Time-dependent patterns in quasivertical cylindrical binary convection

This paper reports on numerical investigations of the effect of a slight inclination a on pattern formation in a shallow vertical cylindrical cell heated from below for binary mixtures with a positive value of the Soret coefficient. By using direct numerical simulation of the three-dimensional Boussinesq equations with Soret effect in cylindrical geometry, we show that a slight inclination of the cell in the range a˜0.036rad=2° strongly influences pattern selection. The large-scale shear flow (LSSF) induced by the small tilt of gravity overcomes the squarelike arrangements observed in noninclined cylinders in the Soret regime, stratifies the fluid along the direction of inclination, and produces an enhanced separation of the two components of the mixture. The competition between shear effects and horizontal and vertical buoyancy alters significantly the dynamics observed in noninclined convection. Additional unexpected time-dependent patterns coexist with the basic LSSF. We focus on an unsual periodic state recently discovered in an experiment, the so-called superhighway convection state (SHC), in which ascending and descending regions of fluid move in opposite directions. We provide numerical confirmation that Boussinesq Navier-Stokes equations with standard boundary conditions contain the essential ingredients that allow for the existence of such a state. Also, we obtain a persistent heteroclinic structure where regular oscillations between a SHC pattern and a state of nearly stationary longitudinal rolls take place. We characterize numerically these time-dependent patterns and investigate the dynamics around the threshold of convection.Postprint (author's final draft

MK-2.0 secretos a voces del social-media

Las redes sociales son un fenómeno emergente al que cada día se suman nuevos adeptos convirtiéndose en un sector exitoso que los expertos en marketing digital tienen que aprovechar. Esta investigación evidencia que la multidisciplinariedad entre ambas puede tener efectos muy beneficiosos y que su puesta en práctica es ya una realidad. Pepsi, Starbucks, Avon, Adidas, infinidad de marcas de reconocido prestigio internacional han apostado muy fuerte por estos nuevos canales de actuación obteniendo resultados lo suficientemente reveladores como para hablar de nuevas modalidades de negocio, y aún más en este momento cuando parece que las formas de hacer marketing y publicidad convencionales están perdiendo protagonismo. Cada vez pasamos menos tiempo frente al televisor y más conectados a la red. Si una marca quiere encontrarnos, es probable que allí pueda hacerlo. Las redes sociales aportan grandes dosis de viralidad a los procesos de comunicación, las cuales son de gran calidad ya que, ¿hay mejores prescriptores que nuestros familiares y amigos?. Y todo esto para satisfacer a un agente que tiene mucho que decir: tu

UV/Vis absorption spectroelectrochemistry of folic acid

UV/Vis absorption spectroelectrochemistry is a very promising analytical technique due to the complementary information that is simultaneously obtained from electrochemistry and spectroscopy. In this work, this technique is used in a parallel configuration to study the oxidation of folic acid in alkaline medium. Herein, UV/Vis absorption spectroelectrochemistry has been used to detect both the oxidation products and the folic acid consumed at the electrode/solution interface, allowing us to develop an analytical protocol to quantify vitamin B9 in pharmaceutical tablets. Linear ranges of three orders of magnitude have been achieved in basic medium (pH = 12.9), obtaining high repeatability and low detection limits. The spectroelectrochemical determination of folic acid in pharmaceutical tablets at alkaline pH values is particularly interesting because of the changes that occur in the optical signal during the electrochemical oxidation of FA, providing results with very good figures of merit and demonstrating the utility and versatility of this hyphenated technique, UV/Vis absorption spectroelectrochemistry.Ministerio de Economía y Competitividad (Grant CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (Grant BU297P18), and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018-102412-T). F.O. is grateful for the contract funded by Junta de Castilla y León, the European Social Fund, and the Youth Employment Initiative.Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

What do Female Consumers Think about Sustainable Packaging?

La revista forma se publica como parte de Emerging Trends in Marketing and Management International Conference[ES] This study explores the level of knowledge among Spanish consumers regarding sustainability and their opinions on new sustainable packaging options, such as bio-based materials or bagasse. We conducted an online questionnaire at a national level, followed by multivariate analysis to derive conclusive results. Our findings, based on 254 participants, indicate that only 44% of consumers integrate sustainability into their daily lives. Key characteristics deemed important for sustainable packaging include environmental friendliness (85%), use of clean energy (72.5%), ease of reuse (85.8%), and recyclable materials (80.8%). Factor analysis reveals three categories: manufacturing characteristics, security, and price. Cluster analysis identifies two groups: one concerned with container safety and another seeking achievable sustainability.S

Estudio mediante cromatografía en capa fina de algunas plantas con pulegona: Mentha pulegium L. y Mentha cervina (L.) Fresen.

l3sJRzAco VIÚAURReTA, A.; M. J. PÉREZ-ALoNso & A. VeLAsco Nr¿r;ueRueI,A ¡992. Estudio mediante cromatograf la en capa fina de algunas mentas con pulegona: Mentha pulegium L. y Mencha cervina (L.) Fresen. Bat. Cornp!utensis 17: 79-85. En este trabajo se hace un estudio comparativo, desde el punto de vista cualitativo, de algunas esencias de poleos comerciales y de las esencias que han sido extraídas a partir de Meníha pulegium L. y Mentha cervina (L.) Fresen recolectadas en la provincia de Toledo. También se han cuantificado los compuestos más importantes por cromatografía de gases. En Men/ha cervina se ha identificado por primera vez 4-OH-Piperitona.l3sJRzAco VIÚAURReTA, A.; M. J. PÉREZ-ALoNso & A. VeLAsco Nr¿r;ueRueI,A ¡992. Estudio mediante cromatograf la en capa fina de algunas mentas con pulegona: Mentha pulegium L. y Mencha cervina (L.) Fresen. Bat. Cornp!utensis 17: 79-85. En este trabajo se hace un estudio comparativo, desde el punto de vista cualitativo, de algunas esencias de poleos comerciales y de las esencias que han sido extraídas a partir de Meníha pulegium L. y Mentha cervina (L.) Fresen recolectadas en la provincia de Toledo. También se han cuantificado los compuestos más importantes por cromatografía de gases. En Men/ha cervina se ha identificado por primera vez 4-OH-Piperitona

