1,721,008 research outputs found
Metamateriali tra materia e microstruttura. Nuovi paradigmi per il design
Get PDFL’argomento oggetto di studio, tratta di una recentissimo filone di ricerca nel campo dei nuovi materiali: i metamateriali (metamaterials), materiali non disponibili in natura, le cui proprietà non dipendono solo dalla composizione chimica, ma principalmente dalla composizione realizzativa della propria struttura, acquisendo quindi la peculiarità di rispondere in maniera preprogrammata ed esotica, ad una specifica sollecitazione. In particolare sono stati approfonditi i metamateriali meccanici (mechanical metamaterials), che a differenza dei metamateriali elettromagnetici, sono caratterizzati da proprietà e fenomeni meccanici definiti dall’architettura della loro trama dispositiva che permette un movimento direzionale controllato tramite funzionalità meccaniche.
Il carattere di originalità della ricerca si installa in relazione alle enormi possibilità di trasferimento tecnologico, dalla ricerca di base, di nuovi materiali, sia al contrario come il design possa guidare la realizzazione di nuovi materiali (material design driven) attraverso la progettazione di nuove prestazioni esperienziali di prodotti. La ricerca parte dall’analisi di un brevetto di compliant mechanism: un meccanismo flessibile costituito da una cerniera con una doppia trave concentrica con spessori differenti, per arrivare alla proposta di applicazione sperimentale di una montatura di occhiali
Micromanipulation: A Challenge for Actuation
No full textManipulating micro objects has become an important task in several applications. Actuation is a crucial aspect of micromanipulation because there are physical restrictions which affect actuators’ performances at the micro or nano scale. One way of getting rid of these limitations is the use of an appropriate mechanical structure which enhances the elasticity of the material or provides mechanical advantage. This Special Issue of Actuators, which is dedicated to micromanipulation, offers a contribution to the development of some promising methods to actuate a microsystem for micromanipulation
A new concept compliant platform with spatial mobility and remote actuation
No full textThis paper presents a new tendon-driven platform with spatial mobility. The system can be obtained as a monolithic structure, and its motion is based on the concept of selective compliance. The latter contributes also to optimizing the use of the material by avoiding parasitic deformations. The presented platform makes use of lumped compliance with three different kinds of elastic joints. An analysis of the platform mobility based on finite element analysis is provided together with an assembly mode analysis of the equivalent pseudo-rigid body mechanism. Surgical operations in laparoscopic environments are the natural fields of applications for this device
Functional Synthesis of a New Class of Micro Electro-Mechanical Systems
No full textThis paper discloses a new method of functional synthesis of a new class of MEMS (Micro Electro-Mechanical Systems) that could be conceived thanks to: (a) a new concept flexural hinge (that has been recently patented by the Author) and (b) the accurate detection of a MEMS device pseudo-rigid-body equivalent mechanism, which allows the application of several classic algorithms well known in kinematic synthesis. The adopted approach is explained and two examples are presented. Finally, basic information is provided for the MEMs technology based construction process that has been used for prototyping.This paper discloses a new method of functional synthesis of a new class of MEMS (Micro Electro-Mechanical Systems) that could be conceived thanks to: (a) a new concept flexural hinge (that has been recently patented by the Author) and (b) the accurate detection of a MEMS device pseudo-rigid-body equivalent mechanism, which allows the application of several classic algorithms well known in kinematic synthesis. The adopted approach is explained and two examples are presented. Finally, basic information is provided for the MEMs technology based construction process that has been used for prototyping
On the Development of CSFH MEMS-Technology based Micro Robots
No full textThe demand of micromanipulation has been in- creasing, during the last decades, in several fields of applications, including microelectronics, minimal invasive surgery, and aerospace. This paper illustrates how a recently developed flexure hinge gave rise to some developments in the fields of micromanipulation and how it could be used for the design of new concept micro robots.https://youtu.be/7j-0Lyn360
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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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