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Ante la transición a universidades emprendedoras, existe la tendencia a incrementar el patentamiento, aunque sin un estudio profundo del potencial comercial, por lo que el porcentaje de los productos que lo logran es muy bajo. El objetivo de esta investigación fue diseñar una estrategia de evaluación tecnológica y comercial de patentes universitarias a partir de la identificación de oportunidades en transferencia de tecnología (TT). Para ello, se examinaron 269 solicitudes de patente de la Benemérita Universidad Autónoma de Puebla (BUAP) y de la Universidad Autónoma del Estado de Morelos (UAEM), de acuerdo con la Clasificación Internacional de Patentes (CIP), en un periodo de 10 años (2009-2018), mediante 4 pasos: (a) construcción de la base de datos con la herramienta del Instituto Mexicano de Propiedad Intelectual, (b) identificación de las capacidades inventivas, a través de la Organización Mundial de la Propiedad Intelectual, (c) distribución por industrias de intensidad y oportunidad de mercado tecnológico, de acuerdo con la Organización para la Cooperación y el Desarrollo Económicos, y (d) análisis del comportamiento del mercado, mediante el estudio de las 36 solicitudes del área farmacéutica de ambas universidades. Los resultados mostraron que el 68.4 % de la BUAP y 75.6 % de la UAEM presentan un posicionamiento competitivo predominante en industrias de alta y mediana-alta tecnología. La ventaja de la herramienta propuesta es que permite reconocer la oportunidad del mercado tecnológico a partir de la construcción de escenarios relacionados con el comportamiento de la CIP.

Electric power transfer maneuvers carried out in the streets of Mexico through medium voltage distribution circuits necessarily imply the interruption of service to users, even though the supplier has several operating procedures to maintain continuity of service.

Nonlinear propagation of short terahertz pulses in the layered structures dielectric -graphene -dielectric … is investigated theoretically on the base of direct simulations of the Maxwell equations and the hydrodynamic equations for electrons in graphene layers. The using of the nonlinear hydrodynamics is justified from a comparison of quasi -classical kinetics, quantum kinetics, and the hydrodynamics. The effective electron mass has been determined for the hydrodynamics. The numerical FDTD scheme is proposed to consider the boundary conditions at graphene sheets. The resonant generation of odd harmonics of THz radiation has been investigated.

The nonlinear baseband electromagnetic pulses of a wide spectrum that covers the lower part of terahertz (THz) range are investigated theoretically in the paraelectric crystals like SrTiO3 at the moderately low temperatures 50–200 K. The frequency dispersion is important there. The dominating nonlinearity of the crystal is cubic. To increase the influence of the nonlinearity, the focusing of the input baseband pulses of small amplitudes has been applied. The main attention is paid to the three-dimensional (3D) geometry of focusing of the input baseband pulses. The nonlinear focusing of input long baseband pulses by the exciting antenna results in the formation of extremely short baseband pulses of subpicosecond durations. Under 3D focusing the peak values of the nonlinear focused pulses are bigger and their durations are shorter than ones under 2D focusing, but the transverse localization is stronger under 2D focusing.

The superheterodyne amplification of electromagnetic waves is investigated when the resonant three-wave interaction of two electromagnetic waves with the space charge wave occurs in the waveguides nitride n-GaN, n-InN films-dielectric. The amplification of SCW waves due to the negative differential conductivity is investigated in nitride n-GaN, n-InN films at the frequencies f ≤ 400 GHz in the lower part of the terahertz (THz) range. The electromagnetic waves are either in the upper part of THz range or in the optical range. The superheterodyne amplification is considered in two geometries, the collinear one in which the three interacting waves travel in the same direction and the anti-collinear geometry where the second electromagnetic wave propagates in the opposite direction. The preferences and drawbacks of each geometry are pointed out. The finite width of space charge waves leads to decrease of increments of amplification.

