Electrorotation of semiconducting microspheres

We study experimentally the electrorotation (ROT) of semiconducting microspheres. ZnO microspheres obtained by a hydrothermal synthesis method are dispersed in KCl aqueous solutions and subjected to rotating electric fields. Two ROT peaks are found in experiments: a counterfield peak and a cofield peak at somewhat higher frequencies. These observations are in accordance with recent theoretical predictions for semiconducting spheres. The counterfield rotation is originated by the charging of the electrical double layer at the particle-electrolyte interface, while the cofield rotation is due to the Maxwell-Wagner relaxation. Additionally, we also found that some microspheres in the sample behaved differently and only showed counterfield rotation. We show that the behavior of these particles can be described by the so-called shell model. The microstructure of the microspheres is analyzed with electron microscope techniques and related to the ROT measurements.Spanish Government Ministry MICINN under Contract No. PGC2018-099217-B-I00Junta de Andalucía Contract No. PEJUS-

Modeling the AC Electrokinetic Behavior of Semiconducting Spheres

We study theoretically the dielectrophoresis and electrorotation of a semiconducting microsphere immersed in an aqueous electrolyte. To this end, the particle polarizability is calculated from first principles for arbitrary thickness of the Debye layers in liquid and semiconductor. We show that the polarizability dispersion arises from the combination of two relaxation interfacial phenomena: charging of the electrical double layer and the Maxwell–Wagner relaxation. We also calculate the particle polarizability in the limit of thin electrical double layers, which greatly simplifies the analytical calculations. Finally, we show the model predictions for two relevant materials (ZnO and doped silicon) and discuss the limits of validity of the thin double layer approximation

Dipolophoresis and Travelling-Wave Dipolophoresis of Metal Microparticles

We study theoretically and numerically the electrokinetic behavior of metal microparticles immersed in aqueous electrolytes. We consider small particles subjected to non-homogeneous ac electric fields and we describe their motion as arising from the combination of electrical forces (dielectrophoresis) and the electroosmotic flows on the particle surface (induced-charge electrophoresis). The net particle motion is known as dipolophoresis. We also study the particle motion induced by travelling electric fields. We find analytical expressions for the dielectrophoresis and induced-charge electrophoresis of metal spheres and we compare them with numerical solutions. This validates our numerical method, which we also use to study the dipolophoresis of metal cylinders.Spanish Research Agency MCI under contract PGC2018-099217-B-I00

Combining DC and AC electric fields with deterministic lateral displacement for micro- And nano-particle separation

This paper describes the behavior of particles in a deterministic lateral displacement (DLD) separation device with DC and AC electric fields applied orthogonal to the fluid flow. As proof of principle, we demonstrate tunable microparticle and nanoparticle separation and fractionation depending on both particle size and zeta potential. DLD is a microfluidic technique that performs size-based binary separation of particles in a continuous flow. Here, we explore how the application of both DC and AC electric fields (separate or together) can be used to improve separation in a DLD device. We show that particles significantly smaller than the critical diameter of the device can be efficiently separated by applying orthogonal electric fields. Following the application of a DC voltage, Faradaic processes at the electrodes cause local changes in medium conductivity. This conductivity change creates an electric field gradient across the channel that results in a nonuniform electrophoretic velocity orthogonal to the primary flow direction. This phenomenon causes particles to focus on tight bands as they flow along the channel countering the effect of particle diffusion. It is shown that the final lateral displacement of particles depends on both particle size and zeta potential. Experiments with six different types of negatively charged particles and five different sizes (from 100 nm to 3 μm) and different zeta potential demonstrate how a DC electric field combined with AC electric fields (that causes negative-dielectrophoresis particle deviation) could be used for fractionation of particles on the nanoscale in microscale devices.Ministerio de Ciencia e Innovación PGC2018-099217-B-I0

Wall Repulsion during Electrophoresis: Testing the Theory of Concentration-Polarization Electroosmosis

We experimentally study the repulsion of charged microscopic particles with the channel walls during electrophoresis in microfluidic devices. For low frequencies of the electric fields (< 10 kHz), this repulsion is mainly due to the hydrodynamic interaction caused by the flow vortices that arise from the slip velocity induced by the electric field on the particle surface, as shown in a recent publication [Fernandez-Mateo et al., Physical Review Letters, 128, 074501, (2022)]. The maximum slip velocity on the particle surface is inferred from measurements of wall-particle separation. Importantly, this procedure allows us to infer very small slip velocities that otherwise are too weak to be measured directly. Data at small electric field amplitudes (E0) agree with theoretical predictions using the model of Concentration Polarization Electroosmosis (CPEO), which has recently been proposed as the mechanism behind the flow vortices on the surface of the particles. Data for higher electric fields show that the predictions of the CPEO theory for weak electric fields are not valid beyond E0 ∼ 60 kV/m. Additionally, we also show that, for sufficiently strong electric fields, the quadrupolar flow structures become disrupted, leading to a weaker wall repulsion.Ministerio de Ciencia e Innovación PGC2018-099217-B-I00, 10.13039/50110001103

