20 research outputs found

    Performance enhancement in the desing of amplifier and amplifier-less circuits in modern CMOS technologies.

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    In the context of nowadays CMOS technology downscaling and the increasing demand of high performance electronics by industry and consumers, analog design has become a major challenge. On the one hand, beyond others, amplifiers have traditionally been a key cell for many analog systems whose overall performance strongly depends on those of the amplifier. Consequently, still today, achieving high performance amplifiers is essential. On the other hand, due to the increasing difficulty in achieving high performance amplifiers in downscaled modern technologies, a different research line that replaces the amplifier by other more easily achievable cells appears: the so called amplifier-less techniques. This thesis explores and contributes to both philosophies. Specifically, a lowvoltage differential input pair is proposed, with which three multistage amplifiers in the state of art are designed, analysed and tested. Moreover, a structure for the implementation of differential switched capacitor circuits, specially suitable for comparator-based circuits, that features lower distortion and less noise than the classical differential structures is proposed, an, as a proof of concept, implemented in a ΔΣ modulator

    Fully differential implementation of a delta-sigma modulator based on the pseudo-pseudo differential technique

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    Flicker noise and distortion are the main limitations in biomedical applications, especially for Switched Capacitor implementations, where the flicker noise is folded into the signal band. To remove the flicker noise and increase the linearity, the Pseudo-Pseudo Differential (P2D) technique has been proposed, where a single-ended signal is processed in a differential way. This paper presents the first silicon implementation of a second order Comparator-Based Switched-Capacitor (CBSC) delta-sigma modulator based on a variation of the P2D technique. Experimental results in a standard 180 nm CMOS technology show an improvement of 10 dB in the Peak SNDR, 5 dB in the DR, and 9 dB in the SFDR over its pseudo differential counterpart, which is the preferred differential implementation for CBSC circuits. Moreover, it is achieved with a reduction in the power consumption

    Radiaciones ionizantes y su impacto Primer Simposio Internacional sobre Medioambiente (ISE 2017)

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    Son ya varias las décadas en las que en América Latina se ha trabajado arduamente sobre las radiaciones ionizantes; tanto en las ionizantes directas, tales como las partículas beta positivas y negativas, las partículas alfa, los protones, los mesones cargados, los muones y los iones pesados, así como también en las ionizantes indirectas (las producidas por partículas sin cargas), como las generadas por fotones con energías superiores a los 10 keV y los neutrones. Por otro lado, las radiaciones no ionizantes también han sido objeto de detallados estudios, y muy especialmente las provenientes del Sol, como el factor natural más influyente sobre la Tierra. En esta obra se presentan algunos de los avances en los que han participado reconocidos científicos latinoamericanos, como el Dr. Héctor Vega Carrillo, Dr. Daniel Palacios, Dra. Patrizia Pereyra, Dra. Sheila Serrano, y el Dr. Manuel Ernesto Delgado, entre otros. Esta obra puede ser de interés para profesionales del área de la protección radiológica, la ingeniería ambiental, física de la atmósfera y áreas afines, así como para estudiantes

    Experiencias en el aula: tercer encuentro de prácticas pedagógicas innovadoras.

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    Experiencias de profesores en su quehacer en los distintos ambientes de aprendizaje presenciales y a distancia.Para el Centro de Excelencia Docente aeiou constituye un honor presentar la publicación del Tercer Encuentro de Prácticas Pedagógicas Innovadoras en el que se destacan cuarenta trabajos de profesores de UNIMINUTO provenientes de diferentes sedes. Con este encuentro son ya tres que bajo la dirección de aeiou los profesores han compartido su quehacer en los distintos ambientes de aprendizaje presenciales y a distancia. Cada año el Centro de Excelencia Docente invita a los profesores a participar en este evento, para el 2108 además de la inscripción voluntaria por parte de cada profesor, se invitó al estudiantado a que postularan a sus profesores que consideraban eran innovadores y creativos en el cumplimiento de su función docente y se obtuvo una respuesta importante por parte de los estudiantes, que para algunos profesores resultó sorpresiva porque quizás no habían considerado que el trabajo que hacían en su ambiente de aprendizaje era diferente, fuera de lo común. Luego de una evaluación de jurados nacionales e internacionales de las prácticas presentadas y de la realización del evento, que tuvo como novedad hacerlo de forma simultánea en cuatro sedes donde UNIMINUTO tiene presencia: Buga, Ibagué, Pereira y Bogotá, se comparte la presente publicación para tener como referencia y evidencia el trabajo que los profesores hacen a diario

    Ciencia Odontológica 2.0

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    Libro que muestra avances de la Investigación Odontológica en MéxicoEs para los integrantes de la Red de Investigación en Estomatología (RIE) una enorme alegría presentar el segundo de una serie de 6 libros sobre casos clínicos, revisiones de la literatura e investigaciones. La RIE está integrada por cuerpos académicos de la UAEH, UAEM, UAC y UdeG

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Indicadores contextuales para evaluar los determinantes sociales de la salud y la crisis económica española = Contextual indicators to assess social determinants of health and the Spanish economic recession

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    Objective To provide indicators to assess the impact on health, its social determinants and health inequalities from a social context and the recent economic recession in Spain and its autonomous regions. Methods Based on the Spanish conceptual framework for determinants of social inequalities in health, we identified indicators sequentially from key documents, Web of Science, and organisations with official statistics. The information collected resulted in a large directory of indicators which was reviewed by an expert panel. We then selected a set of these indicators according to geographical (availability of data according to autonomous regions) and temporal (from at least 2006 to 2012) criteria. Results We identified 203 contextual indicators related to social determinants of health and selected 96 (47%) based on the above criteria; 16% of the identified indicators did not satisfy the geographical criteria and 35% did not satisfy the temporal criteria. At least 80% of the indicators related to dependence and healthcare services were excluded. The final selection of indicators covered all areas for social determinants of health, and 62% of these were not available on the Internet. Around 40% of the indicators were extracted from sources related to the Spanish Statistics Institute. Conclusions We have provided an extensive directory of contextual indicators on social determinants of health and a database to facilitate assessment of the impact of the economic recession on health and health inequalities in Spain and its autonomous regionsObjective To provide indicators to assess the impact on health, its social determinants and health inequalities from a social context and the recent economic recession in Spain and its autonomous regions. Methods Based on the Spanish conceptual framework for determinants of social inequalities in health, we identified indicators sequentially from key documents, Web of Science, and organisations with official statistics. The information collected resulted in a large directory of indicators which was reviewed by an expert panel. We then selected a set of these indicators according to geographical (availability of data according to autonomous regions) and temporal (from at least 2006 to 2012) criteria. Results We identified 203 contextual indicators related to social determinants of health and selected 96 (47%) based on the above criteria; 16% of the identified indicators did not satisfy the geographical criteria and 35% did not satisfy the temporal criteria. At least 80% of the indicators related to dependence and healthcare services were excluded. The final selection of indicators covered all areas for social determinants of health, and 62% of these were not available on the Internet. Around 40% of the indicators were extracted from sources related to the Spanish Statistics Institute. Conclusions We have provided an extensive directory of contextual indicators on social determinants of health and a database to facilitate assessment of the impact of the economic recession on health and health inequalities in Spain and its autonomous region
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