A Proposal for Compensation between TSOs for Cross Border Trades

The increasing amount of power exchanges in the European networks makes necessary to design a method for the allocation of the grid costs incurred by these exchanges. This paper presents a method that complies with the conditions required by the regulatory authorities and is technically sound. It calculates the compensation due to a grid using a differential method, while the contributions of the grid users are calculated by the Simplified Average Participation approachX Portuguese-Spanish Conference in Electrical EngineeringNo publicad

Las masías de El Gironés y La Selva: elementos defensivos en el "Mas" del Bajo Ampurdán

En número dedicado a: Gerona: comarcas de La Selva el Gironés y el Bajo Ampurdá

Dulcería tradicional intemporal en las tres comarcas gerundenses

En número dedicado a: Gerona: comarcas de La Selva el Gironés y el Bajo Ampurdá

Proportionally modular affine semigroups

Producción CientíficaThis work introduces a new kind of semigroup of Np called proportionally modular affine semigroup. These semigroups are defined by modular Diophantine inequalities and they are a generalization of proportionally modular numerical semigroups. We give an algorithm to compute their minimal generating sets. We also specialize on the case p = 2. For this case, we provide a faster algorithm to compute their minimal system of generators, prove they are Cohen-Macaulay and Buchsbaum, and determinate their (minimal) Frobenius vectors. Besides, Gorenstein proportionally modular affine semigroups are characterized.Ministerio de Economía, Industria y Competitividad ( grants MTM2014-55367-P / MTM2015-65764- C3-1-P)Junta de Andalucía (FQM-366 / FQM-298

El turismo alternativo como un sistema integrado: consideraciones sobre el caso andaluz

En el presente trabajo se aborda, desde una perspectiva sistémica, un concepto que hemos recogido bajo el término genérico de turismo alternativo, frente al turismo de masas. El artículo se plantea un doble objetivo: En primer lugar, realizar un análisis teórico de dicho concepto, describiendo los agentes que intervienen en el mismo y los flujos que se establecen entre ellos (físicos, económicos y socio-culturales). En segundo lugar, observar la situación de éste en la Comunidad Autónoma de Andalucía. El turismo alternativo se encuentra en sus primeras fases de desarrollo en esta Comunidad, siendo un campo de amplio potencial. La principal conclusión del trabajo es que debe asegurarse la sostenibilidad de dicha actividad turística.This study deals, from a systematic point of view, about the concept of alternative tourism in opposition to mass tourism. A double aim is presented in the paper: in first place, the setting of a theoretic analysis of that concept, describing its agents as well as the flows intending among them (physic, economic and sociocultural). In second place, a research on the position of alternative tourism in Andalucía. In this autonomous community alternative tourism is in its first steps of development, having reached a wide potential. The main conclusión of the study is to point out the need of making quite sure the possibility of keeping sustainable that tourism activity

La pyme española ante la cooperación transnacional

This study tackle the phenomenon of the cooperation among enierprises, wich is widely taking place, as it is proved by the constant growth of the number of agreements that has been done lengthwise of the past few years. The objective of the article is to study the cooperation, but in the specific case of the spanish Hales and médium entreprises (PYMES). For that, behind making a revisión about the Hterature existing in relation with the theme, it is enumérate the gains and disaventages, as welt as of the barriers thát the PYMES find in relation with the cooperation. Later on it is describe the more important actions that, in the sphere of the Economic Union, is being taken, for promoting this kind of agreements. Firially, it is analysed the PYMES spanish's participation in these programs. From the datas it is known, among other conclusions, the predominance of the agreements of commercial content, unlike that it happens in the agreements among large corporations where the agreements technological-productive are more frequents.Ce travaü aborde le phónoméne de la coopération entre les entreprises, lequel est en train de beaueoup se développer. Pour le montrer nous pouvons signaler la croissance continué du nombre d*accords qui ont été réalisés pendant les derniéres années. L'objectif de cet article est d'étudier la coopération, mais pour le cas concret des petites et moyennes entreprises (PYMES) espagnoles. Pour céla, aprés analyser la litérature existante á ce sujet-lá, nous signalons les avantages et desaventages, et aussi les barriéres que les PYMES trouvent face á la coopération. Aprés nous avons décrit les mesures Ies plus importantes qui ont été prises, dans le cadre de L'Union Europééne, pour développer la formalisation de ce gerice d'accords. Finalment nous avons analysé la participation des PYMES espagnoles dans ees programmes. Á partir des données utilisées nous pouvons établir, parmi d'autres conclusions, la prédominance des accords commerciaux, contrairement á ce qui passe par rapport aux accords entre les grandes corporations, oü les accords tcchnologiques-producüfs sont les plus fréquentes

Modifying RANKL/OPG mRNA expression in differentiating and growing human primary osteoblasts

