A High-Resolution Resistive Probe for Nonlinear Analysis of Two-Phase Flows

Two-phase flow dynamics are highly complex, due to the strong coupling of various independent mechanisms and as demonstrated by the existence of a variety of flow patterns. The adoption of appropriate tools for nonlinear time series analysis tools may lead to a deeper insight in this complexity but requires high quality time series. This study describes a procedure appositely assessed in order to realise an impedance void fraction sensor of resistive type characterised by high-spatial and -temporal resolution. These characteristics have been accomplished through an appropriate geometrical design of the probe electrodes, aiming at obtaining a thin measurement volume so to improve the probe spatial resolution, and through the electronic assessment of the data acquisition system, improving its temporal resolution. A new calibration procedure has been also defined, based on an estimation of void fraction through a code for automatic extraction of bubble contours and the correction of image distortions

Application, validation and comparison in different geographical contexts of an integrated model for the design of ecological networks

The issue of the fragmentation of natural habitats is increasingly at the core of the scientific debate, yet it is not taken into account in planning tools, with particular reference to the dynamism and complexity of landscapes. As it has been recognised at a European level, in order to enable different species to remain in good functional status, a network of green infrastructures is required. The concept of “ecological island” is no longer sufficient to adequately protect the fauna and the ecosystem it lives in. As a consequence, ecological islands must turn into ecological networks. The Ecological connectivity refers to the way habitats are physically connected to each other and how easy it is for species to move in. Good ecological connectivity is fundamental to the effective conservation of biodiversity considering that most species and ecological functions provided by ecosystems (ecosystem services) require a much wider space than that available within the boundaries of a single protected area. The main objective of this paper is to critically compare the application of a model for the design of ecological networks to two very different environmental contexts. This model was first tested in a Mediterranean area (the Province of Reggio Calabria) in 2008; the goal was to integrate the traditional (physiographic and functional) approaches into the design of ecological networks by taking into account biological and orographic elements as well as the anthropic structure of the territory. In 2011, within the ECONNECT European project, the model was applied to the pilot region of South-Western Alps (including the French region of Provence-Alpes - Côte d’Azur and the Italian regions Piedmont and Liguria), which is one of the richest transnational districts in Europe in terms of biodiversity. In such a region, the issue of multidisciplinary ecological connectivity was tackled in order to provide a series of proposals aiming at the development of the ecological potential of the area. The two applications allowed to further investigate the strengths and weaknesses of the implemented model by integrating its validation with information on faunal presence, which obviated one of the major limitations occurred in the first application

Safety performance assessment of food industry facilities using a fuzzy approach

The latest EU policies focus on the issue of food safety with a view to assuring adequate and standard quality levels for the food produced and/or consumed within the EC. To that purpose, the environment where agricultural products are manufactured and processed plays a crucial role in achieving food hygiene. As a consequence, it is of the utmost importance to adopt proper building solutions which meet health and hygiene requirements and to use suitable tools to measure the levels achieved. Similarly, it is necessary to verify and evaluate the level of safety and welfare of the workers in their working environment. The safety of the workers has not only an ethical and social value but also an economic implication, since possible accidents or environmental stressors are the major causes of the lower efficiency and productivity of workers. However, the technical solutions adopted in the manufacturing facilities in order to achieve adequate levels of safety and welfare of the workers are not always consistent with the solutions aimed at achieving adequate levels of food hygiene, even if both of them comply with sectoral rules which are often unconnected with each other. Therefore, it is fundamental to design suitable models of analysis that allow assessing buildings as a whole, taking into account both health and hygiene safety as well as the safety and welfare of workers. Hence, this paper proposes an evaluation model that, based on an established study protocol and on the application of a fuzzy logic procedure, allows evaluating the global safety level of a building. The proposed model allows to obtain a synthetic and global value of the building performance in terms of food hygiene and safety and welfare of the workers as well as to highlight possible weaknesses. Though the model may be applied in either the design or the operational phase of a building, this paper focuses on its application to certain buildings already operational in a specific productive context

Polyhedral Oligomeric Silsesquioxane Based Catalyst for the Efficient Synthesis of Cyclic Carbonates

