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1

MORÈ, NICCOLÒ. « Lipopolysaccharide transport and peptidoglycan remodeling : two related processes in Escherichia coli ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2018. http://hdl.handle.net/10281/198942.

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Il rivestimento dei batteri Gram negativi consiste in una membrana interna (IM) e una membrana esterna (OM) separate da uno spazio periplasmatico contenente un sottile strato di peptidoglicano (PG) ancorato alla OM tramite la lipoproteina di Braun (LPP). Mentre la IM è costituita da un doppio strato di fosfolipidi, la OM è una membrana lipidica asimmetrica, contenente fosfolipidi nel foglietto interno, e un lipide complesso il Lipopolisaccaride (LPS) nel foglietto esterno. Il LPS sintetizzato nel citoplasma, viene traslocato sul lato periplasmatico della IM e preso in carico dal complesso multiproteico Lpt (LPS transport), composto in Escherichia coli da sette proteine essenziali (Lpt ABCDEFG) che si occupano del suo trasporto fino al raggiungimento della sua sede finale, la OM. Analisi biochimiche hanno dimostrato che le sette proteine Lpt formano un complesso “transenvelope” che connette IM e OM e studi di tipo genetico suggeriscono che esse operino in concerto come un singolo macchinario. Infatti, la deplezione di un qualsiasi componente del complesso Lpt causa lo stesso fenotipo, ovvero l’accumulo del LPS nel versante periplasmatico della IM, la decorazione del LPS con acido colanico e la formazione di una IM anomala, con una densità intermedia tra la IM e la OM. Nel nostro laboratorio è stata condotta l’analisi differenziale del proteoma delle membrane totali di E. coli in deplezione di LptC, per studiare la risposta globale al blocco del trasporto del LPS. Tra le proteine il cui livello cambia nel confronto tra il ceppo non depleto e il depleto sono state trovate proteine coinvolte nella biogenesi e nel rimodellamento del PG. Lo scopo di questa tesi è stato lo studio della correlazione tra il blocco del LPS e il rimodellamento del PG. Inizialmente è stata analizzata la struttura del PG in deplezione di LptC. Questa analisi ha evidenziato che in questa condizione la struttura del PG varia sia per composizione che per tipo di legami crociati tra i filamenti glicanici adiacenti. Nei batteri Gram negativi il legame tra i filamenti glicanici è generalmente un legame diretto 3-4, che si forma tra il gruppo aminico del diaminoacido in posizione 3 di un tetrapeptide e il gruppo carbossilico della D-alanina in posizione 4 del tretrapeptide adiacente. Il legame 3-4 avviene ad opera delle D,D transpeptidasi PBP. Un altro tipo di legame crociato presente nel PG è quello tipo 3-3 che si forma tra il gruppo aminico del diaminoacido in posizione 3 ed il gruppo carbossilico del diaminoacido presente nel tetrapeptide del filamento glicanico adiacente ed è catalizzato da L,D-transpeptidasi . In E. coli, sono noti cinque enzimi con attività L,D-transpeptidasica, di cui tre (LdtA, LdtB, LdtC) ancorano la lipoproteina più abbondante della OM (lipoproteina di Braun) al PG e due (LdtD, LdtE) catalizzano il legame crociato 3-3. La delezione di tutti questi geni, singolarmente o in combinazione, non presenta nessun fenotipo, suggerendo che in condizioni normali questo legame è dispensabile. Per studiare la correlazione tra il legame crociato 3-3 e il blocco del trasporto del LPS abbiamo creato mutanti arabinosio dipendenti per alcuni dei componenti del sistema Lpt deleti contemporaneamente per i geni che esprimono le L,D-transpeptidasi LdtD e LdtE. In precedenza, nel nostro laboratorio è stato dimostrato che la deplezione di uno qualsiasi dei geni lpt causa la formazione di cellule filamentose e l’arresto della crescita ma non la lisi cellulare. Invece, nei mutanti ΔldtDΔldtE, in deplezione dei geni lpt, oltre alla formazione di cellule filamentose si osserva la formazione di un setto anomalo e la lisi cellulare. Questi dati suggeriscono che il rimodellamento del peptidoglicano a seguito della formazione di legami 3-3 potrebbe essere una forma di riposta al danno alla membrana esterna.
The cell envelope of Gram-negative bacteria is a complex multi-layered structure consisting of a cytoplasmic and an outer membrane (CM and OM), which delimit the periplasm containing a thin layer of peptidoglycan (PG) called the sacculus. The primary function of the OM is to establish a selective permeability barrier that enables the cell to maintain favourable intracellular conditions even in hash environments and the lipopolysaccharide (LPS) layer greatly contributes to this peculiar property. The integrity of the PG mesh is essential to protect the cell from bursting due to its turgor and maintain the shape of the cell. OM and PG are synthetized and assembled by multiprotein machineries that need to be finely coordinated as imbalanced growth of these layers may compromise structural integrity of the cell. In order to gain more insight in the mechanism by which the cells coordinate the growth of these two layers, we analysed the PG composition when the biogenesis of OM is compromised due to the block of LPS transport. In this work we shown that when OM is impaired, E. coli cells remodel PG architecture by increasing the non-canonical 3- 3 cross-linkage. We can assume that this is a salvage mechanism to prevent cell lysis when OM is damaged.
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Broussot, Loïc. « Implication du noyau latérodorsal du tegmentum dans les réponses au stress adaptatives et mésadaptées ». Electronic Thesis or Diss., Université Côte d'Azur, 2020. http://theses.univ-cotedazur.fr/2020COAZ6014.

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La réponse comportementale au stress est un mécanisme adaptatif qui permet à l’organisme de gérer les stimuli environnementaux nocifs. Les circuits qui la sous-tendent peuvent cependant être dérégulés par un stress intense ou chronique, conduisant à des troubles neuropsychiatriques. L’aire tegmentale ventrale (ATV) est une région du mésencéphale qui joue un rôle crucial dans le traitement de la récompense et l’aversion. On sait qu’elle influence la réponse au stress, mais notre connaissance sur ce rôle reste limitée car on ignore la plupart des structures régulatrices qui le sous-tendent. Le noyau latérodorsal du tegmental (LDTg) est une structure du tronc cérébral qui régule l’activité de l’ATV. Si son influence sur la récompense a été largement décrite, son rôle dans la réponse au stress reste encore inconnu.Cette thèse explore le rôle du LDTg dans deux types de réponse au stress : 1) Les comportements défensifs adaptés face à un stress aigu. 2) Les troubles comportementaux mésadaptés résultant d’un stress chronique. Pour comprendre le rôle du LDTg dans chacune, nous avons utilisé des outils pharmacogénétiques et optogénétiques pour moduler son activité durant des situations stressantes et en observer les effets comportementaux. En administrant de courts chocs électriques, nous avons évalué le rôle du LDTg dans un comportement défensif adaptatif d’immobilisation appelé freezing. Nous avons inhibé sélectivement les projections du LDTg de différentes natures et ciblant différentes structures afin de montrer que les projections GABAergiques du LDTg vers l’ATV régulent le freezing de manière bidirectionnelle. De la même façon, l’utilisation d’outils pharmacogénétiques dans un modèle de souris soumis à un stress social chronique nous a permis d’évaluer le rôle du LDTg dans des comportements de type dépressif. Les projections cholinergiques, mais pas glutamatergiques, du LDTg vers l’ATV sont ainsi nécessaires à l’induction des troubles de type dépressif par un stress chronique.En conclusion, ces résultats nous ont permis de mettre en évidence un rôle nouveau de l’axe LDTg-ATV dans la réponse au stress. Il est impliqué à la fois dans les réponses défensives adaptatives et les troubles comportementaux liés au stress. Ces informations pourraient aider dans le futur au développement de nouvelles thérapies innovantes basées sur la modulation des circuits cérébraux
The behavioural stress response is an adaptive mechanism that allows an organism to cope with threatening environmental stimuli. However, the circuitries that underlie it can be deregulated by intense or chronic stress and lead to maladaptive neuropsychiatric disorders. The ventral tegmental area (VTA) is a midbrain region that plays a crucial role in reward and aversion processing. It also influences the stress response, but our understanding of its role is still limited as the regulatory inputs that shape its activity during stress remain largely unknown. The laterodorsal tegmental nucleus (LDTg) is a brainstem structure regulating VTA activity. While its influence on reward processing has been widely described, its role in the stress response has yet to be determined.This thesis explores the role of the LDTg in two types of stress responses: 1) Adaptive defensive behaviours under acute stress. 2) Maladaptive behaviours following chronic stress. To assess the role of the LDTg in both contexts, we used chemogenetic and optogenetic tools to modulate its activity in mice during stressful situations and observed how it altered their behavioural responses.By using acute electrical shocks, we measured the influence of the LDTg over the freezing defensive response, an adaptive behaviour in mice confronted to an unseen threat. By selectively inhibiting LDTg projections of various natures and to different targets, we unravelled a new GABAergic LDTg-VTA pathway that bidirectionally modulates freezing in response to acute stress. Similarly, we used selective chemogenetic silencing in a mouse model of chronic social defeat to assess the role of the LDTg in stress-related depressive-like disorders. Cholinergic, but not glutamatergic, LDTg projections to the VTA were sufficient and necessary to induce depressive-like disorders after chronic stress. Together, these results unravel a new role of the LDTg-VTA axis in the regulation of the stress response. We show it is involved in both adaptive defensive behaviours and maladaptive stress-related disorders through converging yet different pathways. This may open a new therapeutic window for innovative treatments based on cerebral modulation
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Bourke, Alexandre. « Étude de la désorption thermique laser sur un dépôt de polytétrafluoroéthylène dans une source ionique LDTD ». Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26290/26290.pdf.