La comunicación inalámbrica, mejor conocida como Wi-Fi (Wireless Fidelity), adquiere interés ya que no requiere del uso de cables, los cuales son engorrosos y limitan el espacio libre. Este tipo de comunicación es ampliamente utilizado en equipos electrónicos, principalmente en el hogar y la industria. Las antenas de parche, que usan algunos de estos equipos, son muy populares debido a sus características. El objetivo de este trabajo es obtener un prototipo de antena de parche eficiente y económico para su uso en interiores y exteriores. En principio, se presenta el prototipo de una antena de parche rectangular diseñada para Wi-Fi con polarización lineal. Después, se realizan sobre ella cortes y ranuras, para mejorar su ganancia. Las pruebas realizadas con la antena individual con cuatro cortes muestra la factibilidad de su uso para interiores. Posteriormente, se diseña un arreglo de antenas de parche en base a la antena individual de cuatro cortes, con la finalidad de obtener un prototipo mejorado. Las pruebas demuestran un buen desempeño del arreglo de antenas propuesto, para su uso en interiores y exteriores, como se esperaba.

The excitation of short electric monopulses of space charge waves with wide frequency spectrum of terahertz range in nitride films has been theoretically investigated. The excitation of these pulses with duration ≤ 5 ps and high peak values of electric fields is possible in n-GaN or n-InN films of submicron thickness in the presence of negative differential conductivity. The simulation of nonlinear dynamics of pulses was performed with due regard for the nonlocal dependence of the drift electron velocity on the average electron energy. Optimal values of the applied constant electric fields and equilibrium electron concentration for excitation of monopulses are specified. The monopulse dynamics is weakly dependent on the film width and also on the value and waveform of input excitation pulses. Short electric monopulses differ from domains of strong electric field in Gunn diodes built on bulk crystals with negative differential conductivity.

This article presents the design and implementation of a micropositioning system actuated by three piezoelectric stacks to control its displacements on XYZ axes. The use of conventional piezoelectric buzzers allows us to reduce fabrication costs. The working or mobile platform is the base for objects that will be manipulated, for example, in automated assembling. The micropositioner can be integrated into a microgripper to generate a complete manipulation system. For micropositioner fabrication, at first, Polylactic Acid (PLA) was chosen as the structural material, but after simulation and some experimental tests performed with a micropositioner made of Acrylonitrile Butadiene Styrene (ABS), it showed larger displacement (approx. 20%) due to its lower stiffness. A third test was performed with a positioner made with Polyethylene Terephthalate Glycol (PETG), obtaining an intermediate performance. The originality of this work resides in the geometrical arrangement based on thermoplastic polymer compliance mechanisms, as well as in the use of additive manufacturing to fabricate it. An experimental setup was developed to carry out experimental tests. ANSYS™ was used for simulation.

The design of a novel electrothermal microgripper device is shown, which is based on an improved chevron type actuator developed considering their elements parameterization, whose resistive model is also provided. The performance of the microgripper&rsquo, s parameters, such as displacement, force, and temperature distribution, with convection for the voltage range from 0 up to 5 V, is evaluated through numerical and analytical simulation. Microgripper design was also improved with aid of parameterization. The effect on the microgripper performance due to its thickness is also analyzed, finding a considerable increment in force, when thickness increases. Its main advantage is given by the simplicity of the compliance arrangement of the microgrippers jaws. Considering convection, when 5 V are applied, 37.72 &deg, C was generated at the jaw&rsquo, s tips of the Improved Microgripper 2 (IMG2), implemented with silicon, this relatively low temperature increases its capabilities of application. When the IMG2 is implemented with polysilicon, its response is competitive comparing with a more complex microgripper, increase of displacement (50%) is shown, but a decrement of force (30%). The diameters allowed for the subjection objects are found between 84.64 &micro, m and 108 &micro, m, with weights lower than 612.2 &micro, g. Some tests of subjection were performed using microcylinders of Au, glass ceramic, polycarbonate and carbon fiber, showing a permissible stress on them, considering its Young&rsquo, s modulus, as well as the total reaction force induced. All simulations were done on Ansys software. The results demonstrate the feasibility of the future microgripper fabrication.

