2,399 research outputs found
Land CSEM impulse responses in simple layered models
No full textWe argue that in a half space model with a single layer, the electric field impulse response at different offsets can be understood physically. Diffusive fields travel along paths like wavefields but are not localised in time. Each event that is measured comes from a path with the least attenuation, which corresponds to early arrival. The most prominent TE mode contribution to the detection of a subsurface layer comes from the coupling of the airwave with the subsurface. The most prominent contribution from the TM mode comes from the path through the resistive layer with almost vertical diffusion paths between the surface and the target. The arrival time of the peak of the event from a conductive layer can be understood from this reasoning. The arrival time of the peak of the event from a resistive layer can be understood from this reasoning when the offset is not too large compared with burial depth of the target layer. These predictions lead to estimates of depth to target layer with an error of less than 5% and the resistivity of the resistive layer of less than 50%. The information contained in the impulse responses suggests that inversion would yield good results.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Geophysics and Petrophysic
Molecular composition of the peri-islet basement membrane in NOD mice: a barrier against destructive insulitis
No full textAims/hypothesisThis study examined whether the capsule which encases islets of Langerhans in the NOD mouse pancreas represents a specialised extracellular matrix (ECM) or basement membrane that protects islets from autoimmune attack.MethodsImmunofluorescence microscopy using a panel of antibodies to collagens type IV, laminins, nidogens and perlecan was performed to localise matrix components in NOD mouse pancreas before diabetes onset, at onset of diabetes and after clinical diabetes was established (2-8.5 weeks post-onset).ResultsPerlecan, a heparan sulphate proteoglycan that is characteristic of basement membranes and has not previously been investigated in islets, was localised in the peri-islet capsule and surrounding intra-islet capillaries. Other components present in the peri-islet capsule included laminin chains alpha2, beta1 and gamma1, collagen type IV alpha1 and alpha2, and nidogen 1 and 2. Collagen type IV alpha3-alpha6 were not detected. These findings confirm that the peri-islet capsule represents a specialised ECM or conventional basement membrane. The islet basement membrane was destroyed in islets where intra-islet infiltration of leucocytes marked the progression from non-destructive to destructive insulitis. No changes in basement membrane composition were observed before leucocyte infiltration.Conclusions/interpretationThese findings suggest that the islet basement membrane functions as a physical barrier to leucocyte migration into islets and that degradation of the islet basement membrane marks the onset of destructive autoimmune insulitis and diabetes development in NOD mice. The components of the islet basement membrane that we identified predict that specialised degradative enzymes are likely to function in autoimmune islet damage.H. F. Irving-Rodgers, A. F. Ziolkowski, C. R. Parish, Y. Sado, Y. Ninomiya, C. J. Simeonovic, R. J. Rodger
Les temples A et C du Largo Argentina : quelques considérations
No full textAdam Ziolkowski, Les temples A et C du Largo Argentina : quelques considérations, p. 623-641.
Des quatre temples du Largo Argentina, deux, B et D, sont sûrement identifiés avec les sanctuaires de Fortuna Huiusce Diei et de Lares Permarini. Quant aux deux autres, le temple C est attribué à Feronia et le temple A soit à Iuno Curritis (F. Castagnoli), soit a Iuturna (F. Coarelli). Il semble, cependant, que l'existence, à l'intérieur de l'enclos sacré du temple C, d'un système de bassins et de fontaines artificielles, doive être mise en relation avec le culte de Iuturna. Cette attribution est confirmée par le fait que le temple B, fondé par Q. Lutatius Catulus cos. 102, fut construit à l'intérieur de l'enclos sacré du temple C. Or cette dépendance confirme l'identification du temple C avec le sanctuaire de Iuturna, bâti par l'ancêtre direct de Q. Catulus, C. Lutatius Catulus cos. 242. L'adoption de cette identification empêche d'attribuer le temple A, plus récent que le temple
(v. au verso) que le temple C, à Iuno Curritis dont le sanctuaire fut fondé par un des consuls de 241, c'est-à-dire en même temps que celui de Iuturna. Il en résulte que le temple A était dédié à Feronia; la date de sa construction se plaçant dans les années 230-220, le contexte politique, religieux et idéologique suggère, pour le rôle de son fondateur, la personne de L. Aemilius Papus Cos. 225, le vainqueur de Telamon.Ziolkowski Adam. Les temples A et C du Largo Argentina : quelques considérations. In: Mélanges de l'École française de Rome. Antiquité, tome 98, n°2. 1986. pp. 623-641
Investigations of Energy Conversion and Surface Effect for Laser-Illuminated Gold Nanorod Platforms
No full textAchieving a quick temperature increase is a burning issue for biophysical applications, like germ inactivation and tumor ablation, and for energy performances, like solar collectors and steam generators. Based on the plasmon resonance phenomenon, noble metallic nanoparticles have emerged as promising weapons due to their very high biocompatibility, optical properties, and high surface-to-volume ratio, increasing energy conversion and allowing the maximum temperature to be reached faster. This work examines the energy conversion in sandwiched glassy platforms with gold nanorods. The platforms are kept vertically in the air and illuminated by a 0.5 W near-infrared laser (808 nm). To describe this aspect theoretically, the size and conversion efficiency of the electromagnetic properties are compromised between the proposed model and the stability of the nanorods. As a research approach, our model of cross-sections and polarizability for the surface effect is proposed, coupled with classical CFD numerical calculations. The results of the proposed model, validated by a thermal camera and spectroscopy measurements, indicate that as long as the energy conversion is visible with relatively low-power lasers (ΔT = 18.5 °C), the platforms do not offer fast heat dissipation. The results indicate that, despite the flow forcing by the air inflow, the entropy generation due to heat conduction is more than three orders higher than the dynamic entropy production. Flow forcing corresponds to the value of the velocity for classical convective motions. Therefore, the delivered heat flux must be distributed via convective transport or the associated high-conductive materials
