Contribution of a pumped-storage hydropower plant to reduce the scheduling costs of an isolated power system with high wind power penetration

AbstractThe paper aims at demonstrating that the consideration of constant start-up costs and ramps of the thermal generating units for assessing the contribution of pumped-hydro energy storage to reduce the scheduling costs of hydrothermal power systems with high wind penetration, may yield unrealistic results. For this purpose, an isolated power system is used as a case study. The contribution of a pumped-storage hydropower plant to reduce the system scheduling costs is assessed in the paper by using a hydrothermal weekly unit commitment model. The model considers different start-up costs and ramps of the thermal generating units as a function of the start-up type. The effects of including pumped hydro energy storage in the system on the integration of wind energy, and on the start-ups and capacity factors of the thermal generating units are also evaluated. The results of the paper demonstrate that the consideration of constant start-up costs and ramps of the thermal generating units yields unrealistic results, and that the pumped-storage hydropower plant may help reduce the system scheduling costs by 2.5–11% and integrate wind power and may allow dispensing with some inflexible thermal generating units

Do product innovation-related activities affect downsizing decisions? An organizational efficiency perspective

Firms’ innovation strategy typically involves the need to shape organizational changes within work structures and routines, even those concerning employee downsizing decisions. However, little effort has been directed toward exploring the role of firm innovation strategy as a determinant of downsizing. Drawing on organizational efficiency perspective, this study proposes a framework to examine the impact of product innovation-related activities on downsizing. The model will be tested using data from a longitudinal sample of Spanish innovative manufacturing firms. It is expected that the results show that firms developing product and process innovations are associated with downsizing decisions. Furthermore, companies that use formal protection of intellectual property through patents, utility models, trademarks and copyrights are believed to keep their personnel. The study attempt to unravel the impact of firm innovation on downsizing decisions and to offer guidance on how innovative firms might operate to control negative effects on their workforce

Effect of Vinyl Flooring on the Modal Properties of a Steel Footbridge

Damping ratios associated with non structural elements play an important role in mitigating the pedestrian-induced vibrations of slender footbridges. In particular, this paper analyses the effect of vinyl flooring on the modal parameters of steel footbridges. Motivated by the unexpected high experimental damping ratios of the first vibration modes of a real footbridge, whose deck was covered by a vinyl flooring, this paper aims at assessing more accurately the experimental damping ratios generated by this non-structural element on steel footbridges. For this purpose, a laboratory footbridge was built and vinyl flooring was installed on it. Its numerical and experimental modal parameters without and with the vinyl flooring were determined. The operational modal analysis method was used to estimate experimentally the modal parameters of the structure. The damping ratios associated with the vinyl flooring were obtained via the substraction between the experimental damping ratios of the laboratory footbridge with and without the vinyl flooring. An average increase of the damping ratios of 2.069% was observed due to the vinyl flooring installed. According to this result, this type of pavement may be a useful tool to significantly increase the damping ratios of steel footbridges in order to reduce pedestrian-induced vibrationsMinisterio de Economía y Competitividad DPI2014-53947-RFondo Europeo de Desarrollo Regional DPI2014-53947-

10 Gigabit White Rabbit: sub-nanosecond timing and data distribution

Time synchronization is a critical feature for many scientific facilities and industrial infrastructures. The required performance is progressively increasing everyday, for instance, few tens of nanoseconds for Fifth Generation (5G) networks or sub-nanosecond accuracy on next family of particle accelerators and astrophysics telescopes. Due to this exigent accuracy, many applications require specific timing dedicated networks, increasing the system cost and complexity. Under this context, the new IEEE 1588-2019 High Accuracy (HA) default profile is intensively based on White Rabbit (WR) which can provide sub-nanosecond accurate synchronization for Ethernet networks. However, current WR solutions have not been designed to work properly with high data bandwidth delivery services even in 1 Gigabit Ethernet (GbE) links. On this contribution, the authors propose a new architecture design that enables WR and, consequently, the IEEE 1588-2019 HA profile to be deployed over 10 GbE links solving the already identified data bandwidth problem. Furthermore, this work addresses different experiments needed to characterize the system performance in terms of time synchronization and data transfer. As final result, this contribution presents for the first time in the literature a new WR system which allows high bandwidth data exchange in 10 GbE networks while providing sub-nanosecond accuracy synchronization. The proposed solution maintains the time synchronization performance of existing WR 1 GbE devices with significant advantages in terms of latency and data bandwidth, enabling its deployment in applications that integrate data and synchronization information in the same network.European Union (EU) 725490H2020 ASTERICS 653477AMIGA7 RTI2018-096228-B-C3

