Advanced oxidation of organic matter in natural waters with TiO2 immobilized films

The purpose of this paper is to report the development of a laboratory -scale pilot based on the use of TiO2 photocatalytic thin films for degrading organic matter and pollutants from natural water. The photoreactor consists of a channel inclined with a glass plate coated by TiO2 in both faces and fixed at 1 cm from the bottom. The thin film was immobilized on the glass plates by Sputtering technique. The reactor was designed to be able of reproduce the hydraulic conditions of a water treatment plant. In experimental testing of degradation of organic matter with solar irradiation maximum efficiency of 50% was achieved. At optimal conditions it was possible to exceed the efficiencies of a full scale preozonization in a water treatment plant , thus providing a more sustainable process

Lattice Regularization of the Chiral Schwinger Model

We analyze the chiral Schwinger model on an infinite lattice using the continuum definition of the fermion determinant and a linear interpolation of the lattice gauge fields. For non-compact and Wilson formulation of the gauge field action it is proven that the effective lattice model is Osterwalder-Schrader positive, which is a sufficient condition for the reconstruction of a physical Hilbert space from the model defined on a Euclidean lattice. For the non-compact model we furthermore establish the existence of critical points where the corresponding continuum theory can be reconstructed. We show that the continuum limit for the two-point functions of field strength and chiral densities can be controlled analytically. The article ends with some remarks on fermionic observables.Comment: 18 page

Avaliação de técnicas de oxidação avançada no tratamento de água para consumo humano

Face ao aparecimento de contaminantes emergentes e altos custos associados às novas tecnologias de remoção destes contaminantes e matéria orgânica natural (MON), é necessário e essencial o desenvolvimento de tecnologias de tratamento igualmente eficientes, ambientalmente mais sustentáveis e de baixo custo. Deste modo, o presente artigo tem como principal objetivo o desenvolvimento e avaliação da eficiência de técnicas de oxidação avançada na remoção de MON, baseada na utilização de nanopartículas de dióxido de titânio (TiO2) imobilizadas. São condensados resultados quantitativos e qualitativos de ensaios de fotocatálise heterogénea (FH) com TiO2imobilizado e suspenso de água de alimentação à ETA de Areias de Vilar. É documentada a relação entre a MON e a absorvância através de curvas de calibração. Apresenta-se ainda uma análise comparativa entre os três processos de oxidação avançada (FH com TiO2 suspenso, imobilizado e pré-ozonização) que permitiu aferir o potencial de oxidação de MON do sistema fotocatalítico heterogéneo com TiO2imobilizado. O estudo realizado é um contributo na evolução e otimização do sistema fotocatalítico com TiO2 imobilizado, podendo mesmo se tratar futuramente de uma etapa de tratamento (principal ou complementar) económica, sustentável e eficaz com aplicabilidade em ETA

A comparative thermoacoustic insulation study of silica aerogels reinforced with reclaimed textile fibres: cotton, polyester and wool

Silica aerogels are highly porous materials with exceptional thermal insulation performance. They become even more attractive if combined thermal and acoustic insulation is achieved. Silica aerogel composites reinforced with fibres are an ingenious way to surpass the fragility stemmed from the aerogel’s intrinsic porosity, and textile fibres are good sound absorption materials. Reclaimed fibres are a relatively low-cost feedstock and were obtained in this work exclusively through mechanical processes from textile wastes, thus promoting the concept of circular economy, namely for cotton, polyester and wool fibres. These reclaimed fibres were used as reinforcement matrices for silica aerogel composites obtained from sol–gel transformation of tetraethyl orthosilicate and isobutyltriethoxysilane/or vinyltrimethoxysilane precursors and dried at ambient pressure after silylation. Silica aerogel composites reinforced with reclaimed cotton fibres had the best sound absorption coefficient (a peak value of 0.89), while the polyester-reinforced composite exhibited the lowest thermal conductivity (k = ~24 mW m−1 K−1, Hot Disk). The better combined results on thermal and acoustic insulation were achieved by the wool-reinforced composites. The thermal conductivity values were less than 27 mW m−1 K−1, and the sound absorption coefficient achieved a peak value of 0.85. Therefore, the aerogel composites developed here can be selected for thermal or/and acoustic barriers by choosing a suitable type of fibre. Their design and preparation protocol followed environmental-friendly and cost-effective approaches.Teresa Linhares acknowledges the PhD grant Ref. SFRH/BD/131819/2017, attributed by Fundação para a Ciência e Tecnologia, I.P. (FCT, Portugal), funded by national funds from MCTES (Ministério da Ciência, Tecnologia e Ensino Superior) and, when appropriate, co-funded by the European Commission through the European Social Fund. Consumables for the syntheses and characterizations performed at CIEPQPF and 2C2T research units were funded by the European Regional Development Fund (ERDF), through COMPETE 2020 Operational Programme for Competitiveness and Internationalization, combined with Portuguese National Funds, through FCT, I.P. under the projects POCI-01-0145-FEDER-006910 and POCI-01-0145-FEDER-007136 (FCT Refs. UIDB/EQU/00102/2020 and UID/CTM/00264/2020, respectively)

Efetividade de genes de resistência de trigo a oídio, safra 2005.

bitstream/CNPT-2010/40691/1/p-do73.pd

Pareto Autonomous Local Search

This paper presents a study for the dynamic selection of operators in a local search process. The main purpose is to propose a generic autonomous local search method which manages operator selection from a set of available operators, built on neighborhood relations and neighbor selection functions, using the concept of Pareto dominance with respect to quality and diversity. The latter is measured using two different metrics. This control method is implemented using the Comet language in order to be easily introduced in various constraint local search algorithms. Focusing on permutation-based problems, experimental results are provided for the QAP and ATSP to assess the method’s effectiveness

Arthropods associated with bovine dung pats in Southern Goiás State, Brazil

A study of the arthropod fauna from bovine dung pats in the State of Goiás, Brazil, was carried out from January to December, 1998. Twenty samples of bovine dung were taken at random, each month, from eight day old pats, placed in plastic containers and taken to the laboratory. The arthropods were extracted by flotation in water in order to determine the frequency of Coleoptera, Diptera, Hymenoptera and Macrochelidae (Acarina) considered important in the degradation of cattle dung, and in the control of dung flies. Fifty two arthropod species belonging to 10 families were collected: 20 of Coleoptera (three families), 12 of Diptera (three families), 10 of Hymenoptera (three families) and six of Macrochelidae (Acarina).Realizou-se um estudo sobre a fauna de artrópodes associada às fezes bovinas em Goiás, de janeiro a dezembro de 1998. O objetivo foi verificar a freqüência dos Coleoptera, Diptera, Hymenoptera e Macrochelidae (Acarina) considerados importantes no processo de degradação das fezes bovinas nas pastagens e no controle de Diptera. Vinte placas fecais bovinas foram coletadas aleatoriamente, a cada mês, com oito dias de idade, colocadas em recipientes plásticos e levadas ao laboratório. Os artrópodes foram obtidos pelo método de flutuação em água. Foram coletados 52 espécies de artrópodes em 10 famílias, incluindo, 24 Coleoptera (três famílias), 12 Diptera (três famílias), 10 Hymenoptera (três famílias) e seis Macrochelidae (Acarina).192