Gamma-spectrometric measurement of radioactivity in agricultural soils of the Lombardia region, northern Italy.

PubMed

Guidotti, Laura; Carini, Franca; Rossi, Riccardo; Gatti, Marina; Cenci, Roberto M; Beone, Gian Maria

2015-04-01

This work is part of a wider monitoring project of the agricultural soils in Lombardia, which aims to build a database of topsoil properties and the potentially toxic elements, organic pollutants and gamma emitting radionuclides that the topsoils contain. A total of 156 agricultural soils were sampled according to the LUCAS (Land Use/Cover Area frame statistical Survey) standard procedure. The aim was to provide a baseline to document the conditions present at the time of sampling. The results of the project concerning soil radioactivity are presented here. The aim was to assess the content of (238)U, (232)Th, (137)Cs and (40)K by measuring soil samples by gamma spectrometry. (238)U, (232)Th and (40)K activities range 24-231, 20-70, and 242-1434 Bq kg(-1) respectively. The geographic distribution of (238)U reflects the geophysical framework of the Lombardia region: the soils with high content of uranium are distributed for the most part in the South Alpine belt, where the presence of magmatic rocks is widespread. These soils show an higher activity of (238)U than of (232)Th. The (238)U activities become lower than (232)Th when soils are located in the plain, originating from basic sedimentary rocks. (137)Cs activity ranges 0.4-86.8 kBq m(-2). The lowest activity of (137)Cs is in the plain, whereas the highest is in the North on soils kept as lawn or pasture. The (137)Cs activity of some samples suggests the presence of accumulation processes that lead to (137)Cs enriched soils. This is the first survey of gamma emitting radionuclides in Lombardia that is based on the LUCAS standard sampling. The results from this monitoring campaign are important for the human radiation exposure and provide the zero point, which will be useful for assessing future effects due to external factors such as human activities. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Gamma spectrometry in the ITWG CMX-4 exercise

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

Lakosi, L.; Zsigrai, J.; Kocsonya, A.

Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.

Gamma spectrometry in the ITWG CMX-4 exercise

DOE PAGES

Lakosi, L.; Zsigrai, J.; Kocsonya, A.; ...

2018-01-05

Low enriched uranium samples of unknown origin were analyzed by 16 laboratories in the context of a Collaborative Materials Exercise (CMX), organized by the Nuclear Forensics International Technical Working Group (ITWG). The purpose was to compare and prioritize nuclear forensic methods and techniques, and to evaluate attribution capabilities among participants. This paper gives a snapshot of the gamma spectrometric capabilities of the participating laboratories and summarizes the results achieved by gamma spectrometry.

MOXE: An X-ray all-sky monitor for Soviet Spectrum-X-Gamma Mission

NASA Technical Reports Server (NTRS)

Priedhorsky, W.; Fenimore, E. E.; Moss, C. E.; Kelley, R. L.; Holt, S. S.

1989-01-01

A Monitoring Monitoring X-Ray Equipment (MOXE) is being developed for the Soviet Spectrum-X-Gamma Mission. MOXE is an X-ray all-sky monitor based on array of pinhole cameras, to be provided via a collaboration between Goddard Space Flight Center and Los Alamos National Laboratory. The objectives are to alert other observers on Spectrum-X-Gamma and other platforms of interesting transient activity, and to synoptically monitor the X-ray sky and study long-term changes in X-ray binaries. MOXE will be sensitive to sources as faint as 2 milliCrab (5 sigma) in 1 day, and cover the 2 to 20 KeV band.

Characteristic gamma-lactone odor production of the genus Pityrosporum.

PubMed Central

Labows, J N; McGinley, K J; Leyden, J J; Webster, G F

1979-01-01

Mass spectrometric-gas chromatographic analysis of culture headspaces revealed that members of the genous Pityrosporum produce volatile gamma-lactones during growth on lipid-containing media. Representative members of other yeast genera found on humans failed to produce these compounds. Addition of lecithin, oleic acids, triolein, or human sebum to the culture media stimulated gamma-lactone production by Pityrosporum species. All yeasts tested produced isopentanol and phenylethanol. Production of gamma-lactones may serve as a valuable characteristic in the identification of organisms of the genus Pityrosporum. PMID:533274

Feasibility study of a gamma camera for monitoring nuclear materials in the PRIDE facility

NASA Astrophysics Data System (ADS)

Jo, Woo Jin; Kim, Hyun-Il; An, Su Jung; Lee, Chae Young; Song, Han-Kyeol; Chung, Yong Hyun; Shin, Hee-Sung; Ahn, Seong-Kyu; Park, Se-Hwan

2014-05-01

The Korea Atomic Energy Research Institute (KAERI) has been developing pyroprocessing technology, in which actinides are recovered together with plutonium. There is no pure plutonium stream in the process, so it has an advantage of proliferation resistance. Tracking and monitoring of nuclear materials through the pyroprocess can significantly improve the transparency of the operation and safeguards. An inactive engineering-scale integrated pyroprocess facility, which is the PyRoprocess Integrated inactive DEmonstration (PRIDE) facility, was constructed to demonstrate engineering-scale processes and the integration of each unit process. the PRIDE facility may be a good test bed to investigate the feasibility of a nuclear material monitoring system. In this study, we designed a gamma camera system for nuclear material monitoring in the PRIDE facility by using a Monte Carlo simulation, and we validated the feasibility of this system. Two scenarios, according to locations of the gamma camera, were simulated using GATE (GEANT4 Application for Tomographic Emission) version 6. A prototype gamma camera with a diverging-slat collimator was developed, and the simulated and experimented results agreed well with each other. These results indicate that a gamma camera to monitor the nuclear material in the PRIDE facility can be developed.

In-Orbit Performance of the CALET Gamma-Ray Burst Monitor

NASA Astrophysics Data System (ADS)

Yamaoka, K.; Calet Collaboration

2016-10-01

This poster presentation describes in-orbit operation and performance of the CALET Gamma-ray Burst Monitor (CGBM) which has been operated for about one year since October 2015 on the International Space Station (ISS).

Targeted Selected Reaction Monitoring Mass Spectrometric Immunoassay for Insulin-like Growth Factor 1

PubMed Central

Niederkofler, Eric E.; Phillips, David A.; Krastins, Bryan; Kulasingam, Vathany; Kiernan, Urban A.; Tubbs, Kemmons A.; Peterman, Scott M.; Prakash, Amol; Diamandis, Eleftherios P.; Lopez, Mary F.; Nedelkov, Dobrin

2013-01-01

Insulin-like growth factor 1 (IGF1) is an important biomarker of human growth disorders that is routinely analyzed in clinical laboratories. Mass spectrometry-based workflows offer a viable alternative to standard IGF1 immunoassays, which utilize various pre-analytical preparation strategies. In this work we developed an assay that incorporates a novel sample preparation method for dissociating IGF1 from its binding proteins. The workflow also includes an immunoaffinity step using antibody-derivatized pipette tips, followed by elution, trypsin digestion, and LC-MS/MS separation and detection of the signature peptides in a selected reaction monitoring (SRM) mode. The resulting quantitative mass spectrometric immunoassay (MSIA) exhibited good linearity in the range of 1 to 1,500 ng/mL IGF1, intra- and inter-assay precision with CVs of less than 10%, and lowest limits of detection of 1 ng/mL. The linearity and recovery characteristics of the assay were also established, and the new method compared to a commercially available immunoassay using a large cohort of human serum samples. The IGF1 SRM MSIA is well suited for use in clinical laboratories. PMID:24278387

Absolute prompt-gamma yield measurements for ion beam therapy monitoring

NASA Astrophysics Data System (ADS)

Pinto, M.; Bajard, M.; Brons, S.; Chevallier, M.; Dauvergne, D.; Dedes, G.; De Rydt, M.; Freud, N.; Krimmer, J.; La Tessa, C.; Létang, J. M.; Parodi, K.; Pleskač, R.; Prieels, D.; Ray, C.; Rinaldi, I.; Roellinghoff, F.; Schardt, D.; Testa, E.; Testa, M.

2015-01-01

Prompt-gamma emission detection is a promising technique for hadrontherapy monitoring purposes. In this regard, obtaining prompt-gamma yields that can be used to develop monitoring systems based on this principle is of utmost importance since any camera design must cope with the available signal. Herein, a comprehensive study of the data from ten single-slit experiments is presented, five consisting in the irradiation of either PMMA or water targets with lower and higher energy carbon ions, and another five experiments using PMMA targets and proton beams. Analysis techniques such as background subtraction methods, geometrical normalization, and systematic uncertainty estimation were applied to the data in order to obtain absolute prompt-gamma yields in units of prompt-gamma counts per incident ion, unit of field of view, and unit of solid angle. At the entrance of a PMMA target, where the contribution of secondary nuclear reactions is negligible, prompt-gamma counts per incident ion, per millimetre and per steradian equal to (124 ± 0.7stat ± 30sys) × 10-6 for 95 MeV u-1 carbon ions, (79 ± 2stat ± 23sys) × 10-6 for 310 MeV u-1 carbon ions, and (16 ± 0.07stat ± 1sys) × 10-6 for 160 MeV protons were found for prompt gammas with energies higher than 1 MeV. This shows a factor 5 between the yields of two different ions species with the same range in water (160 MeV protons and 310 MeV u-1 carbon ions). The target composition was also found to influence the prompt-gamma yield since, for 300/310 MeV u-1 carbon ions, a 42% greater yield ((112 ± 1stat ± 22sys) × 10-6 counts ion-1 mm-1 sr-1) was obtained with a water target compared to a PMMA one.

Gamma spectrometric and magnetic interpretation of Cabaçal copper deposit in Mato Grosso (Brazil): Implications for hydrothermal fluids remobilization

NASA Astrophysics Data System (ADS)

Ribeiro, Vanessa Biondo; Mantovani, Marta Silvia Maria

2016-12-01

The Cabaçal Au-Zn-Cu Deposit, Mato Grosso, Brazil, was explored between 1987 and 1991, when 869,279 tons of ore rich in Au and Cu have been extracted. The hydrothermal alteration in the Cabaçal mine suggests a volcanogenic genetic model in which hydrothermal centers generated sericitization, chloritization and silicification alterations at different stages. The hydrothermal alteration affects the radioelements in different ways, generating a characteristic gamma spectrometric signature for the affected area. The eTh/K ratio map evidenced that the hydrothermalized area extends beyond south limits of the Cabaçal gabbro dykes formation, which host Cabaçal and Santa Helena mines. Magnetic data over the region show the same behavior for this formation, indicating that the magnetic source extends in subsurface. This behavior was recovered by the 3D model inverted for the region, which recovered a positive apparent magnetic contrast associated with this body, with an increasing deepness to south. It is possible that the south subsurface portion of the magnetic source may contain economic concentrations of Au remobilized by hydrothermal fluids. However, to confirm this hypothesis it is necessary to develop geochemical and borehole analysis of the area.

Low-background gamma-ray spectrometry for the international monitoring system

DOE PAGES

Greenwood, L. R.; Cantaloub, M. G.; Burnett, J. L.; ...

2016-12-28

PNNL has developed two low-background gamma-ray spectrometers in a new shallow underground laboratory, thereby significantly improving its ability to detect low levels of gamma-ray emitting fission or activation products in airborne particulate in samples from the IMS (International Monitoring System). Furthermore, the combination of cosmic veto panels, dry nitrogen gas to reduce radon and low background shielding results in a reduction of the background count rate by about a factor of 100 compared to detectors operating above ground at our laboratory.

Application of gamma spectrometry in the Kola peninsula (in Russian)

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

Golovin, I.V.; Kolesnik, N.I.; Antipov, V.S.

1973-01-01

The methodology used and results obtained in gamma spectrometric studies of pre-Cambrian formations of some nickel-bearing regions of the Kola Penlnsula are described. The radioactive element contents of typical metamorphic and magmatic complexes and sulfide ores are presented. (au-trans)

Isotopic composition analysis and age dating of uranium samples by high resolution gamma ray spectrometry

NASA Astrophysics Data System (ADS)

Apostol, A. I.; Pantelica, A.; Sima, O.; Fugaru, V.

2016-09-01

Non-destructive methods were applied to determine the isotopic composition and the time elapsed since last chemical purification of nine uranium samples. The applied methods are based on measuring gamma and X radiations of uranium samples by high resolution low energy gamma spectrometric system with planar high purity germanium detector and low background gamma spectrometric system with coaxial high purity germanium detector. The ;Multigroup γ-ray Analysis Method for Uranium; (MGAU) code was used for the precise determination of samples' isotopic composition. The age of the samples was determined from the isotopic ratio 214Bi/234U. This ratio was calculated from the analyzed spectra of each uranium sample, using relative detection efficiency. Special attention is paid to the coincidence summing corrections that have to be taken into account when performing this type of analysis. In addition, an alternative approach for the age determination using full energy peak efficiencies obtained by Monte Carlo simulations with the GESPECOR code is described.

Motion estimation accuracy for visible-light/gamma-ray imaging fusion for portable portal monitoring

NASA Astrophysics Data System (ADS)

Karnowski, Thomas P.; Cunningham, Mark F.; Goddard, James S.; Cheriyadat, Anil M.; Hornback, Donald E.; Fabris, Lorenzo; Kerekes, Ryan A.; Ziock, Klaus-Peter; Gee, Timothy F.

2010-01-01

The use of radiation sensors as portal monitors is increasing due to heightened concerns over the smuggling of fissile material. Portable systems that can detect significant quantities of fissile material that might be present in vehicular traffic are of particular interest. We have constructed a prototype, rapid-deployment portal gamma-ray imaging portal monitor that uses machine vision and gamma-ray imaging to monitor multiple lanes of traffic. Vehicles are detected and tracked by using point detection and optical flow methods as implemented in the OpenCV software library. Points are clustered together but imperfections in the detected points and tracks cause errors in the accuracy of the vehicle position estimates. The resulting errors cause a "blurring" effect in the gamma image of the vehicle. To minimize these errors, we have compared a variety of motion estimation techniques including an estimate using the median of the clustered points, a "best-track" filtering algorithm, and a constant velocity motion estimation model. The accuracy of these methods are contrasted and compared to a manually verified ground-truth measurement by quantifying the rootmean- square differences in the times the vehicles cross the gamma-ray image pixel boundaries compared with a groundtruth manual measurement.

All-Sky Earth Occultation Observations with the Fermi Gamma-Ray Burst Monitor

NASA Technical Reports Server (NTRS)

Wilson-Hodge, C. A.; Beklen, E.; Bhat, P. N.; Briggs, M.; Camero-Arranz, A.; Case, G.; Jenke, P.; Chaplin, V.; Cherry, M.; Connaughton, V.;

Optical photometric monitoring of gamma -ray loud blazars. II. Observations from November 1995 to June 1996

NASA Astrophysics Data System (ADS)

Raiteri, C. M.; Ghisellini, G.; Villata, M.; de Francesco, G.; Lanteri, L.; Chiaberge, M.; Peila, A.; Antico, G.

1998-02-01

New data from the optical monitoring of gamma -ray loud blazars at the Torino Astronomical Observatory are presented. Observations have been taken in the Johnson's B, V, and Cousins' R bands with the 1.05m REOSC telescope equipped with a 1242x1152 pixel CCD camera. Many of the 22 monitored sources presented here show noticeable magnitude variations. Periods corresponding to pointings of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory (CGRO) satellite are indicated on the light curves. The comparison of our data with those taken by CGRO in the gamma -ray band will contribute to better understand the mechanism of the gamma -ray emission. We finally show intranight light curves of 3C 66A and OJ 287, where microvariability was detected. Tables 2--21 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Gamma and fast neutron radiation monitoring inside spent reactor fuel assemblies

NASA Astrophysics Data System (ADS)

Lakosi, L.; Tam Nguyen, C.

2007-09-01

Gamma and neutron signatures of spent reactor fuel were monitored by small-size silicon diode and track etch detectors, respectively, in a nuclear power plant (NPP). These signatures, reflecting gross gamma intensity and the 242,244Cm content, contain information on the burn-up (BU) and cooling time (CT) of the fuel. The small size of the detectors allows close access to inside parts of the assemblies out of reach of other methods. A commercial Si diode was encapsulated in a cylindrical steel case and was used for gross γ monitoring. CR-39 detectors were used for neutron measurements. Irradiation exposures at the NPP were implemented in the central dosimetric channel of spent fuel assemblies (SFAs) stored in borated water. Gross γ and neutron axial profiles were taken up by scanning with the aid of a long steel guide tube, lowered down to the spent fuel pond by crane and fitted to the headpiece of the fuel assemblies. Gamma measurements were performed using a long cable introduced in this tube, with the Si diode at the end. A long steel wire was also led through the guide tube, to which a chain of 15 sample holder capsules was attached, each containing a track detector. Gamma dose rates of 0.1-10 kGy h -1, while neutron fluxes in a range of (0.25-26) 10 4 cm -2 s -1 were recorded. The results are in good correlation with those of a calculation for spent fuel neutron yield.

Mapping of radiation anomalies using UAV mini-airborne gamma-ray spectrometry.

PubMed

Šálek, Ondřej; Matolín, Milan; Gryc, Lubomír

2018-02-01

Localization of size-limited gamma-ray anomalies plays a fundamental role in uranium prospecting and environmental studies. Possibilities of a newly developed mini-airborne gamma-ray spectrometric equipment were tested on a uranium anomaly near the village of Třebsko, Czech Republic. The measurement equipment was based on a scintillation gamma-ray spectrometer specially developed for unmanned aerial vehicles (UAV) mounted on powerful hexacopter. The gamma-ray spectrometer has two 103 cm 3 BGO scintillation detectors of relatively high sensitivity. The tested anomaly, which is 80 m by 40 m in size, was investigated by ground gamma-ray spectrometric measurement in a detail rectangular measurement grid. Average uranium concentration is 25 mg/kg eU attaining 700 mg/kg eU locally. The mini-airborne measurement across the anomaly was carried out on three 100 m long parallel profiles at eight flight altitudes from 5 to 40 m above the ground. The resulting 1 s 1024 channel gamma-ray spectra, recorded in counts per second (cps), were processed to concentration units of K, U and Th, while total count (TC) was reported in cps. Increased gamma ray intensity of the anomaly was indicated by mini-airborne measurement at all profiles and altitudes, including the highest altitude of 40 m, at which the recorded intensity is close to the natural radiation background. The reported instrument is able to record data with comparable quality as standard airborne survey, due to relative sensitive detector, lower flight altitude and relatively low flight speed of 1 m/s. The presented experiment brings new experience with using unmanned semi-autonomous aerial vehicles and the latest mini-airborne radiometric instrument. The experiment has demonstrated the instrument's ability to localize size-limited uranium anomalies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Terrestrial Gamma-Ray Flashes (TGFs) Observed with the Fermi-Gamma-Ray Burst Monitor: The First Hundred TGFs

NASA Technical Reports Server (NTRS)

Fishman, G J.; Briggs, M. S.; Connaughton, V.; Bhat, P. N.

2010-01-01

The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope Observatory (Fermi) is now detecting 2.1 TGFs per week. At this rate, nearly a hundred TGFs will have been detected by the time of this Meeting. This rate has increased by a factor of 8 since new flight software was uploaded to the spacecraft in November 2009 in order to increase the sensitivity of GBM to TGFs. The high time resolution (2 microseconds) allows temporal features to be resolved so that some insight may be gained on the origin and transport of the gamma-ray photons through the atmosphere. The absolute time of the TGFs, known to several microseconds, also allows accurate correlations of TGFs with lightning networks and other lightning-related phenomena. The thick bismuth germanate (BGO) scintillation detectors of the GBM system have observed photon energies from TGFs at energies above 40 MeV. New results on the some temporal aspects of TGFs will be presented.

Application of gamma ray spectrometric measurements and VLF-EM data for tracing vein type uranium mineralization

NASA Astrophysics Data System (ADS)

Gaafar, Ibrahim

2015-12-01

This study is an attempt to use the gamma ray spectrometric measurements and VLF-EM data to identify the subsurface structure and map uranium mineralization along El Sela shear zone, South Eastern Desert of Egypt. Many injections more or less mineralized with uranium and associated with alteration processes were recorded in El Sela shear zone. As results from previous works, the emplacement of these injections is structurally controlled and well defined by large shear zones striking in an ENE-WSW direction and crosscut by NW-SE to NNW-SSE fault sets. VLF method has been applied to map the structure and the presence of radioactive minerals that have been delineated by the detection of high uranium mineralization. The electromagnetic survey was carried out to detect the presence of shallow and deep conductive zones that cross the granites along ENE-WSW fracturing directions and to map its spatial distribution. The survey comprised seventy N-S spectrometry and VLF-EM profiles with 20 m separation. The resulted data were displayed as composite maps for K, eU and eTh as well as VLF-Fraser map. Twelve profiles with 100 m separation were selected for detailed description. The VLF-EM data were interpreted qualitatively as well as quantitatively using the Fraser and the Karous-Hjelt filters. Fraser filtered data and relative current density pseudo-sections indicate the presence of shallow and deep conductive zones that cross the granites along ENE-WSW shearing directions. High uranium concentrations found just above the higher apparent current-density zones that coincide with El-Sela shear zone indicate a positive relation between conductivity and uranium minerals occurrence. This enables to infer that the anomalies detected by VLF-EM data are due to the highly conductive shear zone enriched with uranium mineralization extending for more than 80 m.

Validation of gamma-ray detection techniques for safeguards monitoring at natural uranium conversion facilities

DOE PAGES

Dewji, Shaheen A.; Lee, Denise L.; Croft, Stephen; ...

2016-03-28

Recent IAEA circulars and policy papers have sought to implement safeguards when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under the revised policy, IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed to develop and validate concepts of nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP).more » In particular, uranyl nitrate (UO 2(NO 3) 2) solution exiting solvent extraction was identified as a key measurement point (KMP), where gamma-ray spectroscopy was selected as the process monitoring tool. The Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility at Oak Ridge National Laboratory was employed to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in an NUCP. Nondestructive assay techniques using gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely way. This work investigated gamma-ray signatures of uranyl nitrate circulating in the UNCLE facility and evaluated various gamma-ray detector sensitivities to uranyl nitrate. These detector validation activities include assessing detector responses to the uranyl nitrate gamma-ray signatures for spectrometers based on sodium iodide, lanthanum bromide, and high-purity germanium detectors. The results of measurements under static and dynamic operating conditions at concentrations ranging from 10–90 g U/L of natural uranyl nitrate are presented. A range of gamma

Validation of gamma-ray detection techniques for safeguards monitoring at natural uranium conversion facilities

NASA Astrophysics Data System (ADS)

Dewji, S. A.; Lee, D. L.; Croft, S.; Hertel, N. E.; Chapman, J. A.; McElroy, R. D.; Cleveland, S.

2016-07-01

Recent IAEA circulars and policy papers have sought to implement safeguards when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under the revised policy, IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed to develop and validate concepts of nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UO2(NO3)2) solution exiting solvent extraction was identified as a key measurement point (KMP), where gamma-ray spectroscopy was selected as the process monitoring tool. The Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility at Oak Ridge National Laboratory was employed to simulate the full-scale operating conditions of a purified uranium-bearing aqueous stream exiting the solvent extraction process in an NUCP. Nondestructive assay techniques using gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely way. This work investigated gamma-ray signatures of uranyl nitrate circulating in the UNCLE facility and evaluated various gamma-ray detector sensitivities to uranyl nitrate. These detector validation activities include assessing detector responses to the uranyl nitrate gamma-ray signatures for spectrometers based on sodium iodide, lanthanum bromide, and high-purity germanium detectors. The results of measurements under static and dynamic operating conditions at concentrations ranging from 10-90 g U/L of natural uranyl nitrate are presented. A range of gamma-ray lines is

The Fermi Gamma-ray Burst Monitor (GBM) Terrestrial Gamma-ray Flash (TGF) Catalog

NASA Astrophysics Data System (ADS)

Briggs, M. S.; Roberts, O.; Fitzpatrick, G.; Stanbro, M.; Cramer, E.; Mailyan, B. G.; McBreen, S.; Connaughton, V.; Grove, J. E.; Chekhtman, A.; Holzworth, R.

2017-12-01

The revised Second Fermi GBM TGF catalog includes data on 4144 TGFs detected by the Fermi Gamma-ray Burst Monitor through 2016 July 31. The catalog includes 686 bright TGFs there were detected in orbit and 4135 TGFs that were discovered by ground analysis of GBM data (the two samples overlap). Thirty of the events may have been detected as electrons and positrons rather than gamma-rays: Terrestrial Electron Beams (TEBs). We also provide results from correlating the GBM TGFs with VLF radio detections of the World Wide Lightning Location Network (WWLLN). TGFs with WWLLN associations have their localization uncertainties improved from 800 to 10 km, making it possible to identify specific thunderstorms responsible for the TGFs and opening up new types of scientific investigations. There are 1544 TGFs with WWLLN associations; maps are provided for these and the other TGFs of the catalog. The data tables of the catalog are available for use by the scientific community at the Fermi Science Support Center, at https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/tgf/.

Interpretation of detailed aerial gamma-ray survey, Jabal Ashirah area, southeastern Arabian Shield, Kingdom of Saudi Arabia

USGS Publications Warehouse

Duval, J.S.

1987-01-01

A detailed aerial gamma-ray spectrometric survey of the Jabal Ashirah area in the southeastern Arabian Shield has been analyzed using computer-classification algorithms. The analysis resulted in maps that show radiometric map units and gamma-ray anomalies indicating the presence of possible concentrations of potassium and uranium. The radiometric-unit map was interpreted to 'produce a simplified radiolithic map that was correlated with the mapped geology. The gamma-ray data show uranium anomalies that coincide with a tin-bearing granite, but known gold and nickel mineralization do not have any associated gamma-ray signatures.

Terrestrial Gamma-ray Flashes (TGFs) Observed with the Fermi-Gamma-ray Burst Monitor: Temporal and Spectral Properties

NASA Technical Reports Server (NTRS)

Fishman, G. J.; Briggs, M. S.; Connaughton, W.; Wilson-Hodge, C.; Bhat, P. N.

2010-01-01

The Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope Observatory (Fermi) was detecting 2.1 TGFs per week. This rate has increased by a factor of 8 since new flight software was uploaded to the spacecraft in November 2009 in order to increase the sensitivity of GBM to TGFs. Further upgrades to Fermi-GBM to allow observations of weaker TGFs are in progress. The high time resolution (2 s) allows temporal features to be resolved so that some insight may be gained on the origin and transport of the gamma-ray photons through the atmosphere. The absolute time of the TGFs, known to several microseconds, also allows accurate correlations of TGFs with lightning networks and other lightning-related phenomena. The thick bismuth germanate (BGO) scintillation detectors of the GBM system have observed photon energies from TGFs at energies above 40 MeV. New results on the some temporal aspects of TGFs will be presented along with spectral characteristics and properties of several electron-positron TGF events that have been identified.

Gamma-ray monitoring of AGN and galactic black hole candidates by the Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

Wheaton, Wm. A.; Ling, James C.; Skelton, R. T.; Harmon, Alan; Fishman, Gerald J.; Meegan, Charles A.; Paciesas, William S.; Rubin, Brad; Wilson, Robert B.; Gruber, Duane E.

1992-01-01

The Burst and Transient Spectroscopy Experiment (BATSE) on the Compton Gamma-Ray Observatory has a powerful capability to provide nearly uninterrupted monitoring in the 25 keV-10 MeV range of both AGN and Galactic black hole candidates such as Cygnus X-1, using the occultation of cosmic sources by the Earth. Progress in background modeling indicates that the data accept region, or fit window tau, around the occultation step can be substantially increased over that conservatively assumed in earlier estimates of BATSE's Earth occultation sensitivity. We show samples of large-tau fits to background and source edges. As a result we expect to be able to perform long-term monitoring of Cygnus X-1 and many of the brighter AGN for the duration of the CGRO mission.

Performance analysis of gamma ray spectrometric parameters on digital signal and analog signal processing based MCA systems using NaI(Tl) detector.

PubMed

Kukreti, B M; Sharma, G K

2012-05-01

Accurate and speedy estimations of ppm range uranium and thorium in the geological and rock samples are most useful towards ongoing uranium investigations and identification of favorable radioactive zones in the exploration field areas. In this study with the existing 5 in. × 4 in. NaI(Tl) detector setup, prevailing background and time constraints, an enhanced geometrical setup has been worked out to improve the minimum detection limits for primordial radioelements K(40), U(238) and Th(232). This geometrical setup has been integrated with the newly introduced, digital signal processing based MCA system for the routine spectrometric analysis of low concentration rock samples. Stability performance, during the long counting hours, for digital signal processing MCA system and its predecessor NIM bin based MCA system has been monitored, using the concept of statistical process control. Monitored results, over a time span of few months, have been quantified in terms of spectrometer's parameters such as Compton striping constants and Channel sensitivities, used for evaluating primordial radio element concentrations (K(40), U(238) and Th(232)) in geological samples. Results indicate stable dMCA performance, with a tendency of higher relative variance, about mean, particularly for Compton stripping constants. Copyright © 2012 Elsevier Ltd. All rights reserved.

All-Sky Earth Occultation Observations with the Fermi Gamma Ray Burst Monitor

NASA Technical Reports Server (NTRS)

Wilson-Hodge, C. A.; Beklen, E.; Bhat, P. N.; Briggs, M.; Camero-Arranz, A.; Case, G.; Chaplin, V.; Cherry, M.; Connaughton, V.; Finger, M.;

Calibration and performance of a real-time gamma-ray spectrometry water monitor using a LaBr3(Ce) detector

NASA Astrophysics Data System (ADS)

Prieto, E.; Casanovas, R.; Salvadó, M.

2018-03-01

A scintillation gamma-ray spectrometry water monitor with a 2″ × 2″ LaBr3(Ce) detector was characterized in this study. This monitor measures gamma-ray spectra of river water. Energy and resolution calibrations were performed experimentally, whereas the detector efficiency was determined using Monte Carlo simulations with EGS5 code system. Values of the minimum detectable activity concentrations for 131I and 137Cs were calculated for different integration times. As an example of the monitor performance after calibration, a radiological increment during a rainfall episode was studied.

Gamma-ray Monitoring of Active Galactic Nuclei with HAWC

NASA Astrophysics Data System (ADS)

Lauer, Robert; HAWC Collaboration

2016-03-01

Active Galactic Nuclei (AGN) are extra-galactic sources that can exhibit extreme flux variability over a wide range of wavelengths. TeV gamma rays have been observed from about 60 AGN and can help to diagnose emission models and to study cosmic features like extra-galactic background light or inter-galactic magnetic fields. The High Altitude Water Cherenkov (HAWC) observatory is a new extensive air shower array that can complement the pointed TeV observations of imaging air Cherenkov telescopes. HAWC is optimized for studying gamma rays with energies between 100 GeV and 100 TeV and has an instantaneous field of view of ~2 sr and a duty cycle >95% that allow us to scan 2/3 of the sky every day. By performing an unbiased monitoring of TeV emissions of AGN over most of the northern and part of the southern sky, HAWC can provide crucial information and trigger follow-up observations in collaborations with pointed TeV instruments. Furthermore, HAWC coverage of AGN is complementary to that provided by the Fermi satellite at lower energies. In this contribution, we will present HAWC flux light curves of TeV gamma rays from various sources, notably the bright AGN Markarian 421 and Markarian 501, and highlight recent results from multi-wavelengths and multi-instrument studies.

Gamma Ray Astronomy

NASA Technical Reports Server (NTRS)

Wu, S. T.

2000-01-01

The project has progressed successfully during this period of performance. The highlights of the Gamma Ray Astronomy teams efforts are: (1) Support daily BATSE data operations, including receipt, archival and dissemination of data, quick-look science analysis, rapid gamma-ray burst and transient monitoring and response efforts, instrument state-of-health monitoring, and instrument commanding and configuration; (2) On-going scientific analysis, including production and maintenance of gamma-ray burst, pulsed source and occultation source catalogs, gamma-ray burst spectroscopy, studies of the properties of pulsars and black holes, and long-term monitoring of hard x-ray sources; (3) Maintenance and continuous improvement of BATSE instrument response and calibration data bases; (4) Investigation of the use of solid state detectors for eventual application and instrument to perform all sky monitoring of X-Ray and Gamma sources with high sensitivity; and (5) Support of BATSE outreach activities, including seminars, colloquia and World Wide Web pages. The highlights of this efforts can be summarized in the publications and presentation list.

Implementation of gamma-ray spectrometry in two real-time water monitors using NaI(Tl) scintillation detectors.

PubMed

Casanovas, R; Morant, J J; Salvadó, M

2013-10-01

In this study, the implementation of gamma-ray spectrometry in two real-time water monitors using 2 in. × 2 in. NaI(Tl) scintillation detectors is described. These monitors collect the water from the river through a pump and it is analyzed in a vessel, which is shielded with Pb. The full calibration of the monitors was performed experimentally, except for the efficiency curve, which was set using validated Monte Carlo simulations with the EGS5 code system. After the calibration, the monitors permitted the identification and quantification of the involved isotopes in a possible radioactive increment and made it possible to discard possible leaks in the nuclear plants. As an example, a radiological increment during rain is used to show the advantages of gamma-ray spectrometry. To study the capabilities of the monitor, the minimum detectable activity concentrations for (131)I, (137)Cs and (40)K are presented for different integration times. Copyright © 2013 Elsevier Ltd. All rights reserved.

Design of Dual-Road Transportable Portal Monitoring System for Visible Light and Gamma-Ray Imaging

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

Karnowski, Thomas Paul; Cunningham, Mark F; Goddard Jr, James Samuel

2010-01-01

The use of radiation sensors as portal monitors is increasing due to heightened concerns over the smuggling of fissile material. Transportable systems that can detect significant quantities of fissile material that might be present in vehicular traffic are of particular interest, especially if they can be rapidly deployed to different locations. To serve this application, we have constructed a rapid-deployment portal monitor that uses visible-light and gamma-ray imaging to allow simultaneous monitoring of multiple lanes of traffic from the side of a roadway. The system operation uses machine vision methods on the visible-light images to detect vehicles as they entermore » and exit the field of view and to measure their position in each frame. The visible-light and gamma-ray cameras are synchronized which allows the gamma-ray imager to harvest gamma-ray data specific to each vehicle, integrating its radiation signature for the entire time that it is in the field of view. Thus our system creates vehicle-specific radiation signatures and avoids source confusion problems that plague non-imaging approaches to the same problem. Our current prototype instrument was designed for measurement of upto five lanes of freeway traffic with a pair of instruments, one on either side of the roadway. Stereoscopic cameras are used with a third alignment camera for motion compensation and are mounted on a 50 deployable mast. In this paper we discuss the design considerations for the machine-vision system, the algorithms used for vehicle detection and position estimates, and the overall architecture of the system. We also discuss system calibration for rapid deployment. We conclude with notes on preliminary performance and deployment.« less

Design of dual-road transportable portal monitoring system for visible light and gamma-ray imaging

NASA Astrophysics Data System (ADS)

Karnowski, Thomas P.; Cunningham, Mark F.; Goddard, James S.; Cheriyadat, Anil M.; Hornback, Donald E.; Fabris, Lorenzo; Kerekes, Ryan A.; Ziock, Klaus-Peter; Bradley, E. Craig; Chesser, J.; Marchant, W.

2010-04-01

The use of radiation sensors as portal monitors is increasing due to heightened concerns over the smuggling of fissile material. Transportable systems that can detect significant quantities of fissile material that might be present in vehicular traffic are of particular interest, especially if they can be rapidly deployed to different locations. To serve this application, we have constructed a rapid-deployment portal monitor that uses visible-light and gamma-ray imaging to allow simultaneous monitoring of multiple lanes of traffic from the side of a roadway. The system operation uses machine vision methods on the visible-light images to detect vehicles as they enter and exit the field of view and to measure their position in each frame. The visible-light and gamma-ray cameras are synchronized which allows the gamma-ray imager to harvest gamma-ray data specific to each vehicle, integrating its radiation signature for the entire time that it is in the field of view. Thus our system creates vehicle-specific radiation signatures and avoids source confusion problems that plague non-imaging approaches to the same problem. Our current prototype instrument was designed for measurement of upto five lanes of freeway traffic with a pair of instruments, one on either side of the roadway. Stereoscopic cameras are used with a third "alignment" camera for motion compensation and are mounted on a 50' deployable mast. In this paper we discuss the design considerations for the machine-vision system, the algorithms used for vehicle detection and position estimates, and the overall architecture of the system. We also discuss system calibration for rapid deployment. We conclude with notes on preliminary performance and deployment.

A sensitive mass spectrometric method for hypothesis-driven detection of peptide post-translational modifications: multiple reaction monitoring-initiated detection and sequencing (MIDAS).

PubMed

Unwin, Richard D; Griffiths, John R; Whetton, Anthony D

2009-01-01

The application of a targeted mass spectrometric workflow to the sensitive identification of post-translational modifications is described. This protocol employs multiple reaction monitoring (MRM) to search for all putative peptides specifically modified in a target protein. Positive MRMs trigger an MS/MS experiment to confirm the nature and site of the modification. This approach, termed MIDAS (MRM-initiated detection and sequencing), is more sensitive than approaches using neutral loss scanning or precursor ion scanning methodologies, due to a more efficient use of duty cycle along with a decreased background signal associated with MRM. We describe the use of MIDAS for the identification of phosphorylation, with a typical experiment taking just a couple of hours from obtaining a peptide sample. With minor modifications, the MIDAS method can be applied to other protein modifications or unmodified peptides can be used as a MIDAS target.

Characterization of scintillator crystals for usage as prompt gamma monitors in particle therapy

NASA Astrophysics Data System (ADS)

Roemer, K.; Pausch, G.; Bemmerer, D.; Berthel, M.; Dreyer, A.; Golnik, C.; Hueso-González, F.; Kormoll, T.; Petzoldt, J.; Rohling, H.; Thirolf, P.; Wagner, A.; Wagner, L.; Weinberger, D.; Fiedler, F.

2015-10-01

Particle therapy in oncology is advantageous compared to classical radiotherapy due to its well-defined penetration depth. In the so-called Bragg peak, the highest dose is deposited; the tissue behind the cancerous area is not exposed. Different factors influence the range of the particle and thus the target area, e.g. organ motion, mispositioning of the patient or anatomical changes. In order to avoid over-exposure of healthy tissue and under-dosage of cancerous regions, the penetration depth of the particle has to be monitored, preferably already during the ongoing therapy session. The verification of the ion range can be performed using prompt gamma emissions, which are produced by interactions between projectile and tissue, and originate from the same location and time of the nuclear reaction. The prompt gamma emission profile and the clinically relevant penetration depth are correlated. Various imaging concepts based on the detection of prompt gamma rays are currently discussed: collimated systems with counting detectors, Compton cameras with (at least) two detector planes, or the prompt gamma timing method, utilizing the particle time-of-flight within the body. For each concept, the detection system must meet special requirements regarding energy, time, and spatial resolution. Nonetheless, the prerequisites remain the same: the gamma energy region (2 to 10 MeV), high counting rates and the stability in strong background radiation fields. The aim of this work is the comparison of different scintillation crystals regarding energy and time resolution for optimized prompt gamma detection.

A new apparatus for on-site calibration of gamma dose rate monitors

NASA Astrophysics Data System (ADS)

Zhang, Yu; Chen, Bo; Zhao, Chao; Zhuo, Weihai

2018-01-01

In order to carry out on-site calibrations of environmental gamma dose rate monitors, a new irradiation apparatus was developed in this study. The apparatus mainly consists of a piece of 137Cs source, a set of beam attenuators, and 3 built-in laser rangefinders, and it can be remotely controlled by using a laptop through WiFi network. With an activity of 4.6 × 108 Bq of 137Cs source, the reference air kerma rate could be adjusted from 0.26 μGy h-1 to 140 μGy h-1 by changing the calibration distance from 0.5 m to 5 m and using different beam attenuators (or none), and both the reproducibility and the homogeneity of reference radiation were better than 97%. The overall uncertainty of the calibration was estimated to be 6.5% (k = 2). Both the laboratory and field experiments confirmed that the calibration method met the requirements of ISO 4037-1. As the advantages of portability and simplicity, it is considered that the new irradiation apparatus is applicable to stationary gamma radiation monitors for on-site calibration.

Use of a solar panel as a directionally sensitive large-area radiation monitor for direct and scattered x-rays and gamma-rays.

PubMed

Abdul-Majid, S

1987-01-01

The characteristics of a 25.4 X 91 cm solar cell panel used as an x-ray and gamma-ray radiation monitor are presented. Applications for monitoring the primary x-ray beam are described at different values of operating currents and voltages as well as for directional dependence of scattered radiation. Other applications in gamma-ray radiography are also given. The detector showed linear response to both x-ray and gamma-ray exposures. The equipment is rigid, easy to use, relatively inexpensive and requires no power supply or any complex electronic equipment.

Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

DOEpatents

Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

2013-02-12

A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

Monitoring materials

DOEpatents

Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

2002-01-01

The apparatus and method provide techniques for effectively implementing alpha and/or beta and/or gamma monitoring of items or locations as desired. Indirect alpha monitoring by detecting ions generated by alpha emissions, in conjunction with beta and/or gamma monitoring is provided. The invention additionally provides for screening of items prior to alpha monitoring using beta and/or gamma monitoring, so as to ensure that the alpha monitoring apparatus is not contaminated by proceeding direct to alpha monitoring of a heavily contaminated item or location. The invention provides additional versatility in the emission forms which can be monitored, whilst maintaining accuracy and avoiding inadvertent contamination.

Physical principles of neutron-gamma materials monitoring

NASA Astrophysics Data System (ADS)

Pekarskii, G. Sh.

1986-03-01

The physical principles of secondary radiation methods in nondestructive testing are discussed. Among the techniques considered are: neutron activation analysis (NAA); the induced-radiation method; and quasialbedo recording of secondary gamma-radiation. Emphasis is given to the neutron-gamma method which consists of exposing test material to a neutron flux and recording the secondary gamma-radiation by means of a spectrometer. The limitations of the method in detecting local inhomogeneous defects (filled pores cracks, and inclusions) in metal layers and multicomponents materials are described, and some advantages of the method over NAA are discussed. Formulas are derived for estimating the optimum density of the gamma-ray flux which is received by the detector.

Physical principles of neutron-gamma materials monitoring

NASA Astrophysics Data System (ADS)

Pekarskii, G. Sh.

1985-07-01

The physical principles of secondary radiation methods in nondestructive testing are discussed. Among the techniques considered are: neutron activation analysis (NAA); the induced-radiation method; and quasialbedo recording of secondary gamma-radiation. Emphasis is given to the neutron-gamma method which consists of exposing test material to a neutron flux and recording the secondary gamma-radiation by means of a spectrometer. The limitations of the method in detecting local inhomogeneous defects (filled pores cracks, and inclusions) in metal layers and multicomponents materials are described, and some advantages of the method over NAA are discussed. Formulas are derived for estimating the optimum density of the gamma-ray flux which is received by the detector.

Monitoring Radionuclide Transport and Spatial Distribution with a 1D Gamma-Ray Scanner

NASA Astrophysics Data System (ADS)

Dozier, R.; Erdmann, B.; Sams, A.; Barber, K.; DeVol, T. A.; Moysey, S. M.; Powell, B. A.

2016-12-01

Understanding radionuclide movement in the environment is important for informing strategies for radioactive waste management and disposal. A 1-dimensional (1D) gamma-ray emission scanning system was developed to investigate radionuclide transport behavior within soils. Two case studies illustrate the use of the system for non-destructively monitoring transport processes within a soil column. The first case study explores the system capabilities for simultaneously detecting technetium-99m (99mTc), iodine-131 (131I), and sodium-22 (22Na) moving through a column (length = 14.1 cm, diameter = 3.8 cm) packed with soil from the Department of Energy's Savannah River Site. A sodium iodide (NaI) detector was placed at 4 cm above the influent and a Bismuth germanate (BGO) detector at about 10 cm above the influent. The NaI detector results show 99mTc, 131I, and 22Na having similar breakthrough curves with the tail of 99mTc being lower than that of 131I and 22Na. NaCl tracer results compliment the gamma-ray emission measurements. These results are promising because we are able to monitor movement of the isotopes in the column in real-time. In the second case study, the 1D gamma scanner was used to quantify radionuclide mobility within a lysimeter (length = 51 cm, diameter = 10 cm). A cementitious waste form containing cobalt-60 (60Co), barium-133 (133Ba), cesium-137 (137Cs), and europium-152 (152Eu), with the amount of each contained in the cement ranging from 3 to 8.5 MBq, was placed at the midpoint of the lysimeter. The lysimeter was then exposed to natural rainfall and environmental conditions and effluent samples were collected and quantified on a quarterly basis. Following 3.3 years of exposure, the radionuclide distribution in the lysimeter was quantified with a 0.64 cm collimated high-purity germanium gamma-ray spectrometer. Diffusion of 137Cs away from the cementitious wasteform was observed. No movement was seen for 133Ba, 60Co, or 152Eu within the detection limits

Mass spectrometric determination of early and advanced glycation in biology.

PubMed

Rabbani, Naila; Ashour, Amal; Thornalley, Paul J

2016-08-01

Protein glycation in biological systems occurs predominantly on lysine, arginine and N-terminal residues of proteins. Major quantitative glycation adducts are found at mean extents of modification of 1-5 mol percent of proteins. These are glucose-derived fructosamine on lysine and N-terminal residues of proteins, methylglyoxal-derived hydroimidazolone on arginine residues and N(ε)-carboxymethyl-lysine residues mainly formed by the oxidative degradation of fructosamine. Total glycation adducts of different types are quantified by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Metabolism of glycated proteins is followed by LC-MS/MS of glycation free adducts as minor components of the amino acid metabolome. Glycated proteins and sites of modification within them - amino acid residues modified by the glycating agent moiety - are identified and quantified by label-free and stable isotope labelling with amino acids in cell culture (SILAC) high resolution mass spectrometry. Sites of glycation by glucose and methylglyoxal in selected proteins are listed. Key issues in applying proteomics techniques to analysis of glycated proteins are: (i) avoiding compromise of analysis by formation, loss and relocation of glycation adducts in pre-analytic processing; (ii) specificity of immunoaffinity enrichment procedures, (iii) maximizing protein sequence coverage in mass spectrometric analysis for detection of glycation sites, and (iv) development of bioinformatics tools for prediction of protein glycation sites. Protein glycation studies have important applications in biology, ageing and translational medicine - particularly on studies of obesity, diabetes, cardiovascular disease, renal failure, neurological disorders and cancer. Mass spectrometric analysis of glycated proteins has yet to find widespread use clinically. Future use in health screening, disease diagnosis and therapeutic monitoring, and

Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

NASA Astrophysics Data System (ADS)

Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara

2015-07-01

We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

GAS CHROMATOGRAPHIC/MASS SPECTROMETRIC APPROACH FOR ISOMER-SPECIFIC ENVIRONMENTAL MONITORING OF THE 1700 BROMO-, CHLORO-, AND BROMOCHLORO-DIBENZO-P-DIOXINS

EPA Science Inventory

A combined approach using gas chromatographic retention indices and mass spectrometric characteristics has been elaborated for the isomer-specific identification of the 1700 bromo-, chloro- and bromochloro-dioxins which may be found in the environment. ver 100 dioxins were synthe...

Review of chemical separation techniques applicable to alpha spectrometric measurements

NASA Astrophysics Data System (ADS)

de Regge, P.; Boden, R.

1984-06-01

Prior to alpha-spectrometric measurements several chemical manipulations are usually required to obtain alpha-radiating sources with the desired radiochemical and chemical purity. These include sampling, dissolution or leaching of the elements of interest, conditioning of the solution, chemical separation and preparation of the alpha-emitting source. The choice of a particular method is dependent on different criteria but always involves aspects of the selectivity or the quantitative nature of the separations. The availability of suitable tracers or spikes and modern high resolution instruments resulted in the wide-spread application of isotopic dilution techniques to the problems associated with quantitative chemical separations. This enhanced the development of highly elective methods and reagents which led to important simplifications in the separation schemes. The chemical separation methods commonly used in connection with alpha-spectrometric measurements involve precipitation with selected scavenger elements, solvent extraction, ion exchange and electrodeposition techniques or any combination of them. Depending on the purpose of the final measurement and the type of sample available the chemical separation methods have to be adapted to the particular needs of environment monitoring, nuclear chemistry and metrology, safeguards and safety, waste management and requirements in the nuclear fuel cycle. Against the background of separation methods available in the literature the present paper highlights the current developments and trends in the chemical techniques applicable to alpha spectrometry.

TRIPLICATE SODIUM IODIDE GAMMA RAY MONITORS FOR THE SMALL COLUMN ION EXCHANGE PROGRAM

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

Couture, A.

2011-09-20

This technical report contains recommendations from the Analytical Development (AD) organization of the Savannah River National Laboratory (SRNL) for a system of triplicate Sodium Iodide (NaI) detectors to be used to monitor Cesium-137 ({sup 137}Cs) content of the Decontaminated Salt Solution (DSS) output of the Small Column Ion Exchange (SCIX) process. These detectors need to be gain stabilized with respect to temperature shifts since they will be installed on top of Tank 41 at the Savannah River Site (SRS). This will be accomplished using NaI crystals doped with the alpha-emitting isotope, Americium-241({sup 241}Am). Two energy regions of the detector outputmore » will be monitored using single-channel analyzers (SCAs), the {sup 137}Cs full-energy {gamma}-ray peak and the {sup 241}Am alpha peak. The count rate in the gamma peak region will be proportional to the {sup 137}Cs content in the DSS output. The constant rate of alpha decay in the NaI crystal will be monitored and used as feedback to adjust the high voltage supply to the detector in response to temperature variation. An analysis of theoretical {sup 137}Cs breakthrough curves was used to estimate the gamma activity expected in the DSS output during a single iteration of the process. Count rates arising from the DSS and background sources were predicted using Microshield modeling software. The current plan for shielding the detectors within an enclosure with four-inch thick steel walls should allow the detectors to operate with the sensitivity required to perform these measurements. Calibration, testing, and maintenance requirements for the detector system are outlined as well. The purpose of SCIX is to remove and concentrate high-level radioisotopes from SRS salt waste resulting in two waste streams. The concentrated high-level waste containing {sup 137}Cs will be sent to the Defense Waste Processing Facility (DWPF) for vitrification and the low-level DSS will be sent to the Saltstone Production

A cost-effective monitoring technique in particle therapy via uncollimated prompt gamma peak integration

NASA Astrophysics Data System (ADS)

Krimmer, J.; Angellier, G.; Balleyguier, L.; Dauvergne, D.; Freud, N.; Hérault, J.; Létang, J. M.; Mathez, H.; Pinto, M.; Testa, E.; Zoccarato, Y.

2017-04-01

For the purpose of detecting deviations from the prescribed treatment during particle therapy, the integrals of uncollimated prompt gamma-ray timing distributions are investigated. The intention is to provide information, with a simple and cost-effective setup, independent from monitoring devices of the beamline. Measurements have been performed with 65 MeV protons at a clinical cyclotron. Prompt gamma-rays emitted from the target are identified by means of time-of-flight. The proton range inside the PMMA target has been varied via a modulator wheel. The measured variation of the prompt gamma peak integrals as a function of the modulator position is consistent with simulations. With detectors covering a solid angle of 25 msr (corresponding to a diameter of 3-4 in. at a distance of 50 cm from the beam axis) and 108 incident protons, deviations of a few per cent in the prompt gamma-ray count rate can be detected. For the present configuration, this change in the count rate corresponds to a 3 mm change in the proton range in a PMMA target. Furthermore, simulation studies show that a combination of the signals from multiple detectors may be used to detect a misplacement of the target. A different combination of these signals results in a precise number of the detected prompt gamma rays, which is independent on the actual target position.

Documentation of the data analysis system for the gamma ray monitor aboard OSO-H

NASA Technical Reports Server (NTRS)

Croteau, S.; Buck, A.; Higbie, P.; Kantauskis, J.; Foss, S.; Chupp, D.; Forrest, D. J.; Suri, A.; Gleske, I.

1973-01-01

The programming system is presented which was developed to prepare the data from the gamma ray monitor on OSO-7 for scientific analysis. The detector, data, and objectives are described in detail. Programs presented include; FEEDER, PASS-1, CAL1, CAL2, PASS-3, Van Allen Belt Predict Program, Computation Center Plot Routine, and Response Function Programs.

ESR and mass-spectrometric uranium-series dating studies of a mammoth tooth from stanton harcourt, Oxfordshire, England

NASA Astrophysics Data System (ADS)

Zhou, L. P.; McDermott, F.; Rhodes, E. J.; Marseglia, E. A.; Mellars, P. A.

The age of the Channel Deposits at Stanton Harcourt, Oxfordshire, England, has been a topic of debate with important implications for British Pleistocene stratigraphy. Recent excavations led by K. Scott reveal ample evidence for ancient environmental conditions characteristic of an interglacial. However, the question remains on the assignment of its age. At present it is thought to represent an interglacial corresponding to either marine OI Stage 7 or 5e. In an attempt to constrain the chronology of the site, and to assess the techniques' reliability, we have made electron spin resonance (ESR) measurements on enamel and mass-spectrometric U-series measurements on both enamel and dentine from a mammoth tooth buried in the Channel Deposits at Stanton Harcourt. Four dentine samples gave U-series dates between 65.4±0.4 and 146.5±1.0 ka and two enamel samples between these dentine layers were dated to 53.3±0.2 and 61.1±0.6 ka. The corresponding ESR age estimates for the enamel samples are 59±6 and 62±4 ka (early U-uptake, EU) and 95±11 and 98±7 ka (linear U-uptake, LU). The recent U-uptake (RU) dates are 245±38 and 238±31 ka, but in light of the U-series data we would not expect these to represent realistic age estimates. Similar ESR results were obtained from two other adjacent enamel samples. The effect of the large size of the mammoth tooth on the external gamma dose, and the internal gamma contribution from the high U content of the dentine, are considered. While the recent uptake ESR dates appear to coincide with OI Stage 7, all the early and linear uptake ESR and mass-spectrometric U-series dates are younger than the expected age estimation based on recent geological interpretation and amino acid racemisation measurements (>200 ka) and optical dating studies (200-450 ka). Possible causes of the unexpected dating results are discussed. We conclude that our mass-spectrometric U-series and EU and LU ESR measurements represent minimum age estimates for the

Prompt-gamma monitoring in hadrontherapy: A review

NASA Astrophysics Data System (ADS)

Krimmer, J.; Dauvergne, D.; Létang, J. M.; Testa, É.

2018-01-01

Secondary radiation emission induced by nuclear reactions is correlated to the path of ions in matter. Therefore, such penetrating radiation can be used for in vivo control of hadrontherapy treatments, for which the primary beam is absorbed inside the patient. Among secondary radiations, prompt-gamma rays were proposed for real-time verification of ion range. Such a verification is a desired condition to reduce uncertainties in treatment planning. For more than a decade, efforts have been undertaken worldwide to promote prompt-gamma-based devices to be used in clinical conditions. Dedicated cameras are necessary to overcome the challenges of a broad- and high-energy distribution, a large background, high instantaneous count rates, and compatibility constraints with patient irradiation. Several types of prompt-gamma imaging devices have been proposed, that are either physically-collimated or electronically collimated (Compton cameras). Clinical tests are now undergoing. Meanwhile, other methods than direct prompt-gamma imaging were proposed, that are based on specific counting using either time-of-flight or photon energy measurements. In the present article, we make a review and discuss the state of the art for all techniques using prompt-gamma detection to improve the quality assurance in hadrontherapy.

In situ probing of cholesterol in astrocytes at the single-cell level using laser desorption ionization mass spectrometric imaging with colloidal silver.

PubMed

Perdian, D C; Cha, Sangwon; Oh, Jisun; Sakaguchi, Donald S; Yeung, Edward S; Lee, Young Jin

2010-04-30

Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations at the cellular level. Published in 2010 by John Wiley & Sons, Ltd.

In Situ Probing of Cholesterol in Astrocytes at the Single Cell Level using Laser Desorption Ionization Mass Spectrometric Imaging with Colloidal Silver

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

Perdian, D.C.; Cha, Sangwon; Oh, Jisun

2010-03-18

Mass spectrometric imaging has been utilized to localize individual astrocytes and to obtain cholesterol populations at the single-cell level in laser desorption ionization (LDI) with colloidal silver. The silver ion adduct of membrane-bound cholesterol was monitored to detect individual cells. Good correlation between mass spectrometric and optical images at different cell densities indicates the ability to perform single-cell studies of cholesterol abundance. The feasibility of quantification is confirmed by the agreement between the LDI-MS ion signals and the results from a traditional enzymatic fluorometric assay. We propose that this approach could be an effective tool to study chemical populations atmore » the cellular level.« less

O-GlcNAc modification of PPAR{gamma} reduces its transcriptional activity

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

Ji, Suena; Park, Sang Yoon; Roth, Juergen

2012-01-27

Highlights: Black-Right-Pointing-Pointer We found that PPAR{gamma} is modified by O-GlcNAc in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer The Thr54 of PPAR{gamma}1 is the major O-GlcNAc site. Black-Right-Pointing-Pointer Transcriptional activity of PPAR{gamma}1 was decreased on treatment with the OGA inhibitor. -- Abstract: The peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}), a member of the nuclear receptor superfamily, is a key regulator of adipogenesis and is important for the homeostasis of the adipose tissue. The {beta}-O-linked N-acetylglucosamine (O-GlcNAc) modification, a posttranslational modification on various nuclear and cytoplasmic proteins, is involved in the regulation of protein function. Here, we report that PPAR{gamma} is modified by O-GlcNAc in 3T3-L1more » adipocytes. Mass spectrometric analysis and mutant studies revealed that the threonine 54 of the N-terminal AF-1 domain of PPAR{gamma} is the major O-GlcNAc site. Transcriptional activity of wild type PPAR{gamma} was decreased 30% by treatment with the specific O-GlcNAcase (OGA) inhibitor, but the T54A mutant of PPAR{gamma} did not respond to inhibitor treatment. In 3T3-L1 cells, an increase in O-GlcNAc modification by OGA inhibitor reduced PPAR{gamma} transcriptional activity and terminal adipocyte differentiation. Our results suggest that the O-GlcNAc state of PPAR{gamma} influences its transcriptional activity and is involved in adipocyte differentiation.« less

Neutron monitoring systems including gamma thermometers and methods of calibrating nuclear instruments using gamma thermometers

DOEpatents

Moen, Stephan Craig; Meyers, Craig Glenn; Petzen, John Alexander; Foard, Adam Muhling

2012-08-07

A method of calibrating a nuclear instrument using a gamma thermometer may include: measuring, in the instrument, local neutron flux; generating, from the instrument, a first signal proportional to the neutron flux; measuring, in the gamma thermometer, local gamma flux; generating, from the gamma thermometer, a second signal proportional to the gamma flux; compensating the second signal; and calibrating a gain of the instrument based on the compensated second signal. Compensating the second signal may include: calculating selected yield fractions for specific groups of delayed gamma sources; calculating time constants for the specific groups; calculating a third signal that corresponds to delayed local gamma flux based on the selected yield fractions and time constants; and calculating the compensated second signal by subtracting the third signal from the second signal. The specific groups may have decay time constants greater than 5.times.10.sup.-1 seconds and less than 5.times.10.sup.5 seconds.

Development of an omnidirectional gamma-ray imaging Compton camera for low-radiation-level environmental monitoring

NASA Astrophysics Data System (ADS)

Watanabe, Takara; Enomoto, Ryoji; Muraishi, Hiroshi; Katagiri, Hideaki; Kagaya, Mika; Fukushi, Masahiro; Kano, Daisuke; Satoh, Wataru; Takeda, Tohoru; Tanaka, Manobu M.; Tanaka, Souichi; Uchida, Tomohisa; Wada, Kiyoto; Wakamatsu, Ryo

2018-02-01

We have developed an omnidirectional gamma-ray imaging Compton camera for environmental monitoring at low levels of radiation. The camera consisted of only six CsI(Tl) scintillator cubes of 3.5 cm, each of which was readout by super-bialkali photo-multiplier tubes (PMTs). Our camera enables the visualization of the position of gamma-ray sources in all directions (∼4π sr) over a wide energy range between 300 and 1400 keV. The angular resolution (σ) was found to be ∼11°, which was realized using an image-sharpening technique. A high detection efficiency of 18 cps/(µSv/h) for 511 keV (1.6 cps/MBq at 1 m) was achieved, indicating the capability of this camera to visualize hotspots in areas with low-radiation-level contamination from the order of µSv/h to natural background levels. Our proposed technique can be easily used as a low-radiation-level imaging monitor in radiation control areas, such as medical and accelerator facilities.

A Study Of The Radionuclidic Content Of The Environmental Samples Resulting From NIPNE Activities

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

Stochioiu, Ana I.; Bercea, Sorin I.; Ivan, Constantin G.

2007-04-23

The results of alpha, beta, gamma global activity measurements and gamma spectrometric measurements are presented. For more detailed characterization of samples, gamma-spectrometric measurement, implying identification of radionuclides and their activities are carried-out on significant ambiental annual samples.

Spectrometric Characterization of Active Geosynchronous Satellites

NASA Astrophysics Data System (ADS)

Bedard, D.; Monin, D.; Scott, R.; Wade, G.

2012-09-01

Spectrometric characterization of artificial space objects for the purposes of Space Situational Awareness (SSA) has demonstrated great potential since this technique was first reported at this conference over a decade ago. Yet, much scientific work remains to be done before this tool can be used reliably in an operational context. For example, a detailed study of the impacts of a dynamic illumination-object-sensor geometry during individual spectrometric observations has yet to be described. A thorough understanding of this last problem is considered critical if reflectance spectroscopy will be used to characterize active low Earth orbiting spacecraft, in which the Sun-object-sensor geometry varies considerably over the course of a few seconds, or to study space debris that have uncontrolled and varying attitude. It is with the above questions in mind that two observation campaigns were conducted. The first consisted in using small-aperture telescopes to obtain multi-color photometric light curves of active geosynchronous satellites over a wide range of phase angles. The second observation campaign was conducted at the Dominion Astrophysical Observatory (DAO) using the 1.8-metre Plaskett telescope and its Cassegrain spectrograph. The objective of this experiment was to gather time-resolved spectrometric measurements of active geosynchronous satellites as a function of phase angle. This class of satellites was selected because their attitude is controlled and can be estimated to a high level of confidence. This paper presents the two observation campaigns and provides a summary of the key results of this experiment.

Threshold self-powered gamma detector for use as a monitor of power in a nuclear reactor

DOEpatents

LeVert, Francis E.; Cox, Samson A.

1978-01-01

A self-powered gamma monitor for placement near the core of a nuclear reactor comprises a lead prism surrounded by a coaxial thin nickel sheet, the combination forming a collector. A coaxial polyethylene electron barrier encloses the collector and is separated from the nickel sheet by a vacuum region. The electron barrier is enclosed by a coaxial stainless steel emitter which, in turn, is enclosed within a lead casing. When the detector is placed in a flux of gamma rays, a measure of the current flow in an external circuit between emitter and collector provides a measure of the power level of the reactor.

First results from HAWC: monitoring the TeV gamma-ray sky

NASA Astrophysics Data System (ADS)

Lauer, Robert J.

2015-03-01

The High Altitude Water Cherenkov (HAWC) Observatory is a wide-field gamma-ray detector sensitive to primary energies between 100 GeV and 100 TeV. The array is being built at an altitude of 4100 m a.s.l. on the Sierra Negra volcano near Puebla, Mexico. Data taking has already started while construction continues, with the completion projected for early 2015. The design is optimized to detect extended air showers induced by gamma rays that pass through the array and to reconstruct the directions and energies of the primary photons. With a duty cycle close to 100% and a daily coverage of ~8 sr of the sky, HAWC will perform a survey of TeV emissions from many different sources. The northern active galactic nuclei will be monitored for up to 6 hours each day, providing unprecedented light curve coverage at energies comparable to those of imaging air Cherenkov telescopes. HAWC has been in scientific operation with more than 100 detector modules since August 2013. Here we present a preliminary look at the first results and discuss the efforts to integrate HAWC in multi-wavelength studies of extragalactic jets.

In situ gamma-spectrometry several years after deposition of radiocesium. II. Peak-to-valley method.

PubMed

Gering, F; Hillmann, U; Jacob, P; Fehrenbacher, G

1998-12-01

A new method is introduced for deriving radiocesium soil contaminations and kerma rates in air from in situ gamma-ray spectrometric measurements. The approach makes use of additional information about gamma-ray attenuation given by the peak-to-valley ratio, which is the ratio of the count rates for primary and forward scattered photons. In situ measurements are evaluated by comparing the experimental data with the results of Monte Carlo simulations of photon transport and detector response. The influence of photons emitted by natural radionuclides on the calculation of the peak-to-valley ratio is carefully analysed. The new method has been applied to several post-Chernobyl measurements and the results agreed well with those of soil sampling.

Optical gamma thermometer

DOEpatents

Koster, Glen Peter; Xia, Hua; Lee, Boon Kwee

2013-08-06

An optical gamma thermometer includes a metal mass having a temperature proportional to a gamma flux within a core of a nuclear reactor, and an optical fiber cable for measuring the temperature of the heated metal mass. The temperature of the heated mass may be measured by using one or more fiber grating structures and/or by using scattering techniques, such as Raman, Brillouin, and the like. The optical gamma thermometer may be used in conjunction with a conventional reactor heat balance to calibrate the local power range monitors over their useful in-service life. The optical gamma thermometer occupies much less space within the in-core instrument tube and costs much less than the conventional gamma thermometer.

Irradiation of Population in the Surrounding Area of Nuclear Power Plant Temelin

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

Thinova, Lenka; Kluson, Jaroslav

In monitoring the impact of nuclear facilities operation on ecosystem, it is necessary to consider, what part of biota irradiation can be caused by an artificial source. For the estimation of an effective dose from natural sources were used measurements of dosimetric and gamma spectrometric characteristics of photon fields, (performed in the area of NPP Temelin since year 2000) and data from the Czech Republic radiometric chart, including the results from radon volume activity measurements in dwellings. For gamma spectrometric measurements in situ were selected two methodologies and for measurement were used corresponding types of equipment (Tesla NB3201 and spectrometermore » NaI(TI) 3''x3'') at selected locations within the monitored area: i) determination of air kerma rate (through direct measurement and by calculationfrom spectrometric data); ii) measurement of photon spectra by an scintillating spectrometer. For a dose assessment from artificial sources resulting from past or present operation of NPP Temelin, were used records from all so far performed laboratory and field measurements of NPP releases, food baskets and also results of a 6 year ecosystem monitoring in the surrounding area of NPP Temelin. The ecosystem monitoring is based on studying the contamination of the following bioindicators: forest humus, Pine bark, Schreber's Moss, the Bay Bolete (mushroom) and forest berries. Each year 220 samples are collected and mass activity (Bq/kg) for eventual contaminants is determined using laboratory gamma spectroscopy. For measurements is used a coaxial HPGe detector, with samples in the geometry of 'Marinelli' container. For evaluation of the laboratory results obtained is used trend analysis. The above described monitoring has been performed from the year 2000 until now (the year 2000 is pre-operational). In all measured laboratory spectra, of all analyzed samples, were not identified any non-natural radionuclides, with the exception of {sup 137}Cs, for

A tandem mass spectrometric method for singlet oxygen measurement.

PubMed

Karonen, Maarit; Mattila, Heta; Huang, Ping; Mamedov, Fikret; Styring, Stenbjörn; Tyystjärvi, Esa

2014-01-01

Singlet oxygen, a harmful reactive oxygen species, can be quantified with the substance 2,2,6,6-tetramethylpiperidine (TEMP) that reacts with singlet oxygen, forming a stable nitroxyl radical (TEMPO). TEMPO has earlier been quantified with electron paramagnetic resonance (EPR) spectroscopy. In this study, we designed an ultra-high-performance liquid chromatographic-tandem mass spectrometric (UHPLC-ESI-MS/MS) quantification method for TEMPO and showed that the method based on multiple reaction monitoring (MRM) can be used for the measurements of singlet oxygen from both nonbiological and biological samples. Results obtained with both UHPLC-ESI-MS/MS and EPR methods suggest that plant thylakoid membranes produce 3.7 × 10(-7) molecules of singlet oxygen per chlorophyll molecule in a second when illuminated with the photosynthetic photon flux density of 2000 μmol m(-2 ) s(-1). © 2014 The American Society of Photobiology.

Monitoring of the interconversion of gamma-butyrolactone (GBL) to gamma hydroxybutyric acid (GHB) by Raman spectroscopy.

PubMed

Munshi, Tasnim; Brewster, Victoria L; Edwards, Howell G M; Hargreaves, Michael D; Jilani, Shelina K; Scowen, Ian J

2013-08-01

Gamma-hydroxybutyric acid (GHB) is a drug-of-abuse that has recently become associated with drug-facilitated sexual assault, known as date rape. For this reason the drug is commonly found 'spiked' in alcoholic beverages. When GHB is in solution it may undergo conversion into the corresponding lactone, Gamma-butyrolactone (GBL). Studies have been carried out to determine the detection limits of GHB and GBL in various solutions by Raman spectroscopy and to monitor the interconversion of GHB and GBL in solution with different pH conditions and temperature. In this study, a portable Raman spectrometer was used to study the interconversion of GHB and GBL in water and ethanol solutions as a function of pH, time, and temperature. The aim of this was to determine the optimum pH range for conversion in order to relate this to the pH ranges that the drug is likely to be subjected to, first in spiked beverages and secondly after ingestion in the digestive system. The aim was also to identify a timescale for this conversion in relation to possible scenarios, for example if GHB takes a number of hours to convert to GBL, it is likely for the beverage to be ingested before esterification can take place. GHB and GBL were then spiked into a selection of beverages of known pH in order to study the stability of GHB and GBL in real systems. Copyright © 2012 John Wiley & Sons, Ltd.

On the accuracy of gamma spectrometric isotope ratio measurements of uranium

NASA Astrophysics Data System (ADS)

Ramebäck, H.; Lagerkvist, P.; Holmgren, S.; Jonsson, S.; Sandström, B.; Tovedal, A.; Vesterlund, A.; Vidmar, T.; Kastlander, J.

2016-04-01

The isotopic composition of uranium was measured using high resolution gamma spectrometry. Two acid solutions and two samples in the form of UO2 pellets were measured. The measurements were done in close geometries, i.e. directly on the endcap of the high purity germanium detector (HPGe). Applying no corrections for count losses due to true coincidence summing (TCS) resulted in up to about 40% deviation in the abundance of 235U from the results obtained with mass spectrometry. However, after correction for TCS, excellent agreement was achieved between the results obtained using two different measurement methods, or a certified value. Moreover, after corrections, the fitted relative response curves correlated excellently with simulated responses, for the different geometries, of the HPGe detector.

Mass Spectrometric Immunoassay and Multiple Reaction Monitoring as Targeted MS-based Quantitative Approaches in Biomarker Development: Potential Applications to Cardiovascular Disease and Diabetes

PubMed Central

Yassine, Hussein; Borges, Chad R.; Schaab, Matthew R.; Billheimer, Dean; Stump, Craig; Reaven, Peter; Lau, Serrine S.; Nelson, Randall

2014-01-01

Type 2 diabetes (T2DM) is an important risk factor for cardiovascular disease (CVD)—the leading cause of death in the US. Yet not all subjects with T2DM are at equal risk for CVD complications; the challenge lies in identifying those at greatest risk. Therapies directed towards treating conventional risk factors have failed to significantly reduce this residual risk in T2DM patients. Thus newer targets and markers are needed for the development and testing of novel therapies. Herein we review two complementary mass spectrometry-based approaches—Mass Spectrometric Immunoassay (MSIA) and tandem mass spectrometry as multiple reaction monitoring (MRM)—for the analysis of plasma proteins and post translational modifications (PTMs) of relevance to T2DM and CVD. Together, these complementary approaches allow for high-throughput monitoring of many PTMs and the absolute quantification of proteins near the low picomolar range. In this review article, we discuss the clinical relevance of the HDL proteome and Apolipoprotein A-I PTMs to T2DM and CVD as well as provide illustrative MSIA and MRM data on high density lipoprotein (HDL) proteins from T2DM patients to provide examples of how these mass spectrometry approaches can be applied to gain new insight regarding cardiovascular risk factors. Also discussed are the reproducibility, interpretation and limitations of each technique with an emphasis on their capacities to facilitate the translation of new biomarkers into clinical practice. PMID:23696124

Terrestrial Gamma-Ray Flashes (TGFs)

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2010-01-01

This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of 85 of the TGFs observed by the Fermi GBM.

Calibration of gamma-ray detectors using Gaussian photopeak fitting in the multichannel spectra with a LabVIEW-based digital system

NASA Astrophysics Data System (ADS)

Schlattauer, Leo; Parali, Levent; Pechousek, Jiri; Sabikoglu, Israfil; Celiktas, Cuneyt; Tektas, Gozde; Novak, Petr; Jancar, Ales; Prochazka, Vit

2017-09-01

This paper reports on the development of a gamma-ray spectroscopic system for the (i) recording and (ii) processing of spectra. The utilized data read-out unit consists of a PCI digital oscilloscope, personal computer and LabVIEW™ programming environment. A pulse-height spectra of various sources were recorded with two NaI(Tl) detectors and analyzed, demonstrating the proper usage of the detectors. A multichannel analyzer implements the Gaussian photopeak fitting. The presented method provides results which are in compliance to the ones taken from commercial spectroscopy systems. Each individual hardware or software unit can be further utilized in different spectrometric user-systems. An application of the developed system for research and teaching purposes regarding the design of digital spectrometric systems has been successfully tested at the laboratories of the Department of Experimental Physics.

Electrospray Modifications for Advancing Mass Spectrometric Analysis

PubMed Central

Meher, Anil Kumar; Chen, Yu-Chie

2017-01-01

Generation of analyte ions in gas phase is a primary requirement for mass spectrometric analysis. One of the ionization techniques that can be used to generate gas phase ions is electrospray ionization (ESI). ESI is a soft ionization method that can be used to analyze analytes ranging from small organics to large biomolecules. Numerous ionization techniques derived from ESI have been reported in the past two decades. These ion sources are aimed to achieve simplicity and ease of operation. Many of these ionization methods allow the flexibility for elimination or minimization of sample preparation steps prior to mass spectrometric analysis. Such ion sources have opened up new possibilities for taking scientific challenges, which might be limited by the conventional ESI technique. Thus, the number of ESI variants continues to increase. This review provides an overview of ionization techniques based on the use of electrospray reported in recent years. Also, a brief discussion on the instrumentation, underlying processes, and selected applications is also presented. PMID:28573082

Gamma ray monitoring of a AGN and galactic black hole candidates by the Compton Gamma Ray Observatory

NASA Technical Reports Server (NTRS)

Skelton, R. T.; Ling, James C.; Wheaton, William A.; Harmon, Alan; Fishman, G. J.; Meegan, C. A.; Paciesas, William S.; Gruber, Duane E.; Rubin, Brad; Wilson, R. B.

1992-01-01

The Compton Gamma-Ray Observatory's Burst and Transient Source Experiment (BATSE) has a powerful capability to provide nearly uninterrupted monitoring in the 25 keV-10 MeV range of both active galactic nuclei (AGN) and galactic black hole candidates (GBHC) such as Cygnus X-1, using the occultation of cosmic sources by the Earth. Since the Crab is detected by the BATSE Large Area Detectors with roughly 25(sigma) significance in the 15-125 keV range in a single rise or set, a variation by a factor of two of a source having one-tenth the strength of Cygnus X-1 should be detectable within a day. Methods of modeling the background are discussed which will increase the accuracy, sensitivity, and reliability of the results beyond those obtainable from a linear background fit with a single rise or set discontinuity.

Interferometric Monitoring of Gamma-Ray Bright AGNs: S5 0716+714

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

Lee, Jee Won; Lee, Sang-Sung; Hodgson, Jeffrey A.

We present the results of very long baseline interferometry (VLBI) observations of gamma-ray bright blazar S5 0716+714 using the Korean VLBI Network (KVN) at the 22, 43, 86, and 129 GHz bands, as part of the Interferometric Monitoring of Gamma-ray Bright active galactic nuclei (iMOGABA) KVN key science program. Observations were conducted in 29 sessions from 2013 January 16 to 2016 March 1, with the source being detected and imaged at all available frequencies. In all epochs, the source was compact on the milliarcsecond scale, yielding a compact VLBI core dominating the synchrotron emission on these scales. Based on themore » multiwavelength data between 15 GHz (Owens Valley Radio Observatory) and 230 GHz (Submillimeter Array), we found that the source shows multiple prominent enhancements of the flux density at the centimeter (cm) and millimeter (mm) wavelengths, with mm enhancements leading cm enhancements by −16 ± 8 days. The turnover frequency was found to vary between 21 and 69 GHz during our observations. By assuming a synchrotron self-absorption model for the relativistic jet emission in S5 0716+714, we found the magnetic field strength in the mas emission region to be ≤5 mG during the observing period, yielding a weighted mean of 1.0 ± 0.6 mG for higher turnover frequencies (e.g., >45 GHz).« less

Fission Fragment Studies by Gamma-Ray Spectrometry with the Mass Separator Lohengrin

NASA Astrophysics Data System (ADS)

Materna, T.; Amouroux, C.; Bail, A.; Bideau, A.; Chabod, S.; Faust, H.; Capellan, N.; Kessedjian, G.; Köster, U.; Letourneau, A.; Litaize, O.; Martin, F.; Mathieu, L.; Méplan, O.; Panebianco, S.; Régis, J.-M.; Rudigier, M.; Sage, C.; Serot, O.; Urban, W.

2014-09-01

A gamma spectrometric technique was implemented at the exit of the fission fragment separator of the ILL. It allows a precise measurement of isotopic yields of most important actinides in the heavy fragment region by an unambiguous identification of the nuclear charge of the fragments selected by the mass spectrometer. The status of the project and last results are reviewed. A spin-off of this activity is the identification of unknown nanosecond isomers in exotic nuclei through the observation of a disturbed ionic charge distribution. This technique has been improved to provide an estimation of the lifetime of the isomeric state.

A deviation display method for visualising data in mobile gamma-ray spectrometry.

PubMed

Kock, Peder; Finck, Robert R; Nilsson, Jonas M C; Ostlund, Karl; Samuelsson, Christer

2010-09-01

A real time visualisation method, to be used in mobile gamma-spectrometric search operations using standard detector systems is presented. The new method, called deviation display, uses a modified waterfall display to present relative changes in spectral data over energy and time. Using unshielded (137)Cs and (241)Am point sources and different natural background environments, the behaviour of the deviation displays is demonstrated and analysed for two standard detector types (NaI(Tl) and HPGe). The deviation display enhances positive significant changes while suppressing the natural background fluctuations. After an initialization time of about 10min this technique leads to a homogeneous display dominated by the background colour, where even small changes in spectral data are easy to discover. As this paper shows, the deviation display method works well for all tested gamma energies and natural background radiation levels and with both tested detector systems.

Online fault diagnostics and testing of area gamma radiation monitor using wireless network

NASA Astrophysics Data System (ADS)

Reddy, Padi Srinivas; Kumar, R. Amudhu Ramesh; Mathews, M. Geo; Amarendra, G.

2017-07-01

Periodical surveillance, checking, testing, and calibration of the installed Area Gamma Radiation Monitors (AGRM) in the nuclear plants are mandatory. The functionality of AGRM counting electronics and Geiger-Muller (GM) tube is to be monitored periodically. The present paper describes the development of online electronic calibration and testing of the GM tube from the control room. Two electronic circuits were developed, one for AGRM electronic test and another for AGRM detector test. A dedicated radiation data acquisition system was developed using an open platform communication server and data acquisition software. The Modbus RTU protocol on ZigBee based wireless communication was used for online monitoring and testing. The AGRM electronic test helps to carry out the three-point electronic calibration and verification of accuracy. The AGRM detector test is used to verify the GM threshold voltage and the plateau slope of the GM tube in-situ. The real-time trend graphs generated during these tests clearly identified the state of health of AGRM electronics and GM tube on go/no-go basis. This method reduces the radiation exposures received by the maintenance crew and facilitates quick testing with minimum downtime of the instrument.

[Mass-spectrometric analysis of an anti-microbial preparation decamethoxine].

PubMed

Sukhodub, L F; Kosevich, M V; Shelkovskiĭ, V S; Volianskiĭ, Iu L

1989-11-01

I. I. Mechnikov Kharkov Research Institute of Microbiology, Vaccines and Sera, Ministry of Public Health of the Ukrainian SSR. The results of mass spectrometric investigation of decamethoxine++, an antimicrobial chemotherapeutic drug, are presented. It was shown that desorption-field mass spectrometry provided recording decamethoxine++ intensive quasimolecular ions [M.Cl]+ and [M]++ forming under conditions of high electric intensity only from the intact parent molecule. Hence, the presence of the peaks in the desorption field mass spectra made it possible to definitively determine decamethoxine++ in the samples. Therefore, the procedure of desorption-field mass spectrometry proved reliable in identification of bisquaternary ammonium compounds. Ways for thermal decomposition and mass spectrometric fragmentation of the decamethoxine++ molecule under various ionization conditions are also discussed.

Structure elucidation of metabolite x17299 by interpretation of mass spectrometric data.

PubMed

Zhang, Qibo; Ford, Lisa A; Evans, Anne M; Toal, Douglas R

2017-01-01

A major bottleneck in metabolomic studies is metabolite identification from accurate mass spectrometric data. Metabolite x17299 was identified in plasma as an unknown in a metabolomic study using a compound-centric approach where the associated ion features of the compound were used to determine the true molecular mass. The aim of this work is to elucidate the chemical structure of x17299, a new compound by de novo interpretation of mass spectrometric data. An Orbitrap Elite mass spectrometer was used for acquisition of mass spectra up to MS 4 at high resolution. Synthetic standards of N,N,N -trimethyl-l-alanyl-l-proline betaine (l,l-TMAP), a diastereomer, and an enantiomer were chemically prepared. The planar structure of x17299 was successfully proposed by de novo mechanistic interpretation of mass spectrometric data without any laborious purification and nuclear magnetic resonance spectroscopic analysis. The proposed structure was verified by deuterium exchanged mass spectrometric analysis and confirmed by comparison to a synthetic standard. Relative configuration of x17299 was determined by direct chromatographic comparison to a pair of synthetic diastereomers. Absolute configuration was assigned after derivatization of x17299 with a chiral auxiliary group followed by its chromatographic comparison to a pair of synthetic standards. The chemical structure of metabolite x17299 was determined to be l,l-TMAP.

Fermi Gamma-Ray Space Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie E.; Michelson, Peter F.; Paclesas, William S.; Ritz, Steven

2012-01-01

The Fermi Gamma-ray Space Telescope, launched in June 2008, is an observatory designed to survey the high-energy gamma-ray sky. The primary instrument, the Large Area Telescope (LAT), provides observations from 20 MeV to greater than 300 GeV. A second instrument, the Gamma-ray Burst Monitor (GBM), provides observations of transients from less than 10 keV to 40 MeV. We describe the design and performance of the instruments and their subsystems, the spacecraft and the ground system.

Discoveries by the Fermi Gamma Ray Space Telescope

NASA Technical Reports Server (NTRS)

Gehrels, Neil

2011-01-01

Fermi is a large space gamma-ray mission developed by NASA and the DOE with major contributions from France, Germany, Italy, Japan and Sweden. It was launched in June 2008 and has been performing flawlessly since then. The main instrument is the Large Area Telescope (LAT) operating in the 20 MeV to 300 GeV range and a smaller monitor instrument is the Gamma-ray Burst Monitor (GBM) operating in the 8 keV to 40 MeV range. New findings are occurring every week. Some of the key discoveries are: 1) Discovery of many new gamma-ray pulsars, including gamma-ray only and millisecond pulsars. 2) Detection of high energy gamma-ray emission from globular clusters, most likely due to summed emission from msec pulsars. 3) Discovery of delayed and extended high energy gamma-ray emission from short and long gamma-ray busts. 4) Detection of approximately 250 gamma-ray bursts per year with the GBM instrument. 5) Most accurate measurement of the cosmic ray electron spectrum between 30 GeV and 1 TeV, showing some excess above the conventional diffusion model. The talk will present the new discoveries and their implications.

Piezoelectric wafer active sensors under gamma radiation exposure toward applications for structural health monitoring of nuclear dry cask storage systems

NASA Astrophysics Data System (ADS)

Faisal Haider, Mohammad; Mei, Hanfei; Lin, Bin; Yu, Lingyu; Giurgiutiu, Victor; Lam, Poh-Sang; Verst, Christopher

2018-03-01

Structural health monitoring (SHM) is in urgent need and must be integrated into the nuclear-spent fuel storage systems to guarantee the safe operation. The dry cask storage system (DCSS) is such storage facility, which is licensed for temporary storage for nuclear-spent fuel at the independent spent fuel storage installations (ISFSIs) for certain predetermined period of time. Gamma radiation is one of the major radiation sources near DCSS. Therefore, a detailed experimental investigation was completed on the gamma radiation endurance of piezoelectric wafer active sensors (PWAS) transducers for SHM applications to the DCSS system. The irradiation test was done in a Co-60 gamma irradiator. Lead Zirconate Titanate (PZT) and Gallium Orthophosphate (GaPO4) PWAS transducers were exposed to 40.7 kGy gamma radiation. Total radiation dose was achieved in two different radiation dose rates: (a) slower radiation rate at 0.1 kGy/hr for 20 hours (b) accelerated radiation rate at 1.233 kGy/hr for 32 hours. The total cumulative radiation dose of 40.7 kGy is equivalent to 45 years of operation in DCSS system. Electro-mechanical impedance and admittance (EMIA) signatures and electrical capacitance were measured to evaluate the PWAS performance after each gamma radiation exposure. The change in resonance frequency of PZT-PWAS transducer for both in-plane and thickness mode was observed. The GaPO4-PWAS EMIA spectra do not show a significant shift in resonance frequency after gamma irradiation exposure. Radiation endurance of new high-temperature HPZ-HiT PWAS transducer was also evaluated. The HPZ-HiT transducers were exposed to gamma radiation at 1.233 kGy/hr for 160 hours with 80 hours interval. Therefore, the total accumulated gamma radiation dose is 184 kGy. No significant change in impedance spectra was observed due to gamma radiation exposure.

DO THE FERMI GAMMA-RAY BURST MONITOR AND SWIFT BURST ALERT TELESCOPE SEE THE SAME SHORT GAMMA-RAY BURSTS?

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

Burns, Eric; Briggs, Michael S.; Connaughton, Valerie

2016-02-20

Compact binary system mergers are expected to generate gravitational radiation detectable by ground-based interferometers. A subset of these, the merger of a neutron star with another neutron star or a black hole, are also the most popular model for the production of short gamma-ray bursts (GRBs). The Swift Burst Alert Telescope (BAT) and the Fermi Gamma-ray Burst Monitor (GBM) trigger on short GRBs (SGRBs) at rates that reflect their relative sky exposures, with the BAT detecting 10 per year compared to about 45 for GBM. We examine the SGRB populations detected by Swift BAT and Fermi GBM. We find thatmore » the Swift BAT triggers on weaker SGRBs than Fermi GBM, providing they occur close to the center of the BAT field of view, and that the Fermi GBM SGRB detection threshold remains flatter across its field of view. Overall, these effects combine to give the instruments the same average sensitivity, and account for the SGRBs that trigger one instrument but not the other. We do not find any evidence that the BAT and GBM are detecting significantly different populations of SGRBs. Both instruments can detect untriggered SGRBs using ground searches seeded with time and position. The detection of SGRBs below the on-board triggering sensitivities of Swift BAT and Fermi GBM increases the possibility of detecting and localizing the electromagnetic counterparts of gravitational wave (GW) events seen by the new generation of GW detectors.« less

Gamma-ray Albedo of the Moon

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

Moskalenko, Igor V.; Porter, Troy A.

2007-06-14

We use the GEANT4 Monte Carlo framework to calculate the gamma-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of gamma-rays from the Moon is very steep with an effective cutoff around 3 GeV (600 MeV for the inner part of the Moon disc). Since it is the only (almost) black spot in the gamma-ray sky, it provides a unique opportunity for calibration of gamma-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST).more » The albedo flux depends on the incident CR spectrum which changes over the solar cycle. Therefore, it is possible to monitor the CR spectrum using the albedo gamma-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo -rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the GLAST LAT to monitor the CR spectrum near the Earth beyond the lifetime of PAMELA.« less

Advances in mass spectrometric characterization of naphthenic acids fraction compounds in oil sands environmental samples and crude oil--A review.

PubMed

Headley, John V; Peru, Kerry M; Barrow, Mark P

2016-01-01

There has been a recent surge in the development of mass spectrometric methods for detailed characterization of naphthenic acid fraction compounds (all C(c)H(h)N(n)O(o)S(s), species, including heteroatomic and aromatic components in the acid-extractable fraction) in environmental samples. This surge is driven by the increased activity in oil sands environmental monitoring programs in Canada, the exponential increase in research studies on the isolation and toxicity identification of components in oil sands process water (OSPW), and the analytical requirements for development of technologies for treatment of OSPW. There has been additional impetus due to the parallel studies to control corrosion from naphthenic acids during the mining and refining of heavy bitumen and crude oils. As a result, a range of new mass spectrometry tools have been introduced since our last major review of this topic in 2009. Of particular significance are the developments of combined mass spectrometric methods that incorporate technologies such as gas chromatography, liquid chromatography, and ion mobility. There has been additional progress with respect to improved visualization methods for petroleomics and oil sands environmental forensics. For comprehensive coverage and more reliable characterization of samples, an approach based on multiple-methods that employ two or more ionization modes is recommended. On-line or off-line fractionation of isolated extracts, with or without derivatization, might also be used prior to mass spectrometric analyses. Individual ionization methods have their associated strengths and weaknesses, including biases, and thus dependence upon a single ionization method is potentially misleading. There is also a growing trend to not rely solely on low-resolution mass spectrometric methods (<20,000 resolving power at m/z 200) for characterization of complex samples. Future research is anticipated to focus upon (i) structural elucidation of components to determine

Gas Chromatographic/Mass Spectrometric Differentiation of Atenolol, Metoprolol, Propranolol, and an Interfering Metabolite Product of Metoprolol

DTIC Science & Technology

2004-10-01

Gas Chromatographic/Mass Spectrometric Differentiation of Atenolol, Metoprolol , Propranolol, and an Interfering Metabolite Product of Metoprolol ...4. Title and Subtitle 5. Report Date October 2004 Gas Chromatographic/Mass Spectrometric Differentiation of Atenolol, Metoprolol , Propranolol...and an Interfering Metabolite Product of Metoprolol 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Angier MK

Application of underwater spectrometric system for survey of ponds of the MR reactor (NRC Kurchatov institute)

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

Stepanov, Vyacheslav; Potapov, Victor; Safronov, Alexey

2013-07-01

The underwater spectrometric system for survey the bottom of material science multi-loop reactor MR ponds was elaborated. This system uses CdZnTe (CZT) detectors that allow for spectrometric measurements in high radiation fields. The underwater system was used in the spectrometric survey of the bottom of the MR reactor pool, as well as in the survey located in the MR storage pool of highly radioactive containers and parts of the reactor construction. As a result of these works irradiated nuclear fuel was detected on the bottom of pools, and obtained estimates of the effective surface activity detected radionuclides and created bymore » them the dose rate. (authors)« less

Low energy secondary cosmic ray flux (gamma rays) monitoring and its constrains

NASA Astrophysics Data System (ADS)

Raghav, Anil; Bhaskar, Ankush; Yadav, Virendra; Bijewar, Nitinkumar

2015-02-01

Temporal variation of secondary cosmic rays (SCR) flux was measured during the full and new moon and days close to them at Department of Physics, University of Mumbai, Mumbai (Geomagnetic latitude: 10.6 °N), India. The measurements were done by using NaI (Tl) scintillation detector with energy threshold of 200 keV. The SCR flux showed sudden enhancement for approximately about 2 hour during few days out of all observations. The maximum enhancement in SCR flux is about 200 % as compared to the diurnal trend of SCR temporal variations. Weather parameters (temperature and relative humidity) were continuously monitored during all observations. The influences of geomagnetic field, interplanetary parameters and tidal effect on SCR flux have been considered. Summed spectra corresponding to enhancement duration indicates appearance of atmospheric radioactivity which shows single gamma ray line. Detail investigation revealed the presence of radioactive Ar41. Present study indicates origin of Ar41 could be due to anthropogenic source or due to gravitational tidal forces. This measurements point out limitations on low energy SCR flux monitoring. This study will help many researchers in measurements of SCR flux during eclipses and to find unknown mechanism behind decrease/increase in SCR flux during solar/lunar eclipse.

Distributed Attention Is Implemented through Theta-Rhythmic Gamma Modulation.

PubMed

Landau, Ayelet Nina; Schreyer, Helene Marianne; van Pelt, Stan; Fries, Pascal

2015-08-31

When subjects monitor a single location, visual target detection depends on the pre-target phase of an ∼8 Hz brain rhythm. When multiple locations are monitored, performance decrements suggest a division of the 8 Hz rhythm over the number of locations, indicating that different locations are sequentially sampled. Indeed, when subjects monitor two locations, performance benefits alternate at a 4 Hz rhythm. These performance alternations were revealed after a reset of attention to one location. Although resets are common and important events for attention, it is unknown whether, in the absence of resets, ongoing attention samples stimuli in alternation. Here, we examined whether spatially specific attentional sampling can be revealed by ongoing pre-target brain rhythms. Visually induced gamma-band activity plays a role in spatial attention. Therefore, we hypothesized that performance on two simultaneously monitored stimuli can be predicted by a 4 Hz modulation of gamma-band activity. Brain rhythms were assessed with magnetoencephalography (MEG) while subjects monitored bilateral grating stimuli for a unilateral target event. The corresponding contralateral gamma-band responses were subtracted from each other to isolate spatially selective, target-related fluctuations. The resulting lateralized gamma-band activity (LGA) showed opposite pre-target 4 Hz phases for detected versus missed targets. The 4 Hz phase of pre-target LGA accounted for a 14.5% modulation in performance. These findings suggest that spatial attention is a theta-rhythmic sampling process that is continuously ongoing, with each sampling cycle being implemented through gamma-band synchrony. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: application to pharmacokinetic studies.

PubMed

Issa, M M; Nejem, R M; El-Abadla, N S; Al-Kholy, M; Saleh, Akila A

2008-01-01

A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III) (method I); oxidation of p-aminophenol after the hydrolysis of paracetamol (method II). Iron (II) then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III) in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II) at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 mug/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 mug/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 mug/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%.

Monitoring the distribution of prompt gamma rays in boron neutron capture therapy using a multiple-scattering Compton camera: A Monte Carlo simulation study

NASA Astrophysics Data System (ADS)

Lee, Taewoong; Lee, Hyounggun; Lee, Wonho

2015-10-01

This study evaluated the use of Compton imaging technology to monitor prompt gamma rays emitted by 10B in boron neutron capture therapy (BNCT) applied to a computerized human phantom. The Monte Carlo method, including particle-tracking techniques, was used for simulation. The distribution of prompt gamma rays emitted by the phantom during irradiation with neutron beams is closely associated with the distribution of the boron in the phantom. Maximum likelihood expectation maximization (MLEM) method was applied to the information obtained from the detected prompt gamma rays to reconstruct the distribution of the tumor including the boron uptake regions (BURs). The reconstructed Compton images of the prompt gamma rays were combined with the cross-sectional images of the human phantom. Quantitative analysis of the intensity curves showed that all combined images matched the predetermined conditions of the simulation. The tumors including the BURs were distinguishable if they were more than 2 cm apart.

Fermi GBM Observations of Terrestrial Gamma-Ray Flashes

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.;

Novel Atomic Absorption Spectrometric and Rapid Spectrophotometric Methods for the Quantitation of Paracetamol in Saliva: Application to Pharmacokinetic Studies

PubMed Central

Issa, M. M.; Nejem, R. M.; El-Abadla, N. S.; Al-Kholy, M.; Saleh, Akila. A.

2008-01-01

A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III) (method I); oxidation of p-aminophenol after the hydrolysis of paracetamol (method II). Iron (II) then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III) in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II) at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 μg/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 μg/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 μg/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%. PMID:20046743

Mirion--a software package for automatic processing of mass spectrometric images.

PubMed

Paschke, C; Leisner, A; Hester, A; Maass, K; Guenther, S; Bouschen, W; Spengler, B

2013-08-01

Mass spectrometric imaging (MSI) techniques are of growing interest for the Life Sciences. In recent years, the development of new instruments employing ion sources that are tailored for spatial scanning allowed the acquisition of large data sets. A subsequent data processing, however, is still a bottleneck in the analytical process, as a manual data interpretation is impossible within a reasonable time frame. The transformation of mass spectrometric data into spatial distribution images of detected compounds turned out to be the most appropriate method to visualize the results of such scans, as humans are able to interpret images faster and easier than plain numbers. Image generation, thus, is a time-consuming and complex yet very efficient task. The free software package "Mirion," presented in this paper, allows the handling and analysis of data sets acquired by mass spectrometry imaging. Mirion can be used for image processing of MSI data obtained from many different sources, as it uses the HUPO-PSI-based standard data format imzML, which is implemented in the proprietary software of most of the mass spectrometer companies. Different graphical representations of the recorded data are available. Furthermore, automatic calculation and overlay of mass spectrometric images promotes direct comparison of different analytes for data evaluation. The program also includes tools for image processing and image analysis.

Assessment and improvements of Geant4 hadronic models in the context of prompt-gamma hadrontherapy monitoring

NASA Astrophysics Data System (ADS)

Dedes, G.; Pinto, M.; Dauvergne, D.; Freud, N.; Krimmer, J.; Létang, J. M.; Ray, C.; Testa, E.

2014-04-01

Monte Carlo simulations are nowadays essential tools for a wide range of research topics in the field of radiotherapy. They also play an important role in the effort to develop a real-time monitoring system for quality assurance in proton and carbon ion therapy, by means of prompt-gamma detection. The internal theoretical nuclear models of Monte Carlo simulation toolkits are of decisive importance for the accurate description of neutral or charged particle emission, produced by nuclear interactions between beam particles and target nuclei. We assess the performance of Geant4 nuclear models in the context of prompt-gamma emission, comparing them with experimental data from proton and carbon ion beams. As has been shown in the past and further indicated in our study, the prompt-gamma yields are consistently overestimated by Geant4 by a factor of about 100% to 200% over an energy range from 80 to 310 MeV/u for the case of 12C, and to a lesser extent for 160 MeV protons. Furthermore, we focus on the quantum molecular dynamics (QMD) modeling of ion-ion collisions, in order to optimize its description of light nuclei, which are abundant in the human body and mainly anticipated in hadrontherapy applications. The optimization has been performed by benchmarking QMD free parameters with well established nuclear properties. In addition, we study the effect of this optimization on charged particle emission. With the usage of the proposed parameter values, discrepancies reduce to less than 70%, with the highest values being attributed to the nucleon-ion induced prompt-gammas. This conclusion, also confirmed by the disagreement we observe in the case of proton beams, indicates the need for further investigation on nuclear models which describe proton and neutron induced nuclear reactions.

The Gamma-Ray Albedo of the Moon

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

Moskalenko, I.V.; /Stanford U., HEPL /KIPAC, Menlo Park; Porter, T.A.

2008-03-25

We use the GEANT4 Monte Carlo framework to calculate the {gamma}-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of {gamma}-rays from the Moon is very steep with an effective cutoff around 3-4 GeV (600 MeV for the inner part of the Moon disk) and exhibits a narrow pion-decay line at 67.5 MeV, perhaps unique in astrophysics. Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalization; this makesmore » it a useful 'standard candle' for {gamma}-ray telescopes. The steep albedo spectrum also provides a unique opportunity for energy calibration of {gamma}-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). Since the albedo flux depends on the incident CR spectrum which changes over the solar cycle, it is possible to monitor the CR spectrum using the albedo {gamma}-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo {gamma}-rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the LAT to monitor the CR spectrum near the Earth beyond the lifetime of the PAMELA.« less

The Gamma-ray Albedo of the Moon

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

Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.

2007-09-28

We use the GEANT4 Monte Carlo framework to calculate the {gamma}-ray albedo of the Moon due to interactions of cosmic ray (CR) nuclei with moon rock. Our calculation of the albedo spectrum agrees with the EGRET data. We show that the spectrum of {gamma}-rays from the Moon is very steep with an effective cutoff around 3-4 GeV (600 MeV for the inner part of the Moon disk) and exhibits a narrow pion-decay line at 67.5 MeV, perhaps unique in astrophysics. Apart from other astrophysical sources, the albedo spectrum of the Moon is well understood, including its absolute normalization; this makesmore » it a useful 'standard candle' for {gamma}-ray telescopes. The steep albedo spectrum also provides a unique opportunity for energy calibration of {gamma}-ray telescopes, such as the forthcoming Gamma Ray Large Area Space Telescope (GLAST). Since the albedo flux depends on the incident CR spectrum which changes over the solar cycle, it is possible to monitor the CR spectrum using the albedo {gamma}-ray flux. Simultaneous measurements of CR proton and helium spectra by the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics (PAMELA), and observations of the albedo {gamma}-rays by the GLAST Large Area Telescope (LAT), can be used to test the model predictions and will enable the LAT to monitor the CR spectrum near the Earth beyond the lifetime of the PAMELA.« less

Machine learning-based patient specific prompt-gamma dose monitoring in proton therapy

NASA Astrophysics Data System (ADS)

Gueth, P.; Dauvergne, D.; Freud, N.; Létang, J. M.; Ray, C.; Testa, E.; Sarrut, D.

2013-07-01

Online dose monitoring in proton therapy is currently being investigated with prompt-gamma (PG) devices. PG emission was shown to be correlated with dose deposition. This relationship is mostly unknown under real conditions. We propose a machine learning approach based on simulations to create optimized treatment-specific classifiers that detect discrepancies between planned and delivered dose. Simulations were performed with the Monte-Carlo platform Gate/Geant4 for a spot-scanning proton therapy treatment and a PG camera prototype currently under investigation. The method first builds a learning set of perturbed situations corresponding to a range of patient translation. This set is then used to train a combined classifier using distal falloff and registered correlation measures. Classifier performances were evaluated using receiver operating characteristic curves and maximum associated specificity and sensitivity. A leave-one-out study showed that it is possible to detect discrepancies of 5 mm with specificity and sensitivity of 85% whereas using only distal falloff decreases the sensitivity down to 77% on the same data set. The proposed method could help to evaluate performance and to optimize the design of PG monitoring devices. It is generic: other learning sets of deviations, other measures and other types of classifiers could be studied to potentially reach better performance. At the moment, the main limitation lies in the computation time needed to perform the simulations.

A gamma-gamma coincidence/anticoincidence spectrometer for low-level cosmogenic (22)Na/(7)Be activity ratio measurement.

PubMed

Zhang, Weihua; Ungar, Kurt; Stukel, Matthew; Mekarski, Pawel

2014-04-01

In this study, a digital gamma-gamma coincidence/anticoincidence spectrometer was developed and examined for low-level cosmogenic (22)Na and (7)Be in air-filter sample monitoring. The spectrometer consists of two bismuth germanate scintillators (BGO) and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The spectrometer design allows a more selective measurement of (22)Na with a significant background reduction by gamma-gamma coincidence events processing. Hence, the system provides a more sensitive way to quantify trace amounts of (22)Na than normal high resolution gamma spectrometry providing a critical limit of 3 mBq within a 20 h count. The use of a list-mode data acquisition technique enabled simultaneous determination of (22)Na and (7)Be activity concentrations using a single measurement by coincidence and anticoincidence mode respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Ordinary Gamma-Ray Burst with Extraordinary Consequences

NASA Image and Video Library

2017-10-18

On Aug. 17, the Gamma-ray Burst Monitor on NASA's Fermi Gamma-ray Space Telescope caught a short burst of gamma rays from the spectacular smashup of two neutron stars, setting off a chain of events that marks the first-ever detection of a cosmic event in gravitational waves and different kinds of light. NASA scientists Colleen Wilson-Hodge and Tyson Littenberg explain what happened and what it means for science and discovery.

INTERFEROMETRIC MONITORING OF GAMMA-RAY BRIGHT AGNs. I. THE RESULTS OF SINGLE-EPOCH MULTIFREQUENCY OBSERVATIONS

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

Lee, Sang-Sung; Wajima, Kiyoaki; Algaba, Juan-Carlos

2016-11-01

We present results of single-epoch very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean VLBI Network (KVN) at the 22, 43, 86, and 129 GHz bands, which are part of a KVN key science program, Interferometric Monitoring of Gamma-Ray Bright AGNs. We selected a total of 34 radio-loud AGNs of which 30 sources are gamma-ray bright AGNs with flux densities of >6 × 10{sup −10} ph cm{sup −2} s{sup −1}. Single-epoch multifrequency VLBI observations of the target sources were conducted during a 24 hr session on 2013 November 19 and 20. All observed sources weremore » detected and imaged at all frequency bands, with or without a frequency phase transfer technique, which enabled the imaging of 12 faint sources at 129 GHz, except for one source. Many of the target sources are resolved on milliarcsecond scales, yielding a core-jet structure, with the VLBI core dominating the synchrotron emission on a milliarcsecond scale. CLEAN flux densities of the target sources are 0.43–28 Jy, 0.32–21 Jy, 0.18–11 Jy, and 0.35–8.0 Jy in the 22, 43, 86, and 129 GHz bands, respectively. Spectra of the target sources become steeper at higher frequency, with spectral index means of −0.40, −0.62, and −1.00 in the 22–43 GHz, 43–86 GHz and 86–129 GHz bands, respectively, implying that the target sources become optically thin at higher frequencies (e.g., 86–129 GHz).« less

Measurement and calculation of fast neutron and gamma spectra in well defined cores in LR-0 reactor.

PubMed

Košťál, Michal; Matěj, Zdeněk; Cvachovec, František; Rypar, Vojtěch; Losa, Evžen; Rejchrt, Jiří; Mravec, Filip; Veškrna, Martin

2017-02-01

A well-defined neutron spectrum is essential for many types of experimental topics and is also important for both calibration and testing of spectrometric and dosimetric detectors. Provided it is well described, such a spectrum can also be employed as a reference neutron field that is suitable for validating selected cross sections. The present paper aims to compare calculations and measurements of such a well-defined spectra in geometrically similar cores of the LR-0 reactor with fuel containing slightly different enrichments (2%, 3.3% and 3.6%). The common feature to all cores is a centrally located dry channel which can be used for the insertion of studied materials. The calculation of neutron and gamma spectra was realized with the MCNP6 code using ENDF/B-VII.0, JEFF-3.1, JENDL-3.3, ROSFOND-2010 and CENDL-3.1 nuclear data libraries. Only minor differences in neutron and gamma spectra were found in the comparison of the presented reactor cores with different fuel enrichments. One exception is the gamma spectrum in the higher energy region (above 8MeV), where more pronounced variations could be observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr].

PubMed

Zhong, L X; Ding, B M; Jiang, D; Liu, D Y; Yu, B; Zhu, B L; Ding, L

2016-05-20

To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry. Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection. Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co. The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

PIMACS (Polarimeter and improved modular anti-coincidence system): an effective instrument concept for x-, gamma-ray monitoring, and polarimetry measurements on the International Space Station

NASA Astrophysics Data System (ADS)

Stuffler, Timo; Graue, Roland; Bird, Antony J.; Dean, Antony; Staubert, Rüdiger

2018-04-01

This paper, "PIMACS (Polarimeter and improved modular anti-coincidence system): an effective instrument concept for x-, gamma-ray monitoring, and polarimetry measurements on the International Space Station," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

Method for radioactivity monitoring

DOEpatents

Umbarger, C. John; Cowder, Leo R.

1976-10-26

The disclosure relates to a method for analyzing uranium and/or thorium contents of liquid effluents preferably utilizing a sample containing counting chamber. Basically, 185.7-keV gamma rays following .sup.235 U alpha decay to .sup.231 Th which indicate .sup.235 U content and a 63-keV gamma ray doublet found in the nucleus of .sup.234 Pa, a granddaughter of .sup.238 U, are monitored and the ratio thereof taken to derive uranium content and isotopic enrichment .sup.235 U/.sup.235 U + .sup.238 U) in the liquid effluent. Thorium content is determined by monitoring the intensity of 238-keV gamma rays from the nucleus of .sup.212 Bi in the decay chain of .sup.232 Th.

Development of an aptamer beacon for detection of interferon-gamma.

PubMed

Tuleuova, Nazgul; Jones, Caroline N; Yan, Jun; Ramanculov, Erlan; Yokobayashi, Yohei; Revzin, Alexander

2010-03-01

Traditional antibody-based affinity sensing strategies employ multiple reagents and washing steps and are unsuitable for real-time detection of analyte binding. Aptamers, on the other hand, may be designed to monitor binding events directly, in real-time, without the need for secondary labels. The goal of the present study was to design an aptamer beacon for fluorescence resonance energy transfer (FRET)-based detection of interferon-gamma (IFN-gamma)--an important inflammatory cytokine. Variants of DNA aptamer modified with biotin moieties and spacers were immobilized on avidin-coated surfaces and characterized by surface plasmon resonance (SPR). The SPR studies showed that immobilization of aptamer via the 3' end resulted in the best binding IFN-gamma (K(d) = 3.44 nM). This optimal aptamer variant was then used to construct a beacon by hybridizing fluorophore-labeled aptamer with an antisense oligonucleotide strand carrying a quencher. SPR studies revealed that IFN-gamma binding with an aptamer beacon occurred within 15 min of analyte introduction--suggesting dynamic replacement of the quencher-complementary strand by IFN-gamma molecules. To further highlight biosensing applications, aptamer beacon molecules were immobilized inside microfluidic channels and challenged with varying concentration of analyte. Fluorescence microscopy revealed low fluorescence in the absence of analyte and high fluorescence after introduction of IFN-gamma. Importantly, unlike traditional antibody-based immunoassays, the signal was observed directly upon binding of analyte without the need for multiple washing steps. The surface immobilized aptamer beacon had a linear range from 5 to 100 nM and a lower limit of detection of 5 nM IFN-gamma. In conclusion, we designed a FRET-based aptamer beacon for monitoring of an inflammatory cytokine-IFN-gamma. In the future, this biosensing strategy will be employed to monitor dynamics of cytokine production by the immune cells.

Gamma thermometer based reactor core liquid level detector

DOEpatents

Burns, Thomas J.

1983-01-01

A system is provided which employs a modified gamma thermometer for determining the liquid coolant level within a nuclear reactor core. The gamma thermometer which normally is employed to monitor local core heat generation rate (reactor power), is modified by thermocouple junctions and leads to obtain an unambiguous indication of the presence or absence of coolant liquid at the gamma thermometer location. A signal processor generates a signal based on the thermometer surface heat transfer coefficient by comparing the signals from the thermocouples at the thermometer location. The generated signal is a direct indication of loss of coolant due to the change in surface heat transfer when coolant liquid drops below the thermometer location. The loss of coolant indication is independent of reactor power at the thermometer location. Further, the same thermometer may still be used for the normal power monitoring function.

Quality assurance for gamma knives

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

Jones, E.D.; Banks, W.W.; Fischer, L.E.

1995-09-01

This report describes and summarizes the results of a quality assurance (QA) study of the Gamma Knife, a nuclear medical device used for the gamma irradiation of intracranial lesions. Focus was on the physical aspects of QA and did not address issues that are essentially medical, such as patient selection or prescription of dose. A risk-based QA assessment approach was used. Sample programs for quality control and assurance are included. The use of the Gamma Knife was found to conform to existing standards and guidelines concerning radiation safety and quality control of external beam therapies (shielding, safety reviews, radiation surveys,more » interlock systems, exposure monitoring, good medical physics practices, etc.) and to be compliant with NRC teletherapy regulations. There are, however, current practices for the Gamma Knife not covered by existing, formalized regulations, standards, or guidelines. These practices have been adopted by Gamma Knife users and continue to be developed with further experience. Some of these have appeared in publications or presentations and are slowly finding their way into recommendations of professional organizations.« less

Mass Spectrometric Characteristics of Prenylated Indole Derivatives from Marine-Derived Penicillium sp. NH-SL

PubMed Central

Ding, Hui; Ding, Wanjing; Ma, Zhongjun

2017-01-01

Two prenylated indole alkaloids were isolated from the ethyl acetate extracts of a marine-derived fungus Penicillium sp. NH-SL and one of them exhibited potent cytotoxic activity against mouse hepa 1c1c7 cells. In order to detect other bioactive analogs, we used liquid chromatogram tandem mass spectrometry (LC-MS/MS) to analyze the mass spectrometric characteristics of the isolated compounds as well as the crude extracts. As a result, three other analogs were detected, and their structures were deduced according to the similar fragmentation patterns. This is the first systematic report on the mass spectrometric characteristics of prenylated indole derivatives. PMID:28327529

Mass Spectrometric Characteristics of Prenylated Indole Derivatives from Marine-Derived Penicillium sp. NH-SL.

PubMed

Ding, Hui; Ding, Wanjing; Ma, Zhongjun

2017-03-22

Two prenylated indole alkaloids were isolated from the ethyl acetate extracts of a marine-derived fungus Penicillium sp. NH-SL and one of them exhibited potent cytotoxic activity against mouse hepa 1c1c7 cells. In order to detect other bioactive analogs, we used liquid chromatogram tandem mass spectrometry (LC-MS/MS) to analyze the mass spectrometric characteristics of the isolated compounds as well as the crude extracts. As a result, three other analogs were detected, and their structures were deduced according to the similar fragmentation patterns. This is the first systematic report on the mass spectrometric characteristics of prenylated indole derivatives.

A high pressure modulated molecular beam mass spectrometric sampling system

NASA Technical Reports Server (NTRS)

Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.; Miller, R. A.

1977-01-01

The current state of understanding of free-jet high pressure sampling is critically reviewed and modifications of certain theoretical and empirical considerations are presented. A high pressure, free-jet expansion, modulated molecular beam, mass spectrometric sampling apparatus was constructed and this apparatus is described in detail. Experimental studies have demonstrated that the apparatus can be used to sample high temperature systems at pressures up to one atmosphere. Condensible high temperature gaseous species have been routinely sampled and the mass spectrometric detector has provided direct identification of sampled species. System sensitivity is better than one tenth of a part per million. Experimental results obtained with argon and nitrogen beams are presented and compared to theoretical predictions. These results and the respective comparison are taken to indicate acceptable performance of the sampling apparatus. Results are also given for two groups of experiments related to hot corrosion studies. The formation of gaseous sodium sulfate in doped methane-oxygen flames was characterized and the oxidative vaporization of metals was studied in an atmospheric pressure flowing gas system to which gaseous salt partial pressures were added.

Solar gamma ray monitor for OSO-H (0.3-10 MeV)

NASA Technical Reports Server (NTRS)

Chupp, E. L.; Gleske, I. U.; Forrest, D. J.

