1,721,102 research outputs found
DESIGN for ADDITIVE MANUFACTURING: IS IT AN EFFECTIVE ALTERNATIVE? PART 1 - MATERIAL CHARACTERIZATION and GEOMETRICAL OPTIMIZATION
Additive manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH stainless steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of finite element (FE) simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications
DESIGN for ADDITIVE MANUFACTURING: IS IT AN EFFECTIVE ALTERNATIVE? PART 2 - COST EVALUATION
Additive Manufacturing (AM) is becoming a more and more widespread (and trendy) approach. Its flexibility and capability to manufacture any topology has opened new possibilities: AM could lead to significant performance improvements thanks to the exploitation of lattice or reticular structures as partial replacement of the traditional solid design. The potential of this technology knows no bounds. However, in the real world, the lower performances of the materials and the high manufacturing costs significantly restrict the fields of application for which the adoption of AM results effective. In this context, the mechanical static and fatigue properties of a 17-4 PH Stainless Steel produced via AM were experimentally measured and compared with those of the wrought material to quantify the performance reduction. Based on these data, three components, namely a hip prosthesis, a blow plastic bottle die, and an automotive gear were selected as representative examples to show the pros and contra of AM. The three components were chosen because they belong to three quite dissimilar fields and are produced in different batch sizes. The three original designs were specifically optimized for AM by means of Finite Element (FE) Simulations. The new solutions fulfil the strength requirements of the original parts showing at the same time reduced weights and inertias. The traditional and new designs were compared in terms of production times and costs to quantify the real benefits of AM for different applications
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Imaging agents based on lanthanide doped nanoparticles
Nanotechnology has recently allowed us to design and prepare nanoplatforms with the potential to face currently unresolved problems. Among these platforms, nanoparticles in particular are versatile objects that find applications in many different areas. In the vast ensemble of materials that have been explored to obtain nanoparticles with improved performances, we here focus our attention on lanthanide-based nanocrystals. These recently developed species are extremely interesting and well known particularly for their ability to emit anti-Stokes shifted light (upconversion) with relatively high brightness. Many advantageous characteristics of such materials are emerging, and their use as multimodal imaging agents is rapidly growing. We here survey some recent examples on this subject, mainly focusing on systems having NIR-to-NIR emission properties for in vivo applications
Variations on the Author
“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
A fluorescence nanosensor for Cu2+ on silica particles
A fluorescence nanosensor for Cu2+ ions has been obtained by surface functionalization of silica particles with trialkoxysilane derivatized ligand and fluorescent dye
Letter: Combining 5-Aminolevulinic Acid Fluorescence and Intraoperative Magnetic Resonance Imaging in Glioblastoma Surgery: A Histology-Based Evaluation
Template Assisted Self-Organized Chemosensors
The self-organization of fluorescent dyes and receptors on a proper template to form an organized assembly is a new strategy for the realization of fluorescence chemosensors. In the assembly, the two subunits do not interact directly and the communication between the bound substrate and the dye is only determined by their spatial closeness ensured by the template. The method is simple and the main advantages are related to the minimization of the synthetic work, the ease of modification and optimization of the sensor, the possibility to tune its properties by the simple adjustment of the components ratio. Self-organizing methodologies can open new perspectives to fluorescence chemosensors, both by allowing a simplified preparation and by opening the way to new and more complex functions. This article deals with this new approach and discusses its evolution, applications, and limitations. (c) 2006 Elsevier B.V. All rights reserved
Appropriate Similarity Measures for Author Cocitation Analysis
We 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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