730 results on '"Polietileno"'
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2. CONFECÇÃO DE COMPOSTO DE MADEIRA-PLÁSTICO UTILIZANDO RESÍDUOS DE Eucalyptus grandis HILL EX Maiden E POLIETILENO DE BAIXA DENSIDADE (PEBD)
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Divino Eterno Teixeira, José Mauro Magalhães Ávila Paz Moreira, and Alexandre Florian da Costa
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Composto de madeira-plástico ,polietileno ,resíduos de madeira ,Forestry ,SD1-669.5 - Abstract
RESUMO Neste trabalho foram utilizados resíduos de madeira de Eucalyptus grandis em forma de cavacos e plástico pós-consumo tipo polietileno de baixa densidade (PEBD), nas proporções de 40%/ 60%, 50%/50% e 60%/40% de madeira/plástico no composto. Foi observada uma diferença entre a massa específica aparente (MEA) dos tratamentos, sendo necessário realizar uma análise de covariância em função da densidade para a correta interpretação dos resultados. Os tratamentos com maior percentual de PEBD na sua composição foram os que apresentaram melhor desempenho. De forma geral os valores das propriedades mecânicas atingiram os requisitos mínimos da norma ANSI A208.1, usada para classificar chapas de aglomerado, com exceção do MOR e do MOE do tratamento onde uma menor proporção de plástico foi usada.
- Published
- 2023
3. CARACTERIZAÇÃO DO PEUAMM OBTIDO ATRAVÉS DE MOAGEM DE ALTA ENERGIA CRIOGÊNICA.
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Bassani Sowek, Adriane and Waleska Oliveira, Leticia
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CRYOGENIC grinding ,BLOW molding ,INJECTION molding ,POLYMER structure ,PARTICULATE matter - Abstract
Copyright of Revista Foco (Interdisciplinary Studies Journal) is the property of Revista Foco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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4. Alterações na composição físico-química de pinhões (Araucaria angustifolia) armazenados em diferentes embalagens e ambientes
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Fernanda Janaína Oliveira Gomes da Costa, Rossana Catie Bueno de Godoy, Carolina Lopes Leivas, Leticia Oelke Pereira, and Nina Waszczynskyj
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Pós-colheita ,Frigoconservação ,Polietileno ,Forestry ,SD1-669.5 - Abstract
O pinhão é um alimento de grande importância econômica e gastronômica no Brasil, mas com dificuldade de conservação pós-colheita. No presente estudo avaliou-se as características dos pinhões armazenados no ambiente doméstico, utilizando-se embalagens de polietileno (PEBD) e juta, sob temperatura ambiente ou refrigeração. Foram realizadas análises, a cada 15 dias (durante 90 dias), da composição centesimal, umidade, atividade de água, perda de massa, cor de casca, cor do endosperma, pH, açúcares solúveis, teor de amido e quantificação de sementes avariadas. O pinhão foi melhor conservado em embalagem de polietileno sob refrigeração, mantendo a umidade, menor perda de massa e cor. Embalagens de juta favoreceram maior degradação da cor e aumento do apodrecimento e brotação. Sugere-se que é viável a comercialização de pinhões mantidos sob refrigeração por até três meses, em embalagem de polietileno.
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- 2023
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5. Alterações na composição físico-química de pinhões (Araucaria angustifolia) armazenados em diferentes embalagens e ambientes.
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Oliveira Gomes da Costa, Fernanda Janaína, Bueno de Godoy, Rossana Catie, Lopes Leivas, Carolina, Oelke Pereira, Leticia, and Waszczynskyj, Nina
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POLYETHYLENE , *REFRIGERATION & refrigerating machinery - Abstract
Araucaria angustifolia seeds are considered important food product of Brazilian diet but with post-harvest conservation problems. In the present study, the characteristics of the seeds stored in the domestic environment and under refrigeration, were evaluated. The experiment used low-density polyethylene and jute packaging. Analysis of centesimal composition, moisture, water activity, mass loss, skin color, endosperm color, pH, soluble sugars, starch content and quantification of damaged seeds, were carried out every 15 days for 90 days. The seeds were better preserved in polyethylene packaging under refrigeration, keeping moisture, less loss of mass and color. Jute packaging promoted color degradation and increased rotting and sprouting. It is suggested that the commercialization of Brazilian pine seeds could be viable if kept for up to three months under refrigeration in polyethylene packaging. [ABSTRACT FROM AUTHOR]
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- 2023
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6. Polímeros para Envases y Embalajes. Principales Plásticos Utilizados en el Sector Envase/Embalaje.
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Universitat Politècnica de València. Escuela Politécnica Superior de Alcoy - Escola Politècnica Superior d'Alcoi, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Montañés Muñoz, Néstor, Quiles Carrillo, Luis Jesús, Ivorra Martínez, Juan, Gómez Caturla, Jaume, Universitat Politècnica de València. Escuela Politécnica Superior de Alcoy - Escola Politècnica Superior d'Alcoi, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Montañés Muñoz, Néstor, Quiles Carrillo, Luis Jesús, Ivorra Martínez, Juan, and Gómez Caturla, Jaume
- Abstract
El presente objeto de aprendizaje presenta las propiedades de los principales plásticos de uso común empleados en la industria del envase y embalaje y muestra diferentes aplicaciones de cada uno de ellos en dicho sector.
- Published
- 2024
7. Microplastics control in drinking water in Spain and the UE
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Marín Galvín, Rafael and Marín Galvín, Rafael
- Abstract
In the recently approved spanish RD 3/2023 on human consumption water (text transposed from the EU Directive 2020/2184) the so-called observation list is included in its article 19: there are the emerging concern pollutants taking into account their potential health risk for humans. More specifically, in Annex IV of the RD review, section 4, the national observation list is published with the reference to 17b−stradiol, nonilphenol, azithromycin and diclofenac; likewise, it is literally indicated that “microplastics will be included in the list when the European Commission adopts a standardized methodology to measure microplastics in drinking water”. For above, this article will review the position on the subject published by the EU in September 2022 from the agency that deals with this type of issues, the Common Research Center of the European Commission, known by its English acronym JRC. At the same time, we will also refer the situation in Spain. In this way, the main types of MP detected were polyester (PES), polypropylene (PP) and polyethylene (PE), while polystyrene, ABS and polyamide were also detected. At the same time, results at a DWTP were reduced >93% from raw water (0.96 MP/L) after use of sand filtration, granular actived carbon, and reverse osmosis. Finally, concentration found in drinking water was very low, between 0 and 0.05 MP/L, with an average of 0.01 MP/L., En el recientemente aprobado RD español 3/2023 sobre aguas de consumo humano, adaptación de la primitiva Directiva UE 2020/2184, se incluye en su artículo 19 la denominada Lista de Observación que engloba los denominados «contaminantes de preocupación emergente que se consideren un riesgo para la salud». Así, en el apartado 4 del Anexo IV del reseñado RD, se publica la Lista de Observación nacional con las referencias a 17b-Estradiol, nonilfenol, azitromicina y diclofenaco, indicándose literalmente además que «los microplásticos se incluirán en la lista cuando la Comisión Europea adopte una metodología normalizada para medir los microplásticos en el agua de consumo». Este artículo tiene un doble objetivo: (i) pasar revista a la última posición sobre el tema publicada por la UE en septiembre de 2022 desde el organismo que se ocupa de este tipo de cuestiones, el Centro Común de Investigación de la Comisión Europea (conocido por sus siglas inglesas como JRC); (ii) en segundo lugar, se recogerán los más recientes resultados sobre MP en aguas españolas. En este sentido, los tipos de microplásticos (MP, en adelante) mayoritariamente encontrados fueron poliéster (PES), polipropileno (PP) y polietileno (PE), detectándose, asimismo, poliestireno, ABS y poliamida. Además, los MP reducían su concentración en una ETAP desde agua bruta a (0,96 MP/L) tras filtración por arena, carbón activo granular y ósmosis inversa en más del 93 % respecto al agua cruda de entrada a planta. Finalmente, las concentraciones de MP en aguas de consumo fueron muy bajas, entre 0 y 0,05 MP/L, con un promedio de 0,01 MP/L., No recentemente aprovado RD espanhol 3/2023 sobre água para consumo humano, adaptação da primitiva Diretiva da UE 2020/2184, o Artigo 19 inclui a chamada Lista de Observação, que inclui os chamados “poluentes de preocupação emergente que são considerados um risco para a saúde”. Assim, na secção 4 do Anexo IV do referido RD, é publicada a Lista Nacional de Observação com referências ao 17b-Estradiol, ao nonilfenol, à azitromicina e ao diclofenac, indicando também literalmente que“os microplásticos serão incluídos na lista quando a Comissão Europeia adotar uma metodologia padronizada para medir microplásticos em água potável. Este artigo tem um duplo objetivo: (i)rever a última posição sobre o assunto publicada pela UE em setembro de 2022 pelo órgão que trata deste tipo de questões, o Centro Comum de Investigação da Comissão Europeia (conhecido pela sigla em inglês como JRC); (ii)em segundo lugar, serão recolhidos os resultados mais recentes sobre PM em águas espanholas. Nesse sentido, os tipos de PM mais encontrados foram poliéster (PES), polipropileno (PP) e polietileno (PE), sendo também detectados poliestireno, ABS e poliamida. Além disso, o PM reduziu sua concentração em uma ETAP de água bruta para (0,96 MP/L) após filtração através de areia, carvão ativo granular e osmose reversa em mais de 93% em comparação com a água bruta de entrada na planta. Por fim, as concentrações de MP na água potável foram muito baixas, entre 0 e 0,05 MP/L, com média de 0,01 MP/L.
- Published
- 2024
8. APLICACIÓN DEL SSA PARA EL ESTUDIO DE INTERACCIONES EN NANOCOMPUESTO DE PEZr-g-MAH y PEZr-g-MAH/4-Ampy CON NANOTUBOS DE CARBONO DE PAREDES MÚLTIPLES r.
- Author
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Tenía, Rita and de Gáscue, Blanca Rojas
- Abstract
In the following work, synthesized polyethylene nanocomposites combined with a metallocene zirconium catalyst (PEZr) with 1 and 3 % multi-walled carbon nanotubes (MWCNT) were prepared. Maleic anhydride functionalized polyethylene nanocomposites (PEZr-g-MAH) and 4-aminopyridine functionalized polyethylene (PEZr-g-MAH / 4ampy) with 1 % NTsC were also prepared. All nanocomposites were characterized by: Infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC); Self-nucleation (SN) and Thermal Fractionation by Successive Self-nucleation and annealing (SSA) experiments. The FTIR spectrum of the PEZr-g-MAH/1 %NTsC nanocomposite showed displacement of some absorption bands that increased a higher wave of numbers and that could occurred due to the interaction between the MWCNT and the carbonyl group of the anhydride and acid function of functionalized PE; while, in the PEZr-g-MAH / 4Ampy /1% NTsC nanocomposite, the intensive increment of the bands at 1097 and 1019 cm-1 was visualized. Non-isothermal DSC scans demonstrated the property of nanotubes to act as nucleating agents on the matrix of all the polymers studied. The study by SSA, together with the evaluation of the melting peaks using the software Peakfit 4.12, indicates that a redistribution of the lamellar thicknesses of the fraction with the highest melting temperature, speculating that it is possible the interactions of the π-π type between the pairs of free electrons of the pyridine ring of 4-Ampy and the electron cloud of MWCNTs. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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9. Evaluación fisicoquímica y microbiológica de ahuyama (Cucurbita moschata) troceada en fresco con recubrimiento y polietileno.
- Author
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RUCO-SÁNCHEZ, CRISTINA, SANTIAGO-CAMPO, CARLOS-HOLMES, PAZ-PEÑA, SANDRA-PATRICIA, and MOSQUERA-SÁNCHEZ, SILVIO-ANDRÉS
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CASSAVA starch , *BUTTERNUT squash , *POLYETHYLENE films , *LOW density polyethylene , *FUNGAL growth , *CAROTENOIDS , *EDIBLE coatings , *ESSENTIAL oils - Abstract
Ahuyama (Cucurbita moschata) is recognized by its nutritional value, as it is composed of vitamin A, carbohydrates, phosphorus and minerals. Also, for its content of 45 % of total carotenoids; 66 % of β-carotene; 33 % of α-carotene, and 44 % of lutein. However, its high amount of water, about 90%, is conducive to bacterial and/or fungal growth reducing its useful life. Present study evaluated every three days, over a total of 12, three repetitions and three replications of freshly cut green bolus squash variety. Physicochemical attributes like weight, color, firmness, and respiration rate were observed, as well as those microscopic (MOAR and MET); bromatological, and microbiological characteristics to 4 different treatments as follow: SN (control sample); CV (Vinyl wrap); CR (coated with cassava starch and 1 % thyme essential oil); and CB: (binary system with natural source coating and Vinyl wrap) under environmental conditions of 19 °C temperature and 77,75 % average humidity. Vinyl wrap treatment exhibited lower weight, firmness loss, fewer respiration rate loss, and had better color stability. Control and coated samples showed higher sugar and moisture content but lower ash and protein. Additionally, samples with coated and uncoated stretch film registered minor fungal growth. Fresh cut squash could be properly preserved through the use of low-density polyethylene films (vinyl wrap), allowing to effectively delay the course of quality loss because of handling operations. [ABSTRACT FROM AUTHOR]
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- 2022
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10. Contaminación por microplásticos en playas del Pacífico de Guatemala: abundancia y características
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Carlos Mazariegos-Ortíz, Luis García-Arroyave, Carolina Marroquín-Mora, and Ana L. Mendizábal
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arena ,poliestireno ,polipropileno ,polietileno ,abundancia ,Animal culture ,SF1-1100 ,Medicine (General) ,R5-920 ,Science (General) ,Q1-390 - Abstract
La contaminación por microplásticos (MPs) de tamaño menor a 5 mm ha tomado relevancia en los últimos años debido a su impacto en los ecosistemas. En Guatemala, se carece de información relacionada con MPs, por lo que este estudio tuvo como objetivo evaluar la abundancia y características de MPs en cuatro playas del Pacífico de Guatemala, Ocós, Tulate, Sipacate y Las Lisas. Se colectaron muestras de arena en mayo y octubre de 2019. Los MPs se aislaron y se clasificaron por forma, y el tipo de polímero se identificó a través de un equipo de espectroscopia infrarroja con transformada de Fourier (ATR-FTIR). La abundancia expresada en MPs/m2 en mayo fue de 25.6, 5.6, 0.8 y 0 MPs/m2 para Tulate, Las Lisas, Ocós y Sipacate; mientras que en octubre fue de 59.6, 23.2, 17.6 y 17.6 MPs/m2 en Tulate, Ocós, Las Lisas y Sipacate. Fragmentos, foam, pellets y láminas fueron las formas predominantes de MPs que se encontraron en las playas. El análisis por ATR-FTIR muestra que los principales polímeros identificados en las playas son polietileno, poliestireno y polipropileno. Los resultados de este estudio indican que las playas del Pacífico de Guatemala están contaminadas por MPs de diferentes tipos de polímeros. Además, estos resultados ofrecen información importante a los responsables de la toma de decisiones sobre la eliminación y el manejo de la basura plástica marina.
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- 2021
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11. Experiencia en el manejo del Abdomen abierto contenido con Bolsa de Bogotá en el Hospital Militar Central de las Fuerzas Armadas
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Hernando R. Cardozo-Arias, Cynthia Verdecchia-Insfran, Amanda M. Fretes-Gómez, and Alejandro Caballero-Rodrigues
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bolsa de bogotá ,abdomen abierto ,polietileno ,Medicine ,Surgery ,RD1-811 - Abstract
El abdomen abierto es una técnica quirúrgica en la cual dejamos la cavidad abierta cubriendo los órganos para el manejo de diferentes entidades clínico-patológicas. Materiales y métodos: Se evaluaron prospectivamente 14 pacientes entre febrero del 2018 a febrero del 2020, tratados con técnica de abdomen abierto contenido con Bolsa de Bogotá en el Servicio de Cirugía del Hospital Militar Central. Resultados: La edad promedio fue de 49 años, y el 79% fueron del sexo masculino. Fueron indicaciones para el manejo con abdomen abierto: Sepsis abdominal, control de daños, hipertensión abdominal y second look. En los pacientes con abdomen abierto por control de daños los órganos más frecuentemente lesionados fueron: Lesión esplénica con perforación de colon trasverso y lesión hepática con perforación duodenal. El número de reintervenciones promedio fue de 2,4 por paciente. Todos los pacientes estuvieron en Unidad de Cuidados Intensivos, con un promedio de 15 días. Las complicaciones encontradas: pacientes con fistula intestinal 21,4% y óbitos 21,4%. En 7 pacientes se utilizó en forma concomitante el sistema de aspiración al vacío. Conclusiones: El manejo del abdomen abierto contenido con Bolsa de Bogotá es una técnica simple para nuestro medio debido a su utilización con material de bajo costo como el polietileno obteniendo resultados satisfactorios.
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- 2021
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12. Speed influence on the recycled high-density polyethylene/HDPE handles, tested with a specific adapted industrial method.
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Teusdea, Dan Florin, Vodă, Mircea, and Alfonso Romero-Toledo, Fidel
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HIGH density polyethylene , *WASTE recycling , *TENSILE strength , *SPEED , *PLASTICS , *COMMERCIAL product testing , *MARINE debris - Abstract
This article studies the influence of the tensile speed when testing plastic products used to transport containers that may contain various liquids (drinking water, windshield fluid, cleaning agents, etc.). This case study was conducted on certain parts, generally called "handles", which are basically plastic items obtained largely from recycled technological waste resulting from the injection process of various packaging related to the food industry polyethylene caps and lids more precisely. During the handling and transport process, these parts are subjected to various static stresses, therefore, a minimum mechanical resistance is required. Fatigue stress has not been performed due to a limited number of duty cycles. To determine these quality characteristics, multiple measurements of tensile strength and elongations were performed at different traction speeds, measurements that have been validated on the market for several years. We have observed that testing speed over 500 mm/min is not necessary because the tensile strength values do not vary significantly. These results are very important in determining the constructive form of these products and the methods for validating quality indicators. Also, we have proposed to identify a method able to assess the mechanical performance of the product used in nonstandard conditions. The study can be used for a much wider range of similar applications in the plastics industry. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
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13. O uso do Mulching no cultivo de alface: Revisão de Literatura.
- Author
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Soares Barros, José Anderson and Cavalcante, Marcelo
- Abstract
Copyright of Diversitas Journal is the property of Diversitas Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
- Full Text
- View/download PDF
14. AVALIAÇÃO DA PRESENÇA DE MICROPLÁSTICOS NAS ÁGUAS DO ESTUÁRIO TRAMANDAÍ - ARMAZÉM E SUA RELAÇÃO COM A QUALIDADE DA ÁGUA
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Laura Steffen Corrêa, Thayse Freitas Silveira, Cacinele Mariana da Rocha, and Daiana Maffessoni
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MP ,contaminação ,PET ,PVC ,polietileno ,Hydraulic engineering ,TC1-978 ,Environmental technology. Sanitary engineering ,TD1-1066 - Abstract
A acumulação de partículas de plástico em ambientes aquáticos é acarretada pela produção e uso em grande escala, somada à destinação incorreta enquanto resíduo. Esses pequenos fragmentos, denominados microplásticos (MP), são assunto emergente e considerados um problema mundial, podendo afetar organismos e seus mecanismos. O Litoral Norte do Rio Grande do Sul não possui registros científicos que revelem MP em águas estuarinas. O Sistema Estuarino Tramandaí-Armazém (ETA) recebe grande pressão antrópica, especialmente devido ao aglomerado urbano causado pelo turismo, pelos múltiplos usos de suas águas e por ser parte final receptora de águas de toda a Bacia Hidrográfica do Rio Tramandaí (BHRT). Nesse contexto, o objetivo desse estudo foi avaliar a presença de MP nas águas das lagunas Tramandaí e Armazém, visando classificá-los quanto à sua composição polimérica. Além disso, buscou-se estabelecer uma relação entre a ocorrência de MP e a qualidade da água. Os resultados evidenciam ser uma área que já apresenta contaminação por MP, sendo que na Laguna do Armazém foi contabilizado um total de 240 und/100 m³ e na Laguna Tramandaí foram determinados 225 und/100 m³ de MP. Destaca-se a predominância de PE, PP e PET/PVC que estão estreitamente vinculados às atividades desenvolvidas na região, como a pesca e a ocupação urbana em si. Contudo, não foi possível estabelecer uma relação da presença de MP com os parâmetros de qualidade da água. Embora esteja comprovada a contaminação por MP nessa área estuarina, uma avaliação de mais longo período é interessante e pode, inclusive, indicar o efeito, por exemplo, da ocupação massiva durante o veraneio.
- Published
- 2021
15. Evaluación fisicoquímica y microbiológica de ahuyama (Cucurbita moschata) troceada en fresco con recubrimiento y polietileno
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Silvio Andres Mosquera Sanchez, Carlos Holmes Santiago Campo, Sandra Patricia Paz Peña, and Cristina Ruco Sánchez
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Aceite esencial de tomillo ,Almidón de yuca ,Polietileno ,Recubrimiento natural ,Vinipel ,Evaluación físicoquímica ,Agriculture (General) ,S1-972 ,Biotechnology ,TP248.13-248.65 - Abstract
La ahuyama (Cucurbita moschata) se caracteriza por su valor nutritivo, especialmente por su contenido de vitamina A, carbohidratos, fósforo y minerales. También, por poseer 45 % de carotenoides totales, 66 % de β-caroteno, 33 % de α- caroteno y 44 % de luteína. Su elevado porcentaje de agua cercano al 90 % es propicio para el crecimiento bacteriano y/o fúngico disminuyendo su vida útil. Este estudio evaluó, cada tres días durante un total de 12, con tres repeticiones y tres réplicas, las características fisicoquímicas (peso, color, firmeza, tasa de respiración); microscópicas (MOAR y MET), bromatológicas y microbiológicas, de ahuyama variedad bolo verde troceada en fresco. 4 tratamientos: SN (muestra testigo); CV con vinipel; CR con recubrimiento de almidón de yuca y aceite esencial de tomillo al 1 %; y CB con sistema binario (recubrimiento de fuente natural y vinipel) a una temperatura de 19 °C y humedad media de 77,75 %. Los tratamientos con película de vinilo arrojaron menor pérdida de peso y firmeza, menor tasa de respiración y mayor estabilidad en el color, en tanto que las muestras testigo y recubiertas, arrojaron mayor contenido de azúcares y humedad, pero menor cantidad de proteína y cenizas. Adicionalmente, las muestras con vinipel, con y sin recubrimiento, registraron un menor crecimiento fúngico. La ahuyama troceada en fresco puede conservarse de forma adecuada mediante el uso de películas de polietileno de baja densidad (vinipel), que permiten retrasar de manera efectiva los procesos de pérdida de calidad inducidos por las operaciones de corte y manipulación.
- Published
- 2021
- Full Text
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16. Propiedades espectrales de la cubierta de macro túneles y su relación con el crecimiento y rendimiento del chile poblano (Capsicum annuum L.)
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Alejandro Zermeño González, José Ángel Marroquín Morales, Aaron Isain Melendres Alvarez, Homero Ramírez Rodríguez, Martín Cadena Zapata, and Santos Gabriel Campos Magaña
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Capsicum annuum L. ,policarbonato ,polietileno ,radiación fotosintéticamente activa ,transmisividad ,Agriculture ,Agriculture (General) ,S1-972 - Abstract
Con la agricultura protegida se resguardan las plantas de las condiciones climáticas adversas y se modifica la radiación solar que incide sobre ellas, con el propósito de mejorar su productividad. Por lo que, el objetivo de este estudio fue evaluar el efecto del material y color de cuatro cubiertas de invernadero, en la tasa y características espectrales de la radiación que se transmite y su relación con el contenido de clorofila, crecimiento y rendimiento de un cultivo de chile poblano (Capsicum annuum L.) variedad Ébano. El estudio se realizó en cuatro macro túneles de forma ovalada de 4 m de ancho, 2.5 m de alto y 12 m de longitud. La cubierta de tres túneles fue de láminas de policarbonato de color rojo, azul y translúcido, el otro se cubrió con polietileno difuso de alta densidad. Las características espectrales de la radiación solar que se transmitió en cada cubierta se determinaron con un espectro radiómetro; mientras que, la tasa de radiación fotosintéticamente activa (PAR) dentro y fuera de los túneles, se obtuvo con sensores quantum. Los resultados del estudio mostraron que las plantas que crecieron bajo las láminas de policarbonato de los diferentes colores, tuvieron mayor contenido de clorofila que las del polietileno de alta densidad y las de campo abierto. Debido a una menor incidencia de radiación fotosintéticamente activa (PAR) y casi nula transmisividad de la radiación de 400 a 570 nm, las plantas que se desarrollaron en el túnel con cubierta de policarbonato rojo, fueron de mayor altura y desarrollo foliar, pero con menor rendimiento de frutos. El mayor rendimiento de frutos se obtuvo bajo la cubierta de policarbonato traslúcido y el polietileno difuso de alta densidad.
- Published
- 2019
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17. Biodegradación de espumas plásticas por larvas de insectos: ¿una estrategia sustentable?
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Rodríguez-Carreón, Anlui, Ortiz-Rivera, Yuridia, Carolina Hernández-Peña, Claudia, and Figueroa, Coyolxauhqui
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POLYMER degradation , *PLASTIC foams , *INSECT larvae , *WASTE treatment , *PLASTIC scrap , *PLASTICS - Abstract
Many modern human activities rely greatly on plastic foams, whose consumption and production have considerably increased in the past decades. The use of plastic products has had positive impacts on human general welfare; however, the negative effects derived from their inappropriate disposition have become a major concern, especially during the current COVID-19 sanitary emergency, in which the utilization of single-use plastics has rapidly increased. Although some plastic polymers such as polyethylene (PE) and polystyrene (PS) can be recycled, the high demand for energy and technology, the use of potentially toxic substances and the low profitability of the process, make this option nonoptimal. In this situation, biological treatment of plastic waste is emerging as a promising alternative and the use of PE and PS-eating organisms, such as mealworms and waxworms, has attracted the attention of researchers around the world. The aim of this review is to synthesize the most recent advances in the field of plastics polymers degradation by insects larvae and an analysis of the current and future trends of this developing research area. [ABSTRACT FROM AUTHOR]
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- 2021
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18. Selfis en India
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Amparo Sard
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Polietileno ,reciclaje ,plástico ,Amparo Sard ,Arts in general ,NX1-820 - Abstract
Análisis del comportamiento global en la era de las tecnologías, del ensimismamiento y de las reacciones precarias.
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- 2020
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19. ESTUDO DA INFLUÊNCIA DOS MÉTODOS DE RETICULAÇÃO SOBRE AS PROPRIEDADES DO POLIETILENO.
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de Souza FERREIRA, Mariana Babilone and DOS SANTOS, Claudio Gouvêa
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MELTING points , *THERMAL analysis , *SILOXANES , *CROSSLINKED polymers , *INFRARED spectroscopy , *TENSILE strength , *THERMOPLASTICS - Abstract
Polyethylene (PE) is considered one of the most versatile thermoplastics available today. However, it exhibits several limitations related to its low melting point, low heat resistance, tendency to crack propagation, and its low resistance to rupture under stress. In order to overcome these deficiencies, several processes for crosslinking PE chains were developed, which makes this material more stable to temperature changes. In this work, methods based on peroxide (PEX-A) and silane (PEX-B) as chemical modification agents for PE chain crosslinking were analyzed, aiming to apply PE in pipes for conduction water. The materials were characterized by infrared spectroscopy (FTIR), gel content, and thermal analysis (TGA and DSC) to achieve those objectives. Also, some mechanical properties such as tensile strength and hardness and the determination of the heat deflection temperature (HDT) were evaluated. Spectra demonstrated the presence of the functional groups characteristic of PE and the incorporation of siloxane groups in PEX-B. Gel content values obtained were above 60% and indicated the formation of crosslinked chains between the molecules of the polymers. The thermal analysis suggests a greater efficiency in forming a chain network by the silane crosslinking process compared to the peroxide process. As for the mechanical tests, they also showed improvement in the mechanical properties of the crosslinked polymer when compared to the respective original PE. Thus, the silane method provided sufficient results to conclude that the properties evaluated are superior compared to the peroxide crosslinking method. [ABSTRACT FROM AUTHOR]
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- 2020
20. Pares articulares en prótesis primaria de cadera. ¿Existe alguna diferencia?
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Suárez, J. C., Forero, A., Llinás, A., Bonilla, G., Rodríguez, H., and Amado, O.
- Abstract
Introduction: In primary hip replacement, different materials are used for bearing surfaces. In our medium metal or ceramic heads with highly crossed-linked polyethylene (PA) are the most used. These combinations have good results, but it is not clear which is clinically superior. The objective of this study is to determine whether there is any clinically significant difference based on a systematic review of the literature and national registries of arthroplasty. Material and methods: We conduct a systematic review of the literature and national registries of arthroplasty and we were looking for studies comparing bearing surfaces: ceramic-highly cross-linked polyethylene (CP) and metal-highly cross-linked polyethylene (MP); describing the revision rate according to the surface type with a minimum 10-year follow-up. The outcome evaluated was: review rate for any cause depending on surface type. Results: Two out of fifteen national registries were included. The Australian registry shows a difference in the 15-year revision rate: CP: 6.3 (IC 5.8, 6.7) vs MP: 5.1 (IC 4.6, 5.7). The New Zealand registry shows no differences in revision rate/100 components/year: CP 0.54 (0.48-0.61) vs MP 0.61 (0.57-0.66). We do not find clinical studies with inclusion criteria that answer the research question. Conclusion: The results of this review show a high survival rate with the use of highly cross-linked polyethylene, the results are similar when using ceramic or metal heads. [ABSTRACT FROM AUTHOR]
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- 2020
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21. ESTABILIDADE TÉRMICA E FLAMABILIDADE DE NANOCOMPÓSITOS DE POLIETILENO DE ALTA MASSA MOLAR PRODUZIDOS POR POLIMERIZAÇÃO IN SITU.
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Pereira de Agrela, Sara, Pinho de Andrade Lima, Luiz Rogério, and Cerqueira Souza, Rosemário
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MOLECULAR weights , *THERMAL stability , *GRAPHITE composites , *POLYMER degradation , *HIGH temperatures , *POLYMERIC nanocomposites - Abstract
act High density polyethylene-clay, graphite or talc composites were produced using direct solvent in situ polymerization using a Ziegler catalyst system (TiCl4 and triethylaluminum in hexane). The produced polymer had a high average molecular weight and in inert atmosphere presents a thermal degradation above 400ºC. The thermal degradation of the polymers in the nanocomposites was shifted for higher temperature (until close to 500ºC) indicating an improvement in the thermal stability of the polymeric matrix. The inflammability tests clearly showed a retardation or attenuation effect of the flames progression for all nanocomposites due to the barrier effect for gases and volatile compounds. [ABSTRACT FROM AUTHOR]
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- 2020
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22. Thermal Pyrolysis of LDPE and LLDPE Films in Post-Consumer Packaging.
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da Silva Vallada, Douglas, Mendes Moraes, Carlos Alberto, and Santos da Silva, Paulo Ricardo
- Abstract
Copyright of Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental is the property of Revista Eletronica em Gestao, Educacao e Tecnologia Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2020
- Full Text
- View/download PDF
23. Análisis y evaluación de la calidad de impresión flexográfica en bolsas de polietileno tratadas con exposición a rayos ultravioleta.
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Arenzano Altaif, Jesús Antonio, Sánchez Juarez, Omar Antonio, Márquez Domínguez, Sergio, and Luna Gómez, Alberto Iván
- Abstract
Copyright of Congreso Internacional de Investigacion Academia Journals is the property of PDHTech, LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
24. Evaluación de las propiedades térmicas, reológicas y mecánicas de mezclas entre HDPE virgen con HDPE reciclado
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González Villa, Sandra Milena, Gómez Sandoval, Juan Camilo, González Villa, Sandra Milena, and Gómez Sandoval, Juan Camilo
- Abstract
Las propiedades reológicas, térmicas, morfológicas y mecánicas del polietileno de alta densidad (HDPE) son estudiadas, en mezclas virgen/reciclado a partir de la implementación de un proceso de reciclaje mecánico de guías plásticas, empleadas como dispositivos de acople en moldes de yeso usados en la industria cerámica. A pesar de encontrar pérdidas en sus propiedades, se demuestra la viabilidad de realizar mezclas con material virgen y reciclado, siendo útil aún para múltiples aplicaciones., The rheological, thermal, morphological and mechanical properties of high-density polyethylene (HDPE) are studied in virgin/recycled mixtures from the implementation of a mechanical recycling process of plastic guides, used as coupling devices in used plaster molds. in the ceramic industry. Despite finding losses in its properties, the feasibility of mixing with virgin and recycled material is demonstrated, still being useful for multiple applications.
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- 2023
25. Itsasoko PET hondakinen balorizazioa: Metodo konbentzionaletatik birziklatze kimikora poliuretano berrien sintesirako
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Peña Rodríguez, Cristina, Eceiza Mendiguren, María Aranzazu, Ingeniería química y del medio ambiente, Ingeniaritza kimikoa eta ingurumenaren ingeniaritza, Mendiburu Valor, Eider, Peña Rodríguez, Cristina, Eceiza Mendiguren, María Aranzazu, Ingeniería química y del medio ambiente, Ingeniaritza kimikoa eta ingurumenaren ingeniaritza, and Mendiburu Valor, Eider
- Abstract
241 p. (eusk.) 238 p. (eng.), Lan hau itsasoko poli(tereftalato etileno) hondakinen (PET-m) birziklapenean zentratzen da, hondakin kutsagarri honi bigarren bizitza bat eman ahal izateko. 1. Kapituluan sarrera eta 2. Kapituluan erabilitako material eta metodoen azalpena egiten da. 3. Kapituluan hainbat PET lagin aztertu dira, hala nola PET lehengai gordina eta post-kondentsatua, eta kontsumo osteko hiri-hondakinak eta itsasoko PET hondakinak. Degradazioaren eragina aztertzeko hondakinen karakterizazioa burutu da. 4. Kapituluan, itsasoko PET hondakinak balorizatzeko metodo konbentzionalenak erabili dira: birziklatze termo-mekanikoa eta aprobetxamendu energetikoa. Birziklatzean gerta litezken degradazioak ere aztertu dira. 5. Kapituluan, itsasoko PET hondakinen birziklatze kimikoa aztertu da, oso degradatua dagoen PETaren balorizazio alternatiba onena bezala, PET-m hondakinentzat. Birziklatze kimikoa proposatzeko, glikolisi erreakzioa erreaktore itxi batean optimizatu da, errendimendu handia lortuz erreakzio-denbora oso baxuan eta produktua karakterizatu da. 6. Kapituluan, biooinarritutako eta birziklatutako PU termoplastikoen sintesia egin da, eta, horretarako, makrodiol bioonarritu bat, 5. Kapituluan lortutako BHET birziklatua eta HDI erabili dira. Era berean, sintetizatutako TPUen karakterizazioa egin da, BHET komertziala erabiliz sintetizatutako TPUekin alderatuz. Azkenik, sintetizatutako TPUen birziklagarritasun termo-mekanikoa zein kimikoa aztertu da. 7. Kapituluan, biooinarritutako eta birziklatutako PU termoegonkorrak sintetizatu dira. Horretarako errizino-olio jatorriko poliol baten, BHET birziklatuaren eta pMDIren erlazio desberdinak erabili dira. Helburua osagai berriztagarri/birziklatuen ehuneko handi bat duten PU termoegonkorrak sintetizatzea izan da, itsasoko PET hondakinetatik lortutako BHET birziklatuari balio erantsia emanez. Era berean, sintetizatuko PU termoegonkorren karakterizazioa egin da, haien birziklagarritasun kimikoaren azterketarekin batera. 8. Kapituluan, tesi honen pro
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- 2023
26. Diseño de una planta para la producción de bolsas oxo biodegradables, en la ciudad de Ocaña, Norte de Santander
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Quintero Quintana , Magdala Anyelith, Zambrano Cortés , Lida Margarita, Molina Arévalo, Natalia, Quintero Quintana , Magdala Anyelith, Zambrano Cortés , Lida Margarita, and Molina Arévalo, Natalia
- Abstract
This article presents the design of a plant for the production of oxo-biodegradable bags in the city of Ocaña, Norte de Santander, with the aim of reducing the environmental impact generated by plastic bags in the municipality. A market study is conducted to characterize plastic bag consumers and establish demand. In this particular case, customers are focused on the marketplace, retail supermarkets, and plastic bag distribution establishments. Based on customer preferences, the product design (capacity and type of bag) is developed, along with technical specifications and a generic logo. The design of the production process is carried out using the BPMN (Business Process Model and Notation) modeling technique, outlining each phase of production. Simultaneously, a systemic focus matrix is designed, showing the inputs, activities, and outputs of the process. The plant's layout design applies the SLP (System Layout Planning) method, illustrating the arrangement of workstations through the plant floor plan for production, thus observing the flow of materials. For the final design, 3D design software is used to visualize the area, layout, and dimensions of the plant., Este proyecto muestra el diseño de una planta para la producción de bolsas oxo biodegradables, en la ciudad de Ocaña, Norte de Santander, con el fin de disminuir el impacto ambiental que genera las bolsas plásticas en el municipio. Se elabora un estudio de mercado por medio del cual se caracterizan los consumidores de bolsas plásticas, para establecer la demanda. En este caso en particular los clientes se centran en la plaza de mercado, supermercados minoristas, y establecimientos distribuidores de bolsas plásticas. De acuerdo a las preferencias de los clientes se elabora el diseño del producto junto con ficha técnica, su diseño (capacidad y tipo de bolsa) y logotipo. El diseño del proceso productivo se hace mediante la técnica de modelamiento BPMN (Business Process Model and Notation), exponiendo cada una de las fases de la producción, paralelamente se diseña la matriz de enfoque sistémico, donde se muestran las entradas, actividades y salidas del proceso. Para el diseño de la planta se aplicará el método SLP (System Layout Planning) donde se muestra la disposición de las estaciones de trabajo, por medio del plano de la planta para la producción y de este modo observar el flujo de materiales. Para el diseño final se usa software de diseño 3D, para visualizar la distribución de la planta.
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- 2023
27. Efeitos dos microplásticos na saúde dos peixes de água doce e as implicações para a saúde humana
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Khan, M. L., Hassan, H. U., Khan, F. U., Ghaffar, R. A., Rafiq, N., Bilal, M., Khooharo, A. R., Ullah, S., Jafari, H., Nadeem, K., Siddique, M. A. M., and Arai, T.
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polyethylene ,microplastics ,microplásticos ,poliésteres ,polietileno ,ecotoxicologia ,polyesters ,ecossistema de água doce ,ecotoxicology ,freshwater ecosystem - Abstract
The presence of microplastics in aquatic environments has raised concerns about their abundance and potential hazards to aquatic organisms. This review provides insight into the problem that may be of alarm for freshwater fish. Plastic pollution is not confined to marine ecosystems; freshwater also comprises plastic bits, as the most of plastic fragments enter oceans via rivers. Microplastics (MPs) can be consumed by fish and accumulated due to their size and poor biodegradability. Furthermore, it has the potential to enter the food chain and cause health problems. Evidence of MPs s ingestion has been reported in >150 fish species from both freshwater and marine systems. However, microplastic quantification and toxicity in freshwater ecosystems have been underestimated, ignored, and not reported as much as compared to the marine ecosystem. However, their abundance, influence, and toxicity in freshwater biota are not less than in marine ecosystems. The interaction of MPs with freshwater fish, as well as the risk of human consumption, remains a mystery. Nevertheless, our knowledge of the impacts of MPs on freshwater fish is still very limited. This study detailed the status of the toxicity of MPs in freshwater fish. This review will add to our understanding of the ecotoxicology of microplastics on freshwater fish and give subsequent research directions. Resumo A presença de microplásticos em ambientes aquáticos levantou preocupações sobre sua abundância e perigos potenciais para os organismos que vivem nesse meio. Esta revisão fornece informações sobre o problema que pode ser alarmante para os peixes de água doce. A poluição plástica não se limita aos ecossistemas marinhos; a água doce também contém pedaços de plástico, já que a maioria dos fragmentos de plástico entra nos oceanos por meio dos rios. Os microplásticos (MPs) podem ser consumidos pelos peixes e acumulados devido ao seu tamanho e baixa biodegradabilidade. Além disso, tem o potencial de entrar na cadeia alimentar e causar problemas de saúde. Evidências de ingestão de MPs foram relatadas em mais de 150 espécies de peixes de sistemas de água doce e marinhos. No entanto, a quantificação e a toxicidade de microplásticos em ecossistemas de água doce foram subestimadas, ignoradas e não relatadas tanto quanto em comparação com o ecossistema marinho. No entanto, sua abundância, influência e toxicidade na biota de água doce não são menores que nos ecossistemas marinhos. A interação de MPs com peixes de água doce, bem como o risco de consumo humano, permanece um mistério. Todavia, nosso conhecimento sobre os impactos das MPs em peixes de água doce ainda é muito limitado. Este estudo detalhou o status da toxicidade de MPs em peixes de água doce. Esta revisão aumentará nossa compreensão da ecotoxicologia de microplásticos em peixes de água doce e fornecerá direções de pesquisa subsequentes.
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- 2023
28. Avaliação de microplásticos em peixes do mar arábico: acumulação, caracterização e desenvolvimento de métodos
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S. Riaz, S. Nasreen, Z. Burhan, S. Shafique, S. A. Alvi, and M. A. Khan
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polyethylene ,Karachi coast ,análise de FTIR ,polietileno ,Acanthopagrusarabicus ,FTIR analysis ,Acanthopagrus arabicus ,General Agricultural and Biological Sciences ,polipropileno ,costa de Karachi ,polypropylene - Abstract
Around the globe, plastic has been entering the aquatic system and is ingested by organisms. Identification, optimal digestion method, and characterization of the polymers to trace sources are of growing importance. Hence, the present work investigated microplastics accumulation, digestion protocol efficiency, and characterization of polymers with FTIR analysis in the guts of five fishes (Lethrinus nebulosus, Rastrelliger kanagurta, Acanthopagrus arabicus, Otolithes ruber, and Euryglossa orientalis) from the Karachi coastal area, Arabian Sea. A total of 1154 microplastics (MPs) were ingested by 29 out of 33 fish species (87%). The highest average MP/fish was recorded in Otolithes ruber (54) and the lowest in Rastrelliger kanagurta (19.42). Microfibers were the most abundant shape with the highest numbers (35.52%) as compared to the rest of the MPs identified. Transparent microfibers were recorded as the highest in numbers followed by red, black, blue, and green. In this study, KOH with different concentrations and exposure times along with oxidizing agent hydrogen peroxide was tested (Protocols 3 and 4). Results showed these bases were highly efficient in obtaining optimal digestion of the samples. FTIR analysis confirmed that the majority of the polymers found in the fish guts were polyethylene and polypropylene. This study validated for the first time the presence of these polymers of plastic in marine fish from Pakistan. Resumo Em todo o mundo, o plástico tem entrado no sistema aquático e tem sido ingerido por organismos. A identificação, o método de digestão ideal e a caracterização dos polímeros para rastrear fontes são de crescente importância. Portanto, o presente trabalho investigou o acúmulo de microplásticos, a eficiência do protocolo de digestão e a caracterização de polímeros com análise de FTIR nos tratos digestivos de cinco peixes (Lethrinus nebulosus, Rastrelliger kanagurta, Acanthopagrus arabicus, Otolithes ruber e Euryglossa orientalis) do litoral de Karachi, no mar Arábico. Um total de 1154 microplásticos (MP) foram ingeridos por 29 das 33 espécies de peixes (87%) estudadas. A maior média MP/peixe foi registrada no Otolithes ruber (54), e a menor no Rastrelliger kanagurta (19,42). As microfibras foram a forma mais abundante e com os maiores números (35,52%), em comparação ao restante das MPs identificadas. As microfibras transparentes foram detectadas em maior número, seguidas por vermelho, preto, azul e verde. Neste estudo, o KOH foi testado em diferentes concentrações e tempos de exposição, juntamente com o agente oxidante peróxido de hidrogênio (Protocolos 3 e 4). Os resultados mostraram que essas bases foram altamente eficientes para a obtenção de digestão ideal das amostras. A análise de FTIR confirmou que a maioria dos polímeros encontrados nos tratos digestivos dos peixes eram polietileno e polipropileno. Este estudo validou pela primeira vez a presença desses polímeros de plástico em peixes marinhos do Paquistão.
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- 2023
29. COMPÓSITOS DE PEAD/SÍLICA - PARTE I: PREPARAÇÃO E CARACTERIZAÇÃO DE SÍLICAS ORGANOFUNCIONALIZADAS COM GRUPOS METILSILANO E OCTILSILANO.
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Babinski RAMOS, Vanessa Machado, Gammertt RÖHNELT, Maurício, and BRAMBILLA, Rodrigo
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HYDROPHOBIC surfaces , *SILANE , *SILICA gel , *SCANNING electron microscopy , *THERMAL stability , *PARTICLES , *SILICA - Abstract
This paper reports the main results concerning the synthesis and characterization of methylsilane and octylsilane-modified silicas. The modification of the silicas with these groups aims to make the silica surface hydrophobic and thus compatible with high-density polyethylene (HDPE) in HDPE/silica composites. In the present work, two types of silica were organofunctionalized: a pyrogenic silica and a silica gel. The silicas were characterized by a series of complementary techniques with the objective of investigating the nature of the surface species and their textural and morphological characteristics. The SEM images showed that the modification of the silicas with organosilanes has been not resulted in changes on the morphology and on the size of silica particles. In relation to the texture properties, determined by N2 adsorption-desorption porosimetry, the silica modification resulted in a decrease of the specific area (SBET) and the mean pore volume, a behavior attributed to the partial coverage of the adsorption sites by the organosilane molecules. The TGA analysis showed that both the methylsilane groups and the octylsilane groups on the surface of silica and silica gel are thermally stable up to 200 ° C, which enables the organofunctionalized silicas in terms of thermal stability, for the process of preparing the composites by extrusion. The results of applying these organofunctionalized silicas in the development of HDPE/silica composites will be presented in a subsequent article, part II of this research. [ABSTRACT FROM AUTHOR]
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- 2019
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30. COMPÓSITOS DE PEAD/SÍLICA-PARTE II: EFEITO DO TAMANHO DE PARTÍCULA E DA MODIFICAÇÃO DA SÍLICA SOBRE AS PROPRIEDADES TÉRMICAS E MECÂNICAS.
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Babinski RAMOS, Vanessa Machado, Gammertt RÖHNELT, Maurício, and BRAMBILLA, Rodrigo
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IMPACT strength , *CONTACT angle , *THERMAL properties , *NANOPARTICLES , *SILICA , *SILANE , *SILICA fume , *SILICA gel - Abstract
In this work, the effect of silica particle size and organosilane type used in the silica organofunctionalization on the thermal and mechanical properties of high-density polyethylene (HDPE)/silica composites were evaluated. HDPE/silica composites were prepared by the extrusion method using two types of silica: fumed silica, with nanometric particle size and silica gel, micrometric, modified with organosilanes containing methyl or octyl functional groups. Silicas were added to the HDPE at 1% v/v concentration. The addition of the silicas to the HDPE did not influence the melt (Tm) and the crystallization (Tc) temperatures of the resulting composites but influenced its crystallinity. The mechanical property of Izod impact strength, the dynamic-mechanical rheological test (DMTA) and the surface contact angle analysis showed improvements in relation to pure HDPE when used methyl-modified pyrogenic silica as filler. This result suggests that the surface modification of pyrogenic silica with methylsilane groups results in a stronger interaction of this silica with the HDPE matrix. This effect was not observed for micron-sized silica gel, where modification with organosilanes was not sufficient to guarantee interfacial interaction with the HDPE matrix. [ABSTRACT FROM AUTHOR]
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- 2019
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- View/download PDF
31. LA CUBIERTA PLÁSTICA Y SU RELACIÓN CON LA RADIACIÓN, CRECIMIENTO Y RENDIMIENTO DE UN CULTIVO DE PIMIENTO MORRÓN (Capsicum annuum L.).
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Zermeño-González, Alejandro, Claveria-Cigarrero, Gloria L., Melendres-Alvarez, Aaron I., Ramírez-Rodriguez, Homero, Munguía-López, Juan P., Campos-Magaña, Santos G., and Cadena-Zapata, Martín
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HIGH density polyethylene , *FOLIAGE plants , *SOLAR radiation , *SWEET peppers , *FRUIT yield , *CAPSICUM annuum - Abstract
The roof color of tunnels and greenhouses can modify the spectral characteristics of solar radiation and affect the development and performance of plants. The objective in this study was to evaluate the effect of the color cover of a tunnel on the magnitude and characteristics of radiation on a sweet pepper culture (Capsicum annuum L.) and its relationship with chlorophyll content, growth and yield. This study was carried out in four tunnels covered with red, blue, and translucent polycarbonate and high-density diffuse polyethylene. The spectral properties of the radiation under each cover were determined with a spectroradiometer. The radiation effects on the growth and yield of plants were evaluated in a completely random design with sub-sampling in five treatments (covered tunnels and open field), three repetitions and three samples (plants) per replicate. The Tukey test (p≤0.05) was used for means comparison. The photosynthetically active radiation (PAR) transmitted under each cover during the crop’s growth cycle was of 79.22, 53.40, 49.52 and 23.35% for the translucent polycarbonate, high density diffused polyethylene, blue polycarbonate and red polycarbonate, respectively. The transmissivity wavelength ranging from 400 to 550 nm in the red polycarbonate was almost null. Therefore, plants under the red cover had a greater plant height and leaf area, but lower fruit yield. The highest fruit yield was under the high-density diffused polyethylene, due to its greater diffusivity and PAR penetration in the plants foliage. [ABSTRACT FROM AUTHOR]
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- 2019
32. Propiedades espectrales de la cubierta de macro túneles y su relación con el crecimiento y rendimiento del chile poblano (Capsicum annuum L.).
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Zermeño González, Alejandro, Marroquín Morales, José Ángel, Alvarez, Melendres, Rodríguez, Ramírez, Cadena Zapata, Martín, and Campos Magaña, Santos Gabriel
- Abstract
Copyright of Terra Latinoamericana is the property of Sociedad Mexicana de la Ciencia del Suelo A.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
33. COMPÓSITOS DE PEAD/DIATOMITA MODIFICADA COM GRUPOS METILSILANO: ANÁLISE DAS PROPRIEDADES TÉRMICAS E MECÂNICAS.
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FENSTERSEIFER, Camila Rivaldo and BRAMBILLA, Rodrigo
- Abstract
According to IUPAC, the composites are multicomponent materials comprising multiple, different (nongaseous) phase domains in which at least one type of phase domain is a continuous phase. High density polyethylene (HDPE) reinforced with silica particles is an example of a composite material. Diatomite is a natural silica commonly used in filter media. In the present work, the diatomite was organofunctionalized with methyltriethoxysilane (C1) and then used in the preparation of HDPE/diatomite composites with diatomite content of 2.0 and 5.0 wt%. The composites were evaluated in terms of mechanical properties by dynamicmechanical analysis (DMTA), Izod impact test and flexural strength and tensile strength tests. The Fourier transform infrared spectrum (FTIR) of the organofunctionalized diatomite presented bands characteristic of methyl groups, proving the efficiency of the surface modification. The addition of 5.0% diatomite in HDPE resulted in an increase of 8.0 °C in thermal stability, crystallinity (72 to 78%) and in approximately 4.0% in the storage modulus (G'), compared to pure HDPE.SEM analyzes showed the presence of diatomite agglomerates in the HDPE matrix. The Izod impact strength of the composites for this composite was 50 J / m, half of that observed for pure HDPE. The properties of tensile strength were not influenced by the presence of diatomite in HDPE. [ABSTRACT FROM AUTHOR]
- Published
- 2019
34. Possibilidades de melhorias ambientais no processo de reciclagem do polietileno
- Author
-
Elaine Aparecida da Silva and José Machado Moita Neto
- Subjects
gestão ambiental ,reciclagem mecânica ,polietileno ,Chemical technology ,TP1-1185 - Abstract
Resumo A reciclagem mecânica é uma das possibilidades existentes para revalorização dos resíduos plásticos. Neste trabalho, foram acompanhadas as atividades de uma indústria, localizada em Teresina-PI, que realiza a reciclagem mecânica de polietileno (PEBD e PEAD) para a produção de sacolas. A qualidade da matéria-prima pós-uso influencia a qualidade do produto final e determina etapas adicionais em relação ao processamento da resina virgem, como lavagem, secagem e extrusão para produção de grãos. O efluente gerado na etapa de pré-tratamento dos reciclados, o consumo de energia e recursos humanos envolvidos impactam os aspectos ambientais, econômicos e sociais do processo. A reciclagem mecânica só pode ser considerada vantajosa se for dada uma destinação ou disposição final ambientalmente correta do que não é aproveitado na indústria; incorporada a externalidade econômica de realizar tratamento do efluente gerado, e, por fim, qualificar e remunerar de modo justo o catador que disponibiliza a matéria-prima para a indústria.