1974-01-01

A gamma ray experiment to be flown aboard the OSO-7 spacecraft is described along with a history of the development of the experiment, a description of the gamma ray detector and its operation, and a short preliminary review of the scientific information obtained during the instruments' lifetime. The gamma ray detector operated an average of 18 hours a day for approximately 15 months. The majority of the data was collected in the solar and antisolar direction, but data at right angles to the spacecraft-sun line was also accumulated. In all, at least two full scans of the celestial sphere were completed.

Gamma motes for detection of radioactive materials in shipping containers

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

Harold McHugh; William Quam; Stephan Weeks

Shipping containers can be effectively monitored for radiological materials using gamma (and neutron) motes in distributed mesh networks. The mote platform is ideal for collecting data for integration into operational management systems required for efficiently and transparently monitoring international trade. Significant reductions in size and power requirements have been achieved for room-temperature cadmium zinc telluride (CZT) gamma detectors. Miniaturization of radio modules and microcontroller units are paving the way for low-power, deeply-embedded, wireless sensor distributed mesh networks.

Search for gamma ray lines from supernovae and supernova remnants

NASA Technical Reports Server (NTRS)

Chupp, E. L.; Forrest, D. J.; Suri, A. N.; Adams, R.; Tsai, C.

1974-01-01

A gamma ray monitor with a NaI crystal shielded with a cup-shaped CsI cover was contained in the rotating wheel compartment of the OSO-7 spacecraft for measuring the gamma ray spectra from 0.3 to 10 MeV in search for gamma ray lines from a possible remnant in the Gum Nebula and the apparent Type I supernovae in NGC5253. A brief analysis of data yielded no positive indications for X-rays, gamma ray lines, or continuum from these sources.

Determination of itopride in human plasma by liquid chromatography coupled to tandem mass spectrometric detection: application to a bioequivalence study.

PubMed

Lee, Heon-Woo; Seo, Ji-Hyung; Choi, Seung-Ki; Lee, Kyung-Tae

2007-01-30

A simple method using a one-step liquid-liquid extraction (LLE) with butyl acetate followed by high-performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometric (ESI-MS/MS) detection was developed for the determination of itopride in human plasma, using sulpiride as an internal standard (IS). Acquisition was performed in multiple reaction monitoring (MRM) mode, by monitoring the transitions: m/z 359.5>166.1 for itopride and m/z 342.3>111.6 for IS, respectively. Analytes were chromatographed on an YMC C18 reverse-phase chromatographic column by isocratic elution with 1 mM ammonium acetate buffer-methanol (20: 80, v/v; pH 4.0 adjusted with acetic acid). Results were linear (r2=0.9999) over the studied range (0.5-1000 ng mL(-1)) with a total analysis time per run of 2 min for LC-MS/MS. The developed method was validated and successfully applied to bioequivalence studies of itopride hydrochloride in healthy male volunteers.

DEVELOPMENT OF AN ELECTROSPRAY MASS SPECTROMETRIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS

EPA Science Inventory

An electrospray mass spectrometric method has been developed for application to agricultural and horticultural fertilizers to determine perchlorate. After fertilizers are leached or dissolved in water, the method relies on the formation of stable ion pair complex of the perchlor...

Gamma-radiation monitoring in post-tectonic biotitic granites at Celorico da Beira

NASA Astrophysics Data System (ADS)

Domingos, Filipa; Barbosa, Susana; Pereira, Alcides; Neves, Luís

2017-04-01

Despite its obvious relevance, the effect of meteorological variables such as temperature, pressure, wind, rainfall and particularly humidity on the temporal variability of natural radiation is complex and still not fully understood. Moreover, the nature of their influence with increasing depth is also poorly understood. Thereby, two boreholes were set 3 m apart in the region of Celorico da Beira within post-tectonic biotitic granites of the Beiras Batolith. Continuous measurements were obtained with identical gamma-ray scintillometers deployed at depths of 1 and 6 m during a 6 month period in the years of 2014 and 2015. Temperature, relative humidity, pressure, rainfall, wind speed and direction were measured at the site, as well as temperature and relative humidity inside the boreholes, with the aim of assessing the influence of meteorological parameters on the temporal variability of gamma radiation at two distinct depths. Both time series display a complex temporal structure including multiyear, seasonal and daily variability. At 1 m depth, a daily periodicity on the gamma ray counts time series was noticed with daily maxima occurring most frequently from 8 to 12 p.m. and daily minima between 8 and 12 a.m.. At 6 m depth, maximum and minimum daily means occurred with approximately a 10 h lag from the above. Gamma radiation data exhibited fairly strong correlations with temperature and relative humidity, however, varying with depth. Gamma radiation counts increased with increasing temperature and decreasing relative humidity at 1 m depth, while at a 6 m depth the opposite was recorded, with counts increasing with relative humidity and decreasing with temperature. Wind speed was shown to be inversely related with counts at 6 m depth, while positively correlated at 1 m depth. Pressure and rainfall had minor effects on both short-term and long-term gamma radiation counts.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2015-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Fermi: The Gamma-Ray Large Area Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10 seconds of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

GLAST and Ground-Based Gamma-Ray Astronomy

NASA Technical Reports Server (NTRS)

McEnery, Julie

2008-01-01

The launch of the Gamma-ray Large Area Space Telescope together with the advent of a new generation of ground-based gamma-ray detectors such as VERITAS, HESS, MAGIC and CANGAROO, will usher in a new era of high-energy gamma-ray astrophysics. GLAST and the ground based gamma-ray observatories will provide highly complementary capabilities for spectral, temporal and spatial studies of high energy gamma-ray sources. Joint observations will cover a huge energy range, from 20 MeV to over 20 TeV. The LAT will survey the entire sky every three hours, allowing it both to perform uniform, long-term monitoring of variable sources and to detect flaring sources promptly. Both functions complement the high-sensitivity pointed observations provided by ground-based detectors. Finally, the large field of view of GLAST will allow a study of gamma-ray emission on large angular scales and identify interesting regions of the sky for deeper studies at higher energies. In this poster, we will discuss the science returns that might result from joint GLAST/ground-based gamma-ray observations and illustrate them with detailed source simulations.

The Underwater Spectrometric System Based on CZT Detector for Survey of the Bottom of MR Reactor Pool - 13461

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

Potapov, Victor; Safronov, Alexey; Ivanov, Oleg

2013-07-01

The underwater spectrometer system for detection of irradiated nuclear fuel on the pool bottom of the reactor was elaborated. During the development process metrological studies of CdZnTe (CZT) detectors were conducted. These detectors are designed for spectrometric measurements in high radiation fields. A mathematical model based on the Monte Carlo method was created to evaluate the capability of such a system. A few experimental models were realized and the characteristics of the spectrometric system are represented. (authors)

Derivatization of beta-dicarbonyl compound with 2,4-dinitrophenylhydrazine to enhance mass spectrometric detection: application in quantitative analysis of houttuynin in human plasma.

PubMed

Duan, Xiaotao; Zhong, Dafang; Chen, Xiaoyan

2008-06-01

Houttuynin (decanoyl acetaldehyde), a beta-dicarbonyl compound, is the major antibacterial constituent in the volatile oil of Houttuynina cordata Thunb. In the present work, detection of houttuynin in human plasma based on the chemical derivatization with 2,4-dinitrophenylhydrazine (DNPH) coupled with liquid chromatography/tandem mass spectrometry was described. The primary reaction products between the beta-dicarbonyl compound and DNPH in aqueous phase were identified as heterocyclic structures, of which the mass spectrometric ionization and fragmentation behavior were characterized with the aid of high-resolution multistage mass spectral analysis. For quantification, houttuynin and internal standard (IS, benzophenone) in plasma were firstly converted to their DNPH derivatives without sample purification, then extracted from human plasma with n-hexane and detected by liquid chromatography tandem mass spectrometry performed in selected reaction monitoring (SRM) mode. This method allowed for a lower limit of quantification (LLOQ) of 1.0 ng/ml using 100-microl plasma. The validation results showed high accuracy (%bias < 2.1) and precision (%CV < 7.2) at broad linear dynamic range (1.0-5000 ng/ml). The simple and quantitative derivatization coupled with tandem mass spectrometric analysis facilitates a sensitive and robust method for the determination of plasma houttuynin in pharmacokinetic studies.

Mass spectrometer for real-time metabolism monitoring during anesthesia

NASA Astrophysics Data System (ADS)

Elizarov, A. Yu.; Levshankov, A. I.

2012-06-01

Mass-spectrometric monitoring of metabolism (CO2/O2) in the inspiration-expiration regime is used to estimate the anesthetic protection of the patient against surgical stimulation during combined anesthesia. A correlation between the anesthetic protection of the patient and the metabolic rate is demonstrated, and the periodic variation of the metabolic rate with time is found. The sevoflurane metabolism products and intravenous analgesic fentanyl are found in the blowing air of the patient during anesthesia.

Optical fiber sensor for low dose gamma irradiation monitoring

NASA Astrophysics Data System (ADS)

de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

2016-05-01

An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

Gamma-Ray Astronomy Across 6 Decades of Energy: Synergy between Fermi, IACTs, and HAWC

NASA Technical Reports Server (NTRS)

Hui, C. Michelle

2017-01-01

Gamma Ray Observatories, Gamma-Ray Astrophysics, GeV TeV Sky Survey, Galaxy, Galactic Plane, Source Distribution, The gamma-ray sky is currently well-monitored with good survey coverage. Many instruments from different waveband/messenger (X rays, gamma rays, neutrinos, gravitational waves) available for simultaneous observations. Both wide-field and pointing instruments in development and coming online in the next decade LIGO

Z{gamma}{gamma}{gamma} {yields} 0 Processes in SANC

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

Bardin, D. Yu., E-mail: bardin@nu.jinr.ru; Kalinovskaya, L. V., E-mail: kalinov@nu.jinr.ru; Uglov, E. D., E-mail: corner@nu.jinr.ru

2013-11-15

We describe the analytic and numerical evaluation of the {gamma}{gamma} {yields} {gamma}Z process cross section and the Z {yields} {gamma}{gamma}{gamma} decay rate within the SANC system multi-channel approach at the one-loop accuracy level with all masses taken into account. The corresponding package for numeric calculations is presented. For checking of the results' correctness we make a comparison with the other independent calculations.

Sneaky Gamma-Rays: Using Gravitational Lensing to Avoid Gamma-Gamma-Absorption

NASA Astrophysics Data System (ADS)

Boettcher, Markus; Barnacka, Anna

2014-08-01

It has recently been suggested that gravitational lensing studies of gamma-ray blazars might be a promising avenue to probe the location of the gamma-ray emitting region in blazars. Motivated by these prospects, we have investigated potential gamma-gamma absorption signatures of intervening lenses in the very-high-energy gamma-ray emission from lensedblazars. We considered intervening galaxies and individual stars within these galaxies. We find that the collective radiation field of galaxies acting as sources of macrolensing are not expected to lead to significant gamma-gamma absorption. Individual stars within intervening galaxies could, in principle, cause a significant opacity to gamma-gamma absorption for VHE gamma-rays if the impact parameter (the distance of closest approach of the gamma-ray to the center of the star) is small enough. However, we find that the curvature of the photon path due to gravitational lensing will cause gamma-ray photons to maintain a sufficiently large distance from such stars to avoid significant gamma-gamma absorption. This re-inforces the prospect of gravitational-lensing studies of gamma-ray blazars without interference due to gamma-gamma absorption due to the lensing objects.

Liquid Chromatography Electrospray Ionization Mass Spectrometric (LC-ESI-MS) and Desorption Electrospray Ionization Mass Spectrometric (DESI-MS) Identification of Chemical Warfare Agents in Consumer Products

DTIC Science & Technology

2007-06-01

T ACanadaY Approved for PublicR Distribution Uln& Liquid Chromatography Electrospray Ionization Mass Spectrometric ( LC -ESI- MS) and Desorption...consumer products with chemical warfare agents or other toxic chemicals. Liquid chromatography electrospray ionization mass spectrometry ( LC -ESI-MS) and...house LC -ESI-MS and LC -ESI-MS/MS methods were evaluated for the determination of chemical warfare agents in spiked bottled water samples. The

Time correlation between the radio and gamma-ray activity in blazars and the production site of the gamma-ray emission

DOE PAGES

Max-Moerbeck, W.; Hovatta, T.; Richards, J. L.; ...

2014-09-22

In order to determine the location of the gamma-ray emission site in blazars, we investigate the time-domain relationship between their radio and gamma-ray emission. Light-curves for the brightest detected blazars from the first 3 years of the mission of the Fermi Gamma-ray Space Telescope are cross-correlated with 4 years of 15GHz observations from the OVRO 40-m monitoring program. The large sample and long light-curve duration enable us to carry out a statistically robust analysis of the significance of the cross-correlations, which is investigated using Monte Carlo simulations including the uneven sampling and noise properties of the light-curves. Modeling the light-curvesmore » as red noise processes with power-law power spectral densities, we find that only one of 41 sources with high quality data in both bands shows correlations with significance larger than 3σ (AO0235+164), with only two more larger than even 2.25σ (PKS 1502+106 and B2 2308+34). Additionally, we find correlated variability in Mrk 421 when including a strong flare that occurred in July-September 2012. These results demonstrate very clearly the difficulty of measuring statistically robust multiwavelength correlations and the care needed when comparing light-curves even when many years of data are used. This should be a caution. In all four sources the radio variations lag the gamma-ray variations, suggesting that the gamma-ray emission originates upstream of the radio emission. Continuous simultaneous monitoring over a longer time period is required to obtain high significance levels in cross-correlations between gamma-ray and radio variability in most blazars.« less

[Rapid analysis of the radionuclides plutonium and americium-241 in soils].

PubMed

Egorov, A V; Klochkova, N V

2009-01-01

The paper shows it possible to perform a rapid analysis of the isotopes of plutomium and americium-241. The basis of the developed rapid analysis is X-spectrometric determination of the amount of plutonium isotopes and gamma-spectrometric determination of the radionuclide 241AM.

Spectrometric measurements of radioisotope activity in the thyroid

NASA Astrophysics Data System (ADS)

Osko, Jakub; Golnik, Natalia

2008-01-01

The results of measurements of iodine 131I and technetium 99mTc uptake in human thyroid, performed with scintillation or semiconductor detectors can exhibit a considerable uncertainty due to the differences in the thyroid position in the patient's neck. Basic physical laws of radiation attenuation and scattering show that the final shape of the registered spectrum should depends on the thyroid position in the neck and on the thickness of the tissue between the thyroid and the detector. The use of the spectrometric measuring method is proposed in this work for determination of the iodine gathering effective depth. The performed studies showed that the measurements results can be used for improving the accuracy of the iodine 131I activity in thyroid measurements and for selection of the group of patients for whom the anatomical position of the thyroid or the spatial distribution of the iodine gathering is much different than the standard one, assumed during the calibration of the counters. The results of the measurements were in agreement with Monte-Carlo calculations of the detector response. The method was used in routine monitoring of occupationally exposed persons, using the thyroid counter. A group of six persons with measurable internal contamination was selected and the measurements were performed on consecutive days, so the results could be registered at decreasing iodine activities in the thyroid. Larger series of measurements were performed at Brodno Regional Hospital in Warsaw, for a group of 95 patients after diagnostic administration of iodine 131I.

Space-Borne Observations of Intense Gamma-Ray Flashes (TGFs) Above Thunderstorms

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2011-01-01

Intense millisecond flashes of MeV photons have been observed with space-borne detectors. These terrestrial gamma-ray flashes (TGFs) were discovered with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma- Ray Observatory (CGRO) in the early 1990s. They are now being observed with several other instruments, including the Gamma-ray Burst Monitor (GBM) detectors on the Fermi Gamma-ray Space Telescope. Although Fermi-GBM was designed and optimized for the observation of cosmic gamma-ray bursts (GRBs), it has unprecedented capabilities for these TGF observations. On several occasions, intense beams of high-energy electrons and positrons have been observed at the geomagnetic conjugate points of TGFs.

Development of an all-in-one gamma camera/CCD system for safeguard verification

NASA Astrophysics Data System (ADS)

Kim, Hyun-Il; An, Su Jung; Chung, Yong Hyun; Kwak, Sung-Woo

2014-12-01

For the purpose of monitoring and verifying efforts at safeguarding radioactive materials in various fields, a new all-in-one gamma camera/charged coupled device (CCD) system was developed. This combined system consists of a gamma camera, which gathers energy and position information on gamma-ray sources, and a CCD camera, which identifies the specific location in a monitored area. Therefore, 2-D image information and quantitative information regarding gamma-ray sources can be obtained using fused images. A gamma camera consists of a diverging collimator, a 22 × 22 array CsI(Na) pixelated scintillation crystal with a pixel size of 2 × 2 × 6 mm3 and Hamamatsu H8500 position-sensitive photomultiplier tube (PSPMT). The Basler scA640-70gc CCD camera, which delivers 70 frames per second at video graphics array (VGA) resolution, was employed. Performance testing was performed using a Co-57 point source 30 cm from the detector. The measured spatial resolution and sensitivity were 4.77 mm full width at half maximum (FWHM) and 7.78 cps/MBq, respectively. The energy resolution was 18% at 122 keV. These results demonstrate that the combined system has considerable potential for radiation monitoring.

1973 environmental monitoring report

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

Hull, A.P.; Ash, J.A.

1974-03-01

>Results from radiation monitoring during 1973 in the environment of the Brookhaven National Laboratory are presented. Data are included on: the gross alpha and BETA activity and content of tritium and gamma-emitting radionuclides in surface air; gross BETA activity and gamma and tritium content in atmospheric precipitation; activities and concentration of gamma emitters in liquid effiuents and ground water; gross BETA , tritium and /sup 90/Sr in effluents; gross BETA and tritl um in surface waters; /sup 90/Sr and gamma- emitting radionuclides in river ecosystem; gross alpha , gross BETA , tritium, / sup 90/Sr, and /sup 137/Cs in groundmore » and well water; /sup 137/Cs, K, /sup 131/I, and /sup 90/Sr content in area milk; and gamma-emitting radionuclides in soils and grasses. (LCL)« less

Characterizations of the radioactive waste by the remotely-controlled collimated spectrometric system

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

Stepanov, Vyacheslav E.; Potapov, Victor N.; Smirnov, Sergey V.

Decontamination and decommissioning of the research reactors MR (Testing Reactor) and RFT (Reactor of Physics and Technology) has recently been initiated in the National Research Center (NRC) 'Kurchatov institute', Moscow. In the building, neighboring to the reactor, the storage of HLRW is located. The storage is made of monolithic concrete in which steel cells depth 4 m are located. In cells of storage the HLRW packed into cases are placed. These the radioactive waste are also subject to export on long storage in the specialized organization. For characterization of the radioactive waste in cases the remote-controlled collimated spectrometer system wasmore » used. The system consists of a spectrometric collimated gamma-ray detector, a color video camera and a control unit, mounted on a rotator, which are mounted on a tripod with the host computer. For determination of specific activity of radionuclides in cases, it is developed programs of calculation of coefficients of proportionality of specific activity to the corresponding speeds of the account in peaks of full absorption at single specific activity of radionuclides in cases. For determination of these coefficients the mathematical model of spectrometer system based on the Monte-Carlo method was used. Dependences of calibration coefficients for various radionuclides from distance between the detector and a case at various values of the radioactive waste density in cases are given. Measurements of specific activity in cases are taken and are discussed. By results of measurements decisions on the appeal of the radioactive waste being in cases are made. (authors)« less

The Multi-Isotope Process (MIP) Monitor Project: FY13 Final Report

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

Meier, David E.; Coble, Jamie B.; Jordan, David V.

The Multi-Isotope Process (MIP) Monitor provides an efficient approach to monitoring the process conditions in reprocessing facilities in support of the goal of “… (minimization of) the risks of nuclear proliferation and terrorism.” The MIP Monitor measures the distribution of the radioactive isotopes in product and waste streams of a nuclear reprocessing facility. These isotopes are monitored online by gamma spectrometry and compared, in near-real-time, to spectral patterns representing “normal” process conditions using multivariate analysis and pattern recognition algorithms. The combination of multivariate analysis and gamma spectroscopy allows us to detect small changes in the gamma spectrum, which may indicatemore » changes in process conditions. By targeting multiple gamma-emitting indicator isotopes, the MIP Monitor approach is compatible with the use of small, portable, relatively high-resolution gamma detectors that may be easily deployed throughout an existing facility. The automated multivariate analysis can provide a level of data obscurity, giving a built-in information barrier to protect sensitive or proprietary operational data. Proof-of-concept simulations and experiments have been performed in previous years to demonstrate the validity of this tool in a laboratory setting for systems representing aqueous reprocessing facilities. However, pyroprocessing is emerging as an alternative to aqueous reprocessing techniques.« less

Tritium monitor with improved gamma-ray discrimination

DOEpatents

Cox, Samson A.; Bennett, Edgar F.; Yule, Thomas J.

1985-01-01

Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

Sensitivity analysis of high resolution gamma-ray detection for safeguards monitoring at natural uranium conversion facilities

DOE PAGES

Dewji, Shaheen A.; Croft, Stephen; Hertel, Nolan E.

2016-12-16

Under the policies proposed by recent International Atomic Energy Agency (IAEA) circulars and policy papers, implementation of safeguards exists when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed in previous work to develop and validate gamma-ray nondestructive assay monitoring systemsmore » in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UO 2(NO 3) 2) solution exiting solvent extraction was identified as a key measurement point (KMP). Passive nondestructive assay techniques using high resolution gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely manner. Building upon the aforementioned previous validation work on detector sensitivity to varying concentrations of uranyl nitrate via a series of dilution measurements, this work investigates detector response parameter sensitivities to gamma-ray signatures of uranyl nitrate. The full energy peak efficiency of a detection system is dependent upon the sample, geometry, absorption, and intrinsic efficiency parameters. Perturbation of these parameters translates into corresponding variations of the 185.7 keV peak area of the 235U in uranyl nitrate. Such perturbations in the assayed signature impact the quality or versatility of the safeguards conclusions drawn. Given the potentially high throughput of uranyl nitrate in NUCPs, the ability to assay 1 SQ of material requires uncertainty «1

Sensitivity analysis of high resolution gamma-ray detection for safeguards monitoring at natural uranium conversion facilities

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

Dewji, Shaheen A.; Croft, Stephen; Hertel, Nolan E.

Under the policies proposed by recent International Atomic Energy Agency (IAEA) circulars and policy papers, implementation of safeguards exists when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed in previous work to develop and validate gamma-ray nondestructive assay monitoring systemsmore » in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UO 2(NO 3) 2) solution exiting solvent extraction was identified as a key measurement point (KMP). Passive nondestructive assay techniques using high resolution gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely manner. Building upon the aforementioned previous validation work on detector sensitivity to varying concentrations of uranyl nitrate via a series of dilution measurements, this work investigates detector response parameter sensitivities to gamma-ray signatures of uranyl nitrate. The full energy peak efficiency of a detection system is dependent upon the sample, geometry, absorption, and intrinsic efficiency parameters. Perturbation of these parameters translates into corresponding variations of the 185.7 keV peak area of the 235U in uranyl nitrate. Such perturbations in the assayed signature impact the quality or versatility of the safeguards conclusions drawn. Given the potentially high throughput of uranyl nitrate in NUCPs, the ability to assay 1 SQ of material requires uncertainty «1

Sensitivity analysis of high resolution gamma-ray detection for safeguards monitoring at natural uranium conversion facilities

NASA Astrophysics Data System (ADS)

Dewji, S. A.; Croft, S.; Hertel, N. E.

2017-03-01

Under the policies proposed by recent International Atomic Energy Agency (IAEA) circulars and policy papers, implementation of safeguards exists when any purified aqueous uranium solution or uranium oxides suitable for isotopic enrichment or fuel fabrication exists. Under IAEA Policy Paper 18, the starting point for nuclear material under safeguards was reinterpreted, suggesting that purified uranium compounds should be subject to safeguards procedures no later than the first point in the conversion process. In response to this technical need, a combination of simulation models and experimental measurements were employed in previous work to develop and validate gamma-ray nondestructive assay monitoring systems in a natural uranium conversion plant (NUCP). In particular, uranyl nitrate (UO2(NO3)2) solution exiting solvent extraction was identified as a key measurement point (KMP). Passive nondestructive assay techniques using high resolution gamma-ray spectroscopy were evaluated to determine their viability as a technical means for drawing safeguards conclusions at NUCPs, and if the IAEA detection requirements of 1 significant quantity (SQ) can be met in a timely manner. Building upon the aforementioned previous validation work on detector sensitivity to varying concentrations of uranyl nitrate via a series of dilution measurements, this work investigates detector response parameter sensitivities to gamma-ray signatures of uranyl nitrate. The full energy peak efficiency of a detection system is dependent upon the sample, geometry, absorption, and intrinsic efficiency parameters. Perturbation of these parameters translates into corresponding variations of the 185.7 keV peak area of the 235U in uranyl nitrate. Such perturbations in the assayed signature impact the quality or versatility of the safeguards conclusions drawn. Given the potentially high throughput of uranyl nitrate in NUCPs, the ability to assay 1 SQ of material requires uncertainty «1%. Accounting for

Gas chromatographic/mass spectrometric determination of carbon isotope composition in unpurified samples: methamphetamine example.

PubMed

Low, I A; Liu, R H; Legendre, M G; Piotrowski, E G; Furner, R L

1986-10-01

A gas chromatograph/quadrupole mass spectrometer system, operated in electron impact/selected ion monitoring mode, is used to determine the intensity ratio of the m/z 59 and the m/z 58 ions of the [C3H8N]+ fragment derived from methamphetamine samples synthesized with varying amounts of 13C-labeled methylamine. Crude products are introduced into the gas chromatograph without prior cleanup. The ratios measured were in excellent agreement with those calculated. A change in 0.25% use of 13C-methylamine is sufficient for product differentiation. The feasibility of using isotope labeling and subsequent mass spectrometric isotope ratio measurement as the basis of a compound tracing mechanism is discussed. Specifically, if methamphetamine samples manufactured from legal sources are asked to incorporate distinct 13C compositions, their sources can be traced when samples are diverted into illegal channels. Samples derived from illicit preparations can also be traced if the manufacturers of a precursor (methylamine in this case) incorporate distinct 13C compositions in their products.

Fermi: The Gamma-Ray Large Area Space Telescope

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

The Z {yields} cc-bar {yields} {gamma}{gamma}*, Z {yields} bb-bar {yields} {gamma}{gamma}* triangle diagrams and the Z {yields} {gamma}{psi}, Z {yields} {gamma}Y decays

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

Achasov, N. N., E-mail: achasov@math.nsc.ru

2011-03-15

The approach to the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decay study is presented in detail, based on the sum rules for the Z {yields} cc-bar {yields} {gamma}{gamma}* and Z {yields} bb-bar {yields} {gamma}{gamma}* amplitudes and their derivatives. The branching ratios of the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are calculated for different hypotheses on saturation of the sum rules. The lower bounds of {Sigma}{sub {psi}} BR(Z {yields} {gamma}{psi}) = 1.95 Multiplication-Sign 10{sup -7} and {Sigma}{sub {upsilon}} BR(Z {yields} {gamma}Y) = 7.23 Multiplication-Sign 10{sup -7} are found. Deviations from the lower bounds are discussed, including the possibilitymore » of BR(Z {yields} {gamma}J/{psi}(1S)) {approx} BR(Z {yields} {gamma}Y(1S)) {approx} 10{sup -6}, that could be probably measured in LHC. The angular distributions in the Z {yields} {gamma}{psi} and Z {yields} {gamma}Y decays are also calculated.« less

Considerations regarding the validation of chromatographic mass spectrometric methods for the quantification of endogenous substances in forensics.

PubMed

Hess, Cornelius; Sydow, Konrad; Kueting, Theresa; Kraemer, Michael; Maas, Alexandra

2018-02-01

The requirement for correct evaluation of forensic toxicological results in daily routine work and scientific studies is reliable analytical data based on validated methods. Validation of a method gives the analyst tools to estimate the efficacy and reliability of the analytical method. Without validation, data might be contested in court and lead to unjustified legal consequences for a defendant. Therefore, new analytical methods to be used in forensic toxicology require careful method development and validation of the final method. Until now, there are no publications on the validation of chromatographic mass spectrometric methods for the detection of endogenous substances although endogenous analytes can be important in Forensic Toxicology (alcohol consumption marker, congener alcohols, gamma hydroxy butyric acid, human insulin and C-peptide, creatinine, postmortal clinical parameters). For these analytes, conventional validation instructions cannot be followed completely. In this paper, important practical considerations in analytical method validation for endogenous substances will be discussed which may be used as guidance for scientists wishing to develop and validate analytical methods for analytes produced naturally in the human body. Especially the validation parameters calibration model, analytical limits, accuracy (bias and precision) and matrix effects and recovery have to be approached differently. Highest attention should be paid to selectivity experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: A mass spectrometric and isotope labeling study

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

Svensson, Jan, E-mail: jan.svensson@ki.se; Karolinska Institutet, Department of Clinical Sciences, Danderyd Hospital, SE-182 88 Stockholm; Bergman, Ann-Charlotte

Highlights: Black-Right-Pointing-Pointer Fibrinogen was incubated in vitro with glucose or aspirin. Black-Right-Pointing-Pointer Acetylations and glycations were found at twelve lysine sites by mass spectrometry. Black-Right-Pointing-Pointer The labeling by aspirin and glucose occurred dose-dependently. Black-Right-Pointing-Pointer No competition between glucose and aspirin for binding to fibrinogen was found. -- Abstract: Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called 'aspirin resistance'. We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirinmore » in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to 'aspirin resistance' in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the {alpha}-chain: {alpha}K191, {alpha}K208, {alpha}K224, {alpha}K429, {alpha}K457, {alpha}K539, {alpha}K562, in the {beta}-chain: {beta}K233, and in the {gamma}-chain: {gamma}K170 and {gamma}K273. Glycations were found at {beta}K133 and {gamma}K75, alternatively {gamma}K85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [{sup 14}C-acetyl]salicylic acid and [{sup 14}C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 {mu}M aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen

Apparatus and method for detecting gamma radiation

DOEpatents

Sigg, R.A.

1994-12-13

A high efficiency radiation detector is disclosed for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data. 4 figures.

Apparatus and method for detecting gamma radiation

DOEpatents

Sigg, Raymond A.

1994-01-01

A high efficiency radiation detector for measuring X-ray and gamma radiation from small-volume, low-activity liquid samples with an overall uncertainty better than 0.7% (one sigma SD). The radiation detector includes a hyperpure germanium well detector, a collimator, and a reference source. The well detector monitors gamma radiation emitted by the reference source and a radioactive isotope or isotopes in a sample source. The radiation from the reference source is collimated to avoid attenuation of reference source gamma radiation by the sample. Signals from the well detector are processed and stored, and the stored data is analyzed to determine the radioactive isotope(s) content of the sample. Minor self-attenuation corrections are calculated from chemical composition data.

Tritium monitor with improved gamma-ray discrimination

DOEpatents

Cox, S.A.; Bennett, E.F.; Yule, T.J.

1982-10-21

Apparatus and method are presented for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.

Differentiating organic from conventional peppermints using chromatographic and flow-injection mass spectrometric (FIMS) fingerprints

USDA-ARS?s Scientific Manuscript database

High performance liquid chromatography (HPLC) and flow-injection mass spectrometric (FIMS) fingerprinting techniques were tested for their potential in differentiating organic and conventional peppermint samples. Ten organic and ten conventional peppermint samples were examined using HPLC-UV and FI...

Fully automated spectrometric protocols for determination of antioxidant activity: advantages and disadvantages.

PubMed

Sochor, Jiri; Ryvolova, Marketa; Krystofova, Olga; Salas, Petr; Hubalek, Jaromir; Adam, Vojtech; Trnkova, Libuse; Havel, Ladislav; Beklova, Miroslava; Zehnalek, Josef; Provaznik, Ivo; Kizek, Rene

2010-11-29

The aim of this study was to describe behaviour, kinetics, time courses and limitations of the six different fully automated spectrometric methods--DPPH, TEAC, FRAP, DMPD, Free Radicals and Blue CrO5. Absorption curves were measured and absorbance maxima were found. All methods were calibrated using the standard compounds Trolox® and/or gallic acid. Calibration curves were determined (relative standard deviation was within the range from 1.5 to 2.5%). The obtained characteristics were compared and discussed. Moreover, the data obtained were applied to optimize and to automate all mentioned protocols. Automatic analyzer allowed us to analyse simultaneously larger set of samples, to decrease the measurement time, to eliminate the errors and to provide data of higher quality in comparison to manual analysis. The total time of analysis for one sample was decreased to 10 min for all six methods. In contrary, the total time of manual spectrometric determination was approximately 120 min. The obtained data provided good correlations between studied methods (R=0.97-0.99).

Mass spectrometric detection of siRNA in plasma samples for doping control purposes.

PubMed

Kohler, Maxie; Thomas, Andreas; Walpurgis, Katja; Schänzer, Wilhelm; Thevis, Mario

2010-10-01

Small interfering ribonucleic acid (siRNA) molecules can effect the expression of any gene by inducing the degradation of mRNA. Therefore, these molecules can be of interest for illicit performance enhancement in sports by affecting different metabolic pathways. An example of an efficient performance-enhancing gene knockdown is the myostatin gene that regulates muscle growth. This study was carried out to provide a tool for the mass spectrometric detection of modified and unmodified siRNA from plasma samples. The oligonucleotides are purified by centrifugal filtration and the use of an miRNA purification kit, followed by flow-injection analysis using an Exactive mass spectrometer to yield the accurate masses of the sense and antisense strands. Although chromatography and sensitive mass spectrometric analysis of oligonucleotides are still challenging, a method was developed and validated that has adequate sensitivity (limit of detection 0.25-1 nmol mL(-1)) and performance (precision 11-21%, recovery 23-67%) for typical antisense oligonucleotides currently used in clinical studies.

Fermi GBM Observations of Terrestrial Gamma Flashes

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.;

The role of interferon gamma release assays in the monitoring of response to anti-tuberculosis treatment in children.

PubMed

Shaik, Junaid; Pillay, Manormoney; Jeena, Prakash

2014-09-01

Successful control of childhood TB requires early diagnosis, effective chemotherapy and a method of evaluating the response to therapy. Identification of suitable biomarkers that predict the response to anti-TB therapy may allow the duration of treatment to be shortened. The majority of biomarker studies in paediatric TB have focused on the role of T cell-based interferon-gamma (IFN-γ) release assays (IGRAs) in the diagnosis of either latent or active disease. Little has been published on the role of IGRAs in the monitoring response to therapy in children. We reviewed the available literature to ascertain the value of IGRAs in the monitoring of response to anti-TB therapy in children. We explored the results of the few studies that have investigated the role of IGRAs as markers of response to anti-TB treatment in children. We conclude that the role of IGRAs as surrogate markers appears promising. Robust clinical trials are, however, needed to entrench the value of IGRAs as surrogate biomarkers of response to anti-TB therapy in children. Copyright © 2013 Elsevier Ltd. All rights reserved.

An improved time of flight gamma-ray telescope to monitor diffuse gamma-ray in the energy range 5 MeV - 50 MeV

NASA Technical Reports Server (NTRS)

Dacostafereiraneri, A.; Bui-Van, A.; Lavigne, J. M.; Sabaud, C.; Vedrenne, G.; Agrinier, B.; Gouiffes, C.

1985-01-01

A time of flight measuring device is the basic triggering system of most of medium and high energy gamma-ray telescopes. A simple gamma-ray telescope has been built in order to check in flight conditions the functioning of an advanced time of flight system. The technical ratings of the system are described. This telescope has been flown twice with stratospheric balloons, its axis being oriented at various Zenital directions. Flight results are presented for diffuse gamma-rays, atmospheric secondaries, and various causes of noise in the 5 MeV-50 MeV energy range.

First Year Results from the Fermi Gamma-Ray Space Telescope

NASA Technical Reports Server (NTRS)

Hays, Elizabeth

2009-01-01

After one year of survey observations and more than 70 billion triggers, Fermi is revealing an unprecedented view of the high energy gamma-ray sky. The observatory .carries two instruments, the Gamma-ray Burst Monitor (GB, 8 keV - 40 MeV) and the Large Area Telescope (LAT, 20 MeV greater than or equal to 300 GeV), which in combination cover over 7 orders of magnitude in energy for transient phenomena. The LAT provides substantially more sensitivity than previous instruments in this waveband and has opened up the energy window from 10-100 GeV. The first year has produced many important results, from detections of extremely energetic and distant gamma-ray bursts, to monitoring daily variations in emission caused by massive black holes at the cores of galaxies, to identifying a new population of gamma-ray bright pulsars, to measuring the spectrum of diffuse emission from our own. Galaxy and the spectrum of the local cosmic electrons. I'll review highlights from the first year and discuss how the data are answering questions from the past and raising new ones for the future.

Radioactivity Risk Assessment of Radon and Gamma Dose at One Uranium Tailings Pond in China

NASA Astrophysics Data System (ADS)

Lou, Yalong; Liu, Yong; Peng, Guowen; Zhao, Guodong; Zhang, Yan; Yang, Zhu

2018-01-01

A year-long monitoring of gamma radiation effective dose rate and radon concentration had been done in the reservoir area of one uranium tailings pond in Hunan province (The monitoring area included indoor and outdoor area of residential buildings and workshops, tailings dam slope). Afterwards, the annual effective radiation dose of the people in that radiation environment had been calculated based on the results of monitoring, as well as a radiation risk assessment. According to the assessment, gamma radiation effective dose rate and radon concentration in the monitoring area were low, and the annual effective radiation dose was far below the international standard (30mSv), which showed that the radiation would not put the people’s health at risk. However, the annual effective radiation dose of gamma was far above that of radon in the area of uranium tailings pond; therefore, it’s advisable to take quarantine measures in in the area of uranium tailings pond to keep the surrounding residents away from unnecessary ionizing radiation.

Pulsar timing for the Fermi gamma-ray space telescope

DOE PAGES

Smith, D. A.; Guillemot, L.; Camilo, F.; ...

2008-10-27

Here, we describe a comprehensive pulsar monitoring campaign for the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (formerly GLAST). The detection and study of pulsars in gamma rays give insights into the populations of neutron stars and supernova rates in the Galaxy, into particle acceleration mechanisms in neutron star magnetospheres, and into the “engines” driving pulsar wind nebulae. LAT's unprecedented sensitivity between 20 MeV and 300 GeV together with its 2.4 sr field-of-view makes detection of many gamma-ray pulsars likely, justifying the monitoring of over two hundred pulsars with large spin-down powers. To search for gamma-ray pulsationsmore » from most of these pulsars requires a set of phase-connected timing solutions spanning a year or more to properly align the sparse photon arrival times. We describe the choice of pulsars and the instruments involved in the campaign. Attention is paid to verifications of the LAT pulsar software, using for example giant radio pulses from the Crab and from PSR B1937+21 recorded at Nançay, and using X-ray data on PSR J0218+4232 from XMM-Newton. We demonstrate accuracy of the pulsar phase calculations at the microsecond level.« less

In situ measurement of radioactive contamination of bottom sediments.

PubMed

Zhukouski, A; Anshakou, O; Kutsen, S

2018-04-30

A gamma spectrometric method is presented for in situ radiation monitoring of bottom sediments with contaminated layer of unknown thickness to be determined. The method, based on the processing of experimental spectra using the results of their simulation by the Monte Carlo method, is proposed and tested in practice. A model for the transport of gamma radiation from deposited radionuclides 137 Cs and 134 Cs to a scintillation detection unit located on the upper surface of the contaminated layer of sediments is considered. The relationship between the effective radius of the contaminated site and the thickness of the layer has been studied. The thickness of the contaminated layer is determined by special analysis of experimental and thickness-dependent simulated spectra. The technique and algorithm developed are verified as a result of full-scale studies performed with the submersible gamma-spectrometer. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fermi GBM Observations of Terrestrial Gamma-ray Flashes

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

Briggs, Michael S.

2011-09-21

Terrestrial Gamma-ray Flashes are short pulses of energetic radiation associated with thunderstorms and lightning. While the Gamma-ray Burst Monitor (GBM) on Fermi was designed to observe gamma-ray bursts, its large BGO detectors are excellent for observing TGFs. Using GBM, TGF pulses are seen to either be symmetrical or have faster rise time than fall times. Some TGFs are resolved into double, partially overlapping pulses. Using ground-based radio observations of lightning from the World Wide Lightning Location Network (WWLLN), TGFs and their associated lightning are found to be simultaneous to {approx_equal}40 {mu} s. The lightning locations are typically within 300 kmmore » of the sub-spacecraft point.« less

Detection, characterization and quantification of salicylic acid conjugates in plant extracts by ESI tandem mass spectrometric techniques.

PubMed

Pastor, Victoria; Vicent, Cristian; Cerezo, Miguel; Mauch-Mani, Brigitte; Dean, John; Flors, Victor

2012-04-01

An approach for the detection and characterization of SA derivatives in plant samples is presented based on liquid chromatography coupled to electrospray ionization (ESI) tandem mass spectrometric techniques. Precursor ion scan methods using an ESI triple quadrupole spectrometer for samples from plants challenged with the virulent Pseudomonas syringae pv tomato DC3000 allowed us to detect two potential SA derivatives. The criterion used to consider a potential SA derivative is based on the detection of analytes in the precursor ion scan chromatogram upon selecting m/z 137 and m/z 93 that correspond to the salicylate and its main product ion, respectively. Product ion spectra of the newly-detected analytes as well as accurate m/z determinations using an ESI Q-time-of-flight instrument were registered as means of characterization and strongly suggest that glucosylated forms of SA at the carboxylic and at the phenol functional groups are present in plant samples. The specific synthesis and subsequent chromatography of salicylic glucosyl ester (SGE) and glucosyl salicylate (SAG) standards confirmed the chemical identity of both peaks that were obtained applying different tandem mass spectrometric techniques and accurate m/z determinations. A multiple reaction monitoring method has been developed and applied to plant samples. The advantages of this LC-ESI-MS/MS methods with respect to the traditional analysis of glucosyl conjugates are also discussed. Preliminary results revealed that SA and the glucosyl conjugates are accumulated in Arabidopsis thaliana in a time dependent manner, accordingly to the up-regulation of SA-dependent defenses following P. syringae infection. This technique applied to plant hormones or fragment ions may be useful to obtain chemical family members of plant metabolites and help identify their contribution in the signaling of plant defenses. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Multivariate analysis of gamma spectra to characterize used nuclear fuel

DOE PAGES

Coble, Jamie; Orton, Christopher; Schwantes, Jon

2017-01-17

The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less

Multivariate analysis of gamma spectra to characterize used nuclear fuel

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

Coble, Jamie; Orton, Christopher; Schwantes, Jon

The Multi-Isotope Process (MIP) Monitor provides an efficient means to monitor the process conditions in used nuclear fuel reprocessing facilities to support process verification and validation. The MIP Monitor applies multivariate analysis to gamma spectroscopy of key stages in the reprocessing stream in order to detect small changes in the gamma spectrum, which may indicate changes in process conditions. This research extends the MIP Monitor by characterizing a used fuel sample after initial dissolution according to the type of reactor of origin (pressurized or boiling water reactor; PWR and BWR, respectively), initial enrichment, burn up, and cooling time. Simulated gammamore » spectra were used in this paper to develop and test three fuel characterization algorithms. The classification and estimation models employed are based on the partial least squares regression (PLS) algorithm. A PLS discriminate analysis model was developed which perfectly classified reactor type for the three PWR and three BWR reactor designs studied. Locally weighted PLS models were fitted on-the-fly to estimate the remaining fuel characteristics. For the simulated gamma spectra considered, burn up was predicted with 0.1% root mean squared percent error (RMSPE) and both cooling time and initial enrichment with approximately 2% RMSPE. Finally, this approach to automated fuel characterization can be used to independently verify operator declarations of used fuel characteristics and to inform the MIP Monitor anomaly detection routines at later stages of the fuel reprocessing stream to improve sensitivity to changes in operational parameters that may indicate issues with operational control or malicious activities.« less

Fermi: The Gamma-Ray Large Area Telescope Mission Status

NASA Technical Reports Server (NTRS)

McEnery, Julie

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of an population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of GeV from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as supersymmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Daily Monitoring of TeV Gamma-Ray Emission from Mrk 421, Mrk 501, and the Crab Nebula with HAWC

NASA Astrophysics Data System (ADS)

Abeysekara, A. U.; Albert, A.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Barber, A. S.; Bautista-Elivar, N.; Becerra Gonzalez, J.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Bernal, A.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño de León, S.; De León, C.; De la Fuente, E.; Diaz Hernandez, R.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Engel, K.; Fiorino, D. W.; Fraija, N.; García-González, J. A.; Garfias, F.; Gerhardt, M.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez, S.; Hernandez-Almada, A.; Hona, B.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Kieda, D.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Raya, G. Luis; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Nisa, M. U.; Noriega-Papaqui, R.; Pretz, J.; Pérez-Pérez, E. G.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Vianello, G.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yapici, T.; Younk, P. W.; Zepeda, A.; Zhou, H.

2017-06-01

We present results from daily monitoring of gamma-rays in the energy range from ˜0.5 to ˜100 TeV with the first 17 months of data from the High Altitude Water Cherenkov (HAWC) Observatory. Its wide field of view of 2 steradians and duty cycle of > 95% are unique features compared to other TeV observatories that allow us to observe every source that transits over HAWC for up to ˜6 hr each sidereal day. This regular sampling yields unprecedented light curves from unbiased measurements that are independent of seasons or weather conditions. For the Crab Nebula as a reference source, we find no variability in the TeV band. Our main focus is the study of the TeV blazars Markarian (Mrk) 421 and Mrk 501. A spectral fit for Mrk 421 yields a power-law index {{Γ }}=2.21+/- {0.14}{stat}+/- {0.20}{sys} and an exponential cut-off {E}0=5.4+/- {1.1}{stat}+/- {1.0}{sys} TeV. For Mrk 501, we find an index {{Γ }}=1.60+/- {0.30}{stat}+/- {0.20}{sys} and exponential cut-off {E}0=5.7+/- {1.6}{stat}+/- {1.0}{sys} TeV. The light curves for both sources show clear variability and a Bayesian analysis is applied to identify changes between flux states. The highest per-transit fluxes observed from Mrk 421 exceed the Crab Nebula flux by a factor of approximately five. For Mrk 501, several transits show fluxes in excess of three times the Crab Nebula flux. In a comparison to lower energy gamma-ray and X-ray monitoring data with comparable sampling, we cannot identify clear counterparts for the most significant flaring features observed by HAWC.

Multiple products monitoring as a robust approach for peptide quantification.

PubMed

Baek, Je-Hyun; Kim, Hokeun; Shin, Byunghee; Yu, Myeong-Hee

2009-07-01

Quantification of target peptides and proteins is crucial for biomarker discovery. Approaches such as selected reaction monitoring (SRM) and multiple reaction monitoring (MRM) rely on liquid chromatography and mass spectrometric analysis of defined peptide product ions. These methods are not very widespread because the determination of quantifiable product ion using either SRM or MRM is a very time-consuming process. We developed a novel approach for quantifying target peptides without such an arduous process of ion selection. This method is based on monitoring multiple product ions (multiple products monitoring: MpM) from full-range MS2 spectra of a target precursor. The MpM method uses a scoring system that considers both the absolute intensities of product ions and the similarities between the query MS2 spectrum and the reference MS2 spectrum of the target peptide. Compared with conventional approaches, MpM greatly improves sensitivity and selectivity of peptide quantification using an ion-trap mass spectrometer.

Real-Time Processing System for the JET Hard X-Ray and Gamma-Ray Profile Monitor Enhancement

NASA Astrophysics Data System (ADS)

Fernandes, Ana M.; Pereira, Rita C.; Neto, André; Valcárcel, Daniel F.; Alves, Diogo; Sousa, Jorge; Carvalho, Bernardo B.; Kiptily, Vasily; Syme, Brian; Blanchard, Patrick; Murari, Andrea; Correia, Carlos M. B. A.; Varandas, Carlos A. F.; Gonçalves, Bruno

2014-06-01

The Joint European Torus (JET) is currently undertaking an enhancement program which includes tests of relevant diagnostics with real-time processing capabilities for the International Thermonuclear Experimental Reactor (ITER). Accordingly, a new real-time processing system was developed and installed at JET for the gamma-ray and hard X-ray profile monitor diagnostic. The new system is connected to 19 CsI(Tl) photodiodes in order to obtain the line-integrated profiles of the gamma-ray and hard X-ray emissions. Moreover, it was designed to overcome the former data acquisition (DAQ) limitations while exploiting the required real-time features. The new DAQ hardware, based on the Advanced Telecommunication Computer Architecture (ATCA) standard, includes reconfigurable digitizer modules with embedded field-programmable gate array (FPGA) devices capable of acquiring and simultaneously processing data in real-time from the 19 detectors. A suitable algorithm was developed and implemented in the FPGAs, which are able to deliver the corresponding energy of the acquired pulses. The processed data is sent periodically, during the discharge, through the JET real-time network and stored in the JET scientific databases at the end of the pulse. The interface between the ATCA digitizers, the JET control and data acquisition system (CODAS), and the JET real-time network is provided by the Multithreaded Application Real-Time executor (MARTe). The work developed allowed attaining two of the major milestones required by next fusion devices: the ability to process and simultaneously supply high volume data rates in real-time.

Development of a fiber-guided laser ultrasonic system resilient to high temperature and gamma radiation for nuclear power plant pipe monitoring

NASA Astrophysics Data System (ADS)

Yang, Jinyeol; Lee, Hyeonseok; Lim, Hyung Jin; Kim, Nakhyeon; Yeo, Hwasoo; Sohn, Hoon

2013-08-01

This study develops an embeddable optical fiber-guided laser ultrasonic system for structural health monitoring (SHM) of pipelines exposed to high temperature and gamma radiation inside nuclear power plants (NPPs). Recently, noncontact laser ultrasonics is gaining popularity among the SHM community because of its advantageous characteristics such as (a) scanning capability, (b) immunity against electromagnetic interference (EMI) and (c) applicability to high-temperature surfaces. However, its application to NPP pipelines has been hampered because pipes inside NPPs are often covered by insulators and/or target surfaces are not easily accessible. To overcome this problem, this study designs embeddable optical fibers and fixtures so that laser beams used for ultrasonic inspection can be transmitted between the laser sources and the target pipe. For guided-wave generation, an Nd:Yag pulsed laser coupled with an optical fiber is used. A high-power pulsed laser beam is guided through the optical fiber onto a target structure. Based on the principle of laser interferometry, the corresponding response is measured using a different type of laser beam guided by another optical fiber. All devices are especially designed to sustain high temperature and gamma radiation. The robustness/resilience of the proposed measurement system installed on a stainless steel pipe specimen has been experimentally verified by exposing the specimen to high temperature of up to 350 °C and optical fibers to gamma radiation of up to 125 kGy (20 kGy h-1).

Combining targeted and nontargeted data analysis for liquid chromatography/high-resolution mass spectrometric analyses.

PubMed

Croley, Timothy R; White, Kevin D; Wong, Jon; Callahan, John H; Musser, Steven M; Antler, Margaret; Lashin, Vitaly; McGibbon, Graham A

2013-03-01

Increasing importation of food and the diversity of potential contaminants have necessitated more analytical testing of these foods. Historically, mass spectrometric methods for testing foods were confined to monitoring selected ions (SIM or MRM), achieving sensitivity by focusing on targeted ion signals. A limiting factor in this approach is that any contaminants not included on the target list are not typically identified and retrospective data mining is limited. A potential solution is to utilize high-resolution MS to acquire accurate mass full-scan data. Based on the instrumental resolution, these data can be correlated to the actual mass of a contaminant, which would allow for identification of both target compounds and compounds that are not on a target list (nontargets). The focus of this research was to develop software algorithms to provide rapid and accurate data processing of LC/MS data to identify both targeted and nontargeted analytes. Software from a commercial vendor was developed to process LC/MS data and the results were compared to an alternate, vendor-supplied solution. The commercial software performed well and demonstrated the potential for a fully automated processing solution. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Utility of spatially-resolved atmospheric pressure surface sampling and ionization techniques as alternatives to mass spectrometric imaging (MSI) in drug metabolism.

PubMed

Blatherwick, Eleanor Q; Van Berkel, Gary J; Pickup, Kathryn; Johansson, Maria K; Beaudoin, Marie-Eve; Cole, Roderic O; Day, Jennifer M; Iverson, Suzanne; Wilson, Ian D; Scrivens, James H; Weston, Daniel J

2011-08-01

Tissue distribution studies of drug molecules play an essential role in the pharmaceutical industry and are commonly undertaken using quantitative whole body autoradiography (QWBA) methods. The growing need for complementary methods to address some scientific gaps around radiography methods has led to increased use of mass spectrometric imaging (MSI) technology over the last 5 to 10 years. More recently, the development of novel mass spectrometric techniques for ambient surface sampling has redefined what can be regarded as "fit-for-purpose" for MSI in a drug metabolism and disposition arena. Together with a review of these novel alternatives, this paper details the use of two liquid microjunction (LMJ)-based mass spectrometric surface sampling technologies. These approaches are used to provide qualitative determination of parent drug in rat liver tissue slices using liquid extraction surface analysis (LESA) and to assess the performance of a LMJ surface sampling probe (LMJ-SSP) interface for quantitative assessment of parent drug in brain, liver and muscle tissue slices. An assessment of the utility of these spatially-resolved sampling methods is given, showing interdependence between mass spectrometric and QWBA methods, in particular there emerges a reason to question typical MSI workflows for drug metabolism; suggesting the expedient use of profile or region analysis may be more appropriate, rather than generating time-intensive molecular images of the entire tissue section.

Time-resolved visible/near-infrared spectrometric observations of the Galaxy 11 geostationary satellite

NASA Astrophysics Data System (ADS)

Bédard, Donald; Wade, Gregg A.

2017-01-01

Time-resolved spectrometric measurements of the Galaxy 11 geostationary satellite were collected on three consecutive nights in July 2014 with the 1.6-m telescope at the Observatoire du Mont-Mégantic in Québec, Canada. Approximately 300 low-resolution spectra (R ≈ 700 , where R = λ / Δλ) of the satellite were collected each night, covering a spectral range between 425 and 850 nm. The two objectives of the experiment were to conduct material-type identification from the spectra and to study how the spectral energy distribution inferred from these measurements varied as the illumination and observation geometry changed on nightly timescales. We present results that indicate the presence of a highly reflective aluminized surface corresponding to the solar concentrator arrays of the Galaxy 11 spacecraft. Although other material types could not be identified using the spectra, the results showed that the spectral energy distribution of the reflected sunlight from the Galaxy 11 spacecraft varied significantly, in a systematic manner, over each night of observation. The variations were quantified using colour indices calculated from the time-resolved spectrometric measurements.

Fermi-LAT View of Bright Flaring Gamma-Ray Blazars

NASA Astrophysics Data System (ADS)

Bastieri, D.; Ciprini, S.; Gasparrini, D.

2011-06-01

The Fermi LAT provides a continuous and uniform monitoring of the Universe in the gamma-ray band. During the first year many gamma-ray blazar flares, some unidentified transients and emission by the Sun while in a quiet state were promptly detected. This is mainly due to the design of the mission, featuring a detector, the LAT with a wide field of view, and to the operation of the spacecraft itself, that can cover every region of the sky every 3 hours. Nevertheless, the scientific exploitation of this monitoring is more fruitful when early information about transients reaches a broader community. In this respect, the indefatigable activity of flare advocates, who worked on weekly shifts to validate the results and quickly broadcast information about flares and new detections, was the key to most scientific results.

Treatment of trochanteric fractures with the gamma3 nail - methodology and early results of a prospective consecutive monitored clinical case series.

PubMed

A C, Unger; E, Wilde; B, Kienast; C, Jürgens; A P, Schulz

2014-01-01

There is only sparse data on clinical results and complications of the third-generation Gamma nailing system (Gamma3, Stryker). Therefore, we started a large multi-centre case series in 2008. The aim of this paper is to present the study design and early results of a single arm of a prospective, consecutive, monitored, post-market follow-up evaluation of Gamma3 nails. From September 2009 to January 2012, 154 consecutive patients with an average age of 80 ± 1.43 years (50-99 years) and a trochanteric femoral fracture were included in the local arm of the trial. All patients that fulfilled the inclusion criteria were treated with a Gamma3 nail. Preoperative variables included age, gender, fracture classification, walking ability (Merle d'Aubigné score), daily activity level (retrospective Zuckerman score), ASA rating of operative risk, waiting time for operation, use of walker or crutches and body mass index (BMI). Skin-to-skin time, fluoroscopy time, blood loss, intraoperative complications and device information were recorded for each patient. Follow-up postoperative assessment was undertaken at 4, 12 and 24 months. Hip range of motion, pain around the hip and the tight, walking ability (Merle d'Aubigné score, Sahlgrenska mobility score) and management of daily life (Zuckerman score) were used to evaluate the outcome. The descriptive data of age, gender, BMI, ASA classification, fracture type and skin-to-skin time is similar to other studies. Median fluoroscopy time was 62 seconds (range: 4-225 seconds) and significantly shorter in closed reductions. No intraoperative implant-related complication was recorded. A cut-out of the leg-screw during assessment period occurred in 2.6% patients (n = 4). At the 12-month assessment two (1.8%) non-unions were identified and two patients (1.8%) had broken the femoral shaft below the 180 mm nail after a fall. Analysis of the scores showed significantly declined mobility and activity in daily life four months after operation

The monitoring and verification of nuclear weapons

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

Garwin, Richard L., E-mail: RLG2@us.ibm.com

2014-05-09

This paper partially reviews and updates the potential for monitoring and verification of nuclear weapons, including verification of their destruction. Cooperative monitoring with templates of the gamma-ray spectrum are an important tool, dependent on the use of information barriers.