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4

Capone, Georgina. « Staff and service users' evaluations of therapeutic principles at a High Secure Learning Disability Therapeutic Community (LDTC) ». Thesis, University of Lincoln, 2017. http://eprints.lincoln.ac.uk/29721/.

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Background: Growing evidence has been provided on the efficacy of Democratic Therapeutic Community (DTC) treatment in forensic LD populations (known as learning disability therapeutic communities, LDTC) in the form of reduced violence, personality pathology and interpersonal difficulties. Recently, the LDTC model has been introduced within a high secure setting at one of three high secure hospitals in the U.K., for males with a dual diagnosis of mild LD and PD, and produced equally successful results. While a number of outcome studies exist, on-going difficulties have remained in regard to applying a post-positivist approach to research design of Therapeutic Communities (TCs) as the approach fails to capture its matrix of interrelated treatment components. Consequently, there has been a call for investigation of processes within DTCs to identify important treatment mechanisms that support therapeutic change. While Haigh (2013) has updated the theoretical background on DTCs via formulating ‘quintessential principles’ within a given therapeutic environment the principles have not been empirically validated within a TC setting. Study aims: To explore service user and staff members’ evaluations of the quintessence principles as outlined by Haigh (2013) and identify whether any further important principles exist within the social climate of the LDTC that were not captured by current TC theory. Design: A single case study design was employed, with the ‘case’ being defined as the LDTC based at one of three high secure hospitals in the U.K. A qualitative approach was employed within the case study to enable initial analysis of TC members’ experience of therapeutic principles, any additional principles and to also permit identification of any shared experiences. The results of the qualitative analysis were used to develop a set of statements that can be used by future research to determine the importance of existing TC principles and additional elements identified in qualitative findings to TC members. Method: A qualitative approach was employed to enable analysis of TC members’ experience and evaluation of therapeutic principles in addition to identification of shared experiences. Data were collected via semi-structured interviews with 12 participants (6 staff members and 6 service users). The interview transcripts were initially analysed via deductive content analysis (Mayring, 2001) in order to identify whether Haigh’s (2013) quintessence principles were evident in the LDTC. Inductive thematic analysis (Braun & Clarke, 2006) was then performed on remaining data, which also involved completion of saliency analysis (Buetow, 2010) in the final stage to justify selection of themes and ensure identification of codes that did not recur but remained important to the research questions posed. Results: The deductive content analysis identified all five quintessence principles were experienced in the LDTC environment by staff and service users. Some limits to the principle of ‘agency’ were highlighted, with specific reference to difficulties implementing a flattened hierarchy in a forensic setting. Additional themes were identified via inductive thematic analysis and a saliency analysis indicated the following themes as both important and recurrent; security and risk, responsivity, trust, more physical freedom. Further themes that were identified as important but not recurrent within the saliency analysis included: staff fit with LDTC, moving on, being reflective. The theme of security and risk was specifically related to the context of the LDTC functioning in a high secure environment and ‘trust’ was understood to fall within Haigh’s (2013) conceptualization of the containment quintessence principle. While the remaining themes may not primarily contribute to the experience of secondary emotional development outlined by Haigh’s (2013) five quintessence principles they remain important considerations within therapeutic environments in light of their role in facilitating enactment of TC principles within secure environments, such as the LDTC. Conclusions: This is the first research paper that has attempted to test whether Haigh’s (2013) quintessence principles are evident within a given therapeutic community. The single case study provides empirical evidence for the quintessence principles in a novel TC setting along with further elements in the environment that help support implementation of quintessence principles. Fundamentally, the study suggests important recommendations for future research.
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Landes, Jasmin K. « Hemispheric differences in the temporal updating in short narrative situation models using a LDT ». Thesis, Landes, Jasmin K. (2011) Hemispheric differences in the temporal updating in short narrative situation models using a LDT. Honours thesis, Murdoch University, 2011. https://researchrepository.murdoch.edu.au/id/eprint/10608/.

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Recent research into situation model representations has demonstrated the neglect of the temporal dimension relative to the remaining dimensions that govern the formation of situation model representations. Furthermore, literature has recently demonstrated right hemisphere (RH) involvement in the processing, integrating and revising of semantic information. For the purpose of gaining a cohesive understanding of situation models and the mechanisms involved in their formation, the present study aimed to investigate whether the RH hosts at least the temporal dimension of situation model representations. Thirty-four right-handed psychology students from Murdoch University participated in a computerised go-nogo lexical decision task (LDT) in which participant reaction time and error rates were documented. Temporal shifts in situation model representations were controlled for by presenting participants with short narrative passages that included short or long temporal adverbials or none at all during baseline/ neutral condition. Words and non-words were projected to the left visual field (LVF)/RH, the central visual field (CVF) and the right visual field/ left hemisphere (RVF/LH). Contrary to the hypotheses, the results did not demonstrate any temporal shifts for targets presented to the CVF or LVF/RH, as the degree of facilitation of targets between the short and long temporal references did not vary significantly. These findings are contrary to Zwaan’s (1996) strong iconicity assumption as well as previous behavioural research to suggest temporal updating. Nonetheless, compelling theoretical support lead to the continued maintenance of the claim that temporal awareness is inherent to the LVF/RH.
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Melo, Juraj. « Aplikace pro tvorbu sad testů GUI ». Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2013. http://www.nusl.cz/ntk/nusl-236402.

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This thesis describes a system for automated GUI testing using assistive technologies for accessing and manipulating GUI elements. The only input from the user to automated test system is a description of UI events and activities. For this purpose, a specialized language is proposed. The test system then automatically generates possible sequences of UI events applying a given criterion. Generated test set is executed by Python interpreter exploiting the Linux Desktop Testing Project (LDTP). Test system described in this thesis then provides reports and coverage evaluation for particular test cases and the whole test set.
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Chapman, Valerie M. « A detailed archaeological analysis of LDF-030D (47Vi257) of the Lac du Flambeau Reservation, Vilas County, Wisconsin / ». Connect to online version, 2008. http://minds.wisconsin.edu/handle/1793/36631.

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Bergstrand, Sara. « Tissue Blood Flow Responses to External Pressure Using LDF and PPG : Testing a System Developed for Pressure Ulcer Research ». Licentiate thesis, Linköping : Department of Medical and Health Sciences, Linköping University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-51886.

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Paley, M. T. « The development of an automated optical scanning system and studies of the Earth orbital dust environment by means of the LDEF Micro Abrasion Package ». Thesis, University of Kent, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282485.

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Blachon, Gregory. « Détection et quantification du chloramphénicol dans le miel par thermodésorption laser à la pression atmosphérique couplée à la spectrométrie de masse tandem (LDTD-APCI-MS/MS) ». Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/28066/28066.pdf.

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Blachon, Grégory. « Détection et quantification du chloramphénicol dans le miel par thermodésorption laser à la pression atmosphérique couplée à la spectrométrie de masse tandem (LDTD-APCI-MS/MS) ». Master's thesis, Université Laval, 2011. http://hdl.handle.net/20.500.11794/22637.

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Le sujet de ce mémoire porte sur une nouvelle technologie, permettant d'améliorer l'utilisation d'un spectromètre de masse dans le domaine de l'analyse instrumentale de petites molécules (100 à 1200 uma), tant sur le point de vue de la rapidité d'analyse, que sur les coûts d'opérations et de maintenance. Dans un marché de plusieurs milliards de dollars, incluant entre autre l'industrie pharmaceutique, toxicologique ou environnementale, cela peut se traduire par des gains énormes. Cet instrument, la source d'ionisation LDTD (Laser Diode Thermal Desorption), a été développé entièrement par une entreprise québécoise et sera l'objet central de la présente étude en étant mis à l'essai afin de détecter et quantifier la présence dans le miel d'un résidu d'antibiotique dangereux pour l'être humain, le chloramphenicol (CAP). Lors du développement de cette méthode, une découverte particulière et fortuite a permis une amélioration de l'efficacité d'utilisation de l'appareil pour certaines applications en utilisant des acides gras comme agents exaltants. On démontrera donc l'efficacité de la source LDTD afin de détecter des niveaux de CAP aussi bas que dans les méthodes jusqu'à présent publiées, mais dans un temps d'analyse près de 100 fois plus rapide.
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Rejmstad, Peter. « Optical Monitoring of Cerebral Microcirculation ». Doctoral thesis, Linköpings universitet, Biomedicinsk instrumentteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-133781.

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The cerebral microcirculation consists of a complex network of small blood vessels that support nerve cells with oxygen and nutrition. The blood flow and oxygen delivery in the microcirculatory blood vessels are regulated through mechanisms which may be influenced or impaired by disease or brain damage resulting from conditions such as brain tumors, traumatic brain injury or subarachnoid hemorrhage (SAH). Monitoring of parameters relating to the microvascular circulation is therefore needed in the clinical setting. Optical techniques such as diffuse reflectance spectroscopy (DRS) and laser Doppler flowmetry (LDF) are capable of estimating the oxygen saturation (SO2) and tracking the microvascular blood flow (perfusion) using a fiber optic probe. This thesis presents the work carried out to adapt DRS and LDF for monitoring cerebral microcirculation in the human brain. A method for real-time estimation of SO2 in brain tissue was developed based on the P3 approximation of diffuse light transport and quadratic polynomial fit to the measured DRS signal. A custom-made fiberoptic probe was constructed for measurements during tumor surgery and in neurointensive care. Software modules with specific user interface for LDF and DRS were programmed to process, record and present parameters such as perfusion, total backscattered light, heart rate, pulsatility index, blood fraction and SO2 from acquired signals. The systems were evaluated on skin, and experimentally by using optical phantoms with properties mimicking brain tissue. The oxygen pressure (pO2) in the phantoms was regulated to track spectroscopic changes coupled with the level of SO2. Clinical evaluation was performed during intraoperative measurements during tumor surgery (n = 10) and stereotactic deep brain stimulation implantations (n = 20). The LDF and DRS systems were also successfully assessed in the neurointensive care unit for a patient treated for SAH. The cerebral autoregulation was studied by relating the parameters from the optical systems to signals from the standard monitoring equipment in neurointensive care. In summary, the presented work takes DRS and LDF one step further toward clinical use for optical monitoring of cerebral microcirculation.
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Psiakis, Rafail. « Performance optimization mechanisms for fault-resilient VLIW processors ». Thesis, Rennes 1, 2018. http://www.theses.fr/2018REN1S095/document.

