“Indicators to prevent university drop-out and delayed graduation. An Italian case”

International audiencePurposeResearch on the association between individual characteristics of undergraduate students, drop-out and delayed graduation is still evolving. Therefore, further evidence is required. The paper aims to discuss this issue.Design/methodology/approachThis paper reports on an empirical study examining the relationship between students' individual characteristics and delayed graduation. The analysis is based on a sample of 1,167 students who have registered on and have completed a full-time undergraduate programme in Italy. Using a Probit model, the findings document the individual, background and environmental indicators that play a role in explaining delayed graduation.FindingsThe study observes that students who commute to university perform better than those residing on campus. Other factors increasing the probability of completing the undergraduate programme on time include individual characteristics (e.g. gender and age), student background (family income, education), institutional environment (teaching and research quality) and student satisfaction. Finally, some policy implications are discussed.Social implications - A direct policy implication of these findings is that supporting academic staff in order to enhance their performance in both research and teaching has a positive effect on the performance of the students.Originality/valueThis paper contributes to the debate on the impact of institutional quality on students' performance, aiming to address the question of balance between teaching and research orientation

Electron localization and optical absorption of polygonal quantum rings

We investigate theoretically polygonal quantum rings and focus mostly on the triangular geometry where the corner effects are maximal. Such rings can be seen as short core-shell nanowires, a generation of semiconductor heterostructures with multiple applications. We show how the geometry of the sample determines the electronic energy spectrum, and also the localization of electrons, with effects on the optical absorption. In particular, we show that irrespective of the ring shape low-energy electrons are always attracted by corners and are localized in their vicinity. The absorption spectrum in the presence of a magnetic field shows only two peaks within the corner-localized state domain, each associated with different circular polarization. This picture may be changed by an external electric field which allows previously forbidden transitions, and thus enables the number of corners to be determined. We show that polygonal quantum rings allow absorption of waves from distant ranges of the electromagnetic spectrum within one sample.Comment: 10 pages, 12 figure

Exact finite reduced density matrix and von Neumann entropy for the Calogero model

The information content of continuous quantum variables systems is usually studied using a number of well known approximation methods. The approximations are made to obtain the spectrum, eigenfunctions or the reduced density matrices that are essential to calculate the entropy-like quantities that quantify the information. Even in the sparse cases where the spectrum and eigenfunctions are exactly known the entanglement spectrum, {\em i.e.} the spectrum of the reduced density matrices that characterize the problem, must be obtained in an approximate fashion. In this work, we obtain analytically a finite representation of the reduced density matrices of the fundamental state of the N-particle Calogero model for a discrete set of values of the interaction parameter. As a consequence, the exact entanglement spectrum and von Neumann entropy is worked out.Comment: Journal of Physics A (in press

Simulació de defectes en l'estructura atòmica de metalls i aliatges

Les propietats físiques dels materials amb estructura atòmica ordenada es veuen fortament modifi cades pels defectes en l'ordenació. Aquí es presenta un resum de la metodologia emprada en els estudis per simulació amb ordinador de defectes en metalls i aliatges. Com a exemple es descriuen alguns dels resultats obtinguts recentment pel nostre grup de recerca. En particular, es consideren els defectes que dominen la deformació plàstica (per lliscament de dislocacions i maclat), els produïts per indentació i els creats en materials irradiats

Sorra fina. Aproximació al món dels infants en un parvulari de l’àrea metropolitana de Barcelona, i contrast amb les teories de William A. Corsaro

L’objectiu principal d’aquest estudi és realitzar un aprofundiment en les teories del sociòleg William A. Corsaro sobre els infants com a grup social i confrontar-les amb les dades extretes durant el meu treball de camp realitzat en un parvulari públic de l’àrea metropolitana de Barcelona. El treball de camp es va desenvolupar entre febrer de 2006 i juny de 2007 i va consistir en introduir-me entre els infants a l’hora del joc lliure amb la tècnica de l’observació-participant. Vaig poder comprovar com gran part de les teories d’en Corsaro es reproduïen en aquest parvulari, tot i que amb variacions força remarcables. Es podria sostenir que la voluntat d’autocontrol dels infants així com la voluntat de comprendre la cultura dels adults donen origen a la cultura dels infants, la qual pren sentit en el moment en que es comparteixen coneixements i habilitats per garantir o facilitar aquestes voluntats

Documents i històries que falsejaven la realitat. Descripcions i discursos, reals o no, per construir noves esglésies al segle XVIII.

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