989 resultados para co-generation
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The present study is focused on the development of new VIII group metal on CeO2 – ZrO2 (CZO) catalyst to be used in reforming reaction for syngas production. The catalyst are tested in the oxyreforming process, extensively studied by Barbera [44] in a new multistep process configuration, with intermediate H2 membrane separation, that can be carried out at lower temperature (750°C) with respect the reforming processes (900 – 1000°C). In spite of the milder temperatures, the oxy-reforming conditions (S/C = 0.7; O2/C = 0.21) remain critical regarding the deactivation problems mainly deriving from thermal sintering and carbon formation phenomena. The combination of the high thermal stability characterizing the ZrO2, with the CeO2 redox properties, allows the formation of stable mixed oxide system with high oxygen mobility. This feature can be exploited in order to contrast the carbon deposition on the active metal surface through the oxidation of the carbon by means of the mobile oxygen atoms available at the surface of the CZO support. Ce0.5Zr0.5O2 is the phase claimed to have the highest oxygen mobility but its formation is difficult through classical synthesis (co-precipitation), hence a water-in-oil microemulsion method is, widely studied and characterized. Two methods (IWI and bulk) for the insertion of the active metal (Rh, Ru, Ni) are followed and their effects, mainly related to the metal stability and dispersion on the support, are discussed, correlating the characterization with the catalytic activity. Different parameters (calcination and reduction temperatures) are tuned to obtain the best catalytic system both in terms of activity and stability. Interesting results are obtained with impregnated and bulk catalysts, the latter representing a new class of catalysts. The best catalysts are also tested in a low temperature (350 – 500°C) steam reforming process and preliminary tests with H2 membrane separation have been also carried out.
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The work investigates the feasibility of a new process aimed at the production of hydrogen with inherent separation of carbon oxides. The process consists in a cycle in which, in the first step, a mixed metal oxide is reduced by ethanol (obtained from biomasses). The reduced metal is then contacted with steam in order to split the water and sequestrating the oxygen into the looping material’s structure. The oxides used to run this thermochemical cycle, also called “steam-iron process” are mixed ferrites in the spinel structure MeFe2O4 (Me = Fe, Co, Ni or Cu). To understand the reactions involved in the anaerobic reforming of ethanol, diffuse reflectance spectroscopy (DRIFTS) was used, coupled with the mass analysis of the effluent, to study the surface composition of the ferrites during the adsorption of ethanol and its transformations during the temperature program. This study was paired with the tests on a laboratory scale plant and the characterization through various techniques such as XRD, Mössbauer spectroscopy, elemental analysis... on the materials as synthesized and at different reduction degrees In the first step it was found that besides the generation of the expected CO, CO2 and H2O, the products of ethanol anaerobic oxidation, also a large amount of H2 and coke were produced. The latter is highly undesired, since it affects the second step, during which water is fed over the pre-reduced spinel at high temperature. The behavior of the different spinels was affected by the nature of the divalent metal cation; magnetite was the oxide showing the slower rate of reduction by ethanol, but on the other hand it was that one which could perform the entire cycle of the process more efficiently. Still the problem of coke formation remains the greater challenge to solve.
