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1
Coskun, Yelda. "Synthesis Of Conducting Polymers Of Terepthalic Acid Bis-(2-thiophen-3-yl-ethyl)ester And Investigation Of Their Electrochromic Properties." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605062/index.pdf.
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Terepthalic acid bis-(2-thiophen-3-yl-ethyl)ester (TATE) was synthesized through the reaction of 2-thiophen-3-yl-ethanol and terepthaloyl chloride. Electrochemical behavior of the TATE and TATE in the presence of thiophene were studied by cyclic voltammetry (CV). The chemical structure of monomer is characterized via Nuclear Magnetic Resonance Spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Homopolymer of TATE was synthesized by galvanostatic and potentiostatic methods, and copolymerization of TATE with thiophene was achieved via potentiostatic method. Both homopolymer (PTATE) and copolymer [P(TATE-co-Th)] were characterized by various techniques including cyclic voltammetry, FTIR, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Thermal Gravimetry Analysis (TGA) and UV-VIS Spectrophotometer. Conductivities of samples were measured by four probe technique. Electronic band gap of polymers measured as the onset of the π
-&
#960
* transition using spectroelectrochemical analysis and colorimetry studies were investigated. Dual type polymer electrochromic devices (ECDs) based on PTATE, P(TATE-co-Th) and poly(3,4-ethylenedioxythiophene) (PEDOT) have been constructed. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis Spectrophotometer and Cyclic Voltammetry.
2
Köhler, Claas H. "Radiative Effect of Mixed Mineral Dust and Biomass Burning Aerosol in the Thermal Infrared." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-131635.
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This thesis treats the optical properties of mixed mineral dust and biomass burning aerosol in the thermal infrared (TIR) based on Fourier Transform infrared spectrometer (FTIR) measurements and radiative transfer simulations. The measurements were part of the Saharan Mineral Dust Experiment 2 (SAMUM-2) conducted from January to February 2008 at Praia, Cape Verde. The large amount of different instruments co-located at the main field site during the campaign resulted in a unique dataset comprising in-situ information and remote sensing data perfectly suited for column closure studies. The ultimate goal of this work is to investigate the consistency of microphysical and TIR remote sensing data. This is achieved by reproducing the measured radiances at top and bottom of the atmosphere (TOA, BOA) with a radiative transfer model, which assimilates the microphysical aerosol information gathered during SAMUM-2.
The first part of the thesis describes several experimental efforts, including a novel calibration method and a drift correction algorithm for the ground-based FTIR instrument operated within the scope of SAMUM-2 by the author. The second part introduces the concurrent radiative transfer library PIRATES, which has been developed in the framework of this thesis for the analysis of TIR aerosol optical properties. The third and final part of the treatise compares measured and simulated spectra for various typical scenarios encountered during SAMUM-2.
It is demonstrated in three case studies, that measured radiances in the TIR atmospheric window region (8-12 µm) can be reproduced at BOA and TOA by radiative transfer simulations assuming spheroidal model particles. Moreover,
spherical particles are shown to be an inadequate model for mineral dust aerosol
in this spectral region unless the aerosol optical depth is small.
3
Meredith, David. "2-D and 3-D computer modelling of lithosphere dynamics and sedimentary basin formation." Thesis, Keele University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.288437.
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4
Leclère, Henri. "Comportement sismo-mécanique des failles crustales et interactions fluides-séismes : Une étude de la région de l'Ubaye (Alpes du sud) combinant sismologie, géologie structurale, pétrophysique et modélisation numérique." Electronic Thesis or Diss., Besançon, 2012. http://www.theses.fr/2012BESA2044.
