1,721,080 research outputs found
An analysis of students’ misconceptions on Special Relativity
Full text linkSpecial Relativity is one of the key theories describing our reality but its accommodation among students at different level is still a critical issue. Even after instruction, students’ answers continue to be biased by Classical Mechanics. We present the analysis of high-school students’ answers to open questions concerning topics on Classical Mechanics and
Special Relativity showing the persistence of pre-relativistic reasoning. This study is part of an experimentation on the teaching of Special Relativity with the use of a mechanical instrument that allows students to explore by hand the effects of a change of reference frame
A teaching proposal for the didactics of Special Relativity: The spacetime globe
No full textSpecial Relativity introduces students to Modern Physics, whose importance in the high school is increasing. Nevertheless its teaching and learning is a critical issue. Different solutions have been developed to overcome the encountered difficulties. In this paper we describe the spacetime globe, a mechanical instrument that allows to experience Special Relativity hands-on. We show how it is possible to treat all the main phenomena foreseen by Special Relativity with simple laboratory experiences, using the idea of Minkowski's spacetime diagrams. The aim is to develop the use of geometrical approach in learning Special Relativity in high schools
The refiEXAFS station at the GILDA beamline (BM08) of ESRF
No full textThe experimental station for measuring X-ray absorption spectra in total reflection geometry operative at the GILDA CRG beamline of ESRF is described. The main features of the station are shown, namely: the possibility of detecting very small signals from thin (a few ML) samples, of depositing thin films under controlled conditions and thermal treating the samples in order to study dynamical processes. Case studies are reported in order to show the performances of the apparatus
Temperature modification of the Nb oxidation at the Nb/Al interface studied by reflEXAFS
No full textMultiple-order reflections from monochromating crystals for the collection of X-ray absorption spectra at extremely high energies
No full textA simple method to collect X-ray absorption spectra at extremely high energies (greater than or equal to 50 keV) is presented. The method is based on the use of the third harmonic signal from a conventional double-crystal monochromator. Strengths and limitations of the method are shown, together with a few experimental examples on metallic foils and oxide powders in transmission and fluorescence mode
Studio XAS dei processi coinvolti nella ritenzione del piombo e del nichel da parte dei terreni calcarei.
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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
First evidence of Cu-Ni alloy nanoclusters formation induced by double ion implantation in silica glass
No full textHighlights ESRF 1997/199
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