449 research outputs found

    Low temperature wet oxidation and catalytic wet oxidation of specific organic compounds in highly alkaline solution (synthetic Bayer liquor)

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    Low temperature (165°C) Wet Oxidation (WO) and Catalytic Wet Oxidation (CWO) of 12 organic compounds has been studied in highly alkaline, high ionic strength solution (simulating that encountered in the Bayer process used to refine alumina) for the first time. Most (11 out of 12) of the 12 organic compounds studied (formic, acetic, propionic, butyric, oxalic, malonic, succinic, glutaric, citric, lactic, malic and tartaric acids) have been identified in various worldwide Bayer liquors. The various aspects of WO and CWO studied for each of the above-mentioned compounds were as follows; -Extent of complete oxidation to carbonate (i.e. extent of removal of organic compound) -Extent of overall oxidation (i.e. extent of complete oxidation and partial oxidation to stable products) -The product(s) formed from partial (incomplete) oxidation -The reaction mechanism occurring -Why certain compounds undergo low temperature WO and/or CWO in highly alkaline, high ionic strength solution -The ability of various transition metal oxides to catalyse the WO of the selected organic compounds Of the 12 organic compounds studied only six (formic, malonic, citric, lactic, malic and tartaric acids) underwent appreciable (>2% overall oxidation) WO in isolation under the reaction conditions used (4.4 -7.0 M NaOH, 165°C, 500 kPa Poâ‚‚, 2 hours). Each of these six compounds underwent some complete oxidation and therefore can be partly removed from highly alkaline, high ionic strength solution using low temperature WO. The order of extent of complete oxidation determined was as follows tartaric> citric> malonic> formic> lactic> malic. All of these compounds also underwent some partial oxidation under the reaction conditions used, excluding formic acid, which only underwent complete oxidation. Oxalic acid was a major product of partial oxidation of all of the above-mentioned compounds (excluding formic acid), while acetic acid was a major product of partial oxidation of citric, lactic, malic and tartaric acids. The WO of formic, malonic, citric, lactic, malic and tartaric acids varied considerably with NaOH concentration over the NaOH concentration range studied (4.4 - 7.0 M). The extent of overall oxidation undergone by each of these compounds increased significantly with increasing NaOH concentration. All of the compounds that underwent appreciable WO under the reaction conditions studied contained hydrogen(s) significantly more acidic then the compounds that did not undergo appreciable WO, thus indicating that only organic compounds that contain acidic (albeit weakly acidic) hydrogens undergo low temperature (165°C) WO in highly alkaline, high ionic strength solution. Two different reaction mechanisms were identified to occur during low temperature WO in highly alkaline, high ionic strength solution. Malonic and formic acids underwent WO predominantly via a free radical based reaction mechanism, while citric, lactic, malic and tartaric acids underwent WO predominantly via an ionic based reaction mechanism. The six organic compounds that did not undergo appreciable WO in isolation (acetic, propionic, butyric, oxalic, succinic and glutaric acids) all underwent appreciable WO when in the presence of malonic acid undergoing low temperature WO. Hence, low temperature WO of all of the above-mentioned compounds can be initiated by free radical intermediates produced by malonic acid undergoing WO in highly alkaline, high ionic strength solution. The ability of several transition metal oxides to catalyse the WO of the chosen 12 organic compounds was investigated. Of the transition metal oxides studied CuO was clearly the most active. Five of the organic compounds studied (malonic, citric, lactic, malic and tartaric acids) were catalytically wet oxidised by CuO in highly alkaline, high ionic strength solution in isolation. The order of catalytic activity observed was malonic > tartaric> lactic> malic> citric. Two different catalytic reaction mechanisms were identified for CuO catalysed WO in highly alkaline solution for the organic compounds studied. CuO catalysed the WO of malonic acid predominantly by catalysing the formation of free radical intermediates. CuO catalysed the WO of citric, lactic, malic and tartaric acids predominantly via a complexation-based reaction mechanism

    Creating Effective Style Documents: A Practicum in Trade Publication

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    It is no secret that the field of publication thrives on collaboration: among publishers, editorial and production team members, designers, marketing and publicity staff, sales representatives and promoters, authors, illustrators, reviewers, and, of course, readers. However, an equally important yet less-explored relationship exists within this industry, between publishing staff and a text itself. As such, despite this crucial connection, the technical means by which the final product is created may also be overlooked. This practicum examines these technical resources: style guides/sheets (especially for house style), their creation, and their usage in publishing, specifically how they pertain to sales material. Also guiding the exploration are discussions with Peachtree Publishers Ltd, an Atlanta-based publishing house of children’s and young adult literature, about generating the aforementioned documents. The finished product—the first official style sheet for the company’s sales catalogs—applies this information. The research and subsequent project attempt to facilitate tasks at Peachtree Publishers and, in the grander scheme of things, to shed light on the behind-the-scenes process of effectively creating and maintaining a truly valuable but often underestimated tool in editing

    Finnish Larch Home

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    Finnish Larch is a high quality wood, durable with waterproof qualities, as well as a smooth and knot-free surface. The panels come from sustainably managed cooperatives of small private forest ownershttps://openscholarship.wustl.edu/bcs/1187/thumbnail.jp

    Finnish Larch Home

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    Finnish Larch is a high quality wood, durable with waterproof qualities, as well as a smooth and knot-free surface.https://openscholarship.wustl.edu/bcs/1184/thumbnail.jp

    Hydrogen as a maritime fuel and design of a zero emissions propulsive system

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    Objectius de Desenvolupament Sostenible::14 - Vida SubmarinaObjectius de Desenvolupament Sostenible::6 - Aigua Neta i SanejamentObjectius de Desenvolupament Sostenible::13 - AcciĂł per al Clim

    Reticuloendoteliosis

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    IntroducciĂłn al Cloud Computing y comparativa de plataformas

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    This project contains an introduction and comparisons about the 3 companies that lead the cloud services available. Here you can take their information and compare between these companies, about specific services, costs and learning ways. It also could help new customers to decide which way to choose.En el presente documento se presenta una comparativa, a grandes rasgos y con carácter introductorio, de los tres proveedores que más controlan el mercado del Cloud Computing hoy en día. Se pretende empezar con los aspectos puramente objetivos de cada empresa, donde s e r ecopila toda la información publicada en cada uno de sus sitios web tales como sus Acuerdos de Niveles de Servicio, precios y planes de aprendizaje para los diferentes servicios específicos estudiados, a fin de que un consumidor de estas tecnologías pueda comparar y comprobar cuál es la opción que le resulte más atractiva. Más allá de los detalles teóricos , se presentan demostraciones de uso de diferentes servicios ofrecidos por estos proveedores de cloud que no supongan coste alguno acerca de su utilizaci ón para este trabajo (servicios y productos gratuitos o que otorguen un periodo de prueba) donde la idea se basa en compartir con los lectores nuestras percepciones y experiencias personales acerca de su facilidad de uso y rendimiento. El carácter del an álisis ofrecido aquí pretende ser un punto de partida a aquel personal de perfil técnico con intención de dar el salto a la tecnología de infraestructuras en cloud. Asimismo, puede ayudar a aquellos futuro s potencial es consumidor es de estas tecnologías a d ecidir sobre qué infraestructura en la nube desearía n montar su s nuevo s entorno s , gracias a la comparativa tanto teóricas como experimentales que se exponen aquí, además de las conclusiones personales, que podrían terminar por inclinar la balanza a la hora de decidir su s preferencias
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