Dissertations / Theses on the topic 'Ppev'
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Gouin, Carla. "Tropisme cellulaire initial du SARS-CoV-2 dans le poumon humain : du poumon entier aux sous-populations de macrophages." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASL147.
The pathogenic mechanisms of the initial phase of the SARS-CoV-2 infection remain poorly understood at the pulmonary level, despite strong research efforts since the emergence of the COVID-19 pandemics. Studies conducted with various models, including isolated human cell cultures, explants, organoids or lung-on-a-chip systems have generated conflicting results concerning the primary pulmonary targets of the virus and the induced innate immune responses.In my thesis, I evaluated an original model for studying the early stages of viral infection. This model involves the infection of a whole lung that is maintained ex vivo with a technique used in lung transplantation, allowing the study of infection under conditions that preserve spatial interactions. This technique (ex-vivo lung perfusion, EVLP) involves ventilating and perfusing lungs for several hours and has the potential to evaluate and rehabilitate marginal lungs. We conducted single-cell RNA-seq analyses and we discovered that the whole lung maintained under EVLP without the virus displayed a specific gene activation program, which we analyzed in the first part of my thesis. We found that EVLP in itself induced an inflammatory response that varied over time and across cell types. This response was accompanied by gene signatures indicating reduced signaling of cytoskeleton in alveolar type 2 epithelial cells and endothelial cells, as well as reduced cell migration and activation of lymphocytes and dendritic cells. This work reveals, for the first time, the biological responses to EVLP based on cell types that may be related to the clinical outcomes. In the second part of my thesis, we infected lungs under EVLP with different viral isolates and conducted single-cell RNA-seq analyses. These analyses revealed that alveolar macrophages (AMs) and monocyte-derived macrophages (MoMacs) are the primary targets of the virus. Epithelial cells and pulmonary monocyte subpopulations were not significantly associated with the virus. We studied the response of the monocyte/macrophage populations in vitro after dissociation of human lung tissue, flow cytometry sorting and culture with the virus. We observed specific inflammatory responses depending on cell subsets, viral strain and doses, with MoMacs being the most inflammatory. Our original work reveals the role of monocyte/macrophage subsets in the initial phases of the SARS-CoV-2 infection and suggests that the initial response of alveolar monocyte/macrophages will drive the subsequent development of lung injuries, depending on the composition in AMs and MoMacs, the viral strain and doses. In a parallel project, we investigated the effects of a method aimed at reducing the inflammation during EVLP, on porcine lung, by performing a dialysis of the perfusate to remove accumulated metabolic wastes. However, our findings showed that dialysis did not reduce inflammation; rather, it increased inflammation after 6 or 12 hours.Overall, this thesis project has demonstrated the strengths and limitations of a whole lung viral infection model maintained ex-vivo. It has highlighted the involvement of monocyte/macrophage subpopulations in the initial step of SARS-CoV-2 infection and has also contributed to a better understanding of the cellular and molecular mechanisms involved in the ex vivo lung maintenance technique, which will be useful for improving lung transplantation procedures
Jonasson, Simon. "Phoenix. : PPE wildfire respirator." Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-162081.
Souza, Solange Maria Batista de. "Contribuições à implementação do PPEC: superando dualidades." Universidade Federal de Juiz de Fora, 2015. https://repositorio.ufjf.br/jspui/handle/ufjf/1375.
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O presente trabalho, intitulado “Contribuições à implementação do PPEC: superando dualidades”, foi desenvolvido no Mestrado Profissional em Gestão e Avaliação da Educação Pública da Universidade Federal de Juiz de Fora, com o objetivo de apresentar propostas para o aprimoramento da implementação do PPEC (Projeto de Pesquisa de Enriquecimento Curricular), em uma Escola Técnica Estadual no Estado do Espírito Santo, tendo em vista a importância e a necessidade de avaliação dessa política pública, contribuindo para o seu aprimoramento. Os sujeitos envolvidos foram os professores e alunos do CEET Vasco Coutinho, que participaram desta pesquisa por meio de entrevista semiestruturada para os professores e questionários para os alunos. A realização deste estudo foi estruturada em duas categorias centrais: trabalho como princípio educativo, fundamentado nos autores, Gaudêncio Frigotto, Maria Ciavatta, Marise Ramos, Acácia Kuenzer, Ramon Oliveira, Dermeval Saviani e Ronaldo Araújo e a pesquisa como princípio educativo, baseada nas concepções de Marise Ramos, Pedro Demo, nas Diretrizes Curriculares de EPT e nas Leis Federais e Estaduais. Ao final, foi apresentado um Plano de Ação Educacional, a partir dos resultados obtidos na pesquisa, no que se refere às fragilidades e aos pontos positivos. Esse plano foi organizado com base em três categorias centrais: Interdisciplinaridade, Sustentabilidade e Inovação, tendo como foco a revitalização do currículo de EPT e o aprimoramento e monitoramento dessa política pública.
This work, entitled "Contributions to the Implementation of the PPEC: Overcoming Dualities", was developed in the Professional Masters in Management and Public Education Evaluation of the Federal University of Juiz de Fora, in order to submit proposals for improving the implementation of the PPEC ( Research Project Enrichment Curriculum) in a public technical school in Espírito Santo state, in view of the importance and the need for evaluation of this public policy in order to contribute to its improvement. The subjects involved were teachers and students of CEET Vasco Coutinho, who took part in this research through semi-structured interviews for teachers and questionnaires for students. This research was structured into two main categories: work as an educational principle based on the authors, Gaudêncio Frigotto, Maria Ciavatta, Marise Ramos, Acacia Kuenzer, Ramon Oliveira, Dermeval Saviani and Ronaldo Araújo and research as an educational principle, based on the concepts of Marise Ramos, Pedro Demo, the Curriculum Guidelines of EFA and the Federal and State Laws. At the end, it was presented an Educational Action Plan from the results obtained in the research regarding to the weaknesses and the strengths of the project. The plan was organized from three main categories: Interdisciplinary, Sustainability and Innovation, focusing on the revitalization of the EPT (Professional and Technical Education) curriculum and the improvement as well as the monitoring of this public policy.
