Nonlinear optimal control for triangular tethered multi-satellite formations

Triangular satellite constellations are created by three satellites which are linked through tethers. Such formations serve distributed observation space missions or the creation of high-density satellite communication networks over high-frequency bands. In a tethered multi-satellite system consisting of three-satellites in triangular formation the associated dynamic model exhibits strong nonlinearities. Stabilization and precise positioning of the multi-satellite constellation is a nontrivial task and the solution of the associated nonlinear control problem is an elaborated procedure. In this article a novel nonlinear optimal control method is applied to the above-noted model the tethered multi-satellite system in triangular formation. First, the state-space model of the triangular tethered multi-satellite formation undergoes approximate linearization around a temporary operating point that is recomputed at each time-step of the control method. The linearization relies on Taylor series expansion and on the associated Jacobian matrices. For the linearized state-space model of the tethered satellites a stabilizing optimal (H-infinity) feedback controller is designed. This controller stands for the solution of the nonlinear optimal control problem under model uncertainty and external perturbations. To compute the controller’s feedback gains an algebraic Riccati equation is repetitively solved at each iteration of the control algorithm. The stability properties of the control method are proven through Lyapunov analysis. The proposed nonlinear optimal control approach achieves fast and accurate tracking of setpoints under moderate variations of the control inputs and a minimum dispersion of energy when changing the position of the satellites in their triangular tethered formation.(a) Gerasimos Rigatos has been partially supported by Grant Ref. 301022 ”Nonlinear optimal and flatness-based control methods for complex dynamical systems” of the Unit of Industrial Automation, Industrial Systems Institute, Greece (b) The work of Mohammed S. Al-Numay and Pierluigi Siano was supported by the Distinguished Scientist Fellowship Program, King Saud University, Riyadh, Saudi Arabia

El diferente tratamiento fiscal a los dividendos percibidos por sociedades no residentes a la luz de la libre circulación de capitales: la STJUE de 7 de noviembre de 2024, C-782/22

En esta sentencia, el TJUE analiza si el tratamiento fiscal menos ventajoso que reciben los dividendos abonados a sociedades no residentes es contrario a la libre circulación de capitales garantizada en el art. 63 del TFUE. Para ello, el TJUE examina si la diferencia de trato entre los dividendos pagados a sociedades residentes y los abonados a sociedades no residentes son situaciones objetivamente comparables y si dicha diferencia de trato puede estar justificada por razones imperiosas de interés general.In this judgment, the CJEU analyses whether the less advantageous tax treatment received by dividends paid to non-resident entities contravenes the free movement of capital guaranteed in Article 63 of the TFEU. With this aim, the Court examines whether the difference in treatment between dividends paid to resident entities and those paid to non-resident entities are objectively comparable situations and whether such difference in treatment can be justified by compelling reasons of general interest

Cenozoic tectono-sedimentary evolution of the External Rif Chain (Morocco) derived from mineralogical and geochemical analysis of mudrocks

A model of the Cenozoic tectono-sedimentary evolution of the External Rif Chain (Morocco) is provided by means of the study of the mineralogical and geochemical composition of mudrocks. To date there was a lack of homogeneous data and of a complete and extensive study of the whole External Rif Zone (ERZ). Therefore, this work shows the study of the whole ERZ where the most representative stratigraphic sections have been selected. This work provides important information about the geodynamic evolution and the variations in source-area provenance related to the growing of the Rif orogenic belt. Although there is still much work to be done, this study aims to improve the knowledge of the Cenozoic tectono-sedimentary evolution of the entire western ERZ with a homogeneous method, with a focus on the paleogeographic and paleotectonic evolution, the paleoweathering and the source areas deduced from mineralogical and geochemical data of the Cenozoic mudrocks. The bulk mineralogy is mainly characterized by the presence of calcite, quartz and dolomite plus ankerite. Feldspars have few percentages. The clay minerals are principally represented by mixed-layer illite/smectite (I/S). Illite and kaolinite are in little amount. Femic minerals, mixed-layer chlorite/smectite (C/S) and chlorite are the most abundant. The I/S features suggest a different thermal condition for the three domains. The chemical composition indicates that the mudrocks can be described as mixtures of carbonates with aluminosilicate components. The Al/Ti, Th/Cr, Th/Sc, La/Th and La/Sc ratios, the Cr/V vs. Y/Ni plot, the V-Ni-Th*10 and La-Th-Sc ternary diagrams indicate a predominantly felsic source with a minor mafic input more evident in the Paleocene-Eocene samples of the External Intrarif and Mesorif. The External Rif Zones changed in the Cenozoic from a passive margin to a complex foreland system with the incoming of the Alpine tectonic phases. In general, the felsic contribution should be linked to the foreland area consisting in the Middle Atlas and Mesetas massifs made of a crystalline domain. This margin probably presented an intermediate narrow oceanic branch in the External Intrarif-Mesorif boundary that surprisingly should start to close during Paleogene times providing the mafic contribution. This Paleogene tectonic activity in these domains is corroborated by the thermal maturity indicating late diagenesis. The chemical weathering indices, such as the CIA (Chemical index of Alteration) and its modifications, show medium-high values and thus suggest generally moderate paleoweathering conditions in agreement with the predominant amount of I/S.Research supported by: Research Project PID2020-114381GB-I00, Spanish Ministry of Education and Science; Research Groups and Projects of the Generalitat Valenciana, Alicante University (CTMA-IGA)

