Mudanças na estrutura química do polietileno de alta densidade ao experimentar múltiplos reprocessamentos

In this paper, which presents the original results of a research funded by Colciencias and Facultad de Ingeniería y Arquitectura from the Universidad Nacional de Colombia, headquarters Manizales, publishes the changes of high-density polyethylene extrusion and injection grade identified after being subjected to five reprocessing processes in extrusion, injection and extrusion/injection. The identification of the changes is made through the comparison of the FTIR spectrum with those reported in different bibliographical references. The spectra were obtained by means of a Platinum ATR spectrometer. The thermal degradation was greater in the extrusion/injection process, followed by injection, extrusion at 80 rpm and extrusion at 20 rpm. It is concluded that there is a low degradation of high-density polyethylene after being reprocessed in five cycles, evidencing the appearance of the carbonyl group, vinyl groups and COC group.En este artículo, que presenta los resultados originales de una investigación financiada por Colciencias y la Facultad de Ingeniería y Arquitectura de la Universidad Nacional de Colombia, sede Manizales, se identifican los cambios en la estructura química del polietileno de alta densidad grado extrusión y grado inyección después de ser sometidos a cinco reprocesamientos en procesos de extrusión, inyección y extrusión/inyección. La identificación de los cambios se realiza a través de la comparación del espectro FTIR con los reportados en diferentes referencias bibliográficas. Los espectros FTIR fueron obtenidos mediante un espectrómetro ATR Platinum. La degradación térmica fue mayor en el proceso de extrusión/inyección, seguido por inyección, extrusión, extrusión a 80 rpm y extrusión a 20 rpm. Se concluye que existe una baja degradación del polietileno de alta densidad después de ser reprocesado en cinco ciclos, se evidencia así la aparición del grupo carbonilo, grupos vinilo y grupo COC.Neste artigo, que apresenta os resultados originais de uma pesquisa financiada por Colciencias e pela Faculdade de Engenharia e Arquitetura da Universidad Nacional de Colombia, sede Manizales, são identificadas as mudanças na estrutura química do polietileno de alta densidade grau extrusão e grau injeção depois de serem submetidos a cinco reprocessamentos em processos de extrusão, injeção e extrusão/injeção. A identificação das mudanças é realizada por meio da comparação do espectro FTIR com o que foi relatado em diferentes referências bibliográficas. Os espectros FTIR foram obtidos por meio de um espectrômetro ATR Platinum. A degradação térmica foi maior no processo de extrusão/injeção, seguido por injeção, extrusão, extrusão a 80 rpm e extrusão a 20 rpm. Conclui-se que existe uma baixa degradação do polietileno de alta densidade depois de ser reprocessado em cinco ciclos, assim fica evidente o surgimento do grupo carbonila, grupos vinilo e grupo COC

Modelos cinéticos de degradación térmica de polímeros: una revisión

Esta revisión se dedica al ajuste de parámetros para modelos cinéticos de degradación térmica de polímeros usando termo gravimetría. Primero se describen los fundamentos del análisis de datos y se resumen las ecuaciones básicas. Luegol os modelos cinéticos se clasifican según estas categorías: isotérmicos, diferenciales, integrales, e isoconversionales. Las aproximaciones para la integral de Arrhenius se presentan en una sección aparte. Por último se da un esquema de clasificación para elegir el método de análisis de datos y se muestran algunas expresiones nuevas, desarrolladas a partir de aproximaciones de la integral de Arrhenius

Educación política en el aula de clase

Este ensayo presenta el resultado de la descripción, los análisis narrativos y las conclusiones sociopolíticos que hacen los estudiantes en el curso humanidades I, como ejercicio crítico de las narrativas del conflicto armado que circula en el cine colombiano. El texto presenta una fundamentación teórica de las categorías involucradas en el análisis narrativo, el corpus de las películas seleccionadas en un contexto determinado y los hallazgos realizados. En general, el conflicto pasa a un segundo plano, cobra vida las historias de los personajes, los cuales están insertos en una cruda realidad que es derivada del conflicto. La construcción de las tramas en algunos relatos simplifica la realidad en una construcción ingenua. Se exalta positivamente que la narración de la mayoría de las historias se realiza desde las miradas de las víctimas y no de los victimarios, niñas guerrilleras, niños afectados por el conflicto, mujeres desplazadas por la violencia, campesinos que huyen hacia la capital, joven secuestrado, entre otros

