407 research outputs found
Analysis of the environmental performance of life-cycle building waste management strategies in tertiary buildings
At urban level, the generation Municipal Solid Waste and Construction and Demolition Waste is mostly related to the life-cycle of buildings. An evaluation method based on Life Cycle Assessment methodology is presented in this paper to make an analysis of the environmental performance of different life-cycle building waste management strategies in tertiary buildings. As a case study, several waste management strategies considering a tertiary building located in the city of Zaragoza in Spain, are studied. The aim of the case study is to compare the environmental impacts, in terms of Global Warming Potential, of the scenarios proposed focussing on the waste minimisation and avoidance of landfilling of at least 10% for the Municipal Solid Waste generation during a building''s use stage, and Construction and Demolition Waste generated during its construction and end-of-life. In case of Municipal Solid Waste, the results show that when a recovery scenario includes energy recovery from the residual fraction of the mechanical-biological treatment plant in the form of Refuse Derived Fuel, greater benefits in terms of the Global Warming Potential are obtained than with current scenarios of landfill deposition of the residual fraction. On the other hand, in case of Construction and Demolition Waste, a similar situation can be observed in case of an increase of the recovery rates of metals
Tratamiento quirúrgico de las pérdidas de sustancia cutánea en el carpo, mediante colgajos libres vascularizados en el perro
En el presente trabajo se describe la técnica de la transposición libre microquirúrgica de colgajos de piel, así como los resultados de dicha transferencia, realizada en cinco perros.At the present research the techníque of the free transposition mícrosurgícal of flaps is described, as well as the results from the performed transference in five dogs
Analysis of energy poverty intensity from the perspective of the regional administration: Empirical evidence from households in southern Europe
The current economic situation has increased the number of households in Europe experiencing restrictions and/or limitations of affordability of energy services, demonstrating the urgent need to intervene in those extreme cases in which households suffer the daily consequences of what is internationally defined as energy poverty. In such a context, this paper presents the results obtained in a case study characterising a sample of 615 households with demonstrated energy poverty in the region of Aragón (Spain). In parallel, the intensity of energy poverty in the studied cases is examined by measuring the percentage of energy expenditures with respect to income in the households that suffer it, and a descriptive analysis of the main determinants of energy poverty in the homes studied is presented as well as the policy implication at regional level
Sustainability reporting in view of the European sustainable finance taxonomy: Is the financial sector ready to disclose circular economy?
The European sustainable finance taxonomy requires financial and nonfinancial companies to provide investors with information about the environmental performance of their assets and economic activities. For financial institutions, making socially and environmentally responsible investments visible through a common label that guarantees specific standards for the entire European Union is crucial. Against this background, this study analyzes the evolution of sustainability reporting practices and their assurance in a sample of European financial institutions. To this end, we used a double qualitative methodological approach, based on (a) an external analysis of nonfinancial information and its relationship with the main economic-financial variables of the sample companies, and (b) a case study of a bank carried out through semi-structured interviews. This study provides an external measurement analysis of nonfinancial information in entities from different countries, which can contribute to broadening the scope and level of sustainability and circular economy accountability
Solar-assisted heat pump coupled to solar hybrid panels
A water-water solar-assisted heat pump (SAHP) is going to be installed on an academic building at the University of Zaragoza (Spain). It integrates a heat pump heating system with photovoltaics/thermal collectors and seasonal storage. Considerably higher performances than a conventional type air-source heat pump are expected to be reached. This paper shows the simulation of the system performed in trnsys, a graphically based software used to simulate the behaviour of transient systems. The obtained energy and monetary savings are analysed
Exergy assessment and exergy cost analysis of a renewable-based and hybrid trigeneration scheme for domestic water and energy supply
Exergy and exergy cost analyses are proposed as complementary methods for the assessment and better understanding of the efficiency of a hybrid trigeneration system based on renewable energy sources. The system combines photovoltaic/thermal collectors, an evacuated tube collector and a wind turbine and produces electricity, sanitary hot water and desalted fresh water for a single family house. The system includes two desalination technologies (reverse osmosis and membrane distillation) that consume power and heat respectively, and two kinds of energy storage devices (a hot water tank and two lead-acid batteries). The assessment is based on simulations developed by using TRNSYS software. As a first level of detail, exergy analysis is applied in ten-minute basis to selected plant components. As a second level of detail, it is proposed to apply exergy-based indicators that summarize the system behavior during a longer period of time (monthly basis). By using aggregated values, exergy accumulation terms become negligible, what allows applying symbolic thermoeconomics to calculate exergy cost and to analyze in depth the process of cost formation. The system has an exergy efficiency of 7.76% (6.68 due to electricity, 0.33 due to fresh water and 0.75 due to sanitary hot water)
Structure of a 13-fold superhelix (almost) determined from first principles.
