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361 resultados, página 6 de 10

Drenaje parcelario y sistemas de bombeo con energía alternativa para mitigar y controlar el ensalitramiento en suelos agrícolas

Leonardo Pulido-Madrigal Heber Saucedo LUIS ARTURO BRIZUELA MUNDO (2014, [Documento de trabajo])

Se presentan las actividades realizadas para establecer una parcela piloto equipada con drenaje y sistemas de bombeo con energía eólica o solar, así como medir y analizar las variables relacionadas con la evolución de la salinidad y los efectos del drenaje en el mejoramiento del suelo y la producción agrícola.

Distritos de riego Suelos salitrosos Drenaje parcelario Energía solar Energía eólica Informes de proyectos Navojoa, Sonora Etchojoa, Sonora Huatabampo, Sonora CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

COVID-19 and family participation in school activities.: Teaching experiences around the Learn at Home program

Evangelina Cervantes Holguín Pavel Roel Gutiérrez Sandoval (2022, [Artículo, Artículo])

The article analyzes, from the qualitative method, the participation of families and teaching staff of the first cycle of primary education in the state of Chihuahua (Mexico) to carry out the various activities of the Learn at Home program implemented in March 2020 as a response to the resulting health confinement by COVID-19. It is concluded that the participation of families in school emergency situations implies improving the relationship between teachers, families, and the community in the implementation processes of educational programs with greater support to organize study times, take advantage of the different cultural capitals and promote family co-responsibility.

Aprendizaje Educación a distancia Enseñanza primaria Epidemia Familia COVID-19 Chihuahua HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA Family Elementary education Epidemics Distance education Learning

La construcción del sujeto leproso

Yaminel Bernal Astorga (2008, [Tesis de doctorado])

La lepra es una enfermedad que hasta el día de hoy continúa entre nosotros, irrumpe en la vida de las personas transformando su existencia de manera significativa, pues en cada una ellas delinean marcas que trascienden en el cuerpo, en las relaciones, en lo que hacen y en lo que piensan. Pero, sobre todo, cuando los individuos son identificados como “enfermos de lepra”, de entrada, quedan sujetos a los significados que anteceden a este padecimiento y que, generalmente, están vinculados con las expresiones de horror y miedo debido a la deformidad, la putrefacción, la discapacidad y el contagio que puede causar. De este modo, formular que el “enfermo de lepra” es objeto del dolor, las transformaciones en el cuerpo, los señalamientos, las exclusiones… son percepciones que, prácticamente, pueden vislumbrarse de antemano. Sin embargo, me interesa ir más allá de lo que hasta ahora se tiene por sentado en relación con el “enfermo de lepra”, e incluso la forma en la que puede ser problematizado.

Lepra Piel -- Enfermedades CIENCIAS SOCIALES SOCIOLOGÍA PROBLEMAS SOCIALES ENFERMEDAD ENFERMEDAD

Fabricación de nanopartículas de oro dentro de óxido de aluminio (γ-Al2O3) nanoestructurado con cavidades esféricas

Manufacturing of Gold Nanoparticles within Nanostructured Aluminum Oxide (γ-Al2O3) with Spherical Cavities

Mariela de Jesús Franco Gallegos (2023, [Tesis de maestría])

Los catalizadores basados en nanopartículas de oro han generado gran interés, gracias a su capacidad de ser selectivos en la promoción de reacciones específicas o en la producción de productos deseados, minimizando la formación de productos secundarios no deseados; sus propiedades electrónicas únicas; y su utilización bajo condiciones ambientales. Sin embargo, la desventaja principal de los catalizadores de oro es la sinterización de las nanopartículas debido a su baja temperatura de fusión, lo que provoca la pérdida de actividad catalítica y la desactivación del catalizador. Una de lassoluciones que ofrece el uso de la nanociencia y la nanotecnología es la utilización de soportes nanoestructurados que den mejor estabilidad a las nanopartículas y las protejan de la desactivación. En este trabajo se sintetizaron catalizadores basados en nanopartículas de oro soportados y encapsulados en alúmina macroporosa, por un método de impregnación húmeda asistida por ultrasonido; un método sencillo, rápido y ecológico. El desempeño catalítico de materiales sintetizados se analizó mediante espectroscopía UV-Visible in-situ en la reducción de 4-Nitrofenol a 4-Aminofenol. Así mismo, se presentan las caracterizaciones por TEM, SEM, FT-IR, espectroscopía UV-Visible, y XRD de catalizadores obtenidos. Se obtuvieron catalizadores altamente activos con alto rendimiento gracias al uso de un soporte nanoestructurado.

Catalysts -based on gold nanoparticles have recently gained interest due to their ability to selectively promote specific catalytic reactions or produce desired products, while minimizing the formation of unwanted byproducts, their unique electronic properties, and their utilization under ambient conditions. However, the main drawback of gold catalysts is the sintering of nanoparticles due to their low melting temperature, which leads to loss of catalytic activity and catalyst deactivation. One of the solutions offered by nanoscience and nanotechnology is the use of nanostructured supports that provide better stability to the nanoparticles and protect them from deactivation. In this work, gold nanoparticle-based catalysts supported and encapsulated in macroporous alumina were synthesized using a simple, fast, and eco-friendly method of ultrasound-assisted wet impregnation. The catalytic performance of synthetized materials was evaluated by in-situ UV-Visible spectroscopy in the reduction of 4-Nitrophenol to 4-Aminophenol. In addition, their characterization by TEM, SEM, FT-IR, UV Visible spectroscopy and XRD are presented. Highly active catalysts with high performance were obtained thanks to the use of a nanostructured supports.

nanopartículas de oro, alúmina macroporosa, impregnación, reducción 4-NF gold nanoparticles, macroporous alumina, impregnation, 4-NF reduction INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

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

A Novel Technique for Classifying Bird Damage to Rapeseed Plants Based on a Deep Learning Algorithm.

