Mit der palliativen transarteriellen Chemoembolisation (TACE) läßt sich eine Verkleinerung von malignen Lebertumoren und eine Verlängerung des Überlebens erreichen. Im Verlauf des Therapiezyklus diente die Phosphor-Magnetresonanzspektroskopie mittels Chemical-Shift-Imaging einem nichtinvasiven Einblick in den zellulären Energie- und Membranstoffwechsel. Eine Differenzierung zwischen primären und sekundären Lebertumoren war anhand der 31P-Spektren nicht möglich. Posttherapeutisch zeigten die Patienten einen Anstieg des anorganischen Phosphats bei Abfall des ß-NTP-Signals, die sich während des sechswöchigen Intervalls vor der nächsten Intervention wieder normalisierten. Therapieansprechen und -versagen zeigten während des Therapiezyklus unterschiedliche spektroskopische Quotientenverläufe. Eine deutliche Volumenreduktion als auch eine homogene und dauerhafte Lipiodoleinlagerung im Tumor gehen zuverlässig mit einem spektroskopischen Therapieansprechen einher. Dies zeigte sich bei der ersten Patientengruppe während der Untersuchung direkt nach der Embolisation und bei der zweiten Gruppe erst vor der nächsten Intervention. Therapieversagen, Tumorprogression und geringe Lipiodoleinlagerung bzw. rasche Entspeicherung im Verlauf ließen sich spektroskopisch nach-weisen. Schwierig bleibt die Zuordnung der Patienten mit uneinheitlichen Quotienten-verläufen. Die MRS kann früher als die klinische Routinediagnostik eine Aussage über das Therapieansprechen treffen. Für den Patienten ergibt sich die Vermeidung einer ineffektiven Therapie. Bei nachgewiesenem Ansprechen hingegen profitiert der Patient durch die wiederholte Anwendung der TACE. Der hohe personelle, technische und zeitliche Aufwand für die Phosphorspektroskopie verhindert bisher den klinischen Routineeinsatz dieses Verfahrens. Im Rahmen der klinischen Forschung, insbe-sondere in der onkologischen Therapiekontrolle, hat die MRS als nichtinvasive Methode heute einen großen Stellenwert. / Using palliative transarterial chemoembolization (TACE) a reduction of malignant liver neoplasms and a prolongation of survival time can be achieved. During the course of therapy phosphorous magnetic resonance spectroscopy by means of chemical-shift-imaging was used for noninvasive examination of the cellular metabolism of energy and membranes. Differentiation between primary and secondary liver tumors was not feasible using 31P-spectra. After therapy patients had shown increased inorganic phosphate signal and reduction of the ß-NTP-signals, which normalized during six week intervall before next intervention. Response and non-response to therapy showed different courses of spectroscopic quotients during therapy cycle. Prominent reduction of volume as well as homogeneous and continous retention of lipiodol within the tumor are reliable combined with spectroscopic response to therapy. The first group of patients showed these signs at the examination immediately after embolization whereas patients of the second group showed these signs not before next intervention. Failure of therapy, progression of tumor and slight retention of lipiodol or rapid elemination during course of therapy were detectable by spectroscopy. Categorization of patients with non-uniform courses of quotients remains difficult. Magnetic resonance spectroscopy is able to determine response to therapy earlier than standard diagnostic methods. As a result ineffective therapy is avoided for the patient. On the other hand the patient profits from repeated administration of TACE. Great expense of personnel, equipment and time so far prevents clinical use of phosphorous spectroscopy as a matter of routine. In conjunction with clinical research MRS is an important non-invasive method especially for oncological therapy monitoring.

