Innovative application for bauxite residue: red mud-based inorganic polymer spheres as pH regulators

In this study, and for the first time, red mud (RM)-based geopolymer spheres were synthesised, with varying porosity and RM content, and then their use as pH regulators was evaluated. The aluminosilicate sources of these inorganic polymers were 100% waste-based, consisting of a mixture of RM and fly ash wastes. Geopolymer spheres containing up to 60 wt.% RM were successfully produced, while higher RM contents distorted the specimens' spherical shape. Results showed that alkalis leaching from the spheres over time can be controlled by their porosity, while the RM content induces only minor changes to leaching. The RM-based spheres leached up to 0.0237 mol/dm3g of OH- ions from their structure, this being among the highest values ever reported for geopolymers. This allowed a continuous and prolonged pH buffer capacity with narrow pH decay over the 28 days (2.4 pH units), suggesting the use of the RM-based spheres as pH buffering materials in wastewater treatment and anaerobic digestion systems.publishe

In-depth investigation of the long-term strength and leaching behaviour of inorganic polymer mortars containing green liquor dregs

Green liquor dregs are the most challenging waste stream coming from the pulp and paper industry. Despite tremendous efforts, there are not currently any viable recycling alternatives for this massively produced waste (2 Mt/year), which inevitably ends up in landfills. Urgent actions must be undertaken to tackle this. In this work, a substantial amount of dregs was incorporated into eco-friendly, waste-based inorganic polymer (geopolymer) mortars as fine filler. Then, and for the first time, the long-term strength performance (up to 270 days) and heavy metals leaching behaviour of the dregs-containing mortars was evaluated. The effect of the mixture composition and dregs incorporation content on the fresh- and hardened-state properties of the mortars was also studied. Dregs were found to increase the initial and final setting time of the slurries, thus extending the open time before their in-situ application. The use of dregs as fine filler effectively enhances the compressive strength of the mortars, and decreases their water absorption levels. These eco-friendly building materials showed excellent long-term performance, as their strength continuously increases up to the 270th day (after mixture), and no signs of efflorescence formation were detected. Moreover, the heavy metals leaching levels of the mortars were well below the contamination limits in soil, which demonstrates the feasibility of this recycling methodology.publishe

Sol gel graphene/TiO2 nanoparticles for the photocatalytic-assisted sensing and abatement of NO2

Abstract Human exposure to volatile organic compounds and NO2 can lead to health problems, therefore strategies to mitigate against the risks are required. Abatement and sensing are approaches which could both neutralise and monitor these species thus providing a safer environment and warning occupants of harmful levels. This paper presents pure TiO2 and TiO2/graphene hybrids synthesized through a sol-gel route. Electron optical, helium ion microscopy, X-ray diffraction and spectroscopic methods have been applied to elucidate the physical and chemical behaviour. NO2 sensing properties of TiO2/graphene hybrids formed by the addition of graphene to the reaction vessel prior to initiating the sol gel reaction followed by annealing (GTiO2S), and an alternative manufacturing method involving the addition of graphene to TiO2 nanoparticles which had already been annealed (GTiO2M) were compared and evaluated. A conductometric sensor based on TiO2/graphene prepared using material GTiO2S showed a higher response to NO2 compared to sensors based on pure TiO2 and TiO2/graphene prepared with material GTiO2M. Under UV irradiation generated by a low power LED, the sensor showed a remarkably enhanced response to 1750 ppb NO2, about double the response in the dark, and a limit of detection of about 50 ppb of NO2 (Signal/Noise = 3). Photocatalytic tests to assess the degradation of NOx showed that TiO2/graphene hybrids using material GTiO2S were the most active amongst the whole series of TiO2-based materials. Our data highlights the unique characteristics of material GTiO2S TiO2/graphene and the suitability for multi-purpose applications in the field of environmental monitoring and remediation. The capability of the material for both sensing and abatement of NOx could be exploited to offer a safer environment through providing a warning of the presence of NOx whilst also reducing levels

