Filters








156 Hits in 0.95 sec

On the Estimation of the Moving Mass of a TMD Installed on a Lively Structure

Alvaro Magdaleno, Cesar Pelaez, Alvaro Iglesias-Pordomingo, Antolin Lorenzana
2021 Applied Sciences  
Tuned Mass Dampers are devices which can be assimilated to single-degree-of-freedom systems with a certain amount of moving mass, a natural frequency and a damping ratio intended to be installed on lively structures to reduce the contribution of a certain mode to their response. Once placed on the structure, the movement of the mass damper couples to the structural response and determines its properties as an isolated system becomes challenging. The authors have previously presented a
more » ... y to estimate the natural frequency and damping ratio of an SDOF system installed on a structure and not necessarily tuned to a certain mode. It was based on a transmissibility function and, thus, the moving mass could not be estimated. With this work, the authors go one step further and present a novel procedure to estimate the moving mass value by means of the same transmissibility function and two well selected frequency response functions. The methodology is applied to estimate the properties of a real single-degree-of-freedom system placed on a lively timber platform. The results are compared with the mass modification technique to show that the proposed methodology provides better estimations in a more efficient way.
doi:10.3390/app11104712 fatcat:pxe4eltwqzg3zkx5eoov7pk65u

Broadband-tunable spectral response of perovskite-on-paper photodetectors using halide mixing [article]

Alvaro J. Magdaleno, Riccardo Frisenda, Ferry Prins, Andres Castellanos-Gomez
2022 arXiv   pre-print
Paper offers a low-cost and widely available substrate for electronics. It posses alternative characteristics to silicon, as it shows low density and high-flexibility, together with biodegradability. Solution processable materials, such as hybrid perovskites, also present light and flexible features, together with a huge tunability of the material composition with varying optical properties. In this study, we combine paper substrates with halide-mixed perovskites for the creation of low-cost
more » ... easy-to-fabricate perovskite-on-paper photodetectors with a broadband-tunable spectral response. From the bandgap tunability of halide-mixed perovskites we create photodetectors with a cut-off spectral onset that ranges from the NIR to the green, by increasing the bromide content on MAPb(I_1-xBr_x)_3 perovskite alloys. The devices show a fast and efficient response. The best performances are observed for the pure I and Br perovskite compositions, with a maximum responsivity of 376 mA/W on the MAPbBr_3 device. This study provides an example of the wide range of possibilities that the combination of solution processable materials with paper substrates offer for the development of low-cost, biodegradable and easy-to-fabricate devices.
arXiv:2205.11256v1 fatcat:mwmkowgc35gojanpcrwj4qwh5q

Exciton diffusion in two-dimensional metal-halide perovskites [article]

Michael Seitz, Alvaro J. Magdaleno, Nerea Alcázar-Cano, Marc Meléndez, Tim J. Lubbers, Sanne W. Walraven, Sahar Pakdel, Elsa Prada, Rafael Delgado-Buscalioni, Ferry Prins
2020 arXiv   pre-print
Two-dimensional perovskites, in which inorganic layers are stabilized by organic spacer molecules, are attracting increasing attention as a more robust analogue to the conventional three-dimensional metal-halide perovskites. However, reducing the perovskite dimensionality alters their optoelectronic properties dramatically, yielding excited states that are dominated by bound electron-hole pairs known as excitons, rather than by free charge carriers common to their bulk counterparts. Despite the
more » ... growing interest in two-dimensional perovskites for both light harvesting and light emitting applications, the full impact of the excitonic nature on their optoelectronic properties remains unclear, particularly regarding the spatial dynamics of the excitons within the two-dimensional (2D) plane. Here, we present direct measurements of in-plane exciton transport in single-crystalline layered perovskites. Using time-resolved fluorescence microscopy, we show that excitons undergo an initial fast, intrinsic normal diffusion through the crystalline plane, followed by a transition to a slower subdiffusive regime as excitons get trapped. Interestingly, the early intrinsic exciton diffusivity depends sensitively on the exact composition of the perovskite, such as the choice of organic spacer. We attribute these changes in exciton transport properties to strong exciton-phonon interactions and the formation of large exciton-polarons. Our findings provide a clear design strategy to optimize exciton transport in these systems.
arXiv:2001.05704v1 fatcat:apdymkbpangqdcxt76pifvkvza

Performance of a TMD to Mitigate Wind-Induced Interference Effects between Two Industrial Chimneys

Ali Vasallo Belver, Álvaro Magdaleno, James Mark William Brownjohn, Antolín Lorenzana
2021 Actuators  
The present paper studies the performance of a tuned mass damper (TMD) installed in a 183 m tall chimney located at the edge of the wake shed by another chimney. Numerical and experimental results are available. For the simulations, wind action is considered by solving several 2D flow problems on a selected number of horizontal planes, in the transverse direction to the stacks. On such planes, Navier-Stokes equations are solved to estimate the fluid action at different positions of the chimneys
more » ... and standard interpolation techniques are applied in the vertical direction. An Arbitrary Lagrangian-Eulerian (ALE) approach is used to consider the moving domain, and a fractional-step scheme is used to solve the fluid field. For the structural modelling, chimneys are meshed using 3D beam finite elements. The time integration procedure used for the structural dynamics is based on the standard second order Bossak method. For each period of time, the fluid problem is solved, the aeroelastic analysis is carried out and the geometry of the fluid mesh of each plane is updated according to the structural movements. With this procedure and model updating techniques, the response of the leeward chimney is evaluated for different scenarios, revealing an interesting dependence of the TMD performance on the wind speed and direction.
doi:10.3390/act10010012 fatcat:r6vul3a3tbbs7i64fpjau2mg5a

Paradoxical reversed plantar involvement during ixekizumab therapy for psoriasis

Álvaro Martínez-Doménech, Marta García-Legaz-Martínez, Jorge Magdaleno-Tapial, Macarena Giácaman, Pablo Hernández-Bel, Amparo Pérez-Ferriols
2019 Dermatology Online Journal  
doi:10.5070/d3254043589 fatcat:l6cw7tswgfdgjcoyzcouqrd56q

Exciton diffusion in two-dimensional metal-halide perovskites

Michael Seitz, Alvaro J. Magdaleno, Nerea Alcázar-Cano, Marc Meléndez, Tim J. Lubbers, Sanne W. Walraven, Sahar Pakdel, Elsa Prada, Rafael Delgado-Buscalioni, Ferry Prins
2020 Nature Communications  
Two-dimensional layered perovskites are attracting increasing attention as more robust analogues to the conventional three-dimensional metal-halide perovskites for both light harvesting and light emitting applications. However, the impact of the reduced dimensionality on the optoelectronic properties remains unclear, particularly regarding the spatial dynamics of the excitonic excited state within the two-dimensional plane. Here, we present direct measurements of exciton transport in
more » ... talline layered perovskites. Using transient photoluminescence microscopy, we show that excitons undergo an initial fast diffusion through the crystalline plane, followed by a slower subdiffusive regime as excitons get trapped. Interestingly, the early intrinsic diffusivity depends sensitively on the choice of organic spacer. A clear correlation between lattice stiffness and diffusivity is found, suggesting exciton-phonon interactions to be dominant in the spatial dynamics of the excitons in perovskites, consistent with the formation of exciton-polarons. Our findings provide a clear design strategy to optimize exciton transport in these systems.
doi:10.1038/s41467-020-15882-w pmid:32341361 fatcat:6wzltp5vzzbjfjx35d7ogoow6q

Halide mixing inhibits exciton transport in two-dimensional perovskites despite phase purity [article]

Michael Seitz, Marc Meléndez, Peyton York, Daniel A. Kurtz, Alvaro J. Magdaleno, Nerea Alcázar, Mahesh K. Gangishetty, Rafael Delgado-Buscalioni, Daniel N. Congreve, Ferry Prins
2021 arXiv   pre-print
Metal-halide perovskites are a versatile material platform for light-harvesting and light-emitting applications as their variable chemical composition allows the optoelectronic properties to be tailored to specific applications. Halide mixing is one of the most powerful techniques to tune the optical bandgap of metal-halide perovskites across wide spectral ranges. However, halide mixing has commonly been observed to result in phase segregation, which reduces excited-state transport and limits
more » ... vice performance. While the current emphasis lies on the development of strategies to prevent phase segregation, it remains unclear how halide mixing may affect excited-state transport even if phase purity is maintained. In this work, we study excitonic excited-state transport in phase pure mixed-halide 2D perovskites. Using transient photoluminescence microscopy, we show that, despite phase purity, halide mixing inhibits exciton transport in these materials. We find a significant reduction even for relatively low alloying concentrations, with bromide-rich perovskites being particularly sensitive to the introduction of iodide ions. Performing Brownian dynamics simulations, we are able to reproduce our experimental results and attribute the decrease in diffusivity to the energetically disordered potential landscape that arises due to the intrinsic random distribution of alloying sites. Our results suggest that even in the absence of phase segregation, halide mixing may still impact carrier transport due to the local intrinsic inhomogeneities in the energy landscape.
arXiv:2107.06560v1 fatcat:gvspfk3i6vebzkaihcwrn2k4vq

Digital ulcerative lichenoid dermatitis in a patient receiving anti-PD-1 therapy

Álvaro Martínez-Doménech, Marta García-Legaz Martínez, Jorge Magdaleno-Tapial, Cristian Valenzuela-Oñate, Gemma Pérez-Pastor, Amparo Pérez-Ferriols
2019 Dermatology Online Journal  
doi:10.5070/d3259045515 fatcat:npztq5utybh33a77xfjzofxqda

Measurement of Acceleration Response Functions with Scalable Low-Cost Devices. An Application to the Experimental Modal Analysis

