Evaluación de la degradabilidad de películas plásticas en condiciones de digestión anaerobia

113 páginas. Maestría en Ciencias e Ingeniería Ambientales.Las bolsas hechas de películas plásticas son ampliamente usadas por su versatilidad y bajo costo. Sin embargo, el acelerado ritmo de su consumo, su desecho y su estabilidad en el ambiente las convierte en un residuo de complicada disposición final y elevado costo de tratamiento. En la Ciudad de México, el gobierno local ha promovido el uso de bolsas hechas de plásticos compostables y oxodegradables, y actualmente evalúa alternativas para dar tratamiento a las mismas en conjunto con los residuos orgánicos. Por ello, con el fin de evaluar la factibilidad del proceso de digestión anaerobia como método de tratamiento, en este estudio se evaluó la degradabilidad de película plástica de polietileno de alta densidad (PEAD) oxodegradable oxidado y sin oxidar, PEAD y película plástica composteable Ecovio® en condiciones de digestión anaerobia, adaptando la norma ASTM D5511-12. El proceso se llevó a cabo en dispositivos con un volumen de 1000 cm3 con cierre estanco. A cada dispositivo se le agregó estiércol de vaca como inóculo anaerobio (187.5 cm3), pasto seco como sustrato primario (150 cm3), agua corriente (562.5 cm3) y 30 tiras de película plástica de 1 × 15 cm. El experimento se montó con un control (dispositivo sin plástico) y por triplicado. El proceso de digestión duró 40 días y se mantuvo a una temperatura de 52 ± 2 °C con un baño de temperatura controlada. Se evaluó la elongación a la ruptura, antes y después del proceso de digestión, como indicador de degradación de las películas plásticas. Ésta disminuyó un 91% (σ=19) para el Ecovio®, un 41% (σ=51) para el PEAD oxodegradable oxidado, un 40% (σ=53.5) para el PEAD oxodegradable y un 39% (σ=61) para el PEAD. La producción de biogás también se usó como indicador de la degradación de las películas plásticas. La mayor cantidad de biogás se produjo en los dispositivos con películas plásticas oxodegradables sin oxidar (14360 cm3), seguido de Ecovio® (11520 cm3), PEAD oxodegradable oxidado (10780 cm3), PEAD (10150 cm3) y el control (7850 cm3). Se observó que el proceso de digestión anaerobia no sufre inhibición por la presencia de plásticos en la concentración ensayada, por el contrario, produce un grado de degradación en las películas plásticas estudiadas y generación de biogás.Consejo Nacional de Ciencia y Tecnología (México)

Aspectos metodológicos para la estimación (actualización) de la matriz de insumo-producto de México 2014 (AMIPM_2014): Aspectos metodológicos para a estimativa (atualização) da matriz de entradas-saídas do México 2014 (AMIPM_2014)

Una matriz de insumo-producto (MIP) es un esquema contable en el cual se representa el flujo de los bienes y servicios entre los distintos agentes que participan en la actividad económica, ya sea como productores de bienes y servicios o como consumidores. La MIP de un país, estado, municipio o región determinada es uno de los instrumentos más útiles para el análisis global y, a su vez, pormenorizado por rama productiva del  contexto económico. Una limitante muy significativa de esta herramienta estadística corresponde a su disponibilidad en el espacio y tiempo. La MIP es posible actualizarla a un año de referencia mediante la producción obtenida, la información específica de demanda y consumos intermedios y con el  empleo de los coeficientes y multiplicadores de un año base. Para la actualización de la MIP existe el método directo y los métodos indirectos. Los métodos indirectos son los menos costosos en términos económicos, uno  de estos es el método RAS. En el presente trabajo se hace una revisión de los fundamentos y supuestos del método RAS en su versión básica, el cual es utilizado para la actualización de la Matriz de Insumo-producto de México para el año de 2014, tomando como punto de partida la MIP de México de 2008. Para realizar la actualización de la MIP de 2014 se programa el método RAS en el paquete estadístico R

Relaciones recíprocas en el diseño entre la cerámica de Talavera y las Líneas de Nazca como elementos de identidad

The histories of Mexico and Peru share great cultural similarities in their representations of the world.  Las historias de México y del Perú, comparten grandes similitudes culturales en sus representaciones del mundo. As histórias do México e do Peru compartilham grandes semelhanças culturais em suas representações do mundo.&nbsp

