482 research outputs found
Evaluation of the impact of separative collection and recycling of municipal solid waste on performance: An empirical application for Chile
The collection of municipal solid waste (MSW) is a public service with notable effects on the environment and public health. The objective of this study was to evaluate the impact of selective collection and recycling of MSW on the performance of municipalities in providing MSW services. By employing the data envelopment analysis method, the efficiency and eco-efficiency scores for a sample of 298 municipalities in Chile were analyzed and compared. The efficiency estimation focused on the economic performance of the municipalities in the provision of MSW services, whereas the eco-efficiency assessment also integrated the environmental performance. The results indicated that the selective collection and recycling of MSW had a significant impact on the performance of the municipalities in providing these services. The percentages of efficient and ecoefficient municipalities were very low (4.70% and 4.36%, respectively), thus demonstrating the large room for performance improvement by Chilean municipalities in the management of MSW. The efficient and eco-efficient municipalities were heterogeneously distributed throughout the country, revealing the lack of collaboration between municipalities at the regional level. Finally, exogenous variables to the management of MSW carried out by the municipalities, including the population served, population density, tourism and waste generated per capita, all had an impact on the efficiency and eco-efficiency scores. The results and conclusions of this study are of great relevance for policy makers at the regional and local levels to improve the management of MSW in the context of a circular economy
Stable isotope geochemistry of the Ulldemolins Pb-Zn-Cu deposit (SW Catalonian Coastal Ranges, Spain)
The Pb-Zn-Cu deposit of Ulldemolins occurs within the Carboniferous sedimentary series of the southernmost
Catalonian Coastal Ranges. It consists of sulphide-bearing calc-silicate assemblages, with epidote, Ca-amphiboles
and Ca-garnet, which develop selectively along a dolomicrite bed near the contact with a granite porphyry.
Two mineralisation styles can be differentiated: a) banded and b) irregular. Fluid inclusions and stable isotope
compositions of sulphur in sulphides (sphalerite, galena and chalcopyrite) and carbon and oxygen in carbonates
(calcite and dolomite) were studied in order to constrain the genesis and the source of mineralizing fluids. Fluid
inclusions in sphalerite and calcite are aqueous, liquid+vapour and have a salinity between 1.2 and 7.2 wt%
NaCl eq. and homogenization temperatures in the range of 273Âș to 368ÂșC. The ÎŽ34S(V-CDT) values in the banded
mineralisation are mostly between â1.5 and +2.1â°, and those from the irregular mineralisation are between â1.1
and +20.5â°. These ÎŽ34S values of the banded mineralisation are in agreement with a magmatic origin of sulphur.
In addition, the ÎŽ18O(SMOW) values of hydrothermal calcite, from +6.9 to +12.5â°, are consistent with a magmatic
origin of the fluids that formed the banded ore deposit. Later, a new input of fluids interacted with the previously
formed mineral assemblages and modified part of the deposit, leading locally to an irregular skarn mineralisation
Effect of phytoremediated port sediment as an agricultural medium for pomegranate cultivation: Mobility of contaminants in the plant
Although the dredging of ports is a necessary management activity, it generates immense quantities of sediments, that are defined by the European Union as residues. On the other hand, the relevant peat demand for plant cultivation compromises its availability worldwide. In this context, the present work wanted to find an alternative substrate in order to replace and/or reduce the use of peat in agriculture, through the study of the suitability, concerning the exchange of substrateâplantâwater pollutants, of the dredged remediated sediments as a fruit-growing media. Forty-five pomegranate trees (Punica granatum L. cv âPurple Queenâ) were cultivated in three types of substrates (100% peat as a control, 100% dredged remediated sediments and 50% both mixed). The metal ion content and pesticide residues were analysed in the different plant parts (root, stem, leaves and fruits) and in drainage water. The results showed a limited transfer of pollutants. All the pollutants were below the legal limits, confirming that the dredged sediments could be used as a growing media, alone or mixed with other substrates. Thus, the results point out the need to open a European debate on the reuse and reconsideration of this residue from a circular economy point of view