Tinkuy 2014 : formas de comunicación de nuestros pueblos originarios

ara los pueblos originarios y afrodescendientes la comunicación es inherente a su propia existencia y dependen de la manera en que se comunican con los diversos seres de la naturaleza, humanos y no humanos. En diálogo constante con la naturaleza se fortalecen como personas y como miembros de un pueblo y comunidad. En este proceso, desarrollan formas propias de comunicación que se plasman en cantos, rituales, diseños faciales y corporales, así como en diversos objetos, cerámicas y otros elementos que dan cuenta de su organización y forma de ver el mundo. Considerando que el Tinkuy (palabra quechua que significa ‘encuentro’), busca abrir espacios de diálogo para que niños y niñas de pueblos indígenas y afroperuanos de diferentes regiones del país expresen sus aspiraciones y demandas por una escuela pertinente, democrática y de calidad e intercambien con niños y niñas de ámbitos urbanos de Lima; el tema central para este tercer encuentro se denominó “Diálogo de saberes: formas de comunicación de nuestros pueblos originarios” que se realizó en el mes de setiembre de 2014 en la capital del país. Una vez más, las voces de los niños y niñas de pueblos originarios y afroperuanos se encontraron para intercambiar las prácticas de sus pueblos y mostrarlas a los estudiantes de distintas instituciones educativas de Lima y al público que visitó la feria

