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Photoacoustic Spectroscopy Combined with a Multipass Circular Cell to Detect Low Concentrations of Ammonia
Full text linkPhotoacoustic spectroscopy (PAS) has become a valuable technique for tracePhotoacoustic spectroscopy (PAS) has become a valuable technique for trace gas detection due to its high sensitivity and potential for miniaturization. This study presents the development and evaluation of a near-infrared PAS system using a 1532 nm semiconductor laser and a multipass cell (MPC) designed to enhance the optical path and thereby improve the detection of ammonia (NH3). The minimum detection limit was determined to be 770 ppb, with a normalized noise equivalent absorption (NNEA) coefficient of 1.07 × 10−8 W cm−1 Hz−1/2. While competitive with similar PAS systems, these results indicate that mid-infrared technologies still offer superior detection thresholds. The findings suggest that while this near-infrared setup may not yet match the sensitivity of systems using quantum cascade lasers or QEPAS, it offers notable advantages in terms of simplicity, cost, and potential for field deployment. The system’s configuration makes it a viable and efficient tool for industrial gas monitoring and real-time environmental applications, with future improvements likely to come from transitioning to the mid-infrared region and advancing laser stabilization and miniaturization techniques.The first and fourth authors are supported by the Grants for research activity of young PhD holders, part of the Universidad Carlos III de Madrid (UC3M) Own Research Program (Ayudas para la Actividad Investigadora de los Jóvenes Doctores, del Programa Propio de Investigación de la UC3M - Proyectos Jóvenes PPIT2024). Furthermore, they disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work has been supported by the Madrid Government (Comunidad de Madrid—Spain) under the Multiannual Agreement with the UC3M (IA_aCTRl-CM-UC3M)
Virtual Flux Control Methods for Grid-Forming Converters: A Four-Method Comparison
Full text linkThe increasing penetration of renewable energy generation in recent years has introduced significant changes and challenges to modern power systems. One of the most critical challenges is the reduction in system inertia, which decreases grid stability and subsequently weakens the electrical network. To address this issue, grid-forming (GFM) converters have emerged as a promising solution to maintain stability in weak grids. This paper proposes three novel control schemes for GFM converters and compares them with the performance of another topology recently published by the same authors. The four evaluated control schemes are based on the virtual flux variable which allows current limiting without using internal current loops, improving the stability of the control system. The assessment includes methods based on PI regulators, using the mathematical flatness property of differential algebra, direct control (DC), and model predictive control (MPC). The results demonstrate the robustness and correct operation of all four control strategies as GFM converters. Furthermore, through tests involving disturbances such as frequency variations, voltage sags, phase jumps, and transitions to islanded mode, their differences in terms of dynamic response, switching frequency, and current quality are clearly evidenced.This research was supported by the Spanish Research Agency under Grant TED2021-130468B-I00 MCIN/AEI/MCIN/AEI/10.13039/501100011033. NextGenerationEU/PRTR: CONTRIBUTION OF GRID FORMING CONVERTERS TO POWER SYSTEMS STABILITY AND OPERABILITY WITH HIGH PENETRATION OF RENEWABLE ENERGY SOURCES (GFM-RES). This work was also supported, in part, by the following projects from the Agencia Nacional de Investigacion y Desarrollo (ANID): AC3E (ANID/Basal/AFB240002), SERC Chile (ANID/FONDAP/1523A0006)
FARS: Factor Augmented Regression Scenarios in R
