119 research outputs found
Brachypotherium aurelianense (NOUEL)(Perissodactyla, Rhinocerotidae) del Mioceno inferior continental valenciano (Buñol, Valencia)
En esta nota se cita por primera vez la presencia de Brachypothcrium aurelianense en el Orleaniense de Buñol (Valencia). Se describen las escasas piezas atribuibles a esta especie y se comparan con otros Rinocerdtidos estratigrAficamente próximos. Continuamos utilizando la denominacidn de B. aurelianense ya que consideramos que las pruebas aducidas por Antunes et Ginsburg (1983) no son suficientes para que la especie de NOUEL deba considerarse como Diaceratheriurn
Effect of Low Power 655 and 830 nm Diode Laser Irradiation on the Neuromuscular Junctions of Mouse Diaphragm
https://digitalrepository.unm.edu/abq_citizen_news/4237/thumbnail.jp
Effect of Low Power 655 and 830 nm Diode Laser Irradiation on the Neuromuscular Junctions of Mouse Diaphragm
Experimental simulation of continuous nanofiltration processes by means of a single module in batch mode
[EN] This work proposes a method of simulating the performance of continuous nanofiltration processes by means of experimental runs performed on a laboratory set-up equipped with a spiral-wound module working in batch recirculation mode. It describes how to implement the proper changes in feed concentration and operating conditions in a batch recirculated system in order to obtain similar conditions to those of a continuous one. The analogy between the concentration process in the continuous and in the batch recirculation system is discussed and the difference in ion concentration of the cumulative permeate between the two systems is estimated numerically.
The procedure was applied in a case study to estimate the performance of a continuous process intended to remove nitrate from brackish water using a high rejection nanofiltration membrane (DowFilmtec NF90). The sequence of concentration steps performed in the batch-recirculated set-up yielded an estimation of the ion concentration profiles throughout the continuous system. A mathematical analysis of the results showed that the nitrate concentration in the permeate experimentally obtained in the batch system is 4.5% higher than that expected in the continuous system.
The experimental method described here can be used to design membrane system applications for which the target ions are not accurately predicted by models or are not included in commercial software. (C) 2017 Published by Elsevier B.V.This work was supported by the Spanish Ministry for Economy and Competitiveness [Project OPTIMEM CTM2010-20248].Santafé Moros, MA.; Gozálvez-Zafrilla, JM.; Lora-García, J. (2017). Experimental simulation of continuous nanofiltration processes by means of a single module in batch mode. Separation and Purification Technology. 187:233-243. https://doi.org/10.1016/j.seppur.2017.06.05923324318
Comparison of Artificial Intelligence Control Strategies for a Peristaltically Pumped Low-Pressure Driven Membrane Process
Peristaltic pumping is used in membrane applications where high and sterile sealing is required. However, control is difficult due to the pulsating pump characteristics and the time-varying properties of the system. In this work, three artificial intelligence control strategies (artificial neural networks (ANN), fuzzy logic expert systems, and fuzzy-integrated local models) were used to regulate transmembrane pressure and crossflow velocity in a microfiltration system under high fouling conditions. A pilot plant was used to obtain the necessary data to identify the AI models and to test the controllers. Humic acid was employed as a foulant, and cleaning-in-place with NaOH was used to restore the membrane state. Several starting operating points were studied and setpoint changes were performed to study the plant dynamics under different control strategies. The results showed that the control approaches were able to control the membrane system, but significant differences in the dynamics were observed. The ANN control was able to achieve the specifications but showed poor dynamics. Expert control was fast but showed problems in different working areas. Local models required less data than ANN, achieving high accuracy and robustness. Therefore, the technique to be used will depend on the available information and the application dynamics requirements.This research received no external funding.Peer ReviewedPostprint (published version
Large-scale unsupervised spatio-temporal semantic analysis of vast regions from satellite images sequences
Temporal sequences of satellite images constitute a highly valuable and abundant resource for analyzing regions of interest. However, the automatic acquisition of knowledge on a large scale is a challenging task due to different factors such as the lack of precise labeled data, the definition and variability of the terrain entities, or the inherent complexity of the images and their fusion. In this context, we present a fully unsupervised and general methodology to conduct spatio-temporal taxonomies of large regions from sequences of satellite images. Our approach relies on a combination of deep embeddings and time series clustering to capture the semantic properties of the ground and its evolution over time, providing a comprehensive understanding of the region of interest. The proposed method is enhanced by a novel procedure specifically devised to refine the embedding and exploit the underlying
spatio-temporal patterns. We use this methodology to conduct an in-depth analysis of a 220 km2 region in northern Spain in different settings. The results provide a broad and intuitive perspective of the land where large areas are connected in a compact and well-structured manner, mainly based on climatic, phytological, and hydrological factors
Return period curves for extreme 5-min rainfall amounts at the Barcelona urban network
