1,720,973 research outputs found
The role of stereoelectronic effects on the side-chain fragmentation of alkylaromatic radical cations. The reactivity of 5-methoxy-2,2-dimethylindan-1-ol radical cation
No full textA kinetic and products study of the reaction of 2,2-dimethyl-5-methoxyindan-1-ol (1) radical cation, in acidic aqueous solution (pHless than or equal to4) has been carried out. 1(.+) undergoes C-H deprotonation as the exclusive reaction with k=4.6x10(4) s(-1). The kinetic data have been compared with those obtained for the radical cations of 1-(4-methoxyphenyl)ethanol (2) and 1-(4-methoxyphenyl)-2,2-dimethyl-1-propanol (3), suggesting that the deprotonation rate increases when the C-H bond is forced into a conformation where it is almost aligned with the pi-system. The conclusion that overlap between the scissile bond and the pi-system is an important requisite for the occurrence of bond cleavage is also supported by the results of DFT calculations carried out for 1(.+) and 3(.+). (C) 2002 Elsevier Science Ltd. All rights reserved
Advances in cultural heritage studies
No full textThe announcement of the creation of a European Year of Cultural Heritage (year 2018) by the Decision 2017/864 of the European Parliament – encouraged the creation, in 2017, of the European Students’ Association for Cultural Heritage (ESACH) ESACH has become the first still-growing interdisciplinary and cross-generational network in the field. Currently brings together young researchers and researchers at early stages of their careers, in the fields of culture and heritage, from all kinds of academic disciplines and is made up of members from various European universities and research centres (see www.esach.org).
Within the network, the main questions are: How do we engage with the past elements of our culture(s)? How and why do we protect culture as a genuine element of a contemporary cultural system? What do younger generations state as heritage and what ways do they see to safeguard and experience it? ESACH stands up for a participatory way of involvement and is eager to take part in the cultural discourse at European and national levels.
Since ESACHS’ foundation, the Portuguese publisher Mazu Press (www.mazupress.com) has been associated with the initiatives of the Portuguese branch of ESACH based in Lisbon (Sharing Heritage Lisbon), firstly with the promotion actions and then with the publication of the book “New Perspectives in Interdisciplinary Cultural Heritage Studies. Contributions of the European Students’ Association for Cultural Heritage in the European Year of Cultural Heritage 2018”.
In this atypical Covid-19 pandemic year, Mazu Press again invited ESACH to join the renewed idea of “unifying through Cultural Heritage”, creating the opportunity for all to associate their efforts to this volume of “Advances in Cultural Heritage Studies, Year 2020”. Until now, ESACH members have been given the opportunity to contribute their ideas in several European events organized by the respective stakeholders, such as the Genoa Meeting, in October 2019, which had the cultural, logistic and financial support of the University of Genoa and foremost the PhD Course in Study and Enhancement of the Historical, Artistic-Architectural and Environmental Heritage. This book brings together twenty chapters by twenty four authors from Canada, Greece, Ireland, Italy, Poland, Portugal, Slovakia, Spain and Turkey. This sharing of knowledge, culture and heritage studies, through various disciplines, shows the richness – advances and new perspectives – generated by the common passion for cultural heritage
STUDY ON THE INFLUENCE OF DEFECTS ON THE STRENGTH OF METALLIC HISTORICAL TIE-RODS
No full textThe presence of discontinuities in historical metallic elements is unavoidable owing to their ancient steel-making processes, which produced flaws ranging from microscale (i.e. cracks, inclusions, porosities, micro voids) to macroscale (i.e. welded joints to connect different bars). Therefore, an adequate assessment of their state of conservation cannot leave aside the understanding of the effects induced by material defects on the structural integrity. This work deals with the prestigious case study of historical metallic tie-rods of the Duomo di Milano. Because no information was available on the considered material, particularly dealing with fracture toughness, i.e. the property of withstanding brittle fracture in presence of a flaw, an Elasto-Plastic Fracture Mechanics (EPFM) approach, based on the J-Integral formulation, was investigated to take into account the larger scale of plasticity. This study is coordinated with another one exploiting NDT inspection techniques, to outline, in a damage tolerance perspective, a procedure for the structural assessment of historical metallic tie-rods
Effetto di prodotti di controllo biologico e di biostimolanti su Fusarium culmorum e frumento
No full textEDDY CURRENT NON-DESTRUCTIVE TESTING OF HISTORICAL METALLIC TIE-RODS
No full textDefects reduce the area of the resistant cross-section and produce stress concentration affecting the capacity of load bearing elements. Therefore, their detection is of fundamental importance in the assessment of structural integrity. Regarding historical metallic components, established Non-Destructive Techniques (NDT) are not suited to this purpose because the morphological features of these elements (i.e. heterogeneities, inclusions, corrosion, and surface roughness) boost the problem of false indications. Hence, the applicability of methods commonly used to inspect modern metallic elements has to be carefully evaluated and studied.
In this paper, the application of eddy current testing (ET) on the historical metallic tie-rods of Duomo di Milano is presented. Preliminary laboratory inspections were carried out on an original tie-rod of the cathedral characterized by a visible defect. The involved parameters (frequency, coil size and shape) were adjusted in order to reduce the effects of surface roughness and to increase the detectability of main discontinuities. Moreover, the operational improvements required by in situ application were recognized, allowing achieving a more efficient setup configuration. Interesting information on the manufacturing process were revealed, including a regular set of equally spaced welded joints.
A systematic inspection campaign was then performed in situ on seven active tie-rods. ET was carried out by using a very efficient customized probe. It was properly designed for this application in order to increase the penetration depth of the electromagnetic field and to enhance the sensitivity to welded joints compared to other minor defects. Each indication was classified in terms of magnitude of the recorded signal and documented via a detailed photographic survey.
The customized probe allowed recognizing efficiently just the most significant discontinuities, casting the base for more detailed inspections aimed at assessing the residual load bearing capacity of these historical structural elements
Metallurgical characterisation of a historical metal tie-rod from Milan Cathedral
No full textOne tie-rod from Milan Cathedral (15th century) recently broke in a defective cross-section. In order to infer the causes of failure, a metallurgical characterisation was performed, the results of which are discussed here. First, a visual inspection of the specimen was performed. Next, the fracture surface was analysed using a Scanning Electron Microscope (SEM) combined with Energy Dispersive X-Ray Spectrometry (EDXS) to detect the failure modes involved. A cross-section close to the failure surface was investigated by means of Stereoscopy, Light Optical Microscopy (LOM), SEM and EDXS in order to identify the microstructural compounds and characterise the slag inclusions. Vickers and Rockwell hardness tests were also carried out to correlate microstructural observations with mechanical properties. A strong relationship between failure and defects due to forging was observed, which is a particularly noteworthy result with regard to the representativeness of laboratory tests and the viability of in-situ inspection
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
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