Leptogenesis with heavy neutrino flavours: from density matrix to Boltzmann equations

Leptogenesis with heavy neutrino flavours is discussed within a density matrix formalism. We write the density matrix equation, describing the generation of the matter-antimatter asymmetry, for an arbitrary choice of the right-handed (RH) neutrino masses. For hierarchical RH neutrino masses lying in the fully flavoured regimes, this reduces to multiple-stage Boltzmann equations. In this case we recover and extend results previously derived within a quantum state collapse description. We confirm the generic existence of phantom terms. However, taking into account the effect of gauge interactions, we show that they are washed out at the production with a wash-out rate that is halved compared to that one acting on the total asymmetry. In the N_1-dominated scenario they cancel without contributing to the final baryon asymmetry. In other scenarios they do not in general and they have to be taken into account. We also confirm that there is a (orthogonal) component in the asymmetry produced by the heavier RH neutrinos which completely escapes the washout from the lighter RH neutrinos and show that phantom terms additionally contribute to it. The other (parallel) component is washed out with the usual exponential factor, even for weak washout. Finally, as an illustration, we study the two RH neutrino model in the light of the above findings, showing that phantom terms can contribute to the final asymmetry also in this case.Comment: 39 pages, 5 figures; v2: added Appendix and discussion in 2.2 on lepton-antilepton flavour compositions difference (eq. (28) is a new result); footnotes 4 and 5; new effect of gauge interactions in inducing wash-out of phantom terms but with halved wash-out rate compared to the total asymmetry wash-out rate; matches JCAP versio

Integrated system to perform surrogate based aerodynamic optimisation for high-lift airfoil

This work deals with the aerodynamics optimisation of a generic two-dimensional three element high-lift configuration. Although the high-lift system is applied only during take-off and landing in the low speed phase of the flight the cost efficiency of the airplane is strongly influenced by it [1]. The ultimate goal of an aircraft high lift system design team is to define the simplest configuration which, for prescribed constraints, will meet the take-off, climb, and landing requirements usually expressed in terms of maximum L/D and/or maximum CL. The ability of the calculation method to accurately predict changes in objective function value when gaps, overlaps and element deflections are varied is therefore critical. Despite advances in computer capacity, the enormous computational cost of running complex engineering simulations makes it impractical to rely exclusively on simulation for the purpose of design optimisation. To cut down the cost, surrogate models, also known as metamodels, are constructed from and then used in place of the actual simulation models. This work outlines the development of integrated systems to perform aerodynamics multi-objective optimisation for a three-element airfoil test case in high lift configuration, making use of surrogate models available in MACROS Generic Tools, which has been integrated in our design tool. Different metamodeling techniques have been compared based on multiple performance criteria. With MACROS is possible performing either optimisation of the model built with predefined training sample (GSO) or Iterative Surrogate-Based Optimization (SBO). In this first case the model is build independent from the optimisation and then use it as a black box in the optimisation process. In the second case is needed to provide the possibility to call CFD code from the optimisation process, and there is no need to build any model, it is being built internally during the optimisation process. Both approaches have been applied. A detailed analysis of the integrated design system, the methods as well as th

A fuller flavour treatment of N_2-dominated leptogenesis

We discuss N_2-dominated leptogenesis in the presence of flavour dependent effects that have hitherto been neglected, in particular the off-diagonal entries of the flavour coupling matrix that connects the total flavour asymmetries, distributed in different particle species, to the lepton and Higgs doublet asymmetries. We derive analytical formulae for the final asymmetry including the flavour coupling at the N_2-decay stage as well as at the stage of washout by the lightest right-handed neutrino N_1. We point out that in general part of the electron and muon asymmetries can completely escape the wash-out at the production and a total B-L asymmetry can be generated by the lightest RH neutrino wash-out yielding so called phantom leptogenesis. Taking of all these new effects into account can enhance the final asymmetry produced by the decays of the next-to-lightest RH neutrinos by orders of magnitude, opening up new interesting possibilities for N_2-dominated thermal eptogenesis. We illustrate these effects for two models which describe realistic neutrino masses and mixing based on sequential dominance

Sistemazione and death: the role of the Wittenoom asbestos mine in the lives and deaths of Italian transnational workers

This doctoral thesis records the social history and sacrifices of Italian immigrants who worked and lived at the Wittenoom mine in Western Australia. The Italian miners contributed to Australia’s economic growth in the post-war period. Their lives are explored in the context of transnational migration, the mining of asbestos, and the roles of CSR and the regulatory authorities in the management of the mine and the accumulation of knowledge internationally on asbestos-related diseases. To provide the context for this thesis, Chapter One introduces several themes, some of which are taken up again later in the thesis. It provides a brief outline of asbestos-related diseases and the history of CSR and the Wittenoom mine, discusses the failure of the global asbestos industry to self-regulate, and provides an overview of asbestos litigation. Chapter Two discusses the methodological approach, which has been akin to that of a social historian or a detective. The approach differed in that the investigator was an insider, whose Italian background and ability to speak Italian facilitated rapport with participants. The approach combines oral history, the use of available photographs, archival searches and the Motley Rice papers obtained in the course of legal discovery by a US asbestos litigation firm. Chapter Three contextualises the participants’ stories about life in Italy within a brief discussion of Italy and Australia’s complementary migration objectives after World War 2. Italy needed to offload her millions of unemployed, and Australia wanted to increase her population to fill the jobs created as a result of the National Development Scheme; of which the Wittenoom mine was a part. Desperate to find work, 1,102 Italians, many with families, went to Wittenoom during the 1950s and 1960s. In Chapters Four, Five and Six, the men, women and children, in turn, talk about their lives in Wittenoom. The children’s accounts, most notably those of the boys, suggest that they enjoyed the Wittenoom lifestyle. The men and women speak of their first impressions, working and living conditions, gambling and drinking, their lack of knowledge about ARDs, their re-creation of important rituals and other efforts to make do. To establish the foundations for sistemazione, mainly Italians with families remained for longer periods than the typical four months. Chapter Seven outlines the Italians’ pathways to achieve sistemazione. The next chapter records the consequences of asbestos exposure, asbestosis and mesothelioma, years after workers and families had left Wittenoom. Using CSR/ABA Limited and the Departments of Mines and Health documents supplied by North American legal firm Motley Rice, in Chapter Nine it has been possible to reconstruct the conflicting and sometimes ambivalent positions of the public players in the Wittenoom tragedy. The documents also permit us to identify when government departments and CSR became aware of the health risks. CSR’s negligence and lack of duty of care are confirmed in their strategy planning during the 1970s, implemented in response to media attention on Wittenoom. Until this evidence entered the public domain, CSR would thwart the attempts of early victims to obtain damages

Planning the Integrated Management of Organic Waste Flows and Agricultural Residues for a Circular Economy

In the recent years, the production, management and disposal of both organic waste and agricultural residues has become significantly difficult in Italy, due to the lack of suitable facilities. Very often, indeed, within the different regions, there are no treatment plants for the organic fraction of municipal solid waste or agricultural residues treatment centres, so as to give them a second life in the perspective of a circular economy. The lack of proximity treatment centres, forces local administrations to send these flows to plants outside their territorial area, with a consequent increase for transport and treatment costs. This paper, with reference to the study area of the Matera municipality (Basilicata region - Southern Italy), taking into consideration the organic waste flows of non-domestic users from separate collection and agricultural residues - especially those coming from the wine production chain - provides a state-of-the-art analysis of the problems related to their collection, management and disposal. Subsequently, an alternative model feasibility study - called "proximity composting", aimed at a more sustainable management of these flows based on their “zero-kilometers treatment” – has been implemented. The results obtained have demonstrated that the proposed scenario is much more sustainable when compared to the current situation, both from an economic and environmental point of view. Indeed, thanks to the use of calculation tools, the economic (€/year) and environmental (Kg CO2 avoided/year) advantages, due to the save of transport and disposal of flows outside the region, have been quantified, with consequent reduction of waste tax for citizens (€/year). In addition, the implementation of maps using a Geographical Information System (GIS) has demonstrated a better optimization of the system. Finally, it was highlighted the social utility of the proposed model, because citizens become an active part in the process and self-produce soil fertilisers

