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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimization of Process Variables for Oxidative Coupling of Methane

Alturkistani, Sultan H. 05 1900 (has links)
Oxidative coupling of methane (OCM) is a promising route for converting abundant natural gas resources into more useful chemicals like paraffins and olefins (primarily C2). However, to date, there is no current OCM production plant due to low overall conversion and selectivity to the desired product(s). In this work, different operating factors are studied experimentally and through simulation with respect mainly to three responses: CH4 conversion, C2 main product selectivity, and COx side product selectivity. The aim is to identify the best operating condition for maximum ethylene production combined with COx production. Design of experiments (DoE) method was used to analyze the experimental results by applying the full factorial approach. Simulation results were studied by finding the correlation strength between input factors and responses. It was found that the performance of an OCM reactor could be greatly improved under optimal operating conditions. Operating temperature and CH4/O2 ratio have the highest influence while catalyst weight and flow rate have the lowest influence on the OCM responses and mainly depend on rector dimensions.
2

Evaluative screening of kinetic models for simulating the performances of oxidative coupling of methane catalysts

Gobouri, Abdullah 27 July 2022 (has links)
In this work, multiple kinetic models have been screened as potential candidates for simulating the performances of three oxidative coupling of methane (OCM) catalysts. Two of the proposed models were subjected to testing and optimization. The types of models screened covered both kinetic and microkinetic type models, i.e., radical omitting and radical considering. Some of the models only accounted for catalytic heterogeneous pathways, while others have expanded on the homogeneous gas-phase mechanism of the OCM reaction. The optimization process was carried out in MATLAB® R2020a using an error minimization tool. The range of experimental conditions examined was as follows: 740–800◦C, 100 kPa, 2–4 CH4/O2 ratio, 1–6 gcat h molC –1 spacetime. The results show successful optimization of both models as well as discrepancies in terms of their performances in predicting experimentally obtained values of CH4 and O2 conversions, as well as selectivities towards COx and C2+ products. While a kinetic model served as an easy option to optimize, it expressed limits in terms of achievable performance, mainly failing to simulate experimental runs conducted at low spacetimes. A microkinetic model on the other hand, managed to simulate all experimental conditions, with less accuracy towards COx species and much greater computational demand.
3

Performance des entreprises dans une petite économie insulaire de la Caraïbe : Le cas de la Guadeloupe

Ernatus, Hélène 09 July 2009 (has links) (PDF)
L'ouverture des économies et la mondialisation accentuent la compétition entre firmes et territoires économiques. Dans un espace mondial dominé par les grands pays et les firmes multinationales, les petites économies insulaires peinent à trouver leur place. Ces petites économies ont certes des atouts, mais surtout de nombreux handicaps qui désavantagent leurs entreprises. Celles-ci sont le plus souvent de petites ou moyennes entreprises, doublement pénalisées par leur taille et leur environnement insulaire. Nous voulons analyser cette situation particulière à partir de l'exemple de ces petits territoires, qui présentent les handicaps propres aux petites économies insulaires, mais qui sont aussi intégrés dans un espace économique développé plus vaste : il s'agit des économies de l'Outre-mer français situées dans la Caraïbe.<br />La thèse examine les comportements stratégiques des entreprises situées sur un petit territoire insulaire, pour répondre aux contraintes liées à leur situation insulaire et aux défis engendrés par les modifications de l'environnement socioéconomique. <br />Ces entreprises tirent parti des ressources créées par les politiques publiques mises en place par des Etats à économie développée, mais doivent pouvoir aussi surmonter des difficultés supplémentaires créées par leur situation paradoxale. <br />Nous nous inspirons des concepts de l'Economie Industrielle pour montrer l'existence, pour les entreprises les plus exposées à la pression concurrentielle externe, d'un étroit sentier stratégique fondé sur la recherche de la différenciation de leurs produits. Mais les entreprises les moins exposées peuvent aussi développer des stratégies qui peuvent aller à l'encontre de l'optimum social cher aux économistes néoclassiques.
4