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Les processeurs intégrés dans des domaines critiques exigent une combinaison de fiabilité, de performances et de faible consommation d'énergie. Very Large Instruction Word (VLIW) processeurs améliorent les performances grâce à l'exploitation ILP (Instruction Level Parallelism), tout en maintenant les coûts et la puissance à un niveau bas. L’ILP étant fortement dépendant de l'application, le processeur n'utilise pas toutes ses ressources en permanence et ces ressources peuvent donc être utilisées pour l'exécution d'instructions redondantes. Cette thèse présente une méthodologie d’injection fautes pour processeurs VLIW et trois mécanismes matériels pour traiter les pannes légères, permanentes et à long terme menant à trois contributions.La première contribution présente un schéma d’analyse du facteur de vulnérabilité architecturale et du facteur de vulnérabilité d’instruction pour les processeurs VLIW. Une méthodologie d’injection de fautes au niveau de différentes structures de mémoire est proposée pour extraire les capacités de masquage architecture / instruction du processeur. Un schéma de classification des défaillances de haut niveau est présenté pour catégoriser la sortie du processeur. La deuxième contribution explore les ressources inactives hétérogènes au moment de l'exécution, à l'intérieur et à travers des ensembles d'instructions consécutifs. Pour ce faire, une technique d’ordonnancement des instructions optimisée pour le matériel est appliquée en parallèle avec le pipeline afin de contrôler efficacement la réplication et l’ordonnancement des instructions. Suivant les tendances à la parallélisation croissante, une conception basée sur les clusters est également proposée pour résoudre les problèmes d’évolutivité, tout en maintenant une pénalité surface/énergie raisonnable. La technique proposée accélère la performance de 43,68% avec une surcoût en surface et en énergie de ~10% par rapport aux approches existantes. Les analyses AVF et IVF évaluent la vulnérabilité du processeur avec le mécanisme proposé.La troisième contribution traite des défauts persistants. Un mécanisme matériel est proposé, qui réplique au moment de l'exécution les instructions et les planifie aux emplacements inactifs en tenant compte des contraintes de ressources. Si une ressource devient défaillante, l'approche proposée permet de relier efficacement les instructions d'origine et les instructions répliquées pendant l'exécution. Les premiers résultats de performance d’évaluation montrent un gain de performance jusqu’à 49% sur les techniques existantes.Afin de réduire davantage le surcoût lié aux performances et de prendre en charge l’atténuation des erreurs uniques et multiples sur les transitoires de longue durée (LDT), une quatrième contribution est présentée. Nous proposons un mécanisme matériel qui détecte les défauts toujours actifs pendant l'exécution et réorganise les instructions pour utiliser non seulement les unités fonctionnelles saines, mais également les composants sans défaillance des unités fonctionnelles concernées. Lorsque le défaut disparaît, les composants de l'unité fonctionnelle concernés peuvent être réutilisés. La fenêtre de planification du mécanisme proposé comprend deux ensembles d'instructions pouvant explorer des solutions d'atténuation lors de l'exécution de l'instruction en cours et de l'instruction suivante. Les résultats obtenus sur l'injection de fautes montrent que l'approche proposée peut atténuer un grand nombre de fautes avec des performances, une surface et une surcharge de puissance faibles
Embedded processors in critical domains require a combination of reliability, performance and low energy consumption. Very Long Instruction Word (VLIW) processors provide performance improvements through Instruction Level Parallelism (ILP) exploitation, while keeping cost and power in low levels. Since the ILP is highly application dependent, the processor does not use all its resources constantly and, thus, these resources can be utilized for redundant instruction execution. This thesis presents a fault injection methodology for VLIW processors and three hardware mechanisms to deal with soft, permanent and long-term faults leading to three contributions. The first contribution presents an Architectural Vulnerability Factor (AVF) and Instruction Vulnerability Factor (IVF) analysis schema for VLIW processors. A fault injection methodology at different memory structures is proposed to extract the architectural/instruction masking capabilities of the processor. A high-level failure classification schema is presented to categorize the output of the processor. The second contribution explores heterogeneous idle resources at run-time both inside and across consecutive instruction bundles. To achieve this, a hardware optimized instruction scheduling technique is applied in parallel with the pipeline to efficiently control the replication and the scheduling of the instructions. Following the trends of increasing parallelization, a cluster-based design is also proposed to tackle the issues of scalability, while maintaining a reasonable area/power overhead. The proposed technique achieves a speed-up of 43.68% in performance with a ~10% area and power overhead over existing approaches. AVF and IVF analysis evaluate the vulnerability of the processor with the proposed mechanism.The third contribution deals with persistent faults. A hardware mechanism is proposed which replicates at run-time the instructions and schedules them at the idle slots considering the resource constraints. If a resource becomes faulty, the proposed approach efficiently rebinds both the original and replicated instructions during execution. Early evaluation performance results show up to 49\% performance gain over existing techniques.In order to further decrease the performance overhead and to support single and multiple Long-Duration Transient (LDT) error mitigation a fourth contribution is presented. We propose a hardware mechanism, which detects the faults that are still active during execution and re-schedules the instructions to use not only the healthy function units, but also the fault-free components of the affected function units. When the fault faints, the affected function unit components can be reused. The scheduling window of the proposed mechanism is two instruction bundles being able to explore mitigation solutions in the current and the next instruction execution. The obtained fault injection results show that the proposed approach can mitigate a large number of faults with low performance, area, and power overhead
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Najle, Maxine. « Atheists, devils, and communists cognitive mapping of attitudes and stereotypes of atheists ». Honors in the Major Thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/593.

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Negative attitudes towards atheists are hardly a new trend in our society. However, given the pervasiveness of the prejudices and the lack of foundation for them, it seems warranted to explore the underlying elements of these attitudes. Identifying these constitutive elements may help pick apart the different contributing factors and perhaps mitigate or at least understand them in the future. The present study was designed to identify which myths or stereotypes about atheists are most influential in these attitudes. A Lexical Decision Task was utilized to identify which words related to popular stereotypes are most related to the label atheists. The labels Atheists, Christians, and Students were compared to positive words, negatives words, words or interests, neutral words, and non-word strings. Analyses revealed no significant differences among the participants' reaction times in these various comparisons, regardless of religion, level of belief in god, level of spirituality, or being acquainted with atheists. Possible explanations for these results are discussed in this thesis.
B.S.
Bachelors
Sciences
Psychology
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Alves-Soares, Leonardo. « Investigating the Portuguese-English Bilingual Mental Lexicon : Crosslinguistic Orthographic and Phonological Overlap in Cognates and False Friends ». Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41153.

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This dissertation investigates how cognates are organized in the bilingual mental lexicon and examines whether orthography in one language, via phonological representations, influences the processing of cognates and false friends in the other language. In light of the framework of two well-known models of bilingual visual word recognition, the Bilingual Interactive Activation (BIA) and the Bilingual Interactive Activation Plus (BIA+), the premise is that there is activation from orthography to phonology across a bilingual’s two languages and that this activation is modulated by the degree of orthographic and phonological code overlap. Two objective metrics were used to assess crosslinguistic similarity of Portuguese-English cognates and false friends that were selected for a cross-language lexical decision task with masked priming. Dynamic time warping (DTW), an algorithm that was originally conceived to compare different speech patterns in automatic speech recognition and to measure acoustic similarity between two time-dependent sequences, was used to compute crosslinguistic phonological similarity. The Normalized Levenshtein Distance (NLD), an algorithm that calculates the minimum number of single-character insertions, deletions or substitutions required to change one word into another and normalizes the result by their lengths, was used to compute crosslinguistic orthographic similarity. Portuguese-English bilinguals who acquired their second language after reaching puberty, and English functional monolinguals who grew up speaking primarily English were recruited to participate in the experimental task. Based on collected reaction time and accuracy data, mixed-effects models analyses are used to estimate the individual effects of crosslinguistic orthographic, phonological and semantic similarity and the role each of them, along with English proficiency, word frequency and length play in the organization of the Portuguese-English bilingual mental lexicon.
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16

PASQUA, IRENE. « Significato clinico dell'espressione della proteina ZAP-70 nelle leucemie linfatiche croniche ». Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2009. http://hdl.handle.net/2108/1024.

