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101.
Rodrigo del Pozo Victorino Diez Gonzalo Salazar Juan J Espinosa 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2006,81(3):282-288
This paper evaluates the performance of a laboratory‐scale anaerobic fixed‐film reactor (AFFR) with arranged media treating slaughterhouse wastewater. The reactor was operated at 20 °C, its organic loading rate was increased from 1.8 to 9.2 kg COD m?3 d?1, and it had a short hydraulic residence time (5–9 h). The influence of wastewater concentrations on its performance was studied by artificially increasing the blood content of the wastewater. The efficiency of the removal of organic matter decreased from 70% to 54% as the superficial velocity increased from 0.12 to 0.97 m h?1, due mainly to distribution defects, as had been confirmed experimentally by tracer tests. The kinetics of the anaerobic processes was limited by substrate availability, even at high COD concentrations (between 700 and 1100 mg dm?3) due to a high content of slowly biodegradable and inert compounds present in the wastewater from the slaughterhouse. It was observed that a large amount of the organic matter had accumulated inside the reactor instead of being removed by methanogenic digestion. Furthermore, the fraction of organic matter held inside the reactor varied significantly in relation to the blood content of the wastewater. Copyright © 2005 Society of Chemical Industry 相似文献
102.
The effect of kraft mill sludge addition (25 to 75 ton/ha) to soil derived from volcanic ashes (Andisol) on wheat (Triticum aestivum L.cv. Puken) biomass production, and in the nutrient absorption by the plants was evaluated. Respiration activity and seed germination tests were carried out on the soil/sludge mixtures, in order to evaluate possible toxic effects due to the sludge addition to the soil. Soil without sludge was used as a control treatment. The plants were grown in a greenhouse (25 degrees C, 14 h-photoperiod) during 120 days, then the plants were collected and dried at 65 degrees C for 72 h for the determination of biomass production (root and aerial) and analyzed for mineral content (Ca, Mg, K and P). The mixtures of soil/sludge showed no toxicity. Seed germination and respiration activity increased with the increment of the sludge. The accumulated CO2 in the soil without sludge was 41.66 mg CO2/100; this value shows a low microbial activity. The biomass increased with the increment of sludge addition to the soil and five times more biomass was obtained when 75 ton/ha sludge was added to the soil. The nutrient absorption efficiency was also improved with the sludge addition. 相似文献
103.
Physico-chemical gradients and meromictic stratification in Cueva de la Mora and other acidic pit lakes of the Iberian Pyrite Belt 总被引:1,自引:1,他引:0
Javier Sánchez España Enrique López Pamo Marta Diez Esther Santofimia 《Mine Water and the Environment》2009,28(1):15-29
A marked vertical trend of increasing temperature and dissolved metal concentrations is observed in the monimolimnia of some
meromictic pit lakes of the Iberian Pyrite Belt (IPB) in SW Spain. Temperature differences between the chemocline and the
pit lake bottom can be as high as 15°C (e.g. Herrerías), and the respective concentration of some metals (e.g. Fe) and metalloids
(e.g. As) can increase by several orders of magnitude (e.g. Cueva de la Mora). The redox conditions also change drastically
from the upper and oxygenated mixolimnion (strongly oxidizing) to the lower and anoxic monimolimnion (moderately reducing).
Processes such as the inflow of metal–sulphate laden ground water from flooded shafts and galleries, and other factors such
as the pit geometry or the relative depth of the lakes, must be considered to account for the observed stratification pattern.
The vertical profiles of physico-chemical parameters and water chemistry obtained in Cueva de la Mora and other meromictic
pit lakes of the IPB are also compatible with a reactive bottom in which several geochemical and microbial reactions (including
reductive dissolution of Fe3+ minerals, bacterial reduction of Fe3+ and SO4
2− in pore waters within the sediments, and decomposition of organic matter) could be taking place. 相似文献
104.
Rubio-Loyola Javier Aguilar-Fuster Christian Diez Luis Agüero Ramon Luis-Gorricho Juan Serrat Joan 《Wireless Networks》2020,26(5):3119-3137
Wireless Networks - The cell assignment problem is combinatorial, with increased complexity when it is tackled considering resource allocation. This paper models joint cell assignment and resource... 相似文献
105.
Nunzia La Maida Manuela Pellegrini Esther Papaseit Clara Prez-Ma Lourdes Poyatos Mireia Ventura Liliana Galindo Francesco Paolo Busard Simona Pichini Magí Farr Emilia Marchei 《International journal of molecular sciences》2020,21(24)
The consumption of synthetic cannabinoids (SCs) has significantly increased in the last decade and the analysis of SCs and their metabolites in human specimens is gaining interest in clinical and forensic toxicology. A pilot study has been carried out using a combination of an initial last generation gas chromatography-mass spectrometry (GC-MS) screening method for the determination of JWH-122, JWH-210, UR-144) in oral fluid (OF) of consumers and an ultra-high performance liquid chromatography high resolution mass spectrometry (UHPLC-HRMS) confirmatory method for the quantification of the parent compounds and their metabolites in the same biological matrix. OF samples were simply liquid-liquid extracted before injecting in both chromatographic systems. The developed methods have been successfully validated and were linear from limit of quantification (LOQ) to 50 ng/mL OF. Recovery of analytes was always higher than 70% and matrix effect always lower than 15% whereas intra-assay and inter-assay precision and accuracy were always better than 16%. After smoking 1 mg JWH-122 or UR-144 and 3 mg JWH-210, maximum concentration of 4.00–3.14 ng/mL JWH-122, 8.10–7.30 ng/mL JWH-210 ng/mL and 7.40 and 6.81 ng/mL UR-144 were measured by GC-MS and UHPLC-HRMS respectively at 20 min after inhalation. Metabolites of JWH 122 and 210 were quantified in OF by UHPLC-HRMS, while that of UR144 was only detectable in traces. Our results provide for the first time information about disposition of these SCs and their metabolites in consumers OF. Last generation GC-MS has proven useful tool to identify and quantify parent SCs whereas UHPLC-HRMS also confirmed the presence of SCs metabolites in the OF of SCs consumers. 相似文献
106.
