800 research outputs found
Neutron-induced fission cross section of 234U and 237Np measured at the CERN Neutron Time-of-Flight (n_TOF) facility
No full textA high-resolution measurement of the neutron-induced fission cross section of 234U and 237Np has beenperformed at the CERN Neutron Time-of-Flight facility. The cross sections have been determined in a wideenergy range from 1 eV to 1 GeV using the evaluated 235U cross section as reference. In these measurements theenergy determination for the 234U resonances could be improved, whereas previous discrepancies for the 237Npresonances were confirmed. New cross-section data are provided for high neutron energies that go beyond thelimits of prior evaluations, obtaining important differences in the case of 237Np.© 2010 The American Physical Societ
Effects of COVID-19 lockdown on tumour burden of melanoma and cutaneous squamous cell carcinoma
No full textTejera-Vaquerizo, A (Tejera-Vaquerizo, Antonio); Paradela, S (Paradela, Sabela); Toll, A (Toll, Agusti); Santos-Juanes, J (Santos-Juanes, Jorge); Jaka, A (Jaka, Ane); Lopez, A (Lopez, Alba); Canueto, J (Canueto, Javier); Bernal, A (Bernal, Alvaro); Villegas-Romero, I (Villegas-Romero, Isabel); Fernandez-Pulido, C (Fernandez-Pulido, Carla); Perandones, H (Perandones, Hector); Moreno-Ramirez, D (Moreno-Ramirez, David); Dominguez-Mahamud, C (Dominguez-Mahamud, Carolina); Salido-Vallejo, R (Salido-Vallejo, Rafael); Sanmartin, O (Sanmartin, Onofre); Almazan-Fernandez, FM (Almazan-Fernandez, Francisco M.); Rodriguez-Jimenez, P (Rodriguez-Jimenez, Pedro); Banuls, J (Banuls, Jose); Podlipnik, S (Podlipnik, Sebastian); Sandoval-Clavijo, A (Sandoval-Clavijo, Alejandra); Boada, A (Boada, Aram); Garcia-Bracamonte, B (Garcia-Bracamonte, Beatriz); Palencia, S (Palencia, Sara); Revilla-Nevreda, D (Revilla-Nevreda, David); Reola-Ramirez, E (Reola-Ramirez, Enara); Gomez-Mateo, MD (del Carmen Gomez-Mateo, Maria); Linares-Barrios, M (Linares-Barrios, Mario); Jimenez-Gallo, D (Jimenez-Gallo, David); Gonzalez-Cruz, C (Gonzalez-Cruz, Carlos); Samaniego, E (Samaniego, Elia); Navedo-De Las Heras, M (Navedo-De Las Heras, Maria); Taberner, R (Taberner, Rosa); Rodenas-Herranz, T (Rodenas-Herranz, Teresa); Garcia-Donoso, C (Garcia-Donoso, Carmen); Puig, S (Puig, Susana); Nagore, E (Nagore, Eduardo
Satellite SAR interferometry for monitoring dam deformation in Portugal
No full textThe paper offers three examples of satellite SAR interferometry (InSAR) application for monitoring dam deformations: Paradela, Raiva and Alto Ceira, all of them in Portugal.
Dam deformations were estimated using several sets of ERS and Envisat C-band SAR data by PS-InSAR method that offers accuracy of a millimeter per year at monitoring man-made tructures.
The results show potential of InSAR but also summarize limits of C-band InSAR in these particular cases and can be handful to recognize applicability of new Sentinel-1 data (since 2014) for continuous monitoring of dam deformations.
While Alto Ceira dam lies in SAR radar shadow and was represented by only one observable point, and the movement detected (in satellite line-of-sight direction) appears to fit with geodetical measurements. Raiva and Paradela dams were represented by sufficient number of points feasible for PS-InSAR processing.