Zur Einschätzung der Auswirkungen einer Wiedervernässungsmaßnahme auf den Stoffhaushalt eines degradierten Niedermoores wurde ein ehemals entwässertes und seit 1996 wieder vernässtes ca. 10 Hektar großes Areal im Randow-Welse-Bruch im nordöstlichen Brandenburg über mehrere Jahre untersucht. Stoffkreisläufe wurden vor allem in Abhängigkeit der sich durch die Wiedervernässung ändernden Redoxbedingungen modifiziert. Obwohl Phosphor, ein die Eutrophierung auslösendes Element, selbst direkt nicht durch einen Wechsel von aeroben zu anaeroben Bedingungen durch die Wiedervernässung beeinflusst wird, änderte sich dessen Mobilität auf Grund der Rücklösung seines Sorptionspartners. Infolge der anhaltend reduzierenden Bedingungen fand nach mehrjähriger Wiedervernässung der Prozess der Rücklösung amorpher Eisen(hydr)oxide statt, wobei der ehemals an diese Verbindungen fixierte Phosphor freigesetzt wurde. Bei Niedermooren, die infolge hoher Gehalte an Eisen(hydr)oxiden ein erhöhtes Phosphor-Freisetzungspotenzial besitzen, sollte eine Wiedervernässung mit gereinigtem kommunalen Abwasser nicht in Erwägung gezogen werden. Die Erfassung der gasförmigen Emissionen ermöglichte eine Berücksichtigung innerhalb der Stoffbilanzierung und eine Bewertung der Wiedervernässungsmaßnahme hinsichtlich ihrer Klimarelevanz. Auf Grund des anaeroben Milieus durch die Wiedervernässung wurde neben Lachgas auch molekularer Stickstoff als gasförmige Stickstoffverbindung gebildet. Gegenüber der entwässerten Lysimetervariante zeigte sich ein positiver Beitrag zur Reduzierung des Treibhauseffektes durch die Wiedervernässung. Jedoch ist die Qualität des Zusatzwassers, das zur Wiedervernässung der Torfprofile des Niedermoores Havelländisches Luch eingesetzt wurde, entscheidend. In eutrophen Niedermoorökosystemen sind nährstoffreiche Wasserzuflüsse aus kommunalen Abwasserbehandlungsanlagen als Wiedervernässungsmaßnahme geeignet, so dass gereinigtes Abwasser den Landschaftswasserhaushalt stützen könnte. / A formerly drained, and since 1996 rewetted, 10 ha fen site within the Randow-Welse-Bruch fen area in northeastern Brandenurg (Germany) has been investigated for several years to evaluate the impacts of rewetting on nutrient dynamics of the degraded fen. Modifications of nutrient cycles were attributed to changes in redox conditions after rewetting. Although phosphorus which causes eutrophication is not directly influenced by a change from aerobic to anaerobic conditions following rewetting its availability increased due to the dissolution of reactive iron (hydr)oxides where phosphorus was fixed before.With prolonged water-logging phosphorus was released from Fe(III) (hydr)oxides. A lysimeter study was carried out to promote the reuse of purified municipal wastewater as an alternative solution for water supply required during rewetting of fens. Fen soil lysimeters were irrigated with wastewater of the secondary treatment of a municipal wastewater treatment plant over the growing seasons. The objective of this study was to assess how restoration of a degraded fen by means of wastewater usage affects input/output nutrient mass balances. Furthermore, we assessed the effect on trace gas emissions and discussed potential changes in the greenhouse potential. No adverse impact of wastewater utilisation for rewetting the fen soil lysimeters on soil and water quality was found over the period of study with regard to the investigated nutrients and heavy metals. Gaseous fluxes during alternative rewetting were estimated for a consideration within nutrient balances and to evaluate the global warming and cooling, respectively. Besides nitrous oxide dinitrogen was formed and released under anaerobic conditions following rewetting. A potential increase of the nitrate concentration in wastewater would be harmless because a high denitrification of the fen soil would cause a major share of dinitrogen emissions of the total gaseous nitrogen loss.