TEMPORAL CORRELATIONS BETWEEN OPTICAL AND GAMMA-RAY ACTIVITY IN BLAZARS

DOE PAGES

Cohen, Daniel P.; Romani, Roger W.; Filippenko, Alexei V.; ...

2014-12-08

For this research, we have been using the 0.76 m Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory to optically monitor a sample of 157 blazars that are bright in gamma-rays being detected with high significance (≥10σ) in one year by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope. We attempt to observe each source on a three-day cadence with KAIT, subject to weather and seasonal visibility. The gamma-ray coverage is essentially continuous. KAIT observations extend over much of the five-year Fermi mission for several objects, and most have >100 optical measurements spanning the last three years.more » These blazars (flat-spectrum radio quasars and BL Lac objects) exhibit a wide range of flaring behavior. Using the discrete correlation function (DCF), here we search for temporal relationships between optical and gamma-ray light curves in the 40 brightest sources in hopes of placing constraints on blazar acceleration and emission zones. We find strong optical-gamma-ray correlation in many of these sources at time delays of ~1 to ~10 days, ranging between –40 and +30 days. A stacked average DCF of the 40 sources verifies this correlation trend, with a peak above 99% significance indicating a characteristic time delay consistent with 0 days. These findings strongly support the widely accepted leptonic models of blazar emission. However, we also find examples of apparently uncorrelated flares (optical flares with no gamma-ray counterpart and gamma-ray flares with no optical counterpart) that challenge simple, one-zone models of blazar emission. Moreover, we find that flat-spectrum radio quasars tend to have gamma-rays leading the optical, while intermediate- and high-synchrotron peak blazars with the most significant peaks have smaller lags/leads. In conclusion, it is clear that long-term monitoring at high cadence is necessary to reveal the underlying physical correlation.« less

The Gamma-Ray Emitting Radio-Loud Narrow-Line Seyfert 1 Galaxy PKS 2004-447 II. The Radio View

NASA Technical Reports Server (NTRS)

Schulz, R.; Kreikenbohm, A.; Kadler, M.; Ojha, R.; Ros, E.; Stevens, J.; Edwards, P. G.; Carpenter, B.; Elsaesser, D.; Gehrels, N.;

Development of a three-layer phoswich alpha-beta-gamma imaging detector

NASA Astrophysics Data System (ADS)

Yamamoto, Seiichi; Ishibashi, Hiroyuki

2015-06-01

For radiation monitoring at the sites of such nuclear power plant accidents as Fukushima Daiichi, radiation detectors are needed not only for gamma photons but also for alpha and beta particles because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. In some applications, imaging detectors are required to detect the distribution of plutonium particles that emit alpha particles and radiocesium in foods that emits beta particles and gamma photons. To solve these requirements, we developed an imaging detector that can measure the distribution of alpha and beta particles as well as gamma photons. The imaging detector consists of three-layer scintillators optically coupled to each other and to a position sensitive photomultiplier tube (PSPMT). The first layer, which is made of a thin plastic scintillator (decay time: 5 ns), detects alpha particles. The second layer, which is made of a thin Gd2SiO5 (GSO) scintillator with 1.5 mol% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol% Ce (decay time: 70 ns) detects gamma photons. Using pulse shape discrimination, the images of these layers can be separated. The position information is calculated by the Anger principle from 8×8 anode signals from the PSPMT. The images for the alpha and beta particles and the gamma photons are individually formed by the pulse shape discriminations for each layer. We detected alpha particle images in the first layer and beta particle images in the second layer. Gamma photon images were detected in the second and third layers. The spatial resolution for the alpha and beta particles was 1.25 mm FWHM and less than 2 mm FWHM for the gamma photons. We conclude that our developed alpha-beta-gamma imaging detector is promising for imaging applications not only for the environmental monitoring of radionuclides but also for medical and molecular imaging.

Anticonvulsant properties of alpha, gamma, and alpha, gamma-substituted gamma-butyrolactones.

PubMed

Klunk, W E; Covey, D F; Ferrendelli, J A

1982-09-01

Derivatives of gamma-butyrolactone (GBL) substituted on the alpha- and/or gamma-positions were synthesized and tested for their effects on behavior in mice, on the electroencephalographs and blood pressure of paralyzed-ventilated guinea pigs, and on electrical activity of incubated hippocampal slices. Several compounds, including alpha-ethyl-alpha-methyl GBL (alpha-EMGBL), alpha, alpha-dimethyl GBL, alpha, gamma-diethyl-alpha, gamma-dimethyl GBL, and gamma-ethyl-gamma-methyl GBL, prevented seizures induced by pentylenetetrazol, beta-ethyl-beta-methyl-gamma-butyrolactone (beta-EMGBL), picrotoxin, or all three compounds in mice and guinea pigs but had no effect on seizures induced by maximal electroshock or bicuculline. Neither gamma-hydroxybutyrate (GHB) nor alpha-isopropylidine GBL had any anticonvulsant activity. The anticonvulsant alpha-substituted compounds had a potent hypotensive effect and antagonized the hypertensive effect of beta-EMGBL, alpha-EMGBL was tested in incubated hippocampal slices and was found to depress basal activity and antagonize excitation induced by beta-EMGBL. These results demonstrate that alpha-alkyl-substituted GBL and, to a lesser extent, gamma-substituted derivatives are anticonvulsant agents and that their effects are strikingly different from those of GHB or beta-alkyl-substituted GBLs, which are epileptogenic. Possibly beta- and alpha-substituted GBLs act at the same site as agonists and antagonists, respectively.

Finding Sub-threshold Short Gamma-ray Bursts in Fermi GBM Data

NASA Astrophysics Data System (ADS)

Burns, Eric; Fermi Gamma-ray Burst Monitor Team

2018-01-01

The all-sky monitoring capability of Fermi GBM makes it ideal for finding transients, and the most prolific detector of short gamma-ray bursts with about 40 on-board triggers per year. Because the observed brightness of short gamma-ray bursts has no correlation with redshift, weak short gamma-ray bursts are important during the gravitational wave era. With this in mind, we discuss two searches of GBM data to find short gamma-ray which were below the on-board trigger threshold. The untargeted search looks for significant background-subtracted signals in two or more detectors at various timescales in the continuous data, detecting ~80 additional short GRB candidates per year. The targeted search is the most sensitive search for weak gamma-ray signals in GBM data and is run over limited time intervals around sources of interest like gravitational waves.

Fermi: The Gamma-Ray Large Area Space Telescope Mission Status

NASA Technical Reports Server (NTRS)

McEnery, Julie E

2014-01-01

Following its launch in June 2008, high-energy gamma-ray observations by the Fermi Gamma-ray Space Telescope have unveiled over 1000 new sources and opened an important and previously unexplored window on a wide variety of phenomena. These have included the discovery of a population of pulsars pulsing only in gamma rays; the detection of photons up to 10s of gigaelectronvolts from gamma-ray bursts, enhancing our understanding of the astrophysics of these powerful explosions; the detection of hundreds of active galaxies; a measurement of the high energy cosmic-ray electron spectrum which may imply the presence of nearby astrophysical particle accelerators; the determination of the diffuse gamma-ray emission with unprecedented accuracy and the constraints on phenomena such as super-symmetric dark-matter annihilations and exotic relics from the Big Bang. Continuous monitoring of the high-energy gamma-ray sky has uncovered numerous outbursts from active galaxies and the discovery of transient sources in our galaxy. In this talk I will describe the current status of the Fermi observatory and review the science highlights from Fermi.

Oxidative Ionization Under Certain Negative-Ion Mass Spectrometric Conditions

NASA Astrophysics Data System (ADS)

Hassan, Isra; Pavlov, Julius; Errabelli, Ramu; Attygalle, Athula B.

2017-02-01

1,4-Hydroquinone and several other phenolic compounds generate (M - 2) -• radical-anions, rather than deprotonated molecules, under certain negative-ion mass spectrometric conditions. In fact, spectra generated under helium-plasma ionization (HePI) conditions from 1,4-hydroquinone and 1,4-benzoquinone (by electron capture) were practically indistinguishable. Because this process involves a net loss of H• and H+, it can be termed oxidative ionization. The superoxide radical-anion (O2 -•), known to be present in many atmospheric-pressure plasma ion sources operated in the negative mode, plays a critical role in the oxidative ionization process. The presence of a small peak at m/z 142 in the spectrum of 1,4-hydroquinone, but not in that of 1,4-benzoquinone, indicated that the initial step in the oxidative ionization process is the formation of an O2 -• adduct. On the other hand, under bona fide electrospray ionization (ESI) conditions, 1,4-hydroquinone generates predominantly an (M - 1) - ion. It is known that at sufficiently high capillary voltages, corona discharges begin to occur even in an ESI source. At lower ESI capillary voltages, deprotonation predominates; as the capillary voltage is raised, the abundance of O2 -• present in the plasma increases, and the source in turn increasingly behaves as a composite ESI/APCI source. While maintaining post-ionization ion activation to a minimum (to prevent fragmentation), and monitoring the relative intensities of the m/z 109 (due to deprotonation) and 108 (oxidative ionization) peaks recorded from 1,4-hydroquinone, a semiquantitative estimation of the APCI contribution to the overall ion-generation process can be obtained.

Mass spectrometric profiling of flavonoid glycoconjugates possessing isomeric aglycones.

PubMed

Abrankó, László; Szilvássy, Blanka

2015-01-01

In fields such as food and nutrition science or plant physiology, interest in untargeted profiling of flavonoids continues to expand. The group of flavonoids encompasses several thousands of chemically distinguishable compounds, among which are a number of isobaric compounds with the same elemental composition. Thus, the mass spectrometric identification of these compounds is challenging, especially when reference standards are not available to support their identification. Many different types of isomers of flavonoid glycoconjugates are known, i.e. compounds that differ in their glycosylation position, glycan sequence or type of interglycosidic linkage. This work focuses on the mass spectrometric identification of flavonoid glycoconjugate isomers possessing the same glycan mass and differing only in their aglycone core. A non-targeted HPLC-ESI-MS/MS profiling method using a triple quadrupole MS is presented herein, which utilizes in-source fragmentation and a pseudo-MS(3) approach for the selective analysis of flavonoid glycoconjugates with isomeric/isobaric aglycones. A selective MRM-based identification of the in-source formed isobaric aglycone fragments was established. Additionally, utilizing the precursor scanning capability of the employed triple quadrupole instrument, the developed method enabled the determination of the molecular weight of the studied intact flavonoid glycoconjugate. The versatility of the method was proven with various types of flavonoid aglycones, i.e. anthocyanins, flavonols, flavones, flavanones and isoflavones, along with their representative glycoconjugates. The developed method was also successfully applied to a commercially available sour cherry sample, in which 16 different glycoconjugates of pelargonidin, genistein, cyanidin, kaempferol and quercetin could be tentatively identified, including a number of compounds containing isomeric/isobaric aglycones. Copyright © 2015 John Wiley & Sons, Ltd.

A Liquid Chromatographic-Mass Spectrometric (LC-MS) Method for the Analysis of the Bis-pyridinium Oxime ICD-585 in Plasma: Application in a Guinea Pig Model

DTIC Science & Technology

2010-01-01

Chrom LC –MS...Literature 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE A liquid chromatographic–mass spectrometric ( LC –MS) method for the analysis of the 5a...Journal of Chromatography B journa l homepage: www.e lsev ier .com/ locate /chromb A liquid chromatographic–mass spectrometric ( LC –MS) method for

Accurate Modeling of the Terrestrial Gamma-Ray Background for Homeland Security Applications

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

Sandness, Gerald A.; Schweppe, John E.; Hensley, Walter K.

2009-10-24

Abstract–The Pacific Northwest National Laboratory has developed computer models to simulate the use of radiation portal monitors to screen vehicles and cargo for the presence of illicit radioactive material. The gamma radiation emitted by the vehicles or cargo containers must often be measured in the presence of a relatively large gamma-ray background mainly due to the presence of potassium, uranium, and thorium (and progeny isotopes) in the soil and surrounding building materials. This large background is often a significant limit to the detection sensitivity for items of interest and must be modeled accurately for analyzing homeland security situations. Calculations ofmore » the expected gamma-ray emission from a disk of soil and asphalt were made using the Monte Carlo transport code MCNP and were compared to measurements made at a seaport with a high-purity germanium detector. Analysis revealed that the energy spectrum of the measured background could not be reproduced unless the model included gamma rays coming from the ground out to distances of at least 300 m. The contribution from beyond about 50 m was primarily due to gamma rays that scattered in the air before entering the detectors rather than passing directly from the ground to the detectors. These skyshine gamma rays contribute tens of percent to the total gamma-ray spectrum, primarily at energies below a few hundred keV. The techniques that were developed to efficiently calculate the contributions from a large soil disk and a large air volume in a Monte Carlo simulation are described and the implications of skyshine in portal monitoring applications are discussed.« less

The U.S. Spectrum X Gamma Coordination Facility

NASA Astrophysics Data System (ADS)

Forman, William R.

1999-08-01

Spectrum-X-Gamma (SXG) provides for US participation in a first-class international x-ray mission. Despite launch delays, SXG will provide unique scientific opportunities due to its capability for all-sky monitoring, polarimetry, high resolution spectroscopy, and broad wavelength range-from the ultraviolet (TAUVEX and FUVITA), through the x-ray (SODART and JET-X), to the hard x-ray (MART), and gamma-ray burst detectors. Before describing our completed work, we review the unique properties of SXG and provide some examples of the scientific importance of SXG in the Chandra, XMM, and ASTRO-E era.

The U.S. Spectrum X Gamma Coordination Facility

NASA Technical Reports Server (NTRS)

Forman, William R.

1999-01-01

Spectrum-X-Gamma (SXG) provides for US participation in a first-class international x-ray mission. Despite launch delays, SXG will provide unique scientific opportunities due to its capability for all-sky monitoring, polarimetry, high resolution spectroscopy, and broad wavelength range-from the ultraviolet (TAUVEX and FUVITA), through the x-ray (SODART and JET-X), to the hard x-ray (MART), and gamma-ray burst detectors. Before describing our completed work, we review the unique properties of SXG and provide some examples of the scientific importance of SXG in the Chandra, XMM, and ASTRO-E era.

GC-MS (GAS CHROMATOGRAPHIC-MASS SPECTROMETRIC) SUITABILITY TESTING OF RCRA APPENDIX VIII AND MICHIGAN LIST ANALYTES

EPA Science Inventory

As a first step in a hierarchical scheme to demonstrate the suitability of present U.S. Environmental Protection Agency (USEPA) analysis methods and/or develop new methodology, the gas chromatographic (GC) separation and mass spectrometric (MS) detection characteristics of 328 to...

MoonBEAM: Gamma-Ray Burst Detectors on SmallSAT

NASA Technical Reports Server (NTRS)

Hui, C. M.; Briggs, M. S.; Goldstein, A. M.; Jenke, P. A.; Kocevski, D.; Wilson-Hodge, C. A.

2018-01-01

Moon Burst Energetics All-sky Monitor (MoonBEAM) is a CubeSat concept of deploying gamma-ray detectors in cislunar space to improve localization precision for gamma-ray bursts by utilizing the light travel time difference between a spacecraft in Earth and cislunar orbit. MoonBEAM is designed with high TRL components to be flight ready. This instrument would probe the extreme processes in cosmic collision of compact objects and facilitate multi-messenger time-domain astronomy to explore the end of stellar life cycles and black hole formations.

All-Sky Monitoring of Variable Sources with Fermi GBM

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.; Finger, Mark; Camero-Arranz, Ascension; Becklen, Elif; Jenke, Peter; Cpe. K/ K/; Steele, Iain; Case, Gary; Cherry, Mike; Rodi, James;

The effect of a gamma ray flare on Schumann resonances

NASA Astrophysics Data System (ADS)

Nickolaenko, A. P.; Kudintseva, I. G.; Pechony, O.; Hayakawa, M.; Hobara, Y.; Tanaka, Y. T.

2012-09-01

We describe the ionospheric modification by the SGR 1806-20 gamma flare (27 December 2004) seen in the global electromagnetic (Schumann) resonance. The gamma rays lowered the ionosphere over the dayside of the globe and modified the Schumann resonance spectra. We present the extremely low frequency (ELF) data monitored at the Moshiri observatory, Japan (44.365° N, 142.24° E). Records are compared with the expected modifications, which facilitate detection of the simultaneous abrupt change in the dynamic resonance pattern of the experimental record. The gamma flare modified the current of the global electric circuit and thus caused the "parametric" ELF transient. Model results are compared with observations enabling evaluation of changes in the global electric circuit.

Gamma-ray imaging system for real-time measurements in nuclear waste characterisation

NASA Astrophysics Data System (ADS)

Caballero, L.; Albiol Colomer, F.; Corbi Bellot, A.; Domingo-Pardo, C.; Leganés Nieto, J. L.; Agramunt Ros, J.; Contreras, P.; Monserrate, M.; Olleros Rodríguez, P.; Pérez Magán, D. L.

2018-03-01

A compact, portable and large field-of-view gamma camera that is able to identify, locate and quantify gamma-ray emitting radioisotopes in real-time has been developed. The device delivers spectroscopic and imaging capabilities that enable its use it in a variety of nuclear waste characterisation scenarios, such as radioactivity monitoring in nuclear power plants and more specifically for the decommissioning of nuclear facilities. The technical development of this apparatus and some examples of its application in field measurements are reported in this article. The performance of the presented gamma-camera is also benchmarked against other conventional techniques.

Modern chromatographic and mass spectrometric techniques for protein biopharmaceutical characterization.

PubMed

Sandra, Koen; Vandenheede, Isabel; Sandra, Pat

2014-03-28

Protein biopharmaceuticals such as monoclonal antibodies and therapeutic proteins are currently in widespread use for the treatment of various life-threatening diseases including cancer, autoimmune disorders, diabetes and anemia. The complexity of protein therapeutics is far exceeding that of small molecule drugs; hence, unraveling this complexity represents an analytical challenge. The current review provides the reader with state-of-the-art chromatographic and mass spectrometric tools available to dissect primary and higher order structures, post-translational modifications, purity and impurity profiles and pharmacokinetic properties of protein therapeutics. Copyright © 2013 Elsevier B.V. All rights reserved.

Challenges and recent advances in mass spectrometric imaging of neurotransmitters

PubMed Central

Gemperline, Erin; Chen, Bingming; Li, Lingjun

2014-01-01

Mass spectrometric imaging (MSI) is a powerful tool that grants the ability to investigate a broad mass range of molecules, from small molecules to large proteins, by creating detailed distribution maps of selected compounds. To date, MSI has demonstrated its versatility in the study of neurotransmitters and neuropeptides of different classes toward investigation of neurobiological functions and diseases. These studies have provided significant insight in neurobiology over the years and current technical advances are facilitating further improvements in this field. neurotransmitters, focusing specifically on the challenges and recent Herein, we advances of MSI of neurotransmitters. PMID:24568355

Radon-222 related influence on ambient gamma dose.

PubMed

Melintescu, A; Chambers, S D; Crawford, J; Williams, A G; Zorila, B; Galeriu, D

2018-04-03

Ambient gamma dose, radon, and rainfall have been monitored in southern Bucharest, Romania, from 2010 to 2016. The seasonal cycle of background ambient gamma dose peaked between July and October (100-105 nSv h -1 ), with minimum values in February (75-80 nSv h -1 ), the time of maximum snow cover. Based on 10 m a.g.l. radon concentrations, the ambient gamma dose increased by around 1 nSv h -1 for every 5 Bq m -3 increase in radon. Radon variability attributable to diurnal changes in atmospheric mixing contributed less than 15 nSv h -1 to the overall variability in ambient gamma dose, a factor of 4 more than synoptic timescale changes in air mass fetch. By contrast, precipitation-related enhancements of the ambient gamma dose were 15-80 nSv h -1 . To facilitate routine analysis, and account in part for occasional equipment failure, an automated method for identifying precipitation spikes in the ambient gamma dose was developed. Lastly, a simple model for predicting rainfall-related enhancement of the ambient gamma dose is tested against rainfall observations from events of contrasting duration and intensity. Results are also compared with those from previously published models of simple and complex formulation. Generally, the model performed very well. When simulations underestimated observations the absolute difference was typically less than the natural variability in ambient gamma dose arising from atmospheric mixing influences. Consequently, combined use of the automated event detection method and the simple model of this study could enable the ambient gamma dose "attention limit" (which indicates a potential radiological emergency) to be reduced from 200 to 400% above background to 25-50%. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mass Spectrometric Analysis of Synthetic Organic Pigments.

PubMed

Sugaya, Naeko; Takahashi, Mitsuko; Sakurai, Katsumi; Tanaka, Nobuko; Okubo, Ichiro; Kawakami, Tsuyoshi

2018-04-18

Though synthetic organic colorants are used in various applications nowadays, there is the concern that impurities by-produced during the manufacturing and degradation products in some of these colorants are persistent organic pollutants and carcinogens. Thus, it is important to identify the synthetic organic colorants in various products, such as commercial paints, ink, cosmetics, food, textile, and plastics. Dyes, which are soluble in water and other solvents, could be analyzed by chromatographic methods. In contrast, it is difficult to analyze synthetic organic pigments by these methods because of their insolubility. This review is an overview of mass spectrometric analysis of synthetic organic pigments by various ionization methods. We highlight a recent study of textile samples by atmospheric pressure solid analysis probe MS. Furthermore, the mass spectral features of synthetic organic pigments and their separation from other components such as paint media and plasticizers are discussed.

Analysis of Multi-band Photometry of Violently Variable Gamma-Ray Sources

NASA Astrophysics Data System (ADS)

Kadowaki, Jennifer; Malkan, M. A.

2013-01-01

We studied the relationship between rapid variations in the jet intensities and changes in accretion disk activity of blazar subtype, Flat Spectrum Radio Quasar (FSRQ). Fifteen known FSRQs were specifically chosen for their prominent big blue bumps with redshifts near z=1, in order for the rest-frame UV to be redshifted into the blue-band pass. Flux changes for these 15 FSRQs were monitored for 15 observational nights in BVRI-bands and 20 nights in JHK-bands over a 12 month period using NASA's Fermi Gamma-ray Space Telescope, Lick Observatory's Nickel Telescope, and Kitt Peak National Observatory's 2.1 m Telescope. With 6.3’ x 6.3’ field of view for Nickel’s Direct Imaging Camera and 20’ x 20’ for Flamingos IR Imaging Spectrometer, approximately a half dozen, bright and non-variable stars were available to compare the concurrent changes in each of the quasar’s brightness. This process of differential photometry yielded photometric measurements of quasar brightness with 1-2% level precision. Light curves were then created for these 15 monitored quasars in optical, infrared, and gamma-ray energy bands. Dominating the redder emission spectrum due to non-thermal, synchrotron radiation and compton scattering of gamma-rays off high energy electrons, jet activity was compared to bluer spectral regions having strong accretion disk component with rest frame of approximately 2000 Angstroms. Most of the targeted FSRQs varied significantly over the 12 month monitoring period, with varying levels of fluctuations for each observed wavelength. Some correlations between gamma-ray and optical wavelengths were also present, which will be further discussed in the poster.

Thorium normalization as a hydrocarbon accumulation indicator for Lower Miocene rocks in Ras Ghara area, Gulf of Suez, Egypt

NASA Astrophysics Data System (ADS)

El-Khadragy, A. A.; Shazly, T. F.; AlAlfy, I. M.; Ramadan, M.; El-Sawy, M. Z.

2018-06-01

An exploration method has been developed using surface and aerial gamma-ray spectral measurements in prospecting petroleum in stratigraphic and structural traps. The Gulf of Suez is an important region for studying hydrocarbon potentiality in Egypt. Thorium normalization technique was applied on the sandstone reservoirs in the region to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). This method was applied on the recorded gamma-ray spectrometric logs for Rudeis and Kareem Formations in Ras Ghara oil Field, Gulf of Suez, Egypt. The conventional well logs (gamma-ray, resistivity, neutron, density and sonic logs) were analyzed to determine the net pay zones in the study area. The agreement ratios between the thorium normalization technique and the results of the well log analyses are high, so the application of thorium normalization technique can be used as a guide for hydrocarbon accumulation in the study reservoir rocks.

Topic model-based mass spectrometric data analysis in cancer biomarker discovery studies.

PubMed

Wang, Minkun; Tsai, Tsung-Heng; Di Poto, Cristina; Ferrarini, Alessia; Yu, Guoqiang; Ressom, Habtom W

2016-08-18

A fundamental challenge in quantitation of biomolecules for cancer biomarker discovery is owing to the heterogeneous nature of human biospecimens. Although this issue has been a subject of discussion in cancer genomic studies, it has not yet been rigorously investigated in mass spectrometry based proteomic and metabolomic studies. Purification of mass spectometric data is highly desired prior to subsequent analysis, e.g., quantitative comparison of the abundance of biomolecules in biological samples. We investigated topic models to computationally analyze mass spectrometric data considering both integrated peak intensities and scan-level features, i.e., extracted ion chromatograms (EICs). Probabilistic generative models enable flexible representation in data structure and infer sample-specific pure resources. Scan-level modeling helps alleviate information loss during data preprocessing. We evaluated the capability of the proposed models in capturing mixture proportions of contaminants and cancer profiles on LC-MS based serum proteomic and GC-MS based tissue metabolomic datasets acquired from patients with hepatocellular carcinoma (HCC) and liver cirrhosis as well as synthetic data we generated based on the serum proteomic data. The results we obtained by analysis of the synthetic data demonstrated that both intensity-level and scan-level purification models can accurately infer the mixture proportions and the underlying true cancerous sources with small average error ratios (<7 %) between estimation and ground truth. By applying the topic model-based purification to mass spectrometric data, we found more proteins and metabolites with significant changes between HCC cases and cirrhotic controls. Candidate biomarkers selected after purification yielded biologically meaningful pathway analysis results and improved disease discrimination power in terms of the area under ROC curve compared to the results found prior to purification. We investigated topic model

Determination of cocaine, benzoylecgonine, cocaethylene and norcocaine in human hair using solid-phase extraction and liquid chromatography with tandem mass spectrometric detection.

PubMed

Moore, Christine; Coulter, Cynthia; Crompton, Katherine

2007-11-15

A quantitative analytical procedure for the determination of cocaine, benzoylecgonine and cocaethylene and norcocaine in hair has been developed and validated. The hair samples were washed, incubated, and any drugs present were quantified using mixed mode solid-phase extraction and liquid chromatography with tandem mass spectrometric detection in positive atmospheric pressure chemical ionization mode. For confirmation, two transitions were monitored and one ion ratio was determined, which was within 20% of that of the known calibration standards. The monitoring of the qualifying transition and requirement for its presence within a specific ratio to the primary ion limited the sensitivity of the assay, particularly for benzoylecgonine, however, the additional confidence in the final result as well as forensic defensibility were considered to be of greater importance. Even with simultaneous monitoring, the concentrations proposed by the United States Federal guidelines for hair analysis were achieved. The limits of quantitation were 50 pg/mg; the limit of detection was 25 pg/mg. The intra-day precision of the assays at 100 pg/mg (n=5) was 1.3%, 8.1%, 0.8% and 0.4%; inter-day precision 4.8%, 9.2%, 15.7% and 12.6% (n=10) for cocaine, benzoylecgonine, cocaethylene and norcocaine, respectively. The methods were applied to both proficiency specimens and to samples obtained during research studies in the USA.

Targeted Mass Spectrometric Approach for Biomarker Discovery and Validation with Nonglycosylated Tryptic Peptides from N-linked Glycoproteins in Human Plasma*

PubMed Central

Lee, Ju Yeon; Kim, Jin Young; Park, Gun Wook; Cheon, Mi Hee; Kwon, Kyung-Hoon; Ahn, Yeong Hee; Moon, Myeong Hee; Lee, Hyoung–Joo; Paik, Young Ki; Yoo, Jong Shin

2011-01-01

A simple mass spectrometric approach for the discovery and validation of biomarkers in human plasma was developed by targeting nonglycosylated tryptic peptides adjacent to glycosylation sites in an N-linked glycoprotein, one of the most important biomarkers for early detection, prognoses, and disease therapies. The discovery and validation of novel biomarkers requires complex sample pretreatment steps, such as depletion of highly abundant proteins, enrichment of desired proteins, or the development of new antibodies. The current study exploited the steric hindrance of glycan units in N-linked glycoproteins, which significantly affects the efficiency of proteolytic digestion if an enzymatically active amino acid is adjacent to the N-linked glycosylation site. Proteolytic digestion then results in quantitatively different peptide products in accordance with the degree of glycosylation. The effect of glycan steric hindrance on tryptic digestion was first demonstrated using alpha-1-acid glycoprotein (AGP) as a model compound versus deglycosylated alpha-1-acid glycoprotein. Second, nonglycosylated tryptic peptide biomarkers, which generally show much higher sensitivity in mass spectrometric analyses than their glycosylated counterparts, were quantified in human hepatocellular carcinoma plasma using a label-free method with no need for N-linked glycoprotein enrichment. Finally, the method was validated using a multiple reaction monitoring analysis, demonstrating that the newly discovered nonglycosylated tryptic peptide targets were present at different levels in normal and hepatocellular carcinoma plasmas. The area under the receiver operating characteristic curve generated through analyses of nonglycosylated tryptic peptide from vitronectin precursor protein was 0.978, the highest observed in a group of patients with hepatocellular carcinoma. This work provides a targeted means of discovering and validating nonglycosylated tryptic peptides as biomarkers in human plasma

Monte Carlo Uncertainty Quantification for an Unattended Enrichment Monitor

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

Jarman, Kenneth D.; Smith, Leon E.; Wittman, Richard S.

As a case study for uncertainty analysis, we consider a model flow monitor for measuring enrichment in gas centrifuge enrichment plants (GCEPs) that could provide continuous monitoring of all declared gas flow and provide high-accuracy gas enrichment estimates as a function of time. The monitor system could include NaI(Tl) gamma-ray spectrometers, a pressure signal-sharing device to be installed on an operator\\rq{}s pressure gauge or a dedicated inspector pressure sensor, and temperature sensors attached to the outside of the header pipe, to provide pressure, temperature, and gamma-ray spectra measurements of UFmore » $$_6$$ gas flow through unit header pipes. Our study builds on previous modeling and analysis methods development for enrichment monitor concepts and a software tool that was developed at Oak Ridge National Laboratory to generate and analyze synthetic data.« less

Low-level gamma and neutron monitoring based on use of proportional counter filled with 3He in polythene moderator: study of the responses to gamma and neutrons.

PubMed

Pszona, S; Bantsar, A; Tulik, P; Wincel, K; Zaręba, B

2014-10-01

It has been shown that a proportional counter filled with (3)He placed centrally inside a polythene sphere opens a new possibility for measuring gamma photons and neutrons in the separate pulse-height windows. The responses to gamma and neutrons (in terms of ambient dose equivalent) of the detector assembly consisting of 203-mm polythene sphere with centrally positioned 40-mm diameter (3)He proportional counter have been studied. The response to secondary gammas from capture process in hydrogen has also been studied. The rather preliminary studies indicate that the proposed measuring system has very promising features as an ambient dose equivalent device for mixed gamma-neutron fields. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Combining Internet monitoring processes, packaging and isotopic analyses to determine the market structure: example of Gamma Butyrolactone.

PubMed

Pazos, Diego; Giannasi, Pauline; Rossy, Quentin; Esseiva, Pierre

2013-07-10

The Internet is becoming more and more popular among drug users. The use of websites and forums to obtain illicit drugs and relevant information about the means of consumption is a growing phenomenon mainly for new synthetic drugs. Gamma Butyrolactone (GBL), a chemical precursor of Gamma Hydroxy Butyric acid (GHB), is used as a "club drug" and also in drug facilitated sexual assaults. Its market takes place mainly on the Internet through online websites but the structure of the market remains unknown. This research aims to combine digital, physical and chemical information to help understand the distribution routes and the structure of the GBL market. Based on an Internet monitoring process, thirty-nine websites selling GBL, mainly in the Netherlands, were detected between January 2010 and December 2011. Seventeen websites were categorized into six groups based on digital traces (e.g. IP addresses and contact information). In parallel, twenty-five bulk GBL specimens were purchased from sixteen websites for packaging comparisons and carbon isotopic measurements. Packaging information showed a high correlation with digital data confirming the links previously established whereas chemical information revealed undetected links and provided complementary information. Indeed, while digital and packaging data give relevant information about the retailers, the supply routes and the distribution close to the consumer, the carbon isotopic data provides upstream information about the production level and in particular the synthesis pathways and the chemical precursors. A three-level structured market has been thereby identified with a production level mainly located in China and in Germany, an online distribution level mainly hosted in the Netherlands and the customers who order on the Internet. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Ambient aerodynamic ionization source for remote analyte sampling and mass spectrometric analysis.

PubMed

Dixon, R Brent; Sampson, Jason S; Hawkridge, Adam M; Muddiman, David C

2008-07-01

The use of aerodynamic devices in ambient ionization source development has become increasingly prevalent in the field of mass spectrometry. In this study, an air ejector has been constructed from inexpensive, commercially available components to incorporate an electrospray ionization emitter within the exhaust jet of the device. This novel aerodynamic device, herein termed remote analyte sampling, transport, and ionization relay (RASTIR) was used to remotely sample neutral species in the ambient and entrain them into an electrospray plume where they were subsequently ionized and detected using a linear ion trap Fourier transform mass spectrometer. Two sets of experiments were performed in the ambient environment to demonstrate the device's utility. The first involved the remote (approximately 1 ft) vacuum collection of pure sample particulates (i.e., dry powder) from a glass slide, entrainment and ionization at the ESI emitter, and mass spectrometric detection. The second experiment involved the capture (vacuum collection) of matrix-assisted laser desorbed proteins followed by entrainment in the ESI emitter plume, multiple charging, and mass spectrometric detection. This approach is in principle a RASTIR-assisted matrix-assisted laser desorption electrospray ionization source (Sampson, J. S.; Hawkridge, A. M.; Muddiman, D. C. J. Am. Soc. Mass Spectrom. 2006, 17, 1712-1716; Rapid Commun. Mass Spectrom. 2007, 21, 1150-1154.). A detailed description of the device construction, operational parameters, and preliminary small molecule and protein data are presented.

Mass spectrometric gas composition measurements associated with jet interaction tests in a high-enthalpy wind tunnel

NASA Technical Reports Server (NTRS)

Lewis, B. W.; Brown, K. G.; Wood, G. M., Jr.; Puster, R. L.; Paulin, P. A.; Fishel, C. E.; Ellerbe, D. A.

1986-01-01

Knowledge of test gas composition is important in wind-tunnel experiments measuring aerothermodynamic interactions. This paper describes measurements made by sampling the top of the test section during runs of the Langley 7-Inch High-Temperature Tunnel. The tests were conducted to determine the mixing of gas injected from a flat-plate model into a combustion-heated hypervelocity test stream and to monitor the CO2 produced in the combustion. The Mass Spectrometric (MS) measurements yield the mole fraction of N2 or He and CO2 reaching the sample inlets. The data obtained for several tunnel run conditions are related to the pressures measured in the tunnel test section and at the MS ionizer inlet. The apparent distributions of injected gas species and tunnel gas (CO2) are discussed relative to the sampling techniques. The measurements provided significant real-time data for the distribution of injected gases in the test section. The jet N2 diffused readily from the test stream, but the jet He was mostly entrained. The amounts of CO2 and Ar diffusing upward in the test section for several run conditions indicated the variability of the combustion-gas test-stream composition.

Mass Spectrometric Methodologies for Investigating the Metabolic Signatures of Parkinson's Disease: Current Progress and Future Perspectives.

PubMed

Gill, Emily L; Koelmel, Jeremy P; Yost, Richard A; Okun, Michael S; Vedam-Mai, Vinata; Garrett, Timothy J

2018-03-06

Parkinson's disease (PD) is a neurodegenerative disorder resulting from the loss of dopaminergic neurons of the substantia nigra as well as degeneration of motor and nonmotor basal ganglia circuitries. Typically known for classical motor deficits (tremor, rigidity, bradykinesia), early stages of the disease are associated with a large nonmotor component (depression, anxiety, apathy, etc.). Currently, there are no definitive biomarkers of PD, and the measurement of dopamine metabolites does not allow for detection of prodromal PD nor does it aid in long-term monitoring of disease progression. Given that PD is increasingly recognized as complex and heterogeneous, involving several neurotransmitters and proteins, it is of importance that we advance interdisciplinary studies to further our knowledge of the molecular and cellular pathways that are affected in PD. This approach will possibly yield useful biomarkers for early diagnosis and may assist in the development of disease-modifying therapies. Here, we discuss preanalytical factors associated with metabolomics studies, summarize current mass spectrometric methodologies used to evaluate the metabolic signature of PD, and provide future perspectives of the rapidly developing field of MS in the context of PD.

gamma-Hexachlorocyclohexane (gamma-HCH)

Integrated Risk Information System (IRIS)

gamma - Hexachlorocyclohexane ( gamma - HCH ) ; CASRN 58 - 89 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Asse

A liquid chromatography-mass spectrometric method for the determination of oak moss allergens atranol and chloroatranol in perfumes.

PubMed

Bossi, Rossana; Rastogi, Suresh C; Bernard, Guillaume; Gimenez-Arnau, Elena; Johansen, Jeanne D; Lepoittevin, Jean-Pierre; Menné, Torkil

2004-05-01

This paper describes a validated liquid chromatographic-tandem mass spectrometric method for quantitative analysis of the potential oak moss allergens atranol and chloroatranol in perfumes and similar products. The method employs LC-MS-MS with electrospray ionization (ESI) in negative mode. The compounds are analysed by selective reaction monitoring (SRM) of 2 or 3 ions for each compound in order to obtain high selectivity and sensitivity. The method has been validated for the following parameters: linearity; repeatability; recovery; limit of detection; and limit of quantification. The limits of detection, 5.0 ng/mL and 2.4 ng/mL, respectively, for atranol and chloroatranol, achieved by this method allowed identification of these compounds at concentrations below those causing allergic skin reactions in oak-moss-sensitive patients. The recovery of chloratranol from spiked perfumes was 96+/-4%. Low recoveries (49+/-5%) were observed for atranol in spiked perfumes, indicating ion suppression caused by matrix components. The method has been applied to the analysis of 10 randomly selected perfumes and similar products.

ESA presents INTEGRAL, its space observatory for Gamma-ray astronomy

NASA Astrophysics Data System (ADS)

1998-09-01

more strange than the energetic radiation coming from the centre of distant galaxies are flashes of extremely powerful radiation that suddenly appear somewhere on the gamma-sky and disappear again after a short time. These gamma-bursts seem to be the biggest observed explosions in the Universe. But nobody knows their source. Integral will help to solve this long-standing mystery. ESA, the pioneer in gamma-ray astronomy The satellite as it can now be seen at ESA's test centre is five meters high and weighs more than four tonnes. Two main instruments observe the gamma-rays. An imager will give the sharpest gamma-ray images. It is provided by a consortium led by an Italian scientist. Gamma-rays ignore lenses and mirror, so INTEGRAL makes its images with so-called coded-masks. A coded-mask telescope is basically a pinhole camera, but with a larger aperture, i.e. many pinholes. A spectrometer will gauge gamma-ray energies extremely precisely. It is developed by a team of scientists under joint French-German leadership and will be a 100 times more sensitive than the previous high spectral resolution space instrument. It is made of a high-purity Germanium detector that has to be cooled down to minus 188 degree Celsius. These two gamma-ray-instruments are supported by two monitor instruments that play a crucial role in the detection and identification of the gamma-ray sources. An X-ray monitor developed in Denmark will observe X-rays, still powerful but less energetic than gamma-rays. An optical telescope provided by Spain will observe the visible light emitted by the energetic objects. Switzerland will host the Integral Science Data Centre which will preprocess and distribute the scientific data. The mission is conceived as an observatory led by ESA with Russia contributing the launcher and NASA providing tracking support with its Deep Space Network. Alenia Aerospazio in Turin, Italy is ESA's prime contractor for building INTEGRAL. Launch by a Russian Proton rocket from

Improved extrinsic polymer optical fiber sensors for gamma-ray monitoring in radioprotection applications

NASA Astrophysics Data System (ADS)

de Andrés, A. I.; Esteban, Ó.; Embid, M.

2017-08-01

Gamma radiation detection in the range of 662 keV, the reference for environmental protection, is done through extrinsic optical fiber sensors. The fluorescence rendered by an inorganic scintillator when irradiated with such gamma rays is gathered by a modified polymer optical fiber tip. This modification increases the recorded signal when compared with plain unaltered fiber. Two fiber tip modification are then compared in terms of light gathering capability. A chemically etched fiber, in which the cladding and part of the core are removed, and a tapered fiber in which the core-cladding structure is kept. Both structures are comparable in length and final diameter, and show linear response in the tested range up to 2 Gy/h air Kerma rate. The etched fiber shows a higher slope than the tapered one, although both improve the signal gathered by a plain fiber tip. The easy fabrication and handling of the reported transducers, together with the improved signal gathering, allow to reduce the overall system budget with the use of low-cost optoelectronics in the detection stage. This offers a significant improvement for surveillance systems in radioprotection applications, in which presence of gamma radiation coming out accidental leakage or spurious sources activity is the main target.

The use of gas chromatographic-mass spectrometric-computer systems in pharmacokinetic studies.

PubMed

Horning, M G; Nowlin, J; Stafford, M; Lertratanangkoon, K; Sommer, K R; Hill, R M; Stillwell, R N

1975-10-29

Pharmacokinetic studies involving plasma, urine, breast milk, saliva and liver homogenates have been carried out by selective ion detection with a gas chromatographic-mass spectrometric-computer system operated in the chemical ionization mode. Stable isotope labeled drugs were used as internal standards for quantification. The half-lives, the concentration at zero time, the slope (regression coefficient), the maximum velocity of the reaction and the apparent Michaelis constant of the reaction were determined by regression analysis, and also by graphic means.

Mass spectrometric profiling of low-molecular-weight volatile compounds--diagnostic potential and latest applications.

PubMed

Lechner, Matthias; Rieder, Josef

2007-01-01

The theoretical use of mass spectrometric profiling of low-molecular-weight volatile compounds, as one possible method to non-invasively and rapidly diagnose a variety of diseases, such as cancer, infection, and metabolic disorders has greatly raised the profile of this technique over the last ten years. Despite a number of promising results, this technique has not been introduced into common clinical practice yet. The use of mass spectrometric profiling of exhaled air is particularly hampered by various technical problems and basic methodological issues which have only been partially overcome. However, breath analysis aside, recently published studies reveal completely new ideas and concepts on how to establish fast and reliable diagnosis by using this valuable tool. These studies focussed on the headspace screening of various bodily fluids and sample fluids obtained during diagnostic procedures, as well as microbial cell cultures and demonstrated the vast diagnostic potential of this technique in a wide variety of settings, predominantly in vitro. It is the aim of the present review to discuss the most commonly detected low-molecular-weight volatile compounds and to summarize the current potential applications, latest developments and future perspectives of this promising diagnostic approach.

Fermi GBM Observations of Terrestrial Gamma Flashes

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.; Briggs, M. S.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R.; Kippen, R. M.; von Kienlin, A.; Dwyer, J. R.; Smith, D. M.;

Unidentified Gamma-Ray Sources: Hunting Gamma-Ray Blazars

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

Massaro, F.; D'Abrusco, R.; Tosti, G.

2012-04-02

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of the unidentified {gamma}-ray sources (UGSs). Despite the large improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one third of the Fermi-detected objects are still not associated to low energy counterparts. Recently, using the Wide-field Infrared Survey Explorer (WISE) survey, we discovered that blazars, the rarest class of Active Galactic Nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Basedmore » on this result, we designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated to the UGS sample of the second Fermi {gamma}-ray catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated to {gamma}-ray sources in the 2FGL catalog.« less

UNIDENTIFIED {gamma}-RAY SOURCES: HUNTING {gamma}-RAY BLAZARS

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

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

2012-06-10

One of the main scientific objectives of the ongoing Fermi mission is unveiling the nature of unidentified {gamma}-ray sources (UGSs). Despite the major improvements of Fermi in the localization of {gamma}-ray sources with respect to the past {gamma}-ray missions, about one-third of the Fermi-detected objects are still not associated with low-energy counterparts. Recently, using the Wide-field Infrared Survey Explorer survey, we discovered that blazars, the rarest class of active galactic nuclei and the largest population of {gamma}-ray sources, can be recognized and separated from other extragalactic sources on the basis of their infrared (IR) colors. Based on this result, wemore » designed an association method for the {gamma}-ray sources to recognize if there is a blazar candidate within the positional uncertainty region of a generic {gamma}-ray source. With this new IR diagnostic tool, we searched for {gamma}-ray blazar candidates associated with the UGS sample of the second Fermi {gamma}-ray LAT catalog (2FGL). We found that our method associates at least one {gamma}-ray blazar candidate as a counterpart to each of 156 out of 313 UGSs analyzed. These new low-energy candidates have the same IR properties as the blazars associated with {gamma}-ray sources in the 2FGL catalog.« less

DRIFT CONTROL IN AN ANALYTICAL GAMMA RAY SPECTROMETER

DOEpatents

Fite, L.E.

1963-08-20

A device for automatically and continuously controlling the over-all drift of a multi-channel analyzer so as to permit the accurate processing of spectrometric analytical data by a digital computer is described. Two sources of reference pulses, one of which is stored in the lower channels and the other being stored in the higher channels of a 256 channel analyzer, are provided. The reference pulses are processed in the same manner as the data pulses. The channels that should contain the reference pulses and the adjacent channels above and below those channels are monitored by comparison circuits such that any drift, upward or downward, of the reference pulses is detected to effect a change in high voltage supply in response to a drift in the upper channel, and to effect a change in the lower discriminator level of the analog to digital converter of the analyzer in response to a drift in the lower channel, thereby maintaining the pulses in the proper channels. (AEC)

Installation and calibration of Kayzero-assisted NAA in three Central European countries via a Copernicus project.

PubMed

De Corte, F; van Sluijs, R; Simonits, A; Kucera, J; Smodis, B; Byrne, A R; De Wispelaere, A; Bossus, D; Frána, J; Horák, Z; Jaćimović, R

2001-09-01

An account is given of the installation and calibration of k0-based NAA--assisted by the DSM Kayzero/Solcoi software package--at the KFKI-AEKI, Budapest, the NPI, Rez and the IJS, Ljubljana. Not only the calibration of the Ge-detectors and the irradiation facilities are discussed, but also other important topics such as gamma-spectrometric hard- and software, QC/QA of the IRMM-530 Al-Au flux monitor and the upgrade of the Kayzero/Solcoi code. The work was performed in the framework of a European Copernicus JRP, coordinated by the Laboratory of Analytical Chemistry, Gent, with DSM Research, Geleen, as the industrial partner.

International remote monitoring project Argentina Nuclear Power Station Spent Fuel Transfer Remote Monitoring System

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

Schneider, S.; Lucero, R.; Glidewell, D.

1997-08-01

The Autoridad Regulataria Nuclear (ARN) and the United States Department of Energy (DOE) are cooperating on the development of a Remote Monitoring System for nuclear nonproliferation efforts. A Remote Monitoring System for spent fuel transfer will be installed at the Argentina Nuclear Power Station in Embalse, Argentina. The system has been designed by Sandia National Laboratories (SNL), with Los Alamos National Laboratory (LANL) and Oak Ridge National Laboratory (ORNL) providing gamma and neutron sensors. This project will test and evaluate the fundamental design and implementation of the Remote Monitoring System in its application to regional and international safeguards efficiency. Thismore » paper provides a description of the monitoring system and its functions. The Remote Monitoring System consists of gamma and neutron radiation sensors, RF systems, and video systems integrated into a coherent functioning whole. All sensor data communicate over an Echelon LonWorks Network to a single data logger. The Neumann DCM 14 video module is integrated into the Remote Monitoring System. All sensor and image data are stored on a Data Acquisition System (DAS) and archived and reviewed on a Data and Image Review Station (DIRS). Conventional phone lines are used as the telecommunications link to transmit on-site collected data and images to remote locations. The data and images are authenticated before transmission. Data review stations will be installed at ARN in Buenos Aires, Argentina, ABACC in Rio De Janeiro, IAEA Headquarters in Vienna, and Sandia National Laboratories in Albuquerque, New Mexico. 2 refs., 2 figs.« less

Estimation of the Vertical Distribution of Radiocesium in Soil on the Basis of the Characteristics of Gamma-Ray Spectra Obtained via Aerial Radiation Monitoring Using an Unmanned Helicopter.

PubMed

Ochi, Kotaro; Sasaki, Miyuki; Ishida, Mutsushi; Hamamoto, Shoichiro; Nishimura, Taku; Sanada, Yukihisa

2017-08-17

After the Fukushima Daiichi Nuclear Power Plant accident, the vertical distribution of radiocesium in soil has been investigated to better understand the behavior of radiocesium in the environment. The typical method used for measuring the vertical distribution of radiocesium is troublesome because it requires collection and measurement of the activity of soil samples. In this study, we established a method of estimating the vertical distribution of radiocesium by focusing on the characteristics of gamma-ray spectra obtained via aerial radiation monitoring using an unmanned helicopter. The estimates are based on actual measurement data collected at an extended farm. In this method, the change in the ratio of direct gamma rays to scattered gamma rays at various depths in the soil was utilized to quantify the vertical distribution of radiocesium. The results show a positive correlation between the abovementioned and the actual vertical distributions of radiocesium measured in the soil samples. A vertical distribution map was created on the basis of this ratio using a simple equation derived from the abovementioned correlation. This technique can provide a novel approach for effective selection of high-priority areas that require decontamination.

Estimation of the Vertical Distribution of Radiocesium in Soil on the Basis of the Characteristics of Gamma-Ray Spectra Obtained via Aerial Radiation Monitoring Using an Unmanned Helicopter

PubMed Central

Ochi, Kotaro; Sasaki, Miyuki; Ishida, Mutsushi; Sanada, Yukihisa

2017-01-01

After the Fukushima Daiichi Nuclear Power Plant accident, the vertical distribution of radiocesium in soil has been investigated to better understand the behavior of radiocesium in the environment. The typical method used for measuring the vertical distribution of radiocesium is troublesome because it requires collection and measurement of the activity of soil samples. In this study, we established a method of estimating the vertical distribution of radiocesium by focusing on the characteristics of gamma-ray spectra obtained via aerial radiation monitoring using an unmanned helicopter. The estimates are based on actual measurement data collected at an extended farm. In this method, the change in the ratio of direct gamma rays to scattered gamma rays at various depths in the soil was utilized to quantify the vertical distribution of radiocesium. The results show a positive correlation between the abovementioned and the actual vertical distributions of radiocesium measured in the soil samples. A vertical distribution map was created on the basis of this ratio using a simple equation derived from the abovementioned correlation. This technique can provide a novel approach for effective selection of high-priority areas that require decontamination. PMID:28817098

The postoperative course of gamma-glutamyl transpeptidase--a marker of cytomegalovirus (CMV) replication risk?

PubMed

Schenk, M; Zipfel, A; Kratt, T; Petersen, P; Becker, H D; Viebahn, R

2000-11-01

Cytomegalovirus (CMV) infection is a common complication in the postoperative course of liver transplantation. In order to start early prophylactic therapy, but to avoid unnecessary treatment, or expensive screening, a desirable goal in post-transplant monitoring is to find appropriate markers in standard laboratory diagnostics. In the present study, the results of a 6-week CMV replication monitoring schedule by the pp65 antigenemia assay in 100 liver graft recipients were included. The activities of transaminases, glutamate dehydrogenase and gamma-glutamyl transpeptidase (gamma-GT) were measured by routine laboratory methods. In contrast to the transaminases, the serum activity of gamma-GT increased during the first postoperative week. The maximum levels were 246 +/- 211 U/l in patients without (n = 46) and 140 +/- 89 U/l in patients with early CMV replication (n = 54; p = 0.02). Patients with gamma-GT levels below 200 U/l on the 5th postoperative day (n = 72) had a CMV replication risk of 65%, whereas those patients with gamma-GT levels above this threshold had a risk of 30% (n = 28; p = 0.0007; relative risk = 2.9). These findings provide a routinely usable marker for the identification of patients at an increased risk of CMV replication. It can be considered that these phenomena may be caused by an additional immunosuppressive effect of the CMV virus.

Proof of Principle for Electronic Collimation of a Gamma Ray Detector

DTIC Science & Technology

2016-01-01

complete the Environmental Baseline Survey mission for soldiers. The monitoring of radioactive waste handling, as well as other sources of radioactive ...electronic collimation of a gamma ray spectroscopic detector will include identifying and characterizing environmentally hazardous radioactivity to

Mass Spectrometric Detection of Bacterial Protein Toxins and Their Enzymatic Activity.

PubMed

Kalb, Suzanne R; Boyer, Anne E; Barr, John R

2015-08-31

Mass spectrometry has recently become a powerful technique for bacterial identification. Mass spectrometry approaches generally rely upon introduction of the bacteria into a matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometer with mass spectrometric recognition of proteins specific to that organism that form a reliable fingerprint. With some bacteria, such as Bacillus anthracis and Clostridium botulinum, the health threat posed by these organisms is not the organism itself, but rather the protein toxins produced by the organisms. One such example is botulinum neurotoxin (BoNT), a potent neurotoxin produced by C. botulinum. There are seven known serotypes of BoNT, A-G, and many of the serotypes can be further differentiated into toxin variants, which are up to 99.9% identical in some cases. Mass spectrometric proteomic techniques have been established to differentiate the serotype or toxin variant of BoNT produced by varied strains of C. botulinum. Detection of potent biological toxins requires high analytical sensitivity and mass spectrometry based methods have been developed to determine the enzymatic activity of BoNT and the anthrax lethal toxins produced by B. anthracis. This enzymatic activity, unique for each toxin, is assessed with detection of the toxin-induced cleavage of strategically designed peptide substrates by MALDI-TOF mass spectrometry offering unparalleled specificity. Furthermore, activity assays allow for the assessment of the biological activity of a toxin and its potential health risk. Such methods have become important diagnostics for botulism and anthrax. Here, we review mass spectrometry based methods for the enzymatic activity of BoNT and the anthrax lethal factor toxin.

Growth kinetics of gamma-prime precipitates in a directionally solidified eutectic, gamma/gamma-prime-delta

NASA Technical Reports Server (NTRS)

Tewari, S. N.

1976-01-01

A directionally solidified eutectic alloy (DSEA), of those viewed as potential candidates for the next generation of aircraft gas turbine blade materials, is studied for the gamma-prime growth kinetics, in the system Ni-Nb-Cr-Al, specifically: Ni-20 w/o Nb-6 w/o Cr-2.5 w/o Al gamma/gamma-prime-delta DSEA. Heat treatment, polishing and etching, and preparation for electron micrography are described, and the size distribution of gamma-prime phase following various anneals is plotted, along with gamma-prime growth kinetics in this specific DSEA, and the cube of gamma-prime particle size vs anneal time. Activation energies and coarsening kinetics are studied.

The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)

NASA Astrophysics Data System (ADS)

Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders; Allard, Stefan

2015-05-01

Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak 252Cf neutron-gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

Terrestrial gamma-ray flashes monitor demonstrator on CubeSat

NASA Astrophysics Data System (ADS)

Dániel, V.; Pína, L.; Inneman, A.; Zadražil, V.; Báča, T.; Platkevič, M.; Stehlíková, V.; Nentvich, O.; Urban, M.

2016-09-01

The CubeSat mission with the demonstrator of miniaturized X-ray telescope is presented. The paper presents one of the mission objectives of using the instrument for remote sensing of the Terrestrial Gamma-ray Flashes (TGFs). TGFs are intense sources of gamma-rays associated with lightning bolt activity and tropical thunderstorms. The measurement of TGFs exists and was measured by sounding rockets, high altitude balloons or several satellite missions. Past satellite missions were equipped with different detectors working from 10 keV up to 10 MeV. The RHESSI mission spectrum measurement of TGFs shows the maximum counts per second around 75 keV. The used detectors were in general big in volume and cannot be utilized by the CubeSat mission. The presented CubeSat is equipped with miniaturized X-ray telescope using the Timepix non-cooled pixel detector. The detector works between 3 and 60 keV in counting mode (dosimetry) or in spectrum mode with resolution 5 keV. The wide-field X-ray "Lobster-eye" optics/collimator (depending on energy) is used with a view angle of 3 degrees for the source location definition. The UV detectors with FOV 30 degrees and 1.5 degrees are added parallel with the optic as a part of the telescope. The telescope is equipped with software distinguishing between the photons and other particles. Using this software the TGF's detection is possible also in the field of South Atlantic anomaly. For the total ionization dose, the additional detector is used based on Silicone (12-60 keV) and CdTe (20 keV - 1 MeV). The presented instruments are the demonstrators suitable also for the astrophysical, sun and moon observation. The paper shows the details of TGF's observation modes, detectors details, data processing and handling system and mission. The CubeSat launch is planned to summer 2016.

Power monitoring in space nuclear reactors using silicon carbide radiation detectors

NASA Technical Reports Server (NTRS)

Ruddy, Frank H.; Patel, Jagdish U.; Williams, John G.

2005-01-01

Space reactor power monitors based on silicon carbide (SiC) semiconductor neutron detectors are proposed. Detection of fast leakage neutrons using SiC detectors in ex-core locations could be used to determine reactor power: Neutron fluxes, gamma-ray dose rates and ambient temperatures have been calculated as a function of distance from the reactor core, and the feasibility of power monitoring with SiC detectors has been evaluated at several ex-core locations. Arrays of SiC diodes can be configured to provide the required count rates to monitor reactor power from startup to full power Due to their resistance to temperature and the effects of neutron and gamma-ray exposure, SiC detectors can be expected to provide power monitoring information for the fill mission of a space reactor.

A membrane-separator interface for mass-spectrometric analysis of blood plasma

NASA Astrophysics Data System (ADS)

Elizarov, A. Yu.; Gerasimov, D. G.

2014-09-01

We demonstrate the possibility of rapid mass-spectrometric determination of the content of anesthetic agents in blood plasma with the aid of a membrane-separator interface. The interface employs a hydrophobic selective membrane that is capable of separating various anesthetic drugs (including inhalation anesthetic sevofluran, noninhalation anesthetic thiopental, hypnotic propofol, and opioid analgesic fentanyl) from the blood plasma and introducing samples into a mass spectrometer. Analysis of the blood plasma was not accompanied by the memory effect and did not lead to membrane degradation. Results of clinical investigation of the concentration of anesthetics in the blood plasma of patients are presented.

Searching the Gamma-Ray Sky for Counterparts to Gravitational Wave Sources Fermi Gamma-Ray Burst Monitor and Large Area Telescope Observations of LVT151012 and GW151226

NASA Technical Reports Server (NTRS)

Racusin, J. L.; Burns, E.; Goldstein, A.; Connaughton, V.; Wilson-Hodge, C. A.; Jenke, P.; Blackburn, L.; Briggs, M. S.; Broida, J.; Camp, J.;

Correction to: Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate

NASA Astrophysics Data System (ADS)

Oyler, Benjamin L.; Khan, Mohd M.; Smith, Donald F.; Harberts, Erin M.; Kilgour, David P. A.; Ernst, Robert K.; Cross, Alan S.; Goodlett, David R.

2018-04-01

In the preceding article "Top Down Tandem Mass Spectrometric Analysis of a Chemically Modified Rough-Type Lipopolysaccharide Vaccine Candidate" by Oyler et al., an error in the J5 E. coli LPS chemical structure (Figs. 2 and 4) was introduced and propagated into the final revision.

Detection of gamma-irradiation effect on DNA and protein using magnetic sensor and cyclic voltammetry.

PubMed

Park, Duck-Gun; Song, Hoon; Kishore, M B; Vértesy, G; Lee, Duk-Hyun

2013-11-01

In this study, a magnetic sensor utilizing Planar Hall Resistance (PHR) and cyclic Voltammetry (CV) for detecting the radiation effect was fabricated. Specifically, we applied in parallel a PHR sensor and CV device to monitor the irradiation effect on DNA and protein respectively. Through parallel measurements, we demonstrated that the PHR sensor and CV are sensitive enough to measure irradiation effect. The PHR voltage decreased by magnetic nanobead labeled DNA was slightly recovered after gamma ray irradiation. The behavior of cdk inhibitor protein p21 having a sandwich structure of Au/protein G/Ab/Ag/Ab was checked by monitoring the cyclic Voltammetry signal in analyzing the gamma ray irradiation effect.

FITPix COMBO—Timepix detector with integrated analog signal spectrometric readout

NASA Astrophysics Data System (ADS)

Holik, M.; Kraus, V.; Georgiev, V.; Granja, C.

2016-02-01

The hybrid semiconductor pixel detector Timepix has proven a powerful tool in radiation detection and imaging. Energy loss and directional sensitivity as well as particle type resolving power are possible by high resolution particle tracking and per-pixel energy and quantum-counting capability. The spectrometric resolving power of the detector can be further enhanced by analyzing the analog signal of the detector common sensor electrode (also called back-side pulse). In this work we present a new compact readout interface, based on the FITPix readout architecture, extended with integrated analog electronics for the detector's common sensor signal. Integrating simultaneous operation of the digital per-pixel information with the common sensor (called also back-side electrode) analog pulse processing circuitry into one device enhances the detector capabilities and opens new applications. Thanks to noise suppression and built-in electromagnetic interference shielding the common hardware platform enables parallel analog signal spectroscopy on the back side pulse signal with full operation and read-out of the pixelated digital part, the noise level is 600 keV and spectrometric resolution around 100 keV for 5.5 MeV alpha particles. Self-triggering is implemented with delay of few tens of ns making use of adjustable low-energy threshold of the particle analog signal amplitude. The digital pixelated full frame can be thus triggered and recorded together with the common sensor analog signal. The waveform, which is sampled with frequency 100 MHz, can be recorded in adjustable time window including time prior to the trigger level. An integrated software tool provides control, on-line display and read-out of both analog and digital channels. Both the pixelated digital record and the analog waveform are synchronized and written out by common time stamp.

Angular sensitivities of scintillator slab configurations for location of gamma ray bursts

NASA Technical Reports Server (NTRS)

Gregory, J. C.

1976-01-01

Thin flat scintillator slabs are a useful means of measuring the angular location of gamma ray fluxes of astronomical interest. A statistical estimate of position error was made of two scintillator systems suitable for gamma ray burst location from a balloon or satellite platform. A single rotating scintillator with associated flux monitor is compared with a pair of stationary orthogonal scintillators. Position error for a strong burst is of the order of a few arcmin if systematic errors are ignored.

Quantitation of dissolved gas content in emulsions and in blood using mass spectrometric detection

PubMed Central

Grimley, Everett; Turner, Nicole; Newell, Clayton; Simpkins, Cuthbert; Rodriguez, Juan

2011-01-01

Quantitation of dissolved gases in blood or in other biological media is essential for understanding the dynamics of metabolic processes. Current detection techniques, while enabling rapid and convenient assessment of dissolved gases, provide only direct information on the partial pressure of gases dissolved in the aqueous fraction of the fluid. The more relevant quantity known as gas content, which refers to the total amount of the gas in all fractions of the sample, can be inferred from those partial pressures, but only indirectly through mathematical modeling. Here we describe a simple mass spectrometric technique for rapid and direct quantitation of gas content for a wide range of gases. The technique is based on a mass spectrometer detector that continuously monitors gases that are rapidly extracted from samples injected into a purge vessel. The accuracy and sample processing speed of the system is demonstrated with experiments that reproduce within minutes literature values for the solubility of various gases in water. The capability of the technique is further demonstrated through accurate determination of O2 content in a lipid emulsion and in whole blood, using as little as 20 μL of sample. The approach to gas content quantitation described here should greatly expand the range of animals and conditions that may be used in studies of metabolic gas exchange, and facilitate the development of artificial oxygen carriers and resuscitation fluids. PMID:21497566

Very high-energy gamma rays from gamma-ray bursts.

PubMed

Chadwick, Paula M

2007-05-15

Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

Mass spectrometric identification of an azobenzene derivative produced by smectite-catalyzed conversion of 3-amino-4-hydroxyphenylarsonic acid

USGS Publications Warehouse

Wershaw, R. L.; Rutherford, D.W.; Rostad, C.E.; Garbarino, J.R.; Ferrer, I.; Kennedy, K.R.; Momplaisir, G.-M.; Grange, A.

2003-01-01

The compound 3-amino-4-hydroxyphenylarsonic acid (3-amino-HPAA) reacts with smectite to form a soluble azobenzene arsonic acid compound. This reaction is of particular interest because it provides a possible mechanism for the formation of a new type of arsenic compound in natural water systems. 3-Amino-HPAA is a degradation product excreted by chickens that are fed rations amended with roxarsone. Roxarsone is used to control coccidial intestinal parasites in most of the broiler chickens grown in the United States. The structure of the azobenzene arsonic acid compound was first inferred from negative-ion and positive-ion low-resolution mass-spectrometric analyses of the supernatant of the smectite suspension. Elemental composition of the parent ion determined by high-resolution positive-ion mass spectrometric measurements was consistent with the proposed structure of the azobenzene arsonic acid compound. Published by Elsevier Science B.V.

Monitoring structural features, biocompatibility and biological efficacy of gamma-irradiated methotrexate-loaded spray-dried microparticles.

PubMed

de Oliveira, Alice R; Mesquita, Philippe C; Machado, Paula R L; Farias, Kleber J S; de Almeida, Yêda M B; Fernandes-Pedrosa, Matheus F; Cornélio, Alianda M; do Egito, Eryvaldo Sócrates T; da Silva-Júnior, Arnóbio A

2017-11-01

In this study, biodegradable and biocompatible gamma irradiated poly-(dl-lactide-co-glycolide) (PLGA) spray-dried microparticles were prepared aiming to improve the efficacy of methotrexate (MTX). The experimental design included three formulations of microparticles containing distinct drug amount (9%, 18%, and 27% w/w) and three distinct gamma irradiation dose (15kGy, 25kGy, and 30kGy). The physicochemical and drug release properties of the microparticles supported their biocompatibility and biological efficacy studies in different cell lines. The irradiation induced slight changes in the spherical shape of the microparticles and the formation of free radicals was dependent on the drug loading. However, the amorphous character, particle size, drug loading, and drug release rate of the microparticles were preserved. The drug release data from all microparticles formulation were evaluated by using four drug kinetic models and by comparison of their similarity factor (f 2 ). The gamma irradiation did not induce changes in the biocompatibility of PLGA microparticles and in the biological activity of the MTX-loaded microparticles. Finally, the spray-dried MTX-loaded PLGA microparticles enhanced the efficacy of the drug in the human cervical cancer cells (SiHa cell line). This study demonstrated the feasibility of the gamma irradiated spray dried PLGA microparticles for prolonged release of MTX, supporting a promising antitumor-drug delivery system for parenteral (subcutaneous) or pulmonary use. Copyright © 2017 Elsevier B.V. All rights reserved.

The First FERMI-LAT Gamma-Ray Burst Catalog

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Asano, K.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.;

Mass Spectrometric Detection of Bacterial Protein Toxins and Their Enzymatic Activity

PubMed Central

Kalb, Suzanne R.; Boyer, Anne E.; Barr, John R.

2015-01-01

Mass spectrometry has recently become a powerful technique for bacterial identification. Mass spectrometry approaches generally rely upon introduction of the bacteria into a matrix-assisted laser-desorption time-of-flight (MALDI-TOF) mass spectrometer with mass spectrometric recognition of proteins specific to that organism that form a reliable fingerprint. With some bacteria, such as Bacillus anthracis and Clostridium botulinum, the health threat posed by these organisms is not the organism itself, but rather the protein toxins produced by the organisms. One such example is botulinum neurotoxin (BoNT), a potent neurotoxin produced by C. botulinum. There are seven known serotypes of BoNT, A–G, and many of the serotypes can be further differentiated into toxin variants, which are up to 99.9% identical in some cases. Mass spectrometric proteomic techniques have been established to differentiate the serotype or toxin variant of BoNT produced by varied strains of C. botulinum. Detection of potent biological toxins requires high analytical sensitivity and mass spectrometry based methods have been developed to determine the enzymatic activity of BoNT and the anthrax lethal toxins produced by B. anthracis. This enzymatic activity, unique for each toxin, is assessed with detection of the toxin-induced cleavage of strategically designed peptide substrates by MALDI-TOF mass spectrometry offering unparalleled specificity. Furthermore, activity assays allow for the assessment of the biological activity of a toxin and its potential health risk. Such methods have become important diagnostics for botulism and anthrax. Here, we review mass spectrometry based methods for the enzymatic activity of BoNT and the anthrax lethal factor toxin. PMID:26404376

The gas-chromatographic and gas-chromatographic-mass-spectrometric identification of halogen-containing organic compounds

NASA Astrophysics Data System (ADS)

Gidaspov, B. V.; Zenkevich, I. G.; Rodin, A. A.

1989-09-01

The problem of identifying halogen-containing organic compounds in their gas-chromatographic and gas-chromatographic-mass-spectrometric (GC-MS) determination in different materials has been examined. Particular attention has been paid not to the complete characterisation of methods for carrying out this analysis but to the most important problem of increasing the selectivity at the stages of sampling, separation, and interpretation of the gas-chromatographic and GC-MS information. The bibliography contains 292 references.

High-Pressure Liquid Chromatograph with Mass Spectrometric Detection for Analysis of Supercritical Fuels Pyrolysis Products

DTIC Science & Technology

2006-08-01

conditions will necessarily be supercritical fluids . These temperatures and pressures will also cause the fuel to undergo pyrolytic reactions, which...Spectrometric Detection for 5a. CONTRACT NUMBER Analysis of Supercritical Fuels Pyrolysis Products 5b. GRANT NUMBER FA9550-05-1-0253 5c... supercritical pyrolysis experiments with the model fuels 1-methylnaphthalene and toluene. The HPLC/UV/MS instrument facilitated the identification of fifteen 5

What Can Simbol-X Do for Gamma-ray Binaries?

NASA Astrophysics Data System (ADS)

Cerutti, B.; Dubus, G.; Henri, G.; Hill, A. B.; Szostek, A.

2009-05-01

Gamma-ray binaries have been uncovered as a new class of Galactic objects in the very high energy sky (>100 GeV). The three systems known today have hard X-ray spectra (photon index ~1.5), extended radio emission and a high luminosity in gamma-rays. Recent monitoring campaigns of LSI +61°303 in X-rays have confirmed variability in these systems and revealed a spectral hardening with increasing flux. In a generic one-zone leptonic model, the cooling of relativistic electrons accounts for the main spectral and temporal features observed at high energy. Persistent hard X-ray emission is expected to extend well beyond 10 keV. We explain how Simbol-X will constrain the existing models in connection with Fermi Space Telescope measurements. Because of its unprecedented sensitivity in hard X-rays, Simbol-X will also play a role in the discovery of new gamma-ray binaries, giving new insights into the evolution of compact binaries.

Performance of a miniature mechanically cooled HPGe gamma-spectrometer for space applications

NASA Astrophysics Data System (ADS)

Kondratjev, V.; Pchelintsev, A.; Jakovlevs, O.; Sokolov, A.; Gostilo, V.; Owens, A.

2018-01-01

We report on the development of a miniaturized HPGe gamma-spectrometer for space applications. The instrument is designed around a 158 cm3 intrinsically pure Ge crystal in the closed-end coaxial configuration, cooled by a Thales RM3 miniature Stirling cycle electric cooler. To compensate the noise induced by the mechanical cooler the digital procession of the spectrometric signals with low frequency reject filter (LFR) is applied. The complete spectrometer assembly has a mass of 3.1 kg and consumes less than 10 W under working operation. The spectrometer was tested under a number of operating conditions in a specially designed chamber, which simulates the space environment. With the mechanical cooler switched off, FWHM energy resolutions of 1.5 keV and 2.2 keV were obtained at 122 keV and 1333 keV, respectively, at the nominal operating temperature of 90 K. When the cooler was switched on the energy resolutions degraded to 2.5 keV and 4 keV respectively. However, with the LFR filter switched in, the resolutions improved significantly to 1.8 keV and 2.4 keV.

Observations of Spin-Powered Pulsars with the AGILE Gamma-Ray Telescope

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

Pellizzoni, A.; Pilia, M.; Possenti, M.

2008-12-24

AGILE is a small gamma-ray astronomy satellite mission of the Italian Space Agency dedicated to high-energy astrophysics launched in 2007 April. It provides large sky exposure levels (> or approx. 10{sup 9} cm{sup 2} s per year on the Galactic Plane) with sensitivity peaking at E{approx}400 MeV(and simultaneous X-ray monitoring in the 18-60 keV band) where the bulk of pulsar energy output is typically released. Its {approx}1 {mu}s is absolute time tagging capability makes it perfectly suited for the study of gamma-ray pulsars following up on the CGRO/EGRET heritage. In this paper we summarize the timing results obtained during themore » first year of AGILE observations of the known gamma-ray pulsars Vela, Crab, Geminga and B 1706-4. AGILE collected a large number of gamma-ray photons from EGRET pulsars ({approx}10,000 pulsed counts for Vela) in only few months of observations unveiling new interesting features at sub-millisecond level in the pulsars' high-energy light-curves and paving the way to the discovery of new gamma-ray pulsars.« less

Brilliant gamma beams for industrial applications: new opportunities, new challenges

NASA Astrophysics Data System (ADS)

Iancu, V.; Suliman, G.; Turturica, G. V.; Iovea, M.; Daito, I.; Ohgaki, H.; Matei, C.; Ur, C. A.; Balabanski, D. L.

2016-10-01

The Nuclear Physics oriented pillar of the pan-European Extreme Light Infrastructure (ELI-NP) will host an ultra-bright, energy tunable, and quasi-monochromatic gamma-ray beam system in the range of 0.2-19.5 MeV produced by laser-Compton backscattering technique. The applied research program envisioned at ELI-NP targets to use nuclear resonance fluorescence (NRF) and computed tomography to provide new opportunities for industry and society. High sensitivity NRF-based investigations can be successfully applied to safeguard applications and management of radioactive wastes as well as to uncharted fields like cultural heritage and medical imaging. Gamma-ray radioscopy and computed tomography performed at ELI-NP has the potential to achieve high resolution in industrial-sized objects provided the detection challenges introduced by the unique characteristics of the gamma beam are overcome. Here we discuss the foreseen industrial applications that will benefit from the high quality and unique characteristics of ELI-NP gamma beam and the challenges they present. We present the experimental setups proposed to be implemented for this goal, discuss their performance based on analytical calculations and numerical Monte-Carlo simulations, and comment about constrains imposed by the limitation of current scintillator detectors. Several gamma-beam monitoring devices based on scintillator detectors will also be discussed.

Fermi Observations of High-Energy Gamma-Ray Emission from GRB 080916C

DOE PAGES

Abdo, A. A.; Ackermann, M.; Arimoto, M.; ...

2009-02-19

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. Finally, the known distance of the burstmore » enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.« less

FERMI Observations of High-Energy Gamma-Ray Emission from GRB 080825C

DOE PAGES

Abdo, A. A.; Ackermann, M.; Asano, K.; ...

2009-11-24

The Fermi Gamma-ray Space Telescope has opened a new high-energy window in the study of gamma-ray bursts (GRBs). Here in this paper, we present a thorough analysis of GRB 080825C, which triggered the Fermi Gamma-ray Burst Monitor (GBM), and was the first firm detection of a GRB by the Fermi Large Area Telescope (LAT). We discuss the LAT event selections, background estimation, significance calculations, and localization for Fermi GRBs in general and GRB 080825C in particular. We show the results of temporal and time-resolved spectral analysis of the GBM and LAT data. Finally, we also present some theoretical interpretation ofmore » GRB 080825C observations as well as some common features observed in other LAT GRBs.« less

Fermi observations of high-energy gamma-ray emission from GRB 080916C.

PubMed

Abdo, A A; Ackermann, M; Arimoto, M; Asano, K; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Band, D L; Barbiellini, G; Baring, M G; Bastieri, D; Battelino, M; Baughman, B M; Bechtol, K; Bellardi, F; Bellazzini, R; Berenji, B; Bhat, P N; Bissaldi, E; Blandford, R D; Bloom, E D; Bogaert, G; Bogart, J R; Bonamente, E; Bonnell, J; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Briggs, M S; Brigida, M; Bruel, P; Burnett, T H; Burrows, D; Busetto, G; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Ceccanti, M; Cecchi, C; Celotti, A; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Connaughton, V; Conrad, J; Costamante, L; Cutini, S; Deklotz, M; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Dingus, B L; do Couto E Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Evans, P A; Fabiani, D; Farnier, C; Favuzzi, C; Finke, J; Fishman, G; Focke, W B; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Goldstein, A; Granot, J; Greiner, J; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Haller, G; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hernando Morat, J A; Hoover, A; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kavelaars, A; Kawai, N; Kelly, H; Kennea, J; Kerr, M; Kippen, R M; Knödlseder, J; Kocevski, D; Kocian, M L; Komin, N; Kouveliotou, C; Kuehn, F; Kuss, M; Lande, J; Landriu, D; Larsson, S; Latronico, L; Lavalley, C; Lee, B; Lee, S-H; Lemoine-Goumard, M; Lichti, G G; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marangelli, B; Mazziotta, M N; McBreen, S; McEnery, J E; McGlynn, S; Meegan, C; Mészáros, P; Meurer, C; Michelson, P F; Minuti, M; Mirizzi, N; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Moretti, E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nelson, D; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paciesas, W S; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Perri, M; Pesce-Rollins, M; Petrosian, V; Pinchera, M; Piron, F; Porter, T A; Preece, R; Rainò, S; Ramirez-Ruiz, E; Rando, R; Rapposelli, E; Razzano, M; Razzaque, S; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Reyes, L C; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Segal, K N; Sgrò, C; Shimokawabe, T; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stamatikos, M; Starck, J-L; Stecker, F W; Steinle, H; Stephens, T E; Strickman, M S; Suson, D J; Tagliaferri, G; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Tenze, A; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Turri, M; Tuvi, S; Usher, T L; van der Horst, A J; Vigiani, L; Vilchez, N; Vitale, V; von Kienlin, A; Waite, A P; Williams, D A; Wilson-Hodge, C; Winer, B L; Wood, K S; Wu, X F; Yamazaki, R; Ylinen, T; Ziegler, M

2009-03-27

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. The known distance of the burst enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.

The interference of medical radionuclides with occupational in vivo gamma spectrometry.

PubMed

Kol, R; Pelled, O; Canfi, A; Gilad, Y; German, U; Laichter, Y; Lantsberg, S; Fuksbrauner, R; Gold, B

2003-06-01

Radiation workers undergo routine monitoring for the evaluation of external and internal radiation exposures. The monitoring of internal exposures involves gamma spectrometry of the whole body (whole body counting) and measurements of excreta samples. Medical procedures involving internal administration of radioactive radionuclides are widely and commonly used. Medical radionuclides are typically short-lived, but high activities are generally administered, whereas occupational radionuclides are mostly long-lived and, if present, are found generally in relatively smaller quantities. The aim of the present work was to study the interference of some common medical radionuclides (201Tl, 9mTc, 57Co, and 131I) with the detection of internal occupational exposures to natural uranium and to 137Cs. Workers having undergone a medical procedure with one of the radionuclides mentioned above were asked to give frequent urine samples and to undergo whole body and thyroid counting with phoswich detectors operated at the Nuclear Research Center Negev. Urine and whole body counting monitoring were continued as long as radioactivity was detectable by gamma spectrometry. The results indicate that the activity of medical radionuclides may interfere with interpretation of occupational intakes for months after administration.

Discrimination in measures of knowledge monitoring accuracy

PubMed Central

Was, Christopher A.

2014-01-01

Knowledge monitoring predicts academic outcomes in many contexts. However, measures of knowledge monitoring accuracy are often incomplete. In the current study, a measure of students’ ability to discriminate known from unknown information as a component of knowledge monitoring was considered. Undergraduate students’ knowledge monitoring accuracy was assessed and used to predict final exam scores in a specific course. It was found that gamma, a measure commonly used as the measure of knowledge monitoring accuracy, accounted for a small, but significant amount of variance in academic performance whereas the discrimination and bias indexes combined to account for a greater amount of variance in academic performance. PMID:25339979

Differentiation of whole grain and refined wheat (T. aestivum) flour using a fuzzy mass spectrometric fingerprinting and chemometric approaches

USDA-ARS?s Scientific Manuscript database

A fuzzy mass spectrometric (MS) fingerprinting method combined with chemometric analysis was established to provide rapid discrimination between whole grain and refined wheat flour. Twenty one samples, including thirteen samples from three cultivars and eight from local grocery store, were studied....

MoonBEAM: A Beyond Earth-Orbit Gamma-Ray Burst Detector for Gravitational-Wave Astronomy

NASA Technical Reports Server (NTRS)

Hui, C. M.; Briggs, M. S.; Goldstein, A. M.; Jenke, P. A.; Kocevski, D.; Wilson-Hodge, C. A.

2018-01-01

Moon Burst Energetics All-sky Monitor (MoonBEAM) is a CubeSat concept of deploying gamma-ray detectors in cislunar space to improve localization precision for gamma-ray bursts by utilizing the light travel time difference between different orbits. We present here a gamma-ray SmallSat concept in Earth-Moon L3 halo orbit that is capable of rapid response and provide a timing baseline for localization improvement when partnered with an Earth-orbit instrument. Such an instrument would probe the extreme processes in cosmic collision of compact objects and facilitate multi-messenger time-domain astronomy to explore the end of stellar life cycles and black hole formations.

Differentiation of Aurantii Fructus Immaturus from Poniciri Trifoliatae Fructus Immaturus using Flow- injection Mass spectrometric (FIMS) Metabolic Fingerprinting Method Combined with Chemometrics

PubMed Central

Zhao, Yang; Chang, Yuan-Shiun; Chen, Pei

2015-01-01

A flow-injection mass spectrometric metabolic fingerprinting method in combination with chemometrics was used to differentiate Aurantii Fructus Immaturus from its counterfeit Poniciri Trifoliatae Fructus Immaturus. Flow-injection mass spectrometric (FIMS) fingerprints of 9 Aurantii Fructus Immaturus samples and 12 Poniciri Trifoliatae Fructus Immaturus samples were acquired and analyzed using principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA). The authentic herbs were differentiated from their counterfeits easily. Eight characteristic components which were responsible for the difference between the samples were tentatively identified. Furthermore, three out of the eight components, naringin, hesperidin, and neohesperidin, were quantified. The results are useful to help identify the authenticity of Aurantii Fructus Immaturus. PMID:25622204

Monitoring System for the Gold Target by Radiation Detectors in Hadron Experimental Facility at J-PARC

NASA Astrophysics Data System (ADS)

Muto, Ryotaro; Agari, Keizo; Aoki, Kazuya; Bessho, Kotaro; Hagiwara, Masayuki; Hirose, Erina; Ieiri, Masaharu; Iwasaki, Ruri; Katoh, Yohji; Kitagawa, Jun-ichi; Minakawa, Michifumi; Morino, Yuhei; Saito, Kiwamu; Sato, Yoshinori; Sawada, Shin'ya; Shirakabe, Yoshihisa; Suzuki, Yoshihiro; Takahashi, Hitoshi; Tanaka, Kazuhiro; Toyoda, Akihisa; Watanabe, Hiroaki; Yamanoi, Yutaka

2017-09-01

At the Hadron Experimental Facility in J-PARC, we inject a 30-GeV proton beam into a gold target to produce secondary particle beams required for various particle and nuclear physics experiments. The gold target is placed in a hermetic chamber, and helium gas is circulated in the chamber to monitor the soundness of the target. The radioactivity in helium gas is continuously monitored by gamma-ray detectors such as a germanium detector and a NaI(Tl) detector. Beam operations with those target-monitoring systems were successfully performed from April to June and October to December 2015, and from May to June 2016. In this paper, the details of the helium gas circulation system and gamma-ray detectors and the analysis results of the obtained gamma-ray spectra are reported.

[Monitoring of neopterin and INF-gamma in children with recurrent respiratory tract infection].

PubMed

Shervashidze, M R; Barabadze, K A; Vekua, M V; Akhvlediani, I K

2006-07-01

The upper and lover respiratory tract infections are usually mild and self-limited. Owing to their frequency recurrent upper and lower respiratory tract infection in children and adults constitute a major global health problem. The goal of our study was to observe 30 children with recurrent respiratory tract infection, 17 boy and 13 girl, they were treated with Ribomunyl. The control group consisted of 15 children who received only basic therapy (10 boys and 5 girls). The age of the children ranged between 8 months and 6 years. The study was conducted by the simply randomization method. Clinical and laboratory examinations were evaluated before and after treatment. The concentration of INF-gamma was rather low in study group in comparison with control group before the beginning of the treatment, that indicates insufficient stimulation of T-lymphocytes in children with recurrent infection. INF-gamma lever significantly increased after treatment (Statistically significantly P<0.05) in study group in comparison with control group. Neopterin level unlike INF-gamma in study group was higher than in the control group, before and after treatment. This fact can be explained that neopterin as a slowly acting biologically active substance remains high during the presence of recurrent infections. Ribomunyl treatment significantly increased the level of neopterin. The efficacy of the product is primarily confirmed by significant reductions in the number of recurrent infections episodes and the use of antibacterials. Combined immunostimulating effect of Ribomunyl makes it possible to use Ribomunyl to create a longterm postvaccinal protection of the child.

Quantitation of phlorizin and phloretin using an ultra high performance liquid chromatography-electrospray ionization tandem mass spectrometric method.

PubMed

Lijia, Xu; Guo, Jianru; Chen, QianQian; Baoping, Jiang; Zhang, Wei

2014-06-01

A sensitive and selective ultra high performance liquid chromatography-tandem mass spectrometric (UHPLC-MS/MS) method for the determination of phlorizin and phloretin in human plasma has been firstly developed. Samples were prepared after protein precipitation and analyzed on a C18 column interfaced with a triple quadrupole tandem mass spectrometer. Negative electrospray ionization was employed as the ionization source. The mobile phase consisted of acetonitrile-water (0.02% formic acid), using a gradient procedure. The analytes and internal standard dihydroquercetin were both detected by use of multiple reaction monitoring mode. The method was linear in the concentration range of 2.5-1000.0 ng/mL. The lower limit of quantification (LLOQ) was 2.5 ng/mL. The intra- and inter-day relative standard deviation across three validation runs over the entire concentration range was less than 9.2%. The accuracy determined at three concentrations was within ± 7.3% in terms of relative error. The total run time was 12.0 min. This assay offers advantages in terms of expediency, and suitability for the analysis of phlorizin and phloretin in various biological fluids. Copyright © 2014 Elsevier B.V. All rights reserved.

The on-line characterization of a radium slurry by gamma-ray spectrometry.

PubMed

Philips, S; Croft, S

2005-01-01

We have developed an in-line monitor to directly measure the (226)Ra concentration in a nuclear waste stream using quantitative gamma-ray spectrometry applied to the 186keV emission. The waste stream is in the form of a slurry composed of the solid waste material mixed with water. The concentration measurement includes a self-attenuation correction factor determined from a transmission measurement using the 122keV gamma from (57)Co. Presented here is the model for the measurement system and results from some initial tests.

The Imaging Spectrometric Observatory for the ATLAS 1 mission

NASA Technical Reports Server (NTRS)

Torr, Douglas G.

1995-01-01

The Imaging Spectrometric Observatory (ISO) was flown on the ATLAS 1 mission and was enormously successful, providing a baseline database on the coupled stratospheric, mesospheric, thermospheric, and ionospheric regions. Specific ISO accomplishments include measurements of the hydroxyl radical, studies of the global ionosphere, retrieval of the concentrations of neutral species from the ISO data, studies of mesospheric oxygen emissions, retrieval of mesospheric O from oxygen emissions, studies of the OH Meinel bands and the search for the Herzberg III bands, search for metallic species, studies of thermospheric nitric oxide, auroral study of molecular nitrogen emissions, and studies of thermospheric species. Apart from participation in the data analysis, the primary post-flight responsibility of Marshall Space Flight Center was the delivery of the final post mission dataset. Support provided by the University of Alabama in Huntsville is described.

The transient gamma-ray spectrometer

NASA Technical Reports Server (NTRS)

Owens, A.; Baker, R.; Cline, T. L.; Gehrels, N.; Jermakian, J.; Nolan, T.; Ramaty, R.; Smith, G.; Stilwell, D. E.; Teegarden, B. J.

1991-01-01

The authors describe the Transient Gamma-Ray Spectrometer (TGRS) to be flown onboard the WIND spacecraft. This instrument is designed to detect cosmic gamma-ray bursts over the energy range of 20 keV to 10 MeV with an expected spectroscopic resolution of 2 keV at 1 MeV (E/Delta-E = 500). The active detection element is a 215-cu cm high-purity n-type Ge crystal cooled to cryogenic temperatures by a passive radiative cooler. The geometric field of view (FOV) defined by the cooler is 170 deg FWFM. Burst data are stored directly in an onboard 2.75-Mb burst memory with an absolute timing accuracy of +/-1.5 ms. This capacity is sufficient to store the entire spectral data set of all but the largest bursts. In addition to burst measurements, the instrument will also study solar flares, search for possible diffuse background lines, and monitor the 511-keV positron annihilation radiation from the galactic center. The experiment is scheduled to be launched on a Delta II launch vehicle from Cape Canaveral on December 31, 1992.

Gamma-sky.net: Portal to the gamma-ray sky

NASA Astrophysics Data System (ADS)

Voruganti, Arjun; Deil, Christoph; Donath, Axel; King, Johannes

2017-01-01

http://gamma-sky.net is a novel interactive website designed for exploring the gamma-ray sky. The Map View portion of the site is powered by the Aladin Lite sky atlas, providing a scalable survey image tesselated onto a three-dimensional sphere. The map allows for interactive pan and zoom navigation as well as search queries by sky position or object name. The default image overlay shows the gamma-ray sky observed by the Fermi-LAT gamma-ray space telescope. Other survey images (e.g. Planck microwave images in low/high frequency bands, ROSAT X-ray image) are available for comparison with the gamma-ray data. Sources from major gamma-ray source catalogs of interest (Fermi-LAT 2FHL, 3FGL and a TeV source catalog) are overlaid over the sky map as markers. Clicking on a given source shows basic information in a popup, and detailed pages for every source are available via the Catalog View component of the website, including information such as source classification, spectrum and light-curve plots, and literature references. We intend for gamma-sky.net to be applicable for both professional astronomers as well as the general public. The website started in early June 2016 and is being developed as an open-source, open data project on GitHub (https://github.com/gammapy/gamma-sky). We plan to extend it to display more gamma-ray and multi-wavelength data. Feedback and contributions are very welcome!

Seabed gamma-ray spectrometry: applications at IAEA-MEL.

PubMed

Osvath, I; Povinec, P P

2001-01-01

The technique of underwater gamma-ray spectrometry has been developed to complement or replace the traditional sampling-sample analysis approach for applications with space-time constraints, e.g. large areas of investigation, emergency response or long-term monitoring. IAEA-MEL has used both high-efficiency NaI(Tl) and high-resolution HPGe spectrometry to investigate contamination with anthropogenic radionuclides in a variety of marine environments. Surveys at the South Pacific nuclear test sites of Mururoa and Fangataufa have been used to guide sampling in areas of high contamination around ground zero points. In the Irish Sea offshore from the Sellafield nuclear reprocessing plant, a gamma-ray survey of seabed sediment was carried out to obtain estimates of the distribution and subsequently, for the inventory of 137Cs in the investigated area.

Development of a nuclear technique for monitoring water levels in pressurized vehicles

NASA Technical Reports Server (NTRS)

Singh, J. J.; Davis, W. T.; Mall, G. H.

1983-01-01

A new technique for monitoring water levels in pressurized stainless steel cylinders was developed. It is based on differences in attenuation coefficients of water and air for Cs137 (662 keV) gamma rays. Experimentally observed gamma ray counting rates with and without water in model reservoir cylinder were compared with corresponding calculated values for two different gamma ray detection theshold energies. Calculated values include the effects of multiple scattering and attendant gamma ray energy reductions. The agreement between the measured and calculated values is reasonably good. Computer programs for calculating angular and spectral distributions of scattered radition in various media are included.

Development and application of mass spectrometric techniques for ultra-trace determination of 236U in environmental samples-A review.

PubMed

Bu, Wenting; Zheng, Jian; Ketterer, Michael E; Hu, Sheng; Uchida, Shigeo; Wang, Xiaolin

2017-12-01

Measurements of the long-lived radionuclide 236 U are an important endeavor, not only in nuclear safeguards work, but also in terms of using this emerging nuclide as a tracer in chemical oceanography, hydrology, and actinide sourcing. Depending on the properties of a sample and its neutron irradiation history, 236 U/ 238 U ratios from different sources vary significantly. Therefore, this ratio can be treated as an important fingerprint for radioactive source identification, and in particular, affords a definitive means of discriminating between naturally occurring U and specific types of anthropogenic U. The development of mass spectrometric techniques makes it possible to determine ultra-trace levels of 236 U in environmental samples. In this paper, we review the current status of mass spectrometric approaches for determination of 236 U in environmental samples. Various sample preparation methods are summarized and compared. The mass spectrometric techniques emphasized herein are thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (ICP-MS) and accelerator mass spectrometry (AMS). The strategies or principles used by each technique for the analysis of 236 U are described. The performances of these techniques in terms of abundance sensitivity and detection limit are discussed in detail. To date, AMS exhibits the best capability for ultra-trace determinations of 236 U. The levels and behaviors of 236 U in various environmental media are summarized and discussed as well. Results suggest that 236 U has an important, emerging role as a tracer for geochemical studies. Copyright © 2017 Elsevier B.V. All rights reserved.

How mass spectrometric approaches applied to bacterial identification have revolutionized the study of human gut microbiota.

PubMed

Grégory, Dubourg; Chaudet, Hervé; Lagier, Jean-Christophe; Raoult, Didier

2018-03-01

Describing the human hut gut microbiota is one the most exciting challenges of the 21 st century. Currently, high-throughput sequencing methods are considered as the gold standard for this purpose, however, they suffer from several drawbacks, including their inability to detect minority populations. The advent of mass-spectrometric (MS) approaches to identify cultured bacteria in clinical microbiology enabled the creation of the culturomics approach, which aims to establish a comprehensive repertoire of cultured prokaryotes from human specimens using extensive culture conditions. Areas covered: This review first underlines how mass spectrometric approaches have revolutionized clinical microbiology. It then highlights the contribution of MS-based methods to culturomics studies, paying particular attention to the extension of the human gut microbiota repertoire through the discovery of new bacterial species. Expert commentary: MS-based approaches have enabled cultivation methods to be resuscitated to study the human gut microbiota and thus to fill in the blanks left by high-throughput sequencing methods in terms of culturing minority populations. Continued efforts to recover new taxa using culture methods, combined with their rapid implementation in genomic databases, would allow for an exhaustive analysis of the gut microbiota through the use of a comprehensive approach.

The downfall of TBA-354 - a possible explanation for its neurotoxicity via mass spectrometric imaging.

PubMed

Ntshangase, Sphamandla; Shobo, Adeola; Kruger, Hendrik G; Asperger, Arndt; Niemeyer, Dagmar; Arvidsson, Per I; Govender, Thavendran; Baijnath, Sooraj

2017-10-13

1. TBA-354 was a promising antitubercular compound with activity against both replicating and static Mycobacterium tuberculosis (M.tb), making it the focal point of many clinical trials conducted by the TB Alliance. However, findings from these trials have shown that TBA-354 results in mild signs of reversible neurotoxicity; this left the TB Alliance with no other choice but to stop the research. 2. In this study, mass spectrometric methods were used to evaluate the pharmacokinetics and spatial distribution of TBA-354 in the brain using a validated liquid chromatography tandem-mass spectrometry (LCMS/MS) and mass spectrometric imaging (MSI), respectively. Healthy female Sprague-Dawley rats received intraperitoneal (i.p.) doses of TBA-354 (20 mg/kg bw). 3. The concentrationtime profiles showed a gradual absorption and tissue penetration of TBA-354 reaching the C max at 6 h post dose, followed by a rapid elimination. MSI analysis showed a time-dependent drug distribution, with highest drug concentration mainly in the neocortical regions of the brain. 4. The distribution of TBA-354 provides a possible explanation for the motor dysfunction observed in clinical trials. These results prove the importance of MSI as a potential tool in preclinical evaluations of suspected neurotoxic compounds.

All-Sky Monitoring of Variable Sources with Fermi GBM

NASA Technical Reports Server (NTRS)

Wilson-Hodge, Colleen A.; Cherry, Michael L.; Case, Gary L.; Camero-Arranz, Ascension; Chaplin, Vandiver; Connaughton, Valerie; Finger, Mark H.; Jenke, Pater; Rodi, James C.; Baumgartner, Wayne H.;

RoboPol: connection between optical polarization plane rotations and gamma-ray flares in blazars

NASA Astrophysics Data System (ADS)

Blinov, D.; Pavlidou, V.; Papadakis, I.; Kiehlmann, S.; Liodakis, I.; Panopoulou, G. V.; Angelakis, E.; Baloković, M.; Hovatta, T.; King, O. G.; Kus, A.; Kylafis, N.; Mahabal, A.; Maharana, S.; Myserlis, I.; Paleologou, E.; Papamastorakis, I.; Pazderski, E.; Pearson, T. J.; Ramaprakash, A.; Readhead, A. C. S.; Reig, P.; Tassis, K.; Zensus, J. A.

2018-02-01

We use results of our 3 yr polarimetric monitoring programme to investigate the previously suggested connection between rotations of the polarization plane in the optical emission of blazars and their gamma-ray flares in the GeV band. The homogeneous set of 40 rotation events in 24 sources detected by RoboPol is analysed together with the gamma-ray data provided by Fermi-LAT. We confirm that polarization plane rotations are indeed related to the closest gamma-ray flares in blazars and the time lags between these events are consistent with zero. Amplitudes of the rotations are anticorrelated with amplitudes of the gamma-ray flares. This is presumably caused by higher relativistic boosting (higher Doppler factors) in blazars that exhibit smaller amplitude polarization plane rotations. Moreover, the time-scales of rotations and flares are marginally correlated.

Anomaly Detection in Gamma-Ray Vehicle Spectra with Principal Components Analysis and Mahalanobis Distances

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

Tardiff, Mark F.; Runkle, Robert C.; Anderson, K. K.

2006-01-23

The goal of primary radiation monitoring in support of routine screening and emergency response is to detect characteristics in vehicle radiation signatures that indicate the presence of potential threats. Two conceptual approaches to analyzing gamma-ray spectra for threat detection are isotope identification and anomaly detection. While isotope identification is the time-honored method, an emerging technique is anomaly detection that uses benign vehicle gamma ray signatures to define an expectation of the radiation signature for vehicles that do not pose a threat. Newly acquired spectra are then compared to this expectation using statistical criteria that reflect acceptable false alarm rates andmore » probabilities of detection. The gamma-ray spectra analyzed here were collected at a U.S. land Port of Entry (POE) using a NaI-based radiation portal monitor (RPM). The raw data were analyzed to develop a benign vehicle expectation by decimating the original pulse-height channels to 35 energy bins, extracting composite variables via principal components analysis (PCA), and estimating statistically weighted distances from the mean vehicle spectrum with the mahalanobis distance (MD) metric. This paper reviews the methods used to establish the anomaly identification criteria and presents a systematic analysis of the response of the combined PCA and MD algorithm to modeled mono-energetic gamma-ray sources.« less

Quantitation of dissolved gas content in emulsions and in blood using mass spectrometric detection.

PubMed

Grimley, Everett; Turner, Nicole; Newell, Clayton; Simpkins, Cuthbert; Rodriguez, Juan

2011-06-01

Quantitation of dissolved gases in blood or in other biological media is essential for understanding the dynamics of metabolic processes. Current detection techniques, while enabling rapid and convenient assessment of dissolved gases, provide only direct information on the partial pressure of gases dissolved in the aqueous fraction of the fluid. The more relevant quantity known as gas content, which refers to the total amount of the gas in all fractions of the sample, can be inferred from those partial pressures, but only indirectly through mathematical modeling. Here we describe a simple mass spectrometric technique for rapid and direct quantitation of gas content for a wide range of gases. The technique is based on a mass spectrometer detector that continuously monitors gases that are rapidly extracted from samples injected into a purge vessel. The accuracy and sample processing speed of the system is demonstrated with experiments that reproduce within minutes literature values for the solubility of various gases in water. The capability of the technique is further demonstrated through accurate determination of O(2) content in a lipid emulsion and in whole blood, using as little as 20 μL of sample. The approach to gas content quantitation described here should greatly expand the range of animals and conditions that may be used in studies of metabolic gas exchange, and facilitate the development of artificial oxygen carriers and resuscitation fluids. Copyright © 2011 Elsevier B.V. All rights reserved.

Resonance production in. gamma gamma. collisions

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

Renard, F.M.

1983-04-01

The processes ..gamma gamma.. ..-->.. hadrons can be depicted as follows. One photon creates a q anti q pair which starts to evolve; the other photon can either (A) make its own q anti q pair and the (q anti q q anti q) system continue to evolve or (B) interact with the quarks of the first pair and lead to a modified (q anti q) system in interaction with C = +1 quantum numbers. A review of the recent theoretical activity concerning resonance production and related problems is given under the following headings: hadronic C = +1 spectroscopy (qmore » anti q, qq anti q anti q, q anti q g, gg, ggg bound states and mixing effects); exclusive ..gamma gamma.. processes (generalities, unitarized Born method, VDM and QCD); total cross section (soft and hard contributions); q/sup 2/ dependence of soft processes (soft/hard separation, 1/sup +- +/ resonances); and polarization effects. (WHK)« less

Field-deployable gamma-radiation detectors for DHS use

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Sanjoy

2007-09-01

Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS' requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER TM, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack TM that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field1. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant spectral data and

[Radioecological situation in the impact zone of the accidental underground nuclear explosion "Kraton-3" in the Republic of Sakha (Yakutia)].

PubMed

Sobakin, P I; Gerasimov, Ya R; Chevychelov, A P; Perk, A A; Goryachenkova, T A; Novikov, A P

2014-01-01

The paper reports on the results of a ground walking gamma- and gamma-spectrometric survey made in the impact zone of the accidental underground nuclear explosion "Kraton-3". Patterns of migration, 137Cs, 90Sr and Pu distribution in the soil-vegetable cover of the northern taiga on permafrost are considered. Radioeco- logical situation within the territory surveyed is noted as unfavorable.

GBM Observations of Terrestrial Gamma-Ray Flashes

NASA Technical Reports Server (NTRS)

Briggs, M. S.; Fishman, G. J.; Connaughton, V.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Wilson-Hodge, C.; Chaplin, V. L.; Kippen, R. M.; vonKienlin, A.;

Daily and Long Term Variations of Out-Door Gamma Dose Rate in Khorasan Province, Iran

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

Toossi, M. T. Bahreyni; Bayani, SH.

2008-08-07

In Iran before 1996, only a few hot spots had been identified, no systematic study had been envisaged. Since then preparation of out-door environmental gamma radiation map of Iran was defined as a long term goal in our center, at the same time simultaneous monitoring of outdoor gamma level in Khorasan was also proposed. A Rados area monitoring system (AAM-90) including 10 intelligent RD-02 detector and all associated components were purchased. From 2003 gradually seven stations have been setup in Khorasan. For all seven stations monthly average and one hour daily average on four time intervals have been computed. Statisticallymore » no significant differences have been observed. This is also true for monthly averages. The overall average dose rate for present seven stations varies from 0.11 {mu}Sv{center_dot}h{sup -1} for Ferdows, to 0.04 {mu}Sv{center_dot}h{sup -1} for Dargaz. Based on our data, 50 minutes sample in any time interval is an accurate sample size to estimate out door Gamma dose rate.« less

Terrestrial gamma-ray flashes in the BeppoSAX data archive

NASA Astrophysics Data System (ADS)

Ursi, A.; Guidorzi, C.; Marisaldi, M.; Sarria, D.; Frontera, F.

2017-04-01

Up to now, Terrestrial Gamma-ray Flashes (TGFs) have been mostly observed by instruments on-board satellites devoted to astrophysics: after the discovery by the BATSE/CGRO experiment in the early 90's, this elusive phenomenon has been further detected by RHESSI, by the AGILE satellite and by the Fermi space telescope. The Italian/Dutch satellite BeppoSAX (1996-2002) was one of the most important high-energy astrophysics missions, especially for what concerns the field of Gamma-Ray Bursts (GRBs). Its payload housed the Gamma-Ray Burst Monitor (GRBM), a segmented detector that could, in principle, have observed TGFs as well. Motivated by this possibility, we carried out, for the first time, a systematic search for TGFs in the BeppoSAX data archive, ending up with a sample of 12 TGF candidates. Among them, we also found a peculiar event, whose light curve characteristics may represent the signature of a mirrored Terrestrial Electron Beam (TEB).

A US Coordination Facility for the Spectrum-X-Gamma Observatory

NASA Technical Reports Server (NTRS)

Forman, William R.

1999-01-01

Spectrum-X Gamma (SXG) is a world-class, orbiting astronomical observatory, with capabilities for all-sky monitoring, polarimetry, and high resolution spectroscopy, and wavelength coverage extending from the ultraviolet (TAUVEX and FUVITA), through the x-ray (SODART and JET-X), to the hard x-ray (MART), and gamma-ray (SPIN) regimes. SXG is a multi-national mission developed under the sponsorship of the Russian Academy of Sciences, with participation from several European countries and the U.S. The U.S. involvement in SXG includes both instrumentation and data rights. The U.S. Spectrum X Gamma Coordination Facility (SXGCF) supports U.S. observers in proposing for SXG SODART observations, analyzing SXG data, and conducting archival research. The SXGCF also has the responsibility for organizing the U.S. archive of SXG data, which will eventually include approximately half of the data from most SXG instruments. This report summarizes the activities of the SXGCF scientific and technical staff during the period from Feb. 1 through July 31, 1999.

Space-Borne Observations of Intense Gamma-Ray Flashes (TGFs) Above Thunderstorms

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2010-01-01

Intense millisecond flashes of MeV photons are being observed with space-borne detectors. These terrestrial gamma-ray flashes (TGFs) were discovered with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory (CGRO) in the early 1990s. They are now being observed with several other instruments, including the Gamma-ray Burst Monitor (GBM) detectors on the Fermi Gamma-ray Space Telescope. Although Fermi-GBM was designed and optimized for the observation of cosmic gamma-ray bursts (GRBs), it has unprecedented capabilities for TGF observations. The TGFs usually have extremely hard continuous spectra, typical of highly-Comptonized bremsstrahlung radiation. These spectral are harder than those of GRBs, with photons extending to over 40 MeV. The most likely origin of these high-energy photons is bremsstrahlung radiation produced by a relativistic runaway avalanche electron beam. Such a beam is expected to be produced in an extended, intense electric field in or above thunderstorm regions. The altitude of origin and beaming characteristics of the radiation are quite uncertain. These TGFs may produce an appreciable radiation dose to passengers and crew in nearby aircraft. They have generated considerable observational and theoretical interest in recent years. Instruments are being designed specifically for TGF observations from new spacecraft as well as from airborne platforms.

40 CFR Appendix C to Part 136 - Inductively Coupled Plasma-Atomic Emission Spectrometric Method for Trace Element Analysis of...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Inductively Coupled Plasma-Atomic... to Part 136—Inductively Coupled Plasma—Atomic Emission Spectrometric Method for Trace Element... technique. Samples are nebulized and the aerosol that is produced is transported to the plasma torch where...

40 CFR Appendix C to Part 136 - Inductively Coupled Plasma-Atomic Emission Spectrometric Method for Trace Element Analysis of...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Inductively Coupled Plasma-Atomic... to Part 136—Inductively Coupled Plasma—Atomic Emission Spectrometric Method for Trace Element... technique. Samples are nebulized and the aerosol that is produced is transported to the plasma torch where...

ESR identification of gamma-irradiated albendazole

NASA Astrophysics Data System (ADS)

Çolak, Seyda

2010-01-01

The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

Mass spectrometric detection of peginesatide in human urine in doping control analysis.

PubMed

Möller, Ines; Thomas, Andreas; Delahaut, Philippe; Geyer, Hans; Schänzer, Wilhelm; Thevis, Mario

2012-11-01

Erythropoiesis-stimulating agents (ESAs) have frequently been confessed to be illicitly used in elite sports due to their endurance enhancing effects. Recently, peginesatide, the first representative of a new generation of ESAs, referred to as Erythropoietin (EPO)-mimetic peptides, obtained approval in the USA under the trade name Omontys(®) for the treatment of anaemic patients. Lacking sequence homology with EPO, it consists of a pegylated homodimeric peptide of approximately 45 kDa, and thus, specific approaches for the determination of peginesatide in blood were developed as conventional detection assays for EPO do not allow for the analysis of the EPO-mimetic peptides. However, as urine specimens are the most frequently provided doping control samples and pharmacokinetic studies conducted in rats and monkeys revealed the excretion of the pegylated peptide into urine, a detection method for peginesatide in urine would be desirable. A mass spectrometric assay in human urine was developed consisting of protein precipitation with acetonitrile followed by proteolytic digestion after the removal of the acetonitrile fraction under reduced pressure. Purification and concentration of the resulting proteotypic target peptide was accomplished by means of solid-phase extraction on strong cation-exchange resin prior to liquid chromatographic-tandem mass spectrometric analysis. Method validation was performed for qualitative purposes and demonstrated specificity, precision, linearity as well as sufficient sensitivity (limit of detection: 0.5 ng/ml) while proof-of-concept for the applicability of the assay for the determination of peginesatide in authentic urine samples was obtained by analyzing animal in vivo specimens collected after a single i.v. administration of peginesatide over a period of 4 days. Copyright © 2012 Elsevier B.V. All rights reserved.

Simultaneous observation of the gamma-ray binary LS I+61 303 with GLAST and Suzaku

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

Tanaka, Takuya; Fukazawa, Yasushi; Mizuno, Tsunefumi

2007-07-12

The gamma-ray binary LS I+61 303 is a bright gamma-ray source, and thus an attracting object for GLAST. We proposed to observe this object with the X-ray satellite Suzaku (AO-2), simultaneously with GLAST, radio wave, and optical spectro-polarimetry, in order to probe the geometrical state of the binary system emitting the gamma-ray radiation, as a function of the binary orbital phase for the first time. This is essential to understand the mechanism of jet production and gamma-ray emission. The idea is not only to measure the multi-band overall continuum shape, but also to make use of continuous monitoring capability ofmore » GLAST, wide X-ray band of Suzaku, and good accessibility of the Kanata optical/NIR telescope (Hiroshima University) with the sensitive optical spectro-polarimetry. Further collaboration with TeV gamma-ray telescopes is also hoped to constrain the jet constitution.« less

Search for Very-high-energy Emission from Gamma-Ray Bursts Using the First 18 Months of Data from the HAWC Gamma-Ray Observatory

NASA Astrophysics Data System (ADS)

Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Avila Rojas, D.; Ayala Solares, H. A.; Barber, A. S.; Bautista-Elivar, N.; Becerril, A.; Belmont-Moreno, E.; BenZvi, S. Y.; Bernal, A.; Braun, J.; Brisbois, C.; Caballero-Mora, K. S.; Capistrán, T.; Carramiñana, A.; Casanova, S.; Castillo, M.; Cotti, U.; Cotzomi, J.; Coutiño deLeón, S.; De la Fuente, E.; De León, C.; DeYoung, T.; Diaz Hernandez, R.; Dingus, B. L.; DuVernois, M. A.; Díaz-Vélez, J. C.; Ellsworth, R. W.; Engel, K.; Fiorino, D. W.; Fraija, N.; García-González, J. A.; Garfias, F.; Gerhardt, M.; González Muñoz, A.; González, M. M.; Goodman, J. A.; Hampel-Arias, Z.; Harding, J. P.; Hernandez-Almada, A.; Hernandez, S.; Hona, B.; Hui, C. M.; Hüntemeyer, P.; Iriarte, A.; Jardin-Blicq, A.; Joshi, V.; Kaufmann, S.; Kieda, D.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linnemann, J. T.; Longinotti, A. L.; Raya, G. Luis; Luna-García, R.; López-Coto, R.; Malone, K.; Marinelli, S. S.; Martinez, O.; Martinez-Castellanos, I.; Martínez-Castro, J.; Martínez-Huerta, H.; Matthews, J. A.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Noriega-Papaqui, R.; Pelayo, R.; Pérez-Pérez, E. G.; Pretz, J.; Ren, Z.; Rho, C. D.; Rivière, C.; Rosa-González, D.; Rosenberg, M.; Ruiz-Velasco, E.; Salazar, H.; Salesa Greus, F.; Sandoval, A.; Schneider, M.; Schoorlemmer, H.; Sinnis, G.; Smith, A. J.; Springer, R. W.; Surajbali, P.; Taboada, I.; Tibolla, O.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Vianello, G.; Weisgarber, T.; Westerhoff, S.; Wood, J.; Yapici, T.; Younk, P. W.; Zepeda, A.; Zhou, H.; HAWC Collaboration

2017-07-01

The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory is an extensive air shower detector operating in central Mexico that has recently completed its first two years of full operations. If for a burst like GRB 130427A at a redshift of 0.34 and a high-energy component following a power law with index 1.66, the high-energy component is extended to higher energies with no cutoff other than that from extragalactic background light attenuation, HAWC would observe gamma-rays with a peak energy of ˜300 GeV. This paper reports the results of HAWC observations of 64 gamma-ray bursts (GRBs) detected by Swift and Fermi, including 3 GRBs that were also detected by the Large Area Telescope (Fermi-LAT). An ON/OFF analysis method is employed, searching on the timescale given by the observed light curve at keV-MeV energies and also on extended timescales. For all GRBs and timescales, no statistically significant excess of counts is found and upper limits on the number of gamma-rays and the gamma-ray flux are calculated. GRB 170206A, the third brightest short GRB detected by the Gamma-ray Burst Monitor on board the Fermi satellite (Fermi-GBM) and also detected by the LAT, occurred very close to zenith. The LAT measurements can neither exclude the presence of a synchrotron self-Compton component nor constrain its spectrum. Instead, the HAWC upper limits constrain the expected cutoff in an additional high-energy component to be less than 100 {GeV} for reasonable assumptions about the energetics and redshift of the burst.

Applying a low energy HPGe detector gamma ray spectrometric technique for the evaluation of Pu/Am ratio in biological samples.

PubMed

Singh, I S; Mishra, Lokpati; Yadav, J R; Nadar, M Y; Rao, D D; Pradeepkumar, K S

2015-10-01

The estimation of Pu/(241)Am ratio in the biological samples is an important input for the assessment of internal dose received by the workers. The radiochemical separation of Pu isotopes and (241)Am in a sample followed by alpha spectrometry is a widely used technique for the determination of Pu/(241)Am ratio. However, this method is time consuming and many times quick estimation is required. In this work, Pu/(241)Am ratio in the biological sample was estimated with HPGe detector based measurements using gamma/X-rays emitted by these radionuclides. These results were compared with those obtained from alpha spectroscopy of sample after radiochemical analysis and found to be in good agreement. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improved detector for the measurement of gamma radiation

NASA Astrophysics Data System (ADS)

Zelt, F. B.

