1,924 research outputs found
The Historical Development of the Port of Livorno (Italy) and Its New Port Plan 2010 in Advanced Stage of Elaboration
The geographical location makes the port of Livorno one of the most important in Italy. The port, in fact, benefits of an extended network of roads and rails connecting it with the rest of Italy, and central and southern Europe as well. The history of Livorno and its port is inextricably linked to that of Pisa and Florence, and to the complexity of events that determined the political set-up of the region along several centuries. Looking at the new port plan of Livorno has made it necessary an extensive overview of the history of both the port, and of its planning. This analysis has allowed: to understand the reason for the different choices made in the past for the development of the port, highlighting, when necessary, the errors made; to identify the strengths and weaknesses of the existing port infrastructure; to identify the works needed to boost the port in the European context. The purpose of this paper is to provide a summary of the analysis performed for the implementation of the new Livorno port plan 2010 and show how the port planning in Italy is often conditioned by hundreds of centuries of history
Aggregation and breakup of colloidal particle aggregates in shear flow: A combined Monte Carlo - Stokesian dynamics approach
A method for the simulation of aggregation and breakup processes in colloidal particle suspensions is presented. The method combines a Monte Carlo algorithm to determine, on the basis of probabilistic considerations, the sequence of aggregation and breakup events, and a Discrete Element Method, built in the framework of Stokesian dynamics and contact mechanics, to accurately reproduce them. Liquid-solid suspensions subject to a uniform shear stress are investigated. The model is seen to be able to reproduce the typical dynamic steady state which is observed in colloidal suspensions under severe shearing, in which the effects of aggregation and breakup balance each other. The structural properties of the aggregates and the dynamics of the aggregation and breakup phenomena are characterized in detail. Both fragmentation and erosion are seen to contribute to the breakup process, which is characterized by an exponent similar to the one reported in the literature for compact clusters
Absolute quantification of viruses by TaqMan real-time RT-PCR in grapevines.
The absolute quantification determines the absolute amount of a targeted nucleic acid expressed as a copy number or concentration. The knowledge of virus concentrations in commercial crops possesses high relevance to ensure a reliable diagnosis. The objective of this study was to perform an absolute quantification of five viruses in infected grapevines (Vitis spp.). Different known amounts of the standard sample (cloned viral cDNA or in vitro transcribed viral RNA) were quantified by TaqMan RT-qPCR. Based on these data, standard curves were generated plotting Ct values (threshold cycle) against the log of the standard sample amount. Infected grapevine samples were evaluated to determine virus titers, which were highly variable. This result may contribute to improve virus diagnosis by accurately quantifying virus titre variations in grapevines. Key words: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 and -4. RESUMO: A quantificação absoluta determina a quantidade absoluta de um ácido nucleico alvo expressa como número de cópias ou concentração. O conhecimento das concentrações virais em culturas comerciais tem grande relevância para assegurar um diagnóstico confiável. O objetivo deste trabalho foi realizar uma quantificação absoluta de cinco vÃrus em videiras infectadas (Vitis spp.). Diferentes quantidades conhecidas da amostra padrão (cDNA viral clonado ou RNA viral transcrito in vitro) foram quantificadas por RT-qPCR TaqMan. A partir destes dados, curvas padrão foram geradas plotando-se os valores de Ct (ciclo limiar) contra o log da quantidade da amostra padrão. Amostras de videiras infectadas foram avaliadas visando-se determinar os tÃtulos virais que foram bastante variáveis. Este resultado contribui para melhorar o diagnóstico viral ao quantificar com precisão variações no tÃtulo viral em videiras. Palavras-chave: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 e -4. A quantificação absoluta determina a quantidade absoluta de um ácido nucleico alvo expressa como número de cópias ou concentração. O conhecimento das concentrações virais em culturas comerciais tem grande relevância para assegurar um diagnóstico confiável. O objetivo deste trabalho foi realizar uma quantificação absoluta de cinco vÃrus em videiras infectadas (Vitis spp.). Diferentes quantidades conhecidas da amostra padrão (cDNA viral clonado ou RNA viral transcrito in vitro) foram quantificadas por RT-qPCR TaqMan. A partir destes dados, curvas padrão foram geradas plotando-se os valores de Ct (ciclo limiar) contra o log da quantidade da amostra padrão. Amostras de videiras infectadas foram avaliadas visando-se determinar os tÃtulos virais que foram bastante variáveis. Este resultado contribui para melhorar o diagnóstico viral ao quantificar com precisão variações no tÃtulo viral em videiras. Palavras-chave: RT-qPCR, GRSPaV, GVA, GVD, GLRaV-3 e -4
Exploring efficient imperative handover mechanisms for heterogeneous wireless networks
The Next Generation Internet will provide ubiquitous
computing by the seamless operation of heterogeneous
wireless networks. It will also provide support for quality-ofservice, QoS, fostering new classes of applications and will havea built-in multi-level security environment. A key requirement of this new infrastructure will be support for efficient vertical handover. Y-Comm is a new architecture that will meet the challenge of this new environment. This paper explores the design of efficient imperative handover mechanisms using the Y-Comm Framework. It first looks at different types of handovers, then examines the Y-Comm Framework and shows how Y-Comm maps unto current mobile infrastructure. It then explores support for different handover mechanisms using Y-Comm. Finally, it highlights the development of a new testbed to further investigate
the proposed mechanisms
A QoS framework for heterogeneous networking
In order for next generation networks to support effective handover procedures, there is a need for defining QoS signaling mechanisms that guarantee the provision of point- to- point as well as network level QoS. This paper proposes a QoS signaling mechanism to be implemented by the Y-Comm architecture as a potential 4G framework. The proposed mechanism requires certain level of cooperation among network elements; therefore, it proposes some functional modules/ interfaces to be run on different network entities. As showed in the paper, the proposed mechanism could be implemented in different scenarios such as initial registration and connection, and also in the case of handover
Nonstationary catalytic destruction of lean waste gases in a network of burners and a reverse-flow reactor under nonadiabatic conditions
A Novel Technique for Laryngotracheal Reconstruction for Idiopathic Subglottic Stenosis
Idiopathic subglottic stenosis is the most challenging condition in the field of upper airway reconstruction. We describe a successful novel technique for enlarging the airway space at the site of the laryngotracheal anastomosis in very high-level reconstructions
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