Thermal and mechanical properties of PLA-based multiscale cellulosic biocomposites

MIGUEL ANGEL RUZ CRUZ Pedro Jesús Herrera Franco Emmanuel Alejandro Flores Johnson MARIA VERONICA MORENO CHULIM LUCIANO MIGUEL GALERA MANZANO Alex Valadez González (2022, [Artículo])

In this work polylactic acid (PLA) based multiscale cellulosic biocomposites were prepared with the aim to evaluate the effect of the incorporation of cellulose nanocrystals (CNCs) on the PLA biocomposites reinforced with cellulose microfibers (MFCs). For this, PLA composite materials reinforced with both MFCs and with a combination of MFCs and CNCs were prepared, while keeping the content of cellulosic reinforcements constant. The thermal and mechanical properties of these multiscale PLA biocomposites were characterized by thermogravimetry (TGA), differential scanning calorimetry (DSC), flexural mechanical and, dynamic mechanical (DMA) tests. Likewise, they were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results show that the replacement of MFCs by CNCs in the 1–5% range appreciably modifies the thermal and mechanical properties of multiscale compounds. For example, they increase the thermal stability of the materials, modify the PLA crystallization process and play the role of adhesion promoters since the mechanical properties in flexure increase in the order of 40% and the storage modulus increases in the order of 35% at room temperature. Also, the addition of CNCs increases the relaxation temperature of the material from 50 to 60 °C, thereby expanding the temperature range for its use. © 2022 The Author(s)

MULTISCALE BIOCOMPOSITES CELLULOSE MICROFIBER CELLULOSE NANOCRYSTALS HIERARCHICAL STRUCTURE PROPERTIES INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Las cáscaras de naranja: ¿Desechos de la agricultura o riqueza farmacéutica?

ROLFFY RUBEN ORTIZ ANDRADE JESUS ALFREDO ARAUJO LEON Gregoreo Centeno Hoil MICHELLE SANSORES CHUC (2023, [Artículo])

México se encuentra entre los diez primeros países con la mayor producción de cítricos, siendo Yucatán uno de los principales estados productores, en particular, de naranjas. Actualmente, la producción de cítricos se utiliza para la extracción de jugo para alimentos y bebidas. Sin embargo, las cáscaras de naranjas son desechadas o subutilizadas. En este ensayo abordamos una perspectiva del potencial médico y económico que existe en las cáscaras de naranja y que podrían ser una riqueza farmacéutica por su alto contenido de flavonoides, moléculas que han sido objeto de estudio para la prevénción de la diabetes, hipertensión y la obesidad.

CITRUS SINENSIS DIABETES HESPERIDINA HIPERTENSION NARINGENINA OBESIDAD BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) EXPLOTACIÓN DE LOS CULTIVOS EXPLOTACIÓN DE LOS CULTIVOS

Preparation and characterization of strongly sulfonated acid block and random copolymer membranes for acetic acid esterification with 2-Propanol

Verónica Rosiles González Ronan Le Lagadec ARELLY PAULINA VARGUEZ CATZIM María Isabel de los Dolores Loría Bastarrachea Abigail Gonzalez Diaz EMANUEL HERNANDEZ NUÑEZ Manuel de Jesús Aguilar Vega MARIA ORTENCIA GONZALEZ DIAZ (2022, [Artículo])

In this paper, we report the synthesis of block and random copolymers of 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and methyl methacrylate (MMA), with different AMPS feed ratios. These solution-processable copolymers with strongly sulfonated acid groups resulted in membranes with tunable ion exchange (IEC) and water absorption capacities. AFM images confirmed the microphase separation of PAMPS-b-PMMA-1:1 block copolymer membrane, annealed under the appropriate conditions. The resulting copolymers from the random combination of a 1:1 molar ratio of AMPS and MMA monomers are effective at enhancing the esterification conversion of acetic acid, when compared with a reaction catalyzed by PAMPS-b-PMMA block copolymers and the previously studied catalytic membranes. With the PAMPS-co-PMMA-1:1 membrane, the esterification reaction using acetic acid achieved 85% isopropyl acetate. These results are closely correlated with the increase in IEC (2.63 mmol H+ g−1 ) and the relationship between weight loss (20.3%) and swelling degree (68%) in 2-propanol. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

