scholarly journals Irradiation of spices – a review

2008 ◽  
Vol 25 (No. 5) ◽  
pp. 231-242 ◽  
Author(s):  
J. Sádecká
Keyword(s):  
Food Safety ◽  
Gamma Rays ◽  
Absorbed Dose ◽  
High Energy ◽  
Ionising Radiation ◽  
Food Irradiation ◽  
X Rays ◽  
Storage Losses ◽  
High Energy Electrons ◽  
Biological Organisms

Food irradiation is a process of exposing food to ionising radiation such as gamma rays emitted from the radioisotopes 60Co and 137Cs, or high energy electrons and X-rays produced by machine sources. The use of ionising radiation to destroy harmful biological organisms in food is considered a safe, well proven process that has found many applications. Depending on the absorbed dose of radiation, various effects can be achieved resulting in reduced storage losses, extended shelf life and/or improved microbiological and parasitological safety of foods. The most common irradiated commercial products are spices and vegetable seasonings. Spice irradiation is increasingly recognised as a method that reduces post-harvest losses, ensures hygienic quality, and facilitates trade with food products. This article reviews recent activities concerning food irradiation, focusing on the irradiation of spices and dried vegetable seasonings from the food safety aspect.

scholarly journals Physical Constraints on Models of Gamma-Ray Bursters

1986 ◽  
Vol 89 ◽  
pp. 305-321
Author(s):  
Richard I. Epstein
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Burst Source ◽  
Gamma Ray Burst ◽  
Physical Constraints ◽  
Low Energies ◽  
Energy Gamma ◽  
Photon Interactions

AbstractThe power per logarithmic bandwidth in gamma-ray burst spectra generally increases rapidly with energy through the x-ray range and does not cut off sharply above a few MeV. This spectral form indicates that a very small fraction of the energy from a gamma-ray burst source is emitted at low energies or is reprocessed into x-rays and that the high-energy gamma rays are not destroyed by photon-photon interactions. The implications are that the emission mechanism for the gamma-ray bursts is not synchrotron radiation from electrons that lose most of their energy before being re-accelerated and that either the regions from which the gamma rays are emitted are large compared to the size of a neutron star or the emission is collimated and beamed away from the stellar surface.

scholarly journals The Flare of 1989 September 9, 09:09 UT: Does Coronal Loop Collision Initiate Efficient Gamma-Ray Emission?

1994 ◽  
Vol 142 ◽  
pp. 707-711
Author(s):  
H. Aurass ◽  
A. Hofmann ◽  
E. Rieger
Keyword(s):  
Current Sheet ◽  
Gamma Rays ◽  
Coronal Loop ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
Subject Headings ◽  
Γ Ray ◽  
Gamma Ray Emission ◽  
Magnetogram Data

AbstractVector magnetogram data and Hα pictures together with data published by Chupp et al. lead us to conjecture that in the presented case a contact between the rising two-ribbon flare current sheet and a coronal loop connecting two nearby plage regions initiates efficient high-energy γ-ray emission.Subject headings: Sun: corona — Sun: flares — Sun: X-rays, gamma rays

scholarly journals Detection of TeV Gamma Rays from SN1006

1998 ◽  
Vol 188 ◽  
pp. 121-124 ◽  
Author(s):  
Toru Tanimori
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Gamma Rays ◽  
High Energy ◽  
Shock Acceleration ◽  
Emission Region ◽  
X Ray ◽  
High Energy Electrons ◽  
Tev Gamma Rays ◽  
The Magnetic Field

In spite of the recent progress of high energy gamma-ray astronomy, there still remains quite unclear and important problem about the origin of cosmic rays. Supernova remnants (SNRs) are the favoured site for cosmic rays up to 1016 eV, as they satisfy the requirements such as an energy input rate. But direct supporting evidence is sparse. Recently intense non-thermal X-ray emission from the rims of the Type Ia SNR SN1006 (G327.6+14.6) has been observed by ASCA (Koyama et al. 1995)and ROSAT (Willingale et al. 1996), which is considered, by attributing the emission to synchrotron radiation, to be strong evidence of shock acceleration of high energy electrons up to ~100 TeV. If so, TeV gamma rays would also be expected from inverse Compton scattering (IC) of low energy photons (mostly attributable to the 2.7 K cosmic background photons) by these electrons. By assuming the magnetic field strength (B) in the emission region of the SNR, several theorists (Pohl 1996; Mastichiadis 1996; Mastichiadis & de Jager 1996; Yoshida & Yanagita 1997) calculated the expected spectra of TeV gamma rays using the observed radio/X-ray spectra. Observation of TeV gamma rays would thus provide not only the further direct evidence of the existence of very high energy electrons but also the another important information such as the strength of the magnetic field and diffusion coefficient of the shock acceleration. With this motivation, SN1006 was observed by the CANGAROO imaging air Cerenkov telescope in 1996 March and June, also 1997 March and April.

