1,721,207 research outputs found
Evaluación de riesgos laborales del personal sanitario en la planta octava del hospital universitario Corocota
No full textLuna Garcia, Cesar Gregorio; director de proyecto: Cano Galdón, Juan Manuel2024-2025Máster Universitario en Prevención de Riesgos LaboralesFacultad de Empresa y Tecnologí
Low lying excitations of few electrons in quantum dots
Full text link[Excerpt from the Introduction]: This thesis focuses on neutral excitations of few-electrons states in nanofabricatedQDsmeasured
by inelastic light scattering. The analysis of the spectra demonstrate that this technique can open a venue in the study of quasi-particles
at the nanoscale.
A model of electronic states confined in QDs is presented in the first chapter, while the second one provides a survey of the relevant experimental studies in this field. Special attention is paid to the process of inelastic light scattering by introducing a description of the selection rules for the scattering processes by electrons in semiconductor QDs. Chapter 3 describes the nano-fabrication techniques of doped AlGaAs/GaAs QDs and the different setups used for the measurements. Experiments performedwith μ-photoluminescence that demonstrate
the confinement and the homogeneity of the fabricated QDs are reported
at the end of this chapter.
Chapter 4 reports inelastic light scattering spectra fromQDs with many electrons.
In these experiments the atomic-like shell structure of the electronic states
is demonstrated. The framework used to describe this regime of highly populated
QDs is similar to the one used for transport experiments in the Coulomb
blockade regime.Observations of tunneling excitations in coupled quantumdots
with inelastic light scattering will also be presented.
The most innovative results of this work are presented in chapter 5 that
focuses on the study of interaction phenomena that take place in QDs in the few
electron regime. The correlations that occur among the electrons deeply affect
the inelastic light spectra in these systems. Themain outcome regards the case of
QDs with four electrons where strong correlation effects have been found in the
behavior of spin and charge collective excitations. Light scattering spectra from
these dots at zero and finite perpendicularmagnetic fieldswill be presented. The
evaluation of the excitation spectra as a function of the magnetic field reveals
a ground-state transition between correlated states of the four electrons with
different spin configurations
FIGURE 6 in Two new species of resupinate poroid fungi (Basidiomycota, Polyporaceae) from São Tomé and Príncipe Archipelago
No full textFIGURE 6. Porogramme principes (holotype LISU 254185). a) pores; b) section through basidiome; c) generative and skeletal hyphae; d) dendrohyphidia from the edge of dissepiments; e) basal hyphae; f) basidia and hymenial hyphidia; g) basidiospores; h) crystals. Drawing by I. Melo.Published as part of Melo, Ireneia, Salcedo, Isabel, Garcia, Cesar A. & Olariaga, Ibai, 2023, Two new species of resupinate poroid fungi (Basidiomycota, Polyporaceae) from São Tomé and Príncipe Archipelago, pp. 41-56 in Phytotaxa 607 (1) on page 51, DOI: 10.11646/phytotaxa.607.1.4, http://zenodo.org/record/821219
FIGURE 1 in Two new species of resupinate poroid fungi (Basidiomycota, Polyporaceae) from São Tomé and Príncipe Archipelago
No full textFIGURE 1. Best tree of the Maximum Likelihood analysis of Grammothele s.l. from ITS sequence data. Maximum Likelihood ultrafast bootstrap values (ML-BP) / Bayesian Posterior probabilities (PP) are shown on branches, ordered as ML-BP/PP. Thickened branches received support at least in one analysis (ML-BP ≥95 % and/or PP ≥0.95). Asterisks indicate full support in both analyses. Names recognized are indicated on the right side.Published as part of Melo, Ireneia, Salcedo, Isabel, Garcia, Cesar A. & Olariaga, Ibai, 2023, Two new species of resupinate poroid fungi (Basidiomycota, Polyporaceae) from São Tomé and Príncipe Archipelago, pp. 41-56 in Phytotaxa 607 (1) on page 47, DOI: 10.11646/phytotaxa.607.1.4, http://zenodo.org/record/821219
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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