Modelling of last hypothesis of climate change impacts on water resources in Sierra de las Cabras aquifer (Southern Spain)

Having models that reflect the reality of a system operation becomes critical to the effec-tive management of water resources in a watershed, especially considering the different scenes of climate change predicted for the Mediterranean regions by the Intergovernmen-tal Panel on Climate Change (IPCC). The fifth Assessment Report of IPCC (AR5) esti-mates an increase in average temperatures and a precipitation decrease between 10 and 20% for Mediterranean region which could generate drought events in the study area. The present research tries to determinate the potential impacts that climate change may have on water resources. The Sacramento model has been used to model the water resources of an inertial aquifer, Sierra de las Cabras. In turn, IPCC forecasts of climate change for the study area (Mediterranean region) have been simulated taking into account the degree as-sessing of affection to the water resources opposite to eventual episodes of drought, and the social and environmental implications that will result have been also determined.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Carex castroviejoi Luceño & Jiménez Mejías (Cyperaceae), a new species from North Greek mountains

Una nueva especie de ciperáceas de las montañas del norte de Grecia denominada con el nombre del Dr. Santiago Castroviejo Bolívar -Flora Ibérica - la obra más importante sobre la historia de la botánica en España

Sensitivity Analysis for Convex Multiobjective Programming in Abstract Spaces.

The main object of this paper is to prove that for a linear or convex multiobjective program, a dual program can be obtained which gives the primal sensitivity without any special hypothesis about the way of choosing the optimal solution in the efficient set.

Ideal points in multiobjective programming

The main object of this paper is to give conditions under which a minimal solution to a problem of mathematical programming can be transformed into a minimum solution in the usual sense of the order relations, or in every case, conditions under which that solution is adherent to the set of the points wich verify this last property. The interest of this problem is clear, since many of the usual properties in optimization (like, for instance, the analysis of the sensitivity of the solutions) are studied more easily for minimum solutions than for minimal solutions

Short channel effects in graphene-based field effect transistors targeting radio-frequency applications

Channel length scaling in graphene field effect transistors (GFETs) is key in the pursuit of higher performance in radio frequency electronics for both rigid and flexible substrates. Although two-dimensional (2D) materials provide a superior immunity to Short Channel Effects (SCEs) than bulk materials, they could dominate in scaled GFETs. In this work, we have developed a model that calculates electron and hole transport along the graphene channel in a drift-diffusion basis, while considering the 2D electrostatics. Our model obtains the self-consistent solution of the 2D Poisson's equation coupled to the current continuity equation, the latter embedding an appropriate model for drift velocity saturation. We have studied the role played by the electrostatics and the velocity saturation in GFETs with short channel lengths L. Severe scaling results in a high degradation of GFET output conductance. The extrinsic cutoff frequency follows a 1/L^n scaling trend, where the index n fulfills n < 2. The case n = 2 corresponds to long-channel GFETs with low source/drain series resistance, that is, devices where the channel resistance is controlling the drain current. For high series resistance, n decreases down to n= 1, and it degrades to values of n < 1 because of the SCEs, especially at high drain bias. The model predicts high maximum oscillation frequencies above 1 THz for channel lengths below 100 nm, but, in order to obtain these frequencies, it is very important to minimize the gate series resistance. The model shows very good agreement with experimental current voltage curves obtained from short channel GFETs and also reproduces negative differential resistance, which is due to a reduction of diffusion current.Comment: 27-pages manuscript (10 figures) plus 6 pages of supplementary information. European Union Action H2020 (696656) / Department d'Universitats, Recerca i Societat de la Informaci\'o of the Generalitat de Catalunya (2014 SGR 384) / Ministerio de Econom\'ia y Competitividad of Spain (TEC2012-31330 and TEC2015-67462-C2-1-R) / MINECO FEDE

Electromagnetic wave propagation and absorption in electrodeless plasma thrusters

