Repositorio Institucional del Tecnológico de Monterrey

 

 

Bienvenido al Repositorio Institucional que tiene como propósito ser el sitio centralizado que preserva, organiza y garantiza la visibilidad y acceso a la producción científica, de recursos y de objetos de aprendizaje generados por la comunidad académica de la Institución; así como también colecciones especiales y obras artísticas que se encuentran bajo su resguardo y que están disponibles en Acceso Abierto.

El acceso al contenido completo de los objetos de aprendizaje digitales hace que el Repositorio Institucional se constituya como una pieza de apoyo fundamental y de proyección internacional para la enseñanza y la investigación, a la vez que multiplica la visibilidad institucional y de la comunidad académica de la Institución que aquí publican.

Aquí encontrarás las siguientes Comunidades.

 

 

  • Equilibrios de poder en las entidades federativas. Estudio longitudinal de las legislaturas locales en México en el periodo 2000-2014

    Montero Bagatella, Juan Carlos; Tecnologico de Monterrey (Universidad Autónoma de Guanajuato, 2014-07-01)
    Las entidades federativas reprodujeron el diseño institucional del presidencialismo mexicano. Sin embargo, no han reproducido de la misma manera el proceso de democratización. Este artículo analiza los incentivos que tiene el poder legislativo en las entidades federativas en México para servir de contrapeso frente al ejecutivo, a partir de una revisión teórica sobre los incentivos que genera el diseño del sistema presidencial. Entre los principales hallazgos se identifica que en la mayoría de los estados existen contextos que incentivan el fortalecimiento de los legislativos, así como la identificación de casos excepcionales en donde los contextos plurales se constituyen como amenazas para la gobernabilidad o los de bajo nivel de pluralidad que generan incentivos para la concentración del poder en los gobernadores.
  • Caracterización de emulsiones preparadas mediante un inversor de flujo helicoidal

    López Salinas, José Luis; de la Herrán-Zambada, Mariandrea; Rivera Solorio, Carlos Iván; García Cuéllar, Alejandro Javier (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05)
    In the present work the effect of two emulsifiers in colloidal dispersion (oil / water) was studied using different preparation techniques. The emulsifiers analyzed were hydrophilic silica particles and sodium dodecyl sulfate. Both emulsifiers were previously dispersed using an ultrasonic bath and ultrasonic tip as preparation technique to evaluate the effect in the colloidal dispersion. According to the particle size distribution of each emulsifier, it was found that the ultrasonic tip offers more stability on aqueous dispersion because of the measurements reproducibility. The concentration effects of the silica particles and sodium dodecyl sulfate were studied measuring oil-water glass contact angle and oil-water interfacial tension. Samples were prepared using an ultrasonic tip, a coiled flow inverter and helical pipe. Experimental results suggest that silica particle concentration does not influence the interfacial tension and the contact angle in the oil-water system. The results also show that the interaction between surfactant and silica particle is affected by the mixing conditions during the colloidal dispersion process. Emulsions prepared with the ultrasonic tip show a strong interaction between both emulsifiers surfactant and silica particles, on the other hand, the coiled flow inverter and the helical pipe used under the laminar flow conditions show moderate and almost equal interaction between both emulsifiers according to droplet size distribution measures.
  • Metodología de cálculo de las curvas de demanda de reserva para el mercado eléctrico mexicano

    Llamas Terrés, Armando; Perales-Martínez, Favio; Lezama-Lope, Uriel; Sánchez-Meléndez, David; Llamas-Terrés, Armando; Perales-Martínez, Favio; Lezama-Lope, Uriel (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-14)
    The energy reform to the Mexican electricity sector established the creation of a Wholesale Electricity Market (WEM) which seeks to optimize the production and supply of electric energy by minimizing costs and maximizing the social benefit of all market participants, taking care, at all times, of the reliability of the Electric Power System (EPS) A fundamental safety condition in an EPS is to maintain the equilibrium or constant balance between generation and demand, however, imbalances can occur as a consequence of forecast errors, forced outputs of generators, unexpected variations in demand and volatility in an unconventional generation such as solar and wind generation. These variations between generation and demand must be addressed quickly for which the Market Operator makes use of extra generation capacity known as Operating Reserve. The integration of renewable energies, photovoltaic and wind, besides being friendly to the environment, have multiple benefits in the electricity markets, one of them is the direct impact in reducing costs of generation of electric power, however, this type of technology has a high degree of uncertainty as it is directly dependent on weather conditions, making that the reliability of the EPS is compromised. Given a scenario of high penetration with these sources, adequate operational reserves must be available to deal with all possible operational scenarios. The WEM requires adequate price signals for the participants to indicate them when and where to invest in new generation capacity, also market mechanisms are required to dictate the correct price of the extra capacity as an operating reserve based on the benefit that it provides in the improvement of the reliability and safety of the EPS. The Reserve Demand Curves (RDC) are a dynamic mechanism for the evaluation of the adequate requirements of the reserve that the system requires due to they are obtained taking into account the different sources of uncertainty of the system that cause imbalances between generation and demand, besides they set an adequate price to the reserve based on its contribution in the improvement of the reliability of the system giving clear signals of the real condition of the system through its impact on the Local Marginal Price (LMP)  
  • Immunoaffinity aqueous two-phase systems to establish novel bioprocesses for the primary recovery of CD133+ stem cells

