An Advanced Pavement Management System based on a Genetic Algorithm for a Motorway Network

Maintenance and improvement, through the rehabilitation, of the road infrastructure is a strategic and priority objective for road agencies, nevertheless the economic resources required are often inadequate. Within road management, the pavement management system (PMS) plays an essential role because of both the money needed and the performance that should be provided in terms of safety, ride quality and transport cost. The PMS is based on searching for a balanced solution between the lowest cost and the increased level of performance (i.e. pavement condition). In this paper a PMS multi-objective optimization method, was proposed, using a genetic algorithm (GA) to identify the best solution considering different rehabilitation strategies. The multi-objective optimization GA permits a set of optimal solutions (the Pareto solution set) that takes into account all the considered constraints. Finally on the basis of a specific criteria the best solution was selected in relation to the ranking of the priorities of the agency. A detailed numerical study was conducted on the Italian A18 motorway and the results showed that the proposed model PMS-GA is a suitable support to the decision making process

Proposta di Dimostrazione della variante Riemann di Lagarias (RH1) equivalente all’Ipotesi di Riemann RH, con RH1 = RH.

Scopo del presente lavoro è quello di proporre una dimostrazione dell'Ipotesi di Riemann attraverso quella che tecnicamente viene definita "variante di Lagarias". Anche se l'obiettivo non fosse stato completamente raggiunto, certamente tale lavoro fornirà un notevole contributo al futuro sviluppo ed alle applicazioni fisico-teoriche dell'Ipotesi di Riemann, che ci inducono a credere alla "realtà" dell'Ipotesi medesima

Teoremi sulle coppie di Goldbach e le coppie di numeri primi gemelli: connessioni tra Funzione zeta di Riemann, Numeri Primi e Teoria di Stringa.

Scopo del presente lavoro è quello di evidenziare le relazioni matematiche tra teoria di stringa e funzione zeta di Riemann, in maniera specifica tra teoria di stringa, Congettura di Goldbach (Teorema di Goldbach) e Teorema di Goldston-Montgomery. Nella prima parte, quindi nel primo capitolo, vengono esposti alcuni teoremi e dimostrazioni matematiche sulle coppie di Goldbach e le coppie di numeri primi gemelli, e delle proposte di soluzione per alcuni problemi additivi di tipo Goldbach e sugli insiemi sparsi ed intervalli corti. Il linguaggio matematico usato in questa parte del lavoro è di tipo puramente algebrico. Nella seconda parte, invece, vengono esposti alcuni settori inerenti la teoria di stringa, precisamente le soluzioni cosmologiche da un sistema D3/D7, la soluzione applicata alla supergravità 10-dimensionale di tipo IIB ed alcune soluzioni solitoniche in teoria di campo di stringa. Verrà quindi evidenziato come queste soluzioni di equazioni di teoria di stringa sono ottimamente correlate con i teoremi di Goldbach e di Goldston-Montgomery e, conseguentemente, con la funzione zeta di Riemann

Synthesis, studies and fuel cell performance of “core–shell” electrocatalysts for oxygen reduction reaction based on a PtNix carbon nitride “shell” and a pyrolyzed polyketone nanoball “core”

This report describes a new class of "core-shell" electrocatalysts for oxygen reduction reaction (ORR) processes for application in Proton Exchange Membrane Fuel Cells (PEMFCs). The electrocatalysts are obtained by supporting a "shell" consisting of PtNix alloy nanoparticles embedded into a carbon nitride matrix (indicated as PtNix-CN) on a "core" of pyrolyzed polyketone nanoballs, labeled 'STp'. ST(p)s are obtained by the sulfonation and pyrolysis of a precursor consisting of XC-72R carbon nanoparticles wrapped by polyketone (PK) fibers. The ST(p)s are extensively characterized in terms of the chemical composition, thermal stability, degree of graphitization and morphology. The "core-shell" ORR electrocatalysts are prepared by the pyrolysis of precursors obtained impregnating the STp "cores" with a zeolitic inorganic-organic polymer electrolyte (Z-IOPE) plastic material. The electrochemical performance of the electrocatalysts in the ORR is tested "in situ" by single fuel cell tests. The interplay between the chemical composition, the degree of graphitization of both PtNix-CN "shell" and STpS "cores", the morphology of the electrocatalysts and the fuel cell performance is elucidated. The most crucial preparation parameters for the optimization of the various features affecting the fuel cell performance of this promising class of ORR electrocatalysts are identified

New nanocomposite proton conducting membranes based on a core–shell nanofiller for low relative humidity fuel cells

New hybrid inorganic-organic proton conducting membranes containing a ZrTa nanofiller dispersed in a Nafion® matrix are described. The ZrTa nanofiller exhibits a "core-shell" morphology, where the harder ZrO2 forms the "core", which is covered by a "shell" of the softer Ta2O5. The hybrid membranes are thermally stable up to 170 °C. Interactions between the polymer matrix and the nanofiller increase the thermal stability of both the -SO3H groups and the fluorocarbon polymer backbone. In comparison with Nafion, the hybrid membranes have a lower water uptake (W.U.) that depends on the concentration of nanofiller. The residual water, which is approximately 4 wt%, is likely located at the Nafion-nanofiller interface. Infrared results indicate that the nanofiller does not neutralize all of the R-SO3H groups in the hybrid membrane and the small amount of residual water in the material does not cause the dissociation of the R-SO3H protons. Fuel cell tests show that the maximum power density yielded by the membrane electrode assembly (MEA) containing the hybrid membrane is better than that of the MEA containing Nafion, particularly at low values of relative humidity. The hybrid membranes require much less water to conduct protons effectively and are more efficient at retaining water than Nafion at low water activities

A dynamic model of ballasted rail track with bituminous sub-ballast layer

The bituminous sub-ballast layer within the ballasted rail track allows some mechanical and environmental advantages. An analytical model of a ballasted rail track with sub-ballast layer has been proposed by considering the rail as viscous-elastic continuous beam discretely supported, at four levels of elasticity. The model was used to compare the mechanical performance of both ballasted track with and without bituminous sub-ballast layer. The results confirmed that the bituminous sub-ballast layer reduces the dynamic forces on the ground and achieves the technical objectives as reduction of ground borne vibrations and increase of the design life of the rail track

THE DIAGNOSIS OF ROAD SURFACE DISTRESSES THROUGH IMAGE-BASED MODELING TECHNIQUES. EXPERIMENTAL SURVEY ON LABORATORY-RUTTED SAMPLES

In the past few years, there has been a drastic increase in the use of image-based modeling (IBM) techniques to create high quality, reality-based 3D models. The low costs of these techniques, as well as their attractive visual quality, have led many researchers and professionals to invest their energy and resources in several tests. IBM is rarely used in the field of road surface distresses as diagnosis is usually performed using other techniques and devices. Road safety statistics reveal that about a half of the total number of accidents occur mainly due to the deterioration of the pavement. The goal of effective road network management is often incompatible with economic resources designated for maintenance and rehabilitation. For this reason, IBM diagnosis of distresses seems necessary in order to both increase the level of road safety and to avoid incorrect interventions and treatments of road pavement. One of the strengthens of multi-view stereo techniques is the possibility to capture millions of points in a very short time, and to produce a 3D, textured polygonal model that can easily be used for visualizing and communicating digital assets. Our goal was to implement the IBM techniques on a laboratory-rutted sample and to verify the metric accuracy of the model and its validity for the distress diagnosis in terms of severity (rut depth). In order to assess the IBM technique, we compared its 3D model to the blue LED 3D scan (Artec Spider) of the same rutted sample

Pavement Management System model using a LCCA- microsimulation integrated approach

The maintenance and the rehabilitation of the urban road pavements are not often based on systematic program and scheduling but rather on emergency or on other not identified reasons. Moreover the Life Cycle Cost Analysis (LCCA), the only peculiar procedure for the management pavement, finds its own application for highway and motorway, even if it is possible to search the best investment for the urban interstate and arterials. By the light of the quantity of the involved resources, it seems necessary to define an operative methodology for programming the maintenance and rehabilitation activities for the urban pavement. The paper is oriented towards the development of a multidisciplinary approach to make decision on management of urban pavement using the basic concepts of the LCCA and micro-simulation model to define a scheme of work zone that minimizes the delay on the traffic flow. The best rehabilitation strategy should be characterized by the lowest users’ cost that depends on the time period of the work zone, which is conditioned by both own scheme and the provided treatment, and on “social cost” as increased travel time for queue generation . Different scenarios for different work zone plans were developed and a micro-simulation model was used to assess increased total travel time of a traffic flow within the maintenance area. In this work an analysis by means of the above mentioned approach was carried out on real scenario in the city of Palermo in order to point out the several frames of the adopted methodolog

Draft Genome of Shewanella frigidimarina Ag06-30, a Marine Bacterium Isolated from Potter Peninsula, King George Island, Antarctica

We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica,which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (GC content 41.24%). This strain harbors severalmobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution.Fil: Parmeciano Di Noto, Gisela Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Vázquez, Susana Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: MacCormack, Walter P.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentina. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; ArgentinaFil: Iriarte, Andrés. Universidad de la República; Uruguay. Instituto de Investigaciones Biológicas ; UruguayFil: Quiroga, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin

A multidisciplinary approach using LCCA and micro-simulation 10 model for the management of the urban pavements

The maintenance and the rehabilitation of the urban road pavements are not often based on systematic program and scheduling but rather on emergency or on other not identified reasons. Moreover the Life Cycle Cost Analysis (LCCA), the only peculiar procedure for the management pavement, finds its own application for highway and motorway, even if it is possible to search the best investment for the urban interstate and arterials. By the light of the quantity of the involved resources, it seems necessary to define an operative methodology for programming the maintenance and rehabilitation activities for the urban pavement. The paper is oriented towards the development of a multidisciplinary approach to make decision on management of urban pavement using the basic concepts of the LCCA and micro-simulation model to define a scheme of work zone that minimizes the delay on the traffic flow. The best rehabilitation strategy should be characterized by the lowest users\u2019 cost that depends on the time period of the work zone, which is conditioned by both own scheme and the provided treatment, and on \u201csocial cost\u201d as increased travel time for queue generation . Different scenarios for different work zone plans were developed and a micro-simulation model was used to assess increased total travel time of a traffic flow within the maintenance area. In this work an analysis by means of the above mentioned approach was carried out on real scenario in the city of Palermo in order to point out the several frames of the adopted methodology