Kub, Christopher. "Hyperbranched conjugated polymers: an investigation into the synthesis, properties and postfunctionalization of hyperbranched poly(phenylene vinylene-phenylene ethynylene)s." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34838.
Fischer, Timo. "Parapockenvirus (PPV) als neuartige Vektorvakzine Entwicklung Pseudorabiesvirus-(PRV)-spezifischer PPV-Rekombinanten und Untersuchung deren Immunogenität im Mausmodell /." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965634124.
Gamael, Amin. "Ergebnisse nach kombinierter Operation PPV und Linsenchirurgie /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972337334.
Silva, Ricardo Manuel Pinho. "Células solares orgânicas baseadas em MEH-PPV." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/2626.
No presente trabalho procedeu-se ao estudo e fabrico de células solares orgânicas do tipo bulk heterojunction, baseadas no polímero poly(2-methoxy-5- (2-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV) dopada com a nanoestrutura [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) em filmes finos . A caracterização opto-electrónica revelou uma forte absorção na zona espectral azul-verde, confirmando a aplicabilidade destes materiais para este tipo de dispositivos. Foram obtidos valores relevantes em parâmetros como factor de forma e eficiência. É apresentada uma tentativa de explicação dos resultados com base nas propriedades micro-eléctricas e morfológicas. Produziram-se, de igual forma, células flexíveis baseadas na mesma estrutura, tendo em vista a sua aplicabilidade em larga escala. ABSTRACT: In this work some thin film bulk-heterojunction organic solar cells based on polymer poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) (MEHPPV) doped with nanostructures [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) was made and studied. The opto-electrical characterization showed a strong absorption in the blue-green spectrum region, confirming the applicability of these materials for this kind of devices. Relevant data was obtained for fill-factors and efficiency. An attempt to explain the macroscopic behavior based on micro-electrical and morphological properties was done. Flexible devices based on same structure were also made in order to test the possible application in large scale.
Greenham, Neil Clement. "Electroluminescence in conjugated polymers." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296643.
Bailey, Dalan. "Development of reverse genetics for peste des petets ruminants virus (PPRV)." Thesis, University of Reading, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494788.
Cossiello, Rafael Di Falco 1980. "Fotofisica de polimeros emissores de luz : MEH-PPV." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249455.
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Mestrado
Wallaart, Johannes Christiaan Safety Science Faculty of Science UNSW. "Identification, elimination and reduction of barriers to the effective use of respiratory personal protective equipment." Publisher:University of New South Wales. Safety Science, 2008. http://handle.unsw.edu.au/1959.4/43293.
Lear, Jeremy M. "The Synthesis of Benzyloxy Substituted DP-PPV and Examination of the Horner-Wadsworth-Emmons Reaction in the Synthesis of DP-PPV." Wright State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=wright1401459783.
Janakiraman, Umamaheswari. "Analysis of electrogenerated chemiluminescence of PPV type conducting polymers." Doctoral thesis, [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968755305.
Weir, Bruce Alexander. "Structure and morphology of PPV-derived polymers and oligomers." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621077.
Grimes, Amy Frances. "Toward optimization of photomodulation of azobenzene-modified PPV derivatives." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7607.
Thesis research directed by: Dept. of Chemistry and Biochemistry. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Saar, Brooklynd Dawn. "Fluorescence Quenching of PPV-SO and Bodipy-Naphthalene Systems." W&M ScholarWorks, 2012. https://scholarworks.wm.edu/etd/1539626932.
Masuda, Koji. "Design and Fabrication of Nanostructures by Layer-by-Layer Assembly for Organic Photovoltaic Devices." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/123342.
Thamyongkit, Patchanita. "Synthesis and characterization of pyrazine and phthalocyaninatonickel(II) substituted PPV analogous oligomers Synthese und Charakterisierung von Pyrazin- und Phthalocyaninatonickel(II)-substituierten PPV-anologen Oligomeren /." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963899929.
Wetzel, Thierry. "Obtention d'outils moléculaires pour la détection et la différenciation du virus de la sharka (PPV) : clonage de l'ARN génomique d'une nouvelle souche de PPV." Bordeaux 2, 1991. http://www.theses.fr/1991BOR22016.
Timpanaro, Salvatore. "Conductive properties and morphology of conjugated molecular materials studied by local probe techniques." Phd thesis, [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974115991.
Mahasha, Phetole Walter. "The trafficking of the Mycobacterium tuberculosis PE and PPE proteins." Thesis, Stellenbosch : University of Stellenbosch, 2007. http://hdl.handle.net/10019.1/1862.