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Ce travail s'intéresse à l'étude du comportement en conditions statiques des failles dans la croûte supérieure continentale et plus particulièrement à l'effet des surpressions de fluides sur la réactivation des failles et le déclenchement des séismes. Pour ce faire, une analyse associant sismologie, géologie structurale, pétrophysique, géochimie et modélisation hydromécanique a été menée dans la région de l'Ubaye (Alpes du sud) où a eu lieu, en 2003-2004, un essaim sismique en relation avec des failles régionales affleurant plus au sud dans le massif cristallin de l'Argentera. Les mécanismes au foyer de 74 événements de cet essaim sismique ont été déterminés. À partir de ces mécanismes et d'autres données sismologiques ainsi que de modèles mécaniques basés sur la théorie de Mohr-Coulomb, cette étude a permis de confirmer que l'activité sismique de l'essaim était liée à la présence de surpressions de fluides et d'expliquer l'évolution spatio-temporelle des surpressions. Un modèle hydromécanique est proposé afin de concilier les évolutions spatio-temporelles de la sismicité et des surpressions de fluides. L'étude d'un affleurement d'une faille régionale de l'Argentera combinant analyse structurale, mesures pétrophysiques et modélisation hydromécanique a ensuite permis de préciser le comportement hydromécanique des failles aux profondeurs hypocentrales et plus particulièrement leur capacité à être compactées et à développer des surpressions de fluides. Finalement, l'initiation des séismes à la base de la zone sismogénique est explorée à partir d'analyses géochimiques et mécaniques menées sur de veines à paragénèse quartz-chlorite formées à la base de la zone sismogène. Ces résultats sont comparés avec ceux déduits de l'analyse de l'essaim sismique de l'Ubaye. Ce travail a permis d'étudier le comportement sismomécanique des failles et les interactions entre failles, fluides et séismes à travers la zone sismogène. Il met l'accent sur l'importance de coupler les approches sismologiques, hydrauliques et mécaniques dans l'étude des failles activesThis work adresses the behavior of faults in the upper continental crust under static conditions and moreparticularly the effect of fluid overpressures on fault reactivation and earthquake triggering. In order toreach this goal, an analysis combining seismology, structural geology, petrophysics, geochemistry andhydromechanical modeling has been carried out in the Ubaye region (southern French-Italian Alps) wherea seismic swarm related to regional faults exposed in the Argentera basement massif (located furthersouth) occurred in 2003-2004. Focal mechanisms of 74 events from this seismic swarm have beendetermined. Based on these mechanisms and other seismological data and on mechanical modeling basedon the Mohr-Coulomb theory, this study allows to confirm that the seismic activity of the swarm waslinked to the presence of overpressurized fluids and to explain the spatio-temporal evolution ofoverpressures. A hydromechanical model is proposed in order to account for the spatio-temporalevolutions of both seismicity and pore fluid overpressures. The study of an exposure of an Argenteraregional fault combining a structural analysis, petrophysical measurements and a hydromechanicalmodeling has allowed to decipher the hydromechanical behavior of faults at hypocentral depths, and moreparticularly to determine the ability of faults to be compacted and to develop fluid overpressures. Lastly,the initiation of earthquakes at or near the base of the seismogenic zone is explored through geochemicaland mechanical analyses of quartz-chlorite veins formed at the base of the seismogenic zone. Theseresults are then compared with those deduced from the analysis of the Ubaye seismic swarm. This workallows to study the seismo-mechanical behavior of faults and the interactions between faults, fluids andearthquakes across the seismogenic zone. It emphasizes the importance of associating seismological,hydraulic et mechanical analyses in the study of active faults
5
Weithäuser, Ina, Gunter Stober, Kristina Fröhlich, and Christoph Jacobi. "Untersuchung der Quasi - 2 - Tage Welle im Sommer 2005." Universität Leipzig, 2007. https://ul.qucosa.de/id/qucosa%3A15568.
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Das seit Juli 2004 kontinuierlich arbeitende Meteorradar am Observatorium Collm (53,3°N, 13°E) der Universität Leipzig dient der Messung des horizontalen Windfeldes sowie der Temperatur in der Mesopausenregion. Neben der Betrachtung des jahreszeitlichen Verhaltens von Grund- und Gezeitenwind ist es möglich, die Aktivität planetarer Wellen zu untersuchen. Spezielles Interesse gilt dabei der Quasi-2-Tage Welle im Sommer 2005, da zu dieser Zeit sowohl eine Verschiebung der maximalen Amplituden hin zu kürzeren als auch zu längeren Perioden beobachtbar war. Als mögliche Ursache dafür werden nichtlineare Wechselwirkungen zwischen der Quasi-2-Tage Welle und planetaren Wellen mit größeren Perioden gesehen. Die Untersuchung derartiger Wechselwirkungen erfolgt mit Hilfe der Bispektralanalyse.Since July 2004 the meteor radar operates continuously at the Observatory (53,3°N, 13°E) of the University of Leipzig. It provides data of the horizontal wind field as well as the temperature of the mesopause region. In addition to the consideration of the seasonal behaviour of prevailing and tidal winds it is possible to examine the activity of planetary waves. Because of the shift of maximum amplitudes of the quasi-2-day wave in summer 2005 to shorter as well as longer periods the event has to be considered more in detail. Possible reasons for the displacements are nonlinear couplings between the quasi-2-day wave and planetary waves with longer periods. The examination of those couplings is performed using bispectral analyses.
6
Trautmann, Thomas, and Andreas Bott. "Ein numerisches Modell zur lokalen Nebelvorhersage. Teil 2: Behandlung von Erdboden und Vegetation." Universität Leipzig, 2002. https://ul.qucosa.de/id/qucosa%3A15216.
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Die im Nebelvorhersagemodell PAFOG enthaltenen Modellkomponenten für parametrisierte Wolkenphysik, Strahlung und Sichtweitenbestimmung wurden durch Module zur Beschreibung der Interaktion mit dem Boden und der Vegetation ergänzt. Das auf diese
Weise komplettierte Modellsystem PAFOG-V kann dazu verwendet werden, das lokale Auftreten von Strahlungsnebel und niedriger stratiformer Bewölkung vorherzusagen.The paper presents an extension of the model components for parameterized cloud physics, radiation and visibility determination as implemented in the local forecast model PAFOG to include the interaction with the soil and the vegetation. The resulting forecast system PAFOG-V can be used to predict local events of radiation fogs and of low level stratiform clouds.