Viele seeinterne Maßnahmen zielen darauf, die Phytoplanktonentwicklung über die Verfügbarkeit von Phosphor (P) im Wasserkörper zu steuern. Die meisten Restaurierungsverfahren sollen über eine Erhöhung der P-Bruttosedimentation oder Verminderung der P-Rücklösung die P-Retention im Sediment beeinflussen. Daher sind Sedimentuntersuchungen zur Abschätzung der P-Retention und ihrer Veränderung unter dem Einfluss der erwogenen Maßnahmen eine wichtige Voraussetzung für die Auswahl des im konkreten Einzelfall am besten geeigneten Verfahrens. Eine durch Fragebögen und Literaturauswertung vorgenommene Analyse legt offen, dass die Sedimentuntersuchungen häufig nicht oder mit ungeeigneten Methoden erfolgten und die Therapieversuche daher in der Vergangenheit oft nicht die erwartete Wirkung hatten. Mit einer Kosten-Nutzen-Abschätzung wird gezeigt, dass sich Voruntersuchungen auch finanziell rechnen, obwohl sie aufwendig und teuer sind. Die Forschung der letzten Jahre hat das Prozessverständnis für die Kopplung der verschiedenen Kreisläufe und das Zusammenspiel von chemischen und biologischen Prozessen erheblich vervollständigt. Wegen der Komplexität ist es jedoch immer noch sehr schwierig, die Wirkung eines technischen Eingriffs genau vorherzusagen. Es werden Untersuchungsmethoden benötigt, die die beteiligten Prozesse und Zustandsgrößen mit ausreichender räumlicher und zeitlicher Auflösung erfassen. Besonders wichtige Größen für seeinterne Maßnahmen sind das P-Freisetzungspotential und die P-Freisetzungsrate. Verschiedene Bestimmungsmethoden für die beiden Größen werden in der Arbeit beschrieben, weiterentwickelt, gegenübergestellt, mit Beispielen veranschaulicht und im Bezug auf ihre Vor- und Nachteile diskutiert. Das P-Freisetzungspotential kann aus der Veränderung der Gesamtphosphorgehalte im Sedimenttiefenprofil, aus den P-Bindungsformen der oberen Sedimentschicht oder aus Desorptionsuntersuchungen mit Sediment der oberen Schicht abgeleitet werden. Die P-Freisetzungrate kann als Konzentrationsanstieg des Freiwassers in Säulenversuchen, in Flux-Kammern oder im Hypolimnion gemessen werden. Alternativ ist es möglich, sie aus dem Konzentrationsgradienten des gelösten Phosphors an der Sediment-Wasser-Grenze mit Filtration, Zentrifugation, Sensoren oder Dialysesammlern zu ermitteln. Ein spezielles Augenmerk wird auf die kleinräumige horizontale Heterogenität der P-Porenwasserkonzentrationen gelegt, da diese Variabilitäten zu fehlerhaften P-Freisetzungsraten führen können. Ein neues Probenahmegerät, ein zweidimensionaler Porenwassersammler, wurde entwickelt, um die P-Porenwasserkonzentrationen mit hoher horizontaler und vertikaler Auflösung messen zu können. Das neue Probenahmegerät erwies sich zur Klärung der Frage, wie viele unabhängige Messungen in einem konkreten Fall für zuverlässige Ergebnisse erforderlich sind, als geeignet. Der Einsatz des zweidimensionalen Porenwassersammlers identifizierte biologische Aktivität als Hauptursache räumlicher Variabilität. Ferner wurde deutlich, dass die räumliche Variabilität der P-Porenwasserkonzentrationen in flachen Gewässern größer als in tiefen Gewässern ist. Bei der Probenahmeplanung und Ergebnisauswertung sollte die räumliche Variabilität auf jeden Fall ausreichend berücksichtigt werden. An einem konkreten Anwendungsfall (Auensee) werden die vorgestellten Untersuchungsmethoden eingesetzt, um die Auswahl von Restaurierungsverfahren zu demonstrieren. Erst die kombinierte Interpretation von P-Freisetzungspotential und P-Freisetzungsrate erlaubt, die richtigen Schlussfolgerungen für das Untersuchungsgewässer zu ziehen. In einem weiteren Fallbeispiel (Süßer See) wird gezeigt, dass Nachuntersuchungen nicht nur zur Erfolgskontrolle notwendig sind, sondern auch um wissenschaftliche Erkenntnisse zu gewinnen. Im dargestellten Fall wird anhand von Laborversuchen und einer konzeptionellen Modellierung gezeigt, dass eine mit Neusediment überdeckte P-sorbierende Schicht auch bei noch vorhandener Sorptionskapazität keinen nennenswerten Einfluss auf die P-Konzentrationen im Wasserkörper hat. Die mit der vorliegenden Dissertation erfolge Zusammenschau und kritische Bewertung der