El sistema de participación distrital y su desarrollo en el sector educativo en Bogotá en el periodo 2004 a 2008.

El presente trabajo de grado en maestría de profundización en ciencias sociales, busca acercarse al desarrollo del derecho a la participación especialmente frente a la forma como se origina y comprende su configuración como subsistema de participación en el sector educación de Bogotá en la Administración de la Bogotá sin Indiferencia. Su análisis se alimenta de las narrativas de los sujetos surgidas en la consideración del derecho a la participación como problema público. Como complemento a lo anterior busca establecer el ámbito de tensiones que se suscitaron en su origen normativo constitucional al reconocer su fundamentación en las lógicas orgánicas (Ley 115 de 1994 y Decreto 1860 de 1994) en la lógica de exigibilidad de derechos y de política pública sectorial que marca la administración de la Bogotá sin Indiferencia desde el año 2004 a 2008. Este trabajo de investigación busca encontrar aquellas razones y argumentos que hablan de participación. El ámbito en el que se delinean estas actuaciones será el educativo; el tiempo en el que se genera el análisis será el de las reformas, el de los cambios constitucionales, políticos y económicos en tensión que hablan de desarrollar un nuevo pacto social que conduzca a la sociedad colombiana hacia la paz y, la dimensión participativa será la de las oportunidades políticas que permiten que una corte de sujetos con un basamento ideológico democrático, independiente y alternativo entre a ser poder administrativo y a configurar una exigibilidad de derechos que habían sido establecidos en el año de 1991, en eso que se ha conocido como la norma de normas o marco constitucional

Mercado de trabajo, formación y pensiones

Trabajo distribuido en dos bloques. El primer bloque analiza la evolución del mercado de trabajo en España comparando con el nivel educativo alcanzado entre la población en edad de trabajar. El segundo y último bloque, muestra la evolución financiera de la seguridad social en cuanto a los pagos de las pensiones.<br /

Preparation and characterization of PVA/PASA-PVA/PDDAB bipolar membrane

Bipolar membranes (BMP) were prepared by bonding together separate anion and cation exchange membrane. For the preparation of the cation selective layer, aqueous solution of PVA [poly(vinyl alcohol)], and PASA [poly(anetholesulfonic acid sodium salt)], where the ratio of PVA/PASA was changed for the control of the membrane charge density, were cast for negatively charged membranes. These membranes were annealed at 100 ºC for 45 min and cross-linked in an aqueous solution containing 10% Na2SO4, 1.5% H2SO4, and 0.5% glutaraldehyde in order to control water content of the gel membranes. The anion selective layers were prepared by dispersing a solution of PVA and PDDAB [poly(diallyldiethylammonium bromide)] in DMF, where the ratio of PVA/PDDAB was changed for the membrane charge density control. The electrical resistance of BMP formed by this methodology was slightly increased while the selectivity decreased, while their permselectivity did not change with the acid or alkaline post-treatment

Medium-frequency electrical resistance sintering of oxidized C.P. iron powder

Commercially pure (C.P.) iron powders with a deliberate high degree of oxidation were consolidated by medium-frequency electrical resistance sintering (MF-ERS). This is a consolidation technique where pressure, and heat coming from a low-voltage and high-intensity electrical current, are simultaneously applied to a powder mass. In this work, the achieved densification rate is interpreted according to a qualitative microscopic model, based on the compacts global porosity and electrical resistance evolution. The effect of current intensity and sintering time on compacts was studied on the basis of micrographs revealing the porosity distribution inside the sintered compact. The microstructural characteristics of compacts consolidated by the traditional cold-press and furnace-sinter powder metallurgy route are compared with results of MF-ERS consolidation. The goodness of MF-ERS versus the problems of conventional sintering when working with oxidized powders is analyzed. The electrical consolidation can obtain higher densifications than the traditional route under non-reducing atmospheres.Ministerio de Economía y Competitividad DPI2015-69550-C2-1-PMinisterio de Economía y Competitividad DPI2015-69550-C2-2-

Influence of processing parameters on the conduct of electrical resistance sintering of iron powders