Present-day heat flow model of Mars

Until the acquisition of in-situ measurements, the study of the present-day heat flow of Mars must rely on indirect methods, mainly based on the relation between the thermal state of the lithosphere and its mechanical strength, or on theoretical models of internal evolution. Here, we present a first-order global model for the present-day surface heat flow for Mars, based on the radiogenic heat production of the crust and mantle, on scaling of heat flow variations arising from crustal thickness and topography variations, and on the heat flow derived from the effective elastic thickness of the lithosphere beneath the North Polar Region. Our preferred model finds heat flows varying between 14 and 25 mW m−2, with an average value of 19 mW m−2. Similar results (although about ten percent higher) are obtained if we use heat flow based on the lithospheric strength of the South Polar Region. Moreover, expressing our results in terms of the Urey ratio (the ratio between total internal heat production and total heat loss through the surface), we estimate values close to 0.7–0.75, which indicates a moderate contribution of secular cooling to the heat flow of Mars (consistent with the low heat flow values deduced from lithosphere strength), unless heat-producing elements abundances for Mars are subchondritic

Motion-Based Design of Passive Damping Systems to Reduce Wind-Induced Vibrations of Stay Cables under Uncertainty Conditions

Stay cables exhibit both great slenderness and low damping, which make them sensitive to resonant phenomena induced by the dynamic character of external actions. Furthermore, for these same reasons, their modal properties may vary significantly while in service due to the modification of the operational and environmental conditions. In order to cope with these two limitations, passive damping devices are usually installed at these structural systems. Robust design methods are thus mandatory in order to ensure the adequate behavior of the stay cables without compromising the budget of the passive control systems. To this end, a motion-based design method under uncertainty conditions is proposed and further implemented in this paper. In particular, the proposal focuses on the robust design of di erent passive damping devices when they are employed to control the response of stay cables under wind-induced vibrations. The proposed method transforms the design problem into a constrained multi-objective optimization problem, where the objective function is defined in terms of the characteristic parameters of the passive damping device, together with an inequality constraint aimed at guaranteeing the serviceability limit state of the structure. The performance of the proposed method was validated via its application to a benchmark structure with vibratory problems: The longest stay cable of the Alamillo bridge (Seville, Spain) was adopted for this purpose. Three di erent passive damping devices are considered herein, namely: (i) viscous; (ii) elastomeric; and (iii) frictions dampers. The results obtained by the proposed approach are analyzed and further compared with those provided by a conventional method adopted in the Standards. This comparison illustrates how the newly proposed method allows reduction of the cost of the three types of passive damping devices considered in this study without compromising the performance of the structure.Ministerio de Ciencia, Innovación y Universidades RT12018-099639-B-I00Universidad de Sevilla USE-17047-

Convenção-Quadro das Nações Unidas sobre as Alterações Climáticas. Resumo das conferências de Paris, COP21 e de Marraquexe, COP22