Ali Mirzazadeh Afshin Azizi Yousef Abbaspour_Gilandeh José Luis Hernández-Hernández Mario Hernández Hernández Iván Gallardo Bernal (2021, [Artículo])

Estimation of crop damage plays a vital role in the management of fields in the agricultura sector. An accurate measure of it provides key guidance to support agricultural decision-making systems. The objective of the study was to propose a novel technique for classifying damaged crops based on a state-of-the-art deep learning algorithm. To this end, a dataset of rapeseed field images was gathered from the field after birds¿ attacks. The dataset consisted of three classes including undamaged, partially damaged, and fully damaged crops. Vgg16 and Res-Net50 as pre-trained deep convolutional neural networks were used to classify these classes. The overall classification accuracy reached 93.7% and 98.2% for the Vgg16 and the ResNet50 algorithms, respectively. The results indicated that a deep neural network has a high ability in distinguishing and categorizing different image-based datasets of rapeseed. The findings also revealed a great potential of Deep learning-based models to classify other damaged crops.

rapeseed classification damaged crops deep neural networks INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS

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

Validación del uso de energía renovable para su aplicación en el subsector agrícola

JOSE JASSON FLORES PRIETO Olga Xochitl Cisneros Estrada (2013, [Documento de trabajo])

Desarrollo tecnológico para la desalación de agua salobre con generación híbrida de paneles solares y aerogeneradores – Sistema de bombeo solar para riego presurizado – Sistema de desalación solar por nanofiltración – Referencias bibliográficas.

Energía solar Tecnología apropiada Desalación Nanofiltración Riego Informes de proyectos INGENIERÍA Y TECNOLOGÍA

AFECTIVIDAD, CUIDADO Y SUBJETIVACIÓN ENTRE HOMBRES. ACERCAMIENTO ETNOGRÁFICO A "UNIÓN", UN GRUPO DE ALOHÓLICOS ANÓNIMOS DE OAXACA

Roberto Ignacio Galdames Coloma (2023, [Tesis de maestría])

"Los grupos AA a través de rituales, un discurso común en la tribuna, la práctica del apadrinamiento, la solidaridad promovida y un código de relacionamiento, establecen un contexto en el cual las acciones de cuidado entre hombres son socialmente permitidas y valoradas. El objetivo central de esta investigación es analizar de qué manera los participantes del grupo de Alcohólicos Anónimos "Unión" producen y reproducen prácticas de cuidado, incluyendo relaciones de afecto y sostén emocional con otros hombres y explorar que impacto tiene estos en sus subjetividades".

Alcoholismo - Tratamiento - Oaxaca, México. Alcohólicos anónimos - Estudio de casos - Oaxaca, México. Alcohólicos - Rehabilitación - Oaxaca, México. Tesis - Maestría en Antropología Social, Pacífico Sur. CIENCIAS SOCIALES SOCIOLOGÍA PROBLEMAS SOCIALES ENFERMEDAD ENFERMEDAD

Tensile behavior of 3D printed polylactic acid (PLA) based composites reinforced with natural fiber

Eliana M Agaliotis BALTAZAR DAVID AKE CONCHA ALEJANDRO MAY PAT Juan Pablo Morales Arias Celina Bernal Alex Valadez González Pedro Jesús Herrera Franco Gwenaelle Proust JUAN FRANCISCO KOH DZUL José Gonzalo Carrillo Baeza Emmanuel Alejandro Flores Johnson (2022, [Artículo])

Natural fiber-reinforced composite (NFRC) filaments for 3D printing were fabricated using polylactic acid (PLA) reinforced with 1–5 wt% henequen flour comprising particles with sizes between 90–250 μm. The flour was obtained from natural henequen fibers. NFRCs and pristine PLA specimens were printed with a 0° raster angle for tension tests. The results showed that the NFRCs’ measured density, porosity, and degree of crystallinity increased with flour content. The tensile tests showed that the NFRC Young’s modulus was lower than that of the printed pristine PLA. For 1 wt% flour content, the NFRCs’ maximum stress and strain to failure were higher than those of the printed PLA, which was attributed to the henequen fibers acting as reinforcement and delaying crack growth. However, for 2 wt% and higher flour contents, the NFRCs’ maximum stress was lower than that of the printed PLA. Microscopic characterization after testing showed an increase in voids and defects, with the increase in flour content attributed to particle agglomeration. For 1 wt% flour content, the NFRCs were also printed with raster angles of ±45° and 90° for comparison; the highest tensile properties were obtained with a 0° raster angle. Finally, adding 3 wt% content of maleic anhydride to the NFRC with 1 wt% flour content slightly increased the maximum stress. The results presented herein warrant further research to fully understand the mechanical properties of printed NFRCs made of PLA reinforced with natural henequen fibers. © 2022 by the authors.

POLYLACTIC ACID (PLA) NATURAL FIBER HENEQUEN FIBER NATURAL FIBER REINFORCED COMPOSITE (NFRC) ADDITIVE MANUFACTURING 3D PRINTING MECHANICAL PROPERTY INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES