Droplets of trapped quantum dipolar bosons

Strongly interacting systems of dipolar bosons in three dimensions confined by harmonic traps are analyzed using the exact path integral ground-state Monte Carlo method. By adding a repulsive two-body potential, we find a narrow window of interaction parameters leading to stable ground-state configurations of droplets in a crystalline arrangement. We find that this effect is entirely due to the interaction present in the Hamiltonian without resorting to additional stabilizing mechanisms or specific three-body forces. We analyze the number of droplets formed in terms of the Hamiltonian parameters, relate them to the corresponding s-wave scattering length, and discuss a simple scaling model for the density profiles. Our results are in qualitative agreement with recent experiments showing a quantum Rosensweig instability in trapped Dy atoms.Peer ReviewedPostprint (published version

Addressing the 5G cell switch-off problem with a multi-objective cellular genetic algorithm

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The power consumption foreseen for 5G networks is expected to be substantially greater than that of 4G systems, mainly because of the ultra-dense deployments required to meet the upcoming traffic demands. This paper deals with a multi- objective formulation of the Cell Switch-Off (CSO) problem, a well-known and effective approach to save energy in such dense scenarios, which is addressed with an accurate, yet rather unknown multi-objective metaheuristic called MOCell (multi- objective cellular genetic algorithm). It has been evaluated over a different set of networks of increasing densification levels. The results have shown that MOCell is able to reach major energy savings when compared to a widely used multi-objective algorithm.TIN2016-75097-P Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Determination of Pharmaceuticals in Coastal Systems Using Solid Phase Extraction (SPE) Followed by Ultra Performance Liquid Chromatography – tandem Mass Spectrometry (UPLC-MS/MS)

This paper describes the optimization and validation of an analytical method for the determination of 83 pharmaceutically active compounds (PhACs) in aqueous samples using solid-phase extraction (SPE) followed by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QqQ-MS/MS). First, several experiments were conducted to optimize different SPE extraction parameters such as pH, elution solvents, and Na2EDTA addition. Extraction recovery percentages were between 17 and 146%, being higher than 70% for 47 target analytes. The effect of salinity in the extraction efficiency proved to be negligible ( 90%), and the precision of the method, calculated as the relative standard deviation (RSD) of replicate extractions and analyses, was less than 20%. The optimized method was successfully applied to the analysis of real water samples in estuarine and coastal systems from SW Spain (Cadiz Bay and Huelva Estuary). 49 out of 83 target compounds were found in 75% of samples. Ibuprofen, atenolol, gemfibrozil and caffeine were the most commonly detected substances, reaching concentrations up to 195 ng L-1

Transporte de semillas por las ovejas trashumantes, y sus potenciales implicaciones en la vegetación

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Ecología. Fecha de lectura: 22-12-2015La realización de esta tesis doctoral ha sido financiada por una beca y posteriormente un contrato en prácticas del Programa de Formación de Profesorado Universitario (FPU, ref. AP2002-1162) y por un contrato de técnico dentro del proyecto CGL2007- 63382 del Ministerio de Educación y Ciencia, quien además financió una estancia breve en San Marcos, Texas (EEUU). El trabajo de campo, laboratorio y gabinete fue financiado por los proyectos AMB 99-0382, REN2003- 01562 y CGL2007-63382 de la Comisión Interministerial de Ciencia y Tecnologa (CICyT). La Universidad Autónoma de Madrid, además de proporcionar la infraestructura para realizar esta tesis, financió a través de su Servicio de Investigación una estancia breve en Christchurch, Nueva Zelanda, y dos congresos internacionales que influyeron decisivamente en la maduración y ampliación de conocimientos del doctorado y, por lo tanto, en el resultado fina

Modelación de la propagación de incendios de gran escala producidos por la combustión espontánea en los frentes de explotación en minería de carbón a cielo abierto y diseño de estrategias de apagado

La producción de carbón de Cerrejón es realizada en la Zona Norte del País, específicamente en la península del departamento de La Guajira, abarcando un área aproximada de 78.000 hectáreas. Los carbones del Cerrejón son susceptibles a la combustión espontánea de carbón, ya que al finalizar el año 2.016 se encontraban activos 325 incendios en los tajos abandonado y paredes altas. La combustión espontánea es un tema de gran preocupación, causando problemas ambientales al generar emisiones de gases contaminantes, pérdidas de reservas, problemas de inestabilidad geotécnica y problemas de salud. La propagación de los incendios en paredes finales y tajos abandonados tiene una esponteneidad termodinámica y depende de la cinetica química generado por el desencadenamiento progresivo de las reacciones químicas, sumado a una intensa liberación de calor en el frente de reacción pudiéndose estudiadar teniendo en cuenta la termodinámica y cinética químicas, que obedecen a la ecuación de conservación de la energía y las especies químicas, respectivamente. Por lo tanto, si el manto de carbón presenta un incendio con una temperatura de 200 °C, la tasa de consumo de carbón es aproximadamente 200 cm3/hora, si el incendio presenta una temperatura de 1.200 °C, la tasa de consumo de carbón es aproximadamente 3.000 cm3/hora; si las fisuras predominan en el macizo rocoso la propagación del incendio sería aproximadamente 17 cm/día, mientras que, si se tienen grietas, la propagación del incendio sería aproximadamente 3,5 cm/día. Se mejoró los métodos de remoción y sofocación, y adicionalmente se planteó como método alternativo llamado PROPEX como una propuesta innovadora de extinción a nivel mundial.Abstract: The Cerrejón coal production is carried out in the Northern Zone of the Country, specifically in the peninsula of the department of La Guajira, covering an area of approximately 78.000 hectares. Cerrejón coals are susceptible to spontaneous combustion of coal, since at the end of 2.016 there were 325 fires active. Spontaneous combustion is a subject of great concern, causing mainly environmental problems by generating emissions of polluting gases, losses of reserves, problems of geotechnical instability and health problems. The propagation of fires in highwall and footwall is caused by the progressive unleashing of chemical reactions, coupled with an intense release of heat in the reaction front and can be studied taking into account the thermodynamics and chemical kinetics, which are due to the conservation equation of energy and chemical species, respectively. Therefore, if the coal seams present a fire with a temperature of 200 ° C, the rate of consumption of coal is approximately 200 cm3/hour, if the fire has a temperature of 1.200 °C, the rate of consumption of coal is approximately 3.000 cm3 / hour and if the fissure predominate in the rocky mass the fire propagation would be approximately 17 cm/day, whereas if there are cracks, the fire propagation would be approximately 3,5 cm/day. Technical improvements were proposed in the methods of removal, suffocation and the PROPEX proposal as an alternative method of innovative extinction worldwide.Maestrí

The role of livestock in food security, poverty reduction and wealth creation in West Africa

Peer reviewe

Diffusion Monte Carlo methods for spin-orbit-coupled ultracold Bose gases

We present two diffusion Monte Carlo (DMC) algorithms for systems of ultracold quantum gases featuring synthetic spin-orbit interactions. The first one is a spin-integrated DMC method which provides fixed-phase energy estimates. The second one is a discrete spin generalisation of the T-moves spin-orbit DMC [Melton et al., J. Chem. Phys. 144, 244113 (2016)], which provides an upper bound to the fixed-phase energy. The former is a more accurate method but it is restricted to spin-independent two-body interactions. We report a comparison between both algorithms for different systems. As a check of the efficiency of both methods, we compare the DMC energies with results obtained with other numerical methods, finding agreement between both estimations.Peer ReviewedPostprint (published version