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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

Synthesis of Ferroelectric and Multiferroics Thin films of BiMnO3/ SrTiO3 and Structural, Piezoelectric, Magnetic, Optical, and Mechanical Properties Characterization

Glory Valentine Umoh (2022, [Tesis de doctorado])

Multiferroic characteristics of BiMnO3 thin films offer great prospects to explore, either

in terms of ferroelectricity, ferromagnetism, or ferroelasticity. Ferroelectric and

ferromagnetic materials can be used in data storage due to their electrical and magnetic

properties. Ferroelastic can find its application in microelectromechanical systems

devices. This dissertation focused on the synthesis, characterization, and improvement of

the multiferroic properties of polycrystalline BiMnO3 thin films as well as the elaboration

influence of Cu on the magnetism of BiMnO3 thin films. BiMnO3 films were grown on

three different substrates, Si (001), Pt-buffered Si (001), Nb-doped SrTiO3 (100), and also

doped with different amounts of Cu. The films were characterized using techniques such

as X-Ray diffraction (XRD), scanning electron microscope (SEM), HRTEM

observations, by energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy

(AFM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, Visible-near-IR

spectroscopy (Vis-NIR), electron energy loss spectrometer (EELS), nanoindenter,

superconductor quantum interference device (SQUID) magnetometer, and finally, the

polarization-electric field (P-E) hysteresis loops of the BiMnO3 thin films were conducted

at 200 and 300 K. There are several studies on the growth of thin films, however, they are

not clear and in some cases contradictory, therefore, different parameters were controlled

during the deposition in terms of working pressure, RF power, substrate, deposition

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temperature, and target to substrate distance. After deposition ex-situ thermal treatment

was carried out in order to compensate for the volatility of bismuth and also to eliminate

secondary phase.

Kramer’s–Krӧnig analysis was used to determine bandgap, via a polynomial fit in the

energy loss function (ELF) plot with an Eg = 1.63 eV, complex dielectric function, and

static dielectric constant, ε* = 4.68 of the grown BiMnO3 thin films. The reflection

coefficient Ґl of the BiMnO3 thin films was used to elucidate the reflection loss in the

BiMnO3 thin films. XPS analysis revealed the existence of Mn charge transition of 3+

and 4+ states. Resistivity result describes BIMnO3 as a semiconductor. The

nanomechanical characterization demonstrated that the region of penetration depth was

below 10% of BiMnO3 film thickness. Young's modulus (E), hardness (H), and Stiffness

(S) were measured to be 142 ± 3 GPa, 8 ± 0.2 GPa, and 44072 ± 45 N/m respec

SÍNTESIS DE MATERIALES Materiales Multiferroicos CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA OTRAS ESPECIALIDADES FÍSICAS OTRAS OTRAS

Pertinencia cultural del enfoque de graduación en mujeres en extrema pobreza en México 2019-2021

Benito Salvatierra Laura Itzel Ramírez Ramos Austreberta Nazar_Beutelspacher BARBARA CAROLINA LINARES BRAVO (2023, [Libro])

La presente obra expone los resultados de la evaluación de cinco indicadores de pertinencia cultural (expectativas, experiencias, estrategias, valores y decisiones) del proyecto “Empoderamiento de Mujeres y Jóvenes a través del Enfoque de Graduación en Inclusión Financiera en México”, instrumentado en Chiapas y Yucatán por la ONG internacional Trickle Up con el apoyo de cuatro organizaciones sociales locales. Este libro cobra relevancia en un contexto hasta este momento, caracterizado por 50 años de trayectoria de políticas públicas y programas sociales que no han logrado disminuir las desigualdades sociales y económicas que afectan principalmente a la población rural e indígena del país, por lo que pone en manos del lector un marco teórico conceptual, metodológico y de postulados sobre la importancia de la pertinencia cultural y la necesidad de integrarla a los proyectos y programas, ya sean de carácter público, social o privada, como una forma de garantizar su apropiación y continuidad por la población local. En ese sentido, el Enfoque de Graduación se presenta como una alternativa viable y factible para combatir la pobreza general y pobreza extrema, en la medida en que su diseño, como la instrumentación de cada uno de sus componentes (focalización, alfabetización financiera, acompañamiento, capacitación, transferencia de activos, protección social y apoyo al consumo) se realice tomando en cuenta las buenas prácticas, los aprendizajes y desde luego, considere reajustes que atiendan las barreras y recomendaciones derivadas de esta evaluación integral. Finalmente, podrán encontrar de forma detallada el proceso de construcción de variables e indicadores, la metodología (cuantitativa y cualitativa) utilizada por el equipo evaluador de ECOSUR, por lo que este libro puede ser una referencia metodológica y estadística para futuras evaluaciones de proyectos que buscan una incidencia socioeconómica en el bienestar de la población.

