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Selecciona los temas de tu interés y recibe en tu correo las publicaciones más actuales
Saúl Alejandro Rodríguez Jiménez LEONOR ADRIANA CARDENAS ROBLEDO (2023, [Artículo])
This paper develops a device capable of confirming the minimum coverage area on a thermistor by a thermal paste dispensed and cured in the manufacturing process of Exhaust Gas Recirculation (EGR) temperature sensors to provide the required fixation in the presence of mechanical shock conditions. Such a device leverages the thermistor’s self-heating effect and the thermal conductivity of the paste to read the voltage drop from the sensor, which translates into paste coverage area. The methodology follows a synthesized procedure to develop equipment and processes, considering an early phase for concept confirmation to demonstrate the feasibility of the device development. In a later phase, the optimal parameters are calculated and set to the device for delivering the corresponding classification of the sensors during the test. Once launched in production, the device demonstrates high effectiveness in screening out the sensors with rejectable paste coverage area on the thermistor.
Self-heating effect Thermistor Paste Temperature sensor Heat dissipation INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS
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
Andrea Carolina Godínez Rivera (2023, [Otro, Trabajo terminal, especialidad])
45 páginas. Especialización en Literatura Mexicana del Siglo XX.
Esta investigación recibió apoyo del Sistema Nacional de Posgrados (SNP), del Consejo Nacional de Humanidades, Ciencias y Tecnologías (CONAHCYT)
El propósito de la presente tesina es plantear una guía general con los componentes más sobresalientes que colaboran para la construcción gótica y fantástica de la obra de teatro El fantasma del hotel Alsace de Vicente Quirarte. Se analizarán los recursos como la representación y la simbología del fantasma, el efecto de la ambigüedad, la construcción del espacio y el tiempo como productores de universos ficcionales. En el primer capítulo, “El fantasma literario”, se visualizará la construcción fantástica del fantasma por medio de la teatralidad y el recurso de la fantasmagoría con base en las teorías de Max Milner, David Roas y José Miguel Sardiñas, Anne Ubersfeld y José Luis García Barrientos con el fin de mostrar la subjetividad de los misterios del ser humano donde existen los miedos y las angustias, los terrores del humano y así, mostrar lo que en otro tipo de literaturas no se puede hacer: presentar lo inexpresable de los horrores del hombre. En el segundo capítulo, “La imaginería gótica en lo fantástico”, se desarrolla el efecto de la ambigüedad que parte de la imaginería mental del personaje Oscar Wilde como producto de la locura. Además, se explicará en qué consiste la configuración del espacio encarcelado y el tiempo estático y desdibujado como parte de la construcción de la atmósfera gótica que aparece a lo largo de las cuatro escenas de la obra de teatro.
Wilde, Oscar, 1854-1900--Criticism and interpretation. Ghosts in the theater. Art, Gothic. Fantasmas en la literatura. Arte gótico. PR5824 HUMANIDADES Y CIENCIAS DE LA CONDUCTA CIENCIAS DE LAS ARTES Y LAS LETRAS TEORÍA, ANÁLISIS Y CRÍTICA DE LAS BELLAS ARTES
CIMMYT seed systems Interventions
AbduRahman Issa (2023, [Objeto de congreso])
CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SEED SYSTEMS VALUE CHAINS POLICIES HYBRIDS MAIZE WOMEN FARMERS
Women, economic resilience, gender norms in a time of climate change: what do we know?
Cathy Farnworth Anne Rietveld Rachel Voss Angela Meentzen (2023, [Artículo])
This literature delves into 82 research articles, published between 2016 and 2022, to develop a deep understanding of how women manage their lives and livelihoods within their agrifood systems when these systems are being affected, sometimes devastatingly, by climate change. The Findings show that four core gender norms affect the ability of women to achieve economic resilience in the face of climate change operate in agrifood production systems. Each of these gender norms speaks to male privilege: (i) Men are primary decision-makers, (ii) Men are breadwinners, (iii) Men control assets, and (iv) Men are food system actors. These gender norms are widely held and challenge women’s abilities to become economically resilient. These norms are made more powerful still because they fuse with each other and act on multiple levels, and they serve to support other norms which limit women’s scope to act. It is particularly noteworthy that many institutional actors, ranging from community decision-makers to development partners, tend to reinforce rather than challenge gender norms because they do not critically review their own assumptions.
However, the four gender norms cited are not hegemonic. First, there is limited and intriguing evidence that intersectional identities can influence women’s resilience in significant ways. Second, gender norms governing women’s roles and power in agrifood systems are changing in response to climate change and other forces, with implications for how women respond to future climate shocks. Third, paying attention to local realities is important – behaviours do not necessarily substantiate local norms. Fourth, women experience strong support from other women in savings groups, religious organisations, reciprocal labour, and others. Fifth, critical moments, such as climate disasters, offer potentially pivotal moments of change which could permit women unusually high levels of agency to overcome restrictive gender norms without being negatively sanctioned. The article concludes with recommendations for further research.
Economic Resilience Intersectional Identities Women Groups Support CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA ECONOMICS RESILIENCE CLIMATE CHANGE GENDER NORMS AGRIFOOD SYSTEMS WOMEN
Angela Meentzen (2023, [Objeto de congreso])
CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GENDER EQUALITY FOOD SYSTEMS CLIMATE CHANGE WOMEN'S PARTICIPATION
Maraeva Gianella Daniele Dondi Andreas Börner Anca Macovei Andrea Pagano Filippo Guzzon Alma Balestrazzi (2022, [Artículo])
Thermogravimetry CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CARBOHYDRATES PROLINE TOCOPHEROLS GENETICS PHYSIOLOGY PEAS SEEDS SUGARS DIFFERENTIAL SCANNING CALORIMETRY SEED LONGEVITY THERMOGRAVIMETRIC ANALYSIS
ENRIQUE JURADO YBARRA Joel David Flores Rivas Jonathan Marroquín MARISELA PANDO MORENO DAVID ALBERTO RODRIGUEZ TRAPERO Humberto González Rodríguez José Alejandro Selvera Mancha Juan Ángel López Carmona (2022, [Artículo])
"Competition and facilitation are important factors affecting seedling survival. These factors probably affect plant distribution and abundance. Interactions between species relate to phylogeny, in that closely related species are likely to compete more for resources and facilitation is expected between more distantly related species. We tested for Tamaulipan thornscrub plants, grown with close and distant relatives if they differed in survival, length and weight of shoots and roots, assuming that closely related species would compete more than distant ones. We also explored whether seed mass was associated with plant size from 1-24 months after germination. We grew plants from Tamaulipan thornscrub, with a sibling or with one individual from other species from 1-24 months. Seedling survival was similar for all species when their seedlings grew alone or under competition, at 1, 6 and 12 months. At 24 months seedling survival of Vachellia farnesiana was lower when grown with Havardia pallens. There was no evidence of stronger competition or facilitation for phylogenetically closer species. Seedling size correlated with seed mass one month after germination but not after 6 months. Maximum and mean adult plant height did not correlate with seed mass or with plant height in our trials. We found no evidence of phylogeny explaining nearest neighbors in competition during germination for Tamaulipan thornscrub."
"La competencia y la facilitación son factores importantes que afectan la supervivencia de las plántulas y probablemente afectan la distribución y abundancia de las plantas. Las interacciones entre especies se relacionan con la filogenia, es probable que las especies estrechamente relacionadas compitan más por recursos y que en las menos emparentadas ocurra facilitación. Se investigó si plantas de matorral tamaulipeco creciendo junto a parientes cercanos y lejanos diferían en supervivencia, longitud y peso de tallos y raíces, asumiendo que las especies estrechamente relacionadas competirían más que las lejanas. También se exploró si el peso de semillas se asoció con el tamaño de la planta entre 1 y 24 meses de edad. Se pusieron a crecer plantas de matorral tamaulipeco, con un hermano o con un individuo de otras especies, de 1-24 meses. La supervivencia de plántulas fue similar para todas las especies cuando éstas crecieron solas o en competencia, a los 1, 6 y 12 meses. A los 24 meses, la supervivencia de plántulas de Vachellia farnesiana fue menor cuando creció con Havardia pallens. No hubo evidencia de una competencia o facilitación fuerte para especies filogenéticamente más cercanas. El tamaño de la plántula se correlacionó con el peso de la semilla únicamente al mes de germinadas. La altura máxima y promedio de la planta adulta no se correlacionó con el peso de semillas o con la altura de la planta. La filogenia no explicó la competencia con los vecinos más cercanos durante la germinación de especies del matorral tamaulipeco."
Phylogeny Seed mass Seedling Shoot/root ratio Tamaulipan thornscrub BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) BIOLOGÍA VEGETAL (BOTÁNICA)
In-service weld repair by direct deposition: numerical simulation and experimental validation
LUIS DANTE MELENDEZ MORALES Jose Jorge Ruiz Mondragon MARICRUZ HERNANDEZ HERNANDEZ (2023, [Artículo])
In-Service Welding is a technological process for which interconnection and repair of pipelines can be made while they are in operation, before making it two main risks need to be assessed: hydrogen cracking and burn-through. Current simulations and validations assess these risks independently, but due to its interdependence these risks need to be assessed in conjunction. A repair method not normally used, but with high potential due to its simplicity and versatility is the direct deposition of weld. In the present research, a fluid-thermo-mechanical coupled simulation and validation were done of an in-service welding repair by direct deposition on a flowing pressurized pipe having an internal defect. The results demonstrated the effectiveness of using this repair method to restore the mechanical strength of pipelines. Surface, sub-surface, and volumetric non-destructive examinations evidenced no cracking immediately to finish the repair and delayed. Temperature tendency curves showed good approximations having a maximum difference of 5.09 % between numerical and experimental. Perimeter deformation along the pipe length between numerical and experimental results displayed a similar behaviour with a significant difference in the numerical values attributed to the lack of input data for weld properties. The structural analysis performed in this study used the approach of the risk of burn-through under internal pressure determined by the occurrence of localized radial bulging. Numerical results indicated no relevant plastic strain occurs. Is strongly recommended that thermal analysis assessments using the actual defect morphology would be performed, not only considering the remaining thickness of the pipe.
Declaration of Competing Interest: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements: The authors gratefully acknowledge to Petropipe de Mexico for technical support, materials and equipment needed for the experimental validation. The first author wants also to acknowledge to CONAHCYT (Consejo Nacional de Humanidades, Ciencias y Tecnologías), for the post-graduate scholarship received.
In-service welding Burn-through Hydrogen cracking Weld repair INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS
César Jacobo Pereira MIGUEL ANGEL MUÑIZ CASTRO JOSE ANTONIO VAZQUEZ GARCIA Joel David Flores Rivas ALEJANDRO MUÑOZ URIAS FRANCISCO MARTIN HUERTA MARTINEZ (2022, [Artículo])
"Background: Populus luziarum and P. primaveralepensis are endemic species of western Mexico; growing in riparian forests they are critically endangered. The best way to conserve their seeds is unknown, which could be limiting for their conservation.
Hypothesis: The germinability of both subtropical species is like that of boreal and template Salicaceae species that disperse seeds in spring and early summer, as they germinate quickly with high percentages, and rapidly lose their viability when stored at ambient temperature.
Studied species: Populus luziarum and P. primaveralepensis. Study site and dates: Western Trans-Mexican Volcanic Belt. Jalisco, Mexico. October 2019.
Methods: The physical integrity of the seeds was assessed by X-ray imaging and compared with germinability. In addition, the effect of storage time (nine weeks) under two temperatures (4 and 21 °C) on the percentage and mean germination rate was evaluated.
Results: No significant differences were found between physical integrity and germination in freshly collected seeds for both species. Germination in the first 24 hrs was 91 and 95 % for Populus luziarum and P. primaveralepensis, respectively (week 0). Germination percentages were lower when stored at 21 °C, but P. primaveralepensis was decreased more slowly.
Conclusions: Seeds of subtropical Populus respond similarly to those of species from temperate and boreal climates with early seed dispersal, a crucial condition for establishing ex situ reforestation and conservation programs."
Salicaceae Seed physical integrity Seed storage conditions Subtropical endemic species White poplars BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) BIOLOGÍA VEGETAL (BOTÁNICA)