Cord Mesenchymal Stem Cells on Glioblastoma Stem Cells by Direct Cell Interaction or Via Released Soluble Factors

PubMed Central

Bajetto, Adriana; Pattarozzi, Alessandra; Corsaro, Alessandro; Barbieri, Federica; Daga, Antonio; Bosio, Alessia; Gatti, Monica; Pisaturo, Valerio; Sirito, Rodolfo; Florio, Tullio

2017-01-01

Glioblastoma (GBM), the most common primary brain tumor in adults, is an aggressive, fast-growing and highly vascularized tumor, characterized by extensive invasiveness and local recurrence. In GBM and other malignancies, cancer stem cells (CSCs) are believed to drive invasive tumor growth and recurrence, being responsible for radio- and chemo-therapy resistance. Mesenchymal stem cells (MSCs) are multipotent progenitors that exhibit tropism for tumor microenvironment mediated by cytokines, chemokines and growth factors. Initial studies proposed that MSCs might exert inhibitory effects on tumor development, although, to date, contrasting evidence has been provided. Different studies reported either MSC anti-tumor activity or their support to tumor growth. Here, we examined the effects of umbilical cord (UC)-MSCs on in vitro GBM-derived CSC growth, by direct cell-to-cell interaction or indirect modulation, via the release of soluble factors. We demonstrate that UC-MSCs and CSCs exhibit reciprocal tropism when co-cultured as 3D spheroids and their direct cell interaction reduces the proliferation of both cell types. Contrasting effects were obtained by UC-MSC released factors: CSCs, cultured in the presence of conditioned medium (CM) collected from UC-MSCs, increased proliferation rate through transient ERK1/2 and Akt phosphorylation/activation. Analysis of the profile of the cytokines released by UC-MSCs in the CM revealed a strong production of molecules involved in inflammation, angiogenesis, cell migration and proliferation, such as IL-8, GRO, ENA-78 and IL-6. Since CXC chemokine receptor 2 (CXCR2), a receptor shared by several of these ligands, is expressed in GBM CSCs, we evaluated its involvement in CSC proliferation induced by UC-MSC-CM. Using the CXCR2 antagonist SB225002, we observed a partial but statistically significant inhibition of CSC proliferation and migration induced by the UC-MSC-released cytokines. Conversely, CXCR2 blockade did not reduce the reciprocal tropism between CSCs and UC-MSCs grown as spheroids. In conclusion, we show that direct (cell-to-cell contact) or indirect (via the release of soluble factors) interactions between GBM CSCs and UC-MSCs in co-culture produce divergent effects on cell growth, invasion and migration, with the former mainly causing an inhibitory response and the latter a stimulatory one, involving a paracrine activation of CXCR2. PMID:29081734

Different Effects of Human Umbilical Cord Mesenchymal Stem Cells on Glioblastoma Stem Cells by Direct Cell Interaction or Via Released Soluble Factors.

PubMed

Bajetto, Adriana; Pattarozzi, Alessandra; Corsaro, Alessandro; Barbieri, Federica; Daga, Antonio; Bosio, Alessia; Gatti, Monica; Pisaturo, Valerio; Sirito, Rodolfo; Florio, Tullio

2017-01-01

Glioblastoma (GBM), the most common primary brain tumor in adults, is an aggressive, fast-growing and highly vascularized tumor, characterized by extensive invasiveness and local recurrence. In GBM and other malignancies, cancer stem cells (CSCs) are believed to drive invasive tumor growth and recurrence, being responsible for radio- and chemo-therapy resistance. Mesenchymal stem cells (MSCs) are multipotent progenitors that exhibit tropism for tumor microenvironment mediated by cytokines, chemokines and growth factors. Initial studies proposed that MSCs might exert inhibitory effects on tumor development, although, to date, contrasting evidence has been provided. Different studies reported either MSC anti-tumor activity or their support to tumor growth. Here, we examined the effects of umbilical cord (UC)-MSCs on in vitro GBM-derived CSC growth, by direct cell-to-cell interaction or indirect modulation, via the release of soluble factors. We demonstrate that UC-MSCs and CSCs exhibit reciprocal tropism when co-cultured as 3D spheroids and their direct cell interaction reduces the proliferation of both cell types. Contrasting effects were obtained by UC-MSC released factors: CSCs, cultured in the presence of conditioned medium (CM) collected from UC-MSCs, increased proliferation rate through transient ERK1/2 and Akt phosphorylation/activation. Analysis of the profile of the cytokines released by UC-MSCs in the CM revealed a strong production of molecules involved in inflammation, angiogenesis, cell migration and proliferation, such as IL-8, GRO, ENA-78 and IL-6. Since CXC chemokine receptor 2 (CXCR2), a receptor shared by several of these ligands, is expressed in GBM CSCs, we evaluated its involvement in CSC proliferation induced by UC-MSC-CM. Using the CXCR2 antagonist SB225002, we observed a partial but statistically significant inhibition of CSC proliferation and migration induced by the UC-MSC-released cytokines. Conversely, CXCR2 blockade did not reduce the reciprocal tropism between CSCs and UC-MSCs grown as spheroids. In conclusion, we show that direct (cell-to-cell contact) or indirect (via the release of soluble factors) interactions between GBM CSCs and UC-MSCs in co-culture produce divergent effects on cell growth, invasion and migration, with the former mainly causing an inhibitory response and the latter a stimulatory one, involving a paracrine activation of CXCR2.

Radio Observations of the Tidal Disruption Event XMMSL1 J0740-85

NASA Astrophysics Data System (ADS)

Alexander, K. D.; Wieringa, M. H.; Berger, E.; Saxton, R. D.; Komossa, S.

2017-03-01

We present radio observations of the tidal disruption event candidate (TDE) XMMSL1 J0740-85 spanning 592 to 875 days post X-ray discovery. We detect radio emission that fades from an initial peak flux density at 1.6 GHz of 1.19 ± 0.06 mJy to 0.65 ± 0.06 mJy, suggesting an association with the TDE. This makes XMMSL1 J0740-85 at d = 75 Mpc the nearest TDE with detected radio emission to date and only the fifth TDE with radio emission overall. The observed radio luminosity rules out a powerful relativistic jet like that seen in the relativistic TDE Swift J1644+57. Instead, we infer from an equipartition analysis that the radio emission most likely arises from a non-relativistic outflow similar to that seen in the nearby TDE ASASSN-14li, with a velocity of about 104 km s-1 and a kinetic energy of about 1048 erg, expanding into a medium with a density of about 102 cm-3. Alternatively, the radio emission could arise from a weak initially relativistic but decelerated jet with an energy of ˜ 2× {10}50 erg, or (for an extreme disruption geometry) from the unbound debris. The radio data for XMMSL1 J0740-85 continues to support the previous suggestion of a bimodal distribution of common non-relativistic isotropic outflows and rare relativistic jets in TDEs (in analogy with the relation between Type Ib/c supernovae and long-duration gamma-ray bursts). The radio data also provide a new measurement of the circumnuclear density on a sub-parsec scale around an extragalactic supermassive black hole.

First Joint Observations of Radio Aurora by the VHF and HF Radars of the ISTP SB RAS

NASA Astrophysics Data System (ADS)

Berngardt, O. I.; Lebedev, V. P.; Kutelev, K. A.; Kushnarev, D. S.; Grkovich, K. V.

2018-01-01

Two modern radars for diagnosis of the ionosphere by the radio-wave backscattering method, namely, the Irkutsk incoherent scatter radar at VHF (IISR, 154-162 MHz) and the Ekaterinburg coherent radar at HF (EKB, 8-20 MHz) are operated at the Institute of Solar-Terrestrial Physics, Siberian Branch of the Russian Academy of Sciences (ISTP SB RAS). The paper analyzes the results of joint observations of strong scattering (radio aurora) on June 8, 2015. To determine the geographical position of the radio aurora, we developed original methods that take into account both the features of the radio-wave propagation and the features of the radar antenna systems. It is shown that there are areas where the spatial position of the HF and VHF radio aurora can coincide. This permits using the radars as a single complex for diagnosis of the characteristics of small-scale high-latitude irregularities in the ionospheric E and F layers. A comparative analysis of the characteristics and temporal dynamics of the radio-aurora region in the HF and VHF ranges is performed. Using the DMSP satellite data, it has been shown that the radio aurora dynamics during this experiment with the EKB radar can be related with the spatial dynamics of the localized area with high electric field, which moves from high to equatorial latitudes. It is found that due to the broader field of view, radio aurora at the HF radar was stably observed 6-12 min earlier than at the VHF radar. This permits using the EKB radar data for prediction of the radio-aurora detection by the IISR radar.

Cen A Optical Capella

NASA Image and Video Library

2017-12-08

NASA release April 1, 2010 The giant elliptical galaxy NGC 5128, show here in visible light, hosts the radio source known as Centaurus A. Located 12 million light-years away, it is one of the closest active galaxies. Credit: Capella Observatory To learn more about these images go to: www.nasa.gov/mission_pages/GLAST/news/smokestack-plumes.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Cen A Optical Capella

NASA Image and Video Library

2010-04-01

NASA release April 1, 2010 The giant elliptical galaxy NGC 5128, show here in visible light, hosts the radio source known as Centaurus A. Located 12 million light-years away, it is one of the closest active galaxies. Credit: Capella Observatory To learn more about these images go to: www.nasa.gov/mission_pages/GLAST/news/smokestack-plumes.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Ionospheric Modification by Powerful Radio Waves-the Suzdal Symposium (2th) Held in Tromso, Norway on September 1988

DTIC Science & Technology

1989-03-21

fitting computer S - band KlyStrons , of the type developed at the Stanford program, and he now states that Ti does not change very Linear Accelerator...shift of the seems well justified. heating pattern, intense rapid heating in preexisting den- S . Kuo reported small-chamber studies with S - band sity...21989 U r A 1 0P oJ S - - I-P, r?-Ew (e 0 DGeorge J. Morales 21 March 1989 Approved for public release; distribution unlimited Office of Naval Research

Ion trap device

DOEpatents

Ibrahim, Yehia M.; Smith, Richard D.

2016-01-26

An ion trap device is disclosed. The device includes a series of electrodes that define an ion flow path. A radio frequency (RF) field is applied to the series of electrodes such that each electrode is phase shifted approximately 180 degrees from an adjacent electrode. A DC voltage is superimposed with the RF field to create a DC gradient to drive ions in the direction of the gradient. A second RF field or DC voltage is applied to selectively trap and release the ions from the device. Further, the device may be gridless and utilized at high pressure.

Release and Movement of Radionuclides in Soils Contaminated with Fallout Materials from an Underground Thermonuclear Detonation

DTIC Science & Technology

1962-07-06

Studies The degree of dissolution of the fallout material in H2 0, HCl, DTPA, CDTA, and EDDHA solutions was investigated by the suspension method...days was: EDDHA >DTPA>CDTA>H 2 0. while after 65 days the order of effect was: CDTA> EDDHA >DTPA>H 20. Portions of gamma ray spectra of the 106 day...the same amounts of radionuclides as did H120. The most abundant radio- nuclide was radiotungsten for H120, DTPA, CDTA, and EDDHA supernatant liquids

Skylab Rescue Space Vehicle OAT No. 1 Plugs in Test

NASA Technical Reports Server (NTRS)

Jevitt, S. J.

1973-01-01

A test is described which demonstrates the compatibility of the Skylab Rescue Space Vehicle systems, the ground support equipment, and off-site support facilities by proceeding through a simulated launch countdown, liftoff, and flight. The functions of propellant loading, umbilical ejection, holddown arm release, service arm retraction, liftoff, and inflight separation are simulated. An external power source supplies transfer power to internal, and instrument unit commands are simulated by the digital command system. The test outline is presented along with a list of references, intercommunications information, radio frequency matrix, and interface control chart.

