405 research outputs found

    Reflexiones sobre el liberalismo de Ludwig von Mises

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    The economic liberalism was the organizing principle of a society engaged in the creation of a market system. Born as a mere preference for non-bureaucratic methods, it evolved into a true faith in the secular salvation of man through a regulated market, said Karl Polanyi. This reflection paper, according to the reading of Ludwig von Mises, intends to show the conception of liberalism presented by Ludwig von Mises, and then to propose some elements of debate, not with the pretension of exhausting the discussion or proposing conclusive ideas on the subject, but rather with the intention of contributing ideas to These current thorny issues.El liberalismo económico fue el principio organizador de una sociedad dedicada a la creación de un sistema de mercado. Nacido como una mera preferencia por los métodos no burocráticos, se convirtió en una verdadera fe en la salvación secular del hombre a través de un mercado regulado, dijo Karl Polanyi. Este documento de reflexión, pretende mostrar la concepción del liberalismo presentada por Ludwig von Mises, y luego proponer algunos elementos de debate, no con la pretensión de agotar la discusión o proponer ideas concluyentes sobre su pensamiento, sino más bien con la intención de aportar ideas a estos actuales temas espinosos

    Trajectory Reconstruction and Uncertainty Analysis Using Mars Science Laboratory Pre-Flight Scale Model Aeroballistic Testing

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    As part of the Mars Science Laboratory (MSL) trajectory reconstruction effort at NASA Langley Research Center, free-flight aeroballistic experiments of instrumented MSL scale models was conducted at Aberdeen Proving Ground in Maryland. The models carried an inertial measurement unit (IMU) and a flush air data system (FADS) similar to the MSL Entry Atmospheric Data System (MEADS) that provided data types similar to those from the MSL entry. Multiple sources of redundant data were available, including tracking radar and on-board magnetometers. These experimental data enabled the testing and validation of the various tools and methodologies that will be used for MSL trajectory reconstruction. The aerodynamic parameters Mach number, angle of attack, and sideslip angle were estimated using minimum variance with a priori to combine the pressure data and pre-flight computational fluid dynamics (CFD) data. Both linear and non-linear pressure model terms were also estimated for each pressure transducer as a measure of the errors introduced by CFD and transducer calibration. Parameter uncertainties were estimated using a "consider parameters" approach

    La Accesibilidad Universal en Sevilla para las personas con diversidad funcional

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    El tema en el que se ha enfocado mi reportaje de investigación es el análisis del estado en el que se encuentra la accesibilidad universal de la ciudad de Sevilla para las personas con diversidad funcional, con el objetivo de demostrar la falta de accesibilidad que existe en ella, la cual dificulta y en muchos casos impiden a las personas que tienen problemas físicos, visuales, auditivos o cognitivos, moverse por las calles de la ciudad, entrar en sus comercios y edificios públicos o utilizar el transporte. Además de contribuir a la reivindicación a través de la labor periodística investigadora llevada a cabo, para que las administraciones públicas apliquen la accesibilidad universal en la capital andaluza y garanticen el derecho a la igualdad de oportunidades de las personas con diversidad funcional. Pretendiendo de esta manera que mi reportaje de investigación cumpliera con la función social de ayudar a las personas con diversidad funcional y concienciar al resto de la sociedad de la importancia que tiene para todo el mundo la accesibilidad universal. Querido contribuir de este modo a la reivindicación de la aplicación de la accesibilidad universal en la capital andaluza para que no se siga vulnerando el derecho a la igualdad de oportunidades de las personas con diversidad funcional.Universidad de Sevilla. Grado en Periodism

    Influencia de la vegetación sobre la calidad de un suelo tropical degradado.

