On the Dunford-Pettis Property of the Tensor product of C(K) spaces

We characterize those compact Hausdorff spaces K such that the proyective tensor product of C(K) by itself has the Dunford-Pettis Property, answering thus in the negative a question posed by Castillo and Gonzalez.Comment: 5 page

Effect of the nearby levels on the resonance fluorescence spectrum of the atom-field interaction

We study the resonance fluorescence in the Jaynes-Cummings model when nearby levels are taking into account. We show that the Stark shift produced by such levels generates a displacement of the peaks of the resonance fluorescence due to an induced effective detuning and also induces an asymmetry. Specific results are presented assuming a coherent and a thermal fields

Fast on-wafer electrical, mechanical, and electromechanical characterization of piezoresistive cantilever force sensors

Validation of a technological process requires an intensive characterization of the performance of the resulting devices, circuits, or systems. The technology for the fabrication of micro and nanoelectromechanical systems (MEMS and NEMS) is evolving rapidly, with new kind of device concepts for applications like sensing or harvesting are being proposed and demonstrated. However, the characterization tools and methods for these new devices are still not fully developed. Here, we present an on-wafer, highly precise, and rapid characterization method to measure the mechanical, electrical, and electromechanical properties of piezoresistive cantilevers. The setup is based on a combination of probe-card and atomic force microscopy technology, it allows accessing many devices across a wafer and it can be applied to a broad range of MEMS and NEMS. Using this setup we have characterized the performance of multiple submicron thick piezoresistive cantilever force sensors. For the best design we have obtained a force sensitivity ℜ_F = 158μV/nN, a noise of 5.8 μV (1 Hz–1 kHz) and a minimum detectable force of 37 pN with a relative standard deviation of σ_r ≈ 8%. This small value of σr, together with a high fabrication yield >95%, validates our fabrication technology. These devices are intended to be used as bio-molecular detectors for the measurement of intermolecular forces between ligand and receptor molecule pairs

Biotecnología Moderna para el Desarrollo de la Agricultura en Colombia

Colombia is currently one of the most promising countries with regard to its potential for agricultural development and for generating food supply for current and future human generations. This is owing to factors such as availability of land, water, topographical diversity, as well as political factors. Nevertheless, Colombia will reach this full potential if it adopts available technologies that can meet the current global challenges faced by the agriculture in the 21st century: among others, world population growth, increase in average life expectancy, high degree of malnutrition, climate change, wrong agricultural practices. Here is presented how modern biotechnology is an important ally as a wide range of technologies and innovative systems can be applied where they are most needed: for increasing cultivation productivity, resisting both biotic and abiotic factors, and ensuring food safety. In this study is showed evidence with regard to significant benefits of adopting biotechnological crops to contribute to food safety and how they are already being implemented in both developed and developing countries. Using modern technology, there are open opportunities for the country in search of circular bio-based economy, strengthen its food sovereignty and to serve as an agricultural breadbasket to Latin America and the World.Colombia es actualmente uno de los países más prometedores en cuanto a su potencial para el desarrollo agrícola y para generar alimentos para las generaciones humanas actuales y futuras. Esto se debe a factores como la disponibilidad de tierra, agua, diversidad topográfica, así como a factores políticos. Sin embargo, Colombia alcanzará su pleno potencial de desarrollo agrícola sostenible si adopta las tecnologías disponibles que puedan hacer frente a los desafíos globales actuales que enfrenta la agricultura en el siglo XXI: entre otros, el crecimiento de la población mundial, el incremento en el promedio de la esperanza de vida, alto grado de desnutrición, cambio climático, uso de practicas agrícolas equivocadas. Aquí es presentado cómo la biotecnología moderna es un aliado importante ya que se puede aplicar una amplia gama de tecnologías y sistemas innovadores donde más se necesitan: aumentar la productividad y sostenibilidad del cultivo, resistir los factores de estrés bióticos y abióticos y garantizar la seguridad alimentaria. En este estudio se muestra evidencia sobre los beneficios significativos de la adopción de cultivos biotecnológicos para contribuir a la inocuidad de los alimentos y como ellos ya se están implementando en los países desarrollados y en vía de desarrollo. Usando tecnologías modernas, hay oportunidades abiertas para el país en la búsqueda de una economía circular de base biológica, que fortalezca su soberanía alimentaria y para servir como despensa agrícola para América Latina y el mundo

Transformations due to mylonitization processes in granitic rocks

[Resumen] El objetivo de este estudio es determinar las transformaciones, tanto a nivel mineralógico como textural, experimentadas por rocas graníticas tardihercínicas afectadas por procesos de milonitización en el sector oriental de la Sierra de Gredos (Sistema Central Español). De igual modQ se intenta determinar la influencia de dichas transformaciones en la composición química de las rocas milonitizadas . El incremento progresivo de la deformación provoca una serie de transformaciones texturales en las que a partir de granitoides de grano grueso porfídicos se generan unas milonitas porfidoclásticas planolineares en el núcleo de la banda de fractura. Desde el punto de vista mineralógico se aprecia una total trituración y degradación de la biotita, que se transforma a clorita de grano muy fino dispersa en la matriz milonítica. También se observan ciertas removilizaciones de feldespato potásico y albita y reajustes metamórficos de bajo grado (en facies de esquistos verdes). Los cambios composicionales acompañantes consisten en un enriquecimiento en Si02, CaO y Na20 en la zona de máxima milonitización y un empobrecimiento en K20 y P20 S en el mismo sentido. En cuanto a los elementos traza, tan sólo Rb y Sr muestran un ligero empobrecimiento en la zona milonítica.[Abstract] The aim of this paper is the determination of the textural and mineralogical transformations introduced in late-Hercynian granitic rocks which have undergone mylonitization processes in the Eastern Sierra de Gredos (Spanish Central System). It also is intended to determine the influence of such changes on the chemical composition of the mylonitic rocks. The progressive increasing of strain causes a series of textural transformations in the originally porphyritic, coarse-grained granitoids leading to formation of porphyroclastic mylonitic rocks with development of planelinear fabrics at the core of the fracture zone. From a mineralogical point of view, transformation~ consist in entire crushing and degradation of biotite, which converts into very fine-grained chlorite disseminated within the mylonitic matrix. Likewise, K-feldspar and albite remobilizations and low grade (greenschists facies) metamorphic readjustments can be observed. The accompanying compositional changes are Si02, CaO and Na20 enrichment and K20 and P20S impoverishment towards the zone of maximum mylonitization. Concerning the trace elements, only Rb and Sr show a weak impoverishment within the mylonitic zone