7
Nadin, P. A. "Cretaceous-tertiary post-rift subsidence across the NE Atlantic margin : an analysis using quantitative 2-D and reverse stratigraphic modelling." Thesis, University of Liverpool, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283040.
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8
Jacobi, Christoph, Rudolf Schminder, and Dierk Kürschner. "Long-period (2-18 Days) oscillations of mesopause winds at Collm." Wissenschaftliche Mitteilungen des Leipziger Instituts für Meteorologie ; 4 = Meteorologische Arbeiten aus Leipzig ; 2 (1996), S. 131-143, 1996. https://ul.qucosa.de/id/qucosa%3A15060.
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Daily analyses of the zonal and meridional prevailing wind at the mesopause ( - 95 km height) are investigated with respect to planetary wave scale oscillations with periods ranging between 2 and 18 days. A mean climatology of the years 1983 - 1994 is presented. Time series of planetary wave activity show a significant increase during this period, which is in accordance with results from literature.Tägliche Analysen des zonalen und meridionalen Grundwindes in der Mesopausenregion (- 95 km Höhe) werden hinsichtlich planetarer Wellenaktivität im Periodenbereich von 2 bis 18 Tagen untersucht. Es wird eine mittlere Klimatologie der Jahre 1983 - 1994 dargestellt. In diesem Zeitraum ist eine signifikante Zunahme der Wellenaktivität zu verzeichnen, die in Übereinstimmung mit Literaturangaben steht.
9
Trautmann, Thomas, and Andreas Bott. "Ein numerisches Modell zur lokalen Nebelvorhersage. Teil 2: Behandlung von Erdboden und Vegetation." Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-216944.
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Die im Nebelvorhersagemodell PAFOG enthaltenen Modellkomponenten für parametrisierte Wolkenphysik, Strahlung und Sichtweitenbestimmung wurden durch Module zur Beschreibung der Interaktion mit dem Boden und der Vegetation ergänzt. Das auf diese Weise komplettierte Modellsystem PAFOG-V kann dazu verwendet werden, das lokale Auftreten von Strahlungsnebel und niedriger stratiformer Bewölkung vorherzusagenThe paper presents an extension of the model components for parameterized cloud physics, radiation and visibility determination as implemented in the local forecast model PAFOG to include the interaction with the soil and the vegetation. The resulting forecast system PAFOG-V can be used to predict local events of radiation fogs and of low level stratiform clouds
10
Weithäuser, Ina, Gunter Stober, Kristina Fröhlich, and Christoph Jacobi. "Untersuchung der Quasi - 2 - Tage Welle im Sommer 2005." Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-223188.
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Das seit Juli 2004 kontinuierlich arbeitende Meteorradar am Observatorium Collm (53,3°N, 13°E) der Universität Leipzig dient der Messung des horizontalen Windfeldes sowie der Temperatur in der Mesopausenregion. Neben der Betrachtung des jahreszeitlichen Verhaltens von Grund- und Gezeitenwind ist es möglich, die Aktivität planetarer Wellen zu untersuchen. Spezielles Interesse gilt dabei der Quasi-2-Tage Welle im Sommer 2005, da zu dieser Zeit sowohl eine Verschiebung der maximalen Amplituden hin zu kürzeren als auch zu längeren Perioden beobachtbar war. Als mögliche Ursache dafür werden nichtlineare Wechselwirkungen zwischen der Quasi-2-Tage Welle und planetaren Wellen mit größeren Perioden gesehen. Die Untersuchung derartiger Wechselwirkungen erfolgt mit Hilfe der BispektralanalyseSince July 2004 the meteor radar operates continuously at the Observatory (53,3°N, 13°E) of the University of Leipzig. It provides data of the horizontal wind field as well as the temperature of the mesopause region. In addition to the consideration of the seasonal behaviour of prevailing and tidal winds it is possible to examine the activity of planetary waves. Because of the shift of maximum amplitudes of the quasi-2-day wave in summer 2005 to shorter as well as longer periods the event has to be considered more in detail. Possible reasons for the displacements are nonlinear couplings between the quasi-2-day wave and planetary waves with longer periods. The examination of those couplings is performed using bispectral analyses
11
Zhang, Kai, Declan O''Donnell, Jan Kazil, Philip Stier, Stefan Kinne, Ulrike Lohmann, Sylvaine Ferrachat, et al. "The global aerosol-climate model ECHAM-HAM, version 2: sensitivity to improvements in process representations." Copernicus Publication, 2012. https://ul.qucosa.de/id/qucosa%3A13752.