ZnO Nanostructures Synthesized by Chemical Solutions

Nanomaterials have been synthesized using several different techniques. Some of these techniques are sophisticated, expensive and need certain training before use. However, there are other highly efficient methods for preparing nanomaterials that are easy to work with and require no specialized equipment, making them relatively inexpensive routes for synthesis. The least expensive routes are those that are classified as solution‐based techniques such as colloidal, sol‐gel and microwave‐assisted synthesis. The focus of this chapter is on a general description of each technique with recent advances in synthesis, doping processes and applications. Specifically, these processes are discussed in connection with the synthesis of ZnO compounds and its related nanomaterials

A genome-wide 20 K citrus microarray for gene expression analysis

<p>Abstract</p> <p>Background</p> <p>Understanding of genetic elements that contribute to key aspects of citrus biology will impact future improvements in this economically important crop. Global gene expression analysis demands microarray platforms with a high genome coverage. In the last years, genome-wide EST collections have been generated in citrus, opening the possibility to create new tools for functional genomics in this crop plant.</p> <p>Results</p> <p>We have designed and constructed a publicly available genome-wide cDNA microarray that include 21,081 putative unigenes of citrus. As a functional companion to the microarray, a web-browsable database <abbrgrp><abbr bid="B1">1</abbr></abbrgrp> was created and populated with information about the unigenes represented in the microarray, including cDNA libraries, isolated clones, raw and processed nucleotide and protein sequences, and results of all the structural and functional annotation of the unigenes, like general description, BLAST hits, putative Arabidopsis orthologs, microsatellites, putative SNPs, GO classification and PFAM domains. We have performed a Gene Ontology comparison with the full set of Arabidopsis proteins to estimate the genome coverage of the microarray. We have also performed microarray hybridizations to check its usability.</p> <p>Conclusion</p> <p>This new cDNA microarray replaces the first 7K microarray generated two years ago and allows gene expression analysis at a more global scale. We have followed a rational design to minimize cross-hybridization while maintaining its utility for different citrus species. Furthermore, we also provide access to a website with full structural and functional annotation of the unigenes represented in the microarray, along with the ability to use this site to directly perform gene expression analysis using standard tools at different publicly available servers. Furthermore, we show how this microarray offers a good representation of the citrus genome and present the usefulness of this genomic tool for global studies in citrus by using it to catalogue genes expressed in citrus globular embryos.</p

Photo-detection using Bose-condensed atoms in a micro trap

A model of photo-detection using a Bose--Einstein condensate in an atom-chip based micro trap is analyzed. Atoms absorb photons from the incident light field, receive part of the photon momentum and leave the trap potential. Upon counting of escaped atoms within predetermined time intervals, the photon statistics of the incident light is mapped onto the atom-count statistics. Whereas traditional photo-detection theory treats the emission centers of photo electrons as distinguishable, here the centers of escaping atoms are condensed and thus indistinguishable atoms. From this an enhancement of the photon-number resolution as compared to the commonly known counting formula is derived.Comment: 11 pages, 5 figures; revised versio

IFE Plant Technology Overview and contribution to HiPER proposal

HiPER is the European Project for Laser Fusion that has been able to join 26 institutions and signed under formal government agreement by 6 countries inside the ESFRI Program of the European Union (EU). The project is already extended by EU for two years more (until 2013) after its first preparatory phase from 2008. A large work has been developed in different areas to arrive to a design of repetitive operation of Laser Fusion Reactor, and decisions are envisioned in the next phase of Technology Development or Risk Reduction for Engineering or Power Plant facilities (or both). Chamber design has been very much completed for Engineering phase and starting of preliminary options for Reactor Power Plant have been established and review here

Fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 reduces bacterial translocation in rats treated with carbon tetrachloride

Probiotics can prevent pathological bacterial translocation by modulating intestinal microbiota and improving the gut barrier. The aim was to evaluate the effect of a fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 on bacterial translocation in rats with carbon tetrachloride (CCl)-induced cirrhosis. Sprague-Dawley rats treated with CCl were randomized into a probiotic group that received fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 in drinking water or a water group that received water only. Laparotomy was performed one week after ascites development. We evaluated bacterial translocation, intestinal microbiota, the intestinal barrier and cytokines in mesenteric lymph nodes and serum. Bacterial translocation decreased and gut dysbiosis improved in the probiotic group compared to the water group. The ileal β-defensin-1 concentration was higher and ileal malondialdehyde levels were lower in the probiotic group than in water group. There were no differences between groups in serum cytokines but TNF-α levels in mesenteric lymph nodes were lower in the probiotic group than in the water group. Fermented milk containing Lactobacillus paracasei subsp. paracasei CNCM I-1518 decreases bacterial translocation, gut dysbiosis and ileal oxidative damage and increases ileal β-defensin-1 expression in rats treated with CCl, suggesting an improvement in the intestinal barrier integrity