Untersuchungsmethoden soll auch dazu dienen, die Lücke zwischen wissenschaftlichem Prozessverständnis und wasserwirtschaftlicher Praxis zu verkleinern. / Many internal restoration measures in lakes are directed to control of phytoplankton development by limiting the availability of phosphorus (P). Most such measures are aimed at changing P retention in sediment by increasing gross P sedimentation, or reducing P release (Chapter 2). Thus, pre- and post-restoration investigations of the lake sediment, including estimating the actual P retention and its predicted change caused by the considered measure, are an important means for choosing the most appropriate restoration technique and to determine whether restoration was successful. However, our questionnaires and literature study reveal that, in the past, pre-restoration investigations were frequently either omitted or inadequate. Consequently, effectiveness of lake restorations was often low. In contrast, appropriate pre-restoration investigations, increase the prospect of success. Our cost-benefit estimation proves that pre-restoration investigations, though expensive, reduce costs of lake restorations and increase the cost-benefit relationship (Appendix 1). Last years research has improved the knowledge of the complex coupling of the chemical cycles involved, and of the chemical and biological processes in the lake ecosystem. However, it is still difficult to estimate the effects of a technical measure, because we lack investigation methods that record the involved processes with the necessary temporal and spatial resolution. To evaluate internal measures, the P release potential and the P release rate are necessary. In this dissertation, the methods to determine the P release potential and the P release rate are developed, described, exemplified, compared, and their advantages and disadvantages are discussed. The P release potential can be derived from the change of total phosphorus in the sediment depth profile, from P binding forms, or from P desorption experiments in laboratory (Chapter 3). The P release rate can be measured in the water column as increase of phosphorus in core experiments, in flux chambers, or in the hypolimnion of stratified lakes. Alternatively, the P release rate can be determined from P concentration gradients at the sediment-water interface with filtration, centrifugation, microsensors, or dialysis samplers (Chapter 4). Special attention of this dissertation is focussed on pore water inheterogeneity because in might result in incorrect P release rates. A new device, a two-dimensional pore water sampler, was developed to measure pore water P concentrations with high horizontal and vertical resolution. The new device is shown to be applicable to particular lakes to determine how many independent measurements are necessary to get reliable results. Our use of the two-dimensional pore water sampler determined biological activity as the main cause of the spatial heterogeneity of pore water P concentrations and revealed that the spatial variability is larger in shallow lakes than in deep lakes. The variability should be taken into account when planning a sampling program or evaluating results (Appendix 2). The proposed sediment investigation methods to determine the P release potential and the P release rate are used at Lake Auensee to demonstrate their use for choosing the most appropriate restoration technique. The case study of Lake Auensee points out that only a combined interpretation of P release potential and P release rate leads to the correct conclusion (Appendix 3). Post-restoration investigations are necessary to check whether a restoration was successful or not, and to gain scientific insight. A study of Lake Süsser See is used as an example for post-restoration investigations of the sediment. Core experiments and a conceptual model are used to show that a buried layer, even with P sorption capacity, has no impact on the P release (Appendix 4). Furthermore, the surveys and critical evaluations contained in this dissertation should decrease the gap between scientific understanding of processes in a lake and practical water management.