The thesis aims at developing a numerical code to study the electromagnetic wave-plasma interaction phenomena critical for the operation of electrodeless thrusters, particularly, the Electron Cyclotron Resonance (ECR) Thruster under development in the European H2020 MINOTOR project. Current in-space Electric Propulsion technologies are presented with special attention to their advantageous characteristics compared to conventional techniques. Among those, electrodeless thrusters emerge as efficient and durable alternatives for future propulsion systems. The main limitation hindering the implementation of these devices is the complicated physical phenomena governing the fundamental operational stages i.e. the plasma heating and ionization, and the acceleration of charged particles. The present work is devoted to the study of the plasma heating mechanism by electromagnetic wave interaction. As presented in the chapter on electromagnetic theory, this is a complex physical problem with a considerable amount of phenomena going on; such as absorption, re ection, resonance or cuto . Numerical methods are a suitable tool to address the specific behavior taking place inside a thruster and better understand the physics underneath. Furthermore, future numerical codes should be capable of simulating the complete thruster operation by integrating the plasma wave interaction code with additional ion and neutral, electron, and magnetic nozzle codes. Full simulations will serve to shorten design cycles and complement laboratory testing during the preliminary design phase. This thesis manly focuses on the implementation and verification of the 2D wave-plasma code fdwaves while presenting important concepts on electromagnetism, plasma physics and numerical methods. Specifically, a two dimensional Finite Di erence and Frequency Domain method is used to discretize the Maxwell's Equations. Numerical wave normal surfaces are plotted using von Neumann stability analysis implemented in the wave-explorer code and compared using solutions to the analytic dispersion relation. This is shown to be truly useful to evaluate the behavior of numerical schemes in terms of spurious propagation and divergence from the physical solution. Preliminary results are shown, firstly, propagation through vacuum serving as a verification method for the code due to the existence of straightforward analytic solutions, then, wave behavior in homogeneous cold plasma media is presented. The work carried out in this thesis is intended to be continued in the future, as a consequence, a considerable number of tools currently under study or development are presented. Special mention should be made of the new code for arbitrary geometry simulation fdmesher, non-uniform grids and the Perfectly Matched Layer (PML) boundary conditions.Ingeniería Aeroespacial (Plan 2010

Carex modesti (Cyperaceae), a new species from southern Tanzania

A new species of Carex (Cyperaceae), Carex modesti, is described from southern Tanzania. It grows on stream sides and peat bogs at about 2750 m in the Kitulo Plateau. It is morphologically distinct from the similar species C. vallis-rosetto by its creeping rhizomes, coriaceous leaves and solitary spikes arising in each node. Carex modesti is included in Carex sect. Spirostachyae subsect. Elatae together with other Carex species from the tropical African mountain

Deep Neural Networks for the Recognition and Classification of Heart Murmurs Using Neuromorphic Auditory Sensors

Auscultation is one of the most used techniques for detecting cardiovascular diseases, which is one of the main causes of death in the world. Heart murmurs are the most common abnormal finding when a patient visits the physician for auscultation. These heart sounds can either be innocent, which are harmless, or abnormal, which may be a sign of a more serious heart condition. However, the accuracy rate of primary care physicians and expert cardiologists when auscultating is not good enough to avoid most of both type-I (healthy patients are sent for echocardiogram) and type-II (pathological patients are sent home without medication or treatment) errors made. In this paper, the authors present a novel convolutional neural network based tool for classifying between healthy people and pathological patients using a neuromorphic auditory sensor for FPGA that is able to decompose the audio into frequency bands in real time. For this purpose, different networks have been trained with the heart murmur information contained in heart sound recordings obtained from nine different heart sound databases sourced from multiple research groups. These samples are segmented and preprocessed using the neuromorphic auditory sensor to decompose their audio information into frequency bands and, after that, sonogram images with the same size are generated. These images have been used to train and test different convolutional neural network architectures. The best results have been obtained with a modified version of the AlexNet model, achieving 97% accuracy (specificity: 95.12%, sensitivity: 93.20%, PhysioNet/CinC Challenge 2016 score: 0.9416). This tool could aid cardiologists and primary care physicians in the auscultation process, improving the decision making task and reducing type-I and type-II errors.Ministerio de Economía y Competitividad TEC2016-77785-