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L’apoptosi e il ciclo cellulare privi di normali controlli sono i principali motivi che determinano la mancata risposta dell’LLC nei confronti della chemioterapia convenzionale. Nella LLC-B sembra che il ciclo cellulare sia arrestato alla fase G0/G1, l’inibizione della spontanea apoptosi e l’up-regolazione dell’espressione della proteina anti-apoptotica bcl-2 definisce la prognosi clinica. Comunque, esistono delle evidenze che la progressione della malattia è correlate con il ciclo cellulare delle cellule nella LLC-B: un pool di cellule proliferanti è stato riscontrato nei linfonodi e nel midollo osseo e potrebbe rifornire il pool di cellule in accumulo nel sangue periferico. Inoltre, la presenza di mutazioni nel gene che codifica per le catene leggere delle immunoglobuline (Ig) VH si correla con una rapida progressione di malattia (DP) ed una ridotta sopravvivenza (OS) (Damle, Hamblin, 1999). Le cellule B di pazienti affetti da LLC che presentano geni IgVH non mutati esprimono l’RNA ZAP 70 che codifica per la proteina ZAP-70, una proteina tirosin chinasi di 70-kDa, che ha proprietà di molecola segnale, associata ad un incremento delle cellule B e ad un aumento del rischio di progressione della malattia nella LLC-B. (Del Principe, 2006). Inoltre, ad oggi la disponibilità di rinfamicina o inibitori dei proteosomi contro la proliferazione di cellule B nella LLC e l’uso di oligonucleotidi antisenso bcl-2 ci ha suggerito di valutare il reale impatto del meccanismo dell’apoptosi e della proliferazione sulla prognosi della LLC-B. I principali scopi del nostro studio sono stati: 1) determinare la sopravvivenza libera da progressione (PFS) rispetto all’apoptosi/proliferazione e all’espressione di ZAP-70; 2) se l’apoptosi/proliferazione potrebbe predire percorsi alternativi all’interno del gruppo che presenta ZAP-70; e infine 3) se ZAP-70 e il gruppo apoptosi/proliferazione erano indipendenti da fattori prognostici. Perciò noi abbiamo analizzato 265 pazienti, età mediana di 64 anni (range 37-84), 136 maschi e 129 femmine. In riferimento alla stadio Rai modificato, 87 pazienti avevano un basso stadio, 170 uno stadio intermedio e 8 un alto stadio. ZAP-70 fu quantificato mediante citometria a flusso multicolour utilizzando il metodo di fissaggio e permeabilizzazione ritenendo significativo un valore superiore al 20%. Anche Bcl-2 fu determinata attraverso la citometria a flusso, dividendo per la media dell’intensità di fluorescenza (MFI) delle cellule CD19+B-CLL / MFI delle cellule T (Bcl-2B/T). La threshold fu settata ad un valore mediano >1.6. Il recettore per la Transferrina (CD71) fu utilizzato come stima della proliferazione e la threshold fu settata ad un valore mediano >8%. Combinando Bcl-2B/T con CD71 (Bcl2CD71) sono stati ottenuti tre sottogruppi: 1) Bcl2CD71- [106 pts] con basso livello di proliferazione (CD71 <8%) e alta apoptosi (Bcl-2B/T <1.6); 2) Bcl2CD71+ [49 pts] con alta proliferazione (CD71>8%) e bassa apoptosi (Bcl-2B/T >1.6); e 3) Bcl2CD71+/- [110 pts] con bassa proliferazione e bassa apoptosi oppure con alta proliferazione e alta apoptosi. I pazienti affetti da LLC-B ZAP-70+ erano 95/265 (36%). In 111 pazienti studiati l’espressione di ZAP-70 e lo stato mutazionale del gene Ig V gene erano significativamente correlati (p<0.00001). Inoltre, noi trovammo una significativa associazione sia tra bassi livelli di ZAP-70 e basso Bcl-2B/T index (p=0.001) o basso livello di ZAP-70 e Bcl2CD71- (p=0.002), confermando che bassi livelli di ZAP-70 erano caratterizzati da elevata apoptosi e bassa proliferazione. In riferimento al decorso clinico, una significativa più corta sopravvivenza libera da progressione (PFS) fu osservata nei pazienti ZAP-70+ vs pazienti ZAP-70 negative (0% vs 58% a 13 anni; p<0.00001) e in pazienti Bcl2CD71+ vs pazienti Bcl2CD71- (10% vs 56% a 12 anni; p<0.00001). Il sottogruppo Bcl2CD71+/- mostrava un decorso intermedio (30% a 12 anni). Per analizzare ulteriormente l’impatto prognostico dell’indice Bcl2CD71, noi valutammo la sua espressione all’interno dei pazienti ZAP70+ (95 pts) e ZAP70- (170 pts). In realtà, Bcl2CD71 non fu in grado di identificare un livello prognostico all’interno dei pazienti ZAP-70+, perchè tutti questi pazienti presentavano una più corta PFS senza significative differenze. Del resto, questo indice identifica un livello differente di PFS all’interno del sottogruppo ZAP-70 negativo (73% dei pazienti per Bcl2CD71- vs 29% dei pazienti per Bcl2CD71+ a 12 anni, p=0.00009). Operando una analisi multivariata della PFS, nella quale l’età, lo stadio di Rai modificato, CD38, CD23 solubile (sCD23), raddoppiamento dei linfociti (LDT), Bcl-2CD71 e ZAP-70, ZAP-70 (p=0.00005), LDT (p=0.006), stadio Rai modificato (p=0.03) e sCD23 (p=0.01) risultarono essere dei fattori prognostici indipendenti. Inoltre, si confermò che ZAP-70 era il principale fattore prognostico indipendente con riferimento alla PFS. Del resto, il nostro indice apoptosi/proliferazione (Bcl2CD71), eseguito utilizzando la citometria a flusso, fu molto utilizzato per identificare pazienti a differenti livelli di progressione all’interno del sottogruppo ZAP-70 negativo. Dal momento che ZAP-70 negativo rappresenta un ampio ed eterogeneo gruppo della popolazione di LLC-B con una progressione variabile, altri fattori biologici, come il livello di apoptosi e di proliferazione, devono essere considerati in modo che insieme possano identificare più facilmente i pazienti in progressione e dare modo di prendere in tempo una accurata decisione terapeutica.
Dysfunctional apoptosis and cell cycle are the main reasons for the clinical enigma, that CLL can not yet be cured with conventional chemotherapy. In B-CLL, malignant cells seem to be arrested in the G0/early G1 phase of the cell cycle, and inhibition of spontaneous apoptosis and upregulation of the anti-apoptotic protein bcl-2 define clinical prognosis. However, increasing evidence exists that disease progression relies upon cycling B-CLL cells: a proliferating pool of cells has been described in lymph nodes and bone marrow and might feed the accumulating pool in the blood. Moreover, the lack of immunoglobulin (Ig) VH gene mutation also has been shown to predict a rapid disease progression (DP) and an inferior overall survival (OS) (Damle, Hamblin, 1999). B-CLL cells that use non-mutated IgVH genes express ZAP-70 RNA, which encodes ZAP-70, a 70-kDa protein tyrosine kinase, associated both with an enhanced B cell receptor signaling and with an early DP risk in B-CLL (Del Principe, 2006). Moreover, the today availability of rapamycin or proteasome inhibitors effective against proliferating B-CLL cells and bcl-2 antisense oligonucleotides prompted us to evaluate the real impact of proliferation and apoptosis pathways on B-CLL prognosis. The primary aims of our study were: 1) to determine progression-free survival (PFS) upon apoptosis/proliferation subgroups and ZAP-70 expression; 2) whether apoptosis/proliferation could predict varied outcome within ZAP-70 subgroups; and finally 3) whether ZAP-70 and apoptosis/proliferation groups were independent prognostic factors. Therefore we investigated 265 pts, median age 64 years (range 37-84), 136 males and 129 females. With regard to modified Rai stages, 87 patients had a low stage, 170 an intermediate stage and 8 a high stage. ZAP-70 was quantified by a multicolor flow cytometric method fixing a cut-off value of 20%. Bcl-2 was determined by flow cytometry, dividing mean fluorescence intensity (MFI) of CD19+B-CLL cells / MFI of T-cells (Bcl-2B/T). The threshold was set at the median value >1.6. Transferrin receptor (CD71) was used as a measure of the proliferation and the threshold was set at the median value >8%. Combining Bcl-2B/T with CD71 (Bcl2CD71) we enucleated three subgroups: 1) Bcl2CD71- [106 pts] with low proliferation (CD71 <8%) and high apoptosis (Bcl-2B/T <1.6); 2) Bcl2CD71+ [49 pts] with high proliferation (CD71>8%) and low apoptosis (Bcl-2B/T >1.6); and 3) Bcl2CD71+/- [110 pts] with low proliferation and low apoptosis or with high proliferation and high apoptosis. ZAP-70+ B-CLL patients were 95/265 (36%). In 111 studied pts ZAP-70 expression and Ig V gene mutational status were significantly correlated (p<0.00001). Furthermore, we found significant associations either between lower ZAP-70 and lower Bcl-2B/T index (p=0.001) or lower ZAP-70 and Bcl2CD71- (p=0.002), confirming that low levels of ZAP-70 were characterized by high apoptosis and low proliferation. With regard to clinical outcome, a significant shorter progression-free survival (PFS) was observed in ZAP-70+ pts vs ZAP-70 negative pts (0% vs 58% at 13 years; p<0.00001) and in Bcl2CD71+ pts vs Bcl2CD71- pts (10% vs 56% at 12 years; p<0.00001). The Bcl2CD71+/- subgroup showed an intermediate outcome (30% at 12 years). To further explore the prognostic impact of Bcl2CD71 index, we investigated its expression within ZAP70+ (95 pts) and ZAP70- (170 pts) subsets. As a matter of fact, Bcl2CD71 was not able to identify prognostic subsets within ZAP-70+ pts, because all these cases presented a shorter PFS without significant differences. On the other hand, this index identified subsets at different PFS within the ZAP-70 negative subgroup (73% for Bcl2CD71- pts vs 29% for Bcl2CD71+ at 12 years, p=0.00009). In multivariate analysis of PFS, in which age, Rai modified stages, CD38, soluble CD23 (sCD23), lymphocyte doubling time (LDT), Bcl-2CD71 and ZAP-70 entered, ZAP-70 (p=0.00005), LDT (p=0.006), Rai modified stages (p=0.03) and sCD23 (p=0.01) resulted to be independent prognostic factors. Therefore, ZAP-70 was confirmed as the most important indipendent prognostic factor with regard to PFS. However, our apoptotic/proliferative index (Bcl2CD71), performed by flow cytometry, was very useful to identify pts at different progression rate within the ZAP-70 negative subgroup. Since the ZAP-70 negative subset represents a large and heterogeneous B-CLL population with a variable progression, other biological factors, such as the amount of apoptosis and the proliferative rate, have to be added in order both to identify early progressive pts and to take timely accurate therapeutic decisions.
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Lemoine, Pascal. « Analyse quantitative des cyanotoxines d'eau douce par LDTD-APCI-MS/MS ». Thèse, 2010. http://hdl.handle.net/1866/4265.