1985-07-01

The present invention lies in the field of gamma ray spectrometry of geologic deposits and other materials, such as building materials (cement, asphalt, etc.) More specifically, the invention is an improved device for the gamma ray spetcrometery of gelogical deposits as a tool for petroleum exploration, geologic research and monitoring of radio-active materials such as in uranium mill tailings and the like. Improvement consists in enlarging the area of the receptor face and without any necessarily substantial increase in the volume of the receptor crystal over the current cylindrical shapes. The invention also provides, as a corollary of the increase in area receptor crystal face, a reduction in the weight of the amount of material necessary to provide effective shielding of the crystal from atmospheric radiation and radiation from deposits not under examination. The area of the receptor crystal face is increased by forming the crystal as a truncated cone with the shielding shaped as a hollow frustrum of a cone. A photomultiplier device is secured to the smaller face of the crystal. The improved detector shape can also be used in scintillometers which measure total gamma radiation.

Structure determination of 3-O-caffeoyl-epi-gamma-quinide, an orphan bitter lactone in roasted coffee.

PubMed

Frank, Oliver; Blumberg, Simone; Krümpel, Gudrun; Hofmann, Thomas

2008-10-22

Recent investigations on the bitterness of coffee as well as 5- O-caffeoyl quinic acid roasting mixtures indicated the existence of another, yet unknown, bitter lactone besides the previously identified bitter compounds 5- O-caffeoyl- muco-gamma-quinide, 3- O-caffeoyl-gamma-quinide, 4- O-caffeoyl- muco-gamma-quinide, 5- O-caffeoyl- epi-delta-quinide, and 4- O-caffeoyl-gamma-quinide. In the present study, this orphan bitter lactone was isolated from the reaction products generated by dry heating of 5- O-caffeoylquinic acid model, and its structure was determined as the previously unreported 3- O-caffeoyl- epi-gamma-quinide by means of liquid chromatography-mass spectrometry (LC-MS) and one-/two-dimensional NMR experiments. The occurrence of this bitter lactone, exhibiting a low bitter recognition threshold of 58 micromol/L, in coffee beverages could be confirmed by LC-MS/MS (negative electrospray ionization) operating in the multiple reaction monitoring mode.

Method and apparatus for enhanced sequencing of complex molecules using surface-induced dissociation in conjunction with mass spectrometric analysis

DOEpatents

Laskin, Julia [Richland, WA; Futrell, Jean H [Richland, WA

2008-04-29

The invention relates to a method and apparatus for enhanced sequencing of complex molecules using surface-induced dissociation (SID) in conjunction with mass spectrometric analysis. Results demonstrate formation of a wide distribution of structure-specific fragments having wide sequence coverage useful for sequencing and identifying the complex molecules.

On precipitation monitoring with theoretical statistical distributions

NASA Astrophysics Data System (ADS)

Cindrić, Ksenija; Juras, Josip; Pasarić, Zoran

2018-04-01

A common practice in meteorological drought monitoring is to transform the observed precipitation amounts to the standardised precipitation index (SPI). Though the gamma distribution is usually employed for this purpose, some other distribution may be used, particularly in regions where zero precipitation amounts are recorded frequently. In this study, two distributions are considered alongside with the gamma distribution: the compound Poisson exponential distribution (CPE) and the square root normal distribution (SRN). They are fitted to monthly precipitation amounts measured at 24 stations in Croatia in the 55-year-long period (1961-2015). At five stations, long-term series (1901-2015) are available and they have been used for a more detailed investigation. The accommodation of the theoretical distributions to empirical ones is tested by comparison of the corresponding empirical and theoretical ratios of the skewness and the coefficient of variation. Furthermore, following the common approach to precipitation monitoring (CLIMAT reports), the comparison of the empirical and theoretical quintiles in the two periods (1961-1990 and 1991-2015) is examined. The results from the present study reveal that it would be more appropriate to implement theoretical distributions in such climate reports, since they provide better evaluation for monitoring purposes than the current empirical distribution. Nevertheless, deciding on an optimal theoretical distribution for different climate regimes and for different time periods is not easy to accomplish. With regard to Croatian stations (covering different climate regimes), the CPE or SRN distribution could also be the right choice in the climatological practice, in addition to the gamma distribution.

Prompt gamma-ray imaging for small animals

NASA Astrophysics Data System (ADS)

Xu, Libai

Small animal imaging is recognized as a powerful discovery tool for small animal modeling of human diseases, which is providing an important clue to complete understanding of disease mechanisms and is helping researchers develop and test new treatments. The current small animal imaging techniques include positron emission tomography (PET), single photon emission tomography (SPECT), computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US). A new imaging modality called prompt gamma-ray imaging (PGI) has been identified and investigated primarily by Monte Carlo simulation. Currently it is suggested for use on small animals. This new technique could greatly enhance and extend the present capabilities of PET and SPECT imaging from ingested radioisotopes to the imaging of selected non-radioactive elements, such as Gd, Cd, Hg, and B, and has the great potential to be used in Neutron Cancer Therapy to monitor neutron distribution and neutron-capture agent distribution. This approach consists of irradiating small animals in the thermal neutron beam of a nuclear reactor to produce prompt gamma rays from the elements in the sample by the radiative capture (n, gamma) reaction. These prompt gamma rays are emitted in energies that are characteristic of each element and they are also produced in characteristic coincident chains. After measuring these prompt gamma rays by surrounding spectrometry array, the distribution of each element of interest in the sample is reconstructed from the mapping of each detected signature gamma ray by either electronic collimations or mechanical collimations. In addition, the transmitted neutrons from the beam can be simultaneously used for very sensitive anatomical imaging, which provides the registration for the elemental distributions obtained from PGI. The primary approach is to use Monte Carlo simulation methods either with the specific purpose code CEARCPG, developed at NC State University or with the general purpose

Remote mass spectrometric sampling of electrospray- and desorption electrospray-generated ions using an air ejector.

PubMed

Dixon, R Brent; Bereman, Michael S; Muddiman, David C; Hawkridge, Adam M

2007-10-01

A commercial air ejector was coupled to an electrospray ionization linear ion trap mass spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary mass spectrometric data are presented.

Preview of the BATSE Earth Occultation Catalog of Low Energy Gamma Ray Sources

NASA Technical Reports Server (NTRS)

Harmon, B. A.; Wilson, C. A.; Fishman, G. J.; McCollough, M. L.; Robinson, C. R.; Sahi, M.; Paciesas, W. S.; Zhang, S. N.

1999-01-01

The Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma Ray Observatory (CGRO) has been detecting and monitoring point sources in the high energy sky since 1991. Although BATSE is best known for gamma ray bursts, it also monitors the sky for longer-lived sources of radiation. Using the Earth occultation technique to extract flux information, a catalog is being prepared of about 150 sources potential emission in the large area detectors (20-1000 keV). The catalog will contain light curves, representative spectra, and parametric data for black hole and neutron star binaries, active galaxies, and super-nova remnants. In this preview, we present light curves for persistent and transient sources, and also show examples of what type of information can be obtained from the BATSE Earth occultation database. Options for making the data easily accessible as an "on line" WWW document are being explored.

Portable Intelligent Tritium in Air Monitor

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

Purghel, L.; Calin, M.R.; Bartos, D.

2005-07-15

The tritium detection method used for this monitor is original, patented in Romania. The detection unit consists of a single ionization chamber, a special fast preamplifier and a dedicated software associated to the detection unit, for signals processing. Some results concerning the tritium in relative strong gamma-ray fields are presented.

Development of a Beam Trajectory Monitoring System Using e+/e- Pair Production Events

NASA Astrophysics Data System (ADS)

Kimura, Shota; Emoto, Yusaku; Fujihara, Kento; Ito, Hiroshi; Kawai, Hideyuki; Kobayashi, Atsushi; Mizuno, Takahiro

2018-01-01

In particle therapy, it is important to monitor the Bragg-peak position. It was simulated by GEANT4 Monte Carlo Simulation Code that the distribution of secondary generated gamma rays on the carbon beam therapy and the proton beam therapy. This simulation shows that gamma rays whose energy is 10 MeV or more are intensively generated at the Bragg-peak position. We are developing the system to monitor the Bragg-peak position which can measure pair production events occurred in the detector by gamma rays from irradiation points. The momentum direction of the gamma ray can be determined by measuring passing points and energy of e+ and e- generated by pair production. This system has 5 parts. The first is the conversion part. This part consists of several layers. Each layer is composed of a La-GPS ((Gd0.75La0.24Ce0.01)2Si2O7) scintillator plate and wavelength-shifting fibre (WLSF) sheets. The scintillator plate is sandwiched between sheets, where the directions of the sheets are in orthogonally x and y directions. In this part, gamma rays are converted to e+ e- pairs and the position where the conversion occured is determined. The second is the tracking part. This part consists of 2 layers of scintillating fibre tracker. Each layer has 6 scintillating fibre sheets for x, x', u, u', v, and v'. The third is the energy measurement part. It measures the energy of e+ and e- by scintillator array and Silicon Photomultipliers. The fourth is the veto counter for bremsstrahlung gamma rays from e+ and e-. The fifth is the beam monitor. By experiment, the number of photoelectrons of La-GPS with a WLSF (B-3(300)MJ, Kuraray) sheet and scintillating fibre (SCSF-78, Kuraray) when charged particle passed was measured as 9.7 and 7.6 respectively.

Method of incident low-energy gamma-ray direction reconstruction in the GAMMA-400 gamma-ray space telescope

NASA Astrophysics Data System (ADS)

Kheymits, M. D.; Leonov, A. A.; Zverev, V. G.; Galper, A. M.; Arkhangelskaya, I. V.; Arkhangelskiy, A. I.; Suchkov, S. I.; Topchiev, N. P.; Yurkin, Yu T.; Bakaldin, A. V.; Dalkarov, O. D.

2016-02-01

The GAMMA-400 gamma-ray space-based telescope has as its main goals to measure cosmic γ-ray fluxes and the electron-positron cosmic-ray component produced, theoretically, in dark-matter-particles decay or annihilation processes, to search for discrete γ-ray sources and study them in detail, to examine the energy spectra of diffuse γ-rays — both galactic and extragalactic — and to study gamma-ray bursts (GRBs) and γ-rays from the active Sun. Scientific goals of GAMMA-400 telescope require fine angular resolution. The telescope is of a pair-production type. In the converter-tracker, the incident gamma-ray photon converts into electron-positron pair in the tungsten layer and then the tracks are detected by silicon- strip position-sensitive detectors. Multiple scattering processes become a significant obstacle in the incident-gamma direction reconstruction for energies below several gigaelectronvolts. The method of utilising this process to improve the resolution is proposed in the presented work.

Fast neutron-gamma discrimination on neutron emission profile measurement on JT-60U

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

Ishii, K.; Okamoto, A.; Kitajima, S.

2010-10-15

A digital signal processing (DSP) system is applied to stilbene scintillation detectors of the multichannel neutron emission profile monitor in JT-60U. Automatic analysis of the neutron-{gamma} pulse shape discrimination is a key issue to diminish the processing time in the DSP system, and it has been applied using the two-dimensional (2D) map. Linear discriminant function is used to determine the dividing line between neutron events and {gamma}-ray events on a 2D map. In order to verify the validity of the dividing line determination, the pulse shape discrimination quality is evaluated. As a result, the {gamma}-ray contamination in most of themore » beam heating phase was negligible compared with the statistical error with 10 ms time resolution.« less

Reply to "On Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K- A high temperature mass spectrometric study"

NASA Astrophysics Data System (ADS)

Jain, Uttam; Mukherjee, Abhishek

2018-03-01

This communication is in response to a letter to editor commenting on the authors' earlier paper "Vaporization of liquid Pb-Li eutectic alloy from 1000 K to 1200 K - A high temperature mass spectrometric study".

The BATSE Earth Occultation Catalog of Low Energy Gamma Ray Sources

NASA Technical Reports Server (NTRS)

Harmon, B. A.; WilsonHodge, C. A.; Fishman, G. J.; Paciesas, W.

2002-01-01

The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the hard X-ray/low energy gamma ray sky between April 1991 and June 2000. During that time, a catalog of known sources was derived from existing catalogs such as HEAO A-4, as well as new transient sources discovered with BATSE and other X-ray monitors operating in the CGRO era. The Earth Occultation Technique was used to monitor a combination of these sources, mostly galactic, totaling to about 175 objects. The catalog will present the global properties of these sources and their probability of detection (> 10 mCrab, 20-100 keV) with BATSE. Systematic errors due to unknown sources or background components are included. Cursory analyses to search for new transients (35-80 mCrab in the 20-100 keV band) and super-orbital periods in known binary sources are also presented. Whole mission light curves and associated data production/analysis tools are being delivered to the HEASARC for public use.

Imaging the Crab nebula when it is flaring in gamma-rays

NASA Astrophysics Data System (ADS)

De Luca, Andrea

2013-10-01

One of the most intriguing results of the gamma-ray instruments currently in orbit has been the detection of powerful flares from the Crab Nebula. Such events, detected roughly once per year, can be very spectacular. Indeed, in April 2011, for a few days the Crab was by far the brightest source in the gamma-ray sky. Such a dramatic variability challenges our understanding of how pulsar wind nebulae work and defies current astrophysical models for particle acceleration. With the aim of locating the site{s} of the flares, an ad hoc HST strategy must be put in place to be prepared and react promptly in case of a new brightening in gamma rays. We ask here for a triggered TOO observation of the Crab Nebula with ACS/WFC in case a gamma-ray flare is announced by the Agile and/or Fermi missions. This is a crucial part of a multiwavelength program that we are organizing, based on lessons learnt from our follow-up observations of previous flares, including a regular {monthly} monitoring of the source both in X-ray and optical through a joint Chandra-HST proposal.

Imaging the Crab nebula when it is flaring in gamma-rays

NASA Astrophysics Data System (ADS)

De Luca, Andrea

2014-10-01

One of the most intriguing results of the gamma-ray instruments currently in orbit has been the detection of powerful flares from the Crab Nebula. Such events, with a recurrence time of about once per year, can be so dramatic to make the system the brightest source in the gamma-ray sky, as it occurred in April 2011. Such a discovery challenges our understanding of how pulsar wind nebulae work and defies current astrophysical models for particle acceleration. With the aim of locating the site(s) of the flares, an ad hoc HST strategy have been put in place to be prepared and react promptly in case of a new brightening in gamma rays. We ask here for a triggered TOO observation of the Crab Nebula with ACS/WFC in case a gamma-ray flare is announced by the Agile and/or the Fermi missions. This TOO is crucial part of a multiwavelength program that we have organized, based on lessons learnt from our follow-up observations of previous flares, including a regular (quarterly) monitoring of the source both in X-rays and optical through a joint Chandra-HST proposal.

Imaging the Crab nebula when it is flaring in gamma-rays

NASA Astrophysics Data System (ADS)

De Luca, Andrea

2012-10-01

One of the most intriguing results of the gamma-ray instruments currently in orbit has been the detection of powerful flares from the Crab Nebula in September 2010. In April 2011 a similar flare, lasting several days, made the nebula the brightest source in the gamma-ray sky. A critical reassessment of long term behavior of the Crab flux clearly showed that both Agile and Fermi had already detected similar events in October 2007 and February 2009, pointing to a recurrence time of once per year. A HST observing strategy must be set up to react promptly to any possible new brightening of the Crab in gamma rays. In September 2010 we requested a DD observation which was promptly accepted and carried out. However, the lack of a suitable reference image hampered our efforts to pinpoint the sites of possible variability inside the nebula. Thus, while now we ask for a triggered TOO observation of the Crab Nebula with ACS/WFC in case a gamma-ray flare is announced by the Agile and/or Fermi missions, we are also organizing a regular {monthly} monitoring of the source both in X-ray and optical through a joint Chandra-HST proposal.

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A.M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A.I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.;

INTEGRATED MONITORING HARDWARE DEVELOPMENTS AT LOS ALAMOS

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

R. PARKER; J. HALBIG; ET AL

1999-09-01

The hardware of the integrated monitoring system supports a family of instruments having a common internal architecture and firmware. Instruments can be easily configured from application-specific personality boards combined with common master-processor and high- and low-voltage power supply boards, and basic operating firmware. The instruments are designed to function autonomously to survive power and communication outages and to adapt to changing conditions. The personality boards allow measurement of gross gammas and neutrons, neutron coincidence and multiplicity, and gamma spectra. In addition, the Intelligent Local Node (ILON) provides a moderate-bandwidth network to tie together instruments, sensors, and computers.

Cosmic Gamma-Rays

Science.gov Websites

[Argonne Logo] [DOE Logo] Cosmic Gamma-Rays Home Publications Talks People Students Argonne > ; HEP > Cosmic Gamma-Rays Projects VERITAS Past Projects TrICE What's New CTA Cosmic Gamma-Rays The

Design and Performance of the GAMMA-400 Gamma-Ray Telescope for Dark Matter Searches

NASA Technical Reports Server (NTRS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu V.;

Use of the gamma distribution to represent monthly rainfall in Africa for drought monitoring applications

USGS Publications Warehouse

Husak, Gregory J.; Michaelsen, Joel C.; Funk, Christopher C.

2007-01-01

Evaluating a range of scenarios that accurately reflect precipitation variability is critical for water resource applications. Inputs to these applications can be provided using location- and interval-specific probability distributions. These distributions make it possible to estimate the likelihood of rainfall being within a specified range. In this paper, we demonstrate the feasibility of fitting cell-by-cell probability distributions to grids of monthly interpolated, continent-wide data. Future work will then detail applications of these grids to improved satellite-remote sensing of drought and interpretations of probabilistic climate outlook forum forecasts. The gamma distribution is well suited to these applications because it is fairly familiar to African scientists, and capable of representing a variety of distribution shapes. This study tests the goodness-of-fit using the Kolmogorov–Smirnov (KS) test, and compares these results against another distribution commonly used in rainfall events, the Weibull. The gamma distribution is suitable for roughly 98% of the locations over all months. The techniques and results presented in this study provide a foundation for use of the gamma distribution to generate drivers for various rain-related models. These models are used as decision support tools for the management of water and agricultural resources as well as food reserves by providing decision makers with ways to evaluate the likelihood of various rainfall accumulations and assess different scenarios in Africa. 

Ex-situ and in-situ observations of the effects of gamma radiation on lithium ion battery performance

NASA Astrophysics Data System (ADS)

Tan, Chuting; Bashian, Nicholas H.; Hemmelgarn, Chase W.; Thio, Wesley J.; Lyons, Daniel J.; Zheng, Yuan F.; Cao, Lei R.; Co, Anne C.

2017-07-01

Radiation effects induced by gamma rays on battery performance were investigated by measuring the capacity and resistance of a series of battery coin cells in-situ directly under gamma radiation and ex-situ. An experimental setup was developed to charge and discharge batteries directly under gamma radiation, equipped with precise temperature control, at The Ohio State University Nuclear Reactor Lab. Latent effects induced by gamma radiation on battery components directly influence their performance. Charge and discharge capacity and overall resistance throughout a time span of several weeks post irradiation were monitored and compared to control groups. It was found that exposure to gamma radiation does not significantly alter the available capacity and the overall cell resistance immediately, however, battery performance significantly decreases with time post irradiation. Also, batteries exposed to a higher cumulative dose showed close-to-zero capacity at two-week post irradiation.

Remote Mass Spectrometric Sampling of Electrospray- and Desorption Electrospray-Generated Ions Using an Air Ejector

PubMed Central

Dixon, R. Brent; Bereman, Michael S.; Muddiman, David C.; Hawkridge, Adam M.

2007-01-01

A commercial air ejector was coupled to an electrospray ionization linear ion trap mass spectrometer (LTQ) to transport remotely generated ions from both electrospray (ESI) and desorption electrospray ionization (DESI) sources. We demonstrate the remote analysis of a series of analyte ions that range from small molecules and polymers to polypeptides using the AE-LTQ interface. The details of the ESI-AE-LTQ and DESI-AE-LTQ experimental configurations are described and preliminary mass spectrometric data is presented. PMID:17716909

Neutron and Gamma Imaging for National Security Applications

NASA Astrophysics Data System (ADS)

Hornback, Donald

2017-09-01

The Department of Energy, National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation Research and Development (DNN R&D/NA-22) possesses, in part, the mission to develop technologies in support of nuclear security efforts in coordination with other U.S. government entities, such as the Department of Defense and the Department of Homeland Security. DNN R&D has long supported research in nuclear detection at national labs, universities, and through the small business innovation research (SBIR) program. Research topics supported include advanced detector materials and electronics, detection algorithm development, and advanced gamma/neutron detection systems. Neutron and gamma imaging, defined as the directional detection of radiation as opposed to radiography, provides advanced detection capabilities for the NNSA mission in areas of emergency response, international safeguards, and nuclear arms control treaty monitoring and verification. A technical and programmatic overview of efforts in this field of research will be summarized.

Development of a matrix-assisted laser desorption ionization mass spectrometric method for rapid process-monitoring of phthalocyanine compounds.

PubMed

Chen, Yi-Ting; Wang, Fu-Shing; Li, Zhendong; Li, Liang; Ling, Yong-Chien

2012-07-29

Phthalocyanines (PCs), an important class of chemicals widely used in many industrial sectors, are macrocyclic compounds possessing a heteroaromatic π-electron system with optical properties influenced by chemical structures and impurities or by-products introduced during the synthesis process. Analytical tools allowing for rapid monitoring of the synthesis processes are of significance for the development of new PCs with improved performance in many application areas. In this work, we report a matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry (TOFMS) method for rapid and convenient monitoring of PC synthesis reactions. For this class of compounds, intact molecular ions could be detected by MALDI using retinoic acid as matrix. It was shown that relative quantification results of two PC compounds could be generated by MALDI MS. This method was applied to monitor the bromination reactions of nickel- and copper-containing PCs. It was demonstrated that, compared to the traditional UV-visible method, the MALDI MS method offers the advantage of higher sensitivity while providing chemical species and relative quantification information on the reactants and products, which are crucial to process monitoring. Copyright © 2012 Elsevier B.V. All rights reserved.

NRAO Teams With NASA Gamma-Ray Satellite

NASA Astrophysics Data System (ADS)

2007-06-01

The National Radio Astronomy Observatory (NRAO) is teaming with NASA's upcoming Gamma-ray Large Area Space Telescope (GLAST) to allow astronomers to use both the orbiting facility and ground-based radio telescopes to maximize their scientific payoff. Under the new, streamlined process, astronomers can compete for coordinated observing time and support from both GLAST and NRAO's radio telescopes. GLAST satellite Artist's rendering of the GLAST spacecraft in orbit above the Earth. CREDIT: General Dynamics C4 Systems Click on Image for Larger File Images of NRAO Telescopes Robert C. Byrd Green Bank Telescope Very Long Baseline Array Very Large Array Atacama Large Millimeter/submillimeter Array GLAST is scheduled for launch no earlier than December 14. It will perform a survey of the entire sky at gamma-ray wavelengths every 3 hours using its primary instrument, the Large Area Telescope (LAT). NRAO operates the Very Large Array (VLA) in New Mexico, the continent-wide Very Long Baseline Array (VLBA), and the Robert C. Byrd Green Bank Telescope (GBT) in West Virginia. The NRAO is a research facility of the National Science Foundation (NSF). "Coordinated gamma-ray and radio observations of celestial objects will greatly enhance the ability to fully understand those objects. Astronomy today requires such multiwavelength studies, and this agreement paves the way for exciting, cutting-edge research," said Fred K.Y. Lo, NRAO Director. GLAST will be vastly more capable than previous gamma-ray satellites, and will carry an instrument, the GLAST Burst Monitor, specifically designed to detect gamma-ray bursts. GLAST observers will study objects such as active galaxies, pulsars, and supernova remnants, which are also readily studied with radio telescopes. By working together, NASA's GLAST mission and NSF's NRAO facilities can study flares from blazars over the widest possible range of energies, which is crucial to understanding how black holes, notorious for drawing matter in, can

Prompt gamma and neutron detection in BNCT utilizing a CdTe detector.

PubMed

Winkler, Alexander; Koivunoro, Hanna; Reijonen, Vappu; Auterinen, Iiro; Savolainen, Sauli

2015-12-01

In this work, a novel sensor technology based on CdTe detectors was tested for prompt gamma and neutron detection using boronated targets in (epi)thermal neutron beam at FiR1 research reactor in Espoo, Finland. Dedicated neutron filter structures were omitted to enable simultaneous measurement of both gamma and neutron radiation at low reactor power (2.5 kW). Spectra were collected and analyzed in four different setups in order to study the feasibility of the detector to measure 478 keV prompt gamma photons released from the neutron capture reaction of boron-10. The detector proved to have the required sensitivity to detect and separate the signals from both boron neutron and cadmium neutron capture reactions, which makes it a promising candidate for monitoring the spatial and temporal development of in vivo boron distribution in boron neutron capture therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

INTERLABORATORY STUDY OF A THERMOSPRAY-LIQUID CHROMATOGRAPHIC/MASS SPECTROMETRIC METHOD FOR SELECTED N-METHYL CARBAMATES, N-METHYL CARBAMOYLOXIMES, AND SUBSTITUTED UREA PESTICIDES

EPA Science Inventory

A thermospray-liquid chromatographic/mass spectrometric (TS-LC/MS) method was evaluated in an interlaboratory study for determining 3 N-methyl carbamates (bendiocarb, carbaryl, and carbofuran), 3-N-methyl carbamoyloximes (aldicarb, methomyl, and oxamyl), 2 substituted urea pestic...

Gamma spectrometry application of the Kola Peninsula (in Russian)

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

Golovin, I.V.; Kolesnik, N.N.; Antipov, V.S.

1973-03-01

The methods and results are reported of a spectrometric study, carried out with the SP-3 instrument in Pre-Cambrian fornnations in the northwest ranges of Kola Peninsula for clarification of the radiochemical characteristics of the rocks of the region and of the distribution characteristics of radioactive elements in Cu-Ni mineralizations. It was established that the content of radioactive elements in the rocks varies within a wide interval and corresponds basically to the Vinogradov content. The radioactive element content in typical metamorphic and magmatic complexes and sulfide ores was determined. The spectrometric method can be used for the solution of various geologicalmore » problems. It is particularly useful for studying the separation of strata, the genesis of magmatic and metamorphic complexes, and the metamorphic and geochemical zonality and granitization processes. (tr-auth)« less

Spectral information enhancement using wavelet-based iterative filtering for in vivo gamma spectrometry.

PubMed

Paul, Sabyasachi; Sarkar, P K

2013-04-01

Use of wavelet transformation in stationary signal processing has been demonstrated for denoising the measured spectra and characterisation of radionuclides in the in vivo monitoring analysis, where difficulties arise due to very low activity level to be estimated in biological systems. The large statistical fluctuations often make the identification of characteristic gammas from radionuclides highly uncertain, particularly when interferences from progenies are also present. A new wavelet-based noise filtering methodology has been developed for better detection of gamma peaks in noisy data. This sequential, iterative filtering method uses the wavelet multi-resolution approach for noise rejection and an inverse transform after soft 'thresholding' over the generated coefficients. Analyses of in vivo monitoring data of (235)U and (238)U were carried out using this method without disturbing the peak position and amplitude while achieving a 3-fold improvement in the signal-to-noise ratio, compared with the original measured spectrum. When compared with other data-filtering techniques, the wavelet-based method shows the best results.

Mass spectrometric imaging of flavonoid glycosides and biflavonoids in Ginkgo biloba L.

PubMed

Beck, Sebastian; Stengel, Julia

2016-10-01

Ginkgo biloba L. is known to be rich in flavonoids and flavonoid glycosides. However, the distribution within specific plant organs (e.g. within leaves) is not known. By using HPLC-MS and MS/MS we have identified a number of previously known G. biloba flavonoid glycosides and biflavonoids from leaves. Namely, kaempferol, quercetin, isorhamnetin, myricetin, laricitrin/mearnsetin and apigenin glycosides were identified. Furthermore, biflavonoids like ginkgetin/isoginkgetin were also detected. The application of MALDI mass spectrometric imaging, enabled the compilation of concentration profiles of flavonoid glycosides and biflavonoids in G. biloba L. leaves. Both, flavonoid glycosides and biflavonoids show a distinct distribution in leaf thin sections of G. biloba L. Copyright © 2016 Elsevier Ltd. All rights reserved.

Suzaku Wide-band All-sky Monitor (WAM) observations of GRBs and SGRs

NASA Astrophysics Data System (ADS)

Yamaoka, Kazutaka; Ohno, Masanori; Tashiro, Makoto S.; Hurley, Kevin; Krimm, Hans A.; Lien, Amy Y.; Ohmori, Norisuke; Sugita, Satoshi; Urata, Yuji; Yasuda, Tetsuya; Enomoto, Junichi; Fujinuma, Takeshi; Fukazawa, Yasushi; Hanabata, Yoshitaka; Iwakiri, Wataru; Kawano, Takafumi; Kinoshita, Ryuuji; Kokubun, Motohide; Makishima, Kazuo; Matsuoka, Shunsuke; Nagayoshi, Tsutomu; Nakagawa, Yujin; Nakaya, Souhei; Nakazawa, Kazuhiro; Nishioka, Yusuke; Sakamoto, Takanori; Takahashi, Tadayuki; Takeda, Sawako; Terada, Yukikatsu; Yabe, Seiya; Yamauchi, Makoto; Yoshida, Hiraku

2017-06-01

We will review results for gamma-ray bursts (GRBs) and soft gamma repeaters (SGRs), obtained from the Suzaku Wide-band All-sky Monitor (WAM) which operated for about 10 years from 2005 to 2015. The WAM is a BGO (bismuth germanate: Bi4Ge3O12) lateral shield for the Hard X-ray Detector (HXD), used mainly for rejecting its detector background, but it also works as an all-sky monitor for soft gamma-ray transients in the 50-5000 keV range thanks to its large effective area (˜600 cm2 at 1 MeV for one detector) and wide field of view (about half of the entire sky). The WAM actually detected more than 1400 GRBs and 300 bursts from SGRs, and this detection number is comparable to that of other GRB-specific instruments. Based on the 10 years of operation, we describe timing and spectral performance for short GRBs, weak GRBs with high redshifts, and time-resolved pulses with good statistics.

Feasibility study of single photon emission coupled tomography imaging technique based on prompt gamma ray during antiproton therapy using boron particle

NASA Astrophysics Data System (ADS)

Shin, Han-Back; Jung, Joo-Young; Kim, Moo-Sub; Kim, Sunmi; Choi, Yong; Yoon, Do-Kun; Suh, Tae Suk

2018-06-01

In this study, we proposed an absorbed-dose monitoring technique using prompt gamma rays emitted from the reaction between an antiproton and a boron particle, and demonstrated the greater physical effect of the antiproton boron fusion therapy in comparison with proton beam using Monte Carlo simulation. The physical effect of the treatment, which was 3.5 times greater, was confirmed from the antiproton beam irradiation compared to the proton beam irradiation. Moreover, the prompt gamma ray image is acquired successfully during antiproton irradiation to boron regions. The results show the application feasibility of absorbed dose monitoring technique proposed in our study.

GLAST: Exploring Nature's Highest Energy Processes with the Gamma-ray Large Area Space Telescope

NASA Technical Reports Server (NTRS)

Digel, Seth; Myers, J. D.; White, Nicholas E. (Technical Monitor)

2001-01-01

The Gamma-ray Large Area Space Telescope (GLAST) is an international and multi-agency space mission that will study the cosmos in the energy range 10 keV-300 GeV. Several successful exploratory missions in gamma-ray astronomy led to the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Gamma Ray Observatory (CGRO). Launched in 1991, EGRET made the first complete survey of the sky in the 30 MeV-10 GeV range. EGRET showed the high-energy gamma-ray sky to be surprisingly dynamic and diverse, with sources ranging from the sun and moon to massive black holes at large redshifts. Most of the gamma-ray sources detected by EGRET remain unidentified. In light of the discoveries with EGRET, the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope vastly more capable than instruments flown previously, as well as a secondary instrument to augment the study of gamma-ray bursts. The main instrument, the Large Area Telescope (LAT), will have superior area, angular resolution, field of view, and deadtime that together will provide a factor of 30 or more advance in sensitivity, as well as provide capability for study of transient phenomena. The GLAST Burst Monitor (GBM) will have a field of view several times larger than the LAT and will provide spectral coverage of gamma-ray bursts that extends from the lower limit of the LAT down to 10 keV. The basic parameters of the GBM are compared to those of the Burst and Transient Source Experiment (BATSE) instrument on CGRO in Table 1-2. With the LAT and GBM, GLAST will be a flexible observatory for investigating the great range of astrophysical phenomena best studied in high-energy gamma rays. NASA plans to launch GLAST in late 2005.

Modeling of Pulses in Terrestrial Gamma-ray Flashes

NASA Astrophysics Data System (ADS)

Xu, Wei; Celestin, Sebastien; Pasko, Victor

2015-04-01

Terrestrial Gamma-ray Flashes (TGFs) are high-energy photon bursts originating from the Earth's atmosphere that are associated with lightning activities. After their discovery in 1994 by the Burst and Transient Source Experiment (BATSE) detector aboard the Compton Gamma-Ray Observatory [Fishman et al., Science, 264, 1313, 1994], this phenomenon has been further observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) [Smith et al., Science, 307, 1085, 2005], the Fermi Gamma-ray Space Telescope [Briggs et al., JGR, 115, A07323, 2010] and the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite [Marisaldi et al., JGR, 115, A00E13, 2010]. Photon spectra corresponding to the mechanism of relativistic runaway electron avalanches (RREAs) usually provide a very good agreement with satellite observations [Dwyer and Smith, GRL, 32, L22804, 2005]. On the other hand, Celestin and Pasko [JGR, 116, A03315, 2011] have shown theoretically that the large flux of thermal runaway electrons generated by streamers during the negative corona flash stage of stepping lightning leaders in intracloud lightning flashes could be responsible for TGFs. Recently, based on analysis of the temporal profiles of 278 TGF events observed by the Fermi Gamma-Ray Burst Monitor, Foley et al. [JGR, 119, 5931, 2014] have suggested that 67% of TGF pulses detected are asymmetric and these asymmetric pulses are consistent with the production mechanism of TGFs by relativistic feedback discharges. In the present work, we employ a Monte Carlo model to study the temporal distribution of photons at low-orbit satellite altitudes during TGF events. Using the pulse fitting method described in [Foley et al., 2014], we further investigate the characteristics of TGF pulses. We mainly focus on the effects of Compton scattering on the symmetry properties and the rise and fall times of TGF pulses.

Triple ionization chamber method for clinical dose monitoring with a Be-covered Li BNCT field.

PubMed

Nguyen, Thanh Tat; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Nguyen, Chien Cong; Endo, Satoru

2016-11-01

Fast neutron, gamma-ray, and boron doses have different relative biological effectiveness (RBE). In boron neutron capture therapy (BNCT), the clinical dose is the total of these dose components multiplied by their RBE. Clinical dose monitoring is necessary for quality assurance of the irradiation profile; therefore, the fast neutron, gamma-ray, and boron doses should be separately monitored. To estimate these doses separately, and to monitor the boron dose without monitoring the thermal neutron fluence, the authors propose a triple ionization chamber method using graphite-walled carbon dioxide gas (C-CO 2 ), tissue-equivalent plastic-walled tissue-equivalent gas (TE-TE), and boron-loaded tissue-equivalent plastic-walled tissue-equivalent gas [TE(B)-TE] chambers. To use this method for dose monitoring for a neutron and gamma-ray field moderated by D 2 O from a Be-covered Li target (Be-covered Li BNCT field), the relative sensitivities of these ionization chambers are required. The relative sensitivities of the TE-TE, C-CO 2 , and TE(B)-TE chambers to fast neutron, gamma-ray, and boron doses are calculated with the particle and heavy-ion transport code system (PHITS). The relative sensitivity of the TE(B)-TE chamber is calculated with the same method as for the TE-TE and C-CO 2 chambers in the paired chamber method. In the Be-covered Li BNCT field, the relative sensitivities of the ionization chambers to fast neutron, gamma-ray, and boron doses are calculated from the kerma ratios, mass attenuation coefficient tissue-to-wall ratios, and W-values. The Be-covered Li BNCT field consists of neutrons and gamma-rays which are emitted from a Be-covered Li target, and this resultant field is simulated by using PHITS with the cross section library of ENDF-VII. The kerma ratios and mass attenuation coefficient tissue-to-wall ratios are determined from the energy spectra of neutrons and gamma-rays in the Be-covered Li BNCT field. The W-value is calculated from recoil charged

GTA Beamloss-Monitor System

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

Rose, C.R.; Fortgang, C.M.; Power, J.P.

1992-09-01

The GTA Beamless-Monitor System at Los Alamos National Laboratory has been designed to detect high-energy particle loss in the accelerator beamline and shut down the accelerator before any damage can occur. To do this, the Beamless-Monitor System measures the induced gamma radiation, from (p, {gamma}) reactions, at 15 selected points along the beamline, converts this measured radiation to electrical signals integrates and compares them to preset limits, and, in the event of an over-limit condition causes the Fast-Protect System to shut down the entire accelerator. The system dynamic range exceeds 70 dB which will enable experimenters to use the Beamless-Monitormore » System to help steer the beam as well as provide signals for a Fast-Protect System. The system response time is less than 7 {mu}s assuming a step-function, worst-case beam spill of 50 mA. The system resolution, based on the noise floor of the electronics is about 1.3 mRads/s. Production units have been built and meet the above specifications. The remainder of the system will be installed and tested later in 1992/1993 with the GTA accelerator. The ionization chamber sensitivity and response time are described in the paper.« less

GTA Beamloss-Monitor System

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

Rose, C.R.; Fortgang, C.M.; Power, J.P.

1992-01-01

The GTA Beamless-Monitor System at Los Alamos National Laboratory has been designed to detect high-energy particle loss in the accelerator beamline and shut down the accelerator before any damage can occur. To do this, the Beamless-Monitor System measures the induced gamma radiation, from (p, {gamma}) reactions, at 15 selected points along the beamline, converts this measured radiation to electrical signals integrates and compares them to preset limits, and, in the event of an over-limit condition causes the Fast-Protect System to shut down the entire accelerator. The system dynamic range exceeds 70 dB which will enable experimenters to use the Beamless-Monitormore » System to help steer the beam as well as provide signals for a Fast-Protect System. The system response time is less than 7 {mu}s assuming a step-function, worst-case beam spill of 50 mA. The system resolution, based on the noise floor of the electronics is about 1.3 mRads/s. Production units have been built and meet the above specifications. The remainder of the system will be installed and tested later in 1992/1993 with the GTA accelerator. The ionization chamber sensitivity and response time are described in the paper.« less

Implications of Gamma-Ray Transparency Constraints in Blazars: Minimum Distances and Gamma-Ray Collimation

NASA Technical Reports Server (NTRS)

Becker, Peter A.; Kafatos, Menas

1995-01-01

We develop a general expression for the gamma - gamma absorption coefficient, alpha(sub gamma(gamma)) for gamma-rays propagating in an arbitrary direction at an arbitrary point in space above an X-ray-emitting accretion disk. The X-ray intensity is assumed to vary as a power law in energy and radius between the outer disk radius, R(sub 0), and the inner radius, R(sub ms) which is the radius of marginal stability for a Schwarzschild black hole. We use our result for alpha(sub gamma(gamma)) to calculate the gamma - gamma optical depth, tau(sub gamma(gamma)) for gamma - rays created at height z and propagating at angle Phi relative to the disk axis, and we show that for Phi = 0 and z greater than or approx equal to R(sub 0), tau(sub gamma(gamma)) proportional to Epsilon(sup alpha)z(sup -2(alpha) - 3), where alpha is the X-ray spectral index and Epsilon is the gamma - ray energy. As an application, we use our formalism to compute the minimum distance between the central black hole and the site of production of the gamma-rays detected by EGRET during the 1991 June flare of 3C 279. In order to obtain an upper limit, we assume that all of the X-rays observed contemporaneously by Ginga were emitted by the disk. Our results suggest that the observed gamma - rays may have originated within less than or approx equal to 45 GM/sq c from a black hole of mass greater than or approx equal to 10(exp 9) solar mass, perhaps in active plasma located above the central funnel of the accretion disk. This raises the possibility of establishing a direct connection between the production of the observed gamma - rays and the accretion of material onto the black hole. We also consider the variation of the optical depth as a function of the angle of propagation Phi. Our results indicate that the "focusing" of the gamma - rays along the disk axis due to pair production is strong enough to explain the observed degree of alignment in blazar sources. If the gamma - rays are produced isotropically

Design and performance of the GAMMA-400 gamma-ray telescope for dark matter searches

NASA Astrophysics Data System (ADS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Fradkin, M. I.; Gusakov, Yu. V.; Kaplin, V. A.; Kachanov, V. A.; Kheymits, M. D.; Leonov, A. A.; Longo, F.; Mazets, E. P.; Maestro, P.; Marrocchesi, P.; Mereminskiy, I. A.; Mikhailov, V. V.; Moiseev, A. A.; Mocchiutti, E.; Mori, N.; Moskalenko, I. V.; Naumov, P. Yu.; Papini, P.; Picozza, P.; Rodin, V. G.; Runtso, M. F.; Sparvoli, R.; Spillantini, P.; Suchkov, S. I.; Tavani, M.; Topchiev, N. P.; Vacchi, A.; Vannuccini, E.; Yurkin, Yu. T.; Zampa, N.; Zverev, V. G.; Zirakashvili, V. N.

2013-02-01

The GAMMA-400 gamma-ray telescope is designed to measure the fluxes of gamma-rays and cosmic-ray electrons + positrons, which can be produced by annihilation or decay of the dark matter particles, as well as to survey the celestial sphere in order to study point and extended sources of gamma-rays, measure energy spectra of Galactic and extragalactic diffuse gamma-ray emission, gamma-ray bursts, and gamma-ray emission from the Sun. GAMMA-400 covers the energy range from 100 MeV to 3000 GeV. Its angular resolution is ~0.01° (Eγ > 100 GeV), the energy resolution ~1% (Eγ > 10 GeV), and the proton rejection factor ~106. GAMMA-400 will be installed on the Russian space platform Navigator. The beginning of observations is planned for 2018.

Suzaku Wide-band All-sky Monitor measurements of duration distributions of gamma-ray bursts

NASA Astrophysics Data System (ADS)

Ohmori, Norisuke; Yamaoka, Kazutaka; Ohno, Masanori; Sugita, Satoshi; Kinoshita, Ryuuji; Nishioka, Yusuke; Hurley, Kevin; Hanabata, Yoshitaka; Tashiro, Makoto S.; Enomoto, Junichi; Fujinuma, Takeshi; Fukazawa, Yasushi; Iwakiri, Wataru; Kawano, Takafumi; Kokubun, Motohide; Makishima, Kazuo; Matsuoka, Shunsuke; Nagayoshi, Tsutomu; Nakagawa, Yujin E.; Nakaya, Souhei; Nakazawa, Kazuhiro; Takahashi, Tadayuki; Takeda, Sawako; Terada, Yukikatsu; Urata, Yuji; Yabe, Seiya; Yasuda, Tetsuya; Yamauchi, Makoto

2016-06-01

We report on the T90 and T50 duration distributions and their relations with spectral hardness using 1464 gamma-ray bursts (GRBs), which were observed by the Suzaku Wide-band All-sky Monitor (WAM) from 2005 August 4 to 2010 December 29. The duration distribution is clearly bimodal in three energy ranges (50-120, 120-250, and 250-550 keV), but is unclear in the 550-5000 keV range, probably because of the limited sample size. The WAM durations decrease with energy according to a power-law index of -0.058(-0.034, +0.033). The hardness-duration relation reveals the presence of short-hard and long-soft GRBs. The short:long event ratio tends to be higher with increasing energy. We compared the WAM distribution with ones measured by eight other GRB instruments. The WAM T90 distribution is very similar to those of INTEGRAL/SPI-ACS and Granat/PHEBUS, and least likely to match the Swift/BAT distribution. The WAM short:long event ratio (0.25:0.75) is much different from Swift/BAT (0.08:0.92), but is almost the same as CGRO/BATSE (0.25:0.75). To explain this difference for BAT, we examined three effects: BAT trigger types, energy dependence of the duration, and detection sensitivity differences between BAT and WAM. As a result, we found that the ratio difference could be explained mainly by energy dependence including soft extended emissions for short GRBs and much better sensitivity for BAT which can detect weak/long GRBs. The reason for the same short:long event ratio for BATSE and WAM was confirmed by calculation using the trigger efficiency curve.

The first Fermi-LAT Gamma-Ray burst catalog

DOE PAGES

Ackermann, M.; Ajello, M.; Asano, K.; ...

2013-10-23

In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (gsim 20 MeV) γ-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above ~20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi andmore » processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. Here, we summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model.« less

A Unique Outside Neutron and Gamma Ray Instrumentation Development Test Facility at NASA's Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Bodnarik, J.; Evans, L.; Floyd, S.; Lim, L.; McClanahan, T.; Namkung, M.; Parsons, A.; Schweitzer, J.; Starr, R.; Trombka, J.

2010-01-01

An outside neutron and gamma ray instrumentation test facility has been constructed at NASA's Goddard Space Flight Center (GSFC) to evaluate conceptual designs of gamma ray and neutron systems that we intend to propose for future planetary lander and rover missions. We will describe this test facility and its current capabilities for operation of planetary in situ instrumentation, utilizing a l4 MeV pulsed neutron generator as the gamma ray excitation source with gamma ray and neutron detectors, in an open field with the ability to remotely monitor and operate experiments from a safe distance at an on-site building. The advantage of a permanent test facility with the ability to operate a neutron generator outside and the flexibility to modify testing configurations is essential for efficient testing of this type of technology. Until now, there have been no outdoor test facilities for realistically testing neutron and gamma ray instruments planned for solar system exploration

Increase in neutrophil Fc gamma receptor I expression following interferon gamma treatment in rheumatoid arthritis.

PubMed Central

Goulding, N J; Knight, S M; Godolphin, J L; Guyre, P M

1992-01-01

The therapeutic potential of interferon gamma (IFN gamma) in a number of disease states is still being explored, but progress is hampered by the lack of a suitable measure of in vivo biological activity. To assess the in vivo biological effects of recombinant human IFN gamma (rhIFN gamma), 14 patients were studied in a randomised, prospective, double blind, placebo controlled trial of this cytokine for the treatment of rheumatoid arthritis. The levels of Fc gamma receptors on peripheral blood neutrophils were measured at baseline and after 21 days of once daily, subcutaneous injections of rhIFN gamma or placebo. An induction of neutrophil Fc gamma receptor type I (Fc gamma RI) was seen in the group of patients receiving recombinant human rhIFN gamma but not in those receiving placebo. No change in the expression of Fc gamma RII or Fc gamma RIII was detected. The amount of induction of Fc gamma RI detected on the neutrophils of patients receiving rhIFN gamma did not correlate with clinical measures of response at either 21 days or at the end of the study (24 weeks). No significant clinical responses were observed in the rhIFN gamma group at these times. These data confirm that the reported in vitro effect of IFN gamma on human neutrophil Fc receptor expression can be reproduced in vivo. PMID:1534001

Increase in neutrophil Fc gamma receptor I expression following interferon gamma treatment in rheumatoid arthritis.

PubMed

Goulding, N J; Knight, S M; Godolphin, J L; Guyre, P M

1992-04-01

The therapeutic potential of interferon gamma (IFN gamma) in a number of disease states is still being explored, but progress is hampered by the lack of a suitable measure of in vivo biological activity. To assess the in vivo biological effects of recombinant human IFN gamma (rhIFN gamma), 14 patients were studied in a randomised, prospective, double blind, placebo controlled trial of this cytokine for the treatment of rheumatoid arthritis. The levels of Fc gamma receptors on peripheral blood neutrophils were measured at baseline and after 21 days of once daily, subcutaneous injections of rhIFN gamma or placebo. An induction of neutrophil Fc gamma receptor type I (Fc gamma RI) was seen in the group of patients receiving recombinant human rhIFN gamma but not in those receiving placebo. No change in the expression of Fc gamma RII or Fc gamma RIII was detected. The amount of induction of Fc gamma RI detected on the neutrophils of patients receiving rhIFN gamma did not correlate with clinical measures of response at either 21 days or at the end of the study (24 weeks). No significant clinical responses were observed in the rhIFN gamma group at these times. These data confirm that the reported in vitro effect of IFN gamma on human neutrophil Fc receptor expression can be reproduced in vivo.

Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix.

PubMed

Wang, Hang; Wang, Ying; Wang, Ge; Hong, Lizhi

2017-07-15

Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC-MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC-MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution. Copyright © 2017 Elsevier B.V. All rights reserved.

Gamma Knife

MedlinePlus

... equipment? How is safety ensured? What is this equipment used for? The Gamma Knife® and its associated ... in size. top of page How does the equipment work? The Gamma Knife® utilizes a technique called ...

Gamma-400 Science Objectives Built on the Current HE Gamma-Ray and CR Results

NASA Technical Reports Server (NTRS)

Moiseev, Alexander; Mitchell, John; Thompson, David

2012-01-01

The main scientific interest of the Russian Gamma-400 team: Observe gamma-rays above approximately 50 GeV with excellent energy and angular resolution with the goals of: (1) Studying the fine spectral structure of the isotropic high-energy gamma-radiation, (2) Attempting to identify the many still-unidentified Fermi-LAT gamma-ray sources. Gamma-400 will likely be the only space-based gamma-ray observatory operating at the end of the decade. In our proposed Gamma-400-LE version, it will substantially improve upon the capabilities of Fermi LAT and AGILE in both LE and HE energy range. Measuring gamma-rays from approx 20 MeV to approx 1 TeV for at least 7 years, Gamma-400-LE will address the topics of dark matter, cosmic ray origin and propagation, neutron stars, flaring pulsars, black holes, AGNs, GRBs, and actively participate in multiwavelength campaigns.

Ultralow-dose, feedback imaging with laser-Compton X-ray and laser-Compton gamma ray sources

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

Barty, Christopher P. J.

Ultralow-dose, x-ray or gamma-ray imaging is based on fast, electronic control of the output of a laser-Compton x-ray or gamma-ray source (LCXS or LCGS). X-ray or gamma-ray shadowgraphs are constructed one (or a few) pixel(s) at a time by monitoring the LCXS or LCGS beam energy required at each pixel of the object to achieve a threshold level of detectability at the detector. An example provides that once the threshold for detection is reached, an electronic or optical signal is sent to the LCXS/LCGS that enables a fast optical switch that diverts, either in space or time the laser pulsesmore » used to create Compton photons. In this way, one prevents the object from being exposed to any further Compton x-rays or gamma-rays until either the laser-Compton beam or the object are moved so that a new pixel location may be illumination.« less

Spectrometric analysis and scanning electronic microscopy of two pleural plaques from mediaeval Portuguese period.

PubMed

Fernandes, T; Granja, R; Thillaud, P L

2014-01-01

During an archaeological excavation at a mediaeval monastery (Flor da Rosa, Crato, Portugal), a skeleton of a adult woman was found with two calcifications in the thoracic cage. The location and the macroscopic analysis of the calcifications allowed them to be assigned as pleural plaques. Spectrometric analysis and scanning electronic microscopy enabled to establish that it originated with an infectious process. These results associated with the lesions found in the ribs and vertebrae strongly suggest tuberculosis as the cause of these pleural plaques. Copyright © 2013 Sociedade Portuguesa de Pneumologia. Published by Elsevier España. All rights reserved.

Genomic sequences of murine gamma B- and gamma C-crystallin-encoding genes: promoter analysis and complete evolutionary pattern of mouse, rat and human gamma-crystallins.

PubMed

Graw, J; Liebstein, A; Pietrowski, D; Schmitt-John, T; Werner, T

1993-12-22

The murine genes, gamma B-cry and gamma C-cry, encoding the gamma B- and gamma C-crystallins, were isolated from a genomic DNA library. The complete nucleotide (nt) sequences of both genes were determined from 661 and 711 bp, respectively, upstream from the first exon to the corresponding polyadenylation sites, comprising more than 2650 and 2890 bp, respectively. The new sequences were compared to the partial cDNA sequences available for the murine gamma B-cry and gamma C-cry, as well as to the corresponding genomic sequences from rat and man, at both the nt and predicted amino acid (aa) sequence levels. In the gamma B-cry promoter region, a canonical CCAAT-box, a TATA-box, putative NF-I and C/EBP sites were detected. An R-repeat is inserted 366 bp upstream from the transcription start point. In contrast, the gamma C-cry promoter does not contain a CCAAT-box, but some other putative binding sites for transcription factors (AP-2, UBP-1, LBP-1) were located by computer analysis. The promoter regions of all six gamma-cry from mouse, rat and human, except human psi gamma F-cry, were analyzed for common sequence elements. A complex sequence element of about 70-80 bp was found in the proximal promoter, which contains a gamma-cry-specific and almost invariant sequence (crygpel) of 14 nt, and ends with the also invariant TATA-box. Within the complex sequence element, a minimum of three further features specific for the gamma A-, gamma B- and gamma D/E/F-cry genes can be defined, at least two of which were recently shown to be functional. In addition to these four sequence elements, a subtype-specific structure of inverted repeats with different-sized spacers can be deduced from the multiple sequence alignment. A phylogenetic analysis based on the promoter region, as well as the complete exon 3 of all gamma-cry from mouse, rat and man, suggests separation of only five gamma-cry subtypes (gamma A-, gamma B-, gamma C-, gamma D- and gamma E/F-cry) prior to species separation.

Predicting diffusion paths and interface motion in gamma/gamma + beta, Ni-Cr-Al diffusion couples

NASA Technical Reports Server (NTRS)

Nesbitt, J. A.; Heckel, R. W.

1987-01-01

A simplified model has been developed to predict Beta recession and diffusion paths in ternary gamma/gamma + beta diffusion couples (gamma:fcc, beta: NiAl structure). The model was tested by predicting beta recession and diffusion paths for four gamma/gamma + beta, Ni-Cr-Al couples annealed for 100 hours at 1200 C. The model predicted beta recession within 20 percent of that measured for each of the couples. The model also predicted shifts in the concentration of the gamma phase at the gamma/gamma + beta interface within 2 at. pct Al and 6 at. pct Cr of that measured in each of the couples. A qualitative explanation based on simple kinetic and mass balance arguments has been given which demonstrates the necessity for diffusion in the two-phase region of certain gamma/gamma + beta, Ni-Cr-Al couples.

An Optically Stimulated Luminescence Uranium Enrichment Monitor

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

Miller, Steven D.; Tanner, Jennifer E.; Simmons, Kevin L.

The Pacific Northwest National Laboratory (PNNL) has pioneered the use of Optically Stimulated Luminescence (OSL) technology for use in personnel dosimetry and high dose radiation processing dosimetry. PNNL has developed and patented an alumina-based OSL dosimeter that is being used by the majority of medical X-ray and imaging technicians worldwide. PNNL has conceived of using OSL technology to passively measure the level of UF6 enrichment by attaching the prototype OSL monitor to pipes containing UF6 gas within an enrichment facility. The prototype OSL UF6 monitor utilizes a two-element approach with the first element open and unfiltered to measure both themore » low energy and high energy gammas from the UF6, while the second element utilizes a 3-mm thick tungsten filter to eliminate the low energy gammas and pass only the high energy gammas from the UF6. By placing a control monitor in the room away from the UF6 pipes and other ionizing radiation sources, the control readings can be subtracted from the UF6 pipe monitor measurements. The ratio of the shielded to the unshielded net measurements provides a means to estimate the level of uranium enrichment. PNNL has replaced the commercially available MicroStar alumina-based dosimeter elements with a composite of polyethylene plastic, high-Z glass powder, and BaFBr:Eu OSL phosphor powder at various concentrations. The high-Z glass was added in an attempt to raise the average “Z” of the composite dosimeter and increase the response. Additionally, since BaFBr:Eu OSL phosphor is optimally excited and emits light at different wavelengths compared to alumina, the commercially available MicroStar reader was modified for reading BaFBr:Eu in a parallel effort to increase reader sensitivity. PNNL will present the design and performance of our novel OSL uranium enrichment monitor based on a combination of laboratory and UF6 test loop measurements. PNNL will also report on the optimization effort to achieve the highest

Discovery of gamma-ray pulsations from the transitional redback PSR J1227-4853

DOE PAGES

Johnson, Tyrel J.; Ray, Paul S.; Roy, Jayanta; ...