Die Verfügbarkeit des Makroelementes Phosphor ist für Lebewesen eingeschränkt. Besonders bei der Pflanzenproduktion und der Tierernährung spielt die Phosphorverfügbarkeit eine wichtige Rolle bei der ökonomischen Nutzung der Ressourcen. In den Fokus der Wissenschaft zur Lösung des Phosphorproblems gerieten die Phytasen, da monogastrische Tiere nicht in der Lage sind das in den Pflanzensamen gespeicherte Phytat zu nutzen. Die gentechnische Veränderung von Pflanzen stellt eine effiziente Möglichkeit zur Produktion von phosphatfreisetzenden Enzymen, zur Erhöhung der Biomasseproduktion und zur Veränderung der Inhaltstoffe dar. In dieser Arbeit wurden erfolgreich transgene Pflanzen der Arten Nicotiana tabacum L. cv. Samsun und Hordeum vulgare L. cv. Golden Promise erzeugt, die in der Lage waren die Phytase aus Klebsiella sp. ASR1 bzw. aus Bacillus amyloliquefaciens FZB45 zu produzieren. Es wurde für jedes Protein eine Strategie zur Reinigung des aktiven Enzyms aus den verschiedenen Wirtsorganismen entwickelt und seine biochemischen Eigenschaften charakterisiert. Es wurde gezeigt, dass die β-Propeller-Phytase aus Bacillus im Gegensatz zur sauren Phytase aus Klebsiella durch die posttranslationale Modifikation teilweise ihre Eigenschaften ändert. Die Auswirkungen der heterologen Expression der Phytasen auf die Veränderung der Anteile von Phytinsäure und anorganischem Phosphor, in Relation zum gesamten Phosphor, in den Gerstensamen wurden untersucht. Es wurde eine Reduktion des Phytinsäuregehaltes um 19 % und eine Erhöhung des Gehalts anorganischem Phosphor zwischen 27 % und 78 nachgewiesen. Mit Hilfe von spezifischen Signalsequenzen gelang es die Phytaseproteine aus der Wurzel in das umgebende Medium zu sekretieren. Die Sekretion der Bacillus Phytase führte zu einer Steigerung der Biomasseproduktion von Nicotiana tabacum L. unter unsterilen Wachstumsbedingungen mit Phytat als einziger P-Quelle um 34 %. / Due to the bad availability of phosphorus in natural habitats the improvement of phosphorus accessibility to organisms became an important topic of research, particularly for agriculture and animal nutrition. In plant seeds phosphorus is bound to D-myo-inositol to form phytic acid that is indigestible for mono gastric animals. Therefore the use of phytases to hydrolyze the phytic acid and to mobilize the anorganic phosphorus came in focus to science. Genetic engineering gave the opportunity to improve the phosphorus availability. Genetic manipulation of plants is a suitable tool to produce phosphorus releasing enzymes, thereby increasing the biomass and decreasing the content of phytic acid in plants. In this work I generated transgenic plants of Nicotiana tabacum and Hordeum vulgare vulgare which successfully express the phytase gene phyK from Klebsiella pneumonia ASR1 and phyC from Bacillus amyloliquefaciens FZB42. Chromatographically purification strategies were developed and biochemical properties were characterized for all phytase proteins. All enzymes were active and PhyC was posttranslational modified. The effect of the recombinant phytase activity to total phosphorus, phytic acid and anorganic phosphorus content of barley seeds were elucidated. The phyK-expression in barley seeds yield a reduction of phytic acid content of about 19 % and an increase of anorganic phosphorus of about 78 %. Transgenic barley seeds with phyC gene expression show an increase of anorganic phosphorus content from 27 % to 48 % but no decrease in phytic acid content. In growth experiments no special phenotypes of plant containing the recombinant protein were visible. The insertion of apoplastic signal sequences in front of the phytase genes resulted in secretion of the proteins into the rhizosphere. The secretion of PhyC led to an improved growth of Nicotiana tabacum under unsterile conditions with sodium phytate as single phosphorus source increasing the biomass up to 34 %.

The Arbuscular mycorrhiza (AM) is an endosymbiont of higher plant roots. Most land plants and cultivated crops are concerned to AM symbiosis. This endosymbiosis is based on the mutual exchange of nutrients between plant and fungus. Therefore, AM symbiosis leads to an increased demand for photosynthetic products. The aim of this study was to investigate the pathway used by plants during AM symbiosis to increase photosynthetic performance. Therefore, we have carried out a systematic characterization of photosynthesis in Medicago truncatula (M. truncatula), which is a model legume. We observed colonization by the fungus in roots and that AM symbiosis increases the fresh and dry plant biomass. This could be attributed to an increase in both photosynthetic efficiency and capacity in AM plants. Consistent with these observations, AM symbiosis enhanced phosphorus uptake from the soil into roots, stems and leaves, as based on analyses of phosphorus content. Based on equal chl loading, no differences were found regarding D1, Lhcb1 and Lhcb2 protein content in four plant groups. This indicates similar ratio between chl and PSII proteins. Furthermore, AM symbiosis increases the amount of chlorophyll, steady state oxygen evolution activities, maximum quantum yield (Fv/Fm), and photosynthetic electron transport rate (about 5 fold). Nevertheless, photoprotection was not affected by AM symbiosis. We observed an increase in weight of seed/fruit and weight of seed/plant in AM plants (about 2 fold). Based on these results, we propose that AM symbiosis increases both the efficiency and the capacity of photosynthetic apparatus in the M. truncatula.