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Avec la hausse mondiale de la fréquence des floraisons de cyanobactéries (CB), dont certaines produisent des cyanotoxines (CT), le développement d’une méthode de détection/quantification rapide d’un maximum de CT s’impose. Cette méthode permettrait de faire un suivi quotidien de la toxicité de plans d’eau contaminés par des CB et ainsi d’émettre rapidement des avis d’alerte appropriés afin de protéger la santé publique. Une nouvelle technologie utilisant la désorption thermique induite par diode laser (LDTD) couplée à l’ionisation chimique sous pression atmosphérique (APCI) et reliée à la spectrométrie de masse en tandem (MS/MS) a déjà fait ses preuves avec des temps d'analyse de l’ordre de quelques secondes. Les analytes sont désorbés par la LDTD, ionisés en phase gazeuse par APCI et détectés par la MS/MS. Il n’y a donc pas de séparation chromatographique, et la préparation de l’échantillon avant l’analyse est minimale selon la complexité de la matrice contenant les analytes. Parmi les quatre CT testées (microcystine-LR, cylindrospermopsine, saxitoxine et anatoxine-a (ANA-a)), seule l’ANA-a a généré une désorption significative nécessaire au développement d’une méthode analytique avec l’interface LDTD-APCI. La forte polarité ou le poids moléculaire élevé des autres CT empêche probablement leur désorption. L’optimisation des paramètres instrumentaux, tout en tenant compte de l’interférence isobarique de l’acide aminé phénylalanine (PHE) lors de la détection de l’ANA-a par MS/MS, a généré une limite de détection d’ANA-a de l’ordre de 1 ug/L. Celle-ci a été évaluée à partir d’une matrice apparentée à une matrice réelle, démontrant qu’il serait possible d’utiliser la LDTD pour effectuer le suivi de l’ANA-a dans les eaux naturelles selon les normes environnementales applicables (1 à 12 ug/L). Il a été possible d’éviter l’interférence isobarique de la PHE en raison de sa très faible désorption avec l’interface LDTD-APCI. En effet, il a été démontré qu’une concentration aussi élevée que 500 ug/L de PHE ne causait aucune interférence sur le signal de l’ANA-a.
Within the context of the worldwide increasing frequency of cyanobacterial (CB) blooms, some containing cyanotoxins (CT), the development of a detection/quantification method for the fast analysis a maximum of CT is necessary. This method would allow daily tracking of the toxicity of CB-contaminated water such that, as warranted, appropriate measures can be taken quickly to protect public health. A new technology using laser diode thermal desorption (LDTD) coupled to atmospheric pressure chemical ionization (APCI)-tandem mass spectrometry (MS/MS) has shown great potential to reduce analysis time to seconds. Analytes are desorbed by the LDTD, ionized in gas-phase by APCI and detected by MS/MS. Therefore, there is no chromatographic separation and sample treatment prior to analysis is minimal, depending on the complexity of the sample matrix. Among the four CT tested (microcystin-LR, cylindrospermopsin, saxitoxin and anatoxin-a (ANA-a)), only ANA-a exhibited sufficient desorption which is necessary to develop an analytical method with the LDTD-APCI interface. The strong polarity or high molecular weight of the other CT probably inhibited their efficient desorption. Optimization of instrumental parameters, while accounting for the isobaric interference caused by the acid amino phenylalanine (PHE) in the detection of ANA-a by MS/MS, generated a detection limit of the order of 1 ug/L ANA-a. This value was obtained in a simulated natural matrix, demonstrating that it would be possible to use LDTD to monitor ANA-a in natural waters within the range of current applicable environmental guidelines (1 to 12 ug/L). Because PHE desorption is limited with the LDTD-APCI interface, this method avoids its interference on ANA-a analysis, even at PHE concentrations as high as 500 ug/L.
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Tsai, Ming-Lun, et 蔡明倫. « Verification and Calibration of Laser Doppler Flowmetry(LDF) Prototype ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/74033163793889573014.

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博士
國立中央大學
資訊工程學系
104
In recent years, many researchers have paid attention to health problem in the world. Non-invasive measurement methods were applied to detect health prob lems. Laser Doppler flowmetry (LDF), a non-invasive method, is used to measure red blood cells in a tissue. Researchers used LDF to do research in medicine, and they found that the microcirculation and health condition are closely related. Therefore, LDF is very applicable to healthcare. However, the commercial LDF machines are very expensive and hard to obtain, which lead to very few relevant application and popularization. In this thesis, continuing previous researches, a LDF Prototype was built by electronic materials which can be purchased com mercially; Further, we design an accurate mathematical regression analysis model to calibrate feature of LDF prototype, and we hope to match with business LDF feature. On verification and calibration of the LDF signal feature, we compared the data obtained by business LDF model and LDF prototype to establish a model for calibrating error. We took the center of forefinger as the measure point and measured the signal layer and feature layer. The result of the experiment showed that before calibration, the correlation coefficient of physiological feature is about 0.7, and after we used our Regression Model to calibrate physiological feature, the correlation coefficient reached nearly 0.9999, which was close to a perfect positive correlation. The overall evaluation results showed that the proposed method can verify and insure the correctness of the LDF prototype. Also, LDF prototype can obtain high correlation with business LDF after calibration. The results of this thesis that can help LDF prototype into the commercial ization stage. Since the LDF prototype only cost about fifty thousand NTD, and the estimated cost can be further reduced after the mass production. This price is highly competitive comparing to business LDF. Through regression model to cal ibrate it in this thesis, the applications of all business LDF can be directly applied in the LDF prototype. Therefore, the result of this thesis, the LDF prototype can significantly reduce the cost, and promote popularization to use in medical insti tutions, fitness centers, etc. In addition, the application on the wearable device is also promising. The LDF prototype can be built into integrated circuits that can reduce the size to a single IC. If it is successfully implemented, the LDF prototype IC can be plugged in wearable device. For instance, smart glasses, smart watch, smart clothing and smart pants, etc. The LDF application can be more popular ized, and it has a positive contribution to the action care, remote medical, aging society.
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Huang, Shih-Min, et 黃世銘. « Study on microcirculation of acupuncture point monitored by LDF signal ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36246978478093307001.

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碩士
元智大學
電機工程學系
95
Meridian and acupuncture are important concept in Chinese traditional medicine. There have been many methods to observe the characteristics in acupoint, for example, electrical resistance or temperature measurement in human skin. In this study we try to extract the microcirculatory property of acupuncture point by laser Doppler flowmetry. We performed three groups of experiment to compare the measurement flux between acupoint and non-acupoint. Which include He-Gu(Li4) and Yang-Xi(Li5) in Group A, He-Gu and San-Jian(Li3) in Group B, and Jing-Gu(B46) and Shu-Gu(B45) in Group C. The results revealed that the average LDF flux signal on acupoint is larger than that on non-acupoint, with p all smaller than 0.05 by paired t-test. If implies that, there may exist a more abundant microcirculatory perfusion on acupoint.
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Soares, Rui Alexandre Paixão. « Plano de negócios para o produto LDT - Large Distribution Transformer ». Master's thesis, 2010. http://hdl.handle.net/10071/2777.