Undergraduate nursing students' perceptions and experiences of learning spiritual competencies: A qualitative meta-synthesis

Background: Nursing focuses on improving individuals' overall well-being through a holistic approach that includes spiritual care, which is key for fostering compassionate relationships and addressing patients' spiritual needs. Despite its importance, challenges remain in integrating spiritual care into patient care, and little is known about how nursing students perceive and acquire spiritual care competencies during their education. Aim: This meta-synthesis aims to interpret and synthesize qualitative evidence on the learning process of spiritual care competencies among nursing students. Review methods: Searches in six databases were conducted. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) was used to guide this review. A total of 1248 studies were screened. Inclusion criteria were: qualitative studies published between 2013 and 2023 in Spanish and English languages, and undergraduate nursing students as participants. The quality of the (n=12) identified studies was evaluated using the Consolidated Criteria for Reporting Qualitative Studies (COREQ) checklist. A total of (n=11) studies were analysed using two-step metasynthesis procedures and following Sandelowski and Barroso's (2007) methodology. Results: A total of 686 undergraduate nursing students participated in the studies included in this meta-synthesis. The findings were synthesized into three categories: (1) Approach to Spirituality: back-and-forth actions between theory, care, and self-awareness, (2) From the Known (Intrapersonal-Interpersonal) to the Unknown (Transpersonal) and (3) Knowing how to be, knowing how to do, and knowing how to be present in spiritual care. One meta-theme emerged: ‘Personal and Professional Transformation in the Provision of Spiritual Care: The Journey of Nursing Students Towards Holistic and Empathetic Practice’. Conclusions: Nursing students' understanding of spiritual care is influenced by their personal, cultural, and religious backgrounds. However, there is a lack of formal spiritual care education. Acquiring spiritual care competencies is crucial for delivering holistic care, emphasizing the need for enhanced education in both undergraduate nursing programs and continuing professional development

The impact of heteropatriarchy and support on grief in sexual minorities: A qualitative study

Social support is a crucial element in the grieving process. However, in some social groups, such support may be absent or available only in a limited way. This would be the case for sexual minorities, who face prejudice, stigma, and rejection. The aim of this qualitative study is to explore the particularities of grief experienced by sexual minorities following the loss of a partner, using a Spanish sample. Individual semi-structured interviews were conducted with all participants. Qualitative results from 23 homosexual and bisexual people highlight the effects of heteropatriarchy on sexual minorities: gay men experience privileged status with visible partner relationships and widespread social support during grief, whereas lesbian women experience invisible relationships and instances of family and social rejection, leading to disenfranchized grief

Evaluation of Semiempirical Quantum Mechanical Methods for Zr-Based Metal-Organic Framework Catalysts

Zr-based metal-organic frameworks (MOFs) are typically employed in heterogeneous catalysis due to their porosity, chemical and thermal stability, and well-defined active sites. Density functional theory (DFT) is the workhorse to compute their electronic structure; however, it becomes very costly when dealing with reaction mechanisms involving large unit cells and vast configurational spaces. Semiempirical quantum mechanical (SQM) methods appear as an alternative approach to simulate such chemical systems at low computational cost, but their feasibility to model catalysis with MOFs is still unexplored. Thus, here we present a benchmark study on UiO-66 to evaluate the performance of SQM methods (PM6, PM7, GFN1-xTB, GFN2-xTB) against hybrid DFT (M06). We evaluate defective nodes, ligand exchange reactions, barrier heights, and host–guest interactions with metal nanoclusters. Despite some caveats, GFN1-xTB on properly constrained models is the best SQM method across all studied properties. Under proper supervision, this protocol holds promise for application in exploratory high-throughput screenings of Zr-based MOF catalysts, subject to further refinement with more accurate methods.This work has been funded by MICIU/AEI/10.13039/501100011033 and FSE+ (RYC2022-035453-I, PID2020-119116RA-I00), Xunta Distinguished Researcher program (ED431H 2020/21), the Xunta de Galicia (Centro de Investigación do Sistema Universitario de Galicia accreditation 2023-2027, ED431G 2023/03), and the European Union (European Regional Development Fund─ERDF). The authors acknowledge CESGA (“Centro de Supercomputación de Galicia”) for providing generous computational resources

Nonlinear Optimal Control of an H-Type Gantry Crane Driven by Dual PMLSMs

Gantry cranes of the H-type with dual electric-motor actuation are widely used in industry. In this article, the control problem of an H-type gantry crane which is driven by a pair of linear permanent magnet synchronous motors (dual PMLSMs) is considered. The integrated system that comprises the H-type gantry crane and its two LPMSMs is proven to be differentially flat. The control problem for this robotic system is solved with the use of a nonlinear optimal control method. To apply the nonlinear optimal control method, the dynamic model of the H-type gantry crane with dual LPMSM undergoes approximate linearization at each sampling instant with the use of first-order Taylor series expansion and through the computation of the associated Jacobian matrices. The linearization point is defined by the present value of the system's state vector and by the last sampled value of the control inputs vector. To compute the feedback gains of the optimal controller an algebraic Riccati equation is repetitively solved at each time-step of the control algorithm. The global stability properties of the nonlinear optimal control method are proven through Lyapunov analysis. The proposed control scheme achieves stabilization of the H-type gantry crane with dual LPMSMs without the need of diffeomorphisms and complicated state-space model transformations.Gerasimos Rigatos has been partially supported by Grant Ref. 301022 ‘Nonlinear optimal and flatness-based control methods for complex dynamical systems’ of the Unit of Industrial Automation of the Industrial Systems Institute, Pierluigi Siano and Mohammed AL-Numay acknowledge financial support from the Researchers Supporting Project Number (RSP2024R150), King Saud University, Riyadh, Saudi Arabia

The halotolerant white sea anemone Anthothoe chilensis, highly abundant in brine discharges zones, as a promising biomonitoring species for evaluating the impacts of desalination plants

Seawater desalination raises concerns about its environmental repercussions, particularly the impact of brine discharge on benthic communities. In this study, we evaluated the effects of desalination and artificial brines on the sea anemone Anthothoe chilensis, following its observed proliferation near a brine outfall from a Chilean desalination plant. We measured biomarkers for oxidative stress (ROS content, lipid peroxidation, and protein carbonylation), antioxidant response (thiols), and osmotic stress (free amino acids and proline) in individuals collected from a brine discharge pipe (∼56 psu) and compared them to a population living in natural seawater salinity. Additionally, we conducted controlled laboratory experiments where A. chilensis specimens were exposed to a control salinity of 33 psu and to elevated salinities of 37 and 42 psu for 24 and 48 h. Results revealed a significant decrease in oxidative damage biomarkers, such as protein carbonylation and ROS content, along with an increase in free amino acids, proline, and thiols content at higher salinity levels, particularly under controlled conditions. These findings demonstrate the remarkable efficient cellular stress responses of this highly halotolerant species, which could potentially promote risky A. chilensis blooms in brine discharges areas. Additionally, this study provides valuable biomarker information for assessing the short-term impacts of brine discharges, which can be used in biomonitoring programs within the desalination sector.FRR was financed by Fondecyt #11220425 grant from ANID, Chile. CAS was financed by project ANID InES I + D 2021 (INID210013). FBM was supported by a grant from Universidad de Alicante (Grant ID: FPUUA98). IS was financed by the European Union-Next Generation EU (MARSALAS21-30) grant. JPR was financed by ANID National Doctoral Scholarship #21230403. KG was financed by UPLA inner doctoral scholarship UPA22991. Data obtained for total ROS quantification was granted by Cytation 5 equipment from the Fondequip EQM160131 project of University of Playa Ancha, Chile

Thirty years of ADHD and WISC in scientific research: A systematic review of cognitive profile and index discrepancies

