Time filter

Source Type

Pena R.,University La Cienega Del Estado Of Michoacan Of Ocampo | Medina A.,Universidad Michoacana de San Nicolas de Hidalgo
2012 North American Power Symposium, NAPS 2012 | Year: 2012

This paper deals with the simulation of a power system including renewable energy sources under transient conditions. Hydraulic and wind generation sources are considered. The simulations were carried-out in a specialized computer hardware, RTDS, specifically designed for the real time solution of electromagnetic transients. Power system components were represented using the RSCAD software. © 2012 IEEE.

Ramirez G.,National Autonomous University of Mexico | Nunez J.,University La Cienega Del Estado Of Michoacan Of Ocampo | Hernandez G.N.,National Autonomous University of Mexico | Hernandez-Cruz G.,National Autonomous University of Mexico | Ramos E.,National Autonomous University of Mexico
Review of Scientific Instruments | Year: 2015

We describe a device designed and built to obtain the three-component, steady state velocity field in the whole volume occupied by a fluid in motion contained in a cavity with cylindrical walls. The prototype comprises a two-camera stereoscopic particle image velocimetry system mounted on a platform that rotates around the volume under analysis and a slip ring arrangement that transmits data from the rotating sensors to the data storage elements. Sample observations are presented for natural convection in a cylindrical container but other flows can be analyzed. © 2015 AIP Publishing LLC.

Pottosin I.,University of Colima | Pottosin I.,University of Tasmania | Velarde-Buendia A.M.,University of Colima | Bose J.,University of Tasmania | And 3 more authors.
Journal of Experimental Botany | Year: 2014

Many stresses are associated with increased accumulation of reactive oxygen species (ROS) and polyamines (PAs). PAs act as ROS scavengers, but export of putrescine and/or PAs to the apoplast and their catabolization by amine oxidases gives rise to H2O2 and other ROS, including hydroxyl radicals (•OH). PA catabolization-based signalling in apoplast is implemented in plant development and programmed cell death and in plant responses to a variety of biotic and abiotic stresses. Central to ROS signalling is the induction of Ca2+ influx across the plasma membrane. Different ion conductances may be activated, depending on ROS, plant species, and tissue. Both H2O2 and •OH can activate hyperpolarization-activated Ca2+-permeable channels. •OH is also able to activate both outward K+ current and weakly voltage-dependent conductance (ROSIC), with a variable cation-to-anion selectivity and sensitive to a variety of cation and anion channel blockers. Unexpectedly, PAs potentiated •OH-induced K+ efflux in vivo, as well as ROSIC in isolated protoplasts. This synergistic effect is restricted to the mature root zone and is more pronounced in salt-sensitive cultivars compared with salt-tolerant ones. ROS and PAs suppress the activity of some constitutively expressed K+ and non-selective cation channels. In addition, both •OH and PAs activate plasma membrane Ca2+-ATPase and affect H+ pumping. Overall, •OH and PAs may provoke a substantial remodelling of cation and anion conductance at the plasma membrane and affect Ca2+ signalling. © The Author 2014.

Barragan R.M.,Electric Research Institute of Mexico | Nunez J.,University La Cienega Del Estado Of Michoacan Of Ocampo | Arellano V.M.,Electric Research Institute of Mexico | Nieva D.,Electric Research Institute of Mexico
Computers and Geosciences | Year: 2016

Exploration and exploitation of geothermal resources require the estimation of important physical characteristics of reservoirs including temperatures, pressures and in situ two-phase conditions, in order to evaluate possible uses and/or investigate changes due to exploitation. As at relatively high temperatures (>150°C) reservoir fluids usually attain chemical equilibrium in contact with hot rocks, different models based on the chemistry of fluids have been developed that allow deep conditions to be estimated. Currently either in water-dominated or steam-dominated reservoirs the chemistry of steam has been useful for working out reservoir conditions. In this context, three methods based on the Fischer-Tropsch (FT) and combined H2S-H2 (HSH) mineral-gas reactions have been developed for estimating temperatures and the quality of the in situ two-phase mixture prevailing in the reservoir. For these methods the mineral buffers considered to be controlling H2S-H2 composition of fluids are as follows. The pyrite-magnetite buffer (FT-HSH1); the pyrite-hematite buffer (FT-HSH2) and the pyrite-pyrrhotite buffer (FT-HSH3). Currently from such models the estimations of both, temperature and steam fraction in the two-phase fluid are obtained graphically by using a blank diagram with a background theoretical solution as reference. Thus large errors are involved since the isotherms are highly nonlinear functions while reservoir steam fractions are taken from a logarithmic scale. In order to facilitate the use of the three FT-HSH methods and minimize visual interpolation errors, the EQUILGAS program that numerically solves the equations of the FT-HSH methods was developed. In this work the FT-HSH methods and the EQUILGAS program are described. Illustrative examples for Mexican fields are also given in order to help the users in deciding which method could be more suitable for every specific data set. © 2015 Elsevier Ltd.

Fuentes-Cortes L.F.,Universidad Michoacana de San Nicolas de Hidalgo | Avila-Hernandez A.,University La Cienega Del Estado Of Michoacan Of Ocampo | Serna-Gonzalez M.,Universidad Michoacana de San Nicolas de Hidalgo | Ponce-Ortega J.M.,Universidad Michoacana de San Nicolas de Hidalgo
Applied Thermal Engineering | Year: 2015

(Graph Presented) This paper presents a methodology based on multi-objective optimization techniques for designing residential cogeneration systems. There is proposed an integrated system to provide hot water and electricity for domestic use in a residential complex. The accounted objective functions are the minimization of the total annual cost and the generated greenhouse gas emissions. As optimization decisions are considered the operating regime and sizing of the central generation power equipment (in this case, an internal combustion engine) and the thermal storage tank. The model takes into account the time variation of the energy demands, different rates of purchase - sale of electricity and seasonal temperature changes. Two different residential complexes from Mexico with different weather and energy demands were considered as case studies. Significant economic and environmental benefits were identified by applying the proposed methodology. © 2015 Elsevier Ltd. All rights reserved.

Discover hidden collaborations