Analysis of pozzolanicity of the rind cashew nut ashes by X-ray diffraction

Atualmente, o aproveitamento de resíduos na construção civil tem sido estimulado, uma vez que esse setor apresenta-se como um dos maiores consumidores de materiais naturais em seus processos e produtos. As cinzas ocupam lugar de destaque entre os resíduos agroindustriais por resultarem de processos de geração de energia. Grande parte dessas cinzas possui atividade pozolânica, podendo ser utilizada como substituto parcial do cimento Portland, resultando numa economia significativa de energia e custo. Este trabalho faz parte de uma pesquisa mais ampla, a qual busca avaliar a viabilidade técnica da cinza da casca da castanha de caju (CCCC) como adição mineral em matrizes de cimento Portland, como também, propor uma metodologia de análise de cinzas agroindustriais. Aplicou-se a técnica de difratometria de raios X para avaliar a reatividade do hidróxido de cálcio pela cinza da casca da castanha de caju em pastas, empregaram-se teores de substituição entre 2,5 e 30,0% e os difratogramas das pastas foram comparados com os das pastas confeccionadas com sílica ativa, executados sobre as mesmas condições de ensaio. Os resultados apontam para a ausência de reatividade pozolânica da CCCC com o cimento Portland.Nowadays, the residues exploitation in civil building has been stimulated, mainly because this sector of activity is one of the biggest consumers of natural materials. Some agricultural wastes, such as ashes, have become materials of great interest for building construction because of their pozzolanic activity, and can be used as replacement material for Portland cement, resulting in less energy waste and low cost. This stage of analyses is part of a wider research for the evaluation of the technical viability of the cashew nut rind ashes (CCCC) as mineral admixture in Portland cement products, as well as, the proposition of a methodology of analysis of agroindustrial ashes. In that stage, the technique of X-ray diffraction (XRD) was applied to evaluate the reactivity of the calcium hydroxide for the cashew nut rind ashes in pastes. Substitution rates from 2.5 to 30.0%. The difratograms of the pastes were compared with the ones with silica fume, executed under the same test conditions. The results indicate that the CCCC don't react with the Portland cement

Nonextensive thermostatistics and the H theorem

Using the Boltzmann's transport equation method, the kinetic foundations of Tsallis' nonextensive thermostatistics were investigated. The analysis follows from a nonextensive generalization of the 'molecular chaos hypothesis.' For q > 0, the q-transport equation satisfies an H theorem based on Tsallis entropy. It is also proved that the collisional equilibrium is given by Tsallis' q-nonextensive velocity distribution.Fil: Lima, J.A.. Universidade Federal do Rio Grande do Norte; BrasilFil: Silva, R.. Universidade Federal do Rio Grande do Norte; BrasilFil: Plastino, Ángel Ricardo. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Universitat de les Illes Balears; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Relações entre migmatização e deformação na região de Banabuiù (Domínio Ceará Central, Brasil)

A região de Banabuiú localiza-se no Domínio Ceará Central (DCC), NE do Brasil e é constituída, em grande parte da sua extensão, por uma sequência sedimentar turbidítica de idade paleoproterozóica, intensamente deformada e metamorfizada durante a orogenia brasiliana (ca. 600 Ma). O metamorfismo regional de alto grau (topo da fácies anfibolítica / fácies granulítica) atingiu as condições de fusão parcial e deu origem a um complexo gnáissico-migmatítico, composto por metatexitos estromáticos, diatexitos “schlieren” e diatexitos nebulíticos. Os contactos entre os diferentes tipos litológicos são geralmente transicionais, embora tenha sido possível individualizar faixas alternadas de metatexitos e diatexitos à escala cartográfica. Nos metatexitos estromáticos, reconhecem-se com facilidade três componentes principais (a) o hospedeiro metassedimentar (paleossoma), formado por uma alternância de metapelitos e metagrauvaques, com intercalações pontuais de quartzitos e de rochas calcosilicatadas; (b) o fundido (leucossoma), representado por veios quartzo-feldspáticos, frequentemente pegmatíticos e (c) o resíduo refractário (melanossoma), constituído por finos leitos pelíticos envolvendo os leucossomas. Em contraste, os diatexitos são texturalmente muito mais heterogéneos, contêm maiores proporções de leucossoma (>30%) e não preservam as estruturas pré-migmatização. As observações realizadas no campo permitiram identificar três gerações de leucossomas. A primeira está associada à primeira fase de deformação (D1) e é marcada pela presença de veios de leucossomas com espessura centimétrica, indicando que o início da fusão parcial das litologias férteis da crusta terá ocorrido precocemente durante o engrossamento crustal. O segundo evento de deformação (D2) é responsável pelo dobramento do bandado migmatítico D1 e pela formação de abundantes quantidades de fundido. O último episódio de deformação dúctil (D3) parece estar relacionado com a actuação da zona de cisalhamento de Orós (ZCO), que limita a área estudada a este. Deu origem a dobras com planos axiais de direcção N-S a N30E, inclinação próxima de 90 e eixos mergulhantes para norte e para sul. As lineações minerais e de estiramento, quando visíveis, têm orientação N-S e baixo ângulo de mergulho para sul ou para norte. Durante a D3, formaram-se leucossomas concordantes e discordantes com as estruturas D3. À escala regional, o bandado migmatítico (D2+D3) é a estrutura dominante tanto nos diatexitos como nos metatexitos e chega a adquirir um carácter milonítico nas zonas em que a deformação D3 é mais intensa. A proporção de fundido parece aumentar progressivamente desde a D1 até às fases mais tardias (D2 e D3) e terá culminado com a formação de um granito anatéctico de tipo S que aflora no sector ocidental da região

