11,331 research outputs found

    The public safety zones around small and medium airports

    Get PDF
    Proper planning around airports safeguards the surrounding territory from risks of air accidents. Many countries have defined Public Safety Zones (PSZs) beyond the runway thresholds as a result of targeted risk assessment methods. Therefore, national aviation Authorities could limit building construction and industrial development in order to contain the risk for dwellers to be involved in aircraft accidents. The number of people who live, work or congregate in these areas should be limited. The procedure to set Public Safety Zones is based on advanced technical analyses for major infrastructures. For smaller airports, simplified schemes are used, but, sometimes, they are not as effective when considering the actual safety conditions. This article aims to identify the shape and size of the Public Safety Zones for small and medium one-runway airports. The influence of the volume and mix of traffic on the PSZ geometry has been evaluated using the program named SARA (Sapienza Airport Risk Analysis); the results are correlated with the current Risk Plans generally adopted in Italy. According to the air traffic, the Risk Plans are characterized by a dynamic definition and fit the results obtained from risk assessment

    INFLUENCE OF MATERIAL CHARACTERIZATION IN THE DESIGN OF TUNNEL LIGHTING INSTALLATIONS

    Get PDF
    The paper describes the influence of the characterisation of reflectance behaviour of tunnel pavements and wall materials on the tunnel lighting design. CIE 189 document suggests considering lambertian behaviour for inter-reflection calculations for road luminance evaluation at design stage, because, unfortunately, no bi-directional reflection data for tunnel surfaces are commonly available. This simplification is supported by the low impact of inter- reflection contribution to road luminance. A European funded research project ha the task of developing the metrological support for the road surface characterisation in new geometries of measurements. The paper suggests to apply the outcomes on new geometries to tunnel wall materials characterisation suggesting that the suggested SURFACE observation angle of 2.29° can be useful for short tunnel too, including wall surfaces

    Female-owned innovative startups in Italy: status quo and implications

    Get PDF
    The aim of the paper is to provide an overview of the current literature of this business phenomenon with regard to gender studies and to point out what is substantially happening and what has happened in the Italian economic context. The main research questions were RQ1: How is the phenomenon of female Startups treated from a scientific point of view? RQ2: Which is the Italian situation of this phenomenon? The methodology used is both qualitative and explorative. A bidirectional analysis has been carried out for this purpose. In order to expand the first research question (RQ1), an analysis was carried out of the articles in the EBSCO database on the topic of female startups. In order to expand the second question (RQ2), an analysis was carried out on the data concerning the phenomenon of female startups, using the register of companies held at the Chambers of Commerce which were territorially competent. Our research, carried out within the Italian economic context, demonstrates how the phenomenon of Woman Startups (WSU), even if it is widely expanding, is inherent in all the typical elements of female entrepreneurship, as reported in the literature by gender scholars. The main factors that emerge for the WSU are the small size and the undercapitalization in the startup phase. This work contributes to the expansion of studies on the topic of startups in the context of gender and can be useful to the social context, new entrepreneurs, and practitioners of the sector

    Distinctive pattern and translational control of mitochondrial protein synthesis in rat brain synaptic endings

    Get PDF
    Mitochondrial gene expression has been investigated in synaptic endings from rat cerebral cortex isolated at various stages during the postnatal development and maturation of the animal. The pattern of the mitochondrial translation products labeled in vitro in rat brain synaptosomes revealed some distinctive features when compared with the pattern observed in a rat fibroblast cell line, the most remarkable being the apparent absence of labeling of the ND5 product. This absence contrasted with the presence in synaptosomes of an amount of ND5 mRNA comparable with that found in the rat fibroblast cell line. The rate of mitochondrial protein synthesis per unit amount of mtDNA inbrain synaptosomes showed a characteristic reproducible burst at 10-13 days after birth, thereafter declining sharply in the 3rd week to reach a level that remained constant over a 2-year period. The postnatal burst of mitochondrial protein synthesis coincided with a sharp increase in cytochrome c oxidase activity, pointing to a phase of rapid assembly of respiratory complexes. A comparison of the levels of mitochondrial mRNAs with the corresponding rates of protein synthesis during the animal development and maturation showed a lack of correlation. These observations, together with the apparent lack of translation of the ND5 mRNA, indicate that translational control plays a major role in the regulation of gene expression in rat brain synaptic mitochondria

    Risk analysis in the surrounding areas of one-runway airports: A methodology to preliminary calculus of PSZs dimensions

    Get PDF
    The risk analysis of aeronautical accidents has been faced in several countries in order to plan the territory around airports. In the past, many accidents have had serious consequences in the surrounding of airports. To protect the dwellers in these zones, Sapienza University of Rome has studied a risk assessment model of air crash accident during take-off or landing. In force of an agreement with the National Aviation Authority, the major Italian airports have been analyzed. These studies have highlighted the opportunity to know the influence on the territory of the variation of the traffic volume. This knowledge can be particularly useful for forecasting the impact on the territory in a preliminary phase of the master planning activity of the airport. The influence of the traffic volume and the types of aircraft on the sizes of safety areas around airports has been studied with a computer program developed by the authors. As a result of this first analysis, a simplified approach to study the extension of the Public Safety Zones around an airport is presented. This method calculates the area and the main dimensions of PSZs for a number of representative cases of one-runway airports with more than 30000 operations per year. In Europe, there are a large number of one-runway airports and they have similar operational and traffic conditions. Therefore, the results here presented can be applied for a preliminary study to all the one-runway airports, having the same level of traffic of the airports considered in this paper

    On a generalization of the Dvoretzky-Wald-Wolfowitz theorem with an application to a robust optimization problem

    Get PDF
    A generalization of the Dvoretzky-Wald-Wolfowitz theorem to the case of conditional expectations is provided assuming that the σ\sigma-field on the state space has no conditional atoms.Comment: 10 page

    Line-Recovery by Programmable Particles

    Full text link
    Shape formation has been recently studied in distributed systems of programmable particles. In this paper we consider the shape recovery problem of restoring the shape when ff of the nn particles have crashed. We focus on the basic line shape, used as a tool for the construction of more complex configurations. We present a solution to the line recovery problem by the non-faulty anonymous particles; the solution works regardless of the initial distribution and number f<n−4f<n-4 of faults, of the local orientations of the non-faulty entities, and of the number of non-faulty entities activated in each round (i.e., semi-synchronous adversarial scheduler)

    Comparative life cycle assessment of lighting systems and road pavements in an Italian twin- tube road tunnel

    Get PDF
    This work calculates and discusses the Life Cycle Assessment (LCA) of four scenarios composed of two types of road pavements and two types of lighting systems to be built in an Italian twin-tube road tunnel. A 20-year time horizon is adopted to assess the burdens of construction and maintenance of both flexible and rigid pavements and high-pressure sodium (HPS) and lightemitting diode (LED) lamps, traffic, and switching on of lamps. All considered scenarios are comparable with each other in terms of technical performances, but significantly differ regarding their environmental consequences. The geometrical and technical characteristics of the examined scenarios comply with current Italian standards for highways. In all the examined cases, LCA is carried out according to the European standard, EN 15804, and includes 19 impact categories (IC). The analysis demonstrates that the use of more reflecting surface pavement materials (i.e., concrete vs. asphalt) and more performing lighting systems (i.e., LED vs. HPS) can effectively mitigate the deleterious burdens related to road construction, maintenance, and use. For most of the examined ICs, the most environment-friendly scenario has LED lamps and concrete pavement
    • …
    corecore