GENERAL STUDY OF CLASSICAL AND NONCLASSICAL CONTRIBUTIONS OF TWO PHOTON ABSORPTION PROCESS IN ORGANIC MOLECULES

Freiman Estiven Triana Arango (2023, [Tesis de doctorado])

"Two-photon absorption (TPA), a nonlinear optical phenomenon, is gaining attention for applications like laser scanning, microscopy, and therapy. Recent research explores entangled two photon absorption (ETPA) using correlated photons but faces debates regarding its magnitude and detection. This study introduces a novel method using changes in Hong-Ou-Mandel (HOM) interferogram visibility to probe ETPA's presence. It employs Rhodamine B dye and entangled photons at around 800nm to investigate conditions conducive to observing ETPA-induced changes. This innovative approach distinguishes genuine ETPA signals from linear optical losses often masquerading as ETPA effects, addressing a significant field challenge."

Two-photon absorption Entangled two-photon absorption Hong-Ou-Mandel HOM dip visibility Joint Spectral Intensity Entangled photons CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA OPTICA NO LINEAL OPTICA NO LINEAL

Análisis cuantitativo con diagrama de precedencias de condiciones productivas actuales de 5 líneas de ensamble de amortiguadores mediante el método de balanceo peso posicional

José Humberto Vergara García (2023, [Tesis de maestría])

En este trabajo de investigación se empleó el método de Helgeson & Birnie para realizar el balanceo por peso posicional de cinco líneas de ensamble modular de amortiguadores de la empresa ZF Suspension Technology Guadalajara S.A. de C.V. La metodología empleada permitió establecer las condiciones actuales de operación de las cinco líneas. Mediante el uso del método mencionado se encontró que en la mayoría de las líneas de ensamble analizadas sus tareas se encuentran correctamente balanceadas y ordenadas, corroborando así el buen trabajo realizado al momento de su instalación y puesta en marcha. Si bien en cualquier proceso de ensamble siempre hay oportunidades de mejora, contar con líneas de ensamble bien balanceadas permite a la empresa tener una base sólida para la producción de este tipo de componentes automotrices.

The Helgeson & Birnie method was employed in this research for balancing, by positional weight, five modular strut assembly production lines at ZF Suspension Technology Guadalajara S.A. De C.V. The proposed methodology allowed to know the current operating conditions of the production lines. It was found that most of the analyzed production lines are correctly balanced suggesting a correct commissioning and start up procedure performed when the lines were initially installed. Although every assembling line always can be improved, having well-balanced assembly lines provides a solid base line for any automotive manufacturing company.

Líneas de ensamble modular Método de Helgeson & Birnie Peso posicional Final assembly lines Helgeson & Birnie method Positional weight INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Teacher training in the state of Chihuahua: Between the health challenge and teacher resilience

Evangelina Cervantes Holguín Pavel Roel Gutiérrez Sandoval Cely Celene Ronquillo Chávez (2023, [Artículo, Artículo])

The article proposes to recover the response of the Teacher Training and Updating Institutions in the state of Chihuahua regarding the various challenges imposed by the Coronavirus Disease (COVID-19). The qualitative exercise analyzes the experience of 10 institutions based on the voice of their students, teachers, and principals regarding changes in academic, administrative, and organizational processes. It is concluded that the pandemic has affected each institution in different ways and with diverse intensity. Despite the achievements, the experience analyzed reveals the relative success of the using virtual platforms in the face of three basic conditions: connectivity, technological competencies, and socio-emotional skills of the teaching staff. It highlights the importance of implementing tutoring, resilience, or awareness actions of teachers and students' needs, feelings, and sufferings. It is opportune to recover the experiences of other institutions and to question especially students, thesis students and graduates.

