Showing papers by "Instituto Tecnológico de Morelia published in 2009"
TL;DR: In this article, an ammonia-free chemical-bath deposition was used to obtain CdSe thin films on glass substrate, which were characterized by optical absorption, SEM with the energy dispersive X-ray analysis (EDS) and Xray diffraction.
54 citations
TL;DR: In this article, the authors use discrete event system simulation to study the interactions among fuel and electricity markets and consumers, and the decision-making processes of fuel companies (FUELCOs), GENCOs, and consumers in a simple artificial energy market.
10 citations
01 Jan 2009
TL;DR: Photoplethysmographic augmentation index has shown to be a noninvasive parameter for vascular assessments and was implemented in object-oriented programming C++.
Abstract: A computer based photoplethysmographic analyzer was developed. The signal was obtained by infrared light through the finger. It was converted into digital domain by a signal processing circuitry, which contains amplifying and filtering steps, a microcontroller and an analog to digital 16 bits converter. The acquired signal was displayed and analyzed. First, second and fourth derivatives of the signal were computed. The photoplethysmographic augmentation index was quantified by fourth derivative. The acquisition and mathematical processing programs were implemented in object-oriented programming C++. A study with 38 people, 19 healthy volunteers and 19 subjects with previously diagnosed cardiovascular disease (atherosclerosis, hypertension, diabetes mellitus) was carried out. A t-tested distribution between healthy volunteers and patients showed a significant differences in calculated parameters. Photoplethysmographic augmentation index has shown to be a noninvasive parameter for vascular assessments.
9 citations
Journal Article•
TL;DR: In this paper, the effect of cyclic loading and temperature on the stability of the residual stress field induced by LSP on 6061-T6 aluminum samples was examined and shown to decrease linearly with the logarithm of the number of cycles.
Abstract: The Laser shock processing (LSP) is a new surface treatment technique that induces a compressive residual stress field. This work examines the effect of cyclic loading and temperature on the stability of the stress field induced by LSP on 6061-T6 aluminum samples. Residual stress relaxation due to cyclic loading is reported for different stress amplitudes and temperatures. Due to the cyclic creep effect, the residual stress decreases linearly with the logarithm of the number of cycles, N.
6 citations
TL;DR: In this paper, the SCC susceptibility of API X60 pipeline steel in a soil solution by slow strain rate tests (SSRT), and surface fracture analysis was investigated, at strain rate of 25.4 × 10-6 mm/sec in a glass autoclave containing the soil solution called NS4 with pH of 3 and 10 at room temperature and 50°C.
Abstract: Stress corrosion cracking (SCC) susceptibility of API X60 pipeline steel in a soil solution by slow strain rate tests (SSRT), and surface fracture analysis was investigated. The SSRT were performed at strain rate of 25.4 × 10-6 mm/sec in a glass autoclave containing the soil solution called NS4 with pH of 3 and 10 at room temperature and 50°C. Both anodic and cathodic polarization potentials of 200 mV referred to Ecorr was applied. The results of ratio reduction area (RRA), time to failure ratio (TFR) and elongation plastic ratio (EPR) indicate that X60 pipeline steel was susceptible to SCC at pH 3 and cathodic polarization of -200 mV at room temperature and 50°C. Scanning electron microscopy (SEM) observations of these specimens showed a brittle type of fracture with transgranular appearance. The SCC process and mechanism of X60 steel into NS4 solution was hydrogen based mechanism. With the different applied potentials the dominance of SCC process changes. At low pH the temperature effect on SCC susceptibility is more noticeable at 20°C. However at high pH this effects changes, being the steel more susceptible to SCC at 50°C.
6 citations
18 May 2009
TL;DR: In this article, a new method of calculating parameters of electric arc model of SF6 power circuit breaker is proposed, which consists in the optimization of a theoretical function with respect to a group of parameters of model in order to achieve a better approximation to a set of experimental data.
Abstract: A new method of calculating parameters of electric arc model of SF6 power circuit breaker is proposed. The methodology consists in the optimization of a theoretical function with respect to a group of parameters of model in order to achieve a better approximation to a set of experimental data. The theoretical function is an asymptotic solution for the voltage that is obtained for a selected period of time. The developed method is applied to obtain the parameters of an arc model previously published in the literature. By means of a variation of the cooling power P 0 +P 1 iu, a new electric arc model is obtained including the additional parameters of model. The new model has a very compact form and results in a better correlation between the theoretical voltage curves and the experimental oscillograms.
5 citations
TL;DR: In this article, a special picture of quantum evolution in the phase-space representation is derived, where both the symbols of operators as well as the distribution density carry part of the time dependence.
