Using Multiple Fidelity Numerical Models for Floating Offshore Wind Turbine Advanced Control Design

This paper summarises the tuning process of the Aerodynamic Platform Stabiliser control loop and its performance with Floating Offshore Wind Turbine model. Simplified Low-Order Wind turbine numerical models have been used for the system identification and control tuning process. Denmark Technical University's 10 MW wind turbine model mounted on the TripleSpar platform concept was used for this study. Time-domain simulations were carried out in a fully coupled non-linear aero-hydro-elastic simulation tool FAST, in which wind and wave disturbances were modelled. This testing yielded significant improvements in the overall Floating Offshore Wind Turbine performance and load reduction, validating the control technique presented in this work.This work was partially funded by the Spanish Ministry of Economy and Competitiveness through the research project DPI2017-82930-C2-2-R

An Advanced Control Technique for Floating Offshore Wind Turbines Based on More Compact Barge Platforms

Hydrodynamic Floating Offshore Wind Turbine (FOWT) platform specifications are typically dominated by seaworthiness and maximum operating platform-pitch angle-related requirements. However, such specifications directly impact the challenge posed by an FOWT in terms of control design. The conventional FOWT systems are typically based on large, heavy floating platforms, which are less likely to suffer from the negative damping effect caused by the excessive coupling between blade-pitch control and platform-pitch motion. An advanced control technique is presented here to increase system stability for barge type platforms. Such a technique mitigates platform-pitch motions and improves the generator speed regulation, while maintaining blade-pitch activity and reducing blade and tower loads. The NREL's 5MW + ITI Energy barge reference model is taken as a basis for this work. Furthermore, the capabilities of the proposed controller for performing with a more compact and less hydrodynamically stable barge platform is analysed, with encouraging results.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness through the research project DPI2017-82930-C2-2-R

Anharmonicity Reveals the Tunability of the Charge Density Wave Orders in Monolayer VSe2

VSe2 is a layered compound that has attracted great attention due to its proximity to a ferromagnetic state that is quenched by its charge density wave (CDW) phase. In the monolayer limit, unrelated experiments have reported different CDW orders with different transition temperatures, making this monolayer very controversial. Here we perform first-principles nonperturbative anharmonic phonon calculations in monolayer VSe2 in order to estimate the CDW order and the corresponding transition temperature. They reveal that monolayer VSe2 develops two independent charge density wave orders that compete as a function of strain. Variations of only 1.5% in the lattice parameter are enough to stabilize one order or the other. Moreover, we analyze the impact of external Lennard-Jones interactions, showing that these can act together with anharmonicity to suppress the CDW orders. Our results solve previous experimental contradictions, highlighting the high tunability and substrate dependency of the CDW orders of monolayer VSe2.We acknowledge the computational resources provided by the CESGA and the Aalto Science-IT project. A.O.F. acknowledges the financial support received through the Academy of Finland Project No. 349696. J.D. thanks the Department of Education of the Basque Government for a predoctoral fellowship (Grant No. PRE-2020-1-0220). We thank the Ministry of Science and Education of Spain for financial support through the projects PGC2018-101334-A-C22, GC2018-101334-B-C21, PID2021-122609NB-C22. I.E. acknowledges funding from the Department of Education, Universities and Research of the Eusko Jaurlaritza, and the University of the Basque Country UPV/EHU (Grant No. IT1527-22)

On the Properties of a Class of Impulsive Competition Beverton–Holt Equations

This paper is devoted to a type of combined impulsive discrete Beverton–Holt equations in ecology when eventual discontinuities at sampling time instants are considered. Such discontinuities could be interpreted as impulses in the corresponding continuous-time logistic equations. The set of equations involve competition-type coupled dynamics among a finite set of species. It is assumed that, in general, the intrinsic growth rates and the carrying capacities are eventually distinct for the various species. The impulsive parts of the equations are parameterized by harvesting quotas and independent consumptions which are also eventually distinct for the various species and which control the populations’ evolution. The performed study includes the existence of extinction and non-extinction equilibrium points, the conditions of non-negativity and boundedness of the solutions for given finite non-negative initial conditions and the conditions of asymptotic stability without or with extinction of the solutions.This research was supported by the Spanish Government through grant RTI2018-094336-B-100 (MCIU/AEI/FEDER, UE) and by the Basque Government through grant IT1207-19

La estigmatización de las comunidades gitanas en la pandemia de gripe española. Un estudio de caso a través de la provincia de Bizkaia en 1918