COVID-19 Impact: A Case Study at the School of Agricultural Engineering and Environment of the Universitat Politècnica de València

[EN] To study the first impact of the COVID-19 crisis on the results obtained by students belonging to the School of Agricultural Engineering and Environment at the Universitat Politecnica de Valencia (Spain), the average of the marks corresponding to three academic years (2016-2019) was compared to those obtained in 2019-2020 for a total of four bachelor's degrees and two semesters. Our results suggest a positive effect on the marks obtained during the activation of emergency remote teaching during the spring semester of 2019-2020 in three out of the four degrees, with these differences being significant for the whole study. Moreover, just at the end of that period, instructors and students were surveyed regarding teaching methodologies, evaluation modalities, and difficulties found throughout the process of adapting to distance teaching. Our results allow us to sensibly think about that exceptional situation in order to propose a set of counterweighting measures which could improve the implementation of distance learning in engineering colleges.Clemente Polo, G.; Garcia-Prats, A.; Lisón, P.; Rubio Michavila, C.; Vidal-Puig, S.; Ricarte Benedito, B.; Estruch-Guitart, V.... (2022). COVID-19 Impact: A Case Study at the School of Agricultural Engineering and Environment of the Universitat Politècnica de València. Sustainability. 14(17):1-14. https://doi.org/10.3390/su141710607114141

Distance Learning In Time Of Crisis: A Case Study At The School Of Agricultural Engineering And Environment Of Universitat Politècnica De València

[EN] Higher education is continuously evolving to keep up with the challenges posed by the introduction of information and communication technologies (ICT) to education. In this sense, distance learning is booming, with an increasing number of higher education students taking advantage of the flexibility remote learning provides. The School of Agricultural Engineering and Environment (ETSIAMN) of Universitat Politècnica de València (UPV) has been gradually incorporating ICT tools in its bachelor and master degrees for the last two decades. As a result, many college students and university instructors are familiar with ICT techniques. However, the unprecedented COVID-19 crisis has put distance learning in the spotlight like never before, forcing students, faculty, and staff to adapt to the new situation with hardly any preparation time. For that reason, it is convenient to analyse in depth the results and impact of the teaching and evaluation methodologies developed and applied during this critical period, as a way to detect and amend potential inefficiencies in the learning process. The specific goal of this study was to analyse the teaching period during the COVID-19 crisis in ETSIAMN, which covered the spring semester of the academic year 2019-2020. To this purpose, 114 instructors and 274 students were surveyed in July 2020, belonging to four bachelor degrees (agricultural and biological engineering; forestry engineering; food engineering; and biotechnology), and three master degrees (agricultural and biological engineering; forestry engineering, and oenology). Regarding the experimental design for the survey, three main blocks were identified: the first block corresponds to teaching methodologies, comparing students and faculty preferences for distance lecturing; the second block focuses on evaluation modalities and exam configurations; and the final block centers on the difficulties found by both students and lecturers along the adaptation process from conventional to distance teaching. Results showed that instructors and students preferred a combination of live streaming with recorded lectures, being multiple choice the favourite examination type, although many students rated first a project-based evaluation. Overall, students rejected tests with no possibilities to go back on already answered questions, and instructors mostly preferred limiting the time to complete the on-line tests. The lack of motivation was the main barrier encountered by students to achieve an effective learning. Finally, a set of counterweighting measures to improve and promote the successful implementation of distance learning in engineering colleges is proposed.Clemente Polo, G.; Garcia-Prats, A.; Lisón, P.; Rubio Michavila, C.; Ricarte Benedito, B.; Estruch-Guitart, V.; Fenollosa Ribera, ML.... (2020). Distance Learning In Time Of Crisis: A Case Study At The School Of Agricultural Engineering And Environment Of Universitat Politècnica De València. IATED Academy. 3938-3945. https://doi.org/10.21125/iceri.2020.0889S3938394