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Camposeco-Negrete C.,ITESM Campus Estado de Mexico
Journal of Cleaner Production | Year: 2013

Machine tools are responsible for environmental impacts owing to their energy consumption. Cutting parameters have been optimized to minimize cutting power, power consumed or cutting energy. However, these response variables do not consider the energy demand that ensures the readiness of the machine tool. The present paper outlines an experimental study to optimize cutting parameters during turning of AISI 6061 T6 under roughing conditions in order to get the minimum energy consumption. An orthogonal array, signal to noise (S/N) ratio and analysis of variance (ANOVA) were employed to analyze the effects and contributions of depth of cut, feed rate and cutting speed on the response variable. A comparison was done to highlight the importance of correctly selecting the response variable to be analyzed, due to the difference of the values of cutting parameters needed to optimize cutting power, cutting energy, power consumed and energy consumed during the machining process. Additional, the relationship between cutting parameters, energy consumption, and surface roughness was analyzed in order to determine the levels of the cutting parameters that lead to minimum energy consumption and minimum surface roughness. The results of this research work showed that feed rate is the most significant factor for minimizing energy consumption and surface roughness. Nevertheless, the level of this factor needed to achieve minimum energy consumption is not the same as the one needed to obtain minimum surface roughness. Higher feed rate provides minimum energy consumption but will lead to higher surface roughness. © 2013 Elsevier Ltd. All rights reserved. Source

Modern production is faced with the challenge of reducing the environmental impacts related to machining processes. Machine tools consume large amounts of energy and, as a consequence, environmental impacts are generated owing to this consumption. Many studies have been carried out in order to minimize cutting power, cutting energy or power consumed by the machine tool. Nevertheless, the response variables mentioned before do not take into account the energy required by all the components inside the machine tool during the cutting operation. This paper presents an experimental study related to the optimization of cutting parameters in roughing turning of AISI 6061 T6 aluminum. Energy consumption and surface roughness were minimized, while the material removal rate of the process was maximized. A set of experimental runs was established using a Central Composite Design, and the Response Surface Method was employed to obtain the regression model for the energy consumed during machining, specific energy, surface roughness and material removal rate. The adequacy of the model was proved by Analysis of Variance analysis. The relationship between cutting parameters and the response variables (energy consumption, surface roughness and material removal rate) was analyzed using contour plots. Moreover, the desirability method was used to define the values of the variables that achieved a minimum quantity of specific energy consumed and minimum surface roughness. Feed rate and depth of cut were the most significant factors for minimizing the total specific energy consumed, and for minimizing the surface roughness, feed rate was the most significant factor. Compared to the traditional objective optimization, the optimal turning parameters determined by the proposed optimization method reduced the energy consumption in 14.41%, and the surface roughness in 360.47%. Consequently, sustainability and quality of the machining process were achieved at the same time. © 2014 Elsevier Ltd. All rights reserved. Source

Bermeo N.V.,ITESM Campus Estado de Mexico | Mendoza M.G.,ITESM Campus Estado de Mexico | Castro A.G.,Florida State University
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The design process of a product is iterative due to a series of changes that range from client specifications to quality defects. From each of such changes, designers end up with a considerable amount of design files, additionally, if files have to be exchanged with other partners they have to be translated based on the available neutral file formats. In order to identify specific elements stored on the resulting translated files, the designer needs to make use of a CAD system. If the amount of files to consult is significant, the task becomes excessively time consuming. The approach presented here, focuses on the creation of semantic models providing the user; query capabilities over a collection of CAD models in order to identify a specific design based on particular conditions along with exploration capabilities to detect key elements from any IGES CAD file. Both capabilities possible without the need of using a CAD system. © Springer-Verlag 2013. Source

Kirschel A.N.G.,University of Cyprus | Kirschel A.N.G.,University of California at Los Angeles | Kirschel A.N.G.,University of Oxford | Cody M.L.,University of California at Los Angeles | And 4 more authors.
Ibis | Year: 2011

The ability to monitor interactions between individuals over time can provide us with information on life histories, mating systems, behavioural interactions between individuals and ecological interactions with the environment. Tracking individuals over time has traditionally been a time- and often a cost-intensive exercise, and certain types of animals are particularly hard to monitor. Here we use canonical discriminant analysis (CDA) to identify individual Mexican Ant-thrushes using data extracted with a semi-automated procedure from song recordings. We test the ability of CDA to identify individuals over time, using recordings obtained over a 4-year period. CDA correctly identified songs of 12 individual birds 93.3% of the time from recordings in one year (2009), while including songs of 18 individuals as training data. Predicting singers in one year using recordings from other years indicated some instances of variation, with correct classification in the range of 67-88%; one individual was responsible for the great majority (66%) of classification errors. We produce temporal maps of the study plot showing that considerably more information was provided by identifying individuals from their songs than by ringing and re-sighting colour-ringed individuals. The spatial data show site fidelity in males, but medium-term pair bonds and an apparently large number of female floaters. Recordings can be used to monitor intra- and intersexual interactions of animals, their movements over time, their interactions with the environment and their population dynamics. © 2011 The Authors. Journal compilation © 2011 British Ornithologists' Union. Source

Moreno-Rios M.,National Polytechnic Institute of Mexico | Gallardo-Hernandez E.A.,National Polytechnic Institute of Mexico | Vite-Torres M.,National Polytechnic Institute of Mexico | Pena-Bautista A.,ITESM Campus Estado de Mexico
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2016

The aim of this work was to prove that the oil applied to the wheel flange using on-board lubricators not only alters the friction coefficient between wheel and rail but also influences the braking and acceleration performance of trains on one of the lines of the metro in Mexico City. A series of tests were carried out in the presence of an oil lubricant, both in the laboratory and in the field, using a pendulum tester. It was observed that the oil migrated from the rail corner to the top of the rail. In another set of experiments, water was sprayed onto the lubricant on the top of the rail. The results indicated that under these conditions, the friction coefficient has a low value in rail sections where a high value of the friction coefficient is required. Tests with water/oil mixtures presented similar levels of friction to the oil-only tests. A set of tests were performed after the rail surface was cleaned and the oil lubricant and water were applied together. The laboratory and field tests showed similar behaviour trends for the friction coefficient. The pendulum method can be used to assess railhead friction on short-length sections of rail. Points are made regarding the conditioning of the pads and calibration of the pendulum arm. © 2014 Institution of Mechanical Engineers. Source

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