The Research Journey as a Challenge Towards New Trends

The academic community of the department of Risaralda, in its permanent interest in evidencing the results of the research processes that are carried out from the Higher Education Institutions and as a product of the VI meeting of researchers of the department of Risaralda held in November 2021 presents its work: “The journey of research as a challenge towards new trends”, which reflects the result of the latest research and advances in different lines of knowledge in Agricultural Sciences, Health Sciences, Social Sciences and Technology and Information Sciences, which seek to solve and meet the demands of the different sectors. This work would not have been possible without the help of each of the teachers, researchers and authors who presented their articles that make up each of the chapters of the book, to them our gratitude for their commitment, dedication and commitment, since their sole purpose is to contribute from the academy and science to scientific and technological development in the search for the solution of problems and thus contribute to transform the reality of our society and communities. We also wish to extend our gratitude to the institutions of the Network that made this publication possible: UTP, UCP, UNAD, UNIREMINGTON; UNISARC, CIAF, Universidad Libre, Uniclaretiana, Fundación Universitaria Comfamiliar and UNIMINUTO, institutions that in one way or another allowed this work to become a reality, which we hope will be of interest to you.Preface............................................................................................................................7 Chapter 1. Technologies and Engineering Towards a humanization in Engineering using soft skills in training in Engineers.............................................................................................................11 Omar Iván Trejos Buriticá1, Luis Eduardo Muñoz Guerrero Innovative materials in construction: review from a bibliometric analysis....................................................................................................................27 Cristian Osorio Gómez, Daniel Aristizábal Torres, Alejandro Alzate Buitrago, Cristhian Camilo Amariles López Bibliometric review of disaster risk management: progress, trends, and challenges.........................................................................................................51 Alejandro Alzate Buitrago, Gloria Milena Molina Vinasco. Incidence of land coverage and geology, in the unstability of lands of the micro-basin of the Combia creek, Pereira, Risaralda....................................73 Alejandro Alzate Buitrago, Daniel Aristizábal Torres. Chapter 2. Arts, Humanities, and Social Sciences Training experience with teachers teaching mathematics using the inquiry methodology ...............................................................................................95 Vivian Libeth Uzuriaga López, Héctor Gerardo Sánchez Bedoya. Interpretation of the multiple representations of the fears associated to the boarding of limited visual patients in the elective I students’ written productions and low vision ...................................................................................113 Eliana Bermúdez Cardona, Ana María Agudelo Guevara, Caterine Villamarín Acosta. The relevance of local knowledge in social sciences............................................131 Alberto Antonio Berón Ospina, Isabel Cristina Castillo Quintero. Basic education students’ conceptions of conflict a view from the peace for the education....................................................................................................143 Astrid Milena Calderón Cárdenas,Carolina Aguirre Arias, Carolina Franco Ossa, Martha Cecilia Gutiérrez Giraldo, Orfa Buitrago. Comprehensive risk prevention in educational settings: an interdisciplinary and socio-educational approach ............................................................................163 Olga María Henao Trujillo, Claudia María López Ortiz. Chapter 3. Natural and Agricultural Sciences Physicochemical characterization of three substrates used in the deep bedding system in swine .......................................................................................175 Juan Manuel Sánchez Rubio, Andrés Felipe Arias Roldan, Jesús Arturo Rincón Sanz, Jaime Andrés Betancourt Vásquez. Periodic solutions in AFM models........................................................................187 Daniel Cortés Zapata, Alexander Gutiérrez Gutiérrez. Phenology in flower and fruit of Rubus glaucus benth. Cv. Thornless in Risaralda: elements for phytosanitary management .........................................199 Shirley Palacios Castro, Andrés Alfonso Patiño Martínez, James Montoya Lerma, Ricardo Flórez, Harry Josué Pérez. Socio-economic and technical characterization of the cultivation of avocado (Persea americana) in Risaralda..............................................................217 Andrés Alfonso Patiño Martínez, Kelly Saudith Castañez Poveda, Eliana Gómez Correa. Biosecurity management in backyard systems in Santa Rosa de Cabal, Risaralda................................................................................................................227 Julia Victoria Arredondo Botero, Jaiver Estiben Ocampo Jaramillo, Juan Sebastián Mera Vallejo, Álvaro de Jesús Aranzazu Hernández. CONTENTS Physical-chemical diagnosis of soils in hillside areas with predominance of Lulo CV. La Selva production system in the department of Risaralda.............241 Adriana Patricia Restrepo Gallón, María Paula Landinez Montes, Jimena Tobón López. Digestibility of three concentrates used in canine feeding....................................271 María Fernanda Mejía Silva, Valentina Noreña Sánchez, Gastón Adolfo Castaño Jiménez. Chapter 4. Economic, Administrative, and Accounting Sciences Financial inclusion in households from socioeconomic strata 1 and 2 in the city of Pereira ..................................................................................................285 Lindy Neth Perea Mosquera, Marlen Isabel Redondo Ramírez, Angélica Viviana Morales. Internal marketing strategies as a competitive advantage for the company Mobilautos SAS de Dosquebradas........................................................................303 Inés Montoya Sánchez, Sandra Patricia Viana Bolaños, Ana María Barrera Rodríguez. Uses of tourist marketing in the tourist sector of the municipality of Belén de Umbría, Risaralda.............................................................................................319 Ana María Barrera Rodríguez, Paola Andrea Echeverri Gutiérrez, María Camila Parra Buitrago, Paola Andrea Martín Muñoz, Angy Paola Ángel Vélez, Luisa Natalia Trejos Ospina. Territorial prospective of Risaralda department (Colombia), based on the SDGS...............................................................................................................333 Juan Guillermo Gil García, Samanta Londoño Velásquez. Chapter 5. Health and Sports Sciences Performance evaluation in times of pandemic. What do medical students think?.......................................................................................................353 Samuel Eduardo Trujillo Henao, Rodolfo A. Cabrales Vega, Germán Alberto Moreno Gómez. The relevance of the therapist’s self and self-reference in the training of psychologists.....................................................................................................371 Maria Paula Marmolejo Lozano, Mireya Ospina Botero. Habits related to oral health which influence lifestyle of elder people in a wellness center for the elderly in Pereira 2020. .............................................387 Isadora Blanco Pérez, Olga Patricia Ramírez Rodríguez, Ángela María Rincón Hurtado. Analysis of the suicide trend in the Coffee Region in Colombia during the years 2012-2018 ..............................................................................................405 Germán Alberto Moreno Gómez, Jennifer Nessim Salazar, Jairo Franco Londoño, Juan Carlos Medina Osorio. Hind limb long bone fractures in canines and felines...........................................419 María Camila Cruz Vélez, Valentina Herrera Morales, Alba Nydia Restrepo Jiménez, Lina Marcela Palomino, Gabriel Rodolfo Izquierdo Bravo. Prevalence of overweight and obesity in children in the rural and urban area of Risaralda....................................................................................................439 Angela María Álvarez López, Angela Liceth Pérez Rendón, Alejandro Gómez Rodas, Luis Enrique Isaza Velásquez. Chapter 6. Architecture, Design and Advertising The artisan crafts of Risaralda, characteristics, importance, and risks within the Colombian Coffee Cultural Landscape, CCCL....................................457 Yaffa Nahir Ivette Gómez Barrera, Javier Alfonso López Morales

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R$^{2}$ = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R$^{2}$ = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Geography and ecology shape the phylogenetic composition of Amazonian tree communities

AimAmazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types.LocationAmazonia.TaxonAngiosperms (Magnoliids; Monocots; Eudicots).MethodsData for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny.ResultsIn the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types.Main ConclusionNumerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

Mapping density, diversity and species-richness of the Amazon tree flora

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution