Interpretation of AMS-02 electrons and positrons data

We perform a combined analysis of the recent AMS-02 data on electrons, positrons, electrons plus positrons and positron fraction, in a self-consistent framework where we realize a theoretical modeling of all the astrophysical components that can contribute to the observed fluxes in the whole energy range. The primary electron contribution is modeled through the sum of an average flux from distant sources and the fluxes from the local supernova remnants in the Green catalog. The secondary electron and positron fluxes originate from interactions on the interstellar medium of primary cosmic rays, for which we derive a novel determination by using AMS-02 proton and helium data. Primary positrons and electrons from pulsar wind nebulae in the ATNF catalog are included and studied in terms of their most significant (while loosely known) properties and under different assumptions (average contribution from the whole catalog, single dominant pulsar, a few dominant pulsars). We obtain a remarkable agreement between our various modeling and the AMS-02 data for all types of analysis, demonstrating that the whole AMS-02 leptonic data admit a self-consistent interpretation in terms of astrophysical contributions.Comment: 33 pages, 26 figures and 4 tables, v2: accepted for publication in JCAP, minor changes relative to v

PROCEDURAL MODELLING FOR HBIM OF ITALIAN RAILWAYS IRON BRIDGES

Abstract. The development of the railways network in the 19th century represented a significant scenario for the technological advancement of the entire Italian building sector; consequently, it produced a relevant renewal of construction techniques. Icons of this robust infrastructure building program were the railway bridges built over the Po river; their construction represented an arduous technological challenge. Unfortunately, in the years following the proclamation of the Kingdom of Italy the national industry was disorganized and unprepared to face this ambitious challenge; indeed, the first four bridges were built by foreign companies that could guarantee the necessary technological know-how. However, the industrial scenario immediately changed and the last two bridges were designed and built by Italian engineers and steelwork companies. The railway bridges over the River Po are now lost; the changing needs of railway traffic or bombings during the Second World War unavoidably led to their demolition. Their enhancement through 3d modelling and virtual representation is fundamental for the rediscovering of the role they played not only in the construction of the national infrastructural system but also in the life of the young state. To this aim, the paper proposes the outcomes of research that explores the potentialities of 3d software with Visual Programming Language (VPL), in order to create modelling tools useful for the disclosure and dissemination of the historical value of this lost heritage

THE LOST HERITAGE OF ROMAN IRON AND STEEL BRIDGES. VIRTUAL RECONSTRUCTION OF TWO CASE STUDIES

Abstract. In the second half of 19th century the city of Rome knew a period of great urban transformations: the Pope Pio IX and after, the government of the new Kingdom of Italy, strongly pushed the modernization of the ancient and underdeveloped city, trying to follow the examples of the main European capitals. One of the most relevant signs of that period was the construction of multiple iron and steel bridges along the Tiber, that were built to improve the crossing network guaranteed by the old masonry links. Different supporting systems were used and many experimental technologies for the Italian context were tested, representing a crucial phase for the settle of a design and an industrial know-how that was firstly imported from the most advanced countries of the Northern Europe. In the 20th century most of these connections were unfortunately replaced, losing this precious heritage which was strongly linked to the technological culture of the time. Garibaldi Bridge, still present but radically transformed, and Alari Bridge, completely demolished, have been accurately modelled thanks to the availability of appropriate archival documentation and on-site tests, applied following a proposed methodology. The virtual reconstruction of the two case studies permits to spread the knowledge of this lost heritage, to ease the divulgation of past technologies and to recover the unusual image of exposed iron and steel structures surrounded by the ancient panorama of the Eternal city.</p

HBIM AND THE 20TH CENTURY STEEL BUILDING HERITAGE – A PROCEDURE SUITABLE FOR THE CONSTRUCTION HISTORY IN ITALY

Abstract. The use of steel technologies in Italian architecture still represents an unexplored field of research, characterised by limited and fragmented episodes that reveal important design experimentations and relevant architectural results of the 20th century. For this reason, the aim of the research consists of defining a HBIM methodological approach addressed to the study of modern steel architectures, considering their specific features and their hybrid constructive nature. Indeed these buildings are often characterized by a high level of industrial production of building components merged with the recovery of a craftsmanship tradition, particularly appearing at the scale of structure and envelope details. The balance between standardization and traditional techniques in production processes, leads to the definition of a HBIM method composed of three steps: an operational tools for existing buildings of 20th century made of steel that could support the construction of building digital archives, the organisation of maintenance programs and possible transformative actions, avoiding the loss of this heritage sometimes caused by bad interventions that deeply change original and valuable features of these architectures.</p

Genome Sequencing of Ancient Plant Remains: Findings, Uses and Potential Applications for the Study and Improvement of Modern Crops

The advent of new sequencing technologies is revolutionizing the studies of ancient DNA (aDNA). In the last 30 years, DNA extracted from the ancient remains of several plant species has been explored in small-scale studies, contributing to understand the adaptation, and migration patterns of important crops. More recently, NGS technologies applied on aDNA have opened up new avenues of research, allowing investigation of the domestication process on the whole-genome scale. Genomic approaches based on genome-wide and targeted sequencing have been shown to provide important information on crop evolution and on the history of agriculture. Huge amounts of next-generation sequencing (NGS) data offer various solutions to overcome problems related to the origin of the material, such as degradation, fragmentation of polynucleotides, and external contamination. Recent advances made in several crop domestication studies have boosted interest in this research area. Remains of any nature are potential candidates for aDNA recovery and almost all the analyses that can be made on fresh DNA can also be performed on aDNA. The analysis performed on aDNA can shed light on many phylogenetic questions concerning evolution, domestication, and improvement of plant species. It is a powerful instrument to reconstruct patterns of crop adaptation and migration. Information gathered can also be used in many fields of modern agriculture such as classical breeding, genome editing, pest management, and product promotion. Whilst unlocking the hidden genome of ancient crops offers great potential, the onus is now on the research community to use such information to gain new insight into agriculture

Light-Controlled Direction of Distributed Feedback Laser Emission by Photo-Mobile Polymer Films

We report on the realization of Distributed Feedback (DFB) lasing by a high-resolution reflection grating integrated in a Photomobile Polymer (PMP) film. The grating is recorded in a recently developed holographic mixture basically containing halolakanes/acrylates and a fluorescent dye molecule (Rhodamine 6G). The PMP-mixture is placed around the grating spot and a subsequent curing/photo-polymerization process is promoted by UV-irradiation. Such a process brings to the simultaneous formation of the PMP-film and the covalent link of the PMP-film to the DFB-grating area (PMP-DFB system). The PMP-DFB allows lasing action when optically pumped with a nano-pulsed green laser source. Moreover, under a low-power light-irradiation the PMP-DFB bends inducing a spatial readdressing of the DFB-laser emission. This device is the first example of a light-controlled direction of a DFB laser emission. It could represent a novel disruptive optical technology in many fields of Science, making feasible the approach to free standing and light-controllable lasers

Investigation on the topological optimization of cooling channels for extrusion dies

During the extrusion process, high temperatures are generated, due to friction and deformation works, potentially leading to profile and die defects. Among the suggested solutions aimed at controlling the thermal field of the process, the most accredited one involves the manufacturing of cooling channels at the mating face between the die and a third plate. Despite the proven efficiency of well-designed channels, the main drawback lies in the managing of the many variables involved that strongly affect the cooling efficiency and balancing. In this frame, aim of the work is to investigate the applicability of the topological optimization tool, proposed by COMSOL Multiphysics software, for the design of cooling channels in extrusion dies. To validate the tool, an industrial case study has been selected and results compared between not optimized and optimized cooling solutions