The climate information provided by meteorological organizations on the situation and evolution of climate in the past few years can not be more alarming. From a scientific point of view, the evidence of climate change is indisputable. The causes are also well known: the action of man, which has altered natural processes. There is only some uncertainty about its potential effects, although we know that the worst is yet to come. The Paris COP21 Summit opened a window in the hope that the objectives and agreements that were reached in it - replacing those of the Kyoto Protocol, in force up to 2020 - signify a turning point in the fight against change climate. A maximum increase of 2 °C with respect to pre-industrial temperatures and a revision of the commitments every five years are the most important achievements of this Summit. However, Paris did not specify the operability of the agreements; for example, sanctions in case of non-compliance were not included, financial tools were not defined and the agreements were not binding. These tasks were left pending for the Marrakech Summit, the second part of the Paris event. Unfortunately, Marrakech has not lived up to expectations. The results of Marrakech can not be more disappointing. Without excusing the postponement of vital decisions, the international environment was not the most conducive for the countries that ratified the Paris Agreement to go ahead and do what was necessary for its implementation.La información climática facilitada por las organizaciones meteorológicas sobre la situación y la evolución del clima en los últimos años no pueden resultar más alarmantes. Desde el punto de vista científico, la evidencia del cambio climático es indiscutible. También se conocen perfectamente las causas, la acción del hombre que ha alterado los procesos naturales. Solamente queda alguna incertidumbre sobre los posibles efectos, aunque sabemos que los peores están por llegar. La Cumbre del COP21, celebrada en París, abrió una ventana a la esperanza de que los objetivos y los acuerdos alcanzados en la misma, que sustituyen los del Protocolo de Kioto vigente hasta 2020, signifiquen el punto de inflexión en la lucha contra el cambio climático. El incremento máximo de 2 ºC respecto a la temperatura preindustrial y la revisión de los compromisos cada cinco años son los logros más importantes de esta Cumbre. Sin embargo, París no concretó la operatividad de los acuerdos, por ejemplo, no se incluyeron sanciones en caso de incumplimientos, no se definieron las herramientas financieras, ni el carácter vinculante de los acuerdos. Esta tarea quedó pendiente de la cita de Marrakech, segunda parte de la de París. Desgraciadamente, Marrakech no ha respondido a las expectativas. Los resultados de Marrakech no pueden ser más decepcionantes. Sin disculpar el aplazamiento de decisiones vitales, el entorno internacional no era el más propicio para que los países que ratificaron el Acuerdo de París siguieran más adelante e hicieran lo necesario para su puesta en marcha.A informação disponibilizada pelas organizações meteorológicas sobre o estado e a evolução do clima nos últimos anos não poderia ser mais alarmante. Do ponto de vista científico, a evidência das alterações climáticas é indiscutível. Também são conhecidas as causas, a ação do Homem alterou os processos naturais. Apenas subsiste uma certa incerteza sobre os possíveis efeitos, ainda que saibamos que o pior está para chegar. A COP21, celebrada em Paris, abriu uma “janela” à esperança de que os objetivos e os acordos, celebrados na mesma, que substituemos do Protocolo de Quioto vigente até 2020, signifiquem um ponto de viragem na luta contra as alterações climáticas. O aumento máximo de 2 ºC referente à temperatura pré-industrial e a revisão dos compromissos a cada cinco anos, são as conquistas mais importantes desta conferência. Porém, Paris não estabeleceu a operacionalização dos acordos, por exemplo, não se incluíram sanções para os casos de incumprimento, não se definiram as ferramentas financeiras, nem o caráter vinculativo dos acordos. Esta tarefa ficou pendente para Marraquexe, como segunda parte de Paris. Infelizmente, Marraquexe não correspondeu às expetativas. Os resultados de Marraquexe não poderiam ser mais dececionantes. Sem desculpar o adiamento de decisões vitais, o ambiente internacional não era o mais propício, paraque os países que ratificaram o Acordo de Paris avançassem e fizessem o necessário para a sua implementação

Data maturity analysis and business performance: a Colombian case study

Context: Colombia over the last decade has experienced a historic economic boom and Information Technology (IT) has been emerging as a tool to enable the competitiveness of companies. The last government (2014–2018) took different actions to explain how the use of data science and open data improve the business activity. The question to identify if there is a relationship between IT capacities, the organizational structure and the performance of the companies remains unresolved and is certainly an urgent issue for new government of Iván Duque. Purpose: Our study analyses the relationship between data structure and business performance measured through the efficiency of customer experience and provider operations processes. Methodology: our methodology is novel compared to previous researches which develop linear regression. It is based on the use of a fuzzy-set qualitative comparative analysis (fsQCA). Originality/value: our method allows to reveal multiple and complementary paths to achieve possible correlations between data and business performance. Findings: Our results show that data consistency, data usage and data protection are the three more frequent conditions to a better customer experience and provider operations efficiency. Surprisingly, data-driven profile is a necessary but not sufficient condition. Practical implications: our conclusions allow practitioners to uncover the strength of the data to orientate their digital strategy. Our recommendations could be used for the new governmental program of digital revival for Small and Medium EnterprisesPeer ReviewedPostprint (published version

On the thermo-mechanical structure of the Martian lithosphere: the role of the crust

An adequate knowledge of thermal and rheological properties of crust and mantle is fundamental for deciphering and understanding the thermal state and interior evolution of a planetary body. Previously, indirect methods have been used to calculate heat flows for Mars. A commonly used indirect method is based on the relation between the thermal state of lithospheric rocks and their mechanical strength, usually related through the effective elastic thickness of the lithosphere or from the depth to the brittle–ductile transition beneath large thrust faults. The so-obtained heat flows are valid for the time when the lithosphere was loaded or faulted, and therefore when deduced from regions deformed in different ages provides information on the thermal evolution of Mars

Informe sobre las excavaciones realizadas en el yacimiento de Hornachuelos, Ribera del Fresno (Badajoz). 1986-1988

El presente estudio, lejos de ofrecer una visión pormenorizada de los resultados obtenidos hasta el momento en el yacimiento de Hornachuelos (Ribera del Fresno, Badajoz), pretende tan sólo ser un avance que resuma los trabajos arqueológicos que de forma ininterrumpida venimos desarrollando en este lugar desde 1986.The present study, far from offering a detailed view of the results obtained so far in the site of Hornachuelos (Ribera del Fresno, Badajoz), is intended only to be an advance that summarizes the archaeological works that we have been developing in this site uninterruptedly since 1986.peerReviewe