1,721,078 research outputs found
Carbon footprint, water footprint e CED (Cumulative Energy Demand) di pomodori "Cuor di bue" cresciuti in serra
No full textMicro Scale Slow-Pyrolysis Rotary Kiln for Syngas and Char production from biomass and waste
No full textOptimal sizing of solar-assisted heat pump systems for residential buildings
Full text linkThis paper analyzes the optimal sizing of a particular solution for renewable energy residential building integration. The solution combines a photovoltaic (PV) plant with a heat pump (HP). The idea is to develop a system that permits the maximum level of self-consumption of renewable energy generated by using a small-scale solar array installed on the same building. The problem is analyzed using data obtained from an experimental system installed in a building in Pisa, Italy. The residential house was equipped with a PV plant (about 3.7 kW of peak power), assisting a HP of similar electrical power (3.8 kW). The system was monitored for eight years of continuous operation. With reference to the data acquired from the long-term experimental analysis and considering a more general perspective, we discuss criteria and guidelines for the design of such a system. We focus on the possibility of exporting energy to the electrical grid, from the perspective of obtaining self-consumption schemes. Considering that one of the problems with small-scale PV plants is represented by the bidirectional energy flows from and to the grid, possible alternative solutions for the design are outlined, with both a size reduction in the plant and utilization of a storage system considered. Different design objectives are considered in the analysis
Assessment of Reverberation Times in University Classroom: Comparison between Analytic Formulae, Software Simulations and Measurements
No full textThe quality of listening in schools strongly affect the learning process of pupils. Different techniques have been developed to evaluate it in indoor environments, and among the reverberation time is the most frequently used factor. In the early design stage, the reverberation time can be evaluated by analytical correlations or software simulations. In this paper, the reverberation times obtained using analytical formulae and software simulations have been analysed and compared with those obtained by a measurement campaign, in order to evaluate the accuracy of these design tools. The analysis has been carried out in the classrooms of the School of Engineering of the University of Pisa
Integrated Pyrolysis Regenerated Plant (IPRP): An efficient and scalable concept for gas turbine based energy conversion from biomass and waste
No full textA massive effort towards sustainability is necessary to prevent global warming and energy sources impoverishment: both biomass and waste to energy conversion may represent key actions to reach this goal. At the present, state of the art available technologies for biomass and waste to energy conversion are similar and include low to mid efficiency grate incineration or fluidized bed combustion with steam power cycles or mid to high efficiency gas turbine based cycles through integrated gasification technology. Nevertheless, these plants are all available from mid-to-high scale range that can be highly intrusive on protected areas and socially unacceptable. This paper proposes an innovative, low cost, high efficiency plant in which the residue is gasified in the absence of oxygen (pyrolysis), in a rotary kiln, by means of a highly regenerative gas turbine based cycle. Pyrolysis is preferred to gasification, because the syngas obtained has a higher low heating value and produces char or tar as a by-product with an interesting energy content to be re-utilized inside the cycle. Different plant configurations are proposed and discussed through principal thermodynamic variables parametric analysis. Results show that very interesting efficiencies are obtainable in the 30-40% range for every plant scale. This fact shows how IPRP technology can provide an interesting alternative to traditional technologies, especially for the small size (below 5MW). Moreover, the IPRP technology provides a unique solution for microscale (below 500 kW) power plants, opening a new and competitive possibility for distributed biomass or waste to energy conversion systems where low environmental and social impact turns into higher interest and positive dissemination effect
An evaluation of compliance in the use of mouth protection devices (Mgs) in a group of young athletes
No full textIntroduction: The use of mouth guards is strongly recommended in a number of sports, and there are numerous works in the relevant literature that stress the effectiveness and importance of using personal Mouth Guards (M.Gs.) It is also common knowledge that persuading people, especially young children, to use these protective devices regularly is not an easy task.
Aim:This study has aimed to establish whether or not the use of an electronic system measuring frequency of use, installed directly in the Mouth guard, will encourage young sportspeople to use these devices without the need for continuous motivational reinforcement The appliance used is known as Thera Mon and is a Class I Medical Device. Thera Mon is an electronic system which provides constant documentation of the actual wearing time of removable appliances.
Materials and methods: We carried out a preliminary observational study on the behavior manifested by a group of 12 young males who wore mouth guards equipped with the electronic measuring system four times a week for nine months, without any external motivational reinforcement being provided. The procedure used to produce the mouth-guards was the traditional Tecnica Erkodent for the Medium three-layer model of the Play safe teeth-guard line.
Results: We found that all the young sports-people had remained in the screening program. Specifically, 7 participants had continued to use their mouth guards regularly (4 times a week), 3 had used their devices not more than three times a week and 2 used theirs only during competition events.
Conclusion: These findings show that the use of these devices does not influence participants’ attitude to wearing them. Indeed, they demonstrated a willingness to use them regularly and we believe that particularly in the case of young children who practice sports, it is a method that can replace or provide a valid alternative to the established motivational reinforcement methods that may at times be unreliable
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