The expansion of the Mycobacterium tuberculosis PE and PPE gene families seems to be linked to that of the immunologically-important ESAT-6 (esx) gene clusters secretion system, as the ancestral members of these families are found only within the ESAT-6 gene cluster regions. These ancestral members are also the only copies in the earlier mycobacteria like M. smegmatis. The later duplications of the PE and PPE families belonging to the PGRS and MPTR subgroups, have been implicated in virulence and are only found within the genomes of the pathogenic mycobacteria closely related to the M. tuberculosis complex. The aim of this study was to compare the subcellular localization of the later duplications of the PE and PPE gene families belonging to the PGRS and MPTR subgroups with that of the ancestral PE and PPE proteins found in M. smegmatis and to investigate whether the ESX secretion apparatus is involved in the trafficking of these proteins. The PE (Rv3872) and PPE (Rv3873) genes from M. smegmatis were PCR amplified with a C-terminal HA tag using M. smegmatis genomic DNA as template. Two PPE-MPTR genes, Rv0442c and Rv0878c, and one PE_PGRS gene, Rv2615c, were also PCR amplified with a C-terminal HA tag using M. tuberculosis genomic DNA as template. All genes were cloned into the mycobacterial expression vector p19Kpro. Expression and localization was investigated using SDS-PAGE and Western blotting. The PE and PPE genes expressed in M. smegmatis were found to be present within the cell wall, membrane, and cytosol fractions, but not in the culture filtrate, indicating no secretion. The PPE-MPTR and PE_PGRS genes expressed in M. smegmatis, were also found to be present within the cell wall, membrane and cytosol fractions, but not in the culture filtrate, indicating that they are also not secreted. We hypothesize that their secretion is dependent on ESAT-6 gene cluster region 5, which is absent from the genome of M. smegmatis. Ancestral PE and PPE proteins are secreted efficiently in M. tuberculosis. The ESAT-6 gene cluster Region 3 and Region 4 of M. smegmatis were knocked out, and these knockout mutants could be used in future studies to investigate if the ESAT-6 gene cluster region 1 is involved in the secretion of the ancestral and recent PE and PPE proteins.
Fogle, Jeffrey D. "Synthesis of Fluorinated Indenofluorenediones and Bis(2-fluorophenyl) Substituted PPV." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1309441933.
Costa, Rui Jorge Gonçalves. "Interpretação no turismo: o caso do Portugal dos Pequenitos (PPE)." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/9338.
Atualmente, o Turismo tem-se afirmado como uma das principais atividades económicas a nível mundial. Em Portugal, o Turismo representa cerca de 10% do PIB nacional, sendo vital para o desenvolvimento e crescimento de toda a economia nacional. Com o aparecimento de novas necessidades dos turistas, a interpretação assume-se como uma das principais ferramentas do Turismo, dando resposta às diferentes exigências e motivações dos turistas e tem promovido a identidade cultural das atrações turísticas e uma maior satisfação dos turistas. Assim, pretendeu-se com este projeto: (i) Compreender o que é a interpretação no Turismo; (ii) Analisar o potencial impacte da interpretação para os turistas e para os destinos; (iii) Compreender todo o planeamento de um processo de interpretação, incluindo o processo de avaliação da interpretação; (iv) Avaliar a interpretação no “Portugal dos Pequenitos (PPE)”. No sentido de cumprir os objetivos propostos foi realizada uma entrevista dirigida aos visitantes do PPE, tendo-se obtido vinte entrevistas, divididas por quatro grupos diferentes de visitantes. Feita a análise dos dados recolhidos e entre várias conclusões encontradas, a mais importante que se pode retirar da investigação empírica é que, de facto, um plano de interpretação eficiente pode potenciar a competitividade e o valor cultural/histórico das atrações turísticas.
Nowadays, tourism is one of the main economic activities worldwide. In Portugal, tourism it represents about 10% of national GDP, being vital for the development and growth of the entire national economy. With the emergence of new needs of tourists, the interpretation became one of the main tools of tourism, giving answer to the various requirements and motivations of tourists and has promoted the cultural identity of tourism attractions and a greater satisfaction of tourists. Thus, with this project it was aimed to: (i) Understand what the interpretation in tourism is; (ii) Analyze the potential impact of interpretation for tourists and destinations; (iii) Understand the planning of an interpretation process, including the assessment of interpretation; (iv) Evaluate the interpretation in the "Portugal dos Pequenitos (PPE)." In order to achieve the proposed objectives was held an interview aimed at visitors of PPE was held and twenty interviews were obtained, divided by four different groups of visitors. After doing the analysis of the data collected, among several conclusions found, the more important that can be withdraw from the empirical research is, indeed, that a powerful interpretation plan can boost competitiveness and cultural/historical value of tourist attractions.
Majeed, Awais. "A process performance evaluation framework (PPEF) for partner selection during virtual organisation creation phase." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504699.
Buczkowski, Hubert. "Development of marker vaccines for rinderpest (RPV) and peste des petits ruminants (PPRV) viruses." Thesis, Royal Veterinary College (University of London), 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.558958.
Sanz, Bernardo Beatriz. "Control of host innate immune (interferon) responses by peste des petits ruminants virus (PPRV)." Thesis, St George's, University of London, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.703281.
Olivati, Clarissa de Almeida. "Estudo das propriedades elétricas e ópticas de dispositivos eletroluminescentes poliméricos." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-08122010-094137/.
Polymer electroluminescent devices are promising for a number of applications, in particular due to the possibility of obtaining large area, flexible displays. There are, however, major stumbling blocks associated with the short lifetimes and limited efficiency and brightness of light-emitting diodes (LEDs) fabricated with organic molecules in comparison with the inorganic ones. Severa1 methods have been proposed to increase brightness and eficiency, which include the use of electron and/or hole transporting layers adjacent to the electrodes. ln this thesis, we report the study of severa1 methods to improve the efficiency of the polymer light emitting diodes (PLEDs). In this context, Langmuir-Blodgett (LB) films were used in PLEDs, as emitting and electron transport layer, due to the high degree of thickness control, low number of defects, and some degree of organization at the molecular scale. Besides, improvements in electron injection into the emissive layer using ionic polymers (ionomers) as electron-transporting layers were observed. Othenvise, the combination of POMA and ITO as transparent electrode and PPV+DBS as active layer (ITO/POMA/PPV+DBS/A1) leads to a decrease in the operating voltage compared with the conventional PLED, ITO/PPV/Al. The devices were characterized by electrical and opto-electrical measurements.
Alves, Marcelo Caetano Oliveira. "Estudo de soluções de MEH-PPV em dosimetria de radiação gama." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-03092008-091923/.
