1,720,970 research outputs found
Logistics, transportation and infrastructures at the sea-land interface: the open issues
No full textTransportation and logistics are relevant assets of modern countries and they represent a strong pillar of gross product and economic growth. In the last decades, this sector has extremely increased its market dimension, related operations and corresponding activities so that several issues occurred due to the frequent inadequacy of existing infrastructures and structures if compared to the new trends and needs. The paper gives an overview about the main elements, defining weaknesses and strengths, both from a management and operational point of view and from a building and construction perspective. One important strategy, herein discussed, to tackle these critical issues is the transition to digital models and the implementation of digital twin, with the final aim to investigate the so called “what if” scenarios and plan new projects. In addition, the paper mentions the main problems related to the typical physical constrains for the implementation of civil constructions at the interface between land and see, that is a vulnerable and critical environment. Finally, a very urgent and serious topic that is considered in the paper is the sustainability, analyzed in a “digital” perspective, under the note of Agenda 2030
In plant production of hot recycled mixtures with high reclaimed asphalt pavement content: A performance evaluation
No full textNevertheless hot recycling process is nowadays a widespread technique, many doubts related to the in plant recycling process effects on the performance of recycled mixtures still exist and limit the maximum allowable amount of Reclaimed Asphalt Pavement (RAP). Therefore, the feasibility of an efficient production of plant hot recycled mixtures characterized by high RAP content and suitable performance should be properly addressed. To this aim, the overall performance of hot recycled asphalt mixtures produced in asphalt plant and containing high RAP content were assessed in this study. The mixtures were prepared with two different bitumens (high and low content of SBS polymer modifier) and 40 % of RAP only deriving from asphalt layers containing polymer modified bitumens. The aggregate grading curve was previously optimized through a specific laboratory study by applying the Bailey Method and using selected RAP. A third mixture, currently used for binder layers in motorway pavements, was also studied for comparative purposes. Compactability, stiffness, cracking and rutting resistance and fatigue behavior were investigated. Results of the mechanical tests suggest that mixtures containing 40 % RAP are suitable for the production of new asphalt pavements, especially when low modified bitumens are used. In fact, the performance of such mixtures were comparable or even higher than those of the reference mixture. In particular, the specific and accurate mix design allowed the potential drawbacks due to higher RAP content to be balanced. © RILEM 2016
Mix design validation through performance-related analysis of in plant asphalt mixtures containing high RAP content
No full textEarly life field performance of innovative sustainable semi-flexible pavements
No full textSemi-flexible pavements in heavy loads areas are recommended to guarantee good perfor- mance and safety. They are usually constructed by placing a wearing layer of grouted mac- adam, a composite material consisting of a porous Hot Mix Asphalt (HMA) skeleton grouted with a cementitious matrix. However, its use is limited as the production process is quite complex and laborious. An effective alternative to grouted macadam can be represented by the Ready to Mix (RTM), recently implemented to offer performances comparable to those of the grouted macadam and a most effortless put-in-place process, and contemporarily leading to environmental and economic advantages. The present research investigated the early life field performance of a semi-flexible pavement including an RTM base. Three Falling Weight Deflectometer testing campaigns were carried out from 2017 to 2021. In particular, the semi-flexible pavement was compared to a reference flexible pavement entirely made with HMA in terms of temperature sensitivity as well as bearing capacity
The Port Sector in Italy: Its Keystones for Energy-Efficient Growth
Full text linkItaly has been defined as the “logistics platform” of the Mediterranean Sea. The Italian port system, with 11.6 million TEUs handled and 61.4 million passengers in 2022 (Assoporti data January–December 2022), is the key to fulfilling this title through adequate levels of reliability, safety, and sustainability. This contribution addresses port logistics and shipping, focusing on primary issues related to the energy sector with a specific focus on what can be observed in the Italian context. Specifically, the decarbonization of the maritime sector and related infrastructural problems (e.g., cold ironing or alternative fuels, where the uncertainty about resource availability and related costs do not allow for easy strategic planning by both the ship owner and the port authority), as well as policies such as the Emission Trading System (ETS), will be analyzed. All these issues, hereafter addressed with a systematic critical review of the existing literature and other relevant sources, could represent the driving force of the growth of the national port sector toward its competitiveness at a global scale. The review was performed through a wide search and analysis of studies published in well-known online research databases (Scopus, Web of Science, IEEE Xplore, ScienceDirect), sector studies, or specialized technical magazines. The review focuses on the results of each analyzed contribution rather than on the analysis method adopted with the final aim to identify useful hints and innovative ideas for further studies on the topic
Level of Propensity: a zonal metric for evaluating the multimodal option Electric Micromobility and Public Transport
Full text linkElectric Micromobility (EMM), e.g. e-bikes, e-scooters, light-weight electric vehicles, has a key role in policymakers’ strategies for making cities more liveable. Especially, its combination with Public Transport (PT) can be essential in the transportation sector decarbonization. This work proposes a zonal metric to evaluate EMM and PT integration, named “Level of Propensity” (LoP) to multimodality. LoP is defined adopting a multi-dimensional domain-based classification capturing two main phases of the trip: (1) the access phase by EMM towards PT stops; (2) the accessibility potential to destination by PT. PT open data, road network configuration, activities and Floating Car Data are adopted for the elaboration. LoP has been validated in the medium-size city of Salerno (Italy), but it is easily transferable to other cities. It can support urban planners and PT/EMM operators in identifying zones with low propensity to multimodality, suggesting priorities in terms of PT service improvements and EMM infrastructure implementations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