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This paper introduces and evaluates the second version of the global aerosol-climate model ECHAM-HAM. Major changes have been brought into the model, including new parameterizations for aerosol nucleation and water uptake, an explicit treatment of secondary organic aerosols,
modified emission calculations for sea salt and mineral dust, the coupling of aerosol microphysics to a two-moment stratiform cloud microphysics scheme, and alternative wet scavenging parameterizations. These revisions extend the model’s capability to represent details of the aerosol lifecycle and its interaction with climate. Nudged simulations of the year 2000 are carried out to compare the aerosol properties and global distribution in HAM1 and HAM2, and to evaluate them against various observations. Sensitivity experiments are performed to help identify the impact of each individual update in model formulation. Results indicate that from HAM1 to HAM2 there is a marked weakening of aerosol water uptake in the lower troposphere, reducing the total aerosol water burden from 75 Tg to 51 Tg. The main reason is the newly introduced k-Köhler-theory-based water uptake scheme uses a lower value for the maximum relative humidity cutoff. Particulate organic matter loading in HAM2 is considerably higher in the upper troposphere, because the explicit treatment of secondary organic aerosols allows highly volatile oxidation products of the precursors to be vertically transported to regions of very low temperature and to form aerosols there. Sulfate, black carbon,
particulate organic matter and mineral dust in HAM2 have longer lifetimes than in HAM1 because of weaker incloud scavenging, which is in turn related to lower autoconversion efficiency in the newly introduced two-moment cloud microphysics scheme. Modification in the sea salt emission scheme causes a significant increase in the ratio (from 1.6
to 7.7) between accumulation mode and coarse mode emission
fluxes of aerosol number concentration. This leads to a general increase in the number concentration of smaller particles over the oceans in HAM2, as reflected by the higher Ångström parameters. Evaluation against observation reveals that in terms of model performance, main improvements in HAM2 include a marked decrease of the systematic negative bias in the absorption aerosol optical depth, as well as smaller biases over the oceans in Ångström parameter and in the accumulation
mode number concentration. The simulated geographical distribution of aerosol optical depth (AOD) is better correlated with the MODIS data, while the surface aerosol mass concentrations are very similar to those in the old version. The total aerosol water content in HAM2 is considerably closer to the multi-model average from Phase I of the AeroCom
intercomparison project. Model deficiencies that require further efforts in the future include (i) positive biases in AOD over the ocean, (ii) negative biases in AOD and aerosol mass concentration in high-latitude regions, and (iii) negative biases in particle number concentration, especially that
of the Aitken mode, in the lower troposphere in heavily polluted
regions.
12
Zhang, Kai, Declan O'Donnell, Jan Kazil, Philip Stier, Stefan Kinne, Ulrike Lohmann, Sylvaine Ferrachat, et al. "The global aerosol-climate model ECHAM-HAM, version 2." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184753.
Full textAbstract:
This paper introduces and evaluates the second version of the global aerosol-climate model ECHAM-HAM. Major changes have been brought into the model, including new parameterizations for aerosol nucleation and water uptake, an explicit treatment of secondary organic aerosols,
modified emission calculations for sea salt and mineral dust, the coupling of aerosol microphysics to a two-moment stratiform cloud microphysics scheme, and alternative wet scavenging parameterizations. These revisions extend the model’s capability to represent details of the aerosol lifecycle and its interaction with climate. Nudged simulations of the year 2000 are carried out to compare the aerosol properties and global distribution in HAM1 and HAM2, and to evaluate them against various observations. Sensitivity experiments are performed to help identify the impact of each individual update in model formulation. Results indicate that from HAM1 to HAM2 there is a marked weakening of aerosol water uptake in the lower troposphere, reducing the total aerosol water burden from 75 Tg to 51 Tg. The main reason is the newly introduced k-Köhler-theory-based water uptake scheme uses a lower value for the maximum relative humidity cutoff. Particulate organic matter loading in HAM2 is considerably higher in the upper troposphere, because the explicit treatment of secondary organic aerosols allows highly volatile oxidation products of the precursors to be vertically transported to regions of very low temperature and to form aerosols there. Sulfate, black carbon,
particulate organic matter and mineral dust in HAM2 have longer lifetimes than in HAM1 because of weaker incloud scavenging, which is in turn related to lower autoconversion efficiency in the newly introduced two-moment cloud microphysics scheme. Modification in the sea salt emission scheme causes a significant increase in the ratio (from 1.6
to 7.7) between accumulation mode and coarse mode emission
fluxes of aerosol number concentration. This leads to a general increase in the number concentration of smaller particles over the oceans in HAM2, as reflected by the higher Ångström parameters. Evaluation against observation reveals that in terms of model performance, main improvements in HAM2 include a marked decrease of the systematic negative bias in the absorption aerosol optical depth, as well as smaller biases over the oceans in Ångström parameter and in the accumulation
mode number concentration. The simulated geographical distribution of aerosol optical depth (AOD) is better correlated with the MODIS data, while the surface aerosol mass concentrations are very similar to those in the old version. The total aerosol water content in HAM2 is considerably closer to the multi-model average from Phase I of the AeroCom
intercomparison project. Model deficiencies that require further efforts in the future include (i) positive biases in AOD over the ocean, (ii) negative biases in AOD and aerosol mass concentration in high-latitude regions, and (iii) negative biases in particle number concentration, especially that
of the Aitken mode, in the lower troposphere in heavily polluted
regions.
13
Lima, Vilma. "Evidências da participação de TNF-α e COX-2 nas mucosites oral e intestinal induzidas por 5-fluorouracil e metotrexato em animais." reponame:Repositório Institucional da UFC, 2004. http://www.repositorio.ufc.br/handle/riufc/551.
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A mucosite é caracterizada por úlceras e sintomas orais e intestinais causados por drogas citotóxicas, onde prostaglandinas (PG) e citocinas podem exercer efeitos pró-inflamatórios. O objetivo desse estudo foi verificar os efeitos do celecoxib (CLX) e indometacina (IND), inibidores da síntese de PG, e de pentoxifilina (PTX) e talidomida (TLD), inibidores da síntese de citocinas, em mucosites induzidas por antineoplásicos. Injetou-se 5-fluorouracil (FU 60 e 40 mg/kg-ip) em hamsters Golden machos, para a mucosite oral (MO); e metotrexato (MTX 2,5 mg/kg-sc) em ratos Wistar e em camundongos C57 machos, para a mucosite intestinal (MI). Grupos de hamsters com MO foram tratados sc com CLX (7,5, 15 ou 30 mg/kg), IND (0,25, 0,5 ou 1 mg/kg), PTX (5, 15 ou 45 mg/kg) ou TLD (10, 30 ou 90 mg/kg) diariamente durante 10 d e avaliados os seguintes parâmetros: análises macroscópica e histopatológica, atividade da mieloperoxidase (MPO), leucograma e variação de massa corpórea. O FU causou pico das ulcerações e abscessos no 10º dia (P<0,05), sendo confirmado pela análise histológica e atividade da MPO. Observou-se leucocitose, às custas de neutrófilos, e perda acentuada de massa corpórea. CLX (7,5 e 15 mg/kg), mas não IND, reduziu as úlceras e abscessos (66,6%), a leucocitose e a perda de peso. No entanto, CLX 30 mg/kg apresentou perda de eficácia antiinflamatória, causando aumento da mucosite oral. PTX (45 mg/kg) e TLD (90 mg/kg) reduziram a intensidade dos achados (66,6%), diminuindo as ulcerações e abscessos no 10º dia. Apenas PTX reduziu a leucositose induzida pela mucosite oral induzida. Na mucosite intestinal, ratos foram tratados ip com CLX (7,5, 15 ou 30 mg/kg), PTX (15, 30 ou 60 mg/kg) ou TLD (10, 30 ou 90 mg/kg) durante 5 dias, e avaliados pela análise morfométrica, permeabilidade intestinal via teste da lactulose e manitol, imunohistoquímica para detecção de TNF-α, leucograma e variações de massa corpórea, de ingestões de líquidos e alimentos dos animais. O MTX causou encurtamento dos vilos, aumento da profundidade das criptas, e perda da integridade do epitélio, com conseqüente redução da área absortiva intestinal, principalmente no duodeno, seguido pelo jejuno e em menor grau, no íleo. Observou-se leucopenia no 5º dia, além de redução de massa corpórea e das ingestões de líquidos e alimentos. CLX (30 mg/kg) preveniu a redução da área absortiva duodenal em 37%, além de diminuir a leucopenia. Não reduziu, porém, a perda de peso, nem alterou as ingestões de líquidos ou alimentos. PTX (15 mg/kg) foi capaz de inibir a redução da relação vilos/criptas em 38% no duodeno, com diminuição da solução de continuidade do epitélio, do infiltrado inflamatório e conseqüente proteção da área absortiva. Apesar de não ter prevenido a leucopenia ou as baixas ingestões de líquidos e alimentos, PTX foi capaz de reduzir a perda de massa corpórea significantemente. TLD (30 e 90 mg/kg) reduziu em 37% e 29%, respectivamente, a relação vilos/criptas duodenais induzida por MTX. TLD (90 mg/kg) causou redução significativa da marcação de TNF-α tanto ao nível de epitélio como na lâmina própria, quando comparado a mucosite não tratada. Entretanto, TLD não reduziu a leucopenia vista no 5º dia, nem preveniu a redução de massa corpórea e ingestões de líquidos ou alimentos. Camundongos C57BL/6 knockout para receptor R1 de TNF-α (TNF-R1-/-) apresentam relação vilos/criptas reduzida em relação a animais normais. Estes foram submetidos a MI por MTX e mostraram menores alterações ao nível de jejuno e íleo. Assim, os resultados demonstraram que os modelos animais de mucosites oral e intestinal reproduziram importantes aspectos dessa patologia em humanos. PTX e TLD e em menor grau, CLX, reduziram a inflamação nas mucosas induzidas por antineoplásicos, sugerindo-se que o TNF-α possa ser um mediador importante nas mucosites, enquanto que as prostaglandinas possuam uma função dependente de sua concentração
14
Menon, Surabo, Jean-Louis Brenguier, Olivier Boucher, Paul Davison, Genio Anthony D. Del, Johann Feichter, Steven Ghan, et al. "Evaluating aerosol/cloud/radiation process parameterizations with single-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations: Evaluating aerosol/cloud/radiation process parameterizations withsingle-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations." Wiley, 2003. https://ul.qucosa.de/id/qucosa%3A13455.
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The Second Aerosol Characterization Experiment (ACE-2) data set along with ECMWF reanalysis meteorological fields provided the basis for the single column model (SCM) simulations, performed as part of the PACE (Parameterization of the Aerosol Indirect Climatic Effect) project. Six different SCMs were used to simulate ACE-2 case
studies of clean and polluted cloudy boundary layers, with the objective being to identify limitations of the aerosol/cloud/radiation interaction schemes within the range of uncertainty in in situ, reanalysis and satellite retrieved data. The exercise proceeds in three
steps. First, SCMs are configured with the same fine vertical resolution as the ACE-2 in situ data base to evaluate the numerical schemes for prediction of aerosol activation, radiative transfer and precipitation formation. Second, the same test is performed at the coarser vertical resolution of GCMs to evaluate its impact on the performance of the
parameterizations. Finally, SCMs are run for a 24–48 hr period to examine predictions of boundary layer clouds when initialized with large-scale meteorological fields. Several schemes were tested for the prediction of cloud droplet number concentration (N). Physically based activation schemes using vertical velocity show noticeable discrepancies compared to empirical schemes due to biases in the diagnosed cloud base vertical velocity. Prognostic schemes exhibit a larger variability than the diagnostic ones, due to a coupling between aerosol activation and drizzle scavenging in the calculation of N. When
SCMs are initialized at a fine vertical resolution with locally observed vertical profiles of liquid water, predicted optical properties are comparable to observations. Predictions however degrade at coarser vertical resolution and are more sensitive to the mean liquid
water path than to its spatial heterogeneity. Predicted precipitation fluxes are severely underestimated and improve when accounting for sub-grid liquid water variability. Results from the 24–48 hr runs suggest that most models have problems in simulating boundary
layer cloud morphology, since the large-scale initialization fields do not accurately reproduce observed meteorological conditions. As a result, models significantly overestimate optical properties. Improved cloud morphologies were obtained for models with subgrid inversions and subgrid cloud thickness schemes. This may be a result of
representing subgrid scale effects though we do not rule out the possibility that better large-forcing data may also improve cloud morphology predictions.
15
Jacobi, Christoph, Rudolf Schminder, and Dierk Kürschner. "Long-period (2-18 Days) oscillations of mesopause winds at Collm." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-213040.
Full textAbstract:
Daily analyses of the zonal and meridional prevailing wind at the mesopause ( - 95 km height) are investigated with respect to planetary wave scale oscillations with periods ranging between 2 and 18 days. A mean climatology of the years 1983 - 1994 is presented. Time series of planetary wave activity show a significant increase during this period, which is in accordance with results from literatureTägliche Analysen des zonalen und meridionalen Grundwindes in der Mesopausenregion (- 95 km Höhe) werden hinsichtlich planetarer Wellenaktivität im Periodenbereich von 2 bis 18 Tagen untersucht. Es wird eine mittlere Klimatologie der Jahre 1983 - 1994 dargestellt. In diesem Zeitraum ist eine signifikante Zunahme der Wellenaktivität zu verzeichnen, die in Übereinstimmung mit Literaturangaben steht
16
Ozyurt, Funda. "Synthesis And Electrochromic Properties Of A Multichromic, Conducting, Soluble Polythiophene Derivative And Its Copolymer." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610630/index.pdf.
Full textAbstract:
A new polythiophene derivative, poly-2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl)quinoxaline PHTQ was synthesized by both chemical and electrochemical polymerization and its electrochemical properties were reported. The monomer was electrochemically polymerized in the presence of tetrabutylammonium hexafluorophosphate(TBAPF6) as the supporting electrolyte in dichloromethane-acetonitrile (5:95, v:v). Nuclear magnetic resonance spectroscopy (1H-NMR, 13C-NMR) was utilized for the characterization of the monomer and the soluble polymer. The polymer was further characterized by Gel Permeation Chromatography (GPC). Spectroelectrochemistry and switching ability of the polymer were investigated by UV&ndashvis spectrophotometer and cyclic voltammetry. The polymer revealed three distinctive colors upon doping which indicated that the polymer is multichromic. Tert-butyl group on the pendant phenyl rings and hexyl groups on thiophene enhanced the solution processability of the electrochromic polymer. The electrochemical and spectral properties of the chemically synthesized polymer were investigated via spray coating on ITO glass slides. Electrochemical copolymerization of 2,3-bis(4-tert-butylphenyl)-5,8-bis(4-hexylthiophen-2-yl) quinoxaline (HTQ) with 3,4-ethylenedioxythiophene(EDOT) was performed to fulfill a strategy in achieving fine-tuned electrochromic properties. The copolymer, P(HTQ-co-EDOT) was characterized via detailed studies of cyclic voltammetry and spectroelectrochemistry. Band gap (Eg) of the copolymer was calculated as 1.4 eV and showed 34 % optical contrast with switching times less than 1 second.
17
Yildiz, Ersin. "Synthesis And Electrochromic Properties Of Conducting Polymers Of 4-(2,5-di(thiophen-2-yl)-1h-pyrrol-1-yl) Benzenamine And Their Use In Electrochromic Devices." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610291/index.pdf.
