Push ‘o ver: in situ pushover tests on as built and strengthened existing brickwork constructions

In the last decades several experimental tests were performed to analyse the seismic capacity of unreinforced masonry, mostly involving small size structural elements or small-scale building models, not accounting for the actual complexity of existing constructions. This paper illustrates experimental pushover tests on two very similar portions of an existing masonry building. The first portion was tested as built, while the second one was tested after a strengthening intervention with Composite Reinforced Mortar (CRM) system with Glass Fiber Reinforced Polymer (GFRP) components. The retrofit consisted in the application of a reinforced plaster on both sides of the walls of the first storey and on the external side only of the second storey, a solution that preserves the continuity of use. Comparisons between the experimental response of the two portions as well as the observed behaviour of the intervention at the first storey (both wall sides) and second storey (only outer side) provide very interesting insights and preliminary information on the degree of upgrading, essential steps to support the assessment of seismic vulnerability reduction

Strategic inventories under limited commitment

In a dynamic storable good market where demand changes over time, we investigate the producer's strategic incentives to hold inventories in response to the possibility of buyer stockpiling. The literature on storable goods has demonstrated that buyer stockpiling in anticipation of higher future prices harms the producer's profitability, particularly when the producer cannot commit to future prices. We show that the producer's inventories act as a strategic device to mitigate the loss from the lack of commitment. Our results provide a rationale for the producer's inventory behavior that sheds new light on the well-documented empirical evidence about inventories

Analisi dei tempi d\u2019attesa tra le varie fasi di gestione dei carcinomi mammari screening-detected a Trieste nel biennio 2013-2014: come si pu\uf2 migliorare?

Gli indicatori relativi ai tempi di attesa sono difficili da rispettare, come recentemente evidenziato al XIII Convegno ONS 2015 . Per questo motivo \ue8 fondamentale identificare in quale momento della gestione dei carcinomi screening-detected si concentrino i ritardi e stabilirne le cause (se attribuibili alla paziente o all\u2019organizzazione del programma o intrinseci al tipo di lesione) cos\uec da proporre mirate modifiche migliorative. Metodi: L\u2019analisi riguarda 146 carcinomi screening-detected consecutivi (biennio 2013-2014). Sono stati misurati i tempi tra le varie fasi diagnostiche (Mammografia di I\ub0 livello, Richiamo II\ub0 livello, I\ub0 approfondimento cito/microistologico, Comunicazione diagnosi) e i tempi chirurgici (Visita chirurgica, Intervento chirurgico, Referto istologico con marcatori biologici, Visita oncologica). Per ogni fase sono stati calcolati i tempi medi/mediani rappresentati tramite box plot e giustificati gli outliers.Risultati: La latenza nella presa in carico chirurgica \ue8 legato alla complessit\ue0 degli esami preoperatori (3) (tempo mediano tra richiamo al II\ub0 livello ed intervento: 53 giorni (se unico esame pre-operatorio) vs 73 (se pi\uf9 di un esame pre-operatorio, p<0.0001), mentre rispetto ad un recente studio (4) il tempo mediano tra visita chirurgica e intervento non \ue8 aumentato per i casi con necessit\ue0 di RM (28 vs 26 giorni, p=0.13), perch\ue9 gi\ue0 programmata in fase preoperatoria. Per i casi con mastectomia sempre con ricostruzione, si registra un tempo medio dalla visita chirurgica all\u2019intervento di 7 giorni superiore rispetto alle quadrantectomie. Ulteriore criticit\ue0 \ue8 il tempo mediano tra intervento e visita oncologica (44 giorni), attribuibile in parte ad un \u201critardo\u201d nella disponibilit\ue0 dei marcatori biomolecolari (soprattutto HER2/FISH) ed in parte a rinvii dell\u2019appuntamento da parte della paziente stessa Conclusioni: Soltanto un attento monitoraggio del turnaround time dell\u2019intero percorso delle pazienti con carcinoma screening detected consente l\u2019identificazione dei punti di debolezza su cui intervenire efficacemente per garantire il rispetto degli indicatori

Diagonal shear tests of full scale FRM-strengthened limestone masonry walls

Fiber Reinforced Polymer (FRP) materials have been extensively studied and applied all over the world in the last two decades. Nowadays a new generation of inorganic composite materials is also widely studied for seismic strengthening of ancient masonry construction. The new technique is studied for those cases in which a localized epoxy-bonded reinforced show its limits due to the weak nature of the substrate. In these cases Fiber Reinforced Mortar (FRM) systems are used as external strengthening coating, in forms of fibrous grids immersed in a brittle matrix made by hydraulic or cementitious mortar. The results of an extensive experimental program are presented in this study, which involved twelve full scale masonry walls subjected to diagonal shear tests. Two different configuration of masonry walls were studied: six walls were built with a single layer of limestone masonry blocks and six walls were built with a double curtain of limestone blocks separated by a layer of inconsistent mortar and connected by six transverse bond-stones. Low-strength hydraulic mortar was used as binder between the blocks. These configuration were chosen to replicate typical walls found in real heritage masonry buildings. Two different strengthening FRM systems were applied on both sides of the specimens and studied. The first consisted of an industrially pre-cured rigid Glass FRP grid immersed in a lime-based mortar. The second system was an hybrid system made by a dry glass fiber net immersed in a lime-based mortar in which a polymer primer was added as bond promoter. The results of the mechanical tests highlighted in all cases a remarkable increase of shear strength due to the weak properties of the unstrengthened walls. Brittle failure due to diagonal sliding along the joint was observed in unstrengthened masonry. The presence of the FRM has resulted in a pseudo-ductile behaviour of the specimens in both cases, even if different failure modes were observed for the two FRM systems. Fiber rupture and a full composite action was observed for the polymer added FRM system, while extensive cracks and local spalling was observed by testing the fully inorganic system