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Fresnillo de González Echeverría, Mexico

Carrillo-Reyes J.,San Luis Potosi Institute of Scientific Research and Technology | Carrillo-Reyes J.,National Autonomous University of Mexico | Cortes-Carmona M.A.,San Luis Potosi Institute of Scientific Research and Technology | Cortes-Carmona M.A.,Technical University Zacatecas | And 2 more authors.
Renewable Energy | Year: 2016

Most of the fermentative hydrogen production studies based on mixed cultures have shown enrichment of the microbial community by means of a heat treatment. This heat treatment enrichment strategy selects for Clostridum spp., an efficient hydrogen producer; however, other bacteria that may contribute to the systems performance could be excluded. Another enrichment strategy based on high dilution rates selects different taxonomic groups, which may affect hydrogen production and the system stability. In this work, two enrichment strategies were evaluated, heat shock and cell wash-out, for hydrogen production and the system stability in continuous stirred reactors. The enriched communities were then inoculated in packed bed reactors and operated up to 70 days. Both strategies selected hydrogen producing bacteria, mainly Clostridium spp. The highest hydrogen production rate (6.01 L H2/L-d), molar yield (1.29 mol H2/mol glucoseconsumed), and stability were achieved by the wash-out procedure; this high performance was attributed to facultative bacteria like Lactobacillus and Lactococcus. Furthermore, there was a transition within the community (along the operation time in the reactor with cell wash-out inoculum) and a selection for methanogenic activity (due to the long solids retention time). © 2016 Elsevier Ltd. Source

Cruz O.,CIATEC | Santos R.,Technical University Zacatecas
IIE Annual Conference and Expo 2013 | Year: 2013

This article presents a choice to improve the process of assigning storage allocations in a warehouse. The main inconvenient frequently in these situations are, that existing techniques like model assignment or plant layout representations require the compliance of some assumptions that commonly do not appear in reality. Sometimes it is necessary to deal with complex and diverse variables that make the use of traditional tools difficult. Therefore, considering the complexity of the problem, this document is presented as an alternative to improve the mentioned process. The document is based on simulation using FLEXSIM® and artificial neural networks, considering the problem linearly separable. Source

Carrera J.L.E.,Technical University Zacatecas | Riesco J.M.A.,University of Guanajuato | Martinez S.M.,Autonomous University of Nuevo Leon | Sanchez F.A.C.,Autonomous University of Nuevo Leon | Gallegos A.M.,University of Guanajuato
Thermal Science | Year: 2013

The fuel called biogas is obtained through anaerobic digestion of different types of organic waste, providing a way to tap the energy stored in organic matter. The use of this fuel is also attractive from the standpoint of global warming because its application does not register a net emission of carbon dioxide into the atmosphere. One possible use for this fuel is to feed the spark-ignition internal combustion engines. In the present, there is little information available about the process of combustion in internal combustion engines fueled by biogas. The combustion process of an internal combustion engine ignition powered by biogas is characterized in terms of the duration of combustion, i. e., depending on the time elapsed while the reac-tants (methane and oxygen) are transformed into products (mainly carbon dioxide and water). This study numerically evaluates the way in which the geometrical parameters such as the compression ratio and operating parameters like engine speed, the excess air, the time of spark timing and carbon dioxide content of biogas affect the evolution of the combustion process. To carry out this study, a five factors and two levels experiment was designed and conducted, based on which, the most influential parameters were identified. Equations expressing the combustion characteristic parameters, as a function of the geometric and operation parameters of a spark ignited engines, are delivered as a result. Source

Rivera H.R.A.,National Research Center y Desarrollo Tecnologico | Ortega A.B.,National Research Center y Desarrollo Tecnologico | Bautista R.V.,University of Veracruz | Mendoza L.M.,University of Veracruz | Valdivia C.G.,Technical University Zacatecas
Proceedings - 2013 International Conference on Mechatronics, Electronics and Automotive Engineering, ICMEAE 2013 | Year: 2013

Rehabilitation is very important because it is the means by which functions are recovered injured joints or limbs, and if rehabilitation therapy begins immediately after the injury or some corrective surgery the chances of recovery increase significantly, this rehabilitation achieved with continuous passive motion (CPM). This article presents the design of an ankle rehabilitation CPM, are virtual design, prototyping and control to physical rehabilitation, also presents a preliminary study of myoelectric signals (EMG) showing the importance of rehabilitation CPM. © 2013 IEEE. Source

Valdivia C.H.G.,Technical University Zacatecas | Ortega A.B.,National Research Center y Desarrollo Tecnologico | M'Rquez E.Q.M.,National Research Center y Desarrollo Tecnologico | Salazar M.A.O.,National Research Center y Desarrollo Tecnologico
Proceedings - 8th International Conference on Intelligent Environments, IE 2012 | Year: 2012

In this research project we present the design and construction of a biped robot based on dynamic walking. The main objective of this research is the assimilation of technology in the field of dynamic walking robots, therefore, we built a prototype based on a previously built robot developed at Delft University created by Martjin Wisse. The reason for performing this research is to have a starting point in the development of bipedal robots and human prostheses. The robot was built under a mechatronic approach, i.e. with a synergical relationship between the mechanical, electronics and programming constituent parts. The prototype performes dynamic walking analogous to the locomotion of humans. It was concluded that these technologies can be used for the design, simulation and construction of dynamic walking robots. © 2012 IEEE. Source

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