Full textAbstract:
A monomer, 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) benzenamine (SNS-NH2), was synthesized via the reaction of 1,4-di(2-thienyl)-1,4-butanedione with benzene-1,4-diamine. Chemical polymerization of the monomer yielded a polymer which was completely soluble in organic solvents. The chemical structures of both the monomer and the polymer were characterized by Nuclear Magnetic Resonance Spectroscopy (1H-NMR and 13C-NMR) and Fourier Transform Infrared (FTIR) Spectroscopy. The average molecular weight of the chemically synthesized polymer was determined by Gel Permeation Chromatography (GPC) as Mn = 2.2x103 g/mol. The electrochemical oxidative polymerization of SNS-NH2 was carried out via potentiodynamic electrolysis in the presence of LiClO4, NaClO4 (1:1) supporting electrolyte in acetonitrile. Electrochemical copolymerization of SNS-NH2 in the presence of 3,4-ethylenedioxythiophene (EDOT) was achieved in acetonitrile (ACN) / NaClO4/LiClO4 (0.1M) solvent-electrolyte couple via potentiodynamic electrolysis. Conductivities of samples were measured by four probe technique.
Cyclic Voltammetry (CV) and Ultraviolet&ndashVisible Spectroscopy were used to investigate electrochemical behavior of the monomer and redox reactions of conducting polymers. Surface morphologies of the polymer films were investigated by Scanning Electron Microscope (SEM). Second part of the study was devoted to investigate the one of most interesting property of conducting polymers, the ability to switch reversibly between the two states of different optical properties, &lsquo
electrochromism&rsquo
. The electrochromic properties of the conducting polymers were investigated via spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemistry analysis of homopolymer, P(SNS-NH2), reflected electronic transitions at 376 and 650 nm indicating &
#960
-&
#960
* transition and polaron band formation respectively. The polymer has an electronic bandgap of 2.12 eV with a yellow color in the fully reduced form and a blue color in the fully oxidized form. Switching ability of the homopolymer was evaluated by kinetic studies upon measuring the % transmittance as 20.7 % at the maximum contrast point. The spectroelectrochemical behavior of the P(SNS-NH2-co-EDOT) compare to that of the homopolymer revealed solid evidence of copolymerization based upon the differences in the spectral signatures. Copolymer revealed multichromic property with five different colors at different applied potentials. Colorimetry studies for P(SNS-NH2-co-EDOT) proved that it is possible to provide fine tuning of these colors by varying applied potential during synthesis. The results of colorimetry, spectroelectrochemistry and FTIR studies showed the possible control of the color of the electrochromic material in a predictable, controlled and reproducible manner. As the last part of the study, dual-type complementary colored electrochromic devices (ECD) using P(SNS-NH2) and P(SNS-NH2-co-EDOT)/poly(3,4-ethylenedioxythiophene) (PEDOT) in sandwich configuration were constructed and evaluated. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were investigated by UV-Vis Spectrophotometer and Cyclic Voltammetry. They have shown to possess good switching times, reasonable contrasts and high stabilities.
18
Baran, Derya. "Electrochromic And Photovoltaic Applications Of Benzotriazole Bearing Donor Acceptor Type Conjugated Polymers." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611593/index.pdf.
Full textAbstract:
Organic semi-conductors are of great interest since these compounds can be utilized as active layers in many device applications such as ECDs, LEDs and solar cells. Incorporating the benzotriazole units into the polymer backbone enhances the optical properties of donor units. Hexyl thiophene and pyrrole are commonly used as electron donor materials. Benzotriazole can be coupled to hexyl thiophene or pyrrole to yield materials which can be polymerized to give donor acceptor type polymers. These materials are promising components in fast switching polymeric electrochromic devices and highly efficient photovoltaic devices. During thesis studies,poly(2-dodecyl-4,7-bis(4-hexylthiophen-2-yl)-2H-benzo[d][1,2,3]triazole) (PHTBT) and poly(2-dodecyl-4,7-di(1H-pyrrol-2-yl)- 2H- benzo [d] [1,2,3] triazole) (PPyBT) will be synthesized via N-alkylation, bromination, stannylation and Stille coupling reactions. Electrochromic and photovoltaic properties of the polymers will be investigated in detail.
19
Kerman, Ipek. "Synthesis And Characterization Of Poly(oxalic Acid Dithiophen-3-yl Methyl Ester) And Thiophene Ended Poly-&." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605014/index.pdf.
Full textAbstract:
Synthesis and characterization of thiophene ended poly-ε
-caprolactone (PCL) and oxalic acid dithiophen-3-yl methyl ester (ODME) and their copolymers with both pyrrole and thiophene were achieved. Chemical structure of the precursor polymer and monomer were investigated Redox behavior of polymer and monomers were determined by Cyclic Voltammetry (CV). Structural characterization of samples were carried out by 1H, 13C Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). Conductivities of the films were measured by using four probe technique. Thermal analyses of conducting copolymers were investigated via Differential Scanning Calorimetry (DSC) and Thermal Gravimetry Analysis (TGA). The morphologies of the copolymer films were examined by Scanning Electron Microscopy (SEM). Electrochromic and spectroelectrochemical behavior of the copolymers were investigated, and their ability of employment in device construction has been examined.
