Open-Access Issues in the Chilean Telecommunications and Electricity Sectors

Este trabajo analiza la crisis eléctrica de 1998-1999. Su principal conclusión es que el diagnóstico habitual que sostiene que ocurrió porque las empresas no invirtieron y el regulador no tenía atribuciones, es equivocado. A pesar de la peor sequía del siglo y de la falla de la central Nehuenco, los cortes de energía y el déficit agregado de 450 GWh se podrían haber evitado si el agua embalsada se hubiese manejado recientemente, o bien los reguladores hubiesen usado sus atribuciones para hacer funcionar el sistema de precios, o si el ejecutivo no hubiese temido afectar su imagen decretando racionamiento apenas las condiciones lo exigieran. Argumentamos que la variabilidad hidrológica a la que está sujeta Chile central hace inevitable las reducciones de consumo en años muy secos. Las crisis ocurren porque el sistema de precios es inflexible e inadecuado para acomodarlas sin cortes de energía; ante una escasez tanto usuarios como empresas enfrentan precios muy por debajo del costo de oportunidad de la energía. Esto, además, introduce un problema de moral hazard que incentiva el uso ineficiente del agua embalsada y hace más probable que ocurra una escasez. Es equivocado pensar que las crisis se evitarían dándole más atribuciones discrecionales al regulador. Varios episodios muestran que no usó las atribuciones que tenía. Al ejecutivo le incomoda zanjar conflictos entre privados porque sus intervenciones tienen consecuencias patrimoniales que lo dejan vulnerable a las críticas de quienes se sienten perjudicados. Por ello se debe liberar al regulador de la obligación de zanjar conflictos entre privados. Esto requiere liberalizar la regulación.

Failure Analysis of the Ulnar Collateral Ligament for Youth Baseball Pitchers

The objectives of this study were to (1) use kinetics from motion analysis and inverse dynamics to calculate the stress experienced by the ulnar collateral ligament (UCL) during a typical pitch cycle, (2) compare calculated maximum UCL pitching stresses to failure properties, and (3) investigate correlations between UCL stress with anthropometric and pitching biomechanical parameters. Prior motion analysis experiments of eighteen 10- to 11- year-old baseball pitchers throwing 10 fastballs were analyzed. Maximum internal elbow varus torques were calculated using inverse dynamics methods during a typical pitch cycle. Calculations used axial loading stress equations and maximum internal elbow varus torques to quantify the maximum UCL pitching stresses. UCL ultimate stresses and number of cycles to failure were calculated from prior studies with a scaling procedure to estimate youth participant values. The calculated maximum UCL pitching stresses were then compared to the estimated ultimate stresses using a paired t-test. The first major result of this study was that the maximum UCL pitching stresses were 33.83 MPa lower, on average, than the estimated ultimate stresses (p \u3c 0.001). A second major result of this study was the estimated average number of cycles to failure of the UCL were 80,000+ higher, on average, than the maximum season (p \u3c 0.001) and annual (p \u3c 0.001) pitch counts. A third major result of this study was maximum UCL pitching stresses were significantly and positively correlated with pitch speeds, maximum shoulder external rotation torque, and maximum elbow varus torque. These results suggest 10- to 11- year-old pitchers are not likely to experience a UCL injury. The findings of this study are supported by clinical observations of elbow injuries in youth pitchers occurring primarily in other tissues

Estudio y optimización sobre los costes de operación de una central de energía térmica

Este Trabajo Fin de Grado realiza dos propuestas de reducción de costes en la explotación de la caldera de biomasa, de una fábrica de tableros aglomerados de media densidad, que se encuentra en funcionamiento en la ciudad de Valladolid, que utiliza como combustible biomasa forestal residual de su materia prima. Las dos propuestas son: la inclusión de un recuperado de calor en los humos para precalentar el aire de combustión y la realización del procedimiento de mantenimiento preventivo de la caldera. El recuperador permitirá incrementar el rendimiento de la caldera y por lo tanto reducir el consumo de biomasa y el procedimiento de mantenimiento preventivo permitirá la reducción de costes de explotación.Departamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería en Tecnologías Industriale

La democracia como dictadura

In this essay I propose a radical demystification of the perceived image of Augusto Pinochet Ugarte’s Chilean dictatorship as a period of uniform terror that suffocated all popular contestation. Based on the differentiation of repressive styles and the popular responses to them, I propose that this perceived image has been artificially constructed in order to hide the historical continuity between Pinochet’s dictatorship and the current democratic regime. I relate this historic reconstruction to a more general thesis: I argue that there is an essential continuity between both political periods ruled by the deep dictatorial character of so-called current democratic regimes. To conclude I highlight the dictatorial mechanisms of current democracies as well as the political tasks that would allow for a progressive opposition to these same mechanisms.En este ensayo expongo una radical desmitificación de la imagen que se tiene de la dictadura chilena de Augusto Pinochet Ugarte, que es vista habitualmente como un período de terror uniforme y aplastante, que habría asfixiado todo protagonismo popular. A partir de la distinción de fases en los estilos represivos y en la respuesta popular, propongo que esta imagen ha sido construida artificialmente para encubrir la continuidad histórica entre la dictadura de Pinochet y el actual régimen democrático. Esta reconstrucción histórica la pongo luego en conexión con una tesis, más general: la continuidad esencial entre ambos períodos políticos obedece al carácter dictatorial profundo de los regímenes que actualmente se llaman democráticos. Expongo los mecanismos dictatoriales característicos de las democracias actuales, y planteo tareas políticas que permitirían a una oposición progresista oponerse a ellos

Development of Technologies for Local Composting of Food Waste From Universities

[Abstract] The amount of biowaste generated by university canteens (BWUC) in the faculties of the University of A Coruña (UDC) varies between 6 and 100 kg/day. In addition, the gardening services of the campus generate even higher amounts of garden waste (GrW), including pruning, which, once crushed, serves as bulking material for composting the biowaste from the canteens. Decentralized composting has been chosen with the aim of producing high quality organic fertilizers for university urban gardens while reducing the environmental burdens of both waste management and agricultural practice. Small static home composters of 340 L (SHC) for smaller amounts of generation (up to 20 kg BWUC/day) were used, while, for faculties of higher generation (up to 40 kg BWUC/day on average), the first composting stage was carried out in a closed and dynamic composter (DC). The dynamic composter was designed and built specifically for this project and its features were improved and optimized throughout the study. The pilot project was carried out in two centers of the UDC, which are known as the Philology Faculty (PF) and the School of Architecture (SA). All the organic waste generated by the canteens of these two colleges from January 2011 to July 2011 (approximately 3000 kg) was treated. Composting in SHC included a thermophilic phase that extended one month beyond the loading period for which thermophilic temperatures were also recorded. The use of the DC as the first stage in combination with static composters (SC) for the maturation stage reduced the overall thermophilic phase to 6–8 weeks. The complete maturation (Rottegrade class IV-V) was achieved after about four months in SHC and after two months when using the combined DC-SC system, if the right conditions of moisture were maintained. The chemical quality of the compost produced was compatible with Class A of Spanish legislation (equivalent to organic farmer quality) and the C/N ratio ranged from 9 to 15 depending on the relation BWUC:GrW