In this paper a novel microgripper device is shown. It is based on a chevron type actuator, and a simple configuration of compliance beams. It is also considered a source of thermal energy, which in this case is 2 V, which generates a temperature of 92.7°C at the jaw’s tips. It is main advantage is given by the simplicity and the reduced number of beams, which composed the compliance arrangement of the microgrippers jaws. It is response competitive with other ones, more complex, found it in literature, both in displacement and force. The structural material is Silicon. The effect on the microgripper performance due to its thickness is also analyzed. Some applications of the microgripper are detected, for example, subjection of microwires and manipulation of micro objects with diameters smaller than 85$\mu$m, until 68 $\mu$m, and weights lower than 38.63 $\mu$g. All microgrippers simulations were done on Ansys software.

This article provides an analysis of harmonics existing in the electrical installation at the plant “Chiconautla”, dependent on the General Management Department of Construction and Hydraulic Operation of Mexico State (DGCOH). For electrical power quality studies, monitoring equipment was initially installed at the Point of common coupling, to obtain the maximum average values of the total distortion harmonics of voltage and current. This monitoring is important, due to these signals must meet the standards established by regulatory organizations, to improve the energy quality, reduce costs and to avoid electric equipment’s failures. It can be determined that the main contributions to these distortions are third, fifth and seventh harmonics. The time of transfer given by the automatic transfer equipment, was measured when failures in the network occurred. It can be said that all measurement satisfies the requirements of network code. Some recommendations are given to improve the performance of the system.

In this paper, simulated and experimental analysis of an accelerometer with beams based on arrangements of segments of different width is performed. A comparison with an accelerometer of uniform beams is carried out. Micro accelerometers were scaled to obtain millimeter lengths to obtain low cost prototypes and the possibility to test them, also using an experimental set-up of low cost. The simulation tool employed is Ansys. For experimental validation, additive manufacture using PLA, a type of thermoplastic polymer, is considered. The parameter under analysis is the displacement the proof mass of accelerometers. The larger displacement was obtained for the case of symmetrical beams, with a thinner width equals to 1/3 of width the uniform beam, but a decrease in the natural frequency of the system was also obtained.

This article shows the analysis for load transfer without interruption between two 23 kV distribution feeders. This procedure is not common in this type of system and requires paying primary attention to the characteristics of the electrical network for its application. The distribution circuits discussed here have their own power substation with different voltage levels. The information obtained from a state estimator, the contingency conditions, the electrical parameters of impedances and network configuration allow to carry out the simulation of the load transfer with the Alternative Transients Program software. From the simulation it is shown that load transfer without interruption is possible as long as certain operating conditions are met in the power and distribution networks. The dependence of the transfer on the voltage levels, angular phase shift of voltages and strength of the electrical network is shown, represented by its thevenin impedance at the interconnection point. The results found from the simulation indicate that the success of the interconnection is mainly a function of the electrical strength of the power substations and the phase sequence of the power transformer at the load transfer point. Certain percentages of variation of voltage and currents of the feeders are defined that must not be exceeded. The operational aspects proposed here serve as a basis to have a general interconnection procedure between distribution feeders where special attention is required in the continuity of the service due to the high expectation in the satisfaction of the user of the electrical network. Keywords: feeder, state estimator, medium voltage, power system, load transferring.

It is investigated theoretically the nonlinear down-conversion of powerful extremely low frequency (ELF) modulated acoustic wave beams at the carrier frequencies 1–20 Hz into ultra-low frequency (ULF) acoustic waves at the frequencies 0.01–0.1 Hz under the propagation upwards within the atmosphere and ionosphere. The approximation of the slowly varying profile is used. It is shown that under a fixed value of the integral power of the initial acoustic ELF beam there exists the optimal value of the initial transverse width where the maximum down-conversion is realized. The different types of the modulation are considered, namely the simplest two-frequency modulation and multifrequency noise-like one. The using of the complex multifrequency modulation results in the increase of the efficiency of the down-conversion within the ionosphere E- and F-layers.