Organización Trickle Up Las Américas Organizaciones femeninas Pertinencia cultural Mujeres indígenas Programas de financiamiento Empoderamiento Pobreza Organizaciones no gubernamentales Indicadores económicos Yucatán (México) Chiapas (México) CIENCIAS SOCIALES SOCIOLOGÍA CAMBIO Y DESARROLLO SOCIAL DESARROLLO SOCIO-ECONÓMICO DESARROLLO SOCIO-ECONÓMICO

El municipio como proveedor de servicios públicos en Michoacán: un estudio de la eficiencia a través del análisis de la envolvente de datos (DEA)

Julio César Morán Figueroa (2018, [Tesis de maestría])

Instituto de Investigaciones Económicas y Empresariales. Maestría en Políticas Públicas

The municipal public services are activities carried out by the governments of the municipalities in order to satisfy collective needs. From an economic conception we can understand municipal governments as production units, which make use of their own inputs (resources) to generate a set of outputs (public services) that meet the needs of consumers (inhabitants of the municipality). This process of production of public services has an immediate impact on the quality of life of citizens. For this reason it becomes essential to estimate the efficiency in the use that municipal governments make of public resources to provide basic services of collective interest. The objective of this research is to identify the degree of efficiency of municipal governments in the use of investment expenditure and the cost of personal services in the provision of public lighting services, garbage collection and public safety to citizens of the state of Michoacán in the year 2014. In order to achieve this objective, the Data Envelopment Analysis (DEA) method was used, through which an efficiency frontier was estimated that allowed calculating the efficiency levels of the 113 municipalities of Michoacán to produce public services. An additional benefit of the DEA method is that it generates additional information (slacks variables) to propose to the inefficient municipalities improvement actions based on the results of the efficient municipalities. The results of the model showed that only 22 municipalities (19.47% of the total) had a degree of efficiency of 100% in the management of their resources for the production of municipal public services. From the results, various improvement actions are proposed based on the slacks variables so that the inefficient municipalities improve their policies regarding public services.

Los servicios públicos municipales son actividades que llevan a cabo los gobiernos de los municipios con el fin de satisfacer necesidades colectivas. Desde una concepción económica podemos entender a los gobiernos municipales como unidades de producción, que hacen uso de sus propios inputs (recursos) para generar un conjunto de outputs (servicios públicos) que satisfacen las necesidades de los consumidores (habitantes del municipio). Este proceso de producción de servicios públicos repercute de forma inmediata en la calidad de vida de los ciudadanos. Por tal razón se vuelve imprescindible la medición de la eficiencia en el uso que los gobiernos municipales hacen de los recursos públicos para proveer servicios básicos de interés colectivo. El objetivo de esta investigación consiste en identificar el grado de eficiencia de los gobiernos municipales en la utilización del gasto de inversión y del gasto de servicios personales en la provisión de los servicios de alumbrado público, recolección de basura y seguridad pública a los ciudadanos del estado de Michoacán en el año 2014. Para lograr este objetivo se utilizó el método del Análisis de la Envolvente de Datos (DEA), a través del cual, se estimó una frontera de eficiencia que permitió calcular los niveles de eficiencia de los 113 municipios de Michoacán para producir servicios públicos. Una bondad adicional del método DEA es que genera información adicional (variables slacks) para proponer a los municipios ineficientes acciones de mejora a partir de los resultados de los municipios eficientes. Los resultados del modelo arrojaron que solo 22 municipios tuvieron un grado de eficiencia del 100% en el manejo de sus recursos para la producción de servicios públicos municipales. De los resultados se proponen diversas acciones de mejora a partir de las variables slacks para que los municipios ineficientes mejoren sus políticas en materia de servicios públicos.

