Thesis (B.A.(Hons.))--University of Adelaide, Dept. of German, 1964.

Berlin, Techn. Univ., Diss., 2004. / Computerdatei im Fernzugriff.

No description available.

Techn. Universiẗat, Diss., 2004--Berlin.

Thesis (B.A.Hons. 1973) from the Dept. of German, University of Adelaide.

Programa de Pós-Graduação em Filosofia. Departamento de Filosofia, Instituto de Filosofia, Artes e Cultura, Universidade Federal de Ouro Preto. / Submitted by Maurílio Figueiredo (maurilioafigueiredo@yahoo.com.br) on 2016-02-17T15:49:15Z No. of bitstreams: 1 DISSERTAÇÃO_RealismoBuchnerMorte.pdf: 1209749 bytes, checksum: 7daa900c03d87807c5216b4c4cc35ab4 (MD5) / Approved for entry into archive by Oliveira Flávia (flavia@sisbin.ufop.br) on 2016-04-08T12:56:00Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO_RealismoBuchnerMorte.pdf: 1209749 bytes, checksum: 7daa900c03d87807c5216b4c4cc35ab4 (MD5) / Made available in DSpace on 2016-04-13T14:12:19Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO_RealismoBuchnerMorte.pdf: 1209749 bytes, checksum: 7daa900c03d87807c5216b4c4cc35ab4 (MD5) Previous issue date: 2015 / O objetivo central da dissertação é entender como Lukács pode vir a ter construído a perspectiva apresentada no ensaio O verdadeiro e o fascisticamente falsificado Georg Büchner. Determinado objetivo demanda que sejam demonstrados e explicitados aspectos categoriais e conceitos-chave do pensamento filosófico e estético de Lukács durante a década de 1930. Categorias centrais da ontologia marxiana, como ―trabalho‖, ―teleologia‖ e esfera da práxis (ação), surgem remodelando questões estéticas e o modus operandi com que Lukács compreende a topologia das formas literárias. A partir de então, a ―teoria do reflexo‖ e o caráter objetivo da atividade estética e literária tornam-se pivôs das análises e ensaios da década de 1930. O diagnóstico lukacsiano ainda demonstra como é na Revolução Francesa e nas suas repercussões que surgem o ―irracionalismo‖ e o combate ideológico à razão, plataformas que permitiriam o discurso falsificacionista vir à tona. Sendo Büchner um autor de visão de mundo realista, ele captura e figura de maneira dramática e trágica os bastidores desse processo na revolução. ______________________________________________________________________________________ / ABSTRACT: The central objective of this work is a detail understanding of how Lukács can had built the perspective showed in the essay O verdadeiro e o fascisticamente falsificado Georg Büchner. This objective demands that are demonstrated and explained some categorical aspects and key-concepts of Lukács‘s philosophy and aesthetical though during the decade of 1930. Central categories of marxist‘s ontological, like ―work‖, ―teleologie‖ and praxis‘s sphere (action) became remodeling the aesthetical questions and the modus operandi within Lukács comprises the topology of literary forms. Since this, the ―reflex- theory‖ and the objective character of aesthetical activity and literary became the central of the analyzes and essays of the 1930 decade. The lukacsian diagnosis demonstrate yet how it´s in the French Revolution and in his repercussions that emerge the ―irrationalism‖ and the ideological combat of the reason, the platform of the falsification speech. Being Büchner a realist author, he capture and figured in a dramatic and tragically view the backstage of revolution.

No description available.

The costs of cleaning fine coal are substantially higher than those of cleaning coarse coal. Therefore, many many coal companies in the U.S. choose to discard fine coal (150 micron x 0) by means of 6-inch diameter hydrocyclones. The cyclone overflows are stored in fine coal impoundments, which create environmental concerns and represent loss of valuable national resources. The major component of the high costs of cleaning fine coal is associated with the difficulty in fine coal dewatering. Therefore, the availability of efficient of fine coal dewatering methods will greatly benefit companies. In the present study, three different novel dewatering aids have been tested. These include Reagents W (RW), Reagent U (RU), and Reagent V (RV). These reagents are designed to increase the contact angles of the coal samples to be dewatered, which should help decrease the Laplace pressure of the water trapped in filter cake and, hence, increase dewatering rate. They were tested on i) the fresh coal samples from Consolidation Coal Corporation's Buchanan Preparation Plant, ii) a composite drill core sample from the Smith Branch Impoundment, Pinnacle Mine Mining Company, and iii) a blend of coals from the Smith Branch Impoundment, thickener underflow, and thickener feed. The coal samples were used initially for laboratory-scale tests using a 2.5-inch diameter Buchner vacuum filter. The results showed that the use of the novel dewatering aids can reduce the cake moisture up to 50% over what can be achieved without using any dewatering aid. The use of the dewatering aids also increased the kinetics of dewatering by up to 6 times, as measured by cake formation times. On the basis of the laboratory test results, pilot-scale continuous vacuum filtration tests were conducted using a 2-feet diameter Peterson vacuum disc filter. The cake moistures obtained in the pilot-scale test work were similar to those obtained in the laboratory tests, while the fast dewatering kinetics observed in the laboratory tests was manifested as higher throughput. It was found that high-shear agitation is essential for achieving low cake moistures and high throughput. / Master of Science

