379 research outputs found
Modified POF Sensor for Gaseous Hydrogen Fluoride Monitoring in the Presence of Ionizing Radiations
No full textThis paper describes the development of a sensor designed to detect low concentrations of hydrogen fluoride (HF) in gas mixtures. The sensor employs a plastic optical fiber (POF) covered with a thin layer of glass- like material. HF attacks the glass and alters the fiber transmission capability so that the detection simply requires a LED and a photodiode. The coated POF is obtained by means of low-pressure plasma-enhanced chemical vapor deposition that allows the glass-like film to be deposited at low temperature without damaging the fiber core. The developed sensor will be installed in the recirculation gas system of the resistive plate chamber muon detector of the Compact Muon Solenoid experiment at the Large Hadron Collider accelerator of the European Organization for Nuclear Research (CERN
Exposure-Tolerant Imaging Solution forCultural Heritage Monitoring
No full textThis paper describes a simple and cheap solution specifically designed for monitoring the degradation of thin coatings employed for metal protection. The proposed solution employs a commercial photocamera and a frequency-domain-based approach that is capable of highlighting the surface uniformity changes due to initial corrosion. Even though the proposed solution is specifically designed to monitor the long-time performance of protective coatings employed for the restoration of silver artifacts, it can be successfully used also for assessing the conservation state of other ancient metallic works of art. The proposed solution is made tolerant to exposure changes by using a procedure for sensor nonlinearity identification and correction, does not require a precise lighting control, and employs only free open-source software, so that its overall cost is very low and can be used also by not specifically trained operator
Handheld-Impedance-Measurement System with seven-decade capability and potentiostatic function
No full textThis paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 kΩ to 100 GΩ. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligibl
An "Entirely Personal Success": Intertextuality and Self-Reflexive Ironies in Henry James's "Pandora"
No full textHenry James’s “Pandora” has been read as a rewriting of his former treatment of the “American Girl abroad” in the comic mode. The self-allusive hints at “a Tauchnitz novel by an American author” (90) establish an ironic reversal of the failures of understanding which had led to tragedy in “Daisy Miller.” In this framework, well-known Jamesian topoi appear both as a self-parody and a metaliterary dialogue James engages with his readers and critics. The author’s personal implication in this “American” story is further testified by his Notebooks, in which he states his intention to write about his friends Henry and “Clover” Adams. Thus, “Pandora”’s multi-layered intertextuality also includes undeclared references to Adams’s anonymously published novel, Democracy, a semi-satirical account of U.S. political life. This article focuses on the web of intertextual relations woven in this short story with a view to reflecting on James’s ideas concerning the politics of authorship, readership, and literary success
Characterisation of seafloor imagery from the Sabrina Coast continental shelf
No full textProgress Code: completedStatement: Location information is based on the ship position, and interpolated along the track for the images based on start and end latitude and longitude and ship's speed. Positions are not corrected for layback between the vessel and the towed body.<b>Purpose</b><br/>Characterisation of seafloor habitats and taxa on the Sabrina Coast continental shelf.A total of 701 still images were analysed from 10 transects on the Sabrina Coast continental shelf. Imagery was collected from the RVIB Nathaniel B Palmer (NBP 14-02, 29 January - 16 March 2014) across a greater than 3000 km2 area. A 'yoyo' camera, with downward facing digital still and video cameras mounted within a tubular steel frame, was deployed on a coaxial cable to image the seafloor. The Ocean Imaging Systems DSC 10000 digital still camera (10.2 megapixel, 20 mm, Nikon D-80 camera) was contained within titanium housing. Camera settings were: F-8, focus 1.9 m, ASA-400. An Ocean Imaging Systems 3831 Strobe (200 W-S) was positioned 1m from the camera at an angle of 26 degrees from vertical. A Model 494 bottom contact switch triggered the camera and strobe at 2.5m above the sea floor, imaging ~ 4.8m2 of sea floor. Parallel laser beams (10 cm separation) provided a reference scale for the images. Transects were conducted at a ship's speed of ~1 knot. <br/>Still images were characterised for main taxonomic groups and sediment properties based on the CATAMI scheme of Althaus et al. 2015
The Colombian Constitutional Court and the Peace Process: Slowing Down the Fast-Track?