The Impact of Extracellular Matrix Stiffness on Angiogensis

Lee, Po-Feng 1976- 14 March 2013 (has links)
Sprouting endothelial cells (ECs) use soluble and insoluble cues to guide migration and expand the existing vascular network to meet changing trophic needs of the tissue during angiogenesis. A noninvasive and non-destructive nonlinear optical microscopy (NLOM) technique was used to optically image endothelial sprouting morphogenesis in three dimensional (3D) collagen matrices with simultaneously captured signals from collagen fibers and endothelial cells using second harmonic generation (SHG) and two-photon excited fluorescence (TPF), respectively. Sprout advancement and lumen expansion companying with ECM alteration were the synergistic results of membrane-associated matrix metalloproteinase and cell traction evidenced by proteinase inhibition and Rho-associated kinase (p160ROCK) inhibition experiments. These physical EC-ECM interactions suggest that ECM mechanical properties may influence angiogenic responses. In a 3D angiogenesis model, we measure angiogenic responses as a function of collagen matrix stiffness by inducing collagen cross-linking with microbial transglutaminase (mTG). Collagen matrices stiffen with both mTG treatment and incubation time as evidenced with biaxial mechanical test results and collagen TPF intensity increases with mTG treatment and that the ratio of TPF/SHG correlates with biaxial tested mechanical stiffness. SHG and optical coherence microscopy (OCM) are further used to show that other physical properties of the matrix do not change with mTG treatment, thus providing the same density but different stiffness with which to measure angiogenic responses. Stiffer matrices promote angiogenesis with more invading sprouts that invade deeper. No differences in lumen size were observed between control and mTG stiffened 3D cultures, but there was evidence of greater matrix remodeling in stiffer gels using NLOM. Results of this study show angiogenic responses are enhanced with increasing stiffness and suggest that these properties may be used in tissue engineering and regenerative medicine applications to engineer angiogenesis.
5

Análisis del impacto económico de la reforma de la OCM-Vitivinícola en la comarca Utiel-Requena

Beltrán Roca, Pedro Javier 06 November 2017 (has links)
In the Utiel-Requena region where there is a strong production specialization in the wine sector, the impact of the economic policy affecting the sector is very important, not only in the agents involved in the processes of the predominant productive activity, but also in all the economic activity of the region. The analysis of this impact presented problems derivatives to the low level of disaggregation of information at the county level, including provincial level, so that we remove the decisions that economic agents took in relation to the structures of the vineyards and wineries, and observed the changes. The research has focused mainly on the economic impact of the support measures included in the new reform of the Common Organization of the market in wine. This analysis of the economic impact has been broken down into direct, indirect and induced impacts, differentiating those that have remained within forty-nine and fifty-one percent of the region. The study shows the different degree of utilization and expenditure of the different support measures and how they affect the wine sector and the Gross Domestic Product of the Utiel-Requena region. / En la Comarca Utiel-Requena en la que existe una fuerte especialización productiva en el sector vitivinícola, el impacto de la política económica que afecta al sector es muy importante, no solo en los agentes implicados en los procesos de la actividad productiva predominante, sino en toda la actividad económica de la Comarca. El análisis de este impacto nos presentó problemas derivados del escaso nivel de desagregación de la información a nivel comarcal, incluso provincial, por lo que aislamos las decisiones que tomaron los agentes económicos en relación a las estructuras de la explotaciones vitícolas y bodegas, y observamos los cambios producidos. La investigación se ha centrado principalmente en el impacto económico de las medidas de apoyo incluidas en la nueva reforma de la Organización Común de Mercado del sector vitivinícola. Este análisis del impacto económico se ha desglosado en los impactos directos, indirectos e inducidos diferenciándose los que se han quedado dentro el cuarenta y nueve y fuera el cincuenta y uno por ciento de la comarca. En el estudio se observa el diferente grado de utilización y gasto de las diferentes medidas de apoyo y como estas repercuten en el sector vitivinícola y en el Producto Interior Bruto de la Comarca Utiel-Requena. / En la Comarca Utiel-Requena en la que hi ha una forta especialització productiva en el sector vitivinícola, l'impacte de la política econòmica que afecta el sector és molt important, no sols en els agents implicats en els processos de l'activitat productiva predominant, sinó en tota l'activitat econòmica de la Comarca. L'anàlisi d'este impacte ens va presentar problemes derivats de l'escàs nivell de desagregació de la informació a nivell comarcal, inclús provincial, per la qual cosa aïllem les decisions que van prendre els agents econòmics en relació a les estructures de les explotacions vitícoles i cellers, i observem els canvis produïts. La investigació s'ha centrat principalment en l'impacte econòmic de les mesures de suport incloses en la nova reforma de l'Organització Comuna de Mercat del sector vitivinícola. Esta anàlisi de l'impacte econòmic s'ha desglossat en els impactes directes, indirectes i induïts diferenciant-se els que s'han quedat dins el quaranta-nou i fora el cinquanta-un per cent de la comarca. En l'estudi s'observa el diferent grau d'utilització i gasto de les diferents mesures de suport i com estes repercutixen en el sector vitivinícola i en el Producte Interior Brut de la Comarca Utiel-Requena. / Beltrán Roca, PJ. (2017). Análisis del impacto económico de la reforma de la OCM-Vitivinícola en la comarca Utiel-Requena [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90492 / TESIS
6

Ionic Conducting Ceramic Membrane Reactor for Partial Oxidation of Light Hydrocarbons

Akin, Figen Tulin 21 May 2002 (has links)
No description available.
7

A design flow to automatically Generate on chip monitors during high-level synthesis of Hardware accelarators / Un flot de conception pour générer automatiquement des moniteurs sur puce pendant la synthèse de haut niveau d'accélérateurs matériels

Ben Hammouda, Mohamed 11 December 2014 (has links)
Les systèmes embarqués sont de plus en plus utilisés dans des domaines divers tels que le transport, l’automatisation industrielle, les télécommunications ou la santé pour exécuter des applications critiques et manipuler des données sensibles. Ces systèmes impliquent souvent des intérêts financiers et industriels, mais aussi des vies humaines ce qui impose des contraintes fortes de sûreté. Par conséquent, un élément clé réside dans la capacité de tels systèmes à répondre correctement quand des erreurs se produisent durant l’exécution et ainsi empêcher des comportements induits inacceptables. Les erreurs peuvent être d’origines naturelles telles que des impacts de particules, du bruit interne (problème d’intégrité), etc. ou provenir d’attaques malveillantes. Les architectures de systèmes embarqués comprennent généralement un ou plusieurs processeurs, des mémoires, des contrôleurs d’entrées/sorties ainsi que des accélérateurs matériels utilisés pour améliorer l’efficacité énergétique et les performances. Avec l’évolution des applications, le cycle de conception d’accélérateurs matériels devient de plus en plus complexe. Cette complexité est due en partie aux spécifications des accélérateurs matériels qui reposent traditionnellement sur l’écriture manuelle de fichiers en langage de description matérielle (HDL).Cependant, la synthèse de haut niveau (HLS) qui favorise la génération automatique ou semi-automatique d’accélérateurs matériels à partir de spécifications logicielles, comme du code C, permet de réduire cette complexité.Le travail proposé dans ce manuscrit cible l’intégration d’un support de vérification dans les outils de HLS pour générer des moniteurs sur puce au cours de la synthèse de haut niveau des accélérateurs matériels. Trois contributions distinctes ont été proposées. La première contribution consiste à contrôler les erreurs de comportement temporel des entrées/sorties (impactant la synchronisation avec le reste du système) ainsi que les erreurs du flot de contrôle (sauts illégaux ou problèmes de boucles infinies). La synthèse des moniteurs est automatique sans qu’aucune modification de la spécification utilisée en entrée de la HLS ne soit nécessaire. La deuxième contribution vise la synthèse des propriétés de haut niveau (ANSI-C asserts) qui ont été ajoutées dans la spécification logicielle de l’accélérateur matériel. Des options de synthèse ont été proposées pour arbitrer le compromis entre le surcout matériel, la dégradation de la performance et le niveau de protection. La troisième contribution améliore la détection des corruptions des données qui peuvent modifier les valeurs stockées, et/ou modifier les transferts de données, sans violer les assertions (propriétés) ni provoquer de sauts illégaux. Ces erreurs sont détectées en dupliquant un sous-ensemble des données du programme, limité aux variables les plus critiques. En outre, les propriétés sur l’évolution des variables d’induction des boucles ont été automatiquement extraites de la description algorithmique de l’accélérateur matériel. Il faut noter que l’ensemble des approches proposées dans ce manuscrit, ne s’intéresse qu’à la détection d’erreurs lors de l’exécution. La contreréaction c.à.d. la manière dont le moniteur réagit si une erreur est détectée n’est pas abordée dans ce document. / Embedded systems are increasingly used in various fields like transportation, industrial automation, telecommunication or healthcare to execute critical applications and manipulate sensitive data. These systems often involve financial and industrial interests but also human lives which imposes strong safety constraints.Hence, a key issue lies in the ability of such systems to respond safely when errors occur at runtime and prevent unacceptable behaviors. Errors can be due to natural causes such as particle hits as well as internal noise, integrity problems, but also due to malicious attacks. Embedded system architecture typically includes processor (s), memories, Input / Output interface, bus controller and hardware accelerators that are used to improve both energy efficiency and performance. With the evolution of applications, the design cycle of hardware accelerators becomes more and more complex. This complexity is partly due to the specification of hardware accelerators traditionally based on handwritten Hardware Description Language (HDL) files. However, High-Level Synthesis (HLS) that promotes automatic or semi-automatic generation of hardware accelerators according to software specification, like C code, allows reducing this complexity.The work proposed in this document targets the integration of verification support in HLS tools to generate On-Chip Monitors (OCMs) during the high-level synthesis of hardware accelerators (HWaccs). Three distinct contributions are proposed. The first one consists in checking the Input / Output timing behavior errors (synchronization with the whole system) as well as the control flow errors (illegal jumps or infinite loops). On-Chip Monitors are automatically synthesized and require no modification in their high-level specification. The second contribution targets the synthesis of high-level properties (ANSI-C asserts) that are added into the software specification of HWacc. Synthesis options are proposed to trade-off area overhead, performance impact and protection level. The third contribution improves the detection of data corruptions that can alter the stored values or/and modify the data transfers without causing assertions violations or producing illegal jumps. Those errors are detected by duplicating a subset of program’s data limited to the most critical variables. In addition, the properties over the evolution of loops induction variables are automatically extracted from the algorithmic description of HWacc. It should be noticed that all the proposed approaches, in this document, allow only detecting errors at runtime. The counter reaction i.e. the way how the HWacc reacts if an error is detected is out of scope of this work.
8

