5,162 research outputs found

    Optical spectroscopy of a microsized Rb vapour sample in magnetic fields up to 58 tesla

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    We use a magnetometer probe based on the Zeeman shift of the rubidium resonant optical transition to explore the atomic magnetic response for a wide range of field values. We record optical spectra for fields from few tesla up to 60 tesla, the limit of the coil producing the magnetic field. The atomic absorption is detected by the fluorescence emissions from a very small region with a submillimiter size. We investigate a wide range of magnetic interactions from the hyperfine Paschen-Back regime to the fine one, and the transitions between them. The magnetic field measurement is based on the rubidium absorption itself. The rubidium spectroscopic constants were previously measured with high precision, except the excited state Land\'e gg-factor that we derive from the position of the absorption lines in the transition to the fine Paschen-Back regime. Our spectroscopic investigation, even if limited by the Doppler broadening of the absorption lines, measures the field with a 20 ppm uncertainty at the explored high magnetic fields. Its accuracy is limited to 75 ppm by the excited state Land\'e gg-factor determination

    Local flavour vs global audiences: Elena Ferrante and translatability

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    Through an analysis of the novels written under the pen name ElenaFerrante and of the paratextual elements that surround them, thisarticle examines the portrayal of Naples and its outskirts in thesenarratives, and how the specific geographical and cultural context isrendered and variously translated for different audiences. It arguesthat the concealment of the author’s identity has enhanced theperceived authenticity of the texts, and that the emphasis onmarginal backgrounds and subaltern characters entails a contradictionnot dissimilar to the phenomenon that Huggan (2001) describesas‘staged marginality’in the context of postcolonial narratives.Ferrante’s cultural specificity can therefore be read as a highlyambivalent discourse that entails both resistance and adherenceto the mechanisms of a global market. Lastly, the article examineshow the emphasis on dialect influences the process of translationfor diverse readerships, showing the relevance of the‘Ferranteproject’within world literature debates

    25th International Congress of the European Association for Endoscopic Surgery (EAES) Frankfurt, Germany, 14-17 June 2017 : Oral Presentations

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    Introduction: Ouyang has recently proposed hiatal surface area (HSA) calculation by multiplanar multislice computer tomography (MDCT) scan as a useful tool for planning treatment of hiatus defects with hiatal hernia (HH), with or without gastroesophageal reflux (MRGE). Preoperative upper endoscopy or barium swallow cannot predict the HSA and pillars conditions. Aim to asses the efficacy of MDCT’s calculation of HSA for planning the best approach for the hiatal defects treatment. Methods: We retrospectively analyzed 25 patients, candidates to laparoscopic antireflux surgery as primary surgery or hiatus repair concomitant with or after bariatric surgery. Patients were analyzed preoperatively and after one-year follow-up by MDCT scan measurement of esophageal hiatus surface. Five normal patients were enrolled as control group. The HSA’s intraoperative calculation was performed after complete dissection of the area considered a triangle. Postoperative CT-scan was done after 12 months or any time reflux symptoms appeared. Results: (1) Mean HSA in control patients with no HH, no MRGE was cm2 and similar in non-complicated patients with previous LSG and cruroplasty. (2) Mean HSA in patients candidates to cruroplasty was 7.40 cm2. (3) Mean HSA in patients candidates to redo cruroplasty for recurrence was 10.11 cm2. Discussion. MDCT scan offer the possibility to obtain an objective measurement of the HSA and the correlation with endoscopic findings and symptoms. The preoperative information allow to discuss with patients the proper technique when a HSA[5 cm2 is detected. During the follow-up a correlation between symptoms and failure of cruroplasty can be assessed. Conclusions: MDCT scan seems to be an effective non-invasive method to plan hiatal defect treatment and to check during the follow-up the potential recurrence. Future research should correlate in larger series imaging data with intraoperative findings

    Ash plume properties retrieved from infrared images: a forward and inverse modeling approach

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    We present a coupled fluid-dynamic and electromagnetic model for volcanic ash plumes. In a forward approach, the model is able to simulate the plume dynamics from prescribed input flow conditions and generate the corresponding synthetic thermal infrared (TIR) image, allowing a comparison with field-based observations. An inversion procedure is then developed to retrieve ash plume properties from TIR images. The adopted fluid-dynamic model is based on a one-dimensional, stationary description of a self-similar (top-hat) turbulent plume, for which an asymptotic analytical solution is obtained. The electromagnetic emission/absorption model is based on the Schwarzschild's equation and on Mie's theory for disperse particles, assuming that particles are coarser than the radiation wavelength and neglecting scattering. [...] Application of the inversion procedure to an ash plume at Santiaguito volcano (Guatemala) has allowed us to retrieve the main plume input parameters, namely the initial radius b0b_0, velocity U0U_0, temperature T0T_0, gas mass ratio n0n_0, entrainment coefficient kk and their related uncertainty. Moreover, coupling with the electromagnetic model, we have been able to obtain a reliable estimate of the equivalent Sauter diameter dsd_s of the total particle size distribution. The presented method is general and, in principle, can be applied to the spatial distribution of particle concentration and temperature obtained by any fluid-dynamic model, either integral or multidimensional, stationary or time-dependent, single or multiphase. The method discussed here is fast and robust, thus indicating potential for applications to real-time estimation of ash mass flux and particle size distribution, which is crucial for model-based forecasts of the volcanic ash dispersal process.Comment: 41 pages, 13 figures, submitted pape

