10 documents found, page 1 of 1
Plastic waste-derived carbon nanotubes: Influence of growth catalyst and cataly...
Roman, Fernanda; Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Baldo, Arthur Pietrobon; Lopes, Jéssica Paula Marim; Gonçalves, Giane; Pereira, Ana I.Low-density polyethylene (LDPE) was used in this work to grow carbon nanotubes (CNTs) by chemical vapor deposition (CVD) over catalysts based on Ni, Fe and Al, synthesized either by co-precipitation (C) or wet impregnation (I) methods, with CNT yields in the range of 16–33 %. The morphology of the CNTs was directly influenced by the route used for the CVD catalyst synthesis, with co-precipitation-derived CVD ca...
Skills and competencies expected from HEI students: case study of a less favour...
Pereira, João Paulo; Ferro-Lebres, Vera; Pereira, João; Lopes, Jéssica Paula MarimThe main objective of this study is to understand what are the skills and competences expected from graduates in a context of disadvantaged re-gions. The paper is based on a qualitative case study from Trás-os-Montes sub-region (in Portugal). This region is an example of a disadvantaged region, which is building a strong based knowledge transfer system in order to empha-ses the interaction between region and th...
Carbon nanofibers prepared from ldpe for catalytic wet peroxide oxidation of pa...
Roman, Fernanda; Lopes, Jéssica Paula Marim; Díaz de Tuesta, Jose Luis; Silva, Adrián; Faria, Joaquim; Gomes, HelderPlastic solid waste (PSW) is a strong concern, as there is still a great fraction being sent to landfills (around 25% in EU), mainly plastic used for packaging purposes, such as low- density polyethylene (LDPE). The high content of elemental carbon in plastics (for example, LDPE consists of 85.6% of carbon) makes them alternative precursors for synthesis of carbon-based materials, such as carbon nanotubes and n...
Microbiological contamination in different food service units associated with f...
Alves, Ana Francisca Lemos; Viveiros, Cristina; Lopes, Jéssica Paula Marim; Nogueira, António José M.; Pires, Bruno; Afonso, Andrea Luísa FernandesBackground: A microbiological analysis of samples taken from hands of food handlers and utensils/crockery in food service units was used to assess the risk of food contamination. We aimed to assess indicators of microbiological contamination in different food service units. Methods: We used data for an official inspection proposal (2018–2019) in different food service units serving a district in Northeast Portu...
Catalytic wet peroxide oxidation of paracetamol using carbon nanotubes synthesi...
Roman, Fernanda; Lopes, Jéssica Paula Marim; Silva, Ana P. F.; Díaz de Tuesta, Jose Luis; Lenzi, Giane G.; Silva, Adrián; Gomes, HelderOne of the ongoing concerns related with wastewater treatment is the presence of micropollutants on water bodies, since they accumulate due to its recalcitrant behavior and its constant introduction in the system [1]. Catalytic Wet Peroxide Oxidation (CWPO) is a wastewater treatment technology based on the generation of powerful oxidants (hydroxyl radicals) from the decomposition of H2O2, providing that suitabl...
Contaminação microbiológica em diferentes unidades de restauração associada a m...
Alves, Ana Francisca Lemos; Medeiros, Cristina; Lopes, Jéssica Paula Marim; Teixeira, Cristina; Miranda, Helena; Pires, Bruno; Nogueira, António José M.A contaminação microbiológica dos alimentos é um problema de Saúde Pública, representando uma importância crescente ao nível da segurança alimentar (WHO, 2015). A confeção ou o armazenamento inadequado de alimentos e a deficiência de condições higio-sanitárias durante a preparação dos mesmos, podem potenciar a contaminação dos alimentos com microrganismos (Zeaki et al. 2019; McFarland et al. 2019). Objetivos: A...
Síntese e caracterização de catalisadores de níquel e ferro suportados em alumi...
Lopes, Jéssica Paula Marim; Roman, Fernanda; Díaz de Tuesta, Jose Luis; Lenzi, Giane G.; Gomes, HelderO presente trabalho teve como principal objetivo sintetizar catalisadores de Ni e Fe, utilizando o método de impregnação húmida (IU) e/ou co-precipitação (CO). Foram sintetizados 8 catalisadores: Ni/Al 2 O 3 (IU), Ni-Fe/Al 2 O 3 (IU), Ni-Fe/Al 2 O 3 (CO), Ni-Fe-Al(CO), Ni/HMFI-90(IU), Ni-Fe/HMFI-90(IU), Ni/HBeta-150(IU) e Ni-Fe/H-Beta- 150(IU). Os catalisadores foram tratados termicamente (calcinação) a 800 °C ...
Carbon nanotubes synthesized from LDPE for application in wet peroxide oxidatio...
Roman, Fernanda; Lopes, Jéssica Paula Marim; Díaz de Tuesta, Jose Luis; Lenzi, Giane G.; Silva, Adrián; Faria, Joaquim; Gomes, HelderCarbon nanotubes (CNTs) were produced by chemical vapor deposition (CVD) considering low-density polyethylene (LDPE) as a carbon source and as an alternative to upcycle plastic solid waste. The CNTs were synthesized over bimetallic catalysts (Ni and Fe) supported on Al2O3 and purified with H2SO4 to dissolve the metal particles from the material. Both original (CNT-O) and purified materials (CNT-P) were tested a...
Carbon nanofibers from plastic solid waste
Lopes, Jéssica Paula Marim; Roman, Fernanda; Díaz de Tuesta, Jose Luis; Lenzi, Giane G.; Faria, Joaquim; Silva, Adrián; Gomes, HelderProduction of plastics reached 360 million tonnes in 2018, the EU production corresponding to 62 million tonnes (i.e. 17%), from which only 9.2 million tonnes were collected for recycling. Low- and high-density polyethylene (PE) and polypropylene (PP), commonly used for packaging purposes, represent 40% of EU production [1]. In 2018, landfilling of plastic solid waste still represented 18.5% of the collected ma...
Valorização de resíduos sólidos plásticos em nanomateriais de carbono
Lopes, Jéssica Paula MarimEm Portugal, a percentagem correspondente a resíduos sólidos plásticos (RSP) enviados para aterros (35%) é superior ao valor médio praticado nos demais países europeus. Esse fato, combinado com a baixa degradabilidade dos resíduos plásticos, destaca a necessidade de novas estratégias para reduzir o descarte de RSP e alcançar os objetivos da Diretiva 2008/98-CE e PNRS-12305/2010. Uma alternativa é a valorização ...