In vivo genetic manipulation of inner ear connexin expression by bovine adeno-Associated viral vectors

We have previously shown that in vitro transduction with bovine adeno-associated viral (BAAV) vectors restores connexin expression and rescues gap junction coupling in cochlear organotypic cultures from connexin-deficient mice that are models DFNB1 nonsyndromic hearing loss and deafness. The aims of this study were to manipulate inner ear connexin expression in vivo using BAAV vectors, and to identify the optimal route of vector delivery. Injection of a BAAV vector encoding a bacterial Cre recombinase via canalostomy in adult mice with floxed connexin 26 (Cx26) alleles promoted Cre/LoxP recombination, resulting in decreased Cx26 expression, decreased endocochlear potential, increased hearing thresholds, and extensive loss of outer hair cells. Injection of a BAAV vector encoding GFP-tagged Cx30 via canalostomy in P4 mice lacking connexin 30 (Cx30) promoted formation of Cx30 gap junctions at points of contacts between adjacent non-sensory cells of the cochlear sensory epithelium. Levels of exogenous Cx30 decayed over time, but were still detectable four weeks after canalostomy. Our results suggest that persistence of BAAV-mediated gene replacement in the cochlea is limited by the extensive remodeling of the organ of Corti throughout postnatal development and associated loss of non-sensory cells

Perceptions and preconceptions about chicken and pork meat: A qualitative exploratory study of Argentine consumers in the metropolitan area of Buenos Aires

In the past, the Argentine livestock production system was based on the extensive breeding that used pastures. However, technological progress and the use of land for soybean production are leading to a strong intensification of beef production, with a negative impact on the environment. According to FAO data, Argentina has the third highest meat consumption in the world, half of which is beef. A change in diet is a long and difficult process. The first step in favor of the environment could be the replacement of beef with other types of meat that have a lower impact on the environment, such as chicken and pork. The purpose of this study is to understand the causes limiting the preference for these alternatives and to identify useful tools to encourage their consumption. The results show that the interviewed Argentine consumers in the Metropolitan Area of Buenos Aires have preconceptions about these two types of meat, such as the fact that hormones are still used in the chicken production system, that pork has higher cholesterol content than other meats, and that it carries diseases. These products are instead appreciated for their practicality of use, especially when purchased in portions, and they are not only tasty but also cheap

Simplex-Coded BOTDA Sensor Over 120 km SMF with 1 m Spatial Resolution Assisted by Optimized Bidirectional Raman Amplification

Bidirectional low-noise Raman amplification and simplex coding based on the return-to-zero modulation format are optimized through numerical simulations for long-range Brillouin optical time-domain analysis sensing. Experimental results are reported on sensing capabilities along 120-km distance with 1-m spatial resolution, and worst-case temperature and strain resolution values of 1.3 °C and 26 με, respectively

A rapid aerodynamic prediction method for unconventional transonic aircraft configurations

This paper presents some results comparing the use of the Full Potential equations, coupled with the turbulent integral boundary layer equations for aircraft transonic cruise analysis. Use of such a method in the conceptual design stage is shown to be capable of yielding accurate enough data in a few minutes on a single processor, where Navier - Stokes simulations on 100+ processors take several days

Experimental analysis on concrete blocks reinforced with Arundo donax fibres

Over the last decades, there has been growing attention in research and development on non-conventional building materials, such as vegetable fibres (e.g., flax, hemp, jute, etc.), to be used as eco-friendly materials in a wide range of applications in civil construction. The main reasons for this interest are related to the specific properties, price, and sustainability of natural fibres, which can be considered ‘green’ building materials. In this article, the tensile strength of a new type of fibre extracted from the stem of the Giant Reed Arundo donax L. has been investigated. First, these fibres, which widely grow in Mediterranean areas but are diffused worldwide as well have been extracted from the outer part of the plant stem. Then, in order to have an initial idea of their influence on the mechanical properties of concrete, some experimental bricks have been prepared, with the addition of different weight percentages of this vegetal fibre. Compression and tensile tests on the whole block have been performed to assess the mechanical properties of these bricks. Hence, the differences between concrete bricks without fibre and those reinforced with different weight percentages of natural fibre have been analysed, assessing their potential applications in bio-architecture