Nuclear hormone receptors are cytoplasm-based transcription factors that bind a ligand, translate to the nucleus and initiate gene transcription in complex with a co-activator such as TIF2 (transcriptional intermediary factor 2). For structural studies the co-activator is usually mimicked by a peptide of circa 13 residues, which for the largest part forms an α-helix when bound to the receptor. The aim was to co-crystallize the glucocorticoid receptor in complex with a ligand and the TIF2 co-activator peptide. The 1.82 Å resolution diffraction data obtained from the crystal could not be phased by molecular replacement using the known receptor structures. HPLC analysis of the crystals revealed the absence of the receptor and indicated that only the co-activator peptide was present. The self-rotation function displayed 13-fold rotational symmetry, which initiated an exhaustive but unsuccessful molecular-replacement approach using motifs of 13-fold symmetry such as α- and β-barrels in various geometries. The structure was ultimately determined by using a single α-helix and the software ARCIMBOLDO, which assembles fragments placed by PHASER before using them as seeds for density modification model building in SHELXE. Systematic variation of the helix length revealed upper and lower size limits for successful structure determination. A beautiful but unanticipated structure was obtained that forms superhelices with left-handed twist throughout the crystal, stabilized by ligand interactions. Together with the increasing diversity of structural elements in the Protein Data Bank the results from TIF2 confirm the potential of fragment-based molecular replacement to significantly accelerate the phasing step for native diffraction data at around 2 Å resolution
Irrigation from the Sixties: Flumen-Monegros
53 Pags.- Tabls.- Maps.In arid and semiarid areas, agricultural land use is mainly restricted, in the first place, by the
availability of water for crop growth.
The transformation to irrigation of about 600 000 ha in the Ebro Valley has led to high
increases in yield and in diversity of crops.
After the Spanish Civil War (1936-39), which was followed by II World War, the Spanish
food production system was heavily disrupted and food shortages appeared. This put high
pressure on the development of new irrigated schemes which had been planned many
years ago.
In the Flumen-Monegros area, the technology available in the late fifties was based on
flood-irrigation systems, with no previous soil studies, an empirical land evaluation, no
control of saltinization risk and, finally, levelling without topsoil preservation.
The extension of salinity and/or sodicity-affected soils in the Ebro Valley (IRYDA, 1977) was
200 000 ha, from which 160 000 were located in Aragon, mainly in Bardenas, Cinca and
Flumen-Monegros area. But Alberto et al. (1984) reckron this data in 300 000 ha. As a
result of these studies, ILACO (1975) designed two experimental drainage plots.
Although the existence of salt-affected soils was known, information about the extent,
location and general functioning at landscape level of those soils was lacking in the area.
Some of the problems related to land use and soil management which are present now in
the area or can be expected in the near future are:- Salinity-Sodicity: Diagnosis, monitoring and rehabilitation of salt-affected soils.
- Soil structural degradation and surface crust formation.
- Need for improved efficiency in water use: irrigation technology, water reuse, ...
- Control of drainage-system degradation: open-air drains as well as underground drains.
Several approaches at different scales have been adopted to work on these issues.
Satellite images have been used to monitor land use and its temporal variability. Classical
soil mapping at 1: 100000 level have been performed; in addition various detailed studies
have been undertaken in model areas using the electromagnetic and four electrode
sensors, micromorphological techniques, scanning electronic microscopy, and land
evaluation procedures.
The results have been presented in several papers: about salinity-sodicity trends in the
Flumen sector (Herrero, 1987); about parameters related to water behaviour (Aragues,
1986); about soil porosity in plough horizons (Rodriguez-Ochoa, 1998); about translocation
of solid materials (Rodriguez-Ochoa, et al. 1989; Porta and Rodriguez-Ochoa, 1991;
Rodriguez-Ochoa, 1998); about degradation of underground drainage systems by mineral
siltation (Herrero et al. 1989; Rodriguez-Ochoa, et al. 1989; Munoz, 1991; RodriguezOchoa,
1998).Other studies performed in the area include: Soil-vegetation relationships (Herrero, 1981);
laboratory trials with different amendments in the drainage trench infilling material (Porta et
al. 1996); dispersive processes because of soil structural instability (Amezketa and
Aragues, 1990; Aragues and Amezketa, 1991; Amezketa and Aragues, 1995) and
degradation of the hydraulic conductivity of soils (Amezketa and Aragues, 1989; Aragues
and Amezketa, 1991; Amezketa and Aragues, 1995).
The trip to the Flumen-Monegros area undertakes some of these points, and the stops are
located in some of the main soil units.
Discussion will be centered on aspects of soil genesis, classification and mapping, land use
and soil conservation.Peer reviewe
Analysis of a domestic trigeneration scheme with hybrid renewable energy sources and desalting techniques
In this paper, experimental tests of a hybrid trigeneration pilot unit based on renewable energy sources are presented and analyzed. The plant provides electricity by coupling four photovoltaic/thermal collectors and a micro-wind turbine, fresh water by means of hybrid desalination (membrane distillation, and reverse osmosis), and sanitary hot water coming from the photovoltaic/thermal collectors and an evacuated tubes collector. Plant design was previously modeled to cover the power, freshwater and sanitary hot water for a typical family home (four residents) isolated from the power and water networks. The hybrid pilot unit has been tested from May 2017 to March 2018 in Zaragoza (Spain). Results from those tests show that daytime assessment of power, freshwater and sanitary hot water produced allowed a good coverage of scheduled energy and water demands. Flexible operation due to the combined production of power and heat was also observed. State of charge of the batteries and the temperature of the sanitary hot water tank are the key control variables, which allow to give priority to power, freshwater or sanitary hot water production according to the ordered demands or economic incentives. Environmental assessment of the pilot unit along its life cycle also has shown very low impacts with respect to the conventional supply of energy and water
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