1,720,976 research outputs found
Tantalum as Trabecular Metal for Endosseous Implantable Applications
Full text linkDuring the last 20 years, tantalum has known ever wider applications for the production of endosseous implantable devices in the orthopedic and dental fields. Its excellent performances are due to its capacity to stimulate new bone formation, thus improving implant integration and stable fixation. Tantalum’s mechanical features can be mainly adjusted by controlling its porosity thanks to a number of versatile fabrication techniques, which allow obtaining an elastic modulus similar to that of bone tissue, thus limiting the stress-shielding effect. The present paper aims at reviewing the characteristics of tantalum as a solid and porous (trabecular) metal, with specific regard to biocompatibility and bioactivity. Principal fabrication methods and major applications are described. Moreover, the osteogenic features of porous tantalum are presented to testify its regenerative potential. It can be concluded that tantalum, especially as a porous metal, clearly possesses many advantageous characteristics for endosseous applications but it presently lacks the consolidated clinical experience of other metals such as titanium
“Nora e il mare”: ricerche e tutela attorno agli spazi costieri della città antica
Full text linkIl contributo illustra i risultati delle ricerche condotte presso la città antica di Nora in Sardegna. Lo studio affronta il problema dell'innalzamento del livello marino e della sommissione di parte della città antica, le cui architetture forniscono indicatori di elevata rilevanza per lo studio del rapporto tra mutamenti climatici e contesto archeologico
Uomo e ambiente nell’area della necropoli fenicia e punica occidentale di Nora (Cagliari, Sardegna)
No full textThe paper presents the results of the investigations carried out at the west Phoenician and Punic necropolis of Nora (Sardinia, Italy), located near the northern limit of the isthmus joining the city’s promontory to the hinterland. In particular, the study is oriented to the analysis of the relationship between the anthropic activities documented here and the geological context, characterized
by the presence of a compact sandstone bank on which the necropolis was established. In the first phase (before 7th century B.C.E.), human intervention leads to the creation of a stepped quary; the area is then exploited for the creation of an incineration necropolis, used between the 7th and 6th centuries B.C.E. Later, in the Punic age, the thickness of the rocky bank was fully used for the construction of hypogeal chambers intended for burials, until, in the Roman age, massive stone material extraction operations were carried out
Two Methods of Optimization for an AR Project: Mesh Retopology and Use of PBR Materials
No full textIn an augmented reality project dealing with complex objects with a
large scale, it is necessary to minimize the number of polygons of a mesh. The
challenge is trying to find a compromise between accuracy, details and fluidity
of the representation. Starting from two different surveys (Laser Scanner and
Photogrammetry) with high resolution, two paths have been identified: the first
one consists on the retopology of the mesh obtained from the point cloud with
the help of software like Instant Mesh; the second one relies on the complete remodelling
of the artefact, trying to simplify its structure in macro-elements using
Retopoflow tool in Blender. The level of detail is preserved in both cases: in the
first, the “quad mesh” keeps complex geometries minimizing the number of
polygons; in the other an accurate management of texture of PBR materials
returns realism with simple shapes, with a lower number of polygons. These
methods have been applied to the reconstruction of San Lorenzo Bridge, one of
the ancient monuments of the Roman Padova no longer visible, examined by the
research project PD-Invisible. Results validate that the second method is more
effective, ensuring an excellent realism in the rendering phases, minimizing the
size of the file
Nora e il mare. La necropoli punica orientale: le nuove acquisizioni e il rischio idrogeologico
No full textIl contributo illustra i risultati del rilievo topografico condotto nella necropoli punica orientale di Nor
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
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