Radiation induced degradation of murexide dye in two media for possible use in dosimetric applications

2019 ◽  
Vol 48 (6) ◽  
pp. 540-546 ◽  
Author(s):  
Sameh Mohamed Gafar ◽  
Nehad Magdy Abdel-Kader
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Chemical Yield ◽  
Radiation Sensitivity ◽  
Industrial Applications ◽  
Food Irradiation ◽  
Radiation Chemical ◽  
Content Type ◽  
Wide Range

Purpose The purpose of this paper is to study the effect of gamma-rays on murexide (Mx) dye and its possible use as radiation dosimeters in two different dosimetry systems. The first system depends on the Mx dye as a liquid dosimeter. The second dosimetry system depends also on the same dye but as in a gel form, which is more sensitive to gamma-rays. Design/methodology/approach The prepared Mx (solutions/gels) have a considerable two peaks at 324 and 521 nm that upon irradiation, the intensity of these peaks decreases with the increasing radiation dose. Findings The gamma-ray absorbed dose for these dosimeters was found to be up to 2 kGy for the solution samples and 40 Gy for the gels. Radiation chemical yield, dose response function, radiation sensitivity and before and after-irradiation stability under various conditions were discussed and studied. Practical implications It is expected that the radiolysis of the Mx dye can be used as radiation dosimeters in two different dosimetry systems; liquid and gel dosimeters. This can be applied in a wide range of gamma radiation practical industrial applications in water treatment, food irradiation dosimeters, radiotherapy and fresh food irradiation and seed production. Originality/value Both of the prepared Mx dyes, either as solutions or gel samples, can be facilely prepared from commercially, cheap, safe, available chemicals and suitable for useful applied Mx solutions and gels radiation dosimeters.

Thermoluminescence of irradiated ammonium perchlorate crystals

1976 ◽  
Vol 54 (7) ◽  
pp. 766-770 ◽  
Author(s):  
S. Radhakrishna ◽  
M. Riggin ◽  
P. W. Whippey ◽  
P. W. M. Jacobs
Keyword(s):  
Absorption Spectrum ◽  
Single Crystals ◽  
Heating Rate ◽  
Ammonium Perchlorate ◽  
Uv Light ◽  
High Energy ◽  
X Rays ◽  
Spectroscopic Evidence ◽  
Additional Peak ◽  
High Energy Electrons

The thermoluminescence of single crystals of ammonium perchlorate irradiated with X rays, uv light, or high energy electrons has been measured between 80 and 420 K. With a heating rate of 5 K/min. prominent peaks occur at 95, 113, 134, 246, and 320 K; an additional peak is found at 347 K after longer irradiation times. The absorption spectrum of uv-irradiated ammonium perchlorate has also been measured and shows bands at 300, 360, and 610 nm. A comparison of these data with chemical and spectroscopic evidence obtained by other workers has permitted the probable identification of ClO3−, ClO−, ClO2, and F centres as radiation products. Three thermoluminescent peaks remain unassigned.

Fricke dosimetry: the difference betweenG(Fe3+) for60Co gamma-rays and high-energy x-rays

1999 ◽  
Vol 44 (7) ◽  
pp. 1609-1624 ◽  
Author(s):  
N V Klassen ◽  
K R Shortt ◽  
J Seuntjens ◽  
C K Ross
Keyword(s):  
Gamma Rays ◽  
High Energy ◽  
X Rays ◽  
The Difference

scholarly journals Food Irradiation An Established Food Processing Technology for Food Safety and Security

2019 ◽  
Vol 4 (4) ◽  
pp. 206-213
Author(s):  
Rita Singh ◽  
Antaryami Singh
Keyword(s):  
Food Safety ◽  
Foodborne Pathogens ◽  
Food Processing ◽  
Radiation Treatment ◽  
Ionising Radiation ◽  
Food Irradiation ◽  
Agricultural Produce ◽  
Radiation Sources ◽  
Technology Aids ◽  
Historical Developments

Food irradiation is a well-established and effective technology for food processing and preservation. The technology aids in reducing food losses and ensuring food safety by elimination of pathogens and parasites causing illness and death. Radiation treatment can be applied to agricultural produce and animal food products to get extended shelf life with improved microbiological safety and quality. Irradiating food can greatly reduce illness from foodborne pathogens thereby preventing morbidity and mortality. Various national and international food and health organisations have endorsed and supported the safety of food and foodstuffs subjected to ionising radiation based on the research and testing data of more than 50 year. A review is presented on the historical developments of food irradiation technology, radiation sources for treatment of food and, the safety and wholesomeness of foods processed by ionising radiation.

scholarly journals Gamma-Ray Precursors of Solar Flares

1994 ◽  
Vol 142 ◽  
pp. 645-648
Author(s):  
E. Rieger
Keyword(s):  
Spatial Resolution ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
High Energy Gamma ◽  
Gamma Ray Spectrometer ◽  
Energy Gamma ◽  
Negligible Contribution

AbstractBursts have been observed by the gamma-ray spectrometer on SMM at medium- and high-energy gamma-rays that precede the flare maximum. The negligible contribution of nuclear lines in the spectra of these events and their impulsive appearance suggests that they are hard-electron-dominated events superposed on the flares. Spatial resolution at gamma-ray energies will be necessary to decide whether this kind of bursts is cospatial with the flares or whether they occur in the flares’ vicinity.Subject headings: Sun: flares — Sun: X-rays, gamma rays

scholarly journals Creation of High-Energy Electron Tails by the Lower-Hybrid Waves and its Relevance to Type II and III Bursts

1985 ◽  
Vol 107 ◽  
pp. 505-508
Author(s):  
Motohiko Tanaka ◽  
K. Papadopoulos
Keyword(s):  
High Energy ◽  
Lower Hybrid ◽  
X Rays ◽  
Type Ii ◽  
High Energy Electron ◽  
Acceleration Mechanism ◽  
High Energy Electrons ◽  
Wave Emission ◽  
Hybrid Waves ◽  
Lower Hybrid Waves

It is commonly anticipated that high-energy electrons play an important role for the wave emission in flare bursts. For instance, electrons with >100 KeV are considered to create microwave emissions through gyro-synchrotron process and hard x-rays may be due to bremstrahlung with >25 KeV electrons. However, electron acceleration mechanism itself is still in speculations.

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