The OPG / RANKL system in primary cultures of human osteoblasts has been studied by di ff erent authors. However, very few studies have been performed on gene expression of RANKL and OPG at di ff erent stages of maturation on human osteoblast cultures.The e ff ect of 17-estradiol and 1,25dihydroxyvitamin D3 on the OPG / RANKL system is not known during the di ff erent states of cellular maturation. In this work we quantifi ed OPG and RANKL protein levels (ELISA) and the mRNA of OPG, RANKL, collagen type I, alkaline phosphatase, and osteocalcin (semi-quantita-tive RT-PCR) in human osteoblasts. We analyzed these in basal conditions and after incubation with 17- -estradiol and 1,25dihydroxyvitamin D3 in the first and second phases. We found that OPG secretion and expression levels increased throughout cellular growth.RANKL proteins were detected only in the first stage, and the expression increased throughout the first phase. Thus, the RANKL / OPG ratio was higher in immature osteoblasts than in mature osteoblasts. The evolution of RANKL gene expression was related to collagen I and alkaline phosphatase, while OPG was related to osteocalcin. We observed no modi fi cations after estradiol and 1,25dihydroxyvitamin D3 treatment. Our results suggest that the OB is a positive stimulator at precocious stages of diff erentiation on osteoclastogenic modulates

A Decentralized Local Flexibility Market Considering the Uncertainty of Demand

The role of the distribution system operator (DSO) is evolving with the increasing possibilities of demand management and flexibility. Rather than implementing conventional approaches to mitigate network congestions, such as upgrading existing assets, demand flexibility services have been gaining much attention lately as a solution to defer the need for network reinforcements. In this paper, a framework for a decentralized local market that enables flexibility services trading at the distribution level is introduced. This market operates on two timeframes, day-ahead and real-time and it allows the DSO to procure flexibility services which can help in its congestion management process. The contribution of this work lies in considering the uncertainty of demand during the day-ahead period. As a result, we introduce a probabilistic process that supports the DSO in assessing the true need of obtaining flexibility services based on the probability of congestion occurrence in the following day of operation. Besides being able to procure firm flexibility for high probable congestions, a new option is introduced, called the right-to-use option, which enables the DSO to reserve a specific amount of flexibility, to be called upon later if necessary, for congestions that have medium probabilities of taking place. In addition, a real-time market for flexibility trading is presented, which allows the DSO to procure flexibility services for unforeseen congestions with short notice. Also, the effect of the penetration level of flexibility on the DSO's total cost is discussed and assessed. Finally, a case study is carried out for a real distribution network feeder in Spain to illustrate the impact of the proposed flexibility framework on the DSO's congestion management process

Aggregators' Optimal Bidding Strategy in Sequential Day-Ahead and Intraday Electricity Spot Markets

This paper proposes a probabilistic optimization method that produces optimal bidding curves to be submitted by an aggregator to the day-ahead electricity market and the intraday market, considering the flexible demand of his customers (based in time dependent resources such as batteries and shiftable demand) and taking into account the possible imbalance costs as well as the uncertainty of forecasts (market prices, demand, and renewable energy sources (RES) generation). The optimization strategy aims to minimize the total cost of the traded energy over a whole day, taking into account the intertemporal constraints. The proposed formulation leads to the solution of different linear optimization problems, following the natural temporal sequence of electricity spot markets. Intertemporal constraints regarding time dependent resources are fulfilled through a scheduling process performed after the day-ahead market clearing. Each of the different problems is of moderate dimension and requires short computation times. The benefits of the proposed strategy are assessed comparing the payments done by an aggregator over a sample period of one year following different deterministic and probabilistic strategies. Results show that probabilistic strategy reports better benefits for aggregators participating in power markets.This work was supported by the European research project IDE4L (Ref. FP7-SMARTCITIES-2013-608860) and the Spanish project RESmart (Ref. ENE2013-48690-C2-1-R)

Distribution-Level Flexibility Market for Congestion Management

Nowadays, problems facing Distribution System Operators (DSOs) due to demand increase and the wide penetration of renewable energy are usually solved by means of grid reinforcement. However, the smart grid paradigm enables the deployment of demand flexibility for congestion management in distribution grids. This could substitute, or at least postpone, these needed investments. A key role in this scheme is the aggregator, who can act as a "flexibility provider" collecting the available flexibility from the consumers. Under this paradigm, this paper proposes a flexibility market led by the DSO and aimed at solving distribution grid congestions. The proposal also includes a flexibility market clearing algorithm, which is easy to implement, has low computational requirements and considers the energy rebound effect. The proposed design has the advantage of excluding the DSO's need for trading in energy markets. Also, the solution algorithm proposed is fully compatible with already existing grid analysis tools. The proposed electricity market is tested with two case studies from a real Spanish distribution network, where the proposed clearing algorithm is used, and finally, results are presented and discussed