1,853 research outputs found
An experimental study on adhesive or antiadhesiveand strong bio-inspired nanomaterials
No full textThis experimental PhD thesis presents the results of research performed in five different facilities: in the Laboratory of Bio-inspired Nanomechanics "Giuseppe Maria Pugno" at the Politecnico of Torino, the "Nanofacility Piemonte" at the INRIM Institute in Torino, the Division of Dental Sciences and Biomaterials of the Department of Biomedicine at the University of Trieste, the Physics Department of the Politecnico of Torino, the Toscano- Buono Veterinary Surgery in Torino and the Department of Human and Animal Biology at the University of Torino. The adhesive abilities of insects, spiders and reptiles have inspired researchers for a long time. All these organisms present outstanding performance particularly for force, adhesion and climbing abilities, especially considering their size and weight. Scientists have focused attention on the gecko's adhesive paw system and climbing abilities, and its adhesion mechanism has been an important topic of research for nearly 150 years. However, certain phenomena about geckos are still not completely understood and nowadays these still represent the main challenge of several scientific discussions which aim to better understand the gecko's adhesive ability. This thesis deals first with the influence of surface roughness on the gecko's adhesion on the inverted surface of Poly(methyl meth-acrylate) (PMMA) and glass in Chapter 1, of PMMA with different surface roughness in Chapter 2, while Chapter 3 deals with the gecko's maximum normal adhesive force and Chapter 4 looks at the optimal adhesion angle at different hierarchical levels. The gecko's moult (Appendix 1) is examined in a preliminary way. The Tokay gecko (Gekko gecko) is the most studied gecko among more than 1050 Gekkonid lizard species in the world, due to its strong adhesive ability. Because this thesis reports clear experimental measurements on two living Tokay geckos, it is comparable to scientific results reported in the literature. It is well known how small insects can carry many times their own weight and can walk quickly, but their most interesting ability is their extremely high adhesion. In recent decades, many scientists have studied a number of insects in order to understand and measure their adhesive abilities. Biological adhesion can be obtained through different adhesive mechanisms (e.g. claw, clamp, sucker, glue, friction). In particular, this thesis focuses on living specimens of the non-climbing cockroach (Blatta Orientalis Linnaeus) by evaluating its maximum shear safety factor on artificial surfaces using a centrifuge machine, see Chapter 5. In general, the adhesive structure and mechanism of an animal could be connected to the micro-structured roughness of natural substrata (e.g. plant surfaces), which animals usually find when they move around in the natural environment. In nature, plants show an extraordinary variety of morphologies and surface structures. Some plants possess two special properties; superhydrophobicity (or water-repellency) and self-cleaning (or dirt-freedom). These two related phenomena were observed for the first time by Aristotle more than 2,000 years ago but it was only in the 20th century that scientists examined them accurately on some natural leaves, e.g. the lotus (Nelumbo nucifera) on which "raindrops take a clear, spherical shape without spreading, which probably has to be ascribed to some kind of evaporated essence", as Goethe described in 1817. Accordingly to scientific literature, a strong influence of surface roughness on wettability and self-cleaning behaviour clearly emerges. This well-defined problem was of particular interest (for the Indesit Company) since we wanted to find an industrial solution which would leave the internal sides of refrigerators clean from condensed water or dirt. For this reason, a collaborative project started. Two industrial processes, plasma and thermoforming treatments, were applied to polystyrene surfaces. The Indesit refrigerator box is made of polystyrene. The influence of these industrial treatments on the surface wettability were analysed, see Chapter 6. The focus of the Indesit Company was to understand the role of roughness and to produce a superhydrophobic and self-cleaning surface. Thus, this thesis reports the method which we developed in order to design an artificial biomimetic superhydrophobic polystyrene surface, copying the natural lotus leaf (Chapter 7). In addition, surface roughness implies a modification of the tribological and frictional properties, so it assumes a crucial role when designing two contacting surfaces, in particular at nano-scale (Chapter 8). The nanometer scale characterises this thesis and is involved in everything from gecko spatulae to the waxy nanotubules of the lotus leaf, to the fibroin protein materials which constitute spider silks. In general, spider silks display superior mechanical properties but, only in the last few decades, reserachers have studied various types of silks and have evaluated their very different mechanical properties. The fact that the mechanical behaviour of spider silks varies accordingly to their type is well-known, since silk properties have been demonstrated to be species-specific and are linked to silk-based peptide fibrils or protein aggregates, with different structural and mechanical properties. The dragline silk (or radial silk) and the flag silk (or circumferential silk) of orb weaving spiders have been characterized in scientific literature while, to our knowledge, few studies have been conducted on bundles, which connect the cocoons of Meta menardi to the ceiling of caves. These were tested to determine their mechanical properties in terms of stress, strain and toughness (Chapter 9
Book Preface in Esposito De Falco, S., Alvino, F., Cucari, N., & Lepore, L. (Eds.). (2019). Challenges and opportunities in Italian corporate governance.
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About hereditas, dignitas, adoptio and transmission of power in ancient Rome
No full textA review of the book «Hereditas, adoptio e potere politico in Roma antica» by Attilio Mastrocinque, Silvia Marastoni Beatrice Poletti, edited in Roma by Giorgio Bretschneider Editore in 2011 is presented. It has been translated into
Bulgarian in order to present this interesting and significant research of contemporary scholars of Roman history on the topic of inheritance law, which could be of scientific interest and be sought in the specialized libraries of some
European universities.The author of the review, Paolo Lepore, traces the main points of the authors – Attilio Mastrocinque, a full professor of Ancient studies and in particular the History of Rome at the University of Verona and two of his assistants: Silvia Marastoni and Beatrice Poletti. They are all devoted to the
complex and debated subject of the hereditary transmission of dignitas and of political and moral power in Rome from the Royal period to the Late Empire
Environmental disclosure: Critical issues and new trends
No full textThis book provides a description of the state of the art on environmental disclosure, illustrating the key theoretical issues, the regulatory frameworks, and the main standards developed and reporting the results of an empirical analysis on the environmental disclosure released by listed firms. Luigi Lepore and Sabrina Pisano begin by analysing the origin and evolution of environmental disclosure. They go on to provide a description of the main theoretical frameworks used by scholars, explaining the conceptual basis of each theory and describing how the specific theory has been used to explain the company's decision to release environmental disclosure. The second part of the book highlights the role and evolution of the European regulatory frameworks, emphasising the transition from voluntary to mandatory disclosure, and the major standards and guidance developed. The book ends by providing a picture of the evolution of sustainability reporting practices in European Union nations over the past two decades. This book investigates the critical issues and new directions in environmental disclosure, which are currently under examination by regulators and standard setters. It will therefore be of great interest to academics and students working in the areas of business and sustainability
Section III Preface "The role of Corporate Social Responsibility and innovation in business strategy", in Esposito De Falco, S., Alvino, F., Cucari, N., & Lepore, L. (Eds.). (2019). Challenges and opportunities in Italian corporate governance
No full textCorporate ownership structure and the effectiveness of the Corporate Governance statement in Italian companies
No full textSynthesis of HB lepore Boston in peripheral blood
No full textTwo sisters, double heterozygotes for Hb Lepore and βthalassemia, of Italian origin (Naples), were extensively studied because of their particularly mild clinical and hematological picture, rather unusual in this type of syndrome. Family studies were carried out, and two Hb Lepore heterozygous carriers (the mother and a sister) and two βthalassemia heterozygotes (the father and a brother) were identified. In vitro biosynthetic studies carried out in both a Hb Lepore carrier and the Hb Lepore/βthalassemia double heterozygotes indicated an evident incorporation of radioactivity into the chromatographic peak which structural studies demonstrated to be Boston (= Washington) type of δbeta;chain (i.e., δ87 Gln β116 His). The amounts of synthesis were roughly of the same order of magnitude as the relative levels of Hb Lepore in the red cell hemolysates, indicating the presence, in the reticulocytes of these subjects, of stable δbeta; mRNA molecules. These findings provide the opportunity to reconsider the current views indicating the instability of mRNAs as the cause of the low synthetic activity of the δbeta; and βdelta; fusion genes. © 1979 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
La “romanizzazione” dell’ Italía ionica: nuovi dati
No full textL'articolo pubblica i commenti critici di R. Belli Pasqua, M. Gras e G. Bejor redatti in occasione della presentazione ufficiale degli Atti del Convegno, curato da L. Lepore e C. Giatti, dal titolo "La romanizzazione dell’ Italía ionica. Aspetti e problemi, tenutasi a Firenze nel marzo 2019
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