196,134 research outputs found
RELIGIOSITAì E LUOGHI DI CULTO IN AREA URBANA E PERIURBANA: IL CASO DEI SANTUARI GENOVESI
No full textFive-a-day, a price to pay: an evaluation of the UK program impact accounting for market forces
No full textWe provide an ex-post assessment of the UK 5-a-day information campaign, where the positive effects of information are disentangled from potentially conflicting price dynamics. Using four years of data from the Expenditure and Food Survey between 2002 and 2006, we estimate that the 5-a-day program has lifted fruit and vegetable consumption by 0.3 portions, on average. We also provide quantitative evidence of a differentiated impact by income group, ranging from 0.2 to 0.7 portions. All impacts are larger than those observed by simply comparing pre-policy and post-policy intakes
Life-cycle cost-based risk assessment of aging bridge networks
Get PDFRoad infrastructures and bridge networks are becoming increasingly complex systems due to the development of technology in transportation engineering and the continual growth of urban communities. Infrastructure disservice due to seismic events may lead to unacceptable discomfort for commuters. Moreover, network downtime results into economic losses for the affected community, to be quantified in monetary terms by user costs. Seismically vulnerable bridges are also affected by aging and deterioration processes that can reduce the bridge structural performance over time. This paper presents a comprehensive life-cycle cost-based probabilistic framework for seismic risk assessment of spatially distributed aging bridge networks. The seismic risk measure is formulated in terms of annual exceedance rate of a target threshold of user costs. The methodology is applied to a road system in Lombardy region, Italy, reproducing network connectivity and daily travel demands among four major cities and smaller neighbouring municipalities. Despite the area of interest is characterized by low seismicity, the results allow to quantify the impact of environmental deterioration in exacerbating the network seismic risk, highlighting the need for a life-cycle-informed approach to optimal management of infrastructure systems
Numerical assessment of seismic retrofit interventions on a long-span precast industrial building
No full textResilience of aging structures and infrastructure systems with emphasis on seismic resilience of bridges and road networks: Review
Get PDFRisk assessment and mitigation programs have been carried out over the last decades in the attempt to reduce transportation infrastructure downtime and post-disaster recovery costs. Recently, the concept of resilience gained increasing importance in design, assessment, maintenance, and rehabilitation structures and infrastructure systems, particularly bridges and transportation networks, exposed to natural and man-made hazards. In the field of disaster mitigation, frameworks have been proposed to provide a basis for development of qualitative and quantitative models quantifying the functionality and resilience at various scales, including components, groups and systems within infrastructure networks and communities. In these frameworks, the effects of aging and environmental aggressiveness must be explicitly considered, affecting the structural performance and functionality of civil infrastructure systems. Significant efforts have been made to incorporate risk and resilience assessment frameworks into informed decision making to decide how to best use resources to minimize the impact of hazards on civil infrastructure systems. This review paper is part of these efforts. It presents an overview of the main principles and concepts, methods and strategies, advances and accomplishments in the field of life-cycle reliability, risk and resilience of structures and infrastructure systems, with emphasis on seismic resilience of bridges and road networks
LA GESTIONE DELLE RISORSE IDRICHE E DEL TERRITORIO NELL’AMBITO DELLA PIANIFICAZIONE DI AREA VASTA: L’ESEMPIO DELL’ACQUIFERO DELLA MONTAGNOLA SENESE
Get PDFL’acquifero della Montagnola Senese (conosciuto come “Luco”) codice regionale CIS 99MM030, è considerato un importante serbatoio idrico strategico della Toscana Meridionale.
Questo studio ha consentito l’approfondimento delle conoscenze per una migliore caratterizzazione geometrico-strutturale, idrodinamica e idrochimica dell’acquifero e restituisce i risultati di un lavoro che ha l’obiettivo di realizzare un modello concettuale e un primo approccio al modello numerico di flusso in regime permanente ai fini della valutazione e gestione delle risorse idriche sotterranee valutando anche la sua vulnerabilità all’inquinamento.
I nuovi dati relativi alla geometria dell’acquifero, costituito dalle formazioni carbonatiche del Calcare Cavernoso e della Breccia di Grotti, sono stati acquisiti attraverso sondaggi geoelettrici, tomografie geofisiche, stratigrafie di pozzi, una nuova perforazione profonda e confrontati con la cartografia geologica del continuum regionale.
Ciò ha permesso di valutare la sua estensione, affiorante e non, pari a circa 166,3 Km2 a fronte di un’area di alimentazione pari a circa 91,6 Km2. L’intero complesso idrogeologico permeabile risulta avere uno spessore medio di circa 178 m.
Per quanto riguarda la caratterizzazione idrodinamica dell’acquifero, necessaria alla descrizione dell’andamento spaziale e temporale della superficie piezometrica, si può affermare che, nonostante la disomogenea distribuzione spaziale dei punti di misura, sono state individuate due principali direzioni di flusso della falda idrica sotterranea: verso Sud (Piano di Rosia) e verso Nord-Ovest (Abbadia a Isola e Strove). Tale caratterizzazione sia dei flussi, sia dei parametrici idrodinamici, necessita di futuri approfondimenti con esecuzione di nuove indagini.
La valutazione della ricarica dell’acquifero è stata affrontata con due metodologie:
- La prima, una volta definita la superficie dell’aree di ricarica per infiltrazione, valutando indirettamente l’infiltrazione totale in relazione all’eccedenza idrica calcolata. Tale valutazione (dati medi del periodo 1967-2006) porta a stimare la ricarica media in oltre 21·106 m3/anno.
- La seconda, basata sulle escursioni dei livelli piezometrici di falda misurati (Marzo 2009-Gennaio 2010), individua una risorsa dinamica che, in virtù di una porosità efficace ne del 8% (da letteratura tale complesso è caratterizzato da ne tra 5-10%), può essere valutata in circa 8,1·106 m3/anno a cui andrebbero sommati i circa 12·106 m3/anno di acqua che attualmente vengono prelevati dall’acquifero per un ammontare complessivo della risorsa annua pari a circa 20·106 m3. Pur con tutti i limiti connessi a tale tipo di valutazione, i risultati ottenuti, con i due criteri, sono in pieno accordo tra loro.
Per quanto concerne la riserva idrica la sua valutazione è dell’ordine di 1,5·109 m3, vale a dire circa 100 volte superiore alla risorsa dinamica.
Infine, se confrontiamo le valutazioni della risorsa rinnovabile con l’attuale domanda d’acqua ad uso idropotabile si nota che a fronte di una ricarica media pari circa 21·106 m3, i consumi ammontano a circa 11,7·106 m3, risulta quindi teoricamente possibile un ulteriore utilizzo della falda ospitata nell’acquifero della Montagnola Senese.
Sulla base delle conoscenze acquisite è stato realizzato il modello concettuale dell’acquifero, base fondamentale della modellazione numerica. Il sistema acquifero è stato quindi rappresentato, per mezzo di un modello numerico tridimensionale ad elementi finiti (FEM), con l’utilizzo del codice numerico FEFLOW (Finite Element subsurface FLOW system), operando in regime permanente.
I dati di input sono stati inseriti nel sistema attraverso l’assegnazione di condizioni ai limiti (Boundary Condition) di carico idraulico, di trasferimento di flussi, di emungimenti e delle proprietà dei materiali (Material Properties) come la permeabilità, la porosità e l’infiltrazione.
I risultati finali hanno permesso di stimare i quantitativi d’acqua presenti all’interno dell’acquifero in studio mettendo in risalto l’importanza e il ruolo che ricopre l’infiltrazione meteorica che riesce a bilanciare gli emungimenti e a mantenere in equilibrio tutto il sistema.
Data l’importanza strategica dell’acquifero, a completamento dello studio idrogeologico della Montagnola Senese, è stata effettuata anche la valutazione della sua vulnerabilità intrinseca all’inquinamento attraverso un metodo simiparametrico denominato SIPS.
Questa metodologia originale, riconducibile ad un SINTACS semplificato, ha consentito, attraverso la stima di quattro parametri base, di valutare la vulnerabilità intrinseca del corpo idrico sotterraneo che per il 75% risulta essere compresa tra elevata e medio alta.The Montagnola Senese aquifer (known as “Luco”) is an important and strategic water reserve in Southern Tuscany. With this study we have furthered our knowledge for the geometrical/structural, hydrodynamic and hydrochemical aquifer characterization and for the development of a conceptual model of it. In addition, this model provides the results of a work that aims to create a conceptual model and a first approach to the numerical model of flow in permanent regime for the evaluation and management of groundwater resources, while also assessing its vulnerability to pollution.
New aquifer geometry data, represented by carbonate formation of Calcare Cavernoso and Breccia di Grotti, were acquired through geoelectrical surveys, geophysical tomography, borehole stratigraphy, a new deep borehole and compared with the geological mapping of Regione Toscana Continuum Map.
This allowed to estimate the outcropping and non-outcropping aquifer extension (166,3 Km2), in respect of a feeding area of about 91,6 Km2. The entire permeable hydrogeological complex is found to have an average thickness of about 178 m.
