Search results for " ferro"
showing 10 items of 499 documents
Calibration of microscopic traffic simulation models for evaluating operation and safety performance at roundabouts
Validación del subsistema de presentación de indicaciones del dispositivo ASFA Digital en el ferrocarril español
2012
En el año 2005, se inició un estudio para desarrollar el dispositivo ASFA digital en el que colaboraron Renfe, Adif, Invensys Rail Dimetronic, Ineco Tifsa y la Universidad de Valencia. En este proyecto, se desarrollaron las especificaciones técnicas y funcionales del sistema Embarcado ASFA Digital. La Universidad de Valencia participó en el diseño del subsistema de presentación de indicaciones del dispositivo ASFA Digital. La última etapa de este estudio es la validación del subsistema de presentación de indicaciones, objetivo de la presente tesis doctoral. Siguiendo las recomendaciones de estudios precedentes (Stevenson, et al., 2000), se ha dejado transcurrir cinco años, tiempo suficiente…
Feasibility of using more polishable aggregates in dense-graded asphalt surface mixture: Case study of dolomite
2022
This study aimed to evaluate the feasibility of using more dolomite aggregates in asphalt surface mixtures that are typically used by West Virginia Division of Highways (WVDOH). The laboratory test results indicated that increasing dolomite content in asphalt surface mixtures resulted in a faster deterioration rate at the early polishing stage. In addition, asphalt surface mixtures containing more than 50% dolomite coarse aggregates would significantly reduce roadway safety. The field test results validated that dolomite shall not exceed 50% of coarse aggregate in asphalt surface mixture if the projected traffic volume is greater than 3.0 million equivalent single axle loads (ESALs).
Ruolo del Nucleo di Valutazione per l´attivazione delle procedure per la predisposizione dello schema di APQ per la logistica ed il trasporto merci i…
2006
Il presente contributo riferisce dell´esperienza del Nucleo della Sicilia —Area Valutazione progetti, in merito alla redazione della relazione tecnica di accompagnamento all´APQ per il Trasporto delle Merci e per la Logistica in Sicilia. Partendo dalle Disposizioni contenute nella delibera CIPE n.20/2004 e dalle indicazioni della nota di indirizzo Rete NUVV dic/2004 in proposito, il gruppo di lavoro ha proceduto alla necessaria acquisizione delle informazioni e dei dati relativi a ciascun singolo intervento previsto in APQ, ricostruendo i processi e le procedure, come pure la sequenza tecnico-procedurale con la quale si sono sviluppate le proposte (analisi del fabbisogno, individuazione deg…
Image Based Modeling Technique for Pavement Distress surveys: a Specific Application to Rutting
2016
Image-based modeling (IBM) is a well-known technique to obtain high quality 3D models based on multi view images. IBM started being used in several applications such as inspection, identification of objects and visualization, due to the user-friendly approach, the low cost and highly automated technique. This paper focuses on the investigation of the potential application of IBM in the diagnosis of road pavement distresses and in particular rutting. Indeed, the evaluation of the rutting distress is a fundamental step to define the whole state of a pavement as demonstrated by the calculation of Present Serviceability Index (PSI). Currently, the permanent deformation is measured monitoring vi…
Active repair technology applied to delaminated composite structures
2009
The main target of the present paper is represented by the fracture mechanics charac-terization of delaminated composite structures actively repaired through piezoelectric patches. A boundary element code, formulated for anisotropic piezoelectric solids, including, as limiting case, the applicability to linear elastic anisotropic materials has been then imple-mented. The modeling of the delaminated composite structures as well as of the assembled structures, made of the damaged components and the patches, has been achieved through the multidomain technique. Moreover, to take into account for the adhesive layer between the host structures and the piezoelectric patches, a "spring-model" has b…
Towards a new mix design method for asphalt mixtures containing rap
2016
Recycling is one of the most important aspects to conceive the new construction or rehabilitation of sustainable road infrastructures. Even if Reclaimed Asphalt Pavement (RAP) is commonly used in the practice, its presence may lead to some critical aspects due to the physical and chemical phenomena occurring during the new mix process. For instance, the formation of RAP clusters during a new mix may inhibit the uniform distribution of the virgin binder as well as cause changes in the design grading curve of the mixture. Indeed, laboratory results demonstrate that small-size RAP particles stick together forming clusters. The amount of clusters depends on different parameters observed: The pe…
All-Optical frequency Shifter in a Periodically Poled Lithium Tantalate Waveguide
2011
A frequency shifting device is fabricated and tested in a congruent Lithium Tantalate waveguide. Periodic poling for quasi-phase-matching and channels for operation in the near-infrared C-band were obtained, demonstrating a two-stage parametric conversion.
un approccio teorico-sperimentale per la ricostruzione del profilo trasversale di rotaie usurate
2012
La sovrastruttura ferroviaria durante la sua vita utile è sottoposta oltre ai carichi dinamici generati dai rotabili (azioni verticali, laterali, ecc.), anche ai carichi termici e ad azioni ambientali di varia natura. Tali sollecitazioni, interagendo sinergicamente tra loro, determinano il deterioramento della sovrastruttura ferroviaria inteso come discostamento dalla configurazione geometrica di progetto e l’usura dei singoli componenti del binario e della massicciata. Per valutare lo stato di efficienza della sovrastruttura è consuetudine far riferimento ad alcuni parametri geometrici del binario che, peraltro, permettono di formulare un giudizio oggettivo circa il livello di sicurezza of…