Heavy rainfall episodes are relatively common in the conurbation of Barcelona and neighbouring cities (NE Spain), usually due to storms generated by convective phenomena in summer and eastern and south-eastern advections in autumn. Prevention of local flood episodes and right design of urban drainage have to take into account the rainfall intensity spread instead of a simple evaluation of daily rainfall amounts. The database comes from 5-min rain amounts recorded by tipping buckets in the Barcelona urban network along the years 1994–2009. From these data, extreme 5-min rain amounts are selected applying the peaks-over-threshold method for thresholds derived from both 95% percentile and the mean excess plot. The return period curves are derived from their statistical distribution for every gauge, describing with detail expected extreme 5-min rain amounts across the urban network. These curves are compared with those derived from annual extreme time series. In this way, areas in Barcelona submitted to different levels of flood risk from the point of view of rainfall intensity are detected. Additionally, global time trends on extreme 5-min rain amounts are quantified for the whole network and found as not statistically significant.Peer ReviewedPostprint (author's final draft
Fluid Dynamic Modeling of Oxygen Permeation through Mixed Ionic-Electronic Conducting Membranes
[EN] The oxygen transport in a lab-scale experimental set-up for permeation testing of oxygen transport membranes has been modeled using computational fluid dynamics using Finite Element Analysis. The modeling considered gas hydrodynamics and oxygen diffusion in the gas phase and vacancy diffusion of oxygen in a perovskite disc-shaped membrane at 1273. K. In a first step, the model allowed obtaining the coefficient diffusion of oxygen. The parametric study showed that the set-up geometry and flow rate in the air compartment did not have major influence in the oxygen transport. However, very important polarization effects in the sweep-gas (argon) compartment were identified. The highest oxygen permeation flux and the lowest oxygen concentration on the membrane surface were obtained for the following conditions (in increasing order of importance): (1) a large gas inlet radius; (2) short gas inlet distance; and (3) a high gas flow rate. © 2011 Elsevier B.V.The Spanish Ministry for Science and Innovation (JAE-Pre 08-0058 grant and ENE2008-06302 project) and through FP7 NASA-OTM Project (NMP3-SL-2009-228701) is kindly acknowledged.Gozálvez-Zafrilla, JM.; Santafé Moros, MA.; Escolástico Rozalén, S.; Serra Alfaro, JM. (2011). Fluid Dynamic Modeling of Oxygen Permeation through Mixed Ionic-Electronic Conducting Membranes. Journal of Membrane Science. 378(1-2):290-300. https://doi.org/10.1016/j.memsci.2011.05.016S2903003781-
IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS
[EN] The article presents the main features of a floating photovoltaic cover system (FPCS) for water irrigation reservoirs whose purpose is to reduce the evaporation of water while generating electrical power. The system consists of polyethylene floating modules which are able to adapt to varying reservoir water levels by means of tension bars and elastic fasteners. (C) 2013 Elsevier Ltd. All rights reserved.Redón-Santafé, M.; Ferrer-Gisbert, P.; Sánchez-Romero, F.; Torregrosa Soler, JB.; Ferran Gozalvez, JJ.; Ferrer Gisbert, CM. (2014). IMPLEMENTATION OF A PHOTOVOLTAIC FLOATING COVER FOR IRRIGATION RESERVOIRS. Journal of Cleaner Production. 66:568-570. doi:10.1016/j.jclepro.2013.11.006S5685706
Operating Conditions Optimization via the Taguchi Method to Remove Colloidal Substances from Recycled Paper and Cardboard Production Wastewater
[EN] Optimization of the ultrafiltration (UF) process to remove colloidal substances from a paper mill's treated effluent was investigated in this study. The effects of four operating parameters in a UF system (transmembrane pressure (TMP), cross-flow velocity (CFV), temperature and molecular weight cut-off (MWCO)) on the average permeate flux (J(v)), organic matter chemical oxygen demand (COD) rejection rate and the cumulative flux decline (SFD), was investigated by robust experimental design using the Taguchi method. Analysis of variance (ANOVA) for an L(9)orthogonal array were used to determine the significance of the individual factors, that is to say, to determine which factor has more and which less influence over the UF response variables. Analysis of the percentage contribution (P%) indicated that the TMP and MWCO have the greatest contribution to the average permeate flux and SFD. In the case of the COD rejection rate, the results showed that MWCO has the highest contribution followed by CFV. The Taguchi method and the utility concept were employed to optimize the multiple response variables. The optimal conditions were found to be 2.0 bar of transmembrane pressure, 1.041 m/s of the cross-flow velocity, 15 degrees C of the temperature, and 100 kDa MWCO. The validation experiments under the optimal conditions achievedJ(v), COD rejection rate and SFD results of 81.15 L center dot m(-2)center dot h(-1), 43.90% and 6.01, respectively. Additionally, SST and turbidity decreased by about 99% and 99.5%, respectively, and reduction in particle size from around 458-1281 nm to 12.71-24.36 nm was achieved. The field-emission scanning electron microscopy images under optimal conditions showed that membrane fouling takes place at the highest rate in the first 30 min of UF. The results demonstrate the validity of the approach of using the Taguchi method and utility concept to obtain the optimal membrane conditions for the wastewater treatment using a reduced number of experiments.Sousa, MRS.; Lora-García, J.; López Pérez, MF.; Santafé Moros, MA.; Gozálvez-Zafrilla, JM. (2020). Operating Conditions Optimization via the Taguchi Method to Remove Colloidal Substances from Recycled Paper and Cardboard Production Wastewater. Membranes. 10(8):1-22. https://doi.org/10.3390/membranes10080170S122108Sevimli, M. F. (2005). Post-Treatment of Pulp and Paper Industry Wastewater by Advanced Oxidation Processes. Ozone: Science & Engineering, 27(1), 37-43. doi:10.1080/01919510590908968Key Statistics Report 2017|CEPI-CONFEDERATION OF EUROPEAN PAPER INDUSTRIEShttp://www.cepi.org/keystatistics2017Rajkumar, K. (2016). An Evaluation of Biological Approach for the Effluent Treatment of Paper Boards Industry - An Economic Perspective. 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