[ES] Los carbenos representan una clase de reactivos altamente potentes utilizados en el campo de la síntesis orgánica, que muestran la capacidad de participar eficazmente durante los procesos de inserción en una amplia variedad de enlaces químicos, típicamente inertes, facilitando así la creación de dos nuevos enlaces de manera directa y eficiente. Para ello, son necesario catalizadores. La investigación realizada aquí implicó la fabricación de diversas formas de catalizadores de plata, incluidos átomos individuales, dímeros o clústeres, en sólidos microporosos como zeolitas o polímeros de coordinación porosos, también llamados MOFs (del inglés, Metal-Organic Frameworks), logrados a través de métodos sencillos como el intercambio iónico y procedimientos de calcinación o reducción, como se muestra en los Capítulos 4 y 5. Estos catalizadores innovadores demostraron un rendimiento catalítico excepcional para la reacción de Buchner que involucra carbenos, obteniendo buenos rendimientos del producto mientras mantenían una selectividad favorable. Las zeolitas y los MOFs funcionaron como ligandos macroscópicos que sirvieron para estabilizar los sitios activos de plata, lo que permitió la utilización de catalizadores baratos y reciclables para la generación in-situ de carbenos a partir de diazoacetato, promoviendo posteriormente la inserción selectiva en enlaces C-C, C-H, O-H y O-O. Además, en el Capítulo 6, dimos un paso más allá, generando y estabilizando carbenos en zeolitas HY dealuminizadas, comercialmente disponibles y libres de metal. En esta tesis, se caracterizaron dos carbenos sólidos distintos, que incluyen una variante mediada por carbeno de plata que fue identificada con éxito mediante espectroscopía de Raman in-situ y análisis de RMN 13C CP/MAS in-situ, junto con un carbeno estabilizado en zeolita que fue efectivamente elucidado a través de espectroscopía de infrarrojo con transformada de Fourier in-situ y técnicas de RMN 13C CP/MAS. / [CA] Els carbens representen una classe de reactius altament potents utilitzats en el camp de la síntesi orgànica, que mostren la capacitat de participar d'una manera eficaç durant els processos d'inserció en una àmplia varietat d'enllaços químics, típicament inerts, facilitant així la creació de dos nous enllaços de manera directa i eficient. La investigació realitzada ací va implicar la fabricació de diverses formes de catalitzadors de plata, inclosos àtoms individuals, dímers o clústers, en sòlids microporosos com a zeolites o polímers de coordinació porosos, també anomenats MOFs (de l'anglés, Metal-Organic Frameworks), aconseguits a través de mètodes senzills com l'intercanvi iònic i procediments de calcinació o reducció, com es mostra en els Capítols 4 i 5. Estos catalitzadors innovadors van demostrar un rendiment catalític excepcional per a la reacció de Buchner que inclou carbens, obtenint bons rendiments del producte mentres mantenien una selectivitat favorable. Les zeolites i els MOFs van funcionar com lligands macroscòpics que van servir per a estabilitzar els llocs actius de plata, la qual cosa va permetre la utilització de catalitzadors rendibles i reciclables per a la generació in-situ de carbens a partir de diazoacetat, promovent posteriorment la inserció selectiva en enllaços C-C, C-H, O-H i O-O. A més, en el Capítol 6, vam fer un pas més enllà, generant i estabilitzant carbens en zeolites HY dealuminitzades, comercialment disponibles i lliures de metall. En esta tesi, es van caracteritzar dos carbens sòlids diferents, que inclouen una variant mitjançant carben de plata que va ser identificada amb èxit mitjançant espectroscopía de Raman in-situ i anàlisi de RMN 13C CP/MES in-situ, juntament amb un carben estabilitzat en zeolita que va ser efectivament elucidat per mitjà de espectroscopía d'infraroig amb transformada de Fourier in-situ i tècniques de RMN 13C CP/MAS. / [EN] Carbenes represent a class of highly potent reagents used in the field of organic synthesis, showcasing an ability to effectively engage during insertion processes within a diverse array of typically inert chemical bonds, thereby facilitating the creation of two fresh bonds in a direct and efficient manner. For that, catalysts are needed. The exploration conducted here involved the fabrication of various forms of silver catalysts, including single atoms, dimers or clusters, on microporous solids like zeolites or metal-organic frameworks (MOFs), achieved through uncomplicated methods such as ion exchange and calcination or reduction procedures, as shown in Chapters 4 and 5. These innovative catalysts demonstrated exceptional catalytic performance in facilitating the Buchner reaction involving carbenes, yielding high product quantities while maintaining favorable selectivity. The zeolites and MOFs functioned as macroscopic ligands that served to stabilize the silver active sites, thereby enabling the utilization of cost-effective and recyclable catalysts for in-situ carbene generation from diazoacetate, subsequently promoting the selective insertion into C-C, C-H, O-H, and O-O bonds. Furthermore, in Chapter 6, we have gone one step further, generating and stabilizing carbenes in metal-free commercially available dealuminized HY zeolites. In this thesis, two distinct solid-supported carbenes were characterized, encompassing a silver carbene-mediated variant that was successfully identified through in-situ Raman spectroscopy and in-situ 13C CP/MAS NMR analyses, alongside a zeolite-stabilized carbene that was effectively elucidated via in-situ Fourier Transform Infrared Spectroscopy and 13C CP/MAS NMR techniques. / Zheng, Y. (2024). Carbene reactions catalyzed by silver-supported or metal-free microporous solids [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/207244