    Rito Palomares, Marco Antonio; Zavala Arcos, Judith; González González, Mirna Alejandra; Ornelas González, Alonso; Rito Palomares, Marco Antonio; Zavala Arcos, Judith; González González, Mirna Alejandra (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-25)
    A short processing time and efficient scale-up stem cell isolation bioprocess is essential to exploit the potential of these cells for the treatment of multiple chronic diseases. Various methodologies have been used for stem cell recovery, however, most of them present economical and/or time-consuming drawbacks. In this work, the characterization and optimization of immunoaffinity aqueous two-phase systems, a liquid-liquid based separation technology enhanced with the PEGylation of the antibody, was conducted with the aim of increasing the specificity for the recovery of CD133+ stem cells from human umbilical cord blood samples. The methodology consisted in evaluating the partitioning of the different PEGylated antibodies (amine, carboxyl, thiol, succinimidyl ester, methoxy PEG and maleimide) in three previously studied aqueous two-phase systems (ATPS); PEG-dextran (DEX), Ucon-DEX and Ficoll-DEX. Subsequently, an optimization step was accomplished to manipulate the partition behavior of the CD133/2-pure antibody to the desired phase in the selected systems by varying (increasing and decreasing) two parameters closely related with the partitioning of molecules in aqueous two-phase systems; tie-line length (TLL) and volume ratio (VR). Afterwards, the partitioning behavior of the six different PEGylated antibodies in the optimized systems was tested. According to the results, the PEGylation of the CD133/2-biotin antibody induced a favorable change with respect to the non-PEGylated one when Ucon-DEX system was used, fractionating it to both phases. Likewise, the optimization of the systems showed to be effective to induce a change in the partition preference of the antibody. The best results were obtained when Ucon-DEX or PEG-DEX systems with TLL 15% w/w or 20% w/w with VR 3 were combined. Finally, PEGylated antibodies were added to the selected optimized systems. Even though a shift in the fractionation preference of the PEGylated CD133/2-biotin antibody was achieved in the optimized systems, it was not the adequate partition to justify the evaluation of this immunoaffinity ATPS with human umbilical cord samples. Both PEGylation and optimization showed to be effective to induce a change in the partition preference of the antibody, however, further studies are required to find the optimal system composition that will fractionate 100% of the antibody to the contaminants opposite phase, making this system an ideal candidate to be tested for the selectivity of CD133+ stem cells.
  • Estudio del proceso de atemperación mediante CFD

    Huertas Cardozo, José Ignacio; Xicale de Aquino, Alfredo; Hernández Ramírez, Isaías; López Pulido, Amayraní; Huertas Cardozo, José Ignacio; Montesinos Castellanos, Alejandro; Xicale de Aquino, Alfredo; Hernández Hernández, Isaías (Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-11)
    Actualmente, la búsqueda de una mayor generación eléctrica a partir de energías renovables ha posicionado al ciclo combinado como la tecnología capaza de realizar esta transición. Estos ciclos consisten en la integración de un ciclo Brayton por medio de una caldera de recuperación de vapor a un ciclo Rankine. Un componente fundamental para el correcto funcionamiento de las calderas de recuperación de vapor es el atemperador de vapor. Este sirve como sistema de control de la temperatura del vapor, por medio de la inyección de agua subenfriada. Se contruyeron simulaciones mediante CFD con la finalidad de observar a detalle lo que ocurre cuando el agua es inyectada a un flujo de vapor sobrecalentado, entender los fenómenos de transferencia de masa, energía y momentum es fundamental para el proceso de diseño de estos sistemas de atemperación. En base a los resultados se definieron zonas termodinámicas para asegurar una evapoación completa en base a la relación de flujos másicos. Se observó también, el comportamiento de ambas fases en el proceso de evaporación que se dividió en dos regiones, ahondando en el estudio de la segunda. Se obtuvo una ecuación que permite describir la evolución de la temperatura promedio de la mezcla y con la que se puede tener una estimación de la longitud mínima de evaporación. A su vez se estudió el efecto que tiene el tamaño de gota en el proceso y se concluyó que gotas más pequeñas permiten aumentar la transferencia de masa y calor entre las fases, lo que propicia una mejor evaporación en una distancia menor.  

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