    Electrospun Conjugated Polymer/Fullerene Hybrid Fibers: Photoactive Blends, Conductivity through Tunnelling-AFM, Light-Scattering, and Perspective for Their Use in Bulk-Heterojunction Organic Solar Cells

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    Hybrid conjugated polymer/fullerene filaments based on MEH-PPV/PVP/PCBM are prepared by electrospinning, and their properties assessed by scanning electron, atomic and lateral force, tunnelling, and confocal microscopy, as well as by attenuated total reflection Fourier transform-infrared spectroscopy, photoluminescence quantum yield and spatially-resolved fluorescence. Highlighted features include ribbon-shape of the realized fibers, and the persistence of a network serving as a template for heterogeneous active layers in solar cell devices. A set of favorable characteristics is evidenced in this way in terms of homogeneous charge transport behavior and formation of effective interfaces for diffusion and dissociation of photogenerated excitons. The interaction of the organic filaments with light, exhibiting specific light-scattering properties of the nanofibrous mat, might also contribute to spreading incident radiation across the active layers, thus potentially enhancing photovoltaic performance. This method might be applied to other electron donor-electron acceptor material systems for the fabrication of solar cell devices enhanced by nanofibrillar morphologies embedding conjugated polymers and fullerene compounds.Comment: 35 pages, 9 figure

    Jews in the Papal States between Western Sephardic Diasporas and ghettoization. A trial in Ancona as a case study (1555-1563)

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    Based on the analysis of a case study from Ancona, this article proposes to reread the beginning of the ghettoization in the Papal States (1555) within both the Western Sephardic Diasporas and the so-long Italian Wars (1494-1555). The breaking of an engagement that was celebrated in Ancona in the winter of 1555 (and therefore in the months which preceded the birth of the ghettos and the opening of proceedings against Marranos), and the lengthy legal controversy that followed it, which was argued in front of a regular Christian magistracy between 1555 and 1563, offers ideas for an effort to answer important questions

    Mapping the spatial variation of soil moisture at the large scale using GPR for pavement applications

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    The characterization of shallow soil moisture spatial variability at the large scale is a crucial issue in many research studies and fields of application ranging from agriculture and geology to civil and environmental engineering. In this framework, this work contributes to the research in the area of pavement engineering for preventing damages and planning effective management. High spatial variations of subsurface water content can lead to unexpected damage of the load-bearing layers; accordingly, both safety and operability of roads become lower, thereby affecting an increase in expected accidents. A pulsed ground-penetrating radar system with ground-coupled antennas, i.e., 600-MHz and 1600-MHz center frequencies of investigation, was used to collect data in a 16 m × 16 m study site in the Po Valley area in northern Italy. Two ground-penetrating radar techniques were employed to non-destructively retrieve the subsurface moisture spatial profile. The first technique is based on the evalu¬ation of the dielectric permittivity from the attenuation of signal amplitudes. Therefore, dielectrics were converted into moisture values using soil-specific coefficients from Topp’s relationship. Ground-penetrating-radar-derived values of soil moisture were then compared with measurements from eight capacitance probes. The second technique is based on the Rayleigh scattering of the signal from the Fresnel theory, wherein the shifts of the peaks of frequency spectra are assumed comprehensive indi¬cators for characterizing the spatial variability of moisture. Both ground-penetrating radar methods have shown great promise for mapping the spatial variability of soil moisture at the large scale

    Overcoming challenges in the classification of deep geothermal potential

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    The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed

    Entomological analysis for archeological reconstruction and conservation strategies design: the mummies of Cerreto di Spoleto (Central Italy)

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    Insects found in archeological contexts provide useful information for reconstructing past events. In the context of funerary archeology, insects may help in reconstructing funerary practices or rituals, and in the understanding of the taphonomic processes. Furthermore, studying these insects is fundamental for developing effective conservation strategies for cultural heritage. This article focuses on the entomological investigation of four mummies (nineteenth century) discovered in the church of Santa Maria Annunziata (Cerreto di Spoleto, Central Italy). The research aimed to verify and eventually support archeological hypotheses about the four bodies and to plan an effective conservation strategy. The predominant findings were Diptera puparia and adult Coleoptera. Alongside, common species typical of the hypogean burial, such as Hydrotaea capensis and several mycetophilous (mold feeder) species were also collected. The presence of blowfly remains (Calliphoridae) would suggest that the bodies were exposed before burial
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