Full text linkIn the context of macroeconomic/financial time series, the FARS package provides a comprehensive framework in R for the construction of conditional densities of the variable of interest based on the factor-augmented quantile regressions (FA-QRs) methodology, with the factors extracted from multi-level dynamic factor models (ML-DFMs) with potential overlapping group-specific factors. Furthermore, the package also allows the construction of measures of risk as well as modeling and designing economic scenarios based on the conditional densities. In particular, the package enables users to: (i) extract global and group-specific factors using a flexible multi-level factor structure; (ii) compute asymptotically valid confidence regions for the estimated factors, accounting for uncertainty in the factor loadings; (iii) obtain estimates of the parameters of the FA-QRs together with their standard deviations; (iv) recover full predictive conditional densities from estimated quantiles; (v) obtain risk measures based on extreme quantiles of the conditional densities; and (vi) estimate the conditional density and the corresponding extreme quantiles when the factors are stressed.Financial support from the Spanish Government grant PID2022-139614NBC22 /AIE/10.13039/501100011033 (MINECO/FEDER) is gratefully acknowledged by all author
Enhancing Driving Safety Through Robust Static Output-Feedback Path Tracking and Emergency Braking Control Under Network-Induced Delays
Full text linkAutonomous vehicles represent a transformative technology with the potential to substantially enhance quality of life and revolutionize modern transportation systems. A fundamental objective of autonomous driving is path tracking, which involves ensuring the vehicle accurately follows a predetermined route. This task, however, is complicated by the potential presence of dynamic obstacles, such as pedestrians, stationary objects, or other vehicles, that may lead to collisions if not adequately managed. Additionally, precise path tracking relies on accurate knowledge of the vehicle’s internal states, many of which are difficult or prohibitively expensive to measure directly. Compounding these challenges are time delays that naturally arise in the perception, computation, and actuation loops of autonomous systems. Such delays can degrade control performance and compromise system stability if not properly addressed. To this end, this paper proposes a low-cost, robust static output-feedback path tracking controller that accounts for these inherent delays. A Lyapunov-Krasovskii functional is employed to rigorously ensure the system’s stability under the influence of time delays. In addition, an integrated emergency braking mechanism is incorporated to enhance safety by preventing collisions in critical scenarios. The effectiveness and reliability of the proposed control architecture are validated through comprehensive simulation studies conducted using CarSim.This work was supported in part by UC3M’s grants for young doctors (Grant No. 2024/00741/001) and by the grant [PID2022-136468OB-I00] funded by MCIN/AEI/10.13039/501100011033, and by “ERDF A way of making Europ
Cross-Cultural Adaptation of the Clinical Frailty Scale for Critically Ill Patients in Spain and Concurrent Validity With FRAIL-Es
Full text linkDocumento escrito por un elevado número de autores/as, solo se referencia el/la que aparece en primer lugar y los/as autores/as pertenecientes a la UC3M.Aims: To adapt the Clinical Frailty Scale (CFS) into Spanish and assess its concordance with the Spanish version of the FRAIL scale (FRAIL-Es) in the context of intensive care.
Design: Validation study of frailty assessment scales in critically ill patients.
Methods: The study was conducted in two phases. The first phase consisted of translating, culturally adapting, and validating the CFS into Spanish. The second phase consisted of a metric descriptive study to assess the concurrent criterion validity of the adapted CFS with FRAIL-Es in a cohort of intensive care patients. Both scales were assessed upon admission to intensive care and at 3, 6, 9, and 12 months post-hospital discharge. Analysis was performed using T-Student/Mann–Whitney, chi-squared and Cohen's Kappa tests.
Results: Successful adaptation of the CFS with minimal changes was achieved, demonstrating its applicability in the evaluated context. The pilot study indicated that CFS-Es is easy to assess, but some subjectivity in interpretation was noted. CFS-Es and FRAIL-Es were applied to 212 patients, revealing variations in frailty prevalence. The concordance and correlation between the CFS and FRAIL scales are robust. These differences suggest that the choice of scale may impact the identification of frail patients. These results emphasise the importance of considering specific characteristics of each scale when assessing frailty in critically ill patients, providing valuable information for clinical implementation and research in this field.
