1,021 research outputs found
Non Abelian TQFT and scattering of self dual field configuration
A non-abelian topological quantum field theory describing the scattering of
self-dual field configurations over topologically non-trivial Riemann surfaces,
arising from the reduction of 4-dim self-dual Yang-Mills fields, is introduced.
It is shown that the phase space of the theory can be exactly quantized in
terms of the space of holomorphic structures over stable vector bundles of
degree zero over Riemann surfaces. The Dirac monopoles are particular static
solutions of the field equations. Its relation to topological gravity is
discussed.Comment: 13 pages, Late
Bringing the power of dynamic languages to hardware control systems
Hardware control systems are normally programmed using high-performance languages like C or C++ and increasingly also Java. All these languages are strongly typed and compiled which brings usually good performance but at the cost of a longer development and testing cycle and the need for more programming expertise. Dynamic languages which were long thought to be too slow and not powerful enough for control purposes are, thanks to modern powerful computers and advanced implementation techniques, fast enough for many of these tasks. We present examples from the LHCb Experiment Control System (ECS), which is based on a commercial SCADA software. We have successfully used Python to integrate hardware devices into the ECS. We present the necessary lightweight middle-ware we have developed, including examples for controlling hardware and software devices. We also discuss the development cycle, tools used and compare the effort to traditional solutions
Nuevo material compuesto de matriz geopolimérica activado con ceniza de cascarilla de arroz y KOH: Desempeño a alta temperatura
Geopolymers were produced using an environmentally friendly alkali activator (based on Rice Husk Ash and potassium hydroxide). Aluminosilicates particles, carbon and ceramic fibres were used as reinforcement materials. The effects of reinforcement materials on the flexural strength, linear-shrinkage, thermophysical properties and microstructure of the geopolymers at room and high temperature (1200 ÅãC) were studied. The results indicated that the toughness of the composites is increased 110.4% for geopolymer reinforced by ceramic fibres (G-AF) at room temperature. The presence of particles improved the flexural behaviour 265% for geopolymer reinforced by carbon fibres and particles after exposure to 1200 .C. Linear-shrinkage for geopolymer reinforced by ceramic fibres and particles and the geopolymer G-AF compared with reference sample (without fibres and particles) is improved by 27.88% and 7.88% respectively at 900 ÅãC. The geopolymer materials developed in this work are porous materials with low thermal conductivity and good mechanical properties with potential thermal insulation applications for building applications.Compuestos geopoliméricos fueron producidos usando un activador alcalino alternativo (basado en ceniza de cascarilla de arroz e hidróxido de potasio), partículas aluminosilicatos, fibras de carbono y cerámicas. Se estudió el efecto de fibras y partículas en la resistencia a la flexión, contracción lineal, propiedades termofísicas y microestructura de los geopolímeros a temperatura ambiente y 1200 °C. Los resultados indican que la tenacidad se incrementó 110.4% para el geopolímero reforzado con fibras cerámicas (G-AF) a temperatura ambiente. La presencia de partículas mejora el comportamiento a la flexión 265% para el geopolímero reforzado con fibras de carbono y partículas después de la exposición a 1200 °C. La contracción lineal para el geopolímero reforzado con fibras cerámicas y partículas y el geopolímero G-AF es mejorada 27.88% y 7.88% respectivamente a 900 ºC con respecto al material sin refuerzo. Los materiales geopoliméricos desarrollados en este estudio son materiales porosos de baja conductividad térmica y buenas propiedades mecánicas con potencial aplicación en la industria de la construcción como aislantes térmicos
Nanotechnology measurements of the Young's modulus of polymeric materials