The present work aims the study of the viability of using solutions of poly[2-methoxy-5-(2\'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV), in several solvents such as chloroform (CHCl3), dichloromethane (CH2Cl2), bromoform (CHBr3), dibromomethane (CH2Br2), a mix of dichloromethane (CH2Cl2) and diiodomethane (CH2I2), and toluene (C6H5CH3) as ionizing radiation dosimeters, gamma, in this case. The novelty is in the fact of the dosimeter main characteristic is color change, allowing a visual and direct received radiation measurement. Besides, the sensibility of the dosimeter can be adjusted by the polymer solution concentration variation. In this work, it was used the gamma radiation, 60Co, for the dosimeter viability studies. When exposed to certain doses of this kind of radiation, the studied polymer suffers changes in its optic properties and in its molecular structure. In order to evaluate the optical changes, UV-VIS absorption and photoluminescence spectroscopy measures were performed. Besides, the molecular structure changes, as a consequence of the exposure to gamma radiation, were evaluated by nuclear magnetic resonance (NMR) and Gel Permeation Chromatography (GPC). The results show that the gamma radiation, 60Co, promotes, indirectly, the decrease of the polymer conjugation length probably due the backbone scission caused by reactions with reactive species, probably in the vinyl side groups. These scissions resulted in a blueshift of the absorption spectra maximum peaks. Theses blueshifts depend on the irradiation dose, the used solvent and the solution concentration.
Ferreira, Ana Guida Coutinho. "Promoção da eficiência no consumo de energia eléctrica: o caso do plano de promoção da eficiência no consumo." Master's thesis, Instituto Superior de Economia e Gestão, 2010. http://hdl.handle.net/10400.5/2239.
Com o desenvolvimento económico a estimular a procura de energia, e a existência de barreiras e falhas de mercado que dificultam a eficiência energética, é fundamental a implementação de programas de promoção da eficiência energética e de gestão da procura. Em Portugal, o Plano de Promoção da Eficiência no Consumo de energia eléctrica, que teve a sua primeira edição em 2007, visa promover medidas no âmbito da eficiência energética, mediante um concurso aberto a vários agentes. Este relatório descreve o processo de avaliação das quatro medidas do segmento residencial de 2007, quer a nível ex-ante (aquando da seriação das mesmas para financiamento), quer a nível ex-post (após a implementação). As medidas avaliadas apresentam rácios benefício-custo positivos, demonstrando toda a sua valia económica e social. A grandeza dos números conseguidos reforça assim a ideia de que a promoção da eficiência energética, do lado da procura, se apresenta como uma solução viável na mitigação da dependência dos combustíveis fósseis e do nível de emissões de CO2.
Energy efficiency and demand side management programs are key to cope with increasing energy demand associated with economic growth and with existing barriers to energy efficiency and related market failures. In Portugal, the Plan to Promote the Efficient Consumption of electrical energy, which first took place in 2007, aims to promote energy efficiency measures through a competitive mechanism open to various stakeholders. This report describes the evaluation process for the residential segment used in 2007 both at an ex-ante level (when evaluating financing measures) as well as an ex-post level (following implementation). The measures evaluated show positive cost-benefit ratios, demonstrating their full economic and social value. The size of the figures achieve thus reinforce the idea that promoting energy efficiency, from a demand point of view, is presented as a viable solution in mitigating dependence on fossil fuels and reducing CO2 emissions.
Lenihan, Catherine. "Functional characterisation of VAV-interacting Krüppel-like factor (VIK) in breast cancer." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/24559.
Postacchini, Bruna Bueno. "Fotofísica em heteroestruturas contendo o polímero emissor PPV e espécies supressoras." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-30012009-114630/.
Understanding the pathway of excitation in conjugated polymers is important for using these materials as active layer in devices, photovoltaic cells and sensors. In this thesis, non-radiative processes in layer-by-layer (LbL) films were investigated with measurements of fluorescence quenching in steady-state fluorescence spectroscopy and of the singlet excited state lifetime using time-resolved fluorescence spectroscopy in a single photon counting (SPC) apparatus. The emissive layer of poly(p-phenylene vinylene) (PPV) obtained via thermal conversion of the soluble precursor poly(xylylidene tetrahydrothiophenium) chloride (PTHT) showed lifetime 150-250 ps and weak dependence on the emission wavelength. In the presence of an acceptor layer of either Congo Red (CR) or nickel tetrasulfonated phthalocyanine (NiTsPc) the PL intensity was quenched and the lifetime was shorter (50 -100 ps). Upon increasing the distance between the energy donor (PPV) and acceptor layers by interposing bilayers of inert polyelectrolytes the dynamics tended to the PPV dynamics. The distance-dependence of the energy transfer efficiency (1/r2 or 1/r3) points to a resonant process (RET) with a plane-to-plane or plane-to-slab interaction. The non-radiative processes were also studied for varying dilutions of the PPV segments in a matrix of the polyelectrolyte poly(dodecyl methylamonium chloride) (PDAC). This dilution increased the quantum efficiency and led to longer lifetimes (500 ps) owing to a less effective non-radiative energy transfer. When an energy acceptor layer is present, energy transfer is more efficient for the most diluted systems, indicating that such transfer competes with internal processes in the emissive layer. The lifetime increased in films with low degree of conjugation, for which there was a stronger dependence on the emission wavelength. It is concluded that the LbL methodology was suitable to obtain photophysical film properties that could be controlled at the molecular level, and investigated with varied fluorescence spectroscopies.
Marconi, Flávia Maria. "Síntese e caracterização de polímeros com propriedades eletroluminescentes." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-14112014-102419/.