Stationary localized solutions in binary convection in slightly inclined rectangular cells

We analyze numerically the effect of a slight inclination in the lowest part of the snaking branches of convectons that are present in negative separation ratio binary mixtures in two-dimensional elongated rectangular cells. The exploration reveals the existence of novel stationary localized solutions with striking spatial features different from those of convectons. The numerical continuation of these solutions with respect to the inclination of the cell unveils the existence of even further families of localized structures that can organize in closed branches. A variety of localized solutions coexist for the same heating and inclination, depicting a highly complex scenario for solutions in the lowest part of the snaking diagrams for moderate to high heating. The different localized solutions obtained in the horizontal cell are discussed in detail.Postprint (author's final draft

Thermal binary mixture convection in inclined cylindrical containers

Convection in a fluid layer is affected by its orientation with respect to the gravitational field. In the present work, we investigate numerically pattern selection in a cylindrical cell heated from below and inclined against gravity. We are interested in analyzing the effect of inclination on pattern formation near the onset of convection. We will focus on thermophobic mixtures, i.e. mixtures in which the heavier component of the fluid is driven into the direction of lower temperature, where square patterns, roll structures and cross-roll regimes are expected to arise. In agreement with experimental observations, we will show that pattern formation in disklike cylinders is strongly affected even by very small inclinations.Postprint (published version

Estudio de la Seguridad en Redes de Sensores Corporales aplicadas al Ámbito Sanitario

Nowadays, the technology has become necessary in daily aspects of everyday life, included healthcare and healthy lifestyle. Thus, in the last years has taken place an important development of Body Sensor Networks (BSN) to let a continuous monitoring. Security is becoming increasingly important in all areas related to Information Technology, and becomes even more important when patient’s health is involved. Confiability and privacy are necessary requirements for patients to feel secure with the sensors, but the reliability is necessary too, because if all measured data are lost or damage before reaching their destination, it cannot be made an adequate monitor or make the best diagnosis. The aim of this work is to provide a review of the security for BSN applied to the healthcare, in order to enable the development of applications to improve the patient's diagnosis and treatment with chronic diseases.Keywords: BSN, healthcare,confiability, reliability, chronic diseases

Normal or parallel configuration in spectroelectrochemistry? Bidimensional spectroelectroanalysis in presence of an antioxidant compound

This work demonstrates how the way a chemical system is sampled plays a key role in spectroelectroanalysis, illustrated by the quantification of an analyte in presence of an antioxidant compound. For this purpose, bidimensional spectroelectrochemistry experiments were performed using epinephrine as the model analyte and ascorbic acid as antioxidant and interfering compound, as a proof of concept. This is the first time that three calibration curves are obtained simultaneously on a single spectroelectrochemistry data set, one for the electrochemical signal and two for the optical responses in normal and parallel configurations. The differences between the two optical arrangements, that are related to the diffusion process which is an essential feature for the spectroelectrochemical detection of compounds, have been experimentally demonstrated. As can be observed, the spectral signal in parallel configuration allows us to obtain the best analytical results, since in this configuration only the first micrometers of the solution adjacent to the electrode surface are sampled, thus removing the interfering effect of the antioxidant compound. This fact does not occur with either the electrochemical signal or the spectral response in normal configuration. Furthermore, it has been shown that the parallel configuration provides better results than the normal configuration in terms of sensitivity. In summary, epinephrine is successfully detected in a simple and effective way, even in the presence of a direct antioxidant compound such as ascorbic acid at different concentrations levels, which makes spectroelectrochemistry a good choice for quantitative analysis.Authors acknowledge the financial support given by Ministerio de Ciencia e Innovación and Agencia Estatal de Investigación (MCIN/AEI/ 10.13039/501100011033, PID2020-113154RB-C21) and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018-102412-T). Fabiola Olmo is grateful for the contract funded by Junta de Castilla y León, the European Social Fund, and the Youth Employment Initiative

Spectroelectrochemical Determination of Isoprenaline in a Pharmaceutical Sample

UV/Vis absorption spectroelectrochemistry (SEC) is a multi-response technique that has been commonly used for the characterization of materials and the study of reaction mechanisms. However, it has been scarcely used for quantitative purposes. SEC allows us to obtain two analytical signals simultaneously, yielding a dual sensor in just one experiment. In the last years, our group has developed new devices useful for analysis. In this work, a SEC device in parallel configuration, based on optical fibers fixed on screen-printed electrodes, was used to determine isoprenaline in a commercial drug, using both, the electrochemical and the spectroscopic signals. In this commercial drug, isoprenaline is accompanied in solution by other compounds. Among them is sodium metabisulfite, an antioxidant that strongly interferes in the isoprenaline determination. A simple pretreatment of the drug sample by bubbling wet-air allows us to avoid the interference of metabisulfite. Here, we demonstrate again the capabilities of UV/Vis absorption SEC as double sensor for analysis and we propose a simple pretreatment to remove interfering compounds.Ministerio de Economía y Competitividad (Grant CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (Grant BU297P18), and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018-102412-T). F.O. is grateful for the contract funded by Junta de Castilla y León, the European Social Fund and the Youth Employment Initiative. J.G.R. thanks Ministerio de Economía y Competitividad for his postdoctoral contract (Grant CTQ2017-83935-R AEI/FEDER, UE)