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Conmutador telefónico digital.

JOSE GUADALUPE VIVEROS TALAVERA Víctor Manuel Arévalo Gutiérrez (1986, [Tesis de maestría])

Se presenta el diseño de un conmutador telefónico digital (PABX) con capacidaa para 240 extensiones y 32 líneas urbanas. La matriz de conmutación empleada es del tipo espacial con asignación variable de ranura ele tiempo, en la que se cumple con la norma europea para el rnanejo de canales PCM. Su capacidad permite tener enazadas 128 extensiones y 32 líneas urbanas, con lo que se tiene un límite máximo de 80 enlaces sirnulttáneos, sin perjuicio de que a las extensiones . restantes se les pueda conmutar una señalización. El control es por programa almacenado que se ejecuta en un microprocesador de 8 bits. Se manejan teléfonos de disco y de impulsación multifrecuencial, y se incluye el control para que el consumo de energía sea el mínimo necesario para las extensiones y áneas urbanas qué estén actívas, Se tiene un repertorio de facilidades al usuario y las facilidades de administración al sistema se explotan principalmente por medio de una terminal el propósito general. Todos los suministros de se derivan de un banco de acumulaaores convencionales. Las pruebas se hicieron en el prototipo del conmutador que se construyó, el cual tiene la circuitería necesaria para manejar 4 extensiones una línea urbana y una confe:rencia tripartita modular. El crecimiento del sistema puede ser de forma modular. El diseño fué hecho para satisfacer los requisitos de un convenio de transferencia tecnologica hacia una empresa privada.

Circuitos INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LAS TELECOMUNICACIONES TELÉFONO TELÉFONO

Érase una vez un jardín

BLANCA MARINA VERA KU WENDY MARISOL TORRES AVILEZ (2022, [Artículo])

En la ciudad, existen “refugios de plantas y fauna”, también conocidos como “montes o terrenos baldíos”. Podría pensarse que se trata de un lugar desagradable y sucio, pero no es así. El monte no es más que un jardín luchando por restaurar el esplendor que tenía antes de ser degradado por los cambios de uso (asentamientos humanos o fenómenos naturales). Hace muchos años, un terreno baldío tuvo la suerte de encontrarse con un grupo de ecólogos que fueron capaces de apreciar su importancia. El jardín pudo sentir el aprecio de sus cuidadores y los recompensó dándoles la frescura de su sombra, sus aromas perfumados, el aire fresco lleno de oxígeno y sus frutos. Además, el jardín empezó a ser refugio de aves y ayuda para las nubes al soltar la lluvia que alivia el calor.

CIRCUITO ETNOBIOLOGICO JARDIN MEDICINAL PRESERVACION DE LA VIDA RESTAURACION DE LA BIODIVERSIDAD BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Deterministic Brownian-like Motion: Electronic Approach

JOSE LUIS ECHENAUSIA MONROY Eric Campos Cantón Rider Jaimes Reátegui JUAN HUGO GARCIA LOPEZ GUILLERMO HUERTA CUELLAR (2022, [Artículo])

"Brownian motion is a dynamic behavior with random changes over time (stochastic) that occurs in many vital functions related to fluid environments, stock behavior, or even renewable energy generation. In this paper, we present a circuit implementation that reproduces Brownian motion based on a fully deterministic set of differential equations. The dynamics of the electronic circuit are characterized using four well-known metrics of Brownian motion, namely: (i) Detrended Fluctuation Analysis (DFA), (ii) power law in the power spectrum, (iii) normal probability distribution, and (iv) Mean Square Displacement (MSD); where traditional Brownian motion exhibits linear time growth of the MSD, a Gaussian distribution, a −2 power law of the frequency spectrum, and DFA values close to 1.5. The obtained results show that for a certain combination of values in the deterministic model, the dynamics in the electronic circuit are consistent with the expectations for a stochastic Brownian behavior. The presented electronic circuit improves the study of Brownian behavior by eliminating the stochastic component, allowing reproducibility of the results through fully deterministic equations, and enabling the generation of physical signals (analog electronic signals) with Brownian-like properties with potential applications in fields such as medicine, economics, genetics, and communications, to name a few."