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O segmento da energia caracteriza-se por ser um mercado bastante competitivo especialmente na área da produção/distribuição de energia. Não é esperado nenhuma “revolução” na descoberta de novas formas que possam alterar a forma como é transportada/produzida a energia, no entanto novos produtos que aumentem a performance, qualidade, fiabilidade e baixem os custos irão marcar pela diferença. A Fábrica de transformadores do Sabugo pertencente ao grupo Siemens, produz transformadores para diversos países do mundo: África do Sul, Líbia, Espanha, China, Filipinas, Reino Unido, Alemanha, etc., e naturalmente Portugal. Num mercado constantemente solicitado, a Fábrica de transformadores do Sabugo debate-se para apresentar transformadores de elevada qualidade e fiabilidade em concorrência directa com outros fabricantes. Entre os seus produtos destacam-se transformadores de potência até 250 MVA, 245 kV, mas também os mais pequenos SILFOS que se encontram no interior de cada aerogerador de muitos parques eólicos. Usando parte da capacidade de produção existente, com a realização de pequenos investimentos, utilizando o espaço disponível actual e conduzindo algumas estruturações de layout permitirá criar condições para a produção de um novo produto denominado LDT que servirá de incremento ao valor de vendas total da Fábrica de transformadores do Sabugo. É neste âmbito que se enquadra este projecto através da comercialização do LDT - Large Distribution Transformer que oferece o melhor dos conceitos dos transformadores de potência e distribuição: · Performance de um transformador de potência; · Simplicidade; · Estandardização; · Racionalização de custos; · Dimensões dos transformadores de distribuição.A custos compatíveis com o orçamento do cliente, pode encomendar-se um transformador de potência de média dimensão, com a garantia de qualidade Siemens, a preços mais competitivos e com melhores prazos de entrega. Este plano de negócios contribuirá para alavancar a comercialização deste produto na Europa, mercado onde irá ser focado a sua comercialização, auxiliando o Director de vendas na sua análise de mercado. A recolha de informação referente ao mercado não se mostrou fácil, dado o produto LDT estar entre duas classes de produto (potência e distribuição) e ser um produto numa fase inicial de crescimento e definição, resultando que muita da informação obtida resultou dos briefings realizados com o director de vendas da Siemens e da informação recolhida de relatórios de mercado obtidos. Com a realização deste projecto, verifica-se a existência de uma oportunidade real e potencial, a avaliação do projecto é bastante oportuna, tendo em conta que apresenta um Valor Actual Líquido (VAL) de 3.375.090€, o que revela que o projecto é economicamente viável, remunerando a uma Taxa Interna de Rentabilidade (TIR) de 64%.
The segment of the energy is characterized by being especially a competitive market in the area of the production/distribution of energy. Is not expected any "revolution" in the discovery of new ways that could change the form how the energy is transported/produced, however new products that could increase the performance, quality, reliability and lower the costs will mark for the difference. The transformers factory of Sabugo belongs to the Siemens group and produces transformers for several countries of the world: South Africa, Libya, Spain, China, Philippines, United Kingdom, Germany, etc., and naturally Portugal. In a market constantly requested, the transformers factory of Sabugo struggles to present transformers with high quality and reliability in direct competition with other manufacturers. Among is products stand out the power of the transformers up to 250 MVA, 245 kV, but also the smallest SILFOS which are inside each aerogerador of many eolic parks. Using part of the existent production capacity and with the accomplishment of small investments, using the available space and leading some layout structuration will allow to create conditions for the production of a new denominated product LDT - Large Distribution Transformer, that will provide increment to the total value of sales of the transformers factory of Sabugo. It is in this field that this project is framed through the commercialization of LDT that offers the best of the concepts of the power and distribution transformers: · Performance of a power transformer; · Simplicity; · Standardization; · Rationalization of costs; · Dimensions of the distribution transformers. At compatible costs with the customer's budget, a power transformer of average dimension can be ordered, with the Siemens quality warranty, at more competitive prices and with better delivery times.This businesses plan will contribute to boost the commercialization of this product in the Europe market where will be focused is commercialization, aiding the sales director in is market analysis. The obtention of information regarding the market didn’t show easy, since the LDT product is between two product classes (power and distribution) and is a product in an initial phase of growth and definition, from that results that much of the obtained information resulted from the realized briefings with the sales Director of Siemens and from information obtained of market reports. With the accomplishment of this project, is verified the existence of a real and potential opportunity, the evaluation of this project is quite opportune, considering that it presents an Net Present Value (NPV) of 3.375.090€, which reveals that the project is economically viable, remunerating with an Internal Rate of Return (IRR) of 64%.
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Lin, Ying-chun, et 林盈君. « Neighborhood Size Effect of Chinese Word Recognition in LDT and Reading ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/13861073057788842730.

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碩士
國立陽明大學
神經科學研究所
95
本研究是探討鄰項個數多寡對中文雙字詞詞彙辨識歷程的影響。實驗一及實驗二操弄詞頻和雙字詞首字的鄰項個數(N1),實驗一進行詞彙判斷作業,在反應時間上得到顯著的鄰項個數促進效應,鄰項多對於目標詞的辨識有幫助,在低頻詞尤其顯著。實驗二以眼動儀記錄文句閱讀作業的眼動資料,在早期指標上(skipping rate及gaze duration)看到鄰項個數促進效應,在晚期指標上(regression rate)看到鄰項個數抑制效應,指出詞彙辨識歷程的早期與晚期可能有不同的內在處理歷程。 實驗三、四採低頻詞,操弄目標詞首字的鄰項個數(N1)與詞素意義個數(M1),實驗作業採取詞彙辨識作業(實驗三)與閱讀作業(實驗四)。實驗三、四結果推測,詞素意義個數多與少的目標詞可能有不同處理歷程,詞素意義個數少,詞義單純的情況下,語義層面的影響較小,容易彰顯鄰項個數效應,清楚看到鄰項個數對詞彙辨識歷程早期促進、晚期抑制的結果,與實驗一、二的結果一致。 詞素意義個數多的目標詞處理狀況比較複雜,鄰項個數多的目標詞錯誤率高,呈現抑制的鄰項個數效應(實驗三),似乎顯示選擇的困難度較高;然而實驗四晚期指標regression rate上看到交互作用,在詞素意義個數多的情況下,鄰項個數多的目標詞,逆向凝視的比例較少(鄰項個數促進效應),也許在選擇困難度高的情況下也比較不易有錯認的情況發生。這些推測有待更進一步的研究繼續探討。
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22

« Étude de la désorption thermique laser sur un dépôt de polytétrafluoroéthylène dans une source ionique LDTD ». Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26290/26290.pdf.

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23

Darwano, Hicham. « Développement d’une méthode d’extraction des contaminants émergents dans les solides particulaires par LDTD-APCI-MS/MS ». Thèse, 2013. http://hdl.handle.net/1866/10599.

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Douze contaminants émergents (composés pharmaceutiques, pesticides et hormones) ont été quantifiés et extraits de l'eau de rivières et d’échantillons d'eaux usées municipales. La séparation des solides en suspension est effectuée par filtration des échantillons d'eau. L'effet de filtration sur les concentrations de contaminants dissous a été évaluée afin de minimiser les pertes de composés cibles. Les échantillons ont été lyophilisés et ont été extraits en deux cycles par ultrasons combinés avec une étape de nettoyage sur cartouche d’extraction de type C18. La quantification a été réalisée en utilisant la spectrométrie de masse. Les recouvrements de la méthode pour tous les composés ont varié de 68 à 112% dans toutes les matrices étudiées, sauf pour le sulfaméthoxazole et le diclofénac où des recouvrements plus modestes ont été obtenus (38 à 85%). Les limites de détection pour les 12 analytes dans les sédiments et particules en suspension (SPM) de la rivière variaient de 0,7 à 9,4 ng g-1 et de 21 à 92 ng g-1, pour les échantillons SPM de station d'épuration. Tous les contaminants émergents cibles ont été détectés à des concentrations variant de 3 à 5440 ng g-1 dans les matrices étudiées, les concentrations les plus élevées ont été observées dans les échantillons SPM de stations d'épuration. Une partie importante de certains de ces contaminants est clairement associée aux sédiments de rivière ou aux particules en suspension. L’optimisation des processus de traitement de l'eau et le devenir environnemental doit absolument tenir compte de la fraction de contaminants qui liée à des particules si on espère avoir un bilan de masse raisonnable.
We developed a protocol to quantify 12 emerging contaminants (pharmaceuticals and hormones) and pesticides extracted from suspended particulate matter (SPM) of river water and municipal wastewaters samples. The separation of suspended solids was carried through filtration of water samples. We tested a series of 6 different filter types. The effect of filtration on the concentrations of dissolved contaminants was evaluated in order to minimize losses of target compounds. The river bottom sediments samples were lyophilized and both SPM and sediment samples were subjected to ultrasonic extraction combined with C18 cartridge clean-up. Quantifications were realized using mass spectrometry. The overall method recoveries of all compounds ranged from 38 to 112 % in all studied matrices, poor recoveries were achieved for sulfamethoxazole and diclofenac (recoveries for all other compounds in the wastewater treatment plant (WWTP) samples were 68 to 111%). The detection limits in sediments and SPM from river samples for the 12 analytes varied from 0.7 to 9.4 ng g-1 and from 21 to 92 ng g-1 for WWTP SPM samples. All target emerging contaminants were detected with concentrations ranging from 3 to 5440 ng g-1 in the studied matrices, with the highest concentrations observed in WWTP SPM samples. A significant portion of some of those contaminants is clearly associated with bottom sediments or suspended particulates. Optimization of water treatment processes and environmental fate must absolutely consider the fraction of contaminants which is particulate-bound if one hopes to have a reasonable mass balance.
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Tsai, Cheng-che, et 蔡政哲. « Customer Retention Prediction Using LDF and Decision Tree for a Metal Company in Taiwan ». Thesis, 2007. http://ndltd.ncl.edu.tw/handle/99914466659774401585.

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碩士
國立成功大學
國際管理碩士在職專班
95
The category of this research could be defined as database marketing. That purpose is looking for what determinant shall responsible for customer staying and switching. A vast quantity of customer-related data from ERP is cited for analysis. It is described and identified by eleven predictors (or variables). We set up the certain period, Y2003 ~ Y2006, for selection of two samples from the population. The one is “All Customers”, the other is “Top 20 customers”. The customer will be separated as two groups; stayer and switcher. The discriminant analysis is used in order to find out the significant predictors for customer retention program. Those significant predictors is applied by independent sample-t test for demonstration the difference in two groups. It presents a linear equation for manager to predict customer churn according to the interaction with customer in a certain period. Finally, the significant variable is used by decision tree method. The purpose is to present managerial rules for manger to evaluate the performance of customer retention program time by time and take action to retain if any unusual result in a certain period.
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Zhang, Ke. « Towards Outlier Detection For Scattered Data and Mixed Attribute Data ». Master's thesis, 2010. http://hdl.handle.net/1885/110539.

