Search results for " Efficiency"
showing 10 items of 1091 documents
Climate variability and agriculture in Italy: a stochastic frontier analysis at the regional level
2020
In the next future, climate change effects will represent a challenge for Europe and the Mediterranean area. These will have to cope with a rapid increase in climate variability. Although many economic sectors may be affected, agriculture is the most susceptible as climate heavily affects crop production trends, yield variability and the availability of areas suitable for cultivation. Using the stochastic frontier approach, the aim of this work is to analyse the impacts of climate variability on Italian regional technical efficiency in the agricultural sector for a period spanning from 2000 to 2009. Considering that technical inefficiency could be influenced by two main annual meteorologica…
Le filiere del sistema agricolo per l'energia e l'efficienza energetica
2011
Increasing the use of renewable energies and Energy Efficiency offer significant opportunities for Italy to reduce fossil energy, greenhouse gas emissions and secure its energy supply. This report presents a brief analysis of the most important supply chains of the Agriculture system. Greatest attention is paid to the significant role that agriculture and its supply chains are likely to play in terms of bioenergy production and energy saving. Special attention is devoted to new agricultural activities like those associated with the reduction of vegetable food waste, the agrotourism, the urban agriculture, the plastic coverings and the greenhouses, the plant protection and the fertilizers. D…
Energy use efficiency of livestock farms in a mountain area of Sicily
2009
The research aimed to evaluate the performance (in terms of energy) of livestock farms located in a Mediterranean mountain area and characterized by different stocking rates. Farm data were collected from in-person interviews of farmers of 58 farms representative of the livestock farms of the Madonie and Nebrodi mountains area (Sicily, Italy), including several parameters related to farm characteristics, animal, crop and pasture management. The farm parameters were used to calculate input and output energy values from which agroecosystem performance indicators were derived. Increasing stocking rate corresponded to a more than proportional increase in total inputs per unit area because of a …
Cover crop management and water conservation in vineyard and olive orchards
2021
Abstract Sustainability in orchard crops is an important goal for farmers, decision-makers and consumers. The United Nations Sustainable Development Goals emphasize the importance of the soils in the Earth System to achieve sustainability and accomplish the Land Degradation Neutrality Challenge. Within the world agriculture land, olive and vineyards are within the eldest crops in the world, and they are also the ones with the highest degree of soil degradation. Cover crops (CC) are widely accepted as sustainable crop management that reduces soil and water losses, restores organic matter, increases biodiversity and fertility in degraded agriculture soils. The agriculture land must shift into…
Researches on the Alternative Fuels Which Can Be Used to Motors
2010
The alternative fuels are substances or materials used as fuel, other than the old conventional fuels (oil, natural gases and coals). 
 The paper analyses the most important alternative fuels, such as: bio-diesel, alcohols and hydrogen, presenting at each category the main important characteristics, the advantages and disadvantages presented by them. 
 The methyl-ester which is known as bio-diesel can be used in all motors with ignition by compression, alone or mixed in any proportion with oil, with minor modifications at the injection system. Bio-diesel fuel assures the same motor power as oil does, having even a bigger cetanic number than the usual oil. After tests, it was obser…
Material Substitution for Automotive Applications: A Comparative Life Cycle Analysis
2012
Lightweight materials have become an important strategy in the automotive industry to enable vehicle weight reduction and reduce fuel consumption. However, when developing specific strategies, the overall benefits of any material should be analyzed throughout its life cycle to comprehend energy/environmental differences that arise during its processing and its final use. A key example is aluminum which despite having great potential in the use phase requires large amounts of energy to process. This paper provides a comparison between aluminum and steel utilizing a life-cycle approach. This approach reveals the importance of incorporating a recycling strategy to leverage aluminum’s low-weigh…
An Intelligent System for Energy Efficiency in a Complex of Buildings
2012
Energy efficiency has nowadays become one of the most challenging task for both academic and commercial organizations, and this has boosted research on novel fields, such as Ambient Intelligence. In this paper we address the issue of timely and ubiquitous monitoring of building complexes in order to optimize their energy consumption, and present an intelligent system addressed to the typical end user, i.e. the administrator, or responsible operator, of the complex. A three-level architecture has been designed for detecting the presence of the building inhabitants user and understanding their preferences with respect to the environmental conditions in order to optimize the overall energy eff…
A qualitative examination of performance and energy yield of photovoltaic modules in southern Norway
2010
Three different, commercially available photovoltaic modules have been monitored outdoors in the town of Grimstad, Norway. The present paper describes the experimental setup that was implemented, in particular details of the low-cost electronic loads. Results compare measured performance with manufacturer's data, and temperature measurements enable a comparison with performance at standard test condition temperature. Overall, the monocrystalline module performed best both regarding maximum efficiency and overall energy production, whereas the module based on triple junction amorphous silicon technology had the worst performance considering these criteria. The gross numbers of energy yield c…
Plasmonic and diffractive nanostructures for light trapping—an experimental comparison
2015
Metal nanoparticles and diffractive nanostructures are widely studied for enhancing light trapping efficiency in thin-film solar cells. Both have achieved high performance enhancements, but there are very few direct comparisons between the two. Also, it is difficult to accurately determine the parasitic absorption of metal nanoparticles. Here, we assess the light trapping efficiencies of both approaches in an identical absorber configuration. We use a 240 nm thick amorphous silicon slab as the absorber layer and either a quasi-random supercell diffractive nanostructure or a layer of self-assembled metal nanoparticles for light trapping. Both the plasmonic and diffractive structures strongly…
High-efficiency silicon-compatible photodetectors based on Ge quantum dots
2011
We report on high responsivity, broadband metal/insulator/semiconductor photodetectors with amorphous Ge quantum dots (a-Ge QDs) as the active absorbers embedded in a silicon dioxide matrix. Spectral responsivities between 1-4 A/W are achieved in the 500-900 nm wavelength range with internal quantum efficiencies (IQEs) as high as ∼700%. We investigate the role of a-Ge QDs in the photocurrent generation and explain the high IQE as a result of transport mechanisms via photoexcited QDs. These results suggest that a-Ge QDs are promising for high-performance integrated optoelectronic devices that are fully compatible with silicon technology in terms of fabrication and thermal budget. © 2011 Amer…