BLOCK COPOLYMERS RANDOM COPOLYMERS CATALYTIC MEMBRANES ESTERIFICATION ISOPROPYL ACETATE INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Análisis a escala atómica de interfases magnéticas con aplicaciones en espintrónica

Atomic scale analysis of magnetic interfases with spintronics applications

Rocio González Díaz (2023, [Tesis de maestría])

La espintrónica es un área de la nanociencia que tiene por cometido el estudio y manipulación del espín de los electrones para el desarrollo y mejoramiento de dispositivos electrónicos. De manera particular, se ha orientado a la búsqueda de materiales para la fabricación de memorias magnéticas de acceso aleatorio (MRAM), diseñadas a partir de uniones túnel magnéticas (MTJ). Dichas uniones son heteroestructuras construidas a partir de un material aislante en cuya capa superior e inferior se dispone un compuesto ferromagnético. Una de las características de estos dispositivos es que presentan una anisotropía magnética perpendicular (PMA) y un efecto de torque por transferencia de espín (STT). Recientemente, un estudio experimental señala que la heteroestructura B2-CoAl/L10-MnAl es un candidato idóneo para la fabricación de MRAM, pues presenta PMA y STT. Sin embargo, en el trabajo experimental no se reporta un análisis de la estabilidad termodinámica de la heteroestructura. Dicho lo anterior, en este trabajo se hizo un estudio de la estabilidad termodinámica y estructural de B2-CoAl/L10-MnAl usando la teoría del funcional de la densidad (DFT). Se propusieron diferentes modelos de interfaz CoAl/MnAl y se determinó a través de un análisis energético cuál es la interfaz más estable. Los resultados obtenidos indican que la interfaz más estable sucede entre la última capa de Al del CoAl y la primera capa de Mn del MnAl. Además, se comprobó un efecto PMA en la heteroestructura B2-CoAl/L10-MnAl y se determinó que este comportamiento se origina esencialmente debido a la naturaleza ferromagnética de MnAl, pues CoAl no presenta características ferromagnéticas.

Spintronics is nanoscience area whose aim is the study and manipulation of electrons spin to development and improvement of electronic devices. In a particular way, the spintronics has focused to search of new materials to fabrication of magnetic random-access memory (MRAM), which are designed from devices call magnetic tunnel junctions (MTJ). This devices are heterostructures built from an insulating material with a ferromagnetic compound on top and bottom layers and characterized by the perpendicular magnetic anisotropy and spin-transfer torque (STT) effects prensent on it. Recently, an experimental study indicates the B2-CoAl/L10-MnAl heterostructure is a suitable candidate for the fabrication of MRAM based on MTJ devices. Nevertheless, the thermodynamic stability of the heteroestructure is not reported in the experimental work. Therefore, in this work a study of the thermodynamic and structural stability of B2-CoAl/L10-MnAl was performed using density functional theory (DFT). Different CoAl/MnAl interface models were proposed and the most stable interface was determined by an energy analysis. The results obtained, indicate that the most stable interface occurs between the last Al layer of CoAl and the first Mn layer of MnAl. In addition, a PMA effect in the B2-CoAl/L10-MnAl heterostructure was demonstrated and it was determined that this behaviour is essentially due to the ferromagnetic nature of MnAl, since CoAl does not present ferromagnetic characteristics.

simulaciones computacionales, interfases magnéticas, estabilidad termodinámica computational simulation, magnetic interfaces, termodinamic stability INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

Effect of the noble metals addition on the oxidation behavior of Ni3Al

Jose Juan Ramos-Hernandez JESUS PORCAYO-CALDERON Jan Mayen Chaires GABRIEL ANGEL LARA RODRIGUEZ victor salinas JOSE-GONZALO GONZALEZ-RODRIGUEZ Lorenzo Martínez Gómez (2018, [Artículo])

