¿Qué hacer con Marx?

This article analyzes some fundamental texts and ideas of Marx in order to think about their contemporary relevance. Marxism has to get rid of the base—superstructure schema, and recognize that the theory of value is too speculative. It should also rethink the different meanings of what Marx called “science”, and have in mind the Hegelian legacy in Marx’s thought. In historical terms, it should not forget the context in which Marx lived (first industrialization) and the kind of revolution that he invoked in his writings. It is also useful to read Das Kapital as nothing more (and nothing less) than a language game, and to go against the conception of history of the introduction to the Grundrisse. We have to read Marx with all his contradictions.El artículo pasa revista a algunos textos e ideas fundamentales de Marx interrogándose por su actualidad. El marxismo tiene que quitarse de encima el esquema base—sobreestructura y reconocer la sobrecarga especulativa de la teoría del valor. También le conviene repensar los distintos significados de lo que Marx denominó como “ciencia”, tener presente la herencia hegeliana en Marx y, en términos históricos, no olvidar el contexto de primera industrialización en que éste vivió o el tipo de revolución que invocó en sus escritos. También es útil leer El Capital nada más (y nada menos) que como un juego del lenguaje e ir contra la concepción de la historia de la introducción de los Grundrisse. En definitiva, hay que leer a Marx con todas sus contradicciones

Photon management with nanostructures on concentrator solar cells

Optimizing the feature sizes of dielectric nanostructures on the top (ZnS) and bottom (SiO2) surfaces of a 1 μm thick GaAs solar cell, we obtain a higher efficiency (34.4%) than a similar cell with a state of the art bilayer antireflection coating and a planar mirror (33.2%). The back side nanostructure increases the photocurrent due to enhanced optical path length inside the semiconductor, while the nanostructure on the front side increases the photocurrent due to lower reflectance losses. © 2013 AIP Publishing LLC.We acknowledge the SGAI-CSIC for the allocation of computational resource and the financial support by MINECO (ENE2012-37804-C02-02, FPI grant) and CAM (S2009/ENE-1477).Peer Reviewe

Nota sobre verdad y ficción

Si en la actualidad domina la percepción de que habitamos una realidad hueca, en gran medida se debe la grieta existente entre la “realidad efectiva” (Wirklichkeit) histórica, y la “realidad estática” (Realität). La última no tiene capacidad de legitimar ni dar sentido los hechos. Si las formas de irrealidad nos acosan, ello parece síntoma de encontrarnos en un umbral de época, un momento en el que lo que consideramos real se tambalea y es ocasión para reconocer otra realidad que un metaverso metropolizad

Photonics Crystals on high efficiency III-V Solar Cells

Póster presentado en la 28th European PV Solar Energy Conference and Exhibition (EU PVSEC 2013), celebrada en París del 30 de septiembre al 4 de octubre de 2013.We have explored the following photon management options for increasing the efficiency of concentrator solar cells: increasing the voltage by recycling the luminescence, increasing the current reducing reflection and increasing the optical path. We find that a 1m m thick GaAs solar cell with optimized nanostructured front and back surfaces has significantly higher efficiency than a similar cell with a perfect back side mirror and a state of the art bilayer antireflective coating. We have also designed a multilayer coating with high reflectivity at angles away from the surface normal that results in luminescence trapping, and thus increases the open circuit voltage and the cell efficiency.Peer Reviewe

El diagnóstico del tiempo en el primer Hegel

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Filosofía y Ciencias de la Educación, leída en 1972Fac. de FilosofíaTRUEunpu

Active yellow pages: a pipelined resource management architecture for wide-area network computing

This paper describes a novel, pipelined resource management architecture for computational grids. The design is based on two key realizations. One is that resource management involves a sequence of tasks that is best handled by a pipeline. As shown in the paper, this approach results, in a scalable architecture for decentralized scheduling. The other realization is that static aggregation of resources for improved scheduling is inadequate in wide-area computing environments because the needs of users and jobs change with both, location and time. The described architecture addresses this problem by dynamically aggregating resources in a manner that continuously optimizes system response. This is accomplished by way of an active yellow pages directory that allows aggregation constraints to be (re)defined on the fly. An initial prototype of the active yellow pages service has been deployed in the PUNCH network computing environment. Experiences with the production PUNCH system and preliminary results from controlled experiments indicate that the active yellow pages service performs well.Peer Reviewe

Strain driven migration of In during the growth of InAs/GaAs quantum posts

Using the mechano-optical stress sensor technique, we observe a counter-intuitive reduction of the compressive stress when InAs is deposited on GaAs (001) during the growth of quantum posts. Through modelling of the strain fields, we find that such anomalous behaviour can be related to the strain-driven detachment of In atoms from the crystal and their surface diffusion towards the self-assembled nanostructures.We acknowledge the financial support by Spanish MINECO through Grant Nos. ENE2012-37804-C02-02 and TEC2011-29120-C05-04, and by Spanish CAM through Grant Nos. S2009/ESP-1503 and S2009/ENE-1477.Peer Reviewe

MBE growth of Quantum nanostructures for optoelectronics

Ponencia presemtada en el Workshop on Frontier Photonic and Electronic Materials and Devices - German-Japanese-Spanish Joint Workshop, celebrado en Kyoto del 11 al 14 de julio de 2015.Molecular Beam Epitaxy (MBE) is a powerful technique for the fabrication of several self-assembled III-V nanostructures such as quantum rings, quantum dots, and quantum wires that can cover a wide range of the spectrum from 0.98 μm to 1.6 μm. The possibility of performing in-situ, real-time, measurements of accumulated stress (Σσ) during growth of these nanostructures enables to achieve a deep understanding of the growth processes. For example, whereas quantum rings (QR) formation is crucially linked to the presence of liquid indium on the surface, quantum wires (QWR) are produced as an effective way of relaxing a large asymmetrical accumulated stress present on the sample. This information allows a fine-tuning of the optoelectronic properties by controlling their size and shape. Furthermore, the capability of tracking Σσ during growth is used to engineer strain compensated structures like multilayer quantum dot solar cells.CHE-0641523, CSIC-PIF200950I154,S2009ESP-1503, S2009ENE-1477 and AIC-B-2011-0806, MAT2011-26534.Peer Reviewe

Compositional mapping by Z-contrast imaging

This research was sponsored by the Office of Basic Energy Sciences, Materials Sciences and Engineering Division, U.S. Department of Energy (SJP, MV), by the Spanish MCI (projects CONSOLIDER INGENIO 2010 CSD2009-00013 andTEC2008-06756-C03-02/TEC,) and the Junta de Andalucía (PAI research’s groups TEP-120 and TIC-145; project P08-TEP-03516).Peer Reviewe