DEVELOPMENT OF CERAMIC MIEC MEMBRANES FOR OXYGEN SEPARATION: APPLICATION IN CATALYTIC INDUSTRIAL PROCESSES

García Fayos, Julio 01 September 2017 (has links)
The present Thesis is focused on the development of ceramic membranes for the production of O2, as well as their use in several industrial applications (e.g. power generation, chemical industry). Different materials such as perovskites (BSCF and LSCF), fluorites (CGO) and composites, different membrane architectures have been considered. Catalytic activation was considered for the optimization of permeation, and for improving the selectivity/yield of chemical reactions. In the chapter dedicated to BSCF, the influence of thickness and the use of porous supports in the permeation was studied. An improvement in the permeation was observed for the thinner membranes. With respect to the porous supports, it was found that they contribute with an additional resistance within the permeation process, reducing the potential improvement when reducing thickness. The conducted tests also allowed to study more in deep the different processes affecting oxygen membranes, as well as defining a permeation model for monolithic and asymmetric membranes. Aiming to improve the surface reactions involved in the oxygen permeation the use of catalytic layers was considered, by means the addition of porous BSCF backbones. The best results were obtained when coating both sides of membranes with catalytic layers. The concept of BSCF activated membranes was also considered for the production of C2H4 by means of the oxidative de-hydrogenation of C2H6, obtaining high C2H4 yields. BSCF membranes presenting tubular geometry were characterized for application such as production of O2 and production of C2H4 by means of oxidative coupling of CH4. LSCF was considered for conducting studies under CO2-containing atmospheres. For both systems it was conducted a complete permeation study with a focus on permeation performance under CO2 environments. Furthermore a study focused on the different substrates was carried out for determining the structure presenting the lower gas diffusion resistance. Despite very good results were obtained for both membrane types, even under CO2 conditions, freeze casted membranes reached higher oxygen fluxes, being optimized with the catalytic activation of membranes. Materials presenting fluorite structure stand out for their stability under reaction conditions or when exposed to CO2 environments. Nevertheless, delivered oxygen fluxes are typically low. Hence, a thin 40 micron-thick CGO-Co membrane activated with Pd nanoparticles was considered for conducting a study on O2 permeation performance, and its behaviour when exposed to CO2 and CH4-containing atmospheres. A good stability was demonstrated, as well as a significant improvement in oxygen permeation when exposed to CH4 environments. Thus, CGO membranes present promising properties for their application in oxyfuel and for the conduction of chemical reactions. Composite materials based on NFO-CTO was carried out. An evaluation of the CTO content and its relation with permeation was conducted, determining that a higher ionic phase ratio in the membrane results in a higher permeation. A composite consisting of 50NFO-50CTO was considered for performing a permeation study under harsh application conditions, with presence of SO2. Despite the significant loss in permeation, the composite material resulted to be stable after a long exposure to SO2. A broad study about the effect of CO2 and SO2 on the oxygen surface reactions was conducted by means of EIS measurements on 60NFO-40CTO electrodes. It was observed a significant effect of SO2 on the surface exchange reactions by promoting the deactivation of the O2 active sites, due to a SO2 adsorption on them. This effect was minimized by activating 60NFO-40CTO backbones with different catalysts, being characterized by EIS under CO2&SO2 conditions. This improvement was later confirmed when performing permeation tests. Permeation was improved notably by reducing membrane thickness, depositing composite membranes on LSCF porous substrates. / La presente tesis trata sobre el desarrollo de membranas cerámicas para la producción de O2, así como de su uso en distintas aplicaciones industriales (producción de energía, industria química). Se han considerado distintos tipos de materiales tales como perovskitas (BSCF y LSCF), fluoritas (CGO) y materiales composites, así como distintas arquitecturas de membrana. y activación catalítica para optimizar la permeación y la selectividad/rendimiento en reacciones químicas. Para el BSCF se estudió la influencia del espesor y el uso de soportes porosos en la permeación de O2, con una mejora para las membranas más finas, y también el papel de los soportes porosos, contribuyendo con una resistencia adicional en el proceso de permeación. El estudio permitió también conocer más en profundidad los procesos que afectan a los distintos tipos de membranas, y establecer un modelo de permeación para membranas. Se recurrió a la activación catalítica mediante la adición de capas porosas de BSCF, obteniendo así mejores resultados para las membranas con capas en ambos lados. El concepto de membranas de BSCF activadas superficialmente se consideró también para la producción de C2H4 a partir de la deshidrogenación oxidativa de etano (ODHE), obteniendo rendimientos de C2H4 muy elevados. Membranas de BSCF con geometría tubular fueron caracterizadas para aplicaciones de producción de O2 y C2H4 mediante acoplamiento oxidativo de metano (OCM). Se consideró al LSCF para su uso en aplicaciones con atmósferas conteniendo CO2. Se desarrollaron membranas soportadas en soportes porosos de LSCF mediante tape casting y freeze-casting, realizando completos estudios de permeación, además de estudiar el tipo de soporte poroso ofreciendo menos resistencia a la difusión de los gases. Pese que para ambos tipos de membranas se obtuvieron muy buenos flujos de oxígeno, incluso bajo condiciones de CO2, para el caso de membranas con soporte fabricado mediante freeze-casting se consiguieron mayores valores de permeación, optimizándolos incluso con la activación catalítica. Los materiales con estructura fluorita poseen alta estabilidad bajo condiciones de reacción (atmósferas reductoras) o cuando son expuestos a CO2 (aplicaciones de producción de energía). Sin embargo, los valores de permeación suelen ser muy bajos. Se consideró una membrana de CGO-Co de 40 micras de espesor activada con nanopartículas de Pd para llevar a cabo un estudio de sus propiedades para la producción de O2, su comportamiento en contacto con CO2 y con atmósferas conteniendo CH4. La buena estabilidad demostrada y la mejora sustancial de los flujos de O2 bajo ambientes reductores, hacen que este tipo de materiales posean propiedades prometedoras para aplicaciones de oxicombustión y reacciones químicas. Se realizó un estudio con materiales composites formados por NFO-CTO. Una evaluación del contenido en CTO y su relación con la permeación de O2, resultó en mayores valores para composiciones con mayor contenido en CTO. Un composite consistente en 50NFO-50CTO se consideró para la realización de tests bajo condiciones de oxicombustión, con presencia de SO2. Pese al notable descenso en los flujos de O2, el material resultó ser completamente estable tras una exposición continuada al SO2. Un amplio estudio del efecto del CO2 y del SO2 sobre las reacciones superficiales se realizó mediantes medidas de EIS en electrodos de 60NFO-40CTO, demostrando que el SO2 afecta significativamente a las reacciones superficiales mediante procesos de adsorción competitiva en los centros activos. Se minimizó el efecto del SO2 sobre las reacciones de intercambio superficial al activar las membranas con capas catalíticas porosas de 60NFO-40CTO con distintos catalizadores, confirmando posteriormente esta mejora en tests de permeación en las mismas condiciones. Así mismo, se optimizó notablemente la permeación de las membranas de 60NFO-40CTO reduciendo el espes / La present tesi tracta sobre el desenvolupament de membranes ceràmiques per a la producció d'O2, així com del seu ús en diverses aplicacions industrials (producció d'energia, indústria química). S'han considerat diversos materials tals com perovskites (BSCF i LSCF), fluorites (CGO) i materials composites, així com diferents arquitectures de membrana i l'activació catalítica per a millorar la permeació i la sel·lectivitat/rendiment de les reaccions químiques. Per al BSCF s'estudià la influència de l'espessor i l'ús de suports porosos en la permeació d'O2, amb una millora dels fluxos d'O2 per al cas de les membranes més fines, i també el paper dels suports porosos, els quals contribueixen afegint una resistència al procés de permeació. L'estudi també va permetre conèixer més en profunditat els processos que afecten als diferents tipus de membranes, i establir un model de permeació per a membranes. Es va recórrer a l'activació catalítica mitjançant l'adició de capes poroses de BSCF, obtenint així millors resultats per a les membranes activades a ambdós costats. El concepte de membranes de BSCF activades superficialment es va considerar també per a la producció d'etilè a mitjançant la deshidrogenació oxidativa d'età (ODHE), obtenint rendiments de C2H4 molt elevats. Membranes de BSCF amb geometria tubular van ser caracteritzades per a aplicacions de producció d'O2 i C2H4 mitjançant l'acoplament oxidatiu de metà (OCM). Es va considerar al LSCF per al seu ús en aplicacions amb atmosferes contenint CO2. Així doncs, es van desenvolupar membranes suportades sobre suports porosos de LSCF fabricats per tape càsting i freeze càsting. Es van realitzar estudis complets de permeació per a ambdós casos, a més d'estudiar el tipus de suport porós que ofereix una menor resistència a la difusió dels gasos. Malgrat que es van obtindré molts bons fluxos d'O2 per als dos tipus de membranes, inclús sota condicions amb CO2, per al cas de les membranes amb suport fabricat per freeze càsting es van aconseguir majors valors de permeació, sent inclús optimitzats amb l'activació catalítica. Els materials amb estructura fluorita destaquen per l'alta estabilitat sota condicions de reacció (atmosferes reductores) o quan són exposats a CO2 (aplicacions per a la producció d'energia). Malgrat això, els valors de permeació solen ser molt baixos. Es va considerar una membrana de CGO-Co de 40 micras d'espessor activada amb partícules de Pd per a realitzar un estudi sobre les seues propietats en quant a la producció d'O2, el seu comportament amb el contacte amb CO2 i atmosferes reductores contenint CH4. La bona estabilitat demostrada i una millora substancial dels fluxos d'O2 sota ambients reductors fan que aquest tipus de material presente propietats prometedores per a aplicacions d'oxicombustió i reaccions químiques. Es va realitzar un estudi sobre materials composites formats per NFO-CTO. Es va realitzar una avaluació del contingut en CTO i la relació amb la permeació, observant una millora de la permeació amb un major contingut de CTO. Un composite consistent en 50NFO-40CTO es va considerar per a la realització de tests de permeació en condicions d'oxicombustió amb presència de SO2. Malgrat el notable descens en els fluxos d'O2, el material resultà ser estable després d'una exposició continuada al SO2. Es mesurà l'efecte del CO2 i del SO2 sobre les reaccions superficials fent ús de la tècnica d'EIS en elèctrodes de 60NFO-40CTO. Demostrant que el SO2 afecta significativament a les reaccions superficials degut a una adsorció competitiva O2-SO2 als centres actius. Es minimitzà l'efecte del SO2 sobre les reaccions superficials al activar les membranes amb capes poroses de 60NFO-40CTO amb diferents catalitzadors. Aquestes capes van ser caracteritzades per EIS sota condicions de SO2, confirmant posteriorment la millora al realitzar tests de permeació. S'optimitzà notablement la perme / García Fayos, J. (2017). DEVELOPMENT OF CERAMIC MIEC MEMBRANES FOR OXYGEN SEPARATION: APPLICATION IN CATALYTIC INDUSTRIAL PROCESSES [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86189 / TESIS / Premios Extraordinarios de tesis doctorales
9

The effects of Fraud and Embezzlement in the organizational structures

Nyandwi, Safia, Mohamedbrhan, Ikram, Saadallah, Dima January 2023 (has links)
Level: Bachelor thesis in Business and Administration  Institution: School of business, Society and engineering, Mälardalen University Authors: Ikram Mohamedbrhan, Safia Nyandwi, Dima Saadallah Title: The effects of Fraud and Embezzlement in the organizational structures Supervisor: Stylianos Papaioannou  Keywords: Fraud and Embezzlement, Organizational structure, Organizational Change Management (OCM), Corruption inequality /injustice, Ethic and transparency Research question: How does embezzlement and fraud affect the disparities in organizational structures? Purpose: The purpose of this thesis is to analyze the effect of fraud and embezzlement in organizational structures specifically focusing on the disparities of the tall and flat organizational structures. Method: Semi-structured interviews were conducted as part of the thesis' qualitative research methodology. The data was then analyzed on a thematic level. Conclusion:  The study concludes that the effects of embezzlement and fraud are more severe in the tall organizational structure than in the flat organizational structure. The data show that reporting misconduct is simpler under flat organizational structures.  Resulting, a disparate equilibrium regarding corruption in organizational structures.
10

Design of Affordable Portable Mechanical Ventilator

Komatipalli, Rohith Kumar January 2024 (has links)
This report outlines developing a mechanism for a relatively low in price, portable, and mechanical ventilator prototype designed to bridge the gap in ventilator access brought about the COVID-19 pandemic. The key goal is to create a portable and easy to use device which will be capable of providing constant and effective respiratory support in areas having limited resources. The ventilator uses the Oscillating Cylinder Mechanism (OCM), which makes the ventilation smoothly and continuously. This eliminates the need for the user to put maximum effort and the patient benefits. Different ideas about designs were being put forward, concentrating on the portability, functionality, reliability, safety, and effectiveness. The OCM was selected because of its ventilation parameter adjustment ability to accommodate patient-specific needs, thereby functioning in a variety of clinical settings. Although upfront complexity and cost are developed, long-term perks such as lower user fatigue and maintenance expenses compensate for the financial investment. The end design will help in the emergency medical care especially in demand emergency situations, in ambulances, and in intensive care.

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