Diagnóstico del estado actual de redes y evaluación técnico económica de las alternativas para la optimización del sistema de acueducto del municipio de Anapoima

Gestión y tecnología para la sustentabilidad de las comunidadesTeniendo como premisa que el abastecimiento de agua potable es un derecho fundamental para la sociedad, este trabajo tiene como objetivo determinar las alternativas más viables para optimizar el servicio de acueducto en el municipio de Anapoima, dentro de las cuales se prioriza el proyecto de venta de agua en bloque por parte dela empresa de acueducto y alcantarillado de Bogotá y el proyecto embalse Calandaima; la definición del sistema más eficiente se realiza a partir del diagnóstico del estado actual de redes, para conocer los requerimientos de demanda que requiere dicho municipio, y posteriormente la evaluación técnica y económica de los proyectos antes mencionados. A partir del estudio de la información y el análisis de la misma se determinó que la alternativa más viable, económica, técnica, ambiental y socialmente es el proyecto de venta de agua en bloque desarrollado por parte de la empresa de acueducto y alcantarillado de Bogotá, considerando que este tiene la capacidad de abastecer la totalidad de la demanda solicitada, de manera continua, sin trasmitir altos costos a los usuarios del sistema, lo que conlleva al desarrollo de las poblaciones beneficiadas por el proyecto.Trabajo de InvestigaciónINTRODUCCIÓN 1. GENERALIDADES 2. MARCOS DE REFERENCIA 3. METODOLOGÍA 4. PROCESAMIENTO DE LA INFORMACIÓN 5. ANÁLISIS Y EVALUACIÓN DE ALTERNATIVAS 6. CONCLUSIONES Y RECOMENDACIONES BIBLIOGRAFÍAEspecializaciónEspecialista en Recursos Hídrico

Lagochilascaris minor Leiper, 1909 (Nematoda: Ascarididae) in Mexico: three clinical cases from the Peninsula of Yucatan

Human lagochilascariasis (HL) is a parasite produced by Lagochilascaris minor Leiper 1909 that also can be found in cats and dogs. HL is considered an emerging zoonosis in the Americas, spreading from Mexico to Argentina, and the Caribbean Islands. The present paper describes three HL cases from the Peninsula of Yucatan, Mexico, recorded in the last decade. It describes the characteristics of the lesions and discusses the route of transmission in humans and particularly in the observed patients.La Lagochilascariasis humana (HL) es producida por Lagochilascaris minor Leiper, 1909; el cual es un parásito que puede ser encontrado también en gatos y perros. HL es considerada una zoonosis emergente en América distribuida desde México hasta Argentina y las islas del Caribe. El presente artículo describe tres casos de HL en la Península de Yucatán, México registrados en la última década. Se describen las características de las lesiones y se discute la ruta de transmisión en humanos y particularmente en los pacientes observados

Implementation of Model Reference Adaptive Control in a Dehydration System

[EN] In this article, the use of Model Reference Adaptive Control (MRAC) is proposed as a technique to regulate a system with input delay. As a case study, a thermal system represented by a cabin dehydrator is considered. The analysis of the selected system is carried out to determine the equations that describe its behavior, and a reference signal is designed, which is essential for the proper operation of the control algorithm. The identification of the parameters of the thermal system and the tuning of the adaptation gain are performed. The theory of Lyapunov is used to evaluate the stability of the system and design the control. The performance of the proposed control is compared with other methods using the performance index (L2 norm).[ES] En este artículo se propone el uso del Control Adaptable por Modelo de Referencia (MRAC) como técnica para regular un sistema con retardo en la entrada, como caso de estudio se considera un sistema térmico representado por un deshidratador de cabina. Se realiza el análisis del sistema seleccionado para determinar las ecuaciones que describen su comportamiento, y se diseña una señal de referencia, esencial para el correcto funcionamiento del algoritmo de control. Se realiza la identificación de los parámetros del sistema térmico y la sintonización de la ganancia de adaptación. Para evaluar la estabilidad del sistema y diseñar el control se utiliza la teoría de Lyapunov. El desempeño del control propuesto se compara con otros métodos empleando el índice de desempeño (norma L2).Sánchez-Sánchez, P.; Cebada Reyes, JG.; Montiel Martínez, A.; Reyes Cortés, JF. (2023). Implementación del control adaptable por modelo de referencia en un sistema de deshidratación. Revista Iberoamericana de Automática e Informática industrial. 21(1):39-51. https://doi.org/10.4995/riai.2023.19172395121

Cambios dimensionales, detectados en telerradiografía de perfil y tomografía computarizada cone-beam, producidos en la vía aérea superior de pacientes adultos post-cirugía ortognática. Revisión sistemática de la literatura