In this work, three dialkoxy derivatives of poly(p-phenylenevinylene),which differs from each other by the size of the side chain, were synthesized and characterized: the poly(2-methoxy-5-hexyloxy-p-phenylenevinylene), MH-PPV, the poly(2-methoxy-5-dodecoxy-p-phenylene-vinylene), MD-PPV and the poly(2-methoxy- 5-hexadecoxi-p-phenylene-vinyleno), MHd-PPV. These polymers have electroluminescent properties and can be used in light emitting devices. The synthesis consists in three steps: synthesis of aromatic ether, bischloromethylation of the ether yielding the monomer, and polymerization. The major difference regarding the synthesis processes lies on the monomer synthesis. A larger excess of reagents and longer reaction times were necessary to obtain the MD-PPV and MHd-PPV than that used to obtain the MH-PPV. All the products of the two first steps were characterized mainly by FTIR and NMR (proton and carbon 13). The chemical structures of the polymers were confirmed by FTIR and the molar masses determined by characterized by Size Exclusion Chromatography, revealing a high polydispersity and values of mean mass molecular weight (Mw) around 105. The thermal analysis presented values of glass transition temperatures, Tg, and softening, Ts, above 100 oC, and decomposition temperatures above 400oC for the three polymers. The MHd-PPV, presented, besides the Tg, a transition in 50oC, which may be related to the melting of the side chain. Films of the three polymers prepared from different solvents presented different morphologies, as observed by Atomic Force Microsocopy, slightly different absorptions (500-520 nm) and emission (585-600 nm) maxima and different photo-degradation processes depending on the solvent used to prepare the films. Therefore, the different size of the side chain presented effects mainly on characteristics as thermal transitions and film morphologies, and, in consequence of the late, on the shape of the emission and on the degradation properties
Todescato, Francesco. "Functional dielectric/semiconductor and metal/semiconductor interfaces in organic field-effect transistors." Doctoral thesis, Università degli studi di Padova, 2007. http://hdl.handle.net/11577/3425125.
Cera, Alexandre Manuel Gomes. "Certificados brancos para o caso português : análise económica e contributos para a sua aplicação e implementação." Master's thesis, FEUC, 2012. http://hdl.handle.net/10316/20102.
Dadas as preocupações ambientais e energéticas e os objetivos europeus estabelecidos para 2020, entre os quais o aumento em 20% da eficiência energética (EE), os decisores públicos procuram novos instrumentos que permitam alterar e/ou otimizar os padrões de consumo de energia do lado da procura. Um instrumento de política energética e de EE que tem ganho atenção dos decisores públicos são os Certificados Brancos (CBs). Um esquema de CBs, sendo um instrumento baseado no mercado, está alinhado com a desregulação do lado da oferta nos mercados energéticos como permite minimizar distorções de mercado e refletir com maior precisão as preferências dos consumidores. O objetivo último da presente dissertação é estabelecer uma proposta conceptual da configuração de um esquema de CBs transacionáveis a implementar em Portugal. Neste sentido, procede-se a um estudo com base numa carteira de cinco critérios pré-selecionados, acerca da viabilidade económica dos CBs; da experiência em esquemas de CBs transacionáveis europeus, cuja análise descritiva foi complementada com um estudo comparativo dos esquemas em questão nos países selecionados (e.g. Itália, França, Grã-Bretanha); da incidência energética de um esquema de CBs em Portugal; da integração de um esquema de CBs na política energética nacional e europeia, abarcando a questão da liberalização dos mercados de eletricidade e gás natural; e, por fim, do enquadramento de um esquema de CBs com a experiência portuguesa em EE, nomeadamente com o Plano Nacional de Ação para a Eficiência Energética (PNAEE) e o Programa de Promoção da Eficiência no Consumo de Energia Elétrica (PPEC), incluindo a atuação das entidades que os coordenam. Para além de ser um instrumento custo-eficaz, um esquema de CBs transacionáveis, tem a característica exclusiva, sob determinadas condições, de simultaneamente incentivar melhorias de EE, e reduzir o rebound effect e o efeito de free rider. Esta conclusão, no conhecimento dos autores, é única na literatura da área. Com base nas elações que se teceram, apoiadas na abordagem metodológica adotada, sugeriram-se alguns aspetos que se tomaram como mais relevantes na persecução do objetivo estabelecido (e.g. natureza e objetivo de poupanças energéticas; elegibilidade). Crê-se que um esquema de CBs transacionáveis acrescentará valor ao portefólio de instrumentos de política energética portuguesa.
Given the environmental and energy concerns, and the European targets set for 2020, including the 20% increase in energy efficiency (EE), policy makers are seeking new tools to change and/or optimize current patterns of demand side energy consumption. An energy policy and EE instrument which has gained the attention of policy makers is White Certificates (WCs). A scheme of WCs, being a market-based mechanism, is aligned with deregulation of the supply side of the energy market, and allows to minimise distortions in the market and to more accurately reflect consumer preferences. The ultimate objective of this dissertation is to establish a conceptual proposal of the design of a tradable WCs scheme to implement in Portugal. In this sense, we proceed with a study based on a portfolio of five pre-selected criteria, about the economic viability of WCs; the experience of European tradable WCs schemes, whose descriptive analysis was complemented with a comparative study of the schemes in selected countries (e.g. Italy, France, Great Britain); the energetic scope of a WCs scheme in Portugal; the integration of a WCs scheme in national and European energy policies, covering the issue of electricity and natural gas markets liberalization; and finally, the frame of a WCs scheme with the Portuguese experience in EE, in particular the National Action Plan for Energy Efficiency (PNAEE) and the Program for Promoting Efficiency in Electricity Consumption (PPEC), including its’ coordinator entities performance. Besides being a cost-effective instrument, a tradable WCs scheme has the exclusive feature, under certain conditions, of simultaneously stimulating improvements in EE while reduces the rebound and free rider effects. This conclusion, in the authors' knowledge, is unique in the literature. Based on our elations, supported by the adopted methodological approach, we suggest some aspects that have been taken as more relevant in pursuing our objective (e.g. energy savings nature and target; eligibility). We believe that a tradable WCs scheme will add value to the Portuguese energy policy instruments portfolio.