A different approach in an AAL ecosystem: a mobile assistant for the caregiver

Currently the Ambient Assisted Living and the Ambient Intelligence areas are very prolific. There is a demand of security and comfort that should be ensured at people’s homes. The AAL4ALL (ambient assisted living for all) pro-ject aims to develop a unified ecosystem and a certification process, allowing the development of fully compatible devices and services. The UserAccess emerges from the AAL4ALL project, being a demonstration of its validity. The UserAc-cess architecture, implementation, interfaces and test scenario are presented, along with the sensor platform specially developed for the AAL4ALL project.Project "AAL4ALL", co-financed by the European Community Fund FEDER, through COMPETE - Programa Operacional Factores de Competitividade (POFC). Foundation for Science and Technology (FCT), Lisbon, Portugal, through Project PEst-C/CTM/LA0025/2013 and the project PEst-OE/EEI/UI0752/2014. Project CAMCoF - Context-aware Multimodal Communication Framework funded by ERDF -European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980

Note. Colonisation of bench cover materials by Salmonella typhimurium

Due to the increasing requirements of food safety, it is of utmost importance to know the mechanisms that can determine the occurrence of the phenomenon commonly assigned by cross contamination, which can be expressed by the transference of harmful substances or microorganisms to the human food chain. This is particularly susceptible during food preparation, because it can occur by the transference of the pathogen microorganisms from food to the surfaces where they had been prepared, and from there to foods initially not contaminated, therefore initiating the cycle. This study attempted to investigate the colonisation by Salmonella typhimurium ATCC 13311 of marble and granite, two materials commonly used as bench covers in kitchens of many countries. These materials were selected because there is a lack of studies in the literature about their ability for bacterial colonisation. In addition, the colonisation of stainless steel (SS) 304, a material usually studied, was also analysed in terms of comparison. Surface hydrophobicity and roughness were determined in order to explain the differences in the extent of adhesion. The results showed that SS was the material with a greater extent of colonisation by S. typhimurium, followed by marble and, almost to the same extent, by granite. S. typhimurium adheres to a greater extent to the most hydrophobic material and to the material with roughest surface.Fundação para a Ciência e a Tecnologia (FCT) - PRAXIS SFRH/BPD/11553/2002, projecto POCI/AGR/59358/200

Analysis of a vegetable oil performance in a milling process by MQL lubrication

In this work, we carried out a comparison between the dry machining of an aluminum block with conventional cutting oil and a block with vegetable oil. The two oils had different flow rates. Using the Taguchi method, it was possible to determine the matrices for optimizing the best parameters for each group of tests. Then, we studied the utility of using vegetable oil as a cutting lubricant. We found that the vegetable oil studied in this work had good properties in terms of reducing cutting temperatures but was less effective than conventional cutting oil in reducing the surface roughness of the machined part. Tribological tests were carried out to understand the influence of the selected lubricants in reducing friction and wear. After the sliding experiments, which were performed without lubrication in the presence of the same lubricants that were used in the machining tests and in the presence of distilled water, we concluded that vegetable oil has satisfactory lubricating properties that are similar to those of the conventional cutting fluid, indicating a potential for consideration as an effective alternative to the conventional cutting fluid, with economic, environmental, and health advantages.Financial support was provided by Portugal’s national funding FCT/MCTES (PIDDAC) to Centro de Investigação de Montanha (CIMO) (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020). Additionally, this work was partially supported by Portuguese FCT, under the reference projects UIDB/04077/2020, UIDB/00532/2020 and UIDB/04436/2020. This research was also partially funded by EXPL2021CIMO_01. Inês Afonso acknowledges the financial support of CIMO through EXPL2021CIMO_01.info:eu-repo/semantics/publishedVersio

Constraining the dark energy with galaxy clusters X-ray data

The equation of state characterizing the dark energy component is constrained by combining Chandra observations of the X-ray luminosity of galaxy clusters with independent measurements of the baryonic matter density and the latest measurements of the Hubble parameter as given by the HST key project. By assuming a spatially flat scenario driven by a "quintessence" component with an equation of state $p_x = \omega \rho_x$ we place the following limits on the cosmological parameters $\omega$ and $\Omega_{\rm{m}}$: (i) $-1 \leq \omega \leq -0.55$ and $\Omega_{\rm m} = 0.32^{+0.027}_{-0.014}$ (1$\sigma$) if the equation of state of the dark energy is restricted to the interval $-1 \leq \omega < 0$ (\emph{usual} quintessence) and (ii) $\omega = -1.29^{+0.686}_{-0.792}$ and $\Omega_{\rm{m}} = 0.31^{+0.037}_{-0.034}$ ($1\sigma$) if $\omega$ violates the null energy condition and assume values $< -1$ (\emph{extended} quintessence or ``phantom'' energy). These results are in good agreement with independent studies based on supernovae observations, large-scale structure and the anisotropies of the cosmic background radiation.Comment: 6 pages, 4 figures, LaTe