Patient or Public Contribution: Assessing frailty upon admission can be helpful in the care of frail patients, allowing the development of specific care plans based on pre-existing frailty.The present work was supported by the Ministry of Economy and Competitiveness ISCIII-FIS grant PI20/01231
Norma y diferencias: una década de escena inclusiva en el Centro Dramático Nacional (2013-2023)
Full text linkNuestra sociedad presenta unos perfiles tan complejos que exigen estrategias transversales, consolidar condiciones de vida cada vez más justas y decentes. A las luchas históricas de clase, a las reivindicaciones del movimiento feminista, etc, se han venido sumando durante las últimas décadas las demandas de personas con discapacidad, quienes sufren los efectos discriminatorios comunes a cualquier posición social subalterna. Por ello, es importante revisar cómo se ha ido adaptando la legislación española para corregir algunas de estas discriminaciones, también en el ámbito de la creación escénica, en la que el Centro Dramático Nacional debe ocupar un inexcusable lugar de transformación ética y estética para las artes escénicas españolas del siglo XXI
RESOLUCIÓN de 19 de diciembre de 2024, del Secretario General de la Universidad Carlos III de Madrid, por la que se delega en determinados órganos de la Universidad la competencia de emitir certificados de docencia del personal docente e investigador de la Universidad.
No full text¿Es familiar el ser personal?: una aproximación metafísica a la identidad humana
No full textEn la metafísica del ser personal de inspiración tomista, lo más propio de la persona humana es el amor donal. La raíz ontológica de esta condición se encuentra en el mayor grado de participación del Ser Personal por Esencia. El estudio de las relaciones interpersonales que surgen a partir de la donación exclusiva entre dos personas permite constatar que, a diferencia de lo que acontece en las especies animales, la paternidad/maternidad posee un valor trascendente. Asimismo, el acto originario de cualquier nuevo ser humano es el núcleo de la paternidad/maternidad. En efecto, se trata de una relación constitutivamente originaria, porque trasciende la principialidad corpórea de los progenitores, al insertarse en el origen divino de su ser. Por tanto, las relaciones de conyugalidad, de paternidad/maternidad con la correspondiente filiación, y de fraternidad, propias y exclusivas de la familia, hallan su raíz ontológica en la mayor intensidad del acto de ser de sus miembros. Por eso, la respuesta al interrogante que plantea el título del presente escrito es afirmativa; esto es, el ser personal humano es familiar
The study of the joint ownership from Property Registry regulation and doctrine and jurisprudence (with special attention to the nature of the community and the problems involved in its extinction)
No full text[ES] La situación de comunidad de bienes es un fenómeno complejo, cuyo estudio y comprensión suscita interesantes pero difíciles cuestiones, sobre las que conviene detenerse. Este estudio intenta ofrecer una explicación de algunos de ellos, los que creemos son los más complejos pero con clara proyección práctica: la naturaleza de la comunidad de bienes, y la extinción de la misma y los problemas que plantea la acción de división. Y todo ello analizándolo desde la normativa registral, y desde la doctrina que tanto los autores como la DGRN / DGSJyFP han ido construyendo a lo largo de los años[EN] The situation of joint ownership is a complex phenomenon, the study
and understanding of which raises interesting but difficult questions, on which it is worthwhile to dwell. This study attempts to offer an explanation of some of them, which we believe to be the most complex but with a clear practical projection: the nature of the joint ownership, its extinction and the problems posed by the action for division. And all of this is analysed from the point of view of the Property Registry regulation, and from the doctrine that both the authors and the DGRN / DGSJyFP have been building up over the years
Collusion when players take turns
No full textTraditional collusion models typically assume that players coordinatetheir actions actively during the competition process to influence the outcomes.In contrast, we consider a repeated interaction setting betweentwo players where collusion occurs through well-defined strategies: theplayers take turns, with one holding monopoly power while the other eitherrefrains from participating or behaves as if absent. We provide afull characterization of when taking turns constitutes a subgame perfectNash equilibrium in repeated games. By allowing players to discount timedifferently, we uncover a novel, non-monotonic condition on the discountfactor that sustains collusion. We apply our findings to three specificcontexts: contests, duopoly, and political competition