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Detecting outliers which are grossly different from or inconsistent with the remaining dataset is a major challenge in real-world knowledge discovery and data mining (KDD) applications. The research work in this thesis starts with a critical review on the latest and most popular methodologies available in outlier detection area. Based on a series of performance evaluation of these algorithms, two major issues that exist in outlier detection, namely scattered data problem and mixed attribute problem, are identified, and then being further addressed by the novel approaches proposed in this thesis. Based on our review and evaluation it has been found that the existing outlier detection methods are ineffective for many real-world scatter datasets, due to the implicit data patterns within these sparse datasets. In order to address this issue, we define a novel Local Distance-based Outlier Factor (LDOF) to measure the outlierness of objects in scattered datasets. LDOF uses the relative location of an object to its neighbours to determine the degree that the object deviates from its neighbourhood. The characteristics of LDOF are theoretically analysed, including LDOF's lower bound, false-detection probabilities, as well as its parameter range tolerance. In order to facilitate parameter settings in real-world applications, we employ a top-n technique in the proposed outlier detection approach, where only the objects with the highest LDOF values are regarded as outliers. Compared to conventional approaches (such as top-n KNN and top-n LOF), our method, top-n LDOF, proved more effective for detecting outliers in scattered data. The parameter settings for LDOF is also more practical for real-world applications, since its performance is relatively stable over a large range of parameter values, as illustrated by experimental results on both real-world and synthetic datasets. Secondly, for the mixed attribute problem, traditional outlier detection methods often fail to effectively identify outliers, due to the lack of the mechanisms to consider the interactions among various types of the attributes that might exist in the real-world datasets. To address this issue in mixed attribute datasets, we propose a novel Pattern based Outlier Detection approach (POD). A pattern in this thesis is defined as a mathematical representation that describes the majority of the observations in datasets and captures the interactions among different types of attributes. The POD is designed in the way that the more an object deviates from these patterns, the higher its outlier factor is. We simply use logistic regression to learn patterns and then formulate the outlier factor in mixed attribute datasets. For the datasets which outliers are randomly allocated among normal data objects, distance based methods, i.e. LOF and KNN, would not have effective. On the contrary, as the outlierness definition proposed in POD is able to integrate numeric and categorical attributes into a united definition, the numeric attributes would not represent the final outlierness directly but contribute their anomaly through categorical attributes. Therefore, the POD will be able to offer considerably performance improvement compared to those traditional methods. A series of experiments show that the performance enhancement by the POD is statistically significant comparing to several classic outlier detection methods. However, for POD, the algorithm sometimes shows lower detection precision for some mixed attribute datasets, because POD has a strong assumption that the observed mixed attribute dataset in any subspace is linearly separable. This limitation is determined by the linear classifier, logistic regression, we used in POD algorithm.
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Gaspar, Cátia Sofia Silva. « Dessalinação da água através de um processo híbrido permuta iónica-nanofiltração ». Master's thesis, 2014. http://hdl.handle.net/10316/40265.

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« Sistema de Informacion para la Enseñanza del Tema de la Sexualidad a Niños de 6to de Primaria ». Tesis, Universidad de las Américas Puebla, 2006. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/mata_m_md/.

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« La experimentación como valor agregado al Diseño ». Tesis, Universidad de las Américas Puebla, 2004. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/barreto_v_p/.

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« Sistema de información para fomentar el turismo cultural en Cuernavaca ». Tesis, Universidad de las Américas Puebla, 2005. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/chazaro_c_s/.

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« Analisis y rediseño basado en los intereses de los perfiles de usuarios.reestructuración de mapas de recorrido ». Tesis, Universidad de las Américas Puebla, 2004. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/rodriguez_v_m/.

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« Jugando Juntos : un tercer lugar para niños de 3 a 6 años y su familia ». Tesis, Universidad de las Américas Puebla, 2005. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/galvez_s_mi/.

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« Concepto y producción de la moda pret-a-porter de las temporadas primavera-verano 2001,2002,2003 ». Tesis, Universidad de las Américas Puebla, 2004. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/diaz_j_v/.

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« Influencia del Art Nouveau en la psicodelia ». Tesis, Universidad de las Américas Puebla, 2004. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/massimino_a_l/.

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« Matemáticas para niños. Desarrollo de un material didáctico digital para niños de 6 a 10 años de edad ». Tesis, Universidad de las Américas Puebla, 2005. http://catarina.udlap.mx/u_dl_a/tales/documentos/ldf/loyo_m_p/.

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35

Fiee, Clara Matitireng. « The extent to which learners of the Lesotho Distance Teaching Centre (LDTC) make appropriate use of the English literature self-instructional materials/workbooks ». Thesis, 2003. http://hdl.handle.net/10413/1915.

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Morton, Karen. « Exploring a conflict healing theoretical framework within a Locate, Describe and Transform (LDT™) self-applied energy healing session ». Thesis, 2008. http://hdl.handle.net/1828/922.

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Healing from conflict allows us to bring the best we can be to each relationship and situation, however current healing techniques focus on the involvement of other people. A self-healing road map could be beneficial. The goal of this research was to examine Locate, Describe and Transform (LDT™) and its potential to provide just such a guide. This qualitative case study examined a single, self-applied LDT™ energy session in order to explore what might be revealed about its underlying conflict healing theoretical framework. Using Moustakas’ heuristic methodology, the LDT™ process was formulated and linked to research in embodiment, metaphor, and energy healing. The concept of universal energy was then compared to four conflict theories of connection, including Maslow’s Self-Actualization, Redekop’s Mimetic Structures of Blessing, LeBaron’s Connected Ways of Knowing, and Gopin’s Eight Steps. LDT™ was found to be theoretically grounded and worthy of further exploration.
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Boisvert, Michel. « Développement d’une nouvelle méthode d’analyse multi-résidus par LDTD/APCI-MS/MS pour la quantification de pesticides et de produits pharmaceutiques dans les eaux usées ». Thèse, 2012. http://hdl.handle.net/1866/8607.

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Une nouvelle méthode d'extraction en phase solide (SPE) couplée à une technique d'analyse ultrarapide a été développée pour la détermination simultanée de neuf contaminants émergents (l'atrazine, le déséthylatrazine, le 17(béta)-estradiol, l'éthynylestradiol, la noréthindrone, la caféine, la carbamazépine, le diclofénac et le sulfaméthoxazole) provenant de différentes classes thérapeutiques et présents dans les eaux usées. La pré-concentration et la purification des échantillons a été réalisée avec une cartouche SPE en mode mixte (Strata ABW) ayant à la fois des propriétés échangeuses de cations et d'anions suivie d'une analyse par une désorption thermique par diode laser/ionisation chimique à pression atmosphérique couplée à la spectrométrie de masse en tandem (LDTD-APCI-MS/MS). La LDTD est une nouvelle méthode d'introduction d'échantillon qui réduit le temps total d'analyse à moins de 15 secondes par rapport à plusieurs minutes avec la chromatographie liquide couplée à la spectrométrie de masse en tandem traditionnelle (LC-MS/MS). Plusieurs paramètres SPE ont été évalués dans le but d'optimiser l'efficacité de récupération lors de l'extraction des analytes provenant des eaux usées, tels que la nature de la phase stationnaire, le débit de chargement, le pH d'extraction, le volume et la composition de la solution de lavage et le volume de l'échantillon initial. Cette nouvelle méthode a été appliquée avec succès à de vrais échantillons d'eaux usées provenant d'un réservoir de décantation primaire. Le recouvrement des composés ciblés provenant des eaux usées a été de 78 à 106%, la limite de détection a été de 30 à 122 ng L-1, alors que la limite de quantification a été de 88 à 370 ng L-1. Les courbes d'étalonnage dans les matrices d'eaux usées ont montré une bonne linéarité (R2 > 0,991) pour les analytes cibles ainsi qu’une précision avec un coefficient de variance inférieure à 15%.
A new solid phase extraction (SPE) method coupled to a high throughput sample analysis technique was developed for the simultaneous determination of nine selected emerging contaminants (atrazine, desethylatrazine, 17(beta)-estradiol, ethynylestradiol, northindrone, caffeine, carbamazepine, diclofenac and sulfamethoxazole) comprising drugs from different therapeutic classes present in wastewater. Sample pre-concentration and clean-up was performed with a mixed-mode SPE cartridge (Strata ABW) having both cation and anion exchange properties followed by analysis by laser diode thermal desorption/atmospheric pressure chemical ionization coupled to tandem mass spectrometry (LDTD-APCI-MS/MS). The LDTD is a new high-throughput sample introduction method, which reduces total analysis time to less than 15 seconds compared to minutes with traditional liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS). Several SPE parameters were evaluated in order to optimize recovery efficiencies when extracting analytes from wastewater, such as the nature of stationary phase, the loading flow rate, the extraction pH, the various volume and composition of the washing solution and the initial sample volume. The method was successfully applied to real wastewater samples from a primary sedimentation tank. Recoveries of target compounds from wastewater ranged from 78 to 106 %, the limit of detection ranged from 30 to 122 ng L-1 while the limit of quantification ranged from 88 to 370 ng L-1. Calibration curves in wastewater matrix showed good linearity (R2 > 0.991), for all target analytes, and precision (intraday and interday) showed a coefficient of variance below 15%.
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Campos, Rita Helena Pinto Oliveira. « Two new types of laser doppler flowmeters prototypes validation ». Master's thesis, 2011. http://hdl.handle.net/10316/17766.

