Flores-Hernandez C.G.,Autonomous University of Mexico State |
Flores-Hernandez C.G.,National Autonomous University of Mexico |
Colin-Cruz A.,Autonomous University of Mexico State |
Velasco-Santos C.,Technological Institute of Queretaro |
And 7 more authors.
Polymers | Year: 2014
The performance as reinforcement of a fibrillar protein such as feather keratin fiber over a biopolymeric matrix composed of polysaccharides was evaluated in this paper. Three different kinds of keratin reinforcement were used: short and long biofibers and rachis particles. These were added separately at 5, 10, 15 and 20 wt% to the chitosan-starch matrix and the composites were processed by a casting/solvent evaporation method. The morphological characteristics, mechanical and thermal properties of the matrix and composites were studied by scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and dynamic mechanical analysis. The thermal results indicated that the addition of keratin enhanced the thermal stability of the composites compared to pure matrix. This was corroborated with dynamic mechanical analysis as the results revealed that the storage modulus of the composites increased with respect to the pure matrix. The morphology, evaluated by scanning electron microscopy, indicated a uniform dispersion of keratin in the chitosan-starch matrix as a result of good compatibility between these biopolymers, also corroborated by FTIR. These results demonstrate that chicken feathers can be useful to obtain novel keratin reinforcements and develop new green composites providing better properties, than the original biopolymer matrix. © 2014 by the authors.
Navarro-Pardo F.,Autonomous University of Mexico State |
Navarro-Pardo F.,National Autonomous University of Mexico |
Martinez-Barrera G.,Autonomous University of Mexico State |
Martinez-Hernandez A.L.,National Autonomous University of Mexico |
And 6 more authors.
Materials | Year: 2013
Electrospun one dimensional (1D) and two dimensional (2D) carbon based polymer nanocomposites are studied in order to determine the effect provided by the two differently structured nanofillers on crystallinity and thermo-mechanical properties of the nanofibres. The nanomaterials studied are pristine carbon nanotubes, oxidised carbon nanotubes, reduced graphene oxide and graphene oxide. Functional groups associated with the order structure of the polymers are analysed by infrared and Raman spectroscopies; the morphology is studied by scanning electron microscopy and the crystallinity properties are investigated by differential scanning calorimetry and X-ray diffraction. Differences in crystallisation behaviour between 1D and 2D carbon based nanofibres are shown by their crystallinity degree and their crystal sizes. The nanocomposite crystal sizes perpendicular to the plane (100) decrease with nanofiller content in all cases. The crystallinity trend and crystal sizes are in accordance with storage modulus response. The results also suggest that functionalisation favours interfacial bonding and dispersion of the nanomaterials within the polymer matrix. As a consequence the number of nucleating sites increases which in turn decreases the crystal size in the nanocomposites. These features explain the improved thermo-mechanical properties in the nanocomposites. © 2013 by the authors.
Tapia B.,Technological Institute of Queretaro |
Joaquin P.M.,Technological Institute of Queretaro |
Juan R.F.,Technological Institute of Queretaro
Proceedings of the 2010 International Conference on Artificial Intelligence, ICAI 2010 | Year: 2010
This paper proposes the design of a dynamic balance system in order to control the inertial forces of the links 2 and 3 of a 3 DOF polar robot, the goal is to reduce the level of dynamic stress under high speeds, increasing with this control the stability and accuracy. The robot is not a comercial one, the robot is being designed to be used in a glue application in a shoe factory. The accuracy required is in the order of 0.5 mm and a linear speed of 310 cm/s.
Solis E.D.B.,Technological Institute of Queretaro |
Neto A.M.,Federal University of Lavras |
Huallpa B.N.,Federal University of Lavras
Proceedings - 12th LARS Latin American Robotics Symposium and 3rd SBR Brazilian Robotics Symposium, LARS-SBR 2015 - Part of the Robotics Conferences 2015 | Year: 2015
Energy limitation is one of the most important challenges. Many applications are being developed and one important aspect is the excess of information, frequently redundant, that imposes a great computational cost in data processing and consequently power consummation. Management of all power resources is therefore important for intelligent vehicles and mobile robots. In previous works, we have proposed a discarding method as a simple solution to improve the performance of a real-Time navigation system. The objective in this paper is to analyze the performance of the discarding criteria with a Velodyne sensor, a light detection and ranging (LIDAR) system, which generates around 1.3 million points per second. © 2015 IEEE.
Perez-Ramirez E.E.,University of Guanajuato |
Perez-Ramirez E.E.,Technological Institute of Queretaro |
Perez-Ramirez E.E.,National Autonomous University of Mexico |
De La Rosa-Alvarez G.,University of Guanajuato |
And 5 more authors.
Environmental Engineering Science | Year: 2015
Photocatalytic degradation and removal by adsorption of the Reactive Red 2 (RR2) dye in the presence of different pristine and functionalized one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) carbon structures were investigated and compared, considering also the loading of catalyst/adsorbent. Previous to photocatalytic and adsorption evaluation, all carbon materials were characterized to verify functionalization, structural changes, and surface properties useful in the removal of this pollutant in water. Materials were analyzed by Raman and infrared spectroscopies, transmission electron microscopy, and besides, the pH of the point of zero charge (pHpzc) was determined by potentiometric titrations, and band gap by ultraviolet-visible spectroscopy through Tauc plot. Removal of RR2 increases with the load of carbon materials. One-dimensional materials showed better performance in the decolorization of RR2 dye, removing the whole color of the solution. RR2 removal values obtained by the photocatalytic and adsorption processes are very similar. Thus, the adsorption process predominates over the photocatalytic activity, only the samples of graphene and graphene oxide present slight photocatalytic activity. The adsorption process was strongly influenced by the carbon material dimension. However, other factors like surface oxygenated groups, surface area, and the shape of the carbon structures, as well as the structure and nature of the dye also play an important role in this process. Experimental adsorption data of all carbon materials were best fitted to pseudo second-order kinetic model, and, it is concluded that physisorption with strong interaction is the process by which carbon materials adsorb to the dye. Thus, the mechanism of RR2 adsorption on carbon materials is by the aromatic rings of the RR2 and π delocalized electrons on carbon materials. © Mary Ann Liebert, Inc.
De La Luz-Asuncion M.,Mexico State University |
De La Luz-Asuncion M.,National Autonomous University of Mexico |
De La Luz-Asuncion M.,Technological Institute of Queretaro |
Sanchez-Mendieta V.,Mexico State University |
And 5 more authors.
Journal of Nanomaterials | Year: 2015
Carbon nanomaterials have a great potential in environmental studies; they are considered as superior adsorbents of pollutants due to their physical and chemical properties. Functionalization and dimension play an important role in many functions of these nanomaterials including adsorption. In this research, adsorption process was achieved with one-dimension nanomaterials: single walled and multiwalled carbon nanotubes were used as received and after oxidation treatment also two-dimensional nanomaterials were used: graphene oxide and reduced graphene oxide. Carbon nanotubes were modified by hydrogen peroxide under microwave irradiation. The reduction of graphene oxide was achieved by using ascorbic acid. R 2 values obtained with the pseudo-second-order model are higher than 0.99. The results demonstrate that Freundlich isotherm provides the best fit for the equilibrium data (R 2 > 0.94). R L values are between 0 and 1; this represents favorable adsorption between carbon nanomaterials and phenol. The adsorption process occurs by π - π interactions and hydrogen bonding and not by electrostatic interactions. The results indicate that the adsorption of phenol on carbon nanomaterials depends on the adsorbents' surface area, and it is negatively influenced by the presence of oxygenated groups. © 2015 M. de la Luz-Asunción et al.