Assessing the influence of the carbon oxidation-reduction state on organic pollutant biodegradation in algal-bacterial photobioreactors

The influence of the carbon oxidation-reduction state (CORS) of organic pollutants on their biodegradation in enclosed algal-bacterial photobioreactors was evaluated using a consortium of enriched wild-type methanotrophic bacteria and microalgae. Methane, methanol and glucose (with CORS -4, -2 and 0, respectively) were chosen as model organic pollutants. In the absence of external oxygen supply, microalgal photosynthesis was not capable of supporting a significant methane and methanol biodegradation due to their high oxygen demands per carbon unit, while glucose was fully oxidized by photosynthetic oxygenation. When bicarbonate was added, removal efficiencies of 37¿±¿4% (20 days), 65¿±¿4% (11 days) and 100% (2 days) were recorded for CH(4,) CH(3)OH and C(6)H(12)O(6), respectively due to the additional oxygen generated from photosynthetic bicarbonate assimilation. The use of NO(3)(-) instead of NH(4)(+) as nitrogen source (N oxidation-reduction state of +5 vs. -3) resulted in an increase in CH(4) degradation from 0 to 33¿±¿3% in the absence of bicarbonate and from 37¿±¿4% to 100% in the presence of bicarbonate, likely due to a decrease in the stoichiometric oxygen requirements and the higher photosynthetic oxygen production. Hypothetically, the CORS of the substrates might affect the CORS of the microalgal biomass composition (higher lipid content). However, the total lipid content of the algal-bacterial biomass was 19¿±¿7% in the absence and 16¿±¿2% in the presence of bicarbonat

Development of Edgeless n-on-p Planar Pixel Sensors for future ATLAS Upgrades

The development of n-on-p "edgeless" planar pixel sensors being fabricated at FBK (Trento, Italy), aimed at the upgrade of the ATLAS Inner Detector for the High Luminosity phase of the Large Hadron Collider (HL-LHC), is reported. A characterizing feature of the devices is the reduced dead area at the edge, achieved by adopting the "active edge" technology, based on a deep etched trench, suitably doped to make an ohmic contact to the substrate. The project is presented, along with the active edge process, the sensor design for this first n-on-p production and a selection of simulation results, including the expected charge collection efficiency after radiation fluence of $1 \times 10^{15} {\rm n_{eq}}/{\rm cm}^2$ comparable to those expected at HL-LHC (about ten years of running, with an integrated luminosity of 3000 fb$^{-1}$) for the outer pixel layers. We show that, after irradiation and at a bias voltage of 500 V, more than 50% of the signal should be collected in the edge region; this confirms the validity of the active edge approach.Comment: 20 pages, 9 figures, submitted to Nucl. Instr. and Meth.

Using behavioral modeling and simulation for learning communication circuits and systems

Comunicación presentada al "Global Engineering Education Conference (EDUCON)" celebrado en Marrakech (Marruecos) del 17 al 20 de Abril del 2012.This paper analyzes the use of behavioral simulation techniques to enhance the teaching-learning process in electrical engineering courses, specifically those dealing with circuits for communication systems. The method - which can be applied to both undergraduate and master courses - allows students to better understand complex circuit- and device-level phenomena, by describing them at a higher abstraction level. As a demonstration vehicle of the presented methodology, two examples are considered in this work: an analog front-end of a direct-conversion digital radio receiver and a ΣΔ modulator. In both cases, behavioral models of the different subcircuits have been implemented in MATLAB/SIMULINK and used by the students enrolled in two different courses: an undergraduate course and a master course. The results presented in this paper reveal that students become highly motivated and satisfied with the course contents and the proposed simulation-based learning methodology.This work has been supported in part by the Spanish Ministry of Science and Innovation (with support from the European Regional Development Fund) under contracts TEC2007-67247-C02-01/MIC, TEC2010-14825/MIC, in part by the Consejería de Innovación, Ciencia y Empresa, under contract TIC-2532 and in part by the I Plan Propio de Docencia de la U. de Sevilla, LabCMA2010 project.Peer Reviewe

Reconfigurable switched-current ΣΔ power amplifier

Trabajo presentado al XIV Iberchip celebrado en Puebla (México) del 20 al 22 de febreo de 2008.In this paper a reconfigurable switched-current sigma delta modulator for power amplifier is shown, which is a suitable topology to save energy and integrated area in portable applications. Results have shown the correct operation of a 1.8V , 0.18¿ m CMOS reconfigurable switched-current sigma delta modulator with 11bits dynamic range within 1MHz and 7.8bits within 3.8MHz bandwidth.One of the authors Rosalino Rodríguez Calderon thanks the economic support received from CONACYT (México).Peer Reviewe

Novel Silicon n-on-p Edgeless Planar Pixel Sensors for the ATLAS upgrade

In view of the LHC upgrade phases towards HL-LHC, the ATLAS experiment plans to upgrade the Inner Detector with an all-silicon system. The n-on-p silicon technology is a promising candidate for the pixel upgrade thanks to its radiation hardness and cost effectiveness, that allow for enlarging the area instrumented with pixel detectors. We report on the development of novel n-in-p edgeless planar pixel sensors fabricated at FBK (Trento, Italy), making use of the "active edge" concept for the reduction of the dead area at the periphery of the device. After discussing the sensor technology and fabrication process, we present device simulations (pre- and post-irradiation) performed for different sensor configurations. First preliminary results obtained with the test-structures of the production are shown.Comment: 6 pages, 5 figures, to appear in the proceedings of the 9th International Conference on Radiation Effects on Semiconductor Materials Detectors and Device

Habilidades comunicativas en estudiantes de carreras de apoyo frente a estudiantes de otras carreras

El presente trabajo pretende comprobar las habilidades de comunicación de los estudiantes universitarios y la importancia profesional que les otorgan; al tiempo que observar si existen diferencias entre los estudiantes de carreras de apoyo frente a los de otras carreras.Participaron 418 estudiantes de distintos grados y másteres de la Universidad de La Laguna. Se realizó un análisis de frecuencia para determinar el nivel de uso e importancia otorgada a las habilidades comunicativas y una prueba T para muestras independientes con el objetivo de observar las diferencias entre los dos grupos. La información se recogió mediante el cuestionario de habilidades comunicativas para profesionales HABICOM. Los resultados indican que los estudiantes universitarios utilizan habilidades adecuadas y dan importancia a éstas en el desempeño profesional; aunque los estudiantes de carreras de apoyo destacan frente a los de otras carreras; sin embargo son resultados que deben tomarse con cautela debido al escaso tamaño del efecto. Consideramos necesario continuar la formación en estas habilidades a los estudiantes universitarios, ya que son fundamentales para su desempeño profesional.This paper aims to verify the use of the communication skills from university students and professional importance they given them; and examine whether there are differences between students of support degrees and students of other degrees. It was attended by 418 students of various degrees and Master’s degrees from the University of La Laguna. In the study, a frequency analysis was employed to determine the level of use of communication skills and importance they given them; and a T test for independent samples in order to observe the differences between two groups. The information was collected by questionnaire for professional communication skills HABICOM. The results show that college students use appropriate communication skills and give importance to them in their careers, although students of support degrees stand out from those of other degrees; however results are to be taken with caution due to the small effect size. We consider it’s necessary to continue training in these skills to college students because they are fundamental for their professional performance