Synthesis of red mud derived M-type barium hexaferrites with tuneable coercivity

Hexagonal ferrites can be employed in a multitude of applications, the most common hexaferrites are the M ferrites such as BaFe12O19 (barium hexaferrite, BaM). It is known that if Fe3+ is substituted with a combination of Ti4+/Co2+ the coercivity of BaM can be reduced to produce soft M ferrites with easily switchable magnetisation. They can be utilised as powders, films or bulk ceramics, and can be manufactured from a wide variety of synthesis methods. The production of hexaferrites usually requires commercial raw materials, but if an industrial waste can be utilised, this will help to ease waste disposal and storage costs, valorise a waste material and encourage circular economy. In this study, bauxite residue (red mud) from the production of alumina was used to synthesise M-type hexaferrites, using a simple ceramic process. BaCO3, or BaCO3+Co3O4, were added to the red mud, blended and heated at 1000 °C to produce the M-type hexaferrites. Without cobalt addition up to 81.1 wt% M ferrite was produced, and with Co addition up to 74.3 wt% M ferrite was formed. Without cobalt, the M ferrite phase closely resembled BaFe9Al3O19, and was a hard ferrite with a magnetisation of 12–19 A m2/kg for the whole powder (up to 23.6 A m2/kg for the M ferrite phase) and a coercivity of ~290 kA/m. When cobalt was added, secondary titanate phases vanished, and Ti4+/Co2+ partially substituted very soft M ferrite was formed with a low coercivity of ~16 kA/m but a higher magnetisation of 24.5 A m2/kg for the whole powder (up to 34.9 A m2/kg for the M ferrite phase). Therefore, not only can good quality magnetic materials be easily produced from this common waste material, but its magnetic properties can be tuned by varying the 2 + ions added during the process.publishe

Análise e interpretação dos níveis de actividade física de crianças: um tutorial baseado na modelação hierárquica ou multinível

Este tutorial pretende apresentar, de modo didáctico, uma forma alternativa de análise de dados sobre os níveis de actividade física de crianças a partir da modelação hierárquica ou multinível. São mencionadas as diferentes etapas da modelação, os resultados são interpretados com base nos output's do software utilizado – o HLM 6.02. Em cada etapa do percurso são lançadas as hipóteses mais importantes em grau de complexidade crescente. A sua importância é referida a partir dos resultados disponíveis

Extremely fast and efficient methylene blue adsorption using eco-friendly cork and paper waste-based activated carbon adsorbents

For the first time the feasibility of using an alkaline wastewater coming from the pulp and paper industry as an activator, partially (50 vol%) replacing commercial sodium hydroxide, in the production of cork-based activated carbons was evaluated. The activated carbons showed the highest value of specific surface area ever reported for cork-based activated carbons (1670 m2/g), surpassing several other commercial and waste-based ones. These eco-friendly cork and paper waste-based activated carbons were then evaluated as methylene blue adsorbent materials. The influence of contact time, methylene blue initial concentration and adsorbent amount on the methylene blue removal efficiency by the activated carbons was studied. Extremely fast (>99.9% removal in 5 min) and efficient methylene blue adsorption (uptake of 350 mg/g) by the cork and paper waste-based adsorbents was achieved, which demonstrates the huge potential of these innovative adsorbents. These activated carbons were produced using two unexplored industrial by-products (alkaline wastewater and cork) and, therefore, may be an inexpensive source of activated carbons, which can be used for the effective removal of dyes from wastewaters. Furthermore, despite the very large surface area and high removal efficiency this is not a nano material (being around 30–50 μm in size), its capabilities being due to its unique cork-derived microstructure, and hence it can be handled and removed/filtered much more easily than nanocarbons, and without any associated health or environmental risks.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. R.C. Pullar wishes to thank FCT grant IF/00681/2015 for supporting this work, and R.M. Novais wishes to thank FCT project H2CORK (PTDC/CTM-ENE/6762/ 2014).publishe

A implantação do quesito cor/raça nos serviços de DST/Aids no Estado de São Paulo