- Published
- 2016
- Full Text
- View/download PDF
35. Plastic degrading microorganisms: towards microbial biorecycling factories
- Author
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Gomes, João Pedro Duarte, Machado, Raul, Soares-Silva, Isabel João, and Universidade do Minho
- Subjects
Biorremediação ,Polyethylene ,Ciências Naturais::Outras Ciências Naturais ,Plásticos ,Biodegradação microbiana ,Polietileno ,Plastics ,Bioremediation ,Microbial biodegradation - Abstract
Dissertação de mestrado em Bioquímica Aplicada, Os polímeros de plástico são muito resistentes, têm baixa necessidade de manutenção e um baixo custo, o que os torna preferíveis a outros materiais tais como vidro, madeira e metais. Hoje em dia, os plásticos são essenciais e estão amplamente difundidos na sociedade moderna, tendo aplicações variadas que vão desde o embalamento, construção civil, indústria automóvel, eletrónica, habitação, desporto, agricultura, entre outros. O aumento da utilização e produção de plásticos nos últimos anos, aliado à sua elevada estabilidade e baixa biodegradabilidade, faz com que milhões de toneladas de plástico se acumulem anualmente, ameaçando tanto os ecossistemas como a saúde pública. Os resíduos de plástico são tratados principalmente por 3 métodos: aterro sanitário, incineração e reciclagem. No entanto, estes métodos têm custos enormes, são insustentáveis e têm várias consequências negativas, pelo que há uma necessidade urgente de novas tecnologias para a eliminação destes resíduos. Nos últimos anos, foi reportada a biodegradação de plásticos por microrganismos, o que poderá potenciar o desenvolvimento destas novas tecnologias. Os microrganismos conseguem converter os polímeros de plástico em compostos assimiláveis, fornecendo assim um ponto de partida para a economia global circular destes materiais. Neste trabalho, quatro microrganismos distintos, leveduras e bactérias, foram avaliados pelo seu potencial de biodegradação do polietileno (PE). Este polímero foi selecionado, dada a sua reduzida biodegradabilidade e enorme impacto poluente. O processo de rastreio envolveu a utilização de vários meios seletivos/diferenciais, para a determinação da capacidade de utilização de fontes de carbono específicas. O crescimento nestes meios será indicativo da produção de enzimas extracelulares envolvidas na biodegradação do PE e.g. oxidase, protease, lacase, cutinase, lipase e esterase. Apenas a Yarrowia lipolytica e Pseudomonas aeruginosa apresentaram crescimento nestes meios, não tendo sido detetado em Debaryomyces hansenii e Alcanivorax borkumensis. A capacidade de biodegradação de PE pela Y. lipolytica e P. aeruginosa foi avaliada durante 90 dias em meio líquido suplementado com o filme, tendo sido consideradosvários parâmetros: crescimento microbiano, formação de biofilme, perfil proteico extracelular; enquanto os filmes de PE foram caracterizados por ATR-FTIR, SEM e perda de peso. Os resultados indicam a capacidade dos microrganismos para se fixarem à superfície do plástico, formando biofilmes e produzindo enzimas com atividade catalítica do PE. Além disso, as análises por ATR-FTIR e SEM revelaram alterações significativas nos filmes após o período de incubação. Este trabalho evidenciou o potencial da P. aeruginosa e Y. lipolytica na biodegradação de plásticos recalcitrantes como o PE., Plastic polymers are very resistant and have low maintenance and cost, which makes them preferable to other materials such as glass, wood and metals. Nowadays, plastics are essential and ubiquitous in modern society, having varied applications, ranging from packaging, construction, automobiles, electronics, household, sports, agriculture, among others. The increased use and production of plastics in recent years, combined with their high stability and low biodegradability, causes millions of tons of plastic to accumulate annually, threatening ecosystems and public health, while posing a real and growing environmental problem. The plastic waste produced is mainly eliminated by 3 different methods: landfill, incineration, and recycling. These plastic waste treatment methods have enormous costs, are unsustainable and have several negative consequences. Thus, there is an urgent need for new technologies for the disposal of plastic waste. In recent years, there have been several reports on the biodegradation of plastics by microorganisms which could promote the development of these new technologies. Microorganims can convert plastic polymers into assimilable compounds, providing a starting point for a global circular economy of plastics. In this work, four different microorganisms, yeasts and bacteria, were evaluated for their potential to biodegrade polyethylene (PE), which was selected for its very low biodegradability, and huge impact as pollutant. To do this, a screening process involving the use of several different selective/diferential media was performed to assess the potential of the microorganisms to use specific carbon sources, indicative of the ability to produce extracellular enzymes, e.g. oxidase, proteases, laccase, cutinases, lipases and esterases, involved in polyethylene biodegradation. While Debaryomyces hansenii and Alcanivorax borkumensis were unable to utilize the substrates, Yarrowia lipolytica and Pseudomonas aeruginosa used them as carbon and energy source. The potential plastic biodegradation capacity of Y. lipolytica and P. aeruginosa was then evaluated for 90 days in liquid media supplemented with PE film. During this period, several parameters were investigated namely, microbial growth, biofilm formation and extracellular protein profile, whereas the PE films were characterized by ATR-FTIR, SEM and weight loss. Results indicate the ability of the microorganisms to attach and adhere to the surface of the plastic materials, forming biofilms and producing enzymes with PE catalytic activity. Moreover, ATR-FTIR and SEM analyses revealed significant changes in the PE films after the incubation period. Thus, this work demonstrates the potential of using P. aeruginosa and Y. lipolytica for the biodegradation of recalcitrant plastics such as PE., Projeto ECOBiB (ref. POCI-01-0247-FEDER-033997) cofinanciado pelo Programa Operacional Competitividade e Internacionalização (POCI), através do Portugal2020 e do Fundo Europeu de Desenvolvimento Regional (FEDER) Projeto River2OCean (ref. NORTE-01-0145-FEDER-000068) cofinanciado pelo NORTE2020 através do Fundo Europeu de Desenvolvimento Regional (FEDER).
- Published
- 2023
36. Production of highly soluble foliar fertilizer in a spouted bed dryer
- Author
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Ana Carolina Ribeiro Stoppe, Mario Sérgio da Luz, José Luiz Vieira Neto, and Kássia Graciele dos Santos
- Subjects
LDPE ,General Veterinary ,solubility ,CFD ,Soil Science ,Secagem de pastas ,inert particles ,Drying pastes ,polietileno ,Animal Science and Zoology ,partículas inertes ,Agronomy and Crop Science ,solubilidade ,Food Science - Abstract
The drying process can be useful to change the particulate structure, improving the powder solubility. In this study, we investigated the drying of foliar fertilizer in a spouted bed using polyethylene pellets as inert particles to improve its solubility. A 23 factorial experimental design was used to evaluate how the powder yield and moisture were affected by the feeding time, intermittency time, and feed atomizer position. The spouting instability caused powder retention on the bed wall, which decreased the powder recovery efficiency by 2.3-26.6%. Although the powder recovery efficiency was low, the solubility time was reduced by 5.9 times, probably due to particle agglomeration, which increased the amorphous phase of the fertilizer. Design alterations, suggested by the CFD data, can increase spouted bed stability and facilitate centralized spouting. Based on this, the spouted bed drying technique was applied, and it effectively increased the solubility of commercial fertilizer, thus, incorporating more desirable characteristics for field applications. RESUMO O processo de secagem pode alterar a estrutura de sólidos, aumentando a solubilidade de pós. Este trabalho investigou a secagem de um fertilizante foliar em leito de jorro, empregando pellets de polietileno como sólido inerte, a fim de aumentar sua solubilidade. Utilizou-se um planejamento fatorial 23 para avaliar como a produtividade de pó e sua umidade foram influenciados pelo tempo de alimentação, tempo de intermitência a posição do bico atomizador dentro do leito. A instabilidade do jorro, causou a retenção de pó nas paredes do leito, o que conduziu a baixas eficiências de recuperação de pó (2,3 a 26,6%). Foram propostas alterações na geometria do leito, baseadas nas simulações CFD, a fim de aumentar a estabilidade do leito e centralização da fonte. Apesar da baixa produção de pó, a solubilidade foi reduzida em 5,9 vezes, provavelmente devido à aglomeração e aumento da fase amorfa na estrutura do pó. Assim, a secagem em leito de jorro foi efetiva em aumentar a solubilidade do fertilizante, incorporando uma característica atrativa à sua aplicação nas lavouras.
- Published
- 2023
37. APLICACIÓN DE CUBIERTA DE CAMA CON PLÁSTICO POLIETILENO EN LA PRODUCCIÓN DE TOMATE ORGÁNICO (Solanum lycopersicum L.) VARIEDAD RÍO GRANDE, COMO ALTERNATIVA DE SOSTENIBILIDAD MEDIOAMBIENTAL PUCALLPA
- Author
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Manuel Mario Chuyma Tomaylla and Edwin Miranda Ruiz
- Subjects
Acolchado ,Desarrollo sostenible ,polietileno ,variedad ,sostenibilidad. ,General Works - Abstract
El presente trabajo comprende os aspectos más trascendentales del tratamiento de camas de cultivo con el uso del polietileno como acolchado en el cultivo del tomate, el cual es un aporte al ámbito del desarrollo sostenible medioambiental y agrícola, tiene como objetivo: Determinar el efecto de la cubierta de cama con polietileno en la producción de tomate orgánico (Solanum lycopersicum L.) variedad rio grande, bajo condiciones de Pucallpa. Los resultados mostraron que las camas con acolchado de polietileno es el mejor con 5,496.50 kilos más que el tratamiento sin cubierta de plástico. Los resultados permitieron concluir que hubo efecto positivo del tratamiento con cubierta de plástico que incremento los rendimientos en 40.35% en comparación al tratamiento sin cubierta de plástico o testigo, Se presentó menos ataque de plagas y enfermedades en el tratamiento con cubierta de plástico, pero no hubo diferencias estadísticas, para el número de frutos por planta tampoco se presentó diferencias significativas, pero hubo ligero incremento en el tratamiento del suelo protegido con cubierta de plástico, se nota ligeras diferencias para el tratamiento cubierta del suelo con plástico. Se sugirió: Repetir el experimento con otros cultivos de similar periodo vegetativo que el tomate y usar plástico de diferentes colores, así como repetir ensayos usando rastrojos de plantas.
- Published
- 2018
- Full Text
- View/download PDF
38. Evaluación fisicoquímica y microbiológica de ahuyama (Cucurbita moschata) troceada en fresco con recubrimiento y polietileno
- Author
-
RUCO-SÁNCHEZ, CRISTINA, SANTIAGO-CAMPO, CARLOS-HOLMES, PAZ-PEÑA, SANDRA-PATRICIA, and MOSQUERA-SÁNCHEZ, SILVIO-ANDRÉS
- Subjects
Recubrimiento natural ,Almidón de yuca ,Evaluación físicoquímica ,Vinipel ,Aceite esencial de tomillo ,General Engineering ,Microscopía electrónica ,Crecimiento fúngico ,Polietileno - Abstract
RESUMEN La ahuyama (Cucurbita moschata) se caracteriza por su valor nutritivo, especialmente por su contenido de vitamina A, carbohidratos, fósforo y minerales. También, por poseer 45 % de carotenoides totales, 66 % de β-caroteno, 33 % de α- caroteno y 44 % de luteína. Su elevado porcentaje de agua cercano al 90 % es propicio para el crecimiento bacteriano y/o fúngico disminuyendo su vida útil. Este estudio evaluó, cada tres días durante un total de 12, con tres repeticiones y tres réplicas, las características fisicoquímicas (peso, color, firmeza, tasa de respiración); microscópicas (MOAR y MET), bromatológicas y microbiológicas, de ahuyama variedad bolo verde troceada en fresco. 4 tratamientos: SN (muestra testigo); CV con vinipel; CR con recubrimiento de almidón de yuca y aceite esencial de tomillo al 1 %; y CB con sistema binario (recubrimiento de fuente natural y vinipel) a una temperatura de 19 °C y humedad media de 77,75 %. Los tratamientos con película de vinilo arrojaron menor pérdida de peso y firmeza, menor tasa de respiración y mayor estabilidad en el color, en tanto que las muestras testigo y recubiertas, arrojaron mayor contenido de azúcares y humedad, pero menor cantidad de proteína y cenizas. Adicionalmente, las muestras con vinipel, con y sin recubrimiento, registraron un menor crecimiento fúngico. La ahuyama troceada en fresco puede conservarse de forma adecuada mediante el uso de películas de polietileno de baja densidad (vinipel), que permiten retrasar de manera efectiva los procesos de pérdida de calidad inducidos por las operaciones de corte y manipulación. ABSTRACT Ahuyama (Cucurbita moschata) is recognized by its nutritional value, as it is composed of vitamin A, carbohydrates, phosphorus and minerals. Also, for its content of 45 % of total carotenoids; 66 % of β-carotene; 33 % of α-carotene, and 44 % of lutein. However, its high amount of water, about 90%, is conducive to bacterial and/or fungal growth reducing its useful life. Present study evaluated every three days, over a total of 12, three repetitions and three replications of freshly cut green bolus squash variety. Physicochemical attributes like weight, color, firmness, and respiration rate were observed, as well as those microscopic (MOAR and MET); bromatological, and microbiological characteristics to 4 different treatments as follow: SN (control sample); CV (Vinyl wrap); CR (coated with cassava starch and 1 % thyme essential oil); and CB: (binary system with natural source coating and Vinyl wrap) under environmental conditions of 19 °C temperature and 77,75 % average humidity. Vinyl wrap treatment exhibited lower weight, firmness loss, fewer respiration rate loss, and had better color stability. Control and coated samples showed higher sugar and moisture content but lower ash and protein. Additionally, samples with coated and uncoated stretch film registered minor fungal growth. Fresh cut squash could be properly preserved through the use of low-density polyethylene films (vinyl wrap), allowing to effectively delay the course of quality loss because of handling operations.
