Estudio del flujo turbulento cargado con partículas sólidas a través de un canal

En el presente trabajo se estudia el flujo turbulento cargado con partículas sólidas a través de un canal. Para ello se utiliza un programa comercial de dinámica de fluidos tomputacional, cuyo esquema de discretización es el de volúmenes Guitas. La fase fluida (aue) se estudia mediante un enfoque Euleriano y la fase dispersa (partículas sólidas) mediante un enfoque Lagrangiano, respecto al acoplamiento hidrodinámico entre las fases, solo se considera la acción de la fase fluida sobre la fase dispersa (one-way coupling) para una concentración másica determinada. Se desarrolla un estudio de convergencia de malla y los resultados numéricos se comparan con datos experimentales

Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation

This work is supported by the UK Engineering Physical Sciences Research Council (EPSRC).A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided “point-and-transfect” user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits.Publisher PDFPeer reviewe

Gasoline pre-blending processes for efficient ethanol recovery: effects of process parameters and process modifications for improved performance

With over 20 billion gallons of bio-ethanol produced annually, optimization of bio-ethanol production processes is a major priority for sustainability research. Recent research has made great strides toward improving the efficiency of bio-ethanol production through the development of gasoline pre-blending processes which use liquid–liquid phase separation to eliminate excess water with minimal energy input. This paper investigates the effects of process parameters on the performance and efficiency of this class of processes, offering a design basis for engineers developing new processes along with a broader understanding of their potential performance and economic value. Also explored are a range of process modifications capable of improving process performance. It has been found that blending ratio and initial alcohol concentration are the key parameters in determining ethanol recovery, with the number of liquid–liquid contact stages and the temperature also being significant. It has also been shown that temperature-swing decanting can significantly improve alcohol recovery, reducing ethanol losses by as much as 33% in a typical gasoline pre-blending setup.The authors would like to thank Institute for the Development of Energy for African Sustainability (IDEAS) and the National Research Foundation of South Africa for providing financial support for carrying out this work. Dr. M.J. Fernandez-Torres thanks the visiting researcher program, at the University of South Africa, for financial support

Spatially optimized gene transfection by laser-induced breakdown of optically trapped nanoparticles

We demonstrate laser-induced breakdown of an optically trapped nanoparticle with a nanosecond laser pulse. Controllable cavitation within a microscope sample was achieved, generating shear stress to monolayers of live cells. This efficiently permeabilize their plasma membranes. We show that this technique is an excellent tool for plasmid-DNA transfection of cells with both reduced energy requirements and reduced cell lysis compared to previously reported approaches. Simultaneous multisite targeted nanosurgery of cells is also demonstrated using a spatial light modulator for parallelizing the technique.Publisher PDFPeer reviewe

Simultaneous environmental and economic process synthesis of Isobutane Alkylation

This multidisciplinary study concerns the optimal design of processes with a view to both maximizing profit and minimizing environmental impacts. This can be achieved by a combination of traditional chemical process design methods, measurements of environmental impacts and advanced mathematical optimization techniques. More to the point, this paper presents a hybrid simulation-multiobjective optimization approach that at once optimizes the production cost and minimizes the associated environmental impacts of isobutane alkylation. This approach has also made it possible to obtain the flowsheet configurations and process variables that are needed to manufacture isooctane in a way that satisfies the above-stated double aim. The problem is formulated as a Generalized Disjunctive Programming problem and solved using state-of-the-art logic-based algorithms. It is shown, starting from existing alternatives for the process, that it is possible to systematically generate a superstructure that includes alternatives not previously considered. The optimal solution, in the form a Pareto curve, includes different structural alternatives from which the most suitable design can be selected. To evaluate the environmental impact, Life Cycle Assessment based on two different indicators is employed: Ecoindicator 99 and Global Warming Potential.Spanish Ministry of Science and Innovation (CTQ2012-37039-C02-02)

Economic and environmental assessment of directly converting CO2 into a gasoline fuel

The threat posed by Climate Change demands urgent action on finding clean energy solutions with a view to cutting fossil fuel consumption. However, a sudden stop in the use of fossil fuels is not possible without a profound disruption of the economy. This transition is expected to take several decades, and therefore every type of renewable energy should be considered as part of the solution mix. In this work, we propose including gasoline synthesized from atmospheric CO2 as one possible interim solution while the transition away from liquid fossil fuels intensifies. To that end, we have designed a novel process that produces green gasoline in one stage on an industrial scale. This contrasts with the two or three stages needed in the classical Fischer-Tropsch based processes. Furthermore, we have optimized this process through mass and heat integration, and propose three different options that make the most of the waste streams. Finally, we have studied a total of 144 realistic scenarios that take into account the origin of H2 and CO2 as well as their environmental impacts and costs. According to our findings, such a process will be capable of producing high-quality gasoline to be manufactured competitively in the near future. The significance of our findings is that it is realistic to reduce carbon emissions while also promoting the circular economy.The authors J.A.C and M.J.F.T thank Generalitat Valenciana for the financial support under the project PROMETEO 2020/064

The mammals of La Rioja, eight decades after Yepes

La mastofauna de la provincia de La Rioja es poco conocida, debido a la falta de muestreos sistemáticos y el poco interés para el relevamiento de la misma. La única lista de mamíferos existente fue elaborada por José Yepes en 1936 a partir de los materiales colectados en un viaje de campo a las localidades de Sanagasta, Patquía, Famatina, Villa Unión y La Sierra de Velasco. En este trabajo presentamos una primera actualización a la lista de Yepes, utilizando la literatura disponible, así como los especímenes recolectados por él y alojados en el Museo Argentino de Ciencias Naturales ?Bernardino Rivadavia?. Las especies listadas suman 70 taxones, y muestran un incremento importante de las 23 registradas por Yepes. Sin embargo, dado que una gran área de la provincia todavía no ha sido explorada aún, podemos esperar futuras incorporaciones a esta lista.The mammals of the Province of La Rioja are poorly known, due to the lack of systematic sampling and little interest in its survey. The single list of mammals was elaborated by José Yepes in 1936 mostly from materials collected by him in field trip conducted in several localities, including Sanagasta, Patquía, Famatina, Villa Unión and La Sierra de Velasco. Here we present the first update to the list of Yepes, using the available literature, as well as the specimens collected by him and housed at the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. The species listed account 70, showing an important increment from the 23 recorded by Yepes. However, since a large area of the province is still unexplored, we can expect future additionsFil: FARIÑAS TORRES, THAMARA. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR) - Provincia de La Rioja, UN LaR, SEGEMAR, UNCa, CONICET.; ArgentinaFil: Pardiñas, Ulises Francisco J.. Instituto de Diversidad y Evolución Austral (IDEAus - CONICET); ArgentinaFil: Chemisquy, Maria Amelia. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CR ILAR) - Provincia de La Rioja, UN LaR, SEGEMAR, UNCa, CONICET).; Argentin

A chloroform extract obtained from a decoction of Ficus carica leaves improves the cholesterolaemic status of rats with streptootocin-includede diabetes

The antidiabetic effects of Ficus carica leaf extracts have been reported previously. From the aqueous decoction of fig leaves, after treatment with HCl, centrifuging, treatment with sodium hydroxide (NaOH) and extraction with chloroform (CHCl 3 ), the administration of the organic phase rats with streptozotocin-induced diabetes led to a decline in the levels of total cholesterol and an decrease in the total cholesterol/HDL cholesterol ratio (with respect to the control group), together with a reduction of the hyperglycaemia