This paper describes the experience to implement a systematic collection of these data on color/race in the STD/Aids care services in the State of São Paulo (SSP), through a partnership signed in 2004 between the Prevention Division of the STD/Aids State Program of the SSP and CEERT (initials in Portuguese for Center of Studies on Work Relations and Inequality) to carry out a project question in these services. Thirty-five STD/Aids care services were involved in the project and between 2004 and 2006, seven workshops of sensitization and monitoring of the process of implementation of the color/race question were held. It was observed that the process of discussion and reflection on the ethnic-racial theme renders the implementation easier. The campaign material provides clarification for the team of professionals and for the users, facilitating the implementation of this question. Investing in the qualification of reception professionals is important for the implementation of this question in the health services. CONCLUSION: With this experience, the Work Group Ethnicities of the STD-Aids State Program has broadened its performance. In 2006, with the partnership of the professionals of the AMA-Psique Institute, the process was extended to 13 new cities, consolidating the implementation of the color/race question in the STD-Aids services in the SSP. We hope that the produced information can sensitize the diverse spheres, so that public policies that promote racial equity in health and quality of life for black and aboriginal population are proposed and approved.INTRODUÇÃO: O artigo apresenta experiência de implantação e implementação do quesito cor/raça nos serviços de atendimento às DST/Aids no Estado de São Paulo (ESP), através de parceria firmada em 2004 entre a Divisão de Prevenção do Programa Estadual DST/Aids do ESP e o Centro de Estudos das Relações de Trabalho e Desigualdade (CEERT), visando executar um projeto serviços. Trinta e cinco serviços de atendimento às DST/Aids foram envolvidos no projeto e foram realizadas, de 2004 e 2006, sete oficinas de sensibilização e monitoramento do processo de implantação do quesito cor/raça, segundo metodologia de construção participativa e compartilhada do conhecimento, proposta pelo CEERT. Como resultado, verificou-se que o processo de discussão e de reflexão da temática étnico-racial torna a implantação do quesito cor/raça mais fácil. Os folhetos e cartazes propiciam o esclarecimento de profissionais e usuários, facilitando a implantação do quesito. Investir na capacitação dos profissionais da recepção dos usuários é importante para a implantação desse quesito nos serviços de saúde. CONCLUSÃO: A partir desta experiência o Grupo de Trabalho Etnias do Programa Estadual DST/Aids vem ampliando sua atuação. Em 2006, com a parceria das profissionais do Instituto AMA-Psique, iniciou-se o processo para 13 novos municípios, consolidando a implantação do quesito cor/raça no ESP. Esperamos que as informações produzidas possam sensibilizar as diversas esferas, para que sejam propostas e aprovadas políticas públicas que promovam a eqüidade racial na saúde e a qualidade de vida para população negra e indígena

Sodium alginate/polycaprolactone co-axial wet-spun microfibers modified with N-carboxymethyl chitosan and the peptide AAPV for Staphylococcus aureus and human neutrophil elastase inhibition in potential chronic wound scenarios

In chronic wound (CW) scenarios, Staphylococcus aureus-induced infections are very prevalent. This leads to abnormal inflammatory processes, in which proteolytic enzymes, such as human neutrophil elastase (HNE), become highly expressed. Alanine-Alanine-Proline-Valine (AAPV) is an antimicrobial tetrapeptide capable of suppressing the HNE activity, restoring its expression to standard rates. Here, we proposed the incorporation of the peptide AAPV within an innovative co-axial drug delivery system, in which the peptide liberation was controlled by N-carboxymethyl chitosan (NCMC) solubilization, a pH-sensitive antimicrobial polymer effective against Staphylococcus aureus. The microfibers' core was composed of polycaprolactone (PCL), a mechanically resilient polymer, and AAPV, while the shell was made of the highly hydrated and absorbent sodium alginate (SA) and NCMC, responsive to neutral-basic pH (characteristic of CW). NCMC was loaded at twice its minimum bactericidal concentration (6.144 mg/mL) against S. aureus, while AAPV was loaded at its maximum inhibitory concentration against HNE (50 μg/mL), and the production of fibers with a core-shell structure, in which all components could be detected (directly or indirectly), was confirmed. Core-shell fibers were characterized as flexible and mechanically resilient, and structurally stable after 28-days of immersion in physiological-like environments. Time-kill kinetics evaluations revealed the effective action of NCMC against S. aureus, while elastase inhibitory activity examinations proved the ability of AAPV to reduce HNE levels. Cell biology testing confirmed the safety of the engineered fiber system for human tissue contact, with fibroblast-like cells and human keratinocytes maintaining their morphology while in contact with the produced fibers. Data confirmed the engineered drug delivery platform as potentially effective for applications in CW care.Authors acknowledge the Portuguese Foundation for Science and Technology (FCT), FEDER funds by means of Portugal 2020 Competitive Factors Operational Program (POCI) and the Portuguese Government (OE) for funding the project PEPTEX with reference PTDC/CTMTEX/28074/2017 (POCI-01-0145-FEDER-028074). Authors also acknowledge project UIDP/00264/2020 of 2C2T and UID/QUI/00686/2020 of CQ, funded by national funds through FCT/MCTES. C.S.M. and H.P.F. also acknowledge FCT for PhD funding via scholarship 2020.08547.BD and for auxiliary researcher contract via 2021.02720.CEEIND, respectively

