Decentralised reliable guaranteed cost control of uncertain systems: an LMI design

© 2007 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The problem of designing a decentralised control scheme for a class of linear large scale interconnected systems with norm-bounded time-varying parameter uncertainties under a class of control failures is addressed. These failures are described by a model that considers possible outages or partial failures in every single actuator of each decentralised controller. The control design is performed through two steps. First, a decentralised reliable guaranteed cost control set is derived and, second, a feasible linear matrix inequalities procedure is presented for the effective construction of the control set. A numerical example illustrates the efficiency of the proposed control schemePeer ReviewedPostprint (published version

Economic Analysis of Biodiesel Production from Waste Vegetable Oil in Mexicali, Baja California

Mexicali, capital of Baja California, Mexico, has a motor vehicle fleet of diesel estimated at 14,000 units and cargo transport. The transport cargo sector with 11,861 units, consumes about 169 million liters of diesel. The diesel used in Baja California comes from southern Mexico and is one of the causes of CO2 emissions that affect air quality in Mexicali, it is therefore important to explore options for replacing it with biodiesel, which produces less CO2 and can be obtained from waste material. Thus, in the analysis, was considered the use of waste vegetable oil from the Mexicali restaurant industry as a raw material for the production of 4.78 million liters of biodiesel energy equivalent to 4.45 million liters of diesel. The environmental benefit involving the replacement of such a volume of diesel with biodiesel is to reduce emissions by about 9,700 tons of CO2, 22 tons of SOx and 11 tons of PM10. To determine the economic feasibility of producing biodiesel, were applied the methodologies of net present value and internal rate of return. The results indicate that the production of biodiesel is profitable. However, the recovery time of investment, coupled with the uncertainty presented by the biofuels market, make necessary a policy that implements local tax resources to support the promotion, production and use of biodiesel for the transport sector. Therefore, under the circumstances considered in this analysis, the production of biodiesel is feasible if it is developed a synergy among the productive sectors, education and government. Key words: Biodiesel; Economic analysis; Waste vegetable oil; Transport cargo secto

Mental health and migration: A qualitative study

La migración interregional de venezolanos en Latinoamérica se ha constituido en una problemática compleja y de difícil abordaje pues, pese a tener un impacto colectivo, también tiene implicaciones en la subjetividad de los migrantes, teniendo consecuencias en su salud mental. El presente estudio tuvo como objetivo comprender el impacto de la migración en la salud mental de venezolanos residentes en Quito-Ecuador, a partir de sus historias de vida. Se utilizó el método de historias de vida con ocho participantes migrantes venezolanos, mujeres y hombres mayores de edad que participaron voluntariamente en la investigación. Se generaron categorías de estudio en torno a los elementos asociados con el impacto psíquico de la migración, para posteriormente realizar un análisis de discurso. Este análisis permitió realizar un proceso de codificación que arrojó las siguientes categorías principales: “rol materno y paterno”, “condiciones vulnerables”, “inserción comunitaria”, “duelo”; y, “sentimientos de culpa y depresión”. Se concluyó que los elementos que han permitido a los migrantes simbolizar sus vivencias, se relacionan con sintomatología del estado de ánimo, insomnio y melancolía; lo que ha tenido consecuencias en la inserción de los participantes en el país de acogida y dificultades para relacionarse efectivamente con los miembros de la nueva cultura.The interregional migration of Venezuelans in Latin America has become a complex problem that is difficult to tackle because, despite having a collective impact, it also has implications on the subjectivity of migrants, having consequences on their mental health. The present study aimed to understand the impact of migration on the mental health of Venezuelans residing in Quito-Ecuador, based on their life stories. The life stories method was used with eight Venezuelan migrant participants, women and men of legal age who voluntarily participated in the research. Study categories were generated around the elements associated with the psychic impact of migration, to later carry out a discourse analysis. This analysis made it possible to carry out a coding process that yielded the following main categories: "maternal and paternal role", "vulnerable conditions", "community insertion", "grief"; and, "feelings of guilt and depression." It was concluded that the elements that have allowed migrants to symbolize their experiences are related to mood symptoms, insomnia and melancholy; This has had consequences on the insertion of the participants in the host country and difficulties in relating effectively with the members of the new culture.Fil: Montero Medina, Diana. Universidad Tecnologica Indoamerica.; Ecuador. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Psicología y Psicopedagogía; ArgentinaFil: Delfino, Gisela Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Psicología y Psicopedagogía. Centro de Investigaciones en Psicología y Psicopedagogía; Argentin

