Fission fragment angular distribution measurements of U-235 and U-238 at CERN n_TOF facility

Neutron-induced fission cross sections of U-238 and U-235 are used as standards in the fast neutron region up to 200 MeV. A high accuracy of the standards is relevant to experimentally determine other neutron reaction cross sections. Therefore, the detection efficiency should be corrected by using the angular distribution of the fission fragments (FFAD), which are barely known above 20 MeV. In addition, the angular distribution of the fragments produced in the fission of highly excited and deformed nuclei is an important observable to investigate the nuclear fission process. In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs) has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new U-235(n,f) and U-238(n,f) data in the extended energy range up to 200 MeV compared to the existing experimental data.Postprint (published version

Datasets for transcriptomics, q-proteomics and phenotype microarrays of polyphosphate metabolism mutants from Escherichia coli

Indexación: Scopus.Author acknowledges Fondecyt Grants 1120209, 1121170 and Anillo ACT-1107Here, we provide the dataset associated with our research article on the polyphosphate metabolism entitled, “Multi-level evaluation of Escherichia coli polyphosphate related mutants using global transcriptomic, proteomic and phenomic analyses”. By integrating different omics levels (transcriptome, proteome and phenome), we were able to study Escherichia coli polyphosphate mutant strains (Δppk1, Δppx, and Δppk1-ppx). We have compiled here all datasets from DNA microarrys, q-proteomic (Isotope-Coded Protein Labeling, ICPL) and phenomic (Phenotype microarray) raw data we have obtained in all polyP metabolism mutants.http://www.sciencedirect.com/science/article/pii/S2352340917300860?via%3Dihu

High accuracy 235 U(n,f) data in the resonance energy region

The 235U neutron-induced cross section is widely used as reference cross section for measuring other fission cross sections, but in the resonance region it is not considered as an IAEA standard because of the scarce experimental data covering the full region. In this work, we deal with a new analysis of the experimental data obtained with a detection setup based on parallel plate ionization chambers (PPACs) at the CERN n_TOF facility in the range from 1 eV to 10 keV. The relative cross section has been normalised to the IAEA value in the region between 7.8 and 11 eV, which is claimed as well-known. Comparison with the ENDF/B-VII evaluation and the IAEA reference file from 100 eV to 10 keV are provide

Study of the 234U(n,f) fission fragment angular distribution at the CERN n_TOF facility

The angular distribution of the f ssion fragments (FFAD) produced in neutron induced reactions of actinides have been measured with a fission detection setup based on parallel-plate avalanche counters (PPACs) at the Neutron Time-Of-Flight (n_TOF) facility at CERN. The main features of the setup and preliminary results are reported here for the 234U(n,f) reaction measurement showing a high concordance with previous data, while providing new results up to 100 MeV.Postprint (published version

Co-pyrolysis of pre-treated biomass and wastes to produce added value liquid compounds

ABSTRACT: It is imperative to find novel environmental friendly liquid fuels to be used in the long distance transportation sector. Pyrolysis of wastes may have an important role in the near future to attain this goal. Biomass pyrolysis has also been widely studied by several researchers, but besides the potentialities of such technology, the bio-oil obtained still has to overcome some challenges related to its unsuitable properties to be used in conventional combustion devices. On the contrary, plastics pyrolysis produces oils, whose main compounds are hydrocarbons, thus they can be used in conventional engines without complex and high cost upgrading processes. Thus, co-pyrolysis of plastics blended with biomass may be a suitable option to produce alternative liquid fuels from wastes. The biomass selected for this study was Eucalyptus globulus wastes, because it has been mostly used in the pulp and paper industry in Iberian Peninsula, which has produced high amounts of wastes. On the other hand, PE (polyethylene) was the plastic chosen, because of the huge wastes amounts generated per year. With the aim of facilitating biomass pyrolysis and to increase the production of liquid compounds with suitable properties to be used as fuels, an alternative to the conventional biomass pyrolysis was studied. First eucalyptus wastes were pre-treated by diluted acid hydrolysis, which removed the hemicellulose fraction, produced added value sugar-based compounds and upgraded the remaining solids to better conditions for pyrolysis. Several pathways were studied, including untreated and pre-treated eucalyptus, blended with different contents of PE wastes. The best technical option is the co-pyrolysis of pre-treated eucalyptus mixed with PE, as the highest liquids yields were produced. However, this process needs to be further studied and the economic viability of the overall process still needs to be proven.info:eu-repo/semantics/publishedVersio

Effect of experimental conditions on co-pyrolysis of pre-treated eucalyptus blended with plastic wastes

ABSTRACT: Eucalyptus has been largely used in the pulp and paper industry in Iberian Peninsula, due to its fast growth and high productivity. This eucalyptus utilisation has generated high amounts of wastes, including leaves, branches and stumps. Hence, these wastes were selected for the co-pyrolysis studies to produce liquid fuels or raw materials. As an alternative to the conventional biomass pyrolysis, biomass was pre-treated under mild acidic conditions to obtain valuable sugar-rich stream to be used in fermentation and the solids rich in lignin were mixed with PE (polyethylene) wastes to be used in co-pyrolysis. The pre-treatment process seems to have weakened initial macromolecular structure of eucalyptus wastes and thus might have helped chemical bonds breakdown during co-pyrolysis. The results obtained so far have shown that PE presence seems to have favoured the biomass conversion. The effect of experimental conditions using Response Surface Methodology (RSM) was studied. There was a good agreement between theoretical and experimental data. The highest liquid yield (78 % wt) was obtained at 380 ºC and for the reaction time of 20 min. These conditions led to the lowest gases yield (7 % wt) and also to the lowest solids yield (14 % wt).info:eu-repo/semantics/publishedVersio

iTRAQ Quantitative Proteomic Analysis of Vitreous from Patients with Retinal Detachment

Rhegmatogenous retinal detachment (RRD) is a potentially blinding condition characterized by a physical separation between neurosensory retina and retinal pigment epithelium. Quantitative proteomics can help to understand the changes that occur at the cellular level during RRD, providing additional information about the molecular mechanisms underlying its pathogenesis. In the present study, iTRAQ labeling was combined with two-dimensional LC-ESI-MS/MS to find expression changes in the proteome of vitreous from patients with RRD when compared to control samples. A total of 150 proteins were found differentially expressed in the vitreous of patients with RRD, including 96 overexpressed and 54 underexpressed. Several overexpressed proteins, several such as glycolytic enzymes (fructose-bisphosphate aldolase A, gamma-enolase, and phosphoglycerate kinase 1), glucose transporters (GLUT-1), growth factors (metalloproteinase inhibitor 1), and serine protease inhibitors (plasminogen activator inhibitor 1) are regulated by HIF-1, which suggests that HIF-1 signaling pathway can be triggered in response to RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Nevertheless, the differentially expressed proteins found in this study suggest that different mechanisms are activated after RRD to promote the survival of retinal cells through complex cellular responses.CENTRO-07-ST24-FEDER-002014; POCI-01-0145-FEDER-007491; CNB-CSIC proteomics lab is a member of ProteoRed, supported by PRB2-ISCIII grant [PT13/0001]; Novartis Farma-Produtos Farmacêuticos; PhD fellowship of Sciences Faculty financed by ICI and Santander.info:eu-repo/semantics/publishedVersio