Several decades have passed since the initial exploration of the cognitive profile of ADHD using the WISC. Since then, the scientific evidence on the topic has grown and evolved, at times being contradictory. Therefore, it is considered valuable to collect, analyze, compare, and synthesize the findings from the past 30 years. A systematic review was conducted following the PRISMA guidelines. The sources of information included the WoS, Scopus, PsycInfo, and MedLine databases, and the search terms applied were: (ADHD OR ‘attention deficit’ OR hyperactive*) AND (WISC*). Some of the inclusion criteria were: Participants were males and/or females aged between 6 and 16 years, formally diagnosed with ADHD, and assessed using the WISC-IV and/or the WISC-III. A total of 27 high-quality studies, with 6,486 participants across them, published up to September 2024, were analyzed. The systematic review, supported by a simple complementary statistical approach, suggests a cognitive profile characterized by higher scores on VC and PR/PO and lower scores on WM/FFD and PS. The index discrepancies that arise from comparing VC and PR/PO scores with WM/FFD and PS scores range from five to ten points. For the assessment of ADHD, as a complementary tool to the observation scales, it could be useful to use the WISC, examine the cognitive profile and index discrepancies, always with careful interpretation by an experienced professional in the field of psychology, psychopedagogy, psychiatry or neuropsychology.Treinta años de TDAH y WISC en investigación científica: Una revisión sistemática del perfil cognitivo y discrepancias entre índices. Han pasado varias décadas desde la exploración inicial del perfil cognitivo del TDAH utilizando el WISC. Desde entonces, la evidencia científica sobre el tema ha crecido y evolucionado, siendo en ocasiones contradictoria. Por ello, se considera valioso recopilar, analizar, comparar y sintetizar los hallazgos de los últimos 30 años. Se llevó a cabo una revisión sistemática siguiendo las directrices PRISMA. Las fuentes de información incluyeron las bases de datos de WoS, Scopus, PsycInfo y MedLine, y los términos de búsqueda aplicados fueron: (ADHD OR ‘attention deficit’ OR hyperactive*) AND (WISC*). Algunos de los criterios de inclusión fueron: Participantes de sexo masculino y/o femenino con edades entre 6 y 16 años, diagnosticados formalmente con TDAH y evaluados mediante el WISC-IV y/o WISC-III. Se analizaron un total de 27 estudios de calidad, con 6,486 participantes en total, publicados hasta septiembre de 2024. La revisión sistemática, respaldada por un enfoque estadístico complementario simple, sugiere un perfil cognitivo caracterizado por puntuaciones más altas en CV y RP/OP, y puntuaciones más bajas en MT/ID y VP. Las discrepancias entre índices que surgen al comparar las puntuaciones de CV y RP/OP con las de MT/ID y VP oscilan entre cinco y diez puntos. Para la evaluación del TDAH, como herramienta complementaria a las escalas de observación, podría ser útil utilizar el WISC, examinar el perfil cognitivo y las discrepancias entre índices, siempre con una interpretación cuidadosa por parte de un profesional experimentado del ámbito de la psicología, psicopedagogía, psiquiatría o neuropsicología.This research was funded by the Vice-rectorate of Research, Development and Innovation of the University of Alicante, Grant number: GRE21-15

Summer House Transformations: New Trends in How Families Enjoy the Mediterranean Landscape in Costa Blanca

This essay explores the transformations of summer houses in the Costa Blanca, a coastal region in southeastern Spain whose identity has been shaped by decades of residential tourism. While high-rise tourist developments such as Benidorm have attracted widespread academic attention, the proliferation of single-family houses since the 1970s remains less studied. Drawing on five ethnographic accounts, the article examines how successive generations of residents—local families, North European retirees, and digital nomads—have adapted, extended, and repurposed these dwellings. The research is framed by the Consultorio de la Costa Blanca, a design consultancy inspired by the Community Architect method, which has assisted over a hundred families in renovating their properties. These stories reveal a paradox at the heart of suburban landscapes of leisure: houses are bought to enjoy and preserve the Mediterranean landscape but their continual transformation alters its character. The essay analyzes how ideals of outdoor living, economic considerations, and the pursuit of sustainability converge in design decisions—from adding pools and terraces to reclaiming agricultural land patterns or integrating ecological materials. Drawing on Donna Haraway’s notion of the “quiet country,” the text interrogates whether these suburban landscapes, shaped by global consumption and mobility, can ever become places where care and ecological continuity are visible. Ultimately, the study shows that summer houses are not merely real estate assets but material expressions of shifting aspirations and a collective desire to anchor lives within a landscape that is simultaneously valued and transformed.Generalitat Valenciana (CIGE 2023/227