Acceso a la educación Aprendizaje en línea Educación a distancia Formación de docentes Tecnología educacional HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA Access to education online learning distance education teacher education educational technology

Big data, small explanatory and predictive power: Lessons from random forest modeling of on-farm yield variability and implications for data-driven agronomy

Martin van Ittersum (2023, [Artículo])

Context: Collection and analysis of large volumes of on-farm production data are widely seen as key to understanding yield variability among farmers and improving resource-use efficiency. Objective: The aim of this study was to assess the performance of statistical and machine learning methods to explain and predict crop yield across thousands of farmers’ fields in contrasting farming systems worldwide. Methods: A large database of 10,940 field-year combinations from three countries in different stages of agricultural intensification was analyzed. Random effects models were used to partition crop yield variability and random forest models were used to explain and predict crop yield within a cross-validation scheme with data re-sampling over space and time. Results: Yield variability in relative terms was smallest for wheat and barley in the Netherlands and for wheat in Ethiopia, intermediate for rice in the Philippines, and greatest for maize in Ethiopia. Random forest models comprising a total of 87 variables explained a maximum of 65 % of cereal yield variability in the Netherlands and less than 45 % of cereal yield variability in Ethiopia and in the Philippines. Crop management related variables were important to explain and predict cereal yields in Ethiopia, while predictive (i.e., known before the growing season) climatic variables and explanatory (i.e., known during or after the growing season) climatic variables were most important to explain and predict cereal yield variability in the Philippines and in the Netherlands, respectively. Finally, model cross-validation for regions or years not seen during model training reduced the R2 considerably for most crop x country combinations, while for wheat in the Netherlands this was model dependent. Conclusion: Big data from farmers’ fields is useful to explain on-farm yield variability to some extent, but not to predict it across time and space. Significance: The results call for moderate expectations towards big data and machine learning in agronomic studies, particularly for smallholder farms in the tropics where model performance was poorest independently of the variables considered and the cross-validation scheme used.

Model Accuracy Model Precision Linear Mixed Models CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MACHINE LEARNING SUSTAINABLE INTENSIFICATION BIG DATA YIELDS MODELS AGRONOMY

Point placement of late vegetative stage nitrogen splits increase the productivity, N-use efficiency and profitability of tropical maize under decade long conservation agriculture

Hari Sankar Nayak C.M. Parihar Shankar Lal Jat ML JAT Ahmed Abdallah (2022, [Artículo])

Non-Linear Growth Model Nitrogen Remobilization Right Placement Precision Nitrogen Management CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GROWTH MODELS NITROGEN NUTRIENT MANAGEMENT

Efficacy of plant breeding using genomic information

Osval Antonio Montesinos-Lopez Alison Bentley Carolina Saint Pierre Leonardo Abdiel Crespo Herrera Morten Lillemo Jose Crossa (2023, [Artículo])

Genomic Selection Genomic Prediction Genomic Best Linear Unbiased Predictor CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA PLANT BREEDING GENOMICS MARKER-ASSISTED SELECTION ENVIRONMENT

A novel method for genomic-enabled prediction of cultivars in new environments

Osval Antonio Montesinos-Lopez Brandon Alejandro Mosqueda González Jose Crossa (2023, [Artículo])

Genomic Best Linear Unbiased Prediction Gains in Accuracy Genomic Prediction Novel Methods CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GENOTYPE ENVIRONMENT INTERACTION METHODS ENVIRONMENT

Análisis de la implementación de los lineamientos técnicos específicos para la reapertura de las actividades económicas de las pequeñas empresas en Cuernavaca, Morelos

DIANA LAURA HERNÁNDEZ CARLOS (2023, [Tesis de maestría])

El presente trabajo habla de cómo afecto la pandemia por COVID 19 a las pequeñas y medianas empresas de Cuernavaca, Morelos, y las medidas de prevención que las autoridades de salud emitieron en qué consisten, cómo se debían llevar a cabo para garantizar la continuidad de las operaciones de forma segura durante la etapa crítica de la pandemia.

Se analiza la implementación por parte de estas pequeñas y medianas empresas, y el cómo fueron informados y capacitados para ello, así como los recursos con los que contaron.

CIENCIAS SOCIALES CIENCIAS ECONÓMICAS Pandemia, lineamiento, reapertura, conocimiento, implementación. recursos

XYZ Micropositioning System Based on Compliance Mechanisms Fabricated by Additive Manufacturing

CARLOS ANDRES FERRARA BELLO Pedro Vargas Chable José Gerardo Vera Dimas Margarita Tecpoyotl Torres (2021, [Artículo])

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.

