Search results for "IRRADIATION"

Assessment of contamination of <em>Salmonella</em> spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irr…

2021

This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepp…

Photochemical sample treatment for extracts clean up in PCB analysis from sediments.

2013

Sample purification can be considered the most polluting step of the whole analytical process for PCBs determination in sediment samples. The use of photochemical sample treatment represents an alternative methodology for extracts clean up allowing for a reduction of the used amount of organic solvents. The first application of a photochemical sample treatment for the selective removal or reduction of organic substances interfering with PCBs analyses in sediments is reported. The method's efficiency and robustness were compared with currently used chromatographic purification. Quality parameters such as recovery, linearity and reproducibility were studied. The entire procedure was validated…

Electron Emission of Pt: Experimental Study and Comparison With Models in the Multipactor Energy Range

2016

Experimental data of secondary emission yield (SEY) and electron emission spectra of Pt under electron irradiation for normal incidence and primary energies lower than 1 keV are presented. Several relevant magnitudes, as total SEY, elastic backscattering probability, secondary emission spectrum, and backscattering coefficient, are given for different primary energies. These magnitudes are compared with theoretical or semiempirical formulas commonly used in the related literature.

Use of irradiated pollen to induce Parthenogenesis and haploid production in fruit crops.

2012

Microwave effects on germination and growth of radish (Raphanus sativus L.) seedlings

2002

Germination of radish seeds was delayed and reduced by low-power microwave exposure at 10.5 and 12.5 GHz. Irradiation decreased also hypocotyl growth rate. These effects were increased by rising of the microwave power and by the vertically polarised electromagnetic field. When the irradiation was suspended the seedling growth recovered.

High-energy radiation process, a "facile" and "versatile" approach to obtain PVP-graft- AA nanogels

2012

Poly(N-vinylpyrrolidone)-grafted-acrylic acid biocompatible nanogels (NGs) were prepared using an exiting industrial-type electron accelerator and setups, starting from semi-dilute aqueous solutions of a commercial PVP and the acrylic acid monomer. As a result, NGs with tunable size and structure can be obtained quantitatively. Sterility was also imparted at the integrated dose absorbed. The chemical structure of the NGs produced was confirmed through Fourier Transformer Infrared Spectroscopy (FT-IR). The molecular and physico-chemical properties of NGs, such as the hydrodynamic dimensions and surface charge densities, for various polymer and monomer concentrations in the irradiated solutio…

Photoactivity of Shape-Controlled TiO2 in Gas-Solid Regime Under Solar Irradiation

2018

Shape-controlled TiO2 materials have been tested as photocatalysts under both simulated and natural solar irradiation.

Testing and linearity calibration of films of phenol compounds exposed to thermal neutron field for EPR dosimetry

2015

This paper reports the preliminary results obtained by Electron Paramagnetic Resonance (EPR) measurements on films of IRGANOX® 1076 phenols with and without low content (5% by weight) of gadolinium oxide (Gd2O3) exposed in the thermal column of the Triga Mark II reactor of LENA (Laboratorio Energia Nucleare Applicata) of Pavia (Italy). Thanks to their size, the phenolic films here presented are good devices for the dosimetry of beams with high dose gradient and which require accurate knowledge of the precise dose delivered. The dependence of EPR signal as function of neutron dose was investigated in the fluence range between 10(11) cm(-2) and 10(14) cm(-2). Linearity of EPR response was fou…

Gamma-ray irradiation tests on CCD and CMOS sensors used in imaging techniques

2012

Technologically-enhanced electronic devices are used in various fields as space imaging or diagnostic techniques in medicine. The devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same apparatus, in particular in space applications. In this paper we report the results of a gamma irradiation tests on imaging sensors simulating the space radiation over a long time period. Two types of sensors are taken into consideration: CCD (Charge-Coupled Device) sensors and CMOS based on technology MOS (Metal Oxide semiconductor) used for the realization of transistors widely used in consumer electronics. The devices are supplied by Techno System (Italy),…

Progettazione e realizzazione di un irradiatore neutronico modulare basato su sorgenti Am-Be

2012

Irradiatori neutronici basati su sorgenti radionuclidiche sono impiegati in diversi paesi per studiare le caratteristiche dei materiali sottoposti a irradiazione e/o la risposta di rivelatori e/o dosimetri personali sensibili alla componente neutronica. Per quest’ultima applicazione, l’uso di un irradiatore con sorgenti radionuclidiche risulta molto vantaggioso per la stabilità nel tempo del flusso neutronico, mentre è relativamente poco importante il valore assoluto del flusso neutronico, che può anche essere di qualche ordine di grandezza inferiore a quello di reattori o di acceleratori di particelle. Per l’effettuazione di test su rivelatori e/o dosimetri personali neutronici risulta mol…