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    The influence of various plant species, two leguminous trees (Andira inermes and Albizia procera), two leguminous covercrops (Arachis glabrata and Centrosema acutifolium), and two grasses (Brachiaria humidicola and Hemarthria altissima), on the soil microbial biomass and abiotic parameters, was evaluated in a highly eroded tropical soil of the Corozal series (clayey, mixed isohyperthermic Aquic Haplohumults). Soil samples were taken monthly at two depths (0- to 5- and 5- to 15-cm) from September 1999 to July 2000. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), potentially mineralizable N, extractable N, soil organic matter (SOM), and total organic nitrogen (TON) were significantly greater under grasses. Microbial pools and activities were generally higher at the 0- to 5-cm depth. Soil respiration was significantly affected by plant species and date of sampling; in general, soils under grasses had the highest values. The mean proportions of microbial biomass comprising total organic C and N were 2.8 and 1.4%, respectively, in vegetated soils; higher values for C were observed in bare soil. There was a decrease in the mineralizable C proportion of MBC (respiratory quotient) with increasing MBC values. The lowest respiratory quotients were observed for soils under grasses. In this study, soil ecosystem health appears to benefit from vegetation, with soils under grasses exhibiting improved stability due to higher SOM, TON, biologically active C and N pools and lower relative C losses.Se evaluó la influencia de diferentes materiales vegetativos [dos leguminosas arbóreas (Andira inermes y Albizia procera), dos leguminosas coberturas (Arachis glabrata y Centrosema acutifolium) y dos gramíneas (Brachiaria humidicola y Hemarthria altissima)] sobre la biomasa microbiana y parámetros abióticos en un suelo altamente erodado de la serie Corozal (arcilloso, mixto isohipertérmico Aquic Haplohumults). Mensualmente se tomaron muestras de suelos a dos profundidades (0- a 5- y 5- a 15- cm) por un período de once meses. Los valores de la biomasa microbiana de carbono (BMC), la biomasa microbiana de nitrógeno (BMN), N extraíble, N total y la materia orgánica del suelo fueron mayores (P menor que 0.05) en suelos bajo gramíneas como grupo. La reserva microbiana de C y N y su actividad fue mayor a la profundidad de 0- a 5-cm. La respiración microbiana fue afectada significativamente por las especies y el tiempo, siendo los valores mayores en suelo bajo gramíneas. La biomasa microbiana de C y N fue un 2.8 y 1.4% de la totalidad del C y N orgánico del suelo, con valores mayores para C en suelos desnudos (control). El cociente de respiración (C mineralizable/BMC) disminuyó al aumentar la biomasa microbiana y los valores más bajos se obtuvieron en suelos bajo gramíneas. En este estudio, las propiedades que describen la salud del ecosistema del suelo exhiben una posible mejoría debido a la vegetación, con suelos bajo gramíneas manifestando mayor estabilidad debido a mayor contenido de materia orgánica, nitrógeno total, reservas biológicamente activas y pérdidas de C relativamente menores

    Challenges for the colombian central government in post-agreement financing

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    El presente artículo de investigación analiza las dificultades en el aumento de ingresos del gobierno central en un entorno de post-acuerdo. A través de un análisis de componentes principales y hechos estilizados se encuentra que no existen suficientes recursos monetarios disponibles para ejecutar el acuerdo de paz. Esto puede resultar en una implementación incompleta de los acuerdos que implique una revisión del gasto público en educación, sistema pensional, sistema sanitario, economía rural, servicio de deuda, infraestructuras de transporte y el fortalecimiento de la DIAN para incrementar y redistribuir la carga tributaria.This paper analyzes the difficulties in raising tax revenue for the central government in a post-agreement era. Through an analysis of main components and stylized facts it is found that there are not enough monetary resources available to implement the peace agreement. This may result inan incomplete implementation of the agreement and a revision of public spending in education, pension system, health system, rural economy, debt service, transport infrastructure and strengthening the DIAN to increase and redistribute the tax burden

    Determinantes de la competitividad de las exportaciones mundiales de aceite de palma : un análisis de cointegración 2007-2015

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    El propósito de este trabajo es examinar la relación a largo plazo entre el tipo de cambio nominal, los precios internacionales del aceite de palma, de sus sustitutos y sus complementarios en la competitividad de las exportaciones del sector aceite de palma, para 26 países, incluido Colombia, durante todos los meses del periodo 2007-2015. Se aplicaron las pruebas de raíz unitaria y cointegación para el modelo FMOLS y DOLS de datos de panel con series de tiempo. Los resultados mostraron que sólo 9 países presentaron ventajas comparativas, ocupando el puesto 8 y 9, Colombia, al invertir menos y exportar casi todo en la Costa Caribe. Se encontró en todo el panel que el aumento del tipo de cambio, el precio del biodiesel y de la soya favoreció su competitividad, así mismo la disminución de su precio y del aceite vegetal. De igual forma, dividiéndose el panel en dos grupos, se evidencia el efecto de convergencia, siendo el impacto mayor en los países en desarrollo, intensivos en mano de obra, que en los desarrollados, intensivos en capital, dado que el producto es más abundante en los países en desarrollo, donde presenta ventajas comparativas, en cuanto a la tierra, las condiciones naturales y climáticas, los bajos costos de la mano de obra y su especialización en la exportación de bienes primarios e intermedios de este sector

    Human Mars Entry, Descent and Landing Architecture Study: Deployable Decelerators

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    NASAs Entry, Descent and Landing Architecture Study uses a trajectory simulation framework to evaluate various technologies and concepts of operations for human scale EDL at Mars. The study results inform agency technology investments. This paper summarizes the design assumptions and analysis of two deployable entry concepts performed in Phase 2 of the study. The entry concepts include a rigid deployable called the Adaptable Deployable Entry Placement Technology and an inflatable concept called the Hypersonic Inflatable Aerodynamic Decelerator. This paper describes the concept operations of these vehicles to deliver a 20-metric ton payload to the surface of Mars. Details of vehicle design and flight performance are summarized along with results of analysis on the aft body heating and its effect on the payload. Finally, recommended technology investments based on the results are presented