Open Astronomy Catalogs API

NASA Astrophysics Data System (ADS)

Guillochon, James; Cowperthwaite, Philip S.

2018-05-01

We announce the public release of the application program interface (API) for the Open Astronomy Catalogs (OACs), the OACAPI. The OACs serve near-complete collections of supernova, tidal disruption, kilonova, and fast stars data (including photometry, spectra, radio, and X-ray observations) via a user-friendly web interface that displays the data interactively and offers full data downloads. The OACAPI, by contrast, enables users to specifically download particular pieces of the OAC dataset via a flexible programmatic syntax, either via URL GET requests, or via a module within the astroquery Python package.

SOURCE REGIONS OF THE TYPE II RADIO BURST OBSERVED DURING A CME–CME INTERACTION ON 2013 MAY 22

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mäkelä, P.; Reiner, M. J.; Akiyama, S.

2016-08-20

We report on our study of radio source regions during the type II radio burst on 2013 May 22 based on direction-finding analysis of the Wind /WAVES and STEREO /WAVES (SWAVES) radio observations at decameter–hectometric wavelengths. The type II emission showed an enhancement that coincided with the interaction of two coronal mass ejections (CMEs) launched in sequence along closely spaced trajectories. The triangulation of the SWAVES source directions posited the ecliptic projections of the radio sources near the line connecting the Sun and the STEREO-A spacecraft. The WAVES and SWAVES source directions revealed shifts in the latitude of the radiomore » source, indicating that the spatial location of the dominant source of the type II emission varies during the CME–CME interaction. The WAVES source directions close to 1 MHz frequencies matched the location of the leading edge of the primary CME seen in the images of the LASCO/C3 coronagraph. This correspondence of spatial locations at both wavelengths confirms that the CME–CME interaction region is the source of the type II enhancement. Comparison of radio and white-light observations also showed that at lower frequencies scattering significantly affects radio wave propagation.« less

Status of air-shower measurements with sparse radio arrays

NASA Astrophysics Data System (ADS)

Schröder, Frank G.

2017-03-01

This proceeding gives a summary of the current status and open questions of the radio technique for cosmic-ray air showers, assuming that the reader is already familiar with the principles. It includes recent results of selected experiments not present at this conference, e.g., LOPES and TREND. Current radio arrays like AERA or Tunka-Rex have demonstrated that areas of several km2 can be instrumented for reasonable costs with antenna spacings of the order of 200m. For the energy of the primary particle such sparse antenna arrays can already compete in absolute accuracy with other precise techniques, like the detection of air-fluorescence or air-Cherenkov light. With further improvements in the antenna calibration, the radio detection might become even more accurate. For the atmospheric depth of the shower maximum, Xmax, currently only the dense array LOFAR features a precision similar to the fluorescence technique, but analysis methods for the radio measurement of Xmax are still under development. Moreover, the combination of radio and muon measurements is expected to increase the accuracy of the mass composition, and this around-the-clock recording is not limited to clear nights as are the light-detection methods. Consequently, radio antennas will be a valuable add-on for any air shower array targeting the energy range above 100 PeV.

Chandra Observation of the WAT Radio Source/ICM Interaction in Abell 623

NASA Astrophysics Data System (ADS)

Anand, Gagandeep; Blanton, Elizabeth L.; Randall, Scott W.; Paterno-Mahler, Rachel; Douglass, Edmund

2017-01-01

Galaxy clusters are important objects for studying the physics of the intracluster medium (ICM), galaxy formation and evolution, and cosmological parameters. Clusters containing wide-angle tail (WAT) radio sources are particularly valuable for studies of the interaction between these sources and the surrounding ICM. These sources are thought to form when the ram pressure from the ICM caused by the relative motion between the host radio galaxy and the cluster bends the radio lobes into a distinct wide-angle morphology. We present our results from the analysis of a Chandra observation of the nearby WAT hosting galaxy cluster Abell 623. A clear decrement in X-ray emission is coincident with the southern radio lobe, consistent with being a cavity carved out by the radio source. We present profiles of surface brightness, temperature, density, and pressure and find evidence for a possible shock. Based on the X-ray pressure in the vicinity of the radio lobes and assumptions about the content of the lobes, we estimate the relative ICM velocity required to bend the lobes into the observed angle. We also present spectral model fits to the overall diffuse cluster emission and see no strong signature for a cool core. The sum of the evidence indicates that Abell 623 may be undergoing a large scale cluster-cluster merger.

Radio Gaga? Intra-team communication of Australian Rules Football umpires - effect of radio communication on content, structure and frequency.

PubMed

Neville, Timothy J; Salmon, Paul M; Read, Gemma J M

2018-02-01

Intra-team communication plays an important role in team effectiveness in various domains including sport. As such, it is a key consideration when introducing new tools within systems that utilise teams. The difference in intra-team communication of Australian Rules Football (AFL) umpiring teams was studied when umpiring with or without radio communications technology. A cross-sectional observational study was conducted to analyse the verbal communication of seven umpiring teams (20 participants) grouped according to their experience with radio communication. The results identified that radio communication technology increased the frequency and altered the structure of intra-team communication. Examination of the content of the intra-team communication identified impacts on the 'Big Five' teamwork behaviours and associated coordinating mechanisms. Analysis revealed that the communications utilised did not align with the closed-loop form of communication described in the Big Five model. Implications for teamwork models, coaching and training of AFL umpires are discussed. Practitioner Summary: Assessing the impact of technology on performance is of interest to ergonomics practitioners. The impact of radio communications on teamwork is explored in the highly dynamic domain of AFL umpiring. When given radio technology, intra-team communication increased which supported teamwork behaviours, such as backup behaviour and mutual performance monitoring.

A Jupiter Data Analysis Program (JDAP) research grant on wave accessibility and attributes

NASA Technical Reports Server (NTRS)

Calvert, Wynne

1987-01-01

For more than thirty years the intense decametric radio emissions from Jupiter (DAM) and the corresponding auroral kilometric radiation from the Earth (AKR) have remained major radio science mysteries. Part of the problem, aside from their inherent complexity, has been the difficulty of measuring their source location and emission properties from limited observations. Progress has been made on this problem by locating the source directly, i.e., by analysis of the faraday rotation observed with Voyager as the wave path crossed the Io plasma torus, and indirectly by comparing the peak frequencies of the decametric emission with that at the foot of the Io flux tube. Progress was also made on the general question of how the emissions originate by finding properties of both the AKR and DAM which would imply emission by natural radio lasing.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2003-12-30

A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

Method for high resolution magnetic resonance analysis using magic angle technique

DOEpatents

Wind, Robert A.; Hu, Jian Zhi

2004-12-28

A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

Practical application of electromyogram radiotelemetry: the suitability of applying laboratory-acquired calibration data to field data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geist, David R.; Brown, Richard S.; Lepla, Ken

One of the practical problems with quantifying the amount of energy used by fish implanted with electromyogram (EMG) radio transmitters is that the signals emitted by the transmitter provide only a relative index of activity unless they are calibrated to the swimming speed of the fish. Ideally calibration would be conducted for each fish before it is released, but this is often not possible and calibration curves derived from more than one fish are used to interpret EMG signals from individuals which have not been calibrated. We tested the validity of this approach by comparing EMG data within three groupsmore » of three wild juvenile white sturgeon Acipenser transmontanus implanted with the same EMG radio transmitter. We also tested an additional six fish which were implanted with separate EMG transmitters. Within each group, a single EMG radio transmitter usually did not produce similar results in different fish. Grouping EMG signals among fish produced less accurate results than having individual EMG-swim speed relationships for each fish. It is unknown whether these differences were a result of different swimming performances among individual fish or inconsistencies in the placement or function of the EMG transmitters. In either case, our results suggest that caution should be used when applying calibration curves from one group of fish to another group of uncalibrated fish.« less

Intermediate BL Lac objects

NASA Astrophysics Data System (ADS)

Bondi, M.; Marchã, M. J. M.; Dallacasa, D.; Stanghellini, C.

2001-08-01

The 200-mJy sample, defined by Marchã et al., contains about 60 nearby, northern, flat-spectrum radio sources. In particular, the sample has proved effective at finding nearby radio-selected BL Lac objects with radio luminosities comparable to those of X-ray-selected objects, and low-luminosity flat-spectrum weak emission-line radio galaxies (WLRGs). The 200-mJy sample contains 23 BL Lac objects (including 6 BL Lac candidates) and 19 WLRGs. We will refer to these subsamples as the 200-mJy BL Lac sample and the 200-mJy WLRG sample, respectively. We have started a systematic analysis of the morphological pc-scale properties of the 200-mJy radio sources using VLBI observations. This paper presents VLBI observations at 5 and 1.6GHz of 14 BL Lac objects and WLRGs selected from the 200-mJy sample. The pc-scale morphology of these objects is briefly discussed. We derive the radio beaming parameters of the 200-mJy BL Lac objects and WLRGs and compare them with those of other BL Lac samples and with a sample of FR I radio galaxies. The overall broad-band radio, optical and X-ray properties of the 200-mJy BL Lac sample are discussed and compared with those of other BL Lac samples, radio- and X-ray-selected. We find that the 200-mJy BL Lac objects fill the gap between HBL and LBL objects in the colour-colour plot, and have intermediate αXOX as expected in the spectral energy distribution unification scenario. Finally, we briefly discuss the role of the WLRGs.

Search for transient gravitational waves in coincidence with short-duration radio transients during 2007-2013

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Behnke, B.; Bejger, M.; Bell, A. S.; Bell, C. J.; Berger, B. K.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bodiya, T. P.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bojtos, P.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dattilo, V.; Dave, I.; Daveloza, H. P.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dojcinoski, G.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hofman, D.; Hollitt, S. E.; Holt, K.; Holz, D. E.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Islas, G.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Haris, K.; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Karki, S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Nam-Gyu; Kim, Namjun; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Kokeyama, K.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Levine, B. M.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Logue, J.; Lombardi, A. L.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lück, H.; Lundgren, A. P.; Luo, J.; Lynch, R.; Ma, Y.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R. M.; Mageswaran, M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mendoza-Gandara, D.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, K. N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Necula, V.; Nedkova, K.; Nelemans, G.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Pereira, R.; Perreca, A.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Pletsch, H. J.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S. S.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Ricci, F.; Riles, K.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, J. D.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sentenac, D.; Sequino, V.; Sergeev, A.; Serna, G.; Setyawati, Y.; Sevigny, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stiles, D.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Tomlinson, C.; Tonelli, M.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Wright, J. L.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yap, M. J.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, F.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, X. J.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; Archibald, A. M.; Banaszak, S.; Berndsen, A.; Boyles, J.; Cardoso, R. F.; Chawla, P.; Cherry, A.; Dartez, L. P.; Day, D.; Epstein, C. R.; Ford, A. J.; Flanigan, J.; Garcia, A.; Hessels, J. W. T.; Hinojosa, J.; Jenet, F. A.; Karako-Argaman, C.; Kaspi, V. M.; Keane, E. F.; Kondratiev, V. I.; Kramer, M.; Leake, S.; Lorimer, D.; Lunsford, G.; Lynch, R. S.; Martinez, J. G.; Mata, A.; McLaughlin, M. A.; McPhee, C. A.; Penucci, T.; Ransom, S.; Roberts, M. S. E.; Rohr, M. D. W.; Stairs, I. H.; Stovall, K.; van Leeuwen, J.; Walker, A. N.; Wells, B. L.; LIGO Scientific Collaboration; Virgo Collaboration

2016-06-01

We present an archival search for transient gravitational-wave bursts in coincidence with 27 single-pulse triggers from Green Bank Telescope pulsar surveys, using the LIGO, Virgo, and GEO interferometer network. We also discuss a check for gravitational-wave signals in coincidence with Parkes fast radio bursts using similar methods. Data analyzed in these searches were collected between 2007 and 2013. Possible sources of emission of both short-duration radio signals and transient gravitational-wave emission include starquakes on neutron stars, binary coalescence of neutron stars, and cosmic string cusps. While no evidence for gravitational-wave emission in coincidence with these radio transients was found, the current analysis serves as a prototype for similar future searches using more sensitive second-generation interferometers.

