The capture cross sections of 241Am and 243Am were measured at the n_TOF facility at CERN in the epithermal energy range with a BaF2 Total Absorption Calorimeter. A preliminary analysis of the 241Am ...and a complete analysis of the 243Am measurement, including the data reduction and the resonance analysis, have been performed.
In this paper, the effects of acrylamide (AAm), methylcellulose (MC) contents, pH and ionic strength on kinetic, network and hydrophilic properties of polyacrylamide and methylcellulose hydrogels ...were investigated. The hydrogels were characterized by evaluating of network average molecular weight between crosslinks (M C), crosslink density (q) and the number of elastically effective chains (Ve), and kinetic parameters diffusional exponent (n), diffusion constant (k) and diffusion coefficient (D). Such properties were controlled by adjusting of the AAm, MC contents, pH and ionic strength factors. Due to high hydrophilicity and fast water-uptake, the PAAm-MC hydrogels can be considered as materials for potential applications in agricultural fields, mainly in controlled release of water or pesticides.
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The neutron-induced fission cross-section of
241
Am has been measured relative to the standard fission cross-section of
235
U between 0.5 and 20MeV. The experiment was performed at the CERN n_TOF ...facility. Fission fragments were detected by a fast ionization chamber by discriminating against the
-particles from the high radioactivity of the samples. The high instantaneous neutron flux and the low background of the n_TOF facility enabled us to obtain uncertainties of
5%. With the present results it was possible to resolve discrepancies between previous data sets and to confirm current evaluations, thus providing important information for design studies of future reactors with improved fuel burn-up.
Analyses the role of convenors in facilitating interorganisational collaboration. Consistent with previous research, shows that convenors help overcome the obstacles frequent in interorganisational ...collaboration processes. Also illustrates further how their effectiveness depends on their credibility among the partners, their familiarity with the collaborative project and their being perceived as unbiased intermediaries. (Original abstract - amended)
We have used the 4π BaF2 gamma-ray detector array at the n_TOF neutron time-of-flight facility at CERN for an experiment in order to determine the spins of resonances of n +87Sr by measuring the ...gamma-ray spectra and multiplicity distributions. The first results are presented here. We have assigned the orbital momentum ℓ to all evaluated resonances on the basis of their neutron widths. Further we have assigned the spin J to 16 s-wave resonances on based the population of low-lying levels.
To assess the systemic response of pigs to the intraperitoneal implantation of polypropylene mesh associated with chitosan-based film with a degree of deacetylation of 95%.
Blood samples were ...collected 24 hours before, and two and seven days after surgery. Systemic reactions were evaluated based on white blood cell count, C-reactive protein, and total serum protein, albumin and globulin levels.
The systemic response was proportional to the composite response induced by polypropylene mesh, and the tissue inflammatory response was higher in the PP group (p=0.0033).
The polypropylene mesh/chitosan-based film composite did not elicit a systemic response in pigs.
The main objective of the CDT project is to establish an engineering design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) that is the pilot plant of an industrial-scale of both an ...Accelerator Driven System (ADS) and a Lead Fast Reactor (LFR), based on the MYRRHA reactor concept, planned to be built during the next decade. An important issue regarding the reactor design of the MYRRHA/FASTEF experiment is the in-vessel fuel storage facility for fresh fuel, as it might have an impact on the criticality of the overall system that must be analyzed and quantified. In this work, the neutronic analysis of the in-vessel fuel storage facility and its coupling with the critical core was performed, using the state of the art Monte Carlo program MCNPX 2.6.0. Using this program several parameters were analyzed, like the criticality behavior (namely the K
eff
), the fission power production and the radiation damage (the displacements per atom).
New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent ...evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n_TOF data 1, has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n_TOF neutron flux.
The (n, α) reaction in the radioactive 59Ni is of relevance in nuclear astrophysics as 59Ni can be considered as the first branching point in the astrophysical s-process. Its relevance in nuclear ...technology is especially related to material embrittlement in stainless steel. However, there is a discrepancy between available experimental data and the evaluated nuclear data files for this reaction. At the n_TOF facility at CERN, a dedicated system based on sCVD diamond diodes was set up to measure the 59Ni(n, α)56Fe cross section. The results of this measurement, with special emphasis on the dominant resonance at 203 eV, are presented here.
Summary
Wood density measurement is related to several factors that influence wood quality. In this paper,
a CT image calibration procedure which allows image quantification in terms of dry bulk ...density is
presented for three different X- and gamma-ray energies (28.3, and 59.5, and 662.0 keV). The mass
attenuation coefficients measured for a set of eight wood species did not vary significantly, allowing
a single calibration for determination of bulk density of air-dried wood samples at each energy.
The equation for bulk density calibration obtained was validated using a second set of twelve
wood species. Comparison of bulk density determined by CT images, using the calibration procedure
proposed, with values obtained by gravimetric methods, presented a very good linear correlation
coefficient (R
2
=0.94). The main advantage of CT imaging over conventional techniques for
wood bulk density determination is that it allows detection and quantification of heterogeneities
and internal defects. At the sub-millimetric spatial resolution level, it is possible to identify morphological
and structural aspects of wood samples.
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