    Deployable Aeroshell Flexible Thermal Protection System Testing

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    Deployable aeroshells offer the promise of achieving larger aeroshell surface areas for entry vehicles than otherwise attainable without deployment. With the larger surface area comes the ability to decelerate high-mass entry vehicles at relatively low ballistic coefficients. However, for an aeroshell to perform even at the low ballistic coefficients attainable with deployable aeroshells, a flexible thermal protection system (TPS) is required that is capable of surviving reasonably high heat flux and durable enough to survive the rigors of construction handling, high density packing, deployment, aerodynamic loading and aerothermal heating. The Program for the Advancement of Inflatable Decelerators for Atmospheric Entry (PAIDAE) is tasked with developing the technologies required to increase the technology readiness level (TRL) of inflatable deployable aeroshells, and one of several of the technologies PAIDAE is developing for use on inflatable aeroshells is flexible TPS. Several flexible TPS layups were designed, based on commercially available materials, and tested in NASA Langley Research Center's 8 Foot High Temperature Tunnel (8ft HTT). The TPS layups were designed for, and tested at three different conditions that are representative of conditions seen in entry simulation analyses of inflatable aeroshell concepts. Two conditions were produced in a single run with a sting-mounted dual wedge test fixture. The dual wedge test fixture had one row of sample mounting locations (forward) at about half the running length of the top surface of the wedge. At about two thirds of the running length of the wedge, a second test surface drafted up at five degrees relative to the first test surface established the remaining running length of the wedge test fixture. A second row of sample mounting locations (aft) was positioned in the middle of the running length of the second test surface. Once the desired flow conditions were established in the test section the dual wedge test fixture, oriented at 5 degrees angle of attack down, was injected into the flow. In this configuration the aft sample mounting location was subjected to roughly twice the heat flux and surface pressure of the forward mounting location. The tunnel was run at two different conditions for the test series: 1) 'Low Pressure', and 2) 'High Pressure'. At 'Low Pressure' conditions the TPS layups were tested at 6W/cm2 and 11W/cm2 while at 'High Pressure' conditions the TPS layups were tested at 11W/cm2 and 20W/cm2. This paper details the test configuration of the TPS samples in the 8Ft HTT, the sample holder assembly, TPS sample layup construction, sample instrumentation, results from this testing, as well as lessons learned

    La inconstitucionalidad del desacato y el derecho a la libertad de expresión

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    Sumario: I.¿Qué es el delito de desacato? 1. La definición del delito de desacato. 2. El delito de desacato en el derecho internacional de los derechos humanos. 3. El delito de desacato en el Código Penal ecuatoriano. 4. Características del delito de desacato. 5. Conclusión. II. ¿Cuál es la relación entre libertad de expresión y sociedad democrática? 1. La libertad de expresión y la democracia en la Constitución. 2. La libertad de expresión y su función instrumental para el ejercicio de los derechos a la autonomía individual y a la deliberación colectiva. 3. La libertad de expresión: el ideal de ciudadano deliberante y las instituciones necesarias para realizarlo. 4. Conclusiones. III. ¿Son compatibles las leyes de desacato con la libertad de expresión en una sociedad democrática? 1. La solución de antinomias y el principio de proporcionalidad. 2. Conclusión. IV. Bibliografía

    A Robust Method to Integrate End-to-End Mission Architecture Optimization Tools

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    End-to-end mission simulations include multiple phases of flight. For example, an end-to-end Mars mission simulation may include launch from Earth, interplanetary transit to Mars and entry, descent and landing. Each phase of flight is optimized to meet specified constraints and often depend on and impact subsequent phases. The design and optimization tools and methodologies used to combine different aspects of end-to-end framework and their impact on mission planning are presented. This work focuses on a robust implementation of a Multidisciplinary Design Analysis and Optimization (MDAO) method that offers the flexibility to quickly adapt to changing mission design requirements. Different simulations tailored to the liftoff, ascent, and atmospheric entry phases of a trajectory are integrated and optimized in the MDAO program Isight, which provides the user a graphical interface to link simulation inputs and outputs. This approach provides many advantages to mission planners, as it is easily adapted to different mission scenarios and can improve the understanding of the integrated system performance within a particular mission configuration. A Mars direct entry mission using the Space Launch System (SLS) is presented as a generic end-to-end case study. For the given launch period, the SLS launch performance is traded for improved orbit geometry alignment, resulting in an optimized a net payload that is comparable to that in the SLS Mission Planner's Guide
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