Generating multiple orbital angular momentum vortex beams using a metasurface in radio frequency domain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Shixing; Li, Long, E-mail: lilong@mail.xidian.edu.cn, E-mail: gmshi@xidian.edu.cn; Shi, Guangming, E-mail: lilong@mail.xidian.edu.cn, E-mail: gmshi@xidian.edu.cn

In this paper, an electromagnetic metasurface is designed, fabricated, and experimentally demonstrated to generate multiple orbital angular momentum (OAM) vortex beams in radio frequency domain. Theoretical formula of compensated phase-shift distribution is deduced and used to design the metasurface to produce multiple vortex radio waves in different directions with different OAM modes. The prototype of a practical configuration of square-patch metasurface is designed, fabricated, and measured to validate the theoretical analysis at 5.8 GHz. The simulated and experimental results verify that multiple OAM vortex waves can be simultaneously generated by using a single electromagnetic metasurface. The proposed method paves an effectivemore » way to generate multiple OAM vortex waves in radio and microwave wireless communication applications.« less

Renewed Radio Activity of Age 370 years in the Extragalactic Source 0108+388

NASA Astrophysics Data System (ADS)

Owsianik, I.; Conway, J. E.; Polatidis, A. G.

1998-08-01

We present the results of multi-epoch global VLBI observations of the Compact Symmetric Object (CSO) 0108+388 at 5 GHz. Analysis of data spread over 12 years shows strong evidence for an increase in the separation of the outer components at a rate of 0.197+/-0.026 h(-1) c. Given an overall size of 22.2 h(-1) pc this implies a kinematic age of only 367+/-48 yrs. This result strongly supports the idea that radio emission in Compact Symmetric Objects arises from recently activated radio sources. The presence of weak radio emission on kpc-scales in 0108+388 suggests recurrent activity in this source, and that we are observing it just as a new period of activity is beginning.

Hard state neutron star and black hole X-ray binaries in the radio:X-ray luminosity plane

NASA Astrophysics Data System (ADS)

Gallo, Elena; Degenaar, Nathalie; van den Eijnden, Jakob

2018-07-01

Motivated by the large body of literature around the phenomenological properties of accreting black hole (BH) and neutron star (NS) X-ray binaries in the radio:X-ray luminosity plane, we carry out a comparative regression analysis on 36 BHs and 41 NSs in hard X-ray states, with data over 7 dex in X-ray luminosity for both. The BHs follow a radio to X-ray (logarithmic) luminosity relation with slope β = 0.59 ± 0.02, consistent with the NSs' slope (β =0.44^{+0.05}_{-0.04}) within 2.5σ. The best-fitting intercept for the BHs significantly exceeds that for the NSs, cementing BHs as more radio loud, by a factor ˜22. This discrepancy cannot be fully accounted for by the mass or bolometric correction gap, or by the NS boundary layer contribution to the X-rays, and is likely to reflect physical differences in the accretion flow efficiency, or the jet powering mechanism. Once importance sampling is implemented to account for the different luminosity distributions, the slopes of the non-pulsating and pulsating NS subsamples are formally inconsistent (>3σ), unless the transitional millisecond pulsars (whose incoherent radio emission mechanism is not firmly established) are excluded from the analysis. We confirm the lack of a robust partitioning of the BH data set into separate luminosity tracks.

Is popular radio a source of exposure to alcohol references in mid to later life? A content analysis.

PubMed

Haighton, C; Halligan, J; Scott, S

2017-04-20

There is concern around alcohol consumption in mid to later life yet little understanding about what influences this behaviour. No previous research has explored the extent to which adults in mid to later life may be exposed to alcohol references in the media. This project aimed to determine the frequency of alcohol references on radio stations with a high proportion of listeners in mid to later life. Content analysis of alcohol references on four popular UK music-based radio stations with a high proportion of listeners aged 55-64 years over three time points. Alcohol references occur frequently, but vary by time of year and type of radio station. When alcohol is mentioned its consumption is portrayed as the norm, without negative consequences. On three commercial stations, the majority of mentions came from advertising, whereas on BBC Radio 2 nearly all references were talk-based. All adverts for direct promotion of alcohol were by supermarkets. Alcohol was frequently associated with celebrations, socializing or something to consume for its own sake. Adults in the age group 55-64 may be exposed to references to alcohol that could serve to reinforce norms of consumption of alcohol and promote purchases of cheap alcohol. © The Author 2017. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Hard state neutron star and black hole X-ray binaries in the radio:X-ray luminosity plane

NASA Astrophysics Data System (ADS)

Gallo, Elena; Degenaar, Nathalie; van den Eijnden, Jakob

2018-05-01

Motivated by the large body of literature around the phenomenological properties of accreting black hole (BH) and neutron star (NS) X-ray binaries in the radio:X-ray luminosity plane, we carry out a comparative regression analysis on 36 BHs and 41 NSs in hard X-ray states, with data over 7 dex in X-ray luminosity for both. The BHs follow a radio to X-ray (logarithmic) luminosity relation with slope β = 0.59 ± 0.02, consistent with the NSs' slope (β =0.44^{+0.05}_{-0.04}) within 2.5σ. The best-fitting intercept for the BHs significantly exceeds that for the NSs, cementing BHs as more radio loud, by a factor ˜22. This discrepancy can not be fully accounted for by the mass or bolometric correction gap, nor by the NS boundary layer contribution to the X-rays, and is likely to reflect physical differences in the accretion flow efficiency, or the jet powering mechanism. Once importance sampling is implemented to account for the different luminosity distributions, the slopes of the non-pulsating and pulsating NS subsamples are formally inconsistent (>3σ), unless the transitional millisecond pulsars (whose incoherent radio emission mechanism is not firmly established) are excluded from the analysis. We confirm the lack of a robust partitioning of the BH data set into separate luminosity tracks.

Multiwavelength Studies of Rotating Radio Transients

NASA Astrophysics Data System (ADS)

Miller, Joshua J.

Seven years ago, a new class of pulsars called the Rotating Radio Transients (RRATs) was discovered with the Parkes radio telescope in Australia (McLaughlin et al., 2006). These neutron stars are characterized by strong radio bursts at repeatable dispersion measures, but not detectable using standard periodicity-search algorithms. We now know of roughly 100 of these objects, discovered in new surveys and re-analysis of archival survey data. They generally have longer periods than those of the normal pulsar population, and several have high magnetic fields, similar to those other neutron star populations like the X-ray bright magnetars. However, some of the RRATs have spin-down properties very similar to those of normal pulsars, making it difficult to determine the cause of their unusual emission and possible evolutionary relationships between them and other classes of neutron stars. We have calculated single-pulse flux densities for eight RRAT sources observed using the Parkes radio telescope. Like normal pulsars, the pulse amplitude distributions are well described by log-normal probability distribution functions, though two show evidence for an additional power-law tail. Spectral indices are calculated for the seven RRATs which were detected at multiple frequencies. These RRATs have a mean spectral index of = -3.2(7), or = -3.1(1) when using mean flux densities derived from fitting log-normal probability distribution functions to the pulse amplitude distributions, suggesting that the RRATs have steeper spectra than normal pulsars. When only considering the three RRATs for which we have a wide range of observing frequencies, however, and become --1.7(1) and --2.0(1), respectively, and are roughly consistent with those measured for normal pulsars. In all cases, these spectral indices exclude magnetar-like flat spectra. For PSR J1819--1458, the RRAT with the highest bursting rate, pulses were detected at 685 and 3029 MHz in simultaneous observations and have a spectral index consistent with our other analysis. We also present the results of simultaneous radio and X-ray observations of PSR J1819--1458. Our 94-ks XMM-Newton observation of the high magnetic field (~5x109 T) pulsar reveals a blackbody spectrum ( kT~130 eV) with a broad absorption feature, possibly composed of two lines at ~1.0 and ~1.3 keV. We performed a correlation analysis of the X-ray photons with radio pulses detected in 16.2 hours of simultaneous observations at 1--2 GHz with the Green Bank, Effelsberg, and Parkes telescopes, respectively. Both the detected X-ray photons and radio pulses appear to be randomly distributed in time. We find tentative evidence for a correlation between the detected radio pulses and X-ray photons on timescales of less than 10 pulsar spin periods, with the probability of this occurring by chance being 0.46%. This suggests that the physical process producing the radio pulses may also heat the polar cap.

The Case Against Satellites. The Network Project. Notebook Number Seven.

ERIC Educational Resources Information Center

Columbia Univ., New York, NY. Network Project.

An analysis is presented of the dangers generated by the corporate ownership of a satellite communications technology powerful enough to centralize and control the flow of information. The first part of the report reprints the transcript of a radio documentary on satellite communications, one of a series of five MATRIX radio programs produced by…

Analysis of an Interplanetary Coronal Mass Ejection by a Spacecraft Radio Signal: A Case Study

NASA Astrophysics Data System (ADS)

Molera Calvés, G.; Kallio, E.; Cimo, G.; Quick, J.; Duev, D. A.; Bocanegra Bahamón, T.; Nickola, M.; Kharinov, M. A.; Mikhailov, A. G.

2017-11-01

Tracking radio communication signals from planetary spacecraft with ground-based telescopes offers the possibility to study the electron density and the interplanetary scintillation of the solar wind. Observations of the telemetry link of planetary spacecraft have been conducted regularly with ground antennae from the European Very Long Baseline Interferometry Network, aiming to study the propagation of radio signals in the solar wind at different solar elongations and distances from the Sun. We have analyzed the Mars Express spacecraft radio signal phase fluctuations while, based on a 3-D heliosphere plasma simulation, an interplanetary coronal mass ejection (ICME) crossed the radio path during one of our observations on 6 April 2015. Our measurements showed that the phase scintillation indices increased by a factor of 4 during the passage of the ICME. The method presented here confirms that the phase scintillation technique based on spacecraft signals provides information of the properties and propagation of the ICMEs in the heliosphere.

The LOPES experiment

NASA Astrophysics Data System (ADS)

Link, Katrin; Apel, W. D.; Arteaga, J. C.; Asch, T.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Daumiller, K.; de Souza, V.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huber, D.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Ludwig, M.; Mathes, H. J.; Melissas, M.; Morello, C.; Nehls, S.; Oehlschläger, J.; Palmieri, N.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Rühle, C.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.

2011-03-01

Cosmic ray particles hit the Earth's atmosphere and induce extensive air showers (EAS). These EAS mainly consist of electrons and positrons that produce radio emission due to their interaction with the Earth's magnetic field. Measuring this radio emission is the purpose of the LOPES (LOFAR Prototype Station) experiment. LOPES is located at Campus North of the Karlsruhe Institute of Technology at the same site as the EAS particle detector KASCADE-Grande. Since the first measurements in 2003, LOPES was improved by various experimental setups and could establish the radio technique. By now, detailed studies of the measured radio signal are performed, like the behaviour of the lateral distribution or the polarization of the electric field. Furthermore, with LOPES the dependence of the radio pulse on properties of the incoming cosmic ray, like primary energy, primary mass, or incoming direction is investigated. In this article we describe the different LOPES setups, next we explain our standard analysis procedure and then we discuss some highlights of our recent results.

