CCm performance in Arctic and Antarctic seaweeds in a warming and acidifying marine environment

Presentación oral al congresoOcean acidification and warming are affecting with special intensity the polar coastal ecosystems. The Arctic kelps Saccharina latissima and Laminaria solidungula from Kongsfjorden (Svalbard) were cultured at 4 and 9 ºC in combination with current (390 ppm, CC) and increased (1200 ppm, HC) levels of atmospheric CO2. The Antarctic endemic Desmarestia anceps and D. menziesii were cultured at 2 and 7 ºC, and also at CC and HC.For all these species ∂13C values suggested an absence of deactivation of carbon concentrating mechanisms at increased CO2 levels. The lack of inhibition of CCM at high CO2 shown by ∂13C values seems to be a common pattern in polar species, but it is not related to responses in photosynthesis and growth. Growth of both Arctic species were largely unaffected by increased CO2 conditions, regardless the temperature. In contrast, the Antarctic species were favored by high CO2, specially at the highest temperature. External carbonic anhydrase (eCA) was responsible for about 50% to 80% of the photosynthetic O2 evolution in all the species, according to inhibition assays using DBS. CO2 promoted a decrease in eCA contribution to O2 evolution in the Antarctic species but not in the Arctic ones. The addition of EZ did not promote further inhibition in any species, indicating a low relevance of internal CA, although a concomitant inhibition of eCA may mask this contribution if no other mechanism of active transport was operating. Our latest results of the gene expression of D. anceps reveal that there is a low response to CO2. The relevance of this resilience to CO2 in polar environments will be discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Estabilidad de Sistemas No Lineales Basada en la Teoría de Liapunov

ResumenEl comportamiento dinámico de los sistemas no lineales es mucho más rico que el de los lineales y su análisis mucho más complicado. Para el análisis de estabilidad, las técnicas basadas en la teoría de Liapunov tienen un lugar destacado. En este articulo se revisa parte de esta teoría incluyendo las técnicas de estimación de la cuenca de atracción. También se repasan los resultados que han aparecido en los últimos años sobre la aplicación a este campo de los métodos numéricos de optimización de suma de cuadrados

A new modulation method for multilevel converters

This paper presents a simple method for modulation in multilevel converters, which is hardly affected with the number of levels. The method is based on a simple graph, whose x-axis is directly related to the extra degree of freedom associated with component γ (in the αβγ reference frame) of the desired reference vector. In the y-axis, the different possibilities for the phase averaged references are plotted. In this way, the degree of freedom is more explicit than in Space Vector Modulation (SVM) and it can be the basis of new algorithms to pursue additional control objectives such as voltage balancing or common-mode reduction, among others. A comparison with SVM based on examples is included, showing the benefits of the proposed modulation strategy.Ministerio de Economía y Competitividad. Unión Europe

Nutrient dynamics and related future challenges in Kongsfjorden

Resumen de la conferencia inauguralAbstract The Arctic has waned four times faster than the rest of the world due to Global Warming. In the model Arctic ecosystem of Kongsfjorden (Svalbard archipelago, 79 ºN) warming has occurred more intensely in winter. A warmer winter has led ice-free fjord surface all year round. Under this conditions hydrodynamics are changed and, along with it, the biological and other physicochemical dynamics. Seaweeds start its production when light is available in the water column. Typically, this used to occur in May, after the ice break-up. Late spring-early summer used to be the season when both phytoplankton and the seaweeds forest would uptake the available nutrient and produce biomass. This production season ends during late summer due to nutrient limitation. The atmospheric workgroup has identified the spring as the time of the year with pronounce nutrient-N deposition in the fjord, and the glaciologist has measured that virtually all nutrient deposited over glaciers end up in the fjord water system. Regarding biological primary production, timing of both light and N availability is key. An ice-free N-rich spring may anticipate the season of macroalgal forests productivity and removal of nutrients. We support evidence that macroalgal possess newly developed photosynthetic tissue at the end of the winter, ready to photosynthesise as soon as light is available in February-March. If N removal is intensified by productivity season anticipation, N-limitation could take place before the development of phytoplankton bloom, normally occurring in late Spring. Since most of the animal production relies on phytoplankton productivity, season anticipation of N-limitation has the potential to drastically change the ecosystem.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

A simplified hydrokinetic model for a steady‐state microwave discharge sustained by traveling waves at atmospheric pressure conditions

The properties of a microwave‐induced argon plasma produced by traveling surface wave at atmospheric pressure are investigated theoretically. A hydrokinetic model is elaborated to obtain the nonequilibrium one‐dimensional profiles of electron temperature Te (average electron energy), electron density ne, and the first excited state population density n4s, along the axis of a steady‐state discharge. A three‐level atomic structure is assumed for the argon atom. A particle balance is included through the continuity equations for ne and n4s. These equations are coupled with an energy balance equation for the electrons. The effects of different parameters on the properties of the argon discharge are investigated: discharge tube radius, gas flow rate, resonant radiation‐escape factor, and neutral gas temperature.Ministerio de Educación y Ciencia. Gobierno de España-PB91- 0847 y PB94-145

