1,721,026 research outputs found

    Comparing proximity for couples of close airports. Case studies on city-airports in the pre COVID-19

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    Following the existing relationships between cities and airports, well depicted in the sectorial literature ((Thierstein and Conventz, 2018), (Tira et al., 2006), (Freestone, 2009), (Percoco, 2010), (Ventura et al., 2020), this paper aims to investigate the linkages between the touristic traffic of some airports and the related development of the cities in which they are placed. The chosen case studies regard different remote regions (ONU, 2018) of three different countries (Italy, Norway, Cyprus), considering couples of near airports (Dziedzic and Warnock-Smith, 2015). The paper focuses the analysis on four couples of near airports, two from the South of Italy (Bari and Brindisi in the Apulia Region; Palermo and Trapani in Sicily), one in the North of Norway (Bødo and Narvik in Hålogaland) and the last one in the Republic of Cyprus (Larnaca and Paphos). A GIS analytic methodology has been used to describe the differences between the different couples of airports. Managed by the GIS analytical evaluation, the purpose of this paper is to give support to the different theories about the development of couples of close airports, using geographic tools to support economic and financial planning ((Cook and Billig, 2017) (Graham, 2014), (AntonínKazdaa et al., 2017) (Young and Wells, 2011))]. There has been pointed out the results of the adopted methodology on the working Norwegian network system analysis

    Comparing proximity for couples of near airports: different case studies on city – airports.

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    The paper assess proximity's influences for the development of small Airport-Cities in European Remote Regions. Different couples of city-airports will be studied to understand if the proximity could be an advantage for the investments. The methodology examinates the changes in the plans of the different Airport-Cities given by the touristic traffic and how they affect the GDPpc of the regions and the cities in which they are placed, using the GIS evaluation to enhance urban areas performance. Ordinary Least Squares regression (OLS) to enhance the relationships among the different expectations of each analyzed city and Geographically Weighted Regression (GWR) to verify the model for every single studied airport. Enhancing the relationships among the different expectations of each analyzing city and to verify the model for every single studied airport, the search tries to evaluate what are the benefits deriving from near airports for the remote Regions of Europe

    Circuit modeling of discontinuous planar waveguides at high frequencies

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    We present an accurate theoretical approach in view to design discontinuous optical waveguides at high frequencies. The model is based on the Floquet's theory and on the variational equivalent circuit. The distributed circuit model is developed through the use of the microwave network the- ory and the optical theory of the step discontinuities. This accurate approach considers dielectric periodic structures with high dielectric contrast and the transmission line model applied to guided modes of a discontinuous slab waveguide

    Cheese Fortification: Review and Possible Improvements

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    Food fortification includes micronutrient directly added or by probiotics in food matter, making the final product more enticing to the consumers. Dairy products well represent a category of foods to fortify successfully. Fortification properly enhances cheeses, including micronutrients into the casein matrix. The process exalts either nutritional or technological product features. Food fortification occurs with the adding of primary or secondary compounds from the agrifood production chain. Using vegetable by-products encourages circular economy, generating an eco-sustainable and consumer healthpromoting compounds class. Organic compounds of interest result from probiotic microorganism’s activity, offering micronutrients to “enrich” the profile of the exalted cheese. Allogeneic probiotics may originate from specialised insects-borne microbiota. The latter class offers new challenges to improve the nutritional and sensorial profiles of cheeses. The review focuses on food fortification frameworks; cheese fortification approaches; microencapsulation and stabilisation; cheese fortification with mineral elements; cheese fortification with essential micronutrients; fortification with byproducts of the agrifood industry; fortification with microorganisms. The review considers the cheese matter a driver and an operating carrier for elements and organic compound as vitamins, carotenoids, polyphenols and essential fatty acids. Organic compounds of interest result from probiotic microorganisms’ activity are enzymes, antimicrobial compounds, short-chain fatty acids and some vitamins (A and D). Specialised insects-borne microbiota confers typical smells, flavours, consistency and nutritional attributes, respecting high hygienic-sanitary standards. The review aims to summarise in a single text the techniques, micronutrients and microorganisms most used for Market-Driven Cheese Fortification. Also, there is no review in the literature that includes all these aspects together. The paragraphs are concise dissertations on the nutraceutical, technological and sensory properties of the most widely used fortifiers in cheese. The information reported derived from an indepth analysis of the literature from 1977 to 2020

    Transverse resonance circuit modeling and hertzian potential formulation for integrated optical waveguides

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    In this work we present a new efficient numerical simulator based on the concepts of transverse resonance and electromagnetic Hertzian potentials. The method includes the transverse resonance circuit modelling (TRCM) well suited with scalar time-domain Hertzian potential modelling (HPM). The transverse circuit provides the effective refractive indices related to the guided modes of an optical waveguide. The simultaneous implementation of the TRCM and HPM approaches provides an accurate time domain electromagnetic field solution for two-dimensional and three-dimensional optical waveguides

    Anisotropic effects in circular photonic crystals

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    We analyze accurately in this work the form birefringence effects in circular photonic crystals at optical frequencies. As in dielectric multilayered structures which behave as negative uniaxial crystals the dielectric concentric circular patterns admit two preferred propagation directions defined by an extraordinary and an ordinary refractive index representing two field polarizations. The model is obtained through the geometrical synthesis of the wave front propagation inside the anisotropic structure. The model is applied to Si/SiO2 dielectric rings photonic crystal which behaves as a Bragg reflector, and to GaAs photonic crystal resonator with cylindrical air holes. The theory is validated by analytical, numerical and experimental results, and can be extended to circular microwave photonic crystals

    Air Transport Implications in Tourist Destinations. The Trapani Airport in Western Sicily

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    This search following the Sicily, the largest island in the Mediterranean Sea (25,460 sq km) and a self-governing Region, located in the southernmost part of Italy, has at least four tourist-related airports, sited between the eastern and western coast, separated from each other by a vast territory without efficient transport links and suffering from many diverse environmental problems. Utilizing a desk search methodology based on GIS software, this paper discusses the impact upon the regional development of the tourist traffic of the Trapani Airport situated in the westernmost part of Sicily. Ultimately it analyzes the critical role of connectivity and accessibility in the development of the area and tourism, seeking a maximum involvement of stakeholders. The recent growth of low-cost carriers have had a definite impact on the economic growth of the entire territory, where those choices could determine the life or the death of firms and, inevitably, their annual incomes. Tourism and connectivity are strictly related, thus showing deficiencies of the area in terms of accessibility, as well as the trade-offs between the different government (central and local) investment policies and the specific benefits emerging from the airport in the regional mobility

    Negative Uniaxial Optical Behaviour of Laminated Polarization Beam-splitters

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    In the construction of polarization beam-splitters (PBS) and switches a structure can be employed, that is based on the birefringence of periodically laminated dielectric thin films [2,7]. In this work we derive an estimate of the split angle in laminated polarization splitters behaving as negative uniaxial crystals, in the case of oblique incidence. This analysis has been applied to an artificial anisotropic dielectric medium realized by means of layers of a-Si:H and SiO2 [7]
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