4,755 research outputs found

    Factorial analysis of the trihalomethanes formation in water disinfection using chlorine

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    The factors that affect trihalomethane (THM) (chloroform, bromodichloromethane, chlorodibromomethane and bromoform) formation from the chlorination of aqueous solutions of hydrophobic fulvic acids (FA) were investigated in a prototype laboratorial simulation using factorial analysis. This strategy involved a fractional factorial design (16 plus 5 center experiments) of five factors (fulvic acids concentration, chlorine dose, temperature, pH and bromide concentration) and a Box Behnken design (12 plus 3 center experiments) for the detailed analysis of three factors (FA concentration, chlorine dose and temperature). The concentration ofTHMwas determined by headspace analysis by GC–ECD. The most significant factors that affect the four THM productions were the following: chloroform—FA concentration and temperature; bromodichloromethane—FA concentration and chlorine dose; chlorodibromomethane—chlorine dose; and, bromoform—chlorine dose and bromide concentration. Moreover, linear models were obtained for the four THM concentrations in the disinfection solution as function of the FA concentration, chlorine dose and temperature, and it was observed that the complexity of the models (number of significant factors and interactions) increased with increasing bromine atoms in the THM. Also, this study shows that reducing the FA concentration the relative amount of bromated THM increases

    Nanostructured Polypyrrole Powder: A Structural and Morphological Characterization

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    Polypyrrole (PPY) powder was chemically synthesized using ferric chloride (FeCl3) and characterized by X-ray diffraction (XRD), Le Bail Method, Fourier Transform Infrared Spectrometry (FTIR), and Scanning Electron Microscopy (SEM). XRD pattern showed a broad scattering of a semicrystalline structure composed of main broad peaks centered at 2θ = 11.4°, 22.1°, and 43.3°. Crystallinity percentage was estimated by the ratio between the sums of the peak areas to the area of amorphous broad halo due to the amorphous phase and showed that PPY has around 20 (1)%. FTIR analysis allowed assigning characteristic absorption bands in the structure of PPY. SEM showed micrometric particles of varying sizes with morphologies similar to cauliflower. Crystal data (monoclinic, space group P 21/c, a=7.1499 (2) Å, b=13.9470 (2) Å, c=17.3316 (2) Å, α=90 Å, β=61.5640 (2) Å and γ=90 Å) were obtained using the FullProf package program under the conditions of the method proposed by Le Bail. Molecular relaxation was performed using the density functional theory (DFT) and suggests that tetramer polymer chains are arranged along the “c” direction. Average crystallite size was found in the range of 20 (1) Å. A value of 9.33 × 10−9 S/cm was found for PPY conductivity

    Study of SEY degradation of amorphous carbon coatings

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    Deposition of low secondary electron yield (SEY) carbon coatings by magnetron sputtering onto the inner walls of the accelerator seems to be the most promising solution for suppressing the electron cloud problem. However, these coatings change their electron emission properties during long term exposure to air. The ageing process of carbon coated samples with initial SEY of about 0.9 received from CERN is studied as a function of exposure to different environments. It is shown that samples having the same initial SEY may age with different rates. The SEY increase can be correlated with the surface concentration of oxygen. Annealing of samples in air at 100-200 {\deg}C reduces the ageing rate and even recovers previously degraded samples. The result of annealing is reduction of the hydrogen content in the coatings by triggering its surface segregation followed by desorption.Comment: 4 pages, contribution to the Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects: ECLOUD'12; 5-9 Jun 2012, La Biodola, Isola d'Elba, Italy; CERN Yellow Report CERN-2013-002, pp.149-15

    Implementing geometry-related environmental indicators in a 3d-gis

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    This paper highlights the suitability of applying a 3D GIS to analyze geometry-related environmental indicators. The work starts with a discussion and application of a tool developed to identify sky view factors. Called 3DSKYVIEW extension, this tool was produced as part of a research cooperation effort established between Brazil and Portugal to identify common urban environmental indicators for their medium sized cities. The sky view factor (SVF) is a parameter used to characterize radiation properties on urban areas and to express the relationship between the visible area of the sky and the portion of the sky covered by buildings viewed from a specific point of observation. The 3DSKYVIEW extension is an algorithm developed by applying the software ArcView GIS1 and its 3D Analyst extension, allowing an automatic delineation of the visible sky and obstructions. The implementation of this tool in a 3D GIS is useful because it allows straight and quick urban geometry analysis from several points of observation. Furthermore, it can be seen as a single environmental indicator of thermal, lighting and acoustical performance of urban areas, as suggested by the exploratory study conducted in a medium-sized Brazilian city and summarized in this paper

    The SOAR Gravitational Arc Survey - I: Survey overview and photometric catalogs

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    We present the first results of the SOAR (Southern Astrophysical Research) Gravitational Arc Survey (SOGRAS). The survey imaged 47 clusters in two redshift intervals centered at z=0.27z=0.27 and z=0.55z=0.55, targeting the richest clusters in each interval. Images were obtained in the gg', rr' and ii' bands using the SOAR Optical Imager (SOI), with a median seeing of 0.83, 0.76 and 0.71 arcsec, respectively, in these filters. Most of the survey clusters are located within the Sloan Digital Sky Survey (SDSS) Stripe 82 region and all of them are in the SDSS footprint. Photometric calibration was therefore performed using SDSS stars located in our SOI fields. We reached for galaxies in all fields the detection limits of g23.5g \sim 23.5, r23r \sim 23 and i22.5i \sim 22.5 for a signal-to-noise ratio (S/N) = 3. As a by-product of the image processing, we generated a source catalogue with 19760 entries, the vast majority of which are galaxies, where we list their positions, magnitudes and shape parameters. We compared our galaxy shape measurements to those of local galaxies and concluded that they were not strongly affected by seeing. From the catalogue data, we are able to identify a red sequence of galaxies in most clusters in the lower zz range. We found 16 gravitational arc candidates around 8 clusters in our sample. They tend to be bluer than the central galaxies in the lensing cluster. A preliminary analysis indicates that 10\sim 10% of the clusters have arcs around them, with a possible indication of a larger efficiency associated to the high-zz systems when compared to the low-zz ones. Deeper follow-up images with Gemini strengthen the case for the strong lensing nature of the candidates found in this survey.Comment: 17 pages, 11 figures (most of them multi-panel) MNRAS (2013

    Cidades sustentáveis: um desafio comum para Brasil e Portugal

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    Como conseqüência dos crescentes problemas ambientais, econômicos e sociais de muitas cidades faz-se necessária a criação de métodos para o acompanhamento e gestão do crescimento urbano, de tal forma que se possa promover os conceitos de desenvolvimento sustentável e qualidade de vida urbana. A implementação de estratégias para este fim deve partir da investigação e análise crítica da condição atual de desenvolvimento das cidades, a partir de indicadores que devem refletir o contexto específico em que se inserem. Desta forma, o presente trabalho tem por objetivo realizar uma discussão acerca da problemática de sustentabilidade urbana dirigida a um contexto particular: cidades de pequeno e médio portes no Brasil e em Portugal. O primeiro passo é a identificação das principais características geopolíticas, nos dois países, daquilo que constitui o objeto de estudo deste trabalho: as cidades. A breve discussão que se segue, baseada neste diagnóstico preliminar e em inúmeros trabalhos já produzidos sobre as cidades dos dois países, aponta para algumas preocupações que devem estar presentes na definição de indicadores de sustentabilidade urbana para o contexto específico de Brasil e Portugal, resumidas em três aspectos principais: o desafio da mobilidade, o desafio ambiental e o desafio da eficiência

    Colour profile analysis of Port Wines by different instrumental and visual methods

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    BACKGROUND: Wine colour is an important quality parameter, being the first sensorial attribute evaluated during wine tasting. The perception of wine colour can be different depending on many factors, including the depth of the sample under observation. The main objectives of the present study were to measure the colour of Port wines, using CIE L*a*b* parameters at different depths with different instrumental techniques (spectrophotometry and colorimetry), and to compare the obtained results with the sensory (visual) perception of colour samples. RESULTS: Representative profiles of Lightness (L*), Hue (H*) and Chroma (C*) at different depths were obtained using Port wine samples from different categories and ages. In general, relatively good correlations between the colorimetric and spectrophotometric methods were obtained for the L* and H* parameters. The results of the sensory tests also showed good correlations between the visually-assessed hue scores and the colorimetric measurements of the H* parameter, particularly at the lower depths tested (up to 4.0 mm). CONCLUSIONS: Overall, the results indicate that the colorimetric method can be used for estimating wine colour parameters, providing useful information about the colour profile of wines at different depthsinfo:eu-repo/semantics/acceptedVersio

    Deciding case by case on family presence in the emergency care service

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    Objective: To understand how physicians and nurses experience and perceive the presence of families in the emergency care service. Methods: This was a qualitative study that used symbolic interactionism as a theoretical reference, and grounded theory as a methodological reference. Twenty professionals participated – equally representing physicians and nurses - working in two emergency rooms located in the south of Brazil. Data were collected between October of 2016 and February of 2017, by means of interviews. Results: The existence of a social culture of family exclusion was identifi ed, widely diffused and practiced by professionals. However, families sometimes remain with their loved ones in the emergency room, since professionals analyze and decide “case by case”, considering different aspects throughout the care process. Conclusion: Multiple aspects are related in determining family presence during emergency care for physicians and nurses. Thus, a single directive on the presence of the family is not prudent. In fact, it is suggested that each health unit develop its protocols, considering local particularities.Objetivo: Compreender como médicos e enfermeiros vivenciam e percebem a presença da família no serviço de atendimento emergencial. Métodos: Estudo qualitativo que utilizou o Interacionismo Simbólico como referencial teórico e a Teoria Fundamentada nos Dados como referencial metodológico. Participaram 20 profi ssionais – divididos equitativamente entre médicos e enfermeiros – que atuavam em duas Salas de Emergência localizadas no Sul do Brasil. Os dados foram coletados entre outubro de 2016 e fevereiro de 2017, por meio de entrevistas. Resultados: Identifi cou-se a existência de uma cultura social de exclusão familiar, amplamente difundida e praticada pelos profi ssionais. Contudo, às vezes, as famílias permanecem com seus entes queridos na Sala de Emergência, visto que os profi ssionais analisam e decidem “caso a caso”, considerando diferentes aspectos ao longo do processo assistencial. Conclusão: Para médicos e enfermeiros múltiplos aspectos estão relacionados na determinação da presença familiar durante o atendimento emergencial. Assim, não é aconselhável uma diretiva única para a presença da família. Em realidade, sugere-se que cada unidade de saúde elabore seus protocolos considerando as particularidades locais.Objetivo: Comprender cómo médicos y enfermeros experimentan y perciben la presencia familiar en el servicio de atención de urgencias. Métodos: Estudio cualitativo, aplicando el Interaccionismo Simbólico como referencial teórico, y la Teoría Fundamentada en los Datos como referencial metodológico. Participaron 20 profesionales –equitativamente divididos entre médicos y enfermeros– actuantes en dos Servicios de Urgencias del Sur de Brasil. Datos recolectados de octubre 2016 a febrero 2017 mediante entrevistas. Resultados: Se identifi có la existencia de una cultura social de exclusión familiar, ampliamente difundida y practicada por los profesionales. Igualmente, a veces, las familias permanecen con sus seres queridos en el Servicio de Urgencias, dado que los profesionales analizan y deciden “caso por caso”, considerando diferentes aspectos a lo largo del proceso de atención. Conclusión: Para médicos y enfermeros, múltiples aspectos se relacionan con la determinación de la presencia familiar durante la atención de urgencia. Por ello, no es aconsejable una directiva única sobre presencia familiar. En realidad, se sugiere que cada unidad de salud elabore sus protocolos considerando sus propias características
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