Abstract
This paper reviews flexibility products and flexibility markets, currently being discussed or designed to help in the operation of power systems under their evolving environment. This evolution is characterized by the increase of renewable generation and distributed energy resources (including distributed generation, self-consumption, demand response and electric vehicles). The paper is an attempt to review and classify flexibility products considering its main attributes such as scope, purpose, location or provider, and to summarize some of the main approaches to flexibility markets designs and implementations. Main current literature gaps and most promising research lines for future work are also identified.

Abstract
Aging is a natural process during which a person's physical and mental condition will degrade, imposing limitations on their lifestyle. The consequences of aging can be aggravated when the elderly permanently move to an elderly care center, causing a decline in social relations and contact with family and friends, with negative effects on the person's well-being. Therefore, it is important to act to maintain these relationships in the later stages of life. In this work we propose a roadmap to introduce and evaluate the usage of telepresence robots in elderly care centers, so that family and friends can interact with the elderly more often and with better quality. The proposal defines a set of steps to introduce the robots into the care center environment, as well as an evaluation methodology to assess the success of implementing the roadmap.

Abstract
Synthetic Aperture Radar Interferometry (InSAR) is a remote sensing technique very effective for the measurement of small displacements of the Earth's surface over large areas at a very low cost in comparison with conventional geodetic techniques. Advanced InSAR time series (Multi-Temporal InSAR or MT-InSAR) algorithms for monitoring and investigating surface displacement on Earth are based on conventional radar interferometry. These techniques allow us to measure deformation with uncertainties of one millimeter per year, interpreting time series of interferometric phases at coherent point scatterers (PS) without the need for human or special equipment presence. By applying InSAR processing techniques to a series of radar images over the same region, it is possible to monitor large areas and detect vertical displacements of ground, and infrastructures on the ground, and therefore identify abnormal or excessive movements indicating potential problems requiring detailed ground investigation. In this paper, we apply the PS-InSAR technique to a dataset of ERS-1/2 and Envisat radar images covering the period 1993-2010, to monitor the northern sector of the Valencia basin (Valencia city and its surroundings). Some subsiding areas were detected, with rates up to -5 mm/yr, whose causes are being investigated.

Abstract
Social entrepreneurship is emerging as an innovative approach for dealing with complex social and environmental needs, and is an important lever for the development of a sustainable society. Social entrepreneurship and related concepts have had a growing attention in the academy, giving rise to dissimilar approaches in the United States of America and in Western Europe. Despite the importance of the Third Sector in Portugal, it has been difficult to set ideal definitions for social entrepreneurship, social entrepreneur and social enterprises. By means of a qualitative study involving four Portuguese social ventures, this chapter identifies contemporary socio-cultural and economic factors that foster social innovation and intervention in Portugal, and contributes to understand the role of social entrepreneur in this context. © 2025 Elsevier B.V., All rights reserved.

Abstract
Increasing penetration of distributed energy resources in power distribution systems and appearing the flexible behavior of end-users based on demand response programs make the distribution layer of the power systems more active. In this way, energy transaction management through a decentralized manner could be an appropriate solution to improve the efficiency of energy trading in the distribution power networks. This paper proposes a decentralized method to manage energy flexibility by consumers based on a bottom-up approach in distributed power systems. Also, a 33-bus distribution network is considered to assess the performance of our proposed decentralized energy flexibility management model based on impacts of flexible behaviors of end-user and uncertainty of distribution lines to flow energy in the power network.

Abstract
This article addresses the problem of optimizing electrical power generation using kite power systems (KPSs). KPSs are airborne wind energy systems that aim to harvest the power of strong and steady high-altitude winds. With the aim of maximizing the total energy produced in a given time interval, we numerically solve an optimal control problem and thereby obtain trajectories and controls for kites. Efficiently solving these optimal control problems is crucial when the results are used in real-time control schemes, such as model predictive control. For this highly nonlinear problem, we derive continuous-time models-in 2D and 3D-and implement an adaptive time-mesh refinement algorithm. By solving the optimal control problem with such an adaptive refinement strategy, we generate a block-structured adapted mesh which gives results as accurate as those computed using fine mesh, yet with much less computing effort and high savings in memory and computing time.