Molecular, physico-chemical, and sensory characterization of the traditional spanish apple variety "Pero de CehegĂn"
The "Pero de CehegĂn"is an ancient local variety of apple grown in Murcia (Spain). In this study, microsatellites markers showed evidence of a unique profile that has never been reported before in other Spanish apple germplasm collections. Five "Pero de CehegĂn"clones were evaluated and compared with two commercial apple varieties, "Fuji"and "Golden Delicious", to assess its marketing potential. For this, the physical (weight, height, and width of the fruit, moisture content, firmness, and color of the fruit, among others), and chemical (total soluble solids, total acidity, and maturity index) properties of the fruits were evaluated. In addition, the content of bioactive compounds such as total polyphenol content, total antioxidant activity using the ABTS+, DPPH, and FRAP methods, and the sugar profile were analyzed, and their sensory profile was also evaluated. Physico-chemical differences were found within the "Pero de CehegĂn"clones and between the commercial varieties. "Pero de CehegĂn"had a high firmness, high total soluble solids, very low total acidity, high FRAP antioxidant capacity, and more sucrose content in comparison with "Fuji"and "Golden Delicious". These distinctive characteristics and the good appearance of the fruit make this variety a marketable product that will increase the offering of traditional, local, but underutilized fruit varieties
On the origin of waters responsible for serpentinization processes in the MayarĂ-Baracoa Ophiolitic Belt (Eastern Cuba).
Estudio quimico biodirigido para la evaluacion de actividad antimalarica de la especie vegetal Piper aduncum mediante test FBIT
Performance of a cryogenic system prototype for the XENON1T Detector
We have developed an efficient cryogenic system with heat exchange and
associated gas purification system, as a prototype for the XENON1T experiment.
The XENON1T detector will use about 3 ton of liquid xenon (LXe) at a
temperature of 175K as target and detection medium for a dark matter search. In
this paper we report results on the cryogenic system performance focusing on
the dynamics of the gas circulation-purification through a heated getter, at
flow rates above 50 Standard Liter per Minute (SLPM). A maximum flow of 114
SLPM has been achieved, and using two heat exchangers in parallel, a heat
exchange efficiency better than 96% has been measured
âCondensaciĂłn de 4-Aminopirimidinas con galactosaâ
4-N-glycolsides (II) were prepared by reaction of 4-amino-1,6-dihydro-2- methylthio-6-oxo-pyrimidine (Ia) and 4-amino-1,6-dihydro-1-methylthio-6-oxo-pyrimidine (Ib) with galactose. Their acetyl derivatives III, were obtained by acetylation of the corresponding II with acetic anhydride and pyridine.Se obtienen los 4-N-glicósidos II, por reacción de 4-amino-1,6-dihidro-2- metiltio-6-oxo-pirimidina (Ia) y 4-amino-1,6-dihidro-1-metil-2-metiltio-6-oxopirimidina (Ib) con galactosa. Los compuestos II se acetilan con anhidrido acético y piridina, obteniéndose los correspondientes derivados acetilados III
Application of lca methodology to the production of strawberry on substrates with peat and sediments from ports
The Life Cycle Assessment (LCA) methodology was applied to identify the potential environmental impact of dredged sediments used as growing media for food crops. The dredged sediments used came from Livorno port and were previously phytoremediated. For the assay, strawberry plants (Fragaria x ananassa Duch vr. âSan Andreasâ) were used. The plants were cultivated on three different substrates (100% peat, 100% dredged sediment and 50% mix peat/sediment) to identify the real impact of the culture media on the growing process. LCA was calculated and analyzed according to ISO 14040:2006 by SimaPro software. ReCipe Midpoint (E) V1.13/Europe Recipe E method was applied. One kilogram of produced strawberry, for each crop media tested, was defined as the functional unit. Eighteen impact categories were selected where Marine Eutrophication (ME), Human Toxicity (HT) and Freshwater Ecotoxicity (FET) were identified as relevant impact categories. The LCA results showed an increase in the environmental impact of strawberry cultivation using 100% sediment against 100% peat, due to the decrease in fruit production caused by the sediment. Nevertheless, the decrease in the environmental impact and the fruit production increase identified when the sediment is used mixed (<50%) with other substrates. The appropriate use of these substrates would be justified within the context of the circular economy
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