1,721,017 research outputs found
QUANTA ACQUA SI RISPARMIA Se il raffrescamento è efficiente
No full textRidurre la durata della doccia da 90 a 80 secondi comporta un risparmio di acqua del 9%; aumentare il tempo di ventilazione da 10 a 12 minuti del 13,5%. I piccoli accorgimenti che fanno la differenza
Raffrescare la stalla, quando e per quanto tempo
No full textGli impianti di raffrescamento evaporativo hanno performance migliori con tassi bassi di umidità. Ma è importante sapere come gestire: durata dell' aspersione, durata della fase di ventilazione, portata di acqua dell'aspersore e dimensione delle gocce
An Active Drying Sensor to Drive Dairy Cow Sprinkling Cooling Systems
Full text linkThe use of sprinkling with ventilation to cool dairy cows is considered an appropriate practice to reduce the negative effects of heat stress. However, due to climate change, water will increasingly become a limited resource, so we need to make water use more and more efficient. For this purpose, an active drying sensor has been developed in order to time the sprinkling cooling system. The sensor reproduces the thermal response of a cow, considering both sensible and latent heat exchange, and is located in the feeding alley, about two meters above the floor. This allows the fabric of the sensor (simulating the fur) to be wetted by the sprinkler, and blown by the fan. The water content of the sensor fabric during the drying time is monitored by measuring its electrical conductivity, allowing the estimation of the time the fur becomes dry. Another two specifically designed instruments are presented, the first to estimate the fur's water content after spraying, and the second to detect the time the fur became dry. Sensor output, interpreted through a simplified model, gave a predicted drying time with an error ranging between -11.4% and +14.8% (R-2 = 0.789). In the commercial barn where the experiments were conducted, the use of the sensor allowed an estimated reduction in water consumption of about 57%, with respect to the fixed timing normally used. As a perspective, the sensor could be used to assess cows' heat stress level
La teoria positiva del beneficio e la finanza democratica in una prospettiva storica
No full textThis paper addresses the historical evolution of benefit-based taxation,
with particular reference to the contribution of the Italian school of public
finance. In particular, it is shown that the positive interpretation of the benefit
theory as a criterion of rationality and judgment is well established in the Italian
tradition of public finance. Indeed, the practice of taxation as interpreted by
Italian scholars reflects more the outcome of a political bargaining, rather than
the consistent application of any normative principle. Under this perspective, the
benefit theory may help the functioning of a system of democratic finance, in
order to avoid large deviations of the level of taxation from its natural path.
Thus, the concept remains of a fundamental role played by the benefit principle
in its positive guise as a base for judgments and control of the action of
governments. Furthermore, it could justify both the transition from progressive
to proportional taxation and the transition from central to local finance
The asymmetric impact of the pandemic crisis on interest rates on public debt in the Eurozone
No full textThe outbreak of Covid-19 has played the role of a ‘game changer’ in the way countries of the Eurozone have faced the economic consequences of the pandemic crisis. This paper investigates what has happened to the interest rates of the sovereign bond in selected countries of the Eurozone during 2020. While the pandemic crisis can be interpreted as a symmetric shock, we found some important asymmetric consequences both in the sovereign bond market and the credit default swap market. Even though the European Central Bank (ECB) has played a fundamental role in easening tensions, especially with the announce of the Pandemic Emergency Purchase Programme (PEPP), countries with a higher pre-Covid level of the debt-to-GDP ratio have been found to undergo a significant jump in interest rates and a greater perceived risks of default. Important policies implications emerge in relation to the future role of the ECB
Measuring health inequality in US: a composite index approach
No full textIn this paper, we use the standardized mortality rates for 21 mutual exclusive causes of death to propose a composite index of US county-level health performances in 1980–2014 interval. We aggregate mortality rates by the stochastic multi-criteria acceptability analysis (SMAA), in order to avoid any a priori judgement on the importance given to a specific cause of death. The total observed inequality among counties is then decomposed to estimate the variability between and within states by means of the Theil index on SMAA outcomes. On average, there has been a decrease in the Composite Index of mortality from 1980 to 2014, but while the majority of counties had an increase in health conditions, some counties have shown a decrease in health performances in the same interval. This may be the reason of a persistent increase of total inequality among counties, with inequality within states constantly higher than inequality between states, both responsible of the growing inequality levels of health performances in the period analysed
A decomposition of the Personal income tax changes in Italy: 1995-2000
No full textwww.unipv.it/websiep/wp/406.pd
Optimization of ventilated roofs for livestock housing
No full textThis paper aims at optimizing the performance of roofing components equipped with a ventilated interspace in order to reduce the heat load inside the animal houses. By means of a theoretical model and experimental tests, the three-dimensional profile of the air temperature in the duct is determined. Consequently the air temperature inside a typical house for livestock is calculated. The air flow is considered uniform inside the rectangular duct and the thermal problem is solved by adopting H2 boundary conditions. The air temperature in the house is then calculated and the optimal duct thickness minimizing it was determined
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