Introduction to neutrino astronomy

This writeup is an introduction to neutrino astronomy, addressed to astronomers and written by astroparticle physicists. While the focus is on achievements and goals in neutrino astronomy, rather than on the aspects connected to particle physics, we will introduce the particle physics concepts needed to appreciate those aspects that depend on the peculiarity of the neutrinos. The detailed layout is as follows: In Sect.~1, we introduce the neutrinos, examine their interactions, and present neutrino detectors and telescopes. In Sect.~2, we discuss solar neutrinos, that have been detected and are matter of intense (theoretical and experimental) studies. In Sect.~3, we focus on supernova neutrinos, that inform us on a very dramatic astrophysical event and can tell us a lot on the phenomenon of gravitational collapse. In Sect.~4, we discuss the highest energy neutrinos, a very recent and lively research field. In Sect.~5, we review the phenomenon of neutrino oscillations and assess its relevance for neutrino astronomy. Finally, we offer a brief overall assessment and a summary in Sect.~6. The material is selected - i.e., not all achievements are reviewed - and furthermore it is kept to an introductory level, but efforts are made to highlight current research issues. In order to help the beginner, we prefer to limit the list of references, opting whenever possible for review works and books.Comment: 15 pages, 5 figures. Accepted for publication The European Physical Journal Plus. Based on the lecture given at the "4th Azarquiel School of Astronomy", June 2017, Porto Paolo di Capo Passero, Syracuse (Italy) https://agenda.infn.it/conferenceDisplay.py?confId=1208

Sources of Excitation and Models for Cylindrical Gear Dynamics: A Review

In this paper, a review of the evolution of the study of cylindrical gear dynamics is presented. After a brief historical introduction to the field, the first attempts to describe the complex interactions in those systems are analyzed introducing the dynamic factor and the first methodologies used to compute it. Next, the sources of excitation in geared systems are analyzed in detail and the models of the various contributions are discussed. Then, the paper focuses on the use of those sources in several dynamic models which are wildly different in terms of scope, applicability, complexity and methodology employed, ranging from simple analytical models, to lumped masses models up to multibody and finite element models. Finally, an outlook to the future evolution of the field is given and conclusions are drawn

Crack propagation behavior in planet gears

Abstract Aim of this work is to investigate crack propagation paths in planet gears for aerospace applications in order to find how gears parameters may affect the crack path and, consequently, may provide information about gears design to avoid catastrophic failures. The research activity has been carried on by means of extended finite element models (XFEM). In particular, the effect of rim thickness (expressed as backup ratio) and crack initiation point on crack paths has been considered. Obtained results have been compared with those available for standard gears, to highlight the different behavior in crack propagation

A proposal of a unique formula for computing compliance in bolted joints

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Biochar Emerging applications

This reference text covers the latest developments in biochar materials research, a field which is becoming increasingly popular due to the potential of biochar to replace carbon materials derived from non-renewable sources. Emerging and innovative applications of biochar materials are discussed, and all aspects of the field are covered, from production to applications, including details on the techniques used. There is a particular focus on biochar as a material for composites and sensors. This is the first book to cover emerging applications of biochar as an innovative, versatile, carbon-based renewable material, beyond its traditional uses in agriculture. It is a valuable reference for all researchers in the fields of biochar and carbon materials, including industry practitioners

Investigation of crack propagation path in tube gears.

Abstract In this paper, the crack propagation behaviour in tube gears has been investigated. This kind of gear find application in aerospace and in particular in helicopter drivelines. For this reason, an accurate design against catastrophic failure due to particular crack propagation paths, has to be performed. In this work, the effect of tube length and rim thickness and also speed on crack propagation path has been analysed by means of extended finite elements models. In particular, to better understand the effect of speed, the changes in stress intensity factors KI and KII have been considered. Particular crack propagation shapes (wave propagation) have been found in some cases where the length ratio is particularly high

Rorschach Space responses and anger

In this study, three different subtypes of Space responses to the Rorschach test were hypothesized: S-fusion, S-reversal, and S-integration. The relationship between these subtypes and feelings of anger and aggression was investigated. The Rorschach test, the State-Trait Anxiety Inventory-2 (STAXI-2), and the Aggression Questionnaire (AQ) were administered to 50 university students. Scores on the STAXI-2 were positively associated with S-fusion and negatively associated with S-integration. No significant associations of S subtypes with aggression were found. The findings support the hypothesis that different figure-ground relationships, shown in the subtypes of S responses, indicate different psychological processes. </jats:p

Optimal preliminary design of variable section beams criterion

AbstractThe present paper discusses about optimal shape solution for a non-prismatic planar beam. The proposed model is based on the standard Timoshenko kinematics hypothesis (i.e., planar cross-section remains planar in consequence of a deformation, but it is able to rotate with respect to the beam center-line). The analytical solution for this type of beam is thus used to obtain deformations and stresses of the beam, under different constraints, when load is assumed as the sum of a generic external variable vertical one and the self-weight. The solution is obtained by numerical integration of the beam equation and constraints are posed both on deflection and maximum stress under the hypothesis of an ideal material. The section variability is, thus, described assuming a rectangular cross section with constant base and variable height which can be described in general with a trigonometric series. Other types of empty functions could also be analyzed in order to find the best strategy to get the optimal solution. Optimization is thus performed by minimizing the beam volume considering the effects of non-prismatic geometry on the beam behavior. Finally, several analytical and numerical solutions are compared with results existing in literature, evaluating the solutions' sensibility to some key parameters like beam span, material density, maximum allowable stress and load distribution. In conclusion, the study finds a critical threshold in terms of emptying function beyond which it is not possible to neglect the arch effect and the curvature of the actual axis for every different case study described in this work. In order to achieve this goal, the relevance of beam span, emptying function level and maximum allowable stress are investigated

Bio char as cheap and environmental friendly filler able to improve polymer mechanical properties

Composites and in particular polymer matrix composites (PMCs) have a growing interest in all the applications where both lightweight and mechanical properties are requested. At the same time, environmental problems force to study the low impact materials and, in particular, recycling materials are an added value. To meet both, the ever increasing demands of the PMCs market and develop environmental compatibility, bio based fillers from natural sources have gained substantial interest to reinforce polymer matrices. In this work we study biochar derived by maple based biochar (BC) and same BC heat treated (BCHT) used as carbon filler in epoxy resin (E0). Please click on the file below for full content of the abstract

Adapting towards resilience. Analysis of the construction features and dynamic energy performance of amphibious and floating houses

In the current scenario where urban areas are exposed to extreme climate phenomena, resilience of cities and buildings becomes fundamental. Thus, not only defensive, traditional actions, but also alternative solutions towards resilience need to be implemented. Amphibious and floating houses, still not investigated in literature, allow the building to adapt to water presence due to their specific construction and technical properties. Here, we consider such buildings’ typologies under the construction and thermal-energy performance lenses, by means of yearly dynamic energy simulations