Search results for " meccanica"

Enabling robotic adaptive behaviour capabilities for new industry 4.0 automated quality inspection paradigms

2020

The seamless integration of industrial robotic arms with server computers, sensors and actuators can revolutionise the way in which automated non-destructive testing (NDT) is performed and conceived. Achieving effective integration and realising the full potential of robotic systems presents significant challenges, since robots, sensors and end-effector tools are often not necessarily designed to be put together and form a holistic system. This paper presents recent breakthroughs, opening up new scenarios for the inspection of product quality in advanced manufacturing. Many years of research have brought to software platforms the ability to integrate external data acquisition instrumentatio…

A mathematical model for the prediction of the injected mass diagram of a S.I. engine gas injector

2013

A mathematical model of gaseous fuel solenoid injector for spark ignition engine has been realized and validated through experimental data. The gas injector was studied with particular reference to the complex needle motion during the opening and closing phases, which strongly affects the amount of fuel injected. As is known, in fact, when the injector nozzle is widely open, the mass flow depends only on the fluid pressure and temperature upstream the injector: this allows one to control the injected fuel mass acting on the “injection time” (the period during which the injector solenoid is energized). This makes the correlation between the injected fuel mass and the injection time linear, e…

The evaluation of urban soils aimed at the sustainability of plants in public and private flowerbeds

2020

The authors report the survey of some flowerbeds located in the city of Palermo with the aim of assessing the sustainability of the plants and the interventions to be implemented, i.e. cutting or transfer of plants, to achieve a sustainable green. In the case in which it is possible to insert other plants in the flowerbeds, it is recommended to elaborate a project using programs that allow to have a preview of the spaces available for the new plants. This work is methodological and is aimed at creating a green that can achieve the functional objectives in relation to the site where it is located (sustainability in all aspects) and at low management costs with no or almost no irrigation prac…

Sustainable technologies for greenhouse systems

2020

The greenhouse cultivation system in European countries represents one of the most energy-intensive sectors in the agriculture and agro-industry sector. In this regard, renewable energies represent an innovative solution to reduce energy costs and environmental impacts. Both, the energy demands and the economic aspects are analyzed with regard to the main energy users, i.e.: heating and cooling systems, lighting and pumping for irrigation. This work considers the use of solar photovoltaic and thermal energy. The use of semi-closed greenhouses is also considered.

On relation between J-integral and heat energy dissipation at the crack tip in stainless steel specimens

2019

In this paper, an experimental procedure to evaluate the elastic-plastic J-integral at the tip of a fatigue crack is presented. According to this new approach, the elastic component of the J-integral is derived from Thermoelastic Stress Analysis, while the plastic component of the J-integral is derived from the heat energy loss. An analytical link is proposed to apply this new experimental technique. Therefore, the elastic-plastic J-integral range was evaluated starting from infrared temperature maps measured in situ during crack propagation tests of AISI 304L stainless steel specimens. It was found that the range of the infrared thermography-based J-integral correlated well the crack growt…

Ingegnerizzazione di una macchina prototipale per processi di saldatura linear friction welding

2012

Influence of the anisotropy of sisal fibers on the mechanical properties of high performance unidirectional biocomposite lamina and micromechanical m…

2021

Abstract High performance biocomposites reinforced by sisal fibers, are between the most promising materials that could be used in various fields, from automotive to civil constructions, thanks to their good mechanical performance, as well as to the low cost and the great availability of the fiber. Nevertheless, at present their practical use is prevented by the limited knowledge of their mechanical performance. The results of the present study have shown that the intimate fibrillar structure of the sisal fiber is associated with a high anisotropy involving not only the elastic parameters, but also the damage processes with typical fiber splitting phenomena, that influence noticeably the bi…

A quantitative investigation on the thermoelastic effect of CFRP laminates

2009

The thermoelastic effect on CFRP laminates with various lay-ups is investigated. A thick low crimp unidirectional fabric reinforcement is adopted. The measured thermoelastic signal is compared with predictions from two analytical models based on the meso-mechanical bulk properties of the lamina and on assuming a strain witness behaviour of the surface resin rich layer.

STUDIO DI UN’APPLICAZIONE IN CAMPO AERONAUTICO DI COMPOSITI STRUTTALI IBRIDI RESISTENTI AL FUOCO

2013

In the aeronautical/aerospace structural design the increasing demands of materials having high mechanical performance, has led to the a wide use of Polymeric Matrix Composites (PMCs) mainly reinforced by carbon fibers (Carbon Fiber Reinforced Plastics, CFRP). The main drawbacks in the use of such composites are due to high sensitivity to environmental features and low working temperatures; moreover, these materials do not tolerate the fire exposure because of the inflammability of both the matrix and the fibers. In order to develop a composite that combines the structural performance of CFRP with a good strength to high temperatures and fire, in the present work the use of a hybrid composi…

Biodiversità e caratteristiche bio-agronomiche in lenticchia (lens culinaris medik.).

2016

Tra le leguminose da granella la lenticchia (Lens culinaris Medik.), occupa un posto importante nella alimentazione umana, per la quantità e qualità di proteine contenute nel seme e per il contenuto di carboidrati associati alla bassa presenza di sostanze antinutrizionali. La coltivazione della lenticchia è ancora basata, nella maggior parte del mondo, su ecotipi locali e solo in pochi Paesi, come il Canada, si utilizzano varietà selezionate. La coltura, come molte leguminose minori, risulta poco presente negli ordinamenti colturali italiani e, negli ultimi decenni, la superficiecoltivata ha registrato una notevole riduzione a causa di ,molteplici fattori, come mancanza di germoplasma selez…