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Orientador: Luiz Otavio Saraiva Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-06T21:02:18Z (GMT). No. of bitstreams: 1 Oliveira_LuizClaudioMarangonide_D.pdf: 9710529 bytes, checksum: 4fc22426f2b4d1d845715c4742df71a2 (MD5) Previous issue date: 2006 / Resumo: Scanners são dispositivos que defletem um feixe luminoso e transfonnam um feixe puntual em uma linha de varredura, com amplitude e freqüência controladas. Diversos equipamentos utilizam este padrão luminoso para codificar ou decodificar infonnações, exemplos mais comuns são os leitores de código de barras de bancada, utilizados em supennercados, e as impressoras laser. V ários fenômenos podem ser empregados para defletir um feixe luminoso. Neste trabalho, os scanners utilizam o princípio da reflexão da luz por um espelho em movimento hannônico e ressonante sob ação de forças de origem eletromagnética. Tais forças são geradas pela interação de correntes induzi das na annadura, com o campo magnético produzido por ímãs pennanentes. A principal vantagem deste tipo de scanner é a ausência de conexões elétricas entre as partes móveis e fixas do dispositivo, o que simplifica o processo de fabricação e o toma mais robusto e menos suceptível a falhas. Parte dos scanners similares existentes atualmente são dispositivos eletro-mecânicos complexos, fabricados em série. Trabalhos anteriores demonstraram a viabilidade da geometria planar e da utilização de processos de fabricação em lotes, derivados da microeletrônica, neste tipo de scanner. Os protótipos fabricados, embora funcionais, apresentaram consumo de potência acima da média para este tipo de dispositivo, o que demonstrava a necessidade de melhorias em seu projeto. O processo de fabricação, embora confiável, foi desenvolvido com materiais e métodos baseados no Silício e originários da microeletrônica, o que dificultava sua implantação em indústrias em território nacional. Neste trabalho, foram pr9postos aprimoramentos à tecnologia dos scanners ressonantes planares atuados por indução para tomar seu desempenho compatível com o d~ dispositivos similares, e também para viabilizar sua fabricação utilizando materiais e métodos disponíveis no país. Uma metodologia de projeto, em conjunto com uma série de contribuições ao modelo, foi proposta e avaliada. Para viabilizar a fabricação propôs-se a utilização do Bronze-fosforoso, como material estrutural, e a utilização de foto-fabricação, como processo de fabricação. As contribuições propostas neste trabalho possibilitaram a redução do consumo de potência de 2, 2 W para cerca de 5 m W por grau óptico, e o aumento da freqüência de operação do circuito de cerca de 1 kHz para 4 kHz, com um ângulo de deflexão óptico típico de 20° pico-a-pico, parâmetros compatíveis com os de dispositivos similares, mas mecanicamente mais complexos e fabricados por processo serial / Abstract: Scanners are devices that deftects a light beam and converts a spot light in a well controlled amplitude and frequency scan line. Several applications uses the generated pattem to code or decode data, common examples ar,e barcode readers, and laser printers. A light beam can be deftected by different means. In this work, the scanner deftects the light by reftection in a moving mirror, in a resonant and harmonic movement, subjected to forces of electromagnetic nature. Such forces are generated by the interaction between an induced current in the armature, and a magnetic field, generated by permanent magnets. The main advantage of this kind of scanner is the absence of electrical connections between the mobile, and fixed parts of the device, that simplifies the fabrication process, and make its more reliable and less fault susceptible. Part of the similar devices available today are complex eIectro-mechanical devices, manufactured by serial processo Earlier works established that the planar geometry, and the use of batch fabrication process, derived from microelectronics, are feasible with this kind of device. A1though functional, the earlier prototypes presented a high power consumption, that shown the demand for an improved designo The Silicon-based fabrication process adopted makes the use of materiaIs and methods that are not readily accessible to the Brazilian industry. In this work improvements were proposed to the induction actuated planar resonant scanners technology. The goal was to make its performance compatible with the performance of similar devices, and to enable its fabrication using materiaIs and methods available to the Brazilian industry. A design m~thodology, and a set of model contributions were proposed and validated. The use of Phosphor-bronze, as structural material, and the photqfabrication process, as the machining method, were proposed as an option to the Silicon-based fabrication method. The contributions ofthis work had enabled the reduction ofthe power consumptlon from 2,2 W to about 5 m W per optical degree, and an increase in the working frequency from 1 kHz to 4kHz, with a optical deftection angle of about 20° peak-to-peak. Such parameters are fully compatible with similar devices, mechanically more complexes and manufactured by serial processes / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