The Spanish flu pandemic that took place between 1918 and 1920 has been studied from various perspectives. However, there are social effects of the pandemic that have not yet been sufficiently explored. The stigmatization and discrimination of certain ethnically significant groups such as gypsies were the product of the prophylactic measures applied to stop the spread of the virus. The circulation and presence of the Roma communities served as an argument to explain some social and health problems. Through the specific study of the province of Biscay, this article aims to analyze the social dimension of the conflict and, at the same time, study the situation of these Roma communities in this health crisis. During the pandemic, discourses and practices aimed at controlling these ethnic groups were generated. These have historically had complex relationships with government regulations.La pandemia de gripe española que tuvo lugar entre 1918 y 1920 ha sido profundamente estudiada desde numerosas perspectivas. Sin embargo, existen efectos sociales de la pandemia que todavía no se han explorado lo suficiente. La estigmatización y discriminación de ciertos grupos significados étnicamente como los gitanos fueron producto de las medidas profilácticas aplicadas para poner freno a la extensión del virus. La circulación y presencia de las comunidades gitanas sirvieron como argumento para explicar en ocasiones los desastres sociosanitarios. Por medio del estudio concreto de la provincia de Bizkaia este artículo pretende profundizar en la dimensión social del conflicto y, al mismo tiempo, analizar el encaje de los gitanos ante la situación de crisis sanitaria que dio lugar a discursos y prácticas dirigidas al control de estos grupos étnicos que históricamente han contraído relaciones complejas con las regulaciones gubernativas

Supervision of the Infection in an SI (SI-RC) Epidemic Model by Using a Test Loss Function to Update the Vaccination and Treatment Controls

This paper studies and proposes some supervisory techniques to update the vaccination and control gains through time in a modified SI (susceptible-infectious) epidemic model involving the susceptible and subpopulations. Since the presence of linear feedback controls are admitted, a compensatory recovered (or immune) extra subpopulation is added to the model under zero initial conditions to deal with the recovered subpopulations transferred from the vaccination and antiviral/antibiotic treatment on the susceptible and the infectious, respectively. Therefore, the modified model is referred to as an SI(RC) epidemic model since it integrates the susceptible, infectious and compensatory recovered subpopulations. The defined time-integral supervisory loss function can evaluate weighted losses involving, in general, both the susceptible and the infectious subpopulations. It is admitted, as a valid supervisory loss function, that which involves only either the infectious or the susceptible subpopulations. Its concrete definition involving only the infectious is related to the Shannon information entropy. The supervision problem is basically based on the implementation of a parallel control structure with different potential control gains to be judiciously selected and updated through time. A higher decision level structure of the supervisory scheme updates the appropriate active controller (i.e., that with the control gain values to be used along the next time window), as well as the switching time instants. In this way, the active controller is that which provides the best associated supervisory loss function along the next inter-switching time interval. Basically, a switching action from one active controller to another one is decided as a better value of the supervisory loss function is detected for distinct controller gain values to the current ones.The authors are grateful to the Spanish Government for Grants RTI2018-094336-B-I00 and RTI2018-094902-B-C22 (MCIU/AEI/FEDER, UE), to the Institute of Health Carlos III for Grant COV20/01213 and to the Basque Government for Grant IT1207-19. They also thank the referees for their useful suggestions and corrections

A Study on COVID-19 Incidence in Europe through Two SEIR Epidemic Models Which Consider Mixed Contagions from Asymptomatic and Symptomatic Individuals

The impact of the SARS-CoV-2 (COVID-19) on the world has been partially controlled through different measures of social isolation and prophylaxis. Two new SEIR (Susceptible-Exposed-Infected-Recovered) models are proposed in order to describe this spread through different countries of Europe. In both models the infectivity of the asymptomatic period during the exposed stage of the disease will be taken into account. The different transmission rates of the SEIR models are calculated by considering the different locations and, more importantly, the lockdown measures implemented in each region. A new classification of these intervention measures will be set and their influence on the values of the transmission rates will be estimated through regression analysis.The authors are grateful to the institute Carlos III for grant COV20/01213, to the Spanish Government for Grants RTI2018-094336-B-I00 and RTI2018-094902-BC22 (MCIU/AEI/FEDER, UE) and to the Basque Government for Grant IT1207-19

A Modelization of the Propagation of COVID-19 in Regions of Spain and Italy with Evaluation of the Transmission Rates Related to the Intervention Measures