4 citations
11 Dec 2009
TL;DR: In this article, the authors used genetic algorithms to simulate the trading behavior of artificial agents in the spot market and showed that high market prices do not necessarily mean market power exercise. But they did not discuss why electricity price in a day-ahead electricity market may exhibit peaks without representing market manipulation by any player.
Abstract: Electricity market price may not always be a reference to determine the existence of market power. This paper discusses why electricity price in a day-ahead electricity market may exhibit peaks without representing market manipulation by any of the players. We use Genetic Algorithms to simulate the trading behavior of artificial agents in the spot market. Two case studies are reported and the results show that high market prices do not necessarily mean market power exercise.
4 citations
TL;DR: In this paper, a unified formulation for solving the economic dispatch and reserve scheduling problems in electricity markets, in order to investigate the global efficiency of energy and reserve markets, is presented, which proves in a detailed way that these operated-simultaneously-markets provides more economical benefits for generation or distribution companies.
Abstract: Ancillary services costs were included within the energy price in the first electricity market models. In a decentralized electricity market, it is conceive to have a separate market for energy and each one of the Ancillary Services. However, when the problem is solved jointly it seems to be a better alternative to optimize resources. This paper presents a unified formulation for solving the economic dispatch and reserve scheduling problems in electricity markets, in order to investigate the global efficiency of energy and reserve markets. The formulation allows generation and distribution companies to offer in the market reserve services. Concluding remarks are offered about the results obtained, which proves in a detailed way that these operated-simultaneously-markets provides more economical benefits for generation or distribution companies.
2 citations
18 May 2009
TL;DR: In this article, a computer model for calculating surge distribution in power transformer windings is presented, based on multiconductor transmission line theory, considering each disk coil as the basic element for the analysis.
Abstract: In this work, a computer model for calculating surge distribution in power transformer windings is presented. The model is based on multiconductor transmission line theory, considering each disk coil as the basic element for the analysis. The electric parameters R, L, C and G are calculated by using conventional formulations. The electrical parameters are used for calculating modal parameters in order to represent the winding as a two port network. The transformer model is validated by means of a comparison between measured and calculated transient voltages in a phase winding with 34 coil disks, in a scaled down prototype of a power transformer.
2 citations
26 Jul 2009
TL;DR: In this article, a long-term expansion model for a generation company operating in the deregulated electricity industry is presented, taking into account uncertainties such as electricity demand, fuel cost, pricing, expansion rate and investment under different scenarios and time periods.
Abstract: Liberalization and privatization in the electricity industry have led to increased competition. At the same time, generation companies are now exposed more than ever to risk and uncertainties which they cannot pass through to their customers in the form price increases as in a regulated environment. The central challenge for electricity generators is to maximize profits under uncertainty. But this optimization is not possible without a thorough understanding of long term expansion planning and competitors' behavior. In this paper a long-term expansion model (excluding hydroelectric plants) for a generation company operating in the deregulated electricity industry is presented. The model takes into account uncertainties such as electricity demand, fuel cost, pricing, expansion rate and investment under different scenarios and time periods. Numerical examples are provided.
09 Oct 2009
TL;DR: In this paper, a long-term expansion model for GENCOs operating in the deregulated electricity environment is presented, which considers uncertainty, generation capacity limits, and expansion rate and investment during the expansion period.
Abstract: Traditionally, the objective in undertaking a Generation Expansion Planning (GEP) process has been to minimize the expected sum of yearly discounted costs (incorporate i.e., construction costs, operating costs, salvage value, etc.). Now, the objective is to apply GEP to today's competitive electricity markets in order to maximize the profits of individual GENCOs (i.e., the revenues based on market prices and capital and operating costs) and minimize the impacts of competitors' conflicting objectives. This paper introduces a long-term expansion model for GENCOs operating in the deregulated electricity environment. The model considers uncertainty, generation capacity limits, and expansion rate and investment during the expansion period. Numerical examples are provided.
09 Oct 2009
TL;DR: In this paper, a steady state performance analysis carried out to evaluate the operation and behavior of a two VSC-based level-level frequency converter working as a HVDC link is presented.
Abstract: This paper presents a steady state performance analysis carried out to evaluate the operation and behavior of a two VSC-based level–full scale frequency converter working as a HVDC link. The digital model has been implemented and evaluated using PSCAD/EMTDC©. The emphasis of this work has been put on evaluating the transferred active and reactive power from the rectifying station to the inverting station as well as the influence of the modulation index on the total harmonic distortion (THD).
08 Jun 2009
TL;DR: In this paper, a power management scheme in a multi-terminal DC transmission system for integration of large-scale wind farms spread over a wide area is proposed, where resistive fault current limiters are used to suppress the current to a reasonable level to enable disconnection of the faulty line.