This paper discusses the e1ect of the addition of noble metals on the microstructure, mechanism, and oxidation kinetics of the Ni3Al intermetallic alloy. Ni3Al was doped with 1% (atomic percent) of Au, Ag, Pd, and Pt. Oxidation behavior of the alloys was evaluated at 900, 1000, and 1100°C in O2 for 24 hours. XRD analysis showed that the addition of noble metals favored the oxide growth on preferential crystallographic planes. In addition, the preferential substitution of the noble metals in the Ni3Al structure modi>es the surface composition by increasing the Al/Ni ratio. It was observed that most of the alloys showed a subparabolic behavior, and only the intermetallic base and the alloy doped with Ag show a parabolic behavior at 900°C. ,e developed oxides were analyzed both super>cially and in cross section by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA). It was evident that only the intermetallic base showed the formation of a duplex oxide scale (Al2O3/NiO). ,e alloys doped with noble metals showed the oxide growth practically of pure Al2O3. ,is was due to a decrease in the di1usion of the Ni cations because of the presence of the noble metals in the crystalline structure.

Financial support from Consejo Nacional de Ciencia y Tecnologia (CONACYT, Mexico) (Project no. 159898 and Ph.D. scholarship to J. J. Ramos-Hernandez, Registration no. 202898) is gratefully acknowledged.

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

LA CULTURA DE RESISTENCIA ANTE EL MEGAPROYECTO EN EL RÍO CUAUTLA (2013-2022)

Sendic Sagal Luna (2023, [Tesis de maestría])

“Por más de nueve años los campesinos opositores del municipio de Ayala, al sur del estado de Morelos, han mantenido una defensa del agua del río Cuautla. Durante este tiempo han reivindicado una postura ambientalista y de justicia social, que desborda y enfrenta los objetivos de gestión, administración y mercantilización del agua de la dirigencia de la Asociación de Usuarios del Agua del Río Cuautla, Manantiales y Corrientes tributarias “General Eufemio Zapata Salazar” (ASURCO), asociación que además de aglutinar y representar a más de seis mil ejidatarios y pequeños propietarios, es concesionaria de la infraestructura de riesgo desde 1994 y responsable de las dotaciones de agua de los usuarios. La resistencia en defensa del agua del río Cuautla he prevalecido ante la fase de imposición del acueducto para la termoeléctrica del Proyecto Integral Morelos (PIM), que va del 2013 al 2022. La relevancia político-simbólica de los que observaremos como una cultura de resistencia reside en la re-significación del mito de Zapata y en la reconstitución de las identidades transterritoriales, que toman lugar y forma en la protesta campesina y en los rituales festivo-religiosos de los habitantes afectados de Anenecuilco y Tenextepango. Como pueblos del municipio de Ayala, Morelos, Anenecuilco y Tenextepango se benefician de los terrenos fértiles en el ámbito rural aguas abajo del río Cuautla y se ven afectados por el trasvase de agua, a través del acueducto para la termoeléctrica ubicada en Huexca, municipio de Yecapixtla, al nororiente morelense. Otro proceso que se observa en relación con la imposición del acueducto en el río Cuautla, es el de las intervenciones directas-indirectas de las fuerzas de seguridad y otros grupos armados; intervenciones armadas que han impactado negativamente en la resistencia y en la vida cotidiana de los habitantes en los pueblos al suroriente de Morelos”.

Conflictos en torno al agua - México - Cuautla, Morelos. Abastecimiento de agua - Morelos. Cuautla, río - Aspectos ambientales. Central termoeléctrica Huexca (México). Tesis - Maestría en Antropología Social, CDMX. CIENCIAS SOCIALES SOCIOLOGÍA SOCIOLOGÍA DE LOS ASENTAMIENTOS HUMANOS SOCIOLOGÍA ECOLÓGICA SOCIOLOGÍA ECOLÓGICA

REAL TIME EMBBEDED RGB-D SLAM USING CNNS FOR DEPTH ESTIMATION AND FEATURE EXTRACTION

Marcos Renato Rocha Hernández (2023, [Tesis de maestría])

"A robust and efficient Simultaneous Localization and Mapping (SLAM) system is essential for intelligent mobile robots to work in unknown environments. For visual SLAM algorithms, though the theoretical framework has been well established for most aspects, feature extraction and association is still empirically de signed in most cases, and can be vulnerable in complex environments. Also, most of the most robust SLAM algorithms rely on special devices like a stereo camera or depth sensors, which can be expensive and give more complexity to the system, that is why monocular depth estimation is an essential task in the computer vision community. This work shows that feature extraction and depth estimation using a monocular camera with deep convolutional neural networks (CNNs) can be incorporated into a modern SLAM framework. The proposed SLAM system utilizes two CNNs, one to detect keypoints in each im age frame, and to give not only keypoint descriptors, but also a global descriptor of the whole image and the second one to make depth estimations from a single image frame, all using only a monocular camera."

SLAM Inteligencia Artificial CNN Sistemas embebidos Redes neuronales Cámara monocular INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES INTELIGENCIA ARTIFICIAL INTELIGENCIA ARTIFICIAL

Classification of Cucumber Leaves Based on Nitrogen Content Using the Hyperspectral Imaging Technique and Majority Voting.

Sajad Sabzi Razieh Pourdarbani Mohammad Hossein Rohban Alejandro Fuentes_Penna José Luis Hernández-Hernández Mario Hernández Hernández (2021, [Artículo])

Improper usage of nitrogen in cucumber cultivation causes nitrate accumulation in the fruit and results in food poisoning in humans; therefore, mandatory evaluation of food products becomes inevitable. Hyperspectral imaging has a very good ability to evaluate the quality of fruits and vegetables in a non-destructive manner. The goal of the present paper was to identify excess nitrogen in cucumber plants. To obtain a reliable result, the majority voting method was used, which takes into account the unanimity of five classifiers, namely, the hybrid artificial neural network¿imperialism competitive algorithm (ANN-ICA), the hybrid artificial neural network¿harmonic search (ANN-HS) algorithm, linear discrimination analysis (LDA), the radial basis function network (RBF), and the Knearest- neighborhood (KNN). The wavelengths of 723, 781, and 901 nm were determined as optimal wavelengths using the hybrid artificial neural network¿biogeography-based optimization (ANNBBO) algorithm, and the performance of classifiers was investigated using the optimal spectrum. The results of a t-test showed that there was no significant difference in the precision of the algorithm when using the optimal wavelengths and wavelengths of the whole range. The correct classification rate of the classifiers ANN-ICA, ANN-HS, LDA, RBF, and KNN were 96.14%, 96.11%, 95.73%, 64.03%, and 95.24%, respectively. The correct classification rate of majority voting (MV) was 95.55% for test data in 200 iterations, which indicates the system was successful in distinguishing nitrogen-rich leaves from leaves with a standard content of nitrogen.

artificial neural network cucumber hyperspectral imaging majority voting nitrogen INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS

Comparison of Different Classifiers and the Majority Voting Rule for the Detection of Plum Fruits in Garden Conditions.

Razieh Pourdarbani Sajad Sabzi Mario Hernández Hernández José Luis Hernández-Hernández Ginés García_Mateos Davood Kalantari José Miguel Molina Martínez (2019, [Artículo])

Color segmentation is one of the most thoroughly studied problems in agricultural applications of remote image capture systems, since it is the key step in several different tasks, such as crop harvesting, site specific spraying, and targeted disease control under natural light. This paper studies and compares five methods to segment plum fruit images under ambient conditions at 12 different light intensities, and an ensemble method combining them. In these methods, several color features in different color spaces are first extracted for each pixel, and then the most e

ective features are selected using a hybrid approach of artificial neural networks and the cultural algorithm (ANN-CA). The features selected among the 38 defined channels were the b* channel of L*a*b*, and the color purity index, C*, from L*C*h. Next, fruit/background segmentation is performed using five classifiers: artificial neural network-imperialist competitive algorithm (ANN-ICA); hybrid artificial neural network-harmony search (ANN-HS); support vector machines (SVM); k nearest neighbors (kNN); and linear discriminant analysis (LDA). In the ensemble method, the final class for each pixel is determined using the majority voting method. The experiments showed that the correct classification rate for the majority voting method excluding LDA was 98.59%, outperforming the results of the constituent methods.

remote sensing in agriculture artificial neural network hybridization environmental conditions majority voting plum segmentation INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS

Interfaces hápticas para identificar marcadores digitales del Trastorno del Espectro Autista

Haptic interfaces to identify digital markers of Autism Spectrum Disorder

GLORIA IVONNE MONARCA PINTLE (2023, [Tesis de doctorado])

El uso de herramientas de cribado durante la infancia es de suma importancia para identificar a niños que pueden Trastorno del Espectro Autista (TEA); sin embargo, las pruebas que existen en la actualidad se basan en cuestionarios y observaciones contestadas por los padres por lo que el resultado puede ser subjetivo. Además, la mayoría de las pruebas de cribado se enfocan en el área social y de comunicación, dejando a un lado las características sensoriales, un área donde los padres notan las primeras señales de un desarrollo atípico. En los últimos años, ha crecido el interés por identificar marcadores digitales del TEA que puedan apoyar el cribado de dicho trastorno, usando tecnología que pueda ser usada en cualquier lugar y momento para agilizar el proceso de cribado. Hasta el momento, la investigación en torno a marcadores digitales del TEA relacionados con el procesamiento táctil, ha sido poco explorada debido a que la investigación se ha centrado en explorar otros comportamientos, como la atención visual, movimientos motores, y voz. El crecimiento de las interfaces hápticas abre la posibilidad de explorar el procesamiento táctil e identificar marcadores digitales del TEA. En esta tesis exploramos si las interfaces hápticas pueden ser usadas para promover y recolectar interacciones táctiles que revelen marcadores digitales del TEA. Para tener un mejor entendimiento de las interfaces hápticas, en este trabajo de tesis exploramos dos interfaces hápticas. Una interfaz háptica pasiva llamada BendableSound, la cual cuenta con una retroalimentación por textura y espacio; y una interfaz háptica activa llamada Feel and Touch, la cual es un juego móvil que utiliza patrones vibrotactiles para retroalimentar las interacciones de los niños. Los resultados muestran que las interfaces hápticas tienen la capacidad recolectar interacciones táctiles y revelar marcadores digitales que pueden estar asociados al TEA. En el caso pasivo, participaron 37 niños neurotípicos (NT) y 22 niños con TEA quienes interactuar con BendableSound; los resultados muestran que existen diferencias entre los niños NT y TEA en cuanto al ancho de las interacciones táctiles, la fuerza que aplican y el tiempo que utilizan para realizar interacciones táctiles. En el caso activo, participaron 36 niños NT y 19 niños con TEA quienes interactuaron con Feel and Touch; los resultados muestran que existen diferencias entre los niños NT y TEA en cuanto a la ...

The use of screening tools during infancy is crucial to identify children who are likely to have Autism Spectrum Disorder (ASD); however, the current screening tests are based on questionnaires and observations that parents answer bases on their observations; however, the results might be subjective. In addition, most screening tests focus on the assessment of social and communication skills, disregard sensory skills, an area where parents often notice the first signals of ASD. In recent years, there has been growing interest in identifying digital markers of ASD that can support screening, particularly those that that can be used at any time and any place to speed up the screening process. So far, research on digital markers of ASD related to tactile processing has been little explored due to the lack of tools to assess it. The growth of haptic interfaces opens the possibility to explore tactile processing and identify digital markers of ASD. In this thesis, we propose to investigate the use of haptic interfaces to promote and collect tactile interactions that can reveal digital markers of ASD. To have a better understanding of haptic interfaces, in this thesis work we explore two types of haptic interface. A passive haptic interface called BendableSound, which features texture and spatial feedback; and an active haptic interface called Feel and Touch, which is a mobile game that uses vibrotactile patterns to provide feedback on children’s interactions. The results show that haptic interfaces have the potential to collect touch interactions and reveal digital markers that may be associated with ASD. In the first case, 37 neurotypical (NT) children and 22 children with ASD participated and interacted with BendableSound; the results show that there are differences between NT and ASD children in the width of tactile interactions, the force they apply, and the time they use to perform tactile interactions. In the second case, 36 NT children and 19 children with ASD participated and interacted with Feel and Touch; the results show that there are differences between NT and ASD children in terms of the tilt they produce on the mobile when performing tactile interactions, the total acceleration they produce, and the closeness to the center of the screen of their tactile interactions. The results of this thesis indicate that haptic interfaces have the ability to gather touch interactions and uncover digital markers associated with ASD. The findings of this ...

autismo, cribado, marcadores digitales, interfaces hápticas, aprendizaje automático autism, screnning, digital markers, haptic interfaces, machine learning INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ORDENADORES ORDENADORES DIGITALES ORDENADORES DIGITALES