Making use of atomic force microscopy (AFM) —known as the state-of-the-art technology for handling matter on an atomic and molecular scale—, this paper describes the use of a nanotechnology technique for characterizing properties of polymeric materials. AFM measurement on two materials (polyamide and polystyrene) allowed to compare the performance of two distinct multi-asperity adhesion models based on the JKR (Johnson-Kendall-Robert) and DMT (Derajaguin- Muller-Toporov) theories, when assessing the Young’s Modulus (modulus of elasticity) of the investigated materials. Experimental results confirm that the JKR model processed through a MatLab algorithm produces more reliable results of the Young’s Modulus than the DMT model built-in in the AFM software
Efecto del ensilado de tubérculos de taro (Colocasia esculenta [L.] Schott) sobre indicadores productivos y reproductivos en cerdas F1 Landrace x Duroc
The effect of taro tuber silage (Colocasia esculenta [L.] Schott) on productive and reproductive indicators of commercial sows in pregnancy and lactation was evaluated. Forty F1 Landrace x Duroc sows were used, with an initial body weight of 174.2 ± 2.6 kg. The sows were randomly distributed in two diets. During pregnancy, 0 and 30% silage was included in the diet and the final weight of pregnant sows (FWPS), total number of piglets born at birth (TNPBB), total number of piglets born alive at delivery (TNPBAB), weight of litter at birth (WLB), weight of piglets at birth (WPB), feed consumption per sow in gestation (FCSG) and the cost of feeding in gestation (CFG). In lactation, 0 and 10% silage was included in the diet and the final weight of lactating sows (FWLS), number of piglets weaned per sow (NPWS), weight of piglets at weaning (WPW), weight of litter at weaning (WLW), days for the onset of post-weaning heat (DOPWH), days for conception from weaning (DCFW), feed intake per sow in lactation (FISL) and the cost of feeding in lactation (CFL). In pregnancy there were no significant differences for FWPS, TNPBB, TNPBAB, WLB, WPB and FCSG, but the CFG was lower in sows fed silage (p <0.05). In lactation there was no effect for FWLS, NPWS, WPW, WLW, DOPWH and DCFW, but the FISL and CFL were better (p <0.05) in the sows that consumed silage. It is concluded that the inclusion of silage of taro tubers in the diet of commercial sows in pregnancy and lactation did not affect the productive and reproductive indicators, but reduced feeding costs.Se evaluó el efecto del ensilaje de tubérculos de taro (Colocasia esculenta [L.] Schott) sobre indicadores productivos y reproductivos de cerdas comerciales en gestación y lactancia. Se utilizaron 40 cerdas F1 Landrace x Duroc, con peso inicial de 174.2 ± 2.6 kg, distribuidas aleatoriamente en dos dietas. En gestación se incluyó 0 y 30% de ensilado en la dieta y se determinó el peso final de las cerdas gestantes (PFCG), número total de lechones nacidos al parto (NTLNP), número total de lechones nacidos vivos al parto (NTLNVP), peso de la camada al nacimiento (PCN), peso de los lechones al nacimiento (PLN), consumo de alimento por cerda en gestación (CACG) y el costo de alimentación en gestación (CAG). En lactancia se incluyó 0 y 10% de ensilado en la dieta y se evaluó el peso final de las cerdas lactantes (PFCL), número de lechones destetados por cerda (NLDC), peso de los lechones al destete (PLD), peso de la camada al destete (PCD), días para el inicio del celo posdestete (DICP), días para la concepción desde el destete (DCDD), consumo de alimento por cerda en lactancia (CACL) y el costo de alimentación en lactancia (CAL). En gestación no hubo diferencias significativas para PFCG, NTLNP, NTLNVP, PCN, PLN y CACG, pero el CAG fue menor en cerdas alimentadas con ensilado (p<0.05). En lactancia no hubo efecto para PFCL, NLDC, PLD, PCD, DICP y DCDD, pero el CACL y CAL fueron mejores (p<0.05) en las cerdas que consumieron ensilado. Se concluye que la inclusión de ensilaje de tubérculos de taro en la dieta de cerdas comerciales en gestación y lactancia no afectó los indicadores productivos y reproductivos, pero redujo los costos de alimentación
Acodo
50 p. Recurso Electr?nicoEl Acodo consiste en el enraizamiento de una zona del tallo de la mora, mientras la rama contin?a adherida a la planta madre para prolongar su existencia, retornando a la tierra en un ciclo hereditario. El desplazamiento de cultivos, es una de las principales causas de movilizaci?n de campesinos a la ciudad.