No full textThis contribution offers a critical analysis of the role of the Colombian Constitutional Court within the peace process through the prism of the recent judgment C-332/2017. The Court found partially unconstitutional the regulation of the “fast-track” legislative procedure, established in order to quickly implement the peace agreement between the Government and the FARC. Such procedure was introduced through a constitutional amendment, to which the Court applied the “replacement doctrine”. The author provides a contextualization of the judgment with respect to the former jurisprudence, the arguments in favor and against its outcome, as well as the overall position and self-understanding of the Court in the peace process
Language is purposeful. Some thoughts on teaching Systemic Functional Grammar
No full textThis volume is part of a Festschrift to celebrate the work of Donna R. Miller. The author is also one of the editors of this book. Her chapter suggests a reflection on the role of teaching grammar at university, with a specific focus on Systemic Functional Linguistics for non-native learners of English who aim to achieve a high level of proficiency in the English language. It is explicitly based on the guidance and inspiration Donna R. Miller gave her mentees and younger colleagues at the Department of Modern Languages, Literatures and Cultures (LILEC) of the University of Bologna. The chapter looks at the methodologies used to teach this subject at the LILEC Department, and on the advantages and disadvantages of teaching this grammatical formalism at BA level
Noninvasive Solution for Electrochemical Impedance Spectroscopy on Metallic Works of Art
No full textMetallic works of art of cultural relevance are continuously subjected to corrosion as the environment becomes increasingly polluted. A fast and simple method to in situ assess the conservation conditions is therefore required. This paper describes the development and performance of dry and gel-based electrodes which can be used to assess the surface conservation state without the need to move the artifacts and which do not cause any damage to them. The electrodes can be used with a portable electrochemical impedance spectroscopy system, without employing electrochemical cells. The proposed solution does not provide all the information that one can obtain using an electrochemical cell, but it can discriminate between protective coatings. It can be used to assess the protective capability of corrosion product layers and natural patinas, and it can therefore enable a noninvasive routine surface assessment to be conducted that could be extremely useful for people working in the field of conservation of cultural heritag
La administración en los EE.UU.: Un breve recorrido entre sus reformas hasta la crisis actual
No full textThis essay deals with the evolution of the administrative system of the United States emphasizing the specific features of its origin and its development until the current economic crisis. The author explains the aims and the basic characters of the waves of reforms that have affected it and finally focuses on topical issues. So she analyzes the recent health care reform, the one on the financial sector and the so called “sequester” and proposes comparative conclusions about the specificity of the American case with respect to the European situation.Este estudio aborda la evolución del sistema administrativo de los Estados Unidos resaltando las peculiaridades de su origen y de su desarrollo hasta la crisis económica actual. La autora explica los objetivos y los rasgos esenciales de las olas de reformas que lo han afectado a lo largo de las décadas y se centra finalmente en la actualidad. Para ello, abarca las recientes reformas de la sanidad, del sistema financiero y el “secuestro” y propone unas conclusiones comparadas sobre las peculiaridades del caso estadounidense respecto a la situación europea
Geographic and gender disparities in global education achievement during the COVID-19 pandemic
No full textSchool closures induced by the COVID-19 pandemic have negatively impacted on 1.7 billion children, resulting in losses of learning time and a decline of learning scores. However, the learning losses of students exposed to the COVID-19 pandemic at the country level have been quantitatively unaddressed. Here we model the global learning losses of students due to the COVID-19 in 2020. Our results reveal a global average Harmonized Test Scores (HTS) loss of 2.26 points. Learning continuity measures reduce the global average HTS loss by 1.64 points. South Asia and Sub-Saharan Africa have high HTS losses (5.82 and 2.94 points), while Europe & Central Asia and North America have low HTS losses (0.85 and 0.93 points). Compared with South Asia and Sub-Saharan Africa, North America and Europe & Central Asia implement more effective learning continuity measures. HTS losses in low-income and lower-middle-income countries are higher (3.35 and 3.13 points) than those in high-income and upper-middle-income countries (0.99 and 2.31 points). Learning losses of global female students are higher than their male counterparts, and there is significant heterogeneity across national regions. Our results reveal both global learning losses and gender inequality in learning scores due to the COVID-19 pandemic. Global disparities highlight the importance of the need to mitigate education inequality
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