2015-06-10

Here, the 1.69 ms spin period of PSR J1227–4853 was recently discovered in radio observations of the low-mass X-ray binary XSS J12270–4859 following the announcement of a possible transition to a rotation-powered millisecond pulsar state, inferred from decreases in optical, X-ray, and gamma-ray flux from the source. We report the detection of significant (5σ) gamma-ray pulsations after the transition, at the known spin period, using ~1 year of data from the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. The gamma-ray light curve of PSR J1227–4853 can be fit by one broad peak, which occurs at nearlymore » the same phase as the main peak in the 1.4 GHz radio profile. The partial alignment of light-curve peaks in different wavebands suggests that at least some of the radio emission may originate at high altitude in the pulsar magnetosphere, in extended regions co-located with the gamma-ray emission site. We folded the LAT data at the orbital period, both pre- and post-transition, but find no evidence for significant modulation of the gamma-ray flux. Analysis of the gamma-ray flux over the mission suggests an approximate transition time of 2012 November 30. Continued study of the pulsed emission and monitoring of PSR J1227–4853, and other known redback systems, for subsequent flux changes will increase our knowledge of the pulsar emission mechanism and transitioning systems.« less

The First Fermi Large Area Telescope Catalog of Gamma-ray Pulsars

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2010-03-25

The dramatic increase in the number of known gamma-ray pulsars since the launch of the Fermi Gamma-ray Space Telescope (formerly GLAST) offers the first opportunity to study a sizable population of these high-energy objects. This catalog summarizes 46 high-confidence pulsed detections using the first six months of data taken by the Large Area Telescope (LAT), Fermi's main instrument. Sixteen previously unknown pulsars were discovered by searching for pulsed signals at the positions of bright gamma-ray sources seen with the LAT, or at the positions of objects suspected to be neutron stars based on observations at other wavelengths. The dimmest observed flux among these gamma-ray-selected pulsars is 6.0 × 10 –8 ph cm –2 s –1 (for E>100 MeV). Pulsed gamma-ray emission was discovered from 24 known pulsars by using ephemerides (timing solutions) derived from monitoring radio pulsars. Eight of these new gamma-ray pulsars are millisecond pulsars. The dimmest observed flux among the radio-selected pulsars is 1.4 × 10 –8 ph cm –2 s –1 (for E>100 MeV). The remaining six gamma-ray pulsars were known since the Compton Gamma Ray Observatory mission, or before. The limiting flux for pulse detection is non-uniform over the sky owing to different background levels, especially near the Galactic plane. The pulsed energy spectra can be described by a power law with an exponential cutoff, with cutoff energies in the range ~1-5 GeV. The rotational energy-loss rate (more » $$\\dot{E}$$) of these neutron stars spans five decades, from ~3 × 10 33 erg s –1 to 5 × 10 38 erg s –1, and the apparent efficiencies for conversion to gamma-ray emission range from ~0.1% to ~ unity, although distance uncertainties complicate efficiency estimates. The pulse shapes show substantial diversity, but roughly 75% of the gamma-ray pulse profiles have two peaks, separated by ≳0.2 of rotational phase. For most of the pulsars, gamma-ray emission appears to come mainly from the outer

Comparison of gamma-gamma Phase Coarsening Responses of Three Powder Metal Disk Superalloys

NASA Technical Reports Server (NTRS)

Gabb, T. P.; Gayda, J.; Johnson, D. F.; MacKay, R. A.; Rogers, R. B.; Sudbrack, C. K.; Garg, A.; Locci, I. E.; Semiatin, S. L.; Kang, E.

2016-01-01

The phase microstructures of several powder metal (PM) disk superalloys were quantitatively evaluated. Contents, chemistries, and lattice parameters of gamma and gamma strengthening phase were determined for conventionally heat treated Alloy 10, LSHR, and ME3 superalloys, after electrolytic phase extractions. Several of long term heat treatments were then performed, to allow quantification of the precipitation, content, and size distribution of gamma at a long time interval to approximate equilibrium conditions. Additional coarsening heat treatments were performed at multiple temperatures and shorter time intervals, to allow quantification of the precipitation, contents and size distributions of gamma at conditions diverging from equilibrium. Modest differences in gamma and gamma lattice parameters and their mismatch were observed among the alloys, which varied with heat treatment. Yet, gamma coarsening rates were very similar for all three alloys in the heat treatment conditions examined. Alloy 10 had higher gamma dissolution and formation temperatures than LSHR and ME3, but a lower lattice mismatch, which was slightly positive for all three alloys at room temperature. The gamma precipitates of Alloy 10 appeared to remain coherent at higher temperatures than for LSHR and ME3. Higher coarsening rates were observed for gamma precipitates residing along grain boundaries than for those within grains in all three alloys, during slow-moderate quenching from supersolvus solution heat treatments, and during aging at temperatures of 843 C and higher.

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Afrough, M.; Agarwal, B.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Ajith, P.; Allen, B.; Allen, G.; Allocca, A.; Aloy, M. A.; Altin, P. A.; Amato, A.; Ananyeva, A.; Anderson, S. B.; Anderson, W. G.; Angelova, S. V.; Antier, S.; Appert, S.; Arai, K.; Araya, M. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Atallah, D. V.; Aufmuth, P.; Aulbert, C.; AultONeal, K.; Austin, C.; Avila-Alvarez, A.; Babak, S.; Bacon, P.; Bader, M. K. M.; Bae, S.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Banagiri, S.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barkett, K.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Bawaj, M.; Bayley, J. C.; Bazzan, M.; Bécsy, B.; Beer, C.; Bejger, M.; Belahcene, I.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Bero, J. J.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Billman, C. R.; Birch, J.; Birney, R.; Birnholtz, O.; Biscans, S.; Biscoveanu, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blackman, J.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Bode, N.; Boer, M.; Bogaert, G.; Bohe, A.; Bondu, F.; Bonilla, E.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bossie, K.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T. A.; Calloni, E.; Camp, J. B.; Canepa, M.; Canizares, P.; Cannon, K. C.; Cao, H.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Carney, M. F.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerdá-Durán, P.; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chase, E.; Chassande-Mottin, E.; Chatterjee, D.; Chatziioannou, K.; Cheeseboro, B. D.; Chen, H. Y.; Chen, X.; Chen, Y.; Cheng, H.-P.; Chia, H.; Chincarini, A.; Chiummo, A.; Chmiel, T.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, A. J. K.; Chua, S.; Chung, A. K. W.; Chung, S.; Ciani, G.; Ciolfi, R.; Cirelli, C. E.; Cirone, A.; Clara, F.; Clark, J. A.; Clearwater, P.; Cleva, F.; Cocchieri, C.; Coccia, E.; Cohadon, P.-F.; Cohen, D.; Colla, A.; Collette, C. G.; Cominsky, L. R.; Constancio, M., Jr.; Conti, L.; Cooper, S. J.; Corban, P.; Corbitt, T. R.; Cordero-Carrión, I.; Corley, K. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Covas, P. B.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cullen, T. J.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Dálya, G.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Dasgupta, A.; Da Silva Costa, C. F.; Dattilo, V.; Dave, I.; Davier, M.; Davis, D.; Daw, E. J.; Day, B.; De, S.; DeBra, D.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Demos, N.; Denker, T.; Dent, T.; De Pietri, R.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; De Rossi, C.; DeSalvo, R.; de Varona, O.; Devenson, J.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Renzo, F.; Doctor, Z.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Dorrington, I.; Douglas, R.; Dovale Álvarez, M.; Downes, T. P.; Drago, M.; Dreissigacker, C.; Driggers, J. C.; Du, Z.; Ducrot, M.; Dupej, P.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Eisenstein, R. A.; Essick, R. C.; Estevez, D.; Etienne, Z. B.; Etzel, T.; Evans, M.; Evans, T. M.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Farinon, S.; Farr, B.; Farr, W. M.; Fauchon-Jones, E. J.; Favata, M.; Fays, M.; Fee, C.; Fehrmann, H.; Feicht, J.; Fejer, M. M.; Fernandez-Galiana, A.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Finstad, D.; Fiori, I.; Fiorucci, D.; Fishbach, M.; Fisher, R. P.; Fitz-Axen, M.; Flaminio, R.; Fletcher, M.; Fong, H.; Font, J. A.; Forsyth, P. W. F.; Forsyth, S. S.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fries, E. M.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H.; Gadre, B. U.; Gaebel, S. M.; Gair, J. R.; Gammaitoni, L.; Ganija, M. R.; Gaonkar, S. G.; Garcia-Quiros, C.; Garufi, F.; Gateley, B.; Gaudio, S.; Gaur, G.; Gayathri, V.; Gehrels, N.; Gemme, G.; Genin, E.; Gennai, A.; George, D.; George, J.; Gergely, L.; Germain, V.; Ghonge, S.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glover, L.; Goetz, E.; Goetz, R.; Gomes, S.; Goncharov, B.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Gretarsson, E. M.; Groot, P.; Grote, H.; Grunewald, S.; Gruning, P.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Halim, O.; Hall, B. R.; Hall, E. D.; Hamilton, E. Z.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hannuksela, O. A.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Haster, C.-J.; Haughian, K.; Healy, J.; 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.; Hinderer, T.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Horst, C.; Hough, J.; Houston, E. A.; Howell, E. J.; Hreibi, A.; Hu, Y. M.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Inta, R.; Intini, G.; Isa, H. N.; Isac, J.-M.; Isi, M.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jiménez-Forteza, F.; Johnson, W. W.; Johnson-McDaniel, N. K.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; Junker, J.; Kalaghatgi, C. V.; Kalogera, V.; Kamai, B.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Kastaun, W.; Katolik, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kawabe, K.; Kéfélian, F.; Keitel, D.; Kemball, A. J.; Kennedy, R.; Kent, C.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chunglee; Kim, J. C.; Kim, K.; Kim, W.; Kim, W. S.; Kim, Y.-M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kinley-Hanlon, M.; Kirchhoff, R.; Kissel, J. S.; Kleybolte, L.; Klimenko, S.; Knowles, T. D.; Koch, P.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Krämer, C.; Kringel, V.; Krishnan, B.; Królak, A.; Kuehn, G.; Kumar, P.; Kumar, R.; Kumar, S.; Kuo, L.; Kutynia, A.; Kwang, S.; Lackey, B. D.; Lai, K. H.; Landry, M.; Lang, R. N.; Lange, J.; Lantz, B.; Lanza, R. K.; Lartaux-Vollard, A.; Lasky, P. D.; Laxen, M.; Lazzarini, A.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, H. W.; Lee, K.; Lehmann, J.; Lenon, A.; Leonardi, M.; Leroy, N.; Letendre, N.; Levin, Y.; Li, T. G. F.; Linker, S. D.; Littenberg, T. B.; Liu, J.; Lo, R. K. L.; Lockerbie, N. A.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lousto, C. O.; Lovelace, G.; Lück, H.; Lumaca, D.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macas, R.; Macfoy, S.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña Hernandez, I.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markakis, C.; Markosyan, A. S.; Markowitz, A.; Maros, E.; Marquina, A.; Martelli, F.; Martellini, L.; Martin, I. W.; Martin, R. M.; Martynov, D. V.; Mason, K.; Massera, E.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matas, A.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McCuller, L.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McNeill, L.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Mehmet, M.; Meidam, J.; Mejuto-Villa, E.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, B. B.; Miller, J.; Millhouse, M.; Milovich-Goff, M. C.; Minazzoli, O.; Minenkov, Y.; Ming, J.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moffa, D.; Moggi, A.; Mogushi, K.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Muñiz, E. A.; Muratore, M.; Murray, P. G.; Napier, K.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Neilson, J.; Nelemans, G.; Nelson, T. J. N.; Nery, M.; Neunzert, A.; Nevin, L.; Newport, J. M.; Newton, G.; Ng, K. K. Y.; Nguyen, T. T.; Nichols, D.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Noack, A.; Nocera, F.; Nolting, D.; North, C.; Nuttall, L. K.; Oberling, J.; O'Dea, G. D.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Okada, M. A.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; Ormiston, R.; Ortega, L. F.; O'Shaughnessy, R.; Ossokine, S.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pace, A. E.; Page, J.; Page, M. A.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, Howard; Pan, Huang-Wei; Pang, B.; Pang, P. T. H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Parida, A.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patil, M.; Patricelli, B.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perez, C. J.; Perreca, A.; Perri, L. M.; Pfeiffer, H. P.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pirello, M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Porter, E. K.; Post, A.; Powell, J.; Prasad, J.; Pratt, J. W. W.; Pratten, G.; Predoi, V.; Prestegard, T.; Prijatelj, M.; Principe, M.; Privitera, S.; Prodi, G. A.; Prokhorov, L. G.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rajbhandari, B.; Rakhmanov, M.; Ramirez, K. E.; Ramos-Buades, A.; Rapagnani, P.; Raymond, V.; Razzano, M.; Read, J.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Ren, W.; Reyes, S. D.; Ricci, F.; Ricker, P. M.; Rieger, S.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romel, C. L.; Romie, J. H.; Rosińska, D.; Ross, M. P.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Rutins, G.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sampson, L. M.; Sanchez, E. J.; Sanchez, L. E.; Sanchis-Gual, N.; Sandberg, V.; Sanders, J. R.; Sassolas, B.; Sathyaprakash, B. S.; Saulson, P. R.; Sauter, O.; Savage, R. L.; Sawadsky, A.; Schale, P.; Scheel, M.; Scheuer, J.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schulte, B. W.; Schutz, B. F.; Schwalbe, S. G.; Scott, J.; Scott, S. M.; Seidel, E.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Shaddock, D. A.; Shaffer, T. J.; Shah, A. A.; Shahriar, M. S.; Shaner, M. B.; Shao, L.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, L. P.; Singh, A.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, B.; Smith, J. R.; Smith, R. J. E.; Somala, S.; Son, E. J.; Sonnenberg, J. A.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Spencer, A. P.; Srivastava, A. K.; Staats, K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stevenson, S. P.; Stone, R.; Stops, D. J.; Strain, K. A.; Stratta, G.; Strigin, S. E.; Strunk, A.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Suresh, J.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Tait, S. C.; Talbot, C.; Talukder, D.; Tanner, D. B.; Tápai, M.; Taracchini, A.; Tasson, J. D.; Taylor, J. A.; Taylor, R.; Tewari, S. V.; Theeg, T.; Thies, F.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tonelli, M.; Tornasi, Z.; Torres-Forné, A.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trinastic, J.; Tringali, M. C.; Trozzo, L.; Tsang, K. W.; Tse, M.; Tso, R.; Tsukada, L.; Tsuna, D.; Tuyenbayev, D.; Ueno, K.; 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.; Varma, V.; Vass, S.; Vasúth, M.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Venugopalan, G.; Verkindt, D.; Vetrano, F.; Viceré, A.; Viets, A. D.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walet, R.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, J. Z.; Wang, W. H.; Wang, Y. F.; Ward, R. L.; Warner, J.; Was, M.; Watchi, J.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Wessel, E. K.; Weßels, P.; Westerweck, J.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; Whiting, B. F.; Whittle, C.; Wilken, D.; Williams, D.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Wofford, J.; Wong, K. W. K.; Worden, J.; Wright, J. L.; Wu, D. S.; Wysocki, D. M.; Xiao, S.; Yamamoto, H.; Yancey, C. C.; Yang, L.; Yap, M. J.; Yazback, M.; Yu, Hang; Yu, Haocun; Yvert, M.; Zadrożny, A.; Zanolin, M.; Zelenova, T.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, T.; Zhang, Y.-H.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X. J.; Zimmerman, A. B.; Zucker, M. E.; Zweizig, J.; (LIGO Scientific Collaboration; Virgo Collaboration; Burns, E.; Veres, P.; Kocevski, D.; Racusin, J.; Goldstein, A.; Connaughton, V.; Briggs, M. S.; Blackburn, L.; Hamburg, R.; Hui, C. M.; von Kienlin, A.; McEnery, J.; Preece, R. D.; Wilson-Hodge, C. A.; Bissaldi, E.; Cleveland, W. H.; Gibby, M. H.; Giles, M. M.; Kippen, R. M.; McBreen, S.; Meegan, C. A.; Paciesas, W. S.; Poolakkil, S.; Roberts, O. J.; Stanbro, M.; Gamma-ray Burst Monitor, (Fermi; Savchenko, V.; Ferrigno, C.; Kuulkers, E.; Bazzano, A.; Bozzo, E.; Brandt, S.; Chenevez, J.; Courvoisier, T. J.-L.; Diehl, R.; Domingo, A.; Hanlon, L.; Jourdain, E.; Laurent, P.; Lebrun, F.; Lutovinov, A.; Mereghetti, S.; Natalucci, L.; Rodi, J.; Roques, J.-P.; Sunyaev, R.; Ubertini, P.; (INTEGRAL

2017-10-01

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance is 5.0× {10}-8. We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of (+1.74+/- 0.05) {{s}} between GRB 170817A and GW170817 to: (I) constrain the difference between the speed of gravity and the speed of light to be between -3× {10}-15 and +7× {10}-16 times the speed of light, (II) place new bounds on the violation of Lorentz invariance, (III) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1-1.4 per year during the 2018-2019 observing run and 0.3-1.7 per year at design sensitivity.

High-gamma band fronto-temporal coherence as a measure of functional connectivity in speech motor control.

PubMed

Kingyon, J; Behroozmand, R; Kelley, R; Oya, H; Kawasaki, H; Narayanan, N S; Greenlee, J D W

2015-10-01

The neural basis of human speech is unclear. Intracranial electrophysiological recordings have revealed that high-gamma band oscillations (70-150Hz) are observed in the frontal lobe during speech production and in the temporal lobe during speech perception. Here, we tested the hypothesis that the frontal and temporal brain regions had high-gamma coherence during speech. We recorded electrocorticography (ECoG) from the frontal and temporal cortices of five humans who underwent surgery for medically intractable epilepsy, and studied coherence between the frontal and temporal cortex during vocalization and playback of vocalization. We report two novel results. First, we observed high-gamma band as well as theta (4-8Hz) coherence between frontal and temporal lobes. Second, both high-gamma and theta coherence were stronger when subjects were actively vocalizing as compared to playback of the same vocalizations. These findings provide evidence that coupling between sensory-motor networks measured by high-gamma coherence plays a key role in feedback-based monitoring and control of vocal output for human vocalization. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

A New Approach for the Determination of Dose Rate and Radioactivity for Detected Gamma Nuclides Using an Environmental Radiation Monitor Based on an NaI(Tl) Detector.

PubMed

Ji, Young-Yong; Kim, Chang-Jong; Lim, Kyo-Sun; Lee, Wanno; Chang, Hyon-Sock; Chung, Kun Ho

2017-10-01

To expand the application of dose rate spectroscopy to the environment, the method using an environmental radiation monitor (ERM) based on a 3' × 3' NaI(Tl) detector was used to perform real-time monitoring of the dose rate and radioactivity for detected gamma nuclides in the ground around an ERM. Full-energy absorption peaks in the energy spectrum for dose rate were first identified to calculate the individual dose rates of Bi, Ac, Tl, and K distributed in the ground through interference correction because of the finite energy resolution of the NaI(Tl) detector used in an ERM. The radioactivity of the four natural radionuclides was then calculated from the in situ calibration factor-that is, the dose rate per unit curie-of the used ERM for the geometry of the ground in infinite half-space, which was theoretically estimated by Monte Carlo simulation. By an intercomparison using a portable HPGe and samples taken from the ground around an ERM, this method to calculate the dose rate and radioactivity of four nuclides using an ERM was experimentally verified and finally applied to remotely monitor them in real-time in the area in which the ERM had been installed.

The BATSE Earth Occultation Catalog of Low Energy Gamma Ray Sources

NASA Technical Reports Server (NTRS)

Harmon, B. A.; Wilson-Hodge, C. A.; Fishman, G. J.; Paciesas, W. S.; Zhang, S. N.; Finger, M. H.; Connaughton, V.; Koshut, T. M.; Henze, W.; McCollough, M. L.;

The BATSE Earth Occultation Catalog of Low Energy Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Harmon, B. A.; Wilson-Hodge, C. A.; Fishman, G. J.; Paciesas, W. S.; Zhang, S. N.; Finger, M. H.; Connaughton, V.; Koshut, T. M.; Henze, W.; McCollough, M. L.

2004-01-01

The Burst and Transient Source Experiment (BATSE),aboard the COmptOn Gamma Ray Observatory (CGRO), provided a record of the hard X-ray/low energy gamma ray sky between April 1991 and June 2000. During that time, a catalog of known sources was derived from existing catalogs such as HEAO A-4 (Levine et al. 19841, as well as new transient sources discovered with RATSE and other X-ray monitors operating in the CGRO era. The Earth Occultation Technique (Harmon et al. 2001, astro-ph/0109069) was used to monitor a combination of these sources, mostly galactic, totaling about 175 objects. The catalog will present the global properties of these sources and their probability of detection (>lO mCrab, 20-100 keV) with BATSE. Systematic errors due to unknown sources or background components are included. Cursory analyses to search for new transients (35-80 mCrab in the 20-100 keV band) and super-orbital periods in known binary sources are also presented. Whole mission light curves and associated data production/analysis tools are being delivered to the HEASARC for public use.

The gamma-ray observatory

NASA Technical Reports Server (NTRS)

1991-01-01

An overview is given of the Gamma Ray Observatory (GRO) mission. Detection of gamma rays and gamma ray sources, operations using the Space Shuttle, and instruments aboard the GRO, including the Burst and Transient Source Experiment (BATSE), the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), and the Energetic Gamma Ray Experiment Telescope (EGRET) are among the topics surveyed.

High-frequency gamma oscillations coexist with low-frequency gamma oscillations in the rat visual cortex in vitro.

PubMed

Oke, Olaleke O; Magony, Andor; Anver, Himashi; Ward, Peter D; Jiruska, Premysl; Jefferys, John G R; Vreugdenhil, Martin

2010-04-01

Synchronization of neuronal activity in the visual cortex at low (30-70 Hz) and high gamma band frequencies (> 70 Hz) has been associated with distinct visual processes, but mechanisms underlying high-frequency gamma oscillations remain unknown. In rat visual cortex slices, kainate and carbachol induce high-frequency gamma oscillations (fast-gamma; peak frequency approximately 80 Hz at 37 degrees C) that can coexist with low-frequency gamma oscillations (slow-gamma; peak frequency approximately 50 Hz at 37 degrees C) in the same column. Current-source density analysis showed that fast-gamma was associated with rhythmic current sink-source sequences in layer III and slow-gamma with rhythmic current sink-source sequences in layer V. Fast-gamma and slow-gamma were not phase-locked. Slow-gamma power fluctuations were unrelated to fast-gamma power fluctuations, but were modulated by the phase of theta (3-8 Hz) oscillations generated in the deep layers. Fast-gamma was spatially less coherent than slow-gamma. Fast-gamma and slow-gamma were dependent on gamma-aminobutyric acid (GABA)(A) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and gap-junctions, their frequencies were reduced by thiopental and were weakly dependent on cycle amplitude. Fast-gamma and slow-gamma power were differentially modulated by thiopental and adenosine A(1) receptor blockade, and their frequencies were differentially modulated by N-methyl-D-aspartate (NMDA) receptors, GluK1 subunit-containing receptors and persistent sodium currents. Our data indicate that fast-gamma and slow-gamma both depend on and are paced by recurrent inhibition, but have distinct pharmacological modulation profiles. The independent co-existence of fast-gamma and slow-gamma allows parallel processing of distinct aspects of vision and visual perception. The visual cortex slice provides a novel in vitro model to study cortical high-frequency gamma oscillations.

Fermi Gamma-Ray Space Telescope - Science Highlights for the First Two Years on Orbit

NASA Technical Reports Server (NTRS)

Moiseev, Alexander

2011-01-01

Fermi science objectives cover probably everything in high energy astrophysics: How do super massive black holes in Active Galactic Nuclei create powerful jets of material moving at nearly light speed? What are the jets made of? What are the mechanisms that produce Gamma-Ray Burst (GRB) explosions? What is the energy budget? How does the Sun generate high-energy gamma-rays in flares? How do the pulsars operate? How many of them are around and how different are they? What are the unidentified gamma-ray sources found by EGRET? What is the origin of the cosmic rays that pervade the Galaxy? What is the nature of dark matter? Fermi LAT successfully operates on the orbit for more than 2 years and demonstrates excellent performance, which is continuously monitored and calibrated. LAT collected> 100 billion on-orbit triggers

A method to describe inelastic gamma field distribution in neutron gamma density logging.

PubMed

Zhang, Feng; Zhang, Quanying; Liu, Juntao; Wang, Xinguang; Wu, He; Jia, Wenbao; Ti, Yongzhou; Qiu, Fei; Zhang, Xiaoyang

2017-11-01

Pulsed neutron gamma density logging (NGD) is of great significance for radioprotection and density measurement in LWD, however, the current methods have difficulty in quantitative calculation and single factor analysis for the inelastic gamma field distribution. In order to clarify the NGD mechanism, a new method is developed to describe the inelastic gamma field distribution. Based on the fast-neutron scattering and gamma attenuation, the inelastic gamma field distribution is characterized by the inelastic scattering cross section, fast-neutron scattering free path, formation density and other parameters. And the contribution of formation parameters on the field distribution is quantitatively analyzed. The results shows the contribution of density attenuation is opposite to that of inelastic scattering cross section and fast-neutron scattering free path. And as the detector-spacing increases, the density attenuation gradually plays a dominant role in the gamma field distribution, which means large detector-spacing is more favorable for the density measurement. Besides, the relationship of density sensitivity and detector spacing was studied according to this gamma field distribution, therefore, the spacing of near and far gamma ray detector is determined. The research provides theoretical guidance for the tool parameter design and density determination of pulsed neutron gamma density logging technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fermi detection of delayed GeV emission from the short gamma-ray burst 081024B

DOE PAGES

Abdo, A. A.

2010-03-03

Here, we report on the detailed analysis of the high-energy extended emission from the short gamma-ray burst (GRB) 081024B detected by the Fermi Gamma-ray Space Telescope. Historically, this represents the first clear detection of temporal extended emission from a short GRB. Furthermore, the light curve observed by the Fermi Gamma-ray Burst Monitor lasts approximately 0.8 s whereas the emission in the Fermi Large Area Telescope lasts for about 3 s. Evidence of longer lasting high-energy emission associated with long bursts has been already reported by previous experiments. These observations, together with the earlier reported study of the bright short GRBmore » 090510, indicate similarities in the high-energy emission of short and long GRBs and open the path to new interpretations.« less

Cosmic veto gamma-spectrometry for Comprehensive Nuclear-Test-Ban Treaty samples

NASA Astrophysics Data System (ADS)

Burnett, J. L.; Davies, A. V.

2014-05-01

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a global network of monitoring stations that perform high-resolution gamma-spectrometry on air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of station measurements, providing a mean background reduction of 80.8% with mean MDA improvements of 45.6%. The CTBT laboratory requirement for a 140Ba MDA is achievable after 1.5 days counting compared to 5-7 days using conventional systems. The system consists of plastic scintillation plates that detect coincident cosmic-ray interactions within an HPGe gamma-spectrometer using the Canberra LynxTM multi-channel analyser. The detector is remotely configurable using a TCP/IP interface and requires no dedicated coincidence electronics. It would be especially useful in preventing false-positives at remote station locations (e.g. Halley, Antarctica) where sample transfer to certified laboratories is logistically difficult. The improved sensitivity has been demonstrated for a CTBT air filter sample collected after the Fukushima incident.

Development of a digital method for neutron/gamma-ray discrimination based on matched filtering

NASA Astrophysics Data System (ADS)

Korolczuk, S.; Linczuk, M.; Romaniuk, R.; Zychor, I.

2016-09-01

Neutron/gamma-ray discrimination is crucial for measurements with detectors sensitive to both neutron and gamma-ray radiation. Different techniques to discriminate between neutrons and gamma-rays based on pulse shape analysis are widely used in many applications, e.g., homeland security, radiation dosimetry, environmental monitoring, fusion experiments, nuclear spectroscopy. A common requirement is to improve a radiation detection level with a high detection reliability. Modern electronic components, such as high speed analog to digital converters and powerful programmable digital circuits for signal processing, allow us to develop a fully digital measurement system. With this solution it is possible to optimize digital signal processing algorithms without changing any electronic components in an acquisition signal path. We report on results obtained with a digital acquisition system DNG@NCBJ designed at the National Centre for Nuclear Research. A 2'' × 2'' EJ309 liquid scintillator was used to register mixed neutron and gamma-ray radiation from PuBe sources. A dedicated algorithm for pulse shape discrimination, based on real-time filtering, was developed and implemented in hardware.

Liquid chromatography-high resolution mass spectrometric methods for the surveillance monitoring of cyanotoxins in freshwaters.

PubMed

Bogialli, Sara; Bortolini, Claudio; Di Gangi, Iole Maria; Di Gregorio, Federica Nigro; Lucentini, Luca; Favaro, Gabriella; Pastore, Paolo

2017-08-01

A comprehensive risk management on human exposure to cyanotoxins, whose production is actually unpredictable, is limited by reliable analytical tools for monitoring as many toxic algal metabolites as possible. Two analytical approaches based on a LC-QTOF system for target analysis and suspect screening of cyanotoxins in freshwater were presented. A database with 369 compounds belonging to cyanobacterial metabolites was developed and used for a retrospective data analysis based on high resolution mass spectrometry (HRMS). HRMS fragmentation of the suspect cyanotoxin precursor ions was subsequently performed for correctly identifying the specific variants. Alternatively, an automatic tandem HRMS analysis tailored for cyanotoxins was performed in a single chromatographic run, using the developed database as a preferred precursor ions list. Twenty-five extracts of surface and drinking waters contaminated by cyanobacteria were processed. The identification of seven uncommon microcystins (M(O)R, MC-FR, MSer 7 -YR, D-Asp 3 MSer 7 -LR, MSer 7 -LR, dmAdda-LR and dmAdda-YR) and 6 anabaenopeptins (A, B, F, MM850, MM864, oscyllamide Y) was reported. Several isobaric variants, fully separated by chromatography, were pointed out. The developed methods are proposed to be used by environmental and health agencies for strengthening the surveillance monitoring of cyanotoxins in water. Copyright © 2017 Elsevier B.V. All rights reserved.

2015 Long-Term Hydrologic Monitoring Program Sampling and Analysis Results at Rio Blanco, Colorado

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

Findlay, Rick; Kautsky, Mark

2015-12-01

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 20–21, 2015. This report documents the analytical results of the Rio Blanco annual monitoring event, the trip report, and the data validation package. The groundwater and surface water monitoring samples were shipped to the GEL Group Inc. laboratories for conventional analysis of tritium and analysis of gamma-emitting radionuclides by high-resolution gamma spectrometry. A subset of water samples collected from wells near the Rio Blanco site was also sent to GEL Group Inc.more » for enriched tritium analysis. All requested analyses were successfully completed. Samples were collected from a total of four onsite wells, including two that are privately owned. Samples were also collected from two additional private wells at nearby locations and from nine surface water locations. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry, and they were analyzed for tritium using the conventional method with a detection limit on the order of 400 picocuries per liter (pCi/L). Four locations (one well and three surface locations) were analyzed using the enriched tritium method, which has a detection limit on the order of 3 pCi/L. The enriched locations included the well at the Brennan Windmill and surface locations at CER-1, CER-4, and Fawn Creek 500 feet upstream.« less

The gamma cycle.

PubMed

Fries, Pascal; Nikolić, Danko; Singer, Wolf

2007-07-01

Activated neuronal groups typically engage in rhythmic synchronization in the gamma-frequency range (30-100 Hz). Experimental and modeling studies demonstrate that each gamma cycle is framed by synchronized spiking of inhibitory interneurons. Here, we review evidence suggesting that the resulting rhythmic network inhibition interacts with excitatory input to pyramidal cells such that the more excited cells fire earlier in the gamma cycle. Thus, the amplitude of excitatory drive is recoded into phase values of discharges relative to the gamma cycle. This recoding enables transmission and read out of amplitude information within a single gamma cycle without requiring rate integration. Furthermore, variation of phase relations can be exploited to facilitate or inhibit exchange of information between oscillating cell assemblies. The gamma cycle could thus serve as a fundamental computational mechanism for the implementation of a temporal coding scheme that enables fast processing and flexible routing of activity, supporting fast selection and binding of distributed responses. This review is part of the INMED/TINS special issue Physiogenic and pathogenic oscillations: the beauty and the beast, based on presentations at the annual INMED/TINS symposium (http://inmednet.com).

2DB: a Proteomics database for storage, analysis, presentation, and retrieval of information from mass spectrometric experiments.

PubMed

Allmer, Jens; Kuhlgert, Sebastian; Hippler, Michael

2008-07-07

The amount of information stemming from proteomics experiments involving (multi dimensional) separation techniques, mass spectrometric analysis, and computational analysis is ever-increasing. Data from such an experimental workflow needs to be captured, related and analyzed. Biological experiments within this scope produce heterogenic data ranging from pictures of one or two-dimensional protein maps and spectra recorded by tandem mass spectrometry to text-based identifications made by algorithms which analyze these spectra. Additionally, peptide and corresponding protein information needs to be displayed. In order to handle the large amount of data from computational processing of mass spectrometric experiments, automatic import scripts are available and the necessity for manual input to the database has been minimized. Information is in a generic format which abstracts from specific software tools typically used in such an experimental workflow. The software is therefore capable of storing and cross analysing results from many algorithms. A novel feature and a focus of this database is to facilitate protein identification by using peptides identified from mass spectrometry and link this information directly to respective protein maps. Additionally, our application employs spectral counting for quantitative presentation of the data. All information can be linked to hot spots on images to place the results into an experimental context. A summary of identified proteins, containing all relevant information per hot spot, is automatically generated, usually upon either a change in the underlying protein models or due to newly imported identifications. The supporting information for this report can be accessed in multiple ways using the user interface provided by the application. We present a proteomics database which aims to greatly reduce evaluation time of results from mass spectrometric experiments and enhance result quality by allowing consistent data handling

Wide-Field Gamma-Spectrometer BDRG: GRB Monitor On-Board the Lomonosov Mission

NASA Astrophysics Data System (ADS)

Svertilov, S. I.; Panasyuk, M. I.; Bogomolov, V. V.; Amelushkin, A. M.; Barinova, V. O.; Galkin, V. I.; Iyudin, A. F.; Kuznetsova, E. A.; Prokhorov, A. V.; Petrov, V. L.; Rozhkov, G. V.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Jeong, S.; Kim, M. B.

2018-02-01

The study of GRB prompt emissions (PE) is one of the main goals of the Lomonosov space mission. The payloads of the GRB monitor (BDRG) with the wide-field optical cameras (SHOK) and the ultra-fast flash observatory (UFFO) onboard the Lomonosov satellite are intended for the observation of GRBs, and in particular, their prompt emissions. The BDRG gamma-ray spectrometer is designed to obtain the temporal and spectral information of GRBs in the energy range of 10-3000 keV as well as to provide GRB triggers on several time scales (10 ms, 1 s and 20 s) for ground and space telescopes, including the UFFO and SHOK. The BDRG instrument consists of three identical detector boxes with axes shifted by 90° from each other. This configuration allows us to localize a GRB source in the sky with an accuracy of ˜ 2°. Each BDRG box contains a phoswich NaI(Tl)/CsI(Tl) scintillator detector. A thick CsI(Tl) crystal in size of \\varnothing 130 × 17 mm is placed underneath the NaI(Tl) as an active shield in the soft energy range and as the main detector in the hard energy range. The ratio of the CsI(Tl) to NaI(Tl) event rates at varying energies can be employed as an independent metric to distinguish legitimate GRB signals from false positives originating from electrons in near-Earth vicinities. The data from three detectors are collected in a BA BDRG information unit, which generates a GRB trigger and a set of data frames in output format. The scientific data output is ˜ 500 Mb per day, including ˜ 180 Mb of continuous data for events with durations in excess of 100 ms for 16 channels in each detector, detailed energy spectra, and sets of frames with ˜ 5 Mb of detailed information for each burst-like event. A number of pre-flight tests including those for the trigger algorithm and calibration were carried out to confirm the reliability of the BDRG for operation in space.

A Platinum-Enriched gamma+gamma' Two-Phase Bond Coat on Ni-Base Superalloys

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

Zhang, Ying; Pint, Bruce A; Haynes, James A

2005-01-01

Pt-enriched {gamma} + {gamma}{prime} two-phase coating was applied to directionally-solidified Ni-based superalloy Ren{acute e} 142 substrates with three different Hf levels (0.02, 0.76, and 1.37 wt.%). The coating was prepared by electroplating a thin layer of Pt on the superalloy followed by a diffusion treatment. The as-deposited coating exhibited a {gamma} + {gamma}{prime} two-phase microstructure with a major composition of Ni-16Al-18Pt-7Cr-9Co (in at.%) along with some incorporation of refractory elements from the substrates. Cyclic oxidation testing at 1100 C in air indicated improved oxidation resistance of the Ren{acute e} 142 alloys with the Pt-enriched {gamma} + {gamma}{prime} coatings. In addition,more » the oxidation resistance of both uncoated and coated alloys was proportional to the Hf content in the substrate. Compared with the single-phase {beta}-(Ni,Pt)Al coating, slightly higher mass gains and localized spallation were observed on the {gamma} + {gamma}{prime} two-phase coating, which might be due to the segregation of refractory elements and high sulfur levels in these superalloy substrates.« less

Gamma ray transients

NASA Technical Reports Server (NTRS)

Cline, Thomas L.

1987-01-01

The discovery of cosmic gamma ray bursts was made with systems designed at Los Alamos Laboratory for the detection of nuclear explosions beyond the atmosphere. HELIOS-2 was the first gamma ray burst instrument launched; its initial results in 1976, seemed to deepen the mystery around gamma ray transients. Interplanetary spacecraft data were reviewed in terms of explaining the behavior and source of the transients.

Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

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

Not Available

1999-06-01

The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detectionmore » level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites.« less

Expression of peroxisome proliferator-activated receptor gamma (PPAR-gamma) in canine nasal carcinomas.

PubMed

Paciello, O; Borzacchiello, G; Varricchio, E; Papparella, S

2007-10-01

Peroxisome proliferator-activated receptor gamma (PPAR-gamma) is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-gamma is expressed in multiple normal and neoplastic tissues, such as the breast, colon, lung, ovary and placenta. In addition to adipogenic and anti-inflammatory effects, PPAR-gamma activation has been shown to be anti-proliferative by its differentiation-promoting effect, suggesting that activation of PPAR-gamma may be useful in slowing or arresting the proliferation of de-differentiated tumour cells. In this study, we investigated the expression of PPAR-gamma in normal and neoplastic canine nasal epithelium. Twenty-five samples composed of five normal nasal epithelia and 20 canine nasal carcinomas, were immunohistochemically stained for PPAR-gamma. The specificity of the antibody was verified by Western Blot analysis. Confocal laser scanning microscopical investigation was also performed. In normal epithelium, the staining pattern was cytoplasmic and polarized at the cellular free edge. In carcinomas, the neoplastic cells showed mainly strong cytoplasmatic PPAR-gamma expression; moreover, perinuclear immunoreactivity was also detected and few neoplastic cells exhibited a nuclear positivity. Our results demonstrate different patterns of PPAR-gamma expression in normal canine nasal epithelium when compared with canine nasal carcinoma. The importance of this transcription factor in the pathophysiology of several different tumours has stimulated much research in this field and has opened new opportunities for the treatment of the tumours.

Advanced gamma ray balloon experiment ground checkout and data analysis

NASA Technical Reports Server (NTRS)

Blackstone, M.

1976-01-01

A software programming package to be used in the ground checkout and handling of data from the advanced gamma ray balloon experiment is described. The Operator's Manual permits someone unfamiliar with the inner workings of the software system (called LEO) to operate on the experimental data as it comes from the Pulse Code Modulation interface, converting it to a form for later analysis, and monitoring the program of an experiment. A Programmer's Manual is included.

Study of the effect of gamma irradiation on a commercial polycyclooctene I. Thermal and mechanical properties

NASA Astrophysics Data System (ADS)

García-Huete, N.; Laza, J. M.; Cuevas, J. M.; Vilas, J. L.; Bilbao, E.; León, L. M.

2014-09-01

A gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical, chemical and mechanical properties. Gamma irradiation originates free radicals able to induce chain scission or recombination of radicals, which induces annihilation, branching or crosslinking processes. The aim of this work is to research the structural, thermal and mechanical changes induced on a commercial polycyclooctene (PCO) when it is irradiated with a gamma source of 60Co at different doses (25-200 kGy). After gamma irradiation, gel content was determined by Soxhlet extraction in cyclohexane. Furthermore, thermal properties were evaluated before and after Soxhlet extraction by means of Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), as well as mechanical properties were measured by Dynamic Mechanical Thermal Analysis (DMTA). The results showed the variations of the properties depending on the irradiation dose. Finally, a first approach to evaluate qualitatively the shape memory behaviour of all irradiated PCO samples was performed by a visually monitoring shape recovery process.

Cloning, sequencing and expression of white rhinoceros (Ceratotherium simum) interferon-gamma (IFN-gamma) and the production of rhinoceros IFN-gamma specific antibodies.

PubMed

Morar, D; Tijhaar, E; Negrea, A; Hendriks, J; van Haarlem, D; Godfroid, J; Michel, A L; Rutten, V P M G

2007-01-15

Bovine tuberculosis (BTB) is endemic in African buffalo (Syncerus caffer) in the Kruger National Park (KNP). In addition to buffalo, Mycobacterium bovis has been found in at least 14 other mammalian species in South Africa, including kudu (Tragelaphus strepsiceros), Chacma baboon (Papio ursinus) and lion (Panthera leo). This has raised concern about the spillover into other potentially susceptible species like rhinoceros, thus jeopardising breeding and relocation projects aiming at the conservation of biodiversity. Hence, procedures to screen for and diagnose BTB in black rhinoceros (Diceros bicornis) and white rhinoceros (Ceratotherium simum) need to be in place. The Interferon-gamma (IFN-gamma) assay is used as a routine diagnostic tool to determine infection of cattle and recently African buffalo, with M. bovis and other mycobacteria. The aim of the present work was to develop reagents to set up a rhinoceros IFN-gamma (RhIFN-gamma) assay. The white rhinoceros IFN-gamma gene was cloned, sequenced and expressed as a mature protein. Amino acid (aa) sequence analysis revealed that RhIFN-gamma shares a homology of 90% with equine IFN-gamma. Monoclonal antibodies, as well as polyclonal chicken antibodies (Yolk Immunoglobulin-IgY) with specificity for recombinant RhIFN-gamma were produced. Using the monoclonals as capture antibodies and the polyclonal IgY for detection, it was shown that recombinant as well as native white rhinoceros IFN-gamma was recognised. This preliminary IFN-gamma enzyme-linked immunosorbent assay (ELISA), has the potential to be developed into a diagnostic assay for M. bovis infection in rhinoceros.

A Monte Carlo simulation study for the gamma-ray/neutron dual-particle imager using rotational modulation collimator (RMC).

PubMed

Kim, Hyun Suk; Choi, Hong Yeop; Lee, Gyemin; Ye, Sung-Joon; Smith, Martin B; Kim, Geehyun

2018-03-01

The aim of this work is to develop a gamma-ray/neutron dual-particle imager, based on rotational modulation collimators (RMCs) and pulse shape discrimination (PSD)-capable scintillators, for possible applications for radioactivity monitoring as well as nuclear security and safeguards. A Monte Carlo simulation study was performed to design an RMC system for the dual-particle imaging, and modulation patterns were obtained for gamma-ray and neutron sources in various configurations. We applied an image reconstruction algorithm utilizing the maximum-likelihood expectation-maximization method based on the analytical modeling of source-detector configurations, to the Monte Carlo simulation results. Both gamma-ray and neutron source distributions were reconstructed and evaluated in terms of signal-to-noise ratio, showing the viability of developing an RMC-based gamma-ray/neutron dual-particle imager using PSD-capable scintillators.

Measurements of the $$\\mathrm{ pp \\to W \\gamma\\gamma }$$ and $$\\mathrm{ pp \\to Z \\gamma\\gamma }$$ cross sections and limits on anomalous quartic gauge couplings at $$\\sqrt{s} =$$ 8 TeV

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

Sirunyan, A. M.; Tumasyan, A.; Adam, W.

Here, measurements are presented ofmore » $$ \\mathrm{ W \\gamma\\gamma } $$ and $$ \\mathrm{ Z \\gamma\\gamma } $$ production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb$$^{-1}$$ collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the $$\\mathrm{ W } \\to \\ell\

Measurements of the $$\\mathrm{ pp \\to W \\gamma\\gamma }$$ and $$\\mathrm{ pp \\to Z \\gamma\\gamma }$$ cross sections and limits on anomalous quartic gauge couplings at $$\\sqrt{s} =$$ 8 TeV

DOE PAGES

Sirunyan, A. M.; Tumasyan, A.; Adam, W.; ...

2017-10-11

Here, measurements are presented ofmore » $$ \\mathrm{ W \\gamma\\gamma } $$ and $$ \\mathrm{ Z \\gamma\\gamma } $$ production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb$$^{-1}$$ collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the $$\\mathrm{ W } \\to \\ell\

Freeze-drying process monitoring using a cold plasma ionization device.

PubMed

Mayeresse, Y; Veillon, R; Sibille, P H; Nomine, C

2007-01-01

A cold plasma ionization device has been designed to monitor freeze-drying processes in situ by monitoring lyophilization chamber moisture content. This plasma device, which consists of a probe that can be mounted directly on the lyophilization chamber, depends upon the ionization of nitrogen and water molecules using a radiofrequency generator and spectrometric signal collection. The study performed on this probe shows that it is steam sterilizable, simple to integrate, reproducible, and sensitive. The limitations include suitable positioning in the lyophilization chamber, calibration, and signal integration. Sensitivity was evaluated in relation to the quantity of vials and the probe positioning, and correlation with existing methods, such as microbalance, was established. These tests verified signal reproducibility through three freeze-drying cycles. Scaling-up studies demonstrated a similar product signature for the same product using pilot-scale and larger-scale equipment. On an industrial scale, the method efficiently monitored the freeze-drying cycle, but in a larger industrial freeze-dryer the signal was slightly modified. This was mainly due to the positioning of the plasma device, in relation to the vapor flow pathway, which is not necessarily homogeneous within the freeze-drying chamber. The plasma tool is a relevant method for monitoring freeze-drying processes and may in the future allow the verification of current thermodynamic freeze-drying models. This plasma technique may ultimately represent a process analytical technology (PAT) approach for the freeze-drying process.

Investigation of redshift- and duration-dependent clustering of gamma-ray bursts

DOE PAGES

Ukwatta, T. N.; Woźniak, P. R.

2015-11-05

Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical properties. As a general population, GRBs are distributed isotropically across the sky. However, there are published reports that once binned by duration or redshift, GRBs display significant clustering. We have studied the redshift- and duration-dependent clustering of GRBs using proximity measures and kernel density estimation. Utilizing bursts detected by Burst and Transient Source Experiment, Fermi/gamma-ray burst monitor, and Swift/Burst Alert Telescope, we found marginal evidence for clustering inmore » very short duration GRBs lasting less than 100 ms. As a result, our analysis provides little evidence for significant redshift-dependent clustering of GRBs.« less

In-house validation of a method for determination of silver nanoparticles in chicken meat based on asymmetric flow field-flow fractionation and inductively coupled plasma mass spectrometric detection.

PubMed

Loeschner, Katrin; Navratilova, Jana; Grombe, Ringo; Linsinger, Thomas P J; Købler, Carsten; Mølhave, Kristian; Larsen, Erik H

2015-08-15

Nanomaterials are increasingly used in food production and packaging, and validated methods for detection of nanoparticles (NPs) in foodstuffs need to be developed both for regulatory purposes and product development. Asymmetric flow field-flow fractionation with inductively coupled plasma mass spectrometric detection (AF(4)-ICP-MS) was applied for quantitative analysis of silver nanoparticles (AgNPs) in a chicken meat matrix following enzymatic sample preparation. For the first time an analytical validation of nanoparticle detection in a food matrix by AF(4)-ICP-MS has been carried out and the results showed repeatable and intermediately reproducible determination of AgNP mass fraction and size. The findings demonstrated the potential of AF(4)-ICP-MS for quantitative analysis of NPs in complex food matrices for use in food monitoring and control. The accurate determination of AgNP size distribution remained challenging due to the lack of certified size standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intense Gamma-Ray Flashes Above Thunderstorms on the Earth and Other Planets

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

2010-01-01

Intense millisecond flashes of MeV photons have been observed with space-borne detectors in Earth orbit. They are expected to be present on other planets that exhibit lightning. The terrestrial gamma-ray flashes (TGFs) were discovered with the Burst and Transient Source Experiment (BATSE) aboard the Compton Gamma-Ray Observatory (CGRO) in the early 1990s. They are now being observed with several other instruments, including the Gamma-ray Burst Monitor (GBM) detectors on the Fermi Gamma-ray Space Telescope. Although Fermi- GBM was designed and optimized for the observation of cosmic gamma-ray bursts (GRBs), it has unprecedented capabilities for TGF observations. The TGFs usually have extremely hard continuous spectra, typical of highly- Comptonized bremsstrahlung radiation. These spectral are harder than those of GRBs, with photons extending to over 40 MeV. The most likely origin of these high-energy photons is bremsstrahlung radiation produced by a relativistic "runaway avalanche" electron beam. Such a beam is expected to be produced in an extended, intense electric field in or above thunderstorm regions. The altitude of origin and beaming characteristics of the radiation are quite uncertain. They have generated considerable observational and theoretical interest in recent years. This talk will give an overview of the all of the space-borne observations of TGFs that have been made thus far. Instruments are being designed specifically for TGF observations from new spacecraft as well as from airborne platforms

Basics of Gamma Ray Detection

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

Stinnett, Jacob; Venkataraman, Ram

The objective of this training is to explain the origin of x-rays and gamma rays, gamma ray interactions with matter, detectors and electronics used in gamma ray-spectrometry, and features of a gamma-ray spectrum for nuclear material that is safeguarded.

Dynamic gamma knife radiosurgery

NASA Astrophysics Data System (ADS)

Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

2009-03-01

Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

In-line assay monitor for uranium hexafluoride

DOEpatents

Wallace, Steven A.

1981-01-01

An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The monitor is intended for uses such as safeguard applications to assure that weapons grade uranium is not being produced in an enrichment cascade. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from the uranium-235 present in the specimen. Simultaneously, the gamma emissions from the uranium-235 of the specimen and the source emissions transmitted through the sample are counted and stored in a multiple channel analyzer. The uranium-235 content of the specimen is determined from the comparison of the accumulated 185 keV energy counts and the reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen. The process eliminates the necessity of knowing the system operating conditions and yet obtains the necessary data without need for large scintillation crystals and sophisticated mechanical designs.

Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

NASA Astrophysics Data System (ADS)

Helle, K. B.; Müller, T. O.; Astrup, P.; Dyve, J. E.

2014-05-01

Fast delivery of comprehensive information on the radiological situation is essential for decision-making in nuclear emergencies. Most national radiological agencies in Europe employ gamma dose rate sensor networks to monitor radioactive pollution of the atmosphere. Sensor locations were often chosen using regular grids or according to administrative constraints. Nowadays, however, the choice can be based on more realistic risk assessment, as it is possible to simulate potential radioactive plumes. To support sensor planning, we developed the DETECT Optimisation Tool (DOT) within the scope of the EU FP 7 project DETECT. It evaluates the gamma dose rates that a proposed set of sensors might measure in an emergency and uses this information to optimise the sensor locations. The gamma dose rates are taken from a comprehensive library of simulations of atmospheric radioactive plumes from 64 source locations. These simulations cover the whole European Union, so the DOT allows evaluation and optimisation of sensor networks for all EU countries, as well as evaluation of fencing sensors around possible sources. Users can choose from seven cost functions to evaluate the capability of a given monitoring network for early detection of radioactive plumes or for the creation of dose maps. The DOT is implemented as a stand-alone easy-to-use JAVA-based application with a graphical user interface and an R backend. Users can run evaluations and optimisations, and display, store and download the results. The DOT runs on a server and can be accessed via common web browsers; it can also be installed locally.

Galactic plane gamma-radiation

NASA Technical Reports Server (NTRS)

Hartman, R. C.; Kniffen, D. A.; Thompson, D. J.; Fichtel, C. E.; Ogelman, H. B.; Tumer, T.; Ozel, M. E.

1979-01-01

Analysis of the SAS 2 data together with the COS B results shows that the distribution of galactic gamma-radiation has several similarities to that of other large-scale tracers of galactic structure. The radiation is primarily confined to a thin disc which exhibits offsets from b = 0 degrees similar to warping at radio frequencies. The principal distinction of the gamma-radiation is a stronger contrast in intensity between the region from 310 to 45 degrees in longitude and the regions away from the center that can be attributed to a variation in cosmic-ray density as a function of position in Galaxy. The diffuse galactic gamma-ray energy spectrum shows no significant variation in direction, and the spectrum seen along the plane is the same as that for the galactic component of the gamma-radiation at high altitudes. The uniformity of the galactic gamma-ray spectrum, the smooth decrease in intensity as a function of altitude, and the absence of any galactic gamma-ray sources at high altitudes indicate a diffuse origin for bulk of the galactic gamma-radiation rather than a collection of localized sources.

Gamma-ray burster recurrence timescales

NASA Technical Reports Server (NTRS)

Schaefer, B. E.; Cline, T. L.

1984-01-01

Three optical transients have been found which are associated with gamma-ray bursters (GRBs). The deduced recurrence timescale for these optical transients (tau sub opt) will depend on the minimum brightness for which a flash would be detected. A detailed analysis using all available data of tau sub opt as a function of E(gamma)/E(opt) is given. For flashes similar to those found in the Harvard archives, the best estimate of tau sub opt is 0.74 years, with a 99% confidence interval from 0.23 years to 4.7 years. It is currently unclear whether the optical transients from GRBs also give rise to gamma-ray events. One way to test this association is to measure the recurrence timescale of gamma-ray events tau sub gamma. A total of 210 gamma-ray error boxes were examined and it was found that the number of observed overlaps is not significantly different from the number expected from chance coincidence. This observation can be used to place limits on tau sub gamma for an assumed luminosity function. It was found that tau sub gamma is approx. 10 yr if bursts are monoenergetic. However, if GRBs have a power law luminosity function with a wide dynamic range, then the limit is tau sub gamma 0.5 yr. Hence, the gamma-ray data do not require tau sub gamma and tau sub opt to be different.

Performance of a GM tube based environmental dose rate monitor operating in the Time-To-Count mode

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

Zickefoose, J.; Kulkarni, T.; Martinson, T.

The events at the Fukushima Daiichi power plant in the aftermath of a natural disaster underline the importance of a large array of networked environmental monitors to cover areas around nuclear power plants. These monitors should meet a few basic criteria: have a uniform response over a wide range of gamma energies, have a uniform response over a wide range of incident angles, and have a large dynamic range. Many of these criteria are met if the probe is qualified to the international standard IEC 60532 (Radiation protection instrumentation - Installed dose rate meters, warning assemblies and monitors - Xmore » and gamma radiation of energy between 50 keV and 7 MeV), which specifically deals with energy response, angle of incidence, dynamic range, response time, and a number of environmental characteristics. EcoGamma is a dual GM tube environmental gamma radiation monitor designed specifically to meet the requirements of IEC 60532 and operate in the most extreme conditions. EcoGamma utilizes two energy compensated GM tubes operating with a Time-To-Count (TTC) collection algorithm. The TTC algorithm extends the lifetime and range of a GM tube significantly and allows the dual GM tube probe to achieve linearity over approximately 10 decades of gamma dose rate (from the Sv/hr range to 100 Sv/hr). In the TTC mode of operation, the GM tube is not maintained in a biased condition continuously. This is different from a traditional counting system where the GM tube is held at a constant bias continuously and the total number of strikes that the tube registers are counted. The traditional approach allows for good sensitivity, but does not lend itself to a long lifetime of the tube and is susceptible to linearity issues at high count rates. TTC on the other hand only biases the tube for short periods of time and in effect measures the time between events, which is statistically representative of the total strike rate. Since the tube is not continually biased, the life of

Corrosion monitoring on a large steel pressure vessel by thin-layer activation

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

Wallace, G.; Boulton, L.H.; Hodder, D.

1989-12-01

Thin-layer activation (TLA) is a technique in which a surface is irradiated by a nuclear accelerator and thereby labeled with an accurate depth profile of low-level radioactivity. By monitoring this activity it is possible to calculate how much of that surface has been removed by corrosion. As the radioactivity is marked by the emission of penetrating gamma rays, it is possible to monitor this corrosion remotely through several centimeters of steel. This technique has been used to monitor erosion-corrosion occurring on the inner carbon steel wall of a continuous Kraft pulp digester at a paper mill. Representative coupons of themore » same steel as the digester wall were irradiated and fixed to the walls in the liquor extraction zone during a maintenance shutdown. The loss of metal over the six months was measured by external monitoring of gamma radiation through the vessel wall, and converted to a corrosion rate. Subsequent weight-loss measurements and comparison with ultrasonic thickness measurements established that the corrosion rate measured gave accurate results over a much shorter time scale. TLA thus enables current, rather than historical corrosion rates to be measured in a large steel pressure vessel.« less

Gamma watermarking

DOEpatents

Ishikawa, Muriel Y.; Wood, Lowell L.; Lougheed, Ronald W.; Moody, Kenton J.; Wang, Tzu-Fang

2004-05-25

A covert, gamma-ray "signature" is used as a "watermark" for property identification. This new watermarking technology is based on a unique steganographic or "hidden writing" digital signature, implemented in tiny quantities of gamma-ray-emitting radioisotopic material combinations, generally covertly emplaced on or within an object. This digital signature may be readily recovered at distant future times, by placing a sensitive, high energy-resolution gamma-ray detecting instrument reasonably precisely over the location of the watermark, which location may be known only to the object's owner; however, the signature is concealed from all ordinary detection means because its exceedingly low level of activity is obscured by the natural radiation background (including the gamma radiation naturally emanating from the object itself, from cosmic radiation and material surroundings, from human bodies, etc.). The "watermark" is used in object-tagging for establishing object identity, history or ownership. It thus may serve as an aid to law enforcement officials in identifying stolen property and prosecuting theft thereof. Highly effective, potentially very low cost identification-on demand of items of most all types is thus made possible.