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Approximately 25% of acute myeloid leukemias (AMLs) carry internal tandem duplications (ITD) of various lengths within the gene encoding the FMS-like tyrosine kinase receptor 3 (FLT3). Although varying duplication sites exist, most of these length mutations affect the protein´s juxtamembrane domain. FLT3-ITDs support leukemic transformation by constitutive phosphorylation resulting in uncontrolled activation, and their presence is associated with worse prognosis. As known form previous work, they represent leukemia- and patient-specific neoantigens that can be recognized by autologous AML-reactive CD8+ T cells (Graf et al., 2007; Graf et al., unpublished). Herein, in patient FL, diagnosed with FLT3-ITD+ AML and in first complete remission after induction chemotherapy, T cells against her leukemia´s individual FLT3-ITD were detected at a frequency up to 1.7x10-3 among peripheral blood CD8+ T lymphocytes. This rather high frequency suggested, that FLT3-ITD-reactive T cells had been expanded in vivo due to the induction of an anti-leukemia response.rnrnCell material from AML patients is limited, and the patients´ anti-leukemia T-cell repertoire might be skewed, e.g. due to complex previous leukemia-host interactions and chemotherapy. Therefore, allogeneic sources, i.e. buffy coats (BCs) from health donors and umbilical cord blood (UCB) donations, were exploited for the presence and the expansion of FLT3-ITD-reactive T-cell populations. BC- and UCB-derived CD8+ T cells, were distributed at 105 cells per well on microtiter plates and, were stimulated with antigen-presenting cells (APCs) transfected with in vitro-transcribed mRNA (IVT-mRNA) encoding selected FTL3-ITDs. APCs were autologous CD8- blood mononuclear cells, monocytes or FastDCs.rnrnBuffy coat lymphocytes from 19 healthy individuals were analyzed for CD8+ T-cell reactivity against three immunogenic FLT3-ITDs previously identified in patients VE, IN and QQ and designated as VE_, IN_ and QQ_FLT3-ITD, respectively. These healthy donors carried at least one of the HLA I alleles known to present an ITD-derived peptide from one of these FLT3-ITDs. Reactivities against single ITDs were observed in 8/19 donors. In 4 donors the frequencies of ITD-reactive T cells were determined and were estimated to be in the range of 1.25x10-6 to 2.83x10-7 CD8+ T cells. These frequencies were 1,000- to 10,000-fold lower than the frequency of autologous FLT3-ITD-reactive T cells observed in patient FL. Restricting HLA I molecules were identified in two donors. In one of them, the recognition of VE_FLT3-ITD was found to be restricted by HLA-C*07:02, which is different from the HLA allele restricting the anti-ITD T cells of patient VE. In another donor, the recognition of IN_FLT3-ITD was restricted by HLA-B*35:01, which also had been observed in patient IN (Graf et al., unpublished). By gradual 3´-fragmentation of the IN_FLT3-ITD cDNA, the 10-mer peptide CPSDNEYFYV was identified as the target of allogeneic T cells against IN_FLT3-ITD. rnLymphocytes in umbilical cord blood predominantly exhibit a naïve phenotype. Seven UCB donations were analyzed for T-cell responses against the FLT3-ITDs of patients VE, IN, QQ, JC and FL irrespective of their HLA phenotype. ITD-reactive responses against all stimulatory FLT3-ITDs were observed in 5/7 UCB donations. The frequencies of T cells against single FLT3-ITDs in CD8+ lymphocytes were estimated to be in the range of 1.8x10-5 to 3.6x10-6, which is nearly 15-fold higher than the frequencies observed in BCs. Restricting HLA I molecules were identified in 4 of these 5 positive UCB donations. They were mostly different from those observed in the respective patients. But in one UCB donation T cells against the JC_FLT3-ITD had exactly the same peptide specificity and HLA restriction as seen before in patient JC (Graf et al., 2007). Analyses of UCB responder lymphocytes led to the identification of the 10-mer peptide YESDNEYFYV, encoded by FL_FLT3-ITD, that was recognized in association with the frequent allele HLA-A*02:01. This peptide was able to stimulate and enrich ITD-reactive T cells from UCB lymphocytes in vitro. Peptide responders not only recognized the peptide, but also COS-7 cells co-transfected with FL_FLT3-ITD and HLA-A*02:01.rnrnIn conclusion, T cells against AML- and individual-specific FLT3-ITDs were successfully generated not only from patient-derived blood, but also from allogeneic sources. Thereby, ITD-reactive T cells were detected more readily and at higher frequencies in umbilical cord blood than in buffy coat lymphocytes. It occurred that peptide specificity and HLA restriction of allogeneic, ITD-reactive T cells were identical to autologous patient-derived T cells. As shown herein, allogeneic, FLT3-ITD-reactive T cells can be used for the identification of FLT3-ITD-encoded peptides, e.g. for future therapeutic vaccination studies. In addition, these T cells or their receptors can be applied to adoptive transfer.
Resumo:
The generation of rhythmic electrical activity is a prominent feature of spinal cord circuits that is used for locomotion and also for circuit refinement during development. The mechanisms involved in rhythm generation in spinal cord networks are not fully understood. It is for example not known whether spinal cord rhythms are driven by pacemaker neurons and if yes, which neurons are involved in this function. We studied the mechanisms involved in rhythm generation in slice cultures from fetal rats that were grown on multielectrode arrays (MEAs). We combined multisite extracellular recordings from the MEA electrodes with intracellular patch clamp recordings from single neurons. We found that spatially restricted oscillations of activity appeared in most of the cultures spontaneously. Such activity was based on intrinsic activity in a percentage of the neurons that could activate the spinal networks through recurrent excitation. The local oscillator networks critically involved NMDA, AMPA and GABA / glycine receptors at subsequent phases of the oscillation cycle. Intrinsic spiking in individual neurons (in the absence of functional synaptic coupling) was based on persistent sodium currents. Intrinsic firing as well as persistent sodium currents were increased by 5-HT through 5-HT2 receptors. Comparing neuronal activity to muscle activity in co-cultures of spinal cord slices with muscle fibers we found that a percentage of the intrinsically spiking neurons were motoneurons. These motoneurons were electrically coupled among each other and they could drive the spinal networks through cholinergic recurrent excitation. These findings open the possibility that during development rhythmic activity in motoneurons is not only involved in circuit refinement downstream at the neuromuscular endplates but also upstream at the level of spinal cord circuits.