In this work, the synthesis of a novel imidazolium-based polyhedral oligomeric silsesquioxane (POSS-mim-Cl) material is presented. The new nanometer-size organosilica based compound was employed for chemical fixation of CO2 into epoxide under homogeneous conditions. The target reaction was represented by the obtention of cyclic carbonates starting from epoxides and CO2. Particularly, styrene oxide was chosen as reference substrate. In addition, different parameters (solvent, temperature, pressure of CO2, and mass of the catalyst) were modified to find the best condition for CO2 conversion. The catalyst POSS-mim-Cl displayed good catalytic performances, the best results being obtained at 40 bar of CO2, 150\ub0C, with 110 mg of catalyst and using isopropanol as co-solvent. It is worth to mention that POSS-mim-Cl displayed better catalytic performance than the corresponding 1-butyl-3-methyl imidazolium chloride. As far as we know this study represents the first use of imidazolium-based POSS as catalysts for the chemical fixation of CO2

Multi-sector mitigation strategies at the neighbourhood scale

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Educational cosmic ray experiments with Geiger counters

Experiments concerning the physics of cosmic rays offer to high-school teachers and students a relatively easy approach to the field of research in high energy physics. The detection of cosmic rays does not necessarily require the use of sophisticated equipment, and various properties of the cosmic radiation can be observed and analysed even by the use of a single Geiger counter. Nevertheless, the variety of such kind of experiments and the results obtained are limited because of the inclusive nature of these measurements. A significant improvement may be obtained when two or more Geiger counters are operated in coincidence. In this paper we discuss the potential of performing educational cosmic ray experiments with Geiger counters. In order to show also the educational value of coincidence techniques, preliminary results of cosmic ray experiments carried out by the use of a simple coincidence circuit are briefly discussed

Exergonomic optimization of an air conditioning system

In this paper, exergonomic theory is applied to an air-conditionin

Non-linear simulations of combustion instabilities with a quasi-1D Navier-Stokes code

As lean premixed combustion systems are more susceptible to combustion instabilities than non-premixed systems, there is an increasing demand for improved numerical design tools that can predict the occurrence of combustion instabilities with high accuracy. The inherent non-linearities in combustion instabilities can be of crucial importance, and we here propose an approach in which the one-dimensional Navier-Stokes and scalar transport equations are solved for geometries of variable cross-section. The focus is on attached flames, and for this purpose a new phenomenological model for the unsteady heat release from a flame front is introduced. In the attached flame method (AFM) the heat release occurs over the full length of the flame. The non-linear code with the use of the AFM approach is validated against results from an experimental study of thermoacoustic instabilities in oxy-fuel flames by Ditaranto and Hals [Combustion and Flame, 146, 493-512 (2006)]. The numerical simulations are in accordance with the experimental measurements and both the frequencies and the amplitudes of the resonant acoustic pressure modes are reproduced with good accuracy.Comment: Submitted for publication in "Journal of Sound and Vibration" (30 pages, 8 figures

Application, validation and comparison in different geographical contexts of an integrated model for the design of ecological networks

The issue of the fragmentation of natural habitats is increasingly at the core of the scientific debate, yet it is not taken into account in planning tools, with particular reference to the dynamism and complexity of landscapes. As it has been recognised at a European level, in order to enable different species to remain in good functional status, a network of green infrastructures is required. The concept of "ecological island" is no longer sufficient to adequately protect the fauna and the ecosystem it lives in. As a consequence, ecological islands must turn into ecological networks. The Ecological connectivity refers to the way habitats are physically connected to each other and how easy it is for species to move in. Good ecological connectivity is fundamental to the effective conservation of biodiversity considering that most species and ecological functions provided by ecosystems (ecosystem services) require a much wider space than that available within the boundaries of a single protected area. The main objective of this paper is to critically compare the application of a model for the design of ecological networks to two very different environmental contexts. This model was first tested in a Mediterranean area (the Province of Reggio Calabria) in 2008; the goal was to integrate the traditional (physiographic and functional) approaches into the design of ecological networks by taking into account biological and orographic elements as well as the anthropic structure of the territory. In 2011, within the ECONNECT European project, the model was applied to the pilot region of South-Western Alps (including the French region of Provence-Alpes - Côte d'Azur and the Italian regions Piedmont and Liguria), which is one of the richest transnational districts in Europe in terms of biodiversity. In such a region, the issue of multidisciplinary ecological connectivity was tackled in order to provide a series of proposals aiming at the development of the ecological potential of the area. The two applications allowed to further investigate the strengths and weaknesses of the implemented model by integrating its validation with information on faunal presence, which obviated one of the major limitations occurred in the first application