Pu, Zhengxiang. "A Dynamic Model of the Human/Cooling System/Clothing/Environment System." Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2077.
Ph.D.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Mechanical Engineering
Cossiello, Rafael Di Falco 1980. "Eletroluminescencia e morfologia de blendas polimericas : copolimeros ionicos de SAA e blendas com MEH-PPV." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249467.
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: O copolímero SAA (poli(estireno-co-ácido acrílico-co-1-metacrilato de pirenilmetila)) foi sintetizado por via radicalar em agua e caracterizado por analises termicas (DSC, TGA), espectroscopicas (NMR C e H, UV-VIS, FTIR, fluorescência estacionária e resolvida no tempo) e elétricas (eletroluminescência). As blendas com poli[2-metóxi-5-(2¿-etilóxi)-p-fenilenovinileno] MEH-PPV foram estudadas desde 0,01; 0,05; 0,10; 0,50; 1,0; 10,0; 25; 50; 75 e 90 (% em massa) de MEH-PPV em SAA para ánalise da evolucao da morfologia por microscopia óptica, de fluorescência e eletrônica de varredura em espessuras de 70 mm (fratura criogênica) e 70 nm (espessura do dispositivo). Em baixas concentracões os domínios de MEH-PPV se apresentam em forma de núcleos dispersos e empacotados e conforme se aumenta a concentracao de MEH-PPV, observa-se que há a coalescência destes núcleos até a formação de uma fase interconectada de uma rede tridimensional. As medidas de difração à altos angulos mostram que há uma preferência de orientação do MEH-PPV ao longo do substrato e nao influencia a isotropia do SAA devido a baixa miscibilidade entre estes polímeros. As unidades de 1-pirenil metila foram utilizadas para avaliar a polaridade do microambiente e o mecanismo de transferencia de energia entre o doador (SAA) e o receptor (MEH-PPV). A dependência do tempo de fluorescência das unidades 1-pirenilmetila com a concentracao do MEH-PPV fornece subsídios para concluir que ocorre interpenetração de cadeias e, portanto uma baixíssima solubilidade entre os dois polímeros. O melhor desempenho de eletroluminescência foi do dispositivo preparado a partir da mistura 50:50 de MEH-PPV:SAA, cuja corrente elétrica foi aumentada em 2,5 vezes e a luminância em 4 vezes se comparado com o dispositivo de MEH-PPV puro. A morfologia de fase interconectada se mostrou importante para um melhor processo de transporte de cargas. O copolímero de SAA permitiu uma melhor injeção de cargas devido aos grupos carboxila presentes das unidades de ácido acrílico
Abstract: The copolymer SAA poly(styrene-co- acrylic acid -co-1-pyrenylmethyl methacrylate) was synthesized by radical emulsion in water and characterized by thermal analyses (DSC, TGA), spectroscopic (NMR 13C and 1:00, UV-VIS, FTIR, stationary and time-resolved fluorescence) and electric (electroluminescence). The blends with poly[2-methoxy-5(2'ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) were studied from 0. 01; 0. 05; 0.10; 0.50; 1.0; 10.0; 25; 50; 75 and 90 (% in mass) of MEH-PPV in SAA to analyze the morphology evolution by optical, epifluorescence and electronic microscopy. The films were prepared in two thicknesses: one around 70 mm to be analyzed by cryogenic fractures and 70 nm, to be comparable with the device thickness. In low concentrations the domains of MEH-PPV appears dispersed nuclei and accrete when the concentration of MEH-PPV is increased forming an interconnected phase. The diffraction measures (WAXD) show a preference orientation of MEH-PPV along the substrate plane and it do not influences the SAA due the low miscibility between each other. The increase of the MEH-PPV concentration showed a redshift on electroluminescence spectrum due the inner filter and auto-absorption and re-emission effects. The units of 1-pyrenylmethyl were used to evaluate the polarity of the microenvironment and the mechanism of energy transfer of among the donor (SAA) and the acceptor (MEH-PPV). The timedependence of fluorescence with the increase of MEH-PPV concentration show that occurs an chain interpenetration following the fluorescence non-radiative energy transfer model. The best electroluminescent device was prepared using the mixture 50:50 of MEH-PPV:SAA. The interconnected phases are important for a better process of charge transport. The copolymer SAA allowed for a dilution effect avoiding the aggregation process and facilitating the charge injection processes. This technology of polymeric blends gave good results the increase of the luminance intensity and reduction of the voltage operation
Doutorado
Físico-Química
Doutor em Ciências
Sarnecki, Greg. "Studies in soluble conjugated polymers." Thesis, University of Cambridge, 1994. https://www.repository.cam.ac.uk/handle/1810/272769.
Halliday, David Alan. "The synthesis and characterisation of poly(p-phenylenevinylene)s." Thesis, University of Cambridge, 1992. https://www.repository.cam.ac.uk/handle/1810/272381.
Sorce, Steven R. "The military housing problem Public Private Venture (PPV) and complete privatization alternatives /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2000. http://handle.dtic.mil/100.2/ADA379322.
Thesis advisor(s): Simon, Cary A.; . Eaton, Donald R. "June 2000." Includes bibliographical references (p. 73-74). Also available in print.
Kuch, Serena [Verfasser], Matthias [Akademischer Betreuer] Rehahn, and Stefan [Akademischer Betreuer] Immel. "Neue PPV-Derivate auf ungewöhnlichen Wegen / Serena Kuch ; Matthias Rehahn, Stefan Immel." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2019. http://d-nb.info/1176702017/34.