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The enzymatic co-polymerization of modified nucleoside triphosphates (dN*TPs and N*TPs) is a versatile method for the expansion and exploration of expanded chemical space in SELEX and related combinatorial methods of in vitro selection. This strategy can be exploited to generate aptamers with improved or hitherto unknown properties. In this review, we discuss the nature of the functionalities appended to nucleoside triphosphates and their impact on selection experiments. The properties of the resulting modified aptamers will be described, particularly those integrated in the fields of biomolecular diagnostics, therapeutics, and in the expansion of genetic systems (XNAs).
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The three canonical Rho GTPases RhoA, Rac1 and Cdc42 co-ordinate cytoskeletal dynamics. Recent studies indicate that all three Rho GTPases are activated at the leading edge of motile fibroblasts, where their activity fluctuates at subminute time and micrometer length scales. Here, we use a microfluidic chip to acutely manipulate fibroblast edge dynamics by applying pulses of platelet-derived growth factor (PDGF) or the Rho kinase inhibitor Y-27632 (which lowers contractility). This induces acute and robust membrane protrusion and retraction events, that exhibit stereotyped cytoskeletal dynamics, allowing us to fairly compare specific morphodynamic states across experiments. Using a novel Cdc42, as well as previously described, second generation RhoA and Rac1 biosensors, we observe distinct spatio-temporal signaling programs that involve all three Rho GTPases, during protrusion/retraction edge dynamics. Our results suggest that Rac1, Cdc42 and RhoA regulate different cytoskeletal and adhesion processes to fine tune the highly plastic edge protrusion/retraction dynamics that power cell motility.
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Next-generation DNA sequencing platforms can effectively detect the entire spectrum of genomic variation and is emerging to be a major tool for systematic exploration of the universe of variants and interactions in the entire genome. However, the data produced by next-generation sequencing technologies will suffer from three basic problems: sequence errors, assembly errors, and missing data. Current statistical methods for genetic analysis are well suited for detecting the association of common variants, but are less suitable to rare variants. This raises great challenge for sequence-based genetic studies of complex diseases.^ This research dissertation utilized genome continuum model as a general principle, and stochastic calculus and functional data analysis as tools for developing novel and powerful statistical methods for next generation of association studies of both qualitative and quantitative traits in the context of sequencing data, which finally lead to shifting the paradigm of association analysis from the current locus-by-locus analysis to collectively analyzing genome regions.^ In this project, the functional principal component (FPC) methods coupled with high-dimensional data reduction techniques will be used to develop novel and powerful methods for testing the associations of the entire spectrum of genetic variation within a segment of genome or a gene regardless of whether the variants are common or rare.^ The classical quantitative genetics suffer from high type I error rates and low power for rare variants. To overcome these limitations for resequencing data, this project used functional linear models with scalar response to develop statistics for identifying quantitative trait loci (QTLs) for both common and rare variants. To illustrate their applications, the functional linear models were applied to five quantitative traits in Framingham heart studies. ^ This project proposed a novel concept of gene-gene co-association in which a gene or a genomic region is taken as a unit of association analysis and used stochastic calculus to develop a unified framework for testing the association of multiple genes or genomic regions for both common and rare alleles. The proposed methods were applied to gene-gene co-association analysis of psoriasis in two independent GWAS datasets which led to discovery of networks significantly associated with psoriasis.^