This article presents the design and implementation of a microgripper device actuated by a piezoelectric stack. In order to reduce fabrication costs, conventional piezoelectric buzzers are used that are easily found in the market at very low cost. Polylactic Acid (PLA) was chosen as the structural material for the design of the mechanisms of the microgripper, the choice of this material considerably reduces the total implementation cost. The originality of this work resides in the material used and in the stacked piezoelectric actuator. The main contribution is the demonstration of a design methodology that implements prototype compliance mechanisms at millimeter scale for validation purposes before proceeding to the fabrication in micrometric scale. Even so, the system in mm scale can also be used for micromanipulation due to the range of its microgripper jaws’ aperture and its reliability. ANSYSTM was used as the software tool for simulation.

In this paper, a novel microgripper based on two perpendicular arrangements of beams and a chevron actuator is shown. In each perpendicular arrangement, the constrained displacement of the double clamped beams, joined at their endpoint, produces a buckling in each beam, which favors the displacement of each arm of the microgripper, normally open. These arrangements constitute the highly flexible structures of the microgripper. Their buckling is produced by the force applied by chevron arrow, producing a reaction force in the range of 174.44 $\mu$ N in the microgripper jaws. Chevron actuator is fed by a thermal source. Temperature in microgripper tips is of 34.42°C and the operation frequency is 33.966 kHz, at maximum load thermal applied of 200°C. The mechanical, thermal and modal analyses of this integrated structure was supported by SIMSOLIDTM, based on Finite Element Analysis. The simulation was developed with Polysilicon as structural material.

Los acelerómetros miden las aceleraciones o vibraciones, que experimentan los objetos debido a fuerzas inerciales o excitaciones mecánicas. Los acelerómetros Microelectromecánicos (MEM) tienen diversas aplicaciones en las industrias, aeronáutica, automotriz, petrolera, construcción, manufacturera de equipos de cómputo y electrónica de consumo, entre otras. Estos dispositivos emplean diferentes técnicas para su funcionamiento. El interés en este trabajo, se enfoca en los acelerómetros capacitivos, buscando mejorar su sensibilidad de desplazamiento. Para mejorar este parámetro se ha recurrido generalmente, a la reducción de masa, a la modificación de los brazos de suspensión, o bien, agregando amplificadores de desplazamiento. En este trabajo, después de analizar varias configuraciones, se proponen dos diseños de brazos modificados basados en amplificadores flexibles de manivela deslizante modificados. La mejora en la sensibilidad de desplazamiento, comparada con la obtenida con brazos uniformes, es en uno de los casos, de 72.435% y en el otro de 125%. Los resultados fueron obtenidos usando ANSYS.

Using Poly-Silicon, the implementation of novel Displacement-amplifying Compliant Mechanisms (DaCM), in two geometries of accelerometers, allows for remarkable improvements in their operation frequency and displacement sensitivity, with different proportions. Similar DaCM´s geometries were previously implemented by us with Silicon. In all mentioned cases, the geometries of DaCM´s are adjusted in order to use them with Conventional Capacitive Accelerometer (CCA) and Capacitive Accelerometer with Extended Beams (CAEB), which operate in-plane mode, (y-axis). It should be noted that CAEB shows improvements (95.33%) in displacement sensitivity compared to ACC. Simulations results, carried out using Ansys Workbench software, validate the system’s performance designed with Poly-Silicon. Finally, a comparison with the similar systems, previously designed with Silicon, is also carried out.

In this paper, a modified U-shaped micro-actuator with a compliant mechanism is proposed. It was analyzed with a uniform and modified thin arm, as well as a similar variation in the corresponding flexure, in order to observe the impact of the compliant lumped mechanism. The use of these compliant mechanisms implies an increment in the deformation and a reduction in the equivalent stress of 25% and 52.25%, respectively. This characterization was developed using the Finite Element Method (FEM) in ANSYS Workbench. The design, analysis and simulation were developed with Polysilicon. In this study, the following performance parameters were also analyzed: force and temperature distribution. This device is supplied with voltage from 0 V up to 3 V, at room temperature. The modified U-shaped actuator was applied in both arms of a microgripper, and to evaluate its electrothermal performance, a static structural analysis has been carried out in Ansys Workbench. The microgripper has an increment in deformation of 22.33%, an equivalent stress reduction of 50%, and a decrease in operation frequency of 10.8%. The force between its jaws is of 367 &micro, N. This low level of force could be useful when sensitive particles are manipulated.

Microelectromechanical (MEM) Accelerometers measure the accelerations or vibrations experienced by objects due to inertial forces or mechanical excitations. To improve their proof mass displacement, several alternatives have been used, such as the design of different shapes of suspension beams. In this work, a new shape of beam is proposed based on alternated segments of different widths. To analyze its performance, one-quarter, middle and complete accelerometers were calculated and simulated, the results were compared with similar cases using conventional uniform-shaped beams. A notable improvement in the proof mass displacement was obtained in all cases, especially with the proposed symmetrical-shaped beam. Harmonic response and explicit dynamic analysis were also considered to discover performance when they are subjected to structural load. An improvement in amplitude displacement was also observed, as well as operation frequency reduction. From the explicit dynamic analysis, a faster performance of the accelerometer with uniform arms can be observed, however, it responds at a lower range of input velocities. A performance comparison of the proposed beam is presented considering the two reported accelerometers. Finally, from the variation in the width of the thinner segment of the symmetrical arms, it can be observed that it is possible to obtain an increment in the displacement of the proof mass of 39.57% and a decrement in natural frequency of 15.30%, with respect to the case of the uniform arm. Other advantages of the symmetric beam are the stress distribution, reducing its effect on the proof mass, as well as their low cross-axis sensitivity. Simulations were performed with ANSYS.

The nonlinear waves of terahertz (THz) range are investigated in the paraelectric crystals SrTiO3 at the temperatures ~77 K. The frequency dispersion is important there. In the absence of a bias electric field the dominating nonlinearity is cubic. The frequency dispersion and nonlinearity correspond to existence of envelope solitons and the modulation instability (MI) of long input pulses, whereas in the transverse direction MI is absent. There exists a possibility to generate the regular sequences of short THz pulses due to MI in bounded SrTiO3 crystals. The focusing of input long pulses reduces the threshold of MI, increases the output amplitudes of the short pulses, and provides more stable generation of the short pulses. It is investigated the frequency multiplication of THz electromagnetic radiation in bounded paraelectric SrTiO3 when a bias electric field is applied. The dominating nonlinearity is quadratic there. The frequency dispersion and the transverse width of the input wave beams affect the generation of higher harmonics. It is possible to select the certain numbers of higher harmonics by means of the optimum length of the crystal, by the width of the beam of the input first harmonic, and by the focusing of the input first harmonic.

The displacement of the central shuttle of a Z-shape chevron actuator can be calculated using a developed approach from other authors. Who demonstrated that the actuators with this geometry offer a larger displacement compared with V-shape actuators. Z-shape offers a larger stiffness and output force for the case of only one arm. This paper is focused on the optimization of the Z-shaped beams of a chevron actuator of eight beams, which seeks to increase the previously described response. The structure is designed in parametric solid modeling 3D software Autodesk Inventor, and simulated by finite element method in Ansys 15.0. These simulations were implemented considering several modifications on the length of the Z-shaped beams in order to choose the most appropriate length. The electric potential applied in all cases was from 0.2 V up to 5 V. The Z-shape length of the arms for the case of the optimized Z-shape actuator increases the shuttle’s displacement in approximately 50% compared to V-shape actuator, and 38% compare to the original Z-shape. Analytical adjusted approach is extremely matched with the simulations results. Length of the Z-shape beam is the determinant factor of the displacement. The low stiffness of the optimized Z-shape actuator (89% lower than the original V-shape and 58% compared to Z-shape) can allow its use as load sensor.

This article presents a 3rd Order 1-bit ΔΣ modulator optimized for applications requiring high effective resolution and linearity within the 20-kHz band. Furthermore, this work also describes architectural approaches for designing modulators with different order, oversampling rate, and number of quantization bits. Such approaches can be leveraged in a variety of applications in digital signal processing for data communications, filters, motor controllers, data acquisition, high-fidelity audio, DACs, and others operating in baseband. The 3rd Order modulator was implemented in standard 180nm CMOS; experimental measurements show a SNDR=126dB equivalent to 20-bits of effective resolution with a total harmonic distortion THD=0.03%. The circuit is able to operate in low-voltage conditions from 0.55 to 1.8 Volts.

En este artículo se analiza una red de distribución urbana de 23 kV típica de la zona central de México. El objetivo es determinar la distancia máxima de separación entre apartarrayos de línea que permita reducir las salidas de los circuitos de distribución por descargas atmosféricas directas e indirectas. Con base en las características eléctricas, ambientales, ceráunicas y geográficas de la zona, niveles de cortocircuito y las sobretensiones provocadas por maniobras rutinarias, se selecciona el apartarrayos siempre con el principal objetivo de determinar su espaciamiento adecuado sobre la línea para que éste funcione apropiadamente. La investigación se lleva a cabo con la ayuda del software llamado Alternative Transients Program (ATP) donde se realiza el cálculo de los parámetros de la línea utilizando el modelo de K.C. Lee, las sobretensiones transitorias por onda viajera y por conexión de capacitores también son simuladas. La motivación de este trabajo consiste principalmente en contar con un mayor sustento teórico y técnico (actualmente escueto) para determinar el espaciamiento entre apartarrayos de la red de distribución considerada y así aumentar la calidad del suministro eléctrico de la zona.

Positioning mechanisms are required in order to improve antenna reception through a better orientation, reducing the physical interference produced by coupling of impedance, when orientation is made by hand. In this work, a positioning support for patch antennas was designed in order to know its effect over the patch antenna's performance. It is well-known that fabrication process of the antenna produces a shift in its frequency response, but there was not found information about the effect of the structural support. Simulations to known this effect were performed considering two types of material for the structural support. A patch antenna, designed for Wi-Fi (2.4 GHz), was used to analyze this effect.

In this paper, the dynamic and electric analysis of a novel electrostatically actuated microdevice is presented. This device consist of an arrangement of four parallel microcantilevers, which is fed with 1 V. The analysis was carried out by Finite Element Method (FEM) in Ansys Workbench in order to obtain: current intensity, temperature distribution, Joule effect, structural deformation, natural frequency, and reaction force, which characterize the microgripper performance. The material used in the analysis was Silicon. A thermoelastic model, that describes the behavior mechanical of the device, is developed. The device had an initial gap of 28 µm and a final gap of ~ 4 µm, the force of subjection in grippers is 0.4 µN.

Excitation of nonlinear acoustic monopulses, or baseband waves, is theoretically analyzed. The monopulses have a wide spectrum up till the gigahertz range ≤ 1 GHz. The propagation of waves is along the interface between a solid lm and a solid substrate. A quadratic elastic nonlinearity in both contacting media of the system is taken into account. The nonlinear dynamics of waves depends essentially on the thickness of the lm. The transverse inhomogeneity of the wave pro le in the interface plane and the wave di raction are taken into account, too. The baseband waves are not true solitons and manifest as single shock-like pulses in the case of an excitation from initial long rectangular pulses. The transverse inhomogeneity a ects the dynamics of the shocks, and there is a possibility to focus the nonlinear monopulses.