- Published
- 2021
39. DISEÑO DE UNA TERMOSELLADORA PARA BOLSAS DE POLIPROPILENO.
- Author
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Echeverría Sosa, Darvi, Pérez Aviña, Juan Manuel, Tep Chel, Diana Carmelina, and Pinzón Can, José Carlos
- Abstract
Copyright of Congreso Internacional de Investigacion Academia Journals is the property of PDHTech, LLC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
40. EVALUACIÓN DE BOLSAS PLÁSTICAS PARA EL ENVASADO DE QUESO MOZZARELLA AL VACÍO.
- Author
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Bejerano-Salgado, Danilo, Rodríguez, Ariel, Pacheco, Divina, and Bolumen, Soledad
- Subjects
- *
WATER vapor , *MOZZARELLA cheese , *ORGANIC solvents , *POLYESTERS , *PLASTIC bags - Abstract
The plastic bag used in the packaging of mozzarella cheese was characterized, for which the quality of the bag was evaluated through its identification by the method of solubility in organic and inorganic solvents, the quality of sealing by the colorful solution method, the determination of the speed of transmission to water vapor by the method gravimetric, dimensions and thickness. The results of the functional length and width presented average values of 396 mm and 374 mm respectively, the material proved to be made up of two flexible layers with a total thickness of 67.17 μm; an inner layer of polyethylene with a thickness of 47 μm and an outer layer of polyester with a thickness of 21 μm. The transmission speed to water vapor of the container was 2.33 g/m2d. [ABSTRACT FROM AUTHOR]
- Published
- 2020
41. Polietilè funcionalitzat i hidrolíticament estable
- Author
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Hervàs Arnandis, Susi
- Subjects
Máster Universitario en Química Sostenible-Màster Universitari en Química Sostenible ,Hydrolytic stability ,Estabilidad hidrolítica ,Polyethylene ,Funcionalización ,Functionalization ,Polietileno ,TECNOLOGIA DEL MEDIO AMBIENTE - Abstract
[ES] Funcionalización directa del polietileno con ésteres de diferentes longitudes y formas, adición de carbenos y posterior transesterificación, para el estudio de sus diferentes estabilidades hidrolíticas.
- Published
- 2022
42. Profiles from Henequen Fibres with High-Density Polyethylene Matrix.
- Author
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Díaz-Batista, Daniel, Blancard-Valdés, Walter Saint, Bridi-Tellez, Victor, Mazorra-Mestre, Martha, Valin-Rivera, José Luís, Valenzuela-Díaz, Francisco Rolando, and Wiebeck, Hélio
- Subjects
- *
HENEQUEN (Plant) , *POLYETHYLENE , *FIBROUS composites , *PLANT fibers , *TENSILE strength - Abstract
A process to obtain profiles from henequen (Agave fourcroydes Lem.) fiber reinforced high-density polyethylene (HDPE) matrix composite material by extrusion method is presented. Data on thermal stability and microstructural features of the henequen fibers used are presented. Behavior of material in process and its influence on mechanical properties are analyzed. A comparison between obtained material and another currently in production and incorporating wood particles from pine sawdust (Pinus sp.) as reinforcing element is exposed. Tensile strength of henequen fiber reinforced composites ranges from 12 to 15 MPa, slightly lower than the one obtained from wood particle reinforced composite material. Nevertheless, the impact strength and Young's modulus values double the ones obtained with pine's particles reinforcement. Characterization of both materials obtained and process, it allowed to both identify elements related to differences on tensile strength and propose processing alternatives to allow introducing henequen fibers. [ABSTRACT FROM AUTHOR]
- Published
- 2018
43. Effect of sealing on the feed out face of trench silos on the performance of confined calves
- Author
-
R.S. Oliveira, T.F. Gavlak, M.P. Machado, Mikael Neumann, G.B. Pontarolo, André Martins de Souza, Fernando Braga Cristo, and A.D. Manchur
- Subjects
polyethylene ,Materials science ,Silage ,Plastic film ,Feed conversion ratio ,Seal (mechanical) ,SF1-1100 ,ganho de peso ,chemistry.chemical_compound ,Animal science ,feed efficiency ,Dry matter ,filme plástico ,General Veterinary ,0402 animal and dairy science ,weight gain ,04 agricultural and veterinary sciences ,ingestive behavior ,Polyethylene ,040201 dairy & animal science ,Animal culture ,chemistry ,eficiência alimentar ,Trench ,Feedlot ,040103 agronomy & agriculture ,polietileno ,0401 agriculture, forestry, and fisheries ,comportamento ingestivo ,plastic film - Abstract
This study aimed to evaluate the productive performance, dry matter intake, apparent digestibility and ingestive behavior of feedlot calves fed corn silage from the feed out face of trench silos with different types of sealing. The animals were divided into three treatments with four repetitions: Conventional seal - double-sided polyethylene of 110µm thickness; Double-sided seal - double-sided polyethylene of 200µm thickness; and Double seal - composed of double face polyethylene with a thickness of 80µm superimposed on a polyamide translucent vacuum film with a thickness of 20µm. The use of double face sealing provided 12.63% increase in average daily gain and improved food conversion by 0.62 percentage points. The apparent digestibility of the diet with double-face sealing system silage was 4.30% higher than the diet with double-face sealing silage and 11.00% higher than the diet with conventional sealing silage. It is recommended to use the double face sealing with 200µm polyethylene and double face sealing with 80µm thick polyethylene on top of a 20µm thick polyamide translucent vacuum film. RESUMO Objetivou-se avaliar o desempenho produtivo, o consumo de matéria seca, a digestibilidade aparente e o comportamento ingestivo de novilhos confinados, alimentados com silagem de milho da porção inicial de silos do tipo trincheira, conservada sob distintos tipos de vedação. Os animais foram divididos em três tratamentos, com quatro repetições: vedação convencional - polietileno tipo dupla face, com espessura de 110µm; vedação dupla face - polietileno tipo dupla face, com espessura de 200µm; e dupla vedação - polietileno tipo dupla face, com espessura de 80µm sobreposto a um filme vácuo translúcido de poliamida, com espessura de 20µm. O uso da vedação dupla face proporcionou incremento de 12,63% no ganho de peso médio diário e melhorou em 0,62 ponto percentual a conversão alimentar. A digestibilidade aparente da dieta com silagem do sistema de vedação dupla face foi 4,30% superior em relação à dieta com silagem da dupla vedação e 11,00% superior à dieta com silagem da vedação convencional. Recomenda-se a utilização tanto da vedação dupla face com polietileno de 200µm quanto da dupla vedação com polietileno tipo dupla face, com espessura de 80µm, sobreposto a um filme vácuo translúcido de poliamida com espessura de 20µm.
- Published
- 2021
44. Polietilè funcionalitzat i hidrolíticament estable .
- Author
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Mengual Cuquerella, Jesús, Leyva Perez, Antonio, Oliver Meseguer, Judit, Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, Hervàs Arnandis, Susi, Mengual Cuquerella, Jesús, Leyva Perez, Antonio, Oliver Meseguer, Judit, Universitat Politècnica de València. Departamento de Ingeniería Química y Nuclear - Departament d'Enginyeria Química i Nuclear, and Hervàs Arnandis, Susi
- Abstract
[ES] Funcionalización directa del polietileno con ésteres de diferentes longitudes y formas, adición de carbenos y posterior transesterificación, para el estudio de sus diferentes estabilidades hidrolíticas.
- Published
- 2022
45. Análisis sobre la metodología de conservación del plástico aplicado en obras artísticas contemporáneas
- Author
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Jiménez Martínez, Karla Lilia and Jiménez Martínez, Karla Lilia
- Abstract
Based on the comparative analysis of several case studies related to the application of The Decision-Making Model for the Conservation and Restoration of Modern and Contemporary Art to solve conservation problems of works created with plastic, I propose to delve into the reaches, challenges, implications and, results of this subject, since plastic is an industrial material not produced ex profeso for artistic creation which, when used in this field, presents specific characteristics and properties that influence its behavior, deterioration and, hence, durability. Thus, its ephemeral character makes us question how to conserve such works, where the concept is the most important., Con base en el análisis comparativo de diversos casos de estudio relativos a la aplicación del Modelo de toma de decisiones para la conservación y restauración de arte moderno y contemporáneo para la solución de problemáticas de conservación de piezas realizadas con plástico, se propone ahondar en los alcances, retos, implicaciones y resultados del tema, pues el plástico es un material industrial no producido ex profeso para la creación artística que, usado en ese campo, reviste características y propiedades particulares que influyen en su comportamiento, en su deterioro y, por lo tanto, en su durabilidad. Su carácter efímero, pues, hace que cuestionemos la manera en que debe conservarse este tipo de obras, en las que lo más importante es el concepto.
- Published
- 2022
46. Análisis del flujo de materiales en la fase de fin de vida de botellas PET en el cantón Cuenca
- Author
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Vanegas Peña, Paúl Fernando, Sucozhañay Idrovo, Gabriela Carolina, Minchala Macas, Daniela Estefanía, Ullauri Balarezo, María Paz, Vanegas Peña, Paúl Fernando, Sucozhañay Idrovo, Gabriela Carolina, Minchala Macas, Daniela Estefanía, and Ullauri Balarezo, María Paz
- Abstract
Worldwide, Polyethylene Terephthalate (PET), and particularly PET bottles, are part of our daily life, mainly due to the growing demand for bottled beverages. In Ecuador, as in many developing countries, the information about the input and output flows related to the PET bottle management system is scarce and scattered; therefore, knowing the current situation and operation from Manufacturing to Recycling and Marketing of recycled products helps identify the critical points and problems associated with the management of this material. The present study will be a first approach to the Ecuadorian reality to analyze and recommend improvements in the management of PET bottles, paying particular attention to the end-of-life phase with a case study in Cuenca. Material Flow Analysis (MFA) methodology was used in this study, to deliver a complete and consistent set of information about all flows and stocks of a particular material over time within a spatially defined system. Based on the balance of inputs and outputs through the principle of conservation of mass. The results showed that during 2019, 86,79 % of virgin raw material was used to make PET bottles and only the remaining 13,21 % was recycled PET material. The study also showed that bottled beverages cover 85 % of the market at the national level, while the remaining 15 % corresponds to the bottling of other products. In the end-of-life cycle phase, it was determined that Homes are the main generators of beverage bottle waste with 69,66 %, while Restaurants and Educational Institutions are responsible for 17,95 % and 12,39 % respectively. In addition, this study identified that base recyclers are responsible for approximately 95 % of the collection of this waste material, both at the national and cantonal levels. Also, the main problems in this study were identified, most notably the lack of data, the secrecy of information, and the lack of processes and record standardization. Finally, proposals for improvement we
- Published
- 2022
47. VIABILIDADE DA UTILIZAÇÃO DE GARRAFAS DE POLIETILENO (PET) EM LAJES ESTRUTURAIS
- Author
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Sibila Corral de Area Leao Honda, Ivair Salomão Liboni, and Gabriela Alves de Lima Cardoso
- Subjects
Polietileno ,concreto armado ,laje nervurada ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Science (General) ,Q1-390 - Abstract
As garrafas de Polietileno (PET) são largamente utilizadas no mundo, seja por facilidade de design, por durabilidade ou por facilidade de manuseio, transporte e estocagem. No entanto, problemas de logística reversa onde a embalagem em pós-uso, por não ter uma destinação final adequada, acarreta em poluição ao meio ambiente. Visando à retirada deste material do meio ambiente de forma ecologicamente responsável, associada à redução de custo de produção e de peso próprio de lajes nervuradas de concreto, este artigo vem a discutir pesquisa elaborada por meio de análise laboratorial e de viabilidade de construção de lajes com a utilização de garrafas PET em seu interior. Verificaram-se aspectos positivos, econômicos, técnicos e ambientais.