Evaluate Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faler, Michael P.; Mendel, Glen W.; Fulton, Carl

2005-11-01

We sampled and released 313 bull trout (Salvelinus confluentus) from the Tucannon River in 2004. Passive Integrated Transponder (PIT) tags were inserted in 231 of these individuals, and we detected existing PIT tags in an additional 44 bull trout. Twenty-five of these were also surgically implanted with radio-tags, and we monitored the movements of these fish throughout the year. Ten bull trout that were radio-tagged in 2003 were known to survive and carry their tags through the spring of 2004. One of these fish outmigrated into the Snake River in the fall, and remained undetected until February, when it's tagmore » was located near the confluence of Alkali Flat Creek and the Snake River. The remaining 9 fish spent the winter between Tucannon River miles 2.1 (Powers Road) and 36.0 (Tucannon Fish Hatchery). Seven of these fish retained their tags through the summer, and migrated to known spawning habitat prior to September 2004. During June and July, radio-tagged bull trout again exhibited a general upstream movement into the upper reaches of the Tucannon subbasin. As in past years, we observed some downstream movements of radio-tagged bull trout in mid to late September and throughout October, suggesting post spawning outmigrations. By late November and early December, radio tagged bull trout were relatively stationary, and were distributed from river mile 42 at Camp Wooten downstream to river mile 17, near the Highway 12 bridge. As in previous years, we did not collect data associated with objectives 2, 3, or 4 of this study, because we were unable to monitor migratory movement of radio-tagged bull trout into the vicinity of the hydropower dams on the main stem Snake River. Transmission tests of submerged Lotek model NTC-6-2 nano-tags in Lower Granite Pool showed that audible detection and individual tag identification was possible at depths of 20, 30, and 40 ft. We were able to maintain tag detection and code separation at all depths from both a boat and 200 ft. above water surface in a helicopter. However, we lost detection capability from 40 ft. water depth when we passed 700 ft. above the water surface in a helicopter. Two years of high tag loss, particularly after spawning, has prevented us from documenting fall and winter movements with an adequate sample of radio tagged bull trout. The high transmitter loss after spawning may be a reflection of high natural mortality for large, older age fish that we have been radio tagging to accommodate the longer life transmitters. Therefore, we reduced the size of the radio tags that we implanted, and delayed most of our collection and tagging of bull trout until after spawning. These changes are a new approach to try to maximize the number of radio tagged bull trout available post spawning to adequately document fall and winter movements and any use of the Snake River by bull trout from the Tucannon River.« less

Application of new radio tracking data types to critical spacecraft navigation problems

NASA Technical Reports Server (NTRS)

Ondrasik, V. J.; Rourke, K. H.

1972-01-01

Earth-based radio tracking data types are considered, which involve simultaneous or nearly simultaneous spacecraft tracking from widely separated tracking stations. These data types are conventional tracking instrumentation analogs of the very long baseline interferometry (VLBI) of radio astronomy-hence the name quasi-VLBI. A preliminary analysis of quasi-VLBI is presented using simplified tracking data models. The results of accuracy analyses are presented for a representative mission, Viking 1975. The results indicate that, contingent on projected tracking system accuracy, quasi-VLBI can be expected to significantly improve navigation performance over that expected from conventional tracking data types.

Analysis of the Capability and Limitations of Relativistic Gravity Measurements Using Radio Astronomy Methods

NASA Technical Reports Server (NTRS)

Shapiro, I. I.; Counselman, C. C., III

1975-01-01

The uses of radar observations of planets and very-long-baseline radio interferometric observations of extragalactic objects to test theories of gravitation are described in detail with special emphasis on sources of error. The accuracy achievable in these tests with data already obtained, can be summarized in terms of: retardation of signal propagation (radar), deflection of radio waves (interferometry), advance of planetary perihelia (radar), gravitational quadrupole moment of sun (radar), and time variation of gravitational constant (radar). The analyses completed to date have yielded no significant disagreement with the predictions of general relativity.

Radio Frequency Ablation Registration, Segmentation, and Fusion Tool

PubMed Central

McCreedy, Evan S.; Cheng, Ruida; Hemler, Paul F.; Viswanathan, Anand; Wood, Bradford J.; McAuliffe, Matthew J.

2008-01-01

The Radio Frequency Ablation Segmentation Tool (RFAST) is a software application developed using NIH's Medical Image Processing Analysis and Visualization (MIPAV) API for the specific purpose of assisting physicians in the planning of radio frequency ablation (RFA) procedures. The RFAST application sequentially leads the physician through the steps necessary to register, fuse, segment, visualize and plan the RFA treatment. Three-dimensional volume visualization of the CT dataset with segmented 3D surface models enables the physician to interactively position the ablation probe to simulate burns and to semi-manually simulate sphere packing in an attempt to optimize probe placement. PMID:16871716

Total body calcium analysis. [neutron irradiation

NASA Technical Reports Server (NTRS)

Lewellen, T. K.; Nelp, W. B.

1974-01-01

A technique to quantitate total body calcium in humans is developed. Total body neutron irradiation is utilized to produce argon 37. The radio argon, which diffuses into the blood stream and is excreted through the lungs, is recovered from the exhaled breath and counted inside a proportional detector. Emphasis is placed on: (1) measurement of the rate of excretion of radio argon following total body neutron irradiation; (2) the development of the radio argon collection, purification, and counting systems; and (3) development of a patient irradiation facility using a 14 MeV neutron generator. Results and applications are discussed in detail.

Performance Analysis of Optical Mobile Fronthaul for Cloud Radio Access Networks

NASA Astrophysics Data System (ADS)

Zhang, Jiawei; Xiao, Yuming; Li, Hui; Ji, Yuefeng

2017-10-01

Cloud radio access networks (C-RAN) separates baseband units (BBU) of conventional base station to a centralized pool which connects remote radio heads (RRH) through mobile fronthaul. Mobile fronthaul is a new network segment of C-RAN, it is designed to transport digital sampling data between BBU and RRH. Optical transport networks that provide large bandwidth and low latency is a promising fronthaul solution. In this paper, we discuss several optical transport networks which are candidates for mobile fronthaul, analyze their performances including the number of used wavelength, round-trip latency and wavelength utilization.

Astronomers Discover Spectacular Structure in Distant Galaxy

NASA Astrophysics Data System (ADS)

1999-01-01

Researchers using the National Science Foundation's Very Large Array (VLA) radio telescope have imaged a "spectacular and complex structure" in a galaxy 50 million light-years away. Their work both resolves a decades-old observational mystery and revises current theories about the origin of X-ray emission coming from gas surrounding the galaxy. The new VLA image is of the galaxy M87, which harbors at its core a supermassive black hole spewing out jets of subatomic particles at nearly the speed of light and also is the central galaxy of the Virgo Cluster of galaxies. The VLA image is the first to show detail of a larger structure that originally was detected by radio astronomers more than a half-century ago. Analysis of the new image indicates that astronomers will have to revise their ideas about the physics of what causes X-ray emission in the cores of many galaxy clusters. Frazer Owen of the National Radio Astronomy Observatory (NRAO) in Socorro, NM; Jean Eilek of the New Mexico Institute of Mining and Technology (NM Tech) in Socorro, NM; and Namir Kassim of the Naval Research Laboratory in Washington, DC, announced their discovery at the American Astronomical Society's meeting today in Austin, TX. The new observations show two large, bubble-like lobes, more than 200,000 light-years across, that emit radio waves. These lobes, which are intricately detailed, apparently are powered by gravitational energy released from the black hole at the galaxy's center. "We think that material is flowing outward from the galaxy's core into these large, bright, radio-emitting 'bubbles,'" Owen said. The newly-discovered "bubbles" sit inside a region of the galaxy known to be emitting X-rays. Theorists have speculated that this X-ray emission arises when gas that originally was part of the Virgo Cluster of galaxies, cools and falls inwards onto M87 itself, at the center of the cluster. Such "cooling flows" are commonly thought to be responsible for strong X-ray emission in many galaxy clusters. "The new structures that we found in M87 show that the story is much more complicated," Eilek said. "What we know about radio jets suggests that the energy being pumped into this region from the galaxy's central black hole exceeds the energy being lost in the X-ray emission. This system is more like a heating flow than a cooling flow. We're going to have to revise our ideas about the physics of what's going on in regions like this." M87, discovered by the French astronomer Charles Messier in 1781, is the strongest radio-emitting object in the constellation Virgo. Its jet was described by Lick Observatory astronomer Heber Curtis in 1918 as "a curious straight ray ... apparently connected with the nucleus by a thin line of matter." In 1954, Walter Baade reported that the jet's light is strongly polarized. M87's X-ray emission was discovered in 1966. M87 is the largest of the thousands of galaxies in the Virgo Cluster. The Local Group of galaxies, of which our own Milky Way is one, is part of the Virgo Cluster's outskirts. The galaxy's radio emissions first were observed by Australian astronomers in 1947, but the radio telescopes of that time were unable to discern much detail. They could, however, show that there is a structure more than 100,000 light-years across. Subsequent radio images, particularly those made using the sharp radio "vision" of the VLA, were primarily aimed at studying the inner 10,000 light-years or so, and showed great detail in the galaxy's jet. Astronomers even have followed the motions of concentrations of material within the jet over time. These observations, however, did not show much about the larger structure that was seen by earlier radio astronomers, leaving its details largely a mystery. Radio Images of M87 at Vastly Different Size Scales The mystery was solved by using the VLA to observe at longer radio wavelengths, thus revealing larger-scale structures. The processing speeds of modern computers and recently-developed imaging techniques also were necessary to show the exquisite details seen in the newest VLA image of M87. The result was spectacular. "Not only did we see beautiful details that we hadn't seen before, but we also got a new and more complicated idea of the physics of this region," Owen said. "The theories about cooling flows offered an explanation for the X-ray emission in galaxy clusters, but critics contended that other evidence we should see for this infalling matter, such as new stars forming in the denser parts of the flows, was absent," Owen said. "Now, in this case, we see that the inward flow can be counterbalanced by the energy coming outward from the galaxy's core, so the material may not become dense enough to trigger star formation." The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc. This is a VLA image of the galaxy M87, showing details of the large-scale, radio-emitting "bubbles" believed to be powered by the black hole at the galaxy's center. The galaxy's center (and the black hole) lie deep within the bright, reddish region in this image. The structure in this image is approximately 200,000 light-years across. This image was made at a radio wavelength of 90 centimeters. CREDIT: F.N. Owen, J.A. Eliek and N.E. Kassim, National Radio Astronomy Observatory, Associated Universities, Inc.

Low-frequency Radio Observatory on the Lunar Surface (LROLS)

NASA Astrophysics Data System (ADS)

MacDowall, Robert; Network for Exploration and Space Science (NESS)

2018-06-01

A radio observatory on the lunar surface will provide the capability to image solar radio bursts and other sources. Radio burst imaging will improve understanding of radio burst mechanisms, particle acceleration, and space weather. Low-frequency observations (less than ~20 MHz) must be made from space, because lower frequencies are blocked by Earth’s ionosphere. Solar radio observations do not mandate an observatory on the farside of the Moon, although such a location would permit study of less intense solar bursts because the Moon occults the terrestrial radio frequency interference. The components of the lunar radio observatory array are: the antenna system consisting of 10 – 100 antennas distributed over a square kilometer or more; the system to transfer the radio signals from the antennas to the central processing unit; electronics to digitize the signals and possibly to calculate correlations; storage for the data until it is down-linked to Earth. Such transmission requires amplification and a high-gain antenna system or possibly laser comm. For observatories on the lunar farside a satellite or other intermediate transfer system is required to direct the signal to Earth. On the ground, the aperture synthesis analysis is completed to display the radio image as a function of time. Other requirements for lunar surface systems include the power supply, utilizing solar arrays with batteries to maintain the system at adequate thermal levels during the lunar night. An alternative would be a radioisotope thermoelectric generator requiring less mass. The individual antennas might be designed with their own solar arrays and electronics to transmit data to the central processing unit, but surviving lunar night would be a challenge. Harnesses for power and data transfer from the central processing unit to the antennas are an alternative, but a harness-based system complicates deployment. The concept of placing the antennas and harnesses on rolls of polyimide and rolling them out may be a solution for solar radio observations, but it probably does not provide a sufficiently-uniform beam for other science targets.

'I heard about this study on the radio': using community radio to strengthen Good Participatory Practice in HIV prevention trials.

PubMed

Medeossi, Bonnie-Jeanne; Stadler, Jonathan; Delany-Moretlwe, Sinead

2014-08-26

During the Microbicides Development Program (MDP) 301, a clinical trial of a candidate microbicide amongst women in Johannesburg, South Africa, we used community radio to promote awareness of the trial, to inform community members about specific medical research procedures and terminologies, and to stimulate dialogue between researchers and local citizens. We used mixed methods to undertake a retrospective analysis of the social responses to the radio shows, focusing specifically on recruitment and participation in the MDP301 trial. We collected quantitative data that describes the themes and listener responses, the costs per broadcast, and the impact of the radio broadcasts on trial recruitment. Qualitative data on local reactions to the shows was gleaned from in-depth interviews with trial participants. Over a seven-year period, 205 individual broadcasts were made on two separate community radio stations. Show themes were either specifically related to medical research issues (36%), or focused on general health issues (46%), and sexual and reproductive health, including HIV prevention (18%). 403 listeners made telephone calls to the radio station, and 12% of women enrolled as participants in MDP301 (n = 9, 385) reported that they had first heard about the trial from the radio. Qualitative interviews (n = 401) with female MDP301 participants highlighted the effects of the radio shows in making women aware of the trial, impressing them with the importance of health screening and knowledge, legitimizing trial participation, and stimulating dialogue between trial participants and their male partners. Community radio is a potent tool for raising awareness and local knowledge about medical research and, in addition to other methodologies, can be used to promote recruitment into clinical trials. We suggest that future HIV prevention trials consider an investment in community radio beyond recruitment advertisements that incorporates this into the broader community engagement plan as a key element of Good Participatory Practice in clinical trial settings.

CAVITIES AND SHOCKS IN THE GALAXY GROUP HCG 62 AS REVEALED BY CHANDRA, XMM-NEWTON, AND GIANT METREWAVE RADIO TELESCOPE DATA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gitti, Myriam; O'Sullivan, Ewan; Giacintucci, Simona

2010-05-01

We report on the results of an analysis of Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data of the X-ray bright compact group of galaxies HCG 62, which is one of the few groups known to possess clear, small X-ray cavities in the inner regions. This is part of an ongoing X-ray/low-frequency radio study of 18 groups, initially chosen for the availability of good-quality X-ray data and evidence for active galactic nucleus/hot gas interaction. At higher frequency (1.4 GHz), the HCG 62 cavity system shows minimal if any radio emission, but the new GMRT observations at 235 MHzmore » and 610 MHz clearly detect extended low-frequency emission from radio lobes corresponding to the cavities. By means of the synergy of X-ray and low-frequency radio observations, we compare and discuss the morphology, luminosity, and pressure of the gas and of the radio source. We find that the radio source is radiatively inefficient, with a ratio of radio luminosity to mechanical cavity power of {approx}10{sup -4}, and that the radio pressure of the lobes is about 1 order of magnitude lower than the X-ray pressure of the surrounding thermal gas. Thanks to the high spatial resolution of the Chandra surface brightness and temperature profiles, we also identify a shock front located at 36 kpc to the southwest of the group center, close to the southern radio lobe, with a Mach number {approx}1.5 and a total power which is about 1 order of magnitude higher than the cavity power. Such a shock may have heated the gas in the southern region, as indicated by the temperature map. The shock may also explain the arc-like region of enriched gas seen in the iron abundance map, as this may be produced by a non-Maxwellian electron distribution near its front.« less

The Radio Luminosity Function and Galaxy Evolution in the Coma Cluster

NASA Technical Reports Server (NTRS)

Miller, Neal A.; Hornschemeier, Ann E.; Mabasher, Bahram; Brudgesm Terrry J.; Hudson, Michael J.; Marzke, Ronald O.; Smith, Russell J.

2008-01-01

We investigate the radio luminosity function and radio source population for two fields within the Coma cluster of galaxies, with the fields centered on the cluster core and southwest infall region and each covering about half a square degree. Using VLA data with a typical rms sensitivity of 28 (mu)Jy per 4.4" beam, we identify 249 radio sources with optical counterparts brighter than r = 22 (equivalent to M(sub r) = -13 for cluster member galaxies). Comprehensive optical spectroscopy identifies 38 of these as members of the Coma cluster, evenly split between sources powered by an active nucleus and sources powered by active star formation. The radio-detected star-forming galaxies are restricted to radio luminosities between about 10(exp 21) and 10(exp 22) W/Hz, an interesting result given that star formation dominates field radio luminosity functions below about 10(exp 23) W/Hz. The majority of the radio-detected star-forming galaxies have characteristics of starbursts, including high specific star formation rates and optical spectra with strong emission lines. In conjunction with prior studies on post-starburst galaxies within the Coma cluster, this is consistent with a picture in which late-type galaxies entering Coma undergo a starburst prior to a rapid cessation of star formation. Optically bright elliptical galaxies (Mr less than or equals -20.5) make the largest contribution to the radio luminosity function at both the high (> approx. 3x10(exp 22) W/Hz) and low (< approx. 10(exp 21) W/Hz) ends. Through a stacking analysis of these optically-bright ellipticals we find that they continue to harbor radio sources down to luminosities as faint as 3x10(exp 19) W/Hz. However, contrary to published results for the Virgo cluster we find no evidence for the existence of a population of optically faint (M(sub r) approx. equals -14) dwarf ellipticals hosting strong radio AGN.

Observation of quasi-periodic solar radio bursts associated with propagating fast-mode waves

NASA Astrophysics Data System (ADS)

Goddard, C. R.; Nisticò, G.; Nakariakov, V. M.; Zimovets, I. V.; White, S. M.

2016-10-01

Aims: Radio emission observations from the Learmonth and Bruny Island radio spectrographs are analysed to determine the nature of a train of discrete, periodic radio "sparks" (finite-bandwidth, short-duration isolated radio features) which precede a type II burst. We analyse extreme ultraviolet (EUV) imaging from SDO/AIA at multiple wavelengths and identify a series of quasi-periodic rapidly-propagating enhancements, which we interpret as a fast wave train, and link these to the detected radio features. Methods: The speeds and positions of the periodic rapidly propagating fast waves and the coronal mass ejection (CME) were recorded using running-difference images and time-distance analysis. From the frequency of the radio sparks the local electron density at the emission location was estimated for each. Using an empirical model for the scaling of density in the corona, the calculated electron density was used to obtain the height above the surface at which the emission occurs, and the propagation velocity of the emission location. Results: The period of the radio sparks, δtr = 1.78 ± 0.04 min, matches the period of the fast wave train observed at 171 Å, δtEUV = 1.7 ± 0.2 min. The inferred speed of the emission location of the radio sparks, 630 km s-1, is comparable to the measured speed of the CME leading edge, 500 km s-1, and the speeds derived from the drifting of the type II lanes. The calculated height of the radio emission (obtained from the density) matches the observed location of the CME leading edge. From the above evidence we propose that the radio sparks are caused by the quasi-periodic fast waves, and the emission is generated as they catch up and interact with the leading edge of the CME. The movie associated to Fig. 2 is available at http://www.aanda.org

Performance Evaluation and Comparative Analysis of SubCarrier Modulation Wake-up Radio Systems for Energy-Efficient Wireless Sensor Networks

PubMed Central

Oller, Joaquim; Demirkol, Ilker; Casademont, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard

2014-01-01

Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications. PMID:24451452

Performance evaluation and comparative analysis of SubCarrier Modulation Wake-up Radio systems for energy-efficient wireless sensor networks.

PubMed

Oller, Joaquim; Demirkol, Ilker; Casademont, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard

2013-12-19

Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications.

Radio and γ-ray follow-up of the exceptionally high-activity state of PKS 1510-089 in 2011

DOE PAGES

Orienti, M.; Koyama, S.; D'Ammando, F.; ...

2012-11-09

In this paper, we investigate the radio and γ-ray variability of the flat spectrum radio quasar PKS 1510-089 in the time range between 2010 November and 2012 January. In this period the source showed an intense activity, with two major γ-ray flares detected in 2011 July and October. During the latter episode both the γ-ray and the radio flux density reached their historical peak. Multiwavelength analysis shows a rotation of about 380° of the optical polarization angle close in time with the rapid and strong γ-ray flare in 2011 July. An enhancement of the optical emission and an increase ofmore » the fractional polarization both in the optical and in radio bands are observed about three weeks later, close in time with another γ-ray outburst. On the other hand, after 2011 September a huge radio outburst has been detected, first in the millimetre regime followed with some time delay at centimetre down to decimetre wavelengths. This radio flare is characterized by a rising and a decaying stage, in agreement with the formation of a shock and its evolution, as a consequence of expansion and radiative cooling. Lastly, if the γ-ray flare observed in 2011 October is related to this radio outburst, then this strongly indicates that the region responsible for the γ-ray variability is not within the broad line, but a few parsecs downstream along the jet.« less

Effectiveness and cost effectiveness of television, radio and print advertisements in promoting the New York smokers' quitline

PubMed Central

Farrelly, Matthew C; Hussin, Altijani; Bauer, Ursula E

2007-01-01

Objectives This study assessed the relative effectiveness and cost effectiveness of television, radio and print advertisements to generate calls to the New York smokers' quitline. Methods Regression analysis was used to link total county level monthly quitline calls to television, radio and print advertising expenditures. Based on regression results, standardised measures of the relative effectiveness and cost effectiveness of expenditures were computed. Results There was a positive and statistically significant relation between call volume and expenditures for television (p<0.01) and radio (p<0.001) advertisements and a marginally significant effect for expenditures on newspaper advertisements (p<0.065). The largest effect was for television advertising. However, because of differences in advertising costs, for every $1000 increase in television, radio and newspaper expenditures, call volume increased by 0.1%, 5.7% and 2.8%, respectively. Conclusions Television, radio and print media all effectively increased calls to the New York smokers' quitline. Although increases in expenditures for television were the most effective, their relatively high costs suggest they are not currently the most cost effective means to promote a quitline. This implies that a more efficient mix of media would place greater emphasis on radio than television. However, because the current study does not adequately assess the extent to which radio expenditures would sustain their effectiveness with substantial expenditure increases, it is not feasible to determine a more optimal mix of expenditures. PMID:18048625

Predictive biomarkers for response of esophageal cancer to chemo(radio)therapy: A systematic review and meta-analysis.

PubMed

Li, Yang; Huang, He-Cheng; Chen, Long-Qi; Xu, Li-Yan; Li, En-Min; Zhang, Jian-Jun

2017-12-01

Esophageal cancer remains a major public health issue worldwide. In clinical practice, chemo(radio)therapy is an important approach to patients with esophageal cancer. Only the part of patients who respond to chemo(radio)therapy achieve better long-term outcome. In this case, predictive biomarkers for response of esophageal cancer patients treated with chemo(radio)therapy are of importance. Meta-analysis of P53 for predicting esophageal cancer response has been reported before and is not included in our study. We performed a systematic review and meta-analysis to summarize and evaluate the biomarkers for predicting response to chemo(radio)therapy. PubMed, Web of Science and the Ovid databases were searched to identify eligible studies published in English before March 2017. The risk ratio (or relative risk, RR) was retrieved in articles regarding biomarkers for predicting response of esophageal cancer patients treated with neoadjuvant therapy or chemo(radio)therapy. Fixed and random effects models were used to undertake the meta-analysis as appropriate. Forty-six articles reporting 56 biomarkers correlated with the response were finally included. Meta-analyses were carried out when there was more than one study related to the reported biomarker. Results indicated that low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS was individually associated with prediction of response. The RR was 1.64 (n = 202, 95% CI 1.22-2.19, P < 0.001), 1.96 (n = 162, 95% CI 1.36-2.83, P < 0.001), 2.55 (n = 206, 95% CI 1.80-3.62, P < 0.001) and 1.69 (n = 144, 95% CI 1.10-2.61, P = 0.02), respectively. High expression of (or IHC-positive) CDC25B and p16 was individually related to prediction of response. The RR was 0.62 (n = 159, 95% CI 0.43-0.89, P = 0.01) and 0.62 (n = 142, 95% CI 0.43-0.91, P = 0.01), respectively. Low expression of (or IHC-negative) COX2, miR-200c, ERCC1 and TS, or high expression of (or IHC-positive) CDC25B and p16 are potential biomarkers for predicting the response of esophageal cancer patients treated with chemo(radio)therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radio astronomy Explorer-B in-flight mission control system development effort

NASA Technical Reports Server (NTRS)

Lutsky, D. A.; Bjorkman, W. S.; Uphoff, C.

1973-01-01

A description is given of the development for the Mission Analysis Evaluation and Space Trajectory Operations (MAESTRO) program to be used for the in-flight decision making process during the translunar and lunar orbit adjustment phases of the flight of the Radio Astronomy Explorer-B. THe program serves two functions: performance and evaluation of preflight mission analysis, and in-flight support for the midcourse and lunar insertion command decisions that must be made by the flight director. The topics discussed include: analysis of program and midcourse guidance capabilities; methods for on-line control; printed displays of the MAESTRO program; and in-flight operational logistics and testing.

Combining physical galaxy models with radio observations to constrain the SFRs of high-z dusty star-forming galaxies

NASA Astrophysics Data System (ADS)

Lo Faro, B.; Silva, L.; Franceschini, A.; Miller, N.; Efstathiou, A.

2015-03-01

We complement our previous analysis of a sample of z ˜ 1-2 luminous and ultraluminous infrared galaxies [(U)LIRGs], by adding deep Very Large Array radio observations at 1.4 GHz to a large data set from the far-UV to the submillimetre, including Spitzer and Herschel data. Given the relatively small number of (U)LIRGs in our sample with high signal-to-noise (S/N) radio data, and to extend our study to a different family of galaxies, we also include six well-sampled near-infrared (near-IR)-selected BzK galaxies at z ˜ 1.5. From our analysis based on the radtran spectral synthesis code GRASIL, we find that, while the IR luminosity may be a biased tracer of the star formation rate (SFR) depending on the age of stars dominating the dust heating, the inclusion of the radio flux offers significantly tighter constraints on SFR. Our predicted SFRs are in good agreement with the estimates based on rest-frame radio luminosity and the Bell calibration. The extensive spectrophotometric coverage of our sample allows us to set important constraints on the star formation (SF) history of individual objects. For essentially all galaxies, we find evidence for a rather continuous SFR and a peak epoch of SF preceding that of the observation by a few Gyr. This seems to correspond to a formation redshift of z ˜ 5-6. We finally show that our physical analysis may affect the interpretation of the SFR-M⋆ diagram, by possibly shifting, with respect to previous works, the position of the most dust obscured objects to higher M⋆ and lower SFRs.

Radio Occultation Experiments with Venus Express and Mars Express using the Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique

NASA Astrophysics Data System (ADS)

Bocanegra Bahamon, T.; Gurvits, L.; Molera Calves, G.; Cimo, G.; Duev, D.; Pogrebenko, S.; Dirkx, D.; Rosenblatt, P.

2017-12-01

The Planetary Radio Interferometry and Doppler Experiment (PRIDE) is a technique that can be used to enhance multiple radio science experiments of planetary missions. By 'eavesdropping' on the spacecraft signal using radio telescopes from different VLBI networks around the world, the PRIDE technique provides precise open-loop Doppler and VLBI observables to able to reconstruct the spacecraft's orbit. The application of this technique for atmospheric studies has been assessed by observing ESA's Venus Express (VEX) and Mars Express (MEX) during multiple Venus and Mars occultation events between 2012 and 2014. From these observing sessions density, temperature and pressure profiles of Venus and Mars neutral atmosphere and ionosphere have been retrieved. We present an error propagation analysis where the uncertainties of the atmospheric properties measured with this technique have been derived. These activities serve as demonstration of the applicability of the PRIDE technique for radio occultation studies, and provides a benchmark against the traditional Doppler tracking provided by the NASA's DSN and ESA's Estrack networks for these same purposes, in the framework of the upcoming ESA JUICE mission to the Jovian system.

The Jet-driven Outflow in the Radio Galaxy SDSS J1517+3353: Implications for Double-peaked Narrow-line Active Galactic Nucleus

NASA Astrophysics Data System (ADS)

Rosario, D. J.; Shields, G. A.; Taylor, G. B.; Salviander, S.; Smith, K. L.

2010-06-01

We report on the study of an intriguing active galaxy that was selected as a potential multiple supermassive black hole merger in the early-type host SDSS J151709.20+335324.7 (z = 0.135) from a complete search for double-peaked [O III] lines from the SDSS spectroscopic quasi-stellar object (QSO) database. Ground-based SDSS imaging reveals two blue structures on either side of the photometric center of the host galaxy, separated from each other by about 5.7 kpc. From a combination of SDSS fiber and Keck/HIRES long-slit spectroscopy, it is demonstrated that, in addition to these two features, a third distinct structure surrounds the nucleus of the host galaxy. All three structures exhibit highly ionized line emission with line ratios characteristic of Seyfert II active galactic nuclei. The analysis of spatially resolved emission-line profiles from the HIRES spectrum reveal three distinct kinematic subcomponents, one at rest and the other two moving at -350 km s-1 and 500 km s-1 with respect to the systemic velocity of the host galaxy. A comparison of imaging and spectral data confirm a strong association between the kinematic components and the spatial knots, which implies a highly disturbed and complex active region in this object. A comparative analysis of the broadband positions, colors, kinematics, and spectral properties of the knots in this system lead to two plausible explanations: (1) a multiple active galactic nucleus (AGN) produced due to a massive dry merger, or (2) a very powerful radio jet-driven outflow. Subsequent VLA radio imaging reveals a clear jet aligned with the emission-line gas, confirming the latter explanation. We use the broadband radio measurements to examine the impact of the jet on the interstellar medium of the host galaxy, and find that the energy in the radio lobes can heat a significant fraction of the gas to the virial temperature. Finally, we discuss tests that may help future surveys distinguish between jet-driven kinematics and true black-hole binaries. J1517+3353 is a remarkable laboratory for AGN feedback and warrants deeper follow-up study. In the Appendix, we present high-resolution radio imaging of a second AGN with double-peaked [O III] lines, SDSS J112939.78+605742.6, which shows a sub-arcsecond radio jet. If the double-peaked nature of the narrow lines in radio-loud AGNs are generally due to radio jet interactions, we suggest that extended radio structure should be expected in most of such systems.

Salmon Supplementation Studies in Idaho Rivers; Field Activities Conducted on Clear and Pete King Creeks, 2001 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gass, Carrie; Olson, Jim M.

2004-11-01

In 2001 the Idaho Fisheries Resource Office continued as a cooperator on the Salmon Supplementation Studies in Idaho Rivers (ISS) project on Pete King and Clear creeks. Data relating to supplementation treatment releases, juvenile sampling, juvenile PIT tagging, brood stock spawning and rearing, spawning ground surveys, and snorkel surveys were used to evaluate project data points and augment past data. Due to low adult spring Chinook returns to Kooskia National Fish Hatchery (KNFH) in brood year 1999 there was no smolt supplementation treatment release into Clear Creek in 2001. A 17,014 spring Chinook parr supplementation treatment (containing 1000 PIT tags)more » was released into Pete King Creek on July 24, 2001. On Clear Creek, there were 412 naturally produced spring Chinook parr PIT tagged and released. Using juvenile collection methods, Idaho Fisheries Resource Office staff PIT tagged and released 320 naturally produced spring Chinook pre-smolts on Clear Creek, and 16 natural pre-smolts on Pete King Creek, for minimum survival estimates to Lower Granite Dam. There were no PIT tag detections of brood year 1999 smolts from Clear or Pete King creeks. A total of 2261 adult spring Chinook were collected at KNFH. Forty-three females were used for supplementation brood stock, and 45 supplementation (ventral fin-clip), and 45 natural (unmarked) adults were released upstream of KNFH to spawn naturally. Spatial and temporal distribution of 37 adults released above the KNFH weir was determined through the use of radio telemetry. On Clear Creek, a total of 166 redds (8.2 redds/km) were observed and data was collected from 195 carcasses. Seventeen completed redds (2.1 redds/km) were found, and data was collected data from six carcasses on Pete King Creek.« less

Transfer of radio-cesium from forest soil to woodchips using fungal activities

NASA Astrophysics Data System (ADS)

Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

2014-05-01

Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be removed from forests with fungal bodies. We covered forest floor using wood chips, and observed Cs accumulation, and found that up to 50% of soil radio-cesium was transferred from soil to wood chips after 6-month of field incubation. Therefore this method is effective to decontaminate forest using ecological process. Kaneko N, Huang Y, Nakamori T, Tanaka Y, Nonaka M. Radio-cesium accumulation during decomposition of leaf litter in a deciduous forest after the Fukushima NPP accident. Geophysical Research Abstracts. 2013;15(EGU2013):7809.

Alcohol, young people and the media: a study of radio output in six radio stations in England.

PubMed

Daykin, N; Irwin, R; Kimberlee, R; Orme, J; Plant, M; McCarron, L; Rahbari, M

2009-03-01

This research investigated the representation of alcohol in radio output. The study was prompted by concerns that media output might be part of a developing culture of excessive drinking among young people. Alcohol comments were examined across six radio stations in England. 1200 h of weekend output was screened and the sampling frame included periods when references to alcohol would be expected, such as the Christmas period. Statistical analysis identified the volume and proportion of comments, whereas qualitative analysis explored these in more depth, focusing on the themes and discourses surrounding alcohol talk. Of 703 alcohol comments identified, 244 involved presenters. The volume of comments about alcohol varied between stations, being lower on BBC than on commercial stations and being influenced by music genre. Seventy-three percent of comments initiated by presenters, compared with 45% of comments from all sources, encouraged drinking. The majority of comments by presenters support drinking in relation to partying and socializing. Alcohol comments seem to create identity for programmes and forge connections between presenters and audiences, although some presenters achieve this without mentioning drinking. The assumption that alcohol is necessary to have a good time is seldom directly challenged. While it may be unsurprising that much of this content reflected themes of weekend drinking and partying, the study suggests that alcohol comments play a particular role in marketing and branding of radio output. Comments about alcohol are shaped by broadcasting conventions that make it difficult to challenge discourses surrounding excessive drinking. Further research is needed on the influence that radio output may have on drinking behaviour among young people.

DISCOVERY OF γ -RAY EMISSION FROM THE RADIO-INTERMEDIATE QUASAR III ZW 2: VIOLENT JET ACTIVITY WITH INTRADAY γ -RAY VARIABILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, Neng-Hui; Xin, Yu-Liang; Fan, Yi-Zhong

2016-10-01

III Zw 2 is the prototype of radio-intermediate quasars. Although there is the evidence of possessing strong jet, significant γ -ray emission has not been reported before. In this work, we carry out a detailed analysis of the latest Fermi -LAT Pass  8 data. No significant γ -ray signal has been detected in the time-averaged 7-year Fermi -LAT data of III Zw 2; however, we have identified two distinct γ -ray flares with isotropic luminosities of ∼10{sup 45} erg s{sup −1}. Multiwavelength data analysis (also including the optical photometric observations from Yunnan Observatories) are presented and the main finding ismore » simultaneous optical and γ -ray flares of III Zw 2 appearing in 2009 November. Violent γ -ray variability with a doubling timescale of 2.5 hr was detected in another γ -ray flare in May 2010, for which the 3-hr γ -ray peak flux is ∼250 times of the average flux in 7 years. Rather similar behaviors are observed in blazars and the blazar model can reasonably reproduce the spectral energy distribution of III Zw 2 in a wide energy range, strongly suggesting that its central engine resembles that of blazars. In view of its core, which shares radio similarities with young radio sources, together with weak extended radio lobe emission, we suggest that III Zw 2 harbors a recurrent activity core and thus serves as a valuable target for investigating the fueling and triggering of the activity in radio-loud active galactic nuclei.« less

Detection of a pair of prominent X-ray cavities in Abell 3847

NASA Astrophysics Data System (ADS)

Vagshette, Nilkanth D.; Naik, Sachindra; Patil, Madhav. K.; Sonkamble, Satish S.

2017-04-01

We present the results obtained from a detailed analysis of a deep Chandra observation of the bright FRII radio galaxy 3C 444 in Abell 3847 cluster. A pair of huge X-ray cavities are detected along the north and south directions from the centre of 3C 444. X-ray and radio images of the cluster reveal peculiar positioning of the cavities and radio bubbles. The radio lobes and X-ray cavities are apparently not spatially coincident and exhibit offsets by ˜61 and 77 kpc from each other along the north and south directions, respectively. Radial temperature and density profiles reveal the presence of a cool core in the cluster. Imaging and spectral studies showed the removal of substantial amount of matter from the core of the cluster by the radio jets. A detailed analysis of the temperature and density profiles showed the presence of a rarely detected elliptical shock in the cluster. Detection of inflating cavities at an average distance of ˜55 kpc from the centre implies that the central engine feeds a remarkable amount of radio power (˜6.3 × 1044 erg s-1) into the intra-cluster medium over ˜108 yr, the estimated age of cavity. The cooling luminosity of the cluster was estimated to be ˜8.30 × 1043 erg s-1 , which confirms that the AGN power is sufficient to quench the cooling. Ratios of mass accretion rate to Eddington and Bondi rates were estimated to be ˜0.08 and 3.5 × 104, respectively. This indicates that the black hole in the core of the cluster accretes matter through chaotic cold accretion.

Flare Observations

NASA Astrophysics Data System (ADS)

Benz, Arnold O.

2017-12-01

Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays beyond 1 GeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, SOHO, and more recently Hinode and SDO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections, electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting magnetic reconnection as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth's ionosphere. Flare scenarios have slowly converged over the past decades, but every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions.

Communication interference/jamming and propagation analysis system and its application to radio location

NASA Astrophysics Data System (ADS)

Kuzucu, H.

1992-11-01

Modern defense systems depend on comprehensive surveillance capability. The ability to detect and locate the radio signals is a major element of a surveillance system. With the increasing need for more mobile surveillance systems in conjunction with the rapid deployment of forces and the advent of technology allowing more enhanced use of small aperture systems, tactical direction finding (DF) and radiolocation systems will have to be operated in diverse operational conditions. A quick assessment of the error levels expected and the evaluation of the reliability of the fixes on the targeted areas bears crucial importance to the effectiveness of the missions relying on DF data. This paper presents a sophisticated, graphics workstation based computer tool developed for the system level analysis of radio communication systems and describes its use in radiolocation applications for realizing such accurate and realistic assessments with substantial money and time savings.

STUDIES OF RADIO CONTAMINATION OF FOOD STUFFS EFFECTED BY ATOMIC OR HYDROGEN BOMB EXPLOSION. IX. RADIO CHEMICAL ANALYSIS OF RADIO CONTAMINATED FISH LIVERS IN 1958 (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagasawa, K.; Kasida, Y.; Kametani, K.

The contamination in 224 livers of tunny and sword fish caught in the Pacific 0cean was examined. As a result of radiochemical analysis in the four samples Fe/sup 59/ Zn/sup 65/, Sr/sup 90/, Y/sup 90/, and Cd/sup 115m/ were identified. The maximum concentrations of the elements determined were Fe/sup 59/ , 1.58 x l0/sup -4/ mu c; Zn/sup 65/, 4.58 x 10/sup -3/ mu c; Sr/sup 90/ and Y/ sup 90/, 8. 33 x 10/sup -7/ mu c; and Cd/sup 115m/, 3.66 x l0/sup -4/ mu c. When 10 g of wet sample was assumed to be the daily personalmore » intake dose, these were less than the maximum permissible concentrations. (auth)« less

Electromagnetic interference of cardiac rhythmic monitoring devices to radio frequency identification: analytical analysis and mitigation methodology.

PubMed

Ogirala, Ajay; Stachel, Joshua R; Mickle, Marlin H

2011-11-01

Increasing density of wireless communication and development of radio frequency identification (RFID) technology in particular have increased the susceptibility of patients equipped with cardiac rhythmic monitoring devices (CRMD) to environmental electro magnetic interference (EMI). Several organizations reported observing CRMD EMI from different sources. This paper focuses on mathematically analyzing the energy as perceived by the implanted device, i.e., voltage. Radio frequency (RF) energy transmitted by RFID interrogators is considered as an example. A simplified front-end equivalent circuit of a CRMD sensing circuitry is proposed for the analysis following extensive black-box testing of several commercial pacemakers and implantable defibrillators. After careful understanding of the mechanics of the CRMD signal processing in identifying the QRS complex of the heart-beat, a mitigation technique is proposed. The mitigation methodology introduced in this paper is logical in approach, simple to implement and is therefore applicable to all wireless communication protocols.

Soft Decision Analyzer

NASA Technical Reports Server (NTRS)

Lansdowne, Chatwin; Steele, Glen; Zucha, Joan; Schlesinger, Adam

2013-01-01

We describe the benefit of using closed-loop measurements for a radio receiver paired with a counterpart transmitter. We show that real-time analysis of the soft decision output of a receiver can provide rich and relevant insight far beyond the traditional hard-decision bit error rate (BER) test statistic. We describe a Soft Decision Analyzer (SDA) implementation for closed-loop measurements on single- or dual- (orthogonal) channel serial data communication links. The analyzer has been used to identify, quantify, and prioritize contributors to implementation loss in live-time during the development of software defined radios. This test technique gains importance as modern receivers are providing soft decision symbol synchronization as radio links are challenged to push more data and more protocol overhead through noisier channels, and software-defined radios (SDRs) use error-correction codes that approach Shannon's theoretical limit of performance.

Detection of acoustic-gravity waves in lower ionosphere by VLF radio waves

NASA Astrophysics Data System (ADS)

Nina, A.; Čadež, V. M.

2013-09-01

We present a new method to study harmonic waves in the low ionosphere (60 - 90 km) by detecting their effects on reflection of very low frequency (VLF) radio waves. Our procedure is based on amplitude analysis of reflected VLF radio waves recorded in real time, which yields an insight into the dynamics of the ionosphere at heights where VLF radio waves are being reflected. The method was applied to perturbations induced by the solar terminator motions at sunrises and sunsets. The obtained results show that typical perturbation frequencies found to exist in higher regions of the atmosphere are also present in the lower ionosphere, which indicates a global nature of the considered oscillations. In our model atmosphere, they turn out to be the acoustic and gravity waves with comparatively short and long periods, respectively.

Full-Sky Maps of the VHF Radio Sky with the Owens Valley Radio Observatory Long Wavelength Array

NASA Astrophysics Data System (ADS)

Eastwood, Michael W.; Hallinan, Gregg

2018-05-01

21-cm cosmology is a powerful new probe of the intergalactic medium at redshifts 20 >~ z >~ 6 corresponding to the Cosmic Dawn and Epoch of Reionization. Current observations of the highly-redshifted 21-cm transition are limited by the dynamic range they can achieve against foreground sources of low-frequency (<200 MHz) of radio emission. We used the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA) to generate a series of new modern high-fidelity sky maps that capture emission on angular scales ranging from tens of degrees to ~15 arcmin, and frequencies between 36 and 73 MHz. These sky maps were generated from the application of Tikhonov-regularized m-mode analysis imaging, which is a new interferometric imaging technique that is uniquely suited for low-frequency, wide-field, drift-scanning interferometers.

Radio Observations of the Ionosphere From an Imaging Array and a CubeSat

NASA Astrophysics Data System (ADS)

Isham, B.; Gustavsson, B.; Bullett, T. W.; Bergman, J. E. S.; Rincón-Charris, A.; Bruhn, F.; Funk, P.

2017-12-01

The ionosphere is a source of many radio emissions in the various low-frequency, medium-frequency, and high-frequency bands (0 to 30 MHz). In addition to natural radio emissions, artificial emissions can be stimulated using high-power radiowave ionospheric modification facilities. Two complementary projects are underway for the purpose of improving our knowledge of the processes of radio emissions from the ionosphere. One project is the Aguadilla radio array, located in northwestern Puerto Rico. The Aguadilla array is intended to produce 2 to 25 MHz radio images of the ionosphere, as well as to perform bistatic radar imaging of the ionosphere over Puerto Rico. The array will consist of multiple antenna elements, each of which is a single active (electromagnetically short) crossed electric dipole. The elements are arranged within a roughly 200 by 300-meter core array, in a semi-random pattern providing an optimal distribution of baseline vectors, with 6-meter minimum spacing to eliminate spacial aliasing. In addition, several elements are arranged in a partial ring around the central core, providing a roughly four times expanded region in u-v space for improved image resolution and quality. Phase is maintained via cabled connections to a central location. A remote array is also being developed, in which phase is maintained between elements by through the use of GPS-disciplined rubidium clocks. The other project involves the GimmeRF radio instrument, designed for 0.3 to 30 MHz vector observation of the radio electric field, and planned for launch in 2020 on a CubeSat. The data rate that can be sustained by GimmeRF far exceeds any available communication strategy. By exploiting fast on-board computing and efficient artificial intelligence (AI) algorithms for analysis and data selection, the usage of the telemetry link can be optimized and value added to the mission. Radio images recorded by the radio array from below the ionosphere can be directly compared with the radio data received by GimmeRF in the topside ionosphere, with the goal of better understanding the geometry and therefore the mechanisms of the radio emission processes.

The X-Ray Reflection Spectrum of the Radio-Loud Quasar 4C 74.26

NASA Technical Reports Server (NTRS)

Lohfink, Ann M.; Fabian, Andrew C.; Ballantyne, David R.; Boggs, S. E.; Boorman, Peter; Christensen, F. E.; Craig, W. W.; Farrah, Duncan; Garcia, Javier; Hailey, C. J.;

The X-Ray Reflection Spectrum of the Radio-loud Quasar 4C 74.26

NASA Astrophysics Data System (ADS)

Lohfink, Anne M.; Fabian, Andrew C.; Ballantyne, David R.; Boggs, S. E.; Boorman, Peter; Christensen, F. E.; Craig, W. W.; Farrah, Duncan; García, Javier; Hailey, C. J.; Harrison, F. A.; Ricci, Claudio; Stern, Daniel; Zhang, W. W.

2017-06-01

The relativistic jets created by some active galactic nuclei are important agents of AGN feedback. In spite of this, our understanding of what produces these jets is still incomplete. X-ray observations, which can probe the processes operating in the central regions in the immediate vicinity of the supermassive black hole, the presumed jet launching point, are potentially particularly valuable in illuminating the jet formation process. Here, we present the hard X-ray NuSTAR observations of the radio-loud quasar 4C 74.26 in a joint analysis with quasi-simultaneous, soft X-ray Swift observations. Our spectral analysis reveals a high-energy cutoff of {183}-35+51 keV and confirms the presence of ionized reflection in the source. From the average spectrum we detect that the accretion disk is mildly recessed, with an inner radius of R in = 4-180 R g. However, no significant evolution of the inner radius is seen during the three months covered by our NuSTAR campaign. This lack of variation could mean that the jet formation in this radio-loud quasar differs from what is observed in broad-line radio galaxies.

Light effects on the multicellular magnetotactic prokaryote 'Candidatus Magnetoglobus multicellularis' are cancelled by radiofrequency fields: the involvement of radical pair mechanisms.

PubMed

de Melo, Roger Duarte; Acosta-Avalos, Daniel

2017-02-01

'Candidatus Magnetoglobus multicellularis' is the most studied multicellular magnetotactic prokaryote. It presents a light-dependent photokinesis: green light decreases the translation velocity whereas red light increases it, in comparison to blue and white light. The present article shows that radio-frequency electromagnetic fields cancel the light effect on photokinesis. The frequency to cancel the light effect corresponds to the Zeeman resonance frequency (DC magnetic field of 4 Oe and radio-frequency of 11.5 MHz), indicating the involvement of a radical pair mechanism. An analysis of the orientation angle relative to the magnetic field direction shows that radio-frequency electromagnetic fields disturb the swimming orientation when the microorganisms are illuminated with red light. The analysis also shows that at low magnetic fields (1.6 Oe) the swimming orientation angles are well scattered around the magnetic field direction, showing that magnetotaxis is not efficiently in the swimming orientation to the geomagnetic field. The results do not support cryptochrome as being the responsible chromophore for the radical pair mechanism and perhaps two different chromophores are necessary to explain the radio-frequency effects.

Non-Maximally Decimated Filter Banks Enable Adaptive Frequency Hopping for Unmanned Aircraft Vehicles

NASA Technical Reports Server (NTRS)

Venosa, Elettra; Vermeire, Bert; Alakija, Cameron; Harris, Fred; Strobel, David; Sheehe, Charles J.; Krunz, Marwan

2017-01-01

In the last few years, radio technologies for unmanned aircraft vehicle (UAV) have advanced very rapidly. The increasing need to fly unmanned aircraft systems (UAS) in the national airspace system (NAS) to perform missions of vital importance to national security, defense, and science has pushed ahead the design and implementation of new radio platforms. However, a lot still has to be done to improve those radios in terms of performance and capabilities. In addition, an important aspect to account for is hardware cost and the feasibility to implement these radios using commercial off-the-shelf (COTS) components. UAV radios come with numerous technical challenges and their development involves contributions at different levels of the design. Cognitive algorithms need to be developed in order to perform agile communications using appropriate frequency allocation while maintaining safe and efficient operations in the NAS and, digital reconfigurable architectures have to be designed in order to ensure a prompt response to environmental changes. Command and control (C2) communications have to be preserved during "standard" operations while crew operations have to be minimized. It is clear that UAV radios have to be software-defined systems, where size, weight and power consumption (SWaP) are critical parameters. This paper provides preliminary results of the efforts performed to design a fully digital radio architecture as part of a NASA Phase I STTR. In this paper, we will explain the basic idea and technical principles behind our dynamic/adaptive frequency hopping radio for UAVs. We will present our Simulink model of the dynamic FH radio transmitter design for UAV communications and show simulation results and FPGA system analysis.

Virtual observatory tools and amateur radio observations supporting scientific analysis of Jupiter radio emissions

NASA Astrophysics Data System (ADS)

Cecconi, Baptiste; Hess, Sebastien; Le Sidaner, Pierre; Savalle, Renaud; Stéphane, Erard; Coffre, Andrée; Thétas, Emmanuel; André, Nicolas; Génot, Vincent; Thieman, Jim; Typinski, Dave; Sky, Jim; Higgins, Chuck; Imai, Masafumi

2016-04-01

In the frame of the preparation of the NASA/JUNO and ESA/JUICE (Jupiter Icy Moon Explorer) missions, and the development of a planetary sciences virtual observatory (VO), we are proposing a new set of tools directed to data providers as well as users, in order to ease data sharing and discovery. We will focus on ground based planetary radio observations (thus mainly Jupiter radio emissions), trying for instance to enhance the temporal coverage of jovian decametric emission. The data service we will be using is EPN-TAP, a planetary science data access protocol developed by Europlanet-VESPA (Virtual European Solar and Planetary Access). This protocol is derived from IVOA (International Virtual Observatory Alliance) standards. The Jupiter Routine Observations from the Nancay Decameter Array are already shared on the planetary science VO using this protocol, as well as data from the Iitate Low Frquency Radio Antenna, in Japan. Amateur radio data from the RadioJOVE project is also available. The attached figure shows data from those three providers. We will first introduce the VO tools and concepts of interest for the planetary radioastronomy community. We will then present the various data formats now used for such data services, as well as their associated metadata. We will finally show various prototypical tools that make use of this shared datasets.

Another look at AM Herculis - radio-astrometric campaign with the e-EVN at 6 cm

NASA Astrophysics Data System (ADS)

Gawroński, M. P.; Goździewski, K.; Katarzyński, K.; Rycyk, G.

2018-03-01

We conducted radio-interferometric observations of the well-known binary cataclysmic system AM Herculis. This particular system is formed from a magnetic white dwarf (primary) and a red dwarf (secondary), and it is the prototype of so-called polars. Our observations were conducted with the European VLBI Network (EVN) in e-EVN mode at 5 GHz. We obtained six astrometric measurements spanning 1 yr, which make it possible to update the annual parallax for this system with the best precision to date (π = 11.29 ± 0.08 mas), which is equivalent to a distance of 88.6 ± 0.6 pc. The system was observed mostly in the quiescent phase (visual magnitude mv ˜ 15.3), when the radio emission was at the level of about 300 μJy. Our analysis suggests that the radio flux of AM Herculis is modulated with the orbital motion. Such specific properties of the radiation can be explained using an emission mechanism like the scenario proposed for V471 Tau and, in general, for RS CVn-type stars. In this scenario, the radio emission arises near the surface of the red dwarf, where the global magnetic field strength may reach a few kG. We argue that the quiescent radio emission distinguishes AM Herculis and AR Ursae Majoris (a second known persistent radio polar) from other polars, which are systems with a magnetized secondary star.

Radio and X-ray properties of the source G29.37+0.1 linked to HESS J1844-030

NASA Astrophysics Data System (ADS)

Castelletti, G.; Supan, L.; Petriella, A.; Giacani, E.; Joshi, B. C.

2017-06-01

Aims: We report on the first detailed multiwavelength study of the radio source G29.37+0.1, which is an as-yet-unclassified object linked to the very-high-energy γ-emitting source HESS J1844-030. The origin of the multiwavelength emission toward G29.37+0.1 has not been clarified so far, leaving open the question about the physical relationship between these sources. Methods: Using observations carried out with the Giant Metrewave Radio Telescope (GMRT), we performed high-quality full-synthesis imaging at 610 MHz of the field containing G29.37+0.1. The obtained data, combined with observations at 1400 MHz from The Multi-Array Galactic Plane Imaging Survey (MAGPIS) were used to investigate in detail the properties of its radio emission. Additionally, we reprocessed archival data obtained with the XMM-Newton and Chandra observatories in order to get a multiwavelength view of this unusual source. Results: The radio source G29.37+0.1 mainly consists of a bright twisted structure, named the S-shaped feature. The high sensitivity of the new GMRT observations allowed the identification of potential lobes, jets, and a nuclear central region in the S-shaped morphology of G29.37+0.1. We also highlight the detection of diffuse and low surface brightness emission enveloping the brightest emitting regions. The brightest emission in G29.37+0.1 has a radio synchrotron spectral index α = 0.59 ± 0.09. Variations in the spectral behaviour are observed across the whole radio source with the flattest spectral features in the central nuclear and jets components (α 0.3). These results lead us to conclude that the brightest radio emission from G29.37+0.1 likely represents a newly recognized radio galaxy. The identification of optical and infrared counterparts to the emission arising from the core of G29.37+0.1 strengthens our interpretation of an extragalactic origin of the radio emission. We performed several tests to explain the physical mechanism responsible for the observed X-ray emission, which appears overlapping the northeastern part of the radio emission. Our spectral analysis demonstrated that a non-thermal origin for the X-ray emission compatible with a pulsar wind nebula is quite possible. The analysis of the spatial distribution of the CO gas revealed the presence of a complex of molecular clouds located in projection adjacent to the radio halo emission and probably interacting with it. We propose that the faint halo represents a composite supernova remnant with a pulsar powered component given by the diffuse X-ray emission superimposed along the line of sight to the radio galaxy. Further broadband observations of HESS J1844-030 are needed to disentangle its origin, although its shape and position suggest an extragalactic origin connected to G29.37+0.1. The reduced GMRT image (FITS file) is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/602/A31

Translocation and early post-release demography of endangered Laysan teal

USGS Publications Warehouse

Reynolds, M.H.; Seavy, N.E.; Vekasy, M.S.; Klavitter, J.L.; Laniawe, L.P.

2008-01-01

In an attempt to reduce the high extinction risk inherent to small island populations, we translocated wild Laysan teal Anas laysanensis to a portion of its presumed prehistoric range. Most avian translocations lack the strategic post-release monitoring needed to assess early population establishment or failure. Therefore, we monitored the survival and reproduction of all founders, and their first-generation offspring using radio telemetry for 2 years after the first release. Forty-two Laysan teal were sourced directly from the only extant population on Laysan Island and transported 2 days by ship to Midway Atoll. All birds survived the translocation with nutritional and veterinary support, and spent between 4 and 14 days in captivity. Post-release survival of 42 founders was 0.857 (95% CI 0.86-0.99) during 2004-2006 or annualized 0.92 (95% CI 0.83-0.98). Seventeen of 18 founding hens attempted nesting in the first two breeding seasons. Fledgling success was 0.57 (95% CI 0.55-0.60) in 2005 and 0.63 (95% CI 0.62-0.64) in 2006. The effective founding female population (Ne) was 13. We applied these initial demographic rates to model population growth. The nascent population size increased to >100 after only 2 years post-release (?? = 1.73). If this growth rate continues, the size of the Midway population could surpass the source population before 2010. ?? 2008 The Authors. Journal compilation ?? 2008 The Zoological Society of London.