3,392 research outputs found
Post-test simulations for the NACIE-UP benchmark by STH codes
This paper illustrates the results obtained in the last phase of the NACIE-UP benchmark activity foreseen inside the EU SESAME Project. The purpose of this research activity, performed by system thermal–hydraulic (STH) codes, is finalized to the improvement, development and validation of existing STH codes for Heavy Liquid Metal (HLM) systems. All the participants improved their modelling of the NACIE-UP facility, respect to the initial blind simulation phase, adopting the actual experimental boundary conditions and reducing as much as possible sources of uncertainty in their numerical model. Four different STH codes were employed by the participants to the benchmark to model the NACIE-UP facility, namely: CATHARE for ENEA, ATHLET for GRS, RELAP5-3D© for the “Sapienza” University of Rome and RELAP5/Mod3.3(modified) for the University of Pisa. Three reference tests foreseen in the NACIE-UP benchmark and carried out at ENEA Brasimone Research Centre were analysed from four participants. The data from the post-test analyses, performed independently by the participant using different STH codes, were compared together and with the available experimental results and critically discussed
Large adiabatic temperature and magnetic entropy changes in EuTiO3
We have investigated the magnetocaloric effect in single and polycrystalline
samples of quantum paraelectric EuTiO3 by magnetization and heat capacity
measurements. Single crystalline EuTiO3 shows antiferromagnetic ordering due to
Eu2+ magnetic moments below TN = 5.6 K. This compound shows a giant
magnetocaloric effect around its Neel temperature. The isothermal magnetic
entropy change is 49 Jkg-1K-1, the adiabatic temperature change is 21 K and the
refrigeration capacity is 500 JKg-1 for a field change of 7 T at TN. The single
crystal and polycrystalline samples show similar values of the magnetic entropy
change and adiabatic temperature changes. The large magnetocaloric effect is
due to suppression of the spin entropy associated with localized 4f moment of
Eu2+ ions. The giant magnetocaloric effect together with negligible hysteresis,
suggest that EuTiO3 could be a potential material for magnetic refrigeration
below 20 K.Comment: 12 pages, 4 figure
Beta-decay half-lives and beta-delayed neutron emission probabilities of nuclei in the region below A=110, relevant for the r-process
Measurements of the beta-decay properties of r-process nuclei below A=110
have been completed at the National Superconducting Cyclotron Laboratory, at
Michigan State University. Beta-decay half-lives for Y-105, Zr-106,107 and
Mo-111, along with beta-delayed neutron emission probabilities of Y-104,
Mo-109,110 and upper limits for Y-105, Zr-103,104,105,106,107 and Mo-108,111
have been measured for the first time. Studies on the basis of the quasi-random
phase approximation are used to analyze the ground-state deformation of these
nuclei.Comment: 21 pages, 10 figures, article accepted for publication in Physical
Review
In vivo biodistribution and lifetime analysis of cy5.5-conjugated rituximab in mice bearing lymphoid tumor xenograft using time-domain near-infrared optical imaging
Rituximab is a chimeric monoclonal antibody directed against human CD20 antigen, which is expressed on B-cell lymphocytes and on the majority of B-cell lymphoid malignancies. Herein we report the conjugate of rituximab with the near-infrared (NIR) fluorophore Cy5.5 (RI-Cy5.5) as a tool for in vitro, in vivo, and ex vivo NIR time-domain (TD) optical imaging. In vitro, RI-Cy5.5 retained biologic activity and led to elevated cell-associated fluorescence on tumor cells. In vivo, TD optical imaging analysis of RI-Cy5.5 injected into lymphoma-bearing mice revealed a slow tumor uptake and a specific long-lasting persistence of the probe within the tumor. Biodistribution studies after intraperitoneal and endovenous administration were undertaken to evaluate differences in the tumor uptake. RI-Cy5.5 concentration in the organs after intraperitoneal injection was not as high as after endovenous injection. Ex vivo analysis of biologic tissues and organs by both TD optical imaging and immunohistochemistry confirmed the probe distribution, as demonstrated by imaging experiment in vivo, showing that RI-Cy5.5 selectively accumulated in the tumor tissue and major excretion organs. In summary, the study indicates that NIR TD optical imaging is a powerful tool for rituximab-targeting investigation, furthering understanding of its administration outcome in lymphoma treatment
β-Decay Half-Lives of 76;77Co, 79;80Ni, and 81Cu: Experimental Indication of a Doubly Magic 78Ni
published_or_final_versio
Identification of a millisecond isomeric state in 129Cd81 via the detection of internal conversion and Compton electrons
published_or_final_versio
Monopole-Driven Shell Evolution below the Doubly Magic Nucleus Sn132 Explored with the Long-Lived Isomer in Pd126
published_or_final_versio
Beta-decay of nuclei around Se-90. Search for signatures of a N=56 sub-shell closure relevant the r-process
Nuclear structure plays a significant role on the rapid neutron capture
process (r-process) since shapes evolve with the emergence of shells and
sub-shells. There was some indication in neighboring nuclei that we might find
examples of a new N=56 sub-shell, which may give rise to a doubly magic Se-90
nucleus. Beta-decay half lives of nuclei around Se-90 have been measured to
determine if this nucleus has in fact a doubly-magic character. The
fragmentation of Xe-136 beam at the National Superconducting Cyclotron
Laboratory at Michigan State University was used to create a cocktail of nuclei
in the A=90 region. We have measured the half lives of twenty-two nuclei near
the r-process path in the A=90 region. The half lives of As-88 and Se-90 have
been measured for the first time. The values were compared with theoretical
predictions in the search for nuclear-deformation signatures of a N=56
sub-shell, and its possible role in the emergence of a potential doubly-magic
Se-90. The impact of such hypothesis on the synthesis of heavy nuclei,
particularly in the production of Sr, Y and Zr elements was investigated with a
weak r-process network. The new half lives agree with results obtained from a
standard global QRPA model used in r-process calculations, indicating that
Se-90 has a quadrupole shape incompatible with a closed N=56 sub-shell in this
region. The impact of the measured Se-90 half-life in comparison with a former
theoretical predication associated with a spherical half-life on the
weak-r-process is shown to be strong
The aspectual-distribution of gerunds in Apulian varieties
In this paper we describe and analyze the distribution of embedded gerunds in the Apulian varieties, namely the Romance varieties spoken in the area of Bari. In these varieties gerunds are not found embedded un der the be/stay auxiliary to express the progressive aspect as in the Italian/English periphrases or progressives (). f Gerunds are only found embedded under the verb go in periphrases to express a reiterative meaning or embedded under the negated forms of be to express prohibition (the negative ). The different distribution of gerunds between standard Italian and Apulian varieties is then analyzed as a difference of the aspectual entailment encoded through the gerund morphology: while standard Italian encodes a general imperfective reading, Apulian varieties encode a more specific aspectual entailment, namely continuative aspect. Since Gerunds imply the syntactic embedding of the verb under a preposition, we propose that standard Italian and Apulian varieties differ on the covert preposition incorporated in the gerund inflectional morphology that imply a different aspectual reading.
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