Faleiros, Marcelo Meira. "Espectroscopia ultrarrápida do polímero semicondutor luminescente MEH-PPV com excitação no ultravioleta." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-06122012-084909/.
The optoelectronics industry is currently undergoing a transition period in which inorganic materials are being replaced by organic materials, oligomers and polymers, in the fabrication of some types of devices. However, factors such as low efficiency and low lifetime prevent polymer based devices on entering the market definitely. The solution of these issues requires a thorough knowledge of the electronic structure of these materials, but despite of scientific advances, there are still points to be clarified. For example, there is no consensus on the nature of the primary optical excitations and non-radiative processes in conjugated polymers, specially with ultraviolet excitation. Such processes limit the efficiency and can influence the photochemical processes, determining the device lifetime. These phenomena occur on a femtosecond timescale and therefore, ultrafast spectroscopy is the most appropriate technique for their study. In this work, we implemented the apparatus for pump-probe ultrafast spectroscopy on thin films of conjugated polymers, which can be used with two methods of data acquisition, phase-sensitive and shot-by-shot. The first is the standard method reported in the literature in which the excitation beam is modulated by a chopper and the signals measured by lock-in amplifiers. In the second, the detector signal conditioning is done by conventional amplifier circuits, followed shot-to-shot signal processing. This method provides the best statistics, in principle, because the laser fluctuations are normalized for each pulse, instead of using the average. In addition, the apparatus has a lower cost and the experiment is simpler, having as critical procedures the alignment of the beams on the sample and the determination of zero delay, with all other procedures done via software. The electronic circuitry for signal conditioning was designed and built and data acquisition software that enables measurements with both methods was developed in the LabVIEW programming language. However, the shot-by-shot method provided an inadequate sensitivity for the study of polymeric films (ΔT⁄T ~0.7%, limited by electronic noise in the amplification of detector signals), compared with ΔT⁄T ~ 0.1%, which was achieved by the phase sensitive method, and was the goal at the beginning of the project. Thus, the latter method was used to study the evolution of the spectrum and dynamics of stimulated emission of a film of MEH-PPV, with excitation in the visible and UV, allowing the study of the dynamics of higher lying electronic states. The results in the visible are consistent with those reported in the literature, which demonstrates the performance of the apparatus with respect to sensitivity and time/spectral resolution. The results with UV excitation indicate that the energy transfer among the more energetic bands to the π - π* band (internal conversion) occurs in about 300 fs, confirming the assumptions of the literature on the ultrafast energy relaxation processes (Kashas rule), besides suggesting the existence of even more energetic bands than those currently known. As future work, we plan to measure the efficiency of this energy transfer process, since it may be the limiting step in determining the overall photoluminescence efficiency of conjugated polymers with ultraviolet excitation.
Thamyongkit, Patchanita. "Synthesis and Characterization of Pyrazine and Phthalocyaninatonickel (II) Substituted PPV Analogous Oligomers." [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB9909232.
Martschick, Anja [Verfasser]. "Pathogenese und Prävention der Anthrazyklin-induzierten PPE : eine prospektive Studie / Anja Martschick." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2010. http://d-nb.info/1024502171/34.
Campos, Patrícia Bueno de. "Síntese e caracterização de derivados do poli(fenileno-vinileno) com diferentes massas molares." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-14112014-095557/.
Electroluminescent polymers have been widely investigated due to its potential applications in optoelectronic devices such as polymer light-emitting diodes (PLEDs). Most of the polymers suitable for application in PLEDs are related to the poly(arylenes-vinylene) polymers, including the poly(p-phenylene-vinylene) (PPV) and its derivatives, which are of special interest. Such materials can exhibit significant differences on their final properties upon changes on specific synthesis parameters. In this work it is described the influence of three different additives, viz. 4-methoxyphenol, terc-butyl chloride and benzyl chloride, on the polymerization process of the derivative poly(2-methoxy-5-hexyloxy-p-phenylenevinylene) MHPPV. Size Exclusion Chromatography analyses revealed that the type and rate of incorporation of the additives to the polymerization reaction largely affects the molecular weight of the polymers. In addition, it was observed that the use of additives leads to the synthesis of low molecular weight polymers, increasing their solubilities in common organic solvents, eg. chloroform and tetrahydrofuran. The glass transition temperature (Tg) of the polymers was determined by differential scanning calorimetry (DSC) to be ca. 160oC. Interestingly, all the polymers presented an additional transition point at ca. 75oC. Neither the electronic absorption nor the emission spectra were affected by the differences on the molecular weight of the polymers. Finally, it was possible to establish correlations between the molecular weight analyses (from HPSEC) and viscosity experiments, which can be useful for Mw determination
Mantip, Samuel Elias Lashat. "Molecular characterisation of peste des petits ruminants viruses in sheep and goats from Nigeria." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/40708.
Dissertation (MSc)--University of Pretoria, 2013.
gm2014
Veterinary Tropical Diseases
unrestricted
Faceto, Angelo Danilo. "Simulação dos processos de migração e relexação energética em sistemas orgânicos pi-conjugados emissores de luz." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-06092007-104908/.