Deformations at slope near to Raiva dam and slow linear movements of the center of Paradela dam were detected
Advanced nuclear energy systems and the need of accurate nuclear data: The n-TOF project at CERN
No full textTo satisfy the world's constantly increasing demand for energy, a suitable mix of different energy sources has to be devised. In this scenario, an important role could be played by nuclear energy, provided that major safety, waste and proliferation issues affecting current nuclear reactors are satisfactorily addressed. To this purpose, a large effort has been under way for a few years towards the development of advanced nuclear systems with the aim of closing the fuel cycle. Generation IV reactors, with full or partial waste recycling capability, accelerator driven systems, as well as new fuel cycles are the main options being investigated. The design of advanced systems requires improvements in basic nuclear data, such as cross-sections for neutron-induced reactions on actinides. In this paper, the main concepts of advanced reactor systems are described, together with the related needs of new and accurate nuclear data. The present activity in this field at the neutron facility n\_TOF at CERN is discussed
Lanthanide Complexes with 1H paraCEST and 19F Response for Magnetic Resonance Imaging Applications
No full textWe present a detailed study of the lanthanide(III) complexes with cyclen-based ligands containing phenylacetamide pendants that incorporate CF3 group(s) at different distances from the metal ion. The complexes exhibit square-antiprismatic coordination in solution, as demonstrated by analysis of the Yb3+-induced paramagnetic shifts and the X-ray structure of the [YbL3] complex. Luminescence lifetime measurements and a detailed 1H and 17O relaxometric characterization confirmed the presence of an inner-sphere H2O molecule. The Tm3+ complexes provide chemical-exchange saturation-transfer response upon saturation at the frequency of the amide protons. A 19F relaxation study provided accurate estimates of the Ln···F distances that were used to rationalize the efficiency of the complexes as 19F magnetic resonance imaging (MRI) probes, which was tested in vitro using MRI phantom studies
Las políticas del post-conflicto en Colombia. Una aproximación a la potencialidad de la Cooperación Sur-Sur en el proceso de paz
No full textEl acuerdo entre e
Papéis e interfaces da gestão do conhecimento e da gestão de pessoas: estudo de caso em um laboratório clínico
No full textTCC (graduação) - Universidade Federal de Santa Catarina, Centro Sócio Econômico, Curso de Administração.O trabalho teve como objetivo analisar se as politicas e praticas de gestão de pessoas desenvolvidas pelo Laboratório Médico Santa Luzia contribuem positivamente para a gestão do conhecimento necessário para atuação na sua área. Quanto a abordagem ao problema de pesquisa, esta foi classificada como qualitativa e também quantitativa. Quanto aos seus objetivos, caracterizou-se como exploratória e descritiva. A estratégia de pesquisa utilizada foi a do estudo de caso. 0 campo de investigação foi o Laboratório Médico Santa Luzia, uma empresa prestadora de serviços na área da saúde por meio da realização de exames de analises clinicas. Os dados foram coletados com o uso de observações, pesquisa documental, entrevistas e questionários. Participaram da pesquisa 35 pessoas, entre empregados e gerentes dos setores Imunoquimica e Coleta. Identificados os fatores congruentes entre as políticas e práticas de gestão de pessoas, com base no referencial teórico, concluiu-se que. nesta empresa, muitas das políticas e práticas de gestão de pessoas contribuem positivamente para a gestão do conhecimento necessário para atuação em sua área, entretanto há determinados processos de gestão de pessoas que devem ser reorientados, a saber, o planejamento de pessoal, o treinamento e desenvolvimento com vistas à geração do conhecimento necessário ao futuro da empresa, a administração de cargos e salários, e o planejamento de carreira
High-resolution evaluation of the U5(n,f) cross section from 3 keV to 30 keV
No full textInternational audience235U neutron-induced fission cross-section is commonly used as reference for determining other isotope fission cross-section. However, below 150 keV this cross section is only included as Standard at the thermal point and recently its integral value between 7.8 eV and 11 eV [1]. The resolved resonance region, spanning up to 2.25 keV, has been reevaluated with high resolution in the last ENDF/B-VIII release [2] and a SAMMY resonance analysis was done by L. Leal et al. [3] including the CERN-nTOF experimental work of Paradela el al. [4] up to 10 keV, taken into account the IAEA Reference file.In this work the 235U(n,f) low-background and high-resolution experimental data obtained at the CERN-nTOF facility is combined with previous high-resolution experimental data, in order to produce a very fine grid dataset with normalisation to the IAEA Reference file. The extremelyhigh energy calibration required to reproduce the resonance sharp profiles is based on the nTOF DAQ system with a resolution below 0.1% with reference to the 8.78 eV resonance and to the sharp Al(n,g) capture dip at 5.904 keV.The comparison of the so-evaluated profile with the experimental data and with the evaluated ones will be discussed
The [1,2]-thio-Wittig rearrangement: evidence for a radical mechanism and its suppression
No full textThe lithium enolate formed from methyl S-trityl mercaptoacetate can be C-alkylated in high yield at or below -40 degrees C, but at higher temperatures the [1,2]-thio-Wittig rearrangement of the enolate is the predominant process; ESR evidence indicates that this rearrangement occurs by a radical mechanism
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