1,721,214 research outputs found
Biological markers of neurotoxic diseases
No full textThe paper describes relevant examples of biomarkers of neurotoxicity (biomarkers of exposure, effect, and susceptibility) that can be applied in cinical studies of neurotoxic disease
Versatile multi-channel CMOS frontend with selectable full-scale dynamics from 100 MeV up to 2.2 GeV for the readout of detector's signals in nuclear physics experiments
Full text linkWe developed a versatile multichannel CMOS frontend with selectable full-scale energy range from 100 MeV up to 2.2 GeV for the readout of detector's signals in nuclear physics experiments. The core of the frontend electronics is a custom designed CMOS charge preamplifier able to guarantee an energy resolution of the order of 10 keV FWHM with a power budget of about 10 mW/channel (ASIC only). 16-channel charge preamplifiers are integrated in a single chip in ams 0.35 μm C35B4C3 technology together with the CsI(Tl) frontend and few additional slow control services. A dedicated 8 layer frontend motherboard houses 2 ASICs and the line-drivers needed to provide a differential output and to drive the several-meter long connections. High-density right-angle open-pin-field connectors interconnect the motherboards and a patch-panel responsible of the slow-control and the interconnections to the meters-long cables. The designed frontend is extremely versatile, being suitable to be coupled to different detector topologies and signal polarities with capacitances ranging from about 10 pF up to about 200 pF. The first application of the developed frontend is to instrument the FARCOS (Fem-toscope ARray for Correlation and Spectroscopy) detection system, a novel detector featuring high angular and energy resolution able to reconstruct the particle's momentum at high precision and capable of performing correlation measurements of LCPs and of LCPs and IMFs. A thorough experimental qualification allowed verifying the frontend performance. The measured energy resolution with the frontend coupled with a 300 μm thick Double Sided Silicon Strip Detector (DSSSD) of the FARCOS telescope illuminated with a mixed-nuclei α source shows a resolution below 10 keV FWHM. The paper focuses on the designed frontend system and on the results of its qualification
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Peak-shape Fitting in Presence of Trapping Effects in High-Z Detectors
No full textWe studied a peak-shape function given by the convolution of a Gaussian term and a weighted sum of left-side exponential decay terms and we tested it on X- and gamma-ray spectra acquired by a CdTe detector. The interesting feature of the proposed function is that it well describes the combination of mutually independent variables: the Gaussian term featuring a symmetric probability-density function (e.g. electronic noise) and the tail terms modeling purely asymmetric ones (e.g. incomplete charge collection, trapping, etc.). Fitting results are in agreement with the expected carrier dynamics in presence of trapping and allow a more precise evaluation of noise, peak position and tailing effects
Feasibility Study of the Use of Operational Amplifiers as Forward Gain Stages in Charge Preamplifiers and Shaping Filters for Radiation Detectors
Full text linkDifferent application fields require the development of charge preamplifiers to be coupled with dedicated radiation detectors. In view of fast prototyping and targeting a medium number of readout channels, there are several advantages to the use of operational amplifiers (OpAmps) for the forward gain stage of charge preamplifiers and shaping filters. In this article, we present the feasibility study, design, and qualification of an OpAmp-based, charge preamplifier suited to equip a smart rad-hard detection system for the diagnostics and tagging of radioactive ion beams (RIBs) at high intensities (106 pps or higher). This article illustrates the conception and design of the fast readout system and presents a detailed analysis and qualification of its performance
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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