The influence of the applied pressure and electrical parameters on the macrostructure of specimens consolidated by the medium-frequency electrical resistance sintering technique (MF-ERS) is analysed in this work. This technique is based on the application of pressure to a mass of conductive powder that, simultaneously, is being crossed by a high intensity and low voltage electric current. The simultaneous action of the pressure and the heat released by the Joule effect causes the densification and consolidation of the powder mass in a very short time. The effect of the current intensity and heating time on the global porosity, the porosity distribution, and the microhardness of sintered compacts is studied for two applied pressures (100 and 150 MPa). For the different experiments of electrical consolidation, a commercially available pure iron powder was chosen. For comparison purposes, the properties of the compacts consolidated by MF-ERS are compared with the results obtained by the conventional powder metallurgy route (cold pressing and furnace sintering). Results show that, as expected, higher current intensities and dwelling times, as well as higher pressures and the consolidation of compacts with lower aspects ratios, produce denser materials

A Method to Determine the Electrical Resistance of a Metallic Powder Mass under Compression

In this paper, a phenomenological model to predict the value of the electrical resistance of a compressed metal powder mass is proposed. The model, based on the experimental compressibility and resistivity-porosity curves, is useful in the field of the electrical resistance consolidation. In this area is often required to find out whether a certain mass of powder inside a die of specified inner section, and subjected to a certain compression, reaches a sufficiently small resistance value so that it can be consolidated by electrical means. The model also predicts the electrical resistance value of the powder mass in case of powders with no oxide layers, or after removing them mechanically or electrically by a previous activation process. The model predictions have been successfully validated through direct measurements of electrical resistance in powder aggregates both in as-received state and after electrical activation.Ministerio de Economía y Competitividad y Unión Europea DPI2015-69550-C2-1-P y DPI2015-69550-C2-2-

Speech Signal and Facial Image Processing for Obstructive Sleep Apnea Assessment

Obstructive sleep apnea (OSA) is a common sleep disorder characterized by recurring breathing pauses during sleep caused by a blockage of the upper airway (UA). OSA is generally diagnosed through a costly procedure requiring an overnight stay of the patient at the hospital. This has led to proposing less costly procedures based on the analysis of patients' facial images and voice recordings to help in OSA detection and severity assessment. In this paper we investigate the use of both image and speech processing to estimate the apnea-hypopnea index, AHI (which describes the severity of the condition), over a population of 285 male Spanish subjects suspected to suffer from OSA and referred to a Sleep Disorders Unit. Photographs and voice recordings were collected in a supervised but not highly controlled way trying to test a scenario close to an OSA assessment application running on a mobile device (i.e., smartphones or tablets). Spectral information in speech utterances is modeled by a state-of-the-art low-dimensional acoustic representation, called i-vector. A set of local craniofacial features related to OSA are extracted from images after detecting facial landmarks using Active Appearance Models (AAMs). Support vector regression (SVR) is applied on facial features and i-vectors to estimate the AHI.The activities in this paper were funded by the Spanish Ministry of Economy and Competitiveness and the European Union (FEDER) as part of the TEC2012-37585-C02 (CMC-V2) project. Authors also thank Sonia Martinez Diaz for her effort in collecting the OSA database that is used in this study

Extending the adaptive thermal comfort models for courtyards

Temperatures in Mediterranean cities are rising due to the effects of climate change, with a consequent increase in the heat waves frequency. Recent research has shown the tempering potential of semi-outdoor spaces such as courtyards, which are semi-enclosed spaces that are widely used by the users of buildings in Mediterranean cities. International standards addressing thermal comfort parameters provide technical guidelines for indoor spaces only. Expanding this concept, this paper focuses on the potential to extend and interpret the existing calculation models for indoor thermal comfort, EN 16798 and ASHRAE 55, to determine thermal comfort, monitoring two different courtyards in Cordoba, Spain, during both typical summer and heat wave periods. The results show that during the typical summer, the monitored courtyards can reach temperatures up to 8.4 °C cooler than outside. Subsequently can be considered to be in thermal comfort on average for 88% of the time according to EN 16798, and 75% according to ASHRAE 55, which drop to 71% and 52% respectively during heat wave (HW) periods, in spite of increasing thermal gap (TG) up to 13.9 °C. The results are also compared with the PET indicator used for evaluation of outdoor thermal comfort, which provides comparable figures: 81% summer and 73% HW. Implications of implementing passive shading strategies to increase comfort in these transition spaces are also evaluated. The research highlights the thermal potential and usefulness of courtyards in warm climates, so they can ultimately be included in the building analysis as a potentially comfortable and habitable space