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A fluxometria laser Doppler (LDF) é uma técnica para avaliação em tempo real do fluxo microcirculatório em tecidos biológicos. Esta técnica pode ser usada para monitorização não invasiva da microcirculação (por exemplo, avaliação da perfusão na pele), ou para monitorização da perfusão de forma invasiva (por exemplo, avaliação da perfusão no cérebro). Nesta tese, pretende-se acrescentar ao estado da arte da LDF, quando aplicada à monitorização não invasiva da perfusão na pele, a capacidade de discriminação em profundidade. Para isso, foi desenvolvido um protótipo de um fluxómetro laser Doppler com vários comprimentos de onda e diferentes separações entre as fibras emissora e receptora. Tendo em vista a monitorização de perfusão de cérebro de rato construiu-se um protótipo de um fluxómetro laser Doppler baseado na técnica self-mixing utilizando micro-fibras ópticas de forma invasiva. Para validar estes dois novos protótipos, fizeram-se simulações Monte Carlo do transporte de luz em tecidos. Realizaram-se simulações num fantoma (constituído por seis camadas de fluido a diferentes profundidades), e num modelo da pele para a validação do protótipo não invasivo. Os resultados demonstraram que o primeiro momento do especto de potência (M1), assim como, a profundidade atingida pelos fotões, aumentam com o incremento da distância entre as fibras emissora e receptora. Para além disso, os resultados evidenciaram que o acréscimo do comprimento de onda da luz laser traduz-se numa maior profundidade média amostrada. Medições realizadas com o protótipo não invasivo no fantoma e na pele foram comparados com os resultados das simulações. As simulações aproximam-se bastante dos resultados das medições Para a validação do protótipo invasivo, foram efectuadas simulações Monte Carlo num modelo de cérebro de rato. Foi demonstrado que a profundidade média medida com a sonda construída é de 0.15 mm.
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Cormier, Guillaume. « Dégradation chimique et biologique de neuf contaminants émergents dans les eaux de surfaces et les effluents primaires d’eaux usées municipales ». Thèse, 2014. http://hdl.handle.net/1866/11460.

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Un protocole inspiré du test de simulation 309 de l’Organisation de coopération et de développement économiques (OCDE) nous a permis de mesurer la dégradation chimique (excluant la photolyse) dans des eaux de surface de même que la dégradation chimique et biologique de neuf contaminants émergents dans l’effluent d’un décanteur primaire d’eau usée municipale. Les données étaient compatibles avec le modèle de cinétique de pseudo ordre un. Les résultats démontrant une persistance de plus d’un an dans les eaux de surface et de 71 jours dans l’effluent du décanteur primaire suggèrent que les dégradations chimique et biologique ne contribuent pas significativement à la diminution de: atrazine, déséthylatrazine, carbamazépine et diclofénac dans la phase aqueuse des systèmes testés. Les autres composés se sont dégradés à différents niveaux. Le 17ß-estradiol ainsi que l’éthinylestradiol, la noréthindrone, la caféine et le sulfaméthoxazole ont tous été sujet à la dégradation biologique dans les effluents du décanteur primaire d’eau usée avec des constantes de dégradation k et des demi-vies t1/2 mesurées allant respectivement de 0.0082 à 0.59 j-1 et de 1.2 à 85 jours. Les paramètres de cinétique mesurés peuvent être combinés aux concentrations typiques des composés à l’étude dans un décanteur primaire d’eau usée pour y calculer leur vitesse de dégradation. Cependant, puisque les décanteurs primaires dans les usines de traitement d’eaux usées ont généralement des temps de résidence de quelques heures seulement, il est improbable que les neufs contaminants émergents à l’étude diminuent significativement par ces processus durant leur passage dans le compartiment.
A protocol inspired by the OECD 309 simulation test allowed us to measure the chemical (excluding photolysis) degradation in surface waters as well as the chemical and biological degradation potential of 9 emerging contaminants in urban primary settling tank (PST) effluents. The data confirmed that a pseudo first order kinetic model provided a good fit. The results suggest that chemical and biological degradation will not significantly contribute to the disappearance of atrazine, desethylatrazine, carbamazepine and sulfamethoxazole in the aqueous phase of the tested systems given the reported persistency of more than a year in surface waters and 71 days in PST effluents. Other compounds were more easily degraded and 17ß-estradiol, ethinylestradiol, norethindrone, caffeine and sulfamethoxazole were all amenable to biological degradation in PST effluents, with measured degradation rate constants k and half-lives ranging respectively from 0.0082-0.59 d-1 and 1.2-85 days. Since PSTs in WWTPs generally have a water residence time of a few hours and considering the typical concentrations of such ECs’ in those compartments, it is unlikely that significant disappearance will occur during their passage through the PST.
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(5930285), Karen N. Son. « Improved Prediction of Adsorption-Based Life Support for Deep Space Exploration ». Thesis, 2019.

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Adsorbent technology is widely used in many industrial applications including waste heat recovery, water purification, and atmospheric revitalization in confined habitations. Astronauts depend on adsorbent-based systems to remove metabolic carbon dioxide (CO2) from the cabin atmosphere; as NASA prepares for the journey to Mars, engineers are redesigning the adsorbent-based system for reduced weight and optimal efficiency. These efforts hinge upon the development of accurate, predictive models, as simulations are increasingly relied upon to save cost and time over the traditional design-build-test approach. Engineers rely on simplified models to reduce computational cost and enable parametric optimizations. Amongst these simplified models is the axially dispersed plug-flow model for predicting the adsorbate concentration during flow through an adsorbent bed. This model is ubiquitously used in designing fixed-bed adsorption systems. The current work aims to improve the accuracy of the axially dispersed plug-flow model because of its wide-spread use. This dissertation identifies the critical model inputs that drive the overall uncertainty in important output quantities then systematically improves the measurement and prediction of these input parameters. Limitations of the axially dispersed plug-flow model are also discussed, and recommendations made for identifying failure of the plug-flow assumption.

An uncertainty and sensitivity analysis of an axially disperse plug-flow model is first presented. Upper and lower uncertainty bounds for each of the model inputs are found by comparing empirical correlations against experimental data from the literature. Model uncertainty is then investigated by independently varying each model input between its individual upper and lower uncertainty bounds then observing the relative change in predicted effluent concentration and temperature (e.g., breakthrough time, bed capacity, and effluent temperature). This analysis showed that the LDF mass transfer coefficient is the largest source of uncertainty. Furthermore, the uncertainty analysis reveals that ignoring the effect of wall-channeling on apparent axial dispersion can cause significant error in the predicted breakthrough times of small-diameter beds.

In addition to LDF mass transfer coefficient and axial-dispersion, equilibrium isotherms are known to be strong lever arms and a potentially dominant source of model error. As such, detailed analysis of the equilibrium adsorption isotherms for zeolite 13X was conducted to improve the fidelity of CO2 and H2O on equilibrium isotherms compared to extant data. These two adsorbent/adsorbate pairs are of great interest as NASA plans to use zeolite 13X in the next generation atmospheric revitalization system. Equilibrium isotherms describe a sorbent’s maximum capacity at a given temperature and adsorbate (e.g., CO2 or H2O) partial pressure. New isotherm data from NASA Ames Research Center and NASA Marshall Space Flight Center for CO2 and H2O adsorption on zeolite 13X are presented. These measurements were carefully collected to eliminate sources of bias in previous data from the literature, where incomplete activation resulted in a reduced capacity. Several models are fit to the new equilibrium isotherm data and recommendations of the best model fit are made. The best-fit isotherm models from this analysis are used in all subsequent modeling efforts discussed in this dissertation.

The last two chapters examine the limitations of the axially disperse plug-flow model for predicting breakthrough in confined geometries. When a bed of pellets is confined in a rigid container, packing heterogeneities near the wall lead to faster flow around the periphery of the bed (i.e., wall channeling). Wall-channeling effects have long been considered negligible for beds which hold more than 20 pellets across; however, the present work shows that neglecting wall-channeling effects on dispersion can yield significant errors in model predictions. There is a fundamental gap in understanding the mechanisms which control wall-channeling driven dispersion. Furthermore, there is currently no way to predict wall channeling effects a priori or even to identify what systems will be impacted by it. This dissertation aims to fill this gap using both experimental measurements and simulations to identify mechanisms which cause the plug-flow assumption to fail.

First, experimental evidence of wall-channeling in beds, even at large bed-to-pellet diameter ratios (dbed/dp=48) is presented. These experiments are then used to validate a method for accurately extracting mass transfer coefficients from data affected by significant wall channeling. The relative magnitudes of wall-channeling effects are shown to be a function of the adsorption/adsorbate pair and geometric confinement (i.e., bed size). Ultimately, the axially disperse plug-flow model fails to capture the physics of breakthrough when nonplug-flow conditions prevail in the bed.

The final chapter of this dissertation develops a two-dimensional (2-D) adsorption model to examine the interplay of wall-channeling and adsorption kinetics and the adsorbent equilibrium capacity on breakthrough in confined geometries. The 2-D model incorporates the effect of radial variations in porosity on the velocity profile and is shown to accurately capture the effect of wall-channeling on adsorption behavior. The 2-D model is validated against experimental data, and then used to investigate whether capacity or adsorption kinetics cause certain adsorbates to exhibit more significant radial variations in concentration compared than others. This work explains channeling effects can vary for different adsorbate and/or adsorbent pairs—even under otherwise identical conditions—and highlights the importance of considering adsorption kinetics in addition to the traditional dbed/dp criteria.

This dissertation investigates key gaps in our understanding of fixed-bed adsorption. It will deliver insight into how these missing pieces impact the accuracy of predictive models and provide a means for reconciling these errors. The culmination of this work will be an accurate, predictive model that assists in the simulation-based design of the next-generation atmospheric revitalization system for humans’ journey to Mars.
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