Two discrete mathematical SIR models (Susceptible-Infectious-Recovered) are proposed for modelling the propagation of the SARS-CoV-2 (COVID-19) through Spain and Italy. One of the proposed models is delay-free while the other one considers a delay in the propagation of the infection. The objective is to estimate the transmission, also known as infectivity rate, through time taking into account the infection evolution data supplied by the official health care systems in both countries. Such a parameter is estimated through time at different regional levels and it is seen to be strongly dependent on the intervention measures such as the total (except essential activities) or partial levels of lockdown. Typically, the infectivity rate evolves towards a minimum value under total lockdown and it increases again when the confinement measures are partially or totally removed.The authors are grateful to the institute Carlos III for grant COV20/01213, to the Spanish Government for Grants RTI2018- 094336-B-I00 and RTI2018-094902-B-C22 (MCIU/AEI/FEDER, UE) and to the Basque Government for Grant IT1207-19

A planetary-scale disturbance in a long living three vortex coupled system in Saturn's atmosphere

The zonal wind profile of Saturn has a unique structure at 60°N with a double-peaked jet that reaches maximum zonal velocities close to 100 ms−1. In this region, a singular group of vortices consisting of a cyclone surrounded by two anticyclones was active since 2012 until the time of this report. Our observation demonstrates that vortices in Saturn can be long-lived. The three-vortex system drifts at u = 69.0 ± 1.6 ms−1, similar to the speed of the local wind. Local motions reveal that the relative vorticity of the vortices comprising the system is ∼2–3 times the ambient zonal vorticity. In May 2015, a disturbance developed at the location of the triple vortex system, and expanded eastwards covering in two months a third of the latitudinal circle, but leaving the vortices essentially unchanged. At the time of the onset of the disturbance, a fourth vortex was present at 55°N, south of the three vortices and the evolution of the disturbance proved to be linked to the motion of this vortex. Measurements of local motions of the disturbed region show that cloud features moved essentially at the local wind speeds, suggesting that the disturbance consisted of passively advecting clouds generated by the interaction of the triple vortex system with the fourth vortex to the south. Nonlinear simulations are able to reproduce the stability and longevity of the triple vortex system under low vertical wind shear and high static stability in the upper troposphere of Saturn.This work was supported by the Spanish MICIIN projects AYA2015-65041-P (MINECO/FEDER, UE), Grupos Gobierno Vasco IT-765-13, and UFI11/55 from UPV/EHU. EGM is supported by the Serra Hunter Programme, Generalitat de Catalunya. A. Simon, K. Sayanagi and M.H. Wong were supported by a NASA Cassini Data Analysisgrant (NNX15AD33G and NNX15AD34G). We acknowledge the three orbits assigned by the Director Discretionary time from HST for this research (DD Program 14064, IP A. Sánchez-Lavega). We are very grateful to amateur astronomers contributing with their images to open databases such as PVOL (http://pvol2.ehu.eus/) and ALPO-Japan (http://alpo-j.asahikawa-med.ac.jp/)

Plan de negocio para determinar la viabilidad de constituir una empresa de dise?o y fabricaci?n de m?quinas trituradoras de Cizalla

Nuestra tesis, enfocada en la fabricaci?n de maquinaria industrial, aspira a ser una buena opci?n manufacturera que brinde: valor agregado a la materia prima, genere empleo y sobretodo que beneficie a la sociedad y al medio ambiente. Para ello, hemos identificado un problema de com?n denominador a nivel mundial, la excesiva generaci?n de residuos s?lidos, en contraparte hemos revisado soluciones para corregir y/o aliviar esta situaci?n, eligiendo la m?quina trituradora de cizalla como la opci?n m?s amigable y confiable para reducir el tama?o de los residuos s?lidos, cualquiera sea su origen. Para el Estudio de Mercado, ten?amos que estudiar el proceso de gesti?n de residuos s?lidos en Lima Metropolitana; y elegir certeramente nuestra posible cartera de clientes, en algunos casos ideando estrategias para crear la demanda la cual era nula. Estimada la demanda, ideamos el Plan de Marketing que haga atractivo y sostenible nuestro Plan de Negocio y en funci?n a ello creamos nuestro Plan de Operaciones, considerando proveedores, procesos, costos y legislaci?n vigente. Finalmente nuestro Plan Financiero reflej? que nuestra idea de negocio s? era rentable y atractiva. Esperamos que esta Tesis sea de gu?a para futuras ideas de negocios en nuestra incipiente industria manufacturera peruana