Abstract: The paper focuses on a power management scheme in a multi-terminal DC transmission systems for integration of large-scale wind farms spread over a wide area. The proposed power management scheme addresses the reliability concerns in a multi-terminal DC transmission system in case of the most severe fault conditions, such as permanent fault in DC link and open circuit fault at the terminal of the grid-side converter. The primary objective of the proposed scheme is to avoid lost of wind farms power in case permanent faults by providing an alternative path for the power flow through a redundant path. In case of DC faults resistive fault current limiters were used to suppress the current to a reasonable level to enable disconnection of the faulty line. To validate the proposed scheme, a computer model has been built in Matlab-Simulink. Transient and permanent DC link faults are considered in order to demonstrate the effectiveness of the proposed power management scheme.
TL;DR: A model based on forward expectations (FE) is proposed as a learning approach, and through illustrative examples it is shown that the market equilibria found by the CV model are also obtained by the FE model.
23 Nov 2009
TL;DR: The authors presenta un analisis comparativo del clima de negocios entre China and Mexico, tomando como punto de partida un sondeo elaborado by Development Counsellors International (DCI), asi como the Reporte Doing Business 2010, recientemente publicado, buscando encontrar evidencia suficiente que permita establecer aspectos relacionados al nivel competitivo of cada pais, respecto a las oportunidades que ofrecen
Abstract: El presente trabajo presenta un analisis comparativo del clima de negocios entre los paises de China y Mexico, tomando como punto de partida un sondeo elaborado por Development Counsellors International (DCI), asi como el Reporte Doing Business 2010, recientemente publicado, buscando encontrar evidencia suficiente que permita establecer aspectos relacionados al nivel competitivo de cada pais, respecto a las oportunidades que ofrecen para invertir y generar negocios
09 Oct 2009
TL;DR: An integrated multiperiod supply-chain model which includes different types of transportation networks for fuel supply is presented, which considers the impact of reliable fuel supply networks on system reliability.
Abstract: The need for short-term generation scheduling with take-or-pay fuel supply contracts is of increased importance for the new restructured electricity industry. This paper presents an integrated multiperiod supply-chain model which includes different types of transportation networks for fuel supply. The model also considers the impact of reliable fuel supply networks on system reliability. Numerical examples are provided.
01 Jan 2009
TL;DR: This paper presents a high-gain observer implemented in its discrete and continuous-discrete versions and applies both algorithms to a distillation column that uses the Ethanol-Water binary mixture.
Abstract: In this paper we present a high-gain observer implemented in its discrete and continuous-discrete versions in order to compare the performance of both algorithms. The comparison is made considering the sampling time used to perform the observer’s correction stage in order to establish that the continuous-discrete observer is the best option when a low sampling time is used. Under this condition the continuous discrete observer can process data performing a reliable on-line estimation of the system (a slow dynamics of the process is required). We apply both algorithms to a distillation column that uses the Ethanol-Water binary mixture.
TL;DR: In this article, a kinetic study was performed on the growth of a reaction interlayer between molten Al and carbon steel substrates at temperatures between 665 to 820°C by holding Al/flux/steel assemblies, in a tube furnace, at temperature for times up to 120 min.
Abstract: A kinetic study was performed on the growth of a reaction interlayer between molten Al and carbon steel substrates at temperatures between 665 to 820°C by holding Al/flux/steel assemblies, in a tube furnace, at temperature for times up to 120 min An Ar atmosphere and a K-Al-F based flux were used to enable spreading of molten Al on the steel substrates Chemical and microstructural characterization of the samples revealed that the interlayer is composed of FeAl3 and Fe2Al5, being the second phase significantly thicker The Fe2Al5 phase grows toward the steel with a tongue like morphology Isothermal growth profiles of the reaction interlayer followed a parabolic behavior, meaning that at the beginning the reaction is very rapid and once that a continuous interlayer is formed the growth of the interlayer is controlled by interdifussion of species across the interlayer
28 Nov 2009
TL;DR: The competitividad depende, cada vez menos de la disminucion de costos en funcion de la abundancia de los recursos productivos, and cómo en mayor medida en el conocimiento y en la gestion de the tecnologia as discussed by the authors.
Abstract: La competitividad depende, cada vez menos de la disminucion de costos en funcion de la abundancia de los recursos productivos, y cada vez en mayor medida en el conocimiento y en la gestion de la tecnologia. Para la competitividad son mas relevantes las ventajas comparativas que las ventajas competitivas, las cuales se generan al interior de las empresas y las regiones que las cobijan, ademas para lograr el exito competitivo deben considerar criterios de competencia tales como calidad, el gasto en investigacion y desarrollo, el nivel de destreza de la fuerza de trabajo, atencion al cliente, tiempo de entrega y servicios despues de la venta.