The pursuit for improved engine efficiency is driving the demand for accurate temperature measurement inside turbine engines. Accurate measurement can allow engines to be operated closer to their design limits to improve thermal efficiency. It can enable engineers to verify mechanical integrity, provide better prediction of component life, validate CFD and other design tools and aid the development for leaner more efficient engines. Unfortunately, experimentally measuring surface temperatures under harsh rotating conditions is challenging. This EngD study conducted by Ashiq Hussain Khalid at the University of Manchester and Rolls-Royce plc, reviews the rationale of using phosphor thermometry over existing methods, including thermocouples, pyrometry and thermal paints/melts, which lack detail, accuracy, or are too expensive for continuous testing. Although phosphor thermometry exhibits desirable characteristics, the high temperature and fast rotating engine environment presents some challenges that would need to be addressed before a successful measurement system can be implemented. Examples of such issues include: rising blackbody radiation, restricted optical access, fibre optic constraints and limited time period to collect data. These factors will impose measurement limits and greatly influence the design philosophy of the system, including phosphor choice, phosphor lifetime characteristics, bonding technique, excitation/detection methodologies and probe design. Taking these into consideration, the research focuses on the development of phosphor thermometry systems for use in development gas turbine engines, with measurement solutions for specific engine components. The high pressure turbine blade was given research priority. A number of phosphors including YAG:Tb, YAG:Tm. Y2O3:Eu and Mg3F2GeO4:Mn were investigated and characterised in terms of intensity and lifetime decay, with increasing temperature up to 1500oC. Spectral analysis and absolute intensity measurements established emission peaks and permitted comparative quantitative analysis to optimise system setup. The intensity of phosphor emission relative to Planck's blackbody radiation was also performed. YAG:Tm under 355nm illumination was found to exhibit the highest emission intensity at high temperatures, and because its spectral emission peak at 458nm was the lowest, its advantage in terms of blackbody radiation was further amplified. For rotating components, an upper temperature limit is reached based on the emission intensity at rising blackbody radiation levels and the system's ability to detect fast decays. A lower limit is reached based on the quenching temperature, probe design and rotational velocity. There are different methods to correct the distorted decay waveform as it traverses through the acceptance cone of the fibre. A phosphor selection criterion, taking into consideration these limitations, was successfully applied for various rotating engine components. The optical layout was setup and tested on stationary and rotating cases under laboratory conditions using similar design constraints, including fibre choice, maximum permissible lens size and target distances. A series of tests validated design methodologies and assumptions to enable testing on full scale rotating engine components. Mg3F2GeO4:Mn, using 355nm illumination, was found to be the most suitable phosphor for the HP drive cone. The estimated performance under the expected rotational speeds was found to be 624-812°C with a standard uncertainty of ±0.99%. YAG:Tm, illuminated with 355nm, was found to be the most promising phosphor for high pressure turbine blade measurements. The performance under the expected rotational speeds was found to be 1117-1375°C with a standard uncertainty of ±0.97%. This is better than other competing technologies that are currently available for temperature measurement of rotating turbine blades.