20
Menon, Surabo, Jean-Louis Brenguier, Olivier Boucher, Paul Davison, Genio Anthony D. Del, Johann Feichter, Steven Ghan, et al. "Evaluating aerosol/cloud/radiation process parameterizations with single-column models and Second Aerosol Characterization Experiment (ACE-2) cloudy column observations." Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-177303.
Full textAbstract:
The Second Aerosol Characterization Experiment (ACE-2) data set along with ECMWF reanalysis meteorological fields provided the basis for the single column model (SCM) simulations, performed as part of the PACE (Parameterization of the Aerosol Indirect Climatic Effect) project. Six different SCMs were used to simulate ACE-2 case
studies of clean and polluted cloudy boundary layers, with the objective being to identify limitations of the aerosol/cloud/radiation interaction schemes within the range of uncertainty in in situ, reanalysis and satellite retrieved data. The exercise proceeds in three
steps. First, SCMs are configured with the same fine vertical resolution as the ACE-2 in situ data base to evaluate the numerical schemes for prediction of aerosol activation, radiative transfer and precipitation formation. Second, the same test is performed at the coarser vertical resolution of GCMs to evaluate its impact on the performance of the
parameterizations. Finally, SCMs are run for a 24–48 hr period to examine predictions of boundary layer clouds when initialized with large-scale meteorological fields. Several schemes were tested for the prediction of cloud droplet number concentration (N). Physically based activation schemes using vertical velocity show noticeable discrepancies compared to empirical schemes due to biases in the diagnosed cloud base vertical velocity. Prognostic schemes exhibit a larger variability than the diagnostic ones, due to a coupling between aerosol activation and drizzle scavenging in the calculation of N. When
SCMs are initialized at a fine vertical resolution with locally observed vertical profiles of liquid water, predicted optical properties are comparable to observations. Predictions however degrade at coarser vertical resolution and are more sensitive to the mean liquid
water path than to its spatial heterogeneity. Predicted precipitation fluxes are severely underestimated and improve when accounting for sub-grid liquid water variability. Results from the 24–48 hr runs suggest that most models have problems in simulating boundary
layer cloud morphology, since the large-scale initialization fields do not accurately reproduce observed meteorological conditions. As a result, models significantly overestimate optical properties. Improved cloud morphologies were obtained for models with subgrid inversions and subgrid cloud thickness schemes. This may be a result of
representing subgrid scale effects though we do not rule out the possibility that better large-forcing data may also improve cloud morphology predictions.
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Köhler, Claas H. "Radiative Effect of Mixed Mineral Dust and Biomass Burning Aerosol in the Thermal Infrared." Doctoral thesis, 2013. https://ul.qucosa.de/id/qucosa%3A12268.
Full textAbstract:
This thesis treats the optical properties of mixed mineral dust and biomass burning aerosol in the thermal infrared (TIR) based on Fourier Transform infrared spectrometer (FTIR) measurements and radiative transfer simulations. The measurements were part of the Saharan Mineral Dust Experiment 2 (SAMUM-2) conducted from January to February 2008 at Praia, Cape Verde. The large amount of different instruments co-located at the main field site during the campaign resulted in a unique dataset comprising in-situ information and remote sensing data perfectly suited for column closure studies. The ultimate goal of this work is to investigate the consistency of microphysical and TIR remote sensing data. This is achieved by reproducing the measured radiances at top and bottom of the atmosphere (TOA, BOA) with a radiative transfer model, which assimilates the microphysical aerosol information gathered during SAMUM-2.
The first part of the thesis describes several experimental efforts, including a novel calibration method and a drift correction algorithm for the ground-based FTIR instrument operated within the scope of SAMUM-2 by the author. The second part introduces the concurrent radiative transfer library PIRATES, which has been developed in the framework of this thesis for the analysis of TIR aerosol optical properties. The third and final part of the treatise compares measured and simulated spectra for various typical scenarios encountered during SAMUM-2.
It is demonstrated in three case studies, that measured radiances in the TIR atmospheric window region (8-12 µm) can be reproduced at BOA and TOA by radiative transfer simulations assuming spheroidal model particles. Moreover,
spherical particles are shown to be an inadequate model for mineral dust aerosol
in this spectral region unless the aerosol optical depth is small.
22
Lilienthal, F., and Christoph Jacobi. "Comparison of quasi-2-day wave amplitudes and phases over Collm (51.3°N, 13.0°E) based on two different analyses." 2014. https://ul.qucosa.de/id/qucosa%3A16433.
Full textAbstract:
Collm meteor radar (MR) winds have been analyzed with respect to quasi 2-day wave (QTDW) amplitudes and phases. Two methods have been considered, one of them taking into account the varying period and the other one assuming a fixed period of 48 h. While the use of a fixed period leads to a slight underestimation of amplitudes, the seasonal cycle, the inter-annual variability, and the distribution of amplitude and phase diffferences between the zonal and meridional horizontal component are similar for both methods. One may conclude that the use of a fixed period is justified for analyzing QTDW amplitudes and phases as long as only qualitative results are required.