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La mejora de las capacidades de búsqueda y de las interfaces de los opacs sigue siendo uno de los principales desafíos para las bibliotecas, especialmente en lo que respecta al acceso por materias. Las interfaces visuales pueden facilitar la recuperación. El objetivo del presente trabajo es explorar si la combinación de técnicas de análisis de co-términos y de redes sociales resulta ser una metodología válida para la generación de mapas temáticos de la colección. La principal conclusión es que el método es válido, y que los mapas obtenidos podrían servir como interfaz visual para el acceso por materias. También es útil para detectar problemas en los criterios de indización y contribuir a la mejora de la calidad de la descripción temática del conjunto documental
Resumo:
La mejora de las capacidades de búsqueda y de las interfaces de los opacs sigue siendo uno de los principales desafíos para las bibliotecas, especialmente en lo que respecta al acceso por materias. Las interfaces visuales pueden facilitar la recuperación. El objetivo del presente trabajo es explorar si la combinación de técnicas de análisis de co-términos y de redes sociales resulta ser una metodología válida para la generación de mapas temáticos de la colección. La principal conclusión es que el método es válido, y que los mapas obtenidos podrían servir como interfaz visual para el acceso por materias. También es útil para detectar problemas en los criterios de indización y contribuir a la mejora de la calidad de la descripción temática del conjunto documental
Resumo:
La mejora de las capacidades de búsqueda y de las interfaces de los opacs sigue siendo uno de los principales desafíos para las bibliotecas, especialmente en lo que respecta al acceso por materias. Las interfaces visuales pueden facilitar la recuperación. El objetivo del presente trabajo es explorar si la combinación de técnicas de análisis de co-términos y de redes sociales resulta ser una metodología válida para la generación de mapas temáticos de la colección. La principal conclusión es que el método es válido, y que los mapas obtenidos podrían servir como interfaz visual para el acceso por materias. También es útil para detectar problemas en los criterios de indización y contribuir a la mejora de la calidad de la descripción temática del conjunto documental
Resumo:
The study focuses on the generation and distribution of mineral species in fly and bottom ashes. These were formed during a fluidised co-combustion of a fossil fuel (coal) and a non-fossil fuel (tyre rubber) in a small fluidised bed combustor (7cm x 70cm). The pilot plant had continuous fuel feed using varying ratios of coal and rubber. The study also focuses on the lixiviation behaviour of metallic elements with the assessement of zinc recovering.
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El objetivo de este proyecto es realizar la simulación de una central térmica supercrítica de 700 MW con captura de CO₂ para producir electricidad y verterla a la red. El proyecto describe los equipos e instalaciones de la central y define los balances técnicos de la misma, probando que es viable técnicamente la incorporación de una planta de captura de CO₂ a una central térmica, a pesar del bajo rendimiento de la central. Además incluye el estudio económico que indica la viabilidad económica del proyecto, aunque con una rentabilidad baja. Este proyecto mira hacia el futuro debido a la necesidad de reducir las emisiones contaminantes, ya de casi la misma importancia que generar electricidad, y demuestra que es posible generar una energía limpia en centrales de carbón. ABSTRACT The purpose of this project is to carry out the simulation of a 700 MW supercritical coal thermal power plant with CO₂ capture to produce electricity and send it to the grid. The project describes the equipment, the installations and defines technical balances of the power plant. It shows that a CO₂ capture plant in a coal power plant is technically possible, in spite of the low power plant efficiency. In addition, it includes the economic analysis that shows the economic viability of the project, with a low profitability. This project looks into the future due to the need of reducing the pollutant emissions, which are almost as important as the generation of electricity, and demonstrates that a green energy in coal power plants is possible.