El proyecto, surge a partir de una postura de inconformidad hacia el colonialismo cultural que se impone con superioridad ante nuestra memoria, nuestro patrimonio, nuestras costumbres y tradiciones, que son la herencia de nuestros pueblos.
En mi obra, marco pautas de conciencia cultural, que rescatan las costumbres antiguas para que alimenten las nuevas generaciones, entablando un di?logo con la propia ciudad, con una instalaci?n m?vil que consta de una carreta de madera, cargada con 12 guacales, utilizados como matera que contienen plantas de mora acodadas de un guacal a otra, accionada por mi cuerpo, ejerciendo el oficio de carretero, adem?s, en la carreta transporto una bebida hecha a bases de mora llamada ?amor?tica? que comparto con las personas de Ibagu? ? Tolima, y me acodo a mi territorio desde la ciudad, en un clamor como campo que nos identifica a todos como agrodescendientes.The Acodo consists in the rooting of a zone in the stem area of a blackberry, while continuing branch attached to the mother plant to prolong its existence, returning to earth in a hereditary cycle. The displacement of crops, It?s one of the main causes of mobilization of peasants to the city.
The project, it arises from a position of dissent towards cultural colonialism imposed superiority to our memory, our heritage, our customs and traditions that are the heritage of our peoples.
In my work within guidelines of cultural awareness, they are rescuing the old ways that feed the new generations entering into a dialogue with the city itself, with a mobile installation which consists of a wooden cart, loaded with 12 crates used as pot, exercising the profession of carter, also in the wagon I transport a drink made from blackberries called ?amor?tica? who if share with the people of Ibague Tolima and I scion my territory from the city in a clamor as field that identifies us all as peasants.
Keywords: Acodo, blackberry crops, displacement, Territory
Features of dengue and chikungunya infections of colombian children under 24 months of age admitted to the emergency department
We aimed to assess clinical and laboratory differences between dengue and chikungunya in children <24 months of age in a comparative study. We collected retrospective clinical and laboratory data confirmed by NS1/IgM for dengue for 19 months (1 January 2013 to 17 August 2014). Prospective data for chikungunya confirmed by real-time polymerase chain reaction were collected for 4 months (22 September 2014-14 December 2014). Sensitivity and specificity [with 95% confidence interval (CI)] were reported for each disease diagnosis. A platelet count <150 000 cells/ml at emergency admission best characterized dengue, with a sensitivity of 67% (95% CI, 53-79) and specificity of 95% (95% CI, 82-99). The algorithm developed with classification and regression tree analysis showed a sensitivity of 93% (95% CI, 68-100) and specificity of 38% (95% CI, 9-76) to diagnose dengue. Our study provides potential differential characteristics between chikungunya and dengue in young children, especially low platelet counts. © The Author [2017].Universidad Nacional de Colombia, UN
Johns Hopkins University1Departamento de Epidemiologia, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Cartagena, Colombia 2Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia 3Departamento de Epidemiologia, Faculdade de Saúde Publica, Universidade de São Paulo, São Paulo, Brazil 4Facultad de Ingenería, Universidad Tecnológica de Bolívar, Cartagena, Colombia 5Facultad Ciencias Básicas y Biomédicas, Universidad Simón Bolívar, Barranquilla, Colombia 6Facultad de Medicina, Universidad de Cartagena, Cartagena, Colombia 7Instituto de Investigaciones Biologicas del Tropico, Universidad de Córdoba, Montería, Colombia 8Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA Correspondence: Angel Paternina-Caicedo, Hospital Infantil Napoleón Franco Pareja—La Casa del Niño, Bruselas Transversal 36 N. 36-33, Cartagena, Bolívar, Colombia. Tel: +1-412-3267809. E-mail or
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