Navegando por Palavras-chave "Pellets"

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    Análise de pellets nas praias do litoral paulista e seus efeitos ecotoxicológicos em ambientes marinhos
    (Universidade Federal de São Paulo, 2016-10-06) Mendes, Gabriel Izar [UNIFESP]; Christofoletti, Ronaldo Adriano [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Pellets are small grains of resin with a few millimeters (>5 mm), produced and used in large scale, that are among the most found debris in beaches all over the world. It is persistent materials and usually adsorb chemicals compounds, representing a strong harmful to the marine animals and coastal environment in general. This study aim to evaluate the pellets density in the superficial layer in beaches in São Paulo coast, trying to establish a relationship between the spatial distribution along the coast and the distance from a pellet source. We tested the hypothesis that the pellets in the superficial layer were concentrated close to the Santos port, because it is the main pellets source for the area. Then, we tested the toxicity to marine organism and some factors that contribute to this toxicity, like pellets coloration, sampling site (beach) and the density find in the São Paulo coast. To the pellets distribution, twelve beaches were selected in São Paulo coast, with different distances of Santos port. Pellets were collected in the superficial sand layer (5 cm), on the high upper beach limit, with twenty samples per beach. For the ecotoxicity assays, pellets were manually and actively collected in two beaches in two contaminated areas in different levels. These assays were tested with urchin (Lytechinus variegatus), amphipod (Tiburonella viscana) and copepod (Nitokra sp.), in acute and chronic assay. It was noted a decreasing gradient of pellets density along the São Paulo coast, both north and south of Santos port, with higher densities inside the Santos bay, where the port is located. Beyond to the port distance, several other factors may have influenced the dispersion of pellets in São Paulo coast, including environmental factors not assessed in this study, like wind and superficial currents direction and the coast geography, that seem to be a important factor to pellets dispersion in coastal areas. Pellets showed chronic toxicity for both tested organism (L. variegatus and Nitokra sp.) at extremely high densities, however, they were not capable to confer acute toxicity in densities founded in São Paulo Beaches for and literature for T. viscana. The high variability of adsorbed contaminants concentration in each pellet can be a factor with more influence for the pellet toxicity, than the pellets density factor tested in this study.
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    Avaliação da Densidade de Pellets Plásticos na Praia do Gonzaga, Santos, SP
    (Universidade Federal de São Paulo, 2023-12-06) Oliveira, Yasmin Yokomizo [UNIFESP]; Oliveira, Emiliano Castro de [UNIFESP]; http://lattes.cnpq.br/2433172806859859; http://lattes.cnpq.br/3268258528178203; Universidade Federal de São Paulo (UNIFESP)
    Explorando a preocupação global com a poluição plástica, este trabalho de conclusão de curso centra-se nos microplásticos, notadamente em pellets de fabricação primária e secundária, cuja presença nos ambientes marinhos representa uma ameaça substancial à biodiversidade. A análise detalhada dos dados anuais de coletas na Praia do Gonzaga revela uma notável diversidade na tonalidade desses resíduos plásticos, destacando a relação entre a coloração dos pellets e fatores temporais e ambientais. A constante introdução de pellets mais claros no ambiente costeiro destaca a urgência de estratégias abrangentes para lidar não apenas com a quantidade total, mas também com as características individuais que refletem diferentes estágios de interação com o meio ambiente. Ao totalizar 1692 pellets ao longo do ciclo anual de coletas, este estudo reforça a importância da pesquisa contínua para compreender o impacto desses resíduos em ambientes costeiros, subsidiando medidas proativas, como programas de conscientização e regulamentações para a redução da produção de plásticos, emergindo como imperativo para preservar a integridade do ecossistema costeiro e enfrentar os desafios crescentes associados à poluição plástica.
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    Physical characterization of multiparticulate systems
    (Univ Sao Paulo, Conjunto Quimicas, 2017) Issa, Michele Georges; de Souza, Natalia Vieira; Duque, Marcelo Dutra [UNIFESP]; Ferraz, Humberto Gomes
    The search for new pharmaceutical dosage forms and different drug delivery systems already used in therapeutics is a global trend, serving as an opportunity to expand the portfolio for the pharmaceutical industry. In this context, multiparticulate systems, such as pellets, granules, and minitablets, represent an attractive alternative, given the range of possibilities they provide. Among the methods used in the production of these systems, we highlight the process of extrusion-spheronization for pellet manufacture, wet granulation and hot-melt extrusion for the obtention of granules, and direct compression for minitablets. Although highly versatile, depending on the technology chosen, many processes and formulation variables can influence the ensuing stages of manufacture, as well as the final product. Therefore, the characterization of these small units is of fundamental importance for achieving batch homogeneity and optimal product performance. Analyses, including particle size distribution, morphology, density, porosity, mechanical strength and disintegration, are example tests used in this characterization. The objective of this review was to address the most widely used tests for the physical evaluation of multiparticulate systems.