CIENCIAS SOCIALES ININEE-M-2018-0659 Método DEA Gobiernos municipales Inputs Outputs

Do provisioning ecosystem services change along gradients of increasing agricultural production?

Ronju Ahammad Stephanie Tomscha Sarah Gergel Frédéric Baudron Jean-Yves Duriaux Chavarría Samson Foli Dominic Rowland Josh Van Vianen Terence Sunderland (2024, [Artículo])

Context: Increasing agricultural production shapes the flow of ecosystem services (ES), including provisioning services that support the livelihoods and nutrition of people in tropical developing countries. Although our broad understanding of the social-ecological consequences of agricultural intensification is growing, how it impacts provisioning ES is still unknown. Objectives: We examined the household use of provisioning ES across a gradient of increasing agricultural production in seven tropical countries (Bangladesh, Burkina Faso, Cameroon, Ethiopia, Indonesia, Nicaragua and Zambia). We answered two overarching questions: (1) does the use of provisioning ES differ along gradients of agriculture production ranging from zones of subsistence to moderate and to high agriculture production? and (2) are there synergies and/or trade-offs within and among groups of ES within these zones? Methods: Using structured surveys, we asked 1900 households about their assets, livestock, crops, and collection of forest products. These questions allowed us to assess the number of provisioning ES households used, and whether the ES used are functionally substitutable (i.e., used similarly for nutrition, material, and energy). Finally, we explored synergies and trade-offs among household use of provisioning ES. Results: As agricultural production increased, provisioning ES declined both in total number and in different functional groups used. We found more severe decreases in ES for relatively poorer households. Within the functional groups of ES, synergistic relationships were more often found than trade-offs in all zones, including significant synergies among livestock products (dairy, eggs, meat) and fruits. Conclusions: Considering landscape context provides opportunities to enhance synergies among provisioning services for households, supporting resilient food systems and human well-being.

Agricultural Production Zones Agricultural Intensifcation Synergies and Trade-Offs Landscape Multifunctionality Social-Ecological Systems CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA AGRICULTURE INTENSIFICATION ECOSYSTEM SERVICES LANDSCAPE SOCIAL-ECOLOGICAL RESILIENCE ECOSYSTEM SERVICES

Octopus maya white body show sex-specific transcriptomic profiles during the reproductive phase, with high differentiation in signaling pathways

Oscar Juárez (2019, [Artículo])

White bodies (WB), multilobulated soft tissue that wraps the optic tracts and optic lobes, have been considered the hematopoietic organ of the cephalopods. Its glandular appearance and its lobular morphology suggest that different parts of the WB may perform different functions, but a detailed functional analysis of the octopus WB is lacking. The aim of this study is to describe the transcriptomic profile of WB to better understand its functions, with emphasis on the difference between sexes during reproductive events. Then, validation via qPCR was performed using different tissues to find out tissue-specific transcripts. High differentiation in signaling pathways was observed in the comparison of female and male transcriptomic profiles. For instance, the expression of genes involved in the androgen receptor-signaling pathway were detected only in males, whereas estrogen receptor showed higher expression in females. Highly expressed genes in males enriched oxidation-reduction and apoptotic processes, which are related to the immune response. On the other hand, expression of genes involved in replicative senescence and the response to cortisol were only detected in females. Moreover, the transcripts with higher expression in females enriched a wide variety of signaling pathways mediated by molecules like neuropeptides, integrins, MAPKs and receptors like TNF and Toll-like. In addition, these putative neuropeptide transcripts, showed higher expression in females’ WB and were not detected in other analyzed tissues. These results suggest that the differentiation in signaling pathways in white bodies of O. maya influences the physiological dimorphism between females and males during the reproductive phase. © 2019 Juárez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

androgen receptor, integrin, mitogen activated protein kinase, neuropeptide, transcriptome, tumor necrosis factor, argonaute protein, corticotropin releasing factor receptor, corticotropin releasing factor receptor 2, DEAD box protein, estradiol 17be BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) BIOLOGÍA ANIMAL (ZOOLOGÍA)