In the present work, novel dewatering aids and a novel centrifuge configuration were developed and applied for the purpose of dewatering fine particles. Three different types dewatering reagents were tested in different filtration and centrifugation units. These chemicals included low-HLB surfactants, naturally occurring lipids, and modified lipids. Most of these reagents are insoluble in water; therefore, they were used in solutions of appropriate solvents, such as light hydrocarbon oils and short-chain alcohols. The role of these reagents was to increase the hydrophobicity of the coal and selected mineral particles (chalcopyrite, sphalerite, galena, talc, clay, phosphate, PCC and silica) for the dewatering. In the presence of these reagents, the water contact angles on the coal samples were increased up to 90o. According to the Laplace equation, an increase in contact angle with the surfactant addition should decrease the capillary pressure in a filter cake, which should in turn increase the rate of dewatering and help reduce the cake moisture. The use of the novel dewatering aids causes a decrease in the surface tension of water and an increase in the porosity of the cake, both of which also contribute to improved dewatering. A series of batch-scale dewatering tests were conducted on a variety of the coal and mineral samples using the novel dewatering aids. The results obtained with a Buchner funnel and air pressure filters showed that cake moistures could be reduced substantially, the extent of which depends on the particle size, cake thickness, drying time, reagent dosage, conditioning time, reagent type, sample aging, water chemistry, etc. It was determined that use of the novel dewatering aids could reduce the cake formation time by a significant degree due to the increased kinetics of dewatering. At the same time, the use of the dewatering aids reduced the cake moistures by allowing the water trapped in smaller capillaries of the filter cake. It was found that final cake moistures could be reduced by 50% of what can be normally achieved without using the reagents. However, the moisture reduction becomes difficult with increasing cake thickness. This problem can be minimized by applying a mechanical vibration to the cake, spraying a short-chain alcohol on the cake and by adding a small amount of an appropriate coagulant, such as alum and CaCl2 to the coal and mineral slurries. The novel dewatering aids were also tested using several different continuous filters, including a drum filter, disc filter and horizontal belt filter (HBF). The results obtained with these continuous filtration devices were consistent with those obtained from the batch filters. Depending on the coal and mineral samples and the type of the reagent, 40 to 60% reductions in moisture were readily achieved. When using vacuum disc filters, the cake thickness increased substantially in the presence of the novel dewatering aids, which could be attributed to the increased kinetics of dewatering. A dual vacuum system was developed in the present work in order to be able to control the cake thickness, which was necessary to achieve lower cake moistures. It was based on using a lower vacuum pressure during the cake formation time, while a full vacuum pressure was used during the drying cycle time. Thus, use of the dual vacuum system allowed the disc filter to be used in conjunction with the novel dewatering aids. Its performance was similar to that of HBF, which is designed to control cake thickness and cake formation time independently. The effectiveness of using the novel dewatering aids were also tested in a full-continuous pilot plant, in which coal samples were cleaned by a flotation column before the flotation product was subjected to the disc filter. The tests were conducted with and without using novel dewatering aids. These results were consistent with those obtained from the laboratory and batch-scale tests. The novel centrifuge developed in the present work was a unit, which combined a gravity force and air pressure. The new centrifuge was based on increasing the pressure drop across the filter cake formed on the surface of the medium (centrifuge wall). This provision made it possible to take advantage of Darcy s law and improve the removal of capillary water, which should help lower the cake moisture. A series of tests were conducted on several fine coal and mineral particles and obtained more than 50% moisture reduction even at very fine particle size (2 mm x 0). Based on the test results obtained in the present work, two proof-of-concept (POC) plants have been designed. The first was for the recovery of cyclone overflows that are currently being discarded in Virginia, and the other was for the recovery of fines from a pond in southern West Virginia. The former was designed based on the results of the plant tests conducted in the present work. Cost vs. benefit analyses were conducted on the two POC plants. The results showed very favorable internal rates of return when using the novel dewatering aids. Surface chemistry studies were conducted on the coal samples based on the results obtained in the present investigation. These consisted mainly of the surface characterization of the coal samples (surface mineral composition, surface area, zeta potential, x-ray photoelectron microscopy (XPS)), acid-base interactions of the solids and liquids, dewatering kinetic tests, contact angle measurements of the coal samples and surface force measurements using AFM. In addition, carbon coating on a silica plate using palsed laser deposition (PLD) and Langmuir-Blodgett (LB) film deposition tests were conducted on the sample to better understand the surfactant adsorption and dewatering processes. The test results showed that the moisture reductions on the fine particles agree well with the surface chemistry results. / Ph. D.