Currículo na contemporaneidade : internacionalização e contextos locais : atas

Atas do XI Colóquio sobre questões curriculares/ VII Colóquio Luso-Brasileiro sobre questões curriculares/ I Colóquio Luso-Afro-Brasileiro sobre Questões Curriculares 18, 19 e 20 de Setembro, 2014 Universidade do Minho, Braga (Portugal)O XI Colóquio sobre Questões Curriculares / VII Colóquio Luso-Brasileiro e I Colóquio Luso-Afro-Brasileiro de Questões Curriculares decorreu na Universidade do Minho, em Braga (Portugal), nos dias 18, 19 e 20 de setembro de 2014. Tratando-se de um colóquio com uma história já relevante, que desde 2002 se tem desenvolvido em parceria com o Brasil, teve nesta edição, a novidade de incluir entre os seus organizadores três instituições de ensino superior representantes de países africanos da lusofonia – Cabo-Verde, Moçambique e Angola. Este alargamento evidencia o crescimento que o campo do currículo tem conhecido nos últimos anos naqueles países, reconhecendo e procurando criar espaços para ampliar esse desenvolvimento. A riqueza e diversidade proporcionados pelo alargamento do Colóquio vieram ainda contribuir para o esforço de internacionalização do campo do currículo (Pinar, 2014), sem perder de vista a importância do conhecimento das particularidades, (re)contextualizações e apropriações, nem do plano mais amplo das políticas viajantes, tomadas de empréstimo de contextos globais (Steiner-Khamsi & Waldow, 2012). Esta preocupação serviu de pano de fundo ao tema do Colóquio deste ano. Sob a temática "Currículo na contemporaneidade: internacionalização e contextos locais" o colóquio procurou congregar docentes e investigadores da área dos Estudos Curriculares, sendo um espaço privilegiado para a reflexão, discussão e troca de experiências. As intervenções no colóquio reuniram-se em torno de diversos eixos temáticos, que procuraram representar a complexidade e diversidade de temas, consolidados e emergentes, dentro das políticas, teorias e práticas curriculares atuais: 1. Currículo, Globalização e Cosmopolitismo 2. Currículo e Avaliação 3. Currículo e Ensino Superior 4. Associações Curriculares: contributos para a configuração do campo 5. Currículo e Educação Formal e Não-Formal 6. Currículo e Tecnologias 7. Currículo e Desafios Africanos no Século XXI 8. Currículo e Políticas Educacionais 9. Currículo e Culturas 10. Currículo, Éticas e Estéticas 11. Currículo e Gestão 12. Currículo, Didática e Formação de Professores 13. Currículo, Transições e Territórios 14. Currículo, Conhecimento e Disciplinas Escolares Embora não estando ainda entre os objetos de estudo mais trabalhados pelos investigadores em geral, procurámos, com a criação de mesas redondas em torno de temas como as associações curriculares, os desafios africanos ao currículo no Século XXI, ou as transições e territórios curriculares, sensibilizar os participantes para potenciais desenvolvimentos futuros destas temáticas, que se perspetivam vir a influenciar o campo dos estudos curriculares nos anos vindouros. José Carlos Morgado Filipa Seabra Carlos FerreiraFC