The Gamma-ray Sky with Fermi

NASA Technical Reports Server (NTRS)

Thompson, David

2012-01-01

Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Gamma ray detector shield

DOEpatents

Ohlinger, R.D.; Humphrey, H.W.

1985-08-26

A gamma ray detector shield comprised of a rigid, lead, cylindrical-shaped vessel having upper and lower portions with an pneumatically driven, sliding top assembly. Disposed inside the lead shield is a gamma ray scintillation crystal detector. Access to the gamma detector is through the sliding top assembly.

A GIS model-based assessment of the environmental distribution of gamma-hexachlorocyclohexane in European soils and waters.

PubMed

Vizcaíno, P; Pistocchi, A

2010-10-01

The MAPPE GIS based multimedia model is used to produce a quantitative description of the behaviour of gamma-hexachlorocyclohexane (gamma-HCH) in Europe, with emphasis on continental surface waters. The model is found to reasonably reproduce gamma-HCH distributions and variations along the years in atmosphere and soil; for continental surface waters, concentrations were reasonably well predicted for year 1995, when lindane was still used in agriculture, while for 2005, assuming severe restrictions in use, yields to substantial underestimation. Much better results were yielded when same mode of release as in 1995 was considered, supporting the conjecture that for gamma-HCH, emission data rather that model structure and parameterization can be responsible for wrong estimation of concentrations. Future research should be directed to improve the quality of emission data. Joint interpretation of monitoring and modelling results, highlights that lindane emissions in Europe, despite the marked decreasing trend, persist beyond the provisions of existing legislation. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

10 μ m-thick four-quadrant transmissive silicon photodiodes for beam position monitor application: electrical characterization and gamma irradiation effects

NASA Astrophysics Data System (ADS)

Rafí, J. M.; Pellegrini, G.; Quirion, D.; Hidalgo, S.; Godignon, P.; Matilla, O.; Juanhuix, J.; Fontserè, A.; Molas, B.; Pothin, D.; Fajardo, P.

2017-01-01

Silicon photodiodes are very useful devices as X-ray beam monitors in synchrotron radiation beamlines. Owing to Si absorption, devices thinner than 10 μ m are needed to achieve transmission over 90% for energies above 10 keV . In this work, new segmented four-quadrant diodes for beam alignment purposes are fabricated on both ultrathin (10 μ m-thick) and bulk silicon substrates. Four-quadrant diodes implementing different design parameters as well as auxiliary test structures (single diodes and MOS capacitors) are studied. An extensive electrical characterization, including current-voltage (I-V) and capacitance-voltage (C-V) techniques, is carried out on non-irradiated and gamma-irradiated devices up to 100 Mrad doses. Special attention is devoted to the study of radiation-induced charge build-up in diode interquadrant isolation dielectric, as well as its impact on device interquadrant resistance. Finally, the devices have been characterized with an 8 keV laboratory X-ray source at 108 ph/s and in BL13-XALOC ALBA Synchroton beamline with 1011 ph/s and energies from 6 to 16 keV . Sensitivity, spatial resolution and uniformity of the devices have been evaluated.

Long-term monitoring of blazars - the DWARF network

NASA Astrophysics Data System (ADS)

Backes, Michael; Biland, Adrian; Boller, Andrea; Braun, Isabel; Bretz, Thomas; Commichau, Sebastian; Commichau, Volker; Dorner, Daniela; von Gunten, Hanspeter; Gendotti, Adamo; Grimm, Oliver; Hildebrand, Dorothée; Horisberger, Urs; Krähenbühl, Thomas; Kranich, Daniel; Lustermann, Werner; Mannheim, Karl; Neise, Dominik; Pauss, Felicitas; Renker, Dieter; Rhode, Wolfgang; Rissi, Michael; Rollke, Sebastian; Röser, Ulf; Stark, Luisa Sabrina; Stucki, Jean-Pierre; Viertel, Gert; Vogler, Patrick; Weitzel, Quirin

The variability of the very high energy (VHE) emission from blazars seems to be connected with the feeding and propagation of relativistic jets and with their origin in supermassive black hole binaries. The key to understanding their properties is measuring well-sampled gamma-ray lightcurves, revealing the typical source behavior unbiased by prior knowledge from other wavebands. Using ground-based gamma-ray observatories with exposures limited by dark-time, a global network of several telescopes is needed to carry out fulltime measurements. Obviously, such observations are time-consuming and, therefore, cannot be carried out with the present state of the art instruments. The DWARF telescope on the Canary Island of La Palma is dedicated to monitoring observations. It is currently being set up, employing a costefficient and robotic design. Part of this project is the future construction of a distributed network of small telescopes. The physical motivation of VHE long-term monitoring will be outlined in detail and the perspective for a network for 24/7 observations will be presented.

Surface acoustic wave nebulization facilitating lipid mass spectrometric analysis.

PubMed

Yoon, Sung Hwan; Huang, Yue; Edgar, J Scott; Ting, Ying S; Heron, Scott R; Kao, Yuchieh; Li, Yanyan; Masselon, Christophe D; Ernst, Robert K; Goodlett, David R

2012-08-07

Surface acoustic wave nebulization (SAWN) is a novel method to transfer nonvolatile analytes directly from the aqueous phase to the gas phase for mass spectrometric analysis. The lower ion energetics of SAWN and its planar nature make it appealing for analytically challenging lipid samples. This challenge is a result of their amphipathic nature, labile nature, and tendency to form aggregates, which readily precipitate clogging capillaries used for electrospray ionization (ESI). Here, we report the use of SAWN to characterize the complex glycolipid, lipid A, which serves as the membrane anchor component of lipopolysaccharide (LPS) and has a pronounced tendency to clog nano-ESI capillaries. We also show that unlike ESI SAWN is capable of ionizing labile phospholipids without fragmentation. Lastly, we compare the ease of use of SAWN to the more conventional infusion-based ESI methods and demonstrate the ability to generate higher order tandem mass spectral data of lipid A for automated structure assignment using our previously reported hierarchical tandem mass spectrometry (HiTMS) algorithm. The ease of generating SAWN-MS(n) data combined with HiTMS interpretation offers the potential for high throughput lipid A structure analysis.

Wetting characteristics and blood clotting on surfaces of copoly(gamma-Benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine).

PubMed

Yano, E; Komai, T; Kawasaki, T; Kaifu, K; Atsuta, T; Kubo, Y; Fujiwara, Y

1985-09-01

The film surface of poly(gamma-benzyl-L-glutamate) (PBLG) was modified with 2-aminoethanol to enhance its hydrophilicity. Controlling the reaction conditions of PBLG and 2-aminoethanol, various types of copoly(gamma-benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine) film surfaces were obtained. Surface free energy (gamma sv), the dispersive component of gamma sv (gamma dsv), the nondispersive component of gamma sv (gamma psv), and the interfacial free energy of polymer surface with water (gamma sw), which were obtained by using the contact angle measurement and calculation method proposed by Andrade et al., were changed remarkably by the aminolysis. The gamma sv value increased after 2 h of aminolysis from 48.2 (PBLG) to 65.3 dyn/cm and gradually increased to around 70 dyn/cm after 12 h reaction. (gamma dsv) and (gamma psv) changed from 31.0 and 17.2 dyn/cm (PBLG) to 26.5 and 44.3 dyn/cm, respectively. These parameters of the material surfaces, modified over 12 h reaction, were found to be similar to those of the surfaces of canine aorta, vein, and human fibrin membrane. Blood clotting times on these polymer surfaces were comparatively longer than on siliconized glass surfaces.

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

DOE PAGES

Abbott, B. P.; Abbott, R.; Abbott, T. D.; ...

2017-10-16

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance ismore » $$5.0\\times {10}^{-8}$$. We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of $$(+1.74\\pm 0.05)\\,{\\rm{s}}$$ between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between $$-3\\times {10}^{-15}$$ and $$+7\\times {10}^{-16}$$ times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1–1.4 per year during the 2018–2019 observing run and 0.3–1.7 per year at design sensitivity.« less

Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A

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

Abbott, B. P.; Abbott, R.; Abbott, T. D.

On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anti-Coincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. The probability of the near-simultaneous temporal and spatial observation of GRB 170817A and GW170817 occurring by chance ismore » $$5.0\\times {10}^{-8}$$. We therefore confirm binary neutron star mergers as a progenitor of short GRBs. The association of GW170817 and GRB 170817A provides new insight into fundamental physics and the origin of short GRBs. We use the observed time delay of $$(+1.74\\pm 0.05)\\,{\\rm{s}}$$ between GRB 170817A and GW170817 to: (i) constrain the difference between the speed of gravity and the speed of light to be between $$-3\\times {10}^{-15}$$ and $$+7\\times {10}^{-16}$$ times the speed of light, (ii) place new bounds on the violation of Lorentz invariance, (iii) present a new test of the equivalence principle by constraining the Shapiro delay between gravitational and electromagnetic radiation. We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma-rays. GRB 170817A is the closest short GRB with a known distance, but is between 2 and 6 orders of magnitude less energetic than other bursts with measured redshift. A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1–1.4 per year during the 2018–2019 observing run and 0.3–1.7 per year at design sensitivity.« less

Identification and characterization of novel peroxisome proliferator-activated receptor-gamma (PPAR-gamma) transcriptional variants in pig and human.

PubMed

Omi, T; Brenig, B; Spilar Kramer, S; Iwamoto, S; Stranzinger, G; Neuenschwander, S

2005-04-01

The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the steroid/thyroid/retinoid receptor superfamily, and is primarily expressed in fat tissue. To date, two major PPAR-gamma isoforms have been identified in pig, PPAR-gamma1 and PPAR-gamma2. Porcine PPAR-gamma1a consists of two leader exons, designated A1 and A2, followed by six exons containing the open reading frame. Here, we report the isolation and characterization of three novel PPAR-gamma1 transcripts. PPAR-gamma1b is derived from exon A1, with exon A2 spliced out. PPAR-gamma1c and PPAR-gamma1d are derived from the new exon, A', containing exon A2 (gamma1c) or without exon A2 (gamma1d). Based on PCR analysis of PAC clones that included sequences from the 5'-untranslated region of the PPAR-gamma gene, the new A' exon is located between the known exons A1 and A2. We also isolated the human homologue to exon A', as well as the two new PPAR-gamma1c and -gamma1d splice variants, from human adipose tissue. Studies of the expression of porcine PPAR-gamma by real time reverse transcription-polymerase chain reaction analysis show that transcripts derived from exon A1 were not expressed at significantly different levels in visceral fat (lamina subserosa) or subcutaneous fat (back fat, inner and outer layer). In contrast, exon A'-derived transcripts were expressed at progressively higher levels in the inner and outer layers of subcutaneous fat than in visceral fat. The same expression pattern was also observed for PPAR-gamma2. We hypothesize that there are three promoters, which differentially regulate PPAR-gamma1 and PPAR-gamma2 gene expression, depending on the specific localization of the fat tissue.

Analysis of airborne MAIS imaging spectrometric data for mineral exploration

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

Wang Jinnian; Zheng Lanfen; Tong Qingxi

1996-11-01

The high spectral resolution imaging spectrometric system made quantitative analysis and mapping of surface composition possible. The key issue will be the quantitative approach for analysis of surface parameters for imaging spectrometer data. This paper describes the methods and the stages of quantitative analysis. (1) Extracting surface reflectance from imaging spectrometer image. Lab. and inflight field measurements are conducted for calibration of imaging spectrometer data, and the atmospheric correction has also been used to obtain ground reflectance by using empirical line method and radiation transfer modeling. (2) Determining quantitative relationship between absorption band parameters from the imaging spectrometer data andmore » chemical composition of minerals. (3) Spectral comparison between the spectra of spectral library and the spectra derived from the imagery. The wavelet analysis-based spectrum-matching techniques for quantitative analysis of imaging spectrometer data has beer, developed. Airborne MAIS imaging spectrometer data were used for analysis and the analysis results have been applied to the mineral and petroleum exploration in Tarim Basin area china. 8 refs., 8 figs.« less

On the possible gamma-ray burst-gravitational wave association in GW150914

NASA Astrophysics Data System (ADS)

Janiuk, Agnieszka; Bejger, M.; Charzyński, S.; Sukova, P.

2017-02-01

Data from the Fermi Gamma-ray Burst Monitor satellite observatory suggested that the recently discovered gravitational wave source, a pair of two coalescing black holes, was related to a gamma-ray burst. The observed high-energy electromagnetic radiation (above 50 keV) originated from a weak transient source and lasted for about 1 s. Its localization is consistent with the direction to GW150914. We speculate about the possible scenario for the formation of a gamma-ray burst accompanied by the gravitational-wave signal. Our model invokes a tight binary system consisting of a massive star and a black hole which leads to the triggering of a collapse of the star's nucleus, the formation of a second black hole, and finally to the binary black hole merger. For the most-likely configuration of the binary spin vectors with respect to the orbital angular momentum in the GW150914 event, the recoil speed (kick velocity) acquired by the final black hole through gravitational wave emission is of the order of a few hundred km/s and this might be sufficient to get it closer to the envelope of surrounding material and capture a small fraction of matter from the remnant of the host star. The gamma-ray burst is produced by the accretion of this remnant matter onto the final black hole. The moderate spin of the final black hole suggests that the gamma-ray burst jet is powered by weak neutrino emission rather than the Blandford-Znajek mechanism, and hence explains the low power available for the observed GRB signal.

Rio Blanco, Colorado, Long-Term Hydrologic Monitoring Program Sampling and Analysis Results for 2009

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

None

2009-12-21

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rio Blanco, Colorado, Site, for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 13 and 14, 2009. Samples were analyzed by the U.S. Environmental Protection Agency (EPA) Radiation&Indoor Environments National Laboratory in Las Vegas, Nevada. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectroscopy and tritium using the conventional and enriched methods.

Gamma ray camera

DOEpatents

Perez-Mendez, Victor

1997-01-01

A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

Designing a new type of neutron detector for neutron and gamma-ray discrimination via GEANT4.

PubMed

Shan, Qing; Chu, Shengnan; Ling, Yongsheng; Cai, Pingkun; Jia, Wenbao

2016-04-01

Design of a new type of neutron detector, consisting of a fast neutron converter, plastic scintillator, and Cherenkov detector, to discriminate 14-MeV fast neutrons and gamma rays in a pulsed n-γ mixed field and monitor their neutron fluxes is reported in this study. Both neutrons and gamma rays can produce fluorescence in the scintillator when they are incident on the detector. However, only the secondary charged particles of the gamma rays can produce Cherenkov light in the Cherenkov detector. The neutron and gamma-ray fluxes can be calculated by measuring the fluorescence and Cherenkov light. The GEANT4 Monte Carlo simulation toolkit is used to simulate the whole process occurring in the detector, whose optimum parameters are known. Analysis of the simulation results leads to a calculation method of neutron flux. This method is verified by calculating the neutron fluxes using pulsed n-γ mixed fields with different n/γ ratios, and the results show that the relative errors of all calculations are <5%. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Application of Multiple Reaction Monitoring to Assess Apo A-I Methionine Oxidations in Diabetes and Cardiovascular Disease

PubMed Central

Yassine, Hussein N.; Jackson, Angela M.; Reaven, Peter D.; Nedelkov, Dobrin; Nelson, Randall W.; Lau, Serrine S.; Borchers, Christoph H.

2014-01-01

The oxidative modification of apolipoprotein A-I ‘s methionine148(M148) is associated with defective HDL function in vitro. Multiple Reaction Monitoring (MRM) is a mass spectrometric technique that can be used to quantitate post-translational modifications. In this study, we developed an MRM assay to monitor the abundance ratio of the peptide containing oxidized M148 to the native peptide in Apo A-I. Measurement of the oxidized-to-unoxidized-M148 ratio was reproducible (CV<5%). The extent of methionine M148 oxidation in the HDL of healthy controls, and type 2 diabetic participants with and without prior cardiovascular events (CVD) were then examined. The results suggest a significant increase in the relative ratio of the peptide containing oxidized M148 to the unmodified peptide in the HDL of participants with diabetes and CVD (p<0.001), compared to participants without CVD. Monitoring the abundance ratio of the peptides containing oxidized and unoxidized M148 by MRM provides a means of examining the relationship between M148 oxidation and vascular complications in CVD. PMID:25705587

Use of Sensitive and Specific Biomolecular and Mass Spectrometric Techniques to Monitor the Performance of In-Situ Hydrocarbon Biodegradation

NASA Astrophysics Data System (ADS)

Beller, H. R.; Kane, S. R.; Legler, T. C.

2008-12-01

Monitored natural attenuation (MNA) can be a cost-effective and viable approach for remediation of hydrocarbon-contaminated groundwater. However, regulatory acceptance of the approach is often contingent on monitoring that can convincingly demonstrate the role of microbial degradation. Recent advances in anaerobic hydrocarbon biochemistry, analytical chemistry, and molecular biology have fostered the development of powerful techniques that can be applied to MNA of BTEX (benzene, toluene, ethylbenzene, and xylenes). Here, I discuss two independent methods that have been developed to monitor in situ, anaerobic biodegradation of toluene and xylenes. A method has been developed for rapid, sensitive, and highly selective detection of distinctive indicators of anaerobic alkylbenzene metabolism. The target metabolites, benzylsuccinic acid and methylbenzylsuccinic acid isomers, have no known sources other than anaerobic toluene or xylene degradation; thus, their mere presence in groundwater provides definitive evidence of in situ metabolism. The method, which involves small sample size (<1 mL) and no extraction/concentration steps, relies on isotope dilution liquid chromatography/tandem mass spectrometry (LC/MS/MS) with selected reaction monitoring. Detection limits for benzylsuccinates were determined to be ca. 0.3 μg/L and accuracy and precision were favorable in a groundwater matrix. A monitoring method based on quantitative Polymerase Chain Reaction (qPCR) analysis has been developed to specifically quantify populations of anaerobic methylbenzene-degrading bacteria in aquifer sediment. The method targets a catabolic gene (bssA) associated with the first step of anaerobic toluene and xylene degradation. The method has proven to be sensitive (detection limit ca. 5 gene copies) and has a linear range of > 7 orders of magnitude. Application of these two methods in field studies will be discussed in the context of the methods' strengths and limitations. Field data will

Formation of gamma'-Ni3Al via the Peritectoid Reaction: gamma plus beta (+Al2O3) equals gamma'(+Al2O3)

NASA Technical Reports Server (NTRS)

Copland, Evan

2008-01-01

The activities of Al and Ni were measured using multi-cell Knudsen effusion-cell mass spectrometry (multi-cell KEMS), over the composition range 8 - 32 at.%Al and temperature range T = 1400 - 1750 K in the Ni-Al-O system. These measurements establish that equilibrium solidification of gamma'-Ni3Al-containing alloys occurs by the eutectic reaction, L (+ Al2O3) = gamma + beta (+ Al2O3), at 1640 plus or minus 1 K and a liquid composition of 24.8 plus or minus 0.2 at.%Al (at an unknown oxygen content). The {gamma + beta + Al2O3} phase field is stable over the temperature range 1633 - 1640 K, and gamma'-Ni3Al forms via the peritectiod, gamma + beta (+ Al2O3) = gamma'(+ Al2O3), at 1633 plus or minus 1 K. This behavior is inconsistent with the current Ni-Al phase diagram and a new diagram is proposed. This new Ni-Al phase diagram explains a number of unusual steady state solidification structures reported previously and provides a much simpler reaction scheme in the vicinity of the gamma'-Ni3Al phase field.

Gamma-ray astrophysics

NASA Technical Reports Server (NTRS)

Stecker, F. W. (Editor); Trombka, J. I. (Editor)

1973-01-01

Conference papers on gamma ray astrophysics are summarized. Data cover the energy region from about 0.3 MeV to a few hundred GeV and theoretical models of production mechanisms that give rise to both galactic and extragalactic gamma rays.

AGILE/GRID Science Alert Monitoring System: The Workflow and the Crab Flare Case

NASA Astrophysics Data System (ADS)

Bulgarelli, A.; Trifoglio, M.; Gianotti, F.; Tavani, M.; Conforti, V.; Parmiggiani, N.

2013-10-01

During the first five years of the AGILE mission we have observed many gamma-ray transients of Galactic and extragalactic origin. A fast reaction to unexpected transient events is a crucial part of the AGILE monitoring program, because the follow-up of astrophysical transients is a key point for this space mission. We present the workflow and the software developed by the AGILE Team to perform the automatic analysis for the detection of gamma-ray transients. In addition, an App for iPhone will be released enabling the Team to access the monitoring system through mobile phones. In 2010 September the science alert monitoring system presented in this paper recorded a transient phenomena from the Crab Nebula, generating an automated alert sent via email and SMS two hours after the end of an AGILE satellite orbit, i.e. two hours after the Crab flare itself: for this discovery AGILE won the 2012 Bruno Rossi prize. The design of this alert system is maximized to reach the maximum speed, and in this, as in many other cases, AGILE has demonstrated that the reaction speed of the monitoring system is crucial for the scientific return of the mission.

The Gamma-ray Universe through Fermi

NASA Technical Reports Server (NTRS)

Thompson, David J.

2012-01-01

Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

Mass-Spectrometric Studies of Catalytic Chemical Vapor Deposition Processes of Organic Silicon Compounds Containing Nitrogen

NASA Astrophysics Data System (ADS)

Morimoto, Takashi; Ansari, S. G.; Yoneyama, Koji; Nakajima, Teppei; Masuda, Atsushi; Matsumura, Hideki; Nakamura, Megumi; Umemoto, Hironobu

2006-02-01

The mechanism of catalytic chemical vapor deposition (Cat-CVD) processes for hexamethyldisilazane (HMDS) and trisdimethylaminosilane (TDMAS), which are used as source gases to prepare SiNx or SiCxNy films, was studied using three different mass spectrometric techniques: ionization by Li+ ion attachment, vacuum-ultraviolet radiation and electron impact. The results for HMDS show that Si-N bonds dissociate selectively, although Si-C bonds are weaker, and (CH3)3SiNH should be one of the main precursors of deposited films. This decomposition mechanism did not change when NH3 was introduced, but the decomposition efficiency was slightly increased. Similar results were obtained for TDMAS.

Topics in gamma ray astronomy

NASA Technical Reports Server (NTRS)

Ramaty, R.; Lingenfelter, R. E.

1986-01-01

Observations of gamma rays from solar flares, gamma ray bursts, the Galactic center, galactic nucleosynthesis, SS433, and Cygnus X-3, and their effects on astrophysical problems are discussed. It is observed that gamma ray spectra from solar flares are applicable to the study of particle acceleration and confinement and the determination of chemical abundances in the solar atmosphere. The gamma ray lines from the compact galactic object SS433 are utilized to examine the acceleration of jets, and analysis of the gamma ray lines of Cygnus X-3 reveal that particles can be accelerated in compact sources to ultrahigh energies.

A study of interdiffusion in beta + gamma/gamma + gamma prime Ni-Cr-Al. M.S. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Carol, L. A.

1985-01-01

Ternary diffusion in the NiCrAl system at 1200 C was studied with beta + gamma/gamma + gamma prime infinite diffusion couples. Interdiffusion resulted in the formation of complex, multiphase diffusion zones. Concentration/distance profiles for Cr and Al in the phases present in the diffusion zone were measured after 200 hr. The Ni-rich portion of the NiCrAl phase diagram (1200 C) was also determined. From these data, bulk Cr and Al profiles were calculated and translated to diffusion paths on the ternary isotherm. Growth layer kinetics of the layers present in the diffusion zone were also measured.

Pharmacological evidences for DFK167-sensitive presenilin-independent gamma-secretase-like activity.

PubMed

Sevalle, Jean; Ayral, Erwan; Hernandez, Jean-François; Martinez, Jean; Checler, Frédéric

2009-07-01

Amyloid-beta (Abeta) peptides production is thought to be a key event in the neurodegenerative process ultimately leading to Alzheimer's disease (AD) pathology. A bulk of studies concur to propose that the C-terminal moiety of Abeta is released from its precursor beta-amyloid precursor protein by a high molecular weight enzymatic complex referred to as gamma-secretase, that is composed of at least, nicastrin (NCT), Aph-1, Pen-2, and presenilins (PS) 1 or 2. They are thought to harbor the gamma-secretase catalytic activity. However, several lines of evidence suggest that additional gamma-secretase-like activities could potentially contribute to Abeta production. By means of a quenched fluorimetric substrate (JMV2660) mimicking the beta-amyloid precursor protein sequence targeted by gamma-secretase, we first show that as expected, this probe allows monitoring of an activity detectable in several cell systems including the neuronal cell line telencephalon specific murine neurons (TSM1). This activity is reduced by DFK167, N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), and LY68458, three inhibitors known to functionally interact with PS. Interestingly, JMV2660 but not the unrelated peptide JMV2692, inhibits Abeta production in an in vitrogamma-secretase assay as expected from a putative substrate competitor. This activity is enhanced by PS1 and PS2 mutations known to be responsible for familial forms of AD and reduced by aspartyl mutations inactivating PS or in cells devoid of PS or NCT. However, we clearly establish that residual JMV2660-hydrolysing activity could be recovered in PS- and NCT-deficient fibroblasts and that this activity remained inhibited by DFK167. Overall, our study describes the presence of a proteolytic activity displaying gamma-secretase-like properties but independent of PS and still blocked by DFK167, suggesting that the PS-dependent complex could not be the unique gamma-secretase activity responsible for Abeta

Differentiation of the two major species of Echinacea (E. augustifolia and E. purpurea) using a flow injection mass spectrometric (FIMS) fingerprinting method and chemometric analysis

USDA-ARS?s Scientific Manuscript database

A rapid, simple, and reliable flow-injection mass spectrometric (FIMS) method was developed to discriminate two major Echinacea species (E. purpurea and E. angustifolia) samples. Fifty-eight Echinacea samples collected from United States were analyzed using FIMS. Principle component analysis (PCA) a...

Radio-to-Gamma-Ray Monitoring of the Narrow-line Seyfert 1 Galaxy PMN J0948+0022 from 2008 to 2011

NASA Technical Reports Server (NTRS)

Foschini, L.; Angelakis, E.; Fuhrmann, L.; Ghisellini, G.; Hovatta, T.; Lahteenmaki, A.; Lister, M. L.; Braito, V.; Gallo, L.; Hamilton, T. S.;

Radiation portal monitor system and method

DOEpatents

Morris, Christopher [Los Alamos, NM; Borozdin, Konstantin N [Los Alamos, NM; Green, J Andrew [Los Alamos, NM; Hogan, Gary E [Los Alamos, NM; Makela, Mark F [Los Alamos, NM; Priedhorsky, William C [Los Alamos, NM; Saunders, Alexander [Los Alamos, NM; Schultz, Larry J [Los Alamos, NM; Sossong, Michael J [Los Alamos, NM

2009-12-15

A portal monitoring system has a cosmic ray charged particle tracker with a plurality of drift cells. The drift cells, which can be for example aluminum drift tubes, can be arranged at least above and below a volume to be scanned to thereby track incoming and outgoing charged particles, such as cosmic ray muons, whilst also detecting gamma rays. The system can selectively detect devices or materials, such as iron, lead, gold and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can also detect any radioactive sources occupying the volume from gamma rays emitted therefrom. If necessary, the drift tubes can be sealed to eliminate the need for a gas handling system. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

Network-Oriented Radiation Monitoring System (NORMS)

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

Rahmat Aryaeinejad; David F. Spencer

2007-10-01

We have developed a multi-functional pocket radiation monitoring system capable of detecting and storing gamma ray and neutron data and then sending the data through a wireless connection to a remote central facility upon request. The device has programmable alarm trigger levels that can be modified for specific applications. The device could be used as a stand-alone device or in conjunction with an array to cover a small or large area. The data is stored with a date/time stamp. The device may be remotely configured. Data can be transferred and viewed on a PDA via direct connection or wirelessly. Functional/benchmore » tests have been completed successfully. The device detects low-level neutron and gamma sources within a shielded container in a radiation field of 10 uR/hr above the ambient background level.« less

Scientific prospects for spectroscopy of the gamma-ray burst prompt emission with SVOM

NASA Astrophysics Data System (ADS)

Bernardini, M. G.; Xie, F.; Sizun, P.; Piron, F.; Dong, Y.; Atteia, J.-L.; Antier, S.; Daigne, F.; Godet, O.; Cordier, B.; Wei, J.

2017-10-01

SVOM (Space-based multi-band astronomical Variable Objects Monitor) is a Sino-French space mission dedicated to the study of Gamma-Ray Bursts (GRBs) in the next decade, capable to detect and localise the GRB emission, and to follow its evolution in the high-energy and X-ray domains, and in the visible and NIR bands. The satellite carries two wide-field high-energy instruments: a coded-mask gamma-ray imager (ECLAIRs; 4-150 keV), and a gamma-ray spectrometer (GRM; 15-5500 keV) that, together, will characterise the GRB prompt emission spectrum over a wide energy range. In this paper we describe the performances of the ECLAIRs and GRM system with different populations of GRBs from existing catalogues, from the classical ones to those with a possible thermal component superimposed to their non-thermal emission. The combination of ECLAIRs and the GRM will provide new insights also on other GRB properties, as for example the spectral characterisation of the subclass of short GRBs showing an extended emission after the initial spike.

Photoconducting positions monitor and imaging detector

DOEpatents

Shu, Deming; Kuzay, Tuncer M.

2000-01-01

A photoconductive, high energy photon beam detector/monitor for detecting x-rays and gamma radiation, having a thin, disk-shaped diamond substrate with a first and second surface, and electrically conductive coatings, or electrodes, of a predetermined configuration or pattern, disposed on the surfaces of the substrate. A voltage source and a current amplifier is connected to the electrodes to provide a voltage bias to the electrodes and to amplify signals from the detector.

Gamma-ray astronomy

NASA Technical Reports Server (NTRS)

Ramaty, R.; Lingenfelter, R. E.

1982-01-01

Cosmic gamma rays, the physical processes responsible for their production and the astrophysical sites from which they were seen are reported. The bulk of the observed gamma ray emission is in the photon energy range from about 0.1 MeV to 1 GeV, where observations are carried out above the atmosphere. There are also, however, gamma ray observations at higher energies obtained by detecting the Cerenkov light produced by the high energy photons in the atmosphere. Gamma ray emission was observed from sources as close as the Sun and the Moon and as distant as the quasar 3C273, as well as from various other galactic and extragalactic sites. The radiation processes also range from the well understood, e.g. energetic particle interactions with matter, to the still incompletely researched, such as radiation transfer in optically thick electron positron plasmas in intense neutron star magnetic fields.

Monitoring Accreting X-ray Pulsars with the GLAST Burst Monitor

NASA Technical Reports Server (NTRS)

Wilson, Colleen A.; Finger, Mark H.; Patel, Sandeep K.; Bhat, P. Narayana; Preece, Robert D.; Meegan, Charles A.

2007-01-01

Accreting pulsars are exceptionally good laboratories for probing the detailed physics of accretion onto magnetic stars. While similar accretion flows also occur in other types of astrophysical systems, e.g. magnetic CVs, only neutron stars have a small enough moment of inertia for the accretion of angular momentum to result in measurable changes in spin-frequency in a timescale of days. Long-term monitoring of accreting pulsar spin-frequencies and fluxes was demonstrated with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Here we present sample results from BATSE, discuss measurement techniques appropriate for GBM, and estimate the expected GBM sensitivity.

Simulated and measured neutron/gamma light output distribution for poly-energetic neutron/gamma sources

NASA Astrophysics Data System (ADS)

Hosseini, S. A.; Zangian, M.; Aghabozorgi, S.

2018-03-01

In the present paper, the light output distribution due to poly-energetic neutron/gamma (neutron or gamma) source was calculated using the developed MCNPX-ESUT-PE (MCNPX-Energy engineering of Sharif University of Technology-Poly Energetic version) computational code. The simulation of light output distribution includes the modeling of the particle transport, the calculation of scintillation photons induced by charged particles, simulation of the scintillation photon transport and considering the light resolution obtained from the experiment. The developed computational code is able to simulate the light output distribution due to any neutron/gamma source. In the experimental step of the present study, the neutron-gamma discrimination based on the light output distribution was performed using the zero crossing method. As a case study, 241Am-9Be source was considered and the simulated and measured neutron/gamma light output distributions were compared. There is an acceptable agreement between the discriminated neutron/gamma light output distributions obtained from the simulation and experiment.

Measuring the charged pion polarizability in the gamma gamma -> pi+pi- reaction

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

Lawrence, David W.; Miskimen, Rory A.; Mushkarenkov, Alexander Nikolaevich

2013-08-01

Development has begun of a new experiment to measure the charged pion polarizabilitymore » $$\\alpha_{\\pi}-\\beta_{\\pi}$$. The charged pion polarizability ranks among the most important tests of low-energy QCD presently unresolved by experiment. Analogous to precision measurements of $$\\pi^{\\circ}\\rightarrow\\gamma\\gamma$$ that test the intrinsic odd-parity (anomalous) sector of QCD, the pion polarizability tests the intrinsic even-parity sector of QCD. The measurement will be performed using the $$\\gamma\\gamma\\rightarrow\\pi^{+{}}\\pi^{-{}}$$ cross section accessed via the Primakoff mechanism on nuclear targets using the GlueX detector in Hall D at Jefferson Lab. The linearly polarized photon source in Hall-D will be utilized to separate the Primakoff cross-section from coherent $$\\rho^{\\circ}$$ production.« less

Future prospects for gamma-ray

NASA Technical Reports Server (NTRS)

Fichtel, C.

1980-01-01

Astrophysical phenomena discussed are: the very energetic and nuclear processes associated with compact objects; astrophysical nucleo-synthesis; solar particle acceleration; the chemical composition of the planets and other bodies of the solar system; the structure of our galaxy; the origin and dynamic pressure effects of the cosmic rays; the high energy particles and energetic processes in other galaxies, especially active ones; and the degree of matter antimater symmetry of the universe. The gamma ray results of GAMMA-I, the gamma ray observatory, the gamma ray burst network, solar polar, and very high energy gamma ray telescopes on the ground provide justification for more sophisticated telescopes.

Gamma ray camera

DOEpatents

Perez-Mendez, V.

1997-01-21

A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

Histaminergic regulation of interferon-gamma (IFN-gamma) production by human natural killer (NK) cells.

PubMed

Asea, A; Hansson, M; Czerkinsky, C; Houze, T; Hermodsson, S; Strannegård, O; Hellstrand, K

1996-08-01

Monocytes, recovered from human peripheral blood by counter-current centrifugal elutriation, effectively inhibit the production of IFN-gamma by CD3-/56+ NK cells in response to IL-2. This study aimed at defining the nature of the inhibitory signal, particularly the importance of monocyte-derived reactive metabolites of oxygen. It was found that monocytes recovered from patients with chronic granulomatous disease (CGD), a condition characterized by deficient NADPH-oxidase activity of phagocytes, did not inhibit IFN-gamma production by NK cells. Further, catalase, a scavenger of hydrogen peroxide, completely reversed the inhibitory signal whereas scavengers of the superoxide anion, hypohalous acids, the hydroxyl radical, or nitric oxide synthesis inhibitors such as L-NMMA were ineffective. Inhibition of IFN-gamma production was operating on a pretranslational level, as indicated by the inability of enriched NK cells to accumulate IFN-gamma mRNA in the presence of elutriated monocytes. Hydrogen peroxide, at micromolar concentrations, reconstituted the inhibition of IFN-gamma production when added to enriched NK cells. Histamine, a biogenic amine which inhibits the generation of reactive oxygen metabolites in monocytes, abrogated the inhibition of IFN-gamma production in NK cells; by this mechanism, histamine strongly synergized with IL-2 to induce IFN-gamma in mixtures of NK cells and monocytes. The synergizing effect of histamine was specifically mediated by H2-type histamine receptors. We conclude that: (i) the induction of IFN-gamma mRNA in NK cells is effectively down-regulated by products of the oxidative metabolism of monocytes; and (ii) histamine effectively enhances IFN-gamma production by preventing monocyte-induced oxidative damage to NK cells.

Gamma ray astrophysics to the year 2000. Report of the NASA Gamma Ray Program Working Group

NASA Technical Reports Server (NTRS)

1988-01-01

Important developments in gamma-ray astrophysics up to energies of 100 GeV during the last decade are reviewed. Also, the report seeks to define the major current scientific goals of the field and proposes a vigorous program to pursue them, extending to the year 2000. The goals of gamma-ray astronomy include the study of gamma rays which provide the most direct means of studying many important problems in high energy astrophysics including explosive nucleosynthesis, accelerated particle interactions and sources, and high-energy processes around compact objects. The current research program in gamma-ray astronomy in the U.S. including the space program, balloon program and foreign programs in gamma-ray astronomy is described. The high priority recommendations for future study include an Explorer-class high resolution gamma-ray spectroscopy mission and a Get Away Special cannister (GAS-can) or Scout class multiwavelength experiment for the study of gamma-ray bursts. Continuing programs include an extended Gamma Ray Observatory mission, continuation of the vigorous program of balloon observations of the nearby Supernova 1987A, augmentation of the balloon program to provide for new instruments and rapid scientific results, and continuation of support for theoretical research. Long term recommendations include new space missions using advanced detectors to better study gamma-ray sources, the development of these detectors, continued study for the assembly of large detectors in space, collaboration with the gamma-ray astronomy missions initiated by other countries, and consideration of the Space Station attached payloads for gamma-ray experiments.

The effect of alloying on gamma and gamma prime in nickel-base superalloys

NASA Technical Reports Server (NTRS)

Dreshfield, R. L.; Wallace, J. F.

1972-01-01

An investigation was conducted to determine the compositional limits of gamma and gamma prime phases in nickel-base superalloys. Fifty-one nickel-base alloys were melted under vacuum and heat treated for 4 hours at 1190 C followed by 1008 hours at 850 C. The alloys had the following composition ranges: A1 4.0 to 13 atomic percent, Cr 6.5 to 20.5 percent, Ti 0.25 to 4.75 percent, Mo 0.0 to 6.0 percent, and W 0.0 to 4.0 percent. The residues from the ammonium sulfate electrolytic extraction for the two-phase alloys were analyzed chemically and by X-ray diffraction. The results of the investigation were used to assemble a mathematical model of the gamma-gamma prime region of the Ni-Al-Cr-Ti-Mo-W system. A computer program was written to analyze the model of the phase diagram. Some of these results are also presented graphically. The resulting model is capable of satisfactorily predicting the compositions of conjugate gamma-gamma prime phases in the alloys investigated and twelve of fifteen commercial superalloys studied.

Status of the GAMMA-400 Project

NASA Technical Reports Server (NTRS)

Galper, A. M.; Adriani, O.; Aptekar, R. L.; Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Boezio, M.; Bonvicini, V.; Boyarchuk, K. A.; Gusakov, Yu. V.; Farber, M. O.;

An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi -GBM Detection of GRB 170817A

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

Goldstein, A.; Roberts, O. J.; Connaughton, V.

On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 1.7 s prior to this GRB, the Laser Interferometer Gravitational-wave Observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this ordinary short GRB, which extraordinarily confirms that at least some short GRBs are produced by binary compact mergers.

An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A

NASA Astrophysics Data System (ADS)

Goldstein, A.; Veres, P.; Burns, E.; Briggs, M. S.; Hamburg, R.; Kocevski, D.; Wilson-Hodge, C. A.; Preece, R. D.; Poolakkil, S.; Roberts, O. J.; Hui, C. M.; Connaughton, V.; Racusin, J.; von Kienlin, A.; Dal Canton, T.; Christensen, N.; Littenberg, T.; Siellez, K.; Blackburn, L.; Broida, J.; Bissaldi, E.; Cleveland, W. H.; Gibby, M. H.; Giles, M. M.; Kippen, R. M.; McBreen, S.; McEnery, J.; Meegan, C. A.; Paciesas, W. S.; Stanbro, M.

2017-10-01

On 2017 August 17 at 12:41:06 UTC the Fermi Gamma-ray Burst Monitor (GBM) detected and triggered on the short gamma-ray burst (GRB) 170817A. Approximately 1.7 s prior to this GRB, the Laser Interferometer Gravitational-wave Observatory triggered on a binary compact merger candidate associated with the GRB. This is the first unambiguous coincident observation of gravitational waves and electromagnetic radiation from a single astrophysical source and marks the start of gravitational-wave multi-messenger astronomy. We report the GBM observations and analysis of this ordinary short GRB, which extraordinarily confirms that at least some short GRBs are produced by binary compact mergers.

Formation of fine {gamma} grain structure through fine {alpha}{sub 2}/{gamma} lamellar structure in Ti-rich TiAl alloy

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

Kumagai, T.; Abe, E.; Nakamura, M.

1997-12-31

Microstructural development of an extremely fine {alpha}{sub 2}-Ti{sub 32}Al/{gamma}-TiAl lamellar structure, which was formed by ice water quenching after solution-treatment in a high-temperature {alpha}-Ti phase field for a long period of time, was examined during isothermal treatment. In an as-quenched Ti-48at.%Al alloy, the massively transformed {gamma} ({gamma}{sub m}) and untransformed (meaning massively untransformed) fine {alpha}{sub 2}/{gamma} lamellar regions were observed. Fine {gamma} grains, which were similar to {gamma}{sub m}, were generated both within the fine {alpha}{sub 2}/{gamma} lamellae and at the boundary area between the {gamma}{sub m} and the fine {alpha}{sub 2}/{gamma} lamellar regions by aging at low-temperature (1,173 K)more » for a short time (180s). Further aging (1.8ks) caused the coarsening of these newly generated fine {gamma} grains. On the other hand, the coarsening of the {gamma} grains occurred by a high-temperature (1,323 K) aging treatment even for 180s. Fine {alpha}{sub 2} plates and particles, which were aligned to a particular direction, were observed in the {gamma} grain interiors, indicating that the newly generated {gamma} grains grew at the expense of the fine {alpha}{sub 2}/{gamma} lamellae. It can be considered that the {gamma} grain formation through the fine {alpha}{sub 2}/{gamma} lamellae is closely related to the {alpha}{sub 2}{yields}{gamma} reaction of the {alpha}{sub 2} plates sandwiched by the {gamma} plates, and needs the fast heating rate enough to overcome the {alpha}{sub 2}/{gamma}{yields}{gamma}/{gamma} lamellae reaction.« less

Fusion gamma diagnostics

NASA Astrophysics Data System (ADS)

Medley, S. S.; Cecil, F. E.; Cole, D.; Conway, M. A.; Wilkinson, F. J., III

1985-05-01

Nuclear reactions of interest in fusion research often possess a branch yielding prompt emission of gamma radiation in excess of 15 MeV which can be exploited to provide a new fusion reaction diagnostic having applications similar to conventional neutron emission measurements. Conceptual aspects of fusion gamma diagnostics are discussed with emphasis on application to the Tokamak Fusion Test Reactor (TFTR) during deuterium neutral beam heating of D-T and D-3He plasmas. Recent measurements of the D (T, γ)5He, D(3He, γ)5Li, and D(D, γ)4He branching ratios at low center-of-mass energy (30-100 keV) and of the response of a large volume Ne226 detector for gamma detection in high neutron backgrounds are presented. Using a well-shielded Ne226 detector during 20 MW-120 kV deuterium beam heating of a tritium plasma in TFTR, the D(T, γ)5He gamma signal level is estimated to be 3.5×105 cps.

Characterization of interactions between Nedd4 and beta and gammaENaC using surface plasmon resonance.

PubMed

Asher, C; Chigaev, A; Garty, H

2001-09-07

Cell surface expression of the epithelial Na(+) channel ENaC is regulated by the ubiquitin ligase Nedd4. Binding of the WW domains of Nedd4 to the PY region in the carboxy tails of beta and gammaENaC, results in channel ubiquitination and degradation. Kinetic analysis of these interactions has been done using surface plasmon resonance. Synthetic peptides corresponding to the PY regions of beta and gammaENaC were immobilized on a sensor chip and "real-time" kinetics of their binding to recombinant WW proteins was determined. Specificity of the interactions was established by competition experiment, as well as by monitoring effects of a point mutation known to impair Nedd4/ENaC binding. These data provides the first determination of association, dissociation and equilibrium constants for the interactions between WW2 and beta or gammaENaC. Copyright 2001 Academic Press.

A gamma beam profile imager for ELI-NP Gamma Beam System

NASA Astrophysics Data System (ADS)

Cardarelli, P.; Paternò, G.; Di Domenico, G.; Consoli, E.; Marziani, M.; Andreotti, M.; Evangelisti, F.; Squerzanti, S.; Gambaccini, M.; Albergo, S.; Cappello, G.; Tricomi, A.; Veltri, M.; Adriani, O.; Borgheresi, R.; Graziani, G.; Passaleva, G.; Serban, A.; Starodubtsev, O.; Variola, A.; Palumbo, L.

2018-06-01

The Gamma Beam System of ELI-Nuclear Physics is a high brilliance monochromatic gamma source based on the inverse Compton interaction between an intense high power laser and a bright electron beam with tunable energy. The source, currently being assembled in Magurele (Romania), is designed to provide a beam with tunable average energy ranging from 0.2 to 19.5 MeV, rms energy bandwidth down to 0.5% and flux of about 108 photons/s. The system includes a set of detectors for the diagnostic and complete characterization of the gamma beam. To evaluate the spatial distribution of the beam a gamma beam profile imager is required. For this purpose, a detector based on a scintillator target coupled to a CCD camera was designed and a prototype was tested at INFN-Ferrara laboratories. A set of analytical calculations and Monte Carlo simulations were carried out to optimize the imager design and evaluate the performance expected with ELI-NP gamma beam. In this work the design of the imager is described in detail, as well as the simulation tools used and the results obtained. The simulation parameters were tuned and cross-checked with the experimental measurements carried out on the assembled prototype using the beam from an x-ray tube.

Observations of the Crab Nebula with the Chandra X-Ray Observatory During the Gamma-Ray Flare of 2011 April

NASA Technical Reports Server (NTRS)

Weisskopf, Martin C.

2012-01-01

Recently, using the AGILE and Fermi satellites, gamma-ray flares have been discovered from the direction of the Crab Nebula (Tavani et al. 2011, Abdo et al. 2011). We have been using the Chandra X-Ray observatory to monitor the Crab on a monthly cadence since just after the 2010 September gamma-ray flare. We were fortunate to trigger series of pre-planned target of opportunity observations during the 2011 April flare. We present the results of these observations and address some implications both for now and for the future.

Spectrometre de masse a ionisation Penning selective: Elimination des corrections necessaires a la determination du rapport isotopique de l'hydrogene

NASA Astrophysics Data System (ADS)

Letarte, Sylvain

Dans le but d'ameliorer la precision avec laquelle le rapport isotopique de l'hydrogene peut etre determine, un spectrometre de masse a ionisation Penning a ete construit pour provoquer l'ionisation selective de l'hydrogene moleculaire et de l'hydrure de deuterium a partir d'un melange gazeux. L'utilisation d'atomes dans des etats d'excitation metastable s'est averee une solution adequate pour reponde a cette attente. L'emploi de l'helium, a l'interieur d'une source d'atomes metastables construit specifiquement pour ce travail, ne permet pas d'obtenir un spectre de masse compose uniquement des deux molecules d'interet. L'ionisation de ces dernieres provient de deux processus distincts, soient l'ionisation Penning et l'ionisation par bombardement electronique. Contrairement a l'helium, il a ete demontre que le neon metastable est un candidat ideal pour produire l'ionisation selective de type Penning. Le nombre d'ions produits est directement proportionnel au courant de la decharge electrique et de la pression d'operation de la source d'atomes metastables. Ces resultats demontrent le potentiel d'un tel spectrometre de masse pour ameliorer la precision a laquelle le rapport isotopique peut etre determine comparativement aux autres techniques existantes.

Gamma-Ray Bursts: An Overview

NASA Technical Reports Server (NTRS)

Fishman, Gerald J.

1995-01-01

A history and overview of the observed properties of gamma-ray bursts are presented. The phenomenon of gamma-ray bursts is without precedent in astronomy, having no observed property that would be a direct indicator of their distance and no counterpart object in another wavelength region. Their brief, random appearance only in the gamma-ray region has made their study difficult. The observed time profiles, spectral properties, and durations of gamma-ray bursts cover a wide range. All proposed models for their origin must be considered speculative. It is humbling to think that even after 25 years since their discovery, the distance scale of gamma-ray bursts is still very much debatable.

Gamma radiation induced oxidation and tocopherols decrease in in-shell, peeled and blanched peanuts.

PubMed

de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D'Arce, Marisa Aparecida Bismara; de Alencar, Severino Matias; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

2012-01-01

In-shell, peeled and blanched peanut samples were characterized in relation to proximate composition and fatty acid profile. No difference was found in relation to its proximate composition. The three major fatty acids were palmitic acid, oleic acid, and linoleic acid. In order to investigate irradiation and storage effects, peanut samples were submitted to doses of 0.0, 5.0, 7.5 or 10.0 kGy, stored for six months at room temperature and monitored every three months. Peanuts responded differently to irradiation, particularly with regards to tocopherol contents, primary and secondary oxidation products and oil stability index. Induction periods and tocopherol contents were negatively correlated with irradiation doses and decreased moderately during storage. α-Tocopherol was the most gamma radiation sensitive and peeled samples were the most affected. A positive correlation was found among tocopherol contents and the induction period of the oils extracted from irradiated samples. Gamma radiation and storage time increased oxidation compounds production. If gamma radiation is considered an alternative for industrial scale peanut conservation, in-shell samples are the best feedstock. For the best of our knowledge this is the first article with such results; this way it may be helpful as basis for future studies on gamma radiation of in-shell crops.

Gamma Radiation Induced Oxidation and Tocopherols Decrease in In-Shell, Peeled and Blanched Peanuts

PubMed Central

de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D’Arce, Marisa Aparecida Bismara; de Alencar, Severino Matias; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

2012-01-01

In-shell, peeled and blanched peanut samples were characterized in relation to proximate composition and fatty acid profile. No difference was found in relation to its proximate composition. The three major fatty acids were palmitic acid, oleic acid, and linoleic acid. In order to investigate irradiation and storage effects, peanut samples were submitted to doses of 0.0, 5.0, 7.5 or 10.0 kGy, stored for six months at room temperature and monitored every three months. Peanuts responded differently to irradiation, particularly with regards to tocopherol contents, primary and secondary oxidation products and oil stability index. Induction periods and tocopherol contents were negatively correlated with irradiation doses and decreased moderately during storage. α-Tocopherol was the most gamma radiation sensitive and peeled samples were the most affected. A positive correlation was found among tocopherol contents and the induction period of the oils extracted from irradiated samples. Gamma radiation and storage time increased oxidation compounds production. If gamma radiation is considered an alternative for industrial scale peanut conservation, in-shell samples are the best feedstock. For the best of our knowledge this is the first article with such results; this way it may be helpful as basis for future studies on gamma radiation of in-shell crops. PMID:22489128

High energy gamma ray astronomy

NASA Technical Reports Server (NTRS)

Fichtel, Carl E.

1987-01-01

High energy gamma ray astronomy has evolved with the space age. Nonexistent twenty-five years ago, there is now a general sketch of the gamma ray sky which should develop into a detailed picture with the results expected to be forthcoming over the next decade. The galactic plane is the dominant feature of the gamma ray sky, the longitude and latitude distribution being generally correlated with galactic structural features including the spiral arms. Two molecular clouds were already seen. Two of the three strongest gamma ray sources are pulsars. The highly variable X-ray source Cygnus X-3 was seen at one time, but not another in the 100 MeV region, and it was also observed at very high energies. Beyond the Milky Way Galaxy, there is seen a diffuse radiation, whose origin remains uncertain, as well as at least one quasar, 3C 273. Looking to the future, the satellite opportunities for high energy gamma ray astronomy in the near term are the GAMMA-I planned to be launched in late 1987 and the Gamma Ray Observatory, scheduled for launch in 1990. The Gamma Ray Observatory will carry a total of four instruments covering the entire energy range from 30,000 eV to 3 x 10 to the 10th eV with over an order of magnitude increase in sensitivity relative to previous satellite instruments.

GammaM23K, gammaM232K, and gammaL77K single substitutions in the TF1-ATPase lower ATPase activity by disrupting a cluster of hydrophobic side chains.

PubMed

Bandyopadhyay, Sanjay; Allison, William S

2004-07-27

In crystal structures of the bovine F(1)-ATPase (MF(1)), the side chains of gammaMet(23), gammaMet(232), and gammaLeu(77) interact in a cluster. Substitution of the corresponding residues in the alpha(3)beta(3)gamma subcomplex of TF(1) with lysine lowers the ATPase activity to 2.3, 11, and 15%, respectively, of that displayed by wild-type. In contrast, TF(1) subcomplexes containing the gammaM(23)C, gammaM(232)C, and gammaL(77)C substitutions display 36, 36, and 130%, respectively, of the wild-type ATPase activity. The ATPase activity of the gammaM(23)C/gammaM(232)C double mutant subcomplex is 36% that of the wild-type subcomplex before and after cross-linking the introduced cysteines, whereas the ATPase activity of the gammaM(23)C/L(77)C double mutant increased from 50 to 85% that of wild-type after cross-linking the introduced cysteines. Only beta-beta cross-links formed when the alpha(3)(betaE(395)C)(3)gammaM(23)C double mutant was inactivated with CuCl(2). The overall results suggest that the attenuated ATPase of the mutant subcomplexes containing the gammaM(23)K, gammaL(77)K, and gammaM(232)K substitutions is caused by disruption of the cluster of hydrophobic amino acid side chains and that the midregion of the coiled-coil comprised of the amino- and carboxyl-terminal alpha helices of the gamma subunit does not undergo unwinding or major displacement from the side chain of gammaLeu(77) during ATP-driven rotation of the gamma subunit.

1990 Environmental monitoring report, Tonopah Test Range, Tonopah, Nevada

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

Hwang, A.; Phelan, J.; Wolff, T.

1991-05-01

There is no routine radioactive emission from Sandia National Laboratories, Tonopah Test Range (SNL, TTR). However, based on the types of test activities such as air drops, gun firings, ground- launched rockets, air-launched rockets, and other explosive tests, possibilities exist that small amounts of depleted uranium (DU) (as part of weapon components) may be released to the air or to the ground because of unusual circumstances (failures) during testing. Four major monitoring programs were used in 1990 to assess radiological impact on the public. The EPA Air Surveillance Network (ASN) found that the only gamma ({gamma}) emitting radionuclide on themore » prefilters was beryllium-7 ({sup 7}Be), a naturally-occurring spallation product formed by the interaction of cosmic radiation with atmospheric oxygen and nitrogen. The weighted average results were consistent with the area background concentrations. The EPA Thermoluminescent Dosimetry (TLD) Network and Pressurized Ion Chamber (PIC) reported normal results. In the EPA Long-Term Hydrological Monitoring Program (LTHMP), analytical results for tritium ({sup 3}H) in well water were reported and were well below DOE-derived concentration guides (DCGs). In the Reynolds Electrical and Engineering Company (REECo) Drinking Water Sampling Program, analytical results for {sup 3}H, gross alpha ({alpha}), beta ({beta}), and {gamma} scan, strontium-90 ({sup 90}Sr) and plutonium-239 ({sup 239}Pu) were within the EPA's primary drinking water standards. 29 refs., 5 figs., 15 tabs.« less

FERMI Observations of Gamma -Ray Emission From the Moon

NASA Technical Reports Server (NTRS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Atwoo, W. B.; Baldini, I.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.;

Long term monitoring of Gamma-Ray emission from the BL Lacertae object (1ES 2200+420)

NASA Astrophysics Data System (ADS)

Gunawardhana, Isuru; VERITAS Collaboration

2016-03-01

Blazars are a class of Active Galactic Nuclei (AGN) that have relativistic jets pointing along the observer line of sight. Blazars exhibit variable emission extending from radio to TeV energies. The variability timescale of the TeV flux is a key component of understanding the location of the very high energy emission zones. Deep observations of the quiescent state measurements are also required to disentangle the flaring state emission from quiescent state emission, a prerequisite for understanding the origin of blazar spectral variability. BL Lacertae (also known as 1ES 2200+420), as the namesake for all BL Lac objects, is a prime example of one such blazar. The VERITAS Observatory, an Imaging Atmospheric Cherenkov Telescope (IACT) array sensitive to gamma rays in the range from 85 GeV to 30 TeV, dedicates approximately 110 hours per year on deep observations of known gamma-ray blazars. In this talk, I will describe the TeV photon flux variability of BL Lacertae measured by VERITAS from 2013 to 2015.

Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

1991-01-01

This photograph shows the Compton Gamma-Ray Observatory (GRO) being deployed by the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-37 mission in April 1991. The GRO reentered Earth atmosphere and ended its successful mission in June 2000. For nearly 9 years, the GRO Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center (MSFC), kept an unblinking watch on the universe to alert scientists to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of stars, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in the BATSE science program.

Compton Gamma-Ray Observatory

NASA Technical Reports Server (NTRS)

1991-01-01

This photograph shows the Compton Gamma-Ray Observatory being released from the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-35 mission in April 1991. The GRO reentered the Earth's atmosphere and ended its successful mission in June 2000. For nearly 9 years, GRO's Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center, kept an unblinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of star, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in BATSE's science program.

Differentiation of the four major types (C. Burmannii, C. Verum, C. cassia, And C. Loureiroi) of cinnamons using a flow-injection mass spectrometric (FIMS) fingerprinting method

USDA-ARS?s Scientific Manuscript database

A simple and efficient flow-injection mass spectrometric (FIMS) method was developed to differentiate cinnamon (Cinnamomum) bark (CB) samples of the four major species (C. burmannii, C. verum, C. aromaticum, and C. loureiroi) of cinnamon. Fifty cinnamon samples collected from China, Vietnam, Indon...

Low-temperature high-Z gamma-detectors with very high energy resolution