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS PETG, MEMS, micromanipulation, piezoelectric actuation, hysteresis effect linearization

Diseño de arreglos de antenas para entornos de 5G utilizando técnicas de simplificación en la red de alimentación

Design of antenna arrays for 5G environments using simplification techniques in the feeding network

ELIZVAN JUAREZ PACHECO (2023, [Tesis de doctorado])

En los últimos años, las redes de comunicaciones inalámbricas de quinta generación (5G) han tomado gran relevancia debido al crecimiento del número de usuarios móviles que se conectan a estas redes inalámbricas. Estas redes utilizan arreglos de antenas para generar haces de radiación directivos que pueden escanearse en una o múltiples direcciones en el espacio mediante el control de una red de alimentación. En una red de alimentación convencional cada elemento de antena se alimenta con un dispositivo amplificador y desfasador, lo que resulta en sistemas costosos y complejos de implementar. Por lo tanto, esta tesis de investigación propone nuevas técnicas de diseño que simplifican la red de alimentación al reducir el número de puertos de entrada y dispositivos desfasadores necesarios en el sistema de antenas. Las configuraciones propuestas consideran como requisitos de diseño el nivel de lóbulo lateral (SLL por sus siglas en inglés), rango de escaneo del haz principal y ancho de banda de operación adecuados para sistemas de 5G. Así, se introduce la técnica de bloques CORPS (Estructuras Periódicas de Radiación Coherente, en inglés) como una solución para simplificar la red de alimentación en arreglos lineales y planares. Esta técnica aprovecha la propiedad de interpolación de fase de las redes CORPS de una capa para generar los valores cofasales ideales necesarios para escanear el haz principal. Además, la aplicación de una excitación de amplitud de coseno alzado genera un haz de radiación con bajo SLL. Adicionalmente, se aplica la técnica de bloques CORPS en configuraciones con subarreglos para mejorar la reducción de desfasadores en comparación con la implementación individual de cada tecnología. Los resultados obtenidos mediante simulación electromagnética y mediciones experimentales validan los diferentes diseños propuestos. Todo esto contribuye al estado del arte al presentar diferentes diseños de arreglos de antenas que simplifican la red de alimentación manteniendo buenas características en el patrón de radiación en comparación con diseños tradicionales.

In recent years, fifth-generation wireless networks (5G) have become very relevant due to the exponential growth in the number of mobile users connecting to wireless networks. These networks employ antenna arrays to generate directional radiation beams that can be scanned in one or multiple directions in space by controlling a feeding network. In a conventional feeding network, each antenna element is fed with an amplifier and phase shifter device, which results in expensive and complex systems to implement. Therefore, this thesis proposes novel design techniques that simplify the feeding network by reducing the number of input ports and phase shifter devices required in the antenna system. The proposed configurations take into account requirements such as side lobe level (SLL), scanning range, and bandwidth appropriate for 5G systems. Thus, the CORPS (Coherent Radiation Periodic Structures) blocks technique is introduced as a solution to simplify the feeding network in linear and planar phased arrays. This technique takes advantage of the phase interpolation property of single-layer CORPS to generate the ideal cophasal values necessary for the main beam scanning. Furthermore, the application of a raised-cosine amplitude distribution generates a radiation beam with low SLL. Additionally, the CORPS blocks technique is applied in subarrays configurations to improve the phase shifters reduction compared to the individual implementation of each technology. The results obtained by electromagnetic simulation and experimental measurements validate the different proposed designs. This contributes to the state of the art by different designs of antenna arrays that simplify the feeding network while maintaining good radiation pattern characteristics when compared to traditional designs.

Arreglo de antenas, Red de alimentación, Quinta generación, Arreglo lineal, Arreglo planar Antenna array, Feeding network, Fifth Generation, Linear array, Planar array INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LAS TELECOMUNICACIONES ANTENAS ANTENAS