Brownian motion Deterministic Brownian motion DFA analysis Statistical analysis Electronic circuit Electronic implementation CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ELECTRÓNICA ELECTRÓNICA

Structural analysis evaluationfor rollers of chassis dynoUsing finite element software

Jesús Emmanuel López Rizo ALFREDO CHAVEZ LUNA JAIME GONZALO SANTANA ESQUIVEL (2023, [Artículo])

This paper discusses the design considerations for a chassis dynamometer, focused on the rollers system used for measuring the power and torque of a vehicle in a university-level workshop. The design must prioritize factors such as safety, ease of use, adaptability to diverse types of vehicles, and the inclusion of safety systems to protect students and the vehicle. The work suggests adaptative features for the design, such as an adjustable fastening system and a compact and portable design, to adapt the structure into a university laboratory. The study also describes common methods for measuring engine power and torque using a chassis dynamometer, and the accurate and reliable measurement systems used for this purpose. This concludes with a discussion of the manufacturing methods used for the chassis dynamometer and a static analysis of the maximum effort capacity in each roller using Von Mises and Goodman fatigue theories. Developing a chassis dynamometer, in accordance the current patents available for workshop practices in a university is essential for providing students with comprehensive training.

Chassis dynamometer Conceptual design Finite element software Power and torque measurement Structural analysis INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Research for development approaches in mixed crop-livestock systems of the Ethiopian highlands

Million Gebreyes James Hammond Lulseged Tamene Getachew Agegnehu Rabe Yahaya Anthony Whitbread (2023, [Artículo])

This study presents processes and success stories that emerged from Africa RISING's Research for Development project in the Ethiopian Highlands. The project has tested a combination of participatory tools at multiple levels, with systems thinking and concern for sustainable and diversified livelihoods. Bottom-up approaches guided the selection of technological interventions that could address the priority farming system challenges of the communities, leading to higher uptake levels and increased impact. Joint learning, appropriate technology selection, and the creation of an enabling environment such as the formation of farmer research groups, the establishment of innovation platforms, and capacity development for institutional and technical innovations were key to this study. The study concludes by identifying key lessons that focus more on matching innovations to community needs and geographies, systems orientation/integration of innovations, stepwise approaches to enhance the adoption of innovations, documenting farmers' capacity to modify innovations, building successful partnerships, and facilitating wider scaling of innovations for future implementation of agricultural research for development projects.

Action Research Systems Thinking CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA INNOVATION PARTNERSHIPS SCALING UP INTEGRATED CROP-LIVESTOCK SYSTEMS

Unanswered questions and unquestioned answers: the challenges of crop residue retention and weed control in Conservation Agriculture systems of southern Africa

Christian Thierfelder Blessing Mhlanga Hambulo Ngoma Paswel Marenya Md Abdul Matin Adane Tufa (2024, [Artículo])

Production and utilization of crop residues as mulch and effective weed management are two central elements in the successful implementation of Conservation Agriculture (CA) systems in southern Africa. Yet, the challenges of crop residue availability for mulch or the difficulties in managing weed proliferation in CA systems are bigger than a micro-level focus on weeds and crop residues themselves. The bottlenecks are symptoms of broader systemic complications that cannot be resolved without appreciating the interactions between the current scientific understanding of CA and its application in smallholder systems, private incentives, social norms, institutions, and government policy. In this paper, we elucidate a series of areas that represent some unquestioned answers about chemical weed control and unanswered questions about how to maintain groundcover demanding more research along the natural and social sciences continuum. In some communities, traditional rules that allow free-range grazing of livestock after harvesting present a barrier in surface crop residue management. On the other hand, many of the communities either burn, remove, or incorporate the residues into the soil thus hindering the near-permanent soil cover required in CA systems. The lack of soil cover also means that weed management through soil mulch is unachievable. Herbicides are often a successful stopgap solution to weed control, but they are costly, and most farmers do not use them as recommended, which reduces efficacy. Besides, the use of herbicides can cause environmental hazards and may affect human health. Here, we suggest further assessment of the manipulation of crop competition, the use of vigorously growing cover crops, exploration of allelopathy, and use of microorganisms in managing weeds and reducing seed production to deplete the soil weed seed bank. We also suggest in situ production of plant biomass, use of unpalatable species for mulch generation and change of grazing by-laws towards a holistic management of pastures to reduce the competition for crop residues. However, these depend on the socio-economic status dynamics at farmer and community level.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA INTEGRATED CROP-LIVESTOCK SYSTEMS CROP RESIDUES ZERO TILLAGE SOCIAL NORMS SUSTAINABLE INTENSIFICATION WEED CONTROL

Propuesta paisajística integral para la UAM, Unidad Azcapotzalco

Cynthia García Marín (2023, [Tesis de maestría])

315 páginas. Maestría en Diseño, Planificación y Conservación de Paisajes y Jardines.

En México, la educación superior comienza en 1521 cuando la universidad se crea como institución educativa, inaugurando en 1553 La Real y Pontificia Universidad de México. En 1910 se funda la Universidad Nacional de México y en 1954 fue inaugurada la Ciudad Universitaria de la UNAM, esta fecha representa un hito en la historia de los espacios físicos de las universidades mexicanas. Debido a la demanda de educación superior y al movimiento estudiantil de 1968, se concibe la idea de crear una nueva universidad en la ZONA METROPOLITANA de la Ciudad de México, la Universidad Autónoma Metropolitana con sus Unidades al norte, al oriente y al sur, posteriormente se abrieron 2 Unidades más. Cada una de estas Unidades funciona de manera independiente, teniendo sus propios órganos de decisión, lo que se refleja en la planta física de conjunto. Es al norte de la ciudad donde surge la Unidad Azcapotzalco, que con el paso de los años se ha ido conformando de acuerdo a sus necesidades inmediatas tratando de seguir el proyecto inicial, sin embargo, debido a los ajustes en sus diferentes intervenciones arquitectónicas, se ha propiciado una falta de integración entre el espacio arquitectónico y el espacio abierto impactando directamente en el paisaje y en la pérdida gradual de identidad de la Unidad. Este trabajo reúne la información que describe la conformación del paisaje en la Unidad a lo largo de casi 50 años, en donde se analizan los componentes del paisaje en sus diferentes sistemas; ecológico-conformación medioambiental, sociocultural-conformación de la estructura urbana, polisensorial-conformación a través de los sentidos y su contexto histórico-conformación a través del tiempo. Esta identificación, permite realizar el análisis detallado de los factores que intervienen directa e indirectamente en el estado actual del paisaje de la Unidad, con este diagnóstico se elabora una síntesis creativa que especifica las limitaciones y potencialidades que afectan la conformación del espacio abierto. A partir de esto se elaboró un plan maestro, que integra las principales líneas de acción, estructuradas en ejes de diseño que tienen como propósito ordenar y facilitar la programación para mejorar las condiciones actuales por medio de acciones específicas que contribuyan al mejoramiento, conservación y creación de un paisaje que se integre en su conjunto y permita a la UAM-Azcapotzalco ser revalorizada como un sitio con identidad y con valores históricos, sociales, estéticos, biológicos y paisajísticos.

In Mexico, higher education began in 1521 when the university was created as an educational institution, inaugurating in 1553 La Real y Pontificia Universidad de México. The National University of Mexico was founded in 1910 and the UNAM University City was inaugurated in 1954, this date represents a milestone in the history of the physical spaces of Mexican universities. Due to the demand for higher education and the student movement of 1968, the idea of creating a new university in the METROPOLITAN ZONE of Mexico City was conceived, the Universidad Autónoma Metropolitana with its Units to the north, east and south, later 2 more Units were opened. Each one of these Units works independently, having its own decision-making bodies, which is reflected in the physical plant as a whole. It is to the north of the city where the Azcapotzalco Unit arises, which over the years has had to conform according to its immediate needs trying to follow the initial project, however, due to adjustments in its different architectural interventions, a lack of integration between the architectural space and the open space has been fostered, directly impacting the landscape and the gradual loss of identity of the Unit. This work gathers the information that describes the conformation of the landscape in the Unit over almost 50 years, where the components of the landscape in its different systems are analyzed; ecological-environmental conformation, sociocultural-conformation of the urban structure, polysensory-conformation through the senses and its historical context-conformation through time. This identification allows a detailed analysis of the factors that intervene directly and indirectly in the current state of the landscape of the Unit, with this diagnosis a creative synthesis is elaborated that specifies the limitations and potentialities that affect the conformation of the open space. Based on this, a master plan was prepared, which integrates the main lines of action, structured into design axes whose purpose is to order and facilitate programming to improve current conditions through specific actions that contribute to the improvement, conservation and creation of a landscape that is integrated as a whole and allows the UAM-Azcapotzalco to be revalued as a site with identity and with historical, social, aesthetic, biological and landscape values.

Paisaje, universidad, conformación, diagnóstico, lineamientos, identidad, integrar, revalorizar, plan maestro, propuesta. Landscape, university, conformation, diagnosis, guidelines, identity, integrate, revalue, master plan, proposal. Landscape design. Landscape assessment. Landscape changes. Landscapes--Social aspects. Universidad Autónoma Metropolitana. Diseño de paisajes. Evaluación del paisaje. Cambios de paisaje. SB472.45 HUMANIDADES Y CIENCIAS DE LA CONDUCTA CIENCIAS DE LAS ARTES Y LAS LETRAS ARQUITECTURA JARDINES Y PARQUES