Small static radiosurgery field dosimetry with small volume ionization chambers

Purpose: To evaluate the response of the four smallest active volume thimble type ionization chambers commercially available (IBA-dosimetry RAZOR Nano Chamber, Standard Imaging Exradin A16, IBA-dosimetry CC01 and PTW T31022) when measuring SRS cone collimated Flattening Filter Free (FFF) fields. Methods: We employed Monte Carlo simulation for calculating correction factors as defined in IAEA TRS-483. Monte Carlo simulation beam model and ion chamber geometry definitions were supported by an extensive set of measurements. Type A and B uncertainty components were evaluated.Results: Commissioning of Monte Carlo 6 MV and 10 MV FFF beam models yielded relative differences between measured and simulated dose distributions lower than 1.5%. Monte Carlo simulated output factors for 5 mm SRS field agree with experimental values within 1% local relative difference for all chambers. Smallest active volume ion chamber (IBA-dosimetry RAZOR Nano Chamber) exhibits smallest correction, being compatible with unity. Correction factor combined uncertainties range between 0.7% and 0.9%. Smallest uncertainties were recorded for smallest and largest active volume ion chambers, although the latter exhibited largest correction factor. Highest contribution to combined uncertainty was type B component associated with beam model initial electron spatial Full Width Half Maximum (FWHM) uncertainty. Conclusions: Among the investigated chambers, the IBA RAZOR Nano Chamber was found to be an excellent choice for narrow beam output factor measurement since it requires minimum correction (in line with IAEA TRS-483 recommendations). This is caused by its tiny size and tissue equivalence materials which produce minimum volume averaging and fluence perturbationS

Producción de hojarasca y retorno potencial de nutrientes en tres sitios del Estado de Nuevo León, México = Litterfall and potential nutrient return in three sites of the state of Nuevo León, México

RESUMEN Los objetivos de este estudio fueron estimar y cuantificar la dinámica mensual (enero a diciembre 2009) de la deposición de la hojarasca y macro (Ca, K, Mg, N y P) y microminerales (Cu, Fe, Mn, y Zn) de las hojas de la hojarasca en los municipios Los Ramones, China y Linares, del estado de Nuevo León, México. La vegetación está caracterizada como matorral espinoso tamaulipeco. La deposición anual total de hojarasca fue de 321.5 (Los Ramones), 431.6 (China) y 462.9 (Linares) g/m2/año. Las hojas representaron el mayor componente (154.4 a 304.5 g/m2/año) del total de hojarasca depositada. La deposición de ramas varió de 48.25 a 75.16 g/m2/año y la de estructuras reproductivas de 58.4 a 98.9 g/m2/año. La de otros componentes (material vegetal no identifi cado, cuerpos y heces de insecto) varió de 19.9 a 29.2 g/m2/año. La deposición anual de Caen los tres sitios fl uctuó de 3.4 a 8.1; K de 1.4 a 3.2; Mg de 0.76 a 1.6; N de 3.0 a 5.5 y P de 0.05 a 0.11 g/m2/año. El Cu fl uctuó de 0.84 a 2.8; Fe de 14.7 a 21.7; Mn de 5.5 a 11.8 y Zn de 3.3 a 5.2 mg/m2/año. En invierno se depositó la mayor cantidad de minerales. Además, en Linares se depositó la mayor cantidad de minerales y en Los Ramones la menor. Hubo diferencias espaciales y temporales en cantidad de hojarasca colectada y retorno de minerales, mas no así en la calidad foliar entre los sitios de estudio. ABSTRACT The aims of the study were to estimate and quantify the monthly dynamics (January to December 2009) of litterfall deposition and macro (Ca, K, Mg, N y P) and microminerals (Cu, Fe, Mn, y Zn) of litterfall leaves in the counties Los Ramones, China y Linares, of Nuevo León State, México. The plant community is named as Tamaulipan Thornscrub Annual deposition was 321.5 (Los Ramones), 431.6 (China) and 462.9 (Linares) g/m2/year. Leaves represented the highest component (154.4 to 304.5 g/m2/year) of total litterfall production. Branches varied from 48.25 to 75.16 g/m2/year. Reproductive structures from 58.4 to 98.9 g/m2/year and other components (unidentifi ed material, bodies and insect feces) ranked from 19.9 to 29.2 g/m2/year. Annual deposition of Ca in the three sites varied from 3.4 to 8.1; K from 1.4 to 3.2; Mg from 0.76 to 1.6; N from 3.0 to 5.5 and P from 0.05 to 0.11 g/m2/year. Cu ranked from 0.84 to 2.8; Fe from 14.7 to 21.7; Mn from 5.5 to 11.8 and Zn from 3.3 to 5.2 mg/m2/year. In winter mineral deposition was higher. Moreover, the highest mineral deposition occurred in Linares and Los Ramones was the lowest. There were spatiotemporal variations in quantity of literfall collected and return of minerals, but not so in leaf quality between study sites