Monitoring a PGD solver for parametric power flow problems with goal‐oriented error assessment
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R. García‐Blanco D. Borzacchiello F. Chinesta P. Diez 《International journal for numerical methods in engineering》2017,111(6):529-552
The parametric analysis of electric grids requires carrying out a large number of power flow computations. The different parameters describe loading conditions and grid properties. In this framework, the proper generalized decomposition (PGD) provides a numerical solution explicitly accounting for the parametric dependence. Once the PGD solution is available, exploring the multidimensional parametric space is computationally inexpensive. The aim of this paper is to provide tools to monitor the error associated with this significant computational gain and to guarantee the quality of the PGD solution. In this case, the PGD algorithm consists in three nested loops that correspond to (1) iterating algebraic solver, (2) number of terms in the separable greedy expansion, and (3) the alternated directions for each term. In the proposed approach, the three loops are controlled by stopping criteria based on residual goal‐oriented error estimates. This allows one for using only the computational resources necessary to achieve the accuracy prescribed by the end‐user. The paper discusses how to compute the goal‐oriented error estimates. This requires linearizing the error equation and the quantity of interest to derive an efficient error representation based on an adjoint problem. The efficiency of the proposed approach is demonstrated on benchmark problems. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
107.
M.A. Madre F.M. Costa N.M. Ferreira A. Sotelo M.A. Torres G. Constantinescu Sh. Rasekh J.C. Diez 《Journal of the European Ceramic Society》2013,33(10):1747-1754
High-performance Ca3Co4O9 thermoelectric ceramic has been prepared from a Ca1?xCoxO/CayCo1?yO divorced eutectic structure produced by a directional melt-grown using the laser floating zone technique. This material has been grown at very high solidification rate in order to produce a very fine microstructure to reduce the necessary annealing time to recover the Ca3Co4O9 thermoelectric phase as the major one. As-grown and annealed samples were microstructurally characterized to determine the phases and estimate the extent of Ca3Co4O9 formation with time and related with their thermoelectric performances. The optimum annealing time, 72 h, has been determined by the maximum power factor value (about 0.42 mW K?2m?1), which is around the best values reported in textured materials (~0.40 mW K?2m?1). This high power factor outcome from the high Ca3Co4O9 phase content, apparent density and Co3+/Co4+ relationship determinations performed in the present work. 相似文献
108.
J. Diez R. Bellas J. López G. Santoro C. Marco G. Ellis 《Journal of Polymer Research》2010,17(1):99-107
Vulcanizates of hot and cold styrene-butadiene rubber (SBR) were prepared with five different cure systems based on sulphur,
2-mercaptobenzothiazole disulphide (MBTS) and tetramethylthiuram disulphide (TMTD). The degree of crosslinking was investigated
by swelling in benzene and stress-strain analysis. Thiol-amine chemical probes were employed to determine the type of crosslinks
in the sulphur vulcanizates, and their dynamic-mechanical properties and thermal stability were studied in both the raw (non-crosslinked)
and crosslinked state. The butadiene microstructure and the total unsaturation were determined by Raman spectroscopy. The
influence of the crosslink density and the type of crosslink formed on the measured properties is discussed. 相似文献
109.
Structural, superconducting and mechanical properties of molybdenum substituted Bi1.8Sr2Ca1.1Cu2.1Oy
Berdan Özkurt M. A. Madre A. Sotelo J. C. Diez 《Journal of Materials Science: Materials in Electronics》2013,24(4):1158-1167
The effect of MoO3 addition on the properties of Bi-2212 superconducting ceramic samples prepared by solid state reaction method has been investigated. Mo content was varied from 0 to 0.25 on a general stoichiometric formula Bi1.8Sr2MoxCa1.1Cu2.1Oy. Electrical resistivity showed that transition temperature width increased directly with the Mo amount. XRD data have shown that MoO3 addition in the Bi1.8Sr2MoxCa1.1Cu2.1Oy precursor reduces the amount of Bi-2212 phase. In addition, Jc values of the samples, calculated from the hysteresis loops using the Bean’s model, decreased with increasing Mo substitution. Vickers microhardness measurements show that samples are very sensitive to Mo content and applied load. In addition, various models like Meyer’s Law and Young’s Modulus equations have been used to better explain the mechanical properties of samples. 相似文献
110.
Martín F Diez M García I Simón M Dorronsoro C Iriarte A Aguilar J 《The Science of the total environment》2007,378(1-2):49-52
In the present work, soil profiles were sampled 40 days and three years after an accidental pyrite tailing spill from the Aznalcóllar mine (S Spain) in order to figure out the effects of the acidic solution draining from the tailing. The composition of the acidic solution, the mineralogy, and the total and soluble content of the major elements were analysed at varying depths. The results show a weathering process of carbonates and of primary silicates. Calcium released is leached or reacts with the sulphate ions to form gypsum. Magnesium, aluminium and potassium tend to leach from the uppermost millimetres of the soil, accumulating where the pH>/=5.0; also the iron, probably forming more or less complex hydroxysulphates, precipitate in the upper 5 cm. The strong releasing of soluble salts increases the electrical conductivity, while the soluble potassium tends to decrease in the uppermost part of the soil due to the neoformation of jarosite. Iron is soluble only where the pH=2.3, and aluminium where the pH=5.5. 相似文献