- Published
- 2017
48. Pirólise Térmica de Filmes de PEBD e PELBD de Embalagens Pós-Consumo
- Author
-
Carlos Alberto Mendes Moraes, Douglas da Silva Vallada, and Paulo Ricardo Santos da Silva
- Subjects
Materials science ,General Medicine ,Pirólise ,Polyethylene ,Raw material ,Fluid catalytic cracking ,Polietileno ,Linear low-density polyethylene ,Low-density polyethylene ,chemistry.chemical_compound ,Petrochemical ,chemistry ,Chemical engineering ,Waste ,Resíduos ,Char ,Pyrolysis - Abstract
Thermoplastics are increasingly present in the daily life of society in the most varied applications. Among the thermoplastics, polyethylene is the one that presents the higher volume of worldwide production and consumption. However, a large part of its applications are for products with a short shelf life, especially the food packaging sector. This way, they become expressive constituents in the composition of urban solid waste, leading to large quantities often being deposited in landfills. Pyrolysis appears as a technology for recycling plastic waste, allowing the recovery of the monomers that originated it. Through this thermochemical process, the waste is converted into three different products: oil or, in some cases wax, non-condensable gases, and a solid fraction named char. Thus, the goal of this study is to contribute for the development of pyrolysis as a technology for the final treatment of low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) waste from post-consumer packaging, through the analysis of the influence of the pyrolysis temperature in the chemical composition of the oil produced, as well as the discussion of possible applications. For this purpose, the waste was initially characterized through analyses of attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetry (TGA), differential scanning calorimetry (DSC), and X-ray fluorescence (XRF). The characterization experiments showed that the plastic waste is constituted of 4.07% ash, 0.52% fixed carbon, and 95.54% volatile matter, showing its great potential to produce pyrolytic oil. Thermal degradation of the waste initiated at around 410°C and continued through about 530°C, with maximum rate of thermal degradation at about 488°C. The pyrolysis process was carried out with 50g samples of post-consumer LDPE and LLDPE, previously agglutinated, with particle size ranging from 0.001mm to 4mm, in a horizontal quartz reactor, with an inert atmosphere of N2, heating rate of 10°C/min, and residence time of 30 minutes. The experiments were conducted with experimental temperatures of 500°C and 700°C, in order to verify the influence of the temperature in the chemical composition of the oil obtained in the process. The analysis of the oil collected at 500°C by infrared spectroscopy revealed a specter similar to the one of commercial diesel. Through gas chromatography coupled with mass spectrometry, it was verified a composition constituted mostly by olefins (44%), from 8 to 35 carbon atoms, followed by paraffins (23.8%), and cycloparaffins (10%). There was also a considerable percentage of alpha-olefins, important for the petrochemical industry, and a percentage of aromatic compounds on a trace level. By varying the temperature to 700°C, an increase in the level of aromatic compounds to 16.6% occurred, accompanied by a decrease in the percentage of olefins, paraffins, and cycloparaffins. The oils obtained in both temperatures have potential for application in steam cracking or conventional catalytic cracking processes to obtain the raw materials of the petrochemical industry. Os termoplásticos estão cada vez mais presentes no cotidiano da sociedade e nas mais variadas aplicações. Dentre os termoplásticos, o polietileno é o que apresenta o maior volume mundial de produção e consumo. Entretanto, grande parte de suas aplicações destina-se a produtos de curto tempo de vida útil, principalmente no setor de embalagens de alimentos. Tornam-se, assim, constituintes expressivos da composição do resíduo sólido urbano, levando a grandes quantidades depositadas frequentemente em aterros sanitários. Neste contexto, a pirólise surge como uma tecnologia para a reciclagem de resíduos plásticos, permitindo a recuperação dos monômeros que lhes deram origem. Através desse processo termoquímico, os resíduos são convertidos em três diferentes produtos: óleo ou em alguns casos cera, gases não condensáveis e uma fração sólida denominada carvão ou char. Assim, o objetivo do presente estudo é contribuir para o desenvolvimento da pirólise como tecnologia para tratamento final de resíduos de polietileno de baixa densidade (PEBD) e polietileno linear de baixa densidade (PELBD), provenientes de embalagens pós-consumo, através da análise da influência da temperatura de pirólise na composição química do óleo produzido, assim como a discussão de potenciais aplicações. Para tanto, os resíduos foram inicialmente caracterizados através das análises de espectroscopia por refletância total atenuada no infravermelho com transformada de Fourier (ATR-FTIR), termogravimetria (TGA), calorimetria exploratória diferencial (DSC) e fluorescência de raios-X (FRX). Os ensaios de caracterização mostraram que o resíduo plástico é constituído por 4,07% de cinzas, 0,52% de carbono fixo e 95,54% de matéria volátil, evidenciando seu grande potencial para a produção de óleo pirolítico. A degradação térmica do resíduo iniciou-se em torno de 410°C e se estendeu até cerca de 530°C, com máxima taxa de degradação térmica em cerca de 488°C. O processo de pirólise foi realizado com amostras de 50g de PEBD e PELBD pós-consumo, previamente aglutinados, com tamanho de partícula na faixa de 0,001mm a 4mm, em reator horizontal de quartzo, com atmosfera inerte de N2, taxa de aquecimento de 10°C/min e tempo de residência de 30min. Os ensaios foram conduzidos com temperaturas experimentais de 500°C e 700°C, a fim de verificar a influência da temperatura na composição química do óleo obtido no processo. A análise do óleo coletado a 500°C por espectroscopia de infravermelho, revelou um espectro similar ao do diesel comercial. Através de cromatografia gasosa acoplada a espectrometria de massas, verificou-se uma composição constituída predominantemente por olefinas (44%), de 8 a 35 átomos de carbono, seguida de parafinas (23,8%) e cicloparafinas (10%). Evidenciou-se ainda um percentual considerável de alfa-olefinas, importantes para a indústria petroquímica, e percentual de compostos aromáticos a nível de traço. Ao variar a temperatura para 700°C, ocorreu um aumento no teor de compostos aromáticos para 16,6%, acompanhado de uma redução no percentual de olefinas, parafinas e cicloparafinas. Os óleos obtidos em ambas as temperaturas têm potencial de aplicação em processos de craqueamento a vapor ou craqueamento catalítico convencional para a obtenção de matérias-primas da indústria petroquímica.
- Published
- 2022
49. Evaluación Ambiental de la Mezcla de Polietileno de Alta Densidad, Polipropileno y Cascarilla de Arroz aplicado en la fabricación de un producto en MDF por medio de Análisis de Ciclo de Vida
- Author
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Díaz Prieto, Deisy Natalia, Solano, Johanna Karina, Gómez, Zully Esmeralda, Orjuela Yepes, David, and Universidad Santo Tomás
- Subjects
Medium Density Fiberboard ,Rice Husk ,Análisis de Ciclo de Vida ,Tableros de Densidad Media ,Cascarilla de Arroz ,Polietileno de Alta Densidad ,High-Density Polyethylene ,Life Cycle Analysis ,Polietileno ,Polipropileno ,polypropylene - Abstract
En los últimos años se ha visto un interés particular por el aprovechamiento de residuos sólidos de origen agropecuario y residuos poliméricos por las propiedades que estos poseen, así, se han estudiado mezclas entre el residuo agroindustrial cascarilla de arroz (CA) y polímeros como el Polietileno de Alta Densidad (PAD) y el Polipropileno (PP) con el fin de reemplazar materiales vírgenes. En este estudio se evaluó el comportamiento ambiental de un producto hecho con una matriz polimérica de PAD, PP y cascarilla de arroz, comparado con la fabricación del mismo a partir de un material virgen. Para el desarrollo del estudio se hizo una comparación de las propiedades mecánicas de la mezcla con las de tableros de densidad media, MDF (Medium Density Fiberboard), se seleccionó un producto hecho con este material y posteriormente se hizo una visita técnica a una empresa para conocer su proceso productivo. Se realizaron balances de materia y energía para ambos escenarios, (producción con MDF y con la matriz polimérica). La metodología utilizada para la evaluación ambiental fue Análisis de Ciclo de Vida (ACV) empleando el software SimaPro. In recent years there has been a particular interest in the use of solid waste, agricultural origin, and polymeric waste for the properties these have. Thus, there have been studied mixtures between the agro-industrial waste rice husk (CA) and polymers such as High-Density Polyethylene (PAD) and Polypropylene (PP) to replace virgin materials. This study evaluated the environmental performance of a product made with a polymer matrix of PAD, PP and rice husk compared manufacturing of the same product made with virgin material. For the development of the study a comparison of the mechanical properties of the mixture with those of Medium Density Fiberboards (MDF), a product was selected, and a technical visit was subsequently made to a company to learn about the process of making the product. Material and energy balances were made for both scenarios (MDF and polymer matrix). The methodology used for the environmental assessment was Life Cycle Analysis (LCA) using SimaPro software. Ingeniero Ambiental Pregrado
- Published
- 2022
50. Estudio del efecto de microorganismos degradadores en el espectro del polietileno de baja densidad a través de técnicas estadísticas multivariables
- Author
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Murillo Brito, Tatiana Elizabeth and Arévalo Moscoso, Pablo Wilson
- Subjects
BIOTECNOLOGÍA ,BIODEGRADACIÓN ,POLIETILENO ,MICROORGANISMOS ,ESPECTROSCOPÍA INFRARROJA POR TRANSFORMADA DE FOURIER - Abstract
En este trabajo se estudió el efecto de microorganismos degradadores sobre el polietileno de baja densidad. Se estableció la relación entre las variables a través de ACP. Los resultados obtenidos de la determinación del porcentaje de pérdida de peso y el análisis por espectroscopía FTIR confirmaron la existencia de biodegradación del polímero. In this work, the effect of degrading microorganisms on low-density polyethylene was studied. The relationship between the variables was established through PCA. The results obtained from the determination of the percentage of weight loss and the analysis by FTIR spectroscopy confirmed the existence of biodegradation of the polymer.
- Published
- 2022
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