Electrothermoplasmonic flow in gold nanoparticles suspensions: nonlinear dependence of flow velocity on aggregate concentration

Efficient mixing and pumping of liquids at the microscale is a technology that is still to be optimized. The combination of an AC electric field with a small temperature gradient leads to a strong electrothermal flow that can be used for multiple purposes. Combining simulations and experiments, an analysis of the performance of electrothermal flow is provided when the temperature gradient is generated by illuminating plasmonic nanoparticles in suspension with a near-resonance laser. Fluid flow is measured by tracking the velocity of fluorescent tracer microparticles in suspension as a function of the electric field, laser power, and concentration of plasmonic particles. Among other results, a non-linear relationship is found between the velocity of the fluid and particle concentration, which is justified in terms of multiple scattering-absorption events, involving aggregates of nanoparticles, that lead to enhanced absorption when the concentration is raised. Simulations provide a description of the phenomenon that is compatible with experiments and constitute a way to understand and estimate the absorption and scattering cross-sections of both dispersed particles and/or aggregates. A comparison of experiments and simulations suggests that there is some aggregation of the gold nanoparticles by forming clusters of about 2–7 particles, but no information about their structure can be obtained without further theoretical and experimental developments. This nonlinear behavior could be useful to get very high ETP velocities by inducing some controlled aggregation of the particles.This research has been supported by Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía and FEDER, “Una manera de hacer Europa”/Projects P18-FR-3583 and FQM-410-UGR18, Ministerio de Ciencia, Innovación y Universidades through Project EQC2018-004693-P, and Grant PID2021-127427NB-I00/ MCIN/AEI/10.13039/501100011033/FEDER,UE. Funding for open access charge: Universidad de Málaga/CBUA

Apuntes para la historia jurídica de Segovia

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Reducing human effort in engineering drawing validation.

Oil & Gas facilities are extremely huge and have complex industrial structures that are documented using thousands of printed sheets. During the last years, it has been a tendency to migrate these paper sheets towards a digital environment, with the final end of regenerating the original computer-aided design (CAD) projects which are useful to visualise and analyse these facilities through diverse computer applications. Usually, this was done manually by re-sketching each page using CAD applications. Nevertheless, some applications have appeared which generate the CAD document automatically given the paper sheets. In this last case, the final document is always verified by an engineer due to the need of being a zero-error process. Since the need of an engineer is absolutely accepted, we present a new method to reduce the required engineer working time. This is done by highlighting the digitised components in the CAD document that the automatic method could have incorrectly identified. Thus, the engineer is required only to look at these components. The experimental section shows our method achieves a reduction of approximately 40% of the human effort keeping a zero-error process

The anatomy of the 2019 Chilean social unrest

We analyze the 2019 Chilean social unrest episode, consisting of a sequence of events, through the lens of an epidemic-like model that considers global contagious dynamics. We adjust the parameters to the Chilean social unrest aggregated public data available from the Undersecretary of Human Rights, and observe that the number of violent events follows a well-defined pattern already observed in various public disorder episodes in other countries since the sixties. Although the epidemic-like models display a single event that reaches a peak followed by an exponential decay, we add standard perturbation schemes that may produce a rich temporal behavior as observed in the 2019 Chilean social turmoil. Although we only have access to aggregated data, we are still able to fit it to our model quite well, providing interesting insights on social unrest dynamics.Comment: To appear in Chao

Effect of the Photoexcitation Wavelength and Polarization on the Generated Heat by a Nd-Doped Microspinner at the Microscale

Thermal control at small scales is critical for studying temperature-dependent biological systems and microfluidic processes. Concerning this, optical trapping provides a contactless method to remotely study microsized heating sources. This work introduces a birefringent luminescent microparticle of NaLuF4:Nd3+ as a local heater in a liquid system. When optically trapped with a circularly polarized laser beam, the microparticle rotates and heating is induced through multiphonon relaxation of the Nd3+ ions. The temperature increment in the surrounding medium is investigated, reaching a maximum heating of ≈5 °C within a 30 μm radius around the static particle under 51 mW laser excitation at 790 nm. Surprisingly, this study reveals that the particle’s rotation minimally affects the temperature distribution, contrary to the intuitive expectation of liquid stirring. The influence of the microparticle rotation on the reduction of heating transfer is analyzed. Numerical simulations confirm that the thermal distribution remains consistent regardless of spinning. Instead, the orientation-dependence of the luminescence process emerges as a key factor responsible for the reduction in heating. The anisotropy in particle absorption and the lag between the orientation of the particle and the laser polarization angle contribute to this effect. Therefore, caution must be exercised when employing spinning polarization-dependent luminescent particles for microscale thermal analysis using rotation dynamics.Projects CNS2022-135495, PID2023-151078OB-I00 and TED2021-129937B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”Spanish Ministerio de Universidades, through the FPU program (FPU19/04803)Consejería de Universidad, Investigación e Innovación de la Junta de Andalucía and by FEDER “Una manera de hacer Europa” (P18-FR-3583

Interaction with a hand rehabilitation exoskeleton in EMG-driven bilateral therapy: Influence of visual biofeedback on the users’ performance

Producción CientíficaThe effectiveness of EMG biofeedback with neurorehabilitation robotic platforms has not been previously addressed. The present work evaluates the influence of an EMG-based visual biofeedback on the user performance when performing EMG-driven bilateral exercises with a robotic hand exoskeleton. Eighteen healthy subjects were asked to perform 1-min randomly generated sequences of hand gestures (rest, open and close) in four different conditions resulting from the combination of using or not (1) EMG-based visual biofeedback and (2) kinesthetic feedback from the exoskeleton movement. The user performance in each test was measured by computing similarity between the target gestures and the recognized user gestures using the L2 distance. Statistically significant differences in the subject performance were found in the type of provided feedback (p-value 0.0124). Pairwise comparisons showed that the L2 distance was statistically significantly lower when only EMG-based visual feedback was present (2.89 ± 0.71) than with the presence of the kinesthetic feedback alone (3.43 ± 0.75, p-value = 0.0412) or the combination of both (3.39 ± 0.70, p-value = 0.0497). Hence, EMG-based visual feedback enables subjects to increase their control over the movement of the robotic platform by assessing their muscle activation in real time. This type of feedback could benefit patients in learning more quickly how to activate robot functions, increasing their motivation towards rehabilitation.Ministerio de Ciencia e Innovación - (project RTC2019-007350-1)Consejería de Educación, Fondo Social Europeo, Gobierno Vasco - (BERC 2022-2025) y (project 3KIA (KK-2020/00049)Ministerio de Ciencia, Innovación y Universidades - (BCAM Severo Ochoa: SEV-2017-0718

Identificación y cuantificación del arsénico unido a las proteínas de tejidos cardiovasculares de pacientes sometidos a cirugía de revascularización coronaria

Introducción: Los efectos de la intoxicación con Arsénico (As) como enfermedades cardiovasculares (CV), pigmentaciones y oclusiones arteriales coronarias están asociados con la ingestión de As inorgánico a través del agua de bebida y a exposiciones ambientales. La unión del As (III) a proteínas y la metilación del As podría ser una primera etapa en el mecanismo de detoxificación. Objetivo: Evaluar la unión de As a proteínas en aurícula derecha y vena safena (VS) en sujetos expuestos de la Región de Antofagasta. Métodos: Se estudió la asociación As-proteína en el citosol de AD y VS de 6 pacientes con enfermedad coronaria grave de la Región de Antofagasta. Para el fraccionamiento del citosol se utilizaron columnas de exclusión molecular de tres diferentes rangos de masas. El perfil del As se detectó por Espectrometría de Masas Inductivamente Acoplado (ICP-MS) y por Espectroscopía Ultra Violeta - Visible de las fracciones moleculares (enlaces As- tiolatos de proteínas). Resultados: En todos los casos el As estuvo ampliamente distribuido en todo el intervalo de fracciones para AUD y VS. Los porcentajes de As colectado en las fracciones de las diferentes columnas usadas fueron 10, 25 y 50%. En la especiación de As en el citosol, por Cromatografía Líquida de Alta Resolución acoplada a la Espectrometría de Masas (IC-HPLC-ICP-MS), solamente se encontró As(III) y As(V) con una distribución Gaussiana para ambas especies, siendo la relación As(III)/As(V) constante para AUD y VS. Conclusión: En los tejidos CV existe asociación As – proteína lo cual podría implicar que el As está unido a biocompuestos de diferente peso molecular a través de grupos sulfhidrilos vecinales. Es probable que el As en AUD y VS se una a fracciones proteicas de masa molecular superior a 80 kDA y a subunidades de la estructura cuaternaria de la proteína nativa

Total and main as species present in cardiovascular tirrues of people living in as contaminated areas

The concentration levels of As in the Chilean II Region of Antofagasta produces non cancer health outcomes such as cardiovascular diseases and in last term heart attack. On this study, the determination of total As content and main inorganic and organoarsenic species found in three heart tissues (auricle, mammary artery and fat) and the saphene vein of people living in the Chilean II Region, suffering coronary thrombosis has been carried out. Comparison with similar tissues of patients from other non-contaminated areas has been undertaken. The extraction of As species occurred in methanol: water (1:1) and As species determination have been used the tandem HPLC-ICP-MS using the Hamilton PRP X100 anion column. For total As determination has been performed by HG-AAS and ICP-MS. The auricle and in less extend the saphene support the higher As concentration (mean values of 7.7 and 2.5 µg g-1, respectively), being As(III) the predominant species. Methylarsonate (MA) and dimethylarsinate (DMA) is not a favoured mechanism. The presence of high total As and high As(III) species content in the auricle and saphene of more contaminated people, the damage found in the saphene tissue and the global characteristics of the people under study in which the As stigmas are present in all of them, suggests that As could be involved in the cardiovascular diseases. e-mail: ipizarro @uantof.cl

Ley de Dependencia: Estudio y situación Datos Normativos y Estadísticos Estatal, Autonómico y Comarca del Bajo Aragón-CAspe (2008-2013)

Se trata de un estudio de la situación de los usuarios mayores de 65 años de la Ley de Dependencia en España, Aragón y la Comarca del Bajo Aragón-Caspe en el periodo del año 2008 al año 2013. Se utiliza una base normativa y datos estadísticos