82 P.INTRODUCCIÓN: Son varios los tipos de intervenciones que se realizan en el territorio maxilofacial, en donde la cirugía ortognática ha sido el método que se utiliza más a menudo en deformidades dentofaciales moderadas o severas. El movimiento de los huesos implica cambios en los tejidos blandos adjuntos, generando cambios significativos en la apariencia facial y en las dimensiones del espacio de la vía aérea faríngea. Estas variaciones en las dimensiones pueden ser medidas en cone beam (CBCT) (3D) o en telerradiografía de perfil (TP) (2D). A partir de esto es que se realizó una revisión sistemática de la literatura que busca encontrar relación de los cambios en la vía aérea de pacientes adultos sometidos a cirugía ortognática, que sean detectados en TP y CBCT, según lo reportado por la literatura científica publicada en bases de datos electrónicas desde enero del año 2010 hasta octubre del año 2015. OBJETIVO: Identificar los cambios dimensionales producidos en la VAS post-cirugía ortognática en pacientes adultos, detectados en telerradiografía de perfil y/o tomografía computarizada cone-beam, en literatura publicada desde enero del 2010 hasta octubre de 2015. METODOLOGÍA: Se realizó un protocolo para la realización de una revisión sistemática de la literatura. Este protocolo se registró en el International Prospective Register of Systematic Review y se encuetra disponible en el sitio web http://www.crd.york.ac.uk/http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015029352. Se realiza una búsqueda principal en los sistemas de bases de datos electrónicos PubMed, Web of Sciences y The Cochrane Library. Y una búsqueda manual adicional en las referencias de artículos analizados a texto completo. Se utilizaron como palabras claves: “Orthognathic Surgery”; “Pharynx”; “Cone-Beam Computed Tomography”; “Cephalometry”. Se incluyeron artículos en idioma español e inglés; revisiones sistemáticas con y sin meta-análisis, ensayos clínicos controlados, estudios de cohorte, estudios de casos y controles; solo estudios realizados en humanos. Se excluyen los artículos que refieran a pacientes con algún síndrome (ejemplo: síndrome apnea obstructiva del sueño), que estén médicamente comprometidos o pacientes fisurados. Todas las fases fueron realizadas por tres evaluadores de forma independiente y las discrepancias fueron resueltas por consenso. RESULTADOS: La estrategia de búsqueda principal arrojó un total de 456 artículos. La búsqueda manual adicional identificó 4 nuevos registros. Se analizan 25 artículos a texto completo. Finalmente sólo se incluyen 12 artículos. CONCLUSIONES: En cirugías de avance maxilar y mandibular, o cada una por sí sola, tanto en CBCT y TP, la vía aérea aumenta. En cirugías de avance maxilar en conjunto con retroceso mandibular, o esta última por sí sola, tanto en CBCT y TP, la vía aérea disminuye. La herramienta CASP evidencia sesgo en la totalidad de los documentos seleccionados en: división de la vía aérea, referencias anatómicas usadas en CBCT o TP, división por género de la muestra, tiempo de seguimiento/control postquirúrgico de los pacientes. Además existen cambios relacionados a la posición del hueso hioides. PALABRAS CLAVES: "Orthognathic Surgery"; "Pharynx"; "Cone-Beam Computed Tomography"; "Cephalometry"/ABSTRACT: INTRODUCTION: There are several types of interventions performed in the maxillofacial territory, where orthognathic surgery has been the method most often used in moderate to severe facial deformities. The movement of the bones involves changes in the accompanying soft tissue, causing significant changes in facial appearance and space dimensions of the pharyngeal airway. These variations in dimensions can be measured in cone beam (CBCT) (3D) or teleradiography profile (TP) (2D). Since this is a systematic review of the literature that seeks to find relation of changes in the airway of adult patients undergoing orthognathic surgery, which are detected in TP and CBCT, as reported by the scientific literature was conducted in electronic databases from January 2010 to October 2015. OBJETIVE: Identify the dimensional changes in the post-orthognathic surgery in adult patients VAS, detected in teleradiography and / or cone-beam computed tomography in literature published from January 2010 to October 2015. METHODOLOGY: Has been made a protocol for conducting a systematic review of the literature. This protocol was recorded in the International Register of Systematic Review Prospective and is available on the website http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42015029352. A main search is performed in the systems of electronic databases PubMed, Web of Sciences and The Cochrane Library. And an additional hand search of references to full-text articles analyzed. They were used as keywords: "Orthognathic Surgery"; "Pharynx"; "Cone-Beam Computed Tomography"; "Cephalometry". Items were included in Spanish and English; systematic reviews with or without meta-analysis, controlled clinical trials, cohort studies, case-control studies; only human studies. Who are medically compromised patients or fissured: items that refer to patients with a syndrome (syndrome obstructive sleep apnea example) are excluded. All phases were carried out by three reviewers independently and discrepancies were resolved by consensus. RESULTS: The primary search strategy yielded a total of 456 items. The additional manual search identified 4 new records. 25 full-text articles are analyzed. Finally only 12 items are included. CONCLUSIONS: In surgeries of maxillary and mandibular advancement, or each one alone, in CBCT and TP, the airway increases. In surgeries maxillary advancement recoil together with mandibular or latter alone, in CBCT and TP, airway decreases. The CASP tool evidence of bias in all selected documents in: division of the airway, anatomical references used in CBCT or TP, gender division of the sample, time tracking / control postsurgical patients. There are also related to the position of the hyoid bone changes. KEYS WORDS: "Orthognathic Surgery"; "Pharynx"; "Cone-Beam Computed Tomography"; "Cephalometry