Search results for "Gamma"
showing 10 items of 3093 documents
GAMMA-I, NUOVO METODO COMPLEMENTARE NON DISTRUTTIVO
2008
Metodo non distruttivo "gamma-i"
2009
Measurement of long-lived radionuclide activity induced in target components of a cyclotron used for [18F ]-[FDG] production
2019
The evaluation of high activity induced in target components in using a medical cyclotron to produce positron-emitting radionuclides for PET (Positron Emission Tomography) diagnostic studies is one of important issue and involves radiation protection concepts when operators are engaged in maintenance and/or substitution of a target or its components. Most of replaced target components are generally classified and stored in a Pb-shielded container in order to wait for their radioactive decay. However, after some years, it can be necessary to start with the removal of the oldest parts, for a temporary storage of the fresh activated ones. The feasibility of these operations and the waste final…
Coincidence-Summing corrections in high resolution gamma-ray spectrometry: simplified analytical expressions
2010
Simplified expressions to determine the coincidence-summing correction factors by using a matrix representation of a decay scheme are reported. Expressions can be used directly for point sources, with the introduction of full-energy-peak and total efficiencies, while for extended sources a more complex procedure, though approximate, is suggested.
On the feasibility of dating the age of a nuclear incidental event by gamma-ray spectrometry of environmental samples
2019
The dating of a nuclear incidental event is an important element for the assessment of its enviromental impact and radiation protection implications on the involved population. In this framework, a procedure has already been proposed to determine the age of a nuclear event by measuring through a gamma-ray spectrometric analysis the activity of two fission products in a small sample of uranium irradiated for a short time in a nuclear reactor [1,2]. However, It may be useful to extend the application of the above mentioned procedure for assessing the “timing of occurrence” of an incidental event considering other samples and in particular, by sampling and measuring environmental samples. The …
Quantum-state-selective decay spectroscopy of 213Ra
2017
An experimental scheme combining the mass resolving power of a Penning trap with contemporary decay spectroscopy has been established at GSI Darmstadt. The Universal Linear Accelerator (UNILAC) at GSI Darmstadt provided a 48Ca beam impinging on a thin 170Er target foil. Subsequent to velocity filtering of reaction products in the Separator for Heavy Ion reaction Products (SHIP), the nuclear ground state of the 5n evaporation channel 213Ra was mass-selected in SHIPTRAP, and the 213Ra ions were finally transferred into an array of silicon strip detectors surrounded by large composite germanium detectors. Based on comprehensive geant4 simulations and supported by theoretical calculations, the …
Study on Supernova Remnants evolution and their gamma-ray emission
2022
Searching for differences in Swift's intermediate GRBs
2010
Gamma-ray bursts are usually classified through their high-energy emission into short-duration and long-duration bursts, which presumably reflect two different types of progenitors. However, it has been shown on statistical grounds that a third, intermediate population is needed in this classification scheme, although an extensive study of the properties of this class has so far not been done. The large amount of follow-up studies generated during the Swift era allows us to have a suficient sample to attempt a study of this third population through the properties of their prompt emission and their afterglows. Our study is focused on a sample of GRBs observed by Swift during its first four y…
Faint γ-ray sources at low redshift: the radio galaxy IC 1531
2018
We present amultiwavelength study of IC 1531 (z=0.02564), an extragalactic radio source associated with the γ -ray object 3FGL J0009.9-3206 and classified as a blazar of uncertain type in the Third Fermi-Large Area Telescope AGN catalog (3LAC). A core-jet structure, visible in radio and X-rays, is enclosed within a ~220 kpc wide radio structure. The morphology and spectral characteristics of the kiloparsec jet in radio and X-rays are typical of Fanaroff-Riley type I galaxies. The analysis of the radio data and optical spectrum and different diagnostic methods based on the optical, infrared, and γ -ray luminosities also support a classification as a low-power RG seen at moderate angles (θ = …
Gammapirona antidemences darbības pētījums ne-transgēnā Alcheimera slimības modelī žurkām
2018
Alcheimera slimība ir nopietna mūsdienu veselības problēma, kas skar 47 miljonus cilvēku visā pasaulē, izraisot progresējošu demenci un tai sekojošu invaliditāti. Līdz šīm nav atrastas efektīvas slimības diagnostiskas un ārstēšanas metodes, kas dotu iespēju savlaicīgi atklāt šo problēmu un pēc iespējas ātrāk uzsākt ārstēšanu. Ņemot vērā savdabīgo gammapirona struktūru, kas satur gamma-aminosviestskābes GABA) molekulu, pievienotu dihidropiridīna gredzenam 4.pozīcijā (“brīvo” GABA) un dihidropiridīna gredzenā ieslēgto t.s. “kripto” GABA, kā arī pēdējā laikā atrastos GABAerģiskās sistēmas atmiņu stimulējošos efektus, šī darba uzdevums bija noskaidrot gammapirona ietekmi uz atmiņas procesiem Al…