Modeling and Full Decoupling Control of a Grid-Connected Five-Level Diode-Clamped Converter

This paper presents a novel approach to deal with the regulation of the dc-link capacitor voltages and ac-side currents in a grid-connected five-level diode-clamped converter. Due to the controllability problems of this topology, guaranteeing a solid current control and, mainly, a correct dc-link voltage sharing, represents a complex technical challenge. With the purpose of coping with it, an averaged model that describes the system dynamics at both sides of the converter is presented, assuming that a modulation strategy is integrated in the system to generate the switching sequence. In order to derive the proposed model, no restriction concerning the use of only the three nearest vectors to the desired voltage reference is taking into account. Then, several changes of variables are carried out in the model equations to obtain control input decoupling for control purposes, while reducing the complexity of the model as well. Finally, the voltage and current controllers are designed separately using different control inputs in a straightforward way. Neither auxiliary hardware nor complicated mathematical calculations are required to achieve the control objectives. The effectiveness and good performance of the system under the proposed control approach is validated by simulation results, suggesting that the five-level diode-clamped converter can be a solid solution as an interfacing system connected to the utility grid for, e.g., industrial drives or renewable energy applications.Ministerio de Economía y Competitividad y Unión Europea : DPI2016-75294-C2-1-RMinisterio de Economía y Competitividad y Unión Europea : DPI2013-41891-

Control de Posición e Inercial de Plataforma de Dos Grados de Libertad

ResumenEste artículo presenta una aplicación de control para la estabilización inercial de una plataforma de dos grados de libertad (2-GDL). El objetivo de la aplicación es, en primer lugar, controlar las posiciones angulares de la plataforma en ausencia de perturbaciones inerciales y en segundo lugar, controlar las velocidades de la plataforma medidas respecto a ejes inerciales independientemente de las perturbaciones a las que se ve sometida. Con respecto al primer objetivo, se propone una estrategia de control de conmutación con el fin de reducir los efectos del rozamiento que es la principal causa del comportamiento no deseado. Respecto al segundo objetivo, se propone un control con estructura en cascada para conseguir las especificaciones deseadas. Se presentan resultados de simulación y experimentales sobre una plataforma que ponen de manifiesto la bondad de los controladores

A new controller for the inverted pendulum on a cart

This paper presents a complete solution to the problem of swinging-up and stabilization of the inverted pendulum on a cart, with a single control law. The resulting law has two parts: first, an energy-shaping law is able to swing and maintain the pendulum up. Then, the second part introduces additional control to stop the cart and it is based on forwarding control with bounded input. The resulting control law is the sum of both parts and does not commute between different laws although there exist switches inside the controller.MEC-FEDER DPI2006-0733

Chemical and thermal impacts of sprite streamers in the Earth's mesosphere

A one-dimensional self-consistent model has been developed to study the chemical and thermal effects of a single sprite streamer in the Earth's mesosphere. We have used sprite streamer profiles with three different driving current durations (5 ms, 50 ms, and 100 ms) between 50 and 80 km of altitude and considering a kinetic scheme of air with more than 90 chemical species. Our model predicts strong increases in practically all the concentrations of the species studied at the moment of the streamer head passage. Moreover, their densities remain high during the streamer afterglow phase. The concentration of electrons can reach values of up to 10 cm in the three cases analyzed. The model also predicts an important enhancement, of several orders of magnitude above ambient values, of nitrogen oxides and several metastables species. On the other hand, we found that the 4.26 μm IR emission brightness of CO can reach 10 GR at low altitudes (< 65 km) for the cases of intermediate (50 ms) and long (100 ms) driving currents. These results suggest the possibility of detecting sprite IR emissions from space with the appropriate instrumentation. Finally, we found that the thermal impact of sprites in the Earth's mesosphere is proportional to the driving current duration. This produces variations of more than 40 K (in the extreme case of a 100 ms driving current) at low altitudes (< 55 km) and at about 10 s after the streamer head. Key Points Chemical and thermal impacts of sprites in the mesosphere are calculated The calculated concentration of electrons exhibits a significant enhancement The model predicts an increase in the gas temperature at low altitudes.©2016. American Geophysical Union. All Rights Reserved.This work was supported by the Spanish Ministry of Economy and Competitiveness, MINECO, under projects AYA2011-29936-C05-02 and ESP2013-48032-C5-5-R and by the Junta de Andalucia, Proyecto de Excelencia, FQM-5965. F.C.P.R. acknowledges MINECO for the FPI grant BES-2010-042367. A.L. was supported by a Ramon y Cajal contract, code RYC-2011-07801Peer Reviewe