2,541 research outputs found

    Supersymmetric probes of wrapped M5-brane backgrounds

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    In this thesis we consider supersymmetric probes in backgrounds sourced by an M5-brane which is wrapped on holomorphic 2-cycles in C(^2) and C(^3), respectively. For the first case, we use M2-brane probes to compute the BPS spectra of the corresponding N = 2 gauge theory, as well as M5-brane probes to calculate field theory parameters such as the gauge coupling, theta angle and complex scalar moduli space metric. This background describes a large class of Hanany-Witten models when dimensionally reduced to Type IIA ten-dimensional supergravity. We calculate the instanton action using a Euclidean DO-brane probe in this limit. For the case of an M5-brane wrapping a 2-cycle in C(^3), we firstly show an alternative method of deriving this solution which involves the projection conditions and certain spinor bilinear differential equations. We also consider M5-brane probes in this background, and analyse the corresponding N = I MQCD gauge theory parameters, in direct analogy with the N = 2 case. We then move on to consider the central charges of the supersymmetry algebra of brane probes in the two backgrounds under consideration. For the case of an M5-brane wrapping a 2-cycle in c2, we find it allows for M2- braneร representing BPS monopoles and vortices. There is also the possibility of a "hidden" M5-brane which is similar to the M2-brane, but which includes a rotation in the complex structure and an extra volume modulus. For the N = I case, we find it allows for a supersymmetric M5-brane probe wrapping a Cayley calibrated 4-cycle, which is interpreted as a system of intersecting domain walls. These results are geometrically linked to M-theory structure groups

    Cell migration within confined sandwich-like nanoenvironments

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    Aim: We introduced sandwich-like cultures to provide cell migration studies with 4 representative nano-bio-environments where both ventral and dorsal cell receptors are activated. Methods: We have investigated different nano-environmental conditions by changing the protein coating (fibronectin, vitronectin) and/or materials (using polymers that adsorb proteins in qualitatively different conformations) of this sandwich system to show their specific role in cell migration. Results: Here we show that cell migration within sandwich cultures greatly differs from 2D cultures and shares some similarities with migration within 3D environments. Beyond differences in cell morphology and migration, dorsal stimulation promotes cell remodeling of the ECM over simple ventral 12 receptor activation in traditional 2D cultures.</p

    PLLA/ZnO nanocomposites: dynamic surfaces to harness cell differentiation

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    This work investigates the effect of the sequential availability of ZnO nanoparticles, (nanorods of ∼40 nm) loaded within a degradable poly(lactic acid) (PLLA) matrix, in cell differentiation. The system constitutes a dynamic surface, in which nanoparticles are exposed as the polymer matrix degrades. ZnO nanoparticles were loaded into PLLA and the system was measured at different time points to characterise the time evolution of the physicochemical properties, including wettability and thermal properties. The micro and nanostructure were also investigated using AFM, SEM and TEM images. Cellular experiments with C2C12 myoblasts show that cell differentiation was significantly enhanced on ZnO nanoparticles—loaded PLLA, as the polymer degrades and the availability of nanoparticles become more apparent, whereas the release of zinc within the culture medium was negligible. Our results suggest PLLA/ZnO nanocomposites can be used as a dynamic system where nanoparticles are exposed during degradation, activating the material surface and driving cell differentiation

    VIRTUAL TOURS OF HISTORICAL AND ARTISTIC HERITAGE IN THE PROVINCE OF CACERES

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    [EN] The 3D visualization of historical-artistic heritage in the province of Caceres is an essential tool for touristic promotion. To this end, a methodology is offered based on the application of panoramic spherical photography and terrestrial laser scanner (TLS). The general aim is the creation of geometric representations of sites of cultural interest by the visualization of spherical scenarios and the application of 3D modelling techniques. Particular aims include the geometric cataloguing and acquisition of this artistic heritage and the development of an interactive tool for tourists. A hypermedia atlas is created in which 3D spherical scenarios is visualized displaying videos obtained from the point of clouds and ASCII format downloadable 3D models are made freely available. Other benefits of this project are gains in the knowledge and assessment of the cultural heritage in Caceres.[ES] La visualización 3D del patrimonio histórico-artístico en la provincia de Cáceres, es una herramienta esencial para su promoción turística. Con este fin, se ofrece una metodología basada en la fotografía panorámica esférica y el uso del láser escáner. Como objetivo general se realiza la caracterización geométrica de los Bienes de Interés Cultural, mediante técnicas de visualización de escenarios esféricos y generación de modelado 3D. Los objetivos particulares son catalogar y adquirir de forma geométrica este patrimonio y desarrollar una herramienta interactiva de consulta. Por ello, se crea un atlas hypermedia donde visualizar escenarios fotográficos tridimensionales, videos a partir de las nubes de puntos e incluso su descarga en formato ASCII, todo de forma gratuita. Otros beneficios del proyecto son el conocimiento y la puesta en valor del patrimonio de CáceresNaranjo, JM.; Parrilla, MÁ.; Sanchez, M. (2016). VIRTUAL TOURS OF HISTORICAL AND ARTISTIC HERITAGE IN THE PROVINCE OF CACERES. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 281-283. https://doi.org/10.4995/arqueologica8.2015.3390OCS28128