A velocity based active vibration control of hysteretic systems

Hysteresis is a property of systems that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state. A velocity based active vibration control, along with a special class of hysteretic models using passive functions are presented in this paper. This hysteretic model is based on a modification of the Bouc–Wen model, where a nonlinear term is replaced by a passive function. The proposed class retains the rate-independence property of the original Bouc–Wen model, and it is able to reproduce several kinds of hysteretic loops that cannot be reproduced with the original Bouc–Wen model. Using this class of hysteretic models, a chattering velocity-based active vibration control scheme is developed to mitigate seismic perturbations on hysteretic base-isolated structures. Our hysteretic model is used because of its simplicity in proving the stability of the closed-loop system; i.e., a controller is designed using the proposed model, and its performance is tested on the original hysteretic system, modeled with Bouc–Wen. Numerical experiments show the robustness and efficiency of the proposed control algorithm.Peer ReviewedPostprint (author's final draft

A velocity based active vibration control of hysteretic systems

Postprint (published version

Development and Implementation of Virtual Instrumentation for the Measurement of Operating Parameters of an Engine Using Diesel-Biodiesel Mixtures

Through a reaction of alkaline transesterification of soybean oil using sodium methoxide, biodiesel denominated as B100 was obtained, with which four mixtures of diesel-biodiesel B2, B5, B10, and B20 were prepared. Kinematic viscosity and high heating value of the four blends, B100, and diesel were determined. The blends, B100, and diesel were used in a motor of four cylinders in-line engine, air intake at atmospheric pressure with a power of 250 hp and 6000 cm3, operating at a constant rate of 850 ± 50 rpm, a temperature of 25°C, and a relative humidity of 50%. To monitor the emissions, rpm, fuel consumption, and temperature in the engine’s exhaust manifold, which operates with diesel-biodiesel mixtures, an integral instrument that uses the virtual instrumentation technology was developed in the programming platforms LabVIEW 2010 and ARDUINO. The development and implementation of the virtual instrument allow monitoring in real time the parameters of internal combustion engines and presents the versatility, flexibility, scalability, and capacity to function in equipment that operates with different liquid fuels at a lower cost than the one that conventional systems offered. These characteristics represent a significant benefit in comparison with the measurement and monitoring systems in the present market

SWOT Analysis Applied to Wheat Straw Utilization as a Biofuel in Mexico

Wheat is one of the main crops worldwide with a production of 733 million of tons by 2015. By 2013, the wheat grain production in Mexico was 3,357,307 t. Wheat straw is generated as a biomass waste once the wheat is harvested. However, the agricultural biomass waste has acquired international relevance as a source of bioenergy. The utilization of bioenergy has significant environmental benefits, and also economic benefits because the biomass waste is valorized as biofuel. The use of wheat straw as raw material for any productive process presents diverse factors that must be considered. Among those factors are the low density of biomass, handling and high transportation cost, an attractive heating value, and the physicochemical characterization. Therefore, the aim of this work was to apply the SWOT analysis to wheat straw utilization as a biofuel in Mexico. The main findings highlighted an estimation of 4,612,950.23 t of wheat straw generated. The experimental results of proximate analysis were 64.42% volatile matter, 19.49% fixed carbon and 16.09% ash. The higher heating was 14.86 MJ/kg. An energy potential of 69 PJ per agricultural cycle was calculated, equivalent to 19% of the biomass energy share reported in Mexico’s National Energy Balance, by 2014