Pasquali, Giorgio
No full textVoce di enciclopedia che mette a fuoco, in modo conciso, il contributo di Giorgio Pasquali agli studi virgiliani
Hel doubled emission lines from A0535+26 equivalent to HDE 245770 - A possible interpretation
No full textWe report results of the spectroscopy for V725 Tau (HDE 245770, BD +26 degrees 883), commonly known as Flavia's star, which is the optical counterpart of the X-ray pulsar A0535+26, carried out at the 1.5 m Loiano telescope during one run of observations of this star spread over a period of years. The HeI emission lines clearly show doubling, which is good evidence for the presence of a disc. In this paper we critically discuss the possibility that this disc is a temporary accretion disc around the neutron star, a view that contrasts to the usual interpretation, which considers that this sort of doubling in the HeI emission lines is due to a disc formed by gas expelled from the Be star. In the former case the outer radius of the accretion disc could range from 5.9 x 10(10) cm to 2.1 x 10(11) cm, taking the most probable range into account for the orbital inclination of the binary system, from 35 degrees to 39 degrees. The presence of such a temporary accretion disc around the neutron star was predicted by Giovannelli & Ziolkowski (1990)
A search for point sources of EeV neutrons
No full textA thorough search of the sky exposed at the Pierre Auger Cosmic Ray Observatory reveals no statistically significant excess of events in any small solid angle that would be indicative of a flux of neutral particles from a discrete source. The search covers from -90° to +15° in declination using four different energy ranges above 1 EeV (1018 eV). The method used in this search is more sensitive to neutrons than to photons. The upper limit on a neutron flux is derived for a dense grid of directions for each of the four energy ranges. These results constrain scenarios for the production of ultrahigh energy cosmic rays in the Galaxy.Fil: Abreu, P.. Technical University of Lisbon; PortugalFil: Aglietta, M.. Università di Torino; ItaliaFil: Ahlers, M.. University of Wisconsin; Estados UnidosFil: Ahn, E. J.. Fermi National Accelerator Laboratory; Estados UnidosFil: Albuquerque, I. F. M.. Universidade de Sao Paulo; BrasilFil: Gomez Berisso, Mariano. Comisión Nacional de Energía Atómica. Gerencia de Área de Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (CAB); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zhou, J.. University of Chicago; Estados UnidosFil: Zhu, Y.. NorthInstitut für Prozessdatenverarbeitung und Elektronik; AlemaniaFil: Zimbres Silva, M.. Universidade Estadual de Campinas; Brasil. NYU Abu Dhabi; Emiratos Arabes UnidosFil: Ziolkowski, M.. Universitat Siegen; Alemani
Per il commento al De inventione del “magister Menegaldus”
No full textThe paper deals with the commentary on Cicero, De inventione which is commonly attributed to the “magister Menegaldus” (11th century) and which – although still unpublished – represents the first systematic commentary on the classical rhetorical handbook after Marius Victorinus (4th century). The paper shows in particular how the medieval glosae on the classical auctor propose many interesting changes which modify and really ‘update’ the auctoritas represented by Victorinus; and several among these changes are immediately accepted in another significant commentary on Cicero, De inventione, that is, the exposition of “magister Guillielmus” (perhaps William of Champeaux, 11th-12th century).
The passages from Menegaldus which are here considered can be divided in two main fields: the wide employment of quotations from other auctores (here e.g. Terence, Sallust, Vergil) and the references to the social and cultural context in which Menegaldus lives. These passages clearly point out that the medieval magister wants either to illustrate in a better way many rhetorical rules (which were explained by Cicero and Victorinus only in theory) or to make these rules nearer to his public
Search for a CP-odd Higgs boson decaying to Zh in pp collisions at root s=8 TeV with the ATLAS detector
No full textSee paper for full list of authors – 13 pages plus author list + cover pages (30 pages total), 5 figures, 2 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-06/International audienceA search for a heavy, CP-odd Higgs boson, , decaying into a boson and a 125 GeV Higgs boson, , with the ATLAS detector at the LHC is presented. The search uses proton--proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb. Decays of CP-even bosons to or pairs with the boson decaying to electron or muon pairs are considered, as well as decays with the boson decaying to neutrinos. No evidence for the production of an boson in these channels is found and the 95% confidence level upper limits derived for \sigma (gg\rightarrow A) \times \mbox{BR}(A \rightarrow Zh) \times \mbox{BR}(h \rightarrow f\bar{f}) are 0.098--0.013 pb for and 0.57--0.014 pb for in a range of 220--1000 GeV. The results are combined and interpreted in the context of two-Higgs doublet models
Bacterial inactivation via laser-driven gold nanoparticle heating: simulation and analysis
No full textThis study utilizes CFD technique to simulate the inactivation of E. coli bacteria within a microfluidic chamber, employing gold nanoparticles irradiated by a laser beam. Employing a single-phase model, the presence of bacteria is considered by treating thermal properties in the governing equations as effective, combining those of water and bacteria using established correlations from scientific literature. The conversion of light into heat is modeled with parameters derived from scientific literature, featuring a defined source term quantifying the converted light into heat. Introducing a User Defined Scalar (UDS) employing a first-order kinetic model described by the Arrhenius equation for the decay coefficient captures the bacteria’s response to irradiation. A dedicated User Defined Function (UDF) is developed to implement this model, allowing the simulation to account for the reduction in bacterial concentration over time. The results uncover intricate dynamics in bacterial response to laser-induced thermal effects, showcasing the potential for effective bacterial control. Furthermore, the model is rigorously validated against experimental data, affirming its accuracy and robustness in reproducing real-world thermal effects
- …