With regard to the hydrodynamic characterisation of the aquifer, which is necessary to describe the spatial and temporal trend of the piezometric surface, it can be stated that, despite the uneven spatial distribution of the measurement points, two main directions of underground water flow have been identified: southward (Piano di Rosia) and northwestward (Abbadia a Isola and Strove). This characterization of flows and hydrodynamic parameters needs further investigation in the future.
The assessment of aquifer recharge was approached with two methodologies:
- First one, evaluating the total infiltration in relation to the calculated water surplus infiltration, once the recharge area has been defined. This assessment (average data from 1967-2006) leads to estimate an average aquifer recharge of over 21·106 m3/year.
- Second one, based on the excursion of the measured groundwater piezometric levels (March 2009-January 2010); it identifies a dynamic resource that, using an effective porosity (ne) of 8%, can be estimated at about 8,1·106 m3/year, to which should be added 12·106 m3/year of water that is currently withdrawn from the aquifer for a total amount of the annual hydric resource of about 20·106 m3.
Even with all the limitations associated with this type of evaluation, the results obtained, with the two criteria, are in complete agreement with each other. As far as the water reserve is concerned, it is evaluated at around 1.5 billion m3, that is to say about 100 times greater than the dynamic resource.
Comparing the renewable resource evaluations with current drinking water demand, we note that in the face of an average aquifer recharge of about 21·106 m3, water consumption is about 11,7·106 m3. Further utilisation of the aquifer hosted in the Montagnola Senese aquifer is therefore theoretically possible.
Based on the knowledge gained, the conceptual model of the aquifer was created. The aquifer system has been represented using a three-dimensional finite element numerical model (FEM), by using FEFLOW (Finite Element subsurface FLOW system) numerical code, operating in permanent regime.
Input data have been entered into the system by assigning boundary conditions at the hydraulic loading, at the water outflows and to the material properties such as permeability, porosity and infiltration.
Final results made possible to estimate water quantities present in the aquifer, highlighting the importance and role played by meteoric infiltration in balancing the water outflows and keeping the system in balance.
Given its strategic importance, to complete the hydrogeological study of Montagnola Senese aquifer, an assessment of its intrinsic vulnerability to pollution was also carried out using a simiparametric method called SIPS.
This original methodology, which can be ascribable to a simplified SINTACS, made it possible, through the estimation of four basic parameters, to assess the intrinsic vulnerability of the groundwater aquifer, which is for 75% high to medium-high
I consumi alimentari
No full textRapporto annuale di Unioncamere e Regione Emilia Romagna, assessorato all'agricoltura. Il capitolo analizza i dati Istat di prezzi al consumo, contabilità nazionale e dei consumi delle famiglie per esplorare le tendenze nei consumi alimentari e non
Numerical assessment of seismic retrofit interventions on a long-span precast industrial building
No full textMost of the industrial buildings of the Italian territory is characterised by precast concrete frame structures. Furthermore, subsequent reviews of the Italian seismic design code updated the classification of most industrialized areas in Italy as seismically active. Therefore, a consistent part of the industrial built heritage may be deemed to be seismically inefficient according to current standards, potentially highlighting issues concerning flexural performance of columns and support connections of both horizontal members and cladding panels. This paper investigates a seismically retrofitted benchmark structure representative of monostorey industrial buildings characterised by large height and structural grids. Rational retrofit solutions of increasing impact and efficiency are presented and implemented into a structural model explicitly including not only structural members, but also cladding panels and connections characterised by non-linear constitutive laws. The beneficial impact of the adopted seismic retrofit strategies is analysed through modal and non-linear static analysis
Causal inference on the impact of nutrition policies using observational data
Get PDFWe discuss the state-of-the-art in the application of quasi-experimental
methods to estimate the impact of nutrition policies based on observational data. This
field of application is less mature compared to other settings, especially labour and
health policy, as food economists have started to implement widely counterfactual
methods only over the last decade. We review the underlying assumptions behind the
most prominent methods, when they can be regarded as credible and if/when they can
be tested. We especially focus on the problem of dealing with unobserved confounding
factors, emphasizing recent evidence on the limitations of propensity score methods,
and the hard task of convincing reviewers about the quality of instrumental variables.
We discuss the application of Difference-in-Difference, with an emphasis on its potential
in consumer panel data applications, and how results from Regression Discontinuity
Design studies should be interpreted. Finally, we cover the estimation of counterfactual
outcomes using structural methods and provide an overview of recent developments
and current gaps
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