1,721,393 research outputs found
Comparison between Laser Scanning and digital photogrammetry techniques used in the production of Digital Terrain Models (DTM) of landslides
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A mesoscopic mechanical model of the surface tension and some simulation results
Full text linkDrops of mercury do not spread on a surface. A metal paper clip can float on water. These phenomena are macroscopic manifestations of molecular interactions and can be explained in terms of surface tension. In this study, we discuss a simple mesoscopic mechanical model of the surface tension and the results of numerical fluid dynamics simulations implemented on the basis of it. We study the droplet formation without and with gravity when it can drop from a narrow hole like a trickling tap and finally the behaviour of free surface liquid in a vessel. Teachers and students can be able to study the surface tension by using the computer simulation as a "tool" for analysing and discussing the droplet and the liquid behaviour in several different conditions
A Study on Engineering Freshman Conceptual Understanding of Newtonian Mechanics
No full textForce concept inventory is a multiple-choice questionnaire commonly used to assess students’ conceptual understanding of Newtonian mechanics. We here show that a cluster analysis method can be used to study student answers to the force concept inventory to investigate their understanding of Newtonian mechanics and provide new insights into the use of the force concept inventory. We identi- fied groups of students characterized by similar correct answers as well as by non- correct answers to the questionnaire, whose analysis allowed us to highlight student misconceptions/non-normative conceptions. Such an analysis of student answers gave us insights into the relationships between the student ideas about the force concept and their ability to correctly answer questions involving the first and second Newton’s law
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
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
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
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