In the present work, the Monte Carlo method is employed to simulate the excitation spectral diffusion process in light emitting polymeric systems. The methodology employed a competition among the internal intra-molecular vibrational relaxation, the inter-molecular incoherent energy transference via Förster mechanism and the final process that may be a radiative emission or a non radiative relaxation through a suppression center. This work main objective is to compare the simulation results with the experiments of absorption, optic excitement and luminescence carried on the IFSC throughout the last years or proceeding from specialized literature. Moreover, the simulation intends to elucidate the nature of the photophysical processes in organic semiconductors and to test the validity of existing theories, what it is essential for the application of this branch of materials as devices in the future. Special attention is given in the analysis of the behavior of the time-resolved luminescence in systems where the energy transfer is carried through a matrix of conjugated segments distributed randomly and acceptor molecules (impurities or defects) coupled by dipole interaction. The comparison of the simulation results with the experimental ones allowed to prove the validity of the model, the used program and to better understand characteristic of parameters for conjugated polymers which are still studied. Different the energy distributions of electronic states, molecular position and orientation are used in order to simulate molecular configurations obtained by different sample preparation methodologies and luminescence suppressor centers. With the simulation, it was possible to reproduce with success the experimental spectra of luminescence, absorption and selective excitation measurements in polymers conjugated described in literature. Besides, the simulation allowed to explain resulted related to the decrease of luminescence efficiency with the increase of the energy of the excitation light, as well as the blue shift and broadening of the spectral lines of conjugated polymer emission with the increase of the density. The characteristic curves of quantum efficiency with the variation of the excitation energy and the not exponential characteristics of the time solved emission intensity curves have been reproduced. Finally, it was possible to study the photophysical processes present in organic heterostructures having molecular level control of the properties of emission via changing the Förster type energy transfer processes between emitting polymers and an azodye. The control photophysical process of the luminescent polymer was accomplished by changing both the orientation and position of the azomolecule in an acceptor layer relative the emitting polymer.
Favarim, Higor Rogerio. "Estudo dos processos fotofísicos em heteroestruturas orgânicas que utilizam chaveamento de luz por fotoalinhamento molecular." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/76/76131/tde-13092007-171145/.
The subject of this work is the study of the photophysics process in poly (p-phenylene vinylene) self-assembled films (PPV), with were synthesized and processed at the Grupo de Polímeros Prof. Bernhard Gross (GPBG) of the IF8C, by the energy transfer process (TEE) for, the azochromophore Brilliant Yellow (BY) or inside the PPV polymeric chain by an energetic gradient. We are interesting in the energetic relaxation pathway meaning, during the spectral diffusion, were the decay acts, radioactive and non-radioactive. By using a specific molecular engineering, propitiated by the self¬assembly method, heterostructures were done to study the energy transfer (TEE) to azochromophores, separated by an inert spacer. The novelty is on the ability of sort the BY states by changes on the pH solution, during the film fabrication process. With such system, we could prove that intermediary states, during spectral diffusion, played an important role for the TEE, and should been transfer to adjacent blocks. This result, with the new methodology adopted for the PTHT to PPV conversion, a long chain ion dodecylbenzenesulfonate (DBS), was enough to develop new structures for the TEE, build by a HOMO and LUMO energetic gradient states in conjugated polymers. These results verify the TEE in the initiate states of the spectral diffusion concomitance with the TEE for a specific film\'s region, implicating in a new methodology for an efficiency increase in organic luminescent devices.
Fernandes, Mauro Roberto. "\"Síntese e caracterização espectroscópica de materiais orgânicos para eletrônica molecular\"." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/75/75132/tde-13042007-171301/.
This work was separated in two parts, in the first, called PART A, the synthesis of the polymers PPV, Cl-PPV, Br-PPV and of the co-polymers (Cl-PPV)m / (PPV)n and (Br-PPV)m / (PPV)n in the following relationships m:n of 30:70; 50:50 and 70:30 are presented. These polymers were characterized by infrared spectroscopy, UVvisible and fluorescence emission. The modifications caused in the polymers due to the doping with iodine vapor and 0,12M ferric chloride in nitrometano solution were studied also by these same techniques. The doping of PPV with iodine vapor have been monitored by optical spectroscopy allowing us to do the attribution of the polaronic and bipolaronic bands. Measurements of cyclic voltametry revealed important electric properties of these polymers, such as the Electronic Affinity (HOMO), Ionization Potential (LUMO) and \" GAP \" that is the difference between those two energy levels. The co-polymers presented smaller values of GAP than PPV and HOMO and of LUMO energy levels that can be appropriate to the use these materials in Light-Emitting Devices (LED). In PARTE B, the synthesis of an unpublished compound is presented, the 4-(2-fenoxi-p-xileno)-N-methyl-1,8-naftalimida, here called as NPOX. The characterization of NPOX was made by of nuclear magnetic resonance of proton vii spectroscopy (1H NMR), Gas Cromatography/ Mass Spectrometry (GC/MS), UVVisible and Fluorescence Emission spectroscopy. NPOX is soluble in chloroform that when evaporated it promotes in a transparent film formation. This film has fluorescence emission in 456 nm when excited in 363 nm. The film also showed a similar behavior as diodes that was demonstrated by the electric measurement of current versus potential (I x V curve). These properties open the possibility of the use of NPOX as activate layer, with emission in the blue region, in OLED (Organic Light- Emitting Devices).
Chen, Chiung-Yun, and 陳瓊筠. "Dilute Solutions Properties of MEH-PPV/THF and MEH-PPV/Toluene." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/97196687059510559788.
元智大學
化學工程與材料科學學系
94
We investigated the molecular conformation of poly[1-methoxy-4- (2’-ethyl- hexyloxy)-2,5-phenylene vinylene] (MEH-PPV) in tetrahydrofuran (THF) and toluene solutions using dynamic light scattering (DLS) and static light scattering (SLS). Moreover the solutions were freeze dried and the molecular conformations of MEH-PPV were observed by Transmission Electron Microscopy (TEM). From the results of light scattering, the second virial coefficient (A2) in THF is slightly negative and in toluene is positive. It revealed that toluene is a better solvent for MEH-PPV than THF. The radius of gyration (Rg) and the weight average molecular weight (Mw) is larger in THF than in toluene, indicating the molecules aggregate in THF.
Qi, Dong Feng. "Photoluminescence from MEH-PPV and DP-PPV in bulk and encapsulated in porous alumina." Thesis, 2001. http://hdl.handle.net/2429/11797.