    Agricultura de terrazas en el cerro Tenismo, Toluca. México

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    Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas.Los campesinos mexicanos practican diversos agroecosistemas tradicionales, caso particular, las terrazas. Este sistema es uno de los más antiguos en el Valle de Toluca y actualmente se encuentra en proceso de abandono. El objetivo fue caracterizar el sistema de terrazas del cerro Tenismo en Calixtlahuaca, Toluca, México, destacando sus componentes principales: muros de contención, zanja, vegetación, cultivos. A partir de la investigación cualitativa, observación directa y la descripción del agroecosistema, se analizan los componentes de quince terrazas de la ladera media y ladera alta del cerro Tenismo. Los resultados indican que las terrazas de Calixtlahuaca con muro de roca y metepantles (semiterraza), son un sistema importante que contribuye a la conservación de las laderas y de donde se obtienen cultivos de autoconsumo. Se concluye que el manejo que realizan los campesinos por medio de las terrazas (muros, zanjas y vegetación) tiene características agroecológicas que contribuyen a la preservación del ambiente.Universidad Autónoma del Estado de México Colegio de Ciencias Geográficas del Estado de México AC

    Fog computing pour l'intégration d'agents et de services Web dans un middleware réflexif autonome

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    International audienceService Oriented Architecture (SOA) has emerged as a dominant architecture for interoperability between applications, by using a weak-coupled model based on the flexibility provided by Web Services, which has led to a wide range of applications, what is known as cloud computing. On the other hand, Multi-Agent System (MAS) is widely used in the industry, because it provides an appropriate solution to complex problems, in a proactive and intelligent way. Specifically, Intelligent Environments (Smart City, Smart Classroom, Cyber Physical System, and Smart Factory, among others) obtain great benefits by using both architectures, because MAS endows intelligence to the environment, while SOA enables users to interact with cloud services, which improve the capabilities of the devices deployed in the environment. Additionally, the fog computing paradigm extends the cloud computing paradigm to be closer to the things that produce and act on the intelligent environment, allowing to deal with issues like mobility, real time, low latency, geo-localization, among other aspects. In this sense, in this article we present a middleware, which not only is capable of allowing MAS and SOA to communicate in a bidirectional and transparent way, but also, it uses the fog computing paradigm autonomously, according to the context and to the system load factor. Additionally, we analyze the performance of the incorporation of the fog-computing paradigm in our middleware and compare it with other works

    Power Factor Corrector Design applied to an 85-kHz Wireless Charger

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    Wireless charging technology extends the battery autonomy by allowing more flexible and practical ways of recharging it even when the electric vehicle is on move. The frequency conversion, which is required to generate a kHz-ranged magnetic field, also leads to considerable harmonics. As a result, the power factor and the corresponding efficiency decrement. This paper proposes a Power Factor Corrector which overcomes this drawback. The most relevant feature of the designed Power Factor Corrector is that it does not need any electrical signal from the secondary side to adjust its operation properly. The simulation results show the ability of the proposed scheme to increment the system efficiency for different State-Of-Charge in the Battery.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Pantoum One

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    Mixing in convective thermal fluxes in unsteady nonhomogeneous flows generating complex three dimensional vorticity patterns

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    Diffusion and scaling of the velocity and vorticity in a thermoelectric driven heating and cooling experimental device is presented in order to map the different patterns and transitions between two and three dimensional convection in an enclosure with complex driven flows. The size of the water tank is of 0.2 x 0.2 x 0.1 m and the heat sources or sinks can be regulated both in power and sign [1-3]. The thermal convective driven flows are generated by means of Peltier effects in 4 wall extended positions of 0.05 x 0.05 cm each. The parameter range of convective cell array varies strongly with the Topology of the boundary conditions. Side heat and momentum fluxes are a function of Rayleigh, Peclet and Nusselt numbers, [4-6] Visualizations are performed by PIV, Particle tracking and shadowgraph. The structure of the flow is shown by setting up a convective flow generated by buoyant heat fluxes. The experiments described here investigate high Prandtl number mixing using brine and fresh water in order to form a density interface and low Prandtl number mixing with temperature gradients. The evolution of the mixing fronts are compared and the topological characteristics of the merging of the convective structures are examined for different configurations. Based on two dimensional Vorticity spectral analysis, new techniques can be very useful to determine the evolution of scales considering the multi-fractal structure of the convective flows.Peer ReviewedPostprint (published version

    Simulations on distribution of phase retardation through liquid crystal lenses

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    [Poster of]: 24th International Liquid Crystal Conference (ILCC 2012), Mainz, Germany, 19th-24th August 2012.For this research work, a simulation programa for simulate liquid crystal lens electrooptical behaviour, based on Frank-Oseen's free energy formulation, has been developed and the results have been compared to previous experimental data...This work was supported in part by the Ministerio de Ciencia e Innovación of Spain (grant nº TEC2009-13991-C02-01) and Comunidad de Madrid (grant nº S2009/ESP-1781)
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