Alvaro Magdaleno, Juan Villacorta, Lara del-Val, Alberto Izquierdo, Antolin Lorenzana
2021 Sensors  
One of the most popular options in the Structural Health Monitoring field is the tracking of the modal parameters, which are estimated through the frequency response functions of the structure, usually in the form of accelerances, which are computed as the ratio between the measured accelerations and the applied forces. This requires the use of devices capable of synchronously recording accelerations at several points of the structure at high sampling rates and the subsequent computational
more » ... sis using the recorded data. To this end, this work presents and validates a new scalable acquisition system based on multiple myRIO devices and digital MEMS (Micro-Electro-Mechanical System) accelerometers, intended for modal analysis of large structures. A simple form of this system was presented by the authors in a previous work, showing that a single board with some accelerometers connected to it got to obtain high quality measurements in both time and frequency domains. Now, a larger system composed by several slave boards connected and synchronized to a master one is presented. Delays lower than 100 ns are found between the synchronised channels of the proposed system. For validation purposes, a case study is presented where the devices are deployed on a timber platform to estimate its modal properties, which are compared with the ones provided by a commercial system, based on analog accelerometers, to show that similar results are obtained at a significantly lower cost.
doi:10.3390/s21196637 pmid:34640957 pmcid:PMC8512721 fatcat:cbnmdkudwvhkrnzs2bs2j4d3x4

PhysEx: A novel procedure to estimate full-rank physical matrices of a structure from an incomplete modal model

Alvaro Magdaleno, Antolin Lorenzana
2021 Journal of Sound and Vibration  
Magdaleno and A. Lorenzana, PhysEx: A novel procedure to estimate full-rank physical matrices of a structure from an incomplete modal model, Journal of Sound and Vibration (2021), doi: https://doi.  ... 
doi:10.1016/j.jsv.2021.116277 fatcat:6n55xlg7uzccrdrmrpz3yqnnbi

Novel PTEN mutation in Cowden syndrome: case report with late diagnosis and non-malignant course

Alvaro Martínez-Doménech, Marta García-Legaz Martínez, Jorge Magdaleno-Tapial, Gemma Pérez-Pastor, Raquel Rodríguez-López, Amparo Pérez-Ferriols
2019 Dermatology Online Journal  
doi:10.5070/d3255044077 fatcat:2ndmmapvxfbblonyh2kt5v4qsy

Improvement of plaque-like cutaneous mucinosis after intravenous immunoglobulins treatment

Jorge Magdaleno-Tapial, Cristian Valenzuela-Oñate, Álvaro Martínez-Doménech, Marta García-Legaz-Martínez, Juan José Tamarit-García, Violeta Zaragoza-Ninet, Víctor Alegre-de Miquel, Amparo Pérez-Ferriols
2020 JAAD Case Reports  
Correspondence to: Jorge Magdaleno-Tapial, MD, Department of Dermatology, Hospital General Universitario de Valencia, Av Tres Creus, 2, 46014 Valencia, Spain.  ... 
doi:10.1016/j.jdcr.2020.06.015 pmid:32715057 pmcid:PMC7369530 fatcat:klbdqdwo3vc2lezd5zkik3c7zy

Apocrine hidrocystoma on the nipple: the first report in this unusual location

Jorge Magdaleno-Tapial, Cristian Valenzuela-Oñate, Álvaro Martínez-Doménech, Marta García- Legaz-Martínez, Antonio Martínez-Aparicio, Víctor Alegre-de Miquel, Amparo Pérez-Ferriols
2019 Dermatology Online Journal  
doi:10.5070/d32510045825 fatcat:s4tns42p6vgylizk72b6jy7ls4

Design and Validation of a Scalable, Reconfigurable and Low-Cost Structural Health Monitoring System

Juan J. Villacorta, Lara del-Val, Roberto D. Martínez, José-Antonio Balmori, Álvaro Magdaleno, Gamaliel López, Alberto Izquierdo, Antolín Lorenzana, Luis-Alfonso Basterra
2021 Sensors  
This paper presents the design, development and testing of a low-cost Structural Health Monitoring (SHM) system based on MEMS (Micro Electro-Mechanical Systems) triaxial accelerometers. A new control system composed by a myRIO platform, managed by specific LabVIEW software, has been developed. The LabVIEW software also computes the frequency response functions for the subsequent modal analysis. The proposed SHM system was validated by comparing the data measured by this set-up with a
more » ... l SHM system based on piezoelectric accelerometers. After carrying out some validation tests, a high correlation can be appreciated in the behavior of both systems, being possible to conclude that the proposed system is sufficiently accurate and sensitive for operative purposes, apart from being significantly more affordable than the traditional one.
doi:10.3390/s21020648 pmid:33477780 fatcat:fnx4fcyb3baubpfb5jg2gor3dy

Nitrate, phosphate and boron content in wastewater for crop irrigation in Mezquital Valley, Hidalgo

José Pedro Pérez Díaz, Héctor Manuel Ortega Escobar, Carlos Ramírez Ayala, Héctor Flores Magdaleno, Edgar Iván Sánchez Bernal, Álvaro Can Chulim, Oscar Raúl Mancilla Villa
2018 Nova Scientia  
., 2007; Flores-Magdaleno et al., 2011) and can be absorbed and accumulated in plants (Vázquez-Alarcón et al., 2001) ; furthermore, contact with wastewater affects the health of the overall population  ... 
doi:10.21640/ns.v10i21.1478 fatcat:tjuyxmnlbfaknfump2no4omxtq
« Previous Showing results 1 — 15 out of 156 results