Search results for "RADIATION"

Radiācijas defektu EPR fluorīdu kristālos un oksifluorīdu stikla keramikā

2008

Elektroniskā versija nesatur pielikumus

Evaluation of the original dose in irradiated dried fruit by EPR spectroscopy

2011

Abstract The electron paramagnetic resonance spectroscopy (EPR) is one of the physical methods, recommended by the European Committee for Standardization, for the identification of irradiated food containing cellulose, such as dried fruit. In this work the applicability of EPR as identification method of irradiated pistachios, hazelnuts, peanuts, chestnuts, pumpkin seeds is evaluated; the time stability of the radiation induced signal is studied and the single aliquot additive dose method is used to evaluate the dose in the product.

A crystalline radical cation derived from Thiele’s hydrocarbon with redox range beyond 1 V

2021

Thiele’s hydrocarbon occupies a central role as an open-shell platform for new organic materials, however little is known about its redox behaviour. While recent synthetic approaches involving symmetrical carbene substitution of the CPh2 termini yield isolable neutral/dicationic analogues, the intervening radical cations are much more difficult to isolate, due to narrow compatible redox ranges (typically  1 V), permitting its isolation in crystalline form. Further single-electron oxidation affords borenium dication 12+, thereby establishing an organoboron redox system fully characterized in all three redox states. We perceive that this strategy can be extended to other transient organic rad…

Ultra-fast direct growth of metallic micro- and nano-structures by focused ion beam irradiation

2019

An ultra-fast method to directly grow metallic micro- and nano-structures is introduced. It relies on a Focused Ion Beam (FIB) and a condensed layer of suitable precursor material formed on the substrate under cryogenic conditions. The technique implies cooling the substrate below the condensation temperature of the gaseous precursor material, subsequently irradiating with ions according to the wanted pattern, and posteriorly heating the substrate above the condensation temperature. Here, using W(CO)6 as the precursor material, a Ga+ FIB, and a substrate temperature of -100 °C, W-C metallic layers and nanowires with resolution down to 38 nm have been grown by Cryogenic Focused Ion Beam Indu…

LACTATE DEHYDROGENASE ISOENZYMES IN THE NERVOUS TISSUE?V..

1965

An allergen-polymeric nanoaggregate as a new tool for allergy vaccination.

2014

Parietaria pollen is one of the major causes of allergic reaction in southern Europe, affecting about 30% of all allergic patients in this area. Specifi immunotherapy is the only treatment able to modify the natural outcome of the disease by restoring a normal immunity against allergens. The preparation of allergen-solid lipid nanoparticles as delivery vehicles for therapeutic proteins, P. judaica major allergen Par j 2, was investigated. The Par j 2 allergen was expressed in a large amount in Escherichia coli and purifid to homogeneity. Its immunological properties were studied by western blotting and enzyme-linked immunosorbent assay inhibition. Solid lipid nanoparticles were obtained by …

Characterization of Sorolla's gouache pigments by means of spectroscopic techniques

2016

Abstract This paper presents the characterization of the Joaquin Sorolla's gouache sketches for the oil on canvas series “Vision of Spain” commissioned by A. M. Huntington to decorate the library of the Hispanic Society of America in New York. The analyses were focused on the identification of the elemental composition of the gouache pigments by means of portable EDXRF spectrometry in a non-destructive mode. Additionally, SEM-EDX and FTIR analyses of a selected set of micro-samples were carried out to identify completely the pigments, the paint technique and the binding media. The obtained results have confirmed the identification of lead and zinc white, vermillion, earth pigments, ochre, z…

Evidence for a teratogenic risk in the offspring of health personnel exposed to ionizing radiation?!

2016

Background The evidence concerning safety of occupational exposure to ionizing radiation on teratogenic effects mainly relies on animal models, disaster epidemiology and experience in cancer etiology. Following an explorative result on maternal exposure in medical occupations we conducted a feasibility study, addressing congenital anomalies (CA) in the offspring of health workers potentially exposed to radiation. Methods In a prospective follow-up study, we enrolled women, identified by mandatory registration at the office of radiation protection as wearing a dosimeter. The participating women answered a questionnaire and if pregnant agreed to an examination of their infant. CA were diagnos…

Optical and electron paramagnetic resonance studies on radiation defects in Mn‐activated RbCdF 3

2007

The photoluminescence of Mn-activated RbCdF3 shows a Mn2+ emission band at 560 nm; the corresponding excitation bands are between 240 and 520 nm. After X-irradiation an increased Mn2+ emission can be observed and the excitation spectrum shows an additional broad intense band at 300 nm. Upon excitation at 300 nm the intensity of the Mn2+ emission decreases, whereas excitation at 240 nm leads to an increase in the PL intensity. Electron paramagnetic resonance shows that the number of Mn2+ ions is reduced upon X-irradiation; the original Mn2+ level can be restored upon optical bleaching. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Modeling transpiration and leaf temperature of urban trees – A case study evaluating the microclimate model ENVI-met against measurement data

2018

Abstract Increasing vegetation cover in cities is a key approach to mitigating urban heat excess. However, both the effect of vegetation on microclimate and the plants’ vitality need to be assessed to support and quantify the effects of such strategies. One way to assess the interactions between vegetation and the urban environment is through microclimate models that can simulate the effects of vegetation onto the urban microclimate as well as effects of urban environments onto vegetation. To provide reliable estimates microclimate models need to be parameterized based on empirically obtained data. In this paper we compare modeled transpiration rates and leaf temperatures of a leading micro…