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El mercado de los semiconductores está saturado de productos similares y de distribuidores con una propuesta de servicios similar. Los procesos de Co-Creación en los que el cliente colabora en la definición y desarrollo del producto y proporciona información sobre su utilidad, prestaciones y valor percibido, con el resultado de un producto que soluciona sus necesidades reales, se están convirtiendo en un paso adelante en la diferenciación y expansión de la cadena de valor. El proceso de diseño y fabricación de semiconductores es bastante complejo, requiere inversiones cada vez mayores y demanda soluciones completas. Se requiere un ecosistema que soporte el desarrollo de los equipos electrónicos basados en dichos semiconductores. La facilidad para el diálogo y compartir información que proporciona internet, las herramientas basadas en web 2.0 y los servicios y aplicaciones en la nube; favorecen la generación de ideas, el desarrollo y evaluación de productos y posibilita la interacción entre diversos co-creadores. Para iniciar un proceso de co-creación se requiere métodos y herramientas adecuados para interactuar con los participantes e intercambiar experiencias, procesos para integrar la co-creación dentro de la operativa de la empresa, y desarrollar una organización y cultura que soporten y fomenten dicho proceso. Entre los métodos más efectivos están la Netnografía que estudia las conversaciones de las comunidades en internet; colaboración con usuarios pioneros que van por delante del Mercado y esperan un gran beneficio de la satisfacción de sus necesidades o deseos; los estudios de innovación que permiten al usuario definir y a menudo crear su propia solución y la externalización a la multitud, que mediante una convocatoria abierta plantea a la comunidad retos a resolver a cambio de algún tipo de recompensa. La especialización de empresas subcontratistas en el desarrollo y fabricación de semiconductores; facilita la innovación abierta colaborando con diversas entidades en las diversas fases del desarrollo del semiconductor y su ecosistema. La co-creación se emplea actualmente en el sector de los semiconductores para detectar ideas de diseños y aplicaciones, a menudo mediante concursos de innovación. El servicio de soporte técnico y la evaluación de los semiconductores con frecuencia es fruto de la colaboración entre los miembros de la comunidad fomentada y soportada por los fabricantes del producto. Con el programa EBVchips se posibilita el acceso a empresas pequeñas y medianas a la co-creación de semiconductores con los fabricantes en un proceso coordinado y patrocinado por el distribuidor EBV. Los semiconductores configurables como las FPGAs constituyen otro ejemplo de co-creación mediante el cual el fabricante proporciona el circuito integrado y el entorno de desarrollo y los clientes crean el producto final definiendo sus características y funcionalidades. Este proceso se enriquece con bloques funcionales de diseño, IP-cores, que a menudo son creados por la comunidad de usuarios. ABSTRACT. The semiconductor market is saturated of similar products and distributors with a similar proposal for services. The processes of co-creation in which the customer collaborates in the definition and development of the product and provides information about its utility, performance and perceived value, resulting in a product that solves their real needs, are becoming a step forward in the differentiation and expansion of the value chain. The design and semiconductor manufacturing process is quite complex, requires increasingly higher investments and demands complete solutions. It requires an ecosystem that supports the development of electronic equipments based on such semiconductors. The ease of dialogue and sharing information that provides internet, web 2.0-based tools and services and applications in the cloud; favor the generation of ideas, the development and evaluation of products and allows the interaction between various co-creators. To start a process of co-creation adequate methods and tools are required to interact with the participants and exchange experiences, processes to integrate the co-creation within the operations of the company, and developing an organization and culture that support and promote such process. Among the most effective methods are the Netnography that studies the conversations of the communities on the internet; collaboration with Lead Users who are ahead of the market and expect a great benefit from the satisfaction of their needs or desires; Innovation studies that allow the user to define and often create their own solution and Crowdsourcing, an open call to the community to solve challenges in exchange for some kind of reward. The specialization of subcontractors in the development and manufacture of semiconductors; facilitates open innovation in the context of collaboration with different entities working in the different phases of the development of the semiconductor and its ecosystem. Co-creation is used currently in the semiconductor sector to detect ideas of designs and applications, often through innovation’s contests. Technical support and evaluation of semiconductors frequently is the result of collaboration between members of the community fostered and supported by the manufacturers of the product. The EBVchips program provides access to small and medium-sized companies to the co-creation of semiconductors with manufacturers in a process coordinated and sponsored by the Distributor EBV. Configurable semiconductors like FPGAs are another example of co-creation whereby the manufacturer provides the integrated circuit and the development environment and customers create the final product by defining their features and functionality. This process is enriched with IP-cores, designs blocks that are often created by the user community.
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"Printed in Great Britain."
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A benzothiazole-derived compound (4a) designed to mimic the C-alpha-C-beta bond vectors and terminal functionalities of Lys2, TyrI3 and Arg17 in omega-conotoxin GVIA was synthesised, together with analogues (4b-d), which had each side-chain mimic systematically truncated or eliminated. The affinity of these compounds for rat brain N-type and P/Q-type voltage gated calcium channels (VGCCs) was determined. In terms of N-type channel affinity and selectivity, two of these compounds (4a and 4d) were found to be highly promising, first generation mimetics of omega-conotoxin. The fully functionalised mimetic (4a) showed low PM binding affinity to N-type VGCCs (IC50 = 1.9 muM) and greater than 20-fold selectivity for this channel sub-type over P/Q-type VGCCs, whereas the mimetic in which the guanidine-type side chain was truncated back to an amine (4d, IC50 = 4.1 muM) showed a greater than 25-fold selectivity for the N-type channel. (C) 2004 Elsevier Ltd. All rights reserved.