Search results for "Gradation"

SHEAR STRENGTH DEGRADATION DUE TO FLEXURAL DUCTILITY DEMAND IN R.C. ELEMENTS

2014

A proposal is formulated that allows to evaluate the residual shear strength of reinforced concrete columns and beams for an assigned flexural ductility demand by limiting the range of the deviation angle between the inclinations of the yield  and the crack lines. In order to take into account the degradation due to cyclic loads, the reduction of the range of the deviation angle is related to the value of cinematic ductility

Sistemazione in situ o musealizzazione dei frammenti architettonici: problemi di conservazione dopo il terremoto di Messina del 1908

2012

After the big earthquake of Messina in 1908, a lot of important fragments of the ancient city, coming from destroyed palaces and churches, were transported in a open space near the ancient church of SS. Salvatore, where in an old silk factory was born the actual Regional Museum of Messina. The arrangement of those elements - as Marble sculptures, big fragments of architectural decorations, stone portals - was long debated and different architects, art historians and archaeologists produced ideas and projects about the costruction of a new museum and the arrangement in open space of many fragments, so important to maintaining the memory of the ancient city of Messina, destroyed by the earthq…

Environmental aging effects on high-performance biocomposites reinforced by sisal fibers

2023

Among the innovative materials, an important role is played by the so-called biocomposites, generally made by an eco-friendly matrix reinforced with natural fibers. Unfortunately, due to the degradability of the green matrixes as well as to hydrophilicity of the natural fibers, the resistance of such innovative materials to the environmental agents is, in general, relativity low, and it can significantly limit their use in outdoor conditions. To contribute to the knowledge of the effects of the leading environmental agents on the mechanical properties of highperformance biocomposites made of a green epoxy matrix reinforced by agave fibers, a systematic experimental testing campaign has been…

Degradation od Mater-Bi/wood flour biocomposites in active sewage sludge

2009

Assessment of performance degradation of hybrid flax-glass fiber reinforced epoxy composites during a salt spray fog/dry aging cycle

2022

The main goal of this paper is the evaluation of the performances reversibility of hybrid composites when they are dried after being aged in salt-fog environment. To this aim, epoxy composites reinforced with flax and glass fabrics respectively in the internal and external laminae were at first exposed to salt-fog (i.e., identified as wet phase) and then stored in controlled conditions (i.e., identified as dry phase). The flexural properties evolution of these composites as well as their water uptake and contact angle were monitored at varying time of both phases. The flexural strength and modulus of hybrid composites is 23.4% (17.9%) and 15.5% (12.9%) lower than unaged ones after 30 (15) d…

Flax–Glass Fiber Reinforced Hybrid Composites Exposed to a Salt-Fog/Dry Cycle: A Simplified Approach to Predict Their Performance Recovery

2023

Despite natural fibers gaining significant attention in recent decades, their limited performance and poor durability under humid environments cannot allow them to fully replace their synthetic counterparts as reinforcement for structural composites. In such a context, this paper aims to investigate how exposure to a humid/dry cycle affects the mechanical response of epoxy laminates reinforced with flax and glass fibers. In particular, the main goal is to assess the performance evolution of a glass–flax hybridized stacking sequence in comparison with the full glass and flax fiber reinforced composites. To this end, the investigated composites were first exposed to salt-fog for 15 or 30 days…

Photocatalysis in dimethyl carbonate green solvent: degradation and partial oxidation of phenanthrene on supported TiO2

2014

Dimethyl carbonate (DMC) is here proposed – for the first time – as a green organic solvent for photocatalytic synthesis. In this work, the photocatalytic partial oxidation of phenanthrene in dimethyl carbonate (DMC) by using anatase TiO2 as the photocatalyst is described as paradigmatic example of a green synthetic process starting from polycyclic aromatic hydrocarbons (PAHs). For comparison, the same reaction carried out also in ethanol, 1-propanol or 2-propanol is reported. The use of DMC as the solvent allowed us to achieve 19% and 23% selectivity towards 9-fluorenone and 6H-benzo[c]chromen- 6-one, respectively. The proposed approach may represent both a new green synthetic process and …

Graphite-supported TiO2 for 4-nitrophenol degradation in a photoelectrocatalytic reactor

2009

WOS: 000274769500044

Photodegradation of pharmaceutical drugs in aqueous TiO2 suspensions: mechanism and kinetics

2007

WOS: 000251165800003

Photocatalytic process intensification by coupling with pervaporation

2011

The integration of photocatalysis with a membrane separation process, in particular pervaporation, permits the recovery of valuable intermediate compounds (aromatic aldehydes) while they are produced avoiding their further degradation in the reactive ambient. In this way the yield and the conversion are enhanced. The coupling of the two processes is straightforward and the integration is complete even maintaining pervaporation and photocatalysis in two separate apparatuses provided that the process stream is continuously